Spectrum sharing is a crucial issue to the overall throughput performance of multi-hop wireless networks. Traditional distributed random medium access control (MAC), such as IEEE 802.11, lacks of efficiency of spectrum usage, while centralized scheduling is not practical for large scale ad hoc networks. It is observed that for multi-hop wireless networks, it is hard to resolve the scheduling conflict, and most distributed algorithms consider the neighbors' traffic independent of each other and ignore the multi-hop nature of flows, leading to the spectrum wastage and inefficiency. By incorporating the multihop nature of flows, we propose a new distributed scheme based on IEEE 802.11 standard, namely "2-hop MAC". Nodes collect traffic dependency information as well as traffic demand information from neighbors and allocate spectrum distributedly with the knowledge of more accurate traffic demand of the nodes in the neighborhood. Moreover, we have also addressed the problem of the asymmetric neighborhood, which was ignored in most previous work. Finally, we introduce a new metric, namely, allocation inefficiency ratio (AIR), to evaluate the performance of distributed algorithms in multi-hop wireless networks. Extensive simulation study shows that our proposed scheme can significantly improve the network performance and spectrum efficiency.
['Rongsheng Huang', 'Yuguang Fang']
Utilizing multi-hop neighbor information in spectrum allocation for wireless networks