AUCTION OF FLEXIBLE-USE SERVICE LICENSES IN THE 3.45-3.55 GHz BAND FOR NEXT- GENERATION WIRELESS SERVICES NOTICE AND FILING REQUIREMENTS, MINIMUM OPENING BIDS, UPFRONT PAYMENTS, AND OTHER PROCEDURES FOR AUCTION 110 BIDDING IN AUCTION 110 SCHEDULED TO BEGIN OCTOBER 5, 2021; RELEASED: JUNE 9, 2021; AU DOCKET 21-62