Zone Routing Protocol (ZRP) is a typical hybrid routing protocol used in Mobile Ad Hoc Networks (MANETs). Hybrid routing protocols are especially suitable for dynamic environments because they combine the best features of proactive and reactive routing protocols. The Gossip-based Zone Routing Protocol (GZRP) uses a gossip scheme, in which the node forwards a packet to some nodes instead of all nodes to further reduce the control overhead. However, GZRP does not perform well when the network includes articulation points since packets will be lost if an articulation node happens not to forward the packet or nodes happen not to forward packets to the articulation point. To raise the packet delivery ratio, the gossip probability of articulation points must be set to 1 and the packets to be forwarded must be sent to the articulation points in peripheral nodes. Accordingly, how to identify articulation nodes in the network becomes a critical issue. This paper proposes an effective scheme, called articulation point detection (APD), to find the articulation points. Simulation results show that the proposed APD-GZRP (GZRP with articulation point detection) can improve the packet delivery ratio and reduce both the control overhead and power consumption.

Wireless sensor networks consist of many small sensor nodes with sensing, computation, and wireless communications capabilities. Recently, there have been numerous research results in the power consumption for routing protocol. Routing protocols in WSNs might difference depending on the application and network architecture. This paper focuses on reducing the power consumption for routing protocol of wireless sensor networks too. We present a routing protocol called ACRP. sensor nodes will organize many clusters voluntarily. Cluster heads will distribute time slot to the sensor nodes in the same cluster and sensor nodes will transmit data to cluster head in it¡¦s time slot. After the data had been aggregated by cluster heads, they will send the aggregated data to base station through the routing path that had been established. In addition, in order to lengthen the living time of wireless sensor network, the base station will periodically adjust the amount of sensor nodes in all clusters according to the cluster information.

Wireless sensor networks(WSNs) are different to traditional networks and are highly dependent on applications, thus traditional routing protocols cannot be applied efficiently to the networks. As the variability of both the application and the network architecture, the majority of the attention, therefore, has been given to the routing protocols. This work surveys and evaluates state-of-the-art routing protocols based on many factors including energy efficiency, delay andcomplexity, and presents several classifications for the various approaches pursued. Additionally, more attention is paid to several routing protocols and their advantages and disadvantages and, indeed, this work implements two of selected protocols, LEACH and THVRG, on the OPNET, and compares them in many aspects based on a large amount of experimental data. The survey also provides a valuable framework for comparing new and existing routing protocols. According to the evaluation for the performance of the routing protocols, this thesis provides assistance in relation to further improving the performance in relation to routing protocols. Finally, future research strategies and trends in relation to routing technology in wireless sensor networks are also provided.

With the wireless mesh network in the embedded systems related applications booming in recent years, the demand of enhancing the overall end to end network traffic and ensuring a stable connection is growing. We proposed a Dynamic Multi-channel Multi-path Routing Protocol (DMMR Protocol) to decompose contending traffics over different channel, different time and different paths to enhance the end to end network traffic. Choosing channel dynamically according to the channel usage around node in the process of finding paths can avoid inter-flow and intra-flow channel competition. We tend to choose paths with less intersection nodes to reduce the probability of multiple paths are broken at same time when a single node cannot work. We can enhance end to end network traffic further by using multiple interfaces at one node. We use NS2 to test DMMR Protocol, and analyzing the overall end to end traffic when multiple connections are setting up in the network. If the network can accept a new connection, the increment of end to end traffic is same as the traffic of the new connection. In connection robust test, a single path broken will not affect other flows in same connection and the end to end traffic in the connection will recovery immediately when the broken path is repaired.

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Clustering schemes can reduce energy consumption, prolong network lifetime and improve scalability in wireless sensor networks (WSNs). In a typical cluster-based WSN, sensor nodes are organized into clusters. Each cluster elects a cluster head (CH) node. The CH is responsible for collecting the sensed data from cluster members, aggregating data and transmitting data to the sink node via a multi-hop path through intermediate CHs. Thus, the use of cluster techniques not only shortens the transmission distances for sensor nodes but also reduces energy consumption; however, each cluster imposes a larger load on the CH. Under this situation, CHs closer to the sink node tend to use up their batteries faster than those farther away from the sink node due to imbalanced traffics among CHs. To overcome this problem, we contribute to the energy balancing issues in WSNs from two aspects. In the first work, we first analyze the corona model. Based on analysis results, we found that nearly balanced energy consumption of WSNs can be achieved with the additional help of arranging different initial conditions. We then propose the Energy-balanced Node Deployment with Balanced Energy (END-BE) scheme and Energy-balanced Node Deployment with Maximum Life-Time (END-MLT) scheme, which determine the cluster density for each corona according to the energy consumption of each CH. Simulation results show that energy consumption is nearly balanced by implementing END-BE, and the network lifetime is greatly improved by adopting END-MLT. In the second work, we development a novel cluster-based routing protocol for corona-structured wireless sensor networks in order to balance the energy consumption among CHs. Based on the relaying traffic of each CH conveys, adequate radius for each corona can be determined through nearly balanced energy depletion analysis, which leads to balanced energy consumption among CHs. Simulation results demonstrate that our clustering approach effectively improves the network lifetime, residual energy and reduces the number of CH rotations in comparison with the Multi-Layer Clustering Routing Algorithm (MLCRA).

We propose a novel multicast routing protocol, called adaptive multicast routing protocol for MANETs (Mobile ad hoc routing protocol). Multicast routing protocols can be classified two types according the structure used to establish route. Existing protocols are either tree-based or mesh-based. In mesh-based routing protocols, a reliable protocol ODMRP was proposed. In ODMRP, each sender has to broadcast control packet periodically in order to build mesh. But with an increase of number of senders, control overhead causes reliability reduced because of a large amount of overhead and collisions. Hence, ODMRP is not work well in this case. We proposed our scheme to aim at the drawback of ODMRP. We use packet delivery ratio (PDR) to determine if the load of network is congestion. When packet delivery ratio is high, it means that the network traffic load is low, and vice versa. We determine whether a sender broadcasts Join-Query control packet or not according to packet delivery ratio. As packet delivery ratio is decrease, a sender does not broadcast Join-Query as far as it can in order to avoid collisions. However the packet delivery ratio is increase, senders have strong probability to broadcast Join-Query to establish mesh nodes. We can improve reliability and reduce overhead is caused by control packets with this way.

Mobile ad hoc network is an architecture which do not exist any infrastructure or centralized administration. There are many routing protocols have been proposed so far, such as AODV, DSR and CGSR. These protocols were classified as reactive in which routes are established only when required. Due to the movement of mobile nodes, network topology changes frequently, and the routing path could be broken easily. This phenomenon will cause higher routing overhead and delivery latency. In conventional routing protocols, the source-destination pair only establishes a single path for data transmission. These routing scheme, however, suffer from the drawback of node movement. When route broken, the source node must reconstruct another new path. This paper presents an adaptive routing protocol named Adaptive Route Selection Scheme of Multiple Paths for Mobile Ad Hoc Network (ARSMA). The aim of the work is to improve the delivery ratio. In the route request phase, source nodes will discovery two routes to the destination node, one for primary path, and the other for the backup path. During the discovery procedure, each node will estimate the link expire time through the movement speed and direction of the precursor node. When a link breakage is about to occur, source node will try to switch the transmission to the backup route.The simulation result shows that ARSMA is able to achieve a remarkable improvement in delivery ratio and end-to-end dealy.

Submitted by Matheus Alves Bulhoes (matheus.bulhoes@ufpe.br) on 2015-05-12T14:36:25Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertação_Luis_Final.pdf: 2794061 bytes, checksum: ca38ae8cdb5e52a8b28f84163a66bc6b (MD5) / Made available in DSpace on 2015-05-12T14:36:25Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertação_Luis_Final.pdf: 2794061 bytes, checksum: ca38ae8cdb5e52a8b28f84163a66bc6b (MD5) Previous issue date: 2014-08-29 / Redes emergenciais são redes móveis utilizadas em cenários de catástrofes onde os meios de transmissão convencionais estão usualmente comprometidos. Neste contexto o estabelecimento de uma MANET (Mobile Ad Hoc Network) é a solução mais indicada para suprir a comunicação entre as equipes de resgate e organizações competentes. Atualmente existe uma gama de trabalhos que, através de simulações, avaliam o desempenho de protocolos de roteamento em cenários variados, alguns de desastres. O cenário apresentado por este trabalho é específico de uma situação de desastre, similar a uma ocorrência de deslizamento de terra. Acontecimentos como esse criam um ambiente com características particulares e, o roteamento usado deveria suprir da melhor forma esses fatores únicos. Portanto, este trabalho apresentou uma hipótese que o roteamento baseado em zonas pode ser a melhor escolha para o cenário proposto. Foi desenvolvido um novo protocolo com base no já existente Zone Routing Protocol e comparado através de métricas de desempenho com os protocolos AODV e DSDV, além do próprio ZRP. Ainda, objetivando modelar uma mobilidade mais condizente com a apresentada pelas equipes de resgate, foi desenvolvida uma adaptação do "disaster mobility model" para junto com o cenário sumarizar as características únicas desse ambiente e gerar simulações mais realistas. As simulações foram feitas com uma variação do número de nós entre os cenários, e a comparação dos protocolos foi analisada pelos valores atingidos por eles nas simulações em métricas de desempenho. Os resultados mostraram que o novo protocolo foi bastante superior ao seu original em todas as métricas, atingindo também um desempenho semelhante ou melhor que o AODV e o DSDV em packet delivery ratio, end to end delay e routing overhead. Dessa forma, concluiu-se que o novo protocolo desenvolvido alcançou seu objetivo, se tornando, entre os protocolos testados, uma opção viável para roteamento em redes emergenciais críticas.

The first part focuses on general routing of computer networks. It describes the importance of routing, basic elements, algorithms and protocols. It also describes the so-called MANET networks, where there are discussed routing protocols in these networks. The next chapter deals with the analysis of routing protocols OSPF version 3 and OLSR protocol. For both protocols basic algorithms, their use and structure are described. In OSPF protocol there is also described historical development and differences between versions 2 and 3. The OLSR protocol properly describes the principle of MPR nodes, which is one of the most important parts of the protocol which differs it from the others. Next there is a brief introduction of a powerful simulation tool OPNET Modeler which allows simulating the operation and behavior of almost any computer network with a very extensive possibility of options for the functioning of the entire network, as well as nodes it selves. The practical part is divided into five parts. The first section describes the structure of process models, the basic elements, variables, and block editors OSLR routing protocol in OPNET Modeler program. The second part is devoted to the ICI data structure, which is used for inter-process communication and verify the creation and reception of messages using this function. The third part deals with the process model of OLSR routing model. There is a description of various blocks and functions involved in its function of protocol and significance. The fourth chapter shows an extension of data unit protocol OLSR HELLO messages to other fields, which is able to transmit a numeric value between neighboring stations, and these values print it in the console. The last block of the practical part is dedicated to creating its own message which is broadcast between stations like part of the OLSR packet messages. This message includes the parameter of actual data traffic rate of each communicating stations. These values are for each station exported to an external file for later processing.