Introduction to GPRS

1. Introduction to GPRS
ZAHRA MANSOORI
1

2. Content
Introduction
History
GPRS Architecture
References
2

3. Introduction
Stands for: General Packet Radio Service
Gateway to Third Generation Mobile Networks
Enables transmission speed up to 160 Kbps
3
By adding GPRS to the GSM network, operators can offer efficient
wireless access to external IP-based networks, such as the Internet
and corporate intranets

4. History
1G
Analog
NMT-450
NMT-900
TACS
AMPS
2G
Digital
GSM
IS-95 (CDMA)
IS-136 (TDMA)
PHS
2.5G
HSCSD
GPRS
EDGE
1xRTT
3G
Multimedia/IMT-
2000
UMTS
cdma2000
4

5. GPRS Architecture
5
Mobile
Station
(MS)
Base
Transiver
Station
(BTS)

6. Mobile Station (MS)
includes
◦ Mobile Equipment with International Mobile Equipment Identity (IMEI)
Number
◦ Subscriber Identity Module (SIM) card with International Mobile Subscriber
Identity (IMSI) Number
6
Mobile Station (MS)
Mobile Equipment
(ME)
Subscriber Identity Module
(SIM)
IMEI IMSI, MSISDN, …
+

7. SIM card
a small chip provided by the network operator
contains all the important data about the subscriber such as
International mobile subscriber identity (IMSI)
(IMSI) serves as the user identifier
The SIM also has an authentication key which serves as a password for
the subscriber
7

8. MS Modes of operation
An MS can operate in any one of the following three modes of
operation
8
Class-A: The MS supports both GPRS and GSM services
simultaneously
Class-B: The MS supports both GPRS and GSM services,
but it can only operate one of the services at a time
Class-C: The MS only supports GPRS services

9. GPRS Architecture
9
Mobile
Station
(MS)
Base
Transiver
Station
(BTS)

10. Base Transceiver Station (BTS)
A hardware device
Allows an MS to connect over air interface
Is controlled by a BSC
Acts as a connector between the MS and the network
Consists of transceiver (TRX), power amplifier (PA), duplex, antenna,
combiner
Base station subsystem(BSS) includes BTS and BSC
10

11. GPRS Architecture
11
Mobile
Station
(MS)
Base
Transiver
Station
(BTS)

12. Base station controller (BSC)
Mainly deals with the communication with BTS and MSC
A BSC can control several BTS at the same time
BSC is smart module in GSM that handles the handover when the
mobile phone moves from BTS to BTS
It also allocates the radio channels for the MS
12

13. GPRS Architecture
13
Mobile
Station
(MS)
Base
Transiver
Station
(BTS)

14. Mobile Switching Centre (MSC)
Take care of the
◦ SMS
◦ call
Functions like
◦ ensuring the network connections
◦ handling of location related information
◦ maintaining the packet flow
communicates with
◦ VLR
◦ HLR
◦ SMSC
14

15. GPRS Architecture
15
Mobile
Station
(MS)
Base
Transiver
Station
(BTS)

16. Home Location Register (HLR)
A network subscribers database
Contains all the information about the subscribers of the network
16
If the network requires any information about the subscriber it is the
HLRs responsibility to provide the necessary information

17. Short Message Service Centre (SMSC)
stores and forwards SMS messages
If the receiver is offline or unavailable due to any reason, then the SMSC
stores the SMS and forwards the SMS as soon as it gets notified that the
receiver is available again
17

18. GPRS Architecture
18
Mobile
Station
(MS)
Base
Transiver
Station
(BTS)

19. Serving GPRS Support Node (SGSN)
takes care of the delivery of data packets from and to the GPRS mobile
stations that are connected to the network
It is responsible for
◦ routing and packet transfer
◦ mobility management services
◦ session management functions
◦ logical link management
◦ services, authorization
◦ Authentication
◦ charging functions and SMS handling
The SGSN location register (SLR) stores subscriber-related information like
the location information and the user profiles of all GPRS subscribers
registered to the SGSN
19

20. GPRS Architecture
20
Mobile
Station
(MS)
Base
Transiver
Station
(BTS)

21. Gateway GPRS Support Node (GGSN)
Takes Care Of The Interworking between GPRS data network and
external packet data networks
Acts as A gateway for the GPRS network
Hides the network from other external networks
Also enables the mobility of the users across the GPRS networks
21
GGSN communicates to SGSN and when it receives data that is addressed
to a user, it checks if the user is active and then forwards it to the SGSN
that serves the mobile user. Although, if the user is not active, the data will
be discarded by GGSN.

22. References
1. Papanash Om Prakash Muthuswamy, “SGSN integration and
implementation”, UPPSALA University
2. Gunnar Heine, Holger Sagkob, “Gprs: Gateway to Third Generation
Mobile Networks”, Artech House (February 2003)
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