USA - Upper C-Band (3.98-4.2 GHz); Expanding Flexible Use of the 3.7 to 4.2 GHz Band

The Federal Communications Commission (FCC) has adopted rules to make 160 MHz of additional C-band spectrum (3.98-4.2 GHz) available for terrestrial wireless services, creating a unified 3.7 GHz Service and establishing procedures for a future spectrum auction. 

The rules generally extend the existing Lower C-band framework to the Upper C-band while introducing enhanced performance requirements and measures to ensure coexistence with radio altimeters, including reimbursement obligations for satellite operators and rebate programs for eligible aircraft owners and operators. 

Most provisions take effect on September 29, 2026, while certain sections containing information collection requirements will become effective only after approval by the Office of Management and Budget (OMB) and publication of a subsequent Federal Register notice.​