Rate-adaptive admission control for bandwidth assurance in multirate wireless mesh networks

Admission control (AC) is an effective mechanism for providing bandwidth assurance in wireless mesh networks. Early AC schemes over multirate WMNs typically use a pre-chosen rate or a MAC-layer adapted rate for each link, denying data sessions that could have been admitted should a better multirate AC be available. Taking full advantage of multirate WMNs, we present a rate-adaptive admission control protocol (RaAC) for IEEE 802.11-based WMNs. RaAC consists of three major components: (1) a rate adaption algorithm to meet the bandwidth requirement of the data session and satisfy the channel condition of the PHY layer; (2) a new path-selection metric to balance between hop counts, bandwidth, rates, and other network parameters; and (3) a routing-coupled, distributed, rate-adaptive admission control algorithm to admit data sessions with bandwidth assurance. Through simulations, we show that RaAC is efficient and effective in meeting bandwidth requirements.