Wireless ATM (WATM) has been widely considered as a solution for broadband wireless services. Handover is one of the most important mobility support functions in the WATM network. Many handover solutions have been proposed, analysed, and benchmarked. Simulations have been broadly used to assess these solutions. However, there are many dilemmas in how simulation has been applied as a research methodology: heterogeneous simulation systems used, lack of comparison with other related work, biased conclusions, and unavailability of simulation models and systems to researchers. The WATM research community lacks a standard and commonly acceptable methodology for applying simulation. To address this problem, a framework for using simulation in assessing wireless ATM handover solutions is proposed. The framework is applied and analysed by implementing a handover simulation model with the COMNET IIITM simulation package.