Mobile Data Collector Assignment and Scheduling for Minimizing Data Delay in Partitioned Wireless Sensor Networks

Mobile Data Collectors (MDCs) can be employed to provide intermittent connectivity in partitioned Wireless Sensor Networks (WSNs). Typically, an MDC serves multiple partitions to collect their sensed data and relay it to the sink node if the sink is in one of the served partitions. If not, then the data needs to be passed to another MDC serving the sink partition at a certain rendezvous location. This causes an extra waiting time for the MDCs that reach the meeting points before others. In this paper, we propose a scheduling algorithm to reduce the rendezvous waiting delay based on the tour lengths. To completely eliminate this waiting delay, we also present a solution with multiple sinks. In this approach, the partitions of the WSN are clustered using p-center optimization and Voronoi cells. An MDC is then assigned for touring each cluster’s partitions. In this way, the dependency of MDCs to relay their data to other MDCs is eliminated and the tour lengths of MDCs are balanced which minimizes the end-to-end delay significantly.