66 research outputs found

    Evaluation of an OPNET Model for Unmanned Aerial Vehicle Networks

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    The concept of Unmanned Aerial Vehicles (UAVs) was first used as early as the American Civil War, when the North and the South unsuccessfully attempted to launch balloons with explosive devices. Since the American Civil War, the UAV concept has been used in all subsequent military operations. Over the last few years, there has been an explosion in the use of UAVs in military operations, as well as civilian and commercial applications. UAV Mobile Ad Hoc Networks (MANETs) are fast becoming essential to conducting Network-Centric Warfare (NCW). As of October 2006, coalition UAVs, exclusive of hand-launched systems, had flown almost 400,000 flight hours in support of Operations Enduring Freedom and Iraqi Freedom [1]. This study develops a verified network model that emulates UAV network behavior during flight, using a leading simulation tool. A flexible modeling and simulation environment is developed to test proposed technologies against realistic mission scenarios. The simulation model evaluation is performed and findings documented. These simulations are designed to understand the characteristics and essential performance parameters of the delivered model. A statistical analysis is performed to explain results obtained, and identify potential performance irregularities. A systemic approach is taken during the preparation and execution simulation phases to avoid producing misleading results

    Assessment of troughput performance under NS2 in Mobile Ad Hoc Networks (MANETs)

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    Providing QoS in the context of Ad Hoc networks includes a very wide field of application from the perspective of every level of the architecture in the network.In order for simulation studies to be useful, it is very important that the simulation results match as closely as possible with the test bed results. In this Paper, we study the throughput performance (parameter QoS) in Mobile Ad Hoc Networks (MANETs) and compares emulated test bed results with simulation results from NS2 (Network Simulator). The performance of the Mobile Ad Hoc Networks is very sensitive to the number of users and the offered load. When the number of users/offered load is high then the collisions increase resulting in larger wastage of the medium and lowering overall throughput. The aim of this research is to compare the throughput of Mobile Ad Hoc Networks using three different scenarios: 97, 100 and 120 users (nodes) using simulator NS2. By analyzing the graphs in MANETs, it is concluded When the number of users o nodes is increased beyond the certain limit, throughput decreases

    FRANC: A Lightweight Java Framework for Wireless Multihop Communication

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    Simulation and emulation are popular means for evaluating wireless Mobile Ad hoc Networks (MANETs) protocols. Since MANETs are highly dependant on their physical environment, these techniques offer only a partial understanding of factors that may influence performance. Deploying real-life MANETs is therefore an indispensable complementary step for the advancement of MANETs. This paper presents FRANC, a dedicated extensible Java framework for the development, deployment and evaluation of applications and algorithms for wireless mobile ad hoc networks

    Improving the Performance of Wireless LANs

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    This book quantifies the key factors of WLAN performance and describes methods for improvement. It provides theoretical background and empirical results for the optimum planning and deployment of indoor WLAN systems, explaining the fundamentals while supplying guidelines for design, modeling, and performance evaluation. It discusses environmental effects on WLAN systems, protocol redesign for routing and MAC, and traffic distribution; examines emerging and future network technologies; and includes radio propagation and site measurements, simulations for various network design scenarios, numerous illustrations, practical examples, and learning aids

    A Novel Communications Protocol Using Geographic Routing for Swarming UAVs Performing a Search Mission

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    This research develops the UAV Search Mission Protocol (USMP) for swarming UAVs and determines the protocol\u27s effect on search mission performance. It is hypothesized that geographically routing USMP messages improves search performance by providing geography-dependent data to locations where it impacts search decisions. It is also proposed that the swarm can use data collected by the geographic routing protocol to accurately determine UAV locations and avoid sending explicit location updates. The hypothesis is tested by developing several USMP designs that are combined with the Greedy Perimeter Stateless Routing (GPSR) protocol and a search mission swarm logic into a single network simulation. The test designs use various transmission power levels, sensor types and swarm sizes. The simulation collects performance metrics for each scenario, including measures of distance traveled, UAV direction changes, number of searches and search concentration. USMP significantly improves mission performance over scenarios without inter-UAV communication. However, protocol designs that simply broadcast messages improve search performance by 83% in total searches and 20% in distance traveled compared to geographic routing candidates. Additionally, sending explicit location updates generates 3%-6% better performance per metric versus harvesting GPSR\u27s location information

    Reputation-Based Internet Protocol Security: A Multilayer Security Framework for Mobil Ad Hoc Networks

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    This research effort examines the theory, application, and results for a Reputation-based Internet Protocol Security (RIPSec) framework that provides security for an ad-hoc network operating in a hostile environment. In RIPSec, protection from external threats is provided in the form of encrypted communication links and encryption-wrapped nodes while internal threats are mitigated by behavior grading that assigns reputations to nodes based on their demonstrated participation in the routing process. Network availability is provided by behavior grading and round-robin multipath routing. If a node behaves faithfully, it earns a positive reputation over time. If a node misbehaves (for any number of reasons, not necessarily intentional), it earns a negative reputation. Each member of the MANET has its own unique and subjective set of Reputation Indexes (RI) that enumerates the perceived reputation of the other MANET nodes. Nodes that desire to send data will eliminate relay nodes they perceive to have a negative reputation during the formulation of a route. A 50-node MANET is simulated with streaming multimedia and varying levels of misbehavior to determine the impact of the framework on network performance. Results of this research were very favorable. Analysis of the simulation data shows the number of routing errors sent in a MANET is reduced by an average of 52% when using RIPSec. The network load is also reduced, decreasing the overall traffic introduced into the MANET and permitting individual nodes to perform more work without overtaxing their limited resources. Finally, throughput is decreased due to larger packet sizes and longer round trips for packets to traverse the MANET, but is still sufficient to pass traffic with high bandwidth requirements (i.e., video and imagery) that is of interest in military networks

    QOS routing for mobile Ad Hoc networks using genetic algorithm

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    Mobile Ad Hoc Networks (MANETs) are a class of infrastructure less network architecture which are formed by a collection of mobile nodes that communicate with each other using multihop wireless links. They eliminate the need for central management, hence each node must operate cooperatively to successfully maintain the network. Each node performs as a source, a sink and a router. Future applications of MANETs are expected to be based on all-IP architecture, carrying a multitude of real-time multimedia applications such as voice, video and data. It would be necessary for MANETs to have an efficient routing and quality of service (QoS) mechanism to support diverse applications. This thesis proposes a set of cooperative protocols that provide support for QoS routing. The first is the on-demand, Non-Disjoint Multiple Routes Discovery protocol (NDMRD). NDMRD allows the establishment of multiple paths with node non-disjoint between source and destination node. It returns to the source a collection of routes with the QoS parameters. The second part of the protocol is the Node State Monitoring protocol for the purpose of monitoring, acquisition, dissemination and accumulation of QoS route information. The third part of the protocol implements the QoS route selection based on a Genetic Algorithm. The GA is implemented online with predetermined initial population and weighted-sum fitness function which operates simultaneously on the node bandwidth, media access delay, end to end delay and the node connectivity index (n). The term node connectivity index is a numerical value designed to predict comparatively the longest time a node-pair might be connected wirelessly.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

    QOS routing for mobile Ad Hoc networks using genetic algorithm

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    Mobile Ad Hoc Networks (MANETs) are a class of infrastructure less network architecture which are formed by a collection of mobile nodes that communicate with each other using multihop wireless links. They eliminate the need for central management, hence each node must operate cooperatively to successfully maintain the network. Each node performs as a source, a sink and a router. Future applications of MANETs are expected to be based on all-IP architecture, carrying a multitude of real-time multimedia applications such as voice, video and data. It would be necessary for MANETs to have an efficient routing and quality of service (QoS) mechanism to support diverse applications. This thesis proposes a set of cooperative protocols that provide support for QoS routing. The first is the on-demand, Non-Disjoint Multiple Routes Discovery protocol (NDMRD). NDMRD allows the establishment of multiple paths with node non-disjoint between source and destination node. It returns to the source a collection of routes with the QoS parameters. The second part of the protocol is the Node State Monitoring protocol for the purpose of monitoring, acquisition, dissemination and accumulation of QoS route information. The third part of the protocol implements the QoS route selection based on a Genetic Algorithm. The GA is implemented online with predetermined initial population and weighted-sum fitness function which operates simultaneously on the node bandwidth, media access delay, end to end delay and the node connectivity index (n). The term node connectivity index is a numerical value designed to predict comparatively the longest time a node-pair might be connected wirelessly.EThOS - Electronic Theses Online ServiceGBUnited Kingdo
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