Channel assignment with transmission power optimization method for high throughput in multi-access point WLAN

The use of multiple channels often increases the capacity of a wireless network, especially, if those channels are orthogonal. However, the challenge lies when we have more nodes than the available orthogonal channels. The 802.11n, 2.4 GHz WLAN has 3 orthogonal channels and 8 partially overlapping channels. These numbers of orthogonal channels put a limitation on the channel usage in a network and thus affect the overall network capacity. To overcome this degradation of network capacity with such limited channel scenario, we must focus on the transmission power of these nodes. In this paper, we describe a smart algorithm with realistic formulation, which divides the complex channel assignment and power optimization problem into two separate solution sets. First solution set solves the channel assignment problem in access points of the 802.11 infrastructure based network utilizing both orthogonal and overlapping channels and the second solution set improves the throughput of the network by optimizing the transmission power of these nodes. We selected optimal channel and transmission power assignment using the algorithm, and then ran simulations on a set of multi-AP WLAN. Experimental results show an improvement of approximately 14% in the throughput of infrastructure based 802.11n WLAN compared to previous work.