Multipath routing and QoS provisioning in mobile ad hoc networks

PhDA Mobile Ad Hoc Networks (MANET) is a collection of mobile nodes that can communicate with each other using multihop wireless links without utilizing any fixed based-station infrastructure and centralized management. Each mobile node in the network acts as both a host generating flows or being destination of flows and a router forwarding flows directed to other nodes. Future applications of MANETs are expected to be based on all-IP architecture and be capable of carrying multitude real-time multimedia applications such as voice and video as well as data. It is very necessary for MANETs to have an efficient routing and quality of service (QoS) mechanism to support diverse applications. This thesis proposes an on-demand Node-Disjoint Multipath Routing protocol (NDMR) with low broadcast redundancy. Multipath routing allows the establishment of multiple paths between a single source and single destination node. It is also beneficial to avoid traffic congestion and frequent link breaks in communication because of the mobility of nodes. The important components of the protocol, such as path accumulation, decreasing routing overhead and selecting node-disjoint paths, are explained. Because the new protocol significantly reduces the total number of Route Request packets, this results in an increased delivery ratio, smaller end-to-end delays for data packets, lower control overhead and fewer collisions of packets. Although NDMR provides node-disjoint multipath routing with low route overhead in MANETs, it is only a best-effort routing approach, which is not enough to support QoS. DiffServ is a standard approach for a more scalable way to achieve QoS in any IP network and could potentially be used to provide QoS in MANETs because it minimises the need for signalling. However, one of the biggest drawbacks of DiffServ is that the QoS provisioning is separate from the routing process. This thesis presents a Multipath QoS Routing protocol for iv supporting DiffServ (MQRD), which combines the advantages of NDMR and DiffServ. The protocol can classify network traffic into different priority levels and apply priority scheduling and queuing management mechanisms to obtain QoS guarantees

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

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

An enhanced Multipath Strategy in Mobile Ad hoc Routing Protocols

The various routing protocols in Mobile Ad hoc Networks follow different strategies to send the information from one node to another. The nodes in the network are non static and they move randomly and are prone to link failure which makes always to find new routes to the destination. This research mainly focused on the study of the characteristics of multipath routing protocols in MANETS. Two of the multipath routing protocols were investigated and a comparative study along with simulation using NS2 was done between DSR and AODV to propose an enhanced approach to reach the destination maintaining the QoS. A possible optimization to the DSR and AODV routing protocols was proposed to make no node to be overburdened by distributing the load after finding the alternate multipath routes which were discovered in the Route discovery process. The simulation shows that the differences in the protocol highlighted major differences with the protocol performance. These differences have been analyzed with various network size, mobility, and network load. A new search table named Search of Next Node Enquiry Table (SONNET) was proposed to find the best neighbor node. Using SONNET the node selects the neighbor which can be reached in less number of hops and with less time delay and maintaining the QoS

Encaminhamento com QoS em redes móveis Ad Hoc

Dissertação de mestrado integrado em Engenharia de ComunicaçõesNos dias de hoje a grande diversidade e o aumento da capacidade dos dispositivos móveis sem fios e simultaneamente a evolução das aplicações multimédia, criou-se a necessidade de propor e avaliar formas de oferecer garantias de Qualidade de Serviço (QoS) ao tráfego fim a fim nas redes móveis ad hoc (Mobile Ad hoc Networks - MANET). Este tipo de redes tem a vantagem de possibilitar aos utilizadores de dispositivos móveis, estabelecerem rapidamente e sem assistência de um ponto de acesso uma rede entre eles, que potencie a utilização de diversos serviços. Devido às suas características, desde a tecnologia sem fios até à mobilidade dos nós, dotar este tipo de redes de garantias de qualidade de serviço no tráfego fim a fim torna-se um desafio. Esta dissertação propõe um protocolo de encaminhamento com QoS para redes ad hoc, que se designa por Ad hoc QoS Multipath Routing with Route Stability (QMRS), que tem como objectivo suportar aplicações com requisitos de qualidade de serviço, nomeadamente requisitos no atraso fim a fim. Este protocolo tem a possibilidade de encontrar até três rotas de nós disjuntos que cumpram o requisito de QoS. Adicionalmente e com o objectivo de garantir a estabilidade do processo de encaminhamento, usa a potência de sinal das ligações entre nós vizinhos para eleger a rota mais estável, rota essa que passa a ser usada para o reenvio do tráfego. Quando se verifica a existência de rotas com uma estabilidade idêntica, dá-se preferência à rota com menor atraso fim a fim. O protocolo detém também um mecanismo de manutenção, recuperação e verificação de incumprimento do requisito de QoS nos caminhos encontrados. Este protocolo teve como base o protocolo Ad Hoc On-Demand Multipath Routing (AMR), também proposto e implementado no âmbito deste trabalho. Ambos os protocolos foram implementados e avaliados usando o simulador ns-3. Os resultados obtidos através de várias simulações realizadas para cada um dos protocolos implementados, assim como para o protocolo Ad hoc On-Demand Distance Vector (AODV) existente no simulador, permitiram verificar que, o protocolo QMRS com os mecanismos existentes de descoberta, manutenção, recuperação rápida de rota e verificação de incumprimento do requisito de QoS nos caminhos encontrados, permite obter resultados significativamente melhores, comparativamente ao protocolo AODV e ao protocolo AMR, no que diz respeito ao atraso fim a fim, taxa de entrega de pacotes no destino e taxa de transferência efectiva.Nowadays with the increasing of the diversity and the capability of the mobile devices and simultaneously the evolution of multimedia applications, has created the need to propose and evaluate ways of offering guarantees of Quality of Service (QoS) for the end-to-end traffic in the Mobile Ad hoc Networks (MANET). Such networks have the advantage of enabling mobile users, establish quickly and without assistance of an access point a network between them, which make best use of various services. Due to its characteristics, from the fact that it uses a wireless technology up to the impact of node mobility, providing quality of service guarantees in this type of networks for the endto- end traffic becomes a challenge. This thesis proposes a QoS routing protocol for ad hoc networks, which is known as Ad hoc QoS Multipath Routing with Route Stability (QMRS), which aims to support applications with quality of service requirements, namely requirements for the end to end delay. This protocol is able to find up to three disjoint routes that complies with the requirement of QoS. Additionally, and for the purpose of guarantee the stability of the routing process, uses the signal strength of the links between neighboring nodes to elect the most stable route, such route which is now used for forwarding traffic. When it is noted routes with the same stability, preference is given to the route with the lowest end to end delay. The protocol also holds a mechanism for maintenance, recovery and verification of compliance of the QoS requirement in the discovered paths. This protocol was based on the protocol Ad Hoc On-Demand Multipath Routing (AMR), also proposed and implemented during this work. Both protocols have been implemented and evaluated using the simulator ns-3. The results obtained through various simulations for each of the protocols implemented, as well as the Ad hoc On-Demand Distance Vector (AODV) protocol existent in the network simulator, allowed to verify that the QMRS protocol with the existent mechanisms for discovery, maintenance, rapid recovery of route and verification of compliance of the QoS requirement in the discovered paths, allow to obtain results with significant improvements compared to AODV protocol and AMR protocol, with respect to the average end to end delay, packet delivery ratio and throughput

Multipath optimized link state routing for mobile ad hoc networks

International audienceMultipath routing protocols for Mobile Ad hoc NETwork (MANET) address the problem of scalability, security (confidentiality and integrity), lifetime of networks, instability of wireless transmissions, and their adaptation to applications. Our protocol, called MP-OLSR (MultiPath OLSR), is a multipath routing protocol based on OLSR. The Multipath Dijkstra Algorithm is proposed to obtain multiple paths. The algorithm gains great flexibility and extensibility by employing different link metrics and cost functions. In addition, route recovery and loop detection are implemented in MP-OLSR in order to improve quality of service regarding OLSR. The backward compatibility with OLSR based on IP source routing is also studied. Simulation based on Qualnet simulator is performed in different scenarios. A testbed is also set up to validate the protocol in real world. The results reveal that MP-OLSR is suitable for mobile, large and dense networks with large traffic, and could satisfy critical multimedia applications with high on time constraints