964 research outputs found

    Energy-aware Ad Hoc on-demand distance vector routing protocol and optimizing the blocking problem induced in wireless Ad Hoc networks

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    The purpose of this thesis was to investigate some of the issues related to routing and medium access control protocol in ad hoc networks. In routing protocol, the goal is to tackle the power consumption problem and to present a case for using new cost energy-aware metric for Ad Hoc On-Demand Distance Vector (AODV). The idea of the new cost metric is to be able to avoid routes with a low energy capacity. By using this approach, high efficiency in energy consumption can be achieved in Ad-Hoc networks. The second goal of this thesis was to investigate the blocking problem induced by Request-to-Send/Clear-to-Send (RTS/CTS) mechanism in detail and provide a solution to overcome that problem. To do so, a new parameter is proposed by which the Medium Access control (MAC) protocol will decide when to switch between RTS/CTS mechanism (the 4-way-handshaking) and the Basic Access method (the 2-way-handshaking) in order to reduce the effect of the blocking problem in Ad Hoc networks

    Energy Efficient MANET Protocol Using Cross Layer Design for Military Applications

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    In military applications mobile adhoc network plays very important role because it is specifically designed network for on demand requirement and in situations where set up of physical network is not possible. This special type of network which takes control in infrastructure less communication handles serious challenges tactfully such as highly robust and dynamic military work stations, devices and smaller sub-networks in the battle field. Therefore there is a high demand of designing efficient routing protocols ensuring security and reliability for successful transmission of highly sensitive and confidential military information in defence networks. With this objective, a power efficient network layer routing protocol in the network for military application is designed and simulated using a new cross layer approach of design to increase reliability and network lifetime up to a greater extent.

    L-AOMDV- An Efficient Proposed Approach in MANETs

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    Mobile Ad hoc Network (MANET) is a collection of mobile devices and is self configuring, dynamically changing, multi-hop wireless network which forms a communication network via multi hop wireless network connection, it is a self-organizing network, without any central control. Nodes in the network communicate with another node only if it lies within its transmission range. Every node acts as both source and router in the network. MANETs are one of the most challenging and growing research field because of their demand and challenges in providing services because of its dynamic nature. Load balancing is one of the key problems in MANETs as load balancing in network is essential for better lifetime of network, Qos, congestion control. The proposed approach in the research emphasises on the stability of the paths and distributing the traffic in the network based on the energy of the nodes

    Wireless Multi Hop Access Networks and Protocols

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    As more and more applications and services in our society now depend on the Internet, it is important that dynamically deployed wireless multi hop networks are able to gain access to the Internet and other infrastructure networks and services. This thesis proposes and evaluates solutions for providing multi hop Internet Access. It investigates how ad hoc networks can be combined with wireless and mesh networks in order to create wireless multi hop access networks. When several access points to the Internet are available, and the mobile node roams to a new access point, the node has to make a decision when and how to change its point of attachment. The thesis describes how to consider the rapid fluctuations of the wireless medium, how to handle the fact that other nodes on the path to the access point are also mobile which results in frequent link and route breaks, and the impact the change of attachment has on already existing connections. Medium access and routing protocols have been developed that consider both the long term and the short term variations of a mobile wireless network. The long term variations consider the fact that as nodes are mobile, links will frequently break and new links appear and thus the network topology map is constantly redrawn. The short term variations consider the rapid fluctuations of the wireless channel caused by mobility and multi path propagation deviations. In order to achieve diversity forwarding, protocols are presented which consider the network topology and the state of the wireless channel when decisions about forwarding need to be made. The medium access protocols are able to perform multi dimensional fast link adaptation on a per packet level with forwarding considerations. This i ncludes power, rate, code and channel adaptation. This will enable the type of performance improvements that are of significant importance for the success of multi hop wireless networks
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