Integrated cross layer QoS supporting in ad hoc networks

QoS supporting in ad hoc networks is a complicated and systematic task. It is hard to be obtained by only one or two layers´ effort. Our research target is SWAN (stateless wireless ad hoc network), which is a prospective ad hoc network model with QoS supporting functions. Two kinds of novel mechanisms and algorithms are proposed to improve system QoS features in this paper. Cross layer cooperation mechanism is developed to protect degraded real-time services. SWAN QoS layer makes fine services differentiating, MAC layer adopts new backoff algorithm, and they cooperate to ensure degraded real-time services have stronger channel competence than best-effort services. Aiming at deleting redundancy functions in SWAN framework, functions of bandwidth probing and routing are integrated in one process. Format of routing request packet is optimized. Simulations based on OPNET show that our optimizing schemes bring better end to end delay features to ad hoc networks. Specially, features of jitter of delay are improved greatly, which are important for audio and video services.