First, the IRD doesnt care if there are 10 satellites in the same Orbital postion - so 101W will always be 101 - not MAST-2, AMC-4, G4R, G16 etc.
If it was important to the techies, it could always be referred to as 101A, 101B, 101C etc - but again, that is worthless info for the IRD to...