Ad-hoc networks and layer 2 tunnels

The reach of an ad hoc network is very limited and researchers have studied this issue with great interest. A node that wants to send data to a remote node that is outside its transmission range depends on the intermediate nodes to relay the packets towards the destination. This leads to poor scalability in ad hoc networks. As the number of nodes increase, the effective throughput per node decreases. Furthermore, the increasing number of intermediate wireless nodes (hops) causes unacceptable delays in the network. In this paper the authors propose two possible solutions to connect remote ad hoc nodes via an infrastructured network. The ad hoc nodes can communicate over the long distances by utilizing the border gateways between ad hoc domain and infrastructured network. The two possible solutions are redistribution of the routes between the wired and wireless domains, and layer 2 tunnels between the gateways. It is shown that the first method does not provide full connectivity when using an on demand routing protocol in the ad hoc domain. The second approach, however, is shown to provide full connectivity between the ad hoc domains.