This paper presents the uDSSP (“micro DSSP”) programming model which simplifies the development of distributed sensor network applications that make use of complex in-network processing. Using uDSSP, an application is composed of state-centric services. These services interact by accessing the state of other services or by subscribing to changes of that state. uDSSP sup-ports heterogeneous networks that consist of PCs, resource-rich sensor nodes, and resource-limited nodes with just a few kilobytes of RAM. The evaluation uses a non-trivial application to compare it to Abstract Regions and Tenet.