Research On The Technology Of Network Middleware In Ubiquitous Computing Environment

With the continuous development of embedded technology and networktechnology, ubiquitous computing is getting more and more wide use. Sinceubiquitous computing system is always a distributed system, network middlewarebecomes increasingly important in constructing a ubiquitous computing system. Theadaptability of the middleware to pervasive network and pervasive devices is animportant criterion for applying in ubiquitous computing system. This paper analyzesa widely used middleware system: OSGi and R-OSGi. Considering the limitations ofthis middleware system, we try to enable it to better adapt to the ubiquitouscomputing environment.In order to solve the problem of performance caused by the instability ofpervasive network, we make it capable to handle network exceptions automatically.As the essential characteristics of the network, network exceptions cannot be avoidedin any network-based applications. Under normal circumstances, the applicationneeds to write a considerable amount of code to handle all sorts of possible networkexceptions. This paper introduces a detection-recovery solution. The middlewaresystem can proactively detect network exceptions, and handle it automatically whenan exception occurs. And the process is transparent to upper layer applications, whichmeans the upper layer application will not perceive the network exceptions, makingapplications only need to focus on their own logic.In order to enable ubiquitous computing environment to better supportheterogeneity of the devices, this paper proposes a service invocation solution basedon a language-independent JSON-RPC mechanism and an interface descriptionlanguage. Exploiting the dynamic characteristics of the OSGi, service agent can begenerated dynamically. By using improved OSGi which has the ability of invokingservices language-independently, different programs which are written in differentprogramming languages can simply call each other’s services. This work expands thelimitation of OSGi and R-OSGi which can only support Java platform, and makes theubiquitous computing environment capable of supporting more types of networks andheterogeneous devices.In experiment part, we verify and test the effectiveness of the work, andeventually prove that the work can make good use and has a good performance. Finally, an analysis of scenario of building pervasive service network throughimproved OSGi and R-OSGi proves its ease of use.