UE information transfer and RRC connection Aspects in LTE
Means for transmitting UE
In order to avoid signaling of the radio access capability of the UE via an air interface at each transition from RRC_IDLE to RRC_CONNECTED, the core network stores AS capabilities (such as E-UTRA and the possibility GERAN), while the UE is in the RRC_IDLE / EMM-registered. After the connection S1, the core network provides opportunities E-UTRAN. If the E-UTRAN does not receive (optional) capabilities of the core network (e.g., in connection with the UE being in the EMM-deregistered), it requests the UE to provide its features using a transmission opportunity procedure.
UE-UTRAN may indicate for each rat (LTE, UMTS, GERAN), if UE wants to obtain the corresponding requested capabilities. UE provides the possibility of using a separate container for each rat. Dynamic change of UE capability is not supported, except for the changes in the GERAN capabilities RRC_IDLE supported tracking area update procedure.
Uplink / downlink transmission
Uplink / downlink communication procedures used to transmit information only the top layer (ie no RRC control information included). Procedure supports 3GPP NAS dedicated information and the selection information CDMA2000.
To reduce latency, NAS information may also be included in the RRC-connection Setup Complete and the RRC Connection Reconfiguration message. In the latest report, NAS information is included only if the AS and NAS procedures vary (i.e. they share the success or failure). This refers to the EPS bearer establishment, modification and release. As noted earlier, some additional procedures transmission NAS were also determined for CDMA2000 for pre-registration.
UE Information Transfer
UE information transfer process was introduced in Release 9 to support SON. The mobility support network optimization robustness presentation of data at a later time point of measurement information available when a radio link failure. E-UTRAN may be used also to transfer the information to the UE to retrieve information about the last successful random access memory that can be used to optimize the RACH.