In order to mitigate the congestion of Ad Hoc network

a novel active queue management method is proposed.In this method

transition probability matrix is presented base on discrete time Erlang loss system at first

and the mathematic formula of average queue length is derived.Then

the drop strategy is designed with node service rate and traffic arrive rate

and a simulation was conducted to research on the relationships between drop rate and utilization rate.The result shows that drop rate is positive correlation with utilization rate.