NAVDAT
NAVDAT (abbreviation for Navigational Data ) is a standard developed between 2008 and 2010 by the French company KENTA for the radio transmission of maritime safety information (MSI) and information on hazard prevention in maritime shipping . NAVDAT can complement the NAVTEX operated for MSI transmission , with NAVDAT having a higher data rate than NAVTEX. The system properties of NAVDAT have been published by the International Telecommunication Union (ITU) as an open standard through the technical recommendations ITU-R M.2010 (medium wave system) and ITU-R M.2058 (short wave system). The International Maritime Organization (IMO) has not yet stipulated it for equipping ships.
Technical functionality
The NAVDAT transmission method is based on the Digital Radio Mondiale (DRM) standard and, like this, uses an OFDM method with an occupied bandwidth of 10 kHz. However, it does not provide audio reception, only data transmission. Similar to NAVTEX, NAVDAT uses time slots , but can not only send messages to all ships, but also address a group of ships or a single ship. Typical data transfer rates are between 12 kbit / s and 18 kbit / s. In addition to the medium wave range (frequencies between 495 kHz and 505 kHz), NAVDAT can also use the short wave range .