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League Counters Another Mimosa Move for 10 GHz Wireless Broadband Sharing


The ARRL has told several US House and Senate members that the 10 GHz band, where the Amateur and Amateur-Satellite services have allocations, is not a suitable choice to expand wireless broadband. Three Republican and three Democratic lawmakers wrote FCC Chairman Tom Wheeler on March 2, asking the Commission to “explore potential sharing opportunities within the 10 GHz band” to alleviate “the well-documented spectrum crunch.” The primary allocation of 10.0-10.5 GHz is for federal radiolocation, with Amateur Radio secondary in the entire band and Amateur-Satellite secondary at 10.45 to 10.50 GHz. The League pointed out that plans for additional sharing are already in the works.

“Based on extensive compatibility studies conducted during preparations for the 2015 World Radiocommunication Conference (WRC-15), additional sharing for an important scientific purpose is already planned,” ARRL CEO David Sumner, K1ZZ, pointed out in a March 4 letter to the Congress members. Sumner explained that several years of work went into an agreed-upon US proposal at WRC-15 for a primary allocation at 9.9 to 10.5 GHz for the Earth Exploration Satellite Service (active), “subject to appropriate protections for incumbent services.”

Sumner said the ARRL is satisfied that the Earth Exploration Satellite Service (active) “can be accommodated in the band without causing intolerable harmful interference to the Amateur Service,” while the same would not be true for wireless broadband. “Accordingly,” he concluded, “the ARRL opposes the introduction of wireless broadband into the 10 GHz band.”

“A request by a wireless broadband equipment manufacturer to permit broadband was considered but could not be accommodated,” Sumner added. That manufacturer, Mimosa Networks, filed a Petition for Rule Making (RM-11715) in 2013 that the FCC put out for comment last year, seeking the allocation of the band for what it has called “lightly licensed fixed wireless broadband use.” Mimosa’s petition included a band plan for 10.0 to 10.5 GHz that would cede to Amateur Radio and Amateur-Satellite users just two small segments of the present allocation. The company claimed its proposal would protect the 10 GHz frequencies most often used by radio amateurs. The FCC has not acted on the Petition.

Sumner noted that the FCC already has initiated a proceeding to identify spectrum above 24 GHz that can be designated for mobile wireless broadband, including additional spectrum that could be authorized on an unlicensed basis.

Democratic House members Doris Matsui and Anna Eshoo, both from California, and US Senator Cory Booker of New Jersey, joined Republican House members Brett Guthrie of Kentucky and Robert Latta of Ohio, and US Senator Marco Rubio of Florida in signing the March 2 letter to Wheeler.

“Sharing opportunities in the 10 GHz band could make more spectrum available and provide another avenue for consumers and innovators to tap into the Internet economy,” the lawmakers told Wheeler. Mimosa Networks expressed support for the lawmakers’ appeal in a March 3 media release.

In comments to the FCC last April, the ARRL told the FCC that Mimosa’s Petition to permit unlicensed wireless broadband services in the 10.0-10.5 GHz band was “fatally flawed” and should be dismissed. The League told the FCC that, among other things, the Mimosa Petition is inconsistent with a US footnote in the domestic Table of Allocations, and that fact alone is sufficient reason for the Commission to quash Mimosa’s request.

“Footnote US128 very clearly and without equivocation prohibits all non-federal services in the band 10-10.5 GHz except for the Amateur Service, the Amateur-Satellite Service, and the non-federal radiolocation service,” the ARRL said in its comments. The FCC “is not at liberty to ignore” the US footnote, the League said, and is obliged on that basis alone to dismiss the Petition, “because it hasn’t the authority to grant it.”