Abstract: A modified binarytree based algorithm with priority scheme was proposed in this paper. The algorithm can guarantee the priority service to access channel in high probability while avoiding congestion. The main factors that affect the grouping measure for priority services and its transmission efficiency were analyzed also in the paper. Computer simulation experiments were carried out under the condition of two priorities, while set different arrival rate, initial access probability, the proportion of high priority service among whole traffic and the retransmission probability, to analyze the delay and throughput of blocked and free access channel. The result indicates that the algorithm is efficent and reliable.

Key words: priority, binary tree algorithm, free access channel, computer simulation, slot

摘要： 提出了一种带优先级的二叉树分裂算法，使得高优先级的分组能以更大的概率接入信道，且不会出现分组的拥塞现象。分析了算法中影响优先级分组划分及传输效率的因素。通过计算机仿真实验，在双优先级条件下，改变到达率、初始接入概率、优先级的比重和重发概率时，对阻塞式接入和自由式接入信道系统的时延和吞吐率进行了分析。结果表明，算法具有较好的有效性和可靠性。

关键词: 优先级, 二叉树分裂算法, 自由接入信道, 计算机仿真, 时隙