A Hybrid Stateless QoS Approach for Wireless Mobile Ad hoc Networks

The Quality of Service (QoS) support of multimedia services over wireless Mobile Ad hoc Networks (MANETs) is one of the hottest challenges facing todays research community working on this area. Most existing works on QoS in ad hoc networks has been carried out under the assumption that the underlying QoS architecture is reservation based. In such architecture, mobile nodes maintain per-flow state information. This results in a processing and storage overhead on mobile nodes. On the other hand, the stateless approach has the advantage it offers the scalability, since no session state information is maintained at intermediate nodes. In this paper, we present a hybrid QoS stateless model for service differentiation, named HybQoS. HybQoS model makes resource reservation in advance before the flow uses it, unlike other models that make the resource exclusively reserved for the flow and no additional traffic is allowed to use the reserved resource. HybQoS uses minimal information available on the network nodes without relying on complex mechanisms. The use of HybQoS mechanisms proved to be efficient, robust, and scalable. The extensive simulations conducted under ns-2 have shown that real-time traffic experiences low delays under various mobility, traffic, and multihop conditions.