Condition and location-aware channel switching scheme for multi-hop multi-band WLANs

Multi-hop relay networks are deployed to restore communication environment in the catastrophe stricken area. Deployment of these networks are fast and easy but performance remains miserably low, as a result of relay nature of the networks. Given the surge of bandwidth hungry applications, performance such as high data rates, high throughput and low latency is a concern in traditional one-hop wireless LANs as well. Performance of wireless networks is subject to the channel conditions and difference in performance of consecutive links that can result in buffer overflow or channel under-utilization. One way to cope up with deteriorating channel conditions is channel switching. However, given the limited number of orthogonal channels, the performance gain may be insignificant and ephemeral. Motivated by this fact, in this paper, we propose channel switching over multiple bands where the relevant characteristics of the bands and physical conditions are taken into the account. We develop a model that dynamically switches the channel of the link when its throughput begins to decline. The proposed model predicts exactly when will packet fail to reach the destination, hence depending upon the channel conditions and location of the node, the new channel is assigned from the band offering the best performance in terms of throughput and delay. To cope up with difference in performance on consecutive links, we propose a receiver's feedback based bitrate adaptation scheme. Simulations results show significant improvement in the throughput and delay of the network.