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GSM overview 1.ppt
- 1. GSM OVERVIEW Others …. MSC BTS BSC BTSPSTN BTS ISDN SS#7 M S M S M S M S M S M S
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- 16. ÑÒNH NGHÓA CAÙCSOÁ VAØ NHAÄN DAÏNG TRONG HEÄ THOÁNG GSM Soá ISDN cuûa traïm di ñoäng MSISDN MSISDN = CC+ NDC+ SN Soá löu ñoäng cuûa maùy di ñoäng MSRN(Mobile Station Roaming Number). MSRN = CC + NDC + SN Nhaän daïng thueâ bao di ñoäng quoác teá IMSI (International Mobile Subscriber identity) IMSI = MCC + MNC + MSIN. Nhaän daïng thueâ bao di ñoäng taïm thôøi TMSI (Temporary Mobile Subscriber Identity) Nhaän daïng thieát bò cuûa traïm di ñoäng quoác teá IMEI (International Mobile Equipment Identity) IMEI = TAC + FAC + SNR + SP Nhaän daïng vuøng ñònh vò LAI (Location Area Identity) LAI = MCC + MNC + LAC Nhaän daïng oâ toaøn caàu (CGI) (Cell Global Identity) CGI = MCC + MNC + LAC + CI Maõ nhaän daïng traïm goác (BSIC) (Base Station Identity Code)
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- 19. Radio Subsystem RPE-LTP encoder RPE-LTP decoder 13 bit uniform to8 bit A-Law 8 bit A-Law to 13 bit uniform MSC PSTN / ISDN 104 kbps 13 kbps 8000 samples/s 13-bit uniform code Analogue speech 8000 samples/s 13-bit uniform code 8000 samples/s 8-bit A-Law ITU-T G.711, G.712, G.713, G.714 RPE-LTP encoder RPE-LTP decoder 13 bit uniform to Analogue O/P Analogue to 13 bit uniform I/P 104 kbps 64 kbps 13 kbps System Description
- 20. Radio Access & Demod GMSK De- Interleaving Forward Error Coding Interleaving RadioAccess & Mod GMSK Interleaving Forward Error Coding Error Correction Radio Access & Mod GMSK Error Correction De- Interleaving Radio Access & Demod GMSK Dup Dup Encoded speech 456 bits/frame 20ms Encoded speech 456 bits/frame 20ms 22.8kbps 22.8kbps 13 kbps 13 kbps System Description
- 22. Signalling in GSMnetwork O A M L A P D BTS MTP2 SCCP MTP3 L A P D O A M R R D T A P B S S M A P BSSAP BSC MTP1 MTP3 MTP2 SCCP MTP2 MTP3 SCCP BSSAP DTAP/ BSSMAP T C A P MM CM M A P NSS R R MM CM MS Um Interface A bis Interface A Interface
- 23. GSM Specification Access methodTDMA/FDMA Frequency band (MS to BS) 890 - 915 MHz Frequency band (BS to MS) 935 - 960 MHz Channel bandwidth 200 kHz Modulation GMSK Bit rate 270.833 kbps Filter BT = 0.3 (Gaussian) Voice channel coding RPE-LPC Convolutional 13 kbps Frequency Hopping Slow hopping (217 hops/s)
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