An Energy-Efficient Learning Automata Based Coordination Topology Maintenance Algorithm for Prolonging Lifetime of Ad Hoc Wireless Networks

One of the basic restrictions in Ad Hoc Wireless Networks is energy supply and because of that proposing of power saving protocols that do the normal tasks of network without significantly diminishing the quality of services of the network and consequently, prolonging the lifetime of network has high importance. So, in this paper a distributed power saving technique for multi-hop ad hoc wireless networks based on learning automata has been proposed that all nodes in the network that are equipped with learning automata don’t need to be synchronized with each other. Learning automata abilities such as low computational load, usability in distributed environments with ambiguous information, and adaptability to changes via low environmental feedbacks, causes to better fitness with local techniques in ad hoc wireless networks. The proposed protocol, SpanLA, consists of two phases; coordinator announcement and coordinator withdrawal. In SpanLA with a randomized algorithm the option of making local decisions on whether a node going to sleep or to join a forwarding backbone as coordinator is given to learning automata of each node. Unlike the basis protocol of this proposed protocol (span) each node after a random backoff delay uses its own learning automata and if it is needed to be a coordinator according to current conditions, selects the correspondent action and with the help of learning automata, the SpanLA’s made decisions more than span protocol prevents from redundant nodes to be coordinator. Coordinator withdrawal is also runs locally, in a distributed manner and periodically after a node has been a coordinator for some period of time and whenever would be needed. To ensure fairness, SpanLA uses each node’s allocated learning automata which are based on the status of nodes during the activity of the network. So, using learning automata with passing of time causes to decreasing in energy consumption and improving network lifetime in SpanLA protocol with an 802.11 network in power saving mode in comparison to other similar protocols such as Span and without any topology management protocols. Simulation results with a practical energy model also show that above result. KeywordsAdaptive protocol, Learning Automata, Topology maintenance, Ad hoc Wireless Networks, Energy Efficient,