DAB Eureka-147: The European Vision for Digital Radio

The digitalisation of radio broadcasting has a long history and as a project has been under active consideration for at least 25 years. A number of different technical approaches to digital radio exist, the longest established of which is the so-called Eureka-147 or DAB (Digital Audio Broadcasting) system. This paper explores the ‘technological imaginary’ of DAB and its distinctly ‘European’ vision for new media and the future of broadcasting. It examines its origins in European R&D policy of the 1980s, and its affinity with European broadcasting practice, particularly within a public service tradition. Ironically, it was DAB’s failure to capitalise on its ‘Europeanness’ that contributed to the fragmentary support it subsequently received at a political level, compromising its subsequent implementation. From a contemporary perspective, DAB’s original mission to provide enhanced, interactive information and entertainment services through audio, text and visual content, while visionary, appears to have misread trends towards convergence and appears out of step with contemporary consumption patterns

Back to the Future: The Emergence of Contrasting European and US Approaches to Digital Radio

Digital radio has been in development for over 25 years and yet is no nearer a point of successful adoption. This paper explores the emergence of contrasting European and American approaches to digital radio. The most established of these, Eureka-147 or Digital Audio Broadcasting (DAB), which originated in Europe, is contrasted with the so-called IBOC or /HD Radio approach, as alternative collective conceptualizations of how technology can bridge contemporary broadcasting practice to an ̳imagined‘ digital future. Drawing on the concept of ̳symptomatic technology‘ (Williams 1974), DAB‘s origins in European R&D policy of the 1980s and its affinity with established European broadcasting practice is characterised as a distinct technological vision for how the frontiers for radio broadcasting could be expanded within the European political and cultural landscape of the time. DAB‘s attempt to map a global solution for digital radio, combining satellite and terrestrial broadcast strategies, met with significant US opposition which subsequently supported the development of the alternative ̳in-band, on-channel‘ approach. While neither solution is guaranteed long term success, their importance lies in the mobilization of the relevant national and international policy frameworks for the construction of radio‘s future. Paying close attention to the discourses of technology inherent in these approaches and drawing on relevant contemporary engineering and technical descriptions, this analysis seeks to complement social shaping of technology studies (Mackay and Gillespie 1992) by focussing on the promotional efforts designed to support a particular technology‘s adoption

INTELLIGENTE TRANSPORT SYSTEMEN ITS EN VERKEERSVEILIGHEID

This report discusses Intelligent Transport Systems (ITS). This generic term is used for a broad range of information-, control- and electronic technology that can be integrated in the road infrastructure and the vehicles themselves, saving lives, time and money bymonitoring and managing traffic flows, reducing conges-tion, avoiding accidents, etc. Because this report was written in the scope of the Policy Research Centre Mobility & Public Works, track Traffic Safety, it focuses on ITS systems from the traffic safety point of view. Within the whole range of ITS systems, two categories can be distinguished: autonomous and cooperative systems. Autonomous systems are all forms of ITS which operate by itself, and do not depend on the cooperation with other vehicles or supporting infrastructure. Example applications are blind spot detection using radar, electronic stability control, dynamic traffic management using variable road signs, emergency call, etc. Cooperative systems are ITS systems based on communication and cooperation, both between vehicles as between vehicles and infrastructure. Example applications are alerting vehicles approaching a traffic jam, exchanging data regarding hazardous road conditions, extended electronic brake light, etc. In some cases, autonomous systems can evolve to autonomous cooperative systems. ISA (Intelligent Speed Adaptation) is an example of this: the dynamic aspect as well as communication with infrastructure (eg Traffic lights, Variable Message Sign (VMS)...) can provide additional road safety. This is the clear link between the two parts of this report. The many ITS applications are an indicator of the high expectations from the government, the academic world and the industry regarding the possibilities made possible by both categories of ITS systems. Therefore, the comprehensive discussion of both of them is the core of this report. The first part of the report covering the autonomous systems treats two aspects: 1. Overview of European projects related to mobility and in particular to road safety 2. Overview for guidelines for the evaluation of ITS projects. Out of the wide range of diverse (autonomous) ITS applications a selection is made; this selection is focused on E Safety Forum and PreVENT. Especially the PreVent research project is interesting because ITS-applications have led to a number of concrete demonstration vehicles that showed - in protected and unprotected surroundings- that these ITS-applications are already technically useful or could be developed into useful products. The component “guidelines for the evaluation of ITS projects” outlines that the government has to have specific evaluation tools if the government has the ambition of using ITS-applications for road safety. Two projects -guidelines for the evaluation of ITS projects- are examined; a third evaluation method is only mentioned because this description shows that a specific targeting of the government can be desirable : 1. TRACE describes the guidelines for the evaluation of ITS projects which are useful for the evaluation of specific ITS-applications. 2. FITS contains Finnish guidelines for the evaluation of ITS project; FIS is an adaptation of methods used for evaluation of transport projects. 3. The third evaluation method for the evaluation of ITS projects is developed in an ongoing European research project, eImpact. eImpact is important because, a specific consultation of stake holders shows that the social importance of some techniques is underestimated. These preliminary results show that an appropriate guiding role for the government could be important. In the second part of this document the cooperative systems are discussed in depth. These systems enable a large number of applications with an important social relevance, both on the level of the environment, mobility and traffic safety. Cooperative systems make it possible to warn drivers in time to avoid collisions (e.g. when approaching the tail of a traffic jam, or when a ghost driver is detected). Hazardous road conditions can be automatically communicated to other drivers (e.g. after the detection of black ice or an oil trail by the ESP). Navigation systems can receive detailed real-time up-dates about the current traffic situation and can take this into account when calculating their routes. When a traffic distortion occurs, traffic centers can immediately take action and can actively influence the way that the traffic will be diverted. Drivers can be notified well in advance about approaching emergency vehicles, and can be directed to yield way in a uniform manner. This is just a small selection from the large number of applications that are made possible because of cooperative ITS systems, but it is very obvious that these systems can make a significant positive contribution to traffic safety. In literature it is estimated that the decrease of accidents with injuries of fatalities will be between 20% and 50% . It is not suprising that ITS systems receive a lot of attention for the moment. On an international level, a number of standards are being established regarding this topic. The International Telecommunications Uniont (ITU), Institute for Electrical and Electronics Engineers (IEEE), International Organization for Standardization (ISO), Association of Radio Industries and Business (ARIB) and European committee for standardization (CEN) are currently defining standards that describe different aspects of ITS systems. One of the names that is mostly mentioned in literature is the ISO TC204/WG16 Communications Architecture for Land Mobile environment (CALM) standard. It describes a framework that enables transparent (both for the application and the user) continuous communication through different communication media. Besides the innumerable standardization activities, there is a great number of active research projects. On European level, the most important are the i2010 Intelligent Car Initiative, the eSafety Forum, and the COMeSafety, the CVIS, the SAFESPOT, the COOPERS and the SEVECOM project. The i2010 Intelligent Car Initiative is an European initiative with the goal to halve the number of traffic casualties by 2010. The eSafety Forum is an initiative of the European Commission, industry and other stakeholders and targets the acceleration of development and deployment of safety-related ITS systems. The COMeSafety project supports the eSafety Forum on the field of vehicle-to-vehicle and vehicle-to-infrastructure communication. In the CVIS project, attention is given to both technical and non-technical issues, with the main goal to develop the first free and open reference implementation of the CALM architecture. The SAFEST project investigates which data is important for safety applications, and with which algorithmsthis data can be extracted from vehicles and infrastructure. The COOPERS project mainly targets communication between vehicles and dedicated roadside infrastructure. Finally, the SEVECOM project researches security and privacy issues. Besides the European projects, research is also conducted in the United States of America (CICAS and VII projects) and in Japan (AHSRA, VICS, Smartway, internetITS). Besides standardization bodies and governmental organizations, also the industry has a considerable interest in ITS systems. In the scope of their ITS activities, a number of companies are united in national and international organizations. On an international level, the best known names are the Car 2 Car Communication Consortium, and Ertico. The C2C CC unites the large European car manufacturers, and focuses on the development of an open standard for vehicle-to-vehicle and vehicle-to-infrastructure communications based on the already well established IEEE 802.11 WLAN standard. Ertico is an European multi-sector, public/private partnership with the intended purpose of the development and introduction of ITS systems. On a national level, FlandersDrive and The Telematics Cluster / ITS Belgium are the best known organizations. Despite the worldwide activities regarding (cooperative) ITS systems, there still is no consensus about the wireless technology to be used in such systems. This can be put down to the fact that a large number of suitable technologies exist or are under development. Each technology has its specific advantages and disadvantages, but no single technology is the ideal solution for every ITS application. However, the different candidates can be classified in three distinct categories. The first group contains solutions for Dedicated Short Range Communication (DSRC), such as the WAVE technology. The second group is made up of several cellular communication networks providing coverage over wide areas. Examples are GPRS (data communication using the GSM network), UMTS (faster then GPRS), WiMAX (even faster then UMTS) and MBWA (similar to WiMAX). The third group consists of digital data broadcast technologies such as RDS (via the current FM radio transmissions, slow), DAB and DMB (via current digital radio transmissions, quicker) and DVB-H (via future digital television transmissions for mobiledevices, quickest). The previous makes it clear that ITS systems are a hot topic right now, and they receive a lot of attention from the academic world, the standardization bodies and the industry. Therefore, it seems like that it is just a matter of time before ITS systems will find their way into the daily live. Due to the large number of suitable technologies for the implementation of cooperative ITS systems, it is very hard to define which role the government has to play in these developments, and which are the next steps to take. These issues were addressed in reports produced by the i2010 Intelligent Car Initiative and the CVIS project. Their state of the art overview revealed that until now, no country has successfully deployed a fully operational ITS system yet. Seven EU countries are the furthest and are already in the deployment phase: Sweden, Germany, the Netherlands, the United Kingdom, Finland, Spain and France. These countries are trailed by eight countries which are in the promotion phase: Denmark, Greece, Italy, Austria, Belgium,Norway, the Czech Republic and Poland. Finally, the last ten countries find themselves in the start-up phase: Estonia, Lithuania, Latvia, Slovenia, Slovakia, Hungary, Portugal, Switzerland, Ireland and Luxembourg. These European reports produced by the i2010 Intelligent Car Initiative and the CVIS project have defined a few policy recommendations which are very relevant for the Belgian and Flemish government. The most important recommendations for the Flemish government are: • Support awareness: research revealed that civilians consider ITS applications useful, but they are not really willing to pay for this technology. Therefore, it is important to convince the general public of the usefulness and the importance of ITS systems. • Fill the gaps: Belgium is situated in the promotion phase. This means that it should focus at identifying the missing stakeholders, and coordinating national and regional ITS activities. Here it is important that the research activities are coordinated in a national and international context to allow transfer of knowledge from one study to the next, as well as the results to be comparable. • Develop a vision: in the scope of ITS systems policies have to be defined regarding a large number of issues. For instance there is the question if ITS users should be educated, meaning that the use of ITS systems should be the subject of the drivers license exam. How will the regulations be for the technical inspection of vehicles equipped with ITS technology? Will ITS systems be deployed on a voluntary base, or will they e.g. be obliged in every new car? Will the services be offered by private companies, by the public authorities, or by a combination of them? Which technology will be used to implement ITS systems? These are just a few of the many questions where the government will have to develop a point of view for. • Policy coordination: ITS systems are a policy subject on an international, national and regional level. It is very important that these policy organizations can collaborate in a coordinated manner. • Iterative approach to policy development: developing policies for this complex matter is not a simple task. This asks for an iterative approach, where policy decisions are continuously refined and adjusted

A T-DAB field trial using a low-mast infrastructure

Between October 2004 and July 2006, the University of Twente carried out a technical T-DAB field trial in Amsterdam which was commissioned by the Dutch Ministry of Economic Affairs. For this trial, a low-power low-mast T-DAB pilot network was constructed both for band III (channel 12B) and the L-band (channel LH).\ud This field trial provided evidence that a low-power low-mast network topology can coexist with a high-mast high-power network in an adjacent channel. Using gap fillers, the holes in the service area of the high-mast high-power network can be neutralized effectively. Other possible\ud solutions such as a smaller vertical opening angle of the antenna system were not investigated. The minimum power level of the gap fillers should be 24 dB below the output power of the low-mast infrastructure.\ud If no gap fillers or other solution is used, there exists an interference area with a radius of 1 km on average, where there is no reception of the high-mast high-power network. The interference area around a high-power mast was not investigated, but it is expected that this\ud interference area will be significantly larger. The T-DAB pilot network was mounted on masts of the C2000 TETRA network. The interference of the T-DAB signal on the TETRA system was investigated by the C2000 organization.\ud For indoor coverage in 95% of the buildings, the indoor penetration loss measurements revealed that the loss for band III is 21.9 dB and for L-band 25.8 dB. For indoor coverage, the outdoor field strength has to be 67.9 dBμV/m for band III and 81.9 dBμV/m for L-band for 50% of the\ud locations and 50% of the time at an antenna height of 1.5 m. This value can be used in coverage planning software.\ud Both the existing T-DAB network of the Publieke Omroep and the pilot network (band III and L-band) do not provide good indoor coverage in Amsterdam. If output power is increased by 10 dB at every transmission site, both band III networks will provide good indoor coverage. Of course,\ud an alternative is to use more transmitter locations. For the L-band more transmitters as well as more output power are required for good indoor reception in Amsterdam.\ud However, current internati-onal regulations are based on outdoor coverage and it was decided at the RRC06 conference that the interference level at the Dutch border may increase by 3 dB and it in particular cases\ud by 6 dB to achieve indoor coverage. So, both the high-mast and low-mast topologies require more transmitter locations to obtain indoor coverage and to be in line with the RRC06 agreement.\ud In addition, the performance of T-DAB consumer receivers was evaluated according to the EN 50248 norm. For a kitchen radio, assuming an urban channel model and a passive whipe antenna, the typically achievable sensitivity will be 39 dBμV/m for band III (which is 4 dB higher than the minimum sensitivity specified in the Wiesbaden agreement); for the L-band this is 51 dBμV/m (5 dB higher). The median T-DAB consumer receiver achieves the typically achievable band III sensitivity. However,\ud for the L-band, the sensitivity of the median T-DAB consumer receiver is 6.5 dB less than the typically achievable L-band sensitivity

Communicating thematic data quality with web map services

Geospatial information of many kinds, from topographic maps to scientific data, is increasingly being made available through web mapping services. These allow georeferenced map images to be served from data stores and displayed in websites and geographic information systems, where they can be integrated with other geographic information. The Open Geospatial Consortium’s Web Map Service (WMS) standard has been widely adopted in diverse communities for sharing data in this way. However, current services typically provide little or no information about the quality or accuracy of the data they serve. In this paper we will describe the design and implementation of a new “quality-enabled” profile of WMS, which we call “WMS-Q”. This describes how information about data quality can be transmitted to the user through WMS. Such information can exist at many levels, from entire datasets to individual measurements, and includes the many different ways in which data uncertainty can be expressed. We also describe proposed extensions to the Symbology Encoding specification, which include provision for visualizing uncertainty in raster data in a number of different ways, including contours, shading and bivariate colour maps. We shall also describe new open-source implementations of the new specifications, which include both clients and servers

The Eureka 147 digital audio broadcasdting system adapted to the U.S.

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1996.Includes bibliographical references (p. 83-85).by Nupur Gupta.M.Eng

Génération rapide et filtrage de configurations canoniques

La configuration sous contraintes présente une nouvelle difficulté à prendre en compte par les méthodes d'élimination de symétries connues par la communauté CSP car elle y introduit un aspect dynamique. Nous présentons ici une amélioration significative d'un algorithme de génération de configurations canoniques. Cette nouvelle version exploite l'incrémentalité que l'on peut faire ressortir de la génération de solutions canoniques et de l'ordre total sur les arbres sur laquelle elle repose. La complexité du test de canonicité passe ainsi de O(Nlog(N)) à O(N). De plus, une technique de filtrage nous permet d'éliminer à l'avance des configurations non canoniques. Des résultats expérimentaux montrent l'intérêt de cette approche sur des problèmes classiques