1. General packet radio service (GPRS)

2. INTRODUCTION
GPRS stands for General Packet Radio Service, and is a relatively low cost technology that offers packet-based radio service and allows data or information to be sent and received across mobile telephone networks. Designed to supplement the existing mobile technologies, like GSM, CDMA, TDMA etc.

3. INTRODUCTION(CONT..) It is a packet oriented mobile data service
It is available to all users having 2G communication system, as well as in the 3G systems.
In 2G systems, GPRS provides data rates of  kbit/second.
GPRS data transfer is typically charged per megabyte of traffic transferred.
2G cellular systems combined with GPRS are often described as 2.5G, that is, a technology between the second (2G) and third (3G) generations of mobile telephony

4. INTRODUCTION(CONT…)
GPRS is classified as a 2.5G technology because it builds upon existing network infrastructure whereas with 3G networks it normally requires building an entirely new network.

5. WHAT DOES GPRS DO?
GPRS provides a permanent connection where information can be sent or received immediately as the need arises, subject to radio coverage.
No dial-up modem connection is necessary.
This is why GPRS users are sometimes referred to be as being anytime-anywhere "always connected".
The GPRS traffic structure is based on a fixed cost, dependent on the quantity of data required.

6. Services offered "Always on" internet access
Multimedia messaging service (MMS)
Instant messaging
Internet applications for smart devices through wireless application protocol (WAP)
Point-to-point (P2P) service: inter-networking with the Internet (IP)

7. GPRS TERMINALS
Class A
MS supports simultaneous operation of GPRS and GSM services
Class A terminal can make or receive calls on two services simultaneously
Class B
MS able to register with the n/w for both GPRS & GSM services simultaneously. It can only use one of the two services at a given time.
Users can make or receive calls on either a packet or a switched call type sequentially, but not simultaneously.

8. MS can attach for either GPRS or GSM services
Class C
MS can attach for either GPRS or GSM services
a Class C terminal can make or receive calls from only the manually (or default) selected service

10. GPRS ARCHITECTURE GPRS Subscriber Terminals GPRS BSS
GPRS Networks Node
GPRS Mobility Management

11. GPRS SUBSCIBER TERMINALS
New terminals are required because existing GSM phones do not handle the enhanced air interface, nor do they have the ability to packetize traffic directly.
A variety of terminals will exist, including a high-speed version of current phones to support high-speed data access.

12. GPRS BSS
Each BSC will require the installation of one or more PCUs (packet control unit) and a software upgrade. The PCU provides a physical and logical data interface out of the base station system (BSS) for packet data traffic.
The BTS (base transceiver site) may also require a software upgrade, but typically will not require hardware enhancement.

13. GPRS NETWORKS NODE
In the core network, the existing MSCs are based upon circuit-switched central-office technology, and they cannot handle packet traffic.
Thus two new components, called GPRS Support Nodes, are added:
Serving GPRS Support Node (SGSN)
Gateway GPRS Support Node (GGSN)
BACK

14. SGSN
The SGSN can be viewed as a "packet-switched MSC;" it delivers packets to mobile stations (MSs) within its service area
SGSN performs mobility management functions such as mobile subscriber attach/detach and location management
GGSN
GGSNs are used as interfaces to external IP networks such as the public Internet
GGSNs maintain routing information that is necessary to tunnel the protocol data units (PDUs) to the SGSNs that service particular MSs

15. GPRS MOBILITY MANAGEMENT
Mobility management within GPRS builds on the mechanisms used in GSM networks.
As a MS moves from one area to another, mobility management functions are used to track its location within each mobile network.

16. OTHER ELEMENTS BG (Border Gateway) DNS (Domain Name Server)
(Not defined within GPRS)
Routes packets from SGSN/GGSN of one operator to a SGSN/GGSN of an other operator
Provides protection against intruders from external networks
DNS (Domain Name Server)
Translates addresses from ggsn1.oper1.fi -format to format (i.e. as used in Internet)

17. OTHER ELEMENTS Charging Gateway
Collects charging information from SGSNs and GGSNs
PTM-SC (Point to Multipoint -Service Center)
PTM Multicast (PTM-M): Downlink broadcast; no subscription; no ciphering
PTM Group call (PTM-G): Closed or open groups; Down/up -link; ciphered
Geographical area limitation

18. HOW GPRS WORKS RADIO INTERFACE
GPRS provides packet data services (similar to the Internet) using the GSM digital radio network. Each voice circuit in GSM transmits the speech on a secure 14kbps digital radio link between the mobile phone and a nearby GSM transceiver station.

19. RADIO INTERFACE
Each transceiver uses TDM to deliver eight voice circuits on one radio channel
The GPRS service joins together multiple speech channels to provide higher bandwidth data connections
The radio bandwidth remains the same, it is just shared between the voice users and the data users
higher the data rate, the more power the mobile device will use and the shorter the battery life and the higher the transmitted RF power

20. GPRS ROAMING
Home Network Roaming - Here all data is transmitted from wherever you connect to a GPRS network to your home GPRS network
Local Network Roaming - Data is just transmitted to a local Internet connection point and will be subject to local conditions for security and performance.

21. GPRS MOBILE DEVICES
The key use for GPRS is to send and receive data to a computer application
To use GPRS, the service is 'dialed' at which point the user is 'attached' and an IP address is allocated
The three standard methods to connect your computer to GPRS mobile phone are:
1… Infrared
2… Data-cable
3… Bluetooth

22. GPRS SECURITY
The radio interface is considered to be relatively secure being controlled by the GSM network's security - (SIM card + HLR). Security issues arise when data needs to leave the GPRS network to be delivered to either the Internet or a company LAN.
Internet connectivity is the cheapest and most common - and here you can take charge of security by encrypting sensitive data.

23. NETWORK CONNECTIVITY Three ways to connect to GPRS network Internet
Leased Lines
Frame Relay

24. LEASED LINES
Leased lines provide the most secure method of connecting to GPRS but are traditionally expensive
FRAME RELAY
If a frame relay connection is available with network suppliers then adding an addition PVC (Private Virtual Circuit) to one of the GPRS networks will make a cost effective solution

25. DATA PACKET ROUTING

26. Data Packet Routing GGSN Three different routing schemes are possible:
handles interaction with the external data network.
routes external data packets to the SGSN
Three different routing schemes are possible:
Mobile-originated message.
Network-initiated messages when the MS is in its home network.
Network-initiated messages when the MS has roamed to another GPRS operator’s network.

27. Data Packet Routing
GPRS operators will allow roaming through an inter-operator backbone network
GPRS operators connect to the inter-operator network by a border Gateway (BG)
The main benefits of the architecture are its flexibility, scalablity, interoperability and roaming
The GPRS network encapsulates all data network protocols into its own encapsulation protocol, called the GPRS Tunning Procotocol (GTP).

28. Data Packet Routing
The operation of GPRS is partly independent of the GSM network. However, some procedures share the network elements with current GSM functions.
A mobile station has three states in the GPRS system:
Idle
Standby
Active

29. KEY USER FEATURES OF GPRS
Speed
Theoretical maximum speeds of up to kilobits per second are achievable with GPRS
Immediacy
GPRS facilitates instant connections whereby information can be sent or received immediately as the need arises
New applications, better applications

30. KEY NETWORK FEATURES OF GPRS
Packet Switching
GPRS involves overlaying a packet based air interface on the existing circuit switched GSM network With GPRS, the information is split into separate but related "packets" before being transmitted and reassembled at the receiving end
Spectrum Efficiency
The available radio resource can be concurrently shared between several users. This efficient use of scarce radio resource means that large numbers of GPRS users can potentially share the same bandwidth and be served from a single cell.

31. KEY NETWORK FEATURES OF GPRS
Internet aware
File Transfer Protocol (FTP), web browsing, chat, , telnet- will be as available over the mobile network because of GPRS. Hence, web browsing is a very important application for GPRS.
Supports TDMA and GSM

32. THANK YOU