Abstract: A beam updating method in a reconfigurable intelligent surface (RIS) is provided. The method includes: receiving data from a base station using a first polarization and receiving an RIS beamforming reference signal using a second polarization; fixing the reflection direction of the first polarization and sequentially changing the reflection direction of the second polarization to transmit reflected waves; and adjusting the direction of the second polarization based on optimal second polarization direction control information determined according to channel power values corresponding to the reflection direction of the second polarization.

Abstract: Various embodiments for beam configuration in a wireless communication system are disclosed. In one embodiment, a method for configuring a beam by a base station may include determining a beam parameter including at least one of a beam width, a beam aiming direction, and a beam transmission power of a beam based on at least one of a location and an area of a reflective surface; generating beam configuration information including at least one beam based on the determined beam parameter and transmitting the beam configuration information to a controller that controls the reflecting surface; forming the at least one beam according to the beam parameter and the beam configuration information; receiving beam quality information from the controller; and adjusting beamforming based on the received beam quality information.

Abstract: A method for performing sidelink groupcast transmission by a transmission terminal includes the steps of: classifying reception terminals belonging to a subject group into two or more subgroups; allocating different groupcast feedback schemes to the two or more subgroups; performing groupcast transmission to the reception terminals; and receiving feedback information from terminals belonging to at least one subgroup among the two or more subgroups according to the different groupcast feedback schemes.

Abstract: An operation method of an IAB node in a communication system may comprise: measuring a power difference between a first signal received from a first node and a second signal received from a second node; controlling a transmit power of each of the first node and the second node based on the power difference; generating scheduling information for allowing the first node and the second node to simultaneously transmit signals; transmitting the scheduling information to the first node and the second node; and receiving signals that the first node and the second node simultaneously transmit according to the scheduling information by using the transmit power.

Abstract: A method of a reconfigurable intelligent surface (RIS) node may comprise: receiving, from a first transmitting node, control information for controlling the first RIS node; grouping reflecting elements of the first RIS node into at least one reflecting element group using the control information; and transmitting at least one signal incident on the at least one reflecting element group to a receiving node.

Abstract: A method for performing sidelink groupcast transmission by a transmission terminal includes the steps of: classifying reception terminals belonging to a subject group into two or more subgroups; allocating different groupcast feedback schemes to the two or more subgroups; performing groupcast transmission to the reception terminals; and receiving feedback information from terminals belonging to at least one subgroup among the two or more subgroups according to the different groupcast feedback schemes.

Abstract: An operation method of an IAB node in a communication system may comprise: measuring a power difference between a first signal received from a first node and a second signal received from a second node; controlling a transmit power of each of the first node and the second node based on the power difference; generating scheduling information for allowing the first node and the second node to simultaneously transmit signals; transmitting the scheduling information to the first node and the second node; and receiving signals that the first node and the second node simultaneously transmit according to the scheduling information by using the transmit power.

Abstract: A method performed by a base station may comprise: transmitting, to a first reconfigurable intelligent surface (RIS) node, first control information for the first RIS node; transmitting, to a terminal, first information of the first RIS node based on the first control information; and transmitting a first signal to the first RIS node and the terminal while the first RIS node is in an activated state according to the first control information, wherein the first signal is transmitted to the terminal through a path reaching the terminal from the base station via the first RIS node and a path directly reaching the terminal from the base station.

Abstract: A method of a first base station may comprise: determining, by a MT of the first base station, whether there is a terminal connected to a BSU of the first base station, when a power-off condition is satisfied in the BSU; instructing, by the MT, the terminal, which is connected to the BSU, to be handed over to a second base station, when there is a terminal connected to the BSU; instructing, by the MT, the BSU to power off the BSU, when the handover of the terminal, which is connected to the BSU, is completed; and transmitting, by the MT, a first message, which indicates a power-off state of the first base station, to the second base station, when the BSU is powered off.

Abstract: An operation method of a first terminal may comprise: configuring a Uu access link with a base station, and receiving a first message from the base station, the first message including a relay RNTI for identifying the first terminal, a node address of the base station, and a RAP entity ID for identifying a RAP entity configured for the first terminal; configuring a relay link with a second terminal when communication with the base station is disconnected; requesting link switching by transmitting to the base station a second message via the second terminal, the second message including the relay RNTI, node address, and RAP entity ID; and receiving a response to the second message from the base station via the second terminal, and switching a link with the base station from the Uu access link to the relay link.

Abstract: A method for managing links, performed by a first communication node in a communication system, includes: obtaining, through an interface, communication status information including communication quality information for each link between the first communication node and at least one other communication node of the communication system; obtaining communication environment information including movement information and location information of each of the at least one other communication node; and obtaining a link probability computational model outputting a first link probability according to input of the communication status information by iteratively performing a machine learning operation based on the communication status information and the communication environment information, wherein the first link probability is used by the first communication node to control multi-connectivity with the at least one other communication node.

Abstract: Disclosed are radio bearer management method and apparatus for multi-radio multi-connectivity. A method of a terminal may comprise: transmitting UP data to at least one node among an MN or SN through a first DRB; and in response to identifying a UL coverage loss in the second SN, determining switching from the first DRB to a second DRB based on a bearer switching rule.

Abstract: A method of user equipment may comprise: determining whether an error condition for a first beam communicating with a base station is met; when it is determined that the error condition for the first beam is met, determining whether a first physical uplink control channel (PUCCH) allocated to the user equipment is present within a predetermined first period of time; when it is determined that the first PUCCH is not present, transmitting a sounding reference signal (SRS) transmission approval request and an identifier of the user equipment to the base station through a second PUCCH pre-configured to be shared by all pieces of user equipment; and when an SRS transmission approval is received from the base station, transmitting an SRS to the base station.

Abstract: A method of a base station may comprise: detecting a beam failure for a terminal; in response to detecting the beam failure, transmitting a beam recovery early indicator (BREI) to the terminal based on a beam sweeping scheme; receiving a BREI response from the terminal; and identifying a preferred beam of the terminal based on reception of the BREI response.

Abstract: A method of a first user equipment (UE) may comprise: receiving a downlink (DL) reference signal transmitted by a base station using a beam included in a beam candidate group to be used for sidelink (SL) communication with a second UE; measuring a DL reference signal received power (RSRP) of the DL reference signal; determining a transmit power of a beam included in the beam candidate group based on the measured DL RSRP; and transmitting SL data to the second UE with the determined transmit power.

Abstract: An operation method of a relay node may include: receiving, from a first communication node, first data composed of n bits; receiving, from a second communication node, second data composed of m bits; in response to determining that n is greater than m, generating first T-data of m bits excluding (n-m) bits from the n-bits of the first data and first R-data of (n-m) bits; generating third data by performing a network coding operation on the first T-data and the second data; transmitting the third data to the first communication node; and transmitting the third data and the first R-data to the second communication node.

Abstract: A method of a first base station may comprise: determining, by a MT of the first base station, whether there is a terminal connected to a BSU of the first base station, when a power-off condition is satisfied in the BSU; instructing, by the MT, the terminal, which is connected to the BSU, to be handed over to a second base station, when there is a terminal connected to the BSU; instructing, by the MT, the BSU to power off the BSU, when the handover of the terminal, which is connected to the BSU, is completed; and transmitting, by the MT, a first message, which indicates a power-off state of the first base station, to the second base station, when the BSU is powered off.

Abstract: A method of a first terminal may include: identifying first RB set(s) to be used for SL communication among consecutive RB sets through an LBT procedure; identifying a first subchannel group included in the first RB set(s) and a second subchannel group including a first PRB in the first RB set(s), the first PRB being not included in the first subchannel group; configuring the first PRB within the second subchannel group as an SL communication resource; and transmitting, to a second terminal, control information indicating that the first PRB is configured as the SL communication resource.

Abstract: Disclosed are a relay method and device in a communication system. An operation method of a first communication node comprises the steps of: transmitting a reference signal to one or more candidate R nodes; receiving first feedback information including a minimum value of a first RSRP from a first candidate R node belonging to the one or more candidate R nodes; receiving second feedback information including a minimum value of a second RSRP from a second candidate R node belonging to the one or more candidate R nodes; comparing a first value based on the first feedback information with a second value based on the second feedback information; when the first value is greater than the second value, selecting the first candidate R node as an R node that is to perform a relaying operation; and communicating with a second communication node via the R node.

Abstract: An operation method of a terminal in a communication system may include: receiving, from a base station, primary RA configuration information for a primary RA procedure; receiving, from the base station, secondary RA configuration information for a secondary RA procedure; transmitting a primary RA preamble to the base station by using a primary RA resource indicated by the primary RA configuration information; receiving, from the base station, secondary RA indication information in response to the primary RA preamble, the secondary RA indication information indicating to perform the secondary RA procedure instead of the primary RA procedure; and transmitting a secondary RA preamble to the base station by using a secondary RA resource indicated by the secondary RA configuration information.