A new traffic model for mobile wireless networks was given and analysed.In the model, it is considered of traffic characteristic for two special periods of time.A pre-emptive priority scheme combined with channel borrowing strategy according to the speciality was proposed.All the channels can be used by non-real-time services,and real-time services are given higher priority for they are allowed to pre-empt channels used by non-real-time services.Either real-time handoff requests or non-real-time handoff requests can be queued in queues when there is no channel can be used.Some channels are reserved for real-time handoff requests, which can also be used by nonreal-time service when they are idle.Simulation results are also given.It is seen that our scheme performs better than other schemes when the arrival rate of real-time services is much higher than non-real-time services.