Center for Embedded Network Sensing

In this paper, we describe an implementation of a ad-hoc, distributed sensor platform that provides synchronized time to its users. By abstracting the time synchronization layer away, we allow developers to focus on the core challenges of their applications (e.g., signal processing, aggregation, routing) rather than dealing with the algorithmic and systems issues that inevitably arise when integrating sensing with distributed synchronization. Through a variety of techniques, notably the use of Reference-Broadcast Synchronization (RBS), our platform offers better than 5µsec precision when comparing streams of audio data sampled at nodes separated by one network hop.