讨论了一种基于开放式环境的QoS实现方案,它是在开放系统中资源有限的条件下,为具有QoS需求的应用提供服务。该方案设计了一系列用来描述端到端应用、系统资源特征的抽象结构和QoS的实现算法。其结果解决了开放系统中为支持QoS所引起的诸如系统各层中缺乏QoS的协调表达等一些重要问题。系统还支持QoS动态重协商,能够同时为尽可能多的应用提供服务。 This paper discusses a QoS implementation scheme based on open environment, which provides services for applications with QoS requirements under the condition of limited resources in an open system. The scheme devised a series of algorithms to describe the abstract structure and QoS of end-to-end applications and system resources. As a result, some important issues such as the lack of coordination of QoS in various layers of the system caused by supporting QoS in an open system are solved. The system also supports QoS dynamic renegotiation, which can serve as many applications as possible simultaneously.