Research On Key Techniques Of Web Middleware For Mobile Computing

Web middleware used in mobile computing must be adaptable to the changefulenvironments of mobile computing. This paper focused on the adaptivity andawareness support of application software in mobile computing platform, analyzed thestate of the art in middleware technology, discussed features and challenges ofmiddleware for mobile computing, and proposed awareness-based web middlewarearchitecture. We aimed to propose a software infrastructure that could meetrequirements of mobile computing and facilitate the development of mobile computingapplications. Experiments made on the prototype middleware system showed thefeasibility and effectiveness of the middleware architecture. The main contents andcontributions include:1. Awareness-based web middleware architecture for mobile computing isproposed, and analysis and design of the middleware for web engine, context-sensingengine and awareness core engine are provided. Using context-sensing engine, themiddleware can acquire the various context in the changeful environments of mobilecomputing. Based on NFC technology, the middleware with awareness core engine canautomatically find and acquire services in the changed environments of mobilecomputing, and solve the adaption problem of mobile computing application.2. A mobile web middleware architecture for the development ofcontext-awareness applications using NFC(Near Field Communication) and fast facerecognition system on mobile phone which is developed based on improved AdaBoostand LBP(Local Binary Pattern) is presented. Based on it, the efficient support foracquiring, interpreting and accessing contexts is provided, and the developedapplications further verify that the improvement of user’s quality of experience isobtained. Moreover, the cross platform NFC stack and its architecture are presented.The NFC stack runtime environment module can offer encapsulated operation systemcore service. The NFC controller abstract layer module can hide the differencebetween different types of NFC controllers to upper layer. The NFC service interface layer module can work with different operation system applicative component anddifferent application framework, and it can support third party NFC applicationperfectly. Now the reference implementation of cross platform NFC stack can work ondifferent platform. The functionality and performance of it can meet the requirement.3. Web middleware architecture for the development of QoE-aware multimediaapplications on a mobile device is presented. A QoS/QoE correlation model formultimedia service is proposed, and the QoE evaluation method using QoS parameterin wireless network environment is studied. Using the proposed QoS/QoE correlationmodel, applications based on our web middleware can predict the objective QoE valueof multimedia service in offered network environment and adjust applicationparameters to improve QoE. Moreover, the comparision with model-based approach tomeasuring QoE verifies that the proposed QoS/QoE correlation model is feasible.4. Web middleware architecture for the development of privacy-aware mobilemultimedia applications is presented. Base on NFC technology, the middleware canacquire the privacy protection contexts in the changed environments, and provide theend-to-end security scheme for video communication. This system can keepinformation secret from all but those who are authorized to see it. Symmetric keyencryption and public-key encryption techniques are used to ensure privacyinformation security. At the same time, a real-time scrambling approach to concealvideo information is presented. The sign of transform coefficients for Intramacro-block is pseudo-randomly flipped, and so only the authorized persons areallowed to correctly decode the code-stream. Furthermore, this is achieved with a smallimpact on coding performance and negligible computation complexity increase.5. HTML Canvas2D vector rendering algorithm. The algorithm improve therender process of Canvas; and implement the linear gradient and radiation gradient fillwhich based on optimized the Grid algorithm; thorough dynamic tracking invalidarea in canvas, collect several regions which will be rendered in canvas to implementpartial rendering. Another optimization strategy is present an outline algorithm forgenerating any circular arc, the algorithm using midpoint rule to calculate controlpoints of cubic bézier curve which is used to fit circular arc. The algorithm has lowercomplexity and higher rendering efficiency compare with the past algorithms, and issuitable for mobile devices implementation. Comparing with the traditional implementation, the methods have obviously performance improvement on highresolution mobile devices. The final simulation tests show above aspects have goodresults in render optimization.