At EUROCONTROL's Maastricht Upper Area Control Centre (MUAC), we have been operating controller-pilot datalink communications (CPDLC) since 2003 to help mitigate the shortcomings of traditional voice communication.
CPDLC - an air/ground datalink application - offers the benefit of an additional, independent and secure channel, which reduces the strain on busy VHF sector frequencies, transmitting clear messages with no risk of misunderstandings. Use of the system increases capacity and safety; it improves the day-to-day efficiency of communications between controllers and pilots. Currently, more than 40% of the traffic crossing the MUAC airspace use CPDLC on a daily basis.
As of February 2020, CPDLC will be required to operate above FL285 in Europe.