This paper reports the modeling and implementation of a general purpose mobile computing environment. The design is modular and it incorporates all intrinsic operations of mobile computing, using the working of a mobile telephony system as a basis. The SES/Workbench has been used as the primary tool for implementation; oneof the purposes was to investigate the usefulness of the tool to simulate a scalable and flexible mobile computing testbed. Models and submodels have been described and the correctness and the scalability of the design have been demonstrated by presenting experimental results of simulating a fixed channel assignment scheme. computing environment. The simulation has been designed in a modular fashion incorporating all the intrinsic operations of mobile computing, taking the working of a mobile telephony system as a basis. To demonstrate the correctness, scalability and flexibility of our simulation model we present results for a fixed channel assignment scheme.