In this paper, we present a "spatiotemporal multicast", called a "mobicast", protocol for supporting applications which require spatiotemporal coordination in vehicular ad hoc networks (VANETs). The spatiotemporal character of a mobicast is to forward a mobicast message to vehicles located in some geographic zone at time t, where the geographic zone is denoted as zone of relevance (ZOR). Vehicles located in ZOR at the time t must keep the connectivity to maintain the real-time data communication between all vehicles in ZOR. The connectivity is kept of all vehicles in ZOR through the vehicular ad hoc networks (VANETs). The connectivity of ZOR is lost if any vehicle in ZOR suddenly accelerates or decelerates its velocity. The temporal network fragmentation problem is occurred such that vehicle in ZOR cannot successfully receive the mobicast messages. To solve the problem, a new mobicast protocol is presented in this work to successfully disseminate mobicast messages to all vehicles in ZOR via a special geographic zone, called as zone of forwarding (ZOF). The main contribution of this work is to develop a new mobicast routing protocol to dynamically estimate the accurate ZOF to successfully disseminate mobicast messages to all vehicles in ZOR. To illustrate the performance achievement, simulation results are examined in terms of dissemination successful rate, packet overhead multiplication, packet delivery delay, and throughput.
- Spatiotemporal multicast
- Vehicular ad hoc network