Channel assignment of cellular mobile systems with nonuniform cells

The degree of co-channel interference and the required number of channels are used as the difficulty degree in assigning channels in cellular mobile systems with nonuniform cells. To minimise the total number of channels required, a heuristic algorithm is proposed with the requirement-exhaustive strategy and new definitions of assignment difficulty degree. In the experiments, the results obtained with the authors' algorithm are compared with near-optimal assignment results. The performance of the algorithm with various types of difficulty degree under different conditions is investigated. The one which gives the minimum total number of channels required in the channel assignment strategy is used and compared with the lower bound using the seven-cell frequency reuse pattern.