13,056 research outputs found
Anonymous network access using the digital marketplace
With increasing usage of mobile telephony, and the trend towards additional mobile Internet usage, privacy and anonymity become more and more important. Previously-published anonymous communication schemes aim to obscure their users' network addresses, because real-world identity can be easily be derived from this information. We propose modifications to a novel call-management architecture, the digital marketplace, which will break this link, therefore enabling truly anonymous network access
Characteristics of WAP traffic
This paper considers the characteristics of Wireless Application Protocol (WAP) traffic. We start by constructing a WAP traffic model by analysing the behaviour of users accessing public WAP sites via a monitoring system. A wide range of different traffic scenarios were considered, but most of these scenarios resolve to one of two basic types. The paper then uses this traffic model to consider the effects of large quantities of WAP traffic on the core network. One traffic characteristic which is of particular interest in network dimensioning is the degree of self-similarity, so the paper looks at the characteristics of aggregated traffic with WAP, Web and packet speech components to estimate its self-similarity. The results indicate that, while WAP traffic alone does not exhibit a significant degree of self-similarity, a combined load from various traffic sources retains almost the same degree of self-similarity as the most self-similar individual source
A personal networking solution
This paper presents an overview of research being conducted on Personal Networking Solutions within the Mobile VCE Personal Distributed Environment Work Area. In particular it attempts to highlight areas of commonality with the MAGNET initiative. These areas include trust of foreign devices and service providers, dynamic real-time service negotiation to permit context-aware service delivery, an automated controller algorithm for wireless ad hoc networks, and routing protocols for ad hoc networking environments. Where possible references are provided to Mobile VCE publications to enable further reading
Adam Smith goes mobile : managing services beyond 3G with the digital marketplace
The next generation of mobile communications systems is expected to offer new business opportunities to existing and new market players. A market-based middleware framework has been recently proposed whereby service providers, independent of network operators, are able to tender online service contracts to network operators in a dynamic and competitive manner. This facilitates a seamless service provision over disparate networks in a consumer-centric manner. Service providers select network bearers according to the network operators' ability to meet the QoS target, which in turn is influenced, among other things, by user's price and quality requirements. The benefits of this proposal are the complementarity of numerous network resources, the decoupling of services and networks in a self-organising distributed environment, and increased competition to consumers’ advantag
Securing personal distributed environments
The Personal Distributed Environment (PDE) is a new concept being developed by Mobile VCE allowing future mobile users flexible access to their information and services. Unlike traditional mobile communications, the PDE user no longer needs to establish his or her personal communication link solely through one subscribing network but rather a diversity of disparate devices and access technologies whenever and wherever he or she requires. Depending on the services’ availability and coverage in the location, the PDE communication configuration could be, for instance, via a mobile radio system and a wireless ad hoc network or a digital broadcast system and a fixed telephone network. This new form of communication configuration inherently imposes newer and higher security challenges relating to identity and authorising issues especially when the number of involved entities, accessible network nodes and service providers, builds up. These also include the issue of how the subscribed service and the user’s personal information can be securely and seamlessly handed over via multiple networks, all of which can be changing dynamically. Without such security, users and operators will not be prepared to trust their information to other networks
Management system requirements for wireless systems beyond 3G
This paper presents a comprehensive description of various management system requirements for systems beyond 3G, which have been identified as a result of the Software Based Systems activities within the Mobile VCE Core 2 program. Specific requirements for systems beyond 3G are discussed and potential technologies to address them proposed. The analysis has been carried out from network, service and security viewpoints
An FPGA implementation of pattern-Selective pyramidal image fusion
The aim of image fusion is to combine multiple images (from one or more sensors) into a single composite image that retains all useful data without introducing artefacts. Pattern-selective techniques attempt to identify and extract whole features in the source images to use in the composite. These techniques usually rely on multiresolution image representations such as Gaussian pyramids, which are localised in both the spatial and spatial-frequency domains, since they enable identification of features at many scales simultaneously. This paper presents an FPGA implementation of pyramidal decomposition and subsequent fusion of dual video streams. This is the first reported instance of a hardware implementation of pattern-selective pyramidal image fusion. Use of FPGA technology has enabled a design that can fuse dual video streams (greyscale VGA, 30fps) in real-time, and provides approximately 100 times speedup over a 2.8GHz Pentium-
Toxic Choices: The Theory and Impact of Smoking Bans
Smoking bans in the workplace and public places are now ubiquitous. While indices of such controls are commonly included in econometric models, there exists little theory that validates or analyzes them. This paper first proposes a theoretical model of maximizing behaviour on the part of smokers which serves as a vehicle to evaluate bans. It is a type of nicotine inventory management model where smoking during one phase of the day impacts utility in other periods. It also includes an intensity choice as part of the optimization. Calibrated model simulations suggest that, with the exception of heavy smokers, workplace bans have relatively minor impacts on smokers throughout most of the distribution due to substitution possibilities. We estimate quantile regressions using Canadian survey data for 2003 and .find that workplace bans have a surprisingly small impact on the number of cigarettes smoked. However, restrictions on smoking in the home are found to be of an order of importance greater, even when instrumented. The policy conclusion is that the effectiveness of workplace bans depends heavily upon whether there exist complementary restrictions on smoking in environments to which individuals may wish to switch their smoking following a workplace ban.Smoking bans, tobacco, nicotine, cotinine, intensity, quantile regression
Longitudinal variations, the opposition effect and monochromatic albedos for Mars
Magnitude at zero phase, phase coefficient, and monochromatic albedo computed for Mars as function of wavelengt
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