IEEE802.5协议是著名的令牌环协议,现已成为国际标准。该协议使用优先级控制机制,使优先级较高的数据可以较早地发送出去,从而能满足各种业务不同的实时性要求。在该协议的实现中会出现多站嵌套和多重嵌套的现象,比较复杂,而且使低优先级数据等待时间过长。该文提出了一种简化的优先级控制方法,该方法在控制机制上比IEEE802.5大大简化,而实际发送数据的过程又在很大程度上与IEEE802.5完全相同。模拟实验表明,简化后的协议能够使低优先级的数据等待时间明显减小。 The IEEE 802.5 protocol is a well-known Token Ring protocol that has now become an international standard. The protocol uses a priority control mechanism, so that higher priority data can be sent out earlier, which can meet a variety of different business real-time requirements. In the realization of the agreement there will be multi-station nesting and multiple nesting phenomenon, more complex, but also to lower priority data waiting time is too long. This paper presents a simplified priority control method that is greatly simplified in control mechanism over IEEE802.5, and the actual process of sending data is again very much the same as IEEE802.5. Simulation experiments show that the simplified protocol can significantly reduce the waiting time of low-priority data.