针对普适环境下上下文感知计算需求,引入广义模型化理论,建立了一种面向通用环境资源的上下文信息数据模型;在此基础上,提出了上下文感知中间件体系框架,并详细阐述了其构件化的实施方案。该中间件平台的上下文获取层能够封装各类感知器捕获的资源信息,中间处理层负责信息的管理、推理和聚合,基于门面模式的上下文访问层提供同步和异步相结合的上下文信息统一访问入口。通过实验测试了平台的时间损耗,表明该中间件可提供通用的上下文感知服务且具有较好的系统性能。
According to the requirement of context-aware computing in ubiquitous environments,this paper proposed a context information data model based on generalized modeling theory with an extensible and multi-leveled hierarchical structure.Moreover,this paper established the context-aware middleware based on the data model which contained context acquisition layer,context handler layer and context access layer.Acquisition layer was used for capturing context information;Handler layer was responsible for context fusion;Access layer implemented the convenient context information access mechanism.Finally,experimental results show that the context-aware middleware has better performance on providing context-aware service.