May 12, 2016 — Industry proponents are sparring in comments and ex parte presentations in the FCC’s proceeding, which examines which higher frequency bands, above 24 GHz, may be suitable for mobile. Among other bands, the FCC proposed high-capacity, high-throughput small cells as part of mobile broadband deployments in the 28 GHz and 39 GHz bands with county-sized geographic area licenses.
Satellite providers, which inhabit 28 GHz, told 5G stakeholders that they need to realize that they are newcomers to this band and have to play nice to get access. On the other hand, mobile providers said the satellite players need to realize that 5G isn’t going to go away and are going to target the 28 GHz band, according to Verizon, which by the way is already in the band because the Local Multipoint Distribution Services (LMDS) licenses that it purchased from XO Communications.
In fact, Verizon filed its own complaint against ViaSat’s plan to use the 28.1-28.35 GHz band, which is designated for LMDS, for its aeronautical uplink.
In that vein, Samsung, Intel and Ericsson filed an ex parte in the proceeding urging the FCC to increase maximum allowable base station power levels from the proposed 62 dBm to 75 dBm EIRP per 100 MHz.
Their reasoning is that the proposed level of 62 dBm results in a much lower spectral density than is achievable in other mobile bands. Because the power is spread over more megahertz in the Upper Microwave Flexible Use Service, the range of base stations would be much smaller than with similar power levels in existing mobile bands.
The satellite industry responded, in a filing, that 5G proposals will likely interfere, in one way or another. Here is their logic, and where 5G can create interference.
In the 27.5-28.35 GHz spectrum:
Aggregate emissions from 5G base stations and user devices in the Earth-to-space direction into the uplink receivers at the satellites, and emissions from satellite uplink earth stations into 5G base stations and user device receivers on the Earth.
In the 37.5-40.0 GHz region:
Emissions from 5G base stations and user devices into satellite downlink earth stations on the Earth, and Emissions from satellite downlinks from space into 5G base stations and user devices on the Earth.
The big objection from the satellite providers is not so much what the power level increases may do, but “the absence of any stated plan or mechanism for managing the aggregate unwanted energy that will be directed toward space and the resulting unwanted energy arriving at a satellite’s location within these bands.” There is also the issue of scatter around the 5G transmitters from earth objects such as a dense cluster of cars, for example.