On the use of out-of-band signaling in ad hoc wireless networks

Abstract

Ad hoc networks consist of a set of uncoordinated nodes which communicate over wireless links. Many of the existing routing protocols proposed for ad hoc networks have significant routing overhead, which includes periodic beacons, flooded RouteRequests, and other path reconfiguration packets. The overhead depends on the routing protocol, frequency of link breaks, the number of nodes in the network, and coverage area of the network. In general, any stability based routing protocol or QoS enhanced routing protocol needs periodic beacons in order to update stability or QoS information. The high routing overhead normally consumes a significant part of total bandwidth available for communication, causing a decrease in the packet delivery ratio and throughput. In this work, we use out-of-band signaling in which the bandwidth is partitioned into dedicated data and control channels and the control channel is used for control traffic (control packets at the network layer). We study the effects of using the out-of-band signaling on a simple model routing protocol. We also develop an analytical model for evaluating the control overhead generated by this routing protocol. We use out-of-band signaling for a protocol similar to the model routing protocol and study its impact. The results show that even though at light load in-band signaling is better than out-of-band signaling, at high network load out-of-band signaling outperforms in-band signaling. Packet delivery ratio is improved with out-of-band signaling at high mobility and high network load.