In ad hoc networks, the energy consumption can be critical as wireless devices are mainly not connected to some constant source of energy. Algorithms that optimize the energy consumption are mainly based on local decisions, as each node tries to minimize the cost of forwarding packets by using information of his own battery state.In this paper, we try to approach the problem of optimizing energy consumption from another point of view. Considering the ad hoc network as a population of nodes, we try to exploit the idea of changing the behavior of the given node, so that they should not work selfishly but altruistically. As showed in evolution theory or in economics, the altruism can bring benefits to the whole population. As our simulation results show, the altruist behavior of the nodes can help us to decrease the energy consumption of the overall population in georouting based ad hoc networks.Ad hoc networks; altruism ; energy efficiency; georouting

This version includes a concrete analysis and supporting simulation results on multi-homed Wireless mesh networks. This research is supported by the Ministry of MKE, Korea, under the "program for CITG" support program supervised by the NIPA (NIPA-2010-0004) and the KCC (Korea Communications Commission), Korea, under the R&D program supervised by the KCA(Korea Communications Agency) (KCA-2011-08913-05001).

This article describes GIS-based models successfully developed for predicting the coverage of Cityphone cellular network, visualizing the predicted signal strength, and analyzing the field strength coverage. In order to predict the signal coverage strength of communication network more accurately, the spatial and nonspatial databases of a mobile cellular network are combined by GIS and produce the necessary parameters. A GIS model named COST-231-Walfisch-Ikegami model (WIM) is developed for signal coverage prediction in Ho Chi Minh City. Radio-line-of-sight and nonradio-lineof-sight conditions can be determined by this model. In addition, in case of nonradio-line-of-sight conditions, average building height, building separation, building width, incident radio path, and road orientation with respect to the direct radio path were obtained using GIS. Road orientation loss, multiscreen diffraction loss, and shadowing gain were predicted more accurate by this model. The scale of maps in the experiment was 1:2000 and the average of floor height was 3 m because there were no exact building height measurements. Statistical results show that the path loss predicted by the COST 231 WIM overcame the real path loss of each cell station. And this method can be used for signal coverage prediction of mobile cellular network in urban areas. Compared to the current situation with the Ho Chi Minh City Posts and Telecommunications system, this model can be effectively applied to improve the Cityphone mobile network quality as well as capability. Developed GIS models can help designers in predicting cell station coverage using real spatial maps that make the results more reliable. This research can help network operators improve the network quality and capability with the best investment efficiently.

No abstract

No abstract