Satellites in 39 GHz Band Don't Need PFD Limits to Protect UMFUS, Boeing Says

Power flux density (PFD) limit changes aren't needed for satellite operations to allow spectrum sharing with upper microwave flexible use service (UMFUS) systems in the 39 GHz band, Boeing said. A docket 14-177 ex parte filing Tuesday said the FCC instead needs only to define conditions under which satellites could increase their transmit PFD limits to compensate for rain fade and to adopt equivalent PFD (EPFD) limits for restricting downlink transmissions. That EPFD approach might require operators of big nongeostationary and geostationary constellations in the same spectrum to sometimes use transmit PFD limits below the current requirements or to limit the number of satellites radiating toward the same ground point, it said. But the EPFD approach would ensure aggregate emissions of satellites in the 39 GHz band wouldn't exceed the power levels needed to protect UMFUS receivers, it said. EPFD limits would require the identification and use of reference UMFUS receive antenna patterns, it said, saying it did a variety of demonstrations showing broadband satellite systems operating in the 39 GHz band without harmful interference to UMFUS systems. The ex parte recapped a meeting between Boeing representatives including Global Broadband Vice President Bruce Chesley and Wireless and International bureaus and Office of Engineering and Technology staffers.