Throughput capacity of mobility-assisted data collection in Wireless Sensor Networks

Recently, mobility-assisted data collection has been proposed to prolong network lifetime. However, the upper bound of throughput capacity in such mobility-assisted data collection models has not been studied. In this work, we first derive the upper bound of throughput capacity when a mobile sink is available for data collection. Given the traveling speed of the mobile sink and the required delay deadline, we analyze the necessary conditions (e.g., optimal number of clusters, minimum buffer size at each cache, and minimum traveling distance) to achieve the maximum throughput capacity. Our analysis shows that 3W/4n per-node throughput capacity can be achieved at a low traveling speed, which is 3 times of the throughput capacity in a static WSN. We further extend the analysis to the case where multiple mobile devices can assist in data collection. We show that 4 mobile relays are enough to achieve the upper bound of throughput capacity O(W/n). Finally, we derive the throughput capacity under existing mobility-assisted data collection models.