Mobile maritime service

from Wikipedia, the free encyclopedia
Radio room on the German research vessel Polarstern (2007)

The Mobile maritime mobile service ( English 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 traffic on board; Rescue equipment radio stations and radio beacons for marking the emergency position may also participate in this radio service.

The VO Funk categorizes this radio service as follows:

history

Marine radio station of a freighter around 1922
Old VHF radio of the brand "Sailor", VHF radio telephone, type RT144B
VHF radio with DSC

Marine radio is one of the oldest applications of radio communication and was regulated internationally at an early stage. For shipping, the ability to connect to other ships or to land by radio has been of great importance since the invention.

Although telegraphy had been known on land for a long time and telephony was already partly available on land , from 1900 radio traffic consisted exclusively of messages that were transmitted with the help of Morse code via radio telegraphy (tactile radio). For the first time in the history of seafaring, ships at sea were able to communicate with one another beyond the visual point of view, to announce their arrival or to call for help.

As the first radio telegraphic emergency signal ( FT emergency call ) in the history of seafaring , the British Marconi Company initially defined the letter group CQD (Morse code: - • - • −− • - - •• ) in 1904 . The more conspicuous SOS ( ••• −−− ••• ) was only officially introduced as a distress signal on July 1, 1908, after confirmation by all seafaring nations . The USA did not recognize the new SOS symbol until 1912.

After the sinking of the RMS  Titanic in April 1912, radio traffic at sea was re-regulated: From now on, all ships at sea were obliged to listen around the clock on the emergency frequency of 500 kHz on medium wave . Messages that were not used to call or to transmit emergency signals were only allowed to be transmitted beyond this frequency.

With the advent of radio communication at sea, communication was considerably simplified and accelerated. As a result, the emergency call sign SOS was replaced by the emergency call sign MAYDAY on VHF channel 16 and MF / HF. It is still mandatory to listen to VHF channel 16 today; it was replaced by an obligation for border and shortwave and supplemented for VHF to operate a DSC watch receiver .

DSC-capable VHF marine radio systems always have VHF channel 70 switched on automatically. On this digital emergency calls with position information can be received and, if necessary, sent. In the case of DSC-capable medium, border and short wave systems, an integrated watch receiver continuously monitors the DSC alarm frequencies and, if necessary, additional DSC frequencies for routine calls in the medium and short wave range.

The international legal foundations of maritime radio are set out in the SOLAS Convention (International Convention for the Safety of Life at Sea) and in the Implementing Regulations for the Radio Service , which supplement the Constitution and Convention of the International Telecommunication Union .

The messages for marine radio stations appeared until 2001 .

Frequency bands

Frequency bands on ultra-short wave (VHF), medium wave (MW), limit wave (GW) and short wave (KW) are assigned to the maritime radio service . In the UHF range, there are also some frequencies available for radio traffic on board.

Marine radio frequency bands
Area Frequency range
[kHz]		 DSC call Distress /
Urgency /
Security		 Emergency frequency Routine DSC call
towards		 Remarks
from to Radiotelephony telex ship country
MW 415, 0 526.5 - - - 455.5 458.5
GW   1605, 0 3800, 0 2187.5 2182, 0 2174.5 2177, 0 2189.5
KW HF04 4000, 0 4438, 0 4207.5 4125, 0 4177.5 4219.5 4208, 0
HF06 6200, 0 6525, 0 6312, 0 6215, 0 6268, 0 6331, 0 6312, 0
HF08 8100, 0 8815, 0 8414.5 8291, 0 8376, 0 8436.5 8415, 0
HF12 12230, 0 13200, 0 12577, 0 12290, 0 12520, 0 12657, 0 12577.5
HF16 16360, 0 17410, 0 16804.5 16420, 0 16895, 0 16903, 0 16805, 0
HF18 18780, 0 18900, 0 - - - - 18898.5
19680, 0 19800, 0 - - - 19703.5 -
HF22 22000, 0 22855, 0 - - - 22444, 0 22374.5
23000, 0 23200, 0 - - - - -
23350, 0 24000, 0 - - - - -
HF26 25010, 0 25550, 0 - - - - 25208.5
26100, 0 26175, 0 - - - 26121, 0 -
26175, 0 27500, 0 - - - - - (including ISM tape )
VHF 156000, 0 162000, 0 156525 (channel 70), 0
 156800 (channel 16), 0
 - Channel 70 Channel 70
UHF 457512.5 457587.5 only radio traffic on board
467512.5 467587.5

For the HF bands, two additional DSC frequency pairs 0.5 and 1 kHz higher are available for routine calls between ships and land radio stations on an international basis; on border and short wave, coast stations can be assigned further DSC frequencies for routine calls on a national basis, which are to be used preferentially for national calls; see e.g. B. Lyngby Radio .

Medium wave (MW)

The frequencies of the medium wave were used in maritime radio traffic for communication by tactile radio / communication by Morse code . The frequency of 500 kHz was reserved for radio for emergency traffic and SOS calls. In modern seafaring as well as in recreational shipping, this frequency range no longer plays a role for ship-to-ship and land traffic. However, the frequencies 490 kHz and 518 kHz are used by NAVTEX for land-to-ship telex broadcasts for emergency and safety traffic, which is mandatory for ships that require equipment and recommended for all others.

Medium waves can be used with a range of up to 1500  nautical miles .

Limit wave (GW)

For radio traffic on SSB is for commercial shipping , the general operating certificate for radio operator ( GOC ) and for the recreational marine environment the general Range Certificate ( LRC ) prescribed as a radio license.

During the day, Grenzwelle can be used with a range of up to 150 nautical miles and after dusk with a range of over 2000 nautical miles.

Short wave (KW)

For wireless communications on shortwave is for commercial shipping , the general operating certificate for radio operator ( GOC ) and for the recreational marine environment the general Range Certificate ( LRC ) prescribed as a radio license.

Shortwave can be used with worldwide coverage.

Ultra short wave (VHF)

VHF radio station for radio traffic on board , a low-power mobile radio station of the mobile maritime radio service .

The radio on the frequencies of the ultra-short wave is still of great importance today: The radio traffic between marine radio stations located close together , between marine radio stations and coastal radio stations near the coast as well as the radio traffic of the internal on-board radio are usually handled via it. VHF can be used up to a distance of approximately 30 nautical miles.

The entire shipping industry is obliged to constantly monitor DSC channel 70 on VHF .

For radio traffic on VHF for the professional shipping the limited valid operating certificate for radio operator ( ROC ) and for recreational boating, the limited valid Range Certificate ( SRC ) prescribed as a radio license.

Decimeter wave (UHF)

In the UHF range, the mobile maritime service is allocated five channels in a 12.5 kHz grid or three channels in a 25 kHz grid on two 75 kHz wide frequency bands. They may only be used for radio communications on board with a low transmission power. This results in 2 times 5 (instead of 6) channels with a width of 12.5 kHz, because the center frequencies of the 25 kHz channels are also used. The center frequencies are specified in note D287 of the frequency usage plan or in the general allocation of frequencies to marine radio.

Operation of a marine radio station

The following prerequisites have to be met for the operation of a marine radio station :

  1. Until May 31, 2013 the frequency and call sign assignment in Germany ( frequency allocation certificate ). The frequencies have been generally allocated since June 1, 2013, only one call sign allocation ("number allocation") is carried out by the Federal Network Agency with the issue of a number allocation certificate
  2. Radio equipment approved for marine radio (in Germany by the Federal Maritime and Hydrographic Agency )
  3. Adequate radio operating certificate from the operator

Priority of radio traffic

Only one call can be handled at a time on a channel of the mobile maritime radio service . If there are several participants who want to use a channel, the participant with the message of the highest ranking gets priority. Radio traffic is therefore divided into four classes:

  1. Need
  2. urgency
  3. safety
  4. routine

Need

An emergency occurs when human life is in danger and help is urgently needed. The aim of radio communications in an emergency is that all ships in the area rush to help immediately, provided that they can provide help.

Example: Man overboard , ship sinks and has to be abandoned, ship is unable to maneuver and threatens to be smashed, single-handed sailor is seriously injured and threatens to bleed to death.

urgency

Urgency exists when the safety of a person or a ship is at risk. The aim of an emergency call is to get targeted help quickly.

Example: The ship is leaking and unable to maneuver, a fire on board that will not affect the ship's ability to swim in the near future, an injured person on board.

safety

A safety message is a message that is intended to warn shipping of dangers. The aim of safety notifications is to prevent dangers at sea.

Example: storm warning, message about an extinguished beacon, message about a new wreck.

routine

Routine traffic includes any radio traffic that does not fit into any of the other categories.

Example: the ship telephones a pilot, the ship announces its arrival in port, two sailors arrange to meet for dinner together.

Historical scheme

Before the introduction of the GMDSS , the traffic in the international maritime service was ranked as follows:

  1. Emergency calls, notifications and emergency traffic
  2. Traffic initiated with the emergency signal
  3. Traffic initiated with the safety sign
  4. Traffic affecting radio bearings
  5. Traffic that affects the navigation and flight safety of aircraft involved in search and rescue operations
  6. Traffic that affects navigation, travel or flight safety and the needs of sea and air vehicles; as well as weather observation reports for an official weather service
  7. ETATPRIORITE - Radiotelegrams related to the application of the United Nations Charter
  8. ETATPRIORITE - radio telegrams, state radio telegrams with priority as well as state radio calls and state radio letters for which priority has been expressly requested
  9. Business traffic that affects the perception of the telecommunications service or the traffic that has already been processed
  10. State radio telegrams (== ETAT ==), state radio calls with priority and state radio calls with the exception of those mentioned under 8, as well as normal private radio telegrams, radio calls and radio telex; RCT radio telegrams
  11. Marine correspondence

In any case, all news concerning the safety of human life at sea, on land, in the air and outside the atmosphere , as well as the extremely urgent epidemic news from the World Health Organization, had absolute priority.

Importance of the mobile maritime radio service today

Although the basic structure of the mobile marine radio service has existed for over a hundred years and numerous technical improvements and additions are available, it has never lost its importance.

The introduction of Digital Selective Calling simplifies eavesdropping. If another ship is in distress, it can send a call for help with its position information at the push of a button. The call for help is automatically picked up by a ship that could possibly help and the ship's command on watch is informed.

The mobile marine radio service is indispensable for B. for area and port calls or to inform other ships of their evasion obligation.

The automatic identification system AIS , which operates on VHF marine radio frequencies, is a navigation aid for ships among each other, in order to expand the information for the navigator obtained via RADAR using ARPA . With regard to AIS, equipment is now mandatory for most ships.

An important advantage of the mobile marine radio service is independence. Two marine radio stations can have unlimited contact with each other. Furthermore, no infrastructure on land or at sea is required to enable communication, which is in contrast to telephony with cell phones . This is how the mobile maritime radio service works in crisis areas or during natural disasters.

See also

literature

  • Karl-Heinz Hochhaus: Information and communication in shipping . In: Hansa , Heft 4/2012, pp. 36-38, Schiffahrts-Verlag Hansa, Hamburg 2012, ISSN 0017-7504  
  • Frequency plan of the Federal Network Agency

Web links

Individual evidence

  1. ↑ VO Funk, 2012 edition, Article 1.28.
  2. ↑ Bernd Januschke, Karl-Friedrich Warner: 1900–1909. The new century . In: Chronicle of the 20th Century , 1983. p. 96.
  3. ↑ Saved by wireless ( memento from August 20, 2016 in the Internet Archive ) on eandt.theiet.org from April 21, 2009.
  4. ↑ Hörwache, Kanal 16 on DP07.com, accessed on September 17, 2015.
  5. ↑ Gerd Heidbrink, radio traffic on board of yachts, Bonn 2013, ISBN 978-3-00-033638-6
  6. ↑ Recommendation ITU-R M.541-10 Operational procedures for the use of digital selective calling equipment in the maritime mobile service. (pdf) Annex 6 Frequencies used for digital selective calling. ITU-R , October 2015, accessed January 28, 2020 .
  7. ↑ a b c General assignment of frequencies for mobile radio applications for maritime and inland navigation radio. (pdf) Federal Network Agency , March 15, 2017, accessed on January 25, 2020 .
  8. ^ Andreas Braun, LRC, 3rd edition, DSV-Verlag 2011.
  9. ↑ a b Frequency plan of the Federal Network Agency ( Memento from January 31, 2016 in the Internet Archive )
  10. ^ BNetzA: Numbering maritime radio / inland waterway radio
  11. ↑ Section 13, Paragraph 2 of the Maritime Radio Manual, Deutsche Bundespost TELEKOM, 5th edition, 1990, p. 49.
  12. ↑ § 13, Paragraph 1, Manual of Maritime Radio, Deutsche Bundespost TELEKOM, 5th edition, 1990, p. 49.