GSM Global System for Mobiles

1 Global System for Mobiles GSM 2 TOPICS • GSM CONCEPTS • GSM SYSTEM ARCHITECTURE • IDENTITIES USED IN GSM • GSM CHANNELS • GSM RADIO LINK • MOBILITY MANAGEMENT • CALL MANAGEMENT • RADIO RESOURCE MANAGEMENT 3 TOPICS • GSM CONCEPTS • GSM SYSTEM ARCHITECTURE • IDENTITIES USED IN GSM • GSM CHANNELS • GSM RADIO LINK • MOBILITY MANAGEMENT • CALL MANAGEMENT • RADIO RESOURCE MANAGEMENT 4 Telecom Basics • Communication – Voice and Data – Analog and Digital – Circuit Switched and Packet Switched – Media - Copper Wire, Co-axial cable, Air, Optical Fibre – Networks -PSTN, ISDN, PDN and Mobile Networks 5 Background to GSM • 1G : Advanced Mobile Phone Service (AMPS) • Analog, Circuit Switched, FDMA, FDD • 2G : Digital Advanced Mobile Phone Service (D-AMPS) • Digital, Circuit Switched, FDMA, FDD • 2G : Global System for Mobile (GSM) • Digital, Circuit Switched, FDMA and TDMA, FDD • 2G : Code Division Multiple Access (CDMA) • Digital, Circuit Switched, FDMA, SS, FDD 6 GSM History 7 1982: Groupe Spécial Mobile (GSM) created 1984: Description of GSM features 1985: List of recommendations settled 1987: Initial MoU (Memorandum of Understanding) aside the drafting of technical specifications was signed by network operators of 13 countries: 1988: Validation and trials, of the radio interface. 1991: First system trials are demonstrated at the Telecom 91 exhibition. 1992: Official commercial launch of GSM service in Europe. First Launch in Finland 1993: The GSM-MoU has 62 signatories in 39 countries worldwide. 1995: Specifications of GSM phase 2 are frozen. 1999: GSM MoU joins 3GPP (UMTS) GPRS Trials begins 2000: 480M GSM subscribers Worldwide First GPRS Networks roll out End 2002: 792M GSM subscribers Worldwide Development of the GSM Standard 12 SERIES OPERATION AND MAINTENANCE 01 SERIES GENERAL 02 SERIES SERVICE ASPECTS 03 SERIES NETWORK ASPECTS 04 SERIES MS-BSS INTERFACE AND PROTOCOLS 05 SERIES PHYSICAL LAYER ON THE RADIO PATH. 06 SERIES SPEECH CODING SPECIFICATIONS 07 SERIES TERMINAL ADAPTERS FOR MOBILE STATIONS 11 SERIES EQUIPMENT AND TYPE APPROVAL SPECIFICATIONS 10 SERIES SERVICE INTERWORKING 09 SERIES NETWORK INTERWORKING 08 SERIES BSS TO MSC INTERFACES GSM Specifications Increasing GSM Data Rates Transmission Time GPRS = General Packet Radio Service HSCSD = High Speed Circuit Switched Data EDGE = Enhanced Data rate for GSM Evolution UMTS = Universal Mobile Telecommunication System 10 sec 1 min 10 min 1 hour0 UMTS E/GPRS ISDN PSTN GSM webe-mail photo web photo e-mail web photo video clip report photo web photo e-mail video clip report video clip report video clip report video clip report 10 throughput kbps 10 k 100 k 64 k 1 M 2 M 1 k 1998 1999 2000 2001 2002 Time frame UMTS UMTS GPRS GPRS HSCSD HSCSD 9.6 9.6 14.4 14.4 p a c k e t GPRS = General Packet Radio Service HSCSD = High Speed Circuit Switched Data EDGE = Enhanced Data rate for GSM Evolution UMTS = Universal Mobile Telecommunication System EDGE c i r c ui t Wireless Data Technology Options [...]... in USA) 15 GSM Band Allocations (MHz) Duplex Spacing Duplex channels 460.4-467.6 2x7.2 488.8-496 2x7.2 869-894 2x25 10 10 35 35 890-915 880-915 876-880 935-960 925-960 921-925 2x25 2x35 2x04 45 45 41 124 174 40 1710-1785 1850-1910 1805-1880 1930-1990 2x75 2x60 95 80 374 299 GSM systems Uplink Downlink GSM 450 GSM 480 450.4-457.6 478.8-486 GSM 900 E -GSM (900) R -GSM (900) GSM 1800 GSM 1900 GSM 850 824-849... Frequency Channel Number GSM Family Radio Band Spectrum Uplink 450.4 457.6 478.8 GSM 450 Downlink 460.4 824 GSM 480 467.6 488.8 849 GSM 850 496 869 894 MHz 915 Uplink 876 880 486 915 890 915 1710 1785 1850 1910 P -GSM E -GSM GSM 1800 GSM 1900 R -GSM 921 925 Downlink 935 960 960 960 1805 1880 1930 1990 MHz Traffic/Signaling Traffic «bla bla bla » Signaling « RING ! » riiiiing Network MS GSM - Network Structure... Interference • Features-CCS7 Signaling – SMS (Short Message Services) – Emergency Calls – CELL Broadcast 34 TOPICS • • • • • • • • GSM CONCEPTS GSM SYSTEM ARCHITECTURE IDENTITIES USED IN GSM GSM CHANNELS GSM RADIO LINK MOBILITY MANAGEMENT CALL MANAGEMENT RADIO RESOURCE MANAGEMENT 35 MS GSM - Network Structure Um HLR VLR BTS BSC Abis MSC A B H C MS AuC GMSC BTS E Abis A MSC F EIR E PSTN BSC Um X.25 BTS VLR X.25... different Time ) 13 GSM Concepts Cellular Structure 2 2 7 3 1 6 7 5 4 1 6 5 Cellular Networking technology that breaks geographic area into cells shaped like honey comb Cell is the radio coverage area of one base transceiver station 14 What are the types in GSM Network? • GSM- 900 (Channels 125 operating band 900Mhz carrier spacing 200khz spacing 45Mhz) • GSM -1800 (Channels 374 spacing 95Mhz) • GSM -1900(Used... BTS CAN GSM CAN RX MS2 TX MS2 +3TS RX MS6 TX MS6 yes W HEN the WHAT ms-isdn yes W HAT D GSM D the ms-isdn RX MS4 TX MS4 RX MS5 TX MS5 HOW TA RX MS1 TX MS1 RX MS3 TX MS3 W HAT HOW Propagation Delay W HEN WHAT RX MS7 TX MS7 RX MS8 TX MS8 32 Timing Advance 3 - With Timing Advance: No Collision CAN TX BTS RX BTS CAN RX MS1 TX MS1 GSM D RX MS6 TX MS6 RX MS7 TX MS7 WHEN the WHAT ms-isdn yes D the GSM ms-isdn... X.25 OMC Server 19 GSM System specifications Frequency band Uplink Downlink Duplex Frequency Spacing Carrier separation Frequency Channels Time Slots /Frame(Full Rate) Voice Coder Bit Rate Modulation Air transmission rate Access method Speech Coder 890 - 915 MHz 935 - 960MHz 45MHz 200KHz 124 8 13Kbps GMSK 270.833333 Kbps FDMA/TDMA RPE-LTP-LPC 20 Paired Radio Channels in GSM Case of GSM 900 Uplink 890... Multiple Access – ( eg: GSM each Frequency channel is 200KHz) • TDMA - Time Division Multiple Access – ( eg: GSM each frequency channel is divided into 8 timeslots) • CDMA - Code Division Multiple Access – (eg: IS95- Each User data is coded with a unique code) 12 Duplex Technique • Duplex - How the up link and Down link of a user is separated • FDD - Frequency Division Duplex – (eg:In GSM the up link and... MS3 TX MS3 WHAT Propagation Delay WHEN WHAT Timing Advance = 2 * Propagation Delay RX MS8 TX MS8 33 GSM in comparison with other Standards • GSM gives mobility without any loss in Audio quality • Encryption techniques used gives high security in the air Interface and also use of SIM • Bit Interleaving for high efficiency in Transmission • Variable Power (Power budgeting- extend battery life) • Minimum... TDMA frame Period is 577 * 8 = 4.616 milli secs 0.577 ms 0 1 2 3 4 4.616 ms 5 6 7 27 28 Fundamentals 960 MHz 124 959.8MHz TS: Time slot 123 GSM utilizes two bands(TDMAMHz 890-915 Downlink of 25 frame) = 8 TS MHz band is used for uplink while the 935960 MHz is used for downlink …… DOWNLINK …… 200KHz 2 0 1 1 935.2 Mhz 915 MHz 124 123 45 MHz UPLINK 200KHz …… …… 2 890.2 MHz 4 5 6 7 The frequency bands are... supports 8 users with each user transmitting / receiving on a particular time Delay 0 1 2 3 4 5 6 7 slot (TS) Uplink (TDMA frame) 1 890 MHz The technology Therefore 1 TDMA frame = 156.25 x 8 = 1250 bits and has a duration of 576.92μs x 8 = 4.615 ms 29 GSM Delays Uplink TDMA Frames BTS side The start of the uplink TDMA is delayed of three time-slots TDMA Frame (4.615 ms) 0 1 2 3 4 5 R R R R R T T T T T Downlink . 1 Global System for Mobiles GSM 2 TOPICS • GSM CONCEPTS • GSM SYSTEM ARCHITECTURE • IDENTITIES USED IN GSM • GSM CHANNELS • GSM RADIO LINK. RADIO RESOURCE MANAGEMENT 3 TOPICS • GSM CONCEPTS • GSM SYSTEM ARCHITECTURE • IDENTITIES USED IN GSM • GSM CHANNELS • GSM RADIO LINK • MOBILITY MANAGEMENT