Hello,
if the network iniates a data transfer it will page the MS to open a TBF and since this paging happens over the CCCH it can only ask the MS to use one PDCH initially.
With this patch (and if there are more PDCH ts available) the PCU will remember that it can upgrade to use multiple timeslots and send a downlink assignment with the new timeslot allocation over the TBF.
Regards, Daniel