ASTERIX is surveillance data format which is being adopted by the world users community as the universal standard in this domain today.
ASTERIX is an extensible standard with a number of different categories, each of which deals with one particular kind of information.
These include target reports from surveillance sensors such as radars as well as processed information such as aircraft tracks and various system status messages.
Each system/sensor using the ASTERIX data format is assigned a unique identifier composed of two 8 bit values, the System Area Code (SAC) and the System Identification Code (SIC).
The ANSP selects the SIC, but the SAC is assigned globally to system operators by Eurocontrol (see external link).