A File System Abstraction and Shell Interface for a Wireless Sensor Network Testbed

Despite tremendous research interest and increased adoption, deeply embedded sensor networks are difficult to design, debug, and deploy; ultra-dependability remains an elusive goal. To address these difficulties, we have previously presented an Interactive, server-centric testbed for wireless sensor networks that targets systems constructed using nesC and TinyOS - the emerging standard in sensor system development. The testbed infrastructure exposes an API suite that enables users to rapidly configure, instrument, compile, install, and profile their systems on one or more remote network deployments. The prototype deployment consists of 80 Tmote Sky devices arranged in a regular grid. The architecture is extensible in both the hardware and software dimensions to foster adoption and specialization. In this paper, we demonstrate the extensibility of the testbed software design, and present a novel file system abstraction and shell interface developed using the original API suite. The design of the new interface is informed by user feedback from client institutions where the standard graphical interface is being used to support research and teaching activities. The new shell interface complements the traditional graphical interface, reducing interaction latency, and enabling programmatic experimentation through an interpreted scripting facility. We present the design and implementation of the new testbed interface, and present a small, but representative case-study that illustrates its utility.