Communications, navigation and surveillance

At the heart of the air traffic management network.


Communications, navigation and surveillance (CNS) infrastructure, and the radio spectrum they require, are the foundation of the aviation operational performance, enabling airspace capacity. Without them air transport would not exist.

At EUROCONTROL, we work to enhance the resilience of the CNS infrastructure to deliver safe, secure, predictable, efficient and sustainable operations that improve the European’s network performance.

We are expanding our CNS monitoring capabilities in order to develop a system-wide view that will help detect and predict CNS problems as well as collect the best information to determine their root causes and cost-effective solutions. Our integrated performance–based approach to CNS combines satellite, ground and airborne solutions that can deliver resilient CNS aviation solutions at reduced cost.

We are fostering improved decision-making mechanisms to better meet future CNS challenges. We work closely with stakeholders to translate civil and military requirements into CNS solutions. In addition, we deliver pan-European services and international specifications and guidelines, ensuring the global interoperability of the CNS infrastructure.

CNS infrastructure overview

Delays caused by CNS infrastructure
June 2024
Annual CNS infrastructure costs
CNS infrastructure implementation progress

Global Navigation Satellite System (GNSS)

The map shows the GNSS operational status across the network. It shows a monthly average of the GNSS position information quality derived from aircraft ADS-B reports. The PIC (Position Integrity Category) provides the containment radius of the aircraft horizontal position with 99.999% probability. The most common cause for a low PIC reported by multiple aircraft in the same region is radio frequency interference

Show map

PBN Procedures

Performance based navigation (PBN) is a key enabler for increasing efficiency, reducing environmental impact, increasing capacity and improving airport access. Our role is to support the implementation of PBN by providing our technical expertise to improve legislation, ensuring common PBN application and a robust infrastructure, while raising awareness of its benefits. The map illustrates implementation status and plans for PBN final approach procedures with vertical guidance at European airports. According to PBN regulation EU 2018/1048 every instrument runway is required to have approaches with vertical guidance by January 2024 (both LNAV/VNAV and LPV).

More info Show map

8.33 kHz conversion rate

Controller-pilot voice communication radios supporting very-high-frequency (VHF) 8.33-kHz channel spacing were introduced in Europe in order to alleviate frequency congestion. The map shows the percentage of voice frequencies converted to 8.33-kHz channel spacing for each European State. At EUROCONTROL, we are coordinating and supporting the implementation of voice communications using 8.33-kHz channel spacing. By increasing the number of radio channels, we make room for the channels required to optimise air traffic services.

More info Show map

Maximum number of Mode S replies/second

Over-interrogation of aircraft transponders by ground-based surveillance Mode S interrogators and ACAS-equipped aircraft may result in loss of surveillance – a serious safety risk. The map shows the peaks in Mode S reply rates (total or long – use selector in top left) per minute for aircraft recorded by the ground based 1030/1090MHz monitoring network – EMIT (European Monitoring of Interrogators and Transponders). In red, purple and blue are locations where the Mode S reply rates exceed the transponder reply capabilities specified in equipment standards. At EUROCONTROL, we are monitoring the surveillance radio frequency environment in order to ensure the safety and efficiency of Europe's ATM Network.

More info Show map

ADS-B equipage density

At EUROCONTROL, we are monitoring and investigating aircraft equipage rates, performance metrics and surveillance avionic anomalies. As Network Manager, we can use our monitored aircraft equipage and flight data to compare the proportion of flights equipped with ADS-B v2 with the total number of flights for a specific airspace (one cell on the map). Applying a holistic approach to surveillance equipage monitoring makes this monitoring process more efficient and significantly more cost-effective for our Member States and stakeholders.

More info Show map

Ground ADS-B implementation and operations

At EUROCONTROL, our ADS-B activity supports our stakeholders in a comprehensive end-to-end approach. We address ground, airborne and space-based ADS-B aspects in all lifecycle phases from research and development, through implementation to operations and post-ops. We are monitoring the continuous progress of ADS-B implementation and operations by European ANSPs.

Further growth of ADS-B ground operations is expected in the next years.

More info Show map

Frequency congestion

The radio frequency spectrum available for communications, navigation and surveillance is limited and in great demand. Frequency congestion makes it difficult to find suitable radio frequencies for new CNS systems. The map shows the number of VHF voice channels available for a new control sector in each geographical location (i.e. the number of 8.33-kHz channels available for a typical ACC frequency assignment). At EUROCONTROL, we are working to optimise the way in which we use this scarce resource in order to ensure that operations are safe and efficient.

More info Show map

DME/DME redundancy map

In cases where GPS is not available, the main fallback is the distance measuring equipment (DME/DME) service. In the event of outages, a lack of redundancy can adversely affect routing and efficiency across Europe's ATM network. To mitigate this risk, we monitor the performance of the services provided by the navigation aid infrastructure and share our findings with stakeholders in order to improve network efficiency. This map shows the number of valid DME pairs available for area navigation using DME/DME position updates at 9,500 feet.

More info Show map

Datalink deployment status

Datalink is a digital alternative to supplement the congested communication bands used in aviation. Flight crew and air traffic controllers can communicate via controller-pilot datalink communications (CPDLC). The map shows the status of CPDLC deployment in Europe’s airspace. When 75% of flights use CPDLC, capacity could be increased by as much as 10%. At EUROCONTROL, one of our functions is to support datalink operations, performance monitoring activities, and the standardisation and deployment of datalink technologies.

More info Service restrictions Show map

Note: The designations employed and the presentation of the material on maps do not imply the expression of any opinion whatsoever on the part of EUROCONTROL concerning the legal status of any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers or borders.


Traffic over Europe is already at record levels and will continue growing over the next twenty years. To safely accommodate this growth, it is essential to manage scarce resources like radio frequency bands, secondary surveillance radar (SSR) codes and Mode S interrogator codes sustainably.

In our role as Network Manager (NM), we manage scarce resources and provide common centralised network support services to ensure the required level of performance, interoperability, compatibility and coordination of activities and contributing to the sustainable development of the air transport system.

We work to protect the interests of the aviation community through our involvement in the International Telecommunication Union (ITU) working groups and the World Radiocommunication Conferences (WRC).

Network performance requires a resilient CNS infrastructure supported by a monitoring system for early detection and prevention of issues with the potential to impact network operations.

At EUROCONTROL, we keep an eye on the European CNS infrastructure by applying a system-wide approach that brings improved predictability. Among many other systems we monitor.

  • the coverage of ground and space-based navigation systems in support of the implementation and operation of navigation applications
  • the performance of surveillance interrogators and avionics, datalink communications, airborne collision avoidance systems (ACAS) and airborne altimetry;
  • the performance of the VDL2 datalink system and the Controller-Pilot Data Link Communications (CPDLC) status.

Efficient and stable communication channels are the bonds that ensure aviation operates efficiently, predictably and safely. They ensure that information is exchanged efficiently among air traffic controllers (ATCOs) and between ATCOs and pilots. 

In order to increase efficiency and capacity, the aviation community is progressively digitalising its data exchanges - replacing or enhancing legacy communications systems. At EUROCONTROL we are leading the way, supporting our stakeholders in achieving readiness for this shift.

We work closely with all aviation stakeholders to address the technological and institutional challenges in safely implementing a harmonised and coherent future systems that, when required, operates in parallel with the existing infrastructure and ensures a smooth transition locally, regionally and globally.

Navigation is a key enabler of aviation, involving sophisticated technology and efficient coordination between pilot and air traffic controller. And yet, knowing where an aircraft is and how to get to it’s destination is still a challenge - laterally (the aircraft must follow the route centre-line); vertically (the aircraft must remain at the right altitude, even on a slope), longitudinally (being over a particular point within permitted margins) and temporally (reaching a point within a particular time).

At EUROCONTROL, we help our stakeholders by providing navigation:

  • applications, such as Performance-Based Navigation (PBN) and precision landing, to adapt navigation to different phases of flight, improve navigation performance the closer the aircraft is to the ground and ensure landing capability during low visibility conditions is also a key goal;
  • infrastructure to provide position information to the aircraft;
  • tools to support stakeholders to make their applications and infrastructure more efficient;
  • trainings developed and delivered by our experts.

We make our considerable operational expertise in PBN and infrastructure available to our stakeholders via three large consultation groups, acting as the pivot point for information sharing, gathering lessons learned and feeding them into research and shaping research ideas towards future stakeholder needs.

Surveillance is a cornerstone of aviation, providing users with knowledge of “who” is “where” and “when”.

At EUROCONTROL, our work is focussed on improving:

  • Interoperability: ensuring that the interfaces between all the components in the chain from the avionics through to the displays - operate as required with each other; globally. Interfacing with non-ATM components is also essential to avoid interference from and to other systems, such as mobile telephones;
  • Performance: all the various components have to perform properly, even in demanding operational environments, so that users like air traffic controllers are able to use the surveillance service effectively;
  • Efficiency: the essential tasks have to be carried out in a cost-effective way. Proper use of the valuable radio frequency spectrum must be made. It may also be important to extend surveillance to airspace in which surveillance could not be done before.

We help our vast network of stakeholders to address surveillance requirements and ensure that they are prepared for any challenges ahead.

Services and projects

8.33 kHz implementation support



Future communications infrastructure and multilink for the long term


New pan-European network service


Global navigation satellite systems


Ground based augmentation systems


Performance-based navigation


Required navigation performance approach


Air traffic management surveillance tracker and server


All-purpose structured EUROCONTROL surveillance information exchange


Automatic dependent surveillance – broadcast

Handling non-equipped Mode S and ADS-B State aircraft


Primary surveillance radar support

Surveillance System and Sensors


Air traffic management ground voice network coordination

Air traffic management voice


European directory service


Flight message transfer protocol address coordination


Internet protocol version 6 address assignment

Radio frequency function and spectrum management


European Regional Monitoring Agency


Surveillance avionics monitoring


Surveillance RF Environment Monitoring - 1030/1090 MHz


Automatic dependent surveillance - broadcast airborne equipage monitoring

4D Skyways

8.33 kHz implementation support


Aeronautical mobile airport communications system datalink


Air traffic management ground voice network coordination


Air traffic management surveillance tracker and server

Air traffic management voice

Our tools


8.33kHz implementation support group workspace

Aircraft communication, navigation and surveillance dashboard


Advanced frequency manager

AGVN database

Air traffic services ground voice network database


Air traffic services messaging management centre


ARTAS Dashboard


Join our training courses

We share our knowledge and experience through trainings and courses at our EUROCONTROL Aviation Learning Centre (ALC).

Latest highlights

Press release

EASA & EUROCONTROL sign MoC to enhance cooperation for the safe and sustainable future of European aviation

Christophe Vivier

New military technologies will require ATM modernisation to manage airspace more dynamically, safely and efficiently

Remus Lacatus

New entrants drive innovations in civil and military airspace management operations

Paul Bosman & Predrag Vranjkovic

The new CNS Programme Manager’s role and challenges

Magda Kopczyńska

U-space design and implementation: EUROCONTROL’s key role in supporting Member States

Eduardo Santander

Towards a unified sky vision: integrating ATM & AAM for future air transport