What is the difference between RRCConnectionReconfiguration and RRCre-establishment?
RRC CONNECTION RECONFIGURATION message is the command to modify an RRC connection.
The purpose of this procedure is,
· To establish/modify/release Radio Bearers
· To perform Handover
· To setup/modify/release Measurements
· To add/modify/release SCells
· Dedicated NAS Information might also be transferred from eNodeB to UE
While the purpose of RRC CONNECTION RE-ESTABLISHMENT procedure is to re-establish the RRC connection, which involves the resumption of SRB1 operation and the re-activation of security (without changing algorithms). The UE shall only initiate this procedure when AS security has been activated.
The UE initiates the RRC CONNECTION RE-ESTABLISHMENT procedure when one of the following conditions is met:
Upon detecting radio link failure; or
Upon handover failure; or
Upon mobility from E-UTRA failure; or
Upon integrity check failure indication from lower layers; or
Upon an [ RRC CONNECTION RECONFIGURATION ] failure