Multitone acoustic sensor network with mobile access: an experimental testbed

Sensor network with mobile access (SENMA) was proposed as an architecture for large scale sensor networks. With promising results in analysis and simulation, we have developed an experimental testbed for SENMA using indoor acoustic transmission. Indoor acoustic signal shows a similar propagation characteristic to radio frequency (RF) transmission in a manageable physical dimension. It shows the average attenuation with distance and fading due to multiple reflections from walls. In this paper, we describe the system design of acoustic SENMA testbed and its application. The developed system includes the basic features of SENMA such as the mobile access point(s), transmission of beacon signal, probabilistic transmission depending on channel state, and multiple access from the sensors. We use the frequency division multiple access (FDMA) in the uplink where sensors transmit acoustic tones in different frequencies. The reception models such as collision channel and signal to interference and noise ratio (SINR) model can be applied and the network performance like throughput is calculated based on the processing of the recorded sound from the sensors.