Maritime broadcast communications net
Encyclopedia
In telecommunication
, a maritime broadcast communications net is 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).
Telecommunication
Telecommunication is the transmission of information over significant distances to communicate. In earlier times, telecommunications involved the use of visual signals, such as beacons, smoke signals, semaphore telegraphs, signal flags, and optical heliographs, or audio messages via coded...
, a maritime broadcast communications net is a communications net that is used for international distress calling, including international lifeboat, lifecraft, and survival-craft high frequency
High frequency
High frequency radio frequencies are between 3 and 30 MHz. Also known as the decameter band or decameter wave as the wavelengths range from one to ten decameters . Frequencies immediately below HF are denoted Medium-frequency , and the next higher frequencies are known as Very high frequency...
(HF); aeronautical emergency very high frequency
Very high frequency
Very high frequency is the radio frequency range from 30 MHz to 300 MHz. Frequencies immediately below VHF are denoted High frequency , and the next higher frequencies are known as Ultra high frequency...
(VHF); survival ultra high frequency
Ultra high frequency
Ultra-High Frequency designates the ITU Radio frequency range of electromagnetic waves between 300 MHz and 3 GHz , also known as the decimetre band or decimetre wave as the wavelengths range from one to ten decimetres...
(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
Medium frequency
Medium frequency refers to radio frequencies in the range of 300 kHz to 3 MHz. Part of this band is the medium wave AM broadcast band. The MF band is also known as the hectometer band or hectometer wave as the wavelengths range from ten down to one hectometers...
(MF) or at high frequency
High frequency
High frequency radio frequencies are between 3 and 30 MHz. Also known as the decameter band or decameter wave as the wavelengths range from one to ten decameters . Frequencies immediately below HF are denoted Medium-frequency , and the next higher frequencies are known as Very high frequency...
(HF).
See also
- Global Maritime Distress Safety SystemGlobal Maritime Distress Safety SystemThe Global Maritime Distress and Safety System is an internationally agreed-upon set of safety procedures, types of equipment, and communication protocols used to increase safety and make it easier to rescue distressed ships, boats and aircraft....
- Distress frequency
- 500 kHz