Voglio sapere a riguardo di…

Federal Register / Vol. 86, No. 19 / Monday, February 1, 2021 / Proposed Rules approach at an early stage in the process, operators submit predicted antenna off-axis gain data and associated PFD calculations at any identified victim DBS space station receiver. No later than two months prior to launch this predicted data is confirmed by submission of measured data and associated PFD calculations.
We propose to amend 25.264a through e of our rules to extend this requirement to FSS applicants proposing space-to-Earth transmissions in the 17.317.8 GHz band. We seek comment on this approach as well as whether it would serve the public interest to adopt a modified data submission process instead. We also seek comment on whether we should retain, update, or modify any part of the process for 17/24 GHz BSS applicants.
In its comments to the Part 25 Second Report and Order, SIA argued that 25.264c should be revised to permit acceptance of simulated antenna gain data in place of measured data to afford applicants additional technical flexibility. In that Order, the Commission acknowledged that strict compliance with 25.264c has proven difficult for some applicants. At that time, however, we declined to adopt SIAs proposal to accept simulated data in place of gain measurements, as the record contained insufficient information to determine whether the simulated data would replicate the accuracy of the required measurements.
To evaluate whether to permit the use of simulated data in place of gain measurements in this instance, we seek comment on whether and how we should modify the two-part submission process to also accept simulated data in lieu of measured data. We ask what requirements we should place on the simulated data to ensure accuracy of required calculations and effectiveness of our rules. Are there specific software programs that should be specified, or certain input assumptions, conditions or other parameters that we should specify? In addition to the resulting gain and PFD levels, what information should we require applicants to include with their showing, e.g., specific input assumptions, conditions or other parameters? If the Commission decides to accept simulated off-axis gain and associated PFD data, what other changes to our rules may be necessary. For example, is it necessary to retain the application, and measured data was required nine months prior to launch. The Commission later amended 25.264 of our rules to provide 17/24 GHz BSS applicants and licensees greater flexibility, and to allow for finalization of antenna design. See Part 25 Second Report and Order, 30 FCC Rcd at 14816, paragraphs 329330.

VerDate Sep<11>2014

16:45 Jan 29, 2021

Jkt 253001

two-part information showing, or is a single simulation output sufficient? If so, at what point in the process should this information be submitted?
Would accepting simulated gain and PFD data obviate a need to reduce the angular ranges over which such measurements are made, based on its ability to alleviate the difficulties applicants and licensees experience in providing measured data? Or rather, would an increased orbital separation between space-to-Earth transmitting FSS
or BSS and DBS space stations alleviate concerns associated with relying upon simulated off-axis gain data for determining likelihood of inference, recognizing that at increased longitudinal separation, the likelihood for space path interference is significantly diminished?
To demonstrate that the coordination trigger is not exceeded, 25.264a6
and b4 of our rules require submission of PFD information calculated from the antenna off-axis gain data. The timing of PFD data submission is tied to the critical design review CDR process,57 a former satellite milestone requirement that was defined to be two years after the license grant. In the Part 25 Second Report and Order, however, the Commission eliminated all interim milestone requirements, including CDR, thereby creating some uncertainty with regard to the timing of PFD submission requirements. To correct this, we propose to replace the phrase within 60 days after completion of critical design review with a requirement to submit information within two years after license grant in these rule sections. We seek comment on our proposed changes.
Measures To Mitigate Ground Path Interference In the 17.317.8 GHz band, receiving FSS earth stations will be vulnerable to ground path interference from the Earthto-space transmissions from nearby cofrequency DBS feeder link earth stations.58 Section 25.203m of our 57 In bounding the timing of PFD information submissions by the critical design review process, the Commission sought to permit licensees to provide gain and PFD predictions at a point when spacecraft design would be more mature, believing that predictions made at that point would generally be more reliable than predictions made at the application stage. Comprehensive Review of Licensing and Operating Rules for Satellite Services, IB Docket No. 12267, Further Notice of Proposed Rulemaking, 29 FCC Rcd 12116, 12166, paragraph 177 2014 Part 25 Further Notice.
58 Ground path interference arises in reverse-band sharing scenarios when the off-axis uplinked signals transmitted by one earth station are detected by the receiving antenna of a nearby co-frequency earth station. It is analogous to space path
PO 00000

Frm 00014

Fmt 4702

Sfmt 4702

7669

rules contains requirements to mitigate ground path interference from DBS
feeder links into BSS earth stations operating in the 17/24 GHz BSS. If FSS
receiving earth stations are permitted to operate in the band with protected status with respect to DBS feeder link earth stations, then we will need to adopt analogous protection requirements. Below, we propose generally to apply the same coordination approach that the Commission adopted to facilitate operations between DBS and 17/24 GHz FSS earth stations to receiving FSS earth stations. We propose to apply this coordination approach to FSS earth stations in the entire 17.317.8 GHz band, although in the 17.717.8 GHz band such earth stations will not be entitled to protection from fixed service stations. As discussed below, we seek comment on modifications to the parameters used with the ITU Radio Regulations Appendix 7 coordination methodology 59 to account for differences between the receiving antennas in the two services.
SES argues that 17 GHz FSS
downlinks readily fit into the existing 17/24 GHz BSS regulatory structure and will not constrain the placement of additional future DBS feeder link facilities. SES points out that all existing DBS feeder link sites are grandfathered and permitted to make modest changes, and that entities seeking to establish protected 17 GHz FSS receiving earth stations would select locations well away from current DBS feeder link facilities.60 We propose generally to amend 25.203m of our rules to include receiving FSS earth stations in the rules. We seek comment on this approach and on any unforeseen effects it may have on incumbent DBS
operations. We also recognize that there are some differences between BSS
receiving earth stations and those FSS
stations that may operate in the band, and we ask commenters for input on if, and how, these differences might need interference which arising between co-frequency space stations as discussed above. As with space path interference, the severity of ground path interference will depend upon the transmitted signal power level, the off-axis gain discrimination characteristics of the transmitting and receiving antennas, and the specific orientation of, and separation between, the transmitting and receiving antennas on both earth stations. In addition, local geography can also influence ground path interference levels.
59 ITU Radio Regulations, Appendix 7 at section 3; Table 9b of Annex 7.
60 SES Petition at 67. SES further argues that the gateway-type receiving FSS earth stations it contemplates would be fewer in number and more resistant to interference than the ubiquitously deployed 17/24 GHz BSS earth stations now permitted in the band. Id.

E:FRFM01FEP1.SGM

01FEP1