communications standards review …april 1995 vol. 6.3 copyright © csr 1995 1 communications...

April 1995 Vol. 6.3 Copyright © CSR 1995 1

COMMUNICATIONS STANDARDSREVIEW

TELECOMMUNICATIONS

Volume 6, Number 3 April 1995

IN THIS ISSUE

The following reports of recent standards meetings represent the view of the reporter and are not official, authorized minutes of the meetings.

SG 15 Working Party 2, Signal Processing, February 6 – 17, 1995, Geneva, Switzerland................................. 3Q4/15 Algorithmic Techniques in Voiceband Telecommunications Networks.......................................... 3Q8/15 Interaction of Facsimile and High Speed Voiceband Data with AlgorithmicProcessing in Voice Networks.................................................................................................... 3Q5/15 Variable Bit Rate/Embedded Operation of LD-CELP................................................................. 3Q6/15 Audio and Wideband Speech Coding in Public Telecommunications Networks................................ 4Q7/15 Encoding of Speech at Bit Rates Around 4 kbit/s.................................................................... 5Q9/15 Speech Packetization and Wideband Packet Systems................................................................ 5Q10/15 Software and Hardware Tools for Standardization of Speech and Audio Coding Algorithms............... 6Q11/15 Equipment for Stored and Digitized Coded Information........................................................... 6Q12/15 Encoding of Speech at Bit Rates Around 8 kbit/s................................................................... 6Q13/15 Digital Circuit Multiplication Equipment (DCME) and Systems (DCMS)..................................... 7Q14/15 Design and Interaction of AcoU.S.tic Processing Devices....................................................... 7Q15/15 Network Echo Control................................................................................................... 7Q16/15 Speech, Voiceband and Audio Transmission in ATM/B-ISDN Systems........................................ 8Q32/15 Impact of Transmission Characteristics on Mobile Satellite Communications System Signal Processing Aspects....................................................................................................... 8

Q 1/14, V.savd rapporteurs meeting, March 2 – 3, 1995, Oxford, UK.......................................................... 10Q1/14 V.savd Rapporteurs Meeting Roster, March 2 – 3, 1995, Oxford, UK........................................... 13

ITU-T Study Group 8 Telematic Services, March 14 – 23, 1995, Geneva, Switzerland...................................... 14Q1/8 Applicom..... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14Q2/8 Syntax Aspects of Interactive Videotex................................................................................. 15Q3/8 Open Document Architecture (ODA)...................................................................................... 15Q4/8 Color Models for Telematic Applications............................................................................... 16Q5/8 Group 3 Facsimile Apparatus.............................................................................................. 17Q6/8 Test Charts and Test Images................................................................................................ 20Q7/8 Protocol Aspects of Interactive Videotex............................................................................... 20Q8/8 Document Transfer and Manipulation (DTAM)......................................................................... 20Q9/8 Group 4 Facsimile............................................................................................................ 20Q10/8 AudioGraphic Conferencing.............................................................................................. 21Q11/8 Protocols for Audiovisual Interactive Services (AVI)............................................................... 24Q12/8 Conversion Rules........ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24Q13/8 Telematics on the ISDN................................................................................................... 25Q14/8 ODA Application Profiles................................................................................................ 25Q15/8 Cooperative Document Handling (CDH)............................................................................... 25Q16/8 Common Components for Image and Audio Communications.................................................... 25Q17/8 Coded Character Sets and Control Functions for Telematic and other ITU-T Application Services......... 26Q18/8 Teletex.... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

COMMUNICATIONS STANDARDS REVIEW – TELECOMMUNICATIONS

2 Vol. 6.3 Copyright © CSR 1995 April 1995

Q19/8 Standardized Modulation Techniques for Telematic Services....................................................... 26Q20/8 General Architecture of Programmable Communications Interfaces.............................................. 27Q21/8 Programming Communications Interface (PCI) for ISDN........................................................... 27ITU-T SG 8 Meeting Roster, March 14 – 23, 1995, Geneva, Switzerland................................................ 28

TR-30, Data Transmission Systems and Equipment, March 27 – 31, 1995, Norcross, GA................................. 29TR-30.1 Modems...... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29TR-30.2, Data Transmission...................................................................................................... 31TR-30.3 Data Communication Network Interfaces........................................................................... 32TR-30.4 DTE-DCE Protocols..................................................................................................... 34TR-30 Partial Meeting Roster, March 27 – 31, 1995, Norcross, GA..................................................... 37

Q1/14 V.8bis Rapporteurs Meeting, April 5 – 7, 1995, Bellevue, WA........................................................ 38Q1/14 V.8bis Meeting Roster, April 5 – 7, 1995, Bellevue, WA......................................................... 44

Acronym Glossary..... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 451995 Meeting Schedules as of April 14. 1995...................................................................................... 47



REPORT OF SG 15 WORKING PARTY 2, SIGNAL PROCESSINGFEBRUARY 6 – 17, 1995, GENEVA, SWITZERLAND

Editor’s Note: The report from SG 15 WP 1 was published in CSR-T 6.2, March 1995.

Q4/15 ALGORITHMIC TECHNIQUES IN VOICEBAND TELECOMMUNICATIONS NETWORKSQ8/15 INTERACTION OF FACSIMILE AND H IGH SPEED VOICEBAND DATA WITH ALGORITHMIC

PROCESSING IN VOICE NETWORKS

TD-72 is the meeting report from the Rapporteur (M.H. Sherif, AT&T). TD-58 is a report on interim activities. Itincludes objectives for this meeting, and, as an attachment, the Rapporteur’s comments on the Motorola proposal(LBC-95-051 , Addition of Throughput_Rate Message to H.24P) from the LBC meeting in Leidschendam (see reportin CSR-T 6.1). The Attachment concludes that an asynchronous protocol is necessary for the multiplexer with linkaddress field and independent multi-link throughput control.

The issue of multimedia transmission in the PSTN (Public Switched Telephone Network) was subject to considerabledebate. (Technical Editor’s Note: This is an outgrowth of the debate on PPM versus LAP multiplexing in SG 15WP1.) It was agreed that work should be done in SG 15 WP 2 to accommodate network operators who want toprovide interoperation between future multimedia terminals conforming to ITU-T Recommendations and existingterminals through the PSTN. It was proposed that a network interface process, perhaps based upon Link AccessProcedures (LAP), provide a protocol to multiplex the data streams from all these terminals.

TD-79 is a liaison from SG 15 to SG 8 and SG 14. It notes the plans to develop a network interface process basedon LAP. SG 15 intends to have stable text available in November 1995. The G.multi_mux draft (TD-75) isattached. TD-90 , on multimedia interoperation on the GSTN, is an Annex to the Rapporteur’s meeting report (TD-72 ). It provides a list of identified requirements, and requests that SG 1 develop the service requirements formultimedia/PSTN interaction. TD-75 (Rapporteur) proposes an initial draft for Recommendation G.multi_mux,Generic multiplexer for multimedia applications over the PSTN. TD-66 is a liaison to SG 15/WP1, SG 8 and SG 14noting the issues identified by Q4/15–Q8/15. It was agreed that an experts’ group progress the work. The groupintends to meet in March 1995, and at the June and September SG 15 Rapporteurs meetings.

TD-71 (M.H. Sherif, AT&T, Q4,8/15 Rapporteur) contains the first draft of proposed recommendation G.fax_test.This draft Recommendation defines the testing methodology for evaluating the performance of G3 facsimile processingequipment in the GSTN. Previous work by COMSAT on the testing of facsimile processing equipment in thenetwork was used to produce this draft.

TD-26 is a liaison to SGs 7, 8, 11, 14, 15 and the IETF from ISO/IEC JTC1 SC6 requesting comments on theirtechnical report TR 10171 on the uses of HDLC in data link layer protocols. TD-26 includes a listing of HDLCprocedures and a listing of which Recommendation or standard utilizes which procedure.

In response to liaisons from SG 8 on the effect of network on fax performance and impact of delay on fax performance(TD-17 and TD-18), three liaisons were created. These liaisons were sent to SG 8:• TD-91 , an overview of the issues including treatment of NSF• TD-59 , describing level measurements on international circuits• TD-57 , the interaction of facsimile and echo control devices and its interaction with circuit multiplication

equipment

Q5/15 VARIABLE BIT RATE/EMBEDDED OPERATION OF LD-CELP

TD-76 is the meeting report from the Rapporteur (S. Hayashi, NTT). Annex A includes the terms of reference forvariable bit rate LD-CELP (Low Delay Code Excited Linear Prediction) operation mainly for DCME (Digital CircuitMultiplication Equipment). It includes:• Net bit rates of 12.8 and 9.6 kbit/s,• Speech quality =G.726-24,• Complexity </=G.726,• Codec delay =G.728 (the algorithmic delay of G.728 is 0.625 ms, codec delay = algorithmic + processing delays).



The plan is to have draft text of Annex H to G.728 (less than 16 kbit/s) in November 1995. Annex B provides termsof reference for the LD-CELP extension for frame erasure conditions (FPLMTS and PCME).

Appendix III of G.728 on the performance of the algorithm when tandemed and with non-speech signals was finalized(Annex D of TD-76). A proposal from Mitsubishi was accepted as the official candidate for variable rate LD-CELPfor DCME operation at bit rates lower than 16 kbit/s. Mitsubishi will provide the test implementation to the host lab(Deutsche Telekom) around July.

AT&T’s backward-compatible decoder modification to enhance the robustness of G.728 to frame erasure/packetdropping was accepted. This extension can be used for cellular and PCME (Packet Circuit Multiplication Equipment)applications. The characterization tests will start as soon as possible, based upon bit-exact fixed point specification inexecutable form.

D.403 (R. Cox, AT&T) contains a draft for a proposed Annex I to Recommendation G.728. It describesmodifications of the G.728 decoder to make it suitable for handling frame erasures in the received bit-stream.

D.412 (U.S.A.) contains a draft appendix to recommendation G.728. It gives a broad outline of the 16 kbit/s LD-CELP algorithm’s performance with voice, non-voice, and artificial voice signals.

TD-48 (S. Hayashi, NTT, Rapporteur Q5/15) identifies several typographical errors in the text of draft Annex G (16kbit/s fixed point specification) to Recommendation G.728. It proposes corrections.

D.394 (CSELT, Italy) describes the internationally coordinated evaluation process on the 16 kbit/s LD-CELPextension candidate algorithm for the standard in FPLMTS/PCME applications, regarding the effect of frame erasures.

D.395 (CSELT, Italy) describes the internationally coordinated evaluation test on the candidate algorithm(s) forvariable bit rate LD-CELP operation at less than 16 kbit/s, mainly for DCME applications.

D.432 (Y. Naito, Mitsubishi) summarizes the experimental results on the preliminary transmission performancemeasurements of variable bit rate LD-CELP codec at rates of 12.8 and 9.6 kbit/s.

TD-56 (S. Hayashi, NTT, Q5/15 Rapporteur) contains test results for variable bit rate LD-CELP. Results includesignal level deviation measurements on continuous test signals, output frequency deviation measurements oncontinuous test signals, and output signal level deviation measurements on continuous test signals.

TD-4 is a liaison reply from SG 12 Speech Quality Experts Group (SQEG) regarding developing subjective tests forLD-CELP G.728extensions of variable bit rate and performance against frame erasures (FPLMTS/PCME applications).This liaison indicated SG 12 support as requested.

Q6/15 AUDIO AND WIDEBAND SPEECH CODING IN PUBLIC TELECOMMUNICATIONSNETWORKS

TD-64 is the meeting report from the Rapporteur (R. Drogo De Iacovo, CSELT, Italy). It includes provisional termsof reference for the wideband (7 kHz) speech coder. The coder has two modes. Mode A is a low-delay, high-complexity coder. Mode B is a high-delay, low-complexity coder. Each coder has 3 bit rates: 16, 24, and 32 kbit/s.Work will start on the Mode B coder. A correspondence group will prepare a qualification test plan by June. Thedeadline for submission of candidate is September 1995. The completion date for the draft wideband speech coderRecommendation was advanced to July 1997.

D.387 (U.S.A.) proposes the specific application of a Mode B codec, desktop videotelephony, and an outline of theapplication-specific codec characteristics.

D.388 (A. Crossman, PictureTel) presents an overview of a wideband codec. It demonstrates that compressiontechnology has advanced significantly beyond that of G.722; the author expects to see codecs presented that satisfy theproposed Mode B codec requirements and applications.

D.392 (P. Combescure, France Telecom/CNET) provides comments on provisional terms of reference for wideband (7kHz) speech coding. It proposes to complete the 16-24 kbit/s bitrate operation of a wideband speech coder by the 32



kbit/s mode in order to provide quality equivalent or better than G.722 at 64 kbit/s for all the defined and testedconditions and input signals.

TD-27 is a liaison from ISO/IEC JTC1/SC29/WG11 (MPEG). It notes similarities between the MPEG audio work(DIS 13818-3) and the wideband coding work, in particular the lower sampling frequencies. WG11 would likeconsideration of MPEG-2 in this area.

TD-19 is a new draft Recommendation on low bit-rate audio coding from ITU-R Question 86/10 and 87/10. It isbased on ISO/IEC 11172-3 (Coding of Moving Picture and Associated Audio for Digital Storage at up to 1.5 Mbit/s)and supports sampling at 32 or 48 kHz and bit rates between 128 and 256 kbit/s.

Q7/15 ENCODING OF SPEECH AT BIT RATES AROUND 4 KBIT/S

TD-74 is the agenda for the meeting from the Rapporteur (G. Schröder, Deutsche Telekom). It provides thepreviously agreed requirements and notes that the applications for the 4 kbit/s coder are:• Primary

–PSTN visual telephony–Personal communications–Mobile-telephony

• Secondary–DCME/PCME–Mobile visual telephony–Message retrieval systems–Private networks

TD-85 is the Rapporteur’s meeting report. TD-73 from SG 12/SQEG (P. Usai CSELT) is a proposal for the 4kbit/s qualification phase based on 95% confidence limit calculation for categories Poor or Worse. TD-6 from thesame source provides input on the phase II test plan and recommends changes to the performance requirements. Theproposed changes to the performance requirements were accepted. The terms of reference for a new toll-quality 4 kbit/svoice coding algorithm were finalized (TD-87). They include:• Speech quality not worse than G.726-32 (with input signal nominal level of -26.15 dB with respect to the 0VL

point [-0dBm0])• Total codec delay of 45 ms• Frame size of sub-multiple of 20 msSubmission of candidate coders was requested by September 1995.

TD-11 from ITU-R Task Group 8/1 requests the support of variable rate transmission. Q7/15 agreed with therequirement but determined to address it after the fixed rate coder was developed.

Q9/15 SPEECH PACKETIZATION AND WIDEBAND PACKET SYSTEMS

TD-95 is the meeting report from the Rapporteur (D. K. Sparrell, AT&T). Appendices to G.764 and G.765 werefinalized and approved. The text of the draft TMN (Telecommunications Management Network) recommendations wereadvanced:• G.sparm (SPTT [Signal Processing Transmission Terminals] Managed Objects)• G.snem (SPTT Network Element Manager)• G.cmif (SPTT Configuration Map Interchange Format)

D.K. Sparrell (Q9/15 Rapporteur) provided the following contributions:TD-33 , reviewed pages of section 1 of draft recommendation G.sparmTD-34 , unreviewed pages of section 2 DCME of draft Recommendation G.sparmTD-35 , unreviewed pages of section 3 PCME of draft Recommendation G.sparmTD-32 , draft text for recommendation G.snemTD-36 , fourth revision of the proposed appendix to G.764. This version includes changes introduced at prior

meetings.

TD-96 (D.K. Sparrell) contains changes made to Recommendation G.sparm during this meeting.



D.399 (N. Gal, MOC, Israel) contains draft text for Recommendation G.cmif on configuration map interchangeformat.

TD-37 (D.K. Sparrell, AT&T, Q9/15 Rapporteur) contains the draft text of the appendix to G.765.

TD-60 contains draft Recommendation V.8bis. The Rapporteur’s report states, “this is understood as a precursor toV.8 and used for a voice-to-data-switch. As long as V.8 still appears and existing V.34 end-of-call procedures are usedfor the data-to-voice switch, then V.8bis provisionally seemed acceptable.” TD-97 is a liaison to SG 14 coveringV.8 registry, V.8bis, and issues on multiplexing of integrated traffic (relative to V.dsvd). This is partially in responseto a previous liaison from SG 14 Q1 on integrated traffic (TD-39). TD-97 notes that a multiplex protocol has toindicate what to do to reinsert the removed silence. Just adding noise is not enough, the transmitter has to inform thereceiver of the level of noise to be inserted.

Q10/15 SOFTWARE AND HARDWARE TOOLS FOR STANDARDIZATION OF SPEECH AND AUDIOCODING ALGORITHMS

TD-94 is the meeting report from the Rapporteur (S.F. Neto, COMSAT).

G.HT (Common Digital Parallel Interface for Speech Coding Standardization Activities) was reviewed (TD-46 , S.F.Campos Neto, COMSAT Labs). The text is considered stable. After additional editing, text will become available asa white contribution before the November meeting and will be determined for Resolution 1 procedures at the NovemberSG 15 meeting.

The software tool library (STL92) is being updated to create a new version of ITU-T STL. This requires the generationof a new manual for STL which will be published as a meeting report, and not an integral part of G.191. Somemodifications to the STL have been done in the interim period:• The STL92 and the eSTL9405 were successfully compiled• Filtering modules have been renamed and split into several files• A half-tilt IRS FIR filter has been added to STL• Makefiles and demos program options have been added to the remaining STL92 files

Q11/15 EQUIPMENT FOR STORED AND DIGITIZED CODED INFORMATION

There were no contributions. This question will be dropped at the next study period.

Q12/15 ENCODING OF SPEECH AT BIT RATES AROUND 8 KBIT/S

TD-86 is the meeting report from the Rapporteur (G. Schröder, Deutsche Telekom AG). The agenda for the meeting(TD-62) includes the terms of reference for the 8 kbit/s coder (not worse than G.726 at 32 kbit/s with backgroundnoise, total codec delay ≤ 32 ms). TD-16 is the Rapporteur’s report from the October 12-13, 1995 interim meetingin Munich, Germany.

The latest 8 kbit/s voice coding algorithm (developed by NTT, CNET, and AT&T) met all the requirements. Thisrepresents a significant breakthrough on voice coding technology. The final text of the recommendation will beaccepted at the November meeting. An ANSI-C level description is planned to be available by June 1995.

TD-54 (SG 12 SQEG Chair) provides the positive results of three subjective experiments on the 8 kbit/s codec.Differences between 8 kbit/s coder and G.726-32 kbit/s were not statistically significant. Experiments 1 and 2 dealwith the evaluation of Speech Quality in Background Noise conditions; Experiment 3 included most of therequirements tested in the first selection phase. The three experiments were performed with six different orders ofpresentation, and employed a minimum of 24 subjects.

TD-63 (G. Schröder, Rapporteur Q12/15) provides a report on the host laboratory session for the 8 kbit/s speech coderoptimization test.

A request from WP 1/14 (TD-38) to develop a new coder for digital simultaneous voice and data applications wasreviewed. It was agreed that an experts’ group will work under an accelerated time frame to develop such a standard.TD-77 provides the draft terms of reference for SG 14 review. Because the development of that algorithm would



require significant effort by SGs 15 and 12 (in an already crowded schedule), a liaison was sent to SG 14 to requestconfirmation of their need for the new coder, since SG 15 is about to approve two new coders.

TD-6 is a liaison reply from SG 12/SQEG regarding the 8 kbit/s speech coding phase II test plan and the 4 kbit/squalification test plan. A correspondence group was set up to develop the characterization testing methodology for thefinal version of the optimized 8 kbit/s candidate algorithm. The following laboratories are interested in authoringportions of the test plan:• AT&T: Effect of frame erasures• BT: Conversational tests• CNET: Effect of background noise• CSELT: Talker dependencyAlso included with this liaison was a report from CSELT on alternative requirements for detected frame erasures whichnoted the inverse relationship between voice quality and immunity to errors, and a report also from CSELT whichcomments on the SG 15 4 kbit/s performance requirements.

Q13/15 DIGITAL CIRCUIT MULTIPLICATION EQUIPMENT (DCME) AND SYSTEMS (DCMS)

TD-98 is the meeting report from the Rapporteur (Y. Naito, Mitsubishi). TD-44 from the Rapporteur provides theagreed changes to G.763 (DCME using 32 kbit/s ADPCM and DSI) and G.766 (PCME) from the Berlin meeting (20-22 September, 1994). The modifications of G.763 and G.766 were approved. Liaison were written in conjunctionwith Q4/15 and Q8/15 on several issues.

TD-25 , a liaison from SG 11 raised two issues: fraud on CCITT No 5 circuits and positive acknowledgment of 64kbit/s requests from a DCME. TD-102 is the response. The most serious issue discussed in TD-102 was that theCCITT No. 5 signal, “release guard,” can be interrupted by some proprietary DCME using nonstandard voice codingalgorithms, thereby losing the fraud protection procedure. This does not happen in PCME. It was believed that G.763DCME does not interrupt these signals, but INTELSAT offered to conduct the necessary tests to confirm properoperations of standard DCME.

TD-53 is the report of the Q13/15 Rapporteur’s meeting December 13-15, 1995 in Cairo, Egypt.

D.400 (S. Benjamin, MOC, Israel) proposes modified SDL diagrams for Annex A of recommendation G.763. Themodifications will facilitate a new message between corresponding DCME machines establishing a transparent call.

TD-68 (Y. Naito, Mitsubishi, Q13/15 Rapporteur) provides a correction to an SDL (Specification and DescriptionLanguage) page (Annex B page 34) of the facsimile call handling process in G.766.

TD-69 (Y. Naito, Mitsubishi, Q13/15 Rapporteur) provides corrections to the channel check procedure in G.763.

Q14/15 DESIGN AND INTERACTION OF ACOU.S.TIC PROCESSING DEVICES

TD-84 is the meeting report from the Rapporteur (Y.T. Tao, AT&T). There was only one contribution on hands-freetelephony (TD-8). It is a liaison from SG 12 on the interaction between network and acoustic echo cancellers forhands-free telephony. SG 12 will take these problems into account for the new Recommendation P.NBHF (narrow-band digital hands-free telephones).

Q15/15 NETWORK ECHO CONTROL

TD-84 is the meeting report from the Rapporteur (Y.T. Tao, AT&T). Attached is the current draft of G.IEC(G.improved echo canceller, update of G.165). Work continued on the development of recommendation G.IEC and inparticular, the first five tests.

TD-1 (Y.T. Tao, AT&T, Q15/15 Rapporteur) is the report of the Rapporteurs meeting September 19-23 in Berlin.The main work of the meeting was on G.IEC. It was agreed that the main differences between G.165 and G.IEC willbe:• Addition of a facsimile test• Addition of a test for tandem echo cancellers• The use of the Composite Signal Source instead of white noise



• Inclusion of type c echo cancellers only• Introduction of a test for residual acoustic echo• Study of a test for non-linearities in the echo path

TD-2 (Y.T. Tao, AT&T, Q15/15 Rapporteur) contains the first draft of G.IEC, dated November 1994.

D.384 (Martis Oy) provides comments, both technical and grammatical, on the first draft of recommendation G.IECdated November 1994. TD-3 (Y.T. Tao, AT&T, Q15/15 Rapporteur) also contains comments on the first draft.Comments were received from DBP Telekom, Ditech, DSC Communications Corp., Tellabs Inc., and MCI.

TD-55 (H. Kullmann, Special Technical Editor, Germany) contains a draft Appendix to recommendation G.IEC. Thedraft Appendix is tutorial in nature, explaining the general principals of echo cancellers, their application, effects inconjunction with DCME and areas of identified problems.

D.312 (W. Perske, Germany) discusses test signals and other influences on the convergence behavior of echocancellers.

D.325 (H. Kullmann, Germany) provides measurements and listening examples with respect to the convergencecharacteristics of echo cancellers.

D.383 (Martis Oy) discusses tandem echo cancellers and infinite end path effects. It provides confirming data that thenoise added by the echo canceller is independent of the end path ERL (Echo Return Loss).

D.354 (S. Bootman, DSC Communications Corp.) contains proposed text for G.IEC tests.

D.373 through D .380 (Martis Oy) contain proposed text for G.IEC Test Nos. 1, 2, 3, 5, 6, 7, 10, and 11. D.382(Martis Oy) provides comments on G.IEC Test No. A. D.381 (Martis Oy) provides comments on the test for non-linearities in the end path of the echo canceller.

TD-80 is a liaison statement to SG 11 on the control of echo cancellers. It requests information on switch to echocanceller standards and requests a comprehensive listing of possible switch to echo canceller methods, in-band and out-of-band.

Q16/15 SPEECH, VOICEBAND AND AUDIO TRANSMISSION IN ATM/B-ISDN S YSTEMS

TD-92 is a working draft of Recommendation I.ATM-V. The scope of this Recommendation is to cover the varioustransmission aspects of voice and voiceband traffic in ATM networks with respect to:1. Interconnection with existing networks2. Transport in ATM end-to-end

Q32/15 I MPACT OF TRANSMISSION CHARACTERISTICS ON MOBILE SATELLITECOMMUNICATIONS SYSTEM SIGNAL PROCESSING ASPECTS

TD-78 is the meeting report from the Rapporteur (R. Smith, INMARSAT). It was agreed to generate a software toolto represent the transmission characteristics of mobile satellite channels. The objective is to utilize these models fortesting coders in the 4 kbit/s work. A recommendation will be developed to provide an analytical and descriptivespecification of these channel models.

TD-49 from the Rapporteur is a short overview of channel model characterization for mobile Satellite Telephony. Itnotes that the error sequence presented to the speech decoder will depend on:• Carrier frequency• User speech• Modulation method• Antenna characteristics• Terrain characteristics• Mean signal to noise ratio• Diversity schemes in use• Satellite handover characteristics



• Error correction method

Candidate channel types include:• High gain• High quality maritime systems (e.g., Inmarsat-B)• General purpose maritime and land mobile systems (e.g., Inmarsat-M)• Low to medium gain portable terminals (e.g., AMSC, MSAT, Inmarsat mini-M)• High gain aeronautical mobile system (e.g., Inmarsat Aero-M).Consideration should also be given to PCN/FLMTS (personal communications network/future land mobile telephonysystems) and NGSO (non-geostationary satellite orbit) (LEO [low earth orbit] or ICO [intermediate earth orbit])satellite hand portable systems. The paper notes that channel models exist for all but the NGSO (LEO) option.

Mostafa Hashem Sherif, AT&T Bell Labs

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REPORT OF Q 1/14, V.SAVD RAPPORTEURS MEETINGMARCH 2 – 3, 1995, OXFORD, UK

SAVD-95-011 (R. Schaphorst, Very Low Bitrate Visual Telephony Rapporteur) is draft Recommendation H.246(H.24P). It specifies the control procedures for packet-based muxing at low bitrates. It is characterized as a “generic”Recommendation because it applies to Digital Simultaneous Voice Data (DSVD) as well as to the video applicationfor which it was originally intended.

SAVD-95-009 is a preliminary liaison from SG 15 on V.8bis indicating SG 15’s intention to use V.8bis withH.324 (videophone). As V.8bis was not a topic for this meeting, the liaison was not presented. Nevertheless, themeeting did drift into a discussion of V.8 versus V.8bis. BT favors V.8. It was clarified that the control channel isalways defined as pattern “zero” in any multiplexing table and therefore is not a part of this Recommendation.Changing tables requires that the stream be interrupted (voice and video would be momentarily interrupted) but this wasseen as an uncommon event.

The following nine documents were all introduced by the Rapporteur, J. Magill (Probe Communications, UK).

SAVD-95-012 (M.H. Sherif, AT&T) is a liaison statement from SG 15. The SG 15 group works on algorithmictechniques in voice band networks and addresses the interaction of facsimile and high speed data communications withnetwork equipment. It invites the participation of SG 14 experts to provide input to their discussions.

SAVD-95-005 (B. DeGrasse) is a liaison statement from Q10/8 regarding audio and modem requirements foraudiographic conferencing on the Public Switched Telephone Network (PSTN). It was not presented as it had alreadybeen addressed at a prior meeting. The Rapporteur, however, reminded the group to consider sending a liaison to SG 8requesting more information on their views regarding audiographics conferencing.

SAVD-95-006 is a liaison from SG 8 which deals with simultaneous facsimile and voice operation. The points ofconcern are related to the issues of control. It requests guidance on the use of the V.savd auxiliary channel versus theuse of exchange identification (XID) in the analog SVF (simultaneous voice and fax) case. It also requests advice onV.8bis versus H.24P for the digital SVF case. It further requests that the two SGs continue to foster close cooperationwith each other.

SAVD-95-008 is a liaison statement from SG 8 that also requests advice on the use of H.24P for SimultaneousVoice and Facsimile (SVF).

SAVD-95-013 is the response from SG 15 to the SG 14 request for a new voice coder for DSVD. SG 15 has set upa Speech Quality Experts Group (SQEG). They state that they will probably have to base their work on modificationsto existing coders (e.g., G.728, new G.723) in order to meet the stated time frame. They also seek SG 14’sreaffirmation of the urgency expressed in the initial liaison.

SAVD-95-014 (G. Schroder, Q12/15 Rapporteur) contains the Terms of Reference from the SQEG. The documentincludes a table listing the parameters (<13 kbit/s gross bit rate, ≤ 10 MIPS, not worse than G.726 at 32 kbit/s) andthe objective values as well as a time table. The report projects completion by November 1995.

J. Magill ( Rapporteur) went over the parameter table. He compared it to the initial request and came to the conclusionthat, in most cases, the table gives values equal to or better than the values requested. There was significant discussionover the few cases that did depart from the SG 14 requirements (i.e., gross bit rate and voice quality). There wasconcern expressed that DSVD should be able to operate over a 14.4 kbit/s data channel. It was not clear how the grossbit rate equated to the actual throughput required. There was considerable support for the position that SG 14 shouldclarify the requirement by specifying a coder with ≤ 13 kbit/s. There was also a question about the availability of “C”code for the G.8kbps coder; however, it was clear that this would have to be followed up after the meeting. It wasindicated by the SG 15 member (DSPGroup) that the coder would probably use a “fixed” frame structure. The rule ofthumb for estimating the end-to-end coder delay is generally considered to be 3 * FS (frame size) + LA (look ahead).Motorola-ISG and BT were in favor of stopping this study and selecting the AV.25Y coder (from H.324, now termedG.723); however, the Rapporteur was unwilling to re-open the issue at this meeting. A discussion followed regardingthe requirement to support Dual Tone Multi Frequency (DTMF) through the coder. In the end, it was clear that thisrequirement was put in by SG 15; therefore, it would not be commented on unless SG 15 questioned SG 14’s need forthis capability. If that were to occur, the response would be that SG 14 has not yet identified this as a requirement.



(The alternative is that DTMF pulses would be intercepted and converted to signal which could be carried over thecontrol channel and reconstructed at the other end.)

SAVD-95-007 (M. Yamashita, JCG/AVMMS Chair) is a report of the informal meeting of members of the JointCoordinators Group/AudioVisual and MultiMedia Services (JCG/AVMMS). The report indicates that it was clear thatinterworking was a good goal; however, this does not mandate the need for harmonization since this interworkingcould be achieved through many different approaches (e.g., V.8bis).

SAVD-95-010 is liaison from SG 15. It addresses the signals that might be necessary to be passed between theDTE (Data Terminal Equipment) and the DCE (Data Circuit Terminating Equipment, in this case, a videotelephone) toaddress the situation where a data port was provided on a videotelephone.

SAVD-95-015 (J. Magill, Rapporteur) is the incomplete list of applications and requirements for SVD that wasstarted at the previous meeting.

SAVD-95-016 (J. Brownlie, Independent Consultant, and former V.8 Rapporteur) discusses the V.8bis proposalfrom the viewpoint influenced by two years of discussion on Recommendation V.8. SAVD-95-017 (J. Brownlie) isa reprint of a paper prepared for an IEE conference regarding applications of the new Recommendation V.8. Althoughboth of these documents address the issue of V.8 versus V.8bis and, therefore, are specifically excluded from thediscussions at this meeting, the Rapporteur allowed them to be briefly introduced by B. Welch (BT, UK). TheRapporteur expressed concern that these documents were being sent to SG 8 since they address a SG 14 issue.

SAVD-95-018 (C. Hansen, Intel U.S.A.) proposes that all the DSVD related Recommendations be grouped as a“suite.” SAVD-95-019 (C. Hansen, Intel U.S.A.) attempts to pull together all of the related DSVD functions underan umbrella Recommendation. Among other things, it proposes the introduction of a optional audio frame header andprovides examples of protocol negotiation, parameters/procedures, and extensions to V.25ter.

Some discussion followed relating to the proposed introduction of what was termed “non-standard parameters.” Thiswas later clarified to be “non-standard values” for standard parameters. There was also a discussion as to whether itwould be more appropriate to negotiate manufacturer specific modes over the control channel or to use V.8bis. Thereappeared to be support for providing both since some manufacturer specific negotiation might be better done at thehigher bit rates.

At the DSVD associate Rapporteurs meeting, the only item discussed relating to SAVD-95-019 was the controlmechanism proposed. The conclusion was that V.8bis would be used primarily up front and that by the time themodem had started training, other procedures for negotiation would be used. It was further decided that it would bedesirable to try to harmonize SAVD-95-19 and H.223 as much as possible.

V.DSVD MULTIPLEXING

The following discussion took place under the chairmanship of B. Pechey, the Associate Rapporteur for Multiplexing.

SAVD-95-020 (F. Burg, AT&T U.S.A., and some other companies) proposes that the work on V.dsvd proceed onthe basis of LAPM (Link Access Protocol Modem) with options to provide improved efficiency. Motorola asked tohave some of the source companies struck from the list that is included in the original document. The source listincludes all of the companies present when the document was approved as a proposed U.S.A. contribution at the TR-30.1 meeting. Subsequently, the document was sent back to TR-30.1 by U.S. SG D for further consideration, as therewas still time to resolve U.S.A. conflicts prior to the deadline for document submission. After some furtherdiscussion, F. Burg (AT&T) agreed to remove the names of those companies which had not been specifically contactedsubsequent to that meeting. The source list will be changed to AT&T, Cresta, GDC, Hayes, IBM, Intel, Penril,Phylon, and Rockwell.

SAVD-95-021 (F. Burg, Editor) is the latest version of draft Recommendation V.GMUX, Generic Multiplexer basedupon V.42 LAPM. Two refinements that were agreed to at the previous meeting are not included in the body of textbut are identified and attached separately as the last two pages of the document. The two refinements are to include asuspend/resume procedure for delay-sensitive information and to include a concatenated procedure wherein differentstreams of information are carried in the same information-bearing frame.



SAVD-95-022 (B. Welsh, BT UK) is the latest version of draft Recommendation H.24P. V. Eyuboglu (Motorola,U.S.A.) gave a brief overview highlighting the changes since the last meeting.

SAVD-95-023 (V. Eyuboglu, Motorola, and 10 other companies) suggests that the LAPM proposal for V.dsvdwould be acceptable if there were no modifications to LAP to improve it’s efficiency and if PMM (ProtocolManagement Module) is used when greater efficiency is required.

Following this presentation, there was considerable circular discussion, primarily between AT&T and Motorola, aboutthe need to include the efficiency options. Neither AT&T, who strongly supported the need for improved efficiencyoptions in LAPM, nor Motorola, who strongly resisted their inclusion, appeared ready to compromise. (Reporter’snote: The names of Intel, Phylon and Rockwell appear on both SAVD-95-020 and SAVD-95-023 which appearto be presenting opposing positions.)

The Associate Rapporteur then moved the discussion to the subject of voice coder requirements and how this mayimpact the need for high efficiency. Under the assumption that a 14.4 kbit/s data rate is desirable (or V.34 @ 16.8kbit/s through an ADPCM (Adaptive Differential Pulse Code Modulation) link, 12 kbit/s would need to be allotted tovoice (with no silence detection and a 10 ms frame). It was made clear that SG 15 was not intending to specify anytype of silence detection although a method of transmitting the silence could be provided. It was decided to accept thatthe mux/control will require 5 bytes of overhead (with no silence detection) or 3 bytes (with silence detector).

ASVD

J. Magill (Rapporteur) suggested that at this point he only wished to allow time for discussion of technical issues and,therefore, only to consider a subset of the ASVD (Analog SVD) documents that had been introduced at the previousmeeting.

The following two documents were presented at the previous meeting, WP1/14 Orlando, FL December 1994 (see CSR5.11), and were only briefly introduced here.

D-72 proposes that if the ASVD work goes forward, it should be based on V.34.

D-73 (Motorola) proposes that if ASVD goes forward, it should be changed to look more like V.32bis. Specifically,the number of symbol rates should be reduced to one, and the training sequences should be made identical to V.32bis.

The Rapporteur expressed his desire to try to move forward on the basis of the existing text so that the group couldagree on a “frozen” text in April. This would allow implementers to proceed. The Rapporteur centred the discussionon the following technical issues:

• Single symbol rate versus two rates. K. Ko (AT&T) responded that it had always been desirable to go to onesymbol rate but that the two rates were chosen on the basis of improved intelligibility on some connections. Adiscussion of 2800 Hz versus 2743 Hz symbol rates operation over ADPCM links occurred (the draft proposes theuse of 2800 and 3000 Hz).

• Rockwell asked for MOS (Mean Opinion Score) tests on the ASVD proposal. The Rapporteur responded that whilehe noted Rockwell’s desire, he understood that MOS tests were quite expensive and time-consuming, and may notbe helpful in coming to a decision.

LIAISONS

SAVD-95-025 is the group’s response to the questions raised by SG 8 regarding the issues associated with thepossible use of an SVD modem for SVF. No specific positions were taken.

SAVD-95-026 is a liaison to Q10/8, Audiographic Conferencing. It asks what level of delay would be tolerable andwhat level would be desirable.

SAVD-95-027 is a liaison statement to SG 8 regarding simultaneous or alternating voice and data on the PSTN. Itwas agreed to at the previous meeting and offers no new positions.

SAVD-95-028 is a liaison to SG 15 that presents SG 14’s reaction to their Terms of Reference. Specifically, itcautions that the target rate of 13 kbit/s specified might be too high for practical use on a 14.4 kbit/s data stream.



What followed was a circular discussion about 3 bytes versus 5 bytes for mux/control. The point of the discussionwas the choice of a value of 3 versus 5 bytes would only significantly impact the 14.4 kbit/s case and that it mightsignificantly impact on the design of the coder. Some members saw the 3 byte restriction as inextricably tied to themultiplexer decision (i.e., it might preempt the specification of basic LAP). At one point, it was proposed that basicLAP could be used within the 3 byte restriction by packing two speech frames into one LAP frame, but this was alsoresisted. It was finally decided to express SG 14’s desire for a value as low as possible with a maximum in the rangeof 11-12 kbit/s.

Dick Brandt, dB Consulting

Q1/14 V.SAVD RAPPORTEURS MEETING ROSTER, MARCH 2 – 3, 1995, OXFORD, UK

John Magill, Probe Communications (UK), Rapporteur for V.savdBill Pechey, Hayes (UK), Associate Rapporteur for Multiplexing

AT&T Dick BrandtAT&T Mike BuckleyAT&T Fred BurgAT&T Ken KoAT&T Krishna MurtiBritish Telecom Bill Welsh (UK)Computency Limited Doreen Pechey (UK)Cray John Moughton (UK)Deaf Advocate Andrea Saks (UK)DSP Group & Tel Aviv University Yair Be’ery (Israel)Intel Chris HansenMGCS Alan Pugh (UK)Motorola - ISG Les BrownMotorola - ISG Vedat EyubogluNokia Lippo Rantanen (Finland)Racal Datacomm Chris Firth (UK)Rockwell Glen Griffith

The next issue of Communications Standards Review – Telecommunications (Vol. 6 #4) is scheduled for lateMay 1995.

Communications Standards Reviewregularly covers the following committee meetings:

CSR-R CSR-TTIA TR-41.6 TIA TR-29

TR-45 TR-30TR-46 TR-41

ITU T: SG 8(CCITT) SG 14 (Formerly SGXVII)

SG 15 / 1 and 15 / 2



REPORT OF ITU-T STUDY GROUP 8 TELEMATIC SERVICESMARCH 14 – 23, 1995, GENEVA, SWITZERLAND

Technical Editor’s Note: There has been some confusion about the operation of Resolution 1 procedures fordeveloping Recommendations. The first phase is when the work is “determined” at the WP or SG level to be readyto go forward for Resolution 1 at the following meeting of the Study Group. At the following meeting, the work is“decided” for Resolution 1. Then the work is sent out to all the ITU members for review. Only the response, orlack thereof, by the ITU members creates an “approval”.

TD-0043 (M.W. Staudinger, Chair) defines how the ITU-T will relate to forums and consortia. Any working relationto such bodies will require that they have policies consistent with the ITU in IPR (Intellectual Property Rights) andworking methods.

TD-0053 describes an electronic document handling system available to registered TIES (Telecom InformationExchange Services) system members exclusively, to support the activities of the Study Group. To subscribe, send ane-mail to [email protected] with the text: “subscribe tsg8 <e-mail address>“. To unsubscribe send to the same addressthe text: “unsubscribe tsg8”. The directory of Study Group 8 on ftp is: /u/tsg8/sg8. It contains subdirectories:sg8plen, wpa, wpc, wpt, q1, q2, (all questions), and march95 with subdirectories sg8plen, wpa, etc.

D-264 is a status report of the projects in ISO/IEC SC29 dated 1/3/95.

D-277 (N. Kenyon, BT Labs) discusses Multimedia Standardization noting the DAVIC work. It suggests that SG 15and SG 8 adopt a system model covering ATM-based multimedia systems, both server-based (SG 8) and terminal-to-terminal (SG 15). Also included is an annex on the subject of broadband multimedia call control. (See also TD-3202 under Q5/8, subtopic Multimedia, below.)

WP A Chair is H. Silbiger (AT&T, U.S.A.). WP A includes the following Questions:Q3 Q11 Q15Q8 Q14 Q18

The WP A meeting report is TD-1148 . The following interim meetings are planned:• Q3 and SC18 WG3 ODA CT will meet in Dublin, Ireland July 17-21, 1995.• Q3, Q8, Q15 and SC18 WG3 ODA CT will meet in Kyoto, Japan October 1995.• Q11 and SC 29 WG 12 will meet in Tokyo July 24-28, 1995.

WP C Chair is A. Macchioni (Italy). WP C covers the following Questions:Q1 Q12 Q20Q4 Q16 Q21Q10 Q17

The WP C meeting report is TD-2203 .

WP T Chair is A. Pugh (Matsushita, UK). WP T covers the following Questions:Q2 Q7 Q13Q5 Q9 Q19Q6

The WP T meeting report is TD-3271 .

Q1/8 APPLICOM

Q1 is responsible for T.611, APPLICOM. J-P Dick (France Telecom) is the Rapporteur. TD-2173 is the meetingreport.

T.611 provides a high level, operating-system-independent, batch-oriented interface between applications andcommunications services. D-252 from the Rapporteur provides a helpful overview of T.611. T.611 was approved inNovember 1994, although work continues to add functionality (e.g., voice extensions, D-244) and address technicalissues (D-251 , D-260 , TD-2161). D-258 (Deutsche Telekom) is the current working draft.



Work is beginning on four related Recommendations:• Implementers Guide, editor France Telecom (to be included in T.611), D-259 , WD-1. This Guide will also

include corrections to T.611 identified by recent implementations.• Overview T.610, editor France Telecom (baseline is D-252).• Run-Time Version T.612, editor France Telecom (initial draft D-256).• Interactive Version T.613, editor Deutsche Telekom (initial draft D-250).

D-284 (H. Schulz, Danet/Deutsche Telekom) provides an overview of a proposed interface XAPI (eXtensiveApplication Programming Interface). The purpose of this interface is to support applications (e.g., AVI, CDH, VoD)that handle different types of media in a homogeneous way. It is based on the concepts of an XTI interface ofX/OPEN, and supports connection-oriented service. Q1/8 agreed to take charge of this work in cooperation with Q8/8,Q11/8, and Q15/8.

SCSA (Signal Computing Systems Architecture), a U.S. based industry group, is implementing T.611 and proposedadding voice record and playback functions to it (D-232). SG 7 noted possible overlapping requirements of T.611 SG7 work on CMC (Common Mail Calls), and ISO/IEC JTC1/SC18/WG4 SWG Messaging (liaison TD-2143).Working paper WD-1 was developed showing how the different interfaces relate. A German delegate from Q1/8 willattend the next SG 7 meeting (June 1995) to present and discuss the T.611 mapping to VIM (Vendor IndependentMessaging), MAPI (Messaging Application Programming Interface), and CMC.

Future work plans (TD-2174) include:• T.61w: T.611 mapping to various E-mail interfaces• T.61x: APPLI/COM for phone access• T.61y: APPLI/COM covering security aspects within telematic services

Q1/8 plans to hold an interim meeting in September 1995, most likely in Germany.

Q2/8 SYNTAX ASPECTS OF INTERACTIVE VIDEOTEX

H. Layec (France Telecom) is the Rapporteur. The meeting report is TD-3258©. It includes, as Appendix 2, an ETSIdraft of the Functional Model for Multimedia Applications (dated December 4, 1994). This draft proposes aCommunications Protocol Stack Independent Interface (CPSII) to support network independent access as well asdifferent end-to-end protocols. A number of different architectures are described, including Presentation Terminal,Multimedia Information Management Terminal, Script Terminal ,Videotex Enhanced Man Machine Interface (VEMMI,see Q7/8), and Multimedia & Hypermedia Terminal (MHEG).

Q2/8, in conjunction with Q7/8 and Q11/8, is opening a new work item, “Multimedia Information Services.” Thechair of this work (Q2/8 or Q11/8) is undecided. The new work item would develop the specifications for the end-to-end protocols (Terminal to Server) for Multimedia Information Retrieval Services.

Q3/8 OPEN DOCUMENT ARCHITECTURE (ODA)

The Rapporteur is H. Silbiger (AT&T). The meeting report is TD-1126 . This work is done jointly with JTC 1/SC18/WG 3 as an ODA Collaborative Team and progress is principally made at joint meetings outside of Geneva.

Recommendations approved at this meeting:

• Rec. T.419 | 8613-9 - Audio Content Architectures (COM 8-89, TD-1105). This Recommendation providesfor the inclusion of audio and speech in an ODA document.

Rec. T.422 | 8613-12 - External References and Identification of Document Fragments (COM 8-90, D285, TD-1124 ). This Recommendation, together with T.424, extends ODA with hypermedia capabilities.

Recommendations proposed for approval at the February, 1996 meeting:

• Amendments to Rec. T.416 | ISO/IEC 8613-6 - Character Content Architectures: Coloured lines and emphasis(TD-1147)



• Amendments to Rec. T.417 | ISO/IEC 8613-7 - Raster Graphics Content Architectures: Additional content codingsfor bi-level and multi-level images (TD-0059Rev). This extension to the Raster Graphic Content Architectureenables the use of JPEG and JBIG encoding for color and gray scale images.

• Revision of Rec. T.418 | ISO/IEC 8613-8 - Geometric Graphics Content Architecture to include the 1992 revisionsof ISO/IEC 8632 - CGM (TD-1115)

• Rec. T.424 | ISO/IEC 8613-14 - Temporal Relationships and Non-linear Structures (COM 8-91) ThisRecommendation, together with T.422, extends ODA with hypermedia capabilities.

• Rec. T.423 | ISO/IEC 8613-13 - Spreadsheet (TD-1117). This Recommendation adds spreadsheet interchangecapability to ODA documents.

• Rec. T.425 | ISO/IEC 8613-15 - Video and Associated Audio Content Architectures (TD-1102) . The use ofMPEG and other standardized video compression methods will be added to ODA after completion of this contentarchitecture.

Most of the work on ODA will be finished at the next meeting of SG 8. It is not clear that much will be done in thenext Study Period other than maintenance work. The ODA Implementer’s Guide (TD-1104), maintained by EWOS(European Workshop on Open Systems) and Q3/8, will become a standing document of SG 8, and published as aWhite Document after each meeting.

Q4/8 COLOR MODELS FOR TELEMATIC APPLICATIONS

M. Matsuki (NTT) is the Rapporteur. TD-2191 is the meeting report. TD-2190 is the list of active collaborators.TD-2189 is the action plan. Q4 will meet September 18 - 22, 1995, at the interim meeting in Palo Alto, CA.

D-185 (Japan) is the proposed draft extensions for color JBIG (T.82, see CSR 5.6 page 32). COM-102 (Japan)discusses coding mode classification, component-independent palette (CIP), and the need for smaller horizontal pixelnumbers (than used by A4) to efficiently support PC-generated color images. D-273 (Japan) continues thesediscussions and makes the following proposals:• Use CIELAB color space only in JBIG color facsimile at the present state, with each bit-plane color for 1 bit/comp.

color mode specified by a color name or color palette• Make Rec. T.42 an extension for N-bit/comp. color mode, with a new Recommendation (T.43) for palette color

mode and 1 bit/comp. color mode• Consider CIP as part of the N-bit/comp. color mode

The Q4/8 attendees agreed to an extension for color value specification from 8 or 12 bit to N-bit. This will bepresented as a White contribution at the next SG 8 meeting. For palette color specification, CIELAB will be therequired color space. A means to identify approximate (primary) color communications in 1-bit/comp. palette colorcommunications will be specified. T.palettecolor is proposed to define a recommendation for palettized colorcommunications.

D-269 (Japan Color Fax Committee) discusses soft copy and color reproduction extensions to T.42, Continuous tonecolor representation method for facsimile, which was decided at the previous meeting of SG 8. This document wasalso considered jointly with Q10/8, under T.126. D-269 raises and answers three questions:Q1. Which is the better color space for soft copy, CIELAB (supported in existing T.42) or RGB?A1. CIELAB. Even if a large weight is given to the input transformation criterion, the previous ordering of color

spaces does not change.Q2. Is the CIELAB hard copy default range also good for soft copy?A2. No. The color gamut is generally wider; however, it was proposed not to change the default, since there is already

an option to specify the range explicitly for each image (as in Group 3 and Group 4 facsimile).Q3. Is it necessary to define the conversion method between hard and soft copy?A3. There are many methods, and the choice should be an implementation matter.

D-263 (France) proposes text to add color facsimile (JPEG) to T.class2. D-247 (U.S.) notes future modifications toT.class2, including the addition of color. At the joint Q4/8, Q5/8, Q9/8, Q16/8 meeting (TD-0065), it was agreed toadd text to draft T.32 (COM 8-70) to include support of color for decision at this meeting. This was supported at theSG 8 plenary.



Q5/8 GROUP 3 FACSIMILE APPARATUS

The Rapporteur is B. Revillet (Canon). The meeting report is TD-3270 , and the action plan is TD-3268 . COM8-74 is the report of the Bethesda, MD meeting November 14-18, 1994. A Rapporteurs meeting is planned for theweek of September 18, 1995 in Palo Alto, CA.

The latest agreed revisions to T.30 are in TD-3235rev which also includes amendments to COM 8-87 . D-266and TD-3194rev provide examples for Appendix V of turn-around polling.

V.34 G3 FAX (JOINT MEETINGS WITH Q19/8)

The major work in this Q5/8 - Q19/8 joint meeting was the revisions to T.30 to support V.34/V.8 operation. D-241(Canon, Fujitsu, Hitachi, Matsushita, Mitsubishi, NEC, OKI, Ricoh and Toshiba) is the draft of Annex X (latertermed Annex F) for T.30. TD-3194rev is the report from the Rapporteur (based on D-241) which includes theamendments to T.30, Annex C (to support duplex V.34 operation), and new Annex F (half duplex V.34 operation).Wording for the initiation of the T1 and T2 timers in Annex F was agreed upon. ECM (Error Correction Mode) andhalf duplex operation is required for V.34 based G3 fax. Full duplex operation (T.30 Annex C) is optional.

D-288 (U.S.A.) contains amendments to T.30 to support the use of V.8 signaling in conjunction with the use ofV.34 modulation. It also contains flow control charts of start-up sequences. It was supported. The T.30 signals,PIN/PIP and PPS-PRI-Q, are not to be used in conjunction with V.34. It was also agreed that V.8 may apply to non-V.34 modem start-up as well.

Since all this will require a redraft of T.30 (planned to be approved at SG 8 in February 1996), it was decided to dropG1, G2, and V.33 operation from T.30. The editor of T.30, A. Pugh (Matsushita), will redraft T.30. Additionalediting of these changes will take place at the September Q5/8 Rapporteurs meeting.

V.8BIS USE (JOINT MEETINGS WITH Q19/8)

TD-3230 is the report of the joint Q5/8 and Q19/8 meeting which focused on V.8bis issues. D-218 (AT&T,Microsoft, and Motorola) describes a number of potential V.8bis applications. D-229 (UK) notes concerns regardingthe current draft of V.8bis. TD-3257 reports on the V.8bis ad hoc meetings.

L. Brown (V.8bis Rapporteur) presented “at call selection” scenarios for discussion. It was pointed out that G3 faxwith either CNG (T.30 Calling Tone, required in G3 fax) or V.8 provides “at call selection.” K. Krechmer(representing Radish) noted that V.8bis is useful for “in call selection.” There was sufficient interest in V.8bis andagreement that work would continue at the September Rapporteurs meeting with the possibility of announcing the useof V.8bis for Resolution 1 in February 1996. Concern over specific technical issues and the lack of a stable draft ofV.8bis prior to decision by SG 14 was expressed by Japan, UK, France, and others.

T.ROUTING

TD-3223 (J. Rafferty, Human Communications, Editor) is the updated draft Recommendation T.routing. Facsimilerouting using the subaddress was determined at this meeting. The decision is planned for the SG 8 meeting inFebruary 1996. T.routing provides placement of the telephone number and the secondary numbers in the SUB(Subaddress) frame, provides encoding and decoding rules, and provides an outline of the routing procedure. D-280from Germany proposes application rules for the Password and Selective Polling functions. There was some interestin adding this to T.routing, but it was agreed to progress this work toward a separate Recommendation.

NEW G3 NEGOTIATION PROCEDURE

D-224 (U.S.) describes a possible new negotiation procedure to take the place of existing T.30. D-222 (U.S.)suggests how to group parameters in such a new procedure. D-223 proposes a code point in V.8 to identify such anew negotiation procedure. TD-3225 is the report of the ad hoc group which reviewed this concept. They determinedthat this octet-based procedure could be made as efficient as the existing T.30 bit-based procedure since many T.30 bitpositions are rarely utilized. In the case where V.8 is not used to identify the new negotiation procedure, a new DES(Digital Extend Signal) frame might be employed. There was some concern for compatibility problems with the new



DES frame in the DIS (Digital Identification Signal) grouping, and a survey of existing fax terminals was deemednecessary before the work could proceed further.

PROGRAMMABLE COMMUNICATIONS INTERFACES

The work in Q5/8 on DTE/DCE (Data Terminal Equipment/Data Circuit Terminating Equipment) interfaces forfacsimile is termed Programmable Communications Interfaces. J. Decuir (Microsoft) is the editor of T.31 (previouslyT.class1) and T.32 (previously T.class2). TD-3240 is the editorial markup version of draft Recommendation T.31.COM 8-70 is the current draft of T.class2 with changes from TD-3239 and TD-3250 . SG 8 agreed to add JPEG(Joint Photographics Expert Group) color fax support to T.32 at this meeting. T.31 and T.32 were decided at thismeeting, and after ITU member balloting (about 4 months), they will become ITU-T Recommendations (if approved).

It was agreed to amend T.31 to support V.8 and V.34 (base text is TD-3222 Attachments 1 & 2) and amend T.32 tosupport JBIG (Joint Binary Image Group) and V.8/V.34 (base text in TD-3222 Section 7 and Attachment 3). Theintention is to announce (determine) both revisions to T.31 and T.32 for Resolution 1 in February 1996. All thesechanges are subject to additional work at the September 1995 Rapporteurs meeting.

Annex C of T.31 is the procedure for V.8 Call Negotiation (base text is TD-3222 Attachment 1). It is designedusing +F8 commands to control V.8 functions and +F34 commands to control V.34 functions. In this way, the DTEdrives the negotiation, thereby avoiding changes to DCE every time V.8 code points change. In a liaison to SG 14(TD-3237), it is suggested that if Q7/14 agrees to provide DTE-DCE commands for V.8 control in time to have finaldraft text available for the February 1996 SG 8 meeting, then SG 8 could delete Annex C and replace it with referencesto the SG 14 documents (likely V.25ter modified).

MULTIMEDIA

D-255 and D-253 (both from I. Sebestyen, Siemens) describe the application of a videophone with fax, and questionwhether SG 8 should study this issue. They propose that G3 fax (also T.84 [JBIG] and T.434 [Binary File Transfer])be multiplexed in the H.223 multiplexer of the H.324 videophone. These contributions also note that work onmultimedia platforms occurs in both SG 14 (digital and analog simultaneous voice and data) and SG 15(videotelephone and mobile videotelephone).

TD-3202 (N. Kenyon BT Labs) is a liaison from Q3/15 on the support of general multimedia service. It proposesusing T.90rev (with changes) to support in-band digital channel negotiation between H.320 (also with changes),T.120, audio, and other modes. In effect, the proposed T.90rev would become the digital channel equivalent of V.8bisfor analog channels.

TD-3198 (M. Sheriff, AT&T, SG 15) notes the work beginning in SG 15 on providing network-based multimediaservices (likely using multipoint multiprotocol hubs). SG 15 plans meetings on these issues in Japan May 31-June 6,1995, and in Virginia September 25-29, 1995.

WIRELESS SUPPORT USING T.35

COM 8-104 (Germany) proposes amendments to T.35 to allow network identification. TD-3269 is a liaison toSG 7 and SG 14 regarding the Resolution 1 proposed amendments to T.35 to allow network identification in facsimilecommunications links and to support GSM (Global System of Mobile Communication) operation (wireless) overnetworks in both facsimile transparent mode (Fax-T) and non-transparent mode (Fax-NT). Details of the GSMprocedures can be found in draft ETS 300 070 and ETS 300 07x. TD-3236 provides two notes to be added to T.35 inorder to define codes indicating that a network-based non-standard facility (e.g., GSM non-transparent mode) is in thenetwork.

FAXPAD AND FAX REMOD-DEMOD

D. MacTaggart (SG 7 FaxPad Rapporteur) requested that the same principal (use of T.30 to identify devices in thetransmission path) be supported for use by FaxPad systems. He plans to pursue this at the Q5/8 meeting inSeptember 1995. The solution proposed in TD-3269 may not be suitable for FaxPad since it appears thatRecommendation X.38 Annex D (one of the FaxPad recommendations) was not considered.



TD-3199 (M. Sherif, AT&T) is a liaison from SG 15. It indicates factors that affect the interaction of fax remod-demod CME (Circuit Multiplication Equipment) and G3 fax. The delay associated with G.764/G.765(asynchronous/packet) CME is about 75 milsec. G.763/G.766 (synchronous/circuit) equipment introduces about a 200milsec delay. TD-3199 also notes that some CME do not support NSF (Non-Standard Facilities) while others do notremod-demod G3 fax with NSF; yet other CME offer proprietary solutions.

OTHER Q5/8 BUSINESS

Quali ty of Service

TD-3252 is the report of A. Giuseppini (PT-ISPT, Italy) on G3 fax QoS (Quality of Service) issues and testing. Itnotes that COM 8-106 (ETS 300 242) and the TR-29 work on fax testing will be the basis for future work on faxtesting. The base TR-29 document is planned to be made available for the September Rapporteurs meeting.

Echo Control

TD-3200 (M. Sherif AT&T) from SG 15 is an excellent tutorial on echo control in networks and its effect on faxand data modems. M. Enver (BT Networks) agreed to chair an ad hoc group to study the effects of echo and delay onG3 facsimile.

Voice DCE Interface

In TD-3272 , Q5/8 indicated that it is not interested in developing interfaces for voice DCE (previously discussed inBethesda MD Rapporteurs meeting in November, see CSR 5.11). Q5/8 expects this work to be done in SG 14. D-245 provides an overview of the MFPI (MultiFunction Peripheral Interface) work. Although there is some interest inthe MFPI work, Q5/8 is not currently interested in starting this work, as facsimile is only one aspect ofMultiFunction Peripherals. The U.S. will likely bring a White contribution to the next SG 8 meeting on MFPI togenerate additional interest.

Security

See Q9 report of joint Q5/Q9 meeting on security, below.

Paper Formats

D-243 (U.S.) contains the amendments to support both B4 and U.S. letter/legal paper size as agreed in November (seeCSR 5.11). This document was approved with the following amendment: “In DCS bits 17, 18, 19, 20 shall be set to0,0,0,0 by the sender if bits X and X+1 have other values than 0,0. Bits 17, 18, 19, 20 shall be ignored by thereceiver if bits X and X+1 have other values than 0,0.” However, the bit numbers X and X+1 were not defined by themeeting. The agreed changes are shown in TD-3235rev.

ECM Issues

SG 1 provides service definitions and has made a decision to require ECM (Error Correction Mode) for modem ratesover 9600 bit/s. They are also considering making ECM mandatory for all transmission rates. A liaison from Q5/8(TD-3265rev) was agreed, and notes that there is strong reservation in SG 8 on “ECM mandatory” since poortransmission facilities may make ECM undesirable (a poor quality fax is better than none). Siemens noted that whatSG 1 means by “ECM mandatory” (i.e., use or availability) is not clear.

TD-0065 is the report of the joint Q4/8, Q5/8, Q9/8, Q16/8 meeting regarding overlapping issues related to T.82 andT.85 (see Q16 report, below) and regarding support of JPEG color in T.32.

Answer Delay

D-270 (Japan) addresses concerns about deleting the period of silence of 1.8 to 2.5 seconds that was agreed inNovember (see CSR 5.11). The concern is about the delay before the network cuts through the connection from thecalled side. Q.543 (from SG 11) allows call control processing delays of up to 250 ms per terminating exchangewhich could delay the opening of the called side audio channel (by a maximum of 1 sec.). The decision will be leftopen until a response from SG 11 is received.



D-268 (Deutsche Telekom) notes, for information, that a German Telefax Association, Verband Deutscher Maschinen-und Anlagenbau (VDMA), has been formed. This association includes suitable test labs to support the rapidintroduction of new fax capabilities into the process of conformance testing. VDMA supports ETSI and ITURecommendations; however, it has created the designation “DTS” for fax devices that also comply with the technicalguidelines of FTZ 18 TR-53 of the former Deutsche Bundespost. COM 8-106© (incomplete) is ETS 300 242, theETSI basic document for fax G3 conformance testing.

TD-3180 is a patent statement from Canon indicating IPR relating to automatic call selection procedures.

Q6/8 TEST CHARTS AND TEST IMAGES

D. Bodson (National Communication System, U.S.) is Rapporteur. TD-3246 is the meeting report. It includes, asAnnex A, a written description (as requested in D-276 , France Telecom) that will be included with T.22 (test charts).The beta version of T.24 (test images, approved in 1994) was distributed on CD-ROM and will be published as T.24,assuming no problems are identified. TD-3243 is the action plan.

Q7/8 PROTOCOL ASPECTS OF INTERACTIVE VIDEOTEX

K. Sambor (FZA, Austria) is the Rapporteur. TD-3254 is the meeting report. Draft Recommendation T.107(COM-8-84, Videotex Enhanced Man Machine Interface (VEMMI) Service, was previously approved and is ready forpublication. VEMMI is a means to improve the ergonomics and interactivity of retrieval systems using graphicdialogue elements such as application bar, button bar, pop-up menus, dialogue boxes, etc. It was agreed not to publishVersion 1 of T.107 as revised T.107. Version 2 (TD-3264) which supersedes Version 1 was approved at thismeeting. TD-3255 is the action plan.

Q8/8 DOCUMENT TRANSFER AND MANIPULATION (DTAM)

The Rapporteur is H-D. Schulz (Danet/Deutsche Telekom, Germany). The meeting report is TD-1141Rev . TheDTAM protocols were designed to facilitate the interchange of ODA documents, but are now also support the use ofthe ISO DFR (Document Filing and Retrieval) standard.

Recommendations approved at this meeting:• Amendments to Rec. T.432 to support G4 color and file transfer (COM 8-94)• Amendments to Rec. T.433 to support G4 color and file transfer (COM 8-95)• Annex B to Rec. T.434 (Binary File Transfer) - Diagnostic messages (for interactive use during the binary file

transfer process)• Rec. T.435 - Abstract services definition and procedures for confirmed document manipulation (COM 8-71, TD-

1129 )• Rec. T.436 - Protocol specifications for confirmed document manipulation (COM 8-72).T.435 and T.436 support interactive remote document manipulation and retrieval.

Q9/8 GROUP 4 FACSIMILE

T. Endoh (KDD) is the Rapporteur. TD-3262 is the meeting report. The following were decided at this meeting:• Amendments to T.521 (Communications Applications Profile BT0 for Document Bulk Transfer Based on Session

Service) to support file transfer function and T.85 (COM 8-86 and TD-3234)• Amendments to T.563 (G4 Terminal Characteristics) to support file transfer function and T.85 (COM 8-85 and

TD-3233)T.85, or T.faxjbig, defines application rules of JBIG (T.82) compression for bi-level monochrome G4 and G3documents.

TD-3242rev is the report of the joint Q5/8–Q9/8 meeting on security. G4 fax and G3 will use the same securitymechanisms. D-230 (UK) proposes procedures for implementing RSA (Public Key Cryptosystem invented byRivest, Shamir and Adleman) and HKM/HFX (Hawthorne Key Management and Hawthorne Facsimile Cipher). D-281 (France Telecom) proposes RSA for the digital signature and details the application to G3. D-271 (Japan)proposes using the Diffie-Hellman method for key management. COM 8-103 (Germany) proposes the SAFER(Secure and Fast Encryption Routine) which is believed free of IPR (see D-220). In November, it was agreed to



define one algorithm as the default carrier cipher and all others as optional (BET-49 is the list of requirements fromSG 1).

The ad hoc group on security met to consider the different approaches proposed for authentication, message integrity,message confidentially, and key establishment, but could not agree on one set of default mechanisms. It was agreedthat the algorithm chosen will be applicable for standalone fax as well as PC-based fax. Due to national regulations,as well as different priorities to services/profiles, it may be impossible to agree on a single basic mechanism. TD-3266rev is a liaison to SG 1 reporting on this problem. The discussions from the security ad hoc are summarized inTable 1.

TD-3221 presents additional details of the ad hoc review. D-278 (H. Hertlein, Deutsche Telekom) is an excellenttutorial (including IPR status and extensive references) on encryption, digital signature, cryptography, and keymanagement. D-267 (Deutsche Telekom) describes a general scheme for key management (symmetric andasymmetric).

TD-3185 is a liaison from SG 1 which notes that SG 1 is considering discontinuing Teletex service but will not takeaction in time for the SG 8 meeting. This could cause the proposed deletion of G4 Classes 2 & 3 from F.184 and,therefore, from the T series Recommendations as well.

Modified T.503 (Amendments to Application Profile for G4) (COM 8-73 and TD-3267) was also decided at thismeeting.

A joint meeting with Q5/8 is planned in September to continue the work on security and color coding.

Q10/8 AUDIOGRAPHIC CONFERENCING

The Rapporteur is B. DeGrasse (U.S.). The meeting report is TD-2188 . The updated action plan is TD-2187 .Electronic drafts of working documents are posted at the anonymous FTP site, ftp.csn.net, in subdirectory,ConferTech. Correspondence may be conducted through the Email reflector, [email protected]. To join,send Email to t120-interest-request.

Interim meetings will be held during the week of July 31 to August 4, 1995, in Quebec City, Canada (in conjunctionwith TR-29.3), and during the weeks of September 18-29, 1995, in Paris, France (dates to be confirmed).

Table 2 lists the Recommendations and Editors of Q10/8.

The T.128 AVC (Audiovisual Conferencing) editor will hold an ad hoc working meeting May 8-10, 1995, inLexington, Kentucky (in conjunction with TR-29.3). A stable draft of T.128 and a stable revision of T.123 will besubmitted as delayed documents for determination of Resolution 1 at the February 1996 meeting of SG 8.

Function\Proposal UK Japan Germany FranceMutual entity authentication HKM password RSA, ISO 9798-3 RSA, ISO 9798-3Message integrity RSA, ISO 9796 RSA, ISO 9796Message confidentiality HFX FEAL-32 SAFER to be determinedSecret (session) key establishment HKM Diffie-

HellmanRSA RSA, if confiden-

tiality neededTable 1. Summary of Discussions from Q9/8 Security Ad Hoc

The following draft Recommendations were submitted for Resolution 1 decision at this meeting:• T.124, Generic Conference Control, TD-2184 (amendment of COM 8-63-E )• T.126, Multipoint still image and annotation protocol, TD-2185 and corrigendum (amendment of COM 8-66-

E)• T.127, Multipoint binary file transfer protocol, TD-2186 and corrigendum (amendment of COM 8-92-E )

TD-2183 contains the abstracts of Recommendations T.120 and T.121 that are proposed for decision at the February1996 meeting. Final drafts of these documents will be submitted as white contributions by October 15, 1995.



T.120, DATA PROTOCOLS FOR MULTIMEDIA CONFERENCING

D-225 (J. Boucher BT), the proposed draft of T.120, was reviewed. Part of the description of MCS (MultipointCommunication Service) will be corrected. The overview of T.126 will be rewritten in line with the approved text.The section on AVC will caution that the work is not yet finalized. Bandwidth control will be deleted from thechannel allocations of Annex A. Appendix 1, a model of the APIs, will be removed entirely since some consortia(e.g., IMTC, International Multimedia Teleconferencing Consortium, URL=http://www.imtc.org/imtc) do not picturethe API structure this way, and the relationship between the data stack and the audio visual system is beyond the scopeof this work.

The conformance requirements of Section 10 will mandate MCS protocol version 2 (Packed Encoding Rules) asspecified in T.125. T.126 will not be mandated as the only solution for application sharing because its provisions forremote keyboard and pointing device events are optional and remain to be proven effective.

T.121, GENERIC APPLICATION TEMPLATE (T.GAT)

D-226 (T. Peers, BT), draft T.GAT, was reviewed. The editor noted that two work items remain from the interimmeeting. The Application Resource Manager (ARM) interface should be made precise enough so that T.126 and T.127can reference T.121 in future editions and need not duplicate its content. A tutorial should be added on the basics ofchannel, token, and registry use.

T.123, AUDIOVISUAL PROTOCOL STACKS

As noted in D-216 , the Q10/8 meeting report from October 1994 (Ipswich, UK), Q10/8 had intended to draftenhancements to T.123 to utilize the data channel provided in H.22P (LBC videophone multiplex layer) by replacingthe V.14 layer with the H.22P multiplex. Since stable text from Q2/15 for H.22P and H.24P (LBC videophonecontrol channel) was not available in time for the SG 8 meeting, this did not happen.

Other challenging issues remain to be discussed: Should the Q10/8 approach be the common denominator now presentin T.123, which applies equally to the use of ASVD (Analog Simultaneous Voice Data) and DSVD (DigitalSimultaneous Voice Data), or should it be specialized to derive value from the Adaptation Layer of H.22P? If thelatter, can

Rec. Working Title EditorT.120 Data Protocols for Multimedia Conferencing J. BoucherT.121 Generic Application Template T. PeersT.122 MCS Service Definition RapporteurT.123 Audiovisual Protocol Stacks T. LyonsT.124 Generic Conference Control J. BernsteinT.125 MCS Protocol Specification T. LyonsT.126 Multipoint Still Image and Annotation Protocol P. RomanoT.127 Multipoint Binary File Transfer Protocol T. PeersT.128 Audio Visual Control for Multipoint Multimedia Systems J. BoucherT.RES Conference Reservation Protocols B. Ceccaldi

Table 2. Recommendations and Editors of Q10/8Q10/8 eliminate redundancy of retransmission protocols? All that was agreed is to encourage the use of V.8bis as anautomated way to exchange modem and multiplexer capabilities and to select a common operating mode. Q10/8 doesnot intend to intrude on the discussions between SG 14 and SG 15 concerning harmonized operation of the multiplexlayer.

TD-0057 from the Q21/7 (OSI Application Layer) and Q22/7 (OSI Presentation and Session Layers) Rapporteursmeeting was accepted for information. TD-0057 discusses mechanisms to improve OSI (Open SystemInterconnection) upper layer protocol efficiency for applications such as G4 facsimile. To support work in Q15/8 onCooperative Document Handling, Q10/8 wishes to complete the full seven-layer extended mode protocol stacks ofT.123 that are now marked for further study. Ways of making OSI more efficient, such as through minimal OSIfunctionality or fast bytes draft recommendations from SG 7 noted in TD-0057 , appear relevant to this study.



TD-2148 (N. Kenyon, BT Labs) notes the need for a standard to govern signals flowing on a V.24 interface betweenpersonal computer and videotelephone for the purpose, among others, of conveying T.120-series protocol data. Localmessages are envisioned for management of the data port interface, for call control, and for audiovisual control.Attached to TD-2148 is a proposal from Norwegian Telecom to use the low speed data (LSD) channel within H.221framed signals to emulate V.24 attached modems. Also attached to TD-2148 is a proposal from N. Kenyonproposing a videotelephone data port using T.120 in the MLP channel, suggesting that the MLP (multi-layer protocol,multiplexed into the H.221 frame structure) channel could operate up to 32 kbit/s with the V.24 channel operating at38.4 kbit/s. The liaison reply from Q10/8 to SG 15 (copy also to SG 14) is TD-2180 . It notes that Q10/8 expectsto use start/stop framing of Q.922 (LAP-F, Link Access Protocol - Frame) data links and specify unused DLCIs (DataLink Connection Identifiers) for management and audio visual control.

This work is closely related to T.123 and will be handled for the time being as an Appendix. It merits furtherdiscussion as to whether the proposed interface should be a normative matter for standardization.

TD-2149 from SG 15 Q2 is a request for comments on H.24X protocol stacks in the interest of harmonizing withthat of the T.120 series. It suggests introducing X.224 Class 0 above the LAP-M (Link Access Protocol-Modem) toprovide an X.214 service. In the Q10/8 meeting, it was remarked that if Q2/15 is able to combine H.24X and H.24P(using LAP-M) into one document, a new issue will arise over harmonizing PSTN stacks. The liaison reply to SG 15is TD-2181 which notes that Q10/8 will review the issue further.

T.124, GENERIC CONFERENCE CONTROL

The amendments to T.124 included in D-248 (Report of the Q10/8 February 6-10, 1995 meeting in Irvine, CA) andTD-2154 were reaffirmed. TD-2154 (Rapporteur) makes clear which side of a connection must act to avoid deadlockduring conference establishment. Also, it elevates the notion of multiport terminal (previously Terminal/MCU)midway between terminal and MCU and completes the conference establishment scenarios to cover connectionsbetween two multiport terminals. D-257 (BT), Challenge-Response Passwording within T.124, was rewritten todetail the changes required, improved through further discussion, and adopted by a plurality vote. Discussion of D-286 (France Telecom), Modification of Call Control Elements, demonstrated a need for more explanation of networkaddress in the service description, but no changes in the ASN.1 were ultimately required. The editorial corrections ofTD-2152 (Rapporteur) were accepted.

The base document for T.124 is COM 8-63 . The final revisions are presented in TD-2184 . T.124 was submittedfor decision under Resolution 1 at this meeting.

T.126, MULTIPOINT STILL IMAGE AND ANNOTATION PROTOCOL

The amendments to T.126 included in D-248 (Report of the Q10/8 February 6-10, 1995 meeting in Irvine, CA) werereaffirmed. The Rapporteurs proposal (TD-2153) to add support for 24-bit RGB (Red Green Blue) JBIG-encodedimages was worked out to a small number of detailed changes, and these were accepted. The predominately editorialcomments in D-274 (Japanese experts group) were appreciated and worked into the document.

D-269 proposes changes to T.42 for soft copy and color reproduction and was discussed jointly with Q4/8 (see theQ4/8 report above). T.126 specifies YCbCr and optionally T.42 (CIELAB), while T.42 specifies CIELAB color spaceonly. During editing of T.126, definitions of YCbCr based on video standards, gamma, white point, and monitorprimaries were described.

D-254 (Siemens), Need for harmonization between draft T.126 and T.84, notes that T.126 is scheduled for decision atthis meeting of SG 8, while T.84 (JPEG extensions) is advancing in ISO/IEC to a DIS ballot and is proposed fordetermination at this meeting. This was resolved through a joint meeting with Q16/8. It was clarified that T.126 usesT.81 (JPEG) as an internal format for image transmission in a multipoint conference and that it does not specify localmatters like import/export to other co-resident applications. However, because T.84 is a compatible extension,implementers could choose to use only this format for their transmissions.




T.127, MULTIPOINT BINARY FILE TRANSFER PROTOCOL

The amendments to T.126 included in D-248 (Report of the Q10/8 February 6-10, 1995, meeting in Irvine, CA) werereaffirmed. D-213© (Austria, France) proposes using ETS 300 383 (copy included), Eurofile, which is equivalent toT.101 Annex C part 9. The editor had researched Eurofile transfer, it was discussed at meetings in 1994, and this was astimulus for adding remote directory listing features to T.127.

D-227 (BT) proposes removing support for optional use of V.42bis compression since new patent issues havedeveloped. It was not adopted. No problem is seen since the use of V.42bis is optional. The text will be reworded inplaces to emphasize this. Since no equally good compression standard exists, Q10/8 hopes that licensing issues willbe resolved quickly. The comments of D-275 (Japan) were appreciated and worked into the document.


T.128, AUDIO VISUAL CONTROL FOR MULTIPOINT MULTIMEDIA SYSTEMS (T.AVC)

D-272 (BT), draft T.AVC, is essentially unchanged from the interim meeting. Since T.128 is a high priority, it wasproposed to form an ad hoc editor’s group to progress the work towards determination at the next meeting of SG 8.

TD-2138 (liaison from SG 1 on multipoint session operation and procedures) announces the intention of Q20/1 toreplace F.701 teleconference, F.710 audiographic conference, and F.730 video conference services with a singleRecommendation and to harmonize their contents. TD-2147 (liaison from SG 15) reports decisions on continuouspresence video. SG 15 decided to standardize screen layout and sub-picture numbering but to leave most of the picturecomposition control to T.AVC. It includes a list of suggested commands. These two liaisons were reviewed and areconsidered consistent with Q10/8’s expectation for the content and coverage of T.128. The liaison replies are TD-2176 and TD-2179 , respectively.

T.RES, CONFERENCE RESERVATION PROTOCOLS

T.RES work proceeds under a new editor in the directions indicated by D-287 . D-287 (France Telecom) is a proposalfor T.RES. It notes that a reservation system is especially useful if it can be accessed by a customer currently engagedin a conference for operations such as extending the time or adding new conferees. It judges that the current idea ofmodeling the reservation-to-MCU interface on X.700 CMISE (Common Management Information Service Element) isnot adapted for such transactional communication. It proposes a new study of configurations involving multiplereservation systems and multiple MCUs. It identifies an explicit phase of operation in which the customer binds tothe appropriate reservation server. It asks to what extent the resulting interface should be functionally oriented andclose to the semantics of reservation.

Q11/8 PROTOCOLS FOR AUDIOVISUAL INTERACTIVE SERVICES (AVI)

The Rapporteur is J. Fromont, CCETT. The meeting report is TD-1136Rev . Recommendations proposed fordecision at the February, 1996 meeting:• Rec. T.171 - Coded representation of multimedia and hypermedia information (COM 8-67)• Rec. T.174 - MHEG API (D-214)

This work is being done in cooperation with JTC1/SC29/WG12, MHEG. Progress was also made on T.172 -Description of AVI scriptware functions. T.171 describes the presentation of multimedia information, while T.172describes their temporal sequences. Progress on this work is extremely slow.

D-228 is the ISO/IEC JTC1/SC29/WG 11 working draft of ISO/IEC 13818-6: MPEG-2 Digital Storage MediaCommand and Control Extension (DSM-CC).

Q12/8 CONVERSION RULES

No meeting was held due to lack of participants. Draft recommendation (COM 8-1) had been created previously. P.Talone (Fondazione Bordoni, Italy) is the Rapporteur. The Rapporteur’s report is TD-2196 . Only one liaison was



received (TD-2140 from SG 1 providing change wording to F.162 and F.163 relative to facsimile format conversion).The decision to continue the question is still pending.

Q13/8 TELEMATICS ON THE ISDN

Y. Sursur (CCETT) is the interim Rapporteur. TD-3216 is the meeting report. Y. Sursur reminded the group thathe will not be able to continue this work to the next SG 8 meeting. No one has yet agreed to be Q13/8 Rapporteur.Q13/8 is responsible for T.90.

TD-3226 proposes changes to Annex F of T.90 to support the operation of G3V (G3 using the T.30 Annex Cprocedures over a duplex modem) over an ISDN 3.1 kHz bearer service. TD-3226 (Q5/8) was agreed to be attached tothe Working Party T meeting report. It indicates that other T.90 changes are also necessary to support interworkingusing Annex C of T.30.

TD-3181 is a liaison from ITU-R SG 4 WP 4B regarding Q13/8 concerns over the variability of end-to-end delay,interruptions, and congestion due to on-board processing (OBP) in FSS (fixed-satellite service). It notes that, due tonon-geostationary satellite networks, these effects will become more prevalent in the future. ITU-R Question 218/4has been opened to study the compatibility between OBP and terrestrial networks.

Q14/8 ODA APPLICATION PROFILES

No further work is scheduled on this Question. The Rapporteur (F. Bourge, SEPT, France) has resigned. Using thenew TSAG procedures, a formal liaison will be opened with EWOS (European Workshop on Open Systems), wherethere still is much activity on ODA Application Profiles and Implementation Requirements. Most important amongthese are the raster and image application profiles, since these are currently the most commonly used ODAapplications.

Q15/8 COOPERATIVE DOCUMENT HANDLING (CDH)

T. Tanaka (KDD, Japan) is the Rapporteur. The meeting report is TD-1142 . Recommendations approved at thismeeting:• Rec. T.190 - General principles for cooperative document handling (TD-1130)

Recommendations for approval at the February, 1996 meeting:• Rec. T.191 - Application Profile for Document Conferencing and Remote Presentation (TD-1110).

This work is being done in close cooperation with the DTAM group (Q8/8). Joint work is also being started withQ10/8, Audiographics Conferencing, with the goal of enabling cooperative document presentation and editing. TheCDH work is one of the growing areas of interest in SG 8. This is potentially the most important forward-lookingwork in Study Group 8, since it deals with the rapidly expanding area known as “Workflow.” Workflow integrates theprocessing of a document (purchase order, customer inquiry, etc.) throughout an enterprise without paper handling.

Q16/8 COMMON COMPONENTS FOR IMAGE AND AUDIO COMMUNICATIONS

I. Sebestyen (Siemens) is the Rapporteur. The meeting report is TD-2195 . TD-2194 is the action plan.

A technical corrigendum to T.82 (ISO/IEC 11544) was produced (TD-2158) based upon editorial defects identified at ajoint ISO/IEC ITU meeting (July 1994). This was approved.

D-164 and TD-0036 , draft T.faxjbig, was previously determined to become T.85, Application Rules for T.82Progressive Bi-level Image Compression, editor T. Inuzaka (Hitachi) (see CSR 5.6 page 41). As a result of the effortsin ad hoc meetings and in the joint Q4/8, Q5/8, Q9/8, and Q16/8 meeting, T.85 was decided for Resolution 1 at thismeeting (TD-0066rev is final version). COM 8-87 and COM 8-88 contain the amendments to T.30 and T.4 thatare necessary to apply the rules defined in T.85 to G3 devices. COM 8-73 and COM 8-85 contain theamendments to T.503 and T.563 that are necessary to apply the rules defined in T.85 to G4 devices.

Draft Rec. T.84, JPEG Digital Compression and Coding of Continuous Tone Still Images: Extensions, is stable; theISO/IEC JTC1 SC29 CD ballot was completed in July 1994. The DIS version is shown in TD-2166©. Q16/8 also



approved this draft. Therefore T.84 was determined at this meeting. TD-2087 requests contributions to ISO/IECJTC1 SC29/WG 1 on next generation lossless coding for natural images and new lossy and lossless compression of bi-level images. This is the focus of future work in Q16/8.

Q17/8 CODED CHARACTER SETS AND CONTROL FUNCTIONS FOR TELEMATIC AND OTHER ITU-T APPLICATION SERVICES

The Rapporteur is S. Fuchs (Bezeq, Israel). The meeting report is TD-2201. TD-2136rev2 (draft) provides auseful guide to ISO and ITU-T character coding standards. International Reference Alphabet (IRA) is now the term usedrather than International Alphabet No. 5 (IA5).

T.51 (ISO 6937), Latin based coded character sets for telematic services, (COM 8-97) was approved with minoreditorial changes (TD-2192) for Resolution 1 decision at this meeting.

T.52 (ISO-8859-x, and others), Non-Latin coded character sets for telematic services, was approved in March 1993.COM 8-65 and D-236 were reviewed. D-236 suggests using the composition method to represent a Cyrilliccharacter with diacritical mark in the Slavic languages. The administrations directly affected (Russia and Ukraine) willreview this proposal and make comments (if necessary) in a White contribution to the next meeting.

T.53 (ISO 6429), Character coded control function for telematic services was approved in April, 1994. No newcontributions were received.

T.5x is Multiple-octet coding and conversion to/from 7/8 bit coding systems for telematic services. TD-2168includes a proposal from the U.S. (ANSI) to develop a registry for conversions between ISO/IEC 10646 (Universalmultiple octet coded character set) and other coded character sets. The U.S. offered to provide an editor and registrationauthority and has prepared a draft of the proposed standard.

T.5y, Character sorting requirements for telematic services (TD-2167), is a draft ISO standard on alphabetic orderingfor Latin based languages. This is an input document; the work is planned for completion in 1997.

Q18/8 TELETEX

The Rapporteur is G. Stoye(Deutsche Telekom). The meeting report is TD-1127 . Recommendation proposed fordeletion in February, 1996:• Rec. T.61 - Teletex

SG 1 will also delete the Teletex Service Recommendations.

Q19/8 STANDARDIZED MODULATION TECHNIQUES FOR TELEMATIC SERVICES

The Rapporteur is G. Griffith (Rockwell). The meeting report is TD-3228rev.

V.8BIS

See the Q5/8 report of joint meetings, above.

V.34 FAX

See the Q5/8 report of joint meetings, above.

D-242 (Canon, Fujitsu, Hitachi, Matsushita, Mitsubishi, NEC, OKI, Ricoh and Toshiba) is a detailed proposal of thechanges needed to apply V.34 half duplex modulation mode to G3 fax. D-242 supports the determination of V.34 forG3 fax for Resolution 1 at this meeting.

TD-3194rev is the Rapporteur’s report describing G3 operation using V.34 (based on D-242). It proposes changesto V.34 to support G3 fax:



• Control channel signaling rates (1200 or 2400 bit/s). Bit 50 of the MPh (half duplex modulation parameters) isassigned to declare asymmetric operation. Asymmetric signaling is only supported when both sides set bit 50.Asymmetric T.30 signaling needs further study. For now, symmetric signaling is to be used.

• Data rate changing in the primary channel. Either terminal can initiate change of the primary channel datatransmission rate by starting a control channel synchronization with PPh, resulting in a new MPh exchange. Whenno data rate change is required, the Sh/Shbar/ALT sequence is used to restart the control channel. EOR/ERR orDCN (Disconnect) is used at the end of block transmission. T.30 signals, CTC/CTR, are not to be used to signaldata rate change.

• Other V.34 refinements. Recovery procedures in the case of corrupted PPh, MPh or E (20 bit sequence) should bedefined in V.34. The retrain procedure of the primary channel in V.34 half duplex mode needs further definition andshould not be used in G3 fax, for now. A number of clarifications on V.34 operations were also requested.

These changes, showing modifications to V.34, should become part of a new Annex F to T.30, or they may beincluded in V.34 by SG 14 at the April 1995 meeting. In either case, additional work will be requireed before thechanges are complete and final.

A liaison to SG 14 requests modifications/ clarifications to V.34 to resolve the above issues (TD-3232). If SG 14cannot make the changes, text will be added to Annex F of T.30 to address these points.

The corrections to the November meeting report proposed in D-242 Appendix 1 were accepted.

TD-3215 is the report of the ad hoc on Turnaround polling for V.34 half duplex operation. Of the two proposalsdeveloped in November, Proposal A was selected by the ad hoc group, and the figures in TD-3215 will be included inAnnex F.

As was previously agreed (TD-3173 June 1994), the support of V.33 modulation in G3 fax will be deleted.

Q20/8 GENERAL ARCHITECTURE OF PROGRAMMABLE COMMUNICATIONS INTERFACES

The Rapporteur is N. Guedalia (Bezeq, Israel). The meeting report is TD-2199 which reports on both Q20/8 andQ21/8. No contributions were received on Q20/8; the meeting was abbreviated to offer more time to the Q21/8 work.

Q21/8 PROGRAMMING COMMUNICATIONS INTERFACE (PCI) FOR ISDN

The Rapporteur is N. Guedalia (Bezeq, Israel). The meeting report is TD-2199 (for both Q20/8 and Q21/8).

COM 8-64 is the report of the interim meeting in Paris, November 2-4, 1994. Agreements were reached to divide theT.isdnpci work (COM-8-58) into parts. This resulted in nine draft Recommendations at this meeting. The nineRecommendations were decided, subject to Germany invoking the six week rule (which allows six weeks to considerhow to vote on these draft Recommendations). The recommendations are:

Rec. # COM- ISDN PCI titleT.210 8-75© General Architecture (ETSI draft DE/TE-02025)T.220 8-76 PCI Basic ServicesT.230 8-77© User Plane Protocols Management ArchitectureT.231 8-78© Layer one protocolsT.232 8-79 Layer two protocolsT.233 8-80© Layer three protocolsT.241 8-81© DOS exchange mechanismT.242 8-82© Windows exchange mechanismT.243 8-83© UNIX exchange mechanism

TD-2198 provides summaries of these draft Recommendations. Germany supported CAPI (Common API) 2.0(COM 8-52) and desired a means to allow interworking between the ISDN PCI Recommendations and CAPI 2.0.They noted that some vendors are providing CAPI 2.0 implementations although the bulk of the CAPIimplementations are currently CAPI 1 (see CSR 5.6 page 45). The other delegates did not support the development ofa “dual stack” to provide such interworking. Germany plans to propose an interface to ISDN PCI that is “bitcompatible” with CAPI 2.0. This will also require common functions to be supported in both stacks.



Initial drafts of exchange mechanisms for OS/2 support (COM 8-107), Windows NT support (COM 8-109) andNetWare support (COM 8-110) were provided. COM 8-107 will be reviewed to ensure WARP compliance.COM 8-108 describes a way to multiplex more than one connection over a network connection object. Proposedextensions for T.30 support (COM 8-111) and V.120 support (COM 8-112) were also provided. A liaison to SG14 for their review of the proposed V.120 operation was generated (TD-2200).

Additional information on ISDN PCI is available from:• BBS: +33 96 48 42 62• Fax: +33 96 48 42 61• Tech support: +33 96 48 36 75• CAPI and APPLI/COM: ftp.uni-oldenburg.de

Ken Krechmer, ACTION Consulting, for WP T and WP CHerman Silbiger, AT&T, for WP A

ITU-T SG 8 MEETING ROSTER, MARCH 14 – 23, 1995, GENEVA, SWITZERLAND

126 experts from 19 countries participated:

Austria 2Brazil 1Canada 2China 3Denmark 2France 27Germany 14Greece 1Israel 2Italy 2Japan 23Korea 2Russia 2Spain 1Switzerland 1Syrian Arab Republic 1Ukraine 2United Kingdom 12United States 22INTELSAT 1ISO 2ITU TSB 1



REPORT OF TR-30, DATA TRANSMISSION SYSTEMS AND EQUIPMENTMARCH 27 – 31, 1995, NORCROSS, GA

TR-30.1 MODEMS

DSU COMPRESSION STANDARD

TR-30.1/95-03-040 (K. Schneider, ADTRAN, Editor) is Revision 3 of the proposed standard for Compression ofSynchronous Data for DSUs (PN-3245). The changes in this revision were reviewed. There was considerablediscussion about Internet RFCs (Request For Comment) given as informative references. It was noted that TR-46 hasreferenced RFCs in the past.

The Chair asked for and received approval to forward TR-30.1/95-03-040 for ANSI ballot.

V.34

TR-30.1/95-03-035 (G. Griffith, Rockwell) addresses issues relating to the use of V.34 in fax applications. Itrequests clarification and modification of some of the procedures in V.34 which they felt were needed for satisfactoryfax operations. The suggestions relate primarily to recovery and retrain procedures. During the discussion it wasunclear whether the changes proposed would require Resolution 1 treatment.

TR-30.1/95-03-060 (J. Moran, Motorola) reports on problems discovered during testing. One problem results indisconnects on connections which have an RT (Round Trip) delay of 100 ms (satellite connection) and also use SS #5(in band signaling). The V.34 start up sequences use an inband frequency of 2400 Hz. A simple fix is to change therelationship of the 2400 Hz and guard tones (i.e., make the guard tone the higher level). The second issue relates to theproposed extension to the rates supported by V.34. A potential problem related to the negotiation of these new rates isalso raised. It was suggested that this latter problem could be addressed in Phase 4 of the startup sequence. There wasalso a short discussion regarding the length of ANSam in V.8. SG 8 suggests shortening this tone.

There was some discussion about the proposed solution related to raising guard tone given in TR-30.1/95-03-060(J. Moran, Motorola). It was decided that a short paper will be drafted identifying the SS #5 problem and suggestingthat the 1800 Hz be changed to 0 dB during the A and A1 sequences as a solution.

V.8BIS

TR-30.1/95-03-034 (L. Brown, Motorola) is a collection of contributions from the March 1995 meeting of SG 8addressing the use of V.8bis with Group 3 fax. There was considerable discussion about the impact on echosuppressers.

TR-30.1/95-03-041 through TR-30.1/95-03-044 were presented by L. Smith (LMS Consulting for AT&T).

TR-30.1/95-03-044 proposes to reduce the duration of and the number of dual tones sent (using appended singlefrequencies to differentiate between the signals) with the stated goal of reducing the probability of “talkoff.” TR-30.1/95-03-042 addresses the number of sets of dual tone signals. It proposes that 2 sets be defined, one forinitiating and one for responding. TR-30.1/95-03-043 provides specific recommendations for the frequencies of thedual tones and appended single frequencies proposed in the above contributions. TR-30.1/95.03-041 proposes thatV.8 CM/JM (Call Menu/Joint Menu) not be required when a modem communications mode is initiated using V.8bissignaling. TR-30.1/95-03-045 proposes that the power levels for the V.8bis signals be specified more explicitly.

TR-30.1/95-03-047 (Radish, Ameritech, Intel, Microsoft, Motorola, MCI, and Digital Sound) was introduced byM. Winseck (Radish). It raises concerns about the technical completeness of the existing Draft Rec. V.8bis. Itprovides the overview for the following nine papers (TR-30.1/95-03-048 through TR-30.1/95-03-056 , alsofrom the same sources. Specifically, TR-30.1/95-03-047 raises concerns about the detectability of the existingsignals, the compatibility with existing terminals, the efficiency of the coding, the use of an asynchronous format, thespecification of an implicit ACK (acknowledgment), the incompleteness of the NAK (Negative Acknowledgment)scenarios, the incompleteness of the error recovery procedures, and the provision for working with inband signalingpresent.



TR-30.1/95-03-048 questions the ability to reliably detect the 3 different dual tone escape sequences. It proposesthat 1 dual tone escape sequence be used.

TR-30.1/95-03-049 raises the compatibility issue. “ADSI” (Analog Display Services Interface) and “VoiceView”are specifically identified as devices with which V.8bis must be compatible (i.e., interoperable). It was proposed thatthis would not result in a loss in performance.

TR-30.1/95-03-050 proposes the implementation of what is referred to as an “express” capability exchange. Itprovides special coding that gives an indication of whether it is desired to return immediately to voice or go on to modeselection.

TR-30.1/95-03-051 proposes that the Mode Select signal be reduced through different mapping of information intothe HDLC (High level Data Link Control) frame.

TR-30.1/95-03-052 proposes that response signals all follow the HDLC UI (Unnumbered Information transferformat) frame formats to provide expanded interoperability with existing devices (e.g., Voice View, ADSI).

TR-30.1/95-03-053 raises an issue regarding the specification of an “implicit” ACK as it may not be appropriatein all cases. TR-30.1/95-03-054 proposes a way to handle NAKs which is not included in the current draft V.8bis.

TR-30.1/95-03-055 provides proposals to handle some of the error conditions. It especially provides recoverywhen the responder does not have V.8bis capability and the false detection of an ES (Escape Sequence) signal. Itpoints out that more scenarios also need to be added.

TR-30.1/95-03-056 proposes a solution for the SS #5 compatibility problem through the use of an 1800 Hz guardtone with the ES signal.

TR-30.1/95-03-064 (A. Sadri, IBM) proposes the elimination of sections 9.1.1.2 and 9.2.1.2 of V.8bis whichbasically eliminates any transaction which begins with ES. It claims that this eliminates incompatibility problemsbetween an initiator that has V.8bis connected with a non V.8bis station as well as decreasing the number of dual tonesneeded to be detected.

There were many circular discussions about of the selection of dual-tone frequencies, power levels, attenuation of theOGM (Out-Going Message), and pre-emphasis. There was also a request to clarity when V.8bis would be used asopposed to V.8. It was suggested that when voice telephony was one of the modes of operation then V.8bis should beused. It was finally agreed that the number of dual tone pairs that must be detected simultaneously will be reducedfrom 3, and that the responding ES signal could be eliminated when in telephony mode, to address the concept of aquick return to telephony mode.

TR-30.1/95-03-046 is Rev. 2.1 of V.8bis.

DSVD, ASVD AND AVD

TR-30.1/95-03-057 (Radish and Ameritech) is a proposal for Alternating Voice/Data Mode of Operation (V.avd).It does not address problems or shortcomings of V.8bis but instead proposes the use of Alternating Voice Data (AVD).This paper notes the major applications for AVD:• Help desk• Transaction processing• Universal messaging• Visual voice response

TR-30.1/95-03-061 (K. Ko, AT&T) proposes that V.asvd be determined for Resolution 1 at the April meeting ofSG 14. It cites the stability of the document and the complementary capabilities it offers to Digital SimultaneousVoice Data (i.e., lower delay). The proposed V.asvd (without coding) is claimed to operate with 5 more MIPs than astandard V.32bis.

TR-30.1/95-03-066 is a liaison from the Q10/8 Rapporteur to SG 14. It stresses the importance of low delay formultipoint conferencing.



TR-30.1/95-03-062 (K. Krechmer, ACTION Consulting) is a set of documents related to the vocoder selection forDSVD (Digital Simultaneous Voice Data) that was provided for information. The first document is the liaison thatoriginated at the December WP1/14 meeting. The second is SG 15’s initial response. (There was a later documentwhich came out of the Oxford Rapporteurs meeting which was not available. See the report on p. 8 of this issue.)

TR-30.1/95-03-037 is correspondence from T1A1.5 requesting to work closely on the V.savd work. G. Griffith(Rockwell) volunteered to act as liaison with T1A1 to help answer this request.

TR-30.1/95-03-063 (J. Derby, IBM) was presented by A. Sadri (IBM). It proposes the use of a modified version ofthe GSM (Global Standard for Mobile communications) or GSM/VQ coder for DSVD. The presenter proposed thatthis document become a U.S. proposal to SG 14 with a recommendation that it be forwarded to SG 15 to help them intheir selection process. During discussion, it was once more made clear that this job was now in SG 15’s hands, and itwould probably not be appropriate to send any proposal to SG 15.

TR-30.1/95-03-038 (Intel, Rockwell, Cresta Systems, Hayes, and IBM) was introduced by C. Hansen (Intel). It isthe latest version of the DSVD Systems document that has shown up in various forms since the last TR-30 meeting.It is now in the form of a draft Recommendation for the control function for DSVD. TR-30.1/95-03-058 (F.Burg, AT&T) recognizes TR-30.1/95-03-038 as a good initial draft, but raises technical points and makes editorialcomments on the specifics of the proposal.

It was agreed that a proposal will be made to SG D stating that ASVD (Analog Simultaneous Voice Data) bedetermined for Resolution 1 out of the April meeting of SG 14 with a caveat relating to the need to address outstandingTechnical Issues.

MULTIPLEXING

TR-30.1/95-03-033 (AMP, Intel, Microsoft, Motorola, Multi-Tech, Phylon, PictureTel, Radish, Rockwell,Telebit) was presented by J. Moran (Motorola). It proposes that V.dsvd work proceed on the basis of basic LAP (LinkAccess Protocol) in order to progress the work quickly and that the work should be a standard LAP scheme withoutcharacterized extensions.

TR-30.1/95-03-039 (V. Krishnan, Racal) proposes that proposals for DSVD multiplexing be evaluated in terms ofcomplexity, efficiency, and extendibility.

TR-30.1/95-03-059 (F. Burg, AT&T) proposes that we progress Basic LAP at the April 1995 meeting andsubsequently, approve the changes at the proposed WP meeting in October. This will allow approval of the completespecification in 1996.

There was considerable discussion over the outstanding difference between the two major factions, LAP and PPM. Itdistilled down to the concept of whether the inclusion of a higher efficiency option was acceptable, with the details tobe worked out (AT&T, et al), or whether a decision needs to be made to include any efficiency improvement (Motorola,et al). Final agreement was to recommend the following U.S. position to SG D:

“The basic LAP protocol, as contained in proposed draft Recommendation V.gmux presented at the Orlando meeting(including the material for Appendix II on retransmission issues), serve as the basis for multiplexing for DSVD.”

The definition of higher efficiency schemes is for further study.

Dick Brandt, dB Consulting

TR-30.2, DATA TRANSMISSION

Editor’s note: This report will be published in the next issue of CSR-T.



TR-30.3 DATA COMMUNICATION NETWORK INTERFACES

PC MAGAZINE LIAISON

TR-30.3/95-03-022© is a copy of an article entitled, “V.34 Off the Starting Blocks,” from PC Magazine, March 14,1995. TR-30.3/95-03-023 (J. Douglass, Chair) is correspondence to PC Magazine regarding the article. Thearticle provides results of testing 16 V.34 modems. It notes that interoperability problems between vendors occurred,similar to those that occurred when V.32bis was introduced.

The Chair indicated that he had a conference call with J. Wolf (PC Magazine), J. Witt (PC Magazine), S. Satchell(Satchell Evaluations), and J. Moran (Motorola) to discuss the questions. He noted that the article is one of the first tofollow the model and procedures from TSB-37A and TSB-38. He requested on behalf of TR-30.3 and received a copy oftest results to analyze for help in improving the TSBs.

FCC LIAISON

TR-30.3/95-03-015 is the FCC BillBoard for March 1995. It was distributed for information.

IEEE LIAISON

J. Ingle (Analog/Digital Testing), editor of IEEE-743, presented TR-30.3/95-03-024 , “New measurements in theIEEE Std 743-1995.” The 23 tones are assigned in such a way that when the signal is sampled at 8000 Hz in groupsof 512 samples, then all the test tones fall exactly on the frequency “bins” of a Fast Fourier Transform. Hence thefrequency increment 8000/512 = 15.625 Hz, and as a result, the test signal is also periodic at a rate of 512/8000 = 64ms.

The following measurement techniques were added to IEEE Std 743-1995:• Round-trip envelope delay• 23 tone testing to measure Attenuation Distortion, Envelope Delay Distortion, Signal-to-Total Distortion, 2nd/3rd

Intermodulation Distortion, Frequency Shift and/or time offset• Network Impulse Response technique to measure Attenuation Distortion, Envelope Delay Distortion, and Signal-

to-Total Distortion• Adaptive Filtering technique to find echo path loss and echo path delay

Electronic copies of IEEE Std 743-1995 ballot were distributed at the meeting. J. Ingle encouraged TR-30.3 membersto comment on the ballot. Technical Editor’s Note: we have attached a listing of the known IPR holders, AT&T,Bellcore and Sage Instruments, with patent numbers to the end of TR-30.3/95-03-024 . This listing is from theIEEE 743 committee.

D. Thomas (SOTAS) presented TR-30.3/95-03-025 , “Empirical 23 Tone Test Measurements.” It includesempirical data on the 23 tone test, signal-to-total distortion, and level measurements. The focus is on the variation ofindividual measurements and the affects of measurement averaging.

PN-3459, PSTN TRANSMISSION MODEL AND TEST PROCEDURES FOR EVALUATION OF 2 WIRE HIGHSPEED DUPLEX MODEMS

S. Satchell (Satchell Evaluations) reviewed TR-30.3/95-03-026 , PN-3459, PSTN Transmission Model and TestProcedures for Evaluation of 2 Wire High Speed Duplex Modems, Draft 1. The committee decided that V.56 lineimpairment conditions should be added to Appendix D.

PN-3509, TEST PROCEDURE FOR EVALUATION OF 2-WIRE 4-KILOHERTZ VOICEBAND DUPLEXMODEMS

S. Satchell (Satchell Evaluation) reviewed TR-30.3/95-03-027 , PN-3509, Test Procedure for Evaluation of 2-Wire4-Kilohertz Voiceband Duplex Modems, Draft 1, and TR-30.3/95-03-028 , Interoperability Test Procedure. TR-30.3/95-03-027 represents a minimal conversion from TSB-38 (PN-2826, Test Procedure for Evaluation of 2 WireDuplex Modems). TR-30.3/95-03-028 provides acceptance criteria for determining whether a particular brand andmodel of modem can interoperate with other brands and models of modems that use the same modulation methods.



PN-3251, CELLULAR MODEM TESTING ANDPN-3507, TEST PROCEDURE FOR EVALUATION OF CELLULAR MODEMS PERFORMANCE

The following documents were distributed and reviewed:

TR-30.3/95-03-016 (M. Pellegrini, TAS) is outgoing correspondence that outlines the plan for gathering “real-world” cellular modem test results.

TR-30.3/95-03-018 (J. Viviano, Motorola) contains a copy of a letter sent to various analog cellular serviceproviders throughout the Southeastern U.S. It documents the relative performance of various cellular markets insupporting V.32bis data calls. It was provided for information.

TR-30.3/95-03-032© (J. Viviano, Motorola) is a database containing 2673 cellular modem data call records containingcall success and throughput information. The tests were done in Huntsville, AL, Nashville, TN, and Atlanta, GA inthe spring and early summer of 1994. This provides a “help” resource for TR-30.3 members wishing to access the celldatabase provided by Motorola. J. Viviano distributed an electronic copy of the Cellular Database (for TR-30.3committee members only).

TR-30.3/95-03-029© (T. Myers, Ameritech Cellular Services) presents four file transfer tests:• Wireless to land line modem direct semi-compressible file• Modem pool connection semi-compressible file• Wireless to land line modem direct compressible file• Modem pool connection compressible fileEach test consisted of 100 attempts logged with connect speed, train time, upload time, total time, upload failure andtransfer rate. The modems used MNP 10 but were not identified by manufacturer.

TR-30.3/95-03-031 (M. Pellegrini, TAS) describes the results from real world testing performed on two cellularmodems. A connection was established between a stationary cellular device and a standard land-line modem across thereal cellular and public-switched network. File transfer throughput tests consisting of ten calls and four file transfersper call were then performed on both modems.

The following suggestions, comments, and work assignments from the last meeting were discussed (see CSR-T 6.2):

• A section on how to do real world testing should be included as an informative annex. This type of testing is verydifficult to reproduce. The ideal model would be a lab-based test that would reflect real world testing.

• The procedure should be defined to do testing with both dual Data Terminal Equipment (transmitting and receivingDTE simulators are connected together) and separate DTEs (transmitting and receiving DTE simulators are notconnected together).

• An ad hoc committee was formed to create a high level block diagram, define the attributes of each block, define theimpairment characteristics, and define the network elements. M. Dolan (Celeritas), M. Pellegrini (TAS), M.Spitzer (PCSI), J. Moran (Motorola ISG), V. Krishnan (Racal Datacom), L. Chenier (Consultronics), and D.Jackson (PTT) volunteered to work on this committee. M. Dolan agreed to head it.

• An ad hoc committee was formed to test the various types of cellular equipment (base stations and cellulartelephones) and characterize them. They plan on using the new IEEE P743 equipment and Smart SAM to makethese measurements. M. Dolan (Celeritas), J. Moran (Motorola ISG), T. Myers (Ameritech), B. Scott (AT&T),and D. Thomas (SOTAS) volunteered to work on this committee. M. Dolan agreed to head it.

• An ad hoc committee was formed to gather cellular network statistics. An effective way of getting statisticalinformation on the cellular network would be to call the RF engineers for each cellular provider listed in the FCCfilings. T. Myers (Ameritech), J. Douglass (Motorola ISG), and M. Dolan (Celeritas) volunteered to work on thiscommittee. T. Myers agreed to head it.

• TR-30.3 should first create a basic model that stresses the cellular modems. Then, the committee should create astatistically based model if and when the statistical data on the cellular network is available.

• An ad hoc committee was formed to submit real world cellular modem testing data for both stationary and mobileenvironments. M. Spitzer (PCSI), M. Pellegrini (TAS), T. Myers (Ameritech), B. Scott (AT&T), and UPS (J.Douglass will contact them) agreed to submit test data to the committee. Several companies submitted test results.M. Pellegrini (TAS) agreed to head this group.



• An ad hoc committee was formed to define the cellular modem test methodology. B. Scott (AT&T), M. Pellegrini(TAS), D. Jackson (PTT), L. Chenier (Consultronics), and M. Gauer (Rockwell) volunteered to work on thiscommittee. B. Scott agreed to head it.

• M. Dolan (Celeritas) will provide information on the Star Data (*3282-Telephone#) cellular service.

PN-3435, MODEM PERFORMANCE OVER ADPCM

TR-30.3/95-03-030 (M. Pellegrini, TAS) describes the results from tests run with a specific V.34 modem todetermine the effect of digital transmission facilities that employ PCM (Pulse Code Modulation) and ADPCM(Adaptive Differential PCM) algorithms on modem performance. Both error rate and file transfer throughput tests wereperformed in the presence of different numbers of PCM links and various ADPCM algorithms. Up to 3 PCM links(µ-law) caused little effect on performance versus an analog channel. Seven different ADPCM algorithms were tested:CCITT-40, CCITT-32, CCITT-24, CCITT-16, ECI-32, OKI-32, and OKI-24. Throughput was significantly reducedin comparison to analog in all cases. The ECI and OKI algorithms did provide significantly better performance thanthe equivalent rate CCITT algorithms.

Jack Douglass

TR-30.4 DTE-DCE PROTOCOLS

J. Bain (Motorola) was unanimously reaffirmed as chair of TR-30.4.

J. Bain noted that the OSI (Open System Interconnection) Global object identifier for PN-3147 (Conversion of CCITTV Series OSI Information Model to SNMP MIB) was provided by ANSI (TR-30.4/95-03-xxx , unnumbered). Thefull OID (Object Identifier) is 1.2.840.10028. 10028 is the ANSI provided OID.

TR-30.4 agreed to develop a draft on how the Q7/14 registration process operates. Registration authority of theinformation octets passed via V.8 was previously agreed to be with SG 14/Q7. TR-30.4/95-03-035 (K. Krechmer,ACTION Consulting) is the U.S. position paper supporting TR-30.4 responsibility for U.S. registration authority of“+” command extensions. It also proposes how the ITU should operate the data base of information octets (ftp access).A liaison was drafted to TR-29, TR-45, and PCCA (Portable Computer Communications Association) noting that TR-30.4 will now be the registration focal point in the U.S. and indicating how coordination will be accomplished.

A paper from D. Bart of TIA (Advisory #5) was distributed. It notes that SP ballot (pink) closing dates will no longercorrespond with the ANSI 60 day comment closing date. Therefore, ANSI comment deadlines will often occur laterthan the TIA committee deadline and must still be addressed.

TR-30.4/95-03-026 (J. Decuir, Microsoft) is a liaison from SG 8 to SG 14 providing Annex C of T.31 (T.Class1)for the purpose of V.8 control. SG 8 proposes to add V.8 call negotiation procedures unless SG 14 provides similarsupport in V.25ter. TR-30.4/95-03-034 (J. Decuir, Microsoft) is the U.S. position paper (via SG D) that supportsSG 14 including the work of draft Annex C of T.31 in V.25ter (as Annex A) in time to be decided by SG 14 in March1996. The only technical change would be to use +A8 commands (+A commands are used in V.25ter for call setup) inAnnex A rather than the +F8 commands (+F commands are used by SG 8 for fax) as proposed by SG 8. Currently inV.25ter, there is indirect control that allows a V.34 modem to function but does not provide exposure of the V.8 octetsto the DTE.

TR-30.4/95-03-028 (J. Decuir, Microsoft) proposes that the IS-101 work (PN-3131, Asynchronous Voice DCEControl, revision of PN-2986) being developed in TR-29.2 should move to TR-30.4 (PN-3319, Voice/DataMultiplexing the DCEs – DTE-DCE Interface Operations) after IS-101-A is complete. This is based on two changesthat have occurred since the PN-3131 work in TR-29.2 began in 1991:• SG 8 thinks the work of PN-3131 should be continued in SG 14.• The SAVD (Simultaneous or Alternating Voice Data) work was developed in TR-30.1 and relates to PN-3131.TR-30.4 agreed with this approach. TR-30.4/95-03-033 is a U.S. paper to Q1/14 and Q7/14 (via SG D) thatprovides an overview of the current U.S. work on Voice DCE control. It indicates that the U.S. would support thiswork in SG 14.

TR-30.4/95-03-022 (J. Decuir, V.25ter Editor) contains editorial changes to V.25ter. All the changes are editorialexcept for a new Appendix V. Areas for further study include:



• In-Band DCE Control (Draft Rec. V.ib)• V.8 Control• Draft Rec. V.8bis Control• New modulations and signaling (e.g., ISDN, Cellular, PCS)• New DCE media types or protocols (Voice, SAVD, H.324)• DCE Testing (e.g. V.54, V.56)This was supported as a U.S. position with some changes (included above) as TR-30.4/95-03-22R1 (TR-30/95-03-10 is the paper to SG D).

TR-30.4/95-03-023 (J. Decuir, V.25ter Editor) proposes editorial changes to V.25ter Supplement (e.g. changereferences to T.31 and T.32 and others). This was supported as a U.S. position in TR-30.4/95-03-23R1 (TR-30/95-03-11 is the paper to SG D).

PN-3319, VOICE/DATA MULTIPLEXING THE DCES – DTE-DCE INTERFACE OPERATIONS

TR-30.4/95-03-32 (B. O’Mahony, Intel) is an overview of DCE configurations with respect to SAVD. Thistutorial paper presents five basic block diagrams of different DCE configurations and a sixth proposed SAVD referenceconfiguration. It also discusses flow control and use of latency control (pacing), and the need for synchronousinterfaces to the DTE to allow functions to be implemented in the DTE.

TR-30.4/95-03-24 (J. Decuir, Microsoft) provides a different view of functional components and data paths of anSAVD DCE.

K. Krechmer (ACTION Consulting) noted that the papers did not address the possible architecture in which the DTEcan load code into the DCE. This needs to be identified because of its effect on timing. B. O’Mahony (Intel) indicatedthat standardizing this general area should not be considered by TR-30.4 at this time.

D. Rife (Hayes) noted the need in both papers for a third telephone interface option. This interface would provide callcontrol (battery, signaling, and ringing) to a local phone/PBX. Then a remote office could be connected to the homeoffice and the DCE would support the remote operator fully utilizing the company PBX (i.e., the remote officetelephone would appear as the home office phone).

TR-30.4/95-03-25 (J. Decuir, Microsoft) addresses requirements for V.8 and V.8bis DCE control. J. Decuir notedthat the major differences between V.8 and V.8bis that he had identified are as follows:

V.8 V.8bisfull duplex V.21 half duplex V.21error control by replication HDLC error controlno escape escapeuni-directional capabilities negotiation bi-directional capabilities negotiation

The paper also reviews the current approaches to V.8/V.8bis call control in a DCE.

V.8 V.8bisparameter based TR-30.4/95-02-13 TR-30.4/95-02-16mode based TR-30.4/95-03-26 T.31 like

(not proposed)

Finally. the paper proposes that TR-30.4/95-02-16 (Radish, proposes commands, parameters and events for an SAVDDCE) be adopted for V.8bis DTE/DCE control. TR-30.4 provisionally agreed to this proposal.

J. Decuir (Microsoft) presented two more documents. TR-30.4/95-03-026 is Draft Annex C/T.31, V.8 Control forService Class 1 Fax DCE. TR-30.4/95-03-027 is Draft Annex B/T.31 Procedure for Service Class 1 support ofV.34 modems. These papers provide the T.31 (T.class1) commands to support V.8 and V.34 operation for fax andwere presented to TR-30.4 for information and possible expansion to support SAVD operation.



K. Krechmer (ACTION Consulting) noted that the diagrams presenting AVD (Alternating Voice Data) in TR-30.4/95-03-032 (B. O’Mahoney, Intel) indicated that AVD has very little functionality left when V.8bis isremoved. This suggests that V.avd may only be additions to V.8bis.

During discussion, it was decided to break the work into three standards: control, local multiplexing, and data streamprocessing. Possible editors for control are: Intel, Radish, Motorola, Microsoft; for local mux: Intel; and for datastream processing: Intel, Microsoft. TR-30.4’s goal is to bring the three standards to committee letter ballot by theSeptember 1995 TR-30 meeting.

PN-3499 WIRELESS MODEM CONTROL

TR-30.4/95-03-029© (J. Decuir, Microsoft) is the second ballot draft of PCCA STD-101, January 1995. (Microsoft isa PCCA member.) The PCCA document makes reference to the use of TR-45 data interfaces for TDMA (TimeDivision Multiple Access) and CDMA (Code Division Multiple Access), commands for analog cellular modem, andother wireless services. This has been harmonized with TIA-602, TIA-615, IS-131, and the comments from TR-30.4.C. Burke (Motorola) has been the editor in the PCCA committee. J. Decuir will be editor if C. Burke does not attendTR-30.4. The plan is to have TR-30.4 develop this into an ANSI standard only making editorial changes andincluding Annex F (TR-30.4/94-12-62©, Miscellaneous Commands) and Annex I (TR-30.4/94-12-63©, CommandExtensions for Analog Cellular Modems) that were previously presented to TR-30.4. TR-30.4 will also replacematerial with reference to TIA-602, TIA-615, and IS-131 where appropriate. Also, the TR-30.4 version will supportboth character and packet mode if possible. J. Decuir will take these points back to PCCA.

PN-2989 EXTENSIONS TO SERIAL ASYNCHRONOU.S. DIALING AND CONTROL

TR-30.4/95-03-030 (J. Bain, PN-2989 Editor) lists the extended command functions that were previously agreedupon (see CSR-T 6.1 Jan-Feb 1995). TR-30.4/95-03-031 (J. Bain, PN-2989 Editor) is the current draft of PN-2989 (Extensions to Asynchronous Serial Automatic Dialing and Control). During discussion, it was agreed that TR-30.4 was interested in defining extended commands for ISDN control. The goal is to go to committee ballot from theSeptember TR-30.4 meeting.

Ken Krechmer, ACTION Consulting

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TR-30 PARTIAL MEETING ROSTER, MARCH 27 – 31, 1995, NORCROSS, GA

Dick Brandt, dB Consulting Chair, TR-30Les Brown, Motorola Codex Chair, TR-30.1Fred Lucas, General Datacomm Chair, TR-30.2Jack Douglass, UDS-Motorola Chair, TR-30.3Jay Bain, UDS-Motorola Chair, TR-30.4Host: Hayes Microcomputer Corp.

Adtran, Inc. Kevin SchneiderAMP, Inc. George LawrenceAnalog/Digital Testing James IngleAT&T Bill BettsAT&T Fred BurgAT&T Ken KoAT&T Larry SmithAT&T Paradyne William GirtonBellcore Ricardo PerezCeleritas Technologies/Airtouch Michael DolanCirrus Logic David KuoCompaq Computers Jess OswaltCompaq Computer Robert WattsCreative Labs Corey GatesCresta Systems Alessandro GattiDigital Equipment Corp Remi LiseeDSP Sandra HaungEricsson Al SacutaHayes Dave RifeHenderson Coms. Labs Warren HendersonIBM Ali SadriIntel King ChengIntel Chris HansenIntel Berry OMahoneyJRC International Lawrence BriseboisMegahertz Wayne ParkMicrosoft Charlie GarthwaiteMotorola ISG Jack MoranMotorola ISG Steve TurnerMotorola ISG Jerry VivianoMulti-Tech Tim GunnPCSI Michael SpitzerPenril Datability Nets Zoran MladenovicPTT Dean JacksonRacal Datacom Veda KrishnanRadish Comm. Ann HeinkeRadish Comm. Ken Krechmer, ACTIONRadish Comm. Mike WinsackRockwell Bernard DebbaschRockwell Mike GauerRockwell Telecom. Joe HoangRockwell Glen GriffithRSA Bill BerneckiRSA Wayne WhitlockSatchell Evaluations Stephen SatchellSOTAS Dan ThomasTAS Michael PellegriniTelebit Systems Ken JonesU.S.Robotics Andy NorrellU.S.Robotics Vladimir ParizhskyVeriphone Kenneth Welch



REPORT OF Q1/14 V.8BIS RAPPORTEURS MEETINGAPRIL 5 – 7, 1995, BELLEVUE, WA

SUMMARY OF AGREEMENTS REACHED AT THIS MEETING:

• During a call, V.8bis and not V.8 should be used to escape from voice mode. The mandatory/optional nature ofV.8bis will be implemented through provisions in the appropriate Recommendations.

• V.8bis should provide a mechanism to allow the calling station to seize control.• A single initiating (ES) DT will be followed by some appended signal.• There will be a total of three DT signals defined, two of which will be identical.• A set of rules, rather than figures, will be provided for every scenario.• Variations of the CR and MR signals will be used to differentiate between the various stages of a call.• Provisional decision was that very little would be gained for the added complexity required for an immediate return

to telephony.• The size of the initial exchange will be limited to 64 octets with the ability to optionally put the proprietary

extensions in a separate exchange. The MS signal will be used to request this separate exchange.• ADSI CAS frequencies will not be used in the V.8bis signals.• Near audio will be silenced after detection of the DT.• DT will be followed by a single frequency (SF) with the time for DT detection extended to 325 ms and SF

detection extended to 175 ms.• Use T.35-based rather than X.208-based exchange to identify Optional Communications Capabilities.

LIAISON

J. Magill (Probe Comm, UK), the Rapporteur for V.dsvd, reported on the March 27-29 SG 15 LBC rapporteursmeeting. Generally, the LBC experts support V.8bis and would like to consider a scenario where start up would be invoice only, then move to voice/video. As they have announced Resolution 1 procedure for their work and would liketo refer to V.8bis in that work, they are requesting that SG 14 move as quickly as possible toward the approval ofV.8bis. J. Magill also mentioned that the voice processing experts of SG 15 reviewed the V.8bis specification andfound no network incompatibilities (see SAVD-95-063 , below).

SAVD-95-34 is a liaison from the Rapporteur on Q2/15, GSTN Videophone. SG 15 urges approval of V.8bis atthe April 1995 meeting. Assuming that this would happen, they propose the specification of a “H.324Communications code point octet” for SG 15’s use. If V.8bis does not get approved, they are seeking advice on howto handle the needed capability exchange.

SAVD-95-63 is a liaison from SG 15 WP 2 voice processing experts (see report of the WP2 meeting on P. 1 ofthis issue). The liaison states that they did not identify any network problems as a result of their initial look at thedraft Recommendation V.8bis.

BACKGROUND AND GENERAL ISSUES

SAVD-95-31 (L. Brown, Motorola) is a summary of the agreements on V.8bis reached to date in TR-30. Theyinclude:• Frequency tolerance for dual tone signals should be ±250 ppm• The 75 ms silent intervals should be reduced• Assignment of code points in Table 9 should be the responsibility of ITU-T SG 8• The number of dual tone signals that need to be detected simultaneously should be reduced (from 3)• The responding escape signal during a call in telephony mode should be eliminated• Support for a quick return to telephony mode should be consideredThere was general agreement to the points made in this paper although there was a question raised about assignment ofcode points in Table 9 as it relates to the request from SG 15 in SAVD-95-34 .

G. Griffith (Rockwell) suggested that performance in the presence of an active echo suppressor be added to the list ofitems to be considered. The possibility of signal clipping on turnaround is the concern. This issue had been raised inan earlier AT&T paper.



SAVD-95-39 (M. Winseck, Radish, source Ameritech, Intel, Microsoft, MCI) is an overview paper describing nineidentified technical deficiencies in draft Recommendation V.8bis (DT-58). The source companies do not support DT-58 as written. SAVD-95-39 identifies why. Follow-on papers SAVD-95-40 through 42 , 46 through 49 , 52and 54 from Ameritech detail the technical deficiencies identified.

SAVD-95-44 (AT&T) provides a functional overview of V.8bis. It identifies basic features and operationalcharacteristics. Several scenarios are also covered for illustrative purposes. It was suggested during the discussion thatthis paper might make a good starting point for an explanatory appendix to V.8bis. SAVD-94-072rev wasgenerated as a draft of such an Appendix.

SAVD-95-49 (Ameritech) stresses the need for V.8bis to be compatible with existing equipment. It proposesseveral changes to V.8bis which it claims will increase the likelihood of compatibility with existing terminals with noloss in performance.

SAVD-95-36 (A. Sadri, IBM) proposes that the development of Recommendations DSVD, ASVD and AVD needsto be interlocked through the use of V.8bis as a common negotiating protocol. It further proposes that V.8bis bemandatory for each of these Recommendations. It is not the intent of SAVD-95-36 to propose the locking of thedevelopment of DSVD, ASVD, and AVD to each other, but locking the progression of DSVD, ASVD and AVD toV.8bis (Technical editors note: A similar statement from IBM and Rockwell was previously approved at U.S. SG Das a U.S. position.)

There was a suggestion that V.8bis be limited to “voice centric” applications, leaving the data-only modes to V.8.However the idea of having both V.8 and V.8bis growing in parallel was not considered desirable by the group. It wasagreed that during a call, V.8bis and not V.8 should be used to escape from voice mode. The discussion then centeredon the issue of mandatory versus optional. It was agreed that the mandatory/ optional nature of V.8bis be implementedthrough provisions in the appropriate Recommendations at call establishment. Action items included drafting anappendix which sets the goal of V.8bis to eventually replace V.8 (SAVD/95-04-72). However, there was notuniversal support for the proposal to replace V.8.

V.8BIS WITH FAX

SAVD-95-32 is a collection of papers from the March 1995 meeting of SG 8. The papers address the use of V.8biswith Group 3 fax. The one question that keeps coming up in SG 8 is when is it appropriate to use V.8bis as opposedto V.8.

SAVD-95-33 (J. Magill, Probe Comm, UK) is a proposed contribution to SG 8, which was not presented to SG 8.It raises concerns about how V.8bis could be applied to a facsimile application. J. Magill later offered to draft aresponse to the UK for consideration.

INITIAL SIGNALS

In SAVD-95-35 , G. Griffith (Rockwell) notes that no calling signal is presently defined in V.8bis. SAVD-95-35highlights the problem by providing a matrix of the signals that must be detected along with possible interferences thatneed to be filtered out.

M. Winseck (Radish) presented SAVD-95-51 , SAVD-95-52 , and SAVD-95-56 on behalf of Ameritech.SAVD-95-51 proposes the specification of an optional guard tone (1800 Hz) at the same level as ES (Escape Signal)to address the problem with false triggering of disconnects when SS #5 is being used. SAVD-95-52 proposes thatthe number of escape DT (Dual Tone) signals at the beginning of a call be reduced to 1. It further suggests that theappended signals be DT signals, and, finally, that OGM signals not be transmitted during V.8bis transactions.

During discussion, the robustness of the signal was questioned. It was pointed out that the penalties associated withmis-detection as opposed to missed detection need to be weighed. There was also a discussion about the suppression ofthe OGM. This proposal asks for a silent period for detection of the response because it uses a single tone response.

SAVD-95-56 proposes that any appended tone be DT as it claims that an appended single tone does not provide anyappreciable protection from Talkoff. During discussion, it was clear that there was no general agreement on whichscheme (DT followed by DT, or DT followed by SF) offers the greatest reliability.



SAVD-95-61 (AT&T. Racal Datacom, Hayes, Penril, General Datacom) proposes that the multiple DT pairs bereplaced by a single DT followed by appended SF tones. It proposes a set of signals based on consideration of:• Network• Other likely tones• Speech spectrum as it relates to loop slope• Spectrum of vowels• Sensitivity of the human earAn additional sheet of paper (attached) was distributed at the meeting showing a plot of the third format for 10 vowels.

SAVD-95-59 (Ameritech) addresses the slope telephone preemphasis aspects of SAVD-95-61 . It concludes thatthe problem becomes much less significant with the use of what is referred to as a “reasonably sophisticated” (activehybrid) detector.

SAVD-95-53 (A. Sadri, IBM) presents results of a limited study of the frequency spectrum of four voices. Itrecommends that dual tones with frequencies above 1700 Hz be used.

SAVD-95-58 , SAVD-95-57 , SAVD-95-54 and SAVD-95-55 were introduced by P. Mathys (consultant toRadish) on behalf of Ameritech.

SAVD-95-58 analyzes the same sort of data as SAVD-95-61 , dealing with the occurrence of vowels, but SAVD-95-58 goes into some detail regarding the use of averages for decision making. It suggests that SG 14 should notmake decisions about which DTs to use, based on the statistical averages. SAVD-95-58 shows that these averagesmay not represent actual likelihood of occurrence. It proposes that the dual tone frequencies be chosen from the bandof frequencies between 2200 to 3000 Hz.

SAVD-95-54 suggests basing the selection of DT frequencies on reliable detection in the presence of interferingaudible energy (including HDLC flags) and minimizing interference with data transmission (again the DT should notmimic HDLC flags). Based on these considerations, SAVD-95-54 proposes the frequencies of 2312.5 and 2912.5Hz for the ES signal.

SAVD-95-55 presents the results of tests performed using the 2312.5 and 2912.5 frequency detectors. Variousinterfering signals were used ranging from human speech to high level music. The test results indicate that detectorstuned to frequencies in the band 2000-3000 Hz have high resistance to talkoff (effectively no talkoffs occurred in 220hours of testing).

M. Buckley (AT&T) introduced SAVD-95-62 , SAVD-95-65 and SAVD-95-45 . SAVD-95-62 proposes thatnear end speech be muted following the detection of the DT signal for a short period of time during which an appendedsingle tone could be detected. If no tone is detected, the call should revert to voice. The proposed signal DT + singletone should still fall within the bounds of the 400 ms presently specified for the DT signal.

SAVD-95-65 recommends that the multiple DT signals be replaced by two DT pairs with appended single tones.This reduces the number of active DT detectors to one.

SAVD-95-45 proposes the possible elimination of the V.8 signals CM/JM/CJ when V.8bis is being used. It issuggested for further study. Another question is whether MS can be used as an alternative to the CM/JM signal forCME (Circuit Multiplication Equipment) demod/remod detection. It was pointed out during the discussion that Figure2 is inaccurate because it creates a situation where the echo control devices would re-enable.

POWER LEVELS

SAVD-95-57 proposes that lower power levels could be used for the DT signals if the assumption were made thatmore sophisticated detectors (directional couplers, active hybrids, etc.) would be used. It also raises Part 68 issues(power averaged over 3 seconds shall not exceed -9 dB with respect to one milliwatt). Discussion centered around thekind of sophistication which could be assumed in a detector of this kind, with the understanding that receiverimplementations are not specified.



SAVD-95-60 (AT&T, Hayes, Penril, General Datacom) proposes that the power levels of the V.8bis signals bespecified in explicit terms. Power levels for the different signals should be based on consideration of potentialannoyance to users and reliability of detection. The OGM should be delayed for at least 400 ms after the end of MR(Mode Request) or CR (Capabilities Request); this allows for the use of lower (less annoying) power levels for thesesignals. In concurrence with the proposal to use different levels at different stages of the call, SAVD-95-60proposes that the V.8bis signal detectors be conditioned to different sensitivity levels at different times.

Later in the meeting, W. Henry (Bellcore) provided more information on the derivation of the Bellcore estimate of thedistribution of Active Speech Level (ASL):

Near End mean -19.0@ CPE std. dev. 4.0Far End mean -28.0@ CPE std. dev. 5.5

SAVD-95-66 (B. O’Mahony, Intel) recommends that the power levels be specified in terms of detectability at normalmodem carrier detect levels (-43 dBm). One proposal to help with the annoyance factor is to ramp the signal over itsduration.

NEGOTIATION

SAVD-95-40 (M. Winseck, Radish, on behalf of Ameritech) proposes error recovery procedures for some of the errorconditions that could occur with the V.8bis procedures.

SAVD-95-64 (A. Sadri, IBM) proposes that ES be used only to respond to CR and MR. This eliminates thescenarios for minimizing potential disturbance to non-V.8bis users, and avoids some compatibility problems. Thereasoning for this proposal hinges on the reduction in the number of DT detectors needed and the lowering of thecomplexity of the Recommendation.

SAVD-95-46 , SAVD-95-47 , SAVD-95-42 , and SAVD-95-41 were introduced by M. Winseck (Radish) onbehalf of Ameritech. SAVD-95-46 proposes changes in the text of Draft Rec. V.8bis to make all of the exchangesin synchronous octet format. This would make the document more consistent and have higher probability ofcompatibility with existing equipment. Specific Communications Function field codes are proposed. This proposalextends the negotiation time with multi-function terminals by requiring separate octets for each function.

SAVD-95-47 proposes a change in format of the MS signal to reduce the length of the frame. Suitability for usewith AVD is cited as one of the reasons for this proposal.

SAVD-95-42 proposes a change in the text to indicate that the implicit ACK be specified in terms of the modeselected, rather than tying it to the receipt of ANS or ANSam.

SAVD-95-41 proposes text for the open section 9.3 “Use of the No Acknowledge (NAK) signal”. This proposalonly addresses one instance of NAK.

SAVD-95-43 (M. Buckley, AT&T) proposes the use of T.35 procedures for the identifying OptionalCommunications Capabilities, rather than using V.208 as specified in the present draft. The rationale given is thatthis would simplify the mechanism for defining Optional Communication Capabilities. This was accepted.

SCENARIOS

SAVD-95-37 and SAVD-95-38 (J. Brownlie, Consultant, and former V.8 Rapporteur, UK) were brieflysummarized by the V.8bis Rapporteur. SAVD-95-37 is a summary of potential applications for V.8. SAVD-95-38 raises questions about the need for V.8bis. It does, however, raise the possibility of a missing scenario where it isdesired to have the answering station be a “slave” rather than the “master” as is the case in the present draft.

The scenario raised led to agreement that V.8bis should provide a mechanism to allow the calling station to seizecontrol. It was also agreed that a single initiating (ES) DT be followed by some appended signal and that there will bea total of three DT signals defined, two of which will be identical. Figure 1 presents three scenarios which address the



cases where the calling party is in control (from SAVD-95-68). In any of the diagrams, CL could replaced by CLR,which would be responded to with a CL followed by MS.

C

A

CR

MR/CR CL

MS

C

A

MR

MR CR

CL

MS

C

A

MR

MR MS

Figure 1. Scenarios in which the Calling Party is in Control.

After further discussion, it was decided to provide a set of rules rather than provide figures for every scenario. SAVD-95-71rev is a state table based on the following rules:

• Mode selection is controlled by initiating station unless taken over by calling station.• There are only 3 allowed mode selections.• MS can be NAKed.

SAVD/95-04-71 created at the meeting, develops the state tables.

SAVD/95-04-74 describes the basic interactions (‘d’ and ‘e’ represent different stage of calling scenarios) as per thefollowing table:

TX Signal Allowed Response

CL MS

CLR CL+MS

MRd MS or CRe

MRe MS or MRd or CRd

CRd CL or CLR

CRe CL or CLR or CRd



When all scenarios (four call establishment and eight during call scenarios) were examined to determine the validity ofthe rules, a discussion took place about the need to send an ES signal during a call. During this prolonged discussion,the major problem was how to handle the fact that the V.8bis device has no way of knowing whether it is in theestablishment stage or the call in-progress stage. It was finally decided to create variations of the CR and MR signalsthat would be used to differentiate between the various stages of a call. This has the penalty of requiring more detectors(five parallel detectors versus the original three). IBM expressed strong reservations about this decision because of therequirement to implement more parallel detectors.

SAVD-95-48 (M. Winseck, Radish, on behalf of Ameritech) proposes the addition of new signals (CL'and CLR')which could be used to probe and return immediately (express CL and express CLR) to telephony mode. Theprovisional decision was that very little would be gained for the added complexity required.

The final discussion in this area was the IBM proposal for inclusion of ABORT signal in all scenarios. Each of thescenarios was examined and none were found in which it would be appropriate to respond with an ABORT. Whatemerged, however, was the possible need to avoid receiving a long list of proprietary modes supported. It was decidedto limit the size of the initial exchange to 64 octets with the optional ability to put the proprietary extensions in aseparate exchange. It was agreed that the MS signal would be used to request this separate exchange.

V.8BIS AND ADSI INTERWORKING

SAVD-95-67 (W. Henry, Bellcore) suggests that the use of the CQ signal (2130 and 2750 Hz), which uses the samefrequencies as the Analog Display Services Interface (ADSI) CPE Alerting Signal (CAS) signal, could result in anundefined condition in cases where both ADSI and V.8bis detectors were on line.

At the request of the Rapporteur, W. Henry gave a short tutorial on the operation of ADSI (Figure 2).

Server Type 3 ADSI device Switch Type 2 ADSI device

CAS--------> SAS* --><----DTMF A CAS---->

data ----- --> <----------DTMF D<----DTMF (1, 2 or 3) data--------------->

<----------DTMF (1, 2, or 3)* The Caller ID signal

Figure 2. Short Tutorial on the Operation of ADSI.

The ADSI device (telephone) is off-hook for all of these transactions. The problem alluded to in the contribution werethe cases where the V.8bis device was also an ADSI terminal, or when several devices connected in parallel were offhook when a CAS signal was received.

The following two papers address the Ameritech proposal to have the V.8bis CQ signal use the same frequencies as theADSI CAS signal.

SAVD-95-69 (M. Winseck, Radish) provides both an endorsement from Digital Sound Corporation and a set offigures which attempts to address all of the potential scenarios of ADSI / V.8bis inter-operation.

SAVD-95-70 (W. Henry, Bellcore) highlights some of the possible situations where ADSI and V.8bis might have aproblem when the CQ and CAS share the same frequencies. It recommends that frequencies other than CASfrequencies be used for CQ.

It was the agreed that the CAS frequencies not be used in the V.8bis signals. It is generally good practice to avoidmimicking network signals, and it is beyond the scope of this group to provide interworking with national networkprotocols. It was agreed there is a potential for problems (although they were not specifically defined).

TWO PROPOSALS FOR ES SEQUENCE

1. DT followed by single tones (5 different tones, one will be the MARK or SPACE):

DT (275 ms) + SF (125 ms)



2. DT followed by different DT (5 different DT pairs):

DT (325 ms) + silence (75 ms) + DT (85 ms)

In both case the near audio would be silenced after detection of the DT. The discussion covered the trade off betweenthe added complexity versus the extra protection the DT would provide. The decision was to use the DT followed bythe SF with the time for DT detection extended to 325 ms and SF detection extended to 175 ms.

SELECTION OF DT FREQUENCIES

Criteria for selection of DT frequencies include:

a) network loss (max. 2 Loop 5 + 12 dB) (min. 3 dB)b) Avoidance of existing frequenciesc) non-harmonic relationshipd) pre-emphasis of phonee) probability of talkofff) probability of talkdowng) ear sensitivity

Proposals for selection of DT frequencies include:First Second

2312.5 + 2912.5 Guard Tone1269 + 1989 1402 + 2198

Without any definitive test data available, there was no basis for a decision.

Time ran out before any meaningful discussion on Error Recovery Mechanisms (prevent lockups), and Coding.

Richard P. Brandt (dB Consulting)

Q1/14 V.8BIS MEETING ROSTER, APRIL 5 – 7, 1995, BELLEVUE, WA

Les Brown, Motorola-ISG V.8bis Rapporteur

AT&T Dick BrandtAT&T Mike BuckleyBellcore Wes HenryGDC Yuri GoldsteinIBM Ali SadriMicrosoft Joe DecuirMicrosoft Charlie GarthwaiteIntel Chris HansenIntel Barry O’MahonyRadish Peter MathysRadish Gregory MuirRadish Mike WinseckProbe Comm. (UK) John MagillRockwell Bernard DebbaschRockwell Glen Griffith



ACRONYM GLOSSARY

ACK AcknowledgementADPCM Adaptive Differential PCMADSI Analog Display Services Interface (Bellcore)ANS Answer ToneANSI American National Standards InstituteAPI Application Programming InterfaceASVD Analog SVDATM Asynchronous Transfer ModeAVD Alternating Voice DataAVI Interactive Audiovisual ServicesCAPI Common APICAS CPE Alerting SignalCCITT Consultative Committee International Telephone and TelegraphCDH Cooperative Document HandlingCDMA Code Division Multiple AccessCELP Code Excited Linear PredictionCIP Component-Independent PaletteCL Capabilities Select (see CR)CLR Capabilities List RequestCM Call MenuCME Circuit Multiplication EquipmentCMISE Common Management Information Service ElementCPE Customer Premise EquipmentCQ CAS SignalCR Capabilities Request (see CL)DAVIC Digital Audio-Visual CouncilDCE Data Circuit Terminating EquipmentDCME Digital Circuit Multiplication EquipmentDCMS Digital Circuit Multiplication SystemsDCN T.30 DisconnectDES Digital Extend SignalDIS/IS Draft International StandardDLCI Data Link Connection IdentifierDSI Digital Speech InterpolationDSU Data Service UnitDSVD Digital SVDDT Dual ToneDTE Data Terminal EquipmentDTMF Dual Tone Multi FrequencyE 20 bit sequenceECM Error Correction ModeERL Echo Return LossES Escape SignalETSI European Telecom. Standards InstituteFCC Federal Communications Commission (U.S.)FIR Finite Impulse ResponseFLMTS Future Land Mobile Telephony SystemsFPLMTS Future Public Land Mobile Telephone SystemsFTP File Transfer ProtocolGSM Global System for Mobile communications (formerly Groupe Speciale Mobile)GSTN General Switched Telephone Network (e.g., PSTN)HDLC High Level Data Link Control



IEEE Institute of Electrical and Electronic EngineersIETF Internet Engineering Task ForceIPR Intellectual Property RightsIRA International Reference AlphabetIRS Intermediate Reference SystemISO International Standards OrganizationITU International Telecommunications UnionITU-T ITU Telecommunications SectorJBIG Joint Binary Image GroupJM Joint MenuJPEG Joint Photographics Expert GroupLAP Link Access ProtocolLAPF Link Access Protocol - FrameLAPM Link Access Protocol Modem (V.42)LBC Low Bit rate CoderLDCELP Low Delay CELPMAPI Messaging APIMCS Multipoint Control Services (T.122)MCU Multipoint Control UnitMFPI Multifunction Peripheral InterfaceMHEG Multimedia and Hypermedia Experts GroupMLP MultiLayer ProtocolMOS Mean Opinion ScoreMPEG Motion Picture Experts GroupMR Mode RequestMS Mode SelectNAK Negative AcknowledgementNSF Non Standard FacilitiesODA Open Document ArchitectureOGM Out-Going MessageOSI Open System InterconnectionPBX Private Branch ExchangePCI Programmable Communications InterfacePCM Pulse Code ModulationPCME Packet Circuit Multiplication EquipmentPCN Personal Communications NetworkPMM Protocol Management ModulePSTN Public Switched Telephone NetworkQoS Quality of ServiceSDL Specification and Description LanguageSF Single FrequencySQEG Speech Quality Expert GroupSS #5 Signaling System 5SVD Simultaneous Voice DataSVF Simultaneous Voice and FacsimileSWG Sub Working GroupVoD Video on Demand



1995 MEETING SCHEDULES AS OF APRIL 14. 1995Subject to Change without Notice

SG 14 Apr 19 - 27 GenevaTR-45.3 Apr 24 - 28 Raleigh-Durham, NCTR-46 Apr 24 - 28 Arlington, VATR-45 May 1 Chicago, ILT1A1 May 1 - 5 Boulder, COTR-29 May 8 - 11 Lexington, KYTR-41.6 May 8 - 12 New Providence, NJTR-45.2 May 8 - 12 Hilton Head, SCTR-45.4 May 15 - 19 Albuquerque, NMTR-45.5 May 8 - 12 Hilton Head, SCTR-30 May 15 - 19 Toronto, OntTR-45.3 May 15 or 22 Kirkland, WATR-46 May 22 - 26 Toronto, OntSG 15 Rapp May 31-Jun 6 JapanJTC(Air) Jun 5 - 9 Nashua, NHT1E1 Jun 5 - 9 New Jersey areaTR-45.2 Jun 5 - 9 Calgary, AlbT1S1 Jun 12 - 16 Washington, DC areaTR-41 Jun 12 - 16 Kansas City, KSTR-45.3 Jun 12 - 16 Montreal, QueTR-45.5 Jun 12 - 16 San Diego, CASG15 LBC Jun 19 - 22 Boston, MATR-45.4 Jun 19 - 23 Durango, COTR-46 Jun 26 - 30 Vancouver, BCTR-30 Jul 10 - 14 Newport Beach, CATR-45.2 Jul 10 - 14 Montreal, QueQ3/8 Rapp Jul 17 - 21 Dublin, IrelandTR-45.3 Jul 17 - 21 Ottawa, OntTR-45.5 Jul 17 - 21 Quebec City, QueQ11/8 Rapp Jul 24 - 28 Tokyo, JapanTR-45.4 Jul 24 - 28 Montreal, QueTR-46 Jul 24 - 28 Calgary, AlbJTC(Air) Jul 31-Aug 4 ---T1P1 Jul 31-Aug 4 ---TR-29 Jul 31-Aug 3 Quebec City, QueQ10/8 Rapp Jul 31-Aug 3 Quebec City, QueT1A1 Aug 7 - 11 Boston, MATR-45.3 Aug 7 - 11 Dallas, TXTR-45.2 Aug 14 - 18 Toronto, OntTR-45.5 Aug 14 - 18 Vancouver, BCTR-41.6 Aug 15 - 17 ---T1E1 Aug 21 - 25 ---TR-45.4 Aug 21 - 25 Vancouver, BC

TR-46 Aug 28-Sep 1 Monterey, CATR-45 Sep 4 Denver, COJTC(Air) Sep 11 - 15 ---TR-30 Sep 11 - 15 Portland, ORTR-41 Sep 11 - 15 Edmonton, AlbTR-45.5 Sep 11 - 15 Portland, MESG8 Rapp Sep 18 - 22 Palo Alto, CAQ10/8 Sep 18 - 29 Paris, FranceT1S1 Sep 18 - 22 New Jersey areaTR-45.2 Sep 18 - 22 San Antonio, TXSG 15 Rapp Sep 25 - 29 VA, U.S.A.TR-45.4 Sep 25 - 29 Orlando, FLQ3, Q8, Q15/8Rapp

Oct Kyoto, Japan

TR-45.3 Oct 2 - 6 Toronto, OntTR-46 Oct 2 - 6 Orlando, FLTR-29 Oct 16 - 19 San Diego, CATR-45.2 Oct 16 - 20 Tampa, FLTR-45.5 Oct 16 - 20 Seattle, WATR-45.3 Oct 30-Nov 3 Orlando, FLTR-45.4 Oct 30-Nov 3 San Francisco, CASG 15 Nov 13 - 24 GenevaJTC(Air) Nov 6 - 10 ---T1P1 Nov 6 - 10 ---TR-45.4 Nov 6 - 10 El Paso, TXTR-46 Nov 6 - 10 San Antonio, TXT1E1 Nov 13 - 17 Orlando, FLTR-30 Nov 13 - 17 Orlando, FLTR-45.2 Nov 13 - 17 Colorado Springs,

COTR-45.5 Nov 13 - 17 Colorado Springs,

COTR-45 Nov 27 Dallas, TXTR-45.3 Nov 27 - Dec 1 Maui, HIT1S1 Dec 4 - 8 ---TR-41 Dec 4 - 8 Fort Meyers, FLTR-45.4 Dec 4 - 8 Orlando, FLTR-45.5 Dec 4 - 8 San Diego, CAT1A1 Dec 11 - 15 San Jose, CATR-45.2 Dec 11 - 15 Atlanta, GATR-46 Dec 18 - 22 Cancelled

Communications Standards Review –Telecommunications (ISSN 1081-4655) is published 6 - 8 times peryear, within days after the latest, related standards meetings. Editor: Elaine J. Baskin, Ph.D. Technical Editor: KenKrechmer. Copyright © 1995, Communications Standards Review. All rights reserved. Copying of individualarticles for distribution within an organization is permitted. Subscriptions: $595.00 per year worldwide. Discounts foradditional subscriptions are available. Submit articles for consideration to: Communications Standards Review, 757Greer Road, Palo Alto, CA 94303-3024 U.S.A. Tel: +1-415-856-9018. Fax: +1-415-856-6591. e-mail:[email protected]. 16903

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