Hi Pix,
I think that the higher value for SACCH (900 ms) is related to the different N200 values which depend on the channel type (GSM 04.08)
Channel Type N200
SACCH 5
SDCCH 23
FACCH (FR) 34
FACCH (HR) 29
So the products T200*(N200+1 are nearly the same:
(5+1) * 900 ms = 5.4 sec
(23+1) * 220 ms = 5.3 sec
Zbigniew