GPRS is a new bearer service for GSM that improves wireless access to packet data networks like the internet. It provides higher speeds, supports new applications, and offers user-friendly billing compared to previous standards. The GPRS architecture includes additional network nodes like SGSN and GGSN to interface with packet data networks. It uses tunnels and protocols like GTP for transmission and control of user data and signaling. Multislot operation allows a mobile to transmit over multiple slots for higher throughput.

1. BABA GHULAM SHAH BADSHAH
UNIVERSITY
Department of computer sciences
Presentation topic:- GPRS
Presented to:- Dr. Qamar Rayess Khan
Presented by:- Suhail Ahmad Khanday
Roll no:- 02-MCA-2015
Course MCA
Course Title:- wireless & Mobile Communication

2. What is GPRS?
 A new bearer service for GSM that
greatly improves and simplifies wireless
access to packet data networks,e.g to
the internet.

3. Motivation
 Speed
 Immediacy
 New and better applications
 User friendly billing

4. GPRS Architecture
BTS
BTS
MS
BSC Gb
SGSN
Gf
Gs
Gr
DEIR
MSC/VLR
HLR
Gc
Gn
GGSN
Gi
PDN
Gp GGSN
Other GPRS
PLMN

5. Protocol Architechture
 Transmission Plane
GPRS specifies a tunnel
mechanism to transfer user data packets .
 Signalling Plane
GTP specifies a tunnel control
management protocol.The signalling is
used to create modify and delete tunnels.

6. Registration of a Mobile Node
A mobile station must register itself with
GPRS network.
 GPRS attach
 GPRS detach
GPRS detach can be initiated by the MS
or the network.

7. Session Management
After Successful attach a MS gets one or more
Packet Data Protocol(PDP) address.This
address is unique only for a particular
session.
It consists of,
 PDP type
 PDP address assigned to MS
 Requested QoS
 Address of the corresponding GGSN

8. Session Management(Contd.)
PDP-Address allocation:
 Static:Assigned by network operator of
User’s home PLMN.
 Dynamic:Assigned by Corresponding
GGSN.

9. PDP Context Activation
MS SGSN GGSN
Activate PDP Context Request
Security Functions
Activate PDP Context Accept
Create PDP Context Request
Create PDP Context Response
PDP type,PDP Address
QoS Requested,Access Point,…
PDP type,PDP Address
QoS Negotiated,Access Point,…
PDP type,QoS Negotiated,…
PDP type,PDP Address
QoS Negotiated,…

10. Routing
PLMN1 PLMN2
MS
BTS
BSC
SGSN
Gn
Intra-PLMN
GPRS Backbone
Gn
Gn
SGSN
GGSN
Gi
Packet Data Network(PDN)
Eg.Internet,Intranet
Border
Gateway
Gp
Inter-PLMN
GPRS Backbone
Border Gateway
Intra-PLMN
GPRS Backbone
GGSN
Router
LAN
Host
SGSN
BSC
BTS

11. Location Management
 MS frequently sends location update
messages to inform the SGSN where it
is.
 Determining frequency of update
messages is non-trivial.
 The location update frequency is
dependent on the state of the MS.

12. Location Management(Contd.)
A MS can be in 3 states:
 IDLE
 READY
 STANDBY

13.  Transmission Plane
 The protocols provide
transmission of user data and its
associated signalling
 Signalling Plane
 Comprises protocols for the
control and support of functions
of the transmission plane
Protocol Architechture

14. Transmission Plane
GPRS Backbone:SGSN GGSN
GTP tunnels the user packets and related signalling
information between the GPRS support nodes.
Subnetwork dependent convergence protocol
It is used to transfer packets between SGSN and MS
Data link layer
LLC(MS-SGSN)
 RLC/MAC(MS-BSS)
Physical layer
PLL:channel coding,detection of errors, forward error
correction, interleaving, detection of physical link congestion
RFL:modulation and demodulation

15. PLL
RFL Phy Layer
MAC Network
Service
Relay
RLC BSSP
Phy Layer Phy Layer
Network Data Link
Service Service
BSSGP IP
LLC TCP/UDP
Relay
SNDCP GTP
Phy layer
Data Link
Layer
IP
TCP/UDP
Network Layer
(IP or X.25)
GTP
RLC :Radio link control BSSGP:BSS GPRS Application protocol
PLL :Physical link layer GTP :GPRS tunneling protocol
RFL :Physical RF layer TCP :Transmission control protocol
MAC:Medium access control UDP :user datagram protocol
IP :Internet Protocol
Transmission Plane
BSS SGSN GGSNGm Gb Gi

16. PLL
RFL
RLC
MAC
LLC
SNDCP
Network Layer
Application
PLL
PHY
RFL Layer
MAC Network
Service
Relay
RLC BSSGP
MS
BSS
SNDCP:Subnetwork dependent convergence protocol
LLC :Logical link control
RLC :Radio link control
Um

17. Application
Application
LLC
RLC
MAC
GSM/RF
GMM/SM
GSM RF Physical layer
MAC Network service
Relay
RLC BSSGP
Phy Layer
Network
layer
BSSGP
LLC
GMM/SM
MS BSS
SGSN
GMM/SM:GPRS Mobilty Management and session Management Protocol
GSM/RF:GSM physical layer(radio interface) I.e.PLL and RFL
Signalling Plane:MSSGSN
Um Gb

18. BSSAP
SCCP
MTP3
MTP2
Phy Layer Phy Layer
MTP2
MTP3
SCCP
BSSAP
Signalling Plane SGSN
MSC/VLR
SGSN MSC/VLR
Gs

19. MAP
TCAP
SCCP
MTP3
MTP2
Phy Layer Phy Layer
MTP2
MTP3
SCCP
TCAP
MAP
MAP :Mobile Application Part
TCAP :Transaction capabilities and application part
SCCP :Signalling connection control part
MTP :Message transfer part
SGSN HLR(and EIR)
Signalling Plane SGSNHLR/SGSNEIR
Gr

20. GSM TDMA Frame Slots and
Bursts
1
123
2
1
124
. . .
. . .
935 MHz
935.2 MHz
960 MHz
959.8 MHz
200 KHz
1
123
2
124
. . .
. . .
890 MHz
890.2 MHz
915 MHz
914.8 MHz
200 KHz
1 2 3 4 5 6 7 8
Data Burst = 156.25 bit periods
11 2 3 4 5 6 7 8
TDMA Frame
TDMA Frame
Uplink
Downlink
Time Slot

21. GPRS Air Inteface
0 1 2 43 5 6 7 0 1 2 3 40 1 2 43 5 6 7 0 1 2 3 4
0 1 2 43 5 6 7 0 1 2 3 40 1 2 43 5 6 7 0 1 2 3 4
Uplink
Downlink
Voice User1
Voice User2
GPRS User1
GPRS User2
GPRS User3
F1
F2
F3
F4
F
1
F
2
F
3
F
4
Time Slot Number
Carrier
Frequency

22. GPRS Air Interface
 Master slave concept

One PDCH acts as Master

Master holds all PCCCH channels

The rest of channels act as Slaves
 Capacity on demand

PDCH(s) are increased or decreased
according to demand

Load supervision is done in MAC Layer

23. GPRS Logical Channels
Group Channel Function Direction
Packet data
Traffic channel
PDTCH Data Traffic MS BSS
Packet broadcast
control channel
PBCCH Broadcast Control MS BSS
Packet common
Control Channel
(PCCCH)
PRACH
PAGCH
PPCH
PNCH
Random Access
Access Grant
Paging
Notification
MS BSS
MS BSS
MS BSS
MS BSS
Packet Dedicated
Control Channels
PACCH
PTCCH
Associated Control
Timing Advance Control
MS BSS
MS BSS

24. Uplink Data Transfer
MS BSS
PRACH or RACH
PAGCH or AGCH
Random Access
Transmission
Packet channel Request
PACCH
PACCH
PDTCH
PACCH
PDTCH
PACCH
Packet Immediate assignment
Packet resource Request
Packet resource assignment
Frame Transmission
Negative Acknowledgement
Retransmission of blocks in error
Acknowledgement

25. Downlink Data Transfer
PRACH or RACH
PAGCH or AGCH
Paging
Transmission
Packet channel Request
PACCH
PACCH or PAGCH
PDTCH
PACCH
PDTCH
PACCH
Packet Immediate assignment
Packet paging response
Packet resource assignment
Frame Transmission
Negative Acknowledgement
Retransmission of blocks in error
Acknowledgement
Packet paging request
PPCH or PCH
MS BSS

26. Multi Slot Operation
 GPRS allows a mobile to transmit data in up
to 8 PDCHs (eight-slot operation)
 3-bit USF at beginning of each radio block in
downlink points to next uplink radio block
 Comparison with single-slot GSM

Higher delay at higher load

Low blocking rate

Improved Throughput

27. Conclusion
 GPRS provides efficient access to
Packet Data Networks.
 Multislot operation in GPRS leads to
efficient channel utilization.
 GPRS is more effective for long data
packet transmission than short ones.

28. References
 “General Packet Radio Service in GSM”, Jian Cai
and David J. Goodman, Rutgers University, IEEE
Communications Magazine, Oct 1997
 http://www.comsoc.org/pubs/surveys/3q99issue/betts
tetter.html
 http://www.wsdmag.com/2000/aug2200/38-45.html
 “Wireless Internet Access based on GPRS”, IEEE
Personal Comm. April 2000.