Wireless sensor and actor networks (WSANs) constitute a new pervasive technology. WSANs have two major requirements: coordination mechanisms for both sensor-actor and actor-actor interactions, and real-time communication to perform correct and timely actions. This paper introduces TC-WSANs, a high-level coordination model that addresses these two requirements and facilitates the application programmer task. Our proposal is based on a (hierarchical) architecture of sensor/actor clusters and the use of tuple channels to achieve communication and synchronization among sensors and actors. A tuple channel is a priority queue structure that allows data structures to be communicated both in a one-to-many and many-to-one way, facilitating the data-centric behavior of sensor queries. The characteristics of TC-WSANs and the primitives that it provides for its integration into a computational host language are presented.