A software system for enabling real-time voice communication over existing ZigBee networks
David D. Zhang, Khashayar Kotobi, Shabnam Sodagari, Sven G. Bilén · International Journal of Systems Control and Communications · 2015
The ZigBee wireless protocol specification, based on the IEEE 802.14.5 standard, is used in many low cost, distributed wireless sensor networks. It is widely used in various embedded applications, such as for industrial, medical, and home automation. Its popularity has spawned an increasing interest in the capability of the protocol to support multimedia applications, including real-time voice transmission. Several vendors have developed hardware codecs for developers to implement 'voice over ZigBee' solutions. However, given the already wide-spread deployment and use of ZigBee sensor nodes, we propose a system for voice transmission over a ZigBee star network using a purely software-based solution, such that it can be applied to existing commercial ZigBee network nodes without additional hardware. A voice detection system optimised for embedded systems is also proposed in order to reduce network load. The proposed system is implemented onboard a common wireless sensor network node, the Freescale MC1322x. The voice quality of the system is measured via a mean opinion score test and compared to other common voice over internet protocol solutions.