Seamless Handoff Between Heterogeneous works.ppt

worksHaipengJinandKameswariChebrolu,UCSDAdityaPandeandXiaohuaChen,StanfordUniversityJavadRazavilar,worksInc.,SanDiegoBaraniSubbiah,3ComCorp.,–,Bluetooth,HomeRF,–GPRS,CDMA2000,,bandwidth,delay,,AnywhereCoverageThreeLayersofCoverage––SatelliteSystemsGlobalCoverageMiddleLayer–worksMetropolitanAreasBottomLayer–-system(Vertical)handoffServicenegotiationacrossdifferentsystemsSeamlessintra-system(Horizontal)handoffOurFocusVerticalHandoffIdentifyissuesrelatedtohandoffbetweenWLANandWWANRequirementsforhandoff:smalldelay,workLayer:MobileIPwithextensionsLinkLayer:HandoffAlgorithmMobileIPIETFstandard,(-ofaddressandregisterswithHomeAgent(HA).-avoidstriangleroutingCHlearnstheMT’scurrentcare-()andWWAN(CDMAPCS).MobileIPbasedExtensionsBeforehandoff,MTnotifiesoldForeignAgent(FA)(CH),Signal-to-NoiseRatio(SNR)ConnectedtoWLAN SNRaboveCThresh,MTstaysconnectedtoWLANSNRfallsbelowCThresh,MTscansforWWANservicesandmakesinitialconnectionsSNRfallsbelowDThresh,MTwillswitchfromWLANtoWWAN