Citing complaints of signal loss by its satellite radio customers in New York City and other major markets, Sirius XM has asked the FCC to intervene in a dispute in which Sprint has fingered wireless transmission facilities owned by T-Mobile US as the cause of the interference. In documents filed with the FCC, Sirius described the disturbances—which were first detected a year ago in New York City—as “alarmingly severe, extensive and frequent.” After satellite radio listeners in that market reported abrupt losses in service during portions of the morning commute, Sirius conducted drive tests through which Sirius determined that cell phone transmitters operated by T-Mobile were interfering with Sirius signals.

According to Sirius, the problem became increasingly apparent as T-Mobile ramped up deployments of fourth-generation wireless broadband services that use spectrum in the Advanced Wireless Services-1 (i.e., 1710-1755 MHz/2110-2155 MHz) band. Although the closest channels under the control of Sirius consist of satellite downlinks and earth station receive frequencies in the 2300 MHz band, Sirius claims that the interference is attributable to an anomaly in which two adjacent airwaves have combined to create a third which is disrupting Sirius’s service. Warning that the problem is likely to worsen as T-Mobile continues to upgrade its network and add wireless broadband subscribers, Sirius has asked T-Mobile to contribute to the cost of a remedy, which could include the addition of ground-based transmitters to the Sirius network that could offset interference.

Insisting that T-Mobile is operating its FCC-licensed frequencies in a manner that complies fully with FCC rules and license terms, T-Mobile senior engineering director Steve Sharkey countered that the problem is actually caused “by inadequate filtering in Sirius XM receivers.” While Sharkey promised that his company will work with Sirius “to identify ways they can fix their problem,” he maintained that T-Mobile is not obligated to shoulder the cost of equipment fixes required by Sirius. Noting that the airwaves in question have been used by both companies for years, a senior FCC official confirmed that agency staff members are working to identify the cause of the problem.