The concept of "cellular network" has great significance in the development of wireless mobile communication. By dividing wireless communication system into independent cells, the cells beyond reuse distance can use the same frequency without interference. Thus the total capacity of wireless communication system is improved greatly. With the rapid increase of cellular mobile communication systems, more people hope to be supported by mobile communication services which lead the limited frequency resource become more stringent. To cope with this problem, many technologies have been developed, among which a valid method to alleviate frequency congestion is efficient channel assignment. The channel assignment problem and optimal algorithm for solving it are introduced in this thesis.
