In RRC_IDLE state, UE is known in EPC and has IP address but not known in E-UTRAN/eNB. In this state UE can perform the following tasks -
- receive broadcast or multi-cast data,
- monitor a paging channel to detect incoming calls,
- perform neighbor cell measurements
- does cell selection as well as reselection
- acquires system information
Note: In RRC_IDLE state, a UE specific DRX (discontinuous reception) cycle may be configured by upper layers to enable UE power savings.