QVS: Quality-aware Voice Streaming for Wireless Sensor Networks

Recent years have witnessed the pilot deployments of audio or low-rate video wireless sensor networks for a class of mission-critical applications including search and rescue, security, surveillance, and disaster management. In this paper, we report the design and implementation of Quality-aware Voice Streaming (QVS) for wireless sensor networks. QVS is built upon SenEar, a new sensor hardware platform we developed for high-bandwidth wireless audio communication. QVS comprises several novel components, which include an empirical model for online voice quality, evaluation and control, dynamic voice compression/duplication adaptation for lossy wireless links, and distributed stream admission control that exploits network capacity for rate allocation. We have extensively tested QVS on a 20-node network deployment. Our experimental results show that QVS delivers satisfactory, voice quality under a range of realistic settings while achieving high network capacity utilization.