Mobile marine service (ultra-short wave)

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Mobile marine service (ultra-short wave)
Frequency range 156 to 162 MHz
Range approx. 30 nm
Emergency / calling frequency Channel 16 / 156.800 MHz
DSC alarm frequency (Emergency / Urgency / Security) Channel 70 / 156.525 MHz
DSC routine calls to land Channel 70 / 156.525 MHz
DSC routine calls towards the ship Channel 70 / 156.525 MHz
Necessary radio operating certificate
Commercial shipping Restricted Operator's Certificate
Recreational boating Short Range Certificate

The mobile marine radio service on ultra-short wave is part of the mobile marine radio service , which is intended exclusively for radio traffic via ultra-short wave .

history

Until 1972 there were 28 channels in the mobile maritime service on ultra-short wave, each of which was assigned a fixed frequency. In 1972 it was possible to halve the frequency spacing of the channels through improved radio technology. This created the additional channels 60 - 88 between the frequencies of the existing channels.

Requirement for participation in the mobile marine radio service on VHF

In principle, every watercraft on sea lanes has the opportunity to participate in the mobile marine radio service on VHF.

Until May 31, 2013, the prerequisite for participation was a radio device approved for marine radio and a frequency allocation certificate . Since June 1, 2013, the frequencies for mobile radio applications for maritime and inland waterway radio have been generally allocated. The actual usage permit depends on the previous individual allocation of numbers in maritime and inland waterway radio such as call signs, Maritime Mobile Service Identity (MMSI) and / or Automatic Transmitter Identification System number ( ATIS number). The certificates already issued remain valid until an application is made to change the number allocation. An exchange of the existing certificates with new number assignment certificates is therefore not planned.

In addition, the skipper must be in possession of a sufficiently valid radio operating certificate . For wireless communications at sea on FM is for commercial shipping , the ROC and for recreational boating, the SRC prescribed as a radio license.

Ships that require equipment must participate in the mobile marine radio service on VHF.

The radio channels and their frequencies and types of modulation

The frequency range from 156 to 162 MHz on VHF is intended for the mobile maritime service. In this frequency range there are fixed frequencies on which radio can be broadcast. The individual channels have a fixed frequency and a fixed name. Some channels are prescribed for a specific use.

channel use Marine radio station Coastal radio station Ship-ship Simplex / duplex Public exchange of messages
60 156.025 160.625 D. X
01 156.050 160.650 D. X
61 156.075 160.675 D. X
02 156.100 160,700 D. X
62 156.125 160.725 D. X
03 156.150 160.750 D. X
63 156.175 160.775 D. X
04 156.200 160,800 D. X
64 156.225 160.825 D. X
05 156.250 160.850 D. X
65 156.275 160.875 D. X
06 international exclusively for ship-to-ship traffic 156.300 X S.
66 156.325 160.925 D. X
07 156.350 160,950 D. X
67 156.375 156.375 X S.
08 international exclusively for ship-to-ship traffic 156,400 X S.
68 156.425 156.425 S.
09 156.450 156.450 X S.
69 In Germany for recreational shipping 156.475 156.475 X S.
10 156,500 156,500 X S.
70 Digital selective calling for emergency, security and calls 156.525 156.525 -
11 156.550 156.550 S.
71 156.575 156.575 S.
12 156.600 156.600 S.
72 In Germany for sport shipping, internationally only for ship-to-ship traffic 156.625 X S.
13 156.650 156.650 X S.
73 156.675 156.675 X S.
14th 156.700 156.700 S.
74 156.725 156.725 S.
15th Radio traffic on board (max 1 W) 156.750 156.750 X S.
75 Radio traffic that only affects navigation. 156.775 S.
16 Distress, security and calls 156.800 156.800 S.
76 Radio traffic that only affects navigation. 156.825 S.
17th Radio traffic on board (max 1 W) 156.850 156.850 X S.
77 international exclusively for ship-to-ship traffic 156.875 X S.
18th 156.900 161,500 D. X
78 156.925 161.525 D. X
1078 156.925 X S.
2078 Use not permitted in Germany 161.525 X S.
19th 156.950 161.550 D. X
1019 156.950 X S.
2019 Use not permitted in Germany 161.550 X S.
79 156.975 161.575 D. X
1079 156.975 X S.
2079 Use not permitted in Germany 161.575 X S.
20th 157,000 161,600 D. X
1020 157,000 X S.
2020 Use not permitted in Germany 161,600 X S.
80 157.025 161.625 D. X
21st 157.050 161.650 D. X
81 157.075 161.675 D. X
22nd 157.100 161.700 D. X
82 157.125 161.725 D. X
23 157.150 161.750 D. X
83 157.175 161.775 D. X
24 157.200 161,800 D. X
84 157.225 161.825 D. X
25th 157.250 161.850 D. X
85 157.275 161.875 D. X
26th 157.300 161,900 D. X
86 157.325 161.925 D. X
27 157.350 161,950 D. X
87 157.375 S. X
28 157,400 162,000 D. X
88 157.425 X S.
AIS 1 Data transmission of the Automatic Identification System (AIS) 161.975 161.975 -
AIS 2 Data transmission of the Automatic Identification System (AIS) 162.025 162.025 -

Modulation type

In the case of the mobile maritime radio service on ultra-short wave, frequency or phase modulation ( F3E / G3E ) is used for voice radio ; this applies to all channels except 70, AIS1 and AIS2. G2B is used for DSC on channel 70 (an FSK-modulated subcarrier is phase-modulated to the VHF frequency). AIS uses GMSK .

Simplex and duplex

A distinction is made between simplex and duplex speech methods in the mobile marine radio service on ultra-short wave .

simplex

Simplex speech occurs on a single frequency. This means that only one radio station can speak while the other is listening. If both radio stations transmit at the same time, both radio stations hear nothing. Marine stations and coast stations use the same frequency. Calls on simplex channels can in principle be heard by all marine radio stations, which is why emergency channel 16 is also a simplex channel.

Duplex

With the duplex speech method, the respective radio stations (e.g. marine radio station and coast radio station) use two different frequencies that both belong to one channel. This procedure enables the coast station to communicate like with a telephone, one frequency is responsible for reception, the other frequency for transmission. With the duplex method, the radios of the marine radio stations (semi-duplex) automatically switch to the reception frequency of the coastal radio station (RX). The radio only switches to its own transmission frequency (TX) when the talk button is pressed. This procedure eliminates the need to switch between transmission and reception for the coast stations. In addition, the duplex method prevents marine radio stations from listening in on transmissions from other marine radio stations. Only the transmissions of the coast radio stations can in principle be overheard by everyone using the duplex method. Often, however, the coast station transmits what is received on its reception frequency on its transmission frequency.

General information for shipping, such as weather reports or navigational warnings, is also usually sent on duplex channels by coast stations. This means that you cannot be disturbed by ships that transmit on the same channel during transmission. Important information is announced on channel 16.

Range

The range of the ultrashort waves is limited by the horizon of electromagnetic wave propagation . This does not correspond to the optical horizon for visible light, since the refractive index of the earth's atmosphere for the VHF frequency range decreases with height above ground. In practice, this means that the range depends largely on the height of the antenna. Ships on which the antenna is attached as high as possible (professional ship, sailing yacht) can transmit to each other up to a range of approx. 30 nautical miles (approx. 56 kilometers). The range of digital selective calling is about twice as wide.

costs

There are private coastal radio stations that offer paid services. The most popular private provider of radio services in Germany is DP07 .

In addition, the issuing authority of the frequency allocation certificate (in Germany the Federal Network Agency ) has been requesting number allocation certificates ( Ship Station License ) since June 1, 2013 , which in the case of allocation by the Federal Network Agency is associated with annual contributions for the number allocation. The contributions are usually less than € 20 per year. One-time (processing) fees are also charged for issuing or changing a certificate, the amount of which is explained on the website of the Federal Network Agency, Marine Radio section.

scope of application

Due to the short range of VHF marine radio, the mobile marine radio service on ultra-short wave is mainly used in commercial shipping for on-board radio communications and radio communications with radio control centers, traffic control centers, the ship guidance radio service , pilots, ports and locks as well as radio communications with other ships in heavily traveled traffic areas.

In recreational shipping, the mobile marine radio service on ultra-short waves serves as an emergency call transmitter, as a source of information for weather and nautical warning messages, for contact with radio stations, ports and locks, but also for social communication.

Individual evidence

  1. ↑ Federal Network Agency: Maritime Radio / Inland Shipping Radio. Retrieved May 5, 2016 .
  2. ↑ General allocation of frequencies for mobile radio applications for maritime and inland waterway radio. (pdf) Federal Network Agency , March 15, 2017, accessed on January 25, 2020 .
  3. ↑ Notes on VHF radio sets of the maritime radio service, BNetzA 224-15. (pdf) Federal Network Agency , May 3, 2017, accessed on January 25, 2020 .
  4. ↑ ITU: RECOMMENDATION ITU-R M.493-11: Digital selective-calling system for use in the maritime mobile service. ITU 2004
  5. ↑ ITU Recommendation ITU-R M1371.5, Technical characteristics for an automatic identification system using time division multiple access in the VHF maritime mobile frequency band. ITU 2014
  6. ↑ Recommendation ITU-R P.453-9: The radio refractive index: its formula and refractivity data , ITU 2003