Thanks Pix for ur doubt.
I didn’t said that these SACCH frames comes after the HO command.In fact,it comes alongwith the HO command or even before.Dummy bits are inserted for the Inband signallingin SACCH or Normal burst.(In case of HO command,it is FACCH).This will result in deterioration of speech quality, since either or
both of the 57 bit information blocks are used for signalling instead of user data.
Also,in case of non-sync neighbours,it takes at least 300 ms for the MS to tune on it.Here also,dummy SACCH comes in play.
I think you have to go beyond 3Gpp to comprehend this.