Performnance Analysis ofEDGEafter aBTSFailure

Inordertoaccomplish efficient spectrumcarrying datatraffic. Theyshare GSM infrastructure with utilization fordatatraffic Enhanced DatarateoverGSM somenewmodules likeSGSN andtheGateway GCN Evolution (EDGE)hasbeendeveloped. Ithasbeenwell (GGSN)(2). Theexternal packet data network (e.g. Internet) integrated inGSM networks. Theconcept ofIncremental communicates withSGSNviaGGSN.Logical linklayer Redundancy (IR)isusedinEDGE forARQ (1). Ithas9 (LLC)isimplemented inSGSN,whichreceives thenetwork different dataformats, called Modulation andCoding layer protocol dataunit (N-PDU) fromGGSNfragment itto Schemes (MCS), oneofthemisuseddepending uponIR. formLLCframes whicharepassed toPacket Control Unit Thedatapackets aresentviaBaseTransreceiver Station(PCU)located atBSS.PCUperforms thetasks ofRadiolink (BTS)ona TDMA logical channel, called Packet Data control (RLC)/MediumAccessControl (MAC)layer Channel (PDCH). segments anLLCframeinto RLCblocks. Thearchitecture IfaBTSstops functioning (i.e. fails) thenpacketsandprotocols ofPDU aredifferent forGPRSandEDGE. could notbedelivered tousers ofthis area. Inthis worka Themajordifference liesinairinterface andpacket scheme issuggested toensure someservice totheEDGE handling. Besidestype-IhybridARQ, itsupports users offailure affected area. A modelisdeveloped tostudy Incremental Redundancy (IR), type-II hybrid ARQ and9 theimprovement achieved bytheabovescheme. Efficient different MCS. utilization ofchannels, Cochannel interference, biterror rate Theradio block isbasic unit oftransmission, which (BER), blocking probability, throughput etcarethemain isdivided into four parts andtransmitted infourconsecutive issues addressed forquantifying theimpact ofBTSfailure on slots ofdesignated packet data channel (PDCH)i.e. length of EDGEusers. aframe isequal to4timeslots. Thestructure ofaradio block depends uponMCS selected byLinkAdaptation (LA)