Identification of metrics used by decision makers to determine the efficacy of wireless communication systems in higher education

This research described the wireless network technologies that are available for use in higher education, determined the categories of metrics used to evaluate wireless network efficacy, and yielded a self-assessment instrument for guiding small college administrators considering wireless local area network systems.;The features and benefits of contemporary wireless systems in higher education were identified through a review of the professional journals, government publications, and standards industry documentation. The literature identified three categories of metrics beneficial for the evaluation of efficacy of wireless campus local area networks: cost, speed, and reliability. After identification of these categories of metrics, a modified Delphi technique was administered to ten wireless network experts in higher education. The expert group was made up of seven higher education wireless decision makers and three wireless industry professionals.;The wireless experts responded to Instrument One which identified 27 metrics in the three categories of metrics. The experts generated 19 essential metrics: four in the category of cost, seven in the category of speed, and eight in the category of reliability. Eight supplemental metrics were also identified in Instrument One: four in the category of cost, two in the category of speed, and two in the category of reliability.;Instrument Two generated 27 questions that could guide wireless decision makers in higher education. These metrics offer a timeless guide to wireless system planning on small college campuses. The self-assessment instrument will assist in gathering information specific to the small college environment, and in gathering current specifications for wireless network systems. The analysis of information gained from the use of this tool will help wireless campus networks to operate as an integrated part of teaching and learning

Ethernet Performance: Design and Implementation Study

General concepts concerning local area network designs, functions and topologies will be presented. Ethernet as a multipoint bus topology local area network will be presented in detail. The Carrier Sense Multiple Access/Collision Detect (CSMA/CD) method of fairly regulating access to the shared network bus is studied. The Ethernet Network in relation to the Open Systems Interconnect (OSI) is reviewed, but only the layers pertaining to Ethernet are discussed throughout the majority of the paper. The specifications as described by Xerox, Digital and Intel are presented to help the designer understand the network\u27s physical limitations. Analytical models are used to predict performance and actual measured performance studies will be used to make performance assumptions. The performance is studied under varying load conditions. The data gathered concerns both limits imposed on the number of users by the finite bandwidth of the channel and efficient utilization of that channel. In conclusion, design specifications and performance data will be used together to formulate a design methodology for building the most efficient Ethernet network

New trends on Optical Access Networks: DBAs for 10G EPON and Long-Reach PON

The access network infrastructure plays an important role in the overall performance of the network, next generation access networks (NGA) must be able to access diverse services, and should incorporate adequate architectures that include mechanisms for the integration of different technologies. New optical access technologies trends are: WDM, 10 Gb/s, and longer reach/higher splits. It is also important to take into account the evolution of the installed legacy PONs to the next generation optical access networks. The present paper goes through such topics, focusing on the research being carried out to develop dynamic bandwidth algorithms for the 10 Gb/s new EPON standard (IEEE 802.3av). We summarize results and point out issues that will require further investigation.Postprint (published version

Wavelength reconfigurability for next generation optical access networks

Next generation optical access networks should not only increase the capacity but also be able to redistribute the capacity on the fly in order to manage larger variations in traffic patterns. Wavelength reconfigurability is the instrument to enable such capability of network-wide bandwidth redistribution since it allows dynamic sharing of both wavelengths and timeslots in WDM-TDM optical access networks. However, reconfigurability typically requires tunable lasers and tunable filters at the user side, resulting in cost-prohibitive optical network units (ONU). In this dissertation, I propose a novel concept named cyclic-linked flexibility to address the cost-prohibitive problem. By using the cyclic-linked flexibility, the ONU needs to switch only within a subset of two pre-planned wavelengths, however, the cyclic-linked structure of wavelengths allows free bandwidth to be shifted to any wavelength by a rearrangement process. Rearrangement algorithm are developed to demonstrate that the cyclic-linked flexibility performs close to the fully flexible network in terms of blocking probability, packet delay, and packet loss. Furthermore, the evaluation shows that the rearrangement process has a minimum impact to in-service ONUs. To realize the cyclic-linked flexibility, a family of four physical architectures is proposed. PRO-Access architecture is suitable for new deployments and disruptive upgrades in which the network reach is not longer than 20 km. WCL-Access architecture is suitable for metro-access merger with the reach up to 100 km. PSB-Access architecture is suitable to implement directly on power-splitter-based PON deployments, which allows coexistence with current technologies. The cyclically-linked protection architecture can be used with current and future PON standards when network protection is required