QWRP: Query-driven virtual wheel based routing protocol for wireless sensor networks with mobile sink

Query-driven routing protocols are broadly used in wireless sensor networks (WSNs) wherein the sink injects queries into the sensor network concerning a Region-of-Interest (RoI). In response to the query, sensor nodes belonging to the RoIs transmit their data towards the sink. Routing of the data is a challenging task when sink is mobile. Due to sink's mobility, the query injection location, and data collection location can change over time and this could deteriorate the overall performance. The most common mechanism of providing mobile sink's location to the sensor nodes is broadcasting, but it puts an overhead on the resource-constrained sensor nodes. This paper takes up the issues and proposes wheel, a virtual infrastructure with the aim of confining the network-wide broadcasting of sink's location, and Query-driven virtual Wheel based Routing Protocol (QWRP), a routing protocol developed over the virtual wheel for query-driven scenarios. Furthermore, an angle based forwarding algorithm, a novel packet forwarding mechanism is developed under QWRP that aims to improve the data delivery performance. It is a common scheme used by wheel nodes to route the query and data packets efficiently to RoIs and sink respectively. Performance evaluation of QWRP shows significant reduction in overall energy consumption while maintaining the high data delivery ratio and low delay.