1. GSM System Architecture
PSTN
ISDN
PDN
BSC MS
BTS
MSC
GMSC
BTS
BSC
VLR MS
EIR
BTS
AUC MS
HLR

2. GSM System Architecture-I
Mobile Station (MS)
Mobile Equipment (ME)
Subscriber Identity Module (SIM)
Base Station Subsystem (BSS)
Base Transceiver Station (BTS)
Base Station Controller (BSC)
Network Switching Subsystem(NSS)
Mobile Switching Center (MSC)
Home Location Register (HLR)
Visitor Location Register (VLR)
Authentication Center (AUC)
Equipment Identity Register (EIR)

3. GSM RF RF Spectrum GSM 900 Mobile to BTS (uplink): 890-915 Mhz
BTS to Mobile(downlink): Mhz
Bandwidth : 2* 25 Mhz
GSM 1800
Mobile to BTS (uplink): Mhz
BTS to Mobile(downlink) Mhz
Bandwidth : 2* 75 Mhz
GSM 850, 1900 also used

4. GSM RF Carrier Separation : 200 Khz Duplex Distance : 45 Mhz
No. of RF carriers : 124
Access Method : TDMA/FDMA
Modulation Method : GMSK
Modulation data rate : Kbps

5. GSM Operation Radio Interface Demodulation Speech decoding
Channel decoding
De-interleaving
Burst Formatting
De-ciphering
Demodulation
Modulation
Ciphering
Interleaving
Channel Coding
Speech coding
Radio Interface
Speech
13 Kbps
22.8 Kbps
33.6 Kbps
Kbps

6. Physical Channel

7. GSM-Frame Structure