§80.385. Frequencies for automated systems.
47 C.F.R. § 80.385
This section describes the carrier frequencies for the Automated Maritime Telecommunications System (AMTS) and for other automated multi-station systems.
Automated Maritime Telecommunications System (AMTS).
The Automated Maritime Communications System (AMTS) is an automated maritime telecommunications system.
The following carrier frequencies are available for assignment to public coast stations for public correspondence communications with ship stations and units on land. AMTS operations must not cause harmful interference to the U.S. Navy SPASUR system which operates in the band 216.880-217.080 MHz.
As listed in the table in this paragraph (a)(3), AMTS Areas (AMTSAs) are based on, and composed of one or more of, the U.S Department of Commerce's 172 Economic Areas (EAs). See 60 FR 13114 (March 10, 1995). In addition, the Commission shall treat Puerto Rico, the United States Virgin Islands, and the Gulf of Mexico as EA-like areas. The Gulf of Mexico EA extends from 12 nautical miles off the United States Gulf coast outward into the Gulf. See § 27.6(a)(2) of this chapter and 62 FR 9636. Maps of the EAs and AMTSAs are available for public inspection through the Federal Communications Commission's Reference Information Center. These maps and data are also available on the FCC website at www.fcc.gov/oet/info/maps/areas/. These maps and data are also available on the FCC Web site at www.fcc.gov/oet/info/maps/areas/. The Group A and B frequency pairs listed in the table in paragraph (a)(2) of this section are available for assignment to a single licensee in each of the AMTSAs listed in the table in this paragraph (a)(3). In addition to the listed EAs listed in the table in this paragraph (a)(3), each AMTSA also includes the adjacent waters under the jurisdiction of the United States.
Channels in the 219-220 MHz band are also used on a secondary, non-interference basis by amateur stations participating in digital message forwarding systems. Amateur stations may not cause harmful interference to AMTS operations and must accept any harmful interference from AMTS operation. Amateur stations within 80 km (50 miles) of an AMTS coast station must obtain written approval from the AMTS licensee prior to operating in the 219-220 MHz band. Amateur stations within 640 km (398 miles) of an AMTS coast station must notify the AMTS licensee in writing at least 30 days prior to initiation of operations in the 219-220 MHz band. All amateur stations must notify the American Radio Relay League in writing at least 30 days prior to initiation of operations in the 219-220 MHz band (ARRL, 225 Main St., Newington, CT 06111-1494).
Subject to the requirements of § 1.924 of this chapter, §§ 80.215(h), and 80.475(a), each AMTS geographic area licensee may place stations anywhere within its region without obtaining prior Commission approval provided:
The AMTS geographic area licensee must locate its stations at least 120 kilometers from the stations of co-channel site-based AMTS licensees. Shorter separations between such stations will be considered by the Commission on a case-by-case basis upon submission of a technical analysis indicating that at least 18 dB protection will be provided to a site-based licensee's predicted 38 dBu signal level contour. The site-based licensee's predicted 38 dBu signal level contour shall be calculated using the F(50, 50) field strength chart for Channels 7-13 in § 73.699 (Fig. 10) of this chapter, with a 9 dB correction for antenna height differential. The 18 dB protection to the site-based licensee's predicted 38 dBu signal level contour shall be calculated using the F(50, 10) field strength chart for Channels 7-13 in § 73.699 (Fig. 10a) of this chapter, with a 9 dB correction factor for antenna height differential.
The locations and/or technical parameters of the transmitters are such that individual coordination of the channel assignment(s) with a foreign administration, under applicable international agreements and rules in this part, is not required.
For any construction or alteration that would exceed the requirements of § 17.7 of this chapter, licensees must notify the appropriate Regional Office of the Federal Aviation Administration (FAA Form 7460-1) and file a request for antenna height clearance and obstruction marking and lighting specifications (FCC Form 854) with the FCC, Attn: Information Processing Branch, 1270 Fairfield Rd., Gettysburg, PA 17325-7245.
[Reserved]
Any recovered frequency blocks will revert automatically to the holder of the geographic area license within which such frequencies are included. Any frequency blocks recovered where there is no geographic area licensee will be retained by the Commission for future licensing.
Notes, amendments, and revision history
Amendments
[51 FR 31213, Sept. 2, 1986, as amended at 54 FR 29041, July 11, 1989; 56 FR 3783, Jan. 31, 1991; 57 FR 26780, June 16, 1992; 60 FR 15687, Mar. 27, 1995; 61 FR 46566, Sept. 4, 1996; 67 FR 48565, July 25, 2002; 69 FR 19948, Apr. 15, 2004; 69 FR 44471, July 26, 2004; 73 FR 4486, Jan. 25, 2008; 75 FR 10692, Mar. 9, 2010 ; 85 FR 64409, Oct. 13, 2020; 88 FR 21449, Apr. 10, 2023; 90 FR 57709, Dec. 12, 2025]
Authority
Authority: 47 U.S.C. 151-155, 301-609; 3 U.S.T. 3450, 3 U.S.T. 4726, 12 U.S.T. 2377.
Source
Source: 51 FR 31213, Sept. 2, 1986, unless otherwise noted.
Amendments
[51 FR 31213, Sept. 2, 1986, as amended at 54 FR 29041, July 11, 1989; 56 FR 3783, Jan. 31, 1991; 57 FR 26780, June 16, 1992; 60 FR 15687, Mar. 27, 1995; 61 FR 46566, Sept. 4, 1996; 67 FR 48565, July 25, 2002; 69 FR 19948, Apr. 15, 2004; 69 FR 44471, July 26, 2004; 73 FR 4486, Jan. 25, 2008; 75 FR 10692, Mar. 9, 2010 ; 85 FR 64409, Oct. 13, 2020; 88 FR 21449, Apr. 10, 2023; 90 FR 57709, Dec. 12, 2025]