A packet scheduling algorithm for max–min fairness in multihop wireless LANs

In this paper, we propose a probabilistic packet scheduling scheme achieving max–min fairness without changing the existing IEEE 802.11 medium access control (MAC) protocol. In the proposed scheme, packets at each wireless node are managed on a per-flow basis. When a wireless node is ready to send a packet, the packet scheduler of the node is likely to select the queue whose number of packets sent in a certain time is the smallest. If the selected queue has no packet, the node defers the transmission by a fixed duration. In order to verify the improvement in per-flow fairness, we evaluate the performance of the proposed scheme by ns-2. The numerical examples show that our proposed scheme achieves better per-flow fairness than the existing schemes in networks of not only chain topologies but also random topologies.