Hi,

This is mentioned in MAC specification 5.7 .

If the Short DRX Cycle is used and [(SFN * 10) + subframe number] modulo (shortDRX-Cycle) = (drxStartOffset)

modulo (shortDRX-Cycle); or

- if the Long DRX Cycle is used and [(SFN * 10) + subframe number] modulo (longDRX-Cycle) = drxStartOffset:

- start onDurationTimer.

For E.g Current subframe number is 9. SFN is 988 , Longdrx cycle is 80 and drxstartoffet in RRC IE as 5

988 * 10 + 9 % 80 should be equal to 5.