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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.
1

Reliable on-demand routing protocols for mobile ad-hoc networks

Khan, Shariq Mahmood January 2015 (has links)
Mobile Ad-Hoc Network (MANET) facilitates the creation of dynamic reconfigurable networks, without centralized infrastructure. MANET routing protocols have to face high challenges like link instability, node mobility, frequently changing topologies and energy consumption of node, due to these challenges routing becomes one of the core issues in MANETs. This Thesis mainly focuses on the reactive routing protocol such as Ad-Hoc On-Demand Distance Vector (AODV) routing protocol. Reliable and Efficient Reactive Routing Protocol (RERRP) for MANET has been proposed to reduce the link breakages between the moving nodes. This scheme selects a reliable route using Reliability Factor (RF); the RF considers Route Expiration Time and Hop Count to select a routing path with high reliability and have less number of hops. The simulation result shows that RERRP outperforms AODV and enhance the packet delivery fraction (PDF) by around 6% and reduces the network routing load (NRL) by around 30%. Broadcasting in MANET could cause serious redundancy, contention, and collision of the packets. A scheme, Effective Broadcast Control Routing Protocol (EBCRP) has been proposed for the controlling of broadcast storm problem in a MANET. The EBCRP is mainly selects the reliable node while controlling the redundant re-broadcast of the route request packet. The proposed algorithm EBCRP is an on-demand routing protocol, therefore AODV route discovery mechanism was selected as the base of this scheme. The analysis of the performance of EBCRP has revealed that the EBCRP have controlled the routing overhead significantly, reduces it around 70% and enhance the packet delivery by 13% as compared to AODV. An Energy Sensible and Route Stability Based Routing Protocol (ESRSBR) have also been proposed that mainly focuses on increasing the network lifetime with better packet delivery. The ESRSBR supports those nodes to participate in the data transfer that have more residual energy related to their neighbour nodes. The proposed protocol also keeps track of the stability of the links between the nodes. Finally, the ESRSBR selects those routes which consist of nodes that have more residual energy and have stable links. The comparative analysis of ESRSBR with AODV and recently proposed routing protocol called Link Stability and Energy Aware (LSEA) routing protocol revealed that the proposed protocol ESRSBR has a significantly affect the network lifetime, increases it around 10% and 13% as compared to LSEA and AODV protocols respectively. The ESRSBR also decreases the routing overhead by 22% over LSEA and by 38% over AODV.
2

Internet-Scale Reactive Routing and Mobility

Nelson, Daniel B 01 June 2009 (has links) (PDF)
Since its commercialization, the Internet has grown exponentially. A large variety of devices can communicate creating advanced services for a diverse ecosystem of applications. However, as the number of Internet hosts has grown, the size of routing tables required to correctly route data between them has also increased exponentially. This growth rate necessitates increasingly frequent upgrades to routing device hardware, providing them with additional memory for fast-access storage of route information. These upgrades are both physically and fiscally untenable, and a new Internet routing solution is necessary for future growth. This research focuses around an incrementally deployable, reactive routing system that is scalable to projected Internet growth. It requires no hardware or software updates to Internet routers, and offoads processing to end hosts and the network's edge. Within this framework, routers can make accurate decisions about optimal data paths; incurring no increase in path length over the current routing system. A new architecture for IP Mobility is considered as a case study within this routing system, and compared with existing standards and implementations. The new architecture eliminates the triangle routing problem, while providing legacy hosts with connectivity to mobile devices. This mobility solution can integrate with a variety of hierarchical reactive routing systems with little overhead.
3

Efficient route discovery for reactive routing

Hamad, Sofian January 2013 (has links)
Information on the location of mobile nodes in Mobile Ad-hoc Networks (MANETs) has the potential to significantly improve network performance. This thesis uses node location information to develop new techniques for route discovery in on-demand routing protocols such as the Ad-hoc On-Demand Distance Vector (AODV), thus making an important contribution to enhancing the experience of using mobile networks. A Candidate Neighbours to Rebroadcast the Route Request (CNRR) approach has been proposed to reduce the deleterious impact, known as the broadcast storm, of RREQ packets flooding in traditional on-demand routing protocols. The main concept behind CNRR is specifying a set of neighbours which will rebroadcast the received RREQ. This is a departure from the traditional approach of all receiving nodes rebroadcasting RREQs and has the effect of reducing the problem of redundancy from which mobile networks suffer. The proposed protocol has been developed in two phases: Closest-CNRR and Furthest-CNRR. The simulation results show that the proposed algorithms have a significant effect as they reduce the routing overhead of the AODV protocol by up to 28% compared to the C-CNRR, and by up to 17.5% compared to the F-CNRR. Notably, the proposed algorithms simultaneously achieve better throughput and less data dropping. The Link Stability and Energy Aware protocol (LSEA) has been developed to reduce the overhead while increasing network lifetimes. The LSEA helps to control the global dissemination of RREQs in the network by eliminating those nodes that have a residual energy level below a specific threshold value from participation in end-to-end routes. The proposed LSEA protocol significantly increases network lifetimes by up to 19% compared with other on-demand routing protocols while still managing to obtain the same packet delivery ratio and network throughput levels. Furthermore, merging the LSEA and CNRR concepts has the great advantage of reducing the dissemination of RREQs in the network without loss of reachability among the nodes. This increases network lifetimes, reduces the overhead and increases the amount of data sent and received. Accordingly, a Position-based Selective Neighbour (PSN) approach has been proposed which combines the advantages of zoning and link stability. The results show that the proposed technique has notable advantages over both the AODV and MAAODV as it improves delivery ratios by 24.6% and 18.8%, respectively.
4

DYRP-VLC: a dynamic routing protocol for visible light communication networks

Matheus, Luiz Eduardo Mendes 03 September 2018 (has links)
Submitted by Renata Lopes (renatasil82@gmail.com) on 2018-11-19T12:44:23Z No. of bitstreams: 1 luizeduardomendesmatheus.pdf: 1606990 bytes, checksum: 2736fa2230ff16ef4aaa41155178b616 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2018-11-23T13:06:46Z (GMT) No. of bitstreams: 1 luizeduardomendesmatheus.pdf: 1606990 bytes, checksum: 2736fa2230ff16ef4aaa41155178b616 (MD5) / Made available in DSpace on 2018-11-23T13:06:46Z (GMT). No. of bitstreams: 1 luizeduardomendesmatheus.pdf: 1606990 bytes, checksum: 2736fa2230ff16ef4aaa41155178b616 (MD5) Previous issue date: 2018-09-03 / Na última década, o interesse (acadêmico e comercial) em torno da Comunicação por Luz Visível (VLC) aumentou consideravelmente, devido a fatores como a crescente demanda por recursos sem fio na Internet e às vantagens oferecidas pela transmissão de dados através da luz visível. Entretanto, a utilização da luz como meio de comunicação, principalmente em ambientes internos, oferece diversos desafios, como interferência e bloqueios criados por obstáculos. Ao mesmo tempo, este tipo de ambiente oferece uma rica infraestrutura de fontes de luz, que podem ser utilizadas para auxiliar na comunicação através de mecanismos multi-hop. A maioria dos trabalhos presentes na literatura adotam técnicas simples para construção de mecanismos multi-hop em redes VLC, focando principalmente em aumento de distância. Neste trabalho, foi desenvolvido um protocolo de roteamento dinâmico, DYRP-VLC (DynamicRoutingProtocolforVisibleLightCommunication),quetemcomoobjetivo aumentar o desempenho de sistemas VLC em ambientes dinâmicos, enquanto reage à obstáculos construindo rotas alternativas na rede. A avaliação do protocolo foi realizada em um ambiente real, utilizando a plataforma embarcada OpenVLC 1.0 e métricas adotadas para problemas de roteamento. Os resultados obtidos mostram que, usando o DYRP-VLC, a rede foi capaz de se adaptar a mudanças dinâmicas na comunicação, como sombras e obstáculos, com pouca sobrecarga. / In the last decade, the interest in Visible Light Communication (VLC) has increased considerably, from both academic and commercial perspectives, due to factors such as the growing demand for wireless resources and the advantages offered by the transmission of data through visible light. However, the use of light as a communication medium, especially in indoor environments, offers several challenges, which includes shadowing and interference caused by obstacles. At the same time, this type of environment offers a rich infrastructure of light sources, which can be used to aid communication through multi-hop mechanisms. Most of the works present in the literature adopt simple techniques to construct multi-hop mechanisms in VLC networks, focusing mainly on increasing distance. Inthisthesis,wedevelopedDYRP-VLC(DynamicRoutingProtocolforVisibleLight Communication), a reactive routing protocol which aims to increase the performance ofVLCsystemsindynamicenvironments,whilereactingtoobstaclesbyconstructing alternative routes in the network. The evaluation of the protocol was performed in a real environment, using OpenVLC 1.0 embedded platform and adopting metrics for routing problems. The results show that, by using DYRP-VLC, the network was able to adapt to dynamic changes in communication, such as shadows and obstacles, with low overhead.
5

Reactive Networking using Dynamic Link Exchange Protocol

Nilsson, Kim January 2014 (has links)
This master thesis studies the possibilities of using a radio-router protocol in order to increase the quality of service in dynamic tactical network environments. We cover three radio-router protocols with emphasis on Dynamic Link Exchange Protocol (DLEP). Many applications, such as voice and video communication, have bandwidth and latency requirements which need to be fulfilled in order to provide a sufficient level of quality. This poses a problem in tactical network environments where links are typically dynamic and both bandwidth andlatency can vary. A radio-router protocol can alleviate this problem and also improve the routing in a network by allowing routers to take part of link-layer information. By using a radio link emulator (RLE) developed by Saab we are able to simulate dynamic network environments. We have performed two experiments by combining the RLE and an implementation of a subset ofthe DLEP specification draft. Both experiments simulate typical military network scenarios and allow us to analyse the effects of utilizing link-layerfeedback.Our results show that by using DLEP it is possible to provide better quality of service in highly dynamic conditions. We also show that DLEP can influence Optimized Link State Routing (OLSR) by making OLSR aware of changes in the network topology. This leads to a reduced network convergence time with only a small increase in OLSR overhead.
6

Směrování v bezdrátových sítích / Routing in Wireless Networks

Janský, Václav January 2008 (has links)
This work deals with routing protocols for ad hoc wireless networks. First ad hoc networks are introduced. Routing protocols are then classified according to several criteria. Four routing protocols algorithms are described. They are proactive protocols DSDV and CGSR, reactive DSR and hybrid ZRP. Next AODV routing protocol is described in details. Advantages and disadvantages of AODV and two variants of AODV are also introduced. A new protocol is designed based on the disadvantages of the AODV protocol. This work also describes the implementation and integration of the new protocol in the ns-2 simulator. Results of the simulations are presented.

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