A proposal of power saving scheme for wireless access networks with access point sharing

There are wireless access networks where many access points (APs) are placed by each user and shared by many user terminals (UTs). In these networks, the coverages of some APs overlap with each other because users place APs without a plan. In this situation, power consumption of overlapped APs would be wasteful when the total number of active UTs is relatively small such as at midnight. To solve this problem, a power saving scheme was proposed. This scheme defines a group of closely placed APs as a cluster, and turns off all APs except one in the cluster. However, when the density of APs is relatively low, it is difficult to turn off many APs without shrinking coverage. This paper proposes an improved power saving scheme which can turn off more APs than the conventional power saving scheme without shrinking coverage. In addition to APs except one in each cluster, the proposed scheme can turn off all APs in clusters whose coverages are covered by neighbor clusters. This paper also clarifies the superiority of the proposed scheme by computer simulations.