Traffic Simulation and the Location of Mobile Units in Wireless Communication Systems 1 Mauro Nacif Rocha 2 Departamento de Informática Universidade Federal de Viçosa – MG – Brazil e-mail: nacif@dcc.ufmg.br Geraldo Robson Mateus and Soraia Lúcia da Silva Departamento de Ciência da Computação Universidade Federal de Minas Gerais – Brazil e-mail: [mateus,soraia]@dcc.ufmg.br ABSTRACT This paper presents some different aspects and problems related to the process of building a simulator for tracking mobile units in wireless communication systems. The work also considers several approaches related to: city area mod- els, location area planning and the storage of user profiles, which are needed for the simulations. RESUMO Este artigo apresenta alguns aspectos e problemas diferentes relacionados ao processo de implementação de um simulador para rastrear unidades móveis em sistemas de comunicação sem fio. O trabalho também leva em consideração diversas abordagens relacionadas a: modelos de área metropolitana, planeja- mento de áreas de localização e o armazenamento de perfis de usuários, os quais são necessários para as simulações. INTRODUCTION The design of wireless communication systems is usually based on a cellular archi- tecture, which consists on a group of fixed Base Stations (BS) covering the service area and interconnected by a fixed backbone network. The coverage area of each BS is called a cell. In addition to the fixed BS we have a number of Mobile Units (MUs) that can freely roam throughout the entire service area. In such systems, MUs place and receive calls through a wireless medium. Although placing a call may not seem very difficult, receiving calls implies in much more effort for the 1 This work has been supported by CAPES, Telemig and Project SIAM/DCC/UFMG, grant MCT/FINEP/PRONEX number 76.97.1016.00 2 Currently a PH.D. level student at “Universidade Federal de Minas Gerais” – Brazil.