Abstract:

An adaptive hybrid gateway discovery algorithm for connecting mobile ad hoc networks to internet was proposed. This algorithm overcomes the limitation that the internet connectivity performance is greatly degraded due to blindly rebroadcasting gateway discovery message when obvious unidirectional links are ignored. Based on the expansion of the AODV protocol, by rebroadcasting the gateway discovery messages and gateway advertisement messages, both of which are extended with local connectivity information, the unidirectional links are successfully removed from global route computations by the algorithm. Furthermore, an adaptive internet working scheme was adopted to provide the best coverage of gateway advertisement by dynamically adjusting broadcast range and sending interval of gateway advertisement messages according to the network conditions. Simulation results show that the proposed algorithm can effectively avoid unidirectional links with reasonable overhead and provide better connectivity performance than others.

Key words: communication, gateway discovery, adaptive, unidirectional link, Ad hoc on-demand distance vector routing(AODV)