Slide 1Bursts
History of GSM Story
CEPT decided to develop unique mobile standard in 1982 and 6 study group established
Results converged to the comprehensive characteristics defined in 1987 and a tender announced
Equipment delivery started in March 1991 and first BTS operated in June 91
Since 1995 area-wide operation started
8000 pages of 13 series recommendation adopted by ETSI
Cellular Mobile Course
TRAU: Transcoding rate and adaptation unit
IWF: Inter Working Functions
HLR: Home location register
VLR: Visitor location register
EIR: Equipment identity register
Smart card
Except emergency calls, MS can only operate if SIM card has first been activated
Type of SIM card
SIM card serial number
Location information
List of carrier frequencies
Speech code/decode and data-rate
Comprises of BTS and BSC
BTS includes TRXs and TRAU
BSC controls radio resource, handover and is transparent for connection-related signaling from/to MSC
Cellular Mobile Course
MSC is responsible for:
Connection to/from ISDN, PSTN, PDN
Handling supplementary services
HLR includes quasi permanent static data of subscriber and current location area (LA) of MS
VLR managing sub.s who are currently roaming
VLR stores information transmitted by HLR and updates it once LA changed
Cellular Mobile Course
OSS comprises of OMC, AuC and EIR
OMC functions
Administration of subscribers and equipment (TMN)
Billing and generation of network state and resources allocation (capacity and frequency)
AuC contains encryption codes and information to protect sub.s identity
EIR is a database including sub.s number and IMEI (white, gray and black lists)
89372
00005
00011
67838
005
0
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Uplink
890
915
935
960
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Channels:
Downlink
time
7 0 1 2 3 4 5 6 7 0 1 2
7 0 1 2 3 4 5 6 7 0 1 2
7 0 1 2 3 4 5 6 7 0 1 2
Fn+1
- Access Burst: for call set up
- Dummy Burst: idle slots
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TB
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