WASHINGTON — Intelsat, SES and Telesat on Oct. 28 acquiesced to demands for more spectrum, saying their group, the C-Band Alliance, would offer 300 megahertz of satellite spectrum to cellular operators for 5G services instead of 200 megahertz as previously planned.

The increase — to 280 usable megahertz plus a 20 megahertz guard band — follows pressure from a Federal Communications Commission official for more spectrum and a competing spectrum plan that called for 370 megahertz.

The FCC expects to decide this year on how to repurpose some or all of the 500 megahertz of C-band downlink spectrum satellite operators use in the U.S. mainly for satellite television and radio broadcasts.

Michael O’Rielly, the FCC’s most vocal commissioner on C-band, said in September that the U.S. needs at a minimum 300 megahertz of the coveted spectrum for 5G cellular services. ACA Connects, a trade association of 700 small and mid-size telecom providers, proposed in July, with cable giant Charter Communications and the Competitive Carriers Association as partners, an alternative to the satellite-operator plan that would repurpose 370 megahertz of C-band (350 usable megahertz and a 20 megahertz guard band).

The C-Band Alliance said Oct. 28 that it concluded clearing 300 megahertz is possible by accelerating the adoption of advanced signal compression technology and “related signal enhancements” for satellite broadcasters.

“Throughout this nearly two-year process, we have sought to work collaboratively as peers, to be responsive to the goals of U.S. policy makers seeking spectrum for 5G, and to work closely with our customers to protect their transmissions and understand their current and future network needs,” Intelsat CEO Stephen Spengler, speaking on behalf of the C-Band Alliance, said in a news release. “Over this time, compression technology has continued to commercialize. We are confident that we can deliver a solution that not only maximizes the clearing of mid-band spectrum to enable 5G in the U.S., but also fully funds a spectrally-efficient, next-generation compression infrastructure for programming distribution in the U.S.”

Spengler and SES CEO Steve Collar had in recent earnings calls acknowledged growing pressure for 300 megahertz, and highlighted High Efficiency Video Coding, or HEVC, as a means of broadcasting content with less capacity.

HEVC is still in its infancy, with much of its adoption linked to the growth of Ultra-HD channels. Ferdinand Kayser, the CEO of SES’s Video division, said during an Oct. 25 earnings call that only 4% of the company’s customers globally use HEVC.

The C-Band Alliance said that since its proposal includes covering all transition costs for broadcasters, shifting them to HEVC “merely accelerates those decision points” for broadcasters who would have been slower to adopt the technology. The alliance said it will also work with broadcasters to eliminate duplicate transmissions that are broadcast today in multiple video formats.

The increase to 300 megahertz is the second time the C-Band Alliance increased its proposal, having doubled it from 100 megahertz to 200 megahertz a year ago in October. The C-Band Alliance also reduced the size of its guard band to 20 megahertz, down from initial estimates of around 50 megahertz.

Selling 300 megahertz won’t increase the number of new satellites the C-Band Alliance says it needs to continue service beyond the eight it said were necessary if it lost 200 megahertz. Those eight satellites will still be purchased from U.S. satellite manufacturers, the C-Band Alliance said.

The C-Band Alliance estimates the cost of refitting the 120 million households and other customers it serves in C-band from 500 megahertz into just 200 megahertz will be $2.5 to $3.5 billion. That cost includes the new satellites, compression technology and signal filters needed to prevent interference from nearby 5G devices.

Under the revised plan, 100 megahertz of C-band would be cleared across 46 of the top metropolitan areas in the U.S. within 18 months of an FCC order. The full 280 megahertz would be available across the continental U.S. within 36 months, the C-Band Alliance said.