13,780 research outputs found

    Data Bit-Rate Instability in Wireless Multi-Rate Ad Hoc Networks

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    Wireless Ad-hoc single-rate environments typically use a Distance Vector routing with a metric based on the minimization of the hop-count. In practice, the technique of minimizing the distance does not reward in the case of multi-rate, therefore it may be prefereable touse protocols privileging the link's transmission speed instead of the minimum distance. Our study aims toward the stability of the link in a wireless high mobility environment; we explore and hypothesize how to privilege, in the choice of routes, the stablest link.Ad Hoc Networks; Routing; Stability.

    Effective link operation duration: a new routing metric for mobile ad hoc networks

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    The dynamic topology of mobile ad hoc networks (MANETs) is caused by node mobility and fading of the wireless link. Link reliability is often measured by the estimated lifetime and the stability of a link. In this paper we propose that the stability of a link can be represented by the time duration in which the two nodes at each end of a link are within each other’s transmission range and the fading is above an acceptable threshold. A novel routing metric, called effective link operation duration (ELOD), is proposed and implemented into AODV (AODV-ELOD). Simulation results show that proposed AODVELOD outperforms both AODV and the Flow Oriented Routing Protocol (FORP)

    Statistical Properties of Transmissions Subject to Rayleigh Fading and Ornstein-Uhlenbeck Mobility

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    In this paper, we derive closed-form expressions for significant statistical properties of the link signal-to-noise ratio (SNR) and the separation distance in mobile ad hoc networks subject to Ornstein-Uhlenbeck (OU) mobility and Rayleigh fading. In these systems, the SNR is a critical parameter as it directly influences link performance. In the absence of signal fading, the distribution of the link SNR depends exclusively on the squared distance between nodes, which is governed by the mobility model. In our analysis, nodes move randomly according to an Ornstein-Uhlenbeck process, using one tuning parameter to control the temporal dependency in the mobility pattern. We derive a complete statistical description of the squared distance and show that it forms a stationary Markov process. Then, we compute closed-form expressions for the probability density function (pdf), the cumulative distribution function (cdf), the bivariate pdf, and the bivariate cdf of the link SNR. Next, we introduce small-scale fading, modelled by a Rayleigh random variable, and evaluate the pdf of the link SNR for rational path loss exponents. The validity of our theoretical analysis is verified by extensive simulation studies. The results presented in this work can be used to quantify link uncertainty and evaluate stability in mobile ad hoc wireless systems

    A novel approach to modeling and flooding in ad-hoc wireless networks

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    This study proposes a new modeling approach for wireless ad-hoc networks. The new approach is based on the construction of fuzzy neighborhoods and essentially consists of assigning a membership or importance degree to each network radio link which reflects the relative quality of this link. This approach is first used to model the flooding problem and then an algorithm is proposed to solve this problem which is of a great importance in ad-hoc wireless networks intrinsically subject to a certain level of node mobility. Simulations carried out in a dynamic environment show promising results and stability compared to the enhanced dominant pruning algorithm. Such an approach is suitable to take into account the volatile aspect of radio links and the physical layer uncertainty when modeling these networks, particularly when the physical layer offers no or insufficient guaranties to high-level protocols as for the flooding

    An altruistic cross-layer recovering mechanism for ad hoc wireless networks

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    Video streaming services have restrictive delay and bandwidth constraints. Ad hoc networks represent a hostile environment for this kind of real-time data transmission. Emerging mesh networks, where a backbone provides more topological stability, do not even assure a high quality of experience. In such scenario, mobility of terminal nodes causes link breakages until a new route is calculated. In the meanwhile, lost packets cause annoying video interruptions to the receiver. This paper proposes a new mechanism of recovering lost packets by means of caching overheard packets in neighbor nodes and retransmit them to destination. Moreover, an optimization is shown, which involves a video-aware cache in order to recover full frames and prioritize more significant frames. Results show the improvement in reception, increasing the throughput as well as video quality, whereas larger video interruptions are considerably reduced. Copyright © 2014 John Wiley & Sons, Ltd.Arce Vila, P.; Guerri Cebollada, JC. (2015). An altruistic cross-layer recovering mechanism for ad hoc wireless networks. Wireless Communications and Mobile Computing. 15(13):1744-1758. doi:10.1002/wcm.2459S174417581513Li J Blake C De Couto DSJ Lee HI Morris R Capacity of ad hoc wireless networks Proceedings of the 7th Annual International Conference on Mobile Computing and Networks (MobiCom) 2001 61 69Akyildiz, I. F., & Xudong Wang. (2005). A survey on wireless mesh networks. IEEE Communications Magazine, 43(9), S23-S30. doi:10.1109/mcom.2005.1509968Hsu, C.-J., Liu, H.-I., & Seah, W. K. G. (2011). Opportunistic routing – A review and the challenges ahead. Computer Networks, 55(15), 3592-3603. doi:10.1016/j.comnet.2011.06.021Huang, X., Zhai, H., & Fang, Y. (2008). Robust cooperative routing protocol in mobile wireless sensor networks. IEEE Transactions on Wireless Communications, 7(12), 5278-5285. doi:10.1109/t-wc.2008.060680Wieselthier, J. E., Nguyen, G. D., & Ephremides, A. (2001). Mobile Networks and Applications, 6(3), 251-263. doi:10.1023/a:1011478717164Clausen T Jacquet P Optimized Link State Routing Protocol (OLSR), IETF RFC 3626 2003 http://www.rfc-editor.org/rfc/rfc3626.txtMarina, M. K., & Das, S. R. (2006). Ad hoc on-demand multipath distance vector routing. Wireless Communications and Mobile Computing, 6(7), 969-988. doi:10.1002/wcm.432Zhou X Lu Y Ma HG Routing improvement using multiple disjoint paths for ad hoc networks International Conference on Wireless and Optical Communications Networks (IFIP) 2006 1 5Fujisawa H Minami H Yamamoto M Izumi Y Fujita Y Route selection using retransmission packets for video streaming on ad hoc networks IEEE Conference on Radio and Wireless Symposium (RWS) 2006 607 610Badis H Agha KA QOLSR multi-path routing for mobile ad hoc networks based on multiple metrics: bandwidth and delay IEEE 59th Vehicular Technology Conference (VTC) 2004 2181 2184Wu Z Wu J Cross-layer routing optimization for video transmission over wireless ad hoc networks 6th International Conference on Wireless Communications Networks and Mobile Computing (WiCOM) 2010 1 6Schier, M., & Welzl, M. (2012). Optimizing Selective ARQ for H.264 Live Streaming: A Novel Method for Predicting Loss-Impact in Real Time. IEEE Transactions on Multimedia, 14(2), 415-430. doi:10.1109/tmm.2011.2178235Nikoupour M Nikoupour A Dehghan M A cross-layer framework for video streaming over wireless ad-hoc networks 3rd International Conference on Digital Information Management (ICDIM) 2008 340 345Yamamoto R Miyoshi T Distributed retransmission method using neighbor terminals for ad hoc networks Proceedings of the 14th Asia-Pacific Conference on Communications (APCC) 2008 1 5Gravalos I Kokkinos P Varvarigos EA Multi-criteria cooperative energy-aware routing in wireless ad-hoc networks Proceedings of the 9th International Wireless Communications and Mobile Computing Conference (IWCMC) 2013 387 393Abid, R. M., Benbrahim, T., & Biaz, S. (2010). IEEE 802.11s Wireless Mesh Networks for Last-Mile Internet Access: An Open-Source Real-World Indoor Testbed Implementation. Wireless Sensor Network, 02(10), 725-738. doi:10.4236/wsn.2010.210088Yen, Y.-S., Chang, R.-S., & Wu, C.-Y. (2011). A seamless handoff scheme for IEEE 802.11 wireless networks. Wireless Communications and Mobile Computing, 13(2), 157-169. doi:10.1002/wcm.1102Liangzhong Yin, & Guohong Cao. (2006). Supporting cooperative caching in ad hoc networks. IEEE Transactions on Mobile Computing, 5(1), 77-89. doi:10.1109/tmc.2006.15Biswas S Morris R ExOR: opportunistic multi-hop routing for wireless networks Proceedings of ACM SIGCOMM 2005 133 144Chachulski S Jennings M Katti S Katabi D Trading structure for randomness in wireless opportunistic routing Proceedings of ACM SIGCOMM 2007 169 180Kohler E Handley M Floyd S Datagram Congestion Control Protocol (DCCP), IETF RFC 4340 2006 http://www.rfc-editor.org/rfc/rfc4340.txtSchierl, T., Ganger, K., Hellge, C., Wiegand, T., & Stockhammer, T. (2006). SVC-based multisource streaming for robust video transmission in mobile ad hoc networks. IEEE Wireless Communications, 13(5), 96-103. doi:10.1109/wc-m.2006.250365Iera, A., Molinaro, A., Paratore, S. Y., Ruggeri, G., & Zurzolo, A. (2011). Making a mesh router/gateway from a smartphone: Is that a practical solution? Ad Hoc Networks, 9(8), 1414-1429. doi:10.1016/j.adhoc.2011.03.00

    Queueing models for mobile ad hoc networks

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    This thesis presents models for the performance analysis of a recent communication paradigm: mobile ad hoc networking. The objective of mobile ad hoc networking is to provide wireless connectivity between stations in a highly dynamic environment. These dynamics are driven by the mobility of stations and by breakdowns of stations, and may lead to temporary disconnectivity of parts \ud of the network. Applications of this novel paradigm can be found in telecommunication services, but also in manufacturing systems, road-traffic control, animal monitoring and emergency networking. The performance of mobile ad hoc networks in terms of buffer occupancy and delay is quantified in this thesis by employing specific queueing models, viz., time-limited polling models. These polling models capture the uncontrollable characteristic of link availability in mobile ad hoc networks. Particularly, a novel, so-called pure exponential time-limited, service discipline is introduced in the context of polling systems. The highlighted performance characteristics for these polling systems include the stability, the queue lengths and the sojourn times of the customers. Stability conditions prescribe limits on the amount of tra±c that can be sustained by the system, so that the establishment of these conditions is a fundamental keystone in the analysis of polling models. Moreover, both exact and approximate analysis is presented for the queue length and sojourn time in time-limited polling systems with a single server. These exact analytical techniques are extended to multi-server polling systems operating under the pure time-limited service discipline. Such polling systems with multiple servers effectively may reflect large communication networks with multiple simultaneously active links, while the systems with a single server represent performance models for small networks in which a single communication link can be active at a time

    Quantifying Link Stability in Ad Hoc Wireless Networks Subject to Ornstein-Uhlenbeck Mobility

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    The performance of mobile ad hoc networks in general and that of the routing algorithm, in particular, can be heavily affected by the intrinsic dynamic nature of the underlying topology. In this paper, we build a new analytical/numerical framework that characterizes nodes' mobility and the evolution of links between them. This formulation is based on a stationary Markov chain representation of link connectivity. The existence of a link between two nodes depends on their distance, which is governed by the mobility model. In our analysis, nodes move randomly according to an Ornstein-Uhlenbeck process using one tuning parameter to obtain different levels of randomness in the mobility pattern. Finally, we propose an entropy-rate-based metric that quantifies link uncertainty and evaluates its stability. Numerical results show that the proposed approach can accurately reflect the random mobility in the network and fully captures the link dynamics. It may thus be considered a valuable performance metric for the evaluation of the link stability and connectivity in these networks.Comment: 6 pages, 4 figures, Submitted to IEEE International Conference on Communications 201

    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
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