1. A method performed by a user equipment (UE), comprising:receiving an RRCConnectionReconfiguration message which contains an indication to reconfigure a first data radio bearer (DRB) to a second DRB and a drb-ToAddModList parameter that contains a list of DRBs needed to be added;
reconfiguring a PDCP entity in accordance with a pdcp-Config parameter, if the pdcp-Config parameter included in the drb-ToAddModList parameter, wherein the pdcp-Config parameter is used to set configurable PDCP parameters for configuring the first DRB to the second DRB; and
reconfiguring an RLC entity and/or a DTCH logical channel in accordance with an rlc-Config parameter and a logicalChannelConfig parameter, if the rlc-Config parameter and the logicalChannelConfig parameter are included in the drb-ToAddModList parameter, wherein the rlc-Config parameter is used to specify RLC configuration for configuring the first DRB to the second DRB, and the logicalChannelConfig parameter is used to configure logical channel parameters, wherein
the first DRB is a bearer whose radio protocols are located in a base station (eNB) and are not located in a WLAN to use eNB radio resources among the eNB radio resources and WLAN resources, and
the second DRB is a bearer whose radio protocols are located in both the eNB and the WLAN to use both the eNB radio resources and the WLAN resources.