Main Categories

The present document specifies technical characteristics and methods of measurements for the following equipment 
used in ground-based ATC Surveillance for civil air navigation: 
• Wide Area Multilateration (WAM) systems with Mode S capabilities which may include Mode A/C, 
transmitting at 1 030 MHz and at 1 090 MHz, and receiving at 1 090 MHz, used for air traffic control with or 
without 1 090 MHz phase overlay. 
The system operates in the frequencies as indicated in Table 1 below. 
Table 1: WAM service frequencies 
Signals Service frequencies
Interrogation Transmission 1 030 MHz 
Reference/Test Transmission 1 090 MHz 
Receive 1 090 MHz 
Antennas for this equipment are passive. 
Remote Field Monitors (RFM) as described in [i.6] as well as Vehicle transmitters as described in [i.7] are not covered 
in the present document. 
NOTE: The relationship between the present document and essential requirements of article 3.2 of 
Directive 2014/53/EU [i.1] is given in Annex A.