GPS Companies, LightSquared Proponents Spar Over OOBE Limits For Terrestrial Network

The Competitive Carriers Association urged the FCC to act promptly to allow mobile wireless use of LightSquared’s spectrum assets. CCA said it rejected a request from the GPS Innovation Alliance for a long-term spectrum planning process to ensure that concerns of interference to GPS are fully resolved (http://bit.ly/19Bn89G). “The unique procedural nature of LightSquared’s requests makes such an endeavor unnecessary.” LightSquared and Inmarsat devices use the L-band uplinks without causing any reported interference to GPS, it said. Given that, it’s difficult “to find justification for an additional, long-term notice and comment rulemaking process,” CCA said.

Inmarsat urged the FCC to reject a recommendation from Greenwood Telecommunications Consultants that the FCC impose an OOBE limit of -105 dBW/MHz. Inmarsat and its partners deploy mobile earth terminals (MET) that comply with the existing OOBE limits, it said (http://bit.ly/1fz5v0k). These METs are widely deployed in the U.S. and internationally, “and are relied upon by a wide range of critical infrastructure, U.S. government and commercial users,” it said. Under FCC rules, the OOBE limit from METs into the GPS band may not exceed -70 dBW/MHz, it said. “This limit has been more than sufficient to ensure the compatibility of GPS receivers and Inmarsat METs."

The NTIA test and the test results of a 2011 commission technical working group referenced by GPSIA “have little, if any, relevance to the current OOBE proceeding sought by the commission,” Greenwood said (http://bit.ly/15qnTXg). The FCC granted LightSquared temporary authority to do tests in a band under-utilized by the National Oceanic and Atmospheric Administration (CD April 30 p7), “which is, at the least, a showing of feasible compatibility with NOAA and presumably GPS spectrum based services,” it said. Operation in that band wasn’t tested in either the 2011 technical working group or subsequent NTIA tests frequently referenced in GPSIA’s comments, Greenwood said.

LightSquared reiterated its stance that there’s no need for the FCC to evaluate further the compatibility of GPS receivers with LightSquared’s authorized L-band terrestrial uplink operations. The GPS parties “offer no affirmative showing” that LightSquared’s uplink operations pose any risk to GPS receivers, it said (http://bit.ly/18nK0dM). Many of GPSIA’s criticisms focus on secondary analyses offered by LightSquared “for the sole purpose of demonstrating that by relaxing certain conservative assumptions, the safety margin enjoyed by GPS receivers would be even greater than that found in the primary analysis” of LightSquared’s assessment, it said. GPSIA fails to demonstrate that such corrections “have any significant impact on the bottom-line conclusion that there is no GPS receiver compatibility issue,” it said.

GPSIA said it’s clear that LightSquared’s proposed use of terrestrial handsets in the 1626.5-1660.5 MHz band “is currently incompatible with GPS operations” (http://bit.ly/14E7axf). GPSIA rejected LightSquared’s argument that it agreed to more restrictive OOBE limits from its handsets than what was agreed to between LightSquared and the GPS industry more than a decade ago, the alliance said. This isn’t accurate, it said: LightSquared proposes to use the same limit from 2002 for an integrated mobile satellite service/ancillary terrestrial component (MSS/ATC) service “proposed 11 years ago, not a mere restrictive one for the terrestrial-only broadband service for which it required a waiver of the integrated MSS/ATC requirement.” The MSS/ATC system contemplated for use in the MSS L band “was ancillary to satellite use only, with a limited number of devices,” it said.