Reliable dual-path geocasting for tactical ad hoc networks

Geocasting is a mechanism to disseminate data messages within a certain geographical region. Since packet forwarding is based on the location information of nodes, it is known to reduce the path maintenance cost significantly. The geocasting can be suitable for several applications in tactical ad hoc networks, such as an event to alarm enemy´s missile attack, guerilla appearance, or local weathercast. However, previous geocast protocols proposed for general ad hoc networks are not satisfactory for the high demands of the reliability in such military applications. In this paper, we propose more reliable geocasting protocol which utilizes dual paths to improve the possibility of the successful message delivery. Moreover the proposed scheme provides two different acknowledge mechanisms, by which a source node can be confirmed of the destined nodes´ message reception. Our simulation study using ns-2 shows that the proposed protocol results in high delivery ratio with reasonable packet overhead and latency.