Distributed Radio Coverage Optimization in Enterprise Femtocell Networks

Radio coverage optimization is a key element in improving the overall performance of femtocell cellular networks. Owing to the increased size and complexity of femtocell networks, there is an imperative need to develop decentralized coverage optimization algorithms, which is a highly challenging task as these algorithms have to work without global information and coordinated central control of network nodes. In this paper, we consider a deployment scenario of a group of $N$ femtocells in an enterprise environment and propose a decentralized algorithm for joint femtocell coverage area optimization. The algorithm updates the femtocell's pilot Tx power only and serves to balance the user load amongst the collocated femtocells as well as minimizing the coverage holes and pilot Tx power. Compared to the fixed pilot Tx power allocation, the algorithm introduces an improvement of approximately 18% in terms of supported user traffic, in addition to a significant reduction of pilot leakage to neighboring cells.