Agenda. GSM900/DCS1800 . The GSM Network & Air Interface . Technical Basics . Speech Coding . Types of Channel . Making a Phone Call Global System for Mobile( Groupe Special Mobile )G S M1982 Groupe Special Mobile?is created within CEPT1986 A Permanent Nucleus is set up1987 Main radio transmission techniques are chosen, based on prototype evalution (1986)1989 GSM becomes an ETSI technical committe1990 The phase 1 GSM 900 specifications are finalized1991 First systems are running 1992 All major European GSM 900 operators begin commercial operator GSM Development History• Speech Services• Data Services• Short Message Services (SMS)• Supplementary Services• Subscriber Identity Module (SIM)• Security FunctionGSM / DCS1800 FunctionalitiesRF Aspects• TDMA• 0.3GMSK Modulation• Burst Power Transmission• Neighbour Cells Measurement• Hopping• Uplink / Downlink DTx• BER & Receiver Testing GSM900GSM900DCS1800DCS1800PCS1900Uplink890 to880 to1710 to1710 to1850 to915MHz915MHz1785MHz1785MHz1910MHzDownlink935 to925 to1805 to1805 to1930 to960MHz960MHz1880MHz1880MHz1990MHzARFCN range1 to 1240 to 124 and512 to 885512 to 885512 to 810975 to 1023TX/RX Spacing45MHz45MHz95MHz95MHz80MHz(Freq.)TX/RX Spacing3 Timeslots(Time)Modulation Data 270.833kbit/sRateFrame Period4.615msTimeslot Period576.9usBit Period3.692usModulation0.3GMSKChannel Spacing200KHzTDMA Mux8MS Max Power20W( 8W is 8W8W1W1Wmax in use)MS Min Power13dBm5dBm4dBm0dBm0dBmMS Power 5 to 190 to 150 to 1530,31,0 to 15Control StepsVoice Coder Bit13kbit/s13kbit/s13kbit/s13kbit/s13kbit/sRate6.5kbit/s6.5kbit/sGSM900/DCS1800/PCS1900GSM Frequency Range• 890 - 915 MHz Uplink / MS Transmit• 935 - 960 MHz Downlink / BS Transmit• Duplex Offset 45 MHz• Channel Spacing 200kHz• Channel numbering 1 - 124• Transmission...
