A coordinated multiple channel assignment scheme and AP deployment for channel reuse in metropolitan scale wireless networks

In a wireless network, when a single channel is employed, hidden terminal and radio interference problems may occur. The two problems are the main factors that cause low network throughput. In fact, the hidden node problem results from radio interference. Up to the present, many researchers have used multi-channel schemes to solve the interference problem. However, a multi-channel system causes other problems, e.g., the multi-channel hidden terminal problem, and the channel assignment problem. Actually, a well-defined channel assignment can effectively solve the former problem. Therefore, in this paper, we propose a multi-channel assignment system, called a corona-oriented multi-channel assignment system (COMAS for short), which as a metropolitan scale system coordinates channel usage for wireless networks to mitigate radio interference among APs and nodes so as to improve network throughput and efficiency, particularly when many nodes are connected to APs. In the COMAS, APs are deployed as concentric circles, named coronas, and channels are grouped and then allocated to coronas. We also cluster APs into groups, and schedule available channels to avoid radio interference and multi-channel hidden terminal problems among adjacent AP groups and among APs in a group. Simulation results show that the COMAS can effectively improve wireless-network throughput, drop rate, packet delivery delay and jitter.