A new load balancing strategy in relay enhanced cellular networks with multiple traffic types

Abstract

In relay enhanced cellular networks, many call requests in hot cells are blocked due to unbalanced traffic load, and it may be more serious in the networks with multiple traffic types. Therefore, load balancing is an important problem in relay enhanced cellular networks. In this paper, we consider two types of services, which are real-time (RT) and non-real-time (NRT) services. Firstly, we formulate the load balancing problem as an optimization problem, and then a five-step strategy with low complexity is proposed to solve it. When new calls come, we give the RT service priority and decrease the allocated subchannels of NRT users dynamically to satisfy more users' requests of accessing the network. Furthermore, we utilize cell selection and handover schemes of mobile stations (MSs) and relay stations (RSs) to transfer traffic from hot cells to cooler ones. Simulation results indicate that the proposed strategy can reduce the new call blocking probability significantly, and guarantee the high priority of RT users. © 2012 Springer-Verlag GmbH.