ATC services are now provided to FANS 1/A equipped aircraft in other oceanic airspaces, such as the North Atlantic. However, although many of FANS-1/A's known deficiencies with respect to its use in high density airspace were addressed in later versions of the product (FANS-1/A+), it has never been fully adopted for use in continental airspace. The ICAO work continued after FANS-1 was announced, and continued to develop the CNS/ATM concepts. The ICAO standard for CPDLC using the Aeronautical Telecommunications Network (ATN) is preferred for continental airspace and is currently being deployed in the core European Airspace by the EUROCONTROL Agency under the LINK2000+ Programme. Mandatory carriage of the ICAO compliant system is now the subject of an Implementing Rule (for aircraft flying above FL280) issued by the European Commission. This rule accommodates the use of FANS-1/A by long haul aircraft. All other airspace users must be ICAO compliant.