523 research outputs found

    ATM optical wireless networks

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    The aim of the research is to propose, design and evaluate a new wireless communication, local area network (LAN). Such a LAN will be able to extend the asynchronous transfer mode (ATM) wireline technology into indoor optical wireless networks

    Book Review

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    A Comparative Review of the Second and Third Editions of the “Mobile Communications Handbook” (Editor: Jerry Don Gibson)Gibson, J.D. (editor-in-chief). 1999. The Mobile Communications Handbook. 2nd ed. CRC Press LLC, Boca Raton, FL, USA.Available: <http://dx.doi.org/10.1201/NOE0849321672>.Gibson, J.D. (editor-in-chief). 2013. Mobile Communications Handbook. 3rd ed.CRC Press, Taylor & Francis Group LLC, Boca Raton, FL, USA.Available: <http://dx.doi.org/10.1201/b12494>

    Technology Directions for the 21st Century

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    New technologies will unleash the huge capacity of fiber-optic cable to meet growing demands for bandwidth. Companies will continue to replace private networks with public network bandwidth-on-demand. Although asynchronous transfer mode (ATM) is the transmission technology favored by many, its penetration will be slower than anticipated. Hybrid networks - e.g., a mix of ATM, frame relay, and fast Ethernet - may predominate, both as interim and long-term solutions, based on factors such as availability, interoperability, and cost. Telecommunications equipment and services prices will decrease further due to increased supply and more competition. Explosive Internet growth will continue, requiring additional backbone transmission capacity and enhanced protocols, but it is not clear who will fund the upgrade. Within ten years, space-based constellations of satellites in Low Earth orbit (LEO) will serve mobile users employing small, low-power terminals. 'Little LEO's' will provide packet transmission services and geo-position determination. 'Big LEO's' will function as global cellular telephone networks, with some planning to offer video and interactive multimedia services. Geosynchronous satellites also are proposed for mobile voice grade links and high-bandwidth services. NASA may benefit from resulting cost reductions in components, space hardware, launch services, and telecommunications services

    New dynamic bandwidth allocation algorithm analysis: DDSPON for ethernet passive optical networks

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    This project aims to present the state of the art in Dynamic Bandwidth Allocation (DBA) solutions, as well as the study and evaluation of one proposal of DBA algorithm: the Distributed Dynamic Scheduling for EPON (DDSPON), which is the UPC contribution to the research in scheduling algorithms for EPON

    The Design of a System Architecture for Mobile Multimedia Computers

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    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

    Channel-aware and Queue-aware Scheduling for Integrated WiMAX and EPON

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    By envisioning that the future broadband access networks have to support many bandwidth consuming applications, such as VoIP, IPTV, VoD, and HDTV, the integration of WiMAX and EPON networks have been taken as one of the most promising network architecture due to numerous advantages in terms of cost-effectiveness, massive-bandwidth provisioning, Ethernet-based technology, reliable transmissions, and QoS guarantee. Under the EPON-WiMAX integration, the development of a scheduling algorithm that could be channel-aware and queue-aware will be a great plus on top of the numerous merits and flexibility in such an integrated architecture. In this thesis, a novel two-level scheduling algorithm for the uplink transmission are proposed by using the principle of proportional fairness for the transmissions from SSs over the WiMAX channels, while a centralized algorithm at the OLT for the EPON uplink from different WiMAX-ONUs. The scheduler at the OLT receives a Report message from each WiMAX-ONU, which contains the average channel condition per cell, queues length, and head-of-line (HOL) delay for rtPS traffic. The EPON data frame is then scheduled based on these Report messages. Numerical results show that the proposed scheme could satisfy the end-to-end real-time QoS requirements. In addition, the centralized scheduler at the OLT can achieve high throughput in presence of traffic load variation

    Hybrid Strategies for Link Adaptation Exploiting Several Degrees of Freedom in WiMAX Systems

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