The utility of hello messages for determining link connectivity

Future wireless applications will take advantage of rapidly deployable, self-configuring multihop ad hoc networks. Because of the difficulty of obtaining IEEE 802.11 feedback about link connectivity in real networks, many multihop ad hoc networks utilize hello messages to determine local connectivity. The paper uses an implementation of the ad hoc on-demand distance vector (AODV) routing protocol to examine the effectiveness of hello messages for monitoring link status. Our study determines that many factors influence the utility of hello messages, including allowed hello message loss settings, discrepancy between data and hello message size and 802.11b packet handling. The paper examines these factors and experimentally evaluates a variety of approaches for improving the accuracy of hello messages as an indicator of local connectivity.