QoS routing in multi-channel multihop wireless networks with infrastructure support

In this paper, a QoS routing protocol is proposed for a multihop wireless network with infrastructure support. Such networks will benefit existing applications in WLAN as the network coverage is greatly extended without incurring additional cost. The network resources can also be more efficiently utilized as load-balance can be achieved among neighboring access points (APs) through multihop connections. Neighboring APs usually operate at orthogonal channels to reduce interference and improve channel utilization. The channel diversity will impact the route choosing. In this paper, a load estimation metric is proposed to effectively estimate the load at AP. Unlike previous load-balance algorithms, mobile host (MH) will connect to AP with more residual bandwidth. MHs will also monitor the QoS to react quickly to the dynamics of the wireless networks. Upon detected QoS violation at the MH or AP, the MHs will perform channel switching and connect to other APs so that congestion is alleviated. Through simulation study, our proposal is proven to be able to efficiently utilize the network resources even when the network traffic changes very fast.