Efficient eNB deployment strategy for heterogeneous cells in 4G LTE systems

Base station deployment is an important issue in cellular communication systems because it determines the cost to construct and maintain a system and also the service quality to users. Conventional 2G and 3G systems assume that base stations are identical in the sense that they have the similar coverage range. For 4G systems, LTE introduces the concept of heterogeneous base stations (also called eNBs), which supports different sizes of coverage range. Given the user distribution and demands in a service area, the problem of deploying heterogeneous eNBs is NP-hard. Therefore, we propose a four-stage eNB deployment strategy to efficiently solve the problem. Our strategy first employs a geometric approach to provide the basic coverage to the service area. Then, it adaptively adjusts the cell range to satisfy the user demands under the power and bandwidth constraints on each eNB. Simulation results verify that the proposed strategy not only significantly saves the system cost, but also reduces the power consumption while balances the traffic loads of eNBs.