QoS support between ad hoc networks and fixed IP networks

We propose a new protocol, named DS-SWAN (Differentiated Services-Stateless Wireless Ad Hoc Networks), to support end-to-end Quality of Service (QoS) in ad hoc networks connected to a fixed DiffServ domain. When congestion is excessive for the correct functioning of real-time applications, DS-SWAN determines the source of the problem, warns the nodes in the ad hoc network if it is the case and the nodes react by slowing down best-effort traffic. Furthermore, we present an associated routing protocol for the ad hoc network in this context, named SD-AODV (Service Differentiation-Ad Hoc On-Demand Distance Vector), where new route requests are suppressed at certain nodes to maintain the desired QoS requirements for real-time flows. A simulation study is presented for the case when traffic is sent from the ad hoc network towards the fixed network as well as in the opposite direction. The scalability of DS-SWAN with respect to the network size, number of real-time traffic sources, node mobility and best-effort traffic load is analyzed. Simulation results indicate that DS-SWAN and SD-AODV significantly improve end-to-end delays and jitter for real-time flows without starvation of background traffic.