1,524 research outputs found

    Requirement analysis for building practical accident warning systems based on vehicular ad-hoc networks

    Get PDF
    An Accident Warning System (AWS) is a safety application that provides collision avoidance notifications for next generation vehicles whilst Vehicular Ad-hoc Networks (VANETs) provide the communication functionality to exchange these notifi- cations. Despite much previous research, there is little agreement on the requirements for accident warning systems. In order to build a practical warning system, it is important to ascertain the system requirements, information to be exchanged, and protocols needed for communication between vehicles. This paper presents a practical model of an accident warning system by stipulating the requirements in a realistic manner and thoroughly reviewing previous proposals with a view to identify gaps in this area

    Flexible HW-SW design and analysis of an MMT-based MANET system on FPGA

    Get PDF
    Recently there has been a rapid growth of research interests in Mobile Ad-hoc Networks (MANETs). Their infrastructureless and dynamic nature demands that new strategies be implemented on a robust wireless communication platform in order to provide efficient end-to-end communication. Many routing algorithms have been developed to serve this purpose. This thesis investigated Multi-Meshed Tree (MMT) algorithm, an integrated solution that combines routing, clustering and medium access control operations based on a common multi-meshed tree concept. It provides the robustness and redundancy inherent in mesh topologies and uses the tree branches to deliver packets. MMT is the first of its kind that enables a single algorithm to form multiple proactive routes within a cluster while supporting reactive routes between different clusters. Recent published research and simulations have shown its favorable features and results. To explore the MMT algorithm\u27s novel feature in real systems against simulation work, this work adopts Field Programmable Gate Arrays (FPGA) as the platform for wireless system implementations. Full hardware and various System-on-Chip Hardware-Software designs are developed and studied, providing a design practice that contributes to low-cost system development in the field of MANET by utilizing the evolving FPGA technology. The results show that the MMT-based systems functioned accurately and effectively; in all proposed test scenarios they demonstrated many of the features that a desired MANET routing algorithm should have: high transmission success rate, low latency, scalability, few queued packets and low overhead. The results give valuable insights into the MMT algorithm\u27s performance and facilitate its future improvements

    Robot Team Formation Control Using Communication Throughput Approach

    Get PDF
    In this thesis, we consider a team of robots forming a mobile robot network cooperating to accomplish a mission in an unknown but structured environment. The team has no a-priori knowledge of the environment. Robots have limited memory storage capabilities, not enough to map the environment. Each robot also has limited sensor capability and computational power. Due to the need to avoid obstacles and other environment effects, some robots get delayed from the rest. Using tracking controller, the robot team should follow the leader in a flexible formation shape without losing network connectivity, and that was achieved by monitoring the end-to-end throughput level

    Fuzzy based load and energy aware multipath routing for mobile ad hoc networks

    Get PDF
    Routing is a challenging task in Mobile Ad hoc Networks (MANET) due to their dynamic topology and lack of central administration. As a consequence of un-predictable topology changes of such networks, routing protocols employed need to accurately capture the delay, load, available bandwidth and residual node energy at various locations of the network for effective energy and load balancing. This paper presents a fuzzy logic based scheme that ensures delay, load and energy aware routing to avoid congestion and minimise end-to-end delay in MANETs. In the proposed approach, forwarding delay, average load, available bandwidth and residual battery energy at a mobile node are given as inputs to a fuzzy inference engine to determine the traffic distribution possibility from that node based on the given fuzzy rules. Based on the output from the fuzzy system, traffic is distributed over fail-safe multiple routes to reduce the load at a congested node. Through simulation results, we show that our approach reduces end-to-end delay, packet drop and average energy consumption and increases packet delivery ratio for constant bit rate (CBR) traffic when compared with the popular Ad hoc On-demand Multipath Distance Vector (AOMDV) routing protocol

    Airborne Directional Networking: Topology Control Protocol Design

    Get PDF
    This research identifies and evaluates the impact of several architectural design choices in relation to airborne networking in contested environments related to autonomous topology control. Using simulation, we evaluate topology reconfiguration effectiveness using classical performance metrics for different point-to-point communication architectures. Our attention is focused on the design choices which have the greatest impact on reliability, scalability, and performance. In this work, we discuss the impact of several practical considerations of airborne networking in contested environments related to autonomous topology control modeling. Using simulation, we derive multiple classical performance metrics to evaluate topology reconfiguration effectiveness for different point-to-point communication architecture attributes for the purpose of qualifying protocol design elements
    corecore