Abstract
A water quality monitoring application often requires the deployment of Internet-of-Things (IoT) sensors over a wide water body with communication links among them to transmit, receive the data, and then uplink it to the cloud for further analytics. Deployment of this kind requires battery-assisted IoT sensors which require monitoring the battery level and replacement when necessary. It is thus desirable to have battery-free sensor tags and a suitable communication infrastructure to obtain data. In this article, a system that facilitates obtaining sensed data, like pH, through passive sensor tags based on surface acoustic wave (SAW) technology and a cellular code-reuse scheme-based reader infrastructure is proposed. The reader in each cell is able to read multiple sensor tags simultaneously, which itself has been a challenge. The SAW sensor tags are appropriately proposed to be designed to be orthogonal to allow simultaneous detection and the cell range of reader-SAW sensor-tags communication is sought to be further enhanced through a resonant loading of interdigital transducer (IDT)-based reflectors.
Highlights
The consistent surge in human activity over the past century is having a deleterious impact on our environment, at the cost to human health [1]
A generic 2 × 2 time-frequency lattice design and detection followed by S11 responses was shown to explain that multiple orthogonal Surface Acoustic Wave (SAW) tags can simultaneously be detected at a time from a longer distance by resonantly loading the Interdigital Transducer (IDT) based reflector
It is worth pointing out that the advantage of cellular codereuse approach with orthogonal SAW sensor-tags can be extended to a water quality monitoring scenario
Summary
The consistent surge in human activity over the past century is having a deleterious impact on our environment, at the cost to human health [1]. In the light of the above, the scope and contributions of our paper are as follows: Comparing with papers [19,20,21,22,23,24,25,26,27], we present a novel and efficient approach to water quality monitoring using cellular code-reuse and to simultaneously identify, and, implicitly, sense multiple orthogonal SAW sensor-tags. The so-developed approach is intended to monitor the water quality over a wide-area pond, lakes, rivers, and coastal sea where many water-based assets and other resources may lie In this method, multiple SAW sensor-tags and readers are strategically divided into several hexagonal cells that form a cellular infrastructure and by appropriately maintaining the distance between the same group of SAW sensor-tags across different cellular hexagonal regions, the inter-tag interference between the same group of codes can be avoided.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
