Mobile Communication Networks and Digital Television Broadcasting Systems in the Same Frequency Bands – Advanced Co-Existence Scenarios

The increasing demand for wireless multimedia services provided by modern communication systems with stable services is a key feature of advanced markets. On the other hand, these systems can many times operate in a neighboring or in the same frequency bands. Therefore, numerous unwanted co-existence scenarios can occur. The aim of this paper is to summarize our results which were achieved during exploration and measurement of the co-existences between still used and upcoming mobile networks (from GSM to LTE) and digital terrestrial television broadcasting (DVB) systems. For all of these measurements and their evaluation universal measurement testbed has been proposed and used. Results presented in this paper are a significant part of our activities in work package WP5 in the ENIAC JU project “Agile RF Transceivers and Front-Ends for Future Smart Multi-Standard Communications Applications (ARTEMOS)”

Radio frequency interference to DVB-T reception from LTE systems in adjacent bands

Australians have recently benefited from the switch-over to digital television which has freed many channels called digital dividend. Australia's digital dividend is the frequency range of 694 MHz to 820 MHz which is used to operate Long Term Evolu- tion (LTE) technology. In Australia there were 57 VHF and UHF channels used for television broadcasting. After the completion of switch-over process, UHF channels 52 to 69 were freed up which is considered as Australian digital dividend. When LTE Frequency Division Duplex (FDD) system and digital television services operate in adjacent UHF bands, LTE FDD transmitters can cause harmful interference to digital video broadcasting-terrestrial (DVB-T). So in this study, we have presented the compatibility of operating LTE FDD services in the digital dividend spectrum identified in Australia. We have used interference analysis method to calculate the minimum separation distance between LTE FDD and DVB-T sys- tem and Monte Carlo Simulation for calculating the probability of location within considered DVB-T area that suffer maximum level of interference. Also, there are some unused channels where digital television operates called TV White Spaces (TVWS). TVWS can be utilized to operate the secondary devices such as LTE Time Division Duplex (TDD) which helps to address spectrum scarcity issue. We have presented the study of the interference on DVB-T when LTE TDD are operating on TVWS. We have used interference analysis method to calculate mini- mum separation distance between LTE TDD and DVB-T. The results of our study show that increasing the guard band reduces the interference to adjacent channel

Analysis of coexistence and mutual interference between mobile and digital television systems

La creciente demanda de servicios de comunicaciones inalámbricas multimedia es un factor clave en los mercados más desarrollados. Así, las palabras de moda en las comunicaciones personales “acceso para cualquier persona, en cualquier sitio, en cualquier momento y para el servicio deseado”, implican una demanda notoria y creciente del Espectro Radioeléctrico. En este sentido, la última Conferencia Mundial de Radiocomunicaciones 2007 (CMR-07) atribuyó la parte alta de la banda UHF a las redes móviles como servicio co-primario a partir del 2015 en la Región 1, aprovechando el Dividendo Digital debido a la mayor eficiencia espectral de la TV digital con respecto a la analógica. Esto tiene el potencial de causar una interferencia perjudicial entre los sistemas de televisión y los sistemas móviles y necesita ser analizado con atención. En este artículo presentamos un estudio del problema de la interferencia co-canal en dicho escenario, proponiendo una metodología para tener en cuenta la interferencia entre una red móvil LTE y un sistema televisivo DVB-T, poniendo de relieve el comportamiento diferente de los dos radioenlaces.The ever increasing demand for multimedia wireless communication systems is a key feature of more advanced markets. The buzzwords of personal communications, meant to provide “access to anyone, anywhere, at anytime to the wanted service”, implies that radio spectrum demands are dramatically increasing in most developed markets. The last World Radiocommunication Conference (WRC-07) allocated on a co-primary basis the upper part of the UHF band to mobile services as from 2015 in Region 1, taking advantage of the Digital Dividend due to the higher spectrum efficiency of digital TV with respect to the analogue system. This will cause potentially harmful mutual interference between TV and mobile radio services, that needs to be carefully analysed. In this paper we present a study of the co-channel interference problem, proposing a methodology to take into account the mutual interference between a LTE mobile network and a DVB-T system and highlighting the different behaviour of the two radio links

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

CellTV - on the Benefit of TV Distribution over Cellular Networks A Case Study

As mobile IP-access is becoming the dominant technology for providing wireless services, the demand for more spectrum for this type of access is increasing rapidly. Since IP-access can be used for all types of services, instead of a plethora of dedicated, single-service systems, there is a significant potential to make spectrum use more efficient. In this paper, the feasibility and potential benefit of replacing the current terrestrial UHF TV broadcasting system with a mobile, cellular data (IP-) network is analyzed. In the cellular network, TV content would be provided as {one} of the services, here referred to as CellTV. In the investigation we consider typical Swedish rural and urban environments. We use different models for TV viewing patterns and cellular technologies as expected in the year 2020. Results of the quantitative analysis indicate that CellTV distribution can be beneficial if the TV consumption trend goes towards more specialized programming, more local contents, and more on-demand requests. Mobile cellular systems, with their flexible unicast capabilities, will be an ideal platform to provide these services. However, the results also demonstrate that CellTV is not a spectrum-efficient replacement for terrestrial TV broadcasting with current viewing patterns (i.e. a moderate number of channels with each a high numbers of viewers). In this case, it is doubtful whether the expected spectrum savings can motivate the necessary investments in upgrading cellular sites and developing advanced TV receiver required for the success of CellTV distribution.Comment: To appear on Trans. Broadcasting 201

TV White Space Network Interference Measurements and Application Pilot Trials. Final report from field measurement campaigns and application pilot trials in WISE projects during 2011-2014

This report describes TV white space network measurements and trials conducted in Finnish WISE projects during 2011-2014. A TV White Space test network environment was developed and built in Turku, Finland, to aid in standardization and to demonstrate technical capabilities of TV white space networks. The test network environment was the first in Europe having a geolocation database to control the frequency use. This report introduces interference measurements conducted to aid in the standardization work in CEPT/ECC SE43 group. These measurements and the work in the SE43 group served as base information in the creation of an ETSI harmonised standard for TV white space devices, ETSI EN 301 598. The report also presents two application pilot trials conducted to demonstrate the technical feasibility of TV white space networks: a long-term video surveillance trial in Turku and Helsinki area public transport ticket sales and transit information screens trial.Siirretty Doriast

Coexistence of DTT and Mobile Broadband: A Survey and Guidelines for Field Measurements

This article provides a survey and a general methodology for coexistence studies between digital terrestrial television (DTT) and mobile broadband (MBB) systems in the ultra high frequency (UHF) broadcasting band. The methodology includes characterization of relevant field measurement scenarios and gives a step-by-step guideline on how to obtain reliable field measurement results to be used in conjunction with link budget analyses, laboratory measurements, and simulations. A survey of potential European coexistence scenarios and regulatory status is given to determine feasible future use scenarios for the UHF television (TV) broadcasting band. The DTT reception system behavior and performance are also described as they greatly affect the amount of spectrum potentially available for MBB use and determine the relevant coexistence field measurement scenarios. Simulation methods used in determining broadcast protection criteria and in coexistence studies are briefly described to demonstrate how the information obtained from field measurements can be used to improve their accuracy. The presented field measurement guidelines can be applied to any DTT-MBB coexistence scenarios and to a wide range of spectrum sharing and cognitive radio system coexistence measurements.</p

Planning the Migration of Digital Terrestrial Broadcasting in Croatia to DVB-T2 Standard

On 31 December 2010 analogue television in Croatia was completely switched off and was replaced by DVB-T television standard. Because of that, it became possible to provide more TV programs with higher quality and it freed up the frequency band for first digital dividend, which is now used for LTE mobile broadband services. Nowadays, newer and more advanced standard DVBT2, which is extension of DVB-T, is being implemented in many countries. In Croatia DVB-T2 is used for terrestrial pay TV platform. DVB-T2 offers significantly higher network capacity in the same frequency band which enables more television programs, easier migration to HD services and possibility to free up additional frequencies for second digital dividend. Second dividend frequencies are fitted for covering broad rural areas with wireless broadband services that can reduce the digital gap. Such benefits will have a positive impact on economic sustainability of traditional broadcasting media in a competitive digital economy. In this paper we give an overview and analysis of digitalisation process in Croatia in terms of technology and regulation, costs and benefits for the state budget and media campaign with lessons learned, in order to enumerate motivation factors for further migration to the DVB-T2 standard. With the help of simulation, a practical example of useful bit rate increase between the DVB-T and DVB-T2 systems is given. Predicted reduction of TV broadcasting costs, migration costs, need for government subsidy to buy new DVB-T2 receivers and other cost factors of the transition to DVB-T2 are discussed. This analysis is a basis for identifying key prerequisites, benefits, obstacles and stakeholders in migration to DVB-T2 and gives further areas that have to be researched in order to prepare the optimal plan for migration to DVB-T2 from technical, economic, market and social perspectives

Planning the Migration of Digital Terrestrial Broadcasting in Croatia to DVB-T2 Standard

On 31 December 2010 analogue television in Croatia was completely switched off and was replaced by DVB-T television standard. Because of that, it became possible to provide more TV programs with higher quality and it freed up the frequency band for first digital dividend, which is now used for LTE mobile broadband services. Nowadays, newer and more advanced standard DVBT2, which is extension of DVB-T, is being implemented in many countries. In Croatia DVB-T2 is used for terrestrial pay TV platform. DVB-T2 offers significantly higher network capacity in the same frequency band which enables more television programs, easier migration to HD services and possibility to free up additional frequencies for second digital dividend. Second dividend frequencies are fitted for covering broad rural areas with wireless broadband services that can reduce the digital gap. Such benefits will have a positive impact on economic sustainability of traditional broadcasting media in a competitive digital economy. In this paper we give an overview and analysis of digitalisation process in Croatia in terms of technology and regulation, costs and benefits for the state budget and media campaign with lessons learned, in order to enumerate motivation factors for further migration to the DVB-T2 standard. With the help of simulation, a practical example of useful bit rate increase between the DVB-T and DVB-T2 systems is given. Predicted reduction of TV broadcasting costs, migration costs, need for government subsidy to buy new DVB-T2 receivers and other cost factors of the transition to DVB-T2 are discussed. This analysis is a basis for identifying key prerequisites, benefits, obstacles and stakeholders in migration to DVB-T2 and gives further areas that have to be researched in order to prepare the optimal plan for migration to DVB-T2 from technical, economic, market and social perspectives