8,793 research outputs found

    Node Disjoint Multipath Routing Approach for Controlling Congestion in MANETs

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    Mobile Ad hoc Networks are highly dynamic networks. Quality of Service (QoS) routing in such networks is usually limited by the network breakage due to either node mobility or energy depletion of the mobile nodes. Nodedisjoint routing becomes inessential technique in communication of packets among various nodes in networks. Meanwhile AODV (Ad Hoc On-demand Multipath Distance Vector) creates single-path route between a pair of source and destination nodes. Some researches has done so far to make multipath node-disjoint routing based on AODV protocol. But however their overhead and end-to-end delay are relatively high, while the detail of their code is not available too. In an ad hoc network, identification of all node-disjoint paths between a given pair of nodes is a challenging task. The phenomena that a protocol is not able to identify all node-disjoint paths that exist between a given pair of nodes is called path diminution. In this paper, we discuss that path diminution is unavoidable when a protocol discovers multiple node-disjoint paths in a single route discovery and working of node disjoint multipath protocol

    A Composite Trust Model for Secure Routing in Mobile Ad-Hoc Networks

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    It is imperative to address the issue of secure routing in mobile ad-hoc networks (MANETs) where the nodes seek for cooperative and trusted behaviour from the peer nodes in the absence of well-established infrastructure and centralized authority. Due to the inherent absence of security considerations in the traditional ad-hoc routing protocols, providing security and reliability in the routing of data packets is a major challenge. This work addresses this issue by proposing a composite trust metric based on the concept of social trust and quality-of-service (QoS) trust. Extended from the ad-hoc on-demand distance vector (AODV) routing protocol, we propose an enhanced trust-based model integrated with an attack-pattern discovery mechanism, which attempts to mitigate the adversaries craving to carry out distinct types of packet-forwarding misbehaviours. We present the detailed mode of operations of three distinct adversary models against which the proposed scheme is evaluated. Simulation results under different network conditions depict that the combination of social and QoS trust components provides significant improvement in packet delivery ratio, routing overhead, and energy consumption compared to an existing trust-based scheme

    An energy-aware and QOS assured wireless multi-hop transmission protocol

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    A thesis submitted in fulfillment of the requirements for the degree of Master of Science by researchThe Ad-hoc network is set up with multiple wireless devices without any pre-existing infrastructure. It usually supports best-effort traffic and occasionally some kinds of Quality of Service (QoS). However, there are some applications with real-time traffic requirements where deadlines must be met. To meet deadlines, the communication network has to support the timely delivery of inter-task messages. Furthermore, energy efficiency is a critical issue for battery-powered mobile devices in ad-hoc networks. Thus, A QoS guaranteed and energy-aware transmission scheme is one hot of research topics in the research area. The MSc research work is based on the idea of Real-Time Wireless Multi-hop Protocol (RT-WMP). RT-WMP is a well known protocol originally used in the robots control area. It allows wireless real-time traffic in relatively small mobile ad-hoc networks using the low-cost commercial IEEE 802.11 technology. The proposed scheme is based on a token-passing approach and message exchange is priority based. The idea of energy-aware routing mechanism is based on the AODV protocol. This energy-saving mechanism is analysed and simulated in our study as an extension of the RT-WMP. From the simulation results and analysis, it has been shown that adding energy-aware mechanism to RT-WMP is meaningful to optimise the performance of traffic on the network

    ENERGY AWARE FUZZY BASED MULTI-CONSTRAINED SINGLE PATH QoS ROUTING PROTOCOL IN MANETs

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    ABSTRACT Routing real-time traffic with good Quality of Service (QoS) is a challenging task in Mobile Ad-Hoc Networks (MANETs). Energy Aware Fuzzy based Multi Constrained Single path QoS Routing (E-FMSQR) protocol which is an extension of AODV is proposed to find an optimal path by considering multiple QoS metrics. Considering Multiconstraints like Bandwidth, Delay, Number of Hops and Energy, a single fuzzy cost is determined as output cost. The protocol also computes Link Expiration Time (LET) based on the speed and direction of movement of the mobile node to predict the nodes mobility to identify a stable path. An optimal path is chosen as one with minimum output cost and maximum LET. Path breakage due to link failure or node failure is prevented. The simulation result shows the improvement in throughput and packet delivery ratio with minimum delay. It shows better energy distribution among nodes minimizing node failures in the network and maximizing the network Lifetime

    Performance Enhancement of Routing in MANETs by using EOMD

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    Usually large scale of network applications requires communication of the single copy of same information packets simultaneously to many destinations. Applying the infrastructure- based multicast routing protocols in Mobile Ad hoc wireless Networks (MANETs) is a big challenge task. The circumstances that make Multicasting in ad hoc networks is extra intricate than in wired networks are node mobility, Interference of Wi-Fi alerts and broadcast nature of the communication. Tree based Protocols aren't suitable for common topology modifications as an excessive amount of overhead for updating the filter information and additionally no longer suitable for partition or isolation. The major impact of routing for multi-hop MANETs comes due to mobility of the node, as performance is prone to modifications in network topology. When any link breaks, the direction should be repaired or changed, similar to direction preservation or route discovery, respectively. The rerouting process charges in radio bandwidth and battery energy, and the extra routing latency can also affect QoS for community packages, degrading communication performance. The ODMRP is more robust to mobility and unreliable wireless links as its core layout relies on periodic floods of path discovery and renovation. ODMRP periodically reconstructs the ?forwarding mesh? on a fixed quick interval. The path refresh is the most essential parameter because it has the important effect at the protocol overhead. We proposed an Extended - On Demand Multicast Routing Protocol with motion detection (EOMD), which reduces communication overhead and performance improvisation in mobile Ad-Hoc Network in Mobility

    A Pheromone-Aided Multipath QoS Routing Protocol and its Applications in MANETs

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    In this paper, we present an ant-based multipath QoS routing protocol that utilizes a single link metric combiningmultiple weighted criteria. The metric is applied to the proposed energy efficient multipath algorithm that considers both energy and latency. Energy efficiency is an important issue in mobile ad hoc networks (MANETs) since node energy supplies are stored in batteries. In order to increase the network lifetime it is important to maximize the minimum node energy along a path. As the network topology changes, failures may occur on active routes,resulting in the need for new route discoveries if only singleroutes per flow are maintained. Frequent new route discovery would, however, increase routing overhead and increase mean and peak packet latency. Using multiple routes simultaneously per flow can be a solution to these problems. Also, a special case of the multipath QoS routing protocol that considers throughput is applied to a security context. A compromised node can obstruct network communication by simply dropping packets that are supposed to be forwarded. In our approach, messages aredistributed over multiple paths between source and destination using ant-based QoS routing. In proportion to the throughput of each path, a pheromone-aided routing table is updated and, subsequently, paths that contain malicious nodes are naturally avoided
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