Communication, Navigation and Surveillance

At the heart of air traffic management, Communications, Navigation and Surveillance (CNS) are essential technological systems, procedures and programs for air traffic controllers on the ground and pilots in the air. They facilitate the process of establishing where the aircraft is as well as when and how it plants to arrive at its destination.

In order to advance its air navigation service performance, CATS has modernized it CNS systems in accordance with Cambodian air navigation regulations and international standards and recommended practices of International Civil Aviation Organization (ICAO).


CATS’s air traffic control facilities are functioned with controller-pilot, air-ground Very High Frequency (VHF) radio and communication network systems which enable air traffic controllers (ATCOs) to establish radio contact with pilots flying in the whole airspace of Cambodia and communicate with other local and neighboring ATCOs.

Air Traffic Services Message Handling System (AMHS) is being used for ground-ground communication for the exchange of air traffic service messages such as flight plan, NOTAM, meteorological data, etc.


Navigation aids system, which consists of three Doppler Very High Frequency Omni-directional Radio Range (DVOR) and Distance Measuring Equipment (DME), supports ATCOs and pilots in navigating aircraft accurately on the intended flight path.

Performance Based Navigation (PBN), which was first introduced in Cambodia in 2013, is being used in navigating aircraft for en-route, arrival and landing at some air routes in Cambodian airspace and the three international airports (Phnom Penh, Siem Reap Angkor and Sihanouk). This contributes to the maximization of safety and efficient access to the airports.


Air traffic control facilities at CATS track the movement of aircraft with precise position, altitude and velocity from its surveillance system which is comprised of three Monopulse Secondary Surveillance Radars (MSSRs), three Automatic Dependent Surveillance - Broadcast (ADS-B) stations and two Multilateration (MLAT).

MSSRs are installed at the three main airports of Cambodia (Phnom Penh, Siem Reap Angkor and Sihanouk), which provide surveillance coverage of the entire airspace of Cambodia. ADS-B at Phnom Penh, Siem Reap Angkor and Stung Treng, and MLAT at Phnom Penh and Siem Reap Angkor provides supplementary tracking capability, increasing the reliability of the surveillance service.