Terrestrial Services Pose Problems for SDARS Feeder Links, Sirius XM Says

A tech industry-backed study showing Wi-Fi can coexist with primary users in the 5.925-7.125 GHz band (see 1801260043) fails to show mid-band use by terrestrial services won't raise the risk of unacceptable interference in the 7.025-7.075 GHz band to Sirius XM's feeder links, the company told International Bureau members, according to a docket 17-183 ex parte filing posted Thursday. It said it's preparing its own analysis of interference risks to the Satellite Digital Audio Radio Service (SDARS) feeder link frequencies that will be submitted when done. Sirius said its own initial review of the tech industry study found analysis defects that call into question the conclusions -- for example, no analysis of potential interference specific to the SDARS' unique characteristics. The tech industry study also focuses only on aggregate interference from terrestrial services to the satellite-received signal quality, ignoring the possibility a meaningful number of terrestrial devices located near Sirius XM feeder link sites on the ground could interfere with SDARS fleet uplinks. It said it doesn't object to sharing its feeder link spectrum with fixed service licensees since that makes coordination with Sirius feeder link sites possible. Outside counsel for the tech companies didn't comment Friday.