Building up to macroprogramming: an intermediate language for sensor networks

There is widespread agreement that a higher level programming model for sensor networks is needed. A variety of models have been developed, but the community is far from consensus. We propose an intermediate language to speed up the exploration of this design space. Our language, called the token machine language (TML) can be targeted by compilers for higher level systems. TML provides a layer of abstraction for a lower-level runtime environment, such as TinyOS. TML is intended to capture coordinated activity in a sensor network. Notable features of TML are its atomic action model of concurrency, and its unification of communication, control, and storage around the concept of a token. Tokens are small objects, typically under a hundred bytes, and can be disseminated across the network. A token causes computation upon its arrival at a site by invoking a token handler. The effect of the computation is to atomically change the token's own state as well as the state of shared variables at the site.