10,380 research outputs found

    Setting the parameters right for two-hop IEEE 802.11e ad hoc networks

    Get PDF
    Two-hop ad-hoc networks, in which some nodes forward traffic for multiple sources, with which they also compete for channel access suffer from large queues building up in bottleneck nodes. This problem can often be alleviated by using IEEE 802.11e to give preferential treatment to bottleneck nodes. Previous results have shown that differentiation parameters can be used to allocate capacity in a more efficient way in the two-hop scenario. However, the overall throughput of the bottleneck may differ considerably, depending on the differentiation method used. By applying a very fast and accurate analysis method, based on steady-state analysis of an QBD-type infinite Markov chain, we find the maximum throughput that is possible per differentiation parameter. All possible parameter settings are explored with respect to the maximum throughput conditioned on a maximum buffer occupancy. This design space exploration cannot be done with network simulators like NS2 or Opnet, as each simulation run simply takes to long.\ud The results, which have been validated by detailed simulations, show that by differentiating TXOP it is possible to achieve a throughput that is about 50% larger than when differentiating AIFS and CW_min.\u

    MWAHCA: A Multimedia Wireless Ad Hoc Cluster Architecture

    Get PDF
    Wireless Ad hoc networks provide a flexible and adaptable infrastructure to transport data over a great variety of environments. Recently, real-time audio and video data transmission has been increased due to the appearance of many multimedia applications. One of the major challenges is to ensure the quality of multimedia streams when they have passed through a wireless ad hoc network. It requires adapting the network architecture to the multimedia QoS requirements. In this paper we propose a new architecture to organize and manage cluster-based ad hoc networks in order to provide multimedia streams. Proposed architecture adapts the network wireless topology in order to improve the quality of audio and video transmissions. In order to achieve this goal, the architecture uses some information such as each node's capacity and the QoS parameters (bandwidth, delay, jitter, and packet loss). The architecture splits the network into clusters which are specialized in specific multimedia traffic. The real system performance study provided at the end of the paper will demonstrate the feasibility of the proposal.Díaz Santos, JR.; Lloret, J.; Jimenez, JM.; Sendra, S. (2014). MWAHCA: A Multimedia Wireless Ad Hoc Cluster Architecture. Scientific World Journal. 2014. doi:10.1155/2014/913046S2014Lacuesta, R., Lloret, J., Garcia, M., & Peñalver, L. (2010). A Spontaneous Ad Hoc Network to Share WWW Access. EURASIP Journal on Wireless Communications and Networking, 2010(1). doi:10.1155/2010/232083Lloret, J., Garcia, M., Tomás, J., & Boronat, F. (2008). GBP-WAHSN: A Group-Based Protocol for Large Wireless Ad Hoc and Sensor Networks. Journal of Computer Science and Technology, 23(3), 461-480. doi:10.1007/s11390-008-9147-6Yu, J. Y., & Chong, P. H. J. (2005). A survey of clustering schemes for mobile ad hoc networks. IEEE Communications Surveys & Tutorials, 7(1), 32-48. doi:10.1109/comst.2005.1423333Lloret, J., Garcia, M., Bri, D., & Diaz, J. (2009). A Cluster-Based Architecture to Structure the Topology of Parallel Wireless Sensor Networks. Sensors, 9(12), 10513-10544. doi:10.3390/s91210513LEHSAINI, M., GUYENNET, H., & FEHAM, M. (2010). Cluster-based Energy-efficient k-Coverage for Wireless Sensor Networks. Network Protocols and Algorithms, 2(2). doi:10.5296/npa.v2i2.325Zhou, C., & Maxemchuk, N. (2011). Distributed Bottleneck Flow Control in Mobile Ad Hoc Networks. Network Protocols and Algorithms, 3(1). doi:10.5296/npa.v3i1.576Zhang, R., Cai, L., Pan, J., & Shen, X. (Sherman). (2011). Resource management for video streaming in ad hoc networks. Ad Hoc Networks, 9(4), 623-634. doi:10.1016/j.adhoc.2010.08.012Tarique, M. (2010). ISSUES OF LONG-HOP AND SHORT-HOP ROUTING IN MOBILE AD HOC NETWORKS: A COMPREHENSIVE STUDY. Network Protocols and Algorithms, 2(2). doi:10.5296/npa.v2i2.430Abdrabou, A., & Zhuang, W. (2009). Statistical QoS routing for IEEE 802.11 multihop ad hoc networks. IEEE Transactions on Wireless Communications, 8(3), 1542-1552. doi:10.1109/twc.2008.080573Kandris, D., Tsagkaropoulos, M., Politis, I., Tzes, A., & Kotsopoulos, S. (2011). Energy efficient and perceived QoS aware video routing over Wireless Multimedia Sensor Networks. Ad Hoc Networks, 9(4), 591-607. doi:10.1016/j.adhoc.2010.09.00

    Queue utilization with hop based enhanced arbitrary inter frame spacing MAC for saturated ad HOC networks

    Get PDF
    © 2015 IEEE. Path length of a multi hop Ad Hoc networks has an adverse impact on the end-to-end throughput especially during network saturation. The success rate of forwarding packets towards destination is limited due to interference, contention, limited buffer space, and bandwidth. Real time applications streaming data fill the buffer space at a faster rate at the source and its nearby forwarding nodes since the channel is shared. The aim of this paper is to increase the success rate of forwarding the packets to yield a higher end-to-end throughput. In order to reduce loss of packets due to buffer overflow and enhance the performance of the network for a saturated network, a novel MAC protocol named Queue Utilization with Hop Based Enhanced Arbitrary Inter Frame Spacing based (QU-EAIFS) MAC is proposed for alleviating the problems in saturated Ad Hoc networks. The protocol prioritises the nodes based on its queue utilization and hops travelled by the packet and it helps achieving higher end-toend performance by forwarding the packets with higher rate towards the destination during network saturation. The proposed MAC enhances the end-to-end performance by approximately 40% and 34% for a 5hop and 6hop communication respectively in a chain topology as compared to the standard IEEE802.11b. The performance of the new MAC also outperforms the performance of IEEE 802.11e MAC. In order to validate the protocol, it is also tested with short hops and varying packet sizes and more realistic random topologies

    Bottlenecks in Two-Hop Ad Hoc Networks - Dividing Radio Capacity in a Smart Way

    Get PDF
    In two-hop ad hoc networks the available radio capacity tends to be equally shard among the contending stations, which may lead to bottleneck situations in case of unbalanced traffic routing. We propose a generic model for evaluating adaptive capacity sharing strategies. We use infinite-state stochastic Petri nets for modeling the system and use the logic CSRL for specifying the measures of interest
    corecore