A Dynamic Frequency Assignment Algorithm in Mobile Radio CommunicationSystems

The efficient use of frequency spectrum is one of the most important problems in mobile radio communication systems. In a small zone system (the so-called cellular system), the algorithm used to make the channel assignment for a call has a great effect on system performance (traffic characteristics). This paper presents the relationships between the traffic-carrying capacity and the graph which represents the relation among a zone and its buffer zones in the system. Furthermore, using these relationships, an algorithm for the dynamic frequency (channel) assignment which has all channel available at all base stations is proposed. The performance characteristics of this algorithm obtained from computer simulations are also presented. The computer simulation treats the two examples (systems), one is the system in which the mobile units does not cross a zone boundary during a communication (the zone size is sufficiently large and the probability of the occurrence can be neglected.), the other is the system in which the mobile unit may cross a zone boundary during a communication. The results from these simulations show that the algorithm carries more traffic per channel at a given blocking rate than the RING method