An energy-aware and QOS assured wireless multi-hop transmission protocol

A thesis submitted in fulfillment of the requirements for the degree of Master of Science by researchThe Ad-hoc network is set up with multiple wireless devices without any pre-existing infrastructure. It usually supports best-effort traffic and occasionally some kinds of Quality of Service (QoS). However, there are some applications with real-time traffic requirements where deadlines must be met. To meet deadlines, the communication network has to support the timely delivery of inter-task messages. Furthermore, energy efficiency is a critical issue for battery-powered mobile devices in ad-hoc networks. Thus, A QoS guaranteed and energy-aware transmission scheme is one hot of research topics in the research area. The MSc research work is based on the idea of Real-Time Wireless Multi-hop Protocol (RT-WMP). RT-WMP is a well known protocol originally used in the robots control area. It allows wireless real-time traffic in relatively small mobile ad-hoc networks using the low-cost commercial IEEE 802.11 technology. The proposed scheme is based on a token-passing approach and message exchange is priority based. The idea of energy-aware routing mechanism is based on the AODV protocol. This energy-saving mechanism is analysed and simulated in our study as an extension of the RT-WMP. From the simulation results and analysis, it has been shown that adding energy-aware mechanism to RT-WMP is meaningful to optimise the performance of traffic on the network

Interfering-aware QoS multipath routing for ad hoc wireless network

[[abstract]]Mobile nodes are interconnected by multihop routing paths consist of unstable radio links in ad hoc wireless network. It is complex and difficult to provide QoS routing in such network because of imprecise network information, insufficient bandwidth and dynamic topology. For improving network stability and throughput, multipath routing protocols are proposed. A sender node discovers multiple disjoined routing paths and spread traffic into multiple streams according to their delay or bandwidth. For real-time streaming, unstable throughput or insufficient bandwidth invites unexpected delay or jitter if it is a multimedia streaming. Some multipath routing protocols pre-evaluate available bandwidth of paths and select enough total bandwidth from them if real-time applications demand for QoS constraint. For minimizing the cost of these paths, a path with smaller hopcounts is prior selected. These disjoined paths are general too closed with each other and the total throughput cannot just be sum up because of "paths interfering". Discovering and selecting multiple high-interfering paths is ineffectual and the total available bandwidth is not precise. In this paper, we proposed an interfering-aware QoS multipath routing protocol for QoS-constraint multimedia and real-time applications in ad hoc wireless network. We apply a scheme to evaluate available bandwidth according to the network capacities with different media access control (MAC) protocols. A concept of "interfering ratio" of multipath is discussed and we evaluate the stability and throughput improvement by simulations.[[notice]]補正完畢[[conferencetype]]國際[[iscallforpapers]]Y[[conferencelocation]]Fukuoka, Japa

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