Thin Middleware for Ubiquitous Computing

As Donald Norman put it in his popular book Invisible Computers [12], “a good technology is a disappearing technology.” A good technology seamlessly permeates into our lives in such a way that we use it without noticing its presence. It is invisible until it is not available. Ever since the invention of microprocessors, many computer researchers have strived to make computer technology a “good” technology. Advances in chip fabrication technology have reached a point where we can physically make computing devices disappear. Bulkier machines have given way to smaller yet more powerful personal computers. It has become possible to implant a complete package of a microprocessor with wireless communication, storage, and a sensor on a cubic millimeter silicon die [8]. Specialized printers print out computer chips on a piece of plastic paper [6]. Computer chips are woven into on a piece of fabric [9]. “Smart labels” (a.k.a passive RFID tags) [7] will soon be attached to every product in the market. The growth of devices with embedded computers will provide task-oriented, simple services which are highly optimized for their operating environment. More user oriented, human friendly services may be created by networking the embedded nodes, and coordinating their software services. Composing existing component services to create higher-level services has been promoted by CORBA, DCOM, Jini, and similar middleware platforms. However, these middleware services were designed without paying much attention to resource management issues pertinent to embedded nodes: the middlewares tend to have large