US utilities outline 6 GHz interference concerns

A group of US organisations representing various types of utilities has objected to plans for unlicensed use of the 6 GHz band on the basis of potential interference issues.

The group comprises the Edison Electric Institute, the American Gas Association, the American Public Power Association, the American Water Works Association, the National Rural Electric Cooperative Association, the Nuclear Energy Institute and the Utilities Technology Council.

The group has submitted a case study to the Federal Communications Commission (FCC), outlining real-world experiences of such interference on the critical infrastructure industry (CII) in Houston, Texas.

In its submission, the group says the purpose of the CII User Study “is to provide a real-world analysis of the potential impact of unlicensed use of the 6 GHz band on the multitude of CII and public safety providers that currently use the band for essential and mission-critical communications”.

“Unlike other studies… the CII User Study is based on actual, real-world user data, and not theoretical or hypothetical assumptions concerning the operations of incumbent fixed microwave systems in the band.”

The study is based on the “actual and detailed” inference impact on 520 microwave sites in the Houston Metropolitan Statistical Area (MSA), as well as “the actual impact of indoor and outdoor Wi-Fi deployments on 2325 point-to-point communications receivers” in the MSA.

Fixed point-to-point networks in the Houston MSA are used by energy companies, transportation, telecommunication backhaul, and utility and municipal infrastructure.

The study, which looked at interference from residential and outdoor Wi-Fi access points and Wi-Fi adjacent channel emissions, shows that “deployment of RLANs as currently proposed in the NPRM would cause all the point-to-point links in the Houston MSA to experience unacceptable levels of interference”.

The analysis shows that “the risk of interference from RLANs is not an isolated issue because to reduce interference to the necessary level, it would be necessary to prohibit U-NII-5 and U-NII-7 operations in approximately 94 percent of the nine-county area of the Houston MSA. Moreover, to avoid interference from adjacent Wi-Fi channels, it would also be necessary to exclude certain Wi-Fi channels.”

In addition, the study’s preliminary analysis of very-low-power operations “indicates that the potential interference from VLP operations has been significantly under estimated”.

You can read the full submission here.

Image credit: ©stock.adobe.com/au/Valmedia