7,958 research outputs found

    An efficient counter-based broadcast scheme for mobile ad hoc networks

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    In mobile ad hoc networks (MANETs), broadcasting plays a fundamental role, diffusing a message from a given source node to all the other nodes in the network. Flooding is the simplest and commonly used mechanism for broadcasting in MANETs, where each node retransmits every uniquely received message exactly once. Despite its simplicity, it however generates redundant rebroadcast messages which results in high contention and collision in the network, a phenomenon referred to as broadcast storm problem. Pure probabilistic approaches have been proposed to mitigate this problem inherent with flooding, where mobile nodes rebroadcast a message with a probability p which can be fixed or computed based on the local density. However, these approaches reduce the number of rebroadcasts at the expense of reachability. On the other hand, counter-based approaches inhibit a node from broadcasting a packet based on the number of copies of the broadcast packet received by the node within a random access delay time. These schemes achieve better throughput and reachability, but suffer from relatively longer delay. In this paper, we propose an efficient broadcasting scheme that combines the advantages of pure probabilistic and counter-based schemes to yield a significant performance improvement. Simulation results reveal that the new scheme achieves superior performance in terms of saved-rebroadcast, reachability and latency

    V2X Content Distribution Based on Batched Network Coding with Distributed Scheduling

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    Content distribution is an application in intelligent transportation system to assist vehicles in acquiring information such as digital maps and entertainment materials. In this paper, we consider content distribution from a single roadside infrastructure unit to a group of vehicles passing by it. To combat the short connection time and the lossy channel quality, the downloaded contents need to be further shared among vehicles after the initial broadcasting phase. To this end, we propose a joint infrastructure-to-vehicle (I2V) and vehicle-to-vehicle (V2V) communication scheme based on batched sparse (BATS) coding to minimize the traffic overhead and reduce the total transmission delay. In the I2V phase, the roadside unit (RSU) encodes the original large-size file into a number of batches in a rateless manner, each containing a fixed number of coded packets, and sequentially broadcasts them during the I2V connection time. In the V2V phase, vehicles perform the network coded cooperative sharing by re-encoding the received packets. We propose a utility-based distributed algorithm to efficiently schedule the V2V cooperative transmissions, hence reducing the transmission delay. A closed-form expression for the expected rank distribution of the proposed content distribution scheme is derived, which is used to design the optimal BATS code. The performance of the proposed content distribution scheme is evaluated by extensive simulations that consider multi-lane road and realistic vehicular traffic settings, and shown to significantly outperform the existing content distribution protocols.Comment: 12 pages and 9 figure

    Optimisation of Mobile Communication Networks - OMCO NET

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    The mini conference “Optimisation of Mobile Communication Networks” focuses on advanced methods for search and optimisation applied to wireless communication networks. It is sponsored by Research & Enterprise Fund Southampton Solent University. The conference strives to widen knowledge on advanced search methods capable of optimisation of wireless communications networks. The aim is to provide a forum for exchange of recent knowledge, new ideas and trends in this progressive and challenging area. The conference will popularise new successful approaches on resolving hard tasks such as minimisation of transmit power, cooperative and optimal routing

    Enhanced termination condition for deterministic broadcasting protocols in mobile ad hoc networks

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    Deterministic approach to broadcasting in Mobile Ad Hoc Networks (MANETs) is effective in reducing redundant broadcasting. In this approach, a transmitting node selects a subset of its immediate or 1-hop neighbors to rebroadcast the message such that all its 2-hop neighbors will receive the message, or being covered. In order to reduce redundant broadcasting, the set of 1-hop neighbors to be covered should be reduced as much as possible. Another important aspect that affects the effectiveness of a deterministic broadcasting protocol is the termination condition that inhibits a node from transmitting a particular message unnecessarily. However, existing termination conditions are not optimized. We propose a new covered/uncovered termination condition where each node is assigned with covered/uncovered status. In this paper, we show that our covered/uncovered termination condition ensures full network coverage, does not incur any control message overhead, and yet requires the least number of rebroadcasting nodes. When we apply the termination condition to some existing deterministic broadcasting protocols, the saving in the number of broadcasting nodes can be as significant as 45% when there are 100 nodes randomly distributed in an area of 1000 x 1000 m2. ©2010 IEEE.published_or_final_versionThe 72nd IEEE Vehicular Technology Conference (VTC 2010-Fall), Ottawa, ON., 6-9 September 2010. In Proceedings of the IEEE-VTS Vehicular Technology Conference, 2010, p. 1-

    Advancing the Potential of Routing Protocol in Mobile Ad Hoc Network

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    An ad hoc network consists of nodes with a radio without wire which has multi hop network surroundings [3]. Their messages can be sent anywhere with the help of intermediate nodes only in limits. Broadcasting is mobile ad hoc networks (MANET) is process to send message one to other nodes of the network [1]. It has far-reaching application in mobile ad hoc networks (MANET). It provides significant control and route administration for all types protocols let it be unicast or multicast protocols. It has become an important and all above to find a strong routing protocol in networking research. MANET has important part like as D.S.R., A.O.D.V. for routing information and location routing are used to established routes [5]. There are many problems in broadcasting of MANETS due to reasons like; Variable and unpredictable characteristics, Fluctuation of Strength, Channel Contention problem and Packet Collision problem [4]. The study had been done to cop up these problems on neighbor coverage based protocol to reduce routing overhead in MANETS. The connectivity factor was also discussed to arrange neighbor coverage system to provide to density adaptation [7]. AODV protocol can be played an important role in optimizing mechanism. This paper presented and completed on new type of rebroadcasting with many performance metrics it is done while using NS-2 Simulator [9]
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