s capabilities to indicate that LAA is not supported. However, from a system operation viewpoint, having the UE per- form detach and attach procedures is considered undesirable. Hence, eNB should enable IDC indications and respond to the IDC requests from the multi-radio UEs. The QoS of some radio bearers might suffer when LAA is used due to support of LBT as there can be various interference sources in the unlicensed spectrum such as other RATs and LAA nodes of other operators. To improve the QoS, the characteristics of an LAA cell should be considered when mapping traffic from radio bearers to carrier(s). For example, it is better not to send critical control information, delay-sensitive data or guaranteed bit rate bearers through LAA cells, if the LBT operation is required. Operation in Unlicensed and Shared Spectrum References 3GPP Specifications [1] 3GPP TS 36.211, Evolved universal terrestrial radio access (E-UTRA), Physical Channels and Modulation (Release 15), June 2018. 3GPP TS 36.212, Evolved universal terrestrial radio access (E-UTRA), Multiplexing and channel coding (Release 15), June 2018. [3] 3GPP TS 36.213, Evolved universal terrestrial radio access (E-UTRA), Physical layer procedures (Release 15), June 2018. 3GPP TS 37.213, Physical layer procedures for shared spectrum channel access (Release 15), June 2018. [5] 3GPP TS 36.300, Evolved universal terrestrial radio access (E-UTRA) and evolved universal terrestrial radio access network (E-UTRAN); Overall Description; Stage 2 (Release 15), June 2018. [6] 3GPP TS 36.321, Evolved universal terrestrial radio access (E-UTRA), Medium Access Control (MAC) Protocol Specification (Release 15), June 2018. [7] 3GPP TS 36.323, Evolved universal terrestrial radio access (E-UTRA), Packet Data Convergence Protocol (PDCP) specification (Release 15), June 2018. [8] 3GPP TS 36.331, Evolved universal terrestrial radio access (E-UTRA), Radio Resource Control (RRC); Protocol Specification (Release 15), June 2018. [9] 3GPP TR 36.889, Study on licensed-assisted access to u