`
`SIEGMUND M. REDL
`MATTHIAS K. WEBER
`
`
`
`
`
`MALCOLM W. OLIPHANT FORD EX. 1017 —
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`FORD EX. 1017
`
`

`

`bl+ RED
`
`ANINTRODUCTION TO GSM
`
`Siegmund M.Redl
`Matthias K. Weber
`Malcolm W. Oliphant
`
`Artech House
`
`Boston e London
`
`
`
`
`
`
`
`FORD EX. 1017
`
`FORD EX. 1017
`
`

`

`Library of Congress Cataloging-in-Publication Data
`Redl, Siegmund M.
`p.
`cm.
`Anintroduction to GSM / Siegmund M.Redl, Matthias K. Weber, Malcolm W.Oliphant.
`Includes bibliographical references and index.
`ISBN 0-89006-785-6
`1. Mobile communication systems. 2. Cellular radio.
`Malcolm W.III. Title.
`TK6570.M6R43
`1995
`621.3845°6-dc20
`
`I. Weber, MatthiasK. II. Oliphant,
`
`94-23893
`CIP
`
`British Library Cataloguing in Publication Data
`Redl, Siegmund M.
`Introduction to GSM
`I. Title
`621.38456
`
`ISBN 0-89006-785-6
`
`Chapters 4 and 6-10 are largely adapted from and Chapters 3, 5 and 11 contain portions of
`text adapted from the German work D-Netz-Technik und Mefpraxis by Siegmund Redl and
`Matthias Weber, © 1993 FRANZIS-Verlag GmbH.
`
`
`
`YAASHLI AURA
`
`
`
` © 1995 ARTECH HOUSE, INC.
`
`685 CantonStreet
`Norwood, MA 02062
`
`—
`
`All rights reserved. Printed and boundin the United States of America. No part of this book
`may be reproduced orutilized in any form or by any means,electronic or mechanical, includ-
`ing photocopying, recording, or by any information storage and retrieval system, without
`permission in writing from the publisher.
`
`International Standard Book Number: 0-89006-785-6
`Library of Congress Catalog Card Number: 94-23893
`
`LOS
`
`CON
`
`Bretace
`Introduction—Cellular Mob
`Bec I
`Gikepeer 1
`The Global Scenario ite
`1.1. Historical Background
`12
`Situation of Global Cellule
`1.2.1 Different Standands
`1.2.2. Commercial Aspects
`
`TheTransition From A:
`Seceer 2
`Zi
`The Capacity Syndrome
`22 Aspects of Quality
`23 SomePolitical and Econom
`24 Focusing on Regions
`2.4.1 North American Dx
`2.4.2
`The European Samm
`2.4.3
`The Cellular Workd
`America
`
`References
`
`P=: 0 Digital Cellular Mobile Rac
`
`~GSM—ADigital Cellak
`Gtepeer 3
`3.1 Development and Introducn
`32 Services Offered in a GSM
`3.2.1 GSM Phase 1 Serwac
`3.2.2 GSM Phase 2 Serwac
`33 What Is a Cellular Network
`3.3.1
`A Little Bit of Hise
`3.3.2 Cellular Structure
`
`FORDEX. 1017
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`

`

`
`
`Clue? rk: 3
`vwvY
`
`GSM—A DIGITAL CELLULAR
`MOBILE RADIO SYSTEM
`
`Oetterent requirements and the dedication to meet them led to the development of
`se GSMstandard. An unprecedented effort has been taken by telecommunication
`wethorities, network operators, and industry sectors to establish and maintain a
`sesce-of-the-art cellular standard for the benefit of the entire industry and all its
`customers.
`
`In this chapter, we confine our focus to GSM. Westart with a brief review of
`= Sustory and then follow with the evolution of the GSM standard andits worldwide
`s®eption. We includea description of someof the services offered by a GSM public
`aac mobile network (PLMN), and introduce some basic terms and the general
`eechetectureofa cellular network. Also introduced are the new terms and the compo-
`ments of a GSM system, and which comefrom the structure and operation of analog
`semworks, which may already be knowntothe reader. We focus especially on security
`“escures inherent in a GSM network.
`A brief note concerning the term GSMis in order now. Since GSM standsfor
`@ebal system for mobile communications, it is redundant to say “GSM system,”
`‘se this would mean wesaid “global system for mobile communications system.”
`“Sewever, since terms such as GSM system are widely used in the industry, it is
`“emmon to be redundant when using system abbreviations(e.g., ISDN network),
`mee the redundancy in such terms has someclarifying effect. This book will use
`
`eee the redundant and nonredundant forms with reckless abandon.
`
`
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`

`20 AN INTRODUCTION TO GSM
`eee
`
`3.1 DEVELOPMENT AND INTRODUCTION OF THE GSM STANDARD
`
`In Table 3.1, the milestones in the course of esta blishing the GSM system specifica-
`tions and the spread of GSM overtheglobearelisted [1].
`Whenlookingonly at the adoption of the GSM standardin Europe,it becomes
`clear that the unification of cellular mobile radio will finally becomea reality. Figure
`3.1 illustrates this.
`Wordscannoteasily expressthetireless efforts expended to propelthe develop-
`mentof the GSM standard, design a network architecture, test and verify technical
`parameters, prove functionalities, promote the systemitself, and design and manufac-
`ture the necessary equipment. What wesee todayis the result of this work.
`With teamworkto an extentneverbefore seen in Europe in the whole industry,
`in administrationsandtheir nationalorinternationalinstitutes, and amongoperators
`and manufacturers,a rich and detailed standard for a promising, future-proofmobile
`communications system has been developed.
`The new standard has given new momentum to the economyandhascreated
`new markets. A commonstandard for a market whose customers number in the
`tens of millions leads to minimized costs for the manufacturers of appropriate
`equipment. They can producelarger numbers of terminals for a large market, which
`drives down the cost to end users. Together with deregulation, the provision of
`cellular service means competition, again to the benefit of end users. Tariffs, products,
`and services becomesubject to the higher dynamics imposed by this competition.
`Newservices and features, especially the roaming and security features, as
`well as the digital advantages, such as reduced power consumption (state-of-the-art
`semiconductor devices, TDMA technology) and improved speech quality are the
`keys that convince network operators and potential subscribers to choose GSM.
`Otherattractive features and services, which have notyet appearedin anycellular
`network, are waiting in line (see following paragraphs).
`The standardization workis not yet finished.It will be continued for years to
`come. The GSM standard can be regarded as an evolving standard. Today, networks
`are already operational, but to what extent does the equipment and the provision
`of cellular services comply with the standard? When it became obvious that the
`whole standardization process could not be completed before an actual launch of
`the services—necessary because of economic factors—a phased approachto rolling
`out the specifications and the networks was adopted. This meantthat a subset of
`network features was to be introduced. The reduced features were initially designed
`to be upwardly compatible add-ons of services and functions. The subset wascalled
`GSM Phase 1. The additional supplements to full implementation ofall the planned
`services and network features were called GSM Phase2. Now,thereis even thought
`given to features beyond Phase 2. These future implementations are known by the
`term Phase 2+. The networks, which are operational now, feature GSM Phase 1,
`whose specifications were frozen as early as 1991. GSM Phase 2 specifications and
`
`
`
`Ta
`Development and Sen
`
`
`EB CEPT decides to eseabiesi
`
`term GSM) to dGewelap ;
`European cellular mabe
`Establishment of three BW
`services offered m 2 GS
`signaling protocols, mam
`Discussion and adopaer «
`the group >100 recome
`A so-called permane=t =m
`work, which is intense:
`Initial Memorandses: of D
`network operator onEas
`Major objectives:
`© Coordinating the mrad
`« Planning of service sere
`« Routing, billmg, aad cx
`Validations and trials (per
`work,
`With the establishmenr of
`Institute (ETSI), the spe
`body. GSM becomes 2 «
`GSM groups 1—4, beter.
`which are technical sabe
`Specifications eventually
`Telecommunications Ste
`European Telecomm
`future. GSM finally stan
`The GSM specifications Sm
`Cellular System on Ge 1
`application initiered = 2
`The GSM Recommendatea:
`including more than 50)
`July: Planned commercsal I
`delayed to 1992 because
`(GSM then stands for G
`Official commercial banc
`Mobiles).
`The GSM-MolUhas 62 =e
`addition 32 potents! =e
`countries [2].
`The end of 1993 shows om
`more than 80% of chem
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`GSM—ADigital Cellular Mobile Radio System 21
`
`Table 3.1
`Development and Spread of the GSM Standard
`
`Year
`
`1982
`
`1984
`
`1985
`
`1986
`
`1987
`
`1988
`
`1988/89
`to
`1991/1992
`
`1990
`
`1991
`
`1991
`
`1992
`
`1993
`
`1993
`
`Events/Decisions/Achievements
`
`CEPT decides to establish a Groupe Spéciale Mobile (the initial origin of the
`term GSM)to develop a set of commonstandards for a future pan-
`European cellular mobile network.
`Establishment of three Working Parties (WP1-3) to define and describe the
`services offered in a GSM PLMN,theradio interface, transmission,
`signaling protocols, interfaces, and networkarchitecture.
`Discussion and adoption ofa list of recommendations to be generated by
`the group >100 recommendations in a series of 12 volumes).
`A so-called permanent nucleusis established to continuously coordinate the
`work, which is intensely supported by industry delegates.
`Initial Memorandum of Understanding (MoU) signed by telecommunication
`network operator organizations (representing 12 countries).
`Major objectives:
`¢ Coordinating the introduction of the standard and timescales
`e Planning of service introduction
`¢ Routing, billing, and tariff coordination
`Validations andtrials (particularly the radio interface) show that GSM will
`work.
`With the establishment of the European Telecommunications Standards
`Institute (ETSI), the specification work was movedto this international
`body. GSM becomesa technical committee within ETSI andsplits up into
`GSM groups 1-4,later called Special Mobile Groups (SMG) 1-4,
`which are technical subcommittees. Recommendations and Technical
`Specifications eventually become Interim European
`Telecommunications Standards (I-ETS), and after approval will become
`European Telecommunications Standards (ETS) some time in the
`future. GSM finally stands for Global System for Mobile Communications.
`The GSMspecifications for the 900-MHzbandarealso applied to a Digital
`Cellular System on the 1,800-MHz band (DCS 1800), a PCN
`application initiated in the United Kingdom.
`The GSM Recommendations comprise more than 130 single documents
`including more than 5,000 pages.
`July: Planned commercial launch of GSM service in Europe (MoU plan)
`delayed to 1992 because of nonavailability of type-approved terminals
`(GSM then stands for God Send Mobiles).
`Official commercial launch of GSM service in Europe (God Has Sent
`Mobiles).
`The GSM-MoUhas 62 members(signatories) in 39 countries worldwide. In
`addition 32 potential members (observers/applicants) in 19 other
`countries [2].
`The end of 1993 shows one million subscribers to GSM networks; however,
`more than 80% of them are to be found in Germanyalone.
`
`(continued)
`
`
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`

`22 AN INTRODUCTION TO GSM
`
`GSM—
`
`Table 3.1
`Development and Spread of the GSM Standard (continued)
`
`1993
`
`1994
`onwards
`
`First commercial services also start outside Europe: Australia, Hong Kong,
`New Zealand. GSM networks are operational in Denmark, Finland,
`France, Greece,Ireland, Italy, Luxembourg, Norway, Portugal, Sweden,
`Switzerland, United Kingdom [2].
`GSM services can be expected in the following additional countries: Andorra,
`Austria, Belgium, Brunei, Cameroon, Cyprus, Estonia, Iceland, Iran,
`Kuwait, Latvia, Malaysia, Netherlands, Pakistan, Qatar, Singapore, South
`Africa, Spain, Syria, Thailand, Turkey, United Arab Emirates, and
`manyothers [2].
`
`
`
`
`plata Bee
`
`
`
`
`
`wae
`
`Europe
`
`
`
`\
`
`S KW
`
`Figure 3.1 The GSM standard in Europe.
`
`products should be available in 1994. Phase 2+ addendumsare intended to be
`updated ona regular basis according to marketneeds and theavailability of specifica-
`tions.
`
`An appropriate comment on this chapter comes from Jonas Twingler, GSM
`coordinator of ETSI [3]:
`
`Originally, GSM wasseen as a Pan-Ex
`version and a fixed step towards t
`reasons, that it would be more ben
`interim version of the standard at an
`to producethe full version of GSM-
`news, situations and experience g2im
`By this, the GSM platform was
`hooks, mechanisms and not at least
`and to provide mobile communicates:
`ties. Even before the Phase 2 stamds
`grown far beyondits original geograg
`System for Mobile communication r=
`Phase 2, and in particular with Phe
`beyondits originally intended fumes
`new applications, new access methoc
`gether for new categories of markets.
`It looks promising.
`
`32 SERVICES OFFERED IN A GSM S¥!
`
`“Whe features andbenefits expected in the ne
`‘eee! to or better than the existing anale
`‘@perational, andservice costs, (3) a high ke
`rerention), (4) international roaming (ume
`‘gepport of low-power hand-portable tem:
`end networkfacilities. This section explore
`BMN.
`It was only a logical consequence of
`—
`orking compatibility with the services
`metworks was sought. In particular
`eeedard can be found in the ISDN conceg
`We can distinguish three categories
`@eeeces, and (3) supplementary services. 2
`‘@pproachto introducing the services led to
`@ Phase 1, and anotherset of services ade
`me listed according to their phases (1 a
`‘@etvidual phases are discussed. Complete
`LSEN can be foundin [4].
`
`3211 GSM Phase 1 Services
`
`‘The Phase 1 technical specifications, valid §
`growide the definitions for the set of servic
`
`
`
`
`
`
`
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`

`GSM—ADigital Cellular Mobile Radio System 23
`
`Originally, GSM wasseen as a Pan-European“only” system,in onesingle
`version and a fixed step towards the future. It turned out, for several
`reasons, that it would be more beneficial for all parties, to launch an
`mterim version of the standardat an early point in time—Phase 1—and
`to produce the full version of GSM—Phase 2—adapted to the “‘latest”’
`news, situations and experience gained in Phase 1.
`By this, the GSM platform wascreated, a platform whichisfull of
`hooks, mechanisms and notat least potential to continue to build on
`and to provide mobile communicationinall its possible forms and varie-
`ties. Even before the Phase 2 standard has been completed, GSM has
`grownfar beyondits original geographical “limitations” and the Global
`System for Mobile communicationreally starts to deserve its name. With
`Phase 2, and in particular with Phase 2+, GSM will also expand far
`beyondits originally intended functional boundaries and open up for
`new applications, new access methods, new technologies and thusalto-
`gether for new categories of markets, needs and users.
`It looks promising.
`
`52 SERVICES OFFERED IN A GSM SYSTEM
`
`~eevide the definitions for the set of services and features listed in Table 3.2 [3]. It
`
`Se features and benefits expected in the new system were (1) superior speech quality
`egeal to or better than the existing analog cellular technology), (2) low terminal,
`eperational, andservicecosts, (3) a high level of security (confidentiality and fraud
`rerention),(4) international roaming (under one subscriber directory number), (5)
`sepport of low-power hand-portable terminals, and (6) a variety of new services
`eed networkfacilities. This section explores the services that are offered in a GSM
`FLMN.
`It was only a logical consequence of the prevailing reality that a measure of
`merworking compatibility with the services offered by other existing telecommunica-
`sem networks was sought. In particular, the basis for the services in the GSM
`endard can be found in the ISDN concept.
`(2) bearer
`We can distinguish three categories of services: (1) teleservices,
`erwices, and (3) supplementary services. As already mentioned above, the phased
`=eroach to introducingtheservices led to a subset of these services being included
`@ Phase 1, and anotherset of services addedlater. In the following, these services
`we listed according to their phases (1 and 2), and the features supplied in the
`-s@vidual phases are discussed. Complete lists of the services defined for a GSM
`MN can be foundin [4].
`
`~11 GSM Phase 1 Services
`
`“Tse Phase 1 technical specifications, valid for the networksin operation since 1992,
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`

`24 AN INTRODUCTION TO GSM
`
`Table 3.2
`GSMPhase1Services
`
`
`
`
`
`Service Category
`Service
`Comment
`
`Teleservices
`Telephony (speech)
`So-called full rate, 13 kbps
`Emergency calls (speech)
`Short-messageservices: point-to-
`Alphanumeric information:user-
`point and point-to-
`to-user and networkto all
`multipoint (cell broadcast)
`users
`Telefax
`Group 3
`Asynchronous data
`300-9,600 bps, 1,200/75 bps
`Synchronousdata
`300-9,600 bps
`Asynchronous PAD (packet-
`300-9,600 bps
`switched, packet assembler/
`disassembler) access
`Alternate speech and data
`Call forwarding
`
`Bearerservices
`
`Supplementary
`services
`
`Call barring
`
`300-9,600 bps
`For example, subscriber busy, not
`reachable or does not answer
`For example,all calls,
`internationalcalls, incoming
`calls
`
`necessary.
`
`mustbe noted that bearer services are restricted to a maximum of 9,600 bps for
`technical reasons. ISDN networks use tates of up to 64 kbps. Adaptations are
`Theseservices are made available, or can be made available, by the operator
`ofa Phase 1 network(their implementationis optionalfor the operators). Ofcourse,
`the manufacturers and developers of infrastructure equipment and mobile terminals
`have to cope with the specifications of these services, since they haveto provide the
`specific functions in their products.
`
`
`
`Service Category
`
`
`Sen
`
`Titeservices
`
`Bese services
`
`“epplementary services
`
`Telephony (speect
`Short-message sex
`Synchronous ded
`data access
`Calling/connmected
`presentation
`
`Calling/conneced
`restniches
`
`Call waiting
`
`Call hold
`
`
`
`33 WHATIS A CELLULAR NETWORK
`
`3.2.2 GSM Phase2 Services
`
`Following the availability of the technical specifications for GSM Phase 2, there will
`be additional services defined that can be madeavailable to end users. There area
`numberof supplementaryservices defined for Phase 2. Table 3.3 gives an overview
`ofthese [3].
`GSM Phase 2 also has many enhancements madepossible through the experi-
`ence with operational Phase 1 networks, through new ideas, and throughthe dedica-
`tion ofthe involved parties to steadily improve the system andits services.
`
`Sew that we know where GSM stands im oh
`gee whatit is supposed to dofor its custome
`‘We start at the very top, at the network ke
`SSM system works. First, however, 2 note
`‘Gees lots of explaining of how radios work i
`‘te radiosarereferred to with language and |
`ech as “when the base station ‘discower
`wh... .” Base stations do notreally “disee
`"commands.Radiosin cellular systems don
`= eadio’s signaling tasks from everything else
`te authors refer to radios asif they were 2
`
`
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`FORD EX. 1017
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`

`

`iser-
`
`y, not
`wer
`
`ng
`
`s for
`s are
`
`rator
`
`urse,
`‘inals
`le the
`
`e will
`aré a
`
`rview
`
`<peri-
`=dica-
`
`GSM—ADigital Cellular Mobile Radio System 25
`
`Table 3.3
`Services Added Through GSM Phase 2
`
`
`
`
` Service Category Service Comment
`
`
`
`the authors refer to radios as if they were alive and have personalities and habits,
`
`Teleservices
`
`Bearer services
`
`Supplementary services
`
`Half rate, 6.5 kbps
`Telephony (speech)
`General improvements
`Short-message services
`Synchronous dedicated packed —2,400-9,600 bps
`data access
`Calling/connectedline identity
`presentation
`
`Calling/connectedline identity
`restriction
`
`Call waiting
`
`Call hold
`
`Multiparty communication
`Closed user group
`
`Advice of charge
`Unstructured supplementary
`services data
`
`Operator-determined barring
`
`Displays calling party’s directory
`numberbefore/after call
`connection
`Restricts the display of the calling
`party’s numberatcalled
`party’s side before/aftercall
`connection
`Informs the user about a second
`(incoming) call and allows to
`answerit
`Puts an active call on hold in order
`to answeror originate
`another (second) call
`Conference calls
`Establishment of groups with
`limited access
`Online charge information
`Offers an open communications
`link for use between network
`and user for operator-defined
`services
`Restriction of different services,
`call types by the operator
`
`3.3 WHATIS A CELLULAR NETWORK?
`
`Now that we know where GSMstandsin the world, how it got to whereit is today,
`and whatit is supposed to doforits customers, we takea first look at how it works.
`We start at the very top, at the network level, to get an initial glimpse of how a
`GSM system works. First, however, a note on language. From now on,this book
`does lots of explaining of how radios workin cellular systems. In these explanations,
`the radios are referred to with language andtermsusually reserved for living beings,
`such as “when the base station ‘discovers’ that ...,” or “the mobile ‘replies’
`with. .
`. .” Base stations do notreally “discover” anything, and only people “reply”
`to commands. Radiosin cellular systems do manythings,andit helps if one separates
`2 radio’s signaling tasks from everythingelse it does (carry voicetraffic). To do this,
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`

`26 AN INTRODUCTION TO GSM
`
`
`
`both good and bad, when describing signaling tasks. Users do not care aboutall
`the signaling taskscellular radios perform; they only wanttheir voices heard at the
`other end of the channel and to hear what is being said to them.In orderfor reliable
`communications to occur in a digital cellular system, radios have to do lots of
`channel maintenancetasks in the background, and they doall these tasks—invisibly
`andsilently—with signaling routines as if they were,in fact, alive and carrying on
`their ownlittle private conversations with each other, united in the task of moving
`the user’s voice from one place to another. Think of radios as efficient and busy
`servants, and you will have muchless trouble making senseoutofall the details.
`You may also enjoy this book more.
`
`3.3.1 A Little Bit of History
`It was sometimesince the days of Heinrich Rudolf Hertz until the first real achieve-
`mentsofcellular radio. In the years 1887 and 1888, Hertz discovered that invisible
`waves which originated from an electric spark were able to transportinfluenceor,
`as we callit today, information throughthe air. Only a few yearslater, this phenome-
`non wasfurtherinvestigated and developed until it was possible to actually transmit
`andreceive signals over a distance of several kilometers. Guglielmo Marconi per-
`formed a dramatic demonstration of this several yearslater.
`These early experiments formed the basis not onlyofcellular radio, but also
`ofmanytypesoftransmissions. One merely hasto think of early radio broadcasting,
`which wasintroduced in the early 1920s in the United States and Europe, to see
`howfarthesefirst experiments have taken society. Later applicationsfor radio found
`quick and numerous paths to mass markets, even though the quality of the early
`AM transmissions were not very good by today’s standards. The introduction of
`FM by Edwin H. Armstrong in 1929 was a breakthrough for quality of reception,
`and it becamethe standard for the remainder of the century. The current analog
`cellular networksarestill based on Armstrong’s FM.
`Mobile radio applications took a longer and morehalting path to their markets.
`In the days whenthefirst transmitters started broadcasting, people were trying to
`makeuse ofthis technique for mobile applications, but they had a problem in that
`the transmitters werestill very large.In thefirst applications for mobile radio, only
`the receiving system was mobile, similar to the Paging systems which are so popular
`today. There were experiments by police departments, which used only one high-
`powertransmitter to cover a whole city. The called police officer had to get out of
`his car at the nextpublic telephoneto report backtohisoffice for furtherinstructions,
`This awkward procedure and the limited ability of the receiver to withstand the
`problems of propagation and road hazards werelimiting factors for mobile radio
`[5].
`When FM wasintroduced, the quality of received information increased a
`great deal, but the applications werestill limited by transmitter size and the huge
`
`S@ounts of power consumed at the :
`Meese early transmitters.
`Commercial mobile phone servac
`Sspatch systems, such as police and ,
`Sroughs were(1) small, low-power =
`wehicle), and (2) the move to higher ope
`Gecrease thesize and weight of mobél.
`mobile phoneservice appeared with &
`phoneservice (MTS) systems. These
`Seed with a special control panel, call
`Semmercial use by people who were ax!
`SCC and MTSsystems could direct &
`module, but remained, after all, simple
`© heir calls through a mobile operator.
`ss added to the MTSsystem to make a
`MTS), which automatedto a consider:
`| S=ssomer and thefixed telephone netwoe
`*»em the mobile phone landscape when E
`pepelar only when carefully designed, ,
`Ske AMPSand TACSstarted to work.
`
`332 Cellular Structure
`
`™ the beginningofradio, engineers wen
`a transmitter and a receiver. As
`“ks were not even two-way ones, ber
`@e people whocalled the mobiles did x
`== ect a confirmationthattheir calls be
`"=P was to establish a two-way trans
`=ponse. This came with mobile transeas
`Semplistic and awkward to use. Service =
`Seched with one transmitter or a small =
`es 2t a single basesite (Figure 3.2). We
`@emwork size was determined bythe trans
`“= %=& between twodifferent cells. or ce
`‘Seecting traffic (voice audio) between x
`essing. It was importantto select the fe
`@e cell carefully so that there was no ime
`@e next town, which would interfere wil
`The disadvantage ofthis is obviows
`‘email set of frequencies was used for 2 hue
`
`FORD EX. 1017
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`FORD EX. 1017
`
`

`

`GSM—ADigital Cellular Mobile Radio System 27
`
`smounts of power consumedat the mobile end of the communications links by
`chose early transmitters.
`Commercial mobile phone service had to wait for the perfection of the public
`Sspatch systems, such as police and other public safety applications. The break-
`chroughs were (1) small, low-powertransmitters (run from motorgenerators in the
`eehicle), and (2) the moveto higher operating frequencies (above 30 MHz) to further
`decrease the size and weight of mobile transmitters. An initial step toward viable
`mobile phone service appeared with the radio commoncarrier (RCC) and mobile
`selephoneservice (MTS) systems. These were simply conventional land mobile radios
`Sered with a special control panel, called a control head, which were suitable for
`commercial use by people who were unfamiliar with operating two-wayradios. The
`RCC and MTSsystems could direct calls from a single transmitter to a particular
`sobile, but remained, after all, simple dispatch systems in which the users set up
`all their calls through a mobile operator. Later, some additional inbandtonesignaling
`was added to the MTSsystem to make the newer improved mobile telephone service
`IMTS), which automated to a considerable extent the interface between the mobile
`customerandthefixed telephone network. The mobile operator almost disappeared
`som the mobile phone landscape when IMTSwasintroduced.Cellular radio became
`sepular only when carefully designed, engineered, and thoroughly tested systems
`Ske AMPSand TACSstarted to work.
`
`enall set of frequencies was used for a huge area. The transmitters were so powerful
`
`3.3.2 Cellular Structure
`
`is the beginning of radio, engineers were happyto achieve a simple dedicated link
`between a transmitter and a receiver. As we saw in the previoussection, these first
`inks were not even two-way ones, but remained one-way dispatch links; that is,
`che people whocalled the mobiles did not get a response right away and did not
`even get a confirmation thattheir calls had reached the mobile addressees. The next
`sep was to establish a two-way transmission link that allowed an immediate
`cesponse. This came with mobile transmitters, but the structure of the network was
`simplistic and awkwardto use. Service waslimited to a certain area that could be
`eeached with onetransmitter or a small collection of transmitters on different chan-
`nels at a single base site (Figure 3.2). We call the coverage area a cell. The cell or
`setwork size was determined by the transmitter’s power.It was notpossible to have
`= link between two different cells, or coverage areas, since an orderly means of
`Girecting traffic (voice audio) between transmitter sites and moving mobiles was
`missing. It was importantto select the frequency of the transmitter and receiver in
`che cell carefully so that there was nointerference from other systems, perhaps in
`che next town, which would interfere with the system’s local operation.
`The disadvantage of this is obvious to everyone from today’s perspective. A
`
`the
`ible
`. of
`ibly
`-on
`
`ing
`sy
`ails.
`
`eve-
`
`ible
`or,
`me-
`
`smit
`
`per-
`
`also
`ing,
`see
`
`und
`arly
`n of
`ion,
`alog
`
`cets.
`
`g to
`that
`only
`ular
`‘igh-
`it of
`ons.
`
`| the
`adio
`
`eda
`huge
`
`FORD EX. 1017
`
`FORD EX. 1017
`
`

`

`CHAPTER 12
`vVvY
`
`
`
`NORTH AMERICANDIGITAL
`CELLULAR AND PERSONAL
`DIGITAL CELLULAR
`
`
`
`
`
`
`The UnitedStates has the distinction of running the world’s largest cellular system
`‘the highly successful AMPS system), and the Japanese hold the honor of installing
`she world’s first commercial system (Nippon Telephone and Telegraph Company’s
`NTT) MCSsystem in December 1979). Both of these innovators have proposed
`and are installing their own versions of TDMA digital cellular: the NADC system
`= the United States, and the personaldigital cellular (PDC)or JDC system in Japan.
`The two systems have as much in commonwith each otheras they differ from GSM.
`The differences between them serve to shed additional light on GSM andclarify its
`prominentplace in the world’s cellular markets.
`The NADC and PDCsystemsshare an interesting type of modulation (7/4-
`DQPSK), which wewill explain early in this chapter. The timeslot structures, frame
`“ructures, and certain details of their air interface definitions are also similar in
`soth systems, though the PDCversionsare slightly more reminiscent of GSM. The
`=wo systems, however, diverge in all other matters. The PDC system is a purely
`Sgital TDMAsystem just as GSM is, and someofits operating modes,organization,
`and deployment schemes are similar to GSM. The NADC system graphsdigital
`waffic resources onto the existing AMPS and expanded AMPS (EAMPS)system in
`= fascinating overlay scheme.It holds almost no resemblance to GSM in this regard.
`Since this is a book on GSM,wewill not investigate all the details of the
`“ADC and PDCsystems. We will reserve such a detailed analysis for the next
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`305
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`FORD EX. 1017
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`FORD EX. 1017
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`

`

`306 AN INTRODUCTION TO GSM
`
`North American Daz
`
`chapter, Chapter 13, when wehavea close look at CDMA.Itis only the differences
`in certain aspects that distinguish GSM from its TDMA cousins, NADC and PDC.
`CDMA hasnothing in common with GSM. Wehave to take a broader and closer
`look at CDMAin order to judge the relative benefits of each system and increase
`our understanding of GSM in the same wayasaselective look at NADC and PDC
`does.
`800.0 MHz,
`-}——___}+}________
`
`824.0 MHz
`
`849.0 MH:
`
`12.1 TDMA IN THE UNITED STATES
`
`The United States has a long history of and a noted ability to extend the life of
`various communications systems by devising methods to maintain compatibility
`between older users of a system with traditional
`technologies and new users
`employing enhanced capabilities and technologies. The reasonsforthis are primarily
`economic ones. The United States is a large and wealthy country. American communi-
`Re+>———
`cations systems tend to becomevery large by world standards, so that ripping out
`one system and replacing it with anotheris usually too expensive to even consider.
`This was the case with the American National Television Standard Committee
`(NTSC) color television system (fully compatible with the black and white receivers
`of the 1940s and 1950s), and remains true with the NADCcellular system today.
`
`991 1023/1
`
`333
`
`666
`
`7
`
`/=
`
`Figure 12.1 U.S.cellular frequencies and channels
`
`group. Each operating area in the US_E
`providers. Oneis the localfixed-metwork
`called the wire-line operator, and the of
`non-wire-line operator. The number of &
`dozen channelsin the region near chanm:
`operator for control channels in their re
`
`12.2 DUAL-MODE ACCESS
`
`The most important feature of all the N
`mode systems. This means that all syste
`provide an appropriate traffic channel &
`that mayseek cellular phone service.
`
`12.1.1 Frequency Bands
`
`Figure 12.1 lays out the frequency bands and channel scheme for the EAMPS and
`NADCsystems. The reader will discern two frequency bands of 25 MHz each. The
`mobile transmitter’s uplink is in the lower 824- to 849-MHz band,andthe base
`station transmitter’s downlink is offset 45 MHz up to the 869- to 894-MHzband.
`Each of the uplink and downlink segments is divided into 832 channels of 30-
`kHz width each. The numbering of the channels is a bit strange. The enumeration
`starts at number 1 near the bottom of the bands, continues up to channel number
`799 at the top, then folds back onitself to channel number 991 at the bottom edge
`of the bands, andfinally ends at number 1,023 just below thestarting point. The
`awkward numbering comes fro