Dynamic Updating In Ubiquitous Computing And Its Formal Research

With the widespread use of sensors and mobile computing devices, computing technologyhas made rapid development, it becomes an urgent need to find a corresponding computingparadigm, in this situation, ubiquitous computing as a emerging computing paradigm plays amore and more important role in our daily lives. Ubiquitous computing is a human-centeredcomputing paradigm, with ubiquitous computing, we can get digital services anytime andanywhere transparently, and it has a high requirement to the stability and availability of thesoftware system. To achieve this wonderful vision, the system deployed in ubiquitous computingenvironment requires the ability of dynamic updating. Dynamic updating is a kind of softwareevolution technique, aimed to update software modules without interrupting the running of thesystem, thus to improve the system availability. However, because of the characteristics ofubiquitous computing, such as environmental heterogeneity, distribution, dynamics and therequirement of user transparency, it's more complex to implement dynamic updating inubiquitous computing environment, and it needs to do further research.In this paper, we discuss the dynamic updating in ubiquitous computing, firstly analyzes thenecessity of pervasive computing research on dynamic updating. Then based on the existingresearch on dynamic update in ubiquitous computing environment, combined with thedistribution and dynamic, analysis the limitations of centralized update model, propose adistributed update model suitable for ubiquitous computing environment. Through carefulanalysis of ubiquitous environment characteristics, summed up the detail processes of dynamicupdating under ubiquitous computing, including service registration and discovery, service compatibility analysis, establish the correct updating timing, buffering service requests, old andnew version switch, redirection of buffered service requests, cleaning and error processing steps,and we do thorough analysis to each step of the process. For the service registration anddiscovery, this paper first analyzes some of the existing service registration and discoverymethods, combined with the existing platform, proposes and implements one kind method ofservice self-discovery based on distributed network, makes the update model meet the need ofubiquitous environment better.Secondly, use the type and effect system as a formal tool, to do formal analysis to theupdate mechanism, to formalize the mechanism and theoretically check the correctness of updatemodel.Finally, based on the previously proposed update model, adopting OSGi frameworkplatform, we develop a prototype of distributed dynamic update, named DDSUF, and we developcorresponding Demo to verify the effect and performance of DDSUF, and then we combined with theexperiments to verify the theoretical research, the experimental results show that this methodmeets our research objectives.