Architecture Of Software Migrating On Demand In Wireless Environment Research And Emulate Implementation

All things are affected by change. This is especially true for mobile computing environments. Everything, from devices used, resources available, network bandwidths to user contexts, can change drastically at run-time. It therefore becomes imperative for software systems and applications to be able to adapt to these changes in order to provide a suitable and relatively stable working environment for users.Software users have been paying for much more than they needed. This is because software developers have chosen to bundle all the possible functions in essentially a monolithic chunk of code. Many of these software packages turn out to be much too over-sized for a mobile device.We introduce Architecture of Software Migrating on Demand in Wireless Environment; Mobile devices by their nature have limited resources. To allow as many useful applications as possible to run on a mobile device, we propose changing the software development paradigm from monolithic chunks to small functionalities which can be dynamically downloaded on demand to the mobile device, and disposable. This changes fundamentally the concept that an application has confined functionalities. Different functionalities may be downloaded based on the changing context which could be a function of device resources, the network connection, t?he environment, and the user's preferences.The main work of this paper is as follows:First,we put forward an Architecture of Software Migrating On Demand in Wireless Environment. There are three parts in our architecture; they are Client System, Intelligent Proxy and Piece Servers. Under normal cases, the request is sent to the proxy. The proxy possesses the overall view: it knows what pieces are available in the servers and it knows the requirements of the device. It matches the requirements of the client with the properties of the available pieces, carries out some usage pattern analysis and determines which piece would be most suitable for the client to use. It then returns the piece to the client. Piece servers host pieces, i.e. components. They provide a permanent storage area for pieces on the network. Second, According to designed architecture, we designed Piece-based Programming. Applications can be broken up into Pieces. Every Piece provides certain functionality. There may be more than one Piece achieving the same functionality. At run-time, the appropriate Piece is brought in and executed. This enables applications to be linked by functionalities, rather than by exact components. In order to achieve its functionality, a piece may call upon other pieces. In other words, a piece may depend on other functionalities.Last, the proxies are the main intelligence of the network. They receive requests from clients, match the requirements with description of the components and return the most appropriate components to the clients. The proxies also incorporate techniques to improve performance such as pre-fetching and cooperative caching.