Implicit Location Update Enhanced Reliability for Mobile Sinks in WSNs

In order to disseminate data to a mobile sink by location-based routing, it is important to provide location information of the sink altering continuously with a source in wireless sensor networks. Fundamentally, it could send directly location information message to a source whenever the sink moves. On the other hand, some schemes without additional cost for location update are proposed recently. The schemes could learn location information by utilizing overhearing of broadcasting nature in wireless transmission environments. Transmission path is turned steadily to the new location at an intermediate node hop by hop per packet along the reverse path. However, if the sink moves frequently while the path is being changed, new location information of the sink exists on the other previous paths rather than on the current path. Therefore, the information might not be propagated to a source securely. Namely, it could not guarantee reachability. In this paper, we propose a novel implicit location service scheme, which guarantees the reachability. With this scheme, we exploit location information of static sensor node as destination information instead of actual location of the dynamic sink. Then, packets are delivered toward one sensor node so the packets could be delivered to the destination. We provide the proof of its reachability and simulation result shows that the proposed scheme has improved than previous works in terms of reliability.