Ultrasonic physical layers as building blocks of IoT stacks

Abstract

Instrumental, Scientific and Medical (ISM) bands are essential to the transmission of IoT traffic as most of the physical layers of the Wireless Personal Area Network (WPAN) and Low Power Wide Area Network (LPWAN) families rely on them. ISM bands, however, are associated with a myriad of problems responsible for signal degradation and pollution that lead to application Quality of Service (QoS) issues. In this context, the use of alternative transmission mechanisms serve as backup to traditional schemes. One of such mechanisms relies on sub-ultrasonic and ultrasonic signals for the propagation of IoT device traffic. In this paper, we recycle a well known acoustic modulation scheme intended to be used in legacy Public Switching Telephone Networks (PSTNs) to support sub-ultrasonic and ultrasonic channels. This scheme becomes the basic building block of a physical layer that is combined with other well known elements of the IoT layered architecture. This not only includes a customized link layer but also an adaptation layer that enables full integration with upper layers.