Wireless Sensor Networks, and especially IEEE 802.15.4, are originally defined for low cost applications, with low bit rates and power restrictions in mind. However, the ubiquity of the nodes and their easy connectivity also enable them to be used in supporting real time services, for instance, emergency scenarios, where TETRA is usually the employed audio technology. Focusing on voice transmission, we present a performance evaluation of audio streaming over a multi-hop Low-Rate Wireless Personal Area Network in order to provide bidirectional audio communication using a commercial IEEE 802.15.4 compliant platform. This paper includes an assessment of different software protocols and compression algorithms to support audio transmission on a CC2530 System-on-Chip WSN mote. The results establish the maximum number of hops of a bidirectional single-route network under real- time voice quality constraints.

Peer Reviewed