The following is an extract from an article from Capana:
From the 1st of July 2014, the new EU Roaming Regulations III will become active.
Decoupling using Single IMSI
Decoupling using Local Breakout
Raymond Bouwman from Rabion Consultancy did an excellent presentation last year in the LTE World Summit, here is his presentation explaining more about the EU Roaming Regulations III