QoS support in mobile ad-hoc networks

We present a framework for providing guaranteed quality of service in ad-hoc networks given reasonable limits on rate of change of topology. This is achieved at the expense of higher network resources than required by the flow specification itself. We quantify these extra resources and suggest changes that need to be incorporated in the buffer requirements and the play out times. Central to providing QoS guarantees is the concept of local route repair and buffer flush. The onus for restoring a failed in-use path is on the upstream node of the failed link. The route restoration time after a failure has important consequences on the performance of the proposed scheme and so we propose to add this functionality to the QoS module in general. We also suggest a protocol to reduce this latency under the assumption of slow rate of change of topology. The analysis can be extended to slightly relaxed assumptions on rate of change of topology. But when the topology changes too fast, it shall not be possible for any protocol with reasonable overhead to provide QoS guarantees.