1. Gprs Welcome to the world of internet
Unit – 3
Vipul joshi

2. Contents of Presentation
A) GPRS and packet data network, B) GPRS network architecture, C) GPRS network operation, D) Data services in GPRS, E) Applications of GPRS, F) Billing and charging in GPRS

3. “ GPRS “
GPRS- General Packet Radio Service provides a direct link into the Internet from a GSM phone

4. INTRODUCTION TO GPRS
GPRS will undoubtedly speed up a handset's Internet connection - but it remains to be seen exactly how much speed can be achieved out of the system
GPRS works by aggregating a number of separate data channels. This is possible because data is being broken down into small 'packets' which are re-assembled by the receiving handset back into their original format.

5. INTRODUCTION (cont…)
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.
GPRS provides a permanent connection where information can be sent or received immediately as the need arises, subject to radio coverage.

6. Constraints with existing network
Data Rates too slow – about 9.6 kbps
Connection setup time too long
Inefficient resource utilization for bursty traffic
Proves expensive for bursty traffic utilization
No efficient method for packet transfers

7. Comparison of GSM & GPRS
Data Rates
9.6 Kbps
14.4 to Kbps
Modulation Technique
GMSK
Billing
Duration of connection
Amount of data transferred
Type of Connection
Circuit – Switched Technology
Packet - Switched Technology

8. BPL Mobile Bharti Cellular Hutchison Max Hutchison Essar Idea Cellular
GPRS in INDIA
BPL Mobile
Bharti Cellular
Hutchison Max
Hutchison Essar
Idea Cellular

9. a) GPRS and Packet Data N/W
Capacity and other end user aspects : It has ability to offer data speeds of 14.1 Kbps to Kbps, which allow easy Internet access.
QoS (Quality of Service) :
Service precedence : is the priority of a service in relation to another service. High , normal and low
Reliability : loss, duplication and mis- sequencing
Delay : end to end transfer time
Throughput : Maximum bit rate
Integral Part of the future 3G Systems : the use of GPRS in GSM n/w is known as 2.5G with limited Internet accessibility speed.

10. B) GPRS ARCHITECTURE & n/w enhancement
GPRS Subscriber Terminals
GPRS BSS
GPRS Networks Node
GPRS Mobility Management

11. GPRS SYSTEM ARCHITECTURE
Other GPRS
PLMN Gd
SMS-GMSC
SMS-INMSC
SGSN Gp
GGSN Gb Gn
GGSN Gf
BTS
BSC Gr Gs
PDN Gi Gc
BTS
EIR
HLR+GPRS Register MS D
MSC/VLR

12. Interfaces Gb – Connects BSC with SGSN
Gn – SGSN – SGSN/GGSN (in the same network)
Gp – SGSN –GGSN (in different networks)
Gf – For equipment querying at registering time
Gi – Connects PLMN with external Packet Data Networks (PDNs)
Gr – To exchange User profile between HLR & SGSN
Gs – To exchange Database between SGSN & MSC
Gd – Interface between SMS & GPRS

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)

14. 1) Gateway GPRS support node (GGSN):
The Gateway GPRS Support Node acts as an interface and a router to external networks.
The GGSN contains routing information for GPRS mobiles, which is used to tunnel packets through the IP based internal backbone to the correct Serving GPRS Support Node.
The GGSN also collects charging information connected to the use of the external data networks and can act as a packet filter for incoming traffic.

15. 2) Serving GPRS support node (SGSN):
The Serving GPRS Support Node is responsible for authentication of GPRS mobiles, registration of mobiles in the network, mobility management, and collecting information for charging for the use of the air interface.

17. GPRS BSS
Each BSC will require the installation of one or more PCUs 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 may also require a software upgrade, but typically will not require hardware enhancement.

18. Transmission Plane & Protocol Architecture
SNDCP Subnetwork Dependent Convergence Protocol
RFL Physical RF Layer
BSSGP Base Station System GPRS Protocol

19. Protocol Stack Transmission Plane & Protocol Architecture MS BSS (PCU)
MAC
RLC
LLC
IP / X.25
GTP L1 L2
GSM RF
Frame
Relay
BSSGP
L1bis
SNDCP IP MS
BSS (PCU)
SGSN
GGSN Gi
UDP/
TCP
Application
IP / X.25
SNDCP
GSM RF Um Gb Gn

20. Information transfer control procedures (e. g
Information transfer control procedures (e.g., flow control, error detection, error correction and error recovery), see Figure . The needed protocols are
SNDCP Subnetwork Dependent Convergence Protocol
LLC Logical Link Control
RLC Radio Link Control
MAC Medium Access Control
PLL Physical Link Layer
RFL Physical RF Layer
BSSGP Base Station System GPRS Protocol
IP Internet Protocol
TCP Transmission Control Protocol
UDP User Datagram Protocol
GTP GPRS Tunneling Protocol

21. 1) SNDCP - Sub Network Dependent Convergence Protocol
Used to transfer data packets between SGSN and MS
Multiplexing of several connections of network layer onto one logical connection of underlying LLC layer
Compression and decompression of user data and header information

22. 2) BSSGP-(BSS GPRS Application Protocol)
Delivers routing & Quality of Service related information between BSS and SGSN
LLC
N/W Service.

23. LLC layer (between MS-SGSN) RLC/MAC (between MS-BSS)
3) Data Link layer
Divided into two sub layers :
LLC layer (between MS-SGSN)
RLC/MAC (between MS-BSS)

24. LLC-Logical Link Control
Establishes highly reliable logical link between MS & its assigned SGSN
Works either in acknowledged or unacknowledged modes
Data confidentiality is ensured by ciphering functions

25. RLC/MAC Layer Radio Link Control(RLC)
Establish a reliable link between MS & BSS
Segmentation and reassembly of LLC frames into RLC data blocks
Medium Access Control(MAC)
Controls access attempts of an MS on radio channels shared by several MSs
Employs algos. for contention resolution, multiuser multiplexing on PDTCH
Both ack and unack. Modes of operation are supported in RLC/MAC layer

26. 4) Physical Layer Divided into two sub layers :
Physical Link Layer (PLL)
Physical RF Layer (RFL)
PLL – Provides a physical channel between MS and BSS
Channel coding, interleaving, detection of physical link congestion
RFL - Operates below PLL

27. c) GPRS Network Operations
Attachment and De-attachment procedure
APN- Access Point Name
Mobility Management
Routing
Communicating with IP N/W

28. 1.Attachment and De-attachment procedure

29. Attachment & Detachment Procedure
GPRS attach
User is registered in SGSN, after authentication check from HLR
SGSN assigns P-TMSI to MS
GPRS detach
Disconnection of MS from GPRS network is called GPRS detach
It can be initiated by MS or by network(SGSN or HLR)

30. Session Management in Attachment procedure

31. PDP Context Activation

32. 2. Access Point Name
Access Point Name (APN) is a configurable network identifier used by a mobile device when connecting to a GSM carrier.
The carrier will then examine this identifier to determine what type of network connection should be created.
for example: what IP addresses should be assigned to the wireless device, what security methods should be used, and how or if, it should be connected to some private customer network.

33. Structure of APN
Network Identifier: Defines the external network to which the Gateway GPRS Support Node (GGSN) is connected. Optionally, it may also include the service requested by the user. This part of the APN is mandatory
Operator Identifier: Defines the specific operator’s packet domain network in which the GGSN is located. This part of the APN is optional. The MCC is the Mobile Country Code and the MNC is the Mobile Network Code which together uniquely identify a mobile network operator.

34. 3. Mobility Management
GPRS Mobility Management (GMM) is a GPRS signaling protocol that handles mobility issues such as roaming, authentication, and selection of encryption algorithms.
GPRS Mobility Management, together with Session Management (GMM/SM) protocol support the mobility of user terminal so that the SGSN can know the location of a mobile station (MS) at any time and to activate, modify and deactivate the PDP sessions required by the MS for the user data transfer.

35. If the MS moves to a new Location Area, it also moves to a new Routing Area. Each RA is identified by a routing area identifier (RAI). This is made up of a location area identifier (LAI) and a routing area code (RAC).

36. 4.Routing There are three important routing schemes:
Mobile-originated message: This path begins at the GPRS mobile and ends at the host
Network-initiated message when the MS is in its home network: This path begins at the host and ends at the GPRS mobile.
Network-initiated message when the MS roams to another GPRS network: This path begins at the host of visited network and ends at the GPRS mobile

37. D) Data services in gprs
1. Application Mode
Delivers routing & Quality of Service related information between BSS and SGSN

38. 2.GTP – GPRS Tunneling Protocol
GTP tunnels user data packets and related signaling information between GSNs
Signaling is used to create, modify and delete tunnels
Defined both at Gn and Gp interface
Below GTP, TCP or UDP are employed to transport the GTP Packets within backbone network

39. Inter working with IP networks
GPRS n/w can be interconnected with an IP- based packet data network
GPRS supports both IPv4 and IPv6
GPRS n/w looks like IP sub network and GGSN looks like a IP router
DHCP, DNS servers are installed

40. GPRS –Internet Connection

41. WORKING OF GPRS
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.
The GPRS service joins together multiple speech channels to provide higher bandwidth data connections for GPRS data users. The radio bandwidth remains the same, it is just shared between the voice users and the data users.

42. GPRS handsets
The key use for GPRS is to send and receive data to a computer application such as , web browsing or even telemetry.
To use GPRS the service is 'dialed' in a similar manner to a standard data call at which point the user is 'attached' and an IP address is allocated.

43. GPRS MOBILE DEVICES(cont…)
The three standard methods to connect your computer to GPRS mobile phone are:
1… Infrared
2… Data-cable
3… Bluetooth

44. Bearers in gprs GPRS supports following types of data services: SMS
WAP
MMS

45. GPRS Roaming
In the short term don't expect to be able to roam to many countries with GPRS, many networks are still negotiating to set up roaming agreements. Technically there are two type of GPRS Roaming
1… Home Network Roaming
2… Local Network Roaming

46. 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.

47. E) GENERAL APPLICATIONS OF GPRS
Communications— and fax;
Intranet/Internet access
Value-added services (VAS)—Information services; games
E-commerce—Retail; ticket purchasing; banking; financial trading
Location-based applications—Navigation; traffic conditions; airline/rail schedules; location finder
Vertical applications—Freight delivery; fleet management; sales-force automation
Advertising

48. Applications of GPRS Web browsing Corporate & Internet Email
Vehicle Positioning
Remote LAN Access
Home Automation
Document Sharing/Collaborative working
E-Commerce
Banking
Financial Trading
Unified Messaging

49. LIMITATIONS OF GPRS Limited Cell Capacity for All Users
Speeds Much Lower in Reality
Support of GPRS Mobile Terminate by Terminals is Not Ensured
Suboptimal Modulation
Transit Delays
No Store and Forward

50. ADVANTAGES OF GPRS
GPRS will enable a variety of new and unique services to the mobile wireless subscriber. These mobile applications contain several unique characteristics that enhance the value to the customers.
First among them is mobility—the ability to maintain constant voice and data communications while on the move.
Second is immediacy, which allows subscribers to obtain connectivity when needed, regardless of location and without a lengthy login session.
Finally, localization allows subscribers to obtain information relevant to their current location

51. F) Billing and charging in gprs
“Data sells, voice pays”
Saying in the wireless business community.
For voice NW teriffs are based on distance and time.
Billing:
The GPRS specification charging information that must be collected.
Destination and source address.
Usage of radio interface.
Usage of external packet data networks
GPRS resources and mobile location.

52. Billing MSC MSC PSTN SGSN GGSN GPRS Network BSC Charging Gateway
Mediation
Billing

53. Salient Features of GPRS
Important step on the path to 3G
Standardized by ETSI
GPRS is an overlay network over the GSM
Provides Data Packet delivery service
Support for leading internet communication protocols
Billing based on volume of data transferred
Utilizes existing GSM authentication and privacy procedures.

54. Thank You