Section 90.685 - Authorization, construction and implementation of EA licenses(a) EA licenses in the 809-824/854-869 MHz band will be issued for a term not to exceed ten years.(b) EA licensees in the 809-824/854-869 MHz band must, within three years of the grant of their initial license, construct and place into operation a sufficient number of base stations to provide coverage to at least one-third of the population of its EA-based service area. Further, each EA licensee must provide coverage to at least two-thirds of the population of the EA-based service area within five years of the grant of their initial license. EA-based licensees may, in the alternative, provide substantial service to their markets within five years of the grant of their initial license. Substantial service shall be defined as: "Service which is sound, favorable, and substantially above a level of mediocre service."(c)Channel use requirement. In addition to the population coverage requirements described in this section, we will require EA licensees in Channel blocks A, B and C in the 816-821/861-866 MHz band to construct 50 percent of the total channels included in their spectrum block in at least one location in their respective EA-based service area within three years of initial license grant and to retain such channel usage for the remainder of the construction period.(d) An EA licensee's failure to meet the population coverage requirements of paragraphs (b) and (c) of this section, will result in forfeiture of the entire EA license. Forfeiture of the EA license, however, would not result in the loss of any constructed facilities authorized to the licensee prior to the date of the commencement of the auction for the EA licenses.(e) EA licensees operating on channels listed in § 90.614(b) and (c) must implement an Enhanced Specialized Mobile Radio (ESMR) system-as defined in § 90.7 -on their EA license and any associated site-based licenses prior to the expiration date of the EA license. EA licensees operating on these channels shall follow the construction notification procedures set forth in § 1.946(d) of this chapter. Failure to implement an ESMR system on their EA and site-based licenses before the expiration date of the EA license will result in termination of the EA license and any associated site-based licenses pursuant to § 1.946(c) of this chapter.62 FR 41216, July 31, 1997, as amended at 69 FR 67852 , Nov. 22, 2004; 70 FR 6760 , Feb. 8, 2005; 70 FR 76712 , Dec. 28, 2005; 82 FR 41548 , Sept. 1, 2017