PERFORMANCE EVALUATION OF DVB-T2 BROADCASTING NETWORK: A CASE STUDY OF DAR ES SALAAM, TANZANIA

DVB-T2 is the second generation of the digital terrestrial television broadcasting system which transmits composite (compressed digital audio and video) signal and other data in an MPEG-4 transport stream, using coded orthogonal frequency-division multiplexing (COFDM or OFDM) modulation. DVB-T2 uses multiple MPEG-4 transport streams and have enhanced FEC and higher QAM (256-QAM) constellations. Tanzania switched from analogue to Digital Video Broadcasting Terrestrial second generation (DVB-T2) in 2013, since the official switching there has been complaints from the DVB-T2 users on the coverage and quality of service provided. In this paper we evaluated the DVB-T2 performance and make the recommendations on the ways to optimize the performance. Through measurements it has been observed that, the quality of coverage in some areas (locations) is poor, so to improve the received signal strength coverage and quality we recommend the use of enhanced Yagi-Uda antenna gain which is going to be designed. Keywords: DVB-T2, Received Signal Strength Indicator (RSSI), Bit Error Rate (BER), Carrier to Noise Ratio (CNR), Modulation Error Rate (MER), Polarization, Yagi-Uda antenna

Economically sustainable public security and emergency network exploiting a broadband communications satellite

The research contributes to work in Rapid Deployment of a National Public Security and Emergency Communications Network using Communication Satellite Broadband. Although studies in Public Security Communication networks have examined the use of communications satellite as an integral part of the Communication Infrastructure, there has not been an in-depth design analysis of an optimized regional broadband-based communication satellite in relation to the envisaged service coverage area, with little or no terrestrial last-mile telecommunications infrastructure for delivery of satellite solutions, applications and services. As such, the research provides a case study of a Nigerian Public Safety Security Communications Pilot project deployed in regions of the African continent with inadequate terrestrial last mile infrastructure and thus requiring a robust regional Communications Satellite complemented with variants of terrestrial wireless technologies to bridge the digital hiatus as a short and medium term measure apart from other strategic needs. The research not only addresses the pivotal role of a secured integrated communications Public safety network for security agencies and emergency service organizations with its potential to foster efficient information symmetry amongst their operations including during emergency and crisis management in a timely manner but demonstrates a working model of how analogue spectrum meant for Push-to-Talk (PTT) services can be re-farmed and digitalized as a “dedicated” broadband-based public communications system. The network’s sustainability can be secured by using excess capacity for the strategic commercial telecommunication needs of the state and its citizens. Utilization of scarce spectrum has been deployed for Nigeria’s Cashless policy pilot project for financial and digital inclusion. This effectively drives the universal access goals, without exclusivity, in a continent, which still remains the least wired in the world

Field Measurements in Determining Incumbent Spectrum Utilization and Protection Criteria in Wireless Co-existence Studies

Studies of spectrum sharing and co-existence between different wireless communication systems are important, as the current aim is to optimize their spectrum utilization and shift from static exclusive spectrum allocation to more dynamic co-existence of different systems within same frequency bands. The main goal of this thesis is to provide measurement methodologies for obtaining realistic results in modeling incumbent spectrum utilization and in determining incumbent protection criteria. The following research questions are considered in this thesis: Q1) How should field measurements be conducted and used to model incumbent spectrum utilization? Q2) How should field measurements be conducted and used to determine protection criteria for incumbents in a co-existence scenario with mobile broadband? and Q3) Which licensing methods and technological solutions are feasible to enable spectrum sharing in frequency bands with incumbents? To answer to Q1, this thesis describes the development of a spectrum observatory network concept created through international collaboration and presents measurement methodologies, which allow to obtain realistic spectrum occupancy data over geographical areas using interference map concept. A cautious approach should be taken in making strong conclusions from previous single fixed location spectrum occupancy studies, and measurements covering larger geographical areas might be needed if the measurement results are to be used in making spectrum management decisions. The field interference measurements considered in Q2 are not covered well in the current research literature. The measurements are expensive to conduct as they require substantial human resources, test network infrastructure, professional level measurement devices and radio licenses. However, field measurements are needed to study and verify hypotheses from computer simulations or theoretical analyses in realistic operating conditions, as field measurement conditions can not or are not practical to be adequately modeled in simulations. This thesis proposes measurement methodologies to obtain realistic results from field interference measurements, taking into account the propagation environments and external sources of interference. Less expensive simulations and laboratory measurements should be used both to aid in the planning of field measurements and to complement the results obtained from field measurements. Q3 is investigated through several field interference measurement campaigns to determine incumbent protection criteria and by analyzing the spectrum observatory data to determine the occupancy and trends in incumbent spectrum utilization. The field interference measurement campaigns have been conducted in real TV White Space, LTE Supplemental Downlink and Licensed Shared Access test network environments, and the obtained measurement results have been contributed to the development of the European spectrum regulation. In addition, field measurements have been conducted to contribute to the development and technical validation of the spectrum sharing frameworks. This thesis also presents an overview of the current status and possible directions in spectrum sharing. In conclusion, no single spectrum sharing method can provide universally optimal efficiency in spectrum utilization. Thus, an appropriate spectrum sharing framework should be chosen taking into account both the spectrum utilization of the current incumbents and the future needs in wireless communications.Siirretty Doriast

Redes de nova geração e o serviço universal de telecomunicações em Portugal

Doutoramento em Engenharia EletrónicaThis thesis addresses the issue of Universal Service for telecommunications in the context of the access networks of next generation. This work aims to contribute to the redefinition of the concept of universal telecommunications service focusing primarily on extending it to broadband services as economic and social development factor and taking into account the degree of dependence that currently, modern societies have for the different communication and information services. Complementarily it also intended to meet some of the challenges set out in the European 2020 agenda. Universal Service is defined here as access to a telecommunications network (with obligations in terms of type and quality of service for the operator), by of all citizens at any country's geographical location, with uniform and accessible price. The approach adopted is the State as a mentor for social equity, respectful of the liberalized market dynamics but also knowledgeable of the requirements of modern telecommunications services and its relationship with the different technologies available. The possibility of subsidizing is assumed. The Universal Service´s provision is subject to open to all operators, which are assumed to possess other profitability businesses, than the Universal Service, using technologies similar to those prescribed for the respective Universal Service provision contest. Although the work has components of economic and financial analysis, the approach is the engineering point of view, looking for help to identify technical and organizational solutions which offer prospects for the dissemination and adoption of next generation network solutions. As a point of departure the work gives an overview on the state of the art access networks , trying to identify which of the differences between this reality and possible scenarios for next-generation network with potential access to the generality of the people . The case of the Portuguese reality will be given special attention, taking into account their specific characteristics in terms of geography, demography, economics and market dynamics. The main results of this work are: • Identification of possible scenarios for the evolution of existing networks, in particular in areas with deficit coverage. • Identification of possible operating models and business to the materialization of the above scenarios developed and its economic analysis in an attempt to determine the critical factors associated with sustainability and / or need for subsidies. • Contribution to the regulatory framework of new generation networks from the point of view of the constraints of technology and the specifics of the Universal Service.Esta tese aborda a questão do serviço universal de telecomunicações no contexto das redes de acesso de nova geração. Este trabalho pretende contribuir para a redefinição do conceito de Serviço Universal de Telecomunicações concentrando-se principalmente em estendê-lo a serviços de banda larga como factor de desenvolvimento económico e social e tendo em conta o grau de dependência que, actualmente, as sociedades modernas têm em relação aos diferentes serviços de comunicação e informação. De forma complementar pretende-se também ir ao encontro de alguns dos desafios enunciados na Agenda Europeia 2020. Serviço Universal é aqui definido como o acesso a uma rede de telecomunicações (com obrigações em termos de tipo e qualidade de serviço para o operador), por parte de todos os cidadãos, em qualquer localização geográfica do país, a preços uniformes e acessíveis. A perspectiva adoptada é a Estatal como mentor da equidade social, respeitador das dinâmicas de mercado liberalizado mas também conhecedor dos requisitos dos modernos serviços de telecomunicações e da sua relação com as diferentes tecnologias disponíveis. A possibilidade de subsidiação é assumida. A prestação de Serviço Universal é sujeita a concurso aberto a todos os operadores, que se assume possuírem outros negócios, que não apenas o Serviço Universal, com rentabilidade e usando tecnologias semelhantes às preconizadas para a respectiva prestação de Serviço Universal. Embora o trabalho desenvolvido tenha componentes de análise económico-financeira, a abordagem utilizada é a de engenharia, procurando contribuir para a identificação de soluções técnicas e organizacionais que possam oferecer perspectivas sustentáveis para a disseminação e adopção das soluções redes de nova geração. Como ponto de partida o trabalho apresenta uma visão geral sobre o estado da arte das redes de acesso, procurando identificar quais os diferenciais existentes entre essa realidade e a de possíveis cenários de rede de próxima geração com potencial de acesso para a generalidade dos cidadãos. O caso da realidade Portuguesa será objecto de uma atenção especial, tendo em consideração as suas especificidades em termos de geografia, demografia, economia e dinâmicas do mercado. Os principais resultados deste trabalho são os seguintes: • Identificação de possíveis cenários para a evolução das redes actuais, nomeadamente em áreas com deficit de cobertura de rede. • Identificação de possíveis modelos de operação e negócio para a materialização dos cenários acima desenvolvidos e respectiva análise económica, como tentativa de determinar os factores críticos associados à sua sustentabilidade e /ou necessidade de subsidiação. • Contributo para o quadro regulatório das Redes de Nova Geração sob o ponto de vista dos constrangimentos das tecnologias e das especificidades do Serviço Universal

Roadmapping for Corporate Strategy: Action Research in Convergence of Technologies

This PhD thesis deals with the strategic implications of the penetration of consumer wireless technologies in vehicles, which represents a trend of growing importance. The convergence of such markets, namely the consumer industry and the automotive connectivity and infotainment areas, generates opportunities and threats, and research possibilities. An Action Research project was carried out at a leading Tier 1 automotive firm, aiming to implement a customized Technology Roadmapping (TRM) process, able to recognize and deal with a fast changing context, and to manage implications within the organization, at various levels and very dynamically. A new “on demand” overarching TRM framework was obtained and added to the existing practices, enabling better support to strategic decision making and multi-project planning

Journal of Telecommunications and Information Technology, 2014, nr 3

kwartalni

Simulation model for digital broadcasting technologies efficiency estimation

Digitalizacija zemaljskog emitovanja televizijskih programa prva je velika promena u TV sistemima još od uvoĊenja kolor televizije. Prelazak sa analognog na digitalno emitovanje predstavlja jedan od najvećih izazova u razvoju video i audio tehnologije i desiće se u celom svetu u veoma bliskoj budućnosti. Pored ozbiljnih tehniĉkih zahvata, ovaj proces zahteva znaĉajne finansijske investicije vezane za enorman broj standardnih TV prijemnika i široko rasprostranjene televizijske mreţe. Zbog toga, gde god je moguće u distributivnoj mreţi, potrebno je obezbediti kompatibilnost sa postojećim sistemima. Nasuprot tome, digitalizacija video signala visoke rezolucije zahteva visoko sofisticirane algoritme sa velikom kompresijom i veoma efikasnom tehnologijom prenosa. Trenutno u svetu koriste se tri meĊunarodna standarda za digitalno zemaljsko emitovanje TV programa - Advanced Television Systems Committee (ATSC) u upotrebi u Severnoj Americi i Juţnoj Koreji, Digital Video Broadcasting Terrestrial (DVB-T) pored Evrope upotrebljava se u Australiji, Indiji i nekim zemljama Azije i Afrike, Integrated Services Digital Broadcasting Terrestrial (ISDB-T), koristi se u Japanu i Juţnoj Americi. Fokus ove disertacije je na analizi performansi i razvoju metoda za procenu efikasnosti tehnologija za fiksni prijem koje se koriste u Evropi. Za isporuku TV servisa krajnjim korisnicima postoje tri glavna sistema prenosa, satelitski, kablovski i preko zemaljskih predajnika. Digitalni zemaljski sistem je sposoban za isporuku TV programa ĉak i mobilnim korisnicima. Servisi prenosa podataka i televizije visoke rezolucije (HD) raspoloţivi su preko digitalnih satelitskih i kablovskih mreţa, ali sve do sada korisnici zemaljskih mreţa nisu primali ove servise jer je za njihov prenos potreban veći kapacitet kanala u odnosu na onaj korišćen za televiziju standardne rezolucije (SD) - Digital Video Broadcasting Terrestrial (DVB-T) i Moving Picture Expert Group MPEG-2 standard kompresije. Novije tehnologije, kao što su standard kompresije MPEG-4 verzija 10 i druga generacija standarda za zemaljsko emitovanje (DVB-T2), obezbeĊuju povećan kapacitet i robusnost u zemaljskim mreţama. MeĊutim, pored tehniĉkih prednosti evidentno je da najnovije tehnologije sa sobom donose i više cene opreme i sistema. Sprovodljivost poslovnog plana uvoĊenja digitalnog emitovanja je pod direktnim uticajem ovih tehno-ekonomskih pitanja.The first major change within the TV system since the introduction of color is the digitalization of television terrestrial broadcast network. The digital switchover is one of the main challenges in video and audio technology developments and it is going to happen in the very near future throughout the world. Besides the severe technical requirements, this process is driven by significant financial investments, regarding to an enormous number of standard TV sets and widespread broadcast networks. Consequently, it is necessary, wherever is possible in distribution network, to ensure the compatibility with existing systems. On the contrary, digitization of high-resolution video and audio signals needs highly sophisticated algorithms with high compression and very efficient transmission technology. There are three international standards currently used world-wide for digital terrestrial broadcasting - Advanced Television Systems Committee (ATSC) used in North America and South Korea, Digital Video Broadcasting Terrestrial (DVB-T) used apart from Europe in Australia, India and some other Asian and African countries, Integrated Services Digital Broadcasting Terrestrial (ISDB-T), used in Japan and South America. The focus of this dissertation is the performance analysis and efficiency estimation method applied to the technologies for fixed reception used in our region – Europe. The three main transmission systems for delivering TV service to end-users are satellite, cable and terrestrial networks. The digital terrestrial television (DTT) system is capable of distribution of television content even to the mobile devices. Data-casting services and high-definition (HD) television content is available via digital satellite and digital cable networks but, until now, terrestrial users have not received data and HD content because its transmission requires a higher channel capacity than that used for standard definition (SD) TV - Digital Video Broadcasting Terrestrial (DVB-T) and Moving Picture Expert Group MPEG-2 coding and compression standard. The latest technologies, like compression standard MPEG-4 part 10 and the second generation of digital terrestrial broadcasting standard (DVB-T2), provide increased capacity and ruggedness in the terrestrial transmission networks. But besides technical benefits it is evident that the latest technologies bring also a higher system cost. The viability of digital broadcasting business case is directly influenced by this techno-economic issue