Differentiation mechanisms over IEEE 802.11 wireless LAN for network-adaptive video transmission

Abstract

In this paper, differentiation mechanisms coordinated from both application and network aspects are adapted to realize a networkadaptive video transmission over the wireless LAN. To support the required QoS differentiation for loss/delay sensitive video streams, a relative priority index (RPI) is assigned to each video packet according to its relative importance. At the MAC layer, a modified version of IEEE 802.11e EDCF (enhanced distributed coordination function) is utilized that can provide differentiated services according to access categories. Moreover, by using multiple RED (random early detection) MAC queues with WTP (waiting time priority) scheduler, loss/delay differentiation can be achieved more efficiently. A NS-2 network simulator is utilized to verify that the proposed differentiation mechanism can assist the end-to-end performance of wireless video transmission over the IEEE 802.11 wireless LAN. © Springer-Verlag Berlin Heidelberg 2004.