Improving Data Transmission with Helping Nodes for Geographical Ad Hoc Routing

Ad hoc networks have been extensively deployed in recent years. In such networks, obtaining a high efficiency is difficult to achieve due to mobility. Many routing approaches have been proposed to improve the performance of ad hoc networks, including table-driven and demand-driven routing protocols. Geographic routing provides a suitable solution for large-scale and dynamic networks, and reduces link failure problems during packet routing. In wireless networks, nodes movement may cause a network partition, which hinders both data transmission and information availability within the network. Several schemes have been proposed for resolving the partition problem in wireless ad hoc networks. In general, the previous solutions either relied on the use of mobile devices with known trajectories or introduced additional specific mobile nodes. By contrast, this paper proposes a scheme for overcoming the problem of network partitions using only the available devices in the environment. With the scheme, the source node searches for another mobile node, designated as the helping node, which is able to meet the destination. The selected mobile node then carries the packet toward the destination. If the helping node changes its trajectory before it forwards the packet to the destination node, a hand-off scheme is activated and the data packet is transferred to another mobile node for onward transmission