Skip to main content

Fixed Microwave Rules Upgraded With No BAS Sharing Rule Changes

The FCC this week rejected requests for changes to the rules it previously adopted for sharing private operational fixed (POFS) and broadcast auxiliary service (BAS) microwave frequencies in its Second Report and Order, Second Further Notice of Proposed Rulemaking, Second Notice of Inquiry, Order on Reconsideration, and Memorandum Opinion and Order (FCC 12-87) regarding modification of Part 101 of the FCC rules to facilitate the use of microwave for wireless backhaul among other uses and to provide additional flexibility to broadcast auxiliary service and operational fixed microwave licensees. 

The FCC declined a proposal from the Fixed Wireless Communications Coalition (FWCC) to permit fixed service (FS) operations in channels adjacent to BAS/CARS operations. It argued, “Allowing FS applications into areas where BAS is authorized would necessitate a more formal coordination process, which we do not believe is compatible with the dynamic and rapidly changing nature of electronic newsgathering (ENG) operations.” 

The FCC also noted that broadcasters can use BAS channels for as many as 720 hours annually per frequency and as such, “in some locations, BAS operators could be making extensive short-term use of unlicensed BAS channels in the geographic areas where they have BAS licenses for other channels.” 

The FCC rejected a request from EIBASS (Engineers for the Integrity of Broadcast Auxiliary Services Spectrum) to prohibit newcomer POFS stations in the 7 and 13 GHz bands from degrading the noise threshold of any existing ENG receive-only (RO) site by more than 0.5 dB. The FCC said the EIBASS proposal was unnecessary because the FCC is upholding its prior decision to prohibit the paths of FS stations operating in the 7 and 13 GHz bands from crossing the service areas of TV pickup authorizations. 

The FWCC filed a petition for reconsideration arguing that the final link rule, which prevented broadcasters from using Part 101 stations to provide the final RF link the chain of distribution of program material to broadcast stations, should only be eliminated in areas where the Fixed Service can use the 7 or 13 GHz bands. The FCC denied the petition, stating, “Whatever the precise amount of demand from broadcasters turns out to be, we agree with NSMA that it should be possible to accommodate any incremental use of the affected bands in the general flow of expected FS deployments.” 

Microwave links in the 2655-2690 MHz and 5925-7075 MHz band with transmitters pointed within 2 degrees of the geostationary arc, and fixed service transmitters in the 12700-13250 MHz band with antennas pointed within 1.5 degrees of the geostationary arc, will require a waiver. To be approved, the waiver request must show--among other things--that the transmitter EIRP is below listed limits. 

ITU Radio Regulations place a two-degree restriction on stations in the 1 to 10 GHz band only if the EIRP is greater than 35 dBW and a one-and-a-half-degree restriction on stations in the 10-15 GHz band only if the EIRP is greater than 45 dBW. The FCC modified its rules to require the waivers only if the EIRP is greater than the ITU limits. FS facilities must protect previously authorized satellite facilities and the new rules do not limit the right of satellite licensees to file petitions to deny or informal objections against FS facilities they believe would cause interference to their facilities. 

The FCC asked for comment on proposals to change antenna standards, including allowing use of two-foot antennas in the 13 GHz band under Category B, as proposed by Comsearch. 

Doug Lung is one of America's foremost authorities on broadcast RF technology. He has been with NBC since 1985 and is currently vice president of broadcast technology for NBC/Telemundo stations.