摘要:许多物联网应用根据带有时空关系约束的事件决定其下一步的动作.为了支持物联网应用检测这些时空事件,构建了发布/订阅中间件OPS4ST.OPS4ST允许用户在订阅中表达事件之间的多种时序、空间和逻辑关系；同时实现了时空事件的分布式检测,其能高效地检测到用户在订阅中所关心的时空事件是否发生.通过模拟实验评估了系统的性能和开销,实验结果表明,OPS4ST具有令人满意的性能和可接受的开销.国家自然科学基金(60970027)资助Many applications in the internet of things(IoT) decide their next actions according to the occurrences of events with temporal and spatial constraints.In order to help IoT applications to detect spatio-temporal events,the paper built a Pub/Sub middleware OPS4ST.OPS4ST permits users to express in their subscriptions diverse temporal,spatial and logical relationships of events,implements the detection of spatio-temporal events in a distributed way,and can efficiently detect whether the spatio-temporal events to which the users pay attention in their subscriptions occur.The paper also evaluated OPS4STs matching performance and costs by simulation experiments.The experimental results show that OPS4ST can achieve satisfying performance and acceptable overheads
