The UHF band between 470-790 MHz, currently occupied by digital ter- restrial TV (DTT) distribution in Europe, is widely regarded as a premium spectrum band for providing mobile coverage. With the exponential increase in wireless data traffic in recent years, there has been growing interests in gaining access to this spectrum band for wireless broadband services. The secondary access in TV White Space is considered as one cost-effective way to reuse the spectrum unoccupied by the primary DTT network. On the other hand, the declining influence of DTT and the converging trends of video con- sumption on TV and mobile platforms are new incentives for the regulator to reconsider the optimal utilization of the UHF broadcast band. The proposal to re-farm the UHF band for a converged content distribution network was born under theses circumstances. This thesis intends to develop a methodology for evaluating the technical performance of these options for utilizing UHF broadcast band and quantify- ing their gains in terms of achievable extra capacity and spectrum savings. For the secondary access in TV white space, our study indicates a considerable po- tential for low power secondary, which is mostly limited by the adjacent chan- nel interference generated from the densely deployed secondary devices due to the cumulative effect of multichannel interference. On the other hand, this potential does not translate directly into capacity for a WiFi-like secondary system based on CSMA/CA protocol, as the network congestion and self- interference within the secondary system has a greater impact on the network throughput than the primary interference constraint. Our study on the cellular content distribution network reveals more po- tential benefits for re-farming the UHF broadcast band and reallocating it for a converged platform. This platform is based on cellular infrastructure and can provide TV service with the same level of quality requirement as DTT by delivering the video content via either broadcast or unicast as the situa- tion dictates. We have developed a resource manage framework to minimize its spectrum requirement for providing TV service and identified a significant amount of spectrum that can be reused by the converged platform to provide extra mobile broadband capacity in urban and sparsely populated rural areas. Overall, we have arrived at the conclusion that the concept of cellular con- tent distribution in a re-farmed UHF band shows a more promising prospect than the secondary access in TV white space in the long run. Nevertheless, low power secondary is still considered as a flexible and low-cost way to exploit the underutilized spectrum in the short term, despite its uncertainty in future availability. On the other hand, the re-farming of UHF broadcast band is a long and difficult regulation process with substantial opposition from the in- cumbent.The results from this study could serve as input for future regulatory decisions on the UHF band allocation and cost-benefit analysis for deploying new systems to access this spectrum band. / <p>QC 20140609</p> / EU FP7 QUASAR / EU FP7 METIS

Les techniques à base d’antennes multiples constituent une solution intéressante à l’augmentation du débit sans accroître la bande passante. Cependant, la conception de systèmes à base de diversité soulève de nouveaux défis quant à leur intégration au sein de terminaux à encombrement réduit. Le travail présenté consiste à prendre en compte conjointement les éléments déterminant les performances de communication multi-antennes et les contraintes d’intégration liées aux terminaux. Les systèmes développés fonctionnent dans deux bandes LTE: 790-862 MHz et 2.5-2.69 GHz; certains couvrent également la partie haute de la bande TVWS (TV White Space): 700-790 MHz afin d’offrir des applications de radio cognitive. Pour la première conception, la démarche consiste à obtenir un système performant sans rechercher, dans un premier temps une forte intégration. Néanmoins, le système proposé est intégrable dans des terminaux émergeant dans le marché actuel comme l’hybride téléphone-tablette. Des performances très satisfaisantes en termes de bandes et d’isolation sont atteintes. Ensuite, on privilégie la compacité du système tout en offrant des performances acceptables. Cette démarche permet la conception de trois prototypes, dont le dernier est intégrable dans un téléphone.D’autre part, l’influence de la présence d’un utilisateur mais également de l’intégration dans un terminal multimédia sur les performances des systèmes est étudiée. Enfin, les performances en diversité sont évaluées dans différentes configurations d’environnements. Les résultats ont montré que ces systèmes sont adaptés à la technologie LTE et offrent la possibilité d’établir des communications sans fil MIMO. / Multiple antennas techniques are an interesting solution to increase throughput without increasing the bandwidth. This is an advantage in a context where the proliferation of users and services leads to a saturation of spectrum. However, the systems based on diversity raise new challenges for their integration into terminals. The work presented in this thesis is to consider jointly the performance of multi-antennas systems and integration into terminals constraints. Developed systems operate in two bands LTE: 790-862 MHz and 2.5-2.69 GHz, and cover also for some of them the upper part of the band TVWS (TVWhite Space): 700-790 MHz to provide cognitive radio applications. The first study is concentrated on designing an efficient system while maintaining a reasonable size. The proposed system is integrated into the terminals emerging in the market today such as mini-tablets, the tablet-phone hybrid or laptop. Very satisfactory performance in terms of bands and isolation are achieved. Aiming the size reduction, we propose an alternative compact system providing acceptable performances. For this purpose, three prototypes are proposed where the last could be integrated into a mobile phone. For all systems, we have evaluated the diversity performances in terms of correlation coefficient and Mean Effective Gain. It has been founded that the systems provide good diversity performances even if the terminal's position is changed during the communication. Moreover, the influence on the antennas performances with a presence of users is studied. The results show that these systems are suitable for LTE and can be used for MIMO wireless communications.

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Föreliggande studie syftar till att undersöka hur förpackningsdesignen kan komma att påverka konsumentens uppfattning av produktens prisklass. En visuell innehållsanalys genomfördes av ett femtiotal schampoprodukter, detta för att plocka ut olika karaktäristiska designelement för respektive prisklass. Utifrån resultatet skapades två generiska behållare för vardera prisklasser, dessa behållare testades sedan i en enkätundersökning. I enkäten fick deltagarna bedöma i vilken prisklass de ansåg de olika behållarna att tillhöra på en skala 1– 9, ordningen på hur behållarna slumpades och deltagarna hade ingen aning vilka prisklasser de tillhörde. Resultatet från den visuella innehållsanalysen stämde relativt bra överens med enkätundersökningen, där deltagarna ansåg att majoriteten av behållarna tillhörde den prisklass som generiska behållarna designats för efter den visuella innehållsanalysen. Behållare låg A fick 93 poäng, Låg B fick 112 poäng. Medel A fick 122 poäng och medel B 155 poäng. Till sist fick hög A 153 poäng och hög B 173 poäng. Behållare medel B som fick alltså mer poäng än hög A, vilket var det enda som inte stämde överens med det förväntade resultatet. Slutsatsen som kunde dras var att de olika prisklasserna bestod av olika designmanér, samt att utformning av de grafiska elementen varierar inom prisklasserna. / The present study is aiming to examine how the packaging design can affect the consumer’s perception of the product’s price range. A visual content analysis was performed on fifty shampoo products, to find characteristic design elements for each price range. Two generic containers for each price range was produced out of the result from the analysis, those containers were later tested in a survey. In the survey the participants were asked to rate the generic containers in what price range they thought they were on a scale of 1–9, the order of the containers was randomized and the participants did not have any knowledge of the container’s price. The results of the visual content analysis were nearly consistent with the results from the survey, where the participants felt that the containers belonged to the price range they were given after the visual content analysis. Container low A got 93 points, low B got 112 points. Medium A got 122 points and medium B got 155 points. At last high A got 153 points and high B 173 points. Container medium B got higher points than high A, which was the only result that did not consist with the expected. The conclusion is that each price range do have various design manners, and that the configuration of design elements do vary among different price ranges.

[pt] A tecnologia do rádio cognitivo tem sido pesquisada para utilização mais eficiente do espectro, pois permite o aproveitamento de faixas de frequência subutilizadas. Dispositivos rádio cognitivos que operam na banda de frequência da TV digital são conhecidos como White Space Devices (WSD) e utilizam canais livres sob a condição de não provocar interferência acima do limite estabelecido pelo órgão regulador. A autoridade reguladora do Reino Unido, Office of Communication (Ofcom), publicou, em fevereiro de 2015, a primeira regulação européia permitindo a operação de sistemas WSD na banda da TV digital através do suporte de sistemas de banco de dados geolocalizados. O regulamento Ofcom define uma metodologia para calcular a potência de transmissão máxima de um WSD através de um método de entrada única (single-entry) da interferência intersistema máxima. Devido a isso, a interferência agregada de WSDs co-canais que operam na mesma região pode ultrapassar a interferência intersistema máxima. Além deste problema, verifica-se que a metodologia Ofcom não define a interferência intersistema máxima pelo mesmo critério da interferência intrasistema como foi definida pelo planejamento do sistema primário de TV. Esta tese desenvolve uma nova metodologia de cálculo da potência de transmissão dos WSDs que soluciona os problemas identificados na metodologia Ofcom. A metodologia proposta garante a proteção do receptor de TV digital através de uma abordagem de múltiplas entradas da interferência dos WSDs e, adicionalmente, aumenta a capacidade do sistema WSD quando comparada à metodologia Ofcom. / [en] The technology of cognitive radio has been researched for more efficient use of spectrum, since it allows the use of under-utilized frequency bands. Cognitive radio devices operating in the digital TV frequency band are known as White Space Devices (WSD) and use free channels under the condition of not causing interference above the limit set by the regulator. The UK regulatory authority, Office of Communication (Ofcom), published in February 2015, the first European regulation allowing WSD systems in the digital TV band through the support of geo-database systems. The Ofcom regulation defines a methodology to calculate the maximum WSD transmission power through a single-entry method for the maximum intersystem interference. Due to this, the aggregate interference of cochannel WSDs operating in the same region may exceed this maximum intersystem interference. In addition to this problem, it is verified that the Ofcom methodology does not define maximum intersystem interference by the same criterion of intrasystem interference as was defined by the primary TV system planning. This thesis develops a new methodology for calculating the transmission power of WSDs that solves the problems identified in the Ofcom methodology. The proposed methodology guarantees the protection of the digital TV receiver through a multiple-entry approach of the WSDs interference and, additionally, increases the WSD system capacity when compared to the Ofcom methodology.

The TV white space (TVWS) is one of the promising technologies to provide wide coverage, energy effcient and cost effective Internet of Things (IoT) services. However, its low operating frequency and wide bandwidth poses significant challenges to antenna designs. In this thesis, three antennas are developed using the characteristic mode analysis (CMA) for IoT devices operating over the TVWS. First, a very-low profile circular small antenna is transformed from a vertical monopole antenna. The CMA is used to determine the mode to be excited and to design a specific feeding structure. After being printed on Rogers 5880 substrate, the final antenna structure operates at 474 MHz with a V SWR < 2 bandwidth of 2.2 MHz. Its lateral radius is just 5.2% of the wavelength of its resonant frequency. Second, a compact U-shaped printed UWB monopole antenna is proposed to operate over the entire UHF TV spectrum. This antenna measures 0:36 0 0:06 0 0:01 0 where 0 is the wavelength of its lowest operating frequency. Its V SWR < 2 bandwidth is 87.5%, and the UWB behaviour is discussed by the CMA. Third, a novel antenna design method is established on annular ring-shaped structures with modal characteristics revealed by the CMA. Following the proposed method, another UWB antenna is achieved by creating and exciting multiple modes with resonant frequencies distributed across the UHF TV spectrum. All antenna designs are verified thorough simulations and measurements. Furthermore, antennas are also integrated into IoT devices and their system performance is measured under different communication scenarios. The system measurements also verify the good propagation property and the abundant spectrum resource of the TVWS.

My Trip to Notan charts my own journey from the rawness and acceptance of multiple life losses into understanding, and finally, renewal. The key result of this project is a prototype book, a 48-page digital Print-On-Demand (POD) publication, which also includes a DVD that inserts into book’s back and features live demonstrations, interviews and other segments related to the book. Additionally, the body of work from which the book was gleaned was presented at the thesis exhibition. Ultimately, My Trip to Notan is a sketch of my understanding of the framework that threads through design, physics and philosophy, inspired by the simplicity of the ancient art of Notan, and upon my own fragmentary observations gathered from the journey. My hope was to reveal some sense of the pulse that drives the inquiry, rather than the suggestion of any sort of destination.

The house agency enterprises offer services for promoting the real estate sales and leasing transactions. Due to lower barriers to entry and many house agencies of network trading joining, it becomes more competitive. The main purposes of the thesis listed are to explore how to inject new business model thinking and channel strategies to find a new niche market. A.What is the development and market competition in the industry? B.How the enterprises develop business model in the competitive environment in order to obtain the source of competitive advantage? C.How the enterprises integrate the traditional and virtual channel strategies to get consumers¡¦ attention and revenues. Through the literature reaches and industry interviews, several important findings are summarized as followings: A.The ¡§Seizing the White Space¡¨ of the house agency industry includes that other enterprises has not entered, expand its business to international services, or use its core competence to related businesses. B.The enterprises must offer services for customers in the shortest time to find the correct and attractive objects and give a variety of options of the same price to help determine the value of the house, and related services. C.The traditional and virtual channel strategies of the industry render as a strong complementary relationship. Whether they¡¦re traditional or virtual channels, the industry should focus on its image and giving right services.

No / Opportunistic secondary usage of underutilised radio spectrum is currently of great interest and the use of TV White Spaces (TVWS) has been considered for Long Term Evolution (LTE) broadband services. However, wireless microphones operating in TV bands pose a challenge to TVWS opportunistic access. Efficient and proactive spectrum sensing could prevent harmful interference between collocated devices, but existing spectrum sensing schemes such as energy detection and schemes based on Random Matrix Theory (RMT) have performance limitations. We propose a new blind spectrum sensing scheme with higher performance based on RMT supported by a new formula for the estimation of noise variance. The performance of the proposed scheme has been evaluated through extensive simulations on wireless microphone signals. The proposed scheme has also been compared to energy detection schemes, and shows higher performance in terms of the probability of false alarm (Pfa) and probability of detection (Pd).

As traditional wireless systems that only operate on fixed frequency bands are reaching their capacity limits, advanced frequency-agile radio systems are developed for more efficient spectrum utilization. For example, white space radios dynamically leverage locally unused TV channels to provide high-speed long-distance connectivity. They have already been deployed to connect the unconnected in rural areas and developing countries. However, such application scenarios are still limited due to low commercial demand. Hence, exploring better applications for white space radios needs more effort. With the benefits come the threats. As frequency-agile radio systems (e.g., software-defined radios) are flexible and become extremely low-cost and small-sized, it is very convenient for attackers to build attacking tools and launch wireless attacks using these radios. For example, civilian GPS signals can be easily spoofed by low-cost portable spoofers built with frequency-agile radio systems. In this dissertation, we study both the threat and application of frequency-agile radio systems. Specifically, our work focuses on the spoofing threat of frequency-agile radio towards GPS-based systems and the application of TV white space radio for ocean communications. Firstly, we explore the feasibility of using frequency-agile radio to stealthily manipulate GPS-based road navigation systems without alerting human drivers. A novel attacking algorithm is proposed, where the frequency-agile radio transmits fake GPS signals to lead the victim to drive on a wrong path that looks very similar with the navigation route on the screen. The attack's feasibility is demonstrated with real-world taxi traces in Manhattan and Boston. We implement a low-cost portable GPS spoofer using an off-the-shelf frequency-agile radio platform to perform physical measurements and real-world driving tests, which shows the low level of difficulty of launching the attack in real road environment. In order to study human-in-the-loop factor, a deceptive user study is conducted and the results show that 95% of the users do not recognize the stealthy attack. Possible countermeasures are summarized and sensor fusion defense is explored with preliminary tests. Secondly, we study similar GPS spoofing attack in database-driven cognitive radio networks. In such a network, a secondary user queries the database for available spectrum based on its GPS location. By manipulating GPS locations of surrounding secondary users with a frequency-agile radio, an attacker can potentially cause serious primary user interference and denial-of-service to secondary users. The serious impact of such attacks is examined in simulations based on the WhiteSpaceFinder spectrum database. Inspired by the characteristics of the centralized system and the receiving capability of cognitive radios, a combination of three defense mechanisms are proposed to mitigate the location spoofing threat. Thirdly, we explore the feasibility of building TV white space radio based on frequency-agile radio platform to provide connectivity on the ocean. We design and implement a low-cost low-power white space router ($523, 12 watts) customized for maritime applications. Its communication capability is confirmed by field link measurements and ocean-surface wave propagation simulations. We propose to combine this radio with an energy harvesting buoy so that the radio can operate independently on the ocean and form a wireless mesh network with other similar radios. / PHD / As traditional wireless systems, such as mobile phones and WiFi access points, only operate on some fixed frequency bands, it becomes increasingly crowded for those popular bands. Hence, for more efficient frequency resource utilization, frequency-agile radio systems that can dynamically operate on different frequency bands are developed. With these new technologies come new threats and applications, which are the focus of our work. On the one hand, as frequency-agile radio systems become low-cost and portable, attackers can easily launch wireless attacks with them. For example, we explored the feasibility, impact, and countermeasures for GPS spoofing attacks using frequency-agile radio systems in different scenarios. In a GPS spoofing attack, an attacker transmits false GPS signals to manipulate users’ GPS receivers. This kind of attack can be very dangerous and even life-threatening if it is launched against critical GPS-based applications. For example, once GPS-based navigation systems in self-driving cars are stealthily manipulated by remote attackers, attackers can divert self-driving cars to pre-defined destinations or dangerous situations like wrong-way driving on highway. On the other hand, since there is rich under-utilized spectrum resource in remote areas with no broadband connection yet, frequency-agile radio systems can be used to provide broadband internet connectivity there. For example, based on frequency-agile radio platform, we developed a low-cost low-power wireless router that can dynamically operate on TV broadcasting band. It is able to provide high-speed wireless connection to a large area on the ocean. This technology has the potential to bring low-cost high-speed connection to people and industry on the ocean, which will facilitate various maritime applications.