Blocking and handoff performance analysis of directed retry in cellular mobile systems under discrete time mobility

Abstract

It is of great importance to analyze the performance measures of a given channel allocation (CA) scheme in cellular mobile communication systems as much as to develop a good channel allocation algorithm. However, recent researches on the issue are established under the assumption of a straight line movement of a subscribing mobile. There has been no performance analysis for a given CA scheme with call mobility, where both speed and direction are changeable, in cellular mobile communication systems. A model with call mobility may give a new information about what extend call mobility affects the blocking probability and the handoff performance and this helps us to analyze the given CA scheme more properly. As far as a calling mobile has mobility and encounters various traffic conditions and layout of roads, the performance analysis with call mobility is not only worth researching but also what is interested in. We used discrete time queueing system (DTQS) approach to analyze the performance measures with call mobility. Call duration is distributed in geometric distribution and path length is in Kidian distribution which is a new probability distribution function developed in this thesis. There are r speed states and 6 direction states and we develop their corresponding state transition matrices. Some properties of state transition matrices may affect the performance measures. As a new measure of mobility we introduce the concept inertia ratio(IR). This provides additional information for the handoff analysis of a given CA scheme. Through our model, we can figure out which traffic situation and road layout are appropriate for the CA scheme. We apply our model to directed retry. We obtained the blocking probability through this model which is in good agreement with that in the continuous time queueing model. In a special case where there are no direction changes, our model also shows a good agreement with the reported result in additional handoff probability (AH...