Cooperative Geographic Load Balancing in Hybrid Cellular Networks

Increasing popularity and higher data requirements of new types of service result in higher demand in wireless networks. Hybrid cellular networks have been seen as an effective way to meet the users´ increased bit rate requirements while still retaining the benefits of a cellular structure. The objective of this paper is to propose and illustrate effective and efficient approaches for improving the system capacity and performance of hybrid cellular networks appropriate to the last mile by using flexibility in the antenna system to provide coverage at the right place at the right time. Optimization approaches for cooperatively adjusting the antenna radiation patterns in the context of cellular networks with embedded relay nodes are outlined. Two kinds of simple antenna system are considered, namely omni-directional antennas with variable pilot signal power and sector antennas with simple tilting capability. Experiments show that the proposed approaches have significant improvements. The performance evaluations are based on Mobile WiMAX technology.