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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
221

An Address-Based Routing Scheme for Static Applications of Wireless Sensor Networks

Li, Weibo January 2008 (has links)
Wireless sensor networks (WSNs), being a relatively new technology, largely employ protocols designed for other ad hoc networks, especially mobile ad hoc networks (MANETs). However, on the basis of applications, there are many differences between WSNs and other types of ad hoc network and so WSNs would benefit from protocols which take into account their specific properties, especially in routing. Bhatti and Yue (2006) proposed an addressing scheme for multi-hop networks. It provides a systematic address structure for WSNs and allows network topology to avoid the fatal node failure problem which could occur with the ZigBee tree structure. In this work, a new routing strategy is developed based on Bhatti and Yue’s addressing scheme. The new approach is to implement a hybrid flooding scheme that combines flooding with shortest-path methods to yield a more practical routing protocol for static WSN applications. The primary idea is to set a flooding counter K as an overhead parameter of control messages which are used to discover routes between any arbitrary nodes. These route request messages are flooded for K hops and then oriented by shortest-path routing from multiple nodes in the edge of the flooding area to the destination. The simulation results show that this protocol under certain wireless circumstances is more energy conscious and produces less redundancy than reactive ZigBee routing protocol. Another advantage is that the routing protocol can adapt any dynamic environment in various WSN applications to achieve a satisfactory data delivery ratio in exchange for redundancy.
222

A RELIABILITY-BASED ROUTING PROTOCOL FOR VEHICULAR AD-HOC NETWORKS

Bernsen, James 01 January 2011 (has links)
Vehicular Ad hoc NETworks (VANETs), an emerging technology, would allow vehicles to form a self-organized network without the aid of a permanent infrastructure. As a prerequisite to communication in VANETs, an efficient route between communicating nodes in the network must be established, and the routing protocol must adapt to the rapidly changing topology of vehicles in motion. This is one of the goals of VANET routing protocols. In this thesis, we present an efficient routing protocol for VANETs, called the Reliable Inter-VEhicular Routing (RIVER) protocol. RIVER utilizes an undirected graph that represents the surrounding street layout where the vertices of the graph are points at which streets curve or intersect, and the graph edges represent the street segments between those vertices. Unlike existing protocols, RIVER performs real-time, active traffic monitoring and uses this data and other data gathered through passive mechanisms to assign a reliability rating to each street edge. The protocol then uses these reliability ratings to select the most reliable route. Control messages are used to identify a node’s neighbors, determine the reliability of street edges, and to share street edge reliability information with other nodes.
223

Topological arrangement of nodes in wireless networks suitable for the implementation of network coding / F.J. Böning

Böning, Frans Johan-Henry January 2010 (has links)
Network coding refers to the implementation of coding methods to utilize network connections more efficiently. Network coding is commonly researched in the information theory field, but very little research is being done on the physical implementation thereof. One exception is COPE where network coding is implemented in wireless networks for unicast transmission sessions. In this dissertation, we discuss the physical arrangement of wireless nodes to form topologies suitable for the implementation of network coding. We implement linear network coding in wireless ad hoc networks for multicast transmission sessions. We calculate the areas in which each wireless node must be located for a specific network coding suitable topology to be formed. The identified topologies are simulated in OPNET Modeler and then implemented on a six node testbed, to analyse the effect of implementing network coding in these topologies. We provide results indicating the trade-off between reduced network load and higher end-to-end delay when our developed network coding algorithm is active in the respective topologies. The results indicate that the developed network coding scheme will produce better overall performance when implemented in sensor networks or highly congested ad hoc networks. / Thesis (M.Ing. (Computer and Electronical Engineering))--North-West University, Potchefstroom Campus, 2011.
224

MAZACORNET: Mobility Aware Zone based Ant Colony Optimization Routing for VANET

Rana, Himani 18 December 2012 (has links)
Vehicular Ad hoc Networks (VANET) exhibit highly dynamic behavior with high mobility and random network topologies. The performance of Transmission Control Protocols in such wireless ad hoc networks is plagued by a number of problems: frequent link failures, scalability, multi-hop data transmission and data loss. To address these VANET routing issues, I have used the ideas from swarm intelligence. The Ant Colony Optimization (ACO), which is a branch of swarm intelligence, is the main source of my inspiration. I have designed an ant-based routing algorithm which addresses routing issues prevalent in VANETs: adaptivity, robustness and scalability. One attractive feature of ACO is that they provide multiple routes from source to destination, resulting in more robust network. In this work, together with ACO, I have used the ideas from zone routing protocols to develop my algorithm: Mobility Aware Zone based Ant Colony Optimization Routing for VANET that exhibits locality and scalability.
225

Topological arrangement of nodes in wireless networks suitable for the implementation of network coding / F.J. Böning

Böning, Frans Johan-Henry January 2010 (has links)
Network coding refers to the implementation of coding methods to utilize network connections more efficiently. Network coding is commonly researched in the information theory field, but very little research is being done on the physical implementation thereof. One exception is COPE where network coding is implemented in wireless networks for unicast transmission sessions. In this dissertation, we discuss the physical arrangement of wireless nodes to form topologies suitable for the implementation of network coding. We implement linear network coding in wireless ad hoc networks for multicast transmission sessions. We calculate the areas in which each wireless node must be located for a specific network coding suitable topology to be formed. The identified topologies are simulated in OPNET Modeler and then implemented on a six node testbed, to analyse the effect of implementing network coding in these topologies. We provide results indicating the trade-off between reduced network load and higher end-to-end delay when our developed network coding algorithm is active in the respective topologies. The results indicate that the developed network coding scheme will produce better overall performance when implemented in sensor networks or highly congested ad hoc networks. / Thesis (M.Ing. (Computer and Electronical Engineering))--North-West University, Potchefstroom Campus, 2011.
226

Multiple foreign agents IP mobility management in internet integrated mobile ad hoc networks /

Ding, Shuo. Unknown Date (has links)
Recently, Mobile Ad Hoc Networks (MANETs) have enjoyed a dramatic rise in popularity as potential solutions to connectivity in environments where telecommunication infrastructure is not available. Traditionally, MANETs are assumed to be stand-alone networks which do not require assistance from fixed network infrastructure (e.g. a backbone network). Based on this assumption, routing protocols for MANETs have been designed to work in stand-alone mode. However, throughput and coverage requirements of future 4G all-IP systems may require integration of MANETs into these systems to enhance the flexibility and pervasiveness of the networks. The coverage of existing infrastructure networks (wireless LAN hot-spots of 3G networks) can be effectively extended by the relaying communications via ad hot network nodes (wireless routers). Also, the limited services available within MANET can be extended to a wider range through connecting of the MANET to the Internet infrastructure. To achieve this, effective solutions are needed to many existing challenges in integrating MANETs with the Internet. / In this thesis, we propose solutions to three major challenges of interconnecting MANETs with the Internet. The underlying research problems can be listed as follows: Architecture options for integrating Mobile IP-based MANETs to the Internet via multiple gateways; The Internet extensions to reactive ad hoc routing protocols; Schemes for gateway discovery / Handoff in MANETs. / Thesis (PhDTelecommunications)--University of South Australia, 2007.
227

Defending MANETs against flooding attacks by detective measures

Guo, Yinghua January 2008 (has links)
Mobile ad hoc networks (MANETs), due to their unique characteristics (e.g., unsecured wireless channel, dynamic mobility, absence of central supportive infrastructure and limited resources), are suffering from a wide range of security threats and attacks. Particularly, MANETs are susceptible to the Denial of Service (DoS) attack that aims to disrupt the network by consuming its resources. In MANETs, a special form of DoS attack has emerged recently as a potentially major threat: the flooding attack. This attack recruits multiple attack nodes to flood the MANET with overwhelming broadcast traffic. This flooding traffic is so large that all, or most of, MANET resources are exhausted. As a result, the MANET is not able to provide any services. This thesis aims to investigate the flooding attack and propose detective security measures to defend MANETs against such an attack.
228

Distributed resource allocation and performance optimization for video communication over mesh networks based on swarm intelligence

Wang, Bo, January 2007 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 2007. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed Mar. 3, 2008). Vita. Includes bibliographical references.
229

Statistical approach to neighborhood congestion control in ad hoc wireless networks

Medina, Andres. January 2008 (has links)
Thesis (M.E.E.)--University of Delaware, 2007. / Principal faculty advisor: Gonzalo Arce, Dept. of Electrical and Computer Engineering. Includes bibliographical references.
230

Timer-based protocols in ad hoc and sensor networks

Kim, Bonam, Sun, Min-Te. January 2006 (has links) (PDF)
Dissertation (Ph.D.)--Auburn University, 2006. / Abstract. Vita. Includes bibliographic references (p.99-106).

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