A framework for responsive content adaptation in electronic display networks
- Authors: West, Philip
- Date: 2006
- Subjects: Computer networks , Cell phone systems , Wireless communication systems , Mobile communication systems , HTML (Document markup language) , XML (Document markup language)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4589 , http://hdl.handle.net/10962/d1004824 , Computer networks , Cell phone systems , Wireless communication systems , Mobile communication systems , HTML (Document markup language) , XML (Document markup language)
- Description: Recent trends show an increase in the availability and functionality of handheld devices, wireless network technology, and electronic display networks. We propose the novel integration of these technologies to provide wireless access to content delivered to large-screen display systems. Content adaptation is used as a method of reformatting web pages to display more appropriately on handheld devices, and to remove unwanted content. A framework is presented that facilitates content adaptation, implemented as an adaptation layer, which is extended to provide personalization of adaptation settings and response to network conditions. The framework is implemented as a proxy server for a wireless network, and handles HTML and XML documents. Once a document has been requested by a user, the HTML/XML is retrieved and parsed, creating a Document Object Model tree representation. It is then altered according to the user’s personal settings or predefined settings, based on current network usage and the network resources available. Three adaptation techniques were implemented; spatial representation, which generates an image map of the document, text summarization, which creates a tree view representation of a document, and tag extraction, which replaces specific tags with links. Three proof-of-concept systems were developed in order to test the robustness of the framework. A system for use with digital slide shows, a digital signage system, and a generalized system for use with the internet were implemented. Testing was performed by accessing sample web pages through the content adaptation proxy server. Tag extraction works correctly for all HTML and XML document structures, whereas spatial representation and text summarization are limited to a controlled subset. Results indicate that the adaptive system has the ability to reduce average bandwidth usage, by decreasing the amount of data on the network, thereby allowing a greater number of users access to content. This suggests that responsive content adaptation has a positive influence on network performance metrics.
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- Date Issued: 2006
A framework for secure mobility in wireless overlay networks
- Authors: Chen, Hejun
- Date: 2006
- Subjects: Wireless communication systems , Computer networks
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9778 , http://hdl.handle.net/10948/819 , Wireless communication systems , Computer networks
- Description: Various wireless networks are widely deployed world wide. Current technologies employed in these networks vary widely in terms of bandwidths, latencies, frequencies, and media access methods. Most existing wireless network technologies can be divided into two categories: those that provide a low-bandwidth service over a wide geographic area, for example UMTS, and those that provide a high bandwidth service over a narrow geographic area, for example 802.11. Although it would be desirable to provide a high- bandwidth service over a wide coverage region to mobile users all the time, no single wireless network technology simultaneously satisfies these require- ments. Wireless Overlay Networks, a hierarchical structure of wireless personal area, local area, and wide area data networks, is considered as an efficient and scalable way to solve this problem. Due to the wide deployment of UMTS and 802.11 WLAN, this study attempts to combine them to implement the concept of Wireless Overlay Net- works. Furthermore, the information transmitted over this Wireless Overlay Networks is protected in terms of authentication, integrity and confidentiality. To achieve this goal, this study aims to combine GPRS, Mobile IP and IPSec to propose a framework for secure mobility in Wireless Overlay Networks. The framework is developed in three steps: Firstly, this study addresses the problem of combining GPRS and Mo- bile IP, so that GPRS users are provided with Mobile IP service. This results in presenting a uniform Mobile IP interface to peers regardless of whether mobile users use UMTS or 802.11 WLAN. Secondly, this study discovers the existing problem when combining Mobile IP and IPSec, and proposes a Dual Home Agent Architecture to achieve secure mobility. Finally, based on the output of the previous two steps, a complete framework is proposed, which achieves secure mobility in Wireless Overlay Networks, specifically, in UMTS and 802.11 WLAN. The framework also implements seamless handover when mobile users switch between UMTS and 802.11. This results in UMTS and 802.11 WLAN looking like a single network when participating in this framework, and presents seamless and secure mobility.
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- Date Issued: 2006