Paging frames are the specific radio frames during which a UE checks for the paging message. within this paging frames- Paging Occasion (PO) are define which represents the specific subframe during which a UE check for a paging message.
Paging frame(PF): can occur when the following equation is satisfied:
SFN modT=(T/N) *(UE_IDmodN), UE_ID=IMSI mod1024, T=DRX cycle length in radio frame,N=Info broadcast in SIB2
In both Idle and Connected mode UE tries to search for P-RNTI within PDCCH of the Subframe belonging to the Paging Occasion.Then its proceeds to decode the Resource allocation info from within the PDCCH. This info direct the UE to the PDSCH RB within which the paging message is sent. If the UE find its identity within Paging record then it triggers the RA procedure to establish the RRC connection.