[update_descriptor.SSUUpdateFlag]
Bits = 2
0 = Update has to be activated manually
1 = Update may be performed automatically
2 = reserved for future use
3 = reserved for future use

[update_descriptor.SSUUpdateMethod]
Bits = 4
0    = Immediate update: performed whatever the IRD state
1    = IRD available: update when not interfere with user
2    = Next restart: update at next IRD restart
3-7  = reserved for future use
8-14 = private use
15   = reserved
