OR-Play: An Optimal Relay Placement Scheme for High-Quality Wireless Network Services

With the development of wireless communication and social network, wireless network service demands have increased rapidly in recent years. To amplify the wireless signals and expand the coverage of wireless networks, wireless relay nodes are introduced. This paper addresses the problem of finding an optimal deployment of access points and wireless relay nodes in an arbitrary environment to provide all the potential users with higher quality wireless network services. Our ambition is to maximize the coverage rate and to minimize the energy consumption of the relay nodes. Correspondingly, we design a scheme named OR-Play: an optimal relay placement scheme to provide high-quality wireless services, which consists of three phases. First, OR-Play provides an area coverage for an arbitrary area. We use the virtual force model to determine the positions of wireless devices, including access points and relay nodes, and thus extend the network lifetime. In the second phase, OR-Play selects access points by a 2-approximation algorithm for the metric k-center problem. In the third phase, we define a new problem: k-minimum energy broadcasting trees. We design a distributed greedy strategy to determine the broadcasting trees, based on which the power of relay nodes are precisely assigned. Finally, the simulation results validate the effectiveness and efficiency of OR-Play.