Audio Networking: The Forgotten Wireless Technology

Modern computing and communication devices offer a wide range of wireless communication protocols to transmit data such as infrared, Bluetooth, and Wi-Fi. However, one technology, although even more ubiquitous with lower power requirements, has fallen off the radar in recent years. Audio networking uses audible sounds as a low-bandwidth data channel and can enhance, for example, smart phone usability. In that domain, audio networking offers both short-range communication with nearby devices as well as longer-range data transfer by introducing audio data packets into ongoing telephone conversations. Moreover, applying audio networking to smart phone applications doesn't change the fundamental devices people use to communicate. Instead, it can exploit the programmable interfaces that modern smart phones offer to augment existing modes of communication that people already know and use. In this article, the authors review various modulation schemes they've worked with, covering how to transfer data to nearby smart phones as well as usability and security issues. They also review audio networking as a mechanism for introducing data packets into ongoing mobile phone calls. They consider some real-world problems reported with telephone conferencing and apply audio-networking techniques to them in a case study application.