A credit-based distributed protocol for long-term fairness in IEEE 802.11 single-hop networks

Fair bandwidth allocation is critical in wireless communication networks, since the wireless channel is often shared by a number of stations in the same neighborhood. With fair scheduling, bandwidth can be shared by competing flows in proportion to their assigned weights. In this paper, we propose a credit-based distributed protocol for fair allocation of bandwidth in IEEE 802.11 wireless LANs. Our protocol is derived from the distributed coordination function in the IEEE 802.11 medium access control (MAC) protocol. Analytical and simulation results demonstrate that the protocol achieves the desired bandwidth allocations. An important feature of our protocol is its backward compatibility, which allows legacy IEEE 802.11 stations to coexist with stations adopting the new MAC protocol.