On the use of GNSS for Automatic Detection of Attenuating Environments

TL;DR

This paper explores using GNSS signal quality to automatically detect environments with high attenuation, aiding spectrum sharing and interference mitigation without user input.

Contribution

It introduces a novel method to identify attenuating environments by analyzing GNSS signals, demonstrated with practical measurements on an Android tablet.

Findings

GNSS signals are weaker in attenuating environments.

GNSS raw data can distinguish between low and high attenuation locations.

Feasibility shown with off-the-shelf Android device.

Abstract

When different radio applications share the same spectrum, the separation by attenuating material is a way to mitigate potential interference. The indoor restriction for WLAN devices in 5150-5350 MHz is an example for a regulatory measure that aims at having WLAN devices operating in an environment that provides sufficient attenuation to enable sharing with other services. In this paper we investigate whether an attenuating environment can be automatically detected without user interaction. Instead of detecting an indoor location, we are directly looking for a detection of an attenuating environment. The basic idea is that signals from global navigation satellite services (GNSS) can be received practically everywhere on earth where there is a view to the sky. Where these signals are attenuated, the receiving device is assumed to be in an attenuating environment. In order to characterize such environment, we evaluate the detectable GNSS satellites and their carrier-to-noise density. Example measurements show that GNSS raw data can help to distinguish between low-attenuating locations and higher-attenuating locations. These measurements were conducted with GNSS receiver in an off-the-shelf Android tablet in order to show the feasibility of the approach.