1,711 research outputs found

    Simulation and Performance Analysis of MP-OLSR for Mobile Ad hoc Networks

    Get PDF
    Mobile ad hoc networks (MANETs) consist of a collection of wireless mobile nodes which dynamically exchange data without reliance on a fixed base station or a wired backbone network, which makes routing a crucial issue for the design of a ad hoc networks. In this paper we discussed a hybrid multipath routing protocol named MP-OLSR. It is based on the link state algorithm and employs periodic exchange of messages to maintain topology information of the networks. In the mean time, it updates the routing table in an on-demand scheme and forwards the packets in multiple paths which have been determined at the source. If a link failure is detected, the algorithm recovers the route automatically. Concerning the instability of the wireless networks, the redundancy coding is used to improve the delivery ratio. The simulation in NS2 shows that the new protocol can effectively improve the performance of the networks

    An Improvement in Congestion Control Using Multipath Routing in Manet

    Get PDF
    The ad hoc connections, which opens many opportunities for MANET applications. In ad hoc network nodes are movable and there is no centralised management. Routing is an important factor in mobile ad hoc network which not only works well with a small network, but also it can also work well if network get expanded dynamically. Routing in Manets is a main factor considered among all the issues. Mobile nodes in Manet have limited transmission capacity, they intercommunicate by multi hop relay. Multi hop routing have many challenges such as limited wireless bandwidth, low device power, dynamically changing network topology, and high vulnerability to Failure. To answer those challenges, many routing algorithms in Manets were proposed. But one of the problems in routing algorithm is congestion which decreases the overall performance of the network so in this paper we are trying to identify the best routing algorithm which will improve the congestion control mechanism among all the Multipath routing protocols

    Reliable routing protocols for dynamic wireless ad hoc and sensor networks

    Get PDF
    The vision of ubiquitous computing requires the development of devices and technologies, which can be pervasive without being intrusive. The basic components of such a smart environment will be small nodes with sensing and wireless communications capabilities, able to organize flexibly into a network for data collection and delivery. The constant improvements in digital circuit technology, has made the deployment of such small, inexpensive, low-power, distributed devices, which are capable of information gathering, processing, and communication in miniature packaging, a reality.\ud Realizing such a network presents very significant challenges, especially at the protocol and software level. Major steps forward are required in the field of communications protocol, data processing, and application support. Although sensor nodes will be equipped with a power supply (battery) and embedded processor that makes them autonomous and self-aware, their functionality and capabilities will be very limited. The resource limitations of Wireless Sensor Networks (WSN), especially in terms of energy, require novel and collaborative approach for the wireless communication. Therefore, collaboration between nodes is essential to deliver smart services in a ubiquitous setting. Current research in this area generally assumes a rather static network, leading to a strong performance degradation in a dynamic environment. In this thesis we investigate new algorithms for routing in dynamic wireless environment and evaluate their feasibility through experimentation. These algorithms will be key for building self-organizing and collaborative sensor networks\ud that show emergent behavior and can operate in a challenging environment where\ud nodes move, fail and energy is a scarce resource.\ud We develop the technology needed for building self-organizing and collabora-\ud tive sensor networks using reconfigurable smart sensor nodes, which are self-aware,self-reconfigurable and autonomous. This technology will enable the creation of a new generation of sensors, which can effectively network together so as to provide a flexible platform for the support of a large variety of mobile sensor network applications. In this thesis, we address the dynamics of sink nodes, sensor nodes and event in the routing of wireless sensor networks, while maintaining high reliability and low energy consumption. The hypothesis is that this requires different routing protocols and approaches. The varying application scenarios of wireless sensor\ud networks require different routing protocols and approaches as well.\ud This thesis has three major contributions to the routing in dynamic wireless\ud sensor networks. Firstly, a combination between a new multipath on-Demand Rout-\ud ing protocol and a data-splitting scheme which results in an e±cient solution for high reliability and low traffic. Secondly, a cross-layered approach with a self-organizing medium access control protocol and a tightly integrated source routing protocol is designed for high mobility sensor networks. Finally, a data-centric approach based on cost estimation is designed to disseminate aggregated data from data source to destination with high efficiency

    An Improvement in Congestion Control Using Multipath Routing in MANET

    Get PDF
    The ad hoc connections, which opens many opportunities for MANET applications. In ad hoc network nodes are movable and there is no centralised management. Routing is an important factor in mobile ad hoc network which not only works well with a small network, but also it can also work well if network get expanded dynamically. Routing in Manets is a main factor considered among all the issues. Mobile nodes in Manet have limited transmission capacity, they intercommunicate by multi hop relay. Multi hop routing have many challenges such as limited wireless bandwidth, low device power, dynamically changing network topology, and high vulnerability to Failure. To answer those challenges, many routing algorithms in Manets were proposed. But one of the problems in routing algorithm is congestion which decreases the overall performance of the network so in this paper we are trying to identify the best routing algorithm which will improve the congestion control mechanism among all the Multipath routing protocols. Keywords: Disjoint Multipath, Multi hop, reliability, Congestion Control, Optimizatio

    Wireless industrial monitoring and control networks: the journey so far and the road ahead

    Get PDF
    While traditional wired communication technologies have played a crucial role in industrial monitoring and control networks over the past few decades, they are increasingly proving to be inadequate to meet the highly dynamic and stringent demands of today’s industrial applications, primarily due to the very rigid nature of wired infrastructures. Wireless technology, however, through its increased pervasiveness, has the potential to revolutionize the industry, not only by mitigating the problems faced by wired solutions, but also by introducing a completely new class of applications. While present day wireless technologies made some preliminary inroads in the monitoring domain, they still have severe limitations especially when real-time, reliable distributed control operations are concerned. This article provides the reader with an overview of existing wireless technologies commonly used in the monitoring and control industry. It highlights the pros and cons of each technology and assesses the degree to which each technology is able to meet the stringent demands of industrial monitoring and control networks. Additionally, it summarizes mechanisms proposed by academia, especially serving critical applications by addressing the real-time and reliability requirements of industrial process automation. The article also describes certain key research problems from the physical layer communication for sensor networks and the wireless networking perspective that have yet to be addressed to allow the successful use of wireless technologies in industrial monitoring and control networks
    corecore