When eNB sends RRC Connection Release with "IdleMode Mobility Control Info IE"???

Question

Please can anyone explain me,
In which Scenario, eNB send Idlemodemobilitycontrolinfo IE with release cause "other" inside RRC CONNECTION RELEASE message to UE???

Answer 1

The purpose of including this IE in RRC connection release message is to configure the cell re-selection parameters applicable in the Idle mode. These cell re-selection parameters would be different from the one broad-casted in system information block. Enodes decides on inclusion of "IdleMode Mobility Control Info" IE based on "Subscriber Profile ID for RAT/Frequency Priority" (optional) IE receives from MME. There are couple of messages in S1-AP interface which may carry this information from MME to eNodeB.
In case, "IdleMode Mobility Control Info" IE is not configured for the Idle mode, UE selects the broadcast-ed one.

Comments

Also in case of CSFB, Inter-RAT cell information will be used for fast camping.