An Adaptive Distributed Channel Allocation Strategy for Mobile Cellular Networks

A channel allocation algorithm includes a channel acquisition algorithm and a channel selection algorithm. Most of the previous work concentrates on the channel selection algorithm since early channel allocation algorithms simply use a centralized channel acquisition algorithm, which depends on a mobile switching center (MSC) to accomplish channel acquisition. Recently, distributed channel acquisition algorithms have received considerable attention due to their high reliability and scalability. There are two approaches to designing distributed channel acquisition algorithms: search and update. The update approach has shorter acquisition delay and lower call blocking rate, but higher message complexity. On the other hand, the search approach has lower message complexity, but longer acquisition delay and higher call blocking rate. In this paper, we propose a novel distributed channel acquisition algorithm, which is a significant improvement over both approaches. Also, we identify two guiding principles in designing channel selection algorithms and propose an algorithm which has low call blocking rate and low intrahandoff overhead. By integrating the channel selection algorithm into our channel acquisition algorithm, we get a complete distributed channel allocation algorithm. By keeping the borrowed channels, the channel allocation algorithm makes use of the temporal locality and adapts to the network traffic; i.e., free channels are transferred to hot cells to achieve load balance. Simulation results show that our channel allocation algorithm significantly outperforms the search approach and the update approach in terms of call blocking rate, message complexity, and acquisition delay.