Date Added: Jan 2011
Wireless sensor networks have traditionally focused on low duty-cycle applications where sensor data are reported periodically in the order of seconds or even longer. This is due to typically slow changes in physical variables, the need to keep node costs low and the goal of extending battery lifetime. However, there is a growing need to support real-time streaming of audio and/or low-rate video even in wireless sensor networks for use in emergency situations and short-term intruder detection. In this paper, the author describe a real-time voice stream-capability in wireless sensor networks and summarize the deployment experiences of voice streaming across a large sensor network of FireFly nodes in an operational coal mine.