PI (Paging indication)
a short indicator that is transmitted on the PICH to tell the UE that there is a paging message on an associated paging channel carried by the SCCPCH.
The number of PIs per radio frame (Np) can be 18, 36, 72 or 144.
Once the UE knows paging occasion (SFN), then the UE needs to know which PI to look for in the SFN.
The equation is
PI = DRX index mod Np
DRX index = IMSI div 8192
If the PI bits are set in the paging occasion (SFN), the UE reads the paging message on the PCH transmitted on the associated SCCPCH.
1. direct method using measurement control
2. method using broadcast
In Cell_DCH, the UE makes measurements and reports them to the UTRAN for action by the UTRAN.
However, in other states, the measurements are not reported to the UTRAN and the UE takes action based on the measurements. (though Cell_FACH measurement has some common things with Cell_DCH)
when a UE went through the connection establishment procedure and has been allocated resources in the UTRAN and a U-RNTI.
With RRC connection, some SRBs are allocated.
for PS service.
It consists of
2. CN bearer (bearer between SGSN and GGSN)
The PDP context is created with a defined QoS that is requested by the UE and granted by the network.
RAB (Radio Access Bearer)
created to provide user plane data transfer.
1. RB and
2. connection from the SRNC to the SGSN (Iu bearer).
The RAB is created on reequest from the SGSN with a specific QoS request.
For a given UE, there can be multiple RABs per NAS service (speech or PS data service).