In most industrial processes transfer of data and software from or to sensors is an essential part of the monitoring and control systems. Many of the older, wired communication systems have been or are being replaced with wireless alternatives. A number of challenges are associated with this replacement:
1. Radio receivers are subject to interference from other radio sources. Similarly, radio transmitters may cause undesired interference into other equipment and environments. As a consequence, we have (at least) two concerns
o Spectral and co-existence of radio equipment. While many applications only require low bitrate communications, off-the-shelf solutions (802.11x) are not designed for such applications, and, as a consequence, the number of simultaneous clients is limited.
o Safety in for example EX environments (explosive or flammable compounds) effectively prohibits the use of radio equipment.
2. Compared to wired solutions, security becomes an issue as radio communication links are more vulnerable to eavesdropping.
3. Radio communication with sensors and sensor platforms embedded deeply inside large metal structures or fluid tanks may be difficult or even impossible – radio propagation in these environments simply may not allow for reliable communication.
In this study we will investigate and explore the feasibility of ultrasound as a means for communicating between systems, in environments where radio communication is not suitable. Ultrasound, with its mechanical waves, is insensitive to radio interference. Transmission of low-intensity ultrasound is also intrinsically safe and will not interfere with other sensitive equipment.