【摘要】 <正> 1.背景随着计算技术和通信技术的发展,不仅桌式计算机变得非常普遍,非PC设备正以惊人的速度成为市场的主流,如:机顶盒、移动电话、PDA、家用电器、汽车电子、游戏机等等。特别是随着家庭网络和无线网络的发展,网络变得更加的普遍。计算已经不只限于桌面,它渗透到人们生活和工作的各个环节,这就是所谓的无处不在的计算环境(pervasive computing,简称遍在计算环境)。在这样的环境中,人们希望:即使他们在频繁地移动,或者各种资源在动态地加入或离开,他更多还原

【Abstract】 Pervasive computing has many new features , such as: the wideness related area, mobility of tasks and heterogeneity of devices. How to support user’s tasks in the pervasive computing environment is a challenge for engineer-s. The main idea in the article is that using middleware to mask the heterogeneity of devices and support user’s tasks in a uniform platform. The goal of the middleware is to support mobility of task, to make the better use of resources, and to reduce user’s intervene. The detail way is as follow: first, decompose application into several components, then represent user’s tasks into abstract tasks and encapsulate physical service into virtual service; at last, abstract task is completed by cooperation of several virtual services. A virtual service is mapped into different physical service in different environment. In different environment, the same task could be completed by composing different services. Furthermore, the framework of the middleware has some" features, such as: hierarchy of architecture, extensibility of functions.更多还原