406 MHz Beacon Types

Cospas-Sarsat 406 MHz beacons have been developed for many different environments and for a variety of applications. Beacons designed for maritime use are generically referred to as EPIRBs (emergency position radio beacons), aviation beacons are referred to as ELTs (emergency locator transmitters) and beacons designed for use on land are known as PLBs (personal locator beacons). The encoded data transmitted by distress beacons provide SAR authorities with vital information concerning the vessel, aircraft and/or person in distress. Since each environment and/or application has different demands for information, Cospas-Sarsat has developed several beacon message protocols. Each protocol has strengths and weaknesses, and it is the responsibility of national administrations to select the protocols authorised for use within their jurisdiction.

Cospas-Sarsat has developed two major categories of beacon message protocols, User Protocols, and Location Protocols. User protocols provide for encoding the beacon identification and other important SAR information, but do not allow for encoding beacon position data. Whilst user protocols can be implemented using either the short message format or the long message format, location protocols are to be implemented only with the long message format. As the name implies Location protocols provide for encoding beacon position data as well as beacon identification data. Click here for an overview of the composition of long and short format messages.

Before a beacon is coded, the beacon manufacturer, the beacon owner, and/or the organisations responsible for coding the beacon should contact the appropriate national authorities to:

confirm that the beacon has been authorised for use within the applicable country;
confirm which message protocols should be used; and
any specific nationally assigned information that should be coded into the beacon (e.g. a serial number, if required by the protocol).

Administrations should not authorise coding options which are not currently allocated or permitted by the Cospas-Sarsat specification for 406 MHz beacons (see document C/S T.001 "Specification for Cospas-Sarsat 406 MHz Distress Beacons".