A QoS Scheme forDigital Home Applications inIEEE802.1e WirelessLANs

Sincethelegacy IEEE802.11 standard offers inadequate QoSsupport, IEEE802.1le wasproposed toprovide QoS supportformultimedia applications. However, forthe Enhanced Distributed Channel Access(EDCA)ofIEEE802.1le, whenachannel isoccupied withhigh priority traffic, lowpriority traffic maysuffer starvation duetoits little chance ofcontending forthechannel. Thestarvation oflowpriority traffic mayresult infailure ofthese digital homeapplications, whichisunacceptable. DDRR wasproposed toachieve this goal; however, itcannotbe adapted totraffic condition dynamically. Inthispaper,we proposea QoS scheme,calledStarvation Prevention for Low-Priority Traffic (SPLPT), fordigital homeapplications in IEEE802.1le WLANs.SPLPTprevents starvation oflowpriority traffic byproviding adequate contention-free channel access with itsCompensation Procedure forStarving Traffic (CPST) when starvation isabouttooccur; andithasthesamebehavior as EDCA whentheCPSTisnotactivated. SPLPTintegrates both EDCAandHCCA(HCFControlled Channel Access) oftheIEEE 802.1 letoprovide highthroughput performance aswellas starvation prevention, anditisfully compatible toIEEE802.1le. Simulation results haveshownthatwhentheWLAN isheavily loaded withhighpriority traffic, SPLPTshortens theMAC delay oflowpriority traffic by3.9and5.1times, respectively, compared toEDCAandDDRR.Inaddition, thethroughput oflowpriority traffic israised upfrom0% to5% ofthemaximumthroughput toavoid starvation.