A context-sensitive middleware for dynamic integration of mobile devices with network infrastructures

摘要

Network infrastructures (NI), such as the Internet, grid, smart spaces, and enterprise computing environments usually consists of computing nodes that are stationary, provide the backbone for environment sensing and high-performance computing and communication. NI, in addition, may have various types of application software for performing resource-intensive computation. On the other hand, recent advances in the embedded systems and wireless communication technologies have increased the flexibility of using mobile devices for various practical applications. Mobile devices mostly execute application software that improves the personal productivity of the user. However, despite the rapid technology advances, mobile devices are expected to be always resource poor in comparison with the computing resources in the NIs. On the other hand, the computing resources in an NI cannot readily add the flexibility to individual users due to their fixed location and size. It is therefore desirable to combine the respective strengths of mobile devices and network infrastructures (NI) whenever possible. Dynamic integration is the process using which a mobile device can detect, communicate with, and use the required resources in nearby NIs in an application-transparent way. The benefit of dynamic integration is that the applications in both mobile device and NI can interoperate with each other as if a mobile device itself is an integral part of the NI or vice versa. In this paper, a context-sensitive middleware, called Reconfigurable Context-Sensitive Middleware (RCSM), is presented for addressing this dynamic integration problem. A novel feature of RCSM is that its dynamic integration mechanism is context-sensitive, and as such the integration between the application software in a mobile device and an NI can be restricted to specific contexts, such as a particular location or a particular time. RCSM, furthermore, provides transparency over the dynamic resource discovery and networking aspects so that application-level cohesion can be easily achieved. The integration process does not force any development-time restrictions on the application software in an NI. Our experimental results, based on the implementation of RCSM in integrated ad hoc and infrastructure-based IEEE 802.11 test bed environment, indicate that the integration process is lightweight and results in reasonably high performance in PDA-like devices and desktop PCs.