Dynamic bandwidth management for single-hop ad hoc wireless networks

Distributed weighted fair scheduling schemes for QoS support in wireless networks have not yet become standard. In this paper we propose an admission control and dynamic bandwidth management scheme that provides fairness in the absence of distributed link level weighted fair scheduling. In case weighted fair scheduling becomes available, our system assists it by supplying the scheduler with weights and adjusting them dynamically as network and traffic characteristics vary. To obtain these weights, we convert the bandwidth requirement of the application into a channel time requirement. Our bandwidth manager then allots each flow a share of the channel time depending on its requirement relative to the requirements of other flows in the network. It uses a max-min fairness algorithm with minimum guarantees. The flow controls its packet transmission rate so it only occupies the channel for the fraction of time allotted to it by the bandwidth manager. As available bandwidth in the network and the traffic characteristics of various flows change, the channel time proportion allotted also dynamically varies. Our experiments show that, at the cost of a very low overhead, there is a high probability that every flow in the network will receive at least its minimum requested share of the network bandwidth.