AT&T (NYSE: T) and EchoStar executives presented their potential framework for sharing the 28 GHz band and the 37.0-40.0 band to the FCC, saying they believe it achieves three primary goals.

The framework protects existing fixed satellite services (FSS) licensees and provides them a co-primary status with new upper microwave flexible use (UMFU) licensees; establishes protection zones in the urban cores of key metropolitan areas to prevent potential interference to UMFU systems from new FSS installations; and establishes a set of coordination guidelines and parameters that allows FSS and UMFU licensees to fairly share the spectrum outside the protection zones.

The framework the companies presented comes after AT&T and EchoStar representatives said during an FCC workshop last month that they thought solutions could be found for sharing spectrum in the upper millimeter wave bands. Joan Marsh, vice president for federal regulatory at AT&T, also described it as a "fairly easy lift," particularly compared to the kind of complicated coordination AT&T has done in other bands like WCS.

Indeed, before that workshop even started, FCC Chairman Tom Wheeler advised both mobile and satellite stakeholders to work out the spectrum sharing conundrum in the millimeter wave spectrum.

Under the framework that AT&T, EchoStar, Hughes Network Systems and Alta Wireless submitted to the commission last week, FSS operators in the 28 GHz band would be permitted to add individually-licensed FSS earth stations to existing facilities. In the 37-40 GHz band, UMFU use would be permitted throughout a new band that combines the 37 GHz and 39 GHz bands into 3 GHz of contiguous bandwidth.

The companies also included a table defining urban cores where FSS earth station deployment would be restricted. The urban core definition would be used for the area where UMFU licensees are primary and FSS licensees are secondary for both the 28 GHz band (27.5-28.35 GHz) and the preferred channels for FSS deployment in the 37-40 GHz band (limited to 39-40 GHz; FSS would be secondary as well in 37.5-39.0 GHz in all areas).

While details of coordination, safe harbor and aggregate interference guidelines are still being developed, "AT&T and EchoStar believe that this framework will enable both satellite and mobile services to make intensive and productive use of these valuable spectrum resources in a manner that does not unduly restrict the development of either service," states the letter jointly filed by AT&T and EchoStar.

Verizon (NYSE: VZ) also has promised to work with satellite providers to try to find common ground on potential interference issues between future mobile terrestrial operations and existing satellite earth stations in the 28 GHz band.

For more:

- see this AT&T filing

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Satellite, mobile industries still hashing out spectrum sharing for 5G

Echostar pushes alternative approach to high-band spectrum sharing

Verizon promises to work with satellite industry on potential interference issues in 28 GHz band