Center for Embedded Network Sensing

Wireless network technology is being applied to a wide range of scientific and engineering problems and across a wide dynamic range of spatial scales. When node placement is constrained by the application (e.g, coupled to sensor placement needs), and can not rely on pre-existing infrastructure (e.g., cellular infrastructure or power-lines), such systems may experience erratic link qualities and intermittent node disconnection. These characteristics, combined with unpredictable environmental conditions, make it difficult to rely upon traditional end to end connections for regular high bandwidth data acquisition and for system management and configuration. We have implemented and deployed such a "challenged network" system of 50 nodes for use by seismologists along a part of the Mesoamerican Subduction Experiment (MASE) broadband seismic array, stretching 500 KM from Acapulco to Tampico through Mexico city. In addition to supporting Delay Tolerant data transfer of relatively high bandwidth seismic data, our system includes a reliable asynchronous remote shell interface (referred to as Disruption Tolerant Shell, DTS) to accomplish the management on these types of system. We present the implementation of this solution and its evaluation on a 13 node portion of the MASE network.