[A] procedure by which a distant crypto-equipment is rekeyed electrically, with specific actions required by the receiving terminal operator. [INFOSEC-99]

1. In communications systems, the maximum degree of signal distortion that can be tolerated without affecting the restitution, i.e., without its being interpreted incorrectly by the decision circuit.
2. The allowable error rate, deviation from normal, or degradation of the performance of, a system or device.

A coast station which makes scheduled broadcasts of time, meteorological, and hydrographic information. [NTIA]

A station in the maritime mobile service consisting of one or more hand-held radiotelephone units licensed under a single authorization. Each unit is capable of operation while being hand-carried by an individual.

Communications systems, procedures, operations, and equipment that are used for message traffic between aircraft stations and ship stations in the maritime service.
Note: Commercial, private, naval, and other ships are included in maritime air communications.

A communications net that is used for international distress calling, including international lifeboat, lifecraft, and survival-craft high-frequency (HF); aeronautical emergency very high-frequency (VHF); survival ultra high-frequency (UHF); international calling and safety very high-frequency (VHF); combined scene-of-search-and-rescue; and other similar and related purposes.
Note: Basic international distress calling is performed at either medium frequency (MF) or at high frequency (HF).

A mobile service between coast stations and ship stations, or between ship stations, or between associated on-board communication stations; survival craft stations and emergency position-indicating radiobeacon stations may also participate in this service. [NTIA] [RR]

A mobile-satellite service in which mobile Earth stations are located on board ships; survival craft stations and emergency position-indicating radiobeacon stations may also participate in this service. [NTIA] [RR]

A radionavigation service intended for the benefit and for the safe operation of ships. [NTIA] [RR]

A radionavigation-satellite service in which Earth stations are located on board ships. [NTIA] [RR]