Will Emerging Millimeter-Wave Cellular Networks Cause Harmful Interference to Weather Satellites?

TL;DR

This study assesses whether 5G millimeter-wave cellular networks could cause harmful interference to weather satellites, finding that realistic network densities may indeed pose risks requiring regulatory intervention.

Contribution

It provides a detailed, simulation-based analysis of interference from 5G mm-wave networks to weather satellites, introducing new thresholds related to satellite sensor sensitivity.

Findings

Single 5G device interference is generally below harmful levels under ITU-R thresholds.

Aggregate interference from realistic 5G networks can be harmful to weather satellite sensing.

Additional engineering or regulatory measures are needed for satellite protection.

Abstract

We study whether realistic 5G mm-wave cellular networks would cause harmful out-of-band interference to weather satellites sensing in the 23.8 GHz band. We estimate uplink and downlink interference from a single interferer and a network of interferers in New York City, using real 3D building data and realistic antenna patterns. We perform detailed ray-tracing propagation simulations, for locations of the MetOp-B weather satellite and its scanning orientations and ground interferer antenna orientations for representative urban cell sites. In addition to the ITU-R threshold of -136 dBm/200 MHz, we propose an alternative set of harmful interference thresholds directly related to the sensitivity of the satellite sensor. Our results show that the 3GPP power leakage limits are sufficient to ensure that interference from a single 5G device is not harmful if considering the ITU-R threshold, but not if the weather prediction software can tolerate only very low interference levels. Importantly, aggregate interference resulting in practice from a 5G network with realistic network densities is often harmful, even considering the least conservative ITU-R threshold. Overall, our comprehensive coexistence study thus strongly suggests that additional engineering and/or regulatory solutions will be necessary to protect weather satellite passive sensing from mm-wave cellular network interference.