Middleware development in the growing and promising field of sensor networks is a major challenge in order to facilitate the programmer task and bridge the gap between the applications and the hardware. This paper presents a new middleware for wireless sensor networks based on the Coordination paradigm. The middleware is thought to support both an operational setting based on a (hierarchical) architecture of sensor regions and a coordination model rested on tuple channels. Tuple channels are FIFO structures that allow one-to-many and many-to-one communication between region sensors and the region leader in a single-hop way. The main components of the middleware architecture are described.