gprs welcome to the world of internet
DESCRIPTION
Gprs Welcome to the world of internet. Unit – 3 Vipul joshi. 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. “ GPRS “. - PowerPoint PPT PresentationTRANSCRIPT
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GPRS WELCOME TO THE WORLD OF INTERNETUnit – 3
Vipul joshi
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CONTENTS OF PRESENTATIONA) 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
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“ GPRS “
GPRS- General Packet Radio Service provides a direct link into the Internet from a GSM phone
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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.
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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.
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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
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COMPARISON OF GSM & GPRS
GSM GPRSData Rates 9.6 Kbps 14.4 to 115.2
KbpsModulation Technique
GMSK GMSK
Billing Duration of connection
Amount of data
transferred Type of Connection
Circuit – Switched Technology
Packet - Switched
Technology
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GPRS IN INDIABPL MobileBharti CellularHutchison MaxHutchison EssarIdea Cellular
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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 171.2 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.
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B) GPRS ARCHITECTURE & N/W ENHANCEMENT
GPRS Subscriber Terminals GPRS BSS GPRS Networks Node GPRS Mobility Management
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GPRS SYSTEM ARCHITECTURE
BSC
SGSN
MS
BTS
BTS
Other GPRSPLMN
GGSN
PDN
Gb
GdGp
Gn
Gf
Gs
Gc
GGSN
EIR HLR+GPRS Register
MSC/VLR
D
SMS-GMSCSMS-INMSC
Gi
Gr
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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
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GPRS NETWORKS NODEIn 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)
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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.
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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.
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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.
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TRANSMISSION PLANE & PROTOCOL ARCHITECTURE
RFL Physical RF Layer
SNDCP Subnetwork Dependent Convergence Protocol
BSSGP Base Station System GPRS Protocol
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PROTOCOL STACK
GSM RF
SNDCP
IP / X.25
Application
Um GnGb
MACRLC
LLC
IP / X.25
GTP
L1
L2
LLC
GSM RF
FrameRelayMAC
RLC BSSGP
L1bis
BSSGPFrameRelay
LLC
SNDCP GTP
L1bis L1
L2IP
MS BSS (PCU) SGSN GGSN Gi
IP
UDP/TCP
UDP/TCP
TRANSMISSION PLANE & PROTOCOL ARCHITECTURE
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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
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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
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2) BSSGP-(BSS GPRS APPLICATION PROTOCOL) Delivers routing & Quality of Service related
information between BSS and SGSN
LLC
N/W Service.
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3) DATA LINK LAYER Divided into two sub layers :
• LLC layer (between MS-SGSN)
• RLC/MAC (between MS-BSS)
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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
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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
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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
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C) GPRS NETWORK OPERATIONS
Attachment and De-attachment procedure APN- Access Point Name Mobility Management Routing Communicating with IP N/W
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1.ATTACHMENT AND DE-ATTACHMENT PROCEDURE
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ATTACHMENT & DETACHMENT PROCEDUREGPRS 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)
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SESSION MANAGEMENT IN ATTACHMENT PROCEDURE
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PDP CONTEXT ACTIVATION
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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.
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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.
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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.
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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).
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4.ROUTINGThere 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
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D) DATA SERVICES IN GPRS1. Application Mode
Delivers routing & Quality of Service related information between BSS and SGSN
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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
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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
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GPRS –INTERNET CONNECTION
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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.
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GPRS HANDSETS The key use for GPRS is to send and receive
data to a computer application such as Email, 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.
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GPRS MOBILE DEVICES(CONT…) The three standard methods to connect
your computer to GPRS mobile phone are:
1… Infrared 2… Data-cable3… Bluetooth
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BEARERS IN GPRS GPRS supports following types of data
services:1) SMS2) WAP3) MMS
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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
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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.
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E) GENERAL APPLICATIONS OF GPRS Communications—E-mail 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
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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
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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
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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
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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.
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BILLING
GGSN
MSC PSTN
BSC
SGSNGPRS Network
Charging Gateway
Mediation
MSC
Billing
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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.
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THANK YOU