Does the S1-handover procedure always has to be change in MME ? As per spec it is mentioned MME changes during the S1 handover. But in a case where the source and target enodeB is served by same MME , but let say because of some network problem X2 interface is not available and source enodeB initiates a S1 handover procedure. How do we validate this scenario, as I don't see any call flow in the spec for this?