General Packet Radio System (GPRS) PRESENTEDKINGSHUK BANERJEE BY-SRIMOYEE MUKHOPADHYAY 1. KINGSHUK BANERJEE (35) 2.SRIMOYEE MUKHOPADHYAY (24) 3. AVISHEK PAL (02) 4.JAYITA MAITI (12)
WHAT IS GPRS?GPRS (General Packet Radio Service) is apacket based communication service formobile devices that allows data to be sent andreceived across a mobile telephone network.
TO USE GPRS USERS SPECIFICALLY NEED:1. Mobile phone or terminal that supports GPRS.2. Subscription to a mobile operator that supports GPRS.3. Use of GPRS must be enabled for that user.4. GPRS is designed to make the internet fully available to the user.5.
PROTOCOLS SUPPORTEDGPRS supports the following protocols:INTERNET PROTOCOL(IP). In practice, built-in mobilebrowsers generally use IPv4.POINT TO POINT PROTOCOL(PPP). In this mode PPPis often not supported by the mobile phoneoperator,but if the mobile is used as a modem to theconnected computer, PPP is used to tunnel IP to thephone.When TCP/IP is used, each phone can have one ormore IP addrsses allocated. GPRS will store andforward the IP packets to the phone.
SPEED OF GPRSThe upload and download speeds that can be achieved inGPRS depend on a number of factors such as:The number of TDMA time slots assigned by the operator. The channel encoding used.Using the CS-4 it is possible to achieve a user speed of20.0 kbit/s per time slot.CS-1 can achieve a user speed of only 8.0 kbit/s per timeslot.
KEY FEATURES OF GPRSSpeed:-GPRS is packet switched. Higher connection speeds areattainable at around 56–118 kbps, a vast improvementon circuit switched networks of 9.6 kbps .Always on connectivity:-GPRS is an always-on service.Spectrum Efficiency:-Large number of GPRS users can share the samebandwidth and be served from a single cell.
KEY FEATURES OF GPRS New and Better applications:- Users are able to explore the Internet or their own corporate networks more efficiently than they could when using GSM.GSM operator Costs:- GPRS allows GSM providers to add value totheir business at relatively small costs.
HARDWAREDevices supporting GPRS are divided into three classesClass A Can be connected to GPRS service and GSM service (voice, SMS), using both at the same time. Such devices are known to be available today.Class B Can be connected to GPRS service and GSM service (voice, SMS), but using only one or the other at a given time. During GSM service (voice call or SMS), GPRS service is suspended, and then resumed automatically after the GSM service (voice call or SMS) has concluded. Most GPRS mobile devices are Class B.Class C Are connected to either GPRS service or GSM service (voice, SMS). Must be switched manually between one or the other service.
Difference Between GSM And GPRSGSM GPRSCircuit Switched Architecture Packet Switched ArchitecturePoint to point service Multipoint serviceInefficient use of resources Efficient use of resourcesLower bit rate(14.4KB/S) Higher bit rate(170KB/S)Reserved bandwidth Shared bandwidthFixed access time Variable access timeTime based billing Traffic based billing
HOW GPRS WORK? When a user turns on a GPRS device, typically it will automatically scan for a local GPRS channel. If an appropriate channel is detected, the device will attempt to attach to the network. The SGSN receives the attach request, fetches subscriber profile information from the subscriber’s HLR node, and authenticates the user. Ciphering may be established at this point.
Sending and Receiving Packets When the mobile user sends data, the SGSN routes the packets to the appropriate GGSN. The GGSN then routes the data according to the current "context" established for the session. Conversely, packets destined for the user are routed to the GGSN associated with the users IP address. The GGSN checks the received packets against the current context, identifies the SGSN that is serving the user, and routes the traffic accordingly. The SGSN then forwards the packets to the BSS where the subscriber is located.
MSC(MOBILE SWITCHING CENTRE)-SWITCHING CENTRE WHICH COORDINATES THE ROUTING OF CALLS IN A LARGE SERVICE AREA.MSC CONNECTS THE CELLULAR BASE STATIONS AND THE MOBILES TO THE PSTN. BSC(BASE STATION CONTROLLER)-A base station subsystem (BSS) which typically includes one or more base station controllers and a plurality of base stations, provides all of the radio-related functions PSTN(PUBLIC SWITCHED TELEPHONE NETWORK)- IT UTILISES STANDARDS CREATED BY ITU-T. THIS STANDARDS ALLOWS DIFFERENT NETWORK IN DIFFERENT COUNTRIES TO INTERCONNECT SEAMLESSLY.
GGSN(GATE GPRS SUPPORT NODE)- IT IS USEDAS INTERFACES TO EXTERNAL IP NETWORKS SUCH AS PUBLICINTERNET.OTHER FUNCTION INCLUDES SUBSCIBES SCREENING ANDADDRESS MAPPING.IT MAINTAINS ROUTING INFORMATION.CHARGING GATEWAY- MAIN FUNCTION IS COLLECTIONOF GPRS DATA RECORDS FROM GPRS NODES,INTERMEDIATE DATARECORD STORAGE,BUFFERING AND TRANSFER OF DATA RECORDS TOTHE MEDIATION OR BILLING SYSTEM.SGSN(SERVING GPRS SUPPORT NODE)-ITSENDS QUERIES TO HOME LOCATION REGISTER (HLR) TO OBTAINPROFILE DATA OF GPRS SUBSCRIBER.
APPLICATIONSCHATINFORMATION SERVICES AS TEXT OR GRAPHICSSTILL IMAGESMOVING IMAGESWEB BROWSINGAUDIO REPORTSDOCUMENT SHARINGJOB DISPATCHCORPORATE MAILLAN APPLICATIONSVEHICLE POSITIONINGFILE TRANSFER
SECURITY ISSUES IDENTITY CONFIDENTIALITY IDENTITY AUTHENTICITY USER AND SIGNALING DATA CONFIDENTIALITY THE ALGORITHMS
CONCLUSION 1. In theory, GPRS packet-based services cost users less thancircuit-switched services since communication channels are beingused on a shared-use, as-packets-are-needed basis rather thandedicated to only one user at a time. 2. It is also easier to make applications available to mobileusers because the faster data rate means that middlewarecurrently needed to adapt applications to the slower speedof wireless systems are no longer be needed. 3. GPRS also complements Bluetooth, a standard for replacingwired connections between devices with wireless radio connec-tions. In addition to the Internet Protocol (IP), GPRS supports X.25, a packet-based protocol that is used mainly in Europe.