Showing items related by title, author, creator and subject.

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  Using Link Layer Information to Enhance Mobile IP Handover Mechanism. An investigation in to the design, analysis and performance evaluation of the enhanced Mobile IP handover mechanism using link layer information schemes in the IP environment.

  Awan, Irfan U.; Holton, David R.W.; Alnas, Mohamed J.R. (University of BradfordDepartment of Computing, 2011-06-16)

  Mobile computing is becoming increasingly important, due to the rise in the number of portable computers and the desire to have continuous network connectivity to the Internet, irrespective of the physical location of the node. We have also seen a steady growth of the market for wireless communication devices. Such devices can only have the effect of increasing the options for making connections to the global Internet. The Internet infrastructure is built on top of a collection of protocols called the TCP/IP protocol suite. Transmission Control Protocol (TCP) and Internet Protocol (IP) are the core protocols in this suite. There are currently two standards: one to support the current IPv4 and one for the upcoming IPv6 [1]. IP requires the location of any node connected to the Internet to be uniquely identified by an assigned IP address. This raises one of the most important issues in mobility because, when a node moves to another physical location, it has to change its IP address. However, the higher-level protocols require the IP address of a node to be fixed for identifying connections. The Mobile Internet Protocol (Mobile IP) is an extension to the Internet Protocol proposed by the Internet Engineering Task Force (IETF) that addresses this issue. It enables mobile devices to stay connected to the Internet regardless of their locations, without changing their IP addresses and, therefore, an ongoing IP session will not be interrupted [2, 3, 4]. More precisely, Mobile IP is a standard protocol that builds on the Internet Protocol by making mobility transparent to applications and higher-level protocols like TCP. However, before Mobile IP can be broadly deployed, there are still several technical barriers, such as long handover periods and packet loss that have to be overcome, in addition to other technical obstacles, including handover performance, security issues and routing efficiency [7]. This study presents an investigation into developing new handover mechanisms based on link layer information in Mobile IP and fast handover in Mobile IPv6 environments. The main goal of the developed mechanisms is to improve the overall IP mobility performance by reducing packet loss, minimizing signalling overheads and reducing the handover processing time. These models include the development of a cross-layer handover scheme using link layer information and Mobile Node (MN) location information to improve the performance of the communication system by reducing transmission delay, packet loss and registration signalling overheads. Finally, the new schemes are developed, tested and validated through a set of experiments to demonstrate the relative merits and capabilities of these schemes.
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  IP Mobile Multicast over Next Generation Satellite Networks. Design and Evaluation of a Seamless Mobility Framework for IP Multicast Communications over a Multi-beam Geostationary Satellite Network

  Pillai, Prashant; Hu, Yim Fun; Jaff, Esua K. (University of BradfordFaculty of Engineering and Informatics, 2016)

  The inherent broadcast nature of satellites, their global coverage and direct access to a large number of subscribers give satellites unrivalled advantages in supporting IP multicast applications. A new generation of satellite systems that support regenerative on-board processors and multiple spot beam technology have opened new possibilities of implementing IP multicast communication over satellites. These new features enable satellites to make efficient use of their allocated bandwidth resources and provide cost effective network services but equally, create new challenges for mobile satellite terminals. IP mobility support in general and IP mobile multicast support in particular on mobile satellite terminals like the ones mounted on continental flights, maritime vessels, etc., still remain big challenges that have received very little attention from the research community. Up till now, there are no proposed mechanisms to support IP multicast for mobile receivers/sources in multi-beam satellite networks in open literature. This study explores the suitability of IP multicast mobility support schemes defined for terrestrial networks in a satellite environment and proposes novel schemes based on the concepts of Home and Remote subscription-based approaches, multiple interface and PMIPv6 protocol. Detailed analysis and comparison of results obtained from the proposed schemes, Mobile IP (MIP) Home and Remote subscription-based approaches (for terrestrial networks) when implemented on a reference multi-beam satellite network are presented. From these results, the proposed schemes outperform the MIP Home and Remote subscription-based approaches in terms of gateway handover latency, number of multicast packets lost and signalling cost over the satellite air interface.
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  Mobile Learning using Mixed Reality Games and a Conversational, Instructional and Motivational Paradigm. Design and implementation of technical language learning mobile games for the developing world with special attention to mixed reality games for the realization of a conversational, instructional and motivational paradigm.

  Earnshaw, Rae A.; Robison, David J.; Excell, Peter S.; Fotouhi-Ghazvini, Faranak (University of BradfordSchool of Computing, Informatics and Media, 2012-03-20)

  Mobile learning has significant potential to be very influential in further and higher education. In this research a new definition for Mobile Educational Mixed Reality Games (MEMRG) is proposed based on a mobile learning environment. A questionnaire and a quantifying scale are utilised to assist the game developers in designing a MEMRG. A ¿Conversational Framework¿ is proposed as an appropriate psycho-pedagogical approach to teaching and learning for MEMRG. This methodology is based on the theme of a ¿conversation¿ between different actors of the learning community with the objective of building the architectural framework for MEMRG. Various elements responsible for instructing and motivating learners in educational games are utilised in an instructional-motivational model. User interface design for the games incorporates an efficient navigation system that uses contextual information, and allows the players to move seamlessly between real and virtual worlds. The implementation of MEMRG using the Java 2 Micro Edition (J2ME) platform iii is presented. The hardware and software specification for the MEMRG implementation and deployment are also discussed. MEMRG has produced improvements in the different cognitive processes of the learner, and also produced a deeper level of learning through enculturation, externalising ideas, and socialising. Learners¿ enjoyment, involvement, motivation, autonomy and metacognition skills have improved. This research will assist developers and teachers to gain an insight into learning paradigms which utilise mobile game environments that are formed by mixing real and virtual spaces, and provide them with a vision for effectively incorporating these games into formal and informal classroom sessions.