NGSO Spectrum Sharing Needs Absolute Values: Operators

Appropriate values for measuring long- and short-term interference thresholds are sorely needed, satellite operators said in docked 21-456 reply comments posted Wednesday. There continued to be disagreements about the use of band splitting once interference protections sunset (see 2308080051). The replies were for the non-geostationary orbit (NGSO) Further NPRM adopted in April (see 2304200039). Given the general industry consensus on such issues as assessing short-term interference based on absolute change in link availability rather than a relative change in unavailability, the agency's next step should be getting input and technical analysis to determine objective link availability and degraded throughput values, SpaceX said. Compatibility demonstrations should be needed only if coordination discussions fail to result in an agreement, O3b said. It urged the agency to require compatibility analysis across various latitudes and consider different rain conditions to prevent cherry-picking of locations that could distort interference calculations. The record shows support for opting for an absolute decrease in unavailability metric for short-term interference, but there's no consensus on the appropriate values for the long- and short-term interference thresholds, Intelsat said. It said there's no persuasive justification for the commission to adopt an aggregate interference cap or a post-sunset interference protection regime beyond what already is in its rules. Telesat also urged more study before determining a short-term standard for unavailability. It said the agency "should avoid falling into the trap" of delaying operations of a later-round applicant's system when there's no coordination agreement, particularly when an earlier-round applicant hasn't fully engaged in coordination efforts. Noting support in the record for ensuring operators of poorly designed systems aren't inadvertently rewarded, Viasat said the agency can push efficient spectrum use by taking another look at its band-splitting mechanism, as that incentivizes deployment of systems using spectrum inefficiently. Turning to band splitting after the sunset of interference protections could mean service disruptions, said OneWeb. NGSO systems that aren't fully deployed by the sunset date shouldn't be allowed to operate under default spectrum splitting procedures at least until they have completed deployment, it said. Supporting band splitting, Amazon's Kuiper said the prospect of this equal status promotes coordination. Backing a degraded throughput methodology, Mangata said the FCC should allow operators to use publicly available data such as in their applications but not require the analysis be based on information coming from the coordination process. That analysis should account for only deployed satellites, with there being an option to submit an analysis looking at future deployments of earlier-round systems or a new showing once there has been deployment of that earlier round, it said.