855 research outputs found
Reliable Multicast Transport for Heterogeneous Mobile IP environment using Cross-Layer Information
Reliable multicast transport architecture designed for heterogeneous mobile IP environment using cross-layer information for enhanced Quality of Service (QoS) and seamless handover is discussed. In particular, application-specific reliable multicast retransmission schemes are proposed, which are aimed to minimize the protocol overhead taking into account behaviour of mobile receivers (loss of connectivity and handover) and the specific application requirements for reliable delivery (such as carousel, one-to-many download and streaming delivery combined with recording). The proposed localized retransmission strategies are flexible configured for tree-based multicast transport. Cross layer interactions in order to enhance reliable transport and support seamless handover is discussed considering IEEE 802.21 media independent handover mechanisms. The implementation is based on Linux IPv6 environment. Simulations in ns2 focusing on the benefits of the proposed multicast retransmission schemes for particular application scenarios are presented
Digital television applications
Studying development of interactive services for digital television is a leading edge area of work as there is minimal research or precedent to guide their design. Published research is limited and therefore this thesis aims at establishing a set of computing methods using Java and XML technology for future set-top box interactive services. The main issues include middleware architecture, a Java user interface for digital television, content representation and return channel communications.
The middleware architecture used was made up of an Application Manager, Application Programming Interface (API), a Java Virtual Machine, etc., which were arranged in a layered model to ensure the interoperability. The application manager was designed to control the lifecycle of Xlets; manage set-top box resources and remote control keys and to adapt the graphical device environment. The architecture of both application manager and Xlet forms the basic framework for running multiple interactive services simultaneously in future set-top box designs.
User interface development is more complex for this type of platform (when compared to that for a desktop computer) as many constraints are set on the look and feel (e.g., TV-like and limited buttons). Various aspects of Java user interfaces were studied and my research in this area focused on creating a remote control event model and lightweight drawing components using the Java Abstract Window Toolkit (AWT) and Java Media Framework (JMF) together with Extensible Markup Language (XML).
Applications were designed aimed at studying the data structure and efficiency of the XML language to define interactive content. Content parsing was designed as a lightweight software module based around two parsers (i.e., SAX parsing and DOM parsing). The still content (i.e., text, images, and graphics) and dynamic content (i.e., hyperlinked text, animations, and forms) can then be modeled and processed efficiently.
This thesis also studies interactivity methods using Java APIs via a return channel. Various communication models are also discussed that meet the interactivity requirements for different interactive services. They include URL, Socket, Datagram, and SOAP models which applications can choose to use in order to establish a connection with the service or broadcaster in order to transfer data.
This thesis is presented in two parts: The first section gives a general summary of the research and acts as a complement to the second section, which contains a series of related publications.reviewe
Cooperating broadcast and cellular conditional access system for digital television
This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.The lack of interoperability between Pay‐TV service providers and a horizontally integrated business transaction model have compromised the competition in the Pay‐TV market. In addition, the lack of interactivity with customers has resulted in high churn rate and improper security measures have contributed into considerable business loss. These issues are the main cause of high operational costs and subscription fees in the Pay‐TV systems.
This paper presents a novel end‐to‐end system architecture for Pay‐TV systems cooperating mobile and broadcasting technologies. It provides a cost‐effective, scalable, dynamic and secure access control mechanism supporting converged services and new business opportunities in Pay‐TV systems. It enhances interactivity, security and potentially reduces customer attrition and operational cost. In this platform, service providers can effectively interact with their customers, personalise their services and adopt appropriate security measures. It breaks up the rigid relationship between a viewer and set‐top box as imposed by traditional conditional access systems, thus, a viewer can fully enjoy his entitlements via an arbitrary set‐top box.
Having thoroughly considered state‐of‐the‐art technologies currently being used across the world, the thesis highlights novel use cases and presents the full design and implementation aspects of the system. The design section is enriched by providing possible security structures supported thereby. A business collaboration structure is proposed, followed by a reference model for implementing the system. Finally, the security architectures are analysed to propose the best architecture on the basis of security, complexity and set‐top box production cost criteria
A cooperative cellular and broadcast conditional access system for Pay-TV systems
This is the author's accepted manuscript. The final published article is available from the link below. Copyright @ 2009 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works.The lack of interoperability between Pay-TV service providers and a horizontally integrated business transaction model have compromised the competition in the Pay-TV market. In addition, the lack of interactivity with customers has resulted in high churn rate and improper security measures have contributed into considerable business loss. These issues are the main cause of high operational costs and subscription fees in the Pay-TV systems. As a result, this paper presents the Mobile Conditional Access System (MICAS) as an end-to-end access control solution for Pay-TV systems. It incorporates the mobile and broadcasting systems and provides a platform whereby service providers can effectively interact with their customers, personalize their services and adopt appropriate security measurements. This would result in the decrease of operating expenses and increase of customers' satisfaction in the system. The paper provides an overview of state-of-the-art conditional access solutions followed by detailed description of design, reference model implementation and analysis of possible MICAS security architectures.Strategy & Technology (S&T) Lt
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Digitised engineering knowledge for prefabricated façades
Façade design is a multidisciplinary activity requiring the balancing of many conflicting design requirements. Very often, however, the designed façade does not respond to these requirement, as relevant design and manufacturing knowledge, normally originating downstream in the design process, is not properly used upstream in the process. The inability to respond to this challenge increases the environmental impact of the construction sector, which is currently covering nearly 40% of the global emissions. Also, improving the stagnant sector’s productivity is of paramount importance today, as it is deemed to be nearly as half as that of the manufacturing sector. This research has thus investigated ways to collect, store, represent and digitalise the engineering knowledge that underpins the design of façade products for façades that are better designed. The work has involved a close collaboration with the British general contractor (and façade manufacturer) Laing O’Rourke. The research has explored ways of using design and manufacturing knowledge and it has developed a digital tool and tested its functionalities. In the first part, after a review of the state-of-the-art in knowledge-based approaches in other fields, the digital tool, and relevant methodology, are developed. The tool informs the user about the expected performance and manufacturability of the façade product under analysis. The boundaries of traditional research were also pushed beyond the proof-of-concept by validating the digital tool in both simulated and real-world scenarios. The goal was to understand how people can develop a design solution while being supported by a digital tool. It was found that using such tool increases the user’s awareness about the consequences of the his/her choices in less time. In the last part of the research, the tool was used to develop a novel optimisation algorithm, by including considerations about aesthetics and manufacturability, in parallel with the traditional performance-based approach. The application of the algorithm to a case study has shown that it is possible to improve existing solutions in terms of performance, without affecting aesthetic and manufacturability significantly.EPSRC, Laing O'Rourk
Interactive Digital Terrestrial Television: The Interoperability Challenge in Brazil
This paper introduces different standards implemented in existing Digital Terrestrial Television Broadcasting systems to allow the fruition of interactive services and applications through digital Set Top Boxes. It focuses on the interoperability issue between the Brazilian and the European architectures. In fact, despite in Brazil the GEM specification has been designed to foster wide content compatibility across a range of interactive platforms, it has never come to a final implementation and deployment. As a result the interoperability issue has been deeply explored in the BEACON project and an innovative system architecture has been developed to deploy t-learning services across Europe and Brazil, providing integration of those systems that were not able to interoperate until nowadays. This work is an important step in the direction of standards' interoperability. As a result, MHP and Ginga NCL-Lua implementation appeared to be the very best choice to deliver interactive services in an interoperable mode between European and Brazilian digital television
Delivery of a Certified E-mail Service over the Digital Terrestrial Television Platform
At present, the electronic mail service is probably the most widespread and commonly used asynchronous way of exchanging information among people, thanks to its immediacy and easiness of use. Information delivered through E-mail can be sensitive or confidential: ensuring the sender’s identity and providing privacy has become a vital step in stopping spam, fraud and even more serious crimes. To this aim, public entities have adopted Certified E-mail systems to manage secure interactions with citizens. Digital Terrestrial Television introduced new facilities in the traditional broadcasting environment, and determined the transition of several Electronic based-services to Television basedservices. The availability of commercial Set Top Boxes equipped with network interfaces and smart card readers enables the provisioning of personalized interactive TV services, requiring user’s identification and authentication, that still represent open issues in the TV context. In this paper we discuss the challenges of a Certified E-mail service over Digital Terrestrial Television, and present the case study of the Italian Regione Marche, in which this service is under development to support the remote request of certificates issued by the public administration. In particular, our attention is devoted to user authentication and secure access to the administrative services, addressed through the use of a Regional Service Card, an interactive application, and a centralized authentication framework
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A survey of handover algorithms in DVB-H
Digital Video Broadcasting for Handhelds (DVB-H) is a standard for
broadcasting IP Datacast (IPDC) services to mobile handheld terminals.
Based on the DVB-T standard, DVB-H adds new features such as time
slicing, MPE-FEC, in-depth interleavers, mandatory cell id identifier,
optional 4K-modulation mode and the use of 5 MHz bandwidth in addition
to the usually used 6, 7, or 8 MHz raster. IPDC over DVB-H is proposed
for ETSI to complement the DVB-H standard by combining IPDC and
DVB-H in an end-to-end system. Handover in such unidirectional broadcasting
networks is a novel issue. In the last few years since the birth of
DVB-H technology, great attention has been given to the performance
analysis of DVB-H mobile terminals. Handover is one of the main research
topics for DVB-H in mobile scenarios. Better reception quality and greater
power efficiency are considered to be the main targets of handover
research for DVB-H. New algorithms for different handover stages in
DVB-H have been the subject of recent research and are currently being
studied. Further novel algorithms need to be designed to improve the
mobile reception quality. This article provides a comprehensive survey of
the handover algorithms in DVB-H. A systematic evaluation and categorization
approach is proposed based on the problems the algorithms solve
and the handover stages being focused on. Criteria are proposed and analyzed
to facilitate designing better handover algorithms for DVB-H that
have been identified from the research conducted by the author
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