Freshness-Aware Sensor Mashups Based on Data Services

Sensor mashups provide end-users with an opportunity to aggregate and manipulate data from multiple diverse sensor data sources. A challenging problem is once the data sources are updated and propagate bottom-up to the top level, how to ensure the freshness of mashups. In this paper, an approach is proposed to build sensor mashups based on data services and to generate the synchronous policy of the mashups with good data freshness quality. The paper firstly analyzes the factors that affect the freshness of mashups, gives the problem definition based on the analysis. Then an algorithm to determine the proper synchronous policy is proposed. This paper also illustrates the proposed approach using a particular scenario.