An Efficient and Fair Strategy for Radio Resources Allocation in Multi-radio Wireless Mesh Networks
A Load and Interference aware Resource Allocation strategy (LIRA) is proposed for multi-radio Wireless Mesh Networks (WMNs), combining multiple mechanisms that efficiently optimise radio resources (rate, power and channel) to guarantee maxmin fair capacity to every aggregating Mesh Access Point (MAP). LIRA is composed of a rate adaptation and power control mechanism, sensitive to the fat-tree traffic specificities of WMNs, using the highest bit rates at MAP gateways and using, for the ramified links, the minimum ones that satisfy their capacity needs. This enables to efficiently reduce the transmitted power and interference, advantageous for channel reutilisation. LIRA also integrates a load and interference aware channel assignment mechanism, allowing the simultaneous operation of all links without interference. When this is not achievable, two auxiliary mechanisms of channel sharing and interference-free channel reuse can be sub-sequentially used, reducing the capacity of certain MAPs to guarantee fairness to all nodes. LIRAs gateway flow-control mechanism guarantees that all MAPs respect the allocated capacity, guaranteeing that every MAP is able to operate at its maxmin fair capacity. The performance of LIRA is evaluated through simulation, considering IEEE 802.11a. For a classical hexagonal deployment of 19 MAPs with an Internet gateway, it is shown how with only 5 channels LIRA guarantees to every MAP a maxmin fair capacity of 3.2Mbit/s, without packet loss, and delay below 6ms. It guarantees a maxmin fair throughput to every MAP, having a capacity usage efficiency of 66.7%, an energy efficiency of 26.5Mbit/J and spectrum efficiency of 0.58bit/s/Hz. For a more challenging scenario with 27 MAPs and 4 gateways, it is shown how LIRA uses its mechanisms in heterogeneous conditions to also guarantee maxmin fair throughput to every MAP, between 5 and 11Mbit/s, without packet loss, and a delay below 12ms. Any system improvement will enable to reach higher WMN performance levels using the proposed strategy.
efficiency fairness radio resource allocation wireless mesh networks