Proporciona los pasos y procedimientos para acceder al recurso IEEE Transactions on Signal Processing.

No / Abstract: Avoiding collision among contending customer premise equipments (CPEs) attempting to associate with a base station (BS), the only available solution in IEEE 802.22 standard is binary exponential random backoff process in which the contending CPEs retransmit their association requests. The number of attempts the CPEs sends their requests to the BS are fixed in IEEE 802.22 network. This paper presents a mathematical framework for helping the BS in determining at which attempt the majority of the CPEs become the part of wireless regional area network (WRAN) from a particular number of contending CPEs at a given initial contention window size.

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This thesis presents a program developed to implement techniques for troubleshooting digital boards. There are old boards still in service that have no built in testing circuits. This makes troubleshooting them time consuming and difficult. In making this program two questions were posed; "How would a technician normally perform this operation?" and "How can a program help him/her do this better?" Having experience as a technician himself, the author could easily answer the first question. The experienced technician would put a known sequence of inputs into the board and compare the actual outputs to the expected. Any outputs that did not compare would lead the technician to the section of board most closely related to the fault. Within this new section, new signals are probed while the same patterns of inputs are repeated. This technique is commonly referred to as bracketing. Bracketing involves these four steps: 1.Select where to probe. 2.Run test inputs and sample. 3.Use sampled information to reduce the suspect set. 4.If the suspect set is not a single component then repeat steps 1 through 4. The answer to the second question has no easy answer. That is where it is hoped this program can help. The program uses information from a non-faulted VHDL model of the board to learn what to expect. Since there is no interface to a real probed board, VHDL is also used to model the faulted board. / Master of Science

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International Telemetering Conference Proceedings / October 18-21, 2004 / Town & Country Resort, San Diego, California / The wireless sensor concept has been hindered in the past by the large number of components needed to add the wireless transceiver feature and the additional power consumption needed for that feature. This has been resolved by incorporating all the wireless components into a single, low power modular circuit. Intelligence is being added to legacy sensors to make them Institute of Electrical and Electronics Engineers (IEEE) 1451.4 compatible with an element called a Sensor Identification Transducer Electronic Data Sheet (SITEDS), which contains the Transducer Electronics Data Sheet (TEDS) for that sensor. All the sensor interface parameters are automatically configured by a module called the Universal Smart Transducer Interface Module (USTIM) using the TEDS input from the respective sensor’s SITEDS. An IEEE P1451.5 compatible wireless interface can be incorporated into the SITEDS with the transceiver module giving the legacy sensor full wireless capability.

Denna studie har undersökt möjligheten att implementera ett trådlöst kommunikationssystem i en ugnsmiljö. Den trådlösa kommunikationstekniken som har använts är av standarden IEEE 802.15.4. För denna undersökning har ett trådlöst mätsystem för temperatur konstruerats. För att hålla nere temperaturen på detta mätsystem har kapslingsmaterialen keramik och glasull använts. Resultatet av mätningarna visar att kvalitén på radiokommunikationen kan förväntas vara god för de testade förhållande med kapsling och en temperatur upp till 200 grader. För de testade förhållandena i ugnsmiljön visar mätresultat att positionering är av större betydelse än värmeutvecklingen och kapslingen. / This study has explored the possibility to implement a wireless communication system in an ovenenvironment. For this exploration a wireless measurement system for temperature have beenconstructed. The technology of use is a radio communication system with the standard IEEE 802.15.4. The high temperature in the oven environment is kept down at the electronic by using anenclosure. The enclosure material that have been examined is a ceramic layer and a fibreglasslayer. The result of this study shows that the quality of the radio communication for the tested enclosureis expected to be good for temperatures up to 200 degrees. For the test cases the relation betweenthe radio module’s positioning is more important than the increase of temperature and the use ofan enclosure.

Im Internet der Zukunft werden Menschen nicht nur mit Menschen, sondern auch mit „Dingen“, und sogar „Dinge“ mit „Dingen“ kommunizieren. Zusätzlich wird das Bedürfnis steigen, immer und überall Zugang zum Internet zu haben. Folglich gewinnen drahtlose Sensornetze (WSNs) und drahtlose Mesh-Netze (WMNs) an Bedeutung, da sie Daten über die Umwelt ins Internet liefern, beziehungsweise einfache Internet-Zugangsmöglichkeiten schaffen. In den vier Teilen dieser Arbeit werden unterschiedliche Modellierungs- und Optimierungsmethoden für WSNs und WMNs vorgestellt. Der Energieverbrauch ist die wichtigste Metrik, wenn es darum geht die Kommunikation in einem WSN zu optimieren. Da sich in der Literatur sehr viele unterschiedliche Energiemodelle finden, untersucht der erste Teil der Arbeit welchen Einfluss unterschiedliche Energiemodelle auf die Optimierung von WSNs haben. Aufbauend auf diesen Überlegungen beschäftigt sich der zweite Teil der Arbeit mit drei Problemen, die überwunden werden müssen um eine standardisierte energieeffiziente Kommunikations-Lösung für WSNs basierend auf IEEE 802.15.4 und ZigBee zu realisieren. Für WMNs sind beide Probleme von geringem Interesse, die Leistung des Netzes jedoch umso mehr. Der dritte Teil der Arbeit führt daher Algorithmen für die Berechnung des Max-Min fairen (MMF) Netzwerk-Durchsatzes in WMNs mit mehreren Linkraten und Internet-Gateways ein. Der letzte Teil der Arbeit untersucht die Auswirkungen des LRA-Konzeptes. Dessen grundlegende Idee ist die folgende. Falls für einen Link eine niedrigere Datenrate als theoretisch möglich verwendet wird, sinkt zwar der Link-Durchsatz, jedoch ist unter Umständen eine größere Anzahl von gleichzeitigen Übertragungen möglich und der Gesamt-Durchsatz des Netzes kann sich erhöhen. Mithilfe einer analytischen LRA Formulierung und einer systematischen Studie kann gezeigt werden, dass eine netzwerkweite Zuordnung robusterer Datenraten als nötig zu einer Erhöhung des MMF Netzwerk-Durchsatzes führt. Desweitern kann gezeigt werden, dass sich LRA positiv auf die Leistungsfähigkeit eines IEEE 802.11 WMNs auswirkt und für die Optimierung des Netzes genutzt werden kann. / In the future Internet, the people-centric communication paradigm will be complemented by a ubiquitous communication among people and devices, or even a communication between devices. This comes along with the need for a more flexible, cheap, widely available Internet access. Two types of wireless networks are considered most appropriate for attaining those goals. While wireless sensor networks (WSNs) enhance the Internet’s reach by providing data about the properties of the environment, wireless mesh networks (WMNs) extend the Internet access possibilities beyond the wired backbone. This monograph contains four chapters which present modeling and optimization methods for WSNs and WMNs. Minimizing energy consumptions is the most important goal of WSN optimization and the literature consequently provides countless energy consumption models. The first part of the monograph studies to what extent the used energy consumption model influences the outcome of analytical WSN optimizations. These considerations enable the second contribution, namely overcoming the problems on the way to a standardized energy-efficient WSN communication stack based on IEEE 802.15.4 and ZigBee. For WMNs both problems are of minor interest whereas the network performance has a higher weight. The third part of the work, therefore, presents algorithms for calculating the max-min fair network throughput in WMNs with multiple link rates and Internet gateway. The last contribution of the monograph investigates the impact of the LRA concept which proposes to systematically assign more robust link rates than actually necessary, thereby allowing to exploit the trade-off between spatial reuse and per-link throughput. A systematical study shows that a network-wide slightly more conservative LRA than necessary increases the throughput of a WMN where max-min fairness is guaranteed. It moreover turns out that LRA is suitable for increasing the performance of a contention-based WMN and is a valuable optimization tool.