RAN Information Management(RIM) for SI Tunneling
For the Redirect with System Information feature to function properly, the system information for the target cell must be accessible to the eNodeB.
The eNodeB requests system information from the target cells using RAN Information Management and this feature must be supported by the target RAT. This requires that the RAN Information Management Network Assisted Cell Change (NACC) Packet Data Unit (PDU) is used for retrieving system information from GSM, WCDMA target cells.
Question is how often eNodeB request the SI of the target cell(2G/3G)? At the time of CSFB only? If it is stored in MME, how often it is updated in MME?