Enhancing the performance of multiple IEEE 802.11 network environment by employing a cognitive dynamic fair channel assignment

摘要

Many wireless networks, which are controlled by a fixed spectrum assignment policy, suffer from the irregular utilization of the assigned spectrum. Cognitive Radio (CR) networks are proposed to solve this problem with dynamic spectrum access techniques. CR networks are usually deployed in the IEEE 802.11 based wireless networks, which require an access point (AP) operating on a certain channel. In this paper, we focus on selecting the best transmission channel for multiple IEEE 802.11 networks by using the CR approach. We show that the effect of the interference can be handled by proposing a cognitive dynamic channel assignment technique for a group of IEEE 802.11 networks forming a system. The proposed channel assignment is implemented to select the best available channel not only to improve the performance of a single AP, but also to improve the performance of the neighboring networks taking part of the system. The proposed technique considers the effects caused by the traffic load of the neighboring networks and the interference among them. It is implemented in a test bed environment and the improvement of the whole system performance is shown. The test results also show that the proposed channel assignment scheme provides a fair spectrum sharing among IEEE 802.11 networks.