User behaviour modelling for resource management in a hybrid UMTS/DVB-T network

Third generation mobile networks such as UMTS are designed to enhance the deployment of multimedia services providing high data rates and new flexible communication capabilities. However, these systems are interference limited and as such their performance is lowered in the case of a large number of users generating heavy traffic. A solution to this problem is to interconnect the UMTS network to a Digital Video Broadcasting-Terrestrial (DVB-T) network, so that the lack of capacity of UMTS during busy periods can be offset by the high bit rate available on the broadcast network. In order to justify this choice a prediction of the number of subscribers requesting the new multimedia applications designed for this scenario is needed. This paper focuses on the user behaviour modelling for multimedia services in a hybrid UMTS/DVB-T platform. The aim of the paper is to provide operators with a forecast of the demand for new multimedia services showing how they can be subject to a very high number of subscriptions, which UMTS would hardly be able to handle

Stochastic user behaviour modelling and network simulation for resource management in cooperation with mobile telecommunications and broadcast networks

The latest generations of telecommunications networks have been designed to deliver higher data rates than widely used second generation telecommunications networks, providing flexible communication capabilities that can deliver high quality video images. However, these new generations of telecommunications networks are interference limited, impairing their performance in cases of heavy traffic and high usage. This limits the services offered by a telecommunications network operator to those that the operator is confident their network can meet the demand for. One way to lift this constraint would be for the mobile telecommunications network operator to obtain the cooperation of a broadcast network operator so that during periods when the demand for the service is too high for the telecommunications network to meet, the service can be transferred to the broadcast network. In the United Kingdom the most recent telecommunications networks on the market are third generation UMTS networks while the terrestrial digital broadcast networks are DVB-T networks. This paper proposes a way for UMTS network operators to forecast the traffic associated with high demand services intended to be deployed on the UMTS network and when demand requires to transfer it to a cooperating DVB-T network. The paper aims to justify to UMTS network operators the use of a DVB-T network as a support for a UMTS network by clearly showing how using a DVB-T network to support it can increase the revenue generated by their network

Mobile Television: Challenges of Advanced Service Design

In this paper, we propose an integrative framework based on dynamic models of the evolution of industries. The main arguments are illustrated using the case of mobile TV. One main assertion is that the value network of mobile data services is much more complex than that of previous generations of mobile services, in particular voice and messaging. The new environment requires a significantly higher degree of coordination and integration between more participants in the value net and a consistent constellation of technology, policy and firm strategy. Unless such compatible arrangements are in place, mobile TV will not take off. The paper develops these themes theoretically and illustrates them with a detailed case study of mobile TV in South Korea as well as comments on the situation in Europe and the U.S. The private and public sectors in South Korea were capable of producing conditions in which mobile TV could flourish. Even so, significant challenges remain to create a financially sustainable mobile TV industry. In contrast, in Europe and the U.S. major obstacles to the development of mobile TV continue to exist. Unless these obstacles, including problems with spectrum policy, are addressed, mobile TV may not be able to develop its full market potential

Architectural support for ubiquitous access to multimedia content

Tese de doutoramento. Engenharia Electrotécnica e de Computadores (Telecomunicações). Faculdade de Engenharia. Universidade do Porto. 200

On Transmission System Design for Wireless Broadcasting

This thesis considers aspects related to the design and standardisation of transmission systems for wireless broadcasting, comprising terrestrial and mobile reception. The purpose is to identify which factors influence the technical decisions and what issues could be better considered in the design process in order to assess different use cases, service scenarios and end-user quality. Further, the necessity of cross-layer optimisation for efficient data transmission is emphasised and means to take this into consideration are suggested. The work is mainly related terrestrial and mobile digital video broadcasting systems but many of the findings can be generalised also to other transmission systems and design processes. The work has led to three main conclusions. First, it is discovered that there are no sufficiently accurate error criteria for measuring the subjective perceived audiovisual quality that could be utilised in transmission system design. Means for designing new error criteria for mobile TV (television) services are suggested and similar work related to other services is recommended. Second, it is suggested that in addition to commercial requirements there should be technical requirements setting the frame work for the design process of a new transmission system. The technical requirements should include the assessed reception conditions, technical quality of service and service functionalities. Reception conditions comprise radio channel models, receiver types and antenna types. Technical quality of service consists of bandwidth, timeliness and reliability. Of these, the thesis focuses on radio channel models and errorcriteria (reliability) as two of the most important design challenges and provides means to optimise transmission parameters based on these. Third, the thesis argues that the most favourable development for wireless broadcasting would be a single system suitable for all scenarios of wireless broadcasting. It is claimed that there are no major technical obstacles to achieve this and that the recently published second generation digital terrestrial television broadcasting system provides a good basis. The challenges and opportunities of a universal wireless broadcasting system are discussed mainly from technical but briefly also from commercial and regulatory aspectSiirretty Doriast

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

Evolution of High Throughput Satellite Systems: Vision, Requirements, and Key Technologies

High throughput satellites (HTS), with their digital payload technology, are expected to play a key role as enablers of the upcoming 6G networks. HTS are mainly designed to provide higher data rates and capacities. Fueled by technological advancements including beamforming, advanced modulation techniques, reconfigurable phased array technologies, and electronically steerable antennas, HTS have emerged as a fundamental component for future network generation. This paper offers a comprehensive state-of-the-art of HTS systems, with a focus on standardization, patents, channel multiple access techniques, routing, load balancing, and the role of software-defined networking (SDN). In addition, we provide a vision for next-satellite systems that we named as extremely-HTS (EHTS) toward autonomous satellites supported by the main requirements and key technologies expected for these systems. The EHTS system will be designed such that it maximizes spectrum reuse and data rates, and flexibly steers the capacity to satisfy user demand. We introduce a novel architecture for future regenerative payloads while summarizing the challenges imposed by this architecture

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

Semi-automated mobile television interactive application generation based on XHTML and Java ME

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University, 11/02/2011.Mobile Digital TV (MDTV), the hybrid of Digital Television (DTV) and mobile devices (such as mobile phones), has introduced a new way for people to watch DTV and has brought new opportunities for development in the DTV industry. Nowadays, the development of the next generation MDTV service has progressed in terms of both hardware layers and software, with interactive services/applications becoming one of the future MDTV service trends. However, current MDTV interactive services still lack in terms of attracting the consumers and the service creation and implementation process relies too much on commercial solutions, resulting in most parts of the process being proprietary. In addition, this has increased the technical demands for developers as well as has increased substantially the cost of producing and maintaining MDTV services. In light of the aforementioned situation, the Thesis has contributed to this field, by proposing an innovative MDTV service creation and consumption system based on XHTML and Java ME. On the head-end it introduces a semi-automatic creation mechanism to facilitate a less technical and more efficient interactive service creation process. This enables designers and creative individuals to be actively involved in the MDTV service creation process and to develop interactive-rich MDTV service. On the client-end it employs an open-source software environment as the interactive service MDTV consumption platform, rendering the MDTV service implementation process as less proprietary as possible. Furthermore, the Thesis offers a discussion on the different MDTV interactive application models currently used and based on the proposed software, a novel MDTV service presentation method is further introduced and adopted instead of the Rich Media and ECMAScript based methods. Finally, a series of qualitative testing procedures have been implemented with regards to conducting an essential evaluation on the operability of the proposed software system