GSM Network Architecture ELET 6302 Motivation

GSM Network Architecture ELET 6302

Motivation

Outline Introduction and history. GSM architecture. Implementation. Technology and standards. Summary

Introduction Global System for Mobile Communication (GSM) n n n Anybody – 500 million users (may 2001) Anywhere – 168 countries (may 2001) Any media – voice, messaging, data, multimedia Source: Hillebrand, 1

GSM Architecture Home Location Register BTS = Base Transceiver Station Au. C Network Management Center Au. C = Authentication Center OMC = Operation and Maintenance Center Equipment ID PSTN = Public Switched Telephone Network ME = Mobile Equipment Subscriber Identity Module ME B T S Visitor Location Register Base station controller Mobile switching center OMC Data communication network PSTN Source: Stallings, 313 Source: Mehrotra, 27

GSM Architecture MS Transmission Band : 890 – 915 MHZ BS Transmission Band : 935 – 960 MHZ 45 MHz Year Introduced 1990 Access method TDMA Channel Bandwidth 200 k. Hz Number of duplex channels 125 Users per channel 8 Speech coding bit rate 13 kbps Data coding bit rate 12 kbps Frame size 4. 6 ms

SIM (Subscriber Identity Module) Billions of Calls Millions of Subscribers Thousand of Different Types of Telephones Hundreds of Countries Dozens of Manufacturers…. • Administrative data And only one Card: The SIM • Security data • Subscriber data • Roaming data • PLMN (Public Land Mobile Network Source: Hillebrand, 369 http: //ucables. com/products/simcards/

Implementation Receiver >Channel Decoding Voice decoding Deciphering >De-Interleaving Demodulation >Re-formatting >Channel encoding Voice encoding >Interleaving >Burst generation Ciphering Modulation Amplifier Transmitter Central processor, clock and tone, internal bus system, keyboard (HMI) SIM = Subscriber Identity Module Source: Heine, 14

Input filter O&M Module HF Transmitter (HF-TX) HF Receiver (HF-RX) TRX Digital signal processing (NF functionality) Transmission system Output filter Slow frequency hopping Implementation Abis. Interface Operation and maintenance functionality/clock distribution Block Diagram of a BTS with one TRX Source: Heine, 20

GSM Variants Variant Uplink (MHz) Downlink (MHz) Total Bandwidth Duplex. Channels frequency GSM-400 451 -458 and 479 -486 461 -468 and 489 -496 Twice 14 MHz 10 MHz Twice 72 GSM-900 (primary band) 890 -915 935 -960 Twice 25 MHz 45 MHz Twice 124 Extended GSM-900 880 -915 925 -960 Twice 35 MHz 45 MHz Twice 174 GSM-R 876 -880 921 -925 Twice 4 MHz 45 MHz Twice 19 DCS-1800 1, 710 -1, 785 1, 805 -1, 880 Twice 75 MHz 95 MHz Twice 373 PCS-1900 1, 930 -1, 990 Twice 60 MHz 80 MHz Twice 300 1, 850 -1, 910 Source: Bekkers, 299

Summary Network architecture Implementation Voice application Data application

References Bekkers, Rudi. Mobile Communications Standards: GSM, UMTS, TETRA, and ERMES. Norwood, MA: Artech House, Inc. , 2001. Halonen, Romero, and Melero. GSM, GPRS, and EDGE Performance: Evolution Towards 3 G/UMTS. England: John Wiley & Sons Ltd. , 2003. Hillebrand, Friedhelm. GSM and UMTS: The Creation of Global Mobile Communications. England: John Wiley & Sons Ltd. , 2002. Heine, Gunnar. GSM Networks: Protocols, Terminology, and Implementation. Norwood, MA: Artech House, Inc. , 1999. Mehrotra, Asha. GSM System Engineering. Norwood, MA: Artech House, Inc. , 1997. Harte, Levine, and Livingston. GSM Superphones. United States: APDG Publishing, Inc. A Division of Mc. Graw-Hill, 1999.