Xeptu said:
The difficulty is that as the hours tick by the probability of a ping at the expected time becomes more likely that it could be from a different source, particularly towards Europe on the northern arc as aircraft and satcom units start powering up for their days work.
As previous noted, Inmarsat, while declining to discuss specifics of Flight 370, have said that each handshake always contains a code verifying the identity of the aircraft and it is "virtually impossible" to change an aircraft's identifying code or to confuse one aircraft with another. (Source
CNN).