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EP-4533893-B1 - METHOD AND APPARATUS FOR INTER-UE COORDINATION IN SL CA

EP4533893B1EP 4533893 B1EP4533893 B1EP 4533893B1EP-4533893-B1

Inventors

  • JEONG, KYEONGIN
  • LENG, Shiyang

Dates

Publication Date
20260513
Application Date
20230707

Claims (11)

  1. A user equipment, UE (116), in a communication system, the UE comprising: a transceiver (310), and a processor (340) coupled to the transceiver, wherein the processor is configured to: receive, from a base station, BS, a message including configuration information on candidate sidelink, SL, carriers for SL carrier aggregation, CA, determine whether a hybrid automatic repeat request, HARQ,-based SL Radion Link Failure, RLF, is detected for an SL carrier among the candidate SL carriers, start a timer based on a determination that the HARQ-based SL RLF for the SL carrier is detected, in case that the timer has not expired, transmit, to a peer UE, signals based on at least one activated SL carrier among the candidate SL carriers, not including the SL carrier, and in case that the timer has expired, transmit, to the peer UE, signals based on at least one activated SL carrier among the candidate SL carriers, including the SL carrier.
  2. The UE of claim 1, wherein the message further includes information on a value of the timer.
  3. The UE of claim 1, wherein the processor is further configured to: receive, from the BS, a threshold number of consecutive HARQ discontinuous transmission, DTX, detect the HARQ-based SL RLF for the SL carrier based on a comparison between an actual number of consecutive HARQ DTX and the threshold number, and transmit, to the peer UE, deactivation signal indicating the peer UE to stop monitoring an SL channel on the SL carrier.
  4. A method performed by a user equipment, UE, in a communication system, the method comprising: receiving (1202), from a base station, BS, a message including configuration information on candidate sidelink, SL, carriers for SL carrier aggregation, CA; determining (1204) whether a hybrid automatic repeat request, HARQ,-based SL Radio Link failure, RLF, is detected for an SL carrier among the candidate SL carriers; starting (1206) a timer based on a determination that the HARQ-based SL RLF for the SL carrier is detected; in case that the timer has not expired, transmitting, to a peer UE, signals based on at least one activated SL carrier among the candidate SL carriers, not including the SL carrier; and in case that the timer has expired, transmitting, to the peer UE, signals based on at least one activated SL carrier among the candidate SL carriers, including the SL carrier.
  5. The method of claim 4, wherein the message further includes information on a value of the timer.
  6. The method of claim 4, further comprising: receiving, from the BS, a threshold number of consecutive HARQ discontinuous transmission, DTX; detecting the HARQ-based SL RLF for the SL carrier based on a comparison between an actual number of consecutive HARQ DTX and the threshold number; and transmitting, to the peer UE, deactivation signal indicating the peer UE to stop monitoring an SL channel on the SL carrier.
  7. A base station (102), BS, in a communication system, the BS comprising: a transceiver (210a), and a processor (225) coupled to the transceiver, wherein the processor is configured to: generate configuration information on candidate sidelink, SL, carriers for SL carrier aggregation, CA, and transmit, to a user equipment, UE, a message including the configuration information, wherein a timer for an SL carrier among the candidate SL carriers is started based on a hybrid automatic repeat request, HARQ,-based SL Radio Link failure, RLF, for the SL carrier, wherein, in case that the timer has not expired, the SL carrier is not included in at least one activated SL carrier among the candidate SL carriers, and wherein, in case that the timer has expired, the SL carrier is included in at least one activated SL carrier among the candidate SL carriers.
  8. The BS of claim 7, wherein the message further includes information on a value of the timer.
  9. The BS of claim 7, wherein the processor is further configured to transmit, to the UE, a threshold number of consecutive HARQ discontinuous transmission, DTX, and wherein the HARQ-based SL RLF for the SL carrier is determined based on a comparison between an actual number of consecutive HARQ DTX and the threshold number.
  10. A method performed by a base station (102), BS, in a communication system, the method comprising: generating configuration information on candidate sidelink, SL, carriers for SL carrier aggregation, CA; and transmitting, to a user equipment, UE, a message including the configuration information, wherein a timer for an SL carrier among the candidate SL carriers is started based on a hybrid automatic repeat request, HARQ,-based SL Radio Link failure, RLF, for the SL carrier, wherein, in case that the timer has not expired, the SL carrier is not included in at least one activated SL carrier among the candidate SL carriers, and wherein, in case that the timer has expired, the SL carrier is included in at least one activated SL carrier among the candidate SL carriers.
  11. The method of claim 10, further comprising: transmitting, to the UE, a threshold number of consecutive HARQ discontinuous transmission, DTX, wherein the HARQ-based SL RLF for the SL carrier is determined based on a comparison between an actual number of consecutive HARQ DTX and the threshold number, and wherein the message further includes information on a value of the timer.

Description

Technical Field The present disclosure relates generally to wireless communication systems and, more specifically, the present disclosure relates to inter-user equipment (UE) coordination in sidelink (SL) carrier aggregation (CA) in a wireless communication system. Background Art 5G mobile communication technologies define broad frequency bands such that high transmission rates and new services are possible, and can be implemented not only in "Sub 6GHz" bands such as 3.5GHz, but also in "Above 6GHz" bands referred to as mmWave including 28GHz and 39GHz. In addition, it has been considered to implement 6G mobile communication technologies (referred to as Beyond 5G systems) in terahertz bands (for example, 95GHz to 3THz bands) in order to accomplish transmission rates fifty times faster than 5G mobile communication technologies and ultra-low latencies one-tenth of 5G mobile communication technologies. At the beginning of the development of 5G mobile communication technologies, in order to support services and to satisfy performance requirements in connection with enhanced Mobile BroadBand (eMBB), Ultra Reliable Low Latency Communications (URLLC), and massive Machine-Type Communications (mMTC), there has been ongoing standardization regarding beamforming and massive MIMO for mitigating radio-wave path loss and increasing radio-wave transmission distances in mmWave, supporting numerologies (for example, operating multiple subcarrier spacings) for efficiently utilizing mmWave resources and dynamic operation of slot formats, initial access technologies for supporting multi-beam transmission and broadbands, definition and operation of BWP (BandWidth Part), new channel coding methods such as a LDPC (Low Density Parity Check) code for large amount of data transmission and a polar code for highly reliable transmission of control information, L2 pre-processing, and network slicing for providing a dedicated network specialized to a specific service. Currently, there are ongoing discussions regarding improvement and performance enhancement of initial 5G mobile communication technologies in view of services to be supported by 5G mobile communication technologies, and there has been physical layer standardization regarding technologies such as V2X (Vehicle-to-everything) for aiding driving determination by autonomous vehicles based on information regarding positions and states of vehicles transmitted by the vehicles and for enhancing user convenience, NR-U (New Radio Unlicensed) aimed at system operations conforming to various regulation-related requirements in unlicensed bands, NR UE Power Saving, Non-Terrestrial Network (NTN) which is UE-satellite direct communication for providing coverage in an area in which communication with terrestrial networks is unavailable, and positioning. Moreover, there has been ongoing standardization in air interface architecture/protocol regarding technologies such as Industrial Internet of Things (IIoT) for supporting new services through interworking and convergence with other industries, IAB (Integrated Access and Backhaul) for providing a node for network service area expansion by supporting a wireless backhaul link and an access link in an integrated manner, mobility enhancement including conditional handover and DAPS (Dual Active Protocol Stack) handover, and two-step random access for simplifying random access procedures (2-step RACH for NR). There also has been ongoing standardization in system architecture/service regarding a 5G baseline architecture (for example, service based architecture or service based interface) for combining Network Functions Virtualization (NFV) and Software-Defined Networking (SDN) technologies, and Mobile Edge Computing (MEC) for receiving services based on UE positions. As 5G mobile communication systems are commercialized, connected devices that have been exponentially increasing will be connected to communication networks, and it is accordingly expected that enhanced functions and performances of 5G mobile communication systems and integrated operations of connected devices will be necessary. To this end, new research is scheduled in connection with eXtended Reality (XR) for efficiently supporting AR (Augmented Reality), VR (Virtual Reality), MR (Mixed Reality) and the like, 5G performance improvement and complexity reduction by utilizing Artificial Intelligence (AI) and Machine Learning (ML), AI service support, metaverse service support, and drone communication. Furthermore, such development of 5G mobile communication systems will serve as a basis for developing not only new waveforms for providing coverage in terahertz bands of 6G mobile communication technologies, multi-antenna transmission technologies such as Full Dimensional MIMO (FD-MIMO), array antennas and large-scale antennas, metamaterial-based lenses and antennas for improving coverage of terahertz band signals, high-dimensional space multiplexing technology using OAM (Orbital Angular Mom