Marine and mobile radio telephony
The mobile maritime mobile service is as defined by the International Telecommunication Union, a mobile service between coast stations and ship stations, or between ship stations, or between associated stations for radio communications on board; Rescue device radio stations and emergency position -indicating radio beacons of may also participate in this radio service.
- 4.1 Emergency
- 4.2 urgency
- 4.3 Security
- 4.4 routine
History
The marine radio is the oldest application of radio communication and was regulated early internationally. For the shipping was the opportunity to interact with other ships or in connection with the country by radio, since the invention of great importance.
Although the telegraphy on land has long been known and ashore telephony was available already partly consisted of radio traffic 1900 exclusively of messages that have been transmitted by means of the Morse alphabet in Tastfunkverfahren. For the first time in the history of seafaring ships could occur at sea via the optical point of view also connected to each other to announce their arrival or to call for help. After the sinking of the RMS Titanic in 1912, the radio traffic was revised at sea: Immediately worldwide interception was mandatory for all ships on the medium wave frequency 500 kHz. The new emergency signal was SOS ( · · · --- · · · ). Messages that did not serve the calls or the sharing of flares could be sparked only beyond this frequency.
With advent of Sprechfunkes at sea, the communication has been greatly simplified and accelerated. Thus, the SOS emergency call sign was replaced by Morse through the emergency characters MAYDAY on VHF channel 16. The monitoring is mandatory until today.
DSC -capable devices have always automatically turned on the VHF channel 70. In this emergency calls can be received with position information digitally.
The international legal foundations of marine radio are defined in the SOLAS Convention ( International Convention for the Safety of Life at Sea ) and in the Radio Regulations for the radio service, which complements the Constitution and Convention of the International Telecommunication Union.
Frequency bands
The maritime mobile service are assigned frequency bands at very high frequency ( VHF ), medium wave (MW), SSB (GW ) and short wave (KW). In the UHF range are also some frequencies for the radio traffic available on board.
Medium wave (MW)
The frequencies of medium wave were used in Seefunkverkehr for communication by Morse / communication by Morse code. The frequency 500 kHz was the radio for emergency transport and SOS calls reserved. In the modern maritime world, in the recreational marine environment, this frequency range does not matter anymore.
On medium wave can be sparked with a range up to 1500 nautical miles.
Boundary wave (GW )
For radio communications on SSB the general operating certificate for radio operators (GOC ) and for the recreational marine radio the general operating certificate ( LRC) is prescribed as a radio license for commercial shipping.
In marginal wave can be far sparked with a range up to 150 nautical miles.
Short-wave ( CW )
For the radio traffic on shortwave radio operator for the general operating certificate (GOC ) and for the recreational marine radio the general operating certificate ( LRC) is prescribed as a radio license for commercial shipping.
In short shaft can be sparked with a global reach.
Very high frequency ( VHF )
The radio on the frequencies of the ultra-short wave today is still of great importance: the radio communications between ship stations located close to each other, between ship stations and coast stations near the coast and the radio traffic on the internal board radio is typically made about it. On FM can be sparked up to a distance of about 30 nm.
All shipping is obliged to inform the DSC channel 70 ever listen to FM.
For the radio traffic on VHF the limited valid operating certificate for radio operator (ROC ) and for the recreational marine environment the limited radio valid operating certificate ( SRC) is prescribed as a radio license for commercial shipping.
Operation of a ship station
The following requirements must be fulfilled in principle for the operation of a ship station:
Ranking of radio traffic
On one channel of the mobile maritime radio can always be handled at one time only one call. If there are several participants who want to use a channel, the participant will receive priority with the message of the highest ranking. Radio traffic is therefore divided into four classes:
Distress
An emergency is when human life is in danger and urgent help is needed. The aim of the radio communications in an emergency is that all ships in the vicinity immediately rush to help (assuming that they can afford help).
Example: man overboard, vessel sinks and must be left ship is unable to maneuver and threaten to smash solo sailor is seriously injured and threatens to bleed to death.
Urgency
Urgency exists when the safety of a person or a ship is in danger. Target of an emergency call is to get fast targeted assistance.
Example: Ship licks and is unable to maneuver, fire on board, does not affect the buoyancy of the ship in the near future, injured person on board.
Security
A security message is a message to warn the shipping from danger. Goal of safety messages is to preemptively avoid any risks at sea.
For example, storm warning, notification of extinct beacon message about a new wreck.
Routine
The routine traffic includes all radio traffic that does not fit into the other categories.
Example: ship transmits a pilot on, ship announces its arrival in the port where two sailors arrange to meet for dinner.
Importance of the mobile maritime radio today
Although the mobile maritime mobile service is its basic structure for over one hundred years and numerous technical improvements and additions are available, he has lost in any case important.
With the introduction of Digital Selective Calling the constant listening watch is eliminated. If another ship in distress, this can automatically send a distress call with its position information. From a ship that could potentially help the cry for help is taken automatically and the ship's officers alerted.
Indispensable is the maritime mobile Mobile to alert other ships on their duty evasion.
An important advantage of the mobile maritime radio is independence. Two ship stations can fully come into contact with each other. Furthermore, any equipment on land or at sea required to enable a communication. Thus, the maritime mobile service Mobile works well in areas of conflict or natural disasters, as opposed to calling with mobile phones.