Relay-assisted dynamic load balancing scheme in multi-cell cellular networks

In the recent cellular network environment, data traffic has increased rapidly by virtue of the development of a wide variety of wireless technology, such that it is hard for mobile service providers to satisfy the QoS (Quality of Service) requirement. In the real-world, users are not evenly distributed throughout cells; the base stations with multiple users have a great deal of difficulty of limited resources. In order to resolve this load imbalance problem, relay stations which can increase the transmission rates of cell boundary users by service area expansion have been an attractive technique in current networks. In addition, since users at the cell edge suffer from low throughput because of the inter-cell interference (ICI), we adopt additional scheme to mitigate this problem. In this paper, we propose an adaptive relay scheme which can improve the performance of the overall network by utilizing relay stations to distribute heavy traffic to adjacent cells. Each user calculates the network utility function with the neighboring relay stations and base stations, and each relay station also calculates the utility with adjacent cells. The central node controls the associations of users and relay stations through the utility information gathered from base stations. Simulation results show that our proposed algorithm improves the throughput and utility of the lower 5% users without loss of the total network throughput.