A new query processing model for maintaining data temporal consistency in Wireless Sensor Networks

Maintaining data temporal consistency in a Wireless Sensor Network (WSN) has attracted the attention of many researchers. Nowadays, there are many applications based on WSN which require consistent and valid measures to reflect the current state of the environment being monitored, or to quickly respond to some critical situations. In this paper, we propose a new query processing mechanism, giving each node the possibility to control the temporal validity of data in order to reduce the amount of invalid data delivered by WSN. We also provide a new query model, by introducing new SQL clauses, that allows the user setting the data validity interval and assigning a deadline to each query. Finally, we discuss the performances of our query processing approach and its capacity to maintain the data temporal consistency through two scenarios. The first scenario consists of injecting a single query in the network, then receiving periodic responses from sensors, during a period set by the user. In the second scenario, the user sends periodic queries to sensors according to an epoch, thereafter, it waits for query responses. We concluded by discussing the ability of network to maintain the data temporal consistency, based on the average of query responses time and the amount of valid data transmitted across the network.