ch-1-2 introduction to cellular mobile communications

Cellular Mobile Cellular Mobile Communications-ICommunications-IAn IntroductionAn Introduction

Dr. Nasir D. Dr. Nasir D. GoharGohar

http://www.stanford.edu/class/ee359/lectures.htmlLecture Notes by Professor Reynold Cheung

Other Internet Resourceswww.nmscommunications.com


Cell Phone Growth in Pakistan & WorldwideCell Phone Growth in Pakistan & Worldwide According to a Media Report (Goliath, May 25, 2005), According to a Media Report (Goliath, May 25, 2005),

Cell Phones in Pakistan to Touch 15M mark in December Cell Phones in Pakistan to Touch 15M mark in December 20052005

Another Media Report (Middle East Times, June 20, Another Media Report (Middle East Times, June 20, 2006) Predicts the number of Cell Phones will rise from 2006) Predicts the number of Cell Phones will rise from 2.2 Billion to 3 Billion worldwide by the end of Year 20082.2 Billion to 3 Billion worldwide by the end of Year 2008

According to MOBILEDIA (Jan 20, 2006)According to MOBILEDIA (Jan 20, 2006) U.S. offers more room for growth than Russia, and Japan offers U.S. offers more room for growth than Russia, and Japan offers

greater future growth than South Africagreater future growth than South Africa The number of mobile subscribers worldwide reached over 2 The number of mobile subscribers worldwide reached over 2

billion by the end of 2005, and is predicted to rise to 3.96 billion by billion by the end of 2005, and is predicted to rise to 3.96 billion by 20112011

The Asia Pacific Region will account for 50% of the total number of The Asia Pacific Region will account for 50% of the total number of subscribers worldwide by the end of this decade with a staggering subscribers worldwide by the end of this decade with a staggering 1.067 billion subscribers shared between China and India alone, 1.067 billion subscribers shared between China and India alone,

the world's two biggest mobile marketsthe world's two biggest mobile markets


Several Types of Mobile Radio SystemsSeveral Types of Mobile Radio Systems Garage Door Controller [<100 MHz]Garage Door Controller [<100 MHz] Remote Controllers [TV/VCR/DISH][Infra-Red: 1-100 THz]Remote Controllers [TV/VCR/DISH][Infra-Red: 1-100 THz] Cordless Telephone [<100 MHz]Cordless Telephone [<100 MHz] Hand-Held Radio [Walki-Talki] [VHF-UHF:40-480 MHz]Hand-Held Radio [Walki-Talki] [VHF-UHF:40-480 MHz] Pagers/Beepers [< 1 GHz]Pagers/Beepers [< 1 GHz] Cellular Mobile Telephone[<2 GHz]Cellular Mobile Telephone[<2 GHz]

ClassificationClassification Simplex System:Simplex System: Communication is possible in only one direction :Communication is possible in only one direction :

Garage Door Controller, Remote Controllers [TV/VCR/DISH] Pagers/BeepersGarage Door Controller, Remote Controllers [TV/VCR/DISH] Pagers/Beepers

Semi-Duplex System:Semi-Duplex System: Communication is possible in two directions but Communication is possible in two directions but one talks and other listens at any time[Push to Talk System]: Walki-Talkione talks and other listens at any time[Push to Talk System]: Walki-Talki

Duplex SystemDuplex System:: Communication is possible in both directions at any time: Communication is possible in both directions at any time: Cellular Telephone [FDD or TDD]Cellular Telephone [FDD or TDD]


Paging System:Paging System: For Transmission of For Transmission of Brief Numeric/Alpha-Brief Numeric/Alpha-numeric/Voice Messages [Pages] to Subscribernumeric/Voice Messages [Pages] to Subscriber

To Notify/Alert the UserTo Notify/Alert the User Simplex ServiceSimplex Service Modern Paging Systems Can Send News Head-Lines, Stock Info, or FaxModern Paging Systems Can Send News Head-Lines, Stock Info, or Fax Application Dependent System Range [2 Km to World-wide] Application Dependent System Range [2 Km to World-wide]

PAGING CONTROL CENTRE

Paging Terminal

PSTN

Land Line Link

Land Line LinkPaging Terminal

Paging Terminal

City 1

City 2

City N


Cordless Telephone System:Cordless Telephone System: To Connect a To Connect a Fixed Base Station to a Portable Cordless HandsetFixed Base Station to a Portable Cordless Handset Early Systems (1980s) have very limited range of few Early Systems (1980s) have very limited range of few

tens of meters [within a House Premises]tens of meters [within a House Premises] Modern Systems Modern Systems [PACS, DECT, PHS, PCS][PACS, DECT, PHS, PCS] can provide a can provide a

limited range & mobility within Urban Centerslimited range & mobility within Urban Centers

PSTNFixed Base

Station

Cordless Handset


Limitations of Simple Mobile Radio SystemsLimitations of Simple Mobile Radio SystemsThe Cellular ApproachThe Cellular Approach

Divides the Entire Service Area into Several Small Cells Divides the Entire Service Area into Several Small Cells Reuse the FrequencyReuse the Frequency

Basic Components of a Cellular Telephone SystemBasic Components of a Cellular Telephone System Cellular Mobile PhoneCellular Mobile Phone:: A light-weight hand-held set A light-weight hand-held set

which is an outcome of the marriage of Graham Bell’s Plain Old which is an outcome of the marriage of Graham Bell’s Plain Old Telephone Technology [1876] and Marconi’s Radio Technology Telephone Technology [1876] and Marconi’s Radio Technology [1894] [although a very late delivery but very cute][1894] [although a very late delivery but very cute]

Base StationBase Station:: A Low Power Transmitter, other Radio A Low Power Transmitter, other Radio Equipment [Transceivers] plus a small TowerEquipment [Transceivers] plus a small Tower

Mobile Switching Center [MSC] /Mobile Telephone Mobile Switching Center [MSC] /Mobile Telephone Switching Office[MTSO]Switching Office[MTSO] An Interface between Base Stations and the PSTNAn Interface between Base Stations and the PSTN Controls all the Base Stations in the Region and Processes User ID Controls all the Base Stations in the Region and Processes User ID

and other Call Parametersand other Call Parameters A typical MSC can handle up to 100,000 Mobiles, and 5000 A typical MSC can handle up to 100,000 Mobiles, and 5000

Simultaneous Calls Simultaneous Calls Handles Handoff Requests, Call Initiation Requests, and all Billing & Handles Handoff Requests, Call Initiation Requests, and all Billing &

System Maintenance FunctionsSystem Maintenance Functions


The Cellular ConceptThe Cellular Concept

RF spectrumRF spectrum is a valuable and scarce commodity is a valuable and scarce commodityRF signals attenuate over distanceRF signals attenuate over distanceCellular network divides coverage area into cellsCellular network divides coverage area into cells, each , each

served by its own base station transceiver and antennaserved by its own base station transceiver and antennaLow (er) power transmitters used by BSs; transmission Low (er) power transmitters used by BSs; transmission

range determines cell boundaryrange determines cell boundaryRF spectrum divided into distinct groups of channelsRF spectrum divided into distinct groups of channelsAdjacent cells are (usually) assigned different channel Adjacent cells are (usually) assigned different channel

groups to avoid interferencegroups to avoid interferenceCells separated by a sufficiently large distance to avoid Cells separated by a sufficiently large distance to avoid

mutual interference can be assigned themutual interference can be assigned the same channel group same channel group frequency reuse frequency reuse among co-channel cellsamong co-channel cells


An Example of Frequency ReuseAn Example of Frequency Reuse

Suppose we have spectrum for 100 voice channels

Scenario 1: a high power base station covering entire area – system capacity = 100 channels

Scenario 2: divide spectrum into 4 groups of 25 channels each; cells (1, 7), (2, 4), (3, 5), 6 are assigned distinct channel groups – system capacity = 175 channels


Frequency Reuse FactorFrequency Reuse Factor

Frequency Reuse Factor N = No. of Distinct Channel Groups = Maximum Cluster Size


Frequency Reuse Example-2Frequency Reuse Example-2 Suppose Suppose WW = 25 MHz and = 25 MHz and BB = 25 KHz/voice channel = 25 KHz/voice channel W/BW/B = 1000 voice channels can be supported over the spectrum = 1000 voice channels can be supported over the spectrum Scenario 1:Scenario 1: a high power base station covering entire area ( a high power base station covering entire area (M M = = N N = =

1) 1) system capacity system capacity nn = 1000 users = 1000 users Scenario 2:Scenario 2:

Coverage area divided into Coverage area divided into MM = 20 cells with reuse factor = 20 cells with reuse factor NN = 4 = 4 Each cluster accommodate 1000 active usersEach cluster accommodate 1000 active users 5 clusters in coverage area 5 clusters in coverage area system capacity system capacity nn = 5000 users = 5000 users

Scenario 3:Scenario 3: MM = 100 cells, = 100 cells, NN = 4 = 4 system capacity system capacity nn = 25000 users = 25000 users

Scenario 4:Scenario 4: MM = 100 cells, = 100 cells, NN = 1 = 1 system capacity system capacity nn = 100000 users = 100000 users


Common Air Interface (CAI)Common Air Interface (CAI)

Forward Channel

Reverse Channel

Common Air Interface: A Standard that defines Communication between a Base Station and Mobile

Specifies Four Channels [Voice Channels and Control / Setup Channels]

FVC: Forward Voice ChannelRVC: Reverse Voice ChannelFCC: Forward Control ChannelRCC: Reverse Control Channel


Call Setup ProcedureCall Setup Procedure

Cellular Phone Codes: Special Codes are associated with each Cell

Phone to identify the phone, its owner, and service provider:Electronic Serial Number(ESN) -A Unique 32-bit Code Mobile Identification Number(MIN): A Subscriber’s Telephone Number Station Class mark (SCM): Indicates the Max Tx Power for the User

When a Cellular Phone is turned on and Initiates a Call:[see next slide]

Monitors the Control Channels and gets hold on to the strongest oneMakes a Call Initiation Request[Dials the Called part Number, MIN , ESN and SCM automatically transmitted]Validation Procedure at MSC & Voice-Frequency pair Allocation Base Station Pages the Information for the MobileMSC Connects the Mobile with the Called Party[Another Mobile/Landline Phone]Call is Established and Communication Starts


Call Setup Procedure (Cont’d)Call Setup Procedure (Cont’d)

MSC

3. Receives a Call Initiation Request from

Base Station, and Verifies that User has a Valid MIN & ESN pair

4. Locates the Called Party,

Allocates a VFPs and Instructs the Base Stations via

FCC

7. Connects the Called Party[on

PSTN]/Mobile to the Mobile

FCC

5. Pages for the Called Mobile, the Mobiles are

instructed to move to the Allocated VFPs

respectively

RCC

2. Receives a Call Initiation Request, with MIN, ESN, SCM and Called Part Number

FVC 8. Begins Voice Transmission

RVC 8. Begins Voice Reception

FCC

6. Receives [Called Mobile] the Page and Matches the MIN, the Mobiles get ready to

move to the respective Allocated VFPs

RCC1. Makes a Call Initiation Request, with MIN and

Called Part Number

FVC8. Begins Voice

Reception

RVC8. Begins Voice

Transmission

Base Station

Mobile

TIME


Handoff and RoamingHandoff and RoamingHandoff

When a Mobile is on the edge of a CellRSL of the Mobile in that Cell gets bellow a set LevelBase Station of the Cell originates a Handoff requestMSC gets RSL Info from all the Candidate CellsMSC asks the Originating Cell and the Strongest Candidate Cell to CoordinateIn Case the Handoff is Successful, the Mobile is asked to switch to another VFPAll this happens in a matter of seconds and you hear a little CLICK sound

RoamingWhen SID of the Control Channel and that

programmed in the Mobile does not match:

The Mobile is in another Service Provider’s AreaMSC of the Cell contacts the MSC of the Mobile’s Home SystemAfter Verification, if the Mobile is Allowed, the new MSC is ready to Serve.

M S C


Comparison of Common Wireless Communication Comparison of Common Wireless Communication SystemsSystems

SystemCoverage

Range

Required Infra-

StructureComplexity

Hardware Cost

Carrier Frequency

Functionality

Tv Remote Control Low Low Low Low Infra-Red Tx/Rx

Garage Door Contol Low Low Low Low <100 Mhz Tx/Rx

Paging System High High Low/High Low/High <1GHz Rx/Tx

Cordless Phone Low Low Moderate/Low Low/Moderate <100 MHz Transceiver

Cellular Phone High High High Moderate/High <1 GHz Transceiver

Tx = Transmitter Rx = Receiver

Comparison of Mobile Communication Systems - Mobile/Base Station


Cellular Mobile Access TechnologiesCellular Mobile Access TechnologiesFDMA Assigns each Call a Separate Frequency

Works like Radio StationsMainly Analogue Technology-used by AMPS, NAMPS, E-TACS, NMT-450, JTACSNot an Efficient Method for Digital Transmission

849 MHz

869 MHz


Cellular Mobile Access TechnologiesCellular Mobile Access Technologies

TDMA Assigns each Call a certain Time-Slot on a Designated Frequency

Each Mobile/User gets one-third of a total Channel Time-Slot[6.7 ms]Courtesy of Compression Techniques: Speech Data in Digital Form takes considerably less timeOptimal Frequency Usage: System Capacity improves by three timesOperates both in 800 MHz[IS-54] and 1900 MHz[IS-136]Digital Access Technology use by GSM, USDC, IDEN, PDC and PCS


Cellular Mobile Access TechnologiesCellular Mobile Access TechnologiesCDMA Assigns a Unique Code to each Call and Spreads it over the entire bandwidth available

A form of Spread Spectrum TechnologySpeech Data is sent in small pieces over number of Discrete Frequencies available at any time in a specified range Receiver uses the same unique Code to Recover the Speech DataGPS used for Exact Time StampCan handle 8-10 Calls in the same Channel Space as one Analogue ChannelAn Access Technology for 3G Mobile Systems[IMT-2000]Supports both Bands [800 MHz and 1900 MHz]


Cellular System vs. Personal Communication Cellular System vs. Personal Communication System/Network (PCS/PCN)System/Network (PCS/PCN)

Personal Communication Services [Personal Communication Services [PCSPCS] is a system, very ] is a system, very similar to Cellular Phone Service with great emphasis on similar to Cellular Phone Service with great emphasis on personal servicespersonal services (such as Paging, Caller ID, and E-mail] (such as Paging, Caller ID, and E-mail] and and mobilitymobility

Originated in UK, Originated in UK, to improve its competitiveness in the to improve its competitiveness in the fieldfield

PCS PCS has smaller Cell size, therefore, requires more infra-has smaller Cell size, therefore, requires more infra-structurestructure

PCS works in 1.85-1.99 GHz bandPCS works in 1.85-1.99 GHz band PCS uses TDMA Technology but with 200 KHz Channel PCS uses TDMA Technology but with 200 KHz Channel

Bandwidth with eight time-slots[as compared to 30 KHz Bandwidth with eight time-slots[as compared to 30 KHz and 3 time-slots used by Digital Cellular Phone System IS-and 3 time-slots used by Digital Cellular Phone System IS-54/IS-136]54/IS-136]

GSM and Cellular Digital Packet Data[CDPD] also use PCS GSM and Cellular Digital Packet Data[CDPD] also use PCS Tech.Tech.


Dual Band/Dual Mode Cellular PhonesDual Band/Dual Mode Cellular Phones

Dual Band PhoneDual Band Phone:: Supports both bands 800 MHz Supports both bands 800 MHz and 1900 MHzand 1900 MHz

Dual Mode Phone:Dual Mode Phone: Supports both FDMA and TDMA Supports both FDMA and TDMA Access Access TechnologiesTechnologies

Dual Band/Dual Mode PhoneDual Band/Dual Mode Phone:: Supports both Supports both Bands and Both Access TechnologiesBands and Both Access Technologies

Tri-Mode Phone:Tri-Mode Phone: It can Support It can Support FDMA/TDMA/CDMA all Access Tech. A popular version of FDMA/TDMA/CDMA all Access Tech. A popular version of Tri-Mode Cellular Phone is the one which supports GSM Tri-Mode Cellular Phone is the one which supports GSM [800 MHz as well as 1900 MHz (USA version)] as well as [800 MHz as well as 1900 MHz (USA version)] as well as FDMA.FDMA.


Trends in Cellular radio and Personal Trends in Cellular radio and Personal CommunicationsCommunications

PCS/PCN:PCS/PCN: PCS calls for more personalized services PCS calls for more personalized services whereas PCN refers to Wireless Networking Concept-any whereas PCN refers to Wireless Networking Concept-any person, anywhere, anytime can make a call using PC. person, anywhere, anytime can make a call using PC. PCS and PCN terms are sometime used interchangeablyPCS and PCN terms are sometime used interchangeably

IEEE 802.11IEEE 802.11:: A standard for computer communications A standard for computer communications using wireless links[inside building].using wireless links[inside building].

ETSI’s 20 Mbps HIPER LAN:ETSI’s 20 Mbps HIPER LAN: Standard for indoor Standard for indoor Wireless Networks Wireless Networks

IMT-2000 [International Mobile Telephone-2000IMT-2000 [International Mobile Telephone-2000 StandardStandard]:]: A 3G universal, multi-function, globally A 3G universal, multi-function, globally compatible Digital Mobile Radio Standard is in makingcompatible Digital Mobile Radio Standard is in making

Satellite-based Cellular Phone SystemsSatellite-based Cellular Phone Systems A very good A very good ChanceChance for Developing Nationsfor Developing Nations to to

Improve their Communication NetworksImprove their Communication Networks


Important First Generation Analog SystemsImportant First Generation Analog Systems

TypeType AMPSAMPS ETACSETACS NTTNTTRegionRegion AmericaAmerica EuropeEurope JapanJapan

Multiple Multiple accessaccess

FDMAFDMA FDMAFDMA FDMAFDMA

DuplexingDuplexing FDDFDD FDDFDD FDDFDD

Forward bandForward band 869 - 894 869 - 894 MHzMHz

935 – 960 935 – 960 MHzMHz

870 – 885 870 – 885 MHzMHz

Reverse bandReverse band 824 – 849 824 – 849 MHzMHz

890 – 915 890 – 915 MHzMHz

925 – 940 925 – 940 MHzMHz

Channel Channel spacingspacing

30 KHz30 KHz 25 KHz25 KHz 25 KHz25 KHz

No. of No. of channelschannels

831831 10001000 600600


Important Second Generation Digital SystemsImportant Second Generation Digital Systems

TypeType IS-54IS-54 IS-95IS-95 GSMGSM PDCPDCRegionRegion AmericaAmerica AmericaAmerica EuropeEurope JapanJapan

Multiple Multiple access access /Duplexing/Duplexing

TDMA/FDDTDMA/FDD CDMA/FDDCDMA/FDD TDMA/FDDTDMA/FDD TDMA/FDDTDMA/FDD

ModulationModulation /4 DQPSK/4 DQPSK QPSK/OQPSKQPSK/OQPSK GMSKGMSK /4 DQPSK/4 DQPSK

Forward BandForward Band 869 - 894 869 - 894 MHzMHz

869 - 894 869 - 894 MHzMHz

935 – 960 935 – 960 MHzMHz

810 – 826 810 – 826 MHzMHz

Reverse BandReverse Band 824 – 849 824 – 849 MHzMHz

824 – 849 824 – 849 MHzMHz

890 – 915 890 – 915 MHzMHz

940 – 956 940 – 956 MHzMHz

Channel Channel SpacingSpacing

30 KHz30 KHz 1.25 MHz1.25 MHz 200 KHz200 KHz 25 KHz25 KHz

Data/chip RateData/chip Rate 48.6 Kbps48.6 Kbps 1.2288 Mcps1.2288 Mcps 270.833 270.833 KbpsKbps

42 Kbps42 Kbps

Codec Rate Codec Rate KbpsKbps

7.957.95 1.2/2.4/4.8/9.1.2/2.4/4.8/9.66

13.413.4 6.76.7

Users/channelUsers/channel 33 Up to 55Up to 55 88 33


Difference Between First & Second Generation Difference Between First & Second Generation SystemsSystems

Traffic Channels –Traffic Channels – 1G systems use analog FM 1G systems use analog FM modulation; 2G systems use low bit-rate voice coding and modulation; 2G systems use low bit-rate voice coding and digital transmissiondigital transmissionChannel Access –Channel Access – 2G systems allow each frequency 2G systems allow each frequency channel to be shared by a number of users, using TDMA or channel to be shared by a number of users, using TDMA or CDMA techniquesCDMA techniquesError Detection and Correction –Error Detection and Correction – 2G digital traffic 2G digital traffic channels incorporate FEC for error detection and correction, channels incorporate FEC for error detection and correction, giving higher power and bandwidth efficiencygiving higher power and bandwidth efficiencyEncryption –Encryption – all 2G systems provide encryption to all 2G systems provide encryption to prevent eavesdroppingprevent eavesdropping


World-wide Subscriber Base as a Function of World-wide Subscriber Base as a Function of Technology (June 2006)Technology (June 2006)


GSM (Global System for Mobile)GSM (Global System for Mobile) « « GroupGroupee Special Mobile Special Mobile » later changed to « Global » later changed to « Global System for System for Mobile »Mobile » Developed by ETSI as a pan-European 2G mobile standardDeveloped by ETSI as a pan-European 2G mobile standard Standard activity started in 1982, deployed in 1992 Standard activity started in 1982, deployed in 1992 A complete system standard for ISDN-like mobile servicesA complete system standard for ISDN-like mobile services Time division multiple access (8 users per 200KHz)Time division multiple access (8 users per 200KHz) 900 MHz band; later extended to 1800MHz900 MHz band; later extended to 1800MHz Added 1900 MHz (US PCS bands)Added 1900 MHz (US PCS bands) GSM is dominant world standard todayGSM is dominant world standard today

•Well defined interfaces; many competitorsWell defined interfaces; many competitors

•Tri-band GSM phone can roam the world todayTri-band GSM phone can roam the world today


GSM Growth – From 1993 to June 2006GSM Growth – From 1993 to June 2006


North American StandardsNorth American StandardsPublished by the Telecommunications Industry Published by the Telecommunications Industry Association (TIA) as “Interim Standards” (IS)Association (TIA) as “Interim Standards” (IS)2G air interface standards (PCS) include2G air interface standards (PCS) include

IS-54/136 – TDMA over 30 KHz channelsIS-54/136 – TDMA over 30 KHz channelsIS-95 – CDMA standard developed by Qualcomm in 1991 and IS-95 – CDMA standard developed by Qualcomm in 1991 and adopted by TIA in 1993adopted by TIA in 1993

IS-634 standard for MSC-BSC interfaceIS-634 standard for MSC-BSC interfaceIS-41 standard for MSC-MSC interfaceIS-41 standard for MSC-MSC interfaceServices, interoperability, compatibility and performance Services, interoperability, compatibility and performance issues are addressed by TR-45/46 committeesissues are addressed by TR-45/46 committeesTR-45/46 reference model is similar to the GSM TR-45/46 reference model is similar to the GSM architectural modelarchitectural model


Properties of CDMA Cellular Properties of CDMA Cellular Frequency Diversity –Frequency Diversity – frequency-dependent transmission frequency-dependent transmission impairments have less effect on wide-band signalimpairments have less effect on wide-band signalMultipath ResistanceMultipath Resistance – can use RAKE receiver to coherently – can use RAKE receiver to coherently combine multipath signalscombine multipath signalsPrivacy Privacy – privacy is inherent since spread spectrum is obtained – privacy is inherent since spread spectrum is obtained by use of noise-like signalsby use of noise-like signalsGraceful Degradation –Graceful Degradation – system only gradually degrades as system only gradually degrades as more users access the systemmore users access the systemSoft Handoff –Soft Handoff – mobile acquires new cell before disconnecting mobile acquires new cell before disconnecting from the old; diversity combining of signals from the two cells from the old; diversity combining of signals from the two cells enhance performanceenhance performanceNear-far Problem –Near-far Problem – without power control, signals from MS without power control, signals from MS closer to the BS will overwhelm signals from MS farther awaycloser to the BS will overwhelm signals from MS farther away


Problems with CDMA Cellular Problems with CDMA Cellular Self-Jamming –Self-Jamming – arriving transmissions from multiple users not arriving transmissions from multiple users not aligned on chip boundaries unless users are perfectly aligned on chip boundaries unless users are perfectly synchronizedsynchronized Near-far Problem –Near-far Problem – signals closer to the receiver are received signals closer to the receiver are received with less attenuation than signals farther awaywith less attenuation than signals farther away Soft Handoff –Soft Handoff – requires that the mobile acquires the new cell requires that the mobile acquires the new cell before it relinquishes the old; this is more complex than hard before it relinquishes the old; this is more complex than hard handoff used in FDMA and TDMA schemeshandoff used in FDMA and TDMA schemes


1G and 2G – Voice Centric Systems 1G and 2G – Voice Centric Systems

Cellular Cellular coveragecoverage is designed for voice is designed for voice serviceservice

Area outage, e.g. < 10% or < 5%.Area outage, e.g. < 10% or < 5%.Minimal, but equal, service everywhereMinimal, but equal, service everywhere

Cellular Cellular systemssystems are designed for voice are designed for voice20 ms framing structure20 ms framing structureStrong FEC, interleaving and decoding delaysStrong FEC, interleaving and decoding delays

Spectral EfficiencySpectral Efficiencyaround 0.04-0.07 bps/Hz/sectoraround 0.04-0.07 bps/Hz/sectorcomparable for TDMA and CDMAcomparable for TDMA and CDMA


3G Vision –Multimedia (Voice, Data, and Video) 3G Vision –Multimedia (Voice, Data, and Video)

Universal global roamingUniversal global roamingMultimedia (voice, data & video)Multimedia (voice, data & video)Increased data ratesIncreased data rates

384 kbps while moving384 kbps while moving2 Mbps when stationary at specific locations 2 Mbps when stationary at specific locations

Increased capacity (more spectrally Increased capacity (more spectrally efficient)efficient)IP architectureIP architectureProblemsProblems

No killer application for wireless data as yetNo killer application for wireless data as yetVendor-drivenVendor-driven


Standardization BodiesStandardization Bodies

ITU (International Telecommunication ITU (International Telecommunication Union)Union)

Radio standards and spectrumRadio standards and spectrum

IMT-2000IMT-2000ITU’s umbrella name for 3G which stands for ITU’s umbrella name for 3G which stands for International Mobile Telecommunications 2000International Mobile Telecommunications 2000

National and regional standards bodies National and regional standards bodies are collaborating in 3G partnership are collaborating in 3G partnership projectsprojects

ARIB, TIA, TTA, TTC, CWTS. T1, ETSIARIB, TIA, TTA, TTC, CWTS. T1, ETSI

3G Partnership Projects (3GPP & 3GPP2)3G Partnership Projects (3GPP & 3GPP2)Focused on evolution of access and core Focused on evolution of access and core networksnetworks


IMT-2000 Vision-Integration of Services and IMT-2000 Vision-Integration of Services and Networks Networks

Satellite

MacrocellMicrocell

UrbanIn-Building

Picocell

Global

Suburban

Basic TerminalPDA Terminal

Audio/Visual Terminal


IMT-2000 Radio StandardsIMT-2000 Radio StandardsIMT-SC*IMT-SC* Single Carrier (UWC-136) Single Carrier (UWC-136): EDGE: EDGE

GSM evolution (TDMA); 200 KHz channels; sometimes GSM evolution (TDMA); 200 KHz channels; sometimes called “2.75G”called “2.75G”

IMT-MC*IMT-MC* Multi Carrier CDMA: Multi Carrier CDMA: CDMA2000CDMA2000Evolution of IS-95 CDMA, i.e. cdmaOneEvolution of IS-95 CDMA, i.e. cdmaOne

IMT-DS*IMT-DS* Direct Spread CDMA: Direct Spread CDMA: W-CDMAW-CDMANew from 3GPP; UTRAN FDDNew from 3GPP; UTRAN FDD

IMT-TC**IMT-TC** Time Code CDMA Time Code CDMANew from 3GPP; UTRAN TDDNew from 3GPP; UTRAN TDDNew from China; New from China; TD-SCDMATD-SCDMA

IMT-FT**IMT-FT** FDMA/TDMA (DECT legacy) FDMA/TDMA (DECT legacy)


Cellular Network Evolution PathCellular Network Evolution Path

CDMA

GSM

TDMA

PHS (IP-Based)

64 Kbps

GPRS

115 Kbps

CDMA 1xRTT

144 Kbps

EDGE

384 Kbps

cdma20001X-EV-DV

Over 2.4 Mbps

W-CDMA (UMTS)

Up to 2 Mbps

2G2.5G

2.75G 3G

1992 - 2000+2001+

2003+

1G

1984 - 1996+

2003 - 2004+

TACS

NMT

AMPS

GSM/GPRS

(Overlay) 115 Kbps

9.6 Kbps

9.6 Kbps

14.4 Kbps/ 64 Kbps

9.6 Kbps

PDC

Analog Voice

Digital Voice

Packet Data

IntermediateMultimedia

Multimedia

PHS

TD-SCDMA

2 Mbps?

9.6 Kbps

iDEN

(Overlay)

iDEN

Source: U.S. Bancorp Piper Jaffray


Cellular Network Evolution Path-2Cellular Network Evolution Path-2

Broader Bandwidth Channels with High Spectrum Efficiency

Advanced Network/SoftwareArchitectures

Advanced Coding & SignalProcessing Techniques

Intelligent Antennas

Wideband Radios

Knowledge-BasedNetwork Operations

Unified Service Networks

Digital CellularTechnology

Microcellular &Picocellular

Technologies

Wireless IntelligentNetwork

Analog CellularTechnology

MacrocellularTechnology

Integrated Voice/Data & Wireless/Wireline

Multimedia Services

Location Services

Mobile TelephoneService

Advanced WirelessVoice Services

Wireless Data Services

Tele-Presenting

Distance Learning

Intelligent Agent Services

First Generation Second Generation Third Generation Fourth Generation

Mid-80s Mid-90s Year 2010 ? Year 2000+

W-CDMAUWC-136cdma2000

NMTTACSAnalog AMPS

GSMIS-54/ 136 TDMAIS-95/ cdmaOnePDCDECT

?

Source: IEEE Communications Magazine


High Speed Circuit Switched Data (HSCSD) for High Speed Circuit Switched Data (HSCSD) for 2.5G GSM2.5G GSM

Part of GSM Phase 2 developmentPart of GSM Phase 2 developmentUse dedicated TDMA time slots for circuit switched dataUse dedicated TDMA time slots for circuit switched dataEach time slot yields a data rate of 14.4 KbpsEach time slot yields a data rate of 14.4 KbpsUp to 4 time slots can be used for a data rate up to 57.6 KbpsUp to 4 time slots can be used for a data rate up to 57.6 KbpsHSCSD connection using multiple time slots can be pre-empted by HSCSD connection using multiple time slots can be pre-empted by voice calls to give up the extra slotsvoice calls to give up the extra slotsSuitable for streaming data applications such as digital audio/videoSuitable for streaming data applications such as digital audio/videoInefficient for applications with bursty data traffic, such as Web Inefficient for applications with bursty data traffic, such as Web surfingsurfingThe service is not widely supportedThe service is not widely supported


General Packet Radio Service (GPRS) for 2.5G General Packet Radio Service (GPRS) for 2.5G GSMGSMPart of GSM Phase 2 developmentPart of GSM Phase 2 developmentAlso supported by IS-136 TDMA in N. AmericaAlso supported by IS-136 TDMA in N. AmericaUse shared TDMA time slots for packet switched dataUse shared TDMA time slots for packet switched dataMS uses a reservation MAC protocol to indicate needs for data MS uses a reservation MAC protocol to indicate needs for data bandwidth to BSC which schedules reserved time slots for the MSbandwidth to BSC which schedules reserved time slots for the MSUp to 8 time slots can be used for a data rate up to 171.2 Kbps; in Up to 8 time slots can be used for a data rate up to 171.2 Kbps; in practice MS’s are not assigned 8 time slotspractice MS’s are not assigned 8 time slotsGPRS using multiple time slots can be pre-empted by HSCSD or voice GPRS using multiple time slots can be pre-empted by HSCSD or voice calls to give up the extra slotscalls to give up the extra slotsMuch more efficient for applications with bursty data traffic, such as Much more efficient for applications with bursty data traffic, such as Web surfingWeb surfing


Enhanced Data rates for GSM Evolution (EDGE) Enhanced Data rates for GSM Evolution (EDGE) for 2.5G GSMfor 2.5G GSM

Provides an evolution path from existing GSM/TDMA standards to Provides an evolution path from existing GSM/TDMA standards to deliver 3G services in existing spectrum bandsdeliver 3G services in existing spectrum bandsReuses GSM carrier bandwidth and time slot structureReuses GSM carrier bandwidth and time slot structureCan be introduced in GSM using a minimum of only one time slot Can be introduced in GSM using a minimum of only one time slot per BSper BSReuse of existing GSM and TDMA/IS-136 infrastructureReuse of existing GSM and TDMA/IS-136 infrastructureCan be deployed using as little as 600 kHz of total bandwidthCan be deployed using as little as 600 kHz of total bandwidth384 Kbps data capability to satisfy the IMT-2000 requirements for 384 Kbps data capability to satisfy the IMT-2000 requirements for pedestrian (microcell) and low speed vehicular (macrocell) pedestrian (microcell) and low speed vehicular (macrocell) environmentsenvironments144 Kbps data capability for high speed vehicular environment144 Kbps data capability for high speed vehicular environment


3G WCDMA (UMTS) – Pros and Cons3G WCDMA (UMTS) – Pros and Cons

Wideband CDMAWideband CDMAStandard for Universal Mobile Telephone Service Standard for Universal Mobile Telephone Service (UMTS)(UMTS)

Committed standard for Europe and likely Committed standard for Europe and likely migration path for other GSM operatorsmigration path for other GSM operators

Leverages GSM’s dominant positionLeverages GSM’s dominant position

Requires substantial new spectrumRequires substantial new spectrum5 MHz each way (symmetric)5 MHz each way (symmetric)

Legally mandated in Europe and elsewhereLegally mandated in Europe and elsewhereSales of new spectrum completed in Sales of new spectrum completed in EuropeEurope

At prices that now seem exorbitant At prices that now seem exorbitant


3G cdma2000 3G cdma2000 Specification developed by the Third Generation Partnership Specification developed by the Third Generation Partnership Project 2 (3GPP2)Project 2 (3GPP2)CDMA 2000 1xCDMA 2000 1x

currently deployed as 2.5G overlay on IS 95 systemscurrently deployed as 2.5G overlay on IS 95 systems1.25 MHz channel bandwidth same as IS 951.25 MHz channel bandwidth same as IS 95max data rate 144 Kbps now increasing to 307 Kbps in the future max data rate 144 Kbps now increasing to 307 Kbps in the future

CDMA 2000 1xEV (evolution using 1x channel bandwidth)CDMA 2000 1xEV (evolution using 1x channel bandwidth)1xEV-DO data only, 384 Kbps - 2.4 Mbps max 1xEV-DO data only, 384 Kbps - 2.4 Mbps max 1xEV-DV for data and voice, specified by 2003/4, up to 4.8 Mbps 1xEV-DV for data and voice, specified by 2003/4, up to 4.8 Mbps

CDMA 2000 3x uses 3x1.25 MHz bandwidth, 2-4 MbpsCDMA 2000 3x uses 3x1.25 MHz bandwidth, 2-4 MbpsCDMA 2000 1x EV-DO and CDMA 2000 3x are ITU CDMA 2000 1x EV-DO and CDMA 2000 3x are ITU approved, IMT-2000 (3G) standardsapproved, IMT-2000 (3G) standards


3G cdma2000 – Pros and Cons3G cdma2000 – Pros and Cons

Evolution from original Qualcomm CDMAEvolution from original Qualcomm CDMANow known as cdmaOne or IS-95Now known as cdmaOne or IS-95

Better migration story from 2G to 3GBetter migration story from 2G to 3GcdmaOne operators don’t need additional cdmaOne operators don’t need additional spectrumspectrum1xEVD0 promises higher data rates than UMTS, 1xEVD0 promises higher data rates than UMTS, i.e. W-CDMAi.e. W-CDMA

Better spectral efficiency than W-CDMA(?)Better spectral efficiency than W-CDMA(?)Arguable (and argued!)Arguable (and argued!)

CDMA2000 core network less mature CDMA2000 core network less mature cmdaOne interfaces were vendor-specificcmdaOne interfaces were vendor-specificHopefully CDMA2000 vendors will comply w/ Hopefully CDMA2000 vendors will comply w/ 3GPP23GPP2


3G TD-SCDMA (Time-Division, Synchronous 3G TD-SCDMA (Time-Division, Synchronous CDMA)CDMA)Time division duplex (TDD)Time division duplex (TDD)Chinese developmentChinese development

Will be deployed in ChinaWill be deployed in China

Good match for asymmetrical traffic!Good match for asymmetrical traffic!Single spectral band (1.6 MHz) possibleSingle spectral band (1.6 MHz) possibleCosts relatively lowCosts relatively low

Handset smaller and may cost lessHandset smaller and may cost lessPower consumption lowerPower consumption lowerTDD has the highest spectrum efficiencyTDD has the highest spectrum efficiency

Power amplifiers must be very linearPower amplifiers must be very linearRelatively hard to meet specificationsRelatively hard to meet specifications


Major 3G Standardization Bodies and ForumsMajor 3G Standardization Bodies and ForumsStandard Organization Region

International Telecommunications Union (ITU)

International

European Telecommunications Standard Institute (ETSI)

Europe

Telecommunications Industry Association (TIA)

North America

Association of Radio Industries and Business (ARIB)

Japan

American National Standard Institute (committee T1P1)

North America


Major 3G Standardization Bodies and Forums-Major 3G Standardization Bodies and Forums-Cont’dCont’d

33rdrd Generation Partnership Project (3GPP) Generation Partnership Project (3GPP)Focus on setting global standard for UMTS Terrestrial Radio Focus on setting global standard for UMTS Terrestrial Radio Access (UTRA)Access (UTRA)Involve ETSI (Europe), ARIB (Japan), T1P1 (USA), etc.Involve ETSI (Europe), ARIB (Japan), T1P1 (USA), etc.

33rdrd Generation Partnership Project 2 (3GPP2) Generation Partnership Project 2 (3GPP2)Focus on setting global standard for cdma2000Focus on setting global standard for cdma2000More of a N. American focusMore of a N. American focus


UTRA ParametersUTRA Parameters

UTRA FDDUTRA FDD UTRA TDDUTRA TDD

Official nameOfficial name IMT-DSIMT-DS IMT-TCIMT-TC

Uplink frequencyUplink frequency 1920 - 1980 MHz1920 - 1980 MHz 2010 - 2025 MHz2010 - 2025 MHz

Downlink Downlink frequencyfrequency

2110 - 2170 MHz2110 - 2170 MHz 2010 - 2025 MHz2010 - 2025 MHz

Carrier spacingCarrier spacing 5 MHz5 MHz 5 MHz5 MHz

Duplex schemeDuplex scheme FDDFDD TDDTDD

Chip rateChip rate 3.84 Mcps3.84 Mcps 3.84 Mcps3.84 Mcps

ModulationModulation QPSKQPSK QPSKQPSK

Frame lengthFrame length 10 ms10 ms 10 ms10 ms

Time slots/frameTime slots/frame N/AN/A 1515


Mobile Wireless SpectrumMobile Wireless Spectrum

Bands Frequencies GSM/(MHz) (MHz) Regions EDGE WCDMA CDMA2000

450 450-467 Europe x x480 478-496 Europe x800 824-894 America x x900 880-960 Europe/APAC x x1500 Japan PDC x1700 1750-1870 Korea x1800 1710-1880 Europe/APAC x x x1900 1850-1990 America x x x

21001885-2025 &

2100-2200Europe/APAC x x

2500 2500-2690 ITU Proposal x


Prospectus for Global RoamingProspectus for Global Roaming

Multiple vocoders (AMR, EVRC, SMV,…)Multiple vocoders (AMR, EVRC, SMV,…)Six or more spectral bandsSix or more spectral bands

800, 900, 1800, 1900, 2100, 2500, …? MHz800, 900, 1800, 1900, 2100, 2500, …? MHz

At least four modulation variantsAt least four modulation variantsGSM (TDMA), W-CDMA, CDMA2000, TD-SCMDAGSM (TDMA), W-CDMA, CDMA2000, TD-SCMDA

The handset approachThe handset approachAdvanced silicon Advanced silicon Software defined radioSoftware defined radioImproved batteriesImproved batteries


Biggest Threats to Today’s 3G-Wireless LANsBiggest Threats to Today’s 3G-Wireless LANs

Faster than 3GFaster than 3G11 or 56 Mbps vs. <2 Mbps for 3G when 11 or 56 Mbps vs. <2 Mbps for 3G when stationarystationary

Data experience matches the InternetData experience matches the InternetWith the added convenience of mobileWith the added convenience of mobileSame user interface (doesn’t rely on small Same user interface (doesn’t rely on small screens)screens)Same programs, files, applications, Websites.Same programs, files, applications, Websites.

Low cost, low barriers to entryLow cost, low barriers to entryOrganizations can build own networksOrganizations can build own networks

Like the Internet, will grow virallyLike the Internet, will grow virally

Opportunity for entrepreneurs!Opportunity for entrepreneurs!Opportunity for wireless operators?Opportunity for wireless operators?


Wireless Local Area Networks (WLANs)Wireless Local Area Networks (WLANs)


Wireless LAN StandardsWireless LAN Standards


BluetoothBluetooth


Ultra-Wideband Radio (UWB)Ultra-Wideband Radio (UWB)


Why UWB is more Interesting?Why UWB is more Interesting?


IEEE 820.15.4 (ZigBee Radios)IEEE 820.15.4 (ZigBee Radios)


WLANs Data RatesWLANs Data Rates


WLANs RangeWLANs Range


WLANs Power DissipationWLANs Power Dissipation


Technology TrendsTechnology TrendsImprovements in system capacity through advanced signaling, Improvements in system capacity through advanced signaling, detection and signal processing techniques:detection and signal processing techniques:

Orthogonal frequency division multiplexing OFDMOrthogonal frequency division multiplexing OFDMTurbo codingTurbo codingMultiple-user detection (interference cancellation) Multiple-user detection (interference cancellation) Multiple-input multiple-output (MIMO) processingMultiple-input multiple-output (MIMO) processingSoftware radioSoftware radio

Improvements in features and capabilities for better services:Improvements in features and capabilities for better services:Full integration into the Internet for multimedia servicesFull integration into the Internet for multimedia servicesSeamless roaming between cellular, wireless LAN, and satellite Seamless roaming between cellular, wireless LAN, and satellite networksnetworks


Beyond 3G?Beyond 3G?

Need to provide: “beyond data”Need to provide: “beyond data”Higher data rates (at least on downlink)Higher data rates (at least on downlink)More multimedia contentsMore multimedia contents

Voice, data, video, WWW access.Voice, data, video, WWW access.broadcastbroadcast as well as as well as cellular cellular

Wideband (10 MHz or more)Wideband (10 MHz or more)

Main CandidatesMain CandidatesWOFDM WOFDM WCDMAWCDMAMulti-Carrier CDMAMulti-Carrier CDMAOther???Other???

How will these systems access the Internet How will these systems access the Internet and coexist with wireless LANs?and coexist with wireless LANs?


In Short …In Short …Wireless data and multimedia are the main Wireless data and multimedia are the main drivers for future generations of cellular systemsdrivers for future generations of cellular systems

Several competing standards (as in 2G)Several competing standards (as in 2G)

Evolutionary path unclearEvolutionary path unclear

Killer application unknownKiller application unknownWhat do mobile users want?What do mobile users want?

Will wireless LANs or cellular systems Will wireless LANs or cellular systems dominate the future wireless data landscape?dominate the future wireless data landscape?

ch-1-2 introduction to cellular mobile communications

Documents

number of mobile subscribers

number of cell phones

total number of subscribers

end of year

greater future growth

media report goliath

media report middle

tr oduction