Is implementation of CPDLC mandated by EASA?
according to eurocontrol, http://www.eurocontrol.int/services/link-2000-programme:


  The LINK 2000+ Programme started in 2001 and is now in the full scale
  implementation phase governed by the DLS IR which requires:
  
  • All newly delivered aircraft operating above FL285 to be equipped as
  of 2011,  
  
  • Core European ANSPs to be operational by 7 February  2013, 
  
  • The rest of European ANSPs to be operational by 5 February 2015,  
  
  • All existing aircraft operating above FL295 to be retroffited by 5
  Feb 2015 (unless exempt).


What aircraft are exempt? See page 4 of this pdf: http://ec.europa.eu/transport/modes/air/single_european_sky/doc/implementing_rules/2014_01_22_2nd_exemption_under_29_2009.pdf