Sec. 80.1183  Remote control for maneuvering or navigation.

    (a) An on-board station may be used for remote control of 
maneuvering or navigation control systems aboard the same ship or, where 
that ship is towing a second ship, aboard the towed ship.
    (b) The remote control system transmissions must contain a 
synchronization signal and a message signal composed of a documentation 
number group, a company control group, an actuation instruction group, 
and a termination of transmission group.
    (1) The synchronization signal must be the control character 
``SYN'', transmitted twice.
    (2) The message signal is composed of the following groups:
    (i) The documentation number group must be transmitted once and be 
the ship's U.S. Coast Guard documentation number or, if the ship is not 
documented, the call sign of the on-board station.
    (ii) The company control group, composed of three letters taken from 
AAA through ZZZ, which must be transmitted one time.
    (iiii) The actuation instruction group, composed of two letters 
taken from AA through ZZ, which must be transmitted one time.
    (iv) The termination of transmission group, composed of the control 
character ``EM'', which must be transmitted twice.
    (c) The receiving system must:
    (1) Reject any actuation instruction until it recognizes and accepts 
the company control group.
    (2) Reject any company control group until it recognizes and accepts 
the documentation number group.
    (d) The emission employed must be G2D. The provisions applicable to 
G3E emission are also applicable to G2D emission.
    (e) The binary information must be applied to the carrier as 
frequency-shift keying (FSK) of the standard tones 1070 and 1270 Hz. 
``0'' (low) must correspond to 1070 Hz and ``1'' (high) must correspond 
to 1270 Hz. The signalling rate must be 300 bits per second.
    (f) The alphabet employed must be the United States of America 
Standard Code for Information Interchange (USASCII), contained in the 
United States of America Standards Institute publication USAS X3.4-1968.
    (1) The bit sequence must be least significant bit first to most 
significant bit (bit 1 through 7), consecutively.
    (2) The character structure must consist of 8 bits (seven bits plus 
one character parity bit) having equal time intervals.
    (3) ``Odd'' parity is required.

                        Mobile-Satellite Stations