6,846 research outputs found

    The practice of access pricing : telecommunications in the United Kingdom

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    Telecommunications was the first network utility to be privatized in the United Kingdom. Drawing on 15 years'experience and discussion in the field, the author shows the economic principles of regulation in general and access pricing in particular that have been implemented. British Telecommunications (BT), formed as a public enterprise in 1980-81, was privatized in 1984. Since then the approaches to regulation have changed in three broad periods: the duoply, the transition to competition, and the recently introduced normalization phase. Dealing with each period, the author focuses on how the actual implementation of access charges are determined, at the same time providing background needed on regulatory intervention generally. Rather than follow the model of competition for a common infrastructure, Oftel [the Office of Telecommunications, the regulatory agency]has encouraged competition between alternative networks, which benefits customers but involves duplication of fixed costs. As a result of Oftel's approach, customers have seen their bills reduced 50 percent in real terms since privatization. It is difficult to know how much to attribute this remarkable result to technological progress (BT halved its workforce in the same period), to regulatory intervention (Oftel set string caps until 1997), or to competition (there are hundreds of players in the market). The author contends more weight should probably be given to the first two. Entrants have not achieved big market shares, if one considers the asymmetric regulation that has been in place for more than a decade. Indirectly, at least, competition benefited consumers by applying discipline to BT's behavior. Oftel's approach was interventionist until 1997, when it began trying to normalize the industry, as authority overseeing competition. The odds on complete deregulation are slight, and some controls on industry will remain. In the longer term, Oftel should especially monitor anticompetitive practices and collusive behavior among the bigger players (BT, CWC, and cellulator operators), The United Kingdom's interconnection experience demonstrates the complexity of the problem and its relationship to other topics, such as tariff rebalancing, access deficit, and universal service. Although a bit ad hoc, the recent incentive regulation, with a network cap based on proper accounting procedures and engineering models, may represent the best practice available today in the telecommunications industry, says the author.Public Sector Economics&Finance,Decentralization,Knowledge Economy,Economic Theory&Research,Payment Systems&Infrastructure,Public Sector Economics&Finance,Education for the Knowledge Economy,Knowledge Economy,Economic Theory&Research,ICT Policy and Strategies

    Mobile telephone system and non-wire line network

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    The need to communicate with non-fixed points without the use of wires led to the development of mobile telephone systems in the early 1920\u27s. Since then, the expanding need for mobile phone service and resulting growth have led to the development of the Advanced Mobile Phone Service (AMPS) by the Bell System. This thesis describes the AMPS system and explains how service is provided to mobile units roaming in a typical area of up to 25 square miles. A network is proposed to interconnect service areas to expand the coverage to a much larger geographic area. Efficient use is made of the limited bandwidth available for network communication. The network is able to manage mobile units that move from one service area to another during a call, and can efficiently locate mobile units throughout the network area

    Aerospace medicine and Biology: A continuing bibliography with indexes, supplement 177

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    This bibliography lists 112 reports, articles, and other documents introduced into the NASA scientific and technical information system in January 1978

    A Decision-Theoretic Approach to Resource Allocation in Wireless Multimedia Networks

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    The allocation of scarce spectral resources to support as many user applications as possible while maintaining reasonable quality of service is a fundamental problem in wireless communication. We argue that the problem is best formulated in terms of decision theory. We propose a scheme that takes decision-theoretic concerns (like preferences) into account and discuss the difficulties and subtleties involved in applying standard techniques from the theory of Markov Decision Processes (MDPs) in constructing an algorithm that is decision-theoretically optimal. As an example of the proposed framework, we construct such an algorithm under some simplifying assumptions. Additionally, we present analysis and simulation results that show that our algorithm meets its design goals. Finally, we investigate how far from optimal one well-known heuristic is. The main contribution of our results is in providing insight and guidance for the design of near-optimal admission-control policies.Comment: To appear, Dial M for Mobility, 200

    Aerospace Medicine and Biology: A continuing bibliography with indexes, supplement 140

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    This bibliography lists 306 reports, articles, and other documents introduced into the NASA scientific and technical information system in March 1975

    Aerospace medicine and biology: A continuing bibliography with indexes (supplement 355)

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    This bibliography lists 147 reports, articles and other documents introduced into the NASA Scientific and Technical Information System during October, 1991. Subject coverage includes: aerospace medicine and psychology, life support systems and controlled environments, safety equipment, exobiology and extraterrestrial life, and flight crew behavior and performance

    The Regulatory Framework For Wireless Power Transfer Systems

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    A survey of the regulatory framework pertinent to Wireless Power Transfer systems is given. Both technical (power and frequency) considerations along with health safety radiation compliance are examined. A primer on regulatory processes is also included to facilitate the understanding of the developments. The current state is analysed and ongoing regulatory activities across the globe are discussed. Furthermore, a review of recent radiation safety studies of WPT systems is included

    Reliable and Resilient Surface Water Management through Rapid Scenario Screening

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    Surface water flooding causes significant damage, disruption and loss of life in cities, both in the UK and globally. These impacts have historically been managed through application of conventional urban drainage systems designed to meet specified design standards. Conventional strategies have performed well in the past, but are becoming increasingly unfit for purpose due to intensifying hazards caused by several emerging challenges, including climate change, urban growth and aging drainage infrastructure. In response, an extensive range of alternative novel interventions has been developed. These have been successfully applied across many case studies and their performance to meet design standards on specific sites is now well understood. However, application is still limited and challenges exist regarding how to maximise performance at the urban catchment scale and incorporate resilience to extreme rainfall events within design. This thesis addresses these challenges through evaluating intervention performance using a rapid scenario screening framework. This framework delivers insight into the complex permutations of intervention strategies at a catchment scale through evaluating alternatives, scales, spatial interactions and responses to a range of rainfall events. The study achieves novelty through developing a new modelling methodology which applies cell parameterisation to represent urban drainage systems and interventions using an existing cellular automata model. The framework is applied at a high level to screen intervention performance using easily accessible data and simplified intervention strategies, it is envisaged that this style of analysis is appropriate for initial catchment assessment to evidence and direct future flood management actions. The research finds intervention scale, distribution and placement to be important factors in determining performance within the context of initial catchment screening using theoretical modelling parameters. Although localised interventions provide benefit at a smaller scale, catchment based strategies are required to substantially reduce estimated annual damage costs across urban areas. The most effective intervention was consistently found to be extensive application of decentralised rainfall capture, which reduced expected annual damage in a UK case study by up to 76%. Intervention distribution and placement are also demonstrated to significantly influence cost effectiveness of strategies, with a wide range of ratios predicted, ranging from £0.10 to £26.0 saved per £1 spent. The most cost effective interventions across the case studies investigated were found to be high volume local drainage interventions targeted in areas of intense flooding. Results demonstrate significant variation in strategy performance depending on rainfall intensity and duration. Analysis across events ranging from 2 to 1000 year return periods found many interventions which performed well during design standard events demonstrate substantial decreases in effectiveness during higher magnitude rainfall. Of particular note are interventions with finite storage capacities, which exhibit considerable decreases in performance at certain threshold levels. The implications of this finding are that designing interventions with resilient performance requires simulation of many rainfall scenarios, and that interventions with resilient properties, such as green infrastructure, do not necessarily achieve resilient performance. The research also identifies that rapid screening frameworks contribute an adaptable and useful tool for stakeholder engagement, intervention design and scenario exploration. Case study application of the framework alongside catchment stakeholders in Melbourne, Australia, facilitated an efficient and collaborative design screening process which benefitted from enhanced communication across a wide range of expertise. The simplified development of intervention strategies provided a clear communication tool which supported the multi-disciplinary investigations required for urban planning in a complex environment. Analysis of many strategy permutations highlighted the advantage of multiple smaller intervention strategies accumulating towards catchment scale benefits, a possibility which is advantaged through stakeholder communication tools, such as this framework. Overall, this thesis demonstrates that reliable and resilient surface water management can be achieved through decentralised catchment scale implementation of interventions, complemented by targeted and cost effective high volume measures. Complexity and variation of outcomes across a range of scenarios indicates the importance of encapsulating the complex permutations of options when evaluating interventions and provides justification for future application of rapid scenario screening frameworks.Engineering and Physical Sciences Research Council (EPSRC
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