Last summer, the FCC announced a Notice of Inquiry titled “Expanding Flexible Use in Mid-Band Spectrum Between 3.7 and 24 GHz.” The Notice focused on three specific frequency bands, nearly all in what’s known as C-Band (4-8 GHz). The intent was to make more spectrum available for next-generation wireless broadband networks.

One of the results of that Inquiry was a new Public Notice announcing a temporary freeze on the filing of new or modification applications for C-Band licenses in the 3.7-4.21 GHz range. Unless you regularly explore the FCC website, you may have missed it. It was announced on 19 April 2018, while many were catching up from the 2018 NAB Show.

Licenses and registrations include all Fixed Satellite Service (FSS) earth station licenses, Fixed Service (FS) microwave licenses, and receive-only earth stations operating in the band. A C-Band TVRO dish would be a common example. The purpose of the freeze is to improve control over future interference, and everyone benefits.

The temporary freeze is the FCC’s latest step towards adding future C-Band device users and services while protecting existing C-Band users from future interference. Many existing TV receive only (TVRO) earth stations receive satellite signals in the 3.7 to 4.2 GHz band.

The Exception

There is a limited exception to the freeze. It is a 90-day window for owners or operators of existing FSS earth stations in the 3.7-4.2 GHz band to file an application to register or license the earth station, even if it is not currently registered or licensed, or to file an application to modify a current registration or license, in the International Bureau Filing System (IBFS). The 90-day deadline for filing applications for existing sites is Wednesday 17 July 2018.

Applications for licenses or registration in the 3.7-4.2 GHz band usually require a frequency coordination report, but the FCC has waived the frequency coordination report requirement during the filing window. Sites filing without a frequency coordination report will not be protected from today’s fixed transmission services, but the filing could offer protection from future in-band services the FCC may consider. The FCC can’t protect you if it doesn’t know who and where you are.

The costs of registering or filing for a license can be from several hundred USD to thousands of dollars, depending primarily on the number of sites and how much of the paperwork you can or have time to do yourself. The downside of not registering a receive-only site is that it will have no future protections from new local interference.

Why Now?

According to the FCC, “The purpose of this freeze is to preserve the current landscape of authorized operations in the 3.7-4.2 GHz band pending Commission action as part of its ongoing inquiry into the possibility of permitting mobile broadband use and more intensive fixed use of the band.”

The 90-day window is expected to provide the Commission and commenters more accurate information about existing earth stations. Part of the MOBILE NOW Act requires the Commission to assess the feasibility of Federal and non-Federal sharing of the 3.7-4.2 GHz band and submit a report to the Secretary of Commerce and to Congress within 18 months.

Approximately 48 satellites use this band to provide downlink signals of various bandwidths to approximately 4,700 registered earth stations throughout the US. Geostationary orbit (GSO) FSS satellites typically have 24 transponders, each with a bandwidth of 36 megahertz received by one or more earth stations.

Most GSO FSS uses include direct delivery of program content to television and radio broadcasters, cable television and small master antenna systems, as well as the backhaul of international telephone and data traffic. The band is also used for satellite telemetry signals, usually operating near the 3.7 or 4.2 GHz band edges.

What's On Now? 

The 3 August 2017 Notice of Inquiry focuses on three bands, all within the 4 GHz of spectrum defined as C-Band. The specific bands under inquiry are 3.7-4.2 GHz, 5.925-6.425 GHz and 6.425-7.125 GHz.

The 3.7-4.2 GHz band was the original FS, long-haul, common carrier microwave band, that provided the first terrestrial analog transcontinental network for TV and long-distance telephone circuits. According to a National Telecommunications and Information Administration (NTIA) spectrum usage study, C-Band service in the US peaked in 1988. At that time, 39,000 terrestrial FS licenses, 14,000 receive earth stations and 9,500 uplinks all coexisted. Today, there are only 119 FS licenses operating in the 3.7-4.2 GHz band.

The 5.925-6.425 GHz band is also currently used for FS. FS licensees may be authorized to operate point-to-point microwave links with up to 120 megahertz of paired spectrum for each authorized path. Individual paired channels may be assigned in specified bandwidths ranging from 400 kilohertz up to 60 megahertz. FCC licensing records show more than 27,000 licenses issued for point-to-point operations in the band.

The 5.925-6.425 GHz band is close to spectrum designated for Unlicensed National Information Infrastructure (U-NII) use. Current U-NII devices operate in the 5.15-5.35 GHz and 5.47-5.725 GHz bands. Future U-NII devices could possibly operate in both this new unlicensed band and the existing UNII band. Such spectrum expansion would give devices wider channel bandwidths and higher data rates for increased flexibility in all types of unlicensed operations. The FCC is also currently evaluating the feasibility of U-NII devices sharing the 5.85-5.925 GHz band with Dedicated Short Range Communications (DSRC) systems operating under the Intelligent Transportation Service (ITS).

The 6.425-7.125 GHz band is 700 MHz wide, including BAS channels. The band is now allocated in the US exclusively for non-Federal use on a primary basis for FS at 6.525-7.125 GHz, Mobile Service at 6.425-6.525 GHz and 6.875-7.125 GHz. FSS operates at 6.425-6.700 GHz and 7.025-7.075 GHz for uplink and at 6.700-7.025 GHz for both uplink and downlink. FCC licensing records show a total of 485 in-band BAS licenses.

In the 6.425-6.525 GHz band are 139 BAS, 26 CARS, and 243 Part 101 licenses issued for mobile operations. The 6.875-7.125 GHz band contains 346 BAS, 19 CARS, and 38 Part 101 licenses for mobile operations. Mobile operations are permitted in the 6.425-6.525 GHz band in channel bandwidths ranging from 1 megahertz to 25 megahertz, licensed as defined by parts 74 (BAS), 78 (CARS), and 101 (mobile including Local Television Transmission Service) of FCC rules. Mobile operations are also permitted in the 6.875-7.125 GHz band.

File Here:

The limited window is only available for earth stations constructed and operational before 19 April 2018. All applications must be filed electronically (requires a FRN/User Name and password). The 90-day deadline for filing applications for existing sites is Wednesday 17 July 2018.