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Scope Communications Inc.Page 1
SCOPECOMMUNICATIONS
Cabling Systems for Next Generation Networking
Fanny Mlinarsky
Cabling Systems for Next Generation Networking
Fanny Mlinarsky
Scope Communications Inc.Page 2
SCOPECOMMUNICATIONS OutlineOutline
CABLING FOR ATM AND OTHER FAST NETWORKS
CABLING FOR ATM AND OTHER FAST NETWORKS
OVERVIEW OF INDUSTRY STANDARDS
OVERVIEW OF INDUSTRY STANDARDS
COPPER AND FIBER COMMUNICATIONS CHANNELS
COPPER AND FIBER COMMUNICATIONS CHANNELS
TRENDS IN DATA COMMUNICATIONSTRENDS IN DATA
COMMUNICATIONS
Scope Communications Inc.Page 3
SCOPECOMMUNICATIONS Industry Standards Industry Standards
• Network-specific standards– ATM ( 12, 25, 51, 155 Mb/s)– 100 Mb/s “Fast” Ethernet – 100VGAnyLAN – 10Base-T, Token Ring
• Generic cabling standards– ISO 11801
» Classes B, C, D– TIA 568
» Categories 3, 4, 5 » TSB-67 Field Testing Standard
SNRAMBIENT NOISE
DELAY SKEWPROP DELAY
NEXTATTENUATION
LENGTHCONTINUITY
ETC.
ETC.
NetworkingStandard
CablingStandard
16 MHz
100 MHz160 MHz
Class C / Cat 3Cat 4
Class D / Cat 5? Class E ?
20 MHz
Scope Communications Inc.Page 4
SCOPECOMMUNICATIONS
TIA-568-A Categories 3, 4 and 5 NEXT and AttenuationTIA-568-A Categories 3, 4 and 5 NEXT and Attenuation
CAT 3
CAT 4
CAT 5
Scope Communications Inc.Page 5
SCOPECOMMUNICATIONS
TIA-568-A Fiber Optic Link AttenuationTIA-568-A Fiber Optic Link Attenuation
012345678
Attenuation(dB)
0.5 1 2 2.51.5 30
Distance(km)
Link with 2 connectors, no splices
3.75 dB/km 850 nm MMF
0.5 dB/km Outside plant SMF1310, 1550 nm
1.5 dB/km 1300 nm MMF 1.0 dB/km
Inside plant SMF1310, 1550 nm
Scope Communications Inc.Page 6
SCOPECOMMUNICATIONS Category 3 ApplicationsCategory 3 Applications
0 10 20 30 40 50 60 70 80 90 100MHz
10
20
30
40
50
60
70
10 Mb/s10 Mb/s10Base-T(Estimated)
16 MHz
51.8451.84, 25.92, 12.96 Mb/sATM Mid-range (spectrum mask from AF-PHY-0018.0, Table 2-1)
NOTE: All spectra are normalized; drawn at 10 dB offsets for clarity only
dB25.6 Mb/s25.6 Mb/s ATM(Estimated minimum bandwidthbased on symbol rise time in AF-PHY-0040.000, Fig 2.3e, Table 2.4)
100 Mb/s100 Mb/s IEEE 802.12 100VG-AnyLAN(Frequency roll-off, Table 16-5)
155.52155.52 Mb/s ATM for Category 3 (spectrum mask from AF-PHY-0047.0, Table 2-1)100 Base100 Base--T2T2
802.3v/D3.0(Table 32-5)
Scope Communications Inc.Page 7
SCOPECOMMUNICATIONS Category 5 ApplicationsCategory 5 Applications
NOTE: Both spectra are normalized; drawn at 20 dB offset for clarity only
0 10 20 30 40 50 60 70 80 90 100
MHz
10
20
30
40
50
60
70
155 MHz125 MHz
155.52 Mb/s155.52 Mb/s ATM(First lobe oftheoretical NRZ spectrum;matches most real implementations)
100 Mb/s100 Mb/s IEEE 802.3u100Base-TX PMD based on ANSI X3.263:199X(Estimated bandwidth for 125 Mb/s MLT-3 signaling)
Scope Communications Inc.Page 8
SCOPECOMMUNICATIONS
100 Mb/s 100Base-T4 Physical Layer Specs not covered by TIA-568-A or ISO 11801 100 Mb/s 100Base-T4 Physical Layer Specs not covered by TIA-568-A or ISO 11801
• 100Base-T4, IEEE Std 802.3u-1995– Section 23.6.1: Category 3 or class C channel– Section 23.6.2.1: Insertion loss not to exceed 12 dB at 12.5 MHz
» Inconsistent with cat 3 channel attenuation of 12.7 dB at 12 MHz– Section 23.6.2.3.1: Max NEXT 24.5 dB at 12.5 MHz
» Inconsistent with cat 3 channel NEXT of 21.1 dB at 12.5 MHz– Section 23.6.2.3.2: Multiple Disturber NEXT (MDNEXT)
» Not specified by TIA-568-A or ISO 11801– Section 23.6.2.3.3: Equal Level Far-end Crosstalk (ELFEXT)
» Not specified by TIA-568-A or ISO 11801– Section 23.5.2.4.1: Max link delay 570 ns 2-12.5 MHz
» Specified in TIA Draft 4 “Propagation Delay and Delay Skew Specifications for 100 ohm 4-pair Cabling”
» To be incorporated into the addendum to TIA-568-A– Section 23.6.2.4.3: Max delay skew 50 ns
» Specified in TIA Draft 4 “Propagation Delay and Delay Skew Specifications for 100 ohm 4-pair Cabling”
» To be incorporated into the addendum to TIA-568-A
Scope Communications Inc.Page 9
SCOPECOMMUNICATIONS
100 Mb/s 100VG-AnyLAN Physical Layer Specs not covered by TIA-568-A or ISO 11801 100 Mb/s 100VG-AnyLAN Physical Layer Specs not covered by TIA-568-A or ISO 11801
• 100VG-AnyLAN, IEEE Std 802.12-1995– Section 16.9: Category 3 or class C channel– Section 16.9.1.1: Insertion loss not to exceed 14 dB at 15 MHz
» Inconsistent with cat 3 channel attenuation of 14.4 dB at 15 MHz– Section 16.9.1.3: Max link delay 5.7 ns/m, max 1.2 us total delay
» Specified in TIA Draft 4 “Propagation Delay and Delay Skew Specifications for 100 ohm 4-pair Cabling”
» To be incorporated into the addendum to TIA-568-A – Section 16.9.1.3: Max delay skew 67 ns
» Specified in TIA Draft 4 “Propagation Delay and Delay Skew Specifications for 100 ohm 4-pair Cabling”
» To be incorporated into the addendum to TIA-568-A – Section 16.9.3.1: Impulse noise >264 mV less than 0.2/sec
» Not specified by TIA-568-A or ISO 11801
Scope Communications Inc.Page 10
SCOPECOMMUNICATIONS OutlineOutline
TRENDS IN DATA COMMUNICATIONS
CABLING FOR ATM AND OTHER FAST NETWORKS
OVERVIEW OF INDUSTRY STANDARDS
COPPER AND FIBER COMMUNICATIONS CHANNELS
Scope Communications Inc.Page 11
SCOPECOMMUNICATIONS Twisted Pair TransmissionTwisted Pair Transmission
Transmit
Receive Transmit
Receive Signal coupled from transmit pto receive pair diminishes in intensity over distance
Transmit
Station 1
Transmit
ReceiveStation 2
Transmit
Receive
NEXT
Attenuation
Scope Communications Inc.Page 12
SCOPECOMMUNICATIONS Twisted Pair ChannelTwisted Pair Channel
0 31 62 93 124 1554036322824201612840
)
TIA Channel attenuation
AMBIENT NOISE
TXFilter
Transmitter
NEXT
RXFilter
ReceiverTXFilter
Transmitter
RXFilter
Receiver
Attenuation
+ =
SIGNALELECTROMAGNETIC NOISE SIGNAL + NOISE
DISTORTED AND ATTENUATEDDATA SIGNAL
Scope Communications Inc.Page 13
SCOPECOMMUNICATIONS Fiber Optic TransmissionFiber Optic Transmission
LED(850 or 1300 nm)
LASER(850 or 1300 )
PIN(P-intrinsic N)
APD(Avalanche Photodiode)
DETECTORTRANSMITTER
LASER(1310 or 1550 nm)
TRANSMITTER
APD or PIN
DETECTOR
Multi-Mode Fiber
Single-Mode Fiber
Core diameter is < 10 um; allowsonly a single mode
Core diameter is 50 or 62.5 um graded index; allows multiple modes
Transmit
Receive
Scope Communications Inc.Page 14
SCOPECOMMUNICATIONS
Fiber Optic Channel Properties --Attenuation and DispersionFiber Optic Channel Properties --Attenuation and Dispersion
Single Mode Fiber
Bandwidth vs. Distance1300 nm LED, Multi-Mode Fiber
050
100150
200250
300
1 2 3 4
km
MH
z
Bandwidth vs. Distance1310 nm Laser, Single-Mode Fiber
05000
100001500020000250003000035000
1 2 3 4
km
MH
z
Multi Mode Fiber
Scope Communications Inc.Page 15
SCOPECOMMUNICATIONS Fiber Optic ChannelFiber Optic Channel
LOSS THROUGHCONNECTORS,SPLICES ANDCABLE
PULSE SPREADINGDUE TO DISPERSION
LOSS THROUGHCONNECTORS,SPLICES ANDCABLE
PULSE SPREADINGDUE TO DISPERSION
+ =
SIGNAL NOISE DUE TO AMBIENT LIGHT SIGNAL + NOISE
Multi Mode Fiber
PHOTODETECTOR
LASERORLED
LASERORLED
PHOTODETECTOR
Scope Communications Inc.Page 16
SCOPECOMMUNICATIONS Bit ErrorsBit Errors
Scope Communications Inc.Page 17
SCOPECOMMUNICATIONS Bit ErrorsBit Errors
uncertainsignal level
logic high region
logic lowregion
Valid sampling period
uncertainsignal level
Valid sampling period
noisemargin
uncertainsignal level
Valid sampling period
noisemargin
• Eye pattern opening determines the noise power needed to cause errors.
• The size of this opening is a good indication of the network robustness.
Scope Communications Inc.Page 18
SCOPECOMMUNICATIONS OutlineOutline
CABLING FOR ATM AND OTHER FAST NETWORKS
OVERVIEW OF INDUSTRY STANDARDS
TRENDS IN DATA COMMUNICATIONS
COPPER AND FIBER COMMUNICATIONS CHANNELS
Scope Communications Inc.Page 19
SCOPECOMMUNICATIONS Today’s Local Area NetworksToday’s Local Area Networks
• Network segments connected by bridges, routers or gateways
• Stations on each segment can only transmit one at a time
– Limited data throughput
• Modem connection to remote sites
FDDI Ring
File Server
Local User
POTS,FrameRelay
or T1
Remote User
Local User
10 Base-THub
Token RingHub
Router
Modem
Modem
Bridge orrouter
Bridge orrouter
Scope Communications Inc.Page 20
SCOPECOMMUNICATIONS Trends in Data Communications Trends in Data Communications
• Switches• Protocol consolidation
(IP and Netware)• Increased WAN traffic due to
remote access and the Internet
• Graphics and multi-media • 100 Mb/s Ethernet, VG-AnyLAN • 155 Mb/s ATM
• Shared media hubs• Multi-protocol routers• Mostly LAN traffic
• Shared media hubs• Multi-protocol routers• Mostly LAN traffic
• Mostly data • 10 Mb/s Ethernet• 16 Mb/s Token Ring
• Mostly data • 10 Mb/s Ethernet• 16 Mb/s Token Ring
Traffic
Architecture
• Point to point throughput • Response time
• Sustainable traffic load• Routing efficiency• Sustainable traffic load• Routing efficiencyPerformance
Scope Communications Inc.Page 21
SCOPECOMMUNICATIONS Next Generation NetworksNext Generation Networks
File Server
Private ATM Switch
Local User
PublicATM
Network
PrivateATM UNI
PublicATM UNI
10 Base-T Switch
Remote User
Local User
10/100 Base-THub
Private ATM Switch
PublicATM UNI
• Switched topology• Uniform transport method for both
local and wide area connections– Reduced switch complexity;
increased speed• Fast data throughput, point to point
switched linksNote: UNI = User-to-Network Interface
Scope Communications Inc.Page 22
SCOPECOMMUNICATIONS
Performance Metrics for Next Generation NetworksPerformance Metrics for Next Generation Networks
• Emphasis on high rate of point to point data throughput
– High frequency data signal » Vulnerable to physical layer imperfections
• Bit errors cause re-transmissions and reduce the rate of data throughput
• Integrity of cabling infrastructure is key to maintaining expected rate ofdata throughput
SWITCH
SWITCHSWITCH
SWITCH
Scope Communications Inc.Page 23
SCOPECOMMUNICATIONS OutlineOutline
OVERVIEW OF INDUSTRY STANDARDS
COPPER AND FIBER COMMUNICATIONS CHANNELS
CABLING FOR ATM AND OTHER FAST NETWORKS
TRENDS IN DATA COMMUNICATIONS
Scope Communications Inc.Page 24
SCOPECOMMUNICATIONS ATM Physical Layer InterfacesATM Physical Layer Interfaces
DATA LINE PHYSICALINTERFACE RATE RATE LAYER STANDARD
(Mb/s) (Mbaud)
155.52 Mb/s (8B/10B) 155.52 194.4 MMF, 1300 nm, 2 km UNI v3.1(Fiber Channel based) 150 ohm STP, 100 m
155.52 Mb/s 155.52 155.52 MMF, 1300 nm AF-BICI-0013.003,(SONET, STS-3c based) SMF, 1300 nm TR-NWT-000253
155.52 Mb/s Cat 5 UTP 155.52 155.52 Cat 5 UTP, TIA-568 Channel AF-PHY-0015.000
622.08 Mb/s 622.08 622.08 SMF, 1300nm, 2 or 15 km AF-PHY-0046.000(SONET STS-12c based) MMF, 1300nm LED, 500 m
MMF, SW Laser, 300 m
155.52 Mb/s SW Laser 155.52 155.52 MMF, 850 nm, 1 km, TIA-568 AF-PHY-0062.000 (Ballot)
Mid-range Phy, Cat 3 UTP 51.84, 25.92 12.96 Cat 3 UTP, TIA-568 Channel AF-PHY-0018.00012.96
25.6 Mb/s, Cat 3 25.6 32 Cat 3 UTP, TIA-568 Channel AF-PHY-0040.000
100 Mb/s FDDI-PMD 100 125 SMF, MMF, 1300 nm UNI v3.1, ISO/IEC 9314-3
DS3 44.736 44.736 75 Ohm Coax AF-PHY-0054.000 (Ballot)
E3 34.368 34.368 75 Ohm Coax UNI v3.1, ITU-T G.703
E4 139.264 139.264 UNI v3.1, ITU-T G.703
E1 2.048 2.048 120 Ohm STP, 75 Ohm Coax AF-PHY/94-0422R7 (straw vote)
DS1 1.544 1.544 100 Ohm UTP AF-PHY-0016.000
155.52 Mb/s Cat 3 UTP 155.52 25.92 Cat 3 UTP, TIA-568 Channel AF-PHY-0047.000
155.52 Mb/s POF/HPCF * 155.52, 50 155.52, 50 MMF, 650 nm, 50 / 100 m Proposal
* Plastic Optical Fiber / Hard Polymer Clad Silica Fiber
Scope Communications Inc.Page 25
SCOPECOMMUNICATIONS
155.52 Mb/s Category 5 ATM Physical Layer155.52 Mb/s Category 5 ATM Physical Layer
100 Mhz 155 Mhz
• 155 Mb/s ATM equipment, based on ATM Forum AF-PHY-0015.000 specification, has the transmit spectrum extending to 155 MHz
• It is a good idea to characterize channels expected to carry 155 Mb/s ATM to 155 MHz
Scope Communications Inc.Page 26
SCOPECOMMUNICATIONS
155 Mb/s BER TESTChannel Certification Results155 Mb/s BER TESTChannel Certification Results
Channel NEXTand attenuation;no filteringBER:
2.1 x 10 -11
3.9 x 10 -11
Channel NEXTand attenuation;with a notchBER:
6.1 x 10 -10
7.8 x 10 -10
Channel NEXTand attenuation;With a stubBER:
1.2 x 10 -8
Testing audited by
Scope Communications Inc.Page 27
SCOPECOMMUNICATIONS
gigaBERT-660 DRx
gigaBERT-660 Tx
Evaluation boardreceiving the test pattern
Evaluation boardtransmitting the test pattern Noise source
Importance of Energy Above 100 MHz to 155 Mb/s ATM Operation -- ExampleImportance of Energy Above 100 MHz to 155 Mb/s ATM Operation -- Example
Scope Communications Inc.Page 28
SCOPECOMMUNICATIONS
155 Mb/s ATM Physical Layer Requirements155 Mb/s ATM Physical Layer Requirements
• The 155 Mb/s ATM interface (AF-PHY-0015.000) uses the twisted pair channel beyond the frequency range specified by TIA-568-A and ISO-11801 and relies on the extended frequency response of the channel for maintaining the required BER performance of 10-10.
• This service works only because most category 5 installations behave predictably above 100 MHz.
• Using components beyond their frequency specification is a poor design practice -- it leaves the system vulnerable to new products which might employ emission suppressing filtering and to installation flaws which might be outside the specified frequency range.
Scope Communications Inc.Page 29
SCOPECOMMUNICATIONS
Mid-range Twisted Pair ATM Physical LayerMid-range Twisted Pair ATM Physical Layer
• ATM Forum AF-PHY-0018.000, 9/94; AF-PHY-0047.000• Spectral width and line rate of 12.96 Mbaud are the
same for all data rates– 155.52 Mb/s 64-CAP (Carrierless AM / PM)– 51.84 Mb/s 16-CAP– 25.92 Mb/s 4-CAP– 12.96 Mb/s 2-CAP
0 10 20 30 40 50 60 70 80 90 100
10
20
30
40
50
60
70
51.84, 25.92, 12.96 Mb/sATM Mid-range (spectrum mask from AF-PHY-0018.0, Table 2-1)
dB
MHz16 MHz
155.52155.52 Mb/s ATM for Category 3 (spectrum mask from AF-PHY-0047.0, Table 2-1)
Scope Communications Inc.Page 30
SCOPECOMMUNICATIONS
Mid-range Twisted Pair ATM Physical LayerMid-range Twisted Pair ATM Physical Layer
• Template for the power spectrum of a Mid-range ATM device is specified in AF-PHY-0018.000 Figure 2-8 and Table 2-1
– Spectrum centers around 12.96 MHz and has 100% excess bandwidth,extending to 25.92 MHz25.92 MHz
• Template for the spectrum of 155.52 Mb/s service specified in AF-PHY-0067.000 Figure 2-6 and Table 2-1
– Spectrum centers around 25.92 MHz and has 15% excess bandwidth, extending to 29.8 MHz
• Transmitter and receiver return loss for both services is specified in the frequency range 11--30 MHz 30 MHz to be >15 dB
• If it is important to maintain return loss of 15 dB at the device, then the cable needs to behave consistently in the range of 1-30 MHz as well
– Inconsistent with the 16 MHz range of category 3 specification
Good idea to verify channel NEXT and attenuation beyond the category 3 range of 16 MHz
– Field test range should extend to 26 MHz minimum
Scope Communications Inc.Page 31
SCOPECOMMUNICATIONS
25.6 Mb/s Twisted Pair ATM Physical Layer25.6 Mb/s Twisted Pair ATM Physical Layer
• ATM Forum document AF-PHY-0040.000, 11/95• Line rate is 32 Mbaud after 4B5B encoding (Section 2.1.1)• Spectrum is not specified directly but can be estimated from
the rise time of a One Symbol Element template in Figure 2.3e and Table 2.4
0 10 20 30 40 50 60 70 80 90 100 MHz
10
20
30
40
50
60
70
16 MHz
25.6 Mb/s25.6 Mb/s ATM(Estimated minimum bandwidthbased on symbol rise time in AF-PHY-0040.000, Fig 2.3e, Table 2.4)
dB
Scope Communications Inc.Page 32
SCOPECOMMUNICATIONS
25.6 Mb/s Twisted Pair ATM Physical Layer25.6 Mb/s Twisted Pair ATM Physical Layer
• Sections 2.2.4 and 2.3.2 specify transmitter and receiver return loss in the frequency band of 1-25 MHz
– Transmitter 1-6 MHz 14 dB, 6-17 MHz 12 dB, 17-25 MHz 8 dB– Receiver 1-17 MHz 15 db, 17-25 MHz 8 dB
• If it is important to bound return loss at the device up to 25 MHz, then the cable should be characterized up to 25 MHz as well
– Inconsistent with the 16 MHz range of category 3 specification
Good idea to verify channel NEXT and attenuation beyond the category 3 range of 16 MHz
– Field test range should extend to 25 MHz minimum
Scope Communications Inc.Page 33
SCOPECOMMUNICATIONS 10/100 Base-TX Physical Layer10/100 Base-TX Physical Layer
• IEEE Std 802.3u-1995, Chapter 25, refers to TP-PMD standard, ANSI X3.263, 3/95, for category 5 UTP and 150 ohm STP interfaces
• TP-PMD standard specifies– 100 Mb/s using 4B/5B encoding to produce 125 Mb/s data stream– Multi-Level Transmission-3 (MLT-3) modulation
» 3 voltage levels with the spectral peak at around 30 MHz» Return loss of transmitter and receiver is specified (Sections 9.1.5 and
9.2.2) up to 80 MHz80 MHz• Ranging from 16 to 10 dB as frequency increases
– Insertion loss deviation (Sections 11.1.5) 0.35 dB max» This specification ensures consistent attenuation slope over
frequency and ensures integrity of Structural Return Loss (SRL)
• Maximum medium propagation delay, IEEE Std 802.3u-1995Table 29-1
– Twisted pair link 1140 ns
Category 5 certification with additional measurement of propagation delay is sufficient field verification
Scope Communications Inc.Page 34
SCOPECOMMUNICATIONS
155.52 Mb/s Short Wavelength Laser ATM Physical Layer155.52 Mb/s Short Wavelength Laser ATM Physical Layer
• ATM Forum AF-PHY-0062.000, Letter Ballot, 5/96• TIA-568-A or ISO 11801 compliant Multi-Mode Fiber installation• Cable plant attenuation
– < 7.2 dB for 62.5 um
• Distance – 1 km
• Line code– Optical NRZ, 152.52 MBaud
• Laser wavelength– 770 to 860 nm
• Full Width Half-Maximum (FWHM) spectral width– 9 nm
Field verification of attenuation budget at 850 nm is sufficient
Scope Communications Inc.Page 35
SCOPECOMMUNICATIONS 10/100 Base-FX Physical Layer10/100 Base-FX Physical Layer
• IEEE Std 802.3u-1995, Chapter 26 refers to the FDDI PMD, ISO 9314-3 for the fiber physical layer specification
• ISO 9314-3 specifies the following fiber interfaces– Single-Mode Fiber– Multi-Mode Fiber, 2 km – MMF, 500 m Low Cost Fiber (LCF-PMD)
• Wavelength 1300 nm• Symbol rate 125 Mbaud• Maximum propagation delay, 802.3u-1995, Table 29-1
– Fiber link 4120 ns
Field test should include verification of– Attenuation– Propagation delay
Scope Communications Inc.Page 36
SCOPECOMMUNICATIONS OutlineOutline
CABLING FOR ATM AND OTHER FAST NETWORKS
TRENDS IN DATA COMMUNICATIONS
COPPER AND FIBER COMMUNICATIONS CHANNELS
OVERVIEW OF INDUSTRY STANDARDS