This section describes the carrier frequencies for the Automated Maritime Telecommunications System (AMTS) and for other automated multi-station systems.

1. (a) Automated Maritime Telecommunications System (AMTS).

   1. (1) The Automated Maritime Communications System (AMTS) is an automated maritime telecommunications system.

   2. (2) 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.

      Channel No.	Carrier frequency (MHz)
      Shiptransmit 1 3	Coast transmit 2	Group
      101		216.0125	D
      102		216.0375
      103		216.0625
      104		216.0875
      105		216.1125
      106		216.1375
      107		216.1625
      108		216.1875
      109		216.2125
      110		216.2375
      111		216.2625
      112		216.2875
      113		216.3125
      114		216.3375
      115		216.3625
      116		216.3875
      117		216.4125
      118		216.4375
      119		216.4625
      120		216.4875
      121		216.5125	C
      122		216.5375
      123		216.5625
      124		216.5875
      125		216.6125
      126		216.6375
      127		216.6625
      128		216.6875
      129		216.7125
      130		216.7375
      131		216.7625
      132		216.7875
      133		216.8125
      134		216.8375
      135		216.8625
      136		216.8875
      137		216.9125
      138		216.9375
      139		216.9625
      140		216.9875
      141	219.0125	217.0125	B
      142	219.0375	217.0375
      143	219.0625	217.0625
      144	219.0875	217.0875
      145	219.1125	217.1125
      146	219.1375	217.1375
      147	219.1625	217.1625
      148	219.1875	217.1875
      149	219.2125	217.2125
      150	219.2375	217.2375
      151	219.2625	217.2625
      152	219.2875	217.2875
      153	219.3125	217.3125
      154	219.3375	217.3375
      155	219.3625	217.3625
      156	219.3875	217.3875
      157	219.4125	217.4125
      158	219.4375	217.4375
      159	219.4625	217.4625
      160	219.4875	217.4875
      161	219.5125	217.5125	A
      162	219.5375	217.5375
      163	219.5625	217.5625
      164	219.5875	217.5875
      165	219.6125	217.6125
      166	219.6375	217.6375
      167	219.6625	217.6625
      168	219.6875	217.6875
      169	219.7125	217.7125
      170	219.7375	217.7375
      171	219.7625	217.7625
      172	219.7875	217.7875
      173	219.8125	217.8125
      174	219.8375	217.8375
      175	219.8625	217.8625
      176	219.8875	217.8875
      177	219.9125	217.9125
      178	219.9375	217.9375
      179	219.9625	217.9625
      180	219.9875	217.9875
      1 Ship transmit frequencies in Groups C and D are not authorized for AMTS use.
      2 Coast station operation on frequencies in Groups C and D are not currently assignable and are shared on a secondary basis with the Low Power Radio Service in part 95 of this chapter. Frequencies in the band 216.750-217.000 MHz band are available for low power point-to-point network control communications by AMTS coast stations under the Low Power Radio Service (LPRS). LPRS operations are subject to the conditions that no harmful interference is caused to the United States Navy's SPASUR radar system (216.88-217.08 MHz) or to TV reception within the Grade B contour of any TV channel 13 station or within the 68 dBu predicted contour of any low power TV or TV translator station operating on channel 13.
      3 Ship transmit frequencies in Groups A and B are permitted to provide mobile-to-mobile communications where the written consent of all affected licensees is obtained.

   3. (3) 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.

      AMTS areas (AMTSAs)

      AMTSAs	EAs
      1 (Northern Atlantic)	1-5, 10 9, 11-23, 25, 42, 46
      2 (Mid-Atlantic)	24, 26-34, 37, 38, 40, 41, 174
      3 (Southern Atlantic)	35, 36, 39, 43-45, 47-53, 67-107, 113, 116-120, 122-125, 127, 130-134, 176 6-8, 54-66, 108, 109
      4 (Mississippi River)	160-165 147, 166-170
      5 (Great Lakes)	172
      6 (Southern Pacific)	171 110-112, 114-115, 121, 126, 128, 129, 135-146, 148-159
      7 (Northern Pacific)
      8 (Hawaii)
      9 (Alaska)
      10 (Mountain)

   4. (4) 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).

2. (b) 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:

   1. (1) 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.
   2. (2) 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.
   3. (3) 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.
   4. (4) [Reserved]
3. (c) 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.

[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]