QoS Support in MANETs: a Modular Architecture Based on the IEEE 802.11e Technology

Providing quality-of-service (QoS) in wireless ad hoc networks is an intrinsically complex task due to node mobility, distributed channel access, and fading radio signal effects. This goal can be successfully accomplished only through the cooperation of the different protocol layers involved. In this paper we propose a novel QoS architecture that is able to support applications with the bandwidth, delay, and jitter requirements in MANET environments. The proposed architecture is modular, allowing the plugging in of different protocols, which offers great flexibility. Despite its modularity, we propose optimizations based on interactions between the media access control (MAC), routing, and admission control layers which offer important performance improvements. We validate our proposal in scenarios where different network loads, node mobility degrees, and routing algorithms are tested in order to quantify the benefits offered by our QoS proposal. In particular, we have also used real H.264/AVC video traces to simulate video sources in order to measure the quality in terms of peak signal to noise ratio of the received video, so that the benefits of applying our QoS scheme to video sources can be assessed in terms of user satisfaction (from the applications perspective).