The FCC this week announced a Notice of Proposed Rulemaking (NPRM) and Notice of Inquiry (NOI) (FCC 12-32) proposing rules for use of 2 GHz MSS spectrum for terrestrial wireless broadband. The rules are of interest to broadcasters because part of this spectrum, 2000-2020 MHz, is close to the broadcast auxiliary service (BAS) 2 GHz ENG band.
The FCC proposes using this spectrum for "uplink" (transmission from hand-held subscriber units) that will be limited to 1 watt EIRP. This should greatly reduce the potential for interference from these devices to ENG receive antennas, which are typically located away from or well above areas where 2 GHz hand-held radios would be used. The MSS spectrum would be designated "AWS-4", joining other Advanced Wireless Service (AWS) allocations in adjacent spectrum.
In the NPRM and NOI the FCC asked whether this 2000-2020 MHz MSS allocation should be shifted up to 2005-2025 MHz. This would alleviate some of the concerns about interference between the AWS in the adjacent 1995-2000 MHz band. However, this shift could increase interference to BAS operations. Ancillary Terrestrial Component (ATC) rules originally limited out-of-band emissions to 70+10*log10(P) above 2025 MHz but the FCC waived this rule in 2009 and applied the 43+10*log10(P) standard instead. The FCC NPRM states, "As the interference potential between these bands has not changed significantly since then, we propose that no additional attenuation beyond 43+10*log10(P) dB is needed to protect operations above 2025 MHz. We seek comment on this approach. Commenters should discuss and quantify the costs and benefits of this proposal and any proposed alternative approaches."
The rules as proposed do not include any requirement for coordination with BAS licensees in the 2025-2110 MHz band. The FCC notes that the relocation of BAS users from the 1990-2025 MHz band was completed and the cost-sharing dispute between Sprint and the MSS licensees has been resolved. The NPRM asks, "In light of this, if the Commission assigns terrestrial licenses under Part 27, do any relocation and cost-sharing issues for the 2000-2020 MHz band remain? In addition, should the Commission adopt either of the spectrum shift approaches that would include the 2020-2025 MHz block, we seek comment on any additional relocation or cost-sharing issues including this spectrum block would raise."
The Notice of Inquiry portion of FCC 12-32 focuses on extension of the 2 GHz band to include 1.7 GHz spectrum being transferred from NTIA. One of the proposals includes creating a PCS downlink band from 1995-2025 MHz. This would have a much greater impact on 2 GHz BAS operations than those proposed in the NPRM. The interference to ENG channel 1 would be similar to the interference to channel 7 from the AWS-1 downlink band at 2110-2155 MHz. Licensees in that band have had to provide filters to protect ENG receive sites from interference from nearby base station transmitters.
Comments on the NPRM and NOI will be due 30 days after publication in the Federal Register, with an additional 15 days for reply comments.
2 GHz MSS Terrestrial Spectrum Use Likely to Impact ENG Sites
LightSquared's plans to use its MSS spectrum for a terrestrial network were shot down when tests showed it would cause interference to GPS receivers. Interference to broadcast users is unlikely to get as much attention.