Wireless Personal Communications 4: 185–205, 1997. c 1997 Kluwer Academic Publishers. Printed in the Netherlands. A Novel Modelling Technique for Tracing Mobile Users in a Cellular Mobile Communication System M. M. ZONOOZI and P. DASSANAYAKE Department of Electrical and Electronic Engineering, Victoria University of Technology, P.O. Box 14428, MCMC, Melbourne, VIC 8001, Australia (Tel.: 61396884767; Fax: 61396884908; E-mail: mahmood@cabsav.vut.edu.au) Abstract. Mobility of users in a cellular mobile communication system has been formulated mathematically under generalized conditions. Based on this model a computer simulation has been developed. This mobility model is used to examine cell residence time distribution in cellular environments defined by different cell sizes and mobility parameters. It is shown that cell residence time can be described by the generalized gamma distribution. Key words: cellular, mobile communication, handover, mobility. 1. Introduction Mobility of users is a major difference between fixed and mobile telephony. It is one of the key concerns in the design of cellular mobile networks. A mobility model is of interest for analysing different issues related to teletraffic such as dimensioning of signalling networks, user location updates, registration, paging, etc. Building a teletraffic model, which could realistically evaluate the behaviour of a cellular mobile communication system, requires the incorporation of a suitable mobility model. Depending on whether a call is newly originated in a cell or handed over from a neighbour- ing cell, two different categories of calls can be identified: (a) new call and (b) handover call. New call cell residence time is defined as the length of time a mobile terminal resides in the cell where the call was originated before crossing a cell boundary. Similarly, handover call cell residence time is the time spent by a mobile in a given cell to which the call was handed over from a neighbouring cell before crossing to another cell (Figure 1). New call residence time and the handover call residence time are two random variables whose distributions are to be found. Figure 1. Representation of cell residence time in time and space domains or a mobile moving on a path of (d).