Abstract: A method, performed by a user equipment (UE), of transmitting and receiving signals in a wireless communication system, according to an embodiment, includes receiving a logical channel release request from a next-generation node B (gNB), determining a logical channel to release, an operation mode of the logical channel to release, and whether a packet data convergence protocol (PDCP) layer apparatus connected to the logical channel is re-established, based on the logical channel release request, and performing PDCP data recovery based on the determination result.

Abstract: Methods and apparatuses are provided in a wireless communication system. Packet data convergence protocol (PDCP) configuration information that configures a PDCP entity of the terminal to use an uplink data compression (UDC) is received from a base station. The PDCP entity generates a UDC header and a UDC data block, based on the PDCP configuration information. The PDCP entity ciphers the UDC header and the UDC data block. The PDCP entity generates PDCP data including a PDCP header, the ciphered UDC header and the ciphered UDC data block. The generated PDCP data is transmitted to the base station. A header compression is not configured in case that the UDC is configured.

Abstract: An orthodontic appliance includes an arch wire formed on a trajectory corresponding to an aligned dentition of the lower or upper dentures and installed on the lip side or the tongue side of the dentures. An anchor bracket is fixed on both side molars of the upper or lower dentures, and detachably anchors the arch wire. An adhesive formed in a gel state is cured after being applied to the teeth surface of teeth to be aligned. The adhesive covers the arch wire installed on the anchor bracket to allow the arch wire to move when the teeth to be aligned move. The orthodontic appliance can be easily installed by applying, to the teeth surface, the adhesive covering the arch wire after installing the arch wire in a mouth and can protect the teeth from cavities by applying the adhesive to the teeth surface without existing brackets.