128 research outputs found

    An Overview of Mobile Ad Hoc Networks for the Existing Protocols and Applications

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    Mobile Ad Hoc Network (MANET) is a collection of two or more devices or nodes or terminals with wireless communications and networking capability that communicate with each other without the aid of any centralized administrator also the wireless nodes that can dynamically form a network to exchange information without using any existing fixed network infrastructure. And it's an autonomous system in which mobile hosts connected by wireless links are free to be dynamically and some time act as routers at the same time, and we discuss in this paper the distinct characteristics of traditional wired networks, including network configuration may change at any time, there is no direction or limit the movement and so on, and thus needed a new optional path Agreement (Routing Protocol) to identify nodes for these actions communicate with each other path, An ideal choice way the agreement should not only be able to find the right path, and the Ad Hoc Network must be able to adapt to changing network of this type at any time. and we talk in details in this paper all the information of Mobile Ad Hoc Network which include the History of ad hoc, wireless ad hoc, wireless mobile approaches and types of mobile ad Hoc networks, and then we present more than 13 types of the routing Ad Hoc Networks protocols have been proposed. In this paper, the more representative of routing protocols, analysis of individual characteristics and advantages and disadvantages to collate and compare, and present the all applications or the Possible Service of Ad Hoc Networks.Comment: 24 Pages, JGraph-Hoc Journa

    Building Realistic Mobility Models for Mobile Ad Hoc Networks

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    A mobile ad hoc network (MANET) is a self-configuring wireless network in which each node could act as a router, as well as a data source or sink. Its application areas include battlefields and vehicular and disaster areas. Many techniques applied to infrastructure-based networks are less effective in MANETs, with routing being a particular challenge. This paper presents a rigorous study into simulation techniques for evaluating routing solutions for MANETs with the aim of producing more realistic simulation models and thereby, more accurate protocol evaluations. MANET simulations require models that reflect the world in which the MANET is to operate. Much of the published research uses movement models, such as the random waypoint (RWP) model, with arbitrary world sizes and node counts. This paper presents a technique for developing more realistic simulation models to test and evaluate MANET protocols. The technique is animation, which is applied to a realistic scenario to produce a model that accurately reflects the size and shape of the world, node count, movement patterns, and time period over which the MANET may operate. The animation technique has been used to develop a battlefield model based on established military tactics. Trace data has been used to build a model of maritime movements in the Irish Sea. Similar world models have been built using the random waypoint movement model for comparison. All models have been built using the ns-2 simulator. These models have been used to compare the performance of three routing protocols: dynamic source routing (DSR), destination-sequenced distance-vector routing (DSDV), and ad hoc n-demand distance vector routing (AODV). The findings reveal that protocol performance is dependent on the model used. In particular, it is shown that RWP models do not reflect the performance of these protocols under realistic circumstances, and protocol selection is subject to the scenario to which it is applied. To conclude, it is possible to develop a range of techniques for modelling scenarios applicable to MANETs, and these simulation models could be utilised for the evaluation of routing protocols

    Mobile Ad hoc Networking: Imperatives and Challenges

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    Mobile ad hoc networks (MANETs) represent complex distributed systems that comprise wireless mobile nodes that can freely and dynamically self-organize into arbitrary and temporary, "ad-hoc" network topologies, allowing people and devices to seamlessly internetwork in areas with no pre-existing communication infrastructure, e.g., disaster recovery environments. Ad hoc networking concept is not a new one, having been around in various forms for over 20 years. Traditionally, tactical networks have been the only communication networking application that followed the ad hoc paradigm. Recently, the introduction of new technologies such as the Bluetooth, IEEE 802.11 and Hyperlan are helping enable eventual commercial MANET deployments outside the military domain. These recent evolutions have been generating a renewed and growing interest in the research and development of MANET. This paper attempts to provide a comprehensive overview of this dynamic field. It first explains the important role that mobile ad hoc networks play in the evolution of future wireless technologies. Then, it reviews the latest research activities in these areas, including a summary of MANET\u27s characteristics, capabilities, applications, and design constraints. The paper concludes by presenting a set of challenges and problems requiring further research in the future

    Analysis of Secure Routing Scheme for MANET

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    Mobile ad hoc networks pose various kinds of security problems, caused by their nature of collaborative and open systems and by limited availability of resources. In our work we look at AODV in detail, study and analyses various attacks that can be possible on it. Then we look into some existing mechanism for securing AODV protocol. Our proposed work is an extension to Adaptive-SAODV of the secure AODV protocol extension, which includes tuning strategies aimed at improving its performance. In A-SAODV an intermediate node makes an adaptive reply decision for an incoming request that helps to balance its load that is over-burdened by signing and verification task of incoming messages. Namely, we propose a modification to adaptive mechanism that tunes SAODV behavior. In our paper we have proposed an extension to Adaptive-SAODV of the secure AODV protocol extension, which includes further filtering strategies aimed at further improving its network performance. We have analyzed the how our proposed algorithm can help in further improvement of performance in adaptive SAODV and also compared its performance with existing mechanisms using simulation

    SIP servlets-based service provisioning in MANETs

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    Mobile Ad-hoc NETworks (MANETs) are a part of the fourth generation networks vision. They are new wireless networks having transient mobile nodes with no need for a pre-installed infrastructure. They are of utmost interest for the future networks owing to their flexibility, effortlessness of deployment and related low cost. They come in two flavours: standalone MANETs and integrated with the conventional 3G network. Providing value-added services is the core concept of several paradigms and has been extensively studied in legacy network. However, providing such services in MANETs is a challenging process. Indeed, MANETs are known for their heterogeneous devices, limited resources, dynamic topology and frequent disconnections/connections. New SIP based solutions for signalling and media handling in these networks are emerging. Furthermore, SIP is the primary protocol for 3G networks. Therefore, SIP servlets become a promising paradigm for service provisioning in MANETs. This thesis addresses the service provisioning aspects in both standalone MANETs and integrated 3G/MANETs. The SIP servlets framework is considered as the starting point while Multihop Cellular Networks (MCNs), the widely studied networks, are used as an example of integrated 3G/MANETs. Background information is provided, architectures requirements are derived and related work is reviewed. A novel business model is proposed for service provision in standalone MANETs. The business model defines the business roles and the relationship and interfaces between them. We also propose a service invocation and execution architecture implementing the business model. The solution is based on overlay network and a distribution scheme of the SIP servlets engine. The overlay network enables self-organization and self-recovery to take into account MANETs characteristics. As for the integrated 3G/MANETs we propose high level architectural alternatives for service provisioning in MCNs. We identify the most interesting alternatives from the network operator point of view and proposed a detailed and concrete architecture for the promising alternative. Overall architecture, functional entities and procedures are presented. During this work, we built prototypes as proof-of-concept and made preliminary performance measurements, used SPIN as protocol validation tool and adopted OPNET for simulation. The results show that we can provide services in MANETs as we do in conventional networks with reasonable performance

    Link Quality Prediction in Mobile Ad-Hoc Networks

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    Power Considerations for Sensor Networks

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    Airborne Network Data Availability Using Peer to Peer Database Replication on a Distributed Hash Table

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    The concept of distributing one complex task to several smaller, simpler Unmanned Aerial Vehicles (UAVs) as opposed to one complex UAV is the way of the future for a vast number of surveillance and data collection tasks. One objective for this type of application is to be able to maintain an operational picture of the overall environment. Due to high bandwidth costs, centralizing all data may not be possible, necessitating a distributed storage system such as mobile Distributed Hash Table (DHT). A difficulty with this maintenance is that for an Airborne Network (AN), nodes are vehicles and travel at high rates of speed. Since the nodes travel at high speeds they may be out of contact with other nodes and their data becomes unavailable. To address this the DHT must include a data replication strategy to ensure data availability. This research investigates the percentage of data available throughout the network by balancing data replication and network bandwidth. The DHT used is Pastry with data replication using Beehive, running over an 802.11 wireless environment, simulated in Network Simulator 3. Results show that high levels of replication perform well until nodes are too tightly packed inside a given area which results in too much contention for limited bandwidth
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