HIGHDEFINITIONVIDEOTRANSMISSIONOVER WLANS WITH TIME-SCALEAND R-D OPTIMIZEDRATEADAPTATION MehmetUmutDemircin
Peter vanBeek · 2006
Inthis paper, wepropose atransrating based video rate adaptation technique forcompressed high-definition videotransmission over wireless local areanetworks. Ourapplication layer technique targets toprevent thequality impairments caused byinconsistent wireless bandwidth. Thetransrater attheserver adjusts thetransmission rateforeachvideoframe, basedonbandwidth measurements, tosustain theplayout buffer fullness. Client periodically sends feedbacks after probing theavailable bandwidth using thevideo packet dispersions. Thesuperiority oftheproposed technique over theexisting onescomesfromitsability toselect various time scales forrateadjustments. Thisfeature avoids unnecessary rate reductions. Furthermore, transrating distortion isminimized by encoding typedependent rateallocation amongtheframes that will betransmitted intheprojected timescale. Experimental results show that theproposed technique significantly reduces video glitches. Up to2.43dBaverage PSNRimprovement isachieved compared toa delay-constraint unaware rate adaptation method, whichalso utilizes bandwidth measurements. IndexTerms-HDTV,Wireless LAN,Multimedia streaming, Videocodecs