HVE-mobicast: a hierarchical-variant-egg-based mobicast routing protocol for wireless sensornets

In this paper, we propose a new mobicast routing protocol, called the HVE-mobicast (hierarchical-variant-egg-based mobicast) routing protocol, in wireless sensor networks (WSNs). Existing protocols for a spatiotemporal variant of the multicast protocol called a "mobicast" were designed to support a forwarding zone that moves at a constant velocity, vrarr, through sensornets. The spatiotemporal characteristic of a mobicast is to forward a mobicast message to all sensor nodes that are present at time t in some geographic zone (called the forwarding zone), Z, where both the location and shape of the forwarding zone are a function of time over some interval (t_start, t_end). Mobicast routing protocols aim to provide reliable and just-in-time message delivery for mobile sink nodes. The new HVE-mobicast routing protocol is a cluster-based VE-mobicast routing protocol. The message delivery of nodes in the forwarding zone of the HVE-mobicast routing protocol is transmitted by two phase: cluster-to-cluster and cluster-to-node phases. In the cluster-to-cluster phase, the cluster-head and relay nodes are distributively notified to wake them up. In the cluster-to-node phase, all member nodes are then notified to wake up by cluster-head nodes according to the estimated arrival time of the delivery zone. The key contribution of the HVE-mobicast routing protocol is that it is more power efficient. This effect is mainly achieved by improving the predicted accuracy, especially by considering different moving speeds and directions. Finally, simulation results illustrate performance enhancements in message overhead, power consumption, and predicted accuracy, compared to existing mobicast routing protocols