GSM fundamentals

1. GSM Fundamental
Presented by
Tushar Bhanarkar
third Year
Electronics & Telecommunication
Engineering

2. Agenda




Network Architecture
Frequency Resource
Network Planning
Channel Type

3. GSM Network Structure
OMC
MSC/VLR
BSC
E
BIE
BTS
A
Abi
s
PSTN
ISDN
PSPDN
MSC/VLR
BSS
C
Um
MS
HLR/
AUC
F
H
EIR
SC/VM
MSS
3

4. Mobile Station
( MS )
Equipment used by mobile service subscribers for
access to services.
Mobile Equipment
Subscriber Identity Module (SIM)
Mobile stations are not fixed to one subscriber.
A subscriber is identified with the SIM card.
4

5. GSM Network Entity
Base Transceiver Station
( BTS )
Base Transceiver Station (BTS)
Wireless transmission
Wireless diversity
Wireless channel encryption
Conversion between wired and wireless signals
Frequency Hopping
5
BaseBand Unit:
voice and data speed adapting and channel coding
RF Unit:
modulating/demodulating, transmitter and receiver
Common Control Unit:
BTS operation and maintenance

6. GSM Network Entity
Base Station Controller
( BSC )
Managing Wireless network-BSS
Monitoring BTS
Controls:
Wireless link distribution between MS and BTS
Communication connection and disconnection
MS location, handover and paging
Voice encoding, transecoding (TC), rate, adaptation,
The operation and maintenance functions of BSS.

7. GSM Network Entity
Mobile Service Switching Center
( MSC )
holds all the switching functions
manages the necessary radio resources,
updating the location registration
carrying out the inter-BSC and inter-MSC tender
Inter-working with other networks (IWF).

8. GSM Network Entity
Home Location Register
( HLR )
Manages the mobile subscribers database
 subscriber information
 part of the mobile location information
 3 identities essential
the International Mobile subscriber Identity
the Mobile station ISDN Number
the VLR address

9. GSM Network Entity
Visitor Location Register
( VLR )
dynamically stores subscriber information needed to handle
incoming/outgoing calls
Mobile Station Roaming Number
When a roaming mobile enters an MSC area. This MSC
warns the associated VLR of this situation; the mobile enters
a registration procedure through which it is assigned a
mobile subscriber roaming number (MSRN)
Temporary Mobile Subscriber Identity, if applicable
The location area in which the mobile has been
registered
Data related to supplementary service parameters

10. GSM Network Entity
AUC/EIR
Authentication Center(s) (AUC)
Providing the authentication key used for
authorizing the subscriber access to the
associated GSM PLMN.
Equipment Identity Register(s) (EIR)
Handling Mobile Station Equipment Identity

11. Frequency Resource
GSM900 :
up: 890~915MHz
down: 935~960MHz
duplex interval: 45MHz
bandwidth: 25MHz，
frequency interval: 200KHz
GSM1800 :
up: 1710-1785MHz
down: 1805-1880MHz
duplex interval: 95MHz，
working bandwidth: 75MHz，
frequency interval: 200KHz
EGSM900 :
up: 880~890MHz
down: 925~935MHz
duplex interval: 45MHz
bandwidth: 10MHz，
frequency interval: 200KHz
GSM1900MHz:
up:1850~1910MHz
down:1930~1990MHz
duplex interval: 80MHz，
working bandwidth: 60MHz，
frequency interval: 200KHz

12. Frequency Resource
Single Band Network
Single Band
900MHz
Dual Band
1800MHz
Triple Band
1900MHz
In a sense, the network determines the handsets
can be selected.
But nowadays, most handsets support dual
band.

13. Channel Type
Traffic Channel
Transmit voice and data
Signaling Channel
transmit the signaling and synchronous data between BTS and
MS.