Distributed dynamic channel allocation in mobile networks: combining search and update

Distributed dynamic channel allocation techniques are becoming important with the tremendous growth in mobile cellular communication and demand for wireless multimedia applications. These techniques can be categorized as search based or update based. Search based techniques have low messaging complexity and are suited for high system load and low request rates. On the other hand update based schemes have higher messaging complexity but are more suitable for low system load and high request rates. This paper presents a combined scheme, called UpdateSearch, which provides the advantages of both types of schemes. UpdateSearch is parameterized by the number of channel classes k, 1 k n, where n is the total number of channels in the system. The parameter k can be adjusted to control the number of concurrent searches and degree of contention between cells competing for channels in the system. For k = 1 and k = n the scheme respectively behaves as basic search and basic update scheme [1]. A simple analytical model is used to compare the performance of UpdateSearch for various values of k with the basic update and search techniques in terms of channel allocation time and number of simultaneous channel selections allowed in the system under different system loading conditions.