Dissertations / Theses on the topic 'Computer architecture for LAN'

The increasing popularity of wireless handheld devices with multimedia functionality and IEEE 802.11 based network connectivity generated the need for Quality of Service (QoS) support of real time applications deployed over the wireless LANs. However, the time varying nature of wireless link and network is a serious challenge when attempting to provide Quality of Service support. This thesis proposes a low cost/complexity QoS capable wireless LAN architecture. We designed a distributed network congestion control scheme based on current commercial available hardware. The proposed technique was implemented on a Linux based testbed. Its performance was assessed through extensive experiments. Our evaluation test work includes two parts. First an IEEE802.11b wireless LAN testbed is established and a thorough network capacity measurement test is performed. The actual performance of real wireless LAN products is evaluated in a typical indoor environment. Furthermore, the impacts of multiple competing stations and nearby radio noise are also evaluated in this testbed. In the second part, the QoS capable wireless architecture prototype is implemented using Linux operating system Redhat 7.3 and Orinoco Golden IEEE802.11b wireless network card. The performance evaluation is conducted using the prototype implemented on the IEEE802.11 b wireless LAN testbed.

The thesis work intends to provide architecture for mobile local information search service using Wireless LAN and cellular integration. Search technology has been popular and driving business bodies with increasing e-commerce opportunities. The search technology has been recently brought to portable devices such as mobile phones and PDA devices by extending the research scope. Mobile search revenues are expected to surpass Internet search revenues in near future. Mobile local search on the other hand is getting much popular with growing number of mobile subscribers. Mobile phones have been chosen to provide mobile local search services because of its high possessivity and portable nature. In this thesis work, the author would like to propose a generalized architecture for mobile local information search in a new perspective by involving cellular service provider directly with a minimum co-operation from consumers and retailers. When providing mobile local search services, cellular operator has to maintain a replica of databases of all the existing retailers. Updating the replica at cellular operator at regular intervals has been leading to synchronization problems that produce out-dated results to mobile users. The aspects that have driven the author towards proposing the architecture are solving database synchronization problems and thriving for effective search results. The existing architecture of web search, mobile search and mobile local search are analyzed to identify the domain specific challenges and research gaps. Proposed architecture is designed and evaluated by using an approach called Architecture Tradeoff Analysis Method (ATAM). The architecture is evaluated against its quality attributes and the results are presented.
Sridher Rao Sidduri Lindblomsvagen, 97, Rum no 555, 372 33 Ronneby, Sweden E-mail: srsi05@student.bth.se

International Telemetering Conference Proceedings / October 28-31, 1996 / Town and Country Hotel and Convention Center, San Diego, California
The ever-increasing power of PC hardware combined with the new operating systems available make the PC an excellent platform for a telemetry system. For applications that require multiple users or more processing power than a single PC, a network of PCs can be used to distribute data acquisition and processing tasks. The focus of this paper is on a distributed network approach to solving telemetry test applications. This approach maximizes the flexibility and expandability of the system while keeping the initial capital equipment expenditure low.

Thesis: M. Eng., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2015.
This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (pages 121-122).
In Electrical Engineering courses, it is important that students have hands-on experience with a circuit and components to witness their behavior and compare it with theoretical models. The MIT iLab Project develops online laboratories that allow students to perform experiments through a web browser from anywhere in the world. One such lab used in the Introduction to Circuits class, the NMOS Resistor Amplifier Lab, allows students to analyze the switching waveforms of a transistor. This thesis describes the integration of a thermal camera to the NMOS-Resistor Amplifier Lab to educate students about energy dissipation. The first version of this lab, built entirely in LabVIEW, on iLabs' existing Shared Architecture could not support an interactive lightweight client. In response, the Experimental Lab Server Architecture (ELSA) was developed as a new interface connecting an experiment, client, and Service Broker. In the first prototype of the Thermal Lab in ELSA, a Java Applet Client uses REST calls to send commands and acquire data from the LabVIEW experiment running on the server.
by Letitia Weixia Li.
M. Eng.

International Telemetering Conference Proceedings / November 04-07, 1991 / Riviera Hotel and Convention Center, Las Vegas, Nevada
One of the most challenging technical problems in the development of a spacecraft telemetry simulation is the interface with a flight computer running real-world flight software. The ability of the simulation to satisfy flight software requests for telemetry data, and to load, mode, and control the flight software along with the simulation, can be constrained or degraded using conventional interface solutions. Telemetry dataflow architecture systems can be utilized to solve the interface problems with less constraints. This is an especially attractive solution in a telemetry simulation where the telemetry system can also be used to format and serialize spacecraft telemetry, and receive and preprocess commands. This paper discusses the concepts developed for such a system for a training simulation of the Orbital Maneuvering Vehicle for NASA at Johnson Space Center.

The problem explored in this dissertation report was that at the time of this study, there were no design principles or methodologies based on design science research (DSR) available to use for artifact construction, implementation, and effective evaluation of cloud-based networking lab environments that can be used to foster hands-on technology skills in students. Primarily based on Hevner’s 7 guidelines of DSR, Peffer’s design science research methodology (DSRM), and Gregor’s IS design theory, this study forms the groundwork for the development of procedures and specifications derived from DSR literature to facilitate the construction, implementation, and evaluation of a comprehensive cloud-based computer and information systems (CIS) laboratory artifact that is globally accessible 24 hours a day and 7 days a week. Secondarily, this study guided the construction and implementation of a prototype cloud-based lab environment using the procedures and specifications derived from DSR. The cloud-based lab environment was then evaluated based on the skill level attained by students enrolled in courses that leveraged the proposed system. Results of this study showed that the overwhelming majority of the students who participated in the experiment using the cloud-based lab environment showed statistically significant gains in pretest and posttest scores compared to the students who participated in the experiment using the classroom-based physical equipment. These results fully supported the first hypothesis for this study, that participation in the cloud-based lab environment would promote positive student outcomes. The second hypothesis also was supported. The majority of the experimental group students completed most of the labs and significantly spent more time on the system compared to the control group students using the traditional classroom-based physical lab equipment, which indicated the specifications derived from DSR positively influenced the use of the cloud-based system. An argument was made that the proposed study advances IS and education research through artifact construction and evaluation by correlating Hevner’s 7 steps of effective DSR theory, Peffer’s DSRM, and Gregor’s IS design theory to the problem statement, research questions, and hypothesis in order to develop guiding principles and specifications for building and assessing a cloud-based lab environment.

As a result of rapid progress in research and development, today's wireless world exhibits several heterogeneous communication networks, such as cellular networks, satellite networks, wireless local area networks (WLAN), mobile ad hoc networks (MANET), and sensor networks. These networks are complementary to each other. Hence, their integration can realize a unified wireless system that has the best features of the individual networks. This has spurred much research interest in designing integrated next-generation of wireless systems (NGWS). While existing wireless networks have been extensively studied individually, the integrated wireless system brings new challenges in architecture design, system management, and protocol design. The different wireless networks use different communication technologies and are based on different networking paradigms. Therefore, it is challenging to integrate these networks such that their heterogeneities are hidden from each other and a harmonious inter-operation among them is achieved. The objective of this research is to design a scalable, secure, and robust architecture and to develop seamless mobility management protocols for NGWS. More specifically, an architecture that integrates the heterogeneous wireless systems is first proposed for NGWS. Next, a cross-layer (Layer 2 + 3) handoff management protocol is developed for NGWS. Afterward, analytical modeling is developed to investigate the handoff performance of the existing mobility management protocols for different types of applications. Finally, a framework for multi-layer mobility management is developed to support the seamless handoff support to all types of applications in NGWS.

Introduction de la partie "Contexte" du mémoire :

Avec le développement accéléré du numérique et des réseaux, nous sommes les témoins d'un basculement fantastique des activités humaines, qui porte sur l'expression de la culture et de la communication, la transformation des processus industriels, les relations inter-personnelles, les activités de travail et de loisir des individus, les conditions d'exercice de la démocratie.
En moins d'une vingtaine d'années, le nombre et la puissance des ordinateurs mis dans les mains des individus a explosé, offrant aux personnes et aux groupes une capacité de traitement inimaginable auparavant. Leur couplage avec l'interconnexion des réseaux a bousculé la donne culturelle, relationnelle, économique, politique, géopolitique, éducative, sociale, médiatique....
La maîtrise de techniques symboliques (traitement d'images, stockage de fichiers numériques, usage du réseau comme ressource d'information, recherche documentaire, transcodage de la musique, écriture et publication personnelle) s'est répandue comme une traînée de poudre dans le monde entier.
Les tranches d'âge concernées se sont élargies en quelques années. La jeunesse et plus encore l'adolescence faisant un large usage des médiations techniques dans sa sociabilité et son apprentissage personnel. Le troisième âge découvre avec intérêt les techniques numériques, de l'appareil photo au mail, qui les gardent en contact avec leur descendance. Les différences d'usage entre les sexes se réduisent, et le travail des groupes de femmes pour utiliser la technologie comme un outil d'égalité et de libération porte des fruits dans tous les types de communautés, notamment dans les pays en développement.

Les divers réseaux et pratiques immatérielles convergent de plus en plus vite vers un réseau ubiquitaire, mêlant intimement les activités de communication, de production symbolique (culture, connaissance et divertissement) et de diffusion. Les terminaux se diversifient, se font mobiles (baladeurs, ordinateurs portables, PDA, téléphones mobiles nouvelle génération...) et s'incrustent dans toutes les activités (travail, culture, loisir, vie quotidienne).
Les principes d'individualité, de vie privée, d'autonomie et même de citoyenneté ne sont plus des qualités intrinsèques aux personnes, mais ressortent de l'émergence de " technologies de la personnalité " et de systèmes d'exposition et de gestion de la personnalité (réseaux sociaux, systèmes d'identification, auto-publication, partage d'environnements culturels ou de jeux, mondes virtuels...).

Le " système nerveux " de l'économie mondiale repose sur ces échanges immatériels accrus, sur les formes nouvelles de production qu'ils permettent, et sur la valorisation et la monétarisation des activités de connaissance, de communication, d'éducation et d'échange. Ces événements technologiques accompagnent et rendent possibles, ou imaginables, d'autres bouleversements dans l'organisation du monde, souvent regroupés sous le terme de " mondialisation " d'une part et de " société de l'information " de l'autre.
Ces bouleversements massifs et en profondeur méritent une attention particulière de la recherche, afin d'analyser ce phénomène au moment même de son bouillonnement, et d'en dégager des principes, des concepts et des grilles d'analyse qui permettent :
- de proposer de nouvelles applications, protocoles et architectures, d'une part pour les sciences de l'ingénieur ;
- de replacer les pratiques sociales, économiques et culturelles qui se cristallisent et se recomposent dans le réseau et le numérique, au sein du fil global de l'histoire et des données de long terme ;
- de repérer les fractures qui se constituent, afin que les sciences humaines et sociales puissent jouer un rôle éclairant pour les citoyens et les acteurs politiques et économiques.

[...] et les derniers mots de la conclusion

Les questions du domaine public et des biens communs de l'information, parce qu'elles permettent d'imaginer une société dans laquelle la transmission et le partage des connaissances serait un moment essentiel de la socialisation et de la vie collective me semblent des questions centrales, qu'il faut encore polir et repolir sur le métier de la recherche sur le document numérique et les réseaux.
Le numérique nous apporte des promesses inégalées de coopération et d'extension de la culture et de la connaissance. Comment permettre à tous les habitants de la planète d'en profiter ? Quels verrous faut ils ouvrir ? Quels ressorts de rêve et d'utopie peuvent être remontés pour que se libère une énergie libératrice ? Comment les réflexions techniques peuvent-elles accompagner un projet social mondial ?
Le chercheur, l'intellectuel et le citoyen sont convoqués pour travailler la compréhension de cet univers du numérique qui irrigue et transforme si profondément nos sociétés. Et faire coopérer les solutions techniques, juridiques, sociales et organisationnelles pour ouvrir des espaces publics mondiaux nouveaux. Ici et maintenant.

A combination of evolving technologies, economic circumstances, and the need to manage the increased flow of information culminated in the utilization of computer networks in libraries to enhance information retrieval and document delivery and facilitate access to resources. Computer networks have enabled librarians to streamline support services and reduce the costs of labor intensive operations. A computer network is a structure that makes available to an end user at one place some service performed at another place. Ever since computer users started accessing central processor resources from remote terminals three decades ago, computer networks have become complex, powerful, and versatile. Technically, computer networks have evolved from dedicated private networks to those utilizing multiplexed links or accessing hosts from multiple vendors. Geographically, computer networks have the capability to link several buildings, a few states or span the globe. Advanced telecommunications technology in concert with computer technology triggered the emergence of all sizes, shapes, and types of computer networks to enable terminals and/or users connected to the networks to communicate with each other. While libraries' needs are changing in the fields of video and voice communications, the most profound alterations are in the realm of data communications or telecommunications among computers and between terminals and computers. To cope with the mix of requirements for sharing resources ranging from bibliographic citations and cataloging and circulation records to grant proposals and publications, librarians in the 1980s are turning to a special form of computer network, the extended local area network or linked LAN, as a tool for connecting diverse communications equipment. A local area network is a facility providing data communications within a geographically limited area. Essentially, a local area network can bind together proliferating personal computers, terminals, host computers, and other communications equipment for information interchange. These local area networks can be connected into linked LANs or extended local area networks through fiber optic transmission in a dispersed geographical area for maximum communications efficiency. The dissertation, NETWORKING: CHOOSING A LAN PATH TO INTERCONNECTION, is about the mortar and bricks out of which computer networks are built. Special emphasis is placed on the process of designing, installing, and implementing local area networks and on the linkage of these LANs as a strategy for information management for multi type library consortia such as SEFLIN (SouthEast Library Information Network). Consisting of public and academic libraries in Southeast Florida, SEFLIN is responsible for promoting resource sharing and the dissemination of new knowledge in all areas of study for the 3.2 million residents of Florida's Broward, Dade, and Palm Beach Counties. SEFLIN participants include the Broward Community College Library, the Broward County Library System, the Florida Atlantic University Library, the Florida International University Library, the Miami – Dade Community College Library, the Miami-Dade Public Library, and the University of Miami Library. Scarcity of space, shrinking budgets, growing user demands and expectations, spiraling costs of materials and services, and price reductions in communications and computing equipment contributed to the emergence of multi type library networks such as SEFLIN for resource sharing. SEFLIN was formed to serve the needs of a mixed community of library users by supplying access to a full range of information resources and offering sophisticated support for a host of library and management function including online processing and cataloging, circulation control, serials control, fund accounting, statistical reporting, word processing and electronic mail. SEFLIN's primary mission is to link libraries in a common pattern of information exchange through the creation of an extended local area network or linked LAN. Sharing decision making data among public and academic libraries broadens the scope of sources and services available to the user community. Few areas in data communications much recent offering as technological innovation and local area networks. Local have seen as new commercial area network development has responded to the users' demand for greater transmission speed and capacity .Among user advantages provided by a LAN are enhanced reliability; faster response time; flexibility in applications programming; better supported facilities; and internetworking capabilities for multiple remote locations. Spanning short distances ranging from a few meters to several kilometers and involving high data rates and short propagation delays, local area networks are characterized by a variable number of devices requiring interconnection. As more and more materials become available and the costs of operations skyrocket, library professionals have to come to terms with the facts that not only is there not enough money around to be self-sufficient but often any semblance of self-sufficiency has become an impossibility. As a consequence, computer networks such as linked LANs are playing an increasingly important role in library activities. NETWORKING: CHOOSING A LAN PATH TO INTERCONNECTION is the result of efforts to explore the processes involved in developing a framework for interconnecting disparate computer systems in use by SEFLIN members in an extended local area network (LAN) or linked LAN based on the Open Systems Interconnection (OSI) Reference Model promulgated by the International Organization for Standardization (ISO) . Within a multi-type library consortium such as SEFLIN, an extended local area network or linked LAN facilitates access to decision making data. A networking system such as Network Systems Corporation's HYPERbus which can be extended via private or public communications facilities such as Bell South T1 transmission technology, compatible Timep1ex devices, and Microtel's LaserNet, a fiber optic transmission system, into an extended local area network or linked LAN is a mechanism for facilitating the accomplishment of this mission. Inasmuch as HYPERbus has been utilized since 1984 by the Broward County Main Library, the major reference and research facility of the Broward County Library System, and can provide maximum performance networking capabilities for high speed digital data communications applications, NETWORKING: CHOOSING A LAN PATH TO INTERCONNECTION examines the feasibility of using HYPERbus as the basis for an extended local area network linking two SEFLIN participants, namely, the Broward County Main Library and the Florida Atlantic University Library. Developed by Network Systems Corporation, HYPERbus is a local area network implemented by Broward County's Information Resources Management Division in downtown Fort Lauderdale. Presently, HYPERbus is used to link the Broward County Main Library, the Broward County Governmental Center, the Broward County Courthouse, and the new jail facility. A multi-drop coaxial cable based system which transmits data at speeds up to 10M bps, HYPERbus features a flexible architecture capable of handling simultaneously diverse data rate, traffic types, and protocols and incorporating a variety of transmission media within the network. Moreover, HYPERbus can support extended span geographic distances using communication links. HYPERbus provides a data communications resource that is transparent to differences in communications media and equipment. As a consequence, network reconfiguration and expansion can be readily accomplished as new technologies, protocols, and user requirements emerge. The generic model developed in this dissertation for interconnecting two SEFLIN participants based on HYPERbus technology, however, is by no means exhaustive of all existing schemes; the field is presently so wide open that new schemes are being introduced constantly. Technological advances and economic pressures have stimulated interest in resource sharing through computer networking as an option for overcoming barriers in accessing information. The linking of computerized systems to enable one system to exchange data with another system is an essential and basic goal to any effective cooperative intersystem resource sharing effort. In this world of electronic communications, the future of computer networking which provides tailored data communications services to the user community is definitely on an upward climb as a consequence of such factors as competitive pricing, improved and faster transmission speeds, and conformance to standards devised by the International Organization for Standardization (ISO). NETWORKING: CHOOSING A LAN PATH TO INTERCONNECTION deals with designing and implementing a computer network for resource sharing and is intended for technical service and public service staff of the Broward County Library System who are using the building blocks of a local area network and still appear to be somewhat mystified by its information capabilities as well as for those who are not yet doing so. This dissertation examines the history of library involvement with networking, briefly reviews the history of library networking and automation, presents examples of library use of networking, and provides the user with the basic information needed for understanding networking technology and terminology. Further, NETWORKING: CHOOSING A LAN PATH TO INTERCONNECTION proposes an enhanced role for the Broward County Library System as a community information provider by using an extended local area network or linked LAN to actively pursue, organize, and make available to present and potential library patrons a range of information resources never before offered in today's information based society.

This diploma thesis deals with the proposal and the maintenance of Ethernet computer networks in the Department of Telecommunication property in Brno. There is a description of communication line types used in LAN computer networks in the first parts of the work. Their advantages and disadvantages are introduced too. Further there is an existing situation of the computer network on the third and the fourth floor of the Department of Telecommunication building documented. This documentation includes a design and a list of used components. The existing computer network has some minor inadequacies that were taken into consideration in the new proposal. There is a completely elaborate documentation of the new proposed network on the third and the fourth floor that contains a detailed placement and a single component configuration including their description. This documentation should significantly contribute to more effective network maintenance in the future. The computer network maintenance does not contain only servers, printers or workstations. It's also necessary to consider network parts that are not so perceptible for common users. That means single segments of computer networks with its active devices. A web based application for the effective computer network maintenance is proposed and described in this work too. The application allows administrator to keep a well-arrange view of the single network segments. All network related information is saved into a database that can help with a solution of later occurred problems.

This work has been carried out at a company in the region which has about 30000 employeeswith about 400 sites all over the world. The company outsources their network including theLAN refresh and the WAN migration. They needed help with an upgrade of their LAN at theirScandinavian headquarters and to find a new solution for their WAN. The reason why the upgradeof the LAN was needed was that the equipment was too old and did not pass the securityrequirements. They also required a solution to segment their LAN, which consisted of a singlelarge VLAN with 1,300 employees. their WAN solution was made up of tunnels between all officesand the headquarter were used as the central point. They wanted to get away from beingdependent on a central point while redundancy was not always working as it should.The solution to the WAN problem was to use the ISPs backbone based on MPLS. There are two mainsolutions, layer 2 (Ethernet) VPN or layer 3 (IP) VPN. In the case of IP VPN, there are a couple of differentconnectivity options such as a static route, or use a routing protocol (eg OSPF or BGP). The final solutionwas IP VPN with OSPF as routing protocol to the ISP. With regard to the configuration of the OSPF solutionwas that every office became an own OSPF domain, configured with area 0. The report also includesthe implementation of the WAN migration with its problems.The upgrade of the LAN was a lot of planning, documentation and security. The solution for the segmentationwas to create a VLAN per floor. Because of the new software they can have the required securityfeatures.

[Truncated abstract] This thesis develops a scheduled protocol (time division multiple access, TDMA) called flexible-schedule-based TDMA Protocol (FlexiTP), to address the problem of providing end-to-end guarantees on data delivery, whilst also respecting severe resource constraints of wireless sensor networks. FlexiTP achieves this balance through a distributed, synchronised, and loose slot structure in which sensor nodes can build, modify, or extend their schedules based on their local information. In FlexiTP, it is not necessary to predetermine the number of slots required for a network. FlexiTP's local repair scheme allows nodes to adjust their schedules dynamically and autonomously to recover from node and communication faults. Hence, it maintains a reliable and selforganising multihop network. Most sensor network protocols designed for data gathering applications implicitly assume a periodic rate of data collection from all nodes in the network to the base station. However, nodes may want to report their data more rapidly or slowly depending on the significance and importance of their data to the end-user. The problem is that traditional TDMA-based protocols are not flexible to changes in traffic patterns because of their rigid slot structure schemes. This thesis aims to solve this problem by developing an ondemand TDMA slot transfer method that leverages the flexible-slot structure algorithm of FlexiTP to transfer time slots from one part of the network to another part. ... While these communication patterns are sufficient for monitoring applications, individual sensor nodes may need to send their data to multiple destination nodes across the network in order to execute a distributed cooperative-function based on their local environment. This peer-to-peer communication pattern makes sensor networks more reactive to triggers from the environment. This thesis attempts to solve the problem of lack of peer-to-peer communication in the design of a TDMA-driven protocol by extending the idea of on-demand TDMA slot transfer method to allow each sensor node in the network to claim extra time slots to communicate with any other nodes (peers) in the network, without going through the base station. Nodes in the network may have different priorities of data because of event-triggering sensor readings or various types of sensor readings (e.g., light, temperature, and humidity) they provide. When nodes with high priority packets increase the frequency of their data collections, the network bandwidth may be dominated by these nodes. It is desirable to allow nodes with low priority packets to aggregate their packets and so enabling these nodes to send their data to the base station under the current available network bandwidth. This thesis proposes an on-demand data aggregation algorithm that enables sensor nodes to perform an in-network-aggregation based on their current sensing requirements and network capacity constraints. In summary, this thesis describes the design, implementation, and evaluation of protocols for wireless sensor networks that focus on achieving energy-efficiency, provisioning performance assurances, and supporting reactivity and adaptability in constantly changing environment.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2007.
Includes bibliographical references (p. 147-154).
This thesis focuses on the design of power- and area-efficient parallel integrated receivers for multiple antenna wireless LAN systems. These receivers are part of an indoor parallel radio system that achieves 1 gigabit per second data rates and enables high bandwidth wireless communication between portable user devices and a high speed wired internet connection. Since a critical aspect for efficiency is that an optimal number of transceivers be used to meet system requirements, this thesis first considers power dissipation and area. consumption for parallel integrated transceivers. It develops parallel transceiver power dissipation and area consumption models that are functions of distance, data rate, and noise figure and incorporate the behavior of a multiple-input, multiple-output channel and power dissipation and area consumption values for typical RF circuits. These models properly balance benefits of multiple antennas with drawbacks due to parallel radio overhead. Their application shows that the combined transceiver power dissipation can actually decrease with more antennas and also provides a circuits-based number of antennas upper bound that has not been established previously.
(cont.) The thesis then proposes a solution that applies multiple antenna signal-to-noise ratio (SNR) gain at the receiver to reduce its power dissipation and area consumption. SNR gain trades noise figure for power- and area-efficient circuits. The implementation of a, single chip 5.22-GHz area-efficient parallel receiver RFIC that shows practical application of these models, SNR gain, and area-efficient circuits is demonstrated. The context of this design comes from the Wireless Gigabit Local Area Network (WiGLAN). It's system characteristics such as a wide 150 MHz bandwidth and parallel radios uniquely determine a WiGLAN parallel receiver design.
by Lunal Khuon.
Ph.D.

Företaget är mitt uppe med att segmentera deras nätverk och anledningen till detta är att få en säkrare produktion med att skapa en kontrollerad och isolerad miljö, skydda mot spridning av virus och andra hot samt skapa en kostnadsbesparing genom att slippa uppdatera eller uppgradera utrustningar i onödan bara för att uppfylla nätverkspolicyn. För att underlätta företagets behov för segmentering har det här självständiga arbetet gått ut på att implementera VTP version 3 och MST. VTP skickar ut VLAN och MST uppdateringar runt i nätverket och underlättar vid användning av PVLAN. MST är ett Spanning Tree protokoll som gör det möjligt att mappa VLAN till instanser för på det sättet kunna spara CPU-belastning på switcharna samt att spara in på antal olika VLAN när PVLAN används. Metoden som användes var att sätta upp en testmiljö från backupper från riktiga nätet där det testades att implementera de nya protokollen samt att se hur de fungerade. En utvärdering av nätet gjordes där utvalda switchar och interfaces mättes innan implementationen för att senare jämföras med samma mätningar efter att implementationen var klar. Det visade sig att resultaten före implementeringen var så pass låga att implementeringen av MST sköts upp till att nätverkssegmenteringen var utförd. VTP version 3 implementerades utan problem och tre olika scenarier med färdiga konfigurationer skapades för att hjälpa företaget att ta steget över till MST i framtiden.
The company is on the verge of segmenting their network and the reasons for this are to get a more secure production by creating a controlled and isolated environment, protecting against the spread of virus and  other threats and aswell creating cost savings by not updating or upgrading unnecessary equipment just to meet the network policy. In order to facilitate the company's segmentation needs, this independent project has been about implementing VTP version 3 and MST. VTP sends out VLAN and MST updates around the network and ease the use of PVLAN. MST is a Spanning Tree protocol that enables VLAN to be mapped to instances to save CPU utilization on the switches as well to help load balance the network. The method used was to set up a test environment from backups from the real network where it was tested to implement the new protocols and to see how they acted. An evaluation of the network was made where selected switches and interfaces were measured before the implementation to be compared later with the same measurements after the implementation was completed. It turned out that the results before implementation were low enough that the implementation of MST was postponed until the network segmentation was completed. VTP version 3 was implemented without any problems and three different scenarios with complete configuration were created to help the company take the leap to MST in the future.

Today two major technological forces drive the telecommunication era: the wireless cellular systems and the Internet. As these forces converge, the demand for new services, increasing bandwidth and ubiquitous connectivity continuously grows. The next-generation mobile systems will be based solely or in a large extent, on the Internet Protocol (IP). This thesis begins by addressing the problems and challenges faced in a multimedia, IP-based Wireless LAN environment. The ETSI HiperLAN/2 system has been mainly selected as the test wireless network for our theoretical and simulation experiments. Apart from the simulations, measurements have been taken from real life test scenarios, where the IEEE 802.11 system was used (UniS Test-bed). Furthermore, a brief overview of the All-IP network infrastructure is presented. An extension to the conventional wireless (cellular) architecture, which takes advantage of the IP network characteristics, is considered. Some of the trends driving the 3G and WLANs developments are explored, while the provision of quality of service on the latter for real-time and non-real-time multimedia services is investigated, simulated and evaluated. Finally, an efficient and catholic Q0S framework is proposed. At the same time, the multimedia services should be offered in a seamless and uninterrupted manner to users who access the all-IP infrastructure via a WLAN, meeting the demands of both enterprise and public environments anywhere and anytime. Thus providing support for mobile communications not only in terms of terminal mobility, as is currently the case, but also for session, service and personal mobility. Furthermore, this mobility should be available over heterogeneous networks, such as WLANs, IJMTS, as well as fixed networks. Therefore, this work investigates issues such as, multilayer and multi-protocol (SIP-Mobile IP-Cellular IP) mobility management in wireless LAN and 3G domains. Several local and global mobility protocols and architectures have been tested and evaluated and a complete mobility management framework is proposed. Moreover, integration of simple yet efficient authentication, accounting and authorisation mechanisms with the multimedia service architecture is an important issue of IP-based WLANs. Without such integration providers will not have the necessary means to control their provided services and make revenue from the users. The proposed AAA architecture should support a robust AAA infrastructure providing secure, fast and seamless access granting to multimedia services. On the other hand, a user wishing a service from the All-IP WLAN infrastructure needs to be authenticated twice, once to get access to the network and the other one should be granted for the required service. Hence, we provide insights into these issues by simulating and evaluating pre-authentication techniques and other network authentication scenarios based on the wellknown IEEE 802.lx protocol for multimedia IP-based WLANs.

In this study, a computer simulation model for library CD-ROM LAN systems was created. Using this model, the system optimization problems were examined. The simulation model imitated the process of the actual decision variables changing their values and generated the corresponding results. Under a certain system environment, if the values of decision variables are changing, the system performances are getting changed also. This study investigated these relationships with the created model. The system users' interarrival time, service time, and other relevant data were collected on randomly selected days in a university library. For data collection, both of the observation and the system automatic metering software were used. According to the collected data, a discrete events simulation model was created with GPSS/H. The simulation model was proven valid and accurate by a pilot test and by the calculation with queuing theory. Statistical tests were used for data comparison and analysis. In addition, animation technique was used to show the simulation process by using Proof Animation. By this technique, the simulation process was monitored on the screen.

O ensino e a aprendizagem do tema hierarquia de memória não são tarefas simples, pois muitos assuntos que são abordados em teoria podem desmotivar a aprendizagem em virtude de sua complexidade. Este projeto de mestrado apresenta a transformação do módulo de memória cache da ferramenta Amnesia em um objeto de aprendizagem, que visa facilitar a construção do conhecimento através da simulação da estrutura e da funcionalidade da hierarquia de memória na arquitetura von Neumann de uma maneira mais prática e didática. Este processo permitiu que funcionalidades existentes na ferramenta fossem readequadas e novas funcionalidades desenvolvidas. Aliado a isso, planos de aula e questionários de avaliação e usabilidade também foram concebidos, validados e implementados junto à elaboração de um tutorial para descrever o funcionamento do novo objeto. Os estudos experimentais realizados analisaram dois aspectos: o primeiro, se o objeto de aprendizagem melhorou, de fato, a aprendizagem dos alunos no assunto memória cache; o segundo, a opinião dos alunos em relação à utilização do objeto. Após a análise e avaliação dos resultados obtidos nos experimentos, foi possível demonstrar uma evolução na aprendizagem quando se fez o uso do objeto, além de se perceber que a motivação dos alunos em utilizar outros objetos de aprendizagem aumentou.
The teaching and learning of memory hierarchy are not simple tasks, because many subjects that are covered in theory may demotivate learning because of its complexity. This Master\'s thesis presents the process of transformation of the cache memory module of Amnesia tool in a learning object, aiming to facilitate the construction of knowledge by simulating the structure and functionality of memory hierarchy of von Neumann architecture in a more practice and didactic way. This process allowed existing features in the tool to be adequate and new features developed. In addition, lesson plans and questionnaires of assessment and usability have also been designed, validated and implemented and a tutorial to describe the operation of the new object was developed. Experimental studies have examined two aspects: the first, if the learning object improved, in fact, the students\' learning in the subject cache memory; the second, students\' opinions regarding the use of the object. After the analysis and evaluation of the results obtained in the experiments, was possible show an evolution in learning when it made the use of the object, and also to perceive that students\' motivation to use other learning objects increased.

Thesis (M.Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2000.
Includes bibliographical references (p. [89]-94).
This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
The Wireless Gigabit/s Local-Area Network (WGLAN) project is aimed at providing highspeed data transmission between the Next Generation Internet and end-use devices within the home or office environment. The design of the digital signal processing (DSP) required at the physical layer of the network is the focus of this thesis. In particular, this thesis models the indoor radio channel environment at the 5.x GHz Unlicensed National Information Infrastructure (U-NII) frequency band, and proposes a multipath-resistant transceiver design based on Orthogonal Frequency Division Multiplexing (OFDM) with adaptive multilevel Quadrature Amplitude Modulation (M-QAM). The proposed network design allows two-way communication through a Time Division Duplexing (TDD) scheme and provides multiuser support through a series of algorithms that establish session links and allocate subchannels among devices in an optimal way. Finally, a custom-written software simulation is used to estimate the bit error rate (BER) network performance under different channel conditions.
by Eladio Clemente Arvelo.
M.Eng.

Many small to medium sized computer networks currently in use around the world are based on techniques allowing communications only in the 10 Mbps range. Due to the ever increasing amounts of traffic more efficient network solutions are becoming increasingly important, especially in establishment-wide backbones. ATM is a very interesting choice for network backbones, since it provides virtually seamless integration with existing LANs and a platform for future transitions into more advanced LAN environments. Since network solutions often cost a great deal of money and need to function well in order to properly support users, much thought must be put into how a particular network should be designed. This work concentrates on that problem, the design of an ATM backbone. To be more exact, an existing network infrastructure based partially on ATM LAN needs to be expanded, resulting in a new network backbone based purely on ATM LAN.

When a new network has been designed it is desirable to know what its weak points are and how likely it is that service will be interrupted. For this reason a vulnerability analysis of certain elements in the ATM infrastructure has been performed. This analysis is very lightweight and easy to understand and interpret. There are several reasons for not performing a severely comprehensive analysis. For example, a lightweight analysis can be performed rapidly and is easy to maintain as the network evolves. In order to enable the analysis to be performed rapidly a method for lightweight vulnerability analysis has been constructed. The result of this work is a new ATM backbone design based on a number of ATM nodes and a natively connected router. The probability of certain failures in this structure has been calculated and recommendations for recovery from failures constructed.

Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1999.
Includes bibliographical references (p. 162-165).
by Carlin James Vieri.
Ph.D.

This dissertation describes the analysis, design, and implementation of a session level communication system referred to as PLEXNET. PLEXNET was developed specifically to provide communication services required by Computer Supported Cooperative Work (CSCW) applications but which are not currently available as part of commercially available LAN products. CSCW services include such things as: reliable broadcast communications, dynamic multicasting, and message queuing. Analysis of CSCW networking requirements entailed: reviewing CSCW applications and communications systems; synthesizing a data exchange model for collaborative tools; and defining a target system (PC-LAN). PLEXNET design provides a discussion of: networking tradeoffs, the relationship between PLEXNET and NETBIOS, PLEXNET queue structure, and PLEXNET implementation details. The design and implementation of PLEXNET were validated by performing discrete event simulations comparing response times and resource utilization for three communication paradigms and by developing four collaborative applications which employ PLEXNET for data communications. These applications are: Multi-User LAN Editor, Electronic Discussion System, Contracts Procurement, and Video Switcher.

This thesis is a reception analysis using qualitative interviews to investigate the formation of cultural groups around computer-game LANs present in Rhodes University. It also looks at how issues of social inequalities evident on the university's campus impact on the participation of students in these LANs. The findings of this study are that the participants have established a community around the practice of computer LAN-gameplay based on values developed through the combination of the material and gameworlds. It serves as a home-on-campus for them; where they can fully explore their passion for games thus reaffirming their identity as gamers on a campus where being a gamer is viewed negatively. In this light, computer-game playing is not just a practice these participants perform, but a culture they live out every day. This is a culture predominantly lived out by men. One of the reasons for this is because most women have been raised to believe to have negative predispositions about digital gaming e.g. that it is childish, addictive and anti-social, but also that computer are meant to be used by men - women use them only when it is absolutely necessary, for example, that it is childish, for academic-related purposes. As a result, not many of them will use computers for any otherreason for fear of being socially criticised. In addition, the gaming culture being dominated by whites is due to the fact that admittance in to this community is still unaffordable for the majority of black students on the Rhodes University campus as a result of their social backgrounds.

This master’s thesis deals with a complex solution for the visualization of network topology. The first part of thesis describes the operation principle of LLDP protocol, which was chosen as a tool for retrieving informations from network traffic based on the requirement of the assignment. There is a detailed description of the LLDP protocol implementation in C language to METEL s.r.o. network products. The second part deals with possibilities of graphical interface in software SIMULand intended for managing network devices. It describes tools expansion process for the visualization of the network topology. In conclusion, the results of testing final solution are introduced.

Att snabbt och effektivt kunna dela filer mellan system både genom WAN och LAN är något som många företag idag är beroende av. Till detta så kan fildelningsprotokoll användas, två vanliga fildelningsprotokoll är SMB/CIFS och NFS. I detta arbete så utvärderas de nyaste versionerna av protokollen i en experimentmiljö. Prestandajämförelser sker mellan två olika operativsystem och versioner av protokollen. Syftet är att besvara frågan om vilket protokoll som är mest effektivt i WAN-miljöer där olika operativsystem används. Resultatet visar att SMB är det protokoll med bäst stöd i både Linux och Windows. NFSv4.1 kan dock med en Linuxklient uppnå högre prestanda.

Utilizing ethnographic methods, this work examines how attendees of computer gaming events held by the Gaming@IU club form a community which uses technology to bring people together rather than isolate them and analyzes the ways attendees perform a unique forms of Whiteness and "nerd masculinity." Known as LAN parties, these computer gaming events are social functions where approximately 200 participants collocate their computers and play videogames with and against each other for up to twenty-four hours straight. Drawing years of fieldwork, this work uses participant observation and in depth interviews to examine how this group uses the computer gaming events to create a third place away from work and school where friendships can be created and maintained.

Based on this data, I examine the ways in which the statements of the LAN party attendees draw on a discourse of racial colorblindness to avoid dealing with the overwhelming Whiteness of these events which is not reflective of the racial and ethnic diversity of the area. I show how an avoidance of discussion of Whiteness and a general inability to articulate their thoughts about race prevents the attendees from interrogating the role the LAN party's organization may play in the racial makeup of attendees.

Focusing on issues of sexual harassment within gaming, I also look at the ways in which the games played and the social norms of the LAN party encourage the performance of hegemonic masculinity while playing the videogames but allow the attendees to inhabit a more complicit form of masculinity which is not overtly sexist. I argue that by embracing non-normative masculinity outside the games but discouraging it within the games, the LAN party participants are professing openness and acceptance but are failing to live up to that ideal.

Thesis (Ph.D.)--Indiana University, Dept. of Computer Science, 2007.
Source: Dissertation Abstracts International, Volume: 68-09, Section: B, page: 6098. Adviser: Geoffrey C. Fox. Title from dissertation home page (viewed May 9, 2008).

This thesis describes the design and development of both the hardware and software of an embedded, distributed control system using a LAN infrastructure for communication between nodes. The primary application of this system is for power monitoring and control at Rhodes University. Both the hardware and software have been developed to provide a modular and scalable system capable of growing and adapting to meet the changing demands placed on it. The software includes a custom written Internet Protocol stack for use in the embedded environment, with a small code footprint and low processing overheads. There is also Linux-based control software, which includes a web-based device management interface and graphical output. Problems specific to the application are discussed as well as their solutions, with particular attention to the constraints of an embedded system.

This thesis presents Harmony Oriented Architecture: a novel architectural paradigm that applies the principles of Harmony Oriented Programming to the architecture of scalable and evolvable distributed systems. It is motivated by research on Ultra Large Scale systems that has revealed inherent limitations in human ability to design large-scale software systems that can only be overcome through radical alternatives to traditional object-oriented software engineering practice that simplifies the construction of highly scalable and evolvable system. HOP eschews encapsulation and information hiding, the core principles of object-oriented design, in favor of exposure and information sharing through a spatial abstraction. This helps to avoid the brittle interface dependencies that impede the evolution of object-oriented software. HOA extends these concepts to distributed systems resulting in an architecture in which application components are represented by objects in a spatial database and executed in strict isolation using an embedded application server. Application components store their state entirely in the database and interact solely by diffusing data into a space for proximate components to observe. This architecture provides a high degree of decoupling, isolation, and state exposure allowing highly scalable and evolvable applications to be built. A proof-of-concept prototype of a non-distributed HOA middleware platform supporting JavaScript application components is implemented and evaluated. Results show remarkably good performance considering that little effort was made to optimize the implementation.
ID: 031001554; System requirements: World Wide Web browser and PDF reader.; Mode of access: World Wide Web.; Title from PDF title page (viewed August 26, 2013).; Thesis (M.S.)--University of Central Florida, 2011.; Includes bibliographical references (p. 79-84).
M.S.
Masters
Electrical Engineering and Computer Science
Engineering and Computer Science
Computer Science