Intelsat, SES Say Lower Noise Floor Limits Needed Than What Qualcomm Sought for ATG Broadband

The satellite industry is in disagreement about what it says are allowable rise over thermal limits that could come with air-to-ground mobile broadband in the 14-14.5 GHz band. While Qualcomm has said such aeronautical service broadband could safely increase the rise over thermal -- the ratio between the total interference and thermal noise -- by as much as 1 percent, the safe figure that would protect fixed satellite service (FSS) uplinks is actually 0.33 percent, Intelsat and SES said in a joint FCC filing posted Tuesday in docket 13-114. The companies said the satellite industry previously indicated FSS interference from all noise sources should be capped at a 1 percent increase noise floor, going by ITU-Radiocommunication (ITU-R) recommendations, but those calculations didn't take into account additional secondary services in parts of the 14-14.5 GHz band -- tracking and data relay satellite service and federal fixed and mobile services. SpaceX in a joint letter in October with Qualcomm said it thinks Qualcomm's commitments would protect SpaceX's nongeostationary satellite system. But those calculations also failed to take into account those secondary users in the band, said Intelsat and SES. "That pact cannot change the laws of physics, the Table of Allocations or the ITU-R Recommendations." Thus any authorization of an air-to-ground mobile service in that band should follow ITU-R recommendations and give it no more than 0.33 percent rise in thermal noise, they said. Qualcomm didn't comment Wednesday. In a 2014 filing in the docket, the company said the transmit power levels already proposed by the FCC will ensure the AMS rise over thermal limits is less than 0.5 percent.