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maritim radio

Maritime radio is the oldest commercially used mobile radio service. Even though it is nowhere near as important as modern mobile radio, trunked radio or wireless telephones, it should be mentioned here, even though satellite communications will soon make traditional marine radio a thing of the past.

The maritime radio service has existed for 100 years. As early as 1907, a marine radio station was established in Germany with the Norddeich radio. This service is used to transmit weather and ship news, time signals and navigation information, as well as emergency and private messages. The maritime radio service is an international radio service with worldwide subscribers. Internationally binding regulations are therefore necessary to ensure smooth cooperation between maritime and coastal radio stations in the various countries.

The marine radio system consists of telegraphic radio, voice radio and VHF voice radio. The latter transmits in the frequency range between 156.05 MHz and 157.425 MHz and receives between 160.650 MHz and 162.025 MHz. A total of 88 channels are available in a channel spacing of 50 kHz. Due to the curvature of the earth, frequency ranges had to be used for transmission in the design of the marine radio systems at that time whose waves, as ground waves or space waves, adapt to the curvature of the earth or enable worldwide reception by reflection from the ionosphere. Frequencies in the long-wave range embody the former property, while those in the short-wave range can be received worldwide by means of reflection. For these reasons, telegraphy, for example, operates in the long-wave range at 500 kHz.

Due to ship losses, a new maritime distress and safety system has been set up in recent years called "Global Maritime Distress and Safety System", or GMDSS for short. This system takes equal account of the transmission possibilities in the near-coastal range by means of VHF, distances that can still be reached via medium wave, and the satellite link to Inmarsat.

Englisch: maritim radio
Updated at: 19.11.2012
#Words: 311
Links: mobile radio, service, satellite communications (Satcom), arsenic (As), navigation (NAV)
Translations: DE

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