Adaptive gateway discovery for mobile ad hoc networks based on the characterisation of the link lifetime

Mobile ad hoc networks (MANETs) connected to the Internet require a gateway to operate. The gateway is responsible for providing the configuration parameters to the nodes by means of message exchanges. These messages are also necessary to create and/or update the route to the gateway in the mobile nodes. As MANET nodes move freely, these messages are generated at the beginning of the connections (to obtain the configuration parameters), when the route to the gateway breaks or when the gateway proactively sends them. This message exchange, also known as the gateway discovery procedure, has to be optimised in order to release wireless resources for the data transmissions. In this sense, this study proposes a novel technique by which the messages that the gateway periodically generates are exclusively forwarded in the areas where the links are expected to remain stable. By this, nodes are able to learn stable routes and, in turn, the messages generated because of the breakages of used links are avoided. From this parameter setting, the network performance is improved. The main difficulty of the technique is to determine the paths that are stable. For this purpose, the statistical characterisation of link duration in MANETs is employed in this study. The simulation results show the goodness of applying the proposed technique in terms of packet delivery ratio, protocol overhead and end-to-end delay.