LTE: UL Information Transfer

Direction: UE => E-UTRAN
Signalling Radio Bearer: SRB1 or SRB2
RLC Mode: AM
Logical Channel: DCCH
Transport Channel: UL-SCH

A UE in RRC_CONNECTED state initiates the UL INFORMATION TRANSFER whenever there is a need to transfer NAS or non-3GPP dedicated information, except at RRC connection establishment in which case the NAS information is piggybacked to the RRC CONNECTION SETUP COMPLETE message

The UL INFORMATION TRANSFER procedure is almost similar to UPLINK DIRECT TRANSFER procedure in 3G-RNC

Either SRB2 or SRB1 (only if SRB2 not established yet) is used for this purpose. If SRB2 is suspended, the UE does not send this message until SRB2 is resumed. When CDMA2000 information has to be transferred, the UE shall initiate the procedure only if SRB2 is established

The IE dedicatedInfoType shall carry ‘dedicatedInfoNAS’ or ‘dedicatedInfoCDMA2000-1XRTT ‘(in case of CDMA2000 1XRTT information) or ‘dedicatedInfoCDMA2000-HRPD’ (in case of CDMA2000 HRPD information)

Example1: UL INFORMATION TRANSFER message (carrying Authentication Response)

Example2: UL INFORMATION TRANSFER message (carrying Authentication Failure)

Reference: 3GPP TS 36.331