4 gsm net architecture by Praveen Kumar Prabhat

GSM Network GSM Network ArchitectureArchitecture

ELET 6302ELET 6302

MotivationMotivation

OutlineOutline

Introduction and history.Introduction and history.

GSM architecture.GSM architecture.

Implementation.Implementation.

Technology and standards.Technology and standards.

SummarySummary

IntroductionIntroduction

Global System for Mobile Communication (GSM)Global System for Mobile Communication (GSM) Anybody – 500 million users (may 2001)Anybody – 500 million users (may 2001) Anywhere – 168 countries (may 2001)Anywhere – 168 countries (may 2001) Any media – voice, messaging, data, multimediaAny media – voice, messaging, data, multimedia

Source: Hillebrand, 1

GSM ArchitectureGSM Architecture

OMC

Home Location Register

AuC

Equipment ID

Network Management Center

BTS

BTS

BTS

ME

ME

ME

Subscriber Identity Module



Base station controller

PSTN

Mobile switching center

Data communication network

BTS = Base Transceiver Station

AuC = Authentication Center

OMC = Operation and Maintenance Center

PSTN = Public Switched Telephone Network

ME = Mobile Equipment

Source: Stallings, 313

Source: Mehrotra, 27

Visitor Location Register

GSM ArchitectureGSM Architecture

F1 F2 F1' F2'

Frequency

12345678

45 MHz

BS Transmission Band : 935 – 960 MHZ

MS Transmission Band : 890 – 915 MHZ

Year IntroducedYear Introduced 19901990

Access methodAccess method TDMATDMA

Channel BandwidthChannel Bandwidth 200 kHz200 kHz

Number of duplex Number of duplex channelschannels

125125

Users per channelUsers per channel 88

Speech coding bit Speech coding bit raterate

13 kbps13 kbps

Data coding bit rateData coding bit rate 12 kbps12 kbps

Frame sizeFrame size 4.6 ms4.6 ms

SIM (Subscriber Identity Module)SIM (Subscriber Identity Module)

Billions of Calls

Millions of Subscribers

Thousand of Different Types of Telephones

Hundreds of Countries

Dozens of Manufacturers….

And only one Card: The SIM

Source: Hillebrand, 369

http://ucables.com/products/simcards/

•Administrative data

•Security data

•Subscriber data

•Roaming data

•PLMN (Public Land Mobile Network

ImplementationImplementation

SIM = Subscriber Identity Module

Central processor, clock and tone, internal bus system, keyboard (HMI)

Voice encoding Ciphering Modulation

Voice decoding

>Channel Decoding

>De-Interleaving

>Re-formatting

Deciphering

Amplifier

>Channel encoding

>Interleaving

>Burst generation

Receiver

Transmitter

Demodulation

Source: Heine, 14


Abis-Interface

O&M Module Operation and maintenance functionality/clock distribution

Digital signal processing (NF functionality)

HF Transmitter (HF-TX)

Input filter

Output filter

HF Receiver (HF-RX) S

low

fre

qu

en

cy

ho

pp

ing

Tra

nsm

issi

on

sy

ste

m

TRX

Block Diagram of a BTS with one TRX

Source: Heine, 20

GSM VariantsGSM VariantsVariantVariant Uplink Uplink

(MHz)(MHz)Downlink Downlink (MHz)(MHz)

Total Total BandwidthBandwidth

Duplex-Duplex-frequencyfrequency

ChannelsChannels

GSM-400GSM-400 451-458 and 451-458 and 479-486479-486

461-468 and 461-468 and 489-496489-496

Twice 14 MHzTwice 14 MHz 10 MHz10 MHz Twice 72Twice 72

GSM-900 GSM-900 (primary (primary band)band)

890-915890-915 935-960935-960 Twice 25 MHzTwice 25 MHz 45 MHz45 MHz Twice 124Twice 124

Extended Extended GSM-900GSM-900

880-915880-915 925-960925-960 Twice 35 MHzTwice 35 MHz 45 MHz45 MHz Twice 174Twice 174

GSM-RGSM-R 876-880876-880 921-925921-925 Twice 4 MHzTwice 4 MHz 45 MHz45 MHz Twice 19Twice 19

DCS-1800DCS-1800 1,710-1,7851,710-1,785 1,805-1,8801,805-1,880 Twice 75 MHzTwice 75 MHz 95 MHz95 MHz Twice 373Twice 373

PCS-1900PCS-1900 1,850-1,9101,850-1,910 1,930-1,9901,930-1,990 Twice 60 MHzTwice 60 MHz 80 MHz80 MHz Twice 300Twice 300

Source: Bekkers, 299

SummarySummary

Network architectureNetwork architecture


Voice applicationVoice application

Data applicationData application

ReferencesReferences

Bekkers, Rudi. Mobile Communications Standards: GSM, UMTS, TETRA, and Bekkers, Rudi. Mobile Communications Standards: GSM, UMTS, TETRA, and ERMES. Norwood, MA: Artech House, Inc., 2001.ERMES. Norwood, MA: Artech House, Inc., 2001.

Halonen, Romero, and Melero. GSM, GPRS, and EDGE Performance: Halonen, Romero, and Melero. GSM, GPRS, and EDGE Performance: Evolution Towards 3G/UMTS. England: John Wiley & Sons Ltd., 2003.Evolution Towards 3G/UMTS. England: John Wiley & Sons Ltd., 2003.

Hillebrand, Friedhelm. GSM and UMTS: The Creation of Global Mobile Hillebrand, Friedhelm. GSM and UMTS: The Creation of Global Mobile Communications. England: John Wiley & Sons Ltd., 2002.Communications. England: John Wiley & Sons Ltd., 2002.

Heine, Gunnar. GSM Networks: Protocols, Terminology, and Implementation. Heine, Gunnar. GSM Networks: Protocols, Terminology, and Implementation. Norwood, MA: Artech House, Inc., 1999.Norwood, MA: Artech House, Inc., 1999.

Mehrotra, Asha. GSM System Engineering. Norwood, MA: Artech House, Inc., Mehrotra, Asha. GSM System Engineering. Norwood, MA: Artech House, Inc., 1997.1997.

Harte, Levine, and Livingston. GSM Superphones. United States: APDG Harte, Levine, and Livingston. GSM Superphones. United States: APDG Publishing, Inc. A Division of McGraw-Hill, 1999.Publishing, Inc. A Division of McGraw-Hill, 1999.