Energy-efficient wireless communication

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

Quality of Service over Specific Link Layers: state of the art report

The Integrated Services concept is proposed as an enhancement to the current Internet architecture, to provide a better Quality of Service (QoS) than that provided by the traditional Best-Effort service. The features of the Integrated Services are explained in this report. To support Integrated Services, certain requirements are posed on the underlying link layer. These requirements are studied by the Integrated Services over Specific Link Layers (ISSLL) IETF working group. The status of this ongoing research is reported in this document. To be more specific, the solutions to provide Integrated Services over ATM, IEEE 802 LAN technologies and low-bitrate links are evaluated in detail. The ISSLL working group has not yet studied the requirements, that are posed on the underlying link layer, when this link layer is wireless. Therefore, this state of the art report is extended with an identification of the requirements that are posed on the underlying wireless link, to provide differentiated Quality of Service

Energy-efficient adaptive wireless network design

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

Dynamic bandwidth allocation in ATM networks

Includes bibliographical references.This thesis investigates bandwidth allocation methodologies to transport new emerging bursty traffic types in ATM networks. However, existing ATM traffic management solutions are not readily able to handle the inevitable problem of congestion as result of the bursty traffic from the new emerging services. This research basically addresses bandwidth allocation issues for bursty traffic by proposing and exploring the concept of dynamic bandwidth allocation and comparing it to the traditional static bandwidth allocation schemes

Traffic Control in a Synchronous Transfer Mode Networks

In the 90s, there is an increasing demand for new telecommunication services such as video conferencing, videophone, broadcast television, image transfer and bulk file transfe r etc. At the same time, transmission systems at bit rates of 2.5 Gb/s are now being installed, and the expected next generation of 10 Gb/s systems is emerging from the research laboratories. Coupled with that the development and deployment of new technologies systems such as fiber optics and intelligent high-speed switches have made it possible to provide these services in future high-speed integrated services networks like Asynchronous Transfer Mode (ATM). However, because of their new characteristics, these new services pose great challenges not previously encountered in traditional circuitswitche d or packet switched networks. For example, feature s such as large propagation delay as compared to transmission delay, diverse application demands, constraints on call processing capacity, and Quality-Of-Service (QOS) support for different applications all present new challenges arising from the new technology and new applications. Thus, much research is needed not just to improve existing technologies, but to seek a fundamentally different approach toward network architectures and protocols. In particular, new bandwidth allocation and call admission control algorithms need to be studied to meet these new challenges. A VP bandwidth allocation problem is studied for services which requires guaranteed connection for a fixed duration of time leading to extensive use of facilities like reservations of transmission capacity in advance. In such a case, the network may offer discounts for users reserving capacities in advance due to the advantage of working with predetermined traffic loads. Similarly, charges may differ for customers wanting to book capacity for a specified tie interval. Based on this scenario, various charge classes and booking policies are introduced. An effective bandwidth allocation scheme is proposed at the VP level with multiple nested charge classes where these various classes are allocated bandwidth optimally through some booking policies'. The scheme is also shown to be effective in maximizing network revenue. The best tradeoff between revenue gained through greater demand for discount bandwidth units against revenue lost when full-charge bookings request must be turned away because of prior bookings of discount bandwidth units is also sought for

Dynamic bandwidth allocation in multi-class IP networks using utility functions.

PhDAbstact not availableFujitsu Telecommunications Europe Lt

The Design of a System Architecture for Mobile Multimedia Computers

This chapter discusses the system architecture of a portable computer, called Mobile Digital Companion, which provides support for handling multimedia applications energy efficiently. Because battery life is limited and battery weight is an important factor for the size and the weight of the Mobile Digital Companion, energy management plays a crucial role in the architecture. As the Companion must remain usable in a variety of environments, it has to be flexible and adaptable to various operating conditions. The Mobile Digital Companion has an unconventional architecture that saves energy by using system decomposition at different levels of the architecture and exploits locality of reference with dedicated, optimised modules. The approach is based on dedicated functionality and the extensive use of energy reduction techniques at all levels of system design. The system has an architecture with a general-purpose processor accompanied by a set of heterogeneous autonomous programmable modules, each providing an energy efficient implementation of dedicated tasks. A reconfigurable internal communication network switch exploits locality of reference and eliminates wasteful data copies