Underwater Sensor Networks: Applications, Advances, and Challenges

This paper examines the main approaches and challenges in the design and implementation of underwater wireless sensor networks. We summarize key applications and the main phenomena related to acoustic propagation, and discuss how they affect the design and operation of communication systems and networking protocols at various layers. We also provide an overview of communications hardware, testbeds, and simulation tools available to the research community

Virtual Runtime Application Partitions for Resource Management in Massively Parallel Architectures

This thesis presents a novel design paradigm, called Virtual Runtime Application Partitions (VRAP), to judiciously utilize the on-chip resources. As the dark silicon era approaches, where the power considerations will allow only a fraction chip to be powered on, judicious resource management will become a key consideration in future designs. Most of the works on resource management treat only the physical components (i.e. computation, communication, and memory blocks) as resources and manipulate the component to application mapping to optimize various parameters (e.g. energy efficiency). To further enhance the optimization potential, in addition to the physical resources we propose to manipulate abstract resources (i.e. voltage/frequency operating point, the fault-tolerance strength, the degree of parallelism, and the configuration architecture). The proposed framework (i.e. VRAP) encapsulates methods, algorithms, and hardware blocks to provide each application with the abstract resources tailored to its needs. To test the efficacy of this concept, we have developed three distinct self adaptive environments: (i) Private Operating Environment (POE), (ii) Private Reliability Environment (PRE), and (iii) Private Configuration Environment (PCE) that collectively ensure that each application meets its deadlines using minimal platform resources. In this work several novel architectural enhancements, algorithms and policies are presented to realize the virtual runtime application partitions efficiently. Considering the future design trends, we have chosen Coarse Grained Reconfigurable Architectures (CGRAs) and Network on Chips (NoCs) to test the feasibility of our approach. Specifically, we have chosen Dynamically Reconfigurable Resource Array (DRRA) and McNoC as the representative CGRA and NoC platforms. The proposed techniques are compared and evaluated using a variety of quantitative experiments. Synthesis and simulation results demonstrate VRAP significantly enhances the energy and power efficiency compared to state of the art.Siirretty Doriast

Spectrum avaílability assessment tool for TV white space

The growth of wireless communication relies on the availability of radio frequency for new services. More efficient spectrum allocations are required to serve the increasing data per user. The major regulatory bodies are formulating new spectrum management techniques to forge the growing spectrum scarcity. Exclusive use of spectrum is proved to be inefficient in many spectrum occupancy measurement campaigns. As a result, spectrum sharing methods are being considered. TV broadcasting is not using the allocated frequency in some geographic areas, creating coverage holes known as TV white spaces. Both the industry and the regulators are investigating the capability of TVWS, as a potential source of spectrum for emerging wireless services. The FCC, in the US, has already released the requirements for opportunistic access to the TV whites paces. In a similar fashion, ECC, the pan-European regulator is finalizing the work on the technical and operational requirements for the possible use of cognitive radio in this spectrum. In this thesis work, an integrated web-based spectrum availability assessment tool is developed for Finland. The tool is a front-end visualization of a time intensive computational process to answer key technical questions related to TVWS - what secondary data rate can be supported in the available white space spectrum? The assessment involves estimation of the available TVWS and its capacity for cellular-type secondary systems. The relative effects of the secondary system parameters on the TV system are compared using appropriate signal to noise and interference ratio plots. The tool uses dynamic web technologies for a seamless and user-friendly visualization of the assessment

Low-Power Pıc-Based Sensor Node Devıce Desıgn And Theoretıcal Analysıs Of Energy Consumptıon In Wıreless Sensor Networks

Teknolojinin ilerlemesi, daha enerji verimli ve daha ucuz elektronik bileşenlerinin daha küçük üretilmesini sağlamıştır. Bu nedenle, daha önce mevcut birçok bilgisayar ve elektronik bilim-mühendislik fikirleri uygulanabilir hale gelmiştir. Bunlardan birisi de kablosuz sensör ağları teknolojisidir. Kablosuz algılayıcı ağlar, düşük enerji tüketimi ve gerekli teknik gereksinimlerin gerçekleşmesi ile uygulanabilir hale gelmiştir. Ayrıca, Kablosuz algılayıcı ağlarının tasarımında iletişim algoritmaları, enerji tasarruf protokolleri ve yenilenebilir enerji teknolojileri gibi diğer bilimsel çalışmalar zorunlu hale gelmiştir. Bu tez, mikroelektronik sistemler, kablosuz iletişim ve dijital elektronik teknolojisinin ilerlemesiyle uygulanabilir hale gelmiş sensör ağları teknolojisini kapsamaktadır. Birincisi, algılama görevleri ve potansiyel algılayıcı ağ uygulamaları araştırılmış ve algılayıcı ağlarının tasarımını etkileyen faktörlerin gözden geçirilmesi sağlanmıştır. Ardından sensör ağları için iletişim mimarisi ana hatlarıyla belirtilmiştir. Ayrıca, tek bir düğümün WLAN ile iletişim kurabilmesi için yeni donanım mimarisi tasarlanmış ve düğümlerde yenilenebilir enerji kaynakları kullanılmıştır. Bu tezde WSN, analitik bilim ve uygulamalı bilim açısından incelenmiştir. Düşük enerji tüketimi ve iletişim protokolleri arasındaki ilişki değerlendirilmiş ve bilimsel sonuçlara varılmıştır. Teorik analizler bilimsel uygulamalarla desteklenmiştir. Çalışmalar, düşük enerji ve maksimum verimlilik prensibinin gerçekleştirilmesine dayalı kablosuz sensör ağları üzerinde gerçekleştirilmiştir. Kablosuz sensör ağlari sistemi tasarlandıktan sonra; sensör düğümlerinin enerji tüketimi ve kablosuz ağdaki davranışları test ve analiz edilmiştir. Düşük enerji tüketimi ile sensör düğümleri arasındaki ilişki detaylı olarak değerlendirilmiştir. PIC Tabanlı mikro denetleyiciler sensör düğümlerinin tasarımında kullanılmış ve çok düşük maliyetli tasarım için ultra düşük güçte, nanoWatt teknolojisi ile desteklenen sensör düğümleri tasarlanmıştır. İşleme birimi, bellek birimi ve kablosuz iletişim birimi sensör viii düğümlerine entegre edilmiştir. Tasarlanan sensör düğümünün işletim sistemi PIC C dili ile yazılmıştır ve PIC işletim sistemi nem, sıcaklık, ışığa duyarlılık ve duman sensörü gibi farklı özelliklerin ölçülmesine izin vermiştir. Sensörlerden gelen verilerin merkezi bir konumdan kaydedilmesi ve izlenebilmesi için, C# programlama dili ile bilgisayar yazılımı geliştirilmiştir. Gelişmiş algılayıcı düğümler tarafından alınan kararların uygulanması için yazılım algoritması ve donanım modüllerini içeren karar verme sistemi tasarlanmıştır. Gelişmiş PIC Tabanlı sensör düğümleri, enerji üretimi ve enerji tasarrufu için, güneş enerjisi paneli, şarj edilebilir pil ve süper kapasitör gibi yenilenebilir enerji kaynakları ile benzersiz bir PIC Kontrollü voltaj birimi ile desteklenmiştir. Geliştirilmiş kablosuz sensör ağları sistemi, endüstri uygulamaları, akıllı fabrikalar ve akıllı evler gibi günlük hayat uygulamaları için de kullanılabilecektir. Kablosuz algılayıcı ağlar geniş bir aralıkta kullanılmak üzere tasarlanmıştır. Tezin sonuçları, özellikle yenilenebilir enerji kaynakları ile WSN'nin geliştirilmesine yardımcı olmayı amaçlamaktadır

Sensor Fusion for Location Estimation Technologies

Location estimation performance is not always satisfactory and improving it can be expensive. The performance of location estimation technology can be increased by refining the existing location estimation technologies. A better way of increasing performance is to use multiple technologies and combine the available data provided by them in order to obtain better results. Also, maintaining one's location privacy while using location estimation technology is a challenge. How can this problem be solved? In order to make it easier to perform sensor fusion on the available data and to speed up development, a flexible framework centered around a component-based architecture was designed. In order to test the performance of location estimation using the proposed sensor fusion framework, the framework and all the necessary components were implemented and tested. In order to solve the location estimation privacy issues, a comprehensive design that considers all aspects of the problem, from the physical aspects of using radio transmissions to communicating and using location data, is proposed. The experimental results of testing the location estimation sensor fusion framework show that by using sensor fusion, the availability of location estimation is always increased and the accuracy is always increased on average. The experimental results also allow the profiling of the sensor fusion framework's time and energy consumption. In the case of time consumption, there is a 0.32% - 17.06% - 5.05% - 77.58% split between results overhead, engine overhead, component communication time and component execution time on an average. The more measurements are gathered by the data gathering components, the more the component execution time increases relative to all the other execution times because component execution time is the only one that increases while the others remain constant

The mobile Internet report

Key ponts Material wealth creation / destruction should surpass earlier computing cycles. The mobile Internet cycle, the 5th cycle in 50 years, is just starting. Winners in each cycle often create more market capitalization than in the last. New winners emerge, some incumbents survive – or thrive – while many past winners falter. The mobile Internet is ramping faster than desktop Internet did, and we believe more users may connect to the Internet via mobile devices than desktop PCs within 5 years. Five IP-based products / services are growing / converging and providing the underpinnings for dramatic growth in mobile Internet usage – 3G adoption + social networking + video + VoIP + impressive mobile devices. Apple + Facebook platforms serving to raise the bar for how users connect / communicate – their respective ramps in user and developer engagement may be unprecedented. Decade-plus Internet usage / monetization ramps for mobile Internet in Japan plus desktop Internet in developed markets provide roadmaps for global ramp and monetization. Massive mobile data growth is driving transitions for carriers and equipment providers. Emerging markets have material potential for mobile Internet user growth. Low penetration of fixed-line telephone and already vibrant mobile value-added services mean that for many EM users and SMEs, the Internet will be mobile

Evolution and usability of mobile phone interaction styles

Over one billion people own or use cellular mobile telephones. Therefore, industry practitioners are faced with a question: how big steps can they take when designing the user interfaces for their new products, or how closely should they stick with the already existing user interface conventions that may already be familiar to the consumers. The objective of this research work is to create and communicate new knowledge for design and usability practitioners about how to design and evolve interaction style conventions in mainstream, voice-centric mobile telephones. In the context of this study, interaction style denotes the framework consisting of the physical interaction objects, the abstract interaction elements, and the associated behavior or interaction conventions that are applied throughout the core functionality of the mobile phone, but excludes the stylistic appearance elements of the user interface. The main research problem — how do mobile phone interaction style changes affect the initial usability of a mobile phone for users with earlier experience with mobile phones — is approached via several methods. A literature study compares the interaction styles applied in mainstream computing domains against the aspects relevant in the mobile phones domain. A heuristic analysis of contemporary mobile phones is used to formulate an understanding of the available interaction styles and analyze whether there is convergence towards specific types of interaction styles in the industry. An empirical usability testing experiment with 38 test users is conducted with a novel mobile phone interaction style to investigate differences between users who are already familiar with different mobile phone interaction styles. The study reveals that interaction styles applied in contemporary mobile telephones are designed around menu navigation, and they implement the three primary operations — Select, Back and Menu access — with dedicated hardkeys, context-sensitive softkeys, or using special control devices like joysticks or jog dials. The control keys in the contemporary interaction styles are converging around various two- and three-softkey conventions. The aspects related to indirect manipulation and small displays pose specific usability and UI design challenges on mobile phone user interfaces. The study shows that the mobile handset manufacturers are applying their usually proprietary interaction styles in a rather consistent manner in their products, with the notable exception of mobile Internet browsers that often break the underlying interaction style consistency. Based on the results from the empirical usability testing, we claim that despite differences between interaction styles in contemporary mobile phones, users do not face significant difficulties when transferring to a novel mobile phone model.reviewe

A coarse-grained dynamically reconfigurable MAC processor for power-sensitive multi-standard devices

DRMP, a Dynamically Reconfigurable MAC Processor, is an innovative, dynamically reconfigurable System-on-Chip architecture. The architecture exploits substantial overlaps in the functionality of different wireless MAC layers. Its flexibility is specialized for addressing the requirements of the MAC layer of wireless standards. It is targeted at consumer, multi-standard, handheld devices, and its design is meant to address the balance of flexibility and power-efficiency that this target market demands. The DRMP reconfigures packet-by-packet on the fly, allowing execution of concurrent protocol modes on a single hardware co-processor. An interrupt-driven programming model has also been presented and shown to implement the protocol state-machine of the three protocols on a CPU. These features will allow the DRMP to replace three MAC processors in a hand-held device. The most innovative component of the DRMP architecture is its Interface and Reconfiguration Controller. It uses a combination of asynchronous controllers to dynamically reconfigure the functional units in the architecture and delegate MAC tasks to them. The architecture has been modeled in Simulink at cycle-approximate abstraction. Results of simulations involving transmission and reception of packets have been presented, showing that the platform concurrently handles three protocol streams, reconfigures dynamically, yet meets and exceeds the protocol timing constraints, all at a moderate frequency. Its heterogeneous and coarse-grained functional units, limited connectivity requirements between these units, and proportionally large time that these resources are idle, promise a very modest power-consumption, suitable for mobile devices, while offering flexibility to implement different MAC protocols