Enhanced Link-Status Detection for High Speed Link Aggregation in Cognitive Radio Networks

摘要

The aggregation of Wi-Fi links has been identified as one way of taking advantage of available channels to achieve higher speed data transmission in future cognitive radio networks. However variations in link quality make it difficult to achieve stable performance from aggregated Wi-Fi links. In this paper we present a method for controlling aggregation of Wi-Fi links based on monitoring of link status. We first discuss the requirements for detecting bad-links which degrade the performance of aggregated Wi-Fi links. We then describe the implementation of an enhanced link-status detection algorithm based on monitoring of signal strength and number of retransmissions. In particular, we address the problems of monitoring and recovering links after they have been dropped from use, and adjusting decision thresholds to adapt to changing wireless conditions. Finally, we report the results of tests which demonstrate the effectiveness for attaining efficient aggregation of Wi-Fi links for high throughput under varying wireless conditions.