Dr. Tanuja Patgar-GSM History and TDMA pptx

Future of GSM

1. UNIT-4 GSM&TDMA Dr . TANUJA P BE, ME, PhD, Post Doc Department of Electronics and Communication Dr. AIT, Bangalore

2. SERVICE CATEGORY SERVICE Additional Details GSM Teleservices Telephony Emergency Calls Short Message Service Videotext acess (MMS) Teletex,FAX,etc Full rate at 13kbps “112” is GSM –wide emergency number Point to point (between two users) and Cell broad cast types GSM Bearer Services Asynchronous data Synchronous data Synchronous packet data Others Supplementary Services Call forwarding Call Barring All Calls, when the subscriber is not available Outgoing calls with specifications

3. GSMGSM GSM NETWORK

4. Physical channel - Each timeslot on a carrier is referred to as a physical channel. Per carrier there are 8 physical channels. Logical channel - Variety of information is transmitted between the MS and BTS. There are different logical channels depending on the information sent. The logical channels are of two types Traffic channel Control channel Downlink Uplink CHANNELS CHANNEL CONCEPT

5. NORMAL BURST 1 2 3 4 5 6 7 1 2 3 4 5 6 7 57 bits 57 bits 26 bits 3 3 FRAME1(4.615ms) FRAME2 Training sequence Data Data Tail Bits Tail Bits Flag Bit Flag Bit Guard Period Guard Period 0.546ms 0.577ms Carries traffic channel and control channels BCCH, PCH, AGCH, SDCCH, SACCH and FACCH. CHANNEL CONCEPT

6. NORMAL BURST 1 2 3 4 5 6 7 1 2 3 4 5 6 7 57 bits 57 bits 26 bits 3 3 FRAME1(4.615ms) FRAME2 Training sequence Data Data Tail Bits Tail Bits Flag Bit Flag Bit Guard Period Guard Period 0.546ms 0.577ms Carries traffic channel and control channels BCCH, PCH, AGCH, SDCCH, SACCH and FACCH. CHANNEL CONCEPT

7. GSM Traffic Channels Traffic Channels TCH/F Full rate 22.8kbits/s TCH/H Half rate 11.4 kbits/s CHANNEL CONCEPT

8. GSM Control Channels BCH ( Broadcast channels ) Downlink only Control Channels DCCH( Dedicated Channels ) Downlink & Uplink CCCH( Common Control Chan ) Downlink & Uplink Synch. Channels RACH Random Access Channel CBCH Cell Broadcast Channel SDCCH Standalone dedicated control channel ACCH Associated Control Channels SACCH Slow associated Control Channel FACCH Fast Associated Control Channel PCH/ AGCH Paging/Access grant FCCH Frequency Correction channel SCH Synchronisation channel BCCH Broadcast control channel CHANNEL CONCEPT

9. BCH Channels BCCH( Broadcast Control Channel ) Downlink only Broadcasts general information of the serving cell called System Information BCCH is transmitted on timeslot zero of BCCH carrier Read only by idle mobile at least once every 30 secs. SCH( Synchronisation Channel ) Downlink only Carries information for frame synchronisation. Contains TDMA frame number and BSIC . FCCH( Frequency Correction Channel ) Downlink only. Enables MS to synchronise to the frequency. Also helps mobiles of the ncells to locate TS 0 of BCCH carrier. CHANNEL CONCEPT

10. CCCH Channels RACH( Random Access Channel ) Uplink only Used by the MS to access the Network. AGCH( Access Grant Channel ) Downlink only Used by the network to assign a signalling channel upon succes s full decoding of access bursts. PCH( Paging Channel ) Downlink only. Used by the Network to contact the MS. CHANNEL CONCEPT

11. DCCH Channels SDCCH( Standalone Dedicated Control Channel ) Uplink and Downlink Used for call setup, location update and SMS. SACCH( Slow Associated Control Channel ) Used on Uplink and Downlink only in dedicated mode. Uplink SACCH messages - Measurement reports. Downlink SACCH messages - control info. FACCH( Fast Associated Control Channel ) Uplink and Downlink. Associated with TCH only. Is used to send fast messages like handover messages. Works by stealing traffic bursts. CHANNEL CONCEPT

12. NORMAL BURST 1 2 3 4 5 6 7 1 2 3 4 5 6 7 57 bits 57 bits 26 bits 3 3 FRAME1(4.615ms) FRAME2 Training sequence Data Data Tail Bits Tail Bits Flag Bit Flag Bit Guard Period Guard Period 0.546ms 0.577ms Carries traffic channel and control channels BCCH, PCH, AGCH, SDCCH, SACCH and FACCH. CHANNEL CONCEPT

13. SERVICE CATEGORY SERVICE Additional Details GSM Teleservices Telephony Emergency Calls Short Message Service Videotext acess (MMS) Teletex,FAX,etc Full rate at 13kbps “112” is GSM –wide emergency number Point to point (between two users) and Cell broad cast types GSM Bearer Services Asynchronous data Synchronous data Synchronous packet data Others Supplementary Services Call forwarding Call Barring All Calls, when the subscriber is not available Outgoing calls with specifications TABLE -1 PHASE-1 GSM SERVICES ( Courtesy of ETSI)

14. SERVICE CATEGORY SERVICE Additional Details GSM Teleservices Half-Rate speech coder Enhanced full rate Optional Implementation Supplementary Services Calling line identification Connected line identification Call Waiting Call hold Multiparty Communication Closed user group Advice of Charge Operator determined call baring Presentation or restriction of displaying the caller’s ID Incoming Call during current conversation Put current call hold to answer another Up to five ongoing calls can be included in one conmversation Restriction of certain feature from individual Subscriber by operator TABLE -2 PHASE-2 GSM SERVICES ( Courtesy of ETSI )

15. INTERFACE NAMES Each interface specified in GSM has a name associated with it . NAME INTERFACE Um MS ----- BTS Abis BTS ----- BSC A MSC ------ BSC B MSC ------ VLR C MSC ------ HLR D VLR ----- HLR E MSC ------ MSC F MSC ------ EIR G VLR ------ VLR H HLR ------ AUC