611 research outputs found

    Source Delay in Mobile Ad Hoc Networks

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    Source delay, the time a packet experiences in its source node, serves as a fundamental quantity for delay performance analysis in networks. However, the source delay performance in highly dynamic mobile ad hoc networks (MANETs) is still largely unknown by now. This paper studies the source delay in MANETs based on a general packet dispatching scheme with dispatch limit ff (PD-ff for short), where a same packet will be dispatched out up to ff times by its source node such that packet dispatching process can be flexibly controlled through a proper setting of ff. We first apply the Quasi-Birth-and-Death (QBD) theory to develop a theoretical framework to capture the complex packet dispatching process in PD-ff MANETs. With the help of the theoretical framework, we then derive the cumulative distribution function as well as mean and variance of the source delay in such networks. Finally, extensive simulation and theoretical results are provided to validate our source delay analysis and illustrate how source delay in MANETs are related to network parameters.Comment: 11page

    Validation of Routing Protocol for Mobile Ad Hoc Networks using Colored PetriNets

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    In a Mobile Ad Hoc Network (MANET), mobile nodes directly send messages to each other via other nodes in a wireless environment. A node can send a message to a destination node beyond its transmission range by using other nodes as relay points, and thus a node can function as a router. With the explosive growth of the Internet and mobile communication networks, challenging requirements have been introduced into MANETs and designing routing protocols has become more complex. For a successful application of MANETS, it is very important to ensure that a routing protocol is unambiguous, complete and functionally correct. One approach to ensuring correctness of an existing routing protocol is to create a formal model for the protocol, and analyze the model to determine if needed the protocol provides the defined service correctly. Colored Petri Nets (CPNs) are a suitable modeling language for this purpose, as it can conveniently express non-determinism , concurrency and different levels of abstraction that are inherent in routing protocols. However it is not easy to build a CPN model of a MANET because a node can move in and out of its transmission range and thus the MANET’s topology dynamically changes. So a topology approximation (TA) mechanism has been proposed to address this problem of mobility and perform simulations of routing protocol called Ad Hoc On demand Distance Vector Routing (AODV) and Distance Source Routing(DSR) and to perform comparison based on the simulation results

    Rethinking Information Theory for Mobile Ad Hoc Networks

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    The subject of this paper is the long-standing open problem of developing a general capacity theory for wireless networks, particularly a theory capable of describing the fundamental performance limits of mobile ad hoc networks (MANETs). A MANET is a peer-to-peer network with no pre-existing infrastructure. MANETs are the most general wireless networks, with single-hop, relay, interference, mesh, and star networks comprising special cases. The lack of a MANET capacity theory has stunted the development and commercialization of many types of wireless networks, including emergency, military, sensor, and community mesh networks. Information theory, which has been vital for links and centralized networks, has not been successfully applied to decentralized wireless networks. Even if this was accomplished, for such a theory to truly characterize the limits of deployed MANETs it must overcome three key roadblocks. First, most current capacity results rely on the allowance of unbounded delay and reliability. Second, spatial and timescale decompositions have not yet been developed for optimally modeling the spatial and temporal dynamics of wireless networks. Third, a useful network capacity theory must integrate rather than ignore the important role of overhead messaging and feedback. This paper describes some of the shifts in thinking that may be needed to overcome these roadblocks and develop a more general theory that we refer to as non-equilibrium information theory.Comment: Submitted to IEEE Communications Magazin

    Adaptive Multicast Multimedia Transmission Routing Protocol System (ACMMR) for Congestion Control and Load Balancing Techniques in Mobile Adhoc Networks

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    A MANET is a probable solution for this need to quickly establish interactions in a mobile and transient environment. Proposed congestion controlled adaptive multicasting routing protocol to achieve load balancing and avoid congestion in MANETs. The existing algorithm for finding multicasting routes computes fail-safe multiple paths, which provide all the intermediate nodes on the primary path with multiple routes to target node. Routing may let a congestion happen, which is detected by congestion control, but dealing with congestion in this reactive manner results in longer delay and redundant packet loss and requires significant overhead if a new route is needed. Transmission of real-time video typically has bandwidth, delay, and loss requirements. Video transmission over wireless network poses many challenges. To overcome these challenges, extensive research has been conducted in the various areas of video application
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