Distributed Scheduling with End-to-End Compensation in Multihop Ad Hoc Networks

In this paper, we investigate the problem of providing QoS to end-to-end flows in multihop ad hoc networks with channel errors through packet scheduling. Each flow is associated with some QoS requirement, which is requested and granted in the form of a desired service rate. The achieved rate is estimated at the destination and fed back to the source periodically. Both the desired rate and achieved rate of a multihop flow are piggybacked on the packets of the flow and propagated from the source node to all its downstream relaying nodes. With such information, a compensation-capable scheduling algorithm originally designed for infrastructured wireless networks can be adapted to each ad hoc node for compensating a lagging flow, i.e., a flow with the achieved rate smaller than the desired rate. We propose the feedback and propagation mechanism as an end-to-end compensation framework, which is the key contribution of this work. We use BGFS-EBA, a scheduling algorithm for infrastructured wireless networks, as an example to demonstrate how such an algorithm is adapted to ad hoc networks within the proposed framework. Our simulation results show that the proposed mechanism maintains outcome fairness and compensate flows that suffer sporadic bursty channel errors effectively.