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NOKIA FILENAME.PPT / 13.12.1997 / NN page: 1

Overview of GSM, D-AMPS and CDMAOverview of GSM, D-AMPS and CDMA

TechnologiesTechnologies

Hannu Hietavirta

Nokia de Venezuela

05. January 1999

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Summary GSM vs. CDMASummary GSM vs. CDMA

CDMA network require very careful network planning. To achieve samequality, GSM network planning is much simpler. Also maintaining the network

quality in GSM network is easier and much more cost efficient

If not very carefully planed/maintained, soft handover (CDMA) will eat CDMAcapacity in dense urban areas. Between 30-80 % of all conversations can bein soft-handover state

Cell breathing will complicate the network planning. Under variable network

load conditions, cell breathing may resultin quality degardation Dual mode AMPS-CDMA networks does not support handover from CDMA to

AMPS. This will have an impact on service quality if CDMA coverage print issmaller than AMPS one.

CDMA is vulnerable to interference from inter-modulation products like AMPS(especially in the 800 MHz band)

Filtering of wide band audio, e.g. hearing aid interference. Filtering CDMAinterference out is much more complicated and expensive

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Summary of GSM vs. CDMA cont.Summary of GSM vs. CDMA cont.

CDMA terminals more expensive, heavier and battery life is shorter. Both talk

time and stand by time are much shorter that in GSM. Due to volumes,competition and wide variety of choice, GSM terminals will stay ahead

GSM has more advanced set of services; data, fax, SMS, smart messaging

GSM has advantage in terms of volumes; Firstly the cost of infrastructure islower due to open standard and real competition. Secondly, the volumes ofGSM will attract 3rd party application developers to build applications on top

of GSM. This is furhter enforced by the strong liasion of GSM and 3rdgeneration WCDMA system.

IS-95 is lacking a growht path into 3rd generation mobile system. Theinvestment to IS-95 may be without protection for the future - or the future willbe build on proprietary low volume solutions

Due to large module size in CDMA infra make the implementation of Mircocells currently impractical

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Summary GSM vs. D-AMPSSummary GSM vs. D-AMPS

GSM has more advanced set of services; data, fax, SMS, smart messaging.

GSM has a robust data platform. GSM networks and terminals have a lead ofmore than two year in data services. Therefore, considering any deploymenttiming for data services, GSM currently has a significant advantage

GSM is likelty to maintain the lead in data services the next 5 years

GSM has advantage in terms of volumes. The volume of GSM will attract 3rd

party application developers to build applications on top of GSM The core network IS-41 is a closed standard. Thus, any change in vendor or

access technology will require a complete overlay network (e.g. Telcelimplementing Mobitex)

Price per subscriber for D-AMPS and GSM is similar, while CDMA is moreexpensive

The implementation differences of IS-41 for D-AMPS and CDMA are verysmall. Thus Movilnet and Telcel have similar service capabilities

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Voice QualityVoice Quality Quality of the information (speech or data) is the result of several factors. Error free transmission over the fading radio

channel and a speech coder, which produces natural sounding speech and is tolerant of digital channel error, are the mostimportant factors.

Both TDMA and IS-95 have implement significant error protection. Extra bits are used for error protection and bitinterleaving is employed to prevent long sequences of erroneous bits. All technologies do this well, but no technology issignificantly better than any other

In general, due to the rapid and continuing advance in speech coder technology, the latest speech coder design is betterthan the earlier versions. When IS-95 was first demonstrated using a coder designed in 1990, it had better quality thandigital speech coders used in competitive systems, which had been designed in 1986 and 1984 respectively.

Both IS-136 and GSM have recently deployed the enhanced full rate codec (EFR). With this development the speech qualitywithin all systems is now coming to rival to that of the fixed voice network speech quality.

In the long term, one can expect each system to be upgraded to the latest and best available speech coder, so that thisshould not be viewed as a long-term distinguishing feature of either technology (TDMA vs. CDMA).

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Network QualityNetwork Quality

Network Operator Call Attemps Attemps OK Releases OK Calls OK

CDMA1800 Sprint PCS 384 91,4 94,9 86,7

GSM1900 Bacific Bell 366 98,6 97 95,6

CDMA800 Air Touch 384 96,9 89,2 86,6

AMPS SW Bell 282 90,1 89,8 80,9

Drive test results from San Diego (week 40/1998):

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7/16NOKIA FILENAME.PPT / 13.12.1997 / NN page: 7

Volumes in GSM, D-AMPS and CDMAVolumes in GSM, D-AMPS and CDMA

Global Cellular Subscribe

0

20

40

60

80

100

120

140160

180

200

1997 1998 1999 2000 2001

Millions

IS-136 IS-95 GSM

0

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150

200

250

300

Existing

Jun1997

Existing

Nov1997

GSM

GSM

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endof1999

GSM

MoU

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endof2003

IS-95

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Aug1997

Existing

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21stcentury"

New estimateOld estimate

December: Mobile penetration in Finland hit the 60 %mark. Now, mobile penetration is higher than fixed linepenetration (per person)

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Roaming, Network + HandsetsRoaming, Network + Handsets

Roaming can be achieved via two methods:

same technology (e.g. GSM) multi-mode handsets

GSM is designed for automatic international roaming. The introduction of CAMELwill furhter enhance the automatic use of IN services when roaming

The 900, 1800 and 1900 GSM bands have a very wide geographical footprint. The

fourth variant, Iridium, will provide the required fill in in rural areas The D-AMPS camp (UWCC) has a clear focus to facilitate international roaming

and solve the current problems. Difficult issue is IS-41 proprietary services. Inter-carrier deals are currently beeing used to facilitate seamler service roaming. Theimplementatio of WIN will facilitate service roaming

Commercial products exist that can facilitate roaming between IS-41 and GSM

networks Digitel roaming will initially depend on Swisscom roaming agreements ( USA ?,

Chile ?)

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Roaming, Network and Handsets cont.Roaming, Network and Handsets cont.

GSM MoU has requested volumes of tri-band GSM handsets (900,

1800, 1900) AMPS-IS-136-GSM handsets are expected to come to market very

soon as well (3Q/99, ETSI SMG#27 Tdoc 779/98)

The merger of different TDMA technologies in one handset does notpose any fundamental engineering problmes

Nokia does not have plans to produce a GSM-CDMA dual modehandset

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Nokia and Wireless DataNokia and Wireless Data

Robusts data connections are achieved due to two standard mechanisms:

Radio Link Protocol (RLP). This is an acknowledgement protocol that facilitatesretransmission of errored data. This increases throughput by limiting any re-transmisson to the radio portion of the call reducing the number of end to end re-transmissions.

Additional data over the air interface. The gross bit rate of a full rate channel is 22.8kbit/s, but 13.2 kbit/s of that total capacity is used for error protection code to ensureaccurate transmission of the 9.6 kbit/s data across the fading radio channel.Respectively 8.4 kbit/s is used for error protection of 14.4 kbit/s data transmission

Examples of Nokia Wireless data applications/develoments: Minimise data call set times, eg digital modems and TCP/IP access from the switch to

remove modem handshaking (30secs -> 5secs)

Detect terminal capability and filter information accordingly eg if the terminal is a NokiaCommunicator, do not send graphics unless requested.

Make a circuit switched application acknowledgement based to support breaksconnection. Eg if a mail message is 90% downloaded and the radio connection fails,reconnection within a timeout period will mean that only the additional 10% needs tobe transmitted (Nokia Wireless Data Enhancer)

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Circuit Switched and Packed DataCircuit Switched and Packed Data

Circuit switched data

D-AMPS data gross rate is 9.6 kbit/s, effective max. 7.2 - 7.8 kbt/s

Current GSM effective data speed in 9.6 - 14.4 kbit/s.

Standardisation of higher data rates in D-AMPS is expected during 1998(IS-136+). Normal lead time to products 12-18 months fromstandardisation

CDMA data rates effectively 7.2 - 7.8kbit/s. Without any error correction14.4 kbit/s is achievable today.Implementation of CDMA multi-codehandset is more difficult than TDMA multi-slot one.

Packed data

GSM supports SMS now

GSM supports up to 128 kbit/s using GPRS (year 2000) Commercially available D-AMPS mobiles will support mobile originated

SMS during 1Q/99.

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Mobile networks and InternetMobile networks and Internet

With the growth of the Internet, or more importantly the understanding that the Internet

represents the future application environment, companies are frantically buildingcompetence and products in this area. With this refocused core competence, the mobileenvironment is a logical extension. With the mobile core network evolution to IP,applications can be easily created using core competencies. The potential of 500 millionInternet users and up to 1 billion e-mail users by the year 2000, will provide the motivation

The enhanced capability of mobile technologies to support higher data rates are requiredto leverage off this market, however this only has a second order stimulation effect. Mobileindustry players, such as Nokia, are forming themselves into industry groups and jointventures to promote application driven environments, examples of these are Symbian,Bluetooth and WAP.

As these are industry wide and open groups the protocols/applications they aredeveloping will be the catalyst for increasing activity in 3rd party application development.

GSM is world largest mobile standard. It will attract a large number of 3rd party developerto develop applications on top of GSM and to interwork with GSM

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SymbianSymbian

Symbian is a group formed by Nokia, Ericsson and Psion (recent

additions to the group are Motorola, Phillips and software companiesOracle and JavaSoft) with the objective of creating user friendly wirelessinformation devices, such as smart phones and communicators. Symbianis attempting to promote the interoperation of Wireless InformationDevices (WID) with wireless networks, content services, messaging andenterprise wide solutions. Symbian has developed the EPOC 32-bitoperating system and specifically scaled it for low-power, compact

machines such as handheld PIMs and mobile communicators. Softwaredevelopers can obtain the software developer kit (SDK) cheap, allowingthem to develop applications on top of the EPOC OS. This will encourageand promote many software developers to participate in applicationdevelopment for end users via EPOC

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BluetoothBluetooth

Bluetooth is another special interest group (SIG) aiming at making

seamless voice and data transmission possible via wireless short-rangeradio. Bluetooth uses a short range radio link in the globally available2.45Ghz ISM free band, to exchange information with wirelessconnectivity between mobile terminals, mobile PCs, handheld computersand other peripherals. This essentially eliminates the need for thepurchase or carrying of a number of proprietary cables to allowconnection of multiple communication devices, by instead providing a

single multi-device port. The devices to be connected will not require lineof sight and can maintain a connection when in motion, in the pocket orbrief case.

More information: www.bluetooth.com

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