Multi-channel assignment for heterogeneous wireless mesh networks

Multi-channel assignment schemes have recently been proposed to improve the network throughput of multi-hop wireless mesh networks (WMNs). In these schemes, channel coordination is done either through time synchronization across all the nodes, or through the use of a dedicated channel for the transmission of necessary control messages. Either way, excessive system overhead or waste of bandwidth resource becomes inevitable and undermines the overall network throughput. To resolve these problems, we consider the heterogeneity in large-scale networks and propose a synchronization-free, hybrid temporal-spatial multi-channel assignment scheme. The gateway is allowed to switch its radios to all the available channels sequentially in a round-robin fashion. This temporal channel assignment approach ensures that all the neighboring nodes that communicate with the gateway directly shall have a fair access to the gateway. The channel assignment for the remaining wireless nodes is based on the geographical location and channel/radio availability (a spatial approach) to avoid the interface during the transmission period. Simulation results demonstrate that our proposed scheme can improve the network throughput substantially with the acceptable collision ratio.