International Journal of Engineering and Mathematical Intelligence, Vol. 1 Nos. 1 - 3, 2010 75 MINIMIZATION OF MOBILE-NETWORK CHANNEL INTERFERENCE USING PARTICLE SWARM OPTIMIZATION *Jibrin M. Sadiq **Elijah E. Omizegba Electrical and Electronics Engineering Programme Abubakar Tafawa Balewa University, Bauchi, Bauchi State, Nigeria *E-mail: jibrinsadiq@yahoo.com **omizegbaee@yahoo.co.uk ABSTRACT The global increase in the demand for mobile communication services has raised the need for efficient channel assignment within the limited available bandwidth available to wireless network operators hence one of the most important challenges faced by these operator is that of efficiently assigning available channels such that the utilization of available bandwidth is maximized while minimizing interference from neighborhood channels, and at the same time satisfying as many call demands as possible. This problem is known to belong to a class of very difficult combinatorial optimization problems such that the difficulty of finding a good solution increases exponentially with an increase in the number of cell to be assigned. In this paper, the particle swarm optimization algorithm is used to solve the stated channel assignment problem, using the Philadelphia Benchmark Network as a test case. The results presented in this paper show that channel utilization can be significantly improved with lower channel interference, when compared to comparative solutions reported in literature, and should result into significant gains for network operators. Keywords: PSO, Channel Assignment, Network Optimization, Mobile Communications INTRODUCTION As the demand for and the number of services offered by cellular networks increase, efficient allocation of the limited frequency bandwidth, for the purpose of increasing channel utilization, is a challenge in any cellular communication platform. Channel utilization is improved by the method of frequency re-use, which involves the use of the same frequency or channels simultaneously in separate cells subject to the base transceiver station (BTS) distance also called the re-use distance (Kendal and Mohammed, 2004b). Optimal channel assignment requires an adherence to a specified reuse distance so as to minimize electromagnetic interference among communicating channels, and at the same time servicing as many calls as possible; the foregoing is known as the Channel Assignment Problem (CAP) (Kendal and Mohammed, 2004a). The channel assignment problem can be categorized into three, namely; the Fixed Channel Assignment, Dynamic Channel Assignment and Hybrid Channel Assignment (which is a combination of fixed and dynamic channel assignment) (Katzela and Naghshineh, 1996). In fixed channel assignment, the channels are permanently assigned to base stations based on predetermined traffic demand and interference constraints, therefore it does not adapt to changes in demand or