Data collection in wireless sensor networks assisted by mobile collector

The subject of acquiring sensed data with the aid of a mobile collector from a wireless sensor network (WSN) that possesses partitioned/islanded WSNs is investigated. The battery depletion of sensor nodes can lead to partitioned/islanded WSNs; as a result, the base station collects merely somewhat sensed data while data routing difficulty arisen. To ease the effect of partitioned or islanded WSNs, a mobile collector is employed to assist collecting data in partitioned/islanded WSNs and bring those collected data stored locally back to the base station. To carry out this work, two key tasks are of concerns, identifying the locations of partitioned/islanded WSNs and navigating the mobile collector to the desired location. To identify the locations of partitioned/islanded WSNs, two control approaches, global-based approach and local-based approach, are proposed. Accordingly, the navigating strategy of the mobile collector can be scheduled based on the time and location. Three scheduling strategies are introduced, time-based scheduling, location-based scheduling, and dynamic-moving-based scheduling. Upon these strategies, the mobile collector is about to collect the sensed data back from partitioned/islanded WSNs. Therefore, the efficiency of sensed data collected by the base station in partitioned/islanded WSNs is improved. Through simulation under the environment of ns-2 simulator, the results show that the collecting strategies proposed can dramatically improve sensed data collecting performance in partitioned or islanded WSNs.