Original publication: August 2016
Authors: Steer Davies Gleave: Stephen Wainwright, Rosie Offord, Mark Scott
Short link to this post: http://bit.ly/2EKCeSK
Available languages:

This note has been prepared for the Members of the Committee on Transport and Tourism of the European Parliament. It provides an overview and evaluation of the existing and developing technologies that would enable the provision of “remote” en-route Air Traffic Services.

Air navigation services in Europe
Prospects for “Remote” En-Route Air Traffic Services

Download the Study

Air Navigation Services (ANS) are generally divided into two areas; en-route services are provided for the majority of the flight in upper and lower airspace and tower services are provided at and around airports including landings and departures. Remote tower services, which allow traffic at airports to be managed off-site, are already in use at some airports and are being tested at several others. The meaning of remote en-route services is not well defined and may be different to participants in the industry.

Some define remote en-route services as Virtual Air Traffic Control Centres (ACC), which, in the most extreme example, would enable Air Traffic Controllers (ATCOs) to deliver ANS to aircraft in any ACC to any block of airspace (“any time, any service, anywhere”). Virtual centre technology, in this sense, is in the early stages of development and has only been implemented by a few Air Navigation Service Providers (ANSPs). Delivery of ANS through virtual centres can also refer to a specific function or service, such as flight data processing, being delivered virtually. Virtual centres in this sense are more widespread in en-route ANS; both the NextGen and SESAR are developing information sharing platforms known as System Wide Information Management (SWIM).

Remote en-route services can also be defined as providing infrastructure in remote locations and allowing greater use of technology in the air rather than on the ground. The majority of ANS equipment currently relies on decades old radio technology, consequently, many ANSPs are now implementing modernisation programmes which utilises satellite technology. These technologies have the potential to address some of the key issues facing ANSPs providing en-route services; pressures to manage and reduce costs, rationalising the number of ACCs and improving resilience through affordable contingency arrangements.

Review of existing and developing technologies

Automatic Dependent Surveillance – Broadcast (ADS–B), datalink communication and Ground-based augmentation system (GBAS) are technological developments that can facilitate greater delivery of remote en-route services. These technologies will enable ANSPs to become less reliant on physical assets being placed in a specific location to provide a service to airspace users, often by using airborne technology placed on aircraft.

ADS–B is a piece of equipment installed on each aircraft which automatically broadcasts an aircraft’s position, which is determined using Global Positioning System (GPS) satellites. ASD-B has been widely implemented globally; many systems currently use ground stations to receive these broadcasts from aircraft. As the technology develops satellite receiver stations will begin to replace ground stations; the first satellite systems are expected to be operational by 2018.

Data link is a text-based messaging service which allows ANSPs to send quick and clear messages to aircraft pilots. There are two types of datalink services currently being implemented; Future Air Navigation System (FANS) and controller–pilot data link communications via aeronautical telecommunications network (CPDLC via ATN). FANS was first developed in the mid-1990s and is the most widely used type datalink technology globally as it can be used in oceanic airspace. CPDLC via ATN can provide a superior service in congested continental airspace but is only being implemented in Europe. Although FANS and CPDLC via ATN are both data link networks, the manner in which they operate and the equipment they require differ significantly.

GBAS provides landing assistance at airports using GPS satellites to determine an aircraft’s position which is picked up by a ground station at the airport, the development of the technology is still at a relatively early stage compared to ADS-B surveillance and data link communication. GBAS is currently operational at a small number of airports and is normally capable of supporting landings in the least severe weather and visibility conditions.

Vulnerability to hacking

In spite of the benefits these new technologies can bring, there are concerns about their vulnerability to cyber-attacks. Older, point-to-point communications systems are generally difficult to access remotely because many are not connected to the internet and it is hard to inflict damage on an entire system as it is often not completely interconnected. The introduction of technologies like SWIM means it is easier for potential hackers to access the system remotely and increased interconnectivity means damage can be inflicted more easily throughout the system once it has been accessed. Avionics systems on board aircraft area also at risk as they are increasingly connected to the internet and therefore there is a greater risk an attacker could access and compromise avionics systems remotely.

Although protecting against cyber-attacks represents a serious challenge for the aviation industry, the risk of attack can be reduced by good preparation and a coordinated response. A recent report found that some of the biggest weaknesses in NextGen’s systems were due to lack of preparation and not allocating sufficient resources to guard against cyber security threats, rather than an inherent weakness in the technologies themselves. A separate report also noted that the introduction of more interconnected systems is an opportunity for improved cyber security as it will allow ANSPs address cyber-security systematically through the sharing of vulnerabilities and coordinated incident response.

Contributions of the SESAR and NextGen programmes

The objective of SESAR and NextGen is to modernise and harmonise the technology and operations of Air Traffic Management (ATM), in their respective jurisdictions, in order to increase capacity, improve safety, reduce costs and reduce the environmental impact of the aviation sector.

Both NextGen and SESAR are moving towards the use of virtual centres, although only through System Wide Information Management (SWIM) across different flight sectors; they are not currently pursuing the delivery of ANS independent of the physical location of the personnel and equipment. Although NextGen has begun to roll out SWIM technology, SESAR is still in the relatively early stages of developing the technology and it has not yet been widely implemented.

Both programmes have made more progress introducing ADS-B technology; a large amount of ADS-B ground infrastructure has been installed in Europe and the USA which provides coverage to majority of both areas. Both programmes have also mandated that all commercial aircraft must be fitted with ADS-B technology by 2020.

Both programmes have also made progress with introducing datalink communication, although they are pursuing different kinds of technology. NextGen is seeking to utilise FANS technology and plans to begin providing en-route datalink communication services to begin in 2019. SESAR is pursuing CPDLC via ATN technology, which is being rolled out across European continental airspace. The current mandated dates by which ANPSs and aircraft in Europe must be fitted with datalink technology are February 2018 and February 2020 respectively. The original date was 2015, but this was delayed due to monetary and technical issues.

Although GBAS is operational at a small number of American and European airports, NextGen and SESAR do not have mandates or stipulations regarding its implementation.


The concept of remote en-route services which follows the principle of “air traffic anywhere being managed from anywhere”, is not well defined. Some stakeholders focus on the location of the Air Traffic Control Centre (ACC) and the concept of Virtual en-route ACCs. Others on the infrastructure where greater use of technology in the air facilitates the introduction of remote en-route services, and others on delivering a specific function or service virtually, e.g. flight data processing.

To date there are only a small number of examples of remote en-route services being provided by ANSPs. To provide more widespread implementation of this concept requires the implementation of a range of technologies including satellite-based surveillance, datalink communication, and satellite based landing systems (such as GBAS). The costs of implementing new technologies are significant (and in many cases not yet fully proven), and require coordination of implementation between on the ground and in the air technology.

Uptake of the technology has been relatively slow. Coordinating the implementation of the technology and supporting the costs of the changes will be challenging and directly influence the speed of implementation. To move to greater provision of remote services, service providers, Member States and airspace users will need to be willing to adopt innovative approaches to technology and new arrangements for the provision of services.

The concepts and technology to support widespread implementation of remote en-route services exists, however to deliver it will require greater co-ordination of organisations, on the ground and in the air, as well as the funding and financing of this new technology. Experience to date is that this may take some time to deliver.

Link to the full study: http://bit.ly/585-886

Please give us your feedback on this publication

This slideshow requires JavaScript.


Leave a Reply