A Mobile Sink-initiated Proactive Routing Protocol for Deadline-Aware Data Aggregation Method in Energy-Efficient Wireless Sensor Networks

In this paper, we focus on monitoring environments with wireless sensor networks in which mobile sink nodes traverse sensing fields in a specific spatialtemporal manner and aggregate various types of environmental data with different deadline constraints distributed over sensor nodes. For such environments, we propose an energy-efficient data aggregation method that reduces intermediate transmission in multi-hop communication while guaranteeing predetermined deadlines. The basic approach of the proposed method is to temporarily gather (or buffer) the observed data into several sensor nodes around the moving path of the mobile sink that would meet their deadlines at the next visit. Then, the buffered data is transferred to the mobile sink node when it visits the buffering nodes. We also propose a mobile sink-initiated proactive routing protocol with low cost (MIPR-LC) that efficiently constructs routes to the buffering nodes on each sensor node. Moreover, we simulate the proposed aggregation method and routing protocol to show their effectiveness. Our results confirm that the MIPR-LC method can reduce energy consumption by up to 23% when compared with a simple routing protocol. In addition, the mobile sink nodes can gather almost all of the observed data within the deadline.