The mixer serves the packets according to the state of each queue.And the service rate is exponential.A M/M/1 queueing model with two queues is formed.The state changing figure and Q matrix are given.

• 对混合模块建立了具有两个队列的M/M/1排队模型，给出状态转移图和相应的Q矩阵，并采用矩阵分析的方法对模型求解，得出了两类音频包各自的稳态分布。