The Scalablitiy of WiFi for Mobile Embedded Sensor Interfaces

Johnty Wang, Eduardo Meneses, and Marcelo M. Wanderley
johnty.wang@mail.mcgill.ca		eduardo.meneses@mail.mcgill.ca 	marcelo.wanderley@mcgill.ca

In this research we answer the following questions regarding the use of the ESP32 as a 2.4Ghz WiFi sensor interface via OSC:

How fast can we send data with acceptable latency (<10ms)?
How many devices can operate on a single channel at a time?
How consistent is WiFi performance in potentially crowded environments? 
July 2020 - NIME
Test Procedure
End to end latency measurement device 
(trigger in - audio out)

ESP32-based trigger receiver - message sender with configurable send rates

Computer for receiving signal and synthesizing output
Results
Up to 7 devices can operate at 100Hz while achieving <10ms latency
# of Additional devices (00 = 1 Device)
Single device can send up to 2300 msgs/s
Significant performance difference due to network conditions (30 Jan == Weekday)
Conclusion
Up to 7 devices possible at 100 Hz (with less than 10ms overall latency)
Performance varies depending on environment