6 research outputs found

    Energy-efficient adaptive wireless network design

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    Energy efficiency is an important issue for mobile computers since they must rely on their batteries. We present an energy-efficient highly adaptive architecture of a network interface and novel data link layer protocol for wireless networks that provides quality of service (QoS) support for diverse traffic types. Due to the dynamic nature of wireless networks, adaptations are necessary to achieve energy efficiency and an acceptable quality of service. The paper provides a review of ideas and techniques relevant to the design of an energy efficient adaptive wireless networ

    Energy-efficient wireless communication

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    In this chapter we present an energy-efficient highly adaptive network interface architecture and a novel data link layer protocol for wireless networks that provides Quality of Service (QoS) support for diverse traffic types. Due to the dynamic nature of wireless networks, adaptations in bandwidth scheduling and error control are necessary to achieve energy efficiency and an acceptable quality of service. In our approach we apply adaptability through all layers of the protocol stack, and provide feedback to the applications. In this way the applications can adapt the data streams, and the network protocols can adapt the communication parameters

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

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    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

    VoIP capacity over multiple IEEE 802.11 WLANs.

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    Chan, An.Thesis (M.Phil.)--Chinese University of Hong Kong, 2007.Includes bibliographical references (leaves 80-84).Abstracts in Chinese and English.Chapter Chapter 1 --- Introduction --- p.1Chapter 1.1 --- Motivations and Contributions --- p.1Chapter 1.2 --- Related Works --- p.3Chapter 1.3 --- Organization of the Thesis --- p.4Chapter Chapter 2 --- Background --- p.5Chapter 2.1 --- IEEE 802.11 --- p.5Chapter 2.1.1 --- Basic IEEE 802.11 Standards --- p.5Chapter 2.1.2 --- Types of Networks --- p.7Chapter 2.2 --- Voice over IP (VoIP) Codecs --- p.8Chapter 2.3 --- VoIP over WLAN --- p.9Chapter 2.3.1 --- System Architecture of VoIP over WLAN --- p.9Chapter 2.3.2 --- VoIP Capacity over an Isolated WLAN --- p.10Chapter Chapter 3 --- VoIP Capacity over Multiple WLANs --- p.12Chapter 3.1 --- Topology Settings and Assumptions --- p.12Chapter 3.2 --- Low VoIP Capacity Found in NS2 Simulations --- p.16Chapter 3.3 --- Applying Frequency Channel Assignment --- p.18Chapter Chapter 4 --- Clique Analysis and Call Admission Control --- p.21Chapter 4.1 --- Conflict Graph Model and Cliques --- p.21Chapter 4.2 --- Cliques in Multi-Cell WLANs --- p.22Chapter 4.3 --- Clique-Based Call Admission Control Algorithm --- p.24Chapter 4.3.1 --- Algorithm Description --- p.24Chapter 4.3.2 --- Algorithm Performance Evaluation --- p.27Chapter 4.3.3 --- Clique-Based Admission Control in Three-Frequency- Channel WLAN --- p.29Chapter Chapter 5 --- Time Division Multiple Access (TDMA) on IEEE 802.11MAC --- p.32Chapter 5.1 --- Coarse-Grained Time-Division Multiple Access (CTDMA) --- p.33Chapter 5.1.1 --- Basic Ideas of CTDMA --- p.33Chapter 5.1.2 --- Conflict Graph Modeling of CTDMA --- p.35Chapter 5.1.3 --- Parameter Values in CTDMA --- p.41Chapter 5.2 --- Possible Realization of TDMA on 802.11 Standards --- p.47Chapter Chapter 6 --- Coloring Problem in Wireless Networks: A Theoretical Treatment --- p.52Chapter 6.1 --- Coloring of One-Dimensional Linear Network --- p.53Chapter 6.1.1 --- Network with Same Link Length --- p.53Chapter 6.1.2 --- Network with Variable Link Length --- p.54Chapter 6.2 --- Coloring of Two-Dimensional Network --- p.63Chapter Chapter 7 --- Conclusion --- p.66Appendices --- p.69References --- p.8

    Design and analysis of low-power access protocols for wireless and mobile ATM networks

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    [[abstract]]This paper describes the design and analysis of a low-power medium access control (MAC) protocol for wireless/mobile ATM networks. The protocol - denoted EC-MAC (energy conserving medium access control) - is designed to support different traffic types with quality-of-service (QoS) provisions. The network is based on the infrastructure model where a base station (BS) serves all the mobiles currently in its cell. A reservation-based approach is proposed, with appropriate scheduling of the requests from the mobiles. This strategy is utilized to accomplish the dual goals of reduced energy consumption and quality of service provision over wireless links. A priority round robin with dynamic reservation update and error compensation scheduling algorithm is used to schedule the transmission requests of the mobiles. Discrete-event simulation has been used to study the performance of the protocol. A comparison of energy consumption of the EC-MAC to a number of other protocols is provided. This comparison indicates the EC-MAC has, in general, better energy consumption characteristics. Performance analysis of the proposed protocol with respect to different quality-of-service parameters using video, audio and data traffic models is provided.[[fileno]]2030228010007[[department]]資訊工程學

    Design and analysis of low-power access protocols for wireless and mobile ATM networks ∗

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    This paper describes the design and analysis of a low-power medium access control (MAC) protocol for wireless/mobile ATM networks. The protocol – denoted EC-MAC (energy conserving medium access control) – is designed to support different traffic types with quality-of-service (QoS) provisions. The network is based on the infrastructure model where a base station (BS) serves all the mobiles currently in its cell. A reservation-based approach is proposed, with appropriate scheduling of the requests from the mobiles. This strategy is utilized to accomplish the dual goals of reduced energy consumption and quality of service provision over wireless links. A priority round robin with dynamic reservation update and error compensation scheduling algorithm is used to schedule the transmission requests of the mobiles. Discrete-event simulation has been used to study the performance of the protocol. A comparison of energy consumption of the EC-MAC to a number of other protocols is provided. This comparison indicates the EC-MAC has, in general, better energy consumption characteristics. Performance analysis of the proposed protocol with respect to different quality-of-service parameters using video, audio and data traffic models is provided. 1
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