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EP-4297451-B1 - TERMINAL, WIRELESS COMMUNICATION METHOD, BASE STATION AND SYSTEM

EP4297451B1EP 4297451 B1EP4297451 B1EP 4297451B1EP-4297451-B1

Inventors

  • MATSUMURA, YUKI
  • NAGATA, SATOSHI
  • WANG, JING

Dates

Publication Date
20260506
Application Date
20210218

Claims (7)

  1. A terminal (20) comprising: a receiving section (220) configured to receive, from a base station (10), an indication of update of a serving cell; the terminal being characterized in that it further comprises: a control section (210) configured to, when a serving cell is updated by the indication, select one cell radio network temporary identifier, C-RNTI, from a plurality of C-RNTIs, based on the indication; and a transmitting section configured to transmit, to the base station (10), an uplink signal using the selected C-RNTI.
  2. The terminal (20) according to claim 1, wherein the control section (210) is configured to select the one C-RNTI, based on a transmission configuration indication state, TCI state, corresponding to the serving cell updated.
  3. The terminal (20) according to claim 1, wherein the control section (210) is configured to select the one C-RNTI, based on a unified transmission configuration indication state, TCI state, corresponding to the serving cell updated.
  4. The terminal (20) according to claim 1, wherein association between the one C-RNTI and a physical cell ID, PCI, of a non-serving cell is configured by radio resource control, RRC.
  5. A radio communication method for a terminal (20), the radio communication method comprising: receiving, from a base station (10), an indication of update of a serving cell; being characterized in that it further comprises: when a serving cell is updated by the indication, selecting one cell radio network temporary identifier, C-RNTI, from a plurality of C-RNTIs, based on the indication; and transmitting, to the base station (10), an uplink signal using the selected C-RNTI.
  6. A base station (10) comprising: a transmitting section (120) configured to transmit, to a terminal (20), an indication of update of a serving cell; being characterized in that it further comprises a receiving section (120) configured to, when a serving cell is updated by the indication, receive from a terminal (20) an uplink signal using one cell radio network temporary identifier, C-RNTI, selected from a plurality of C-RNTIs based on the indication.
  7. A system comprising a terminal (20) according to any of claims 1-4 and a base station (10) according to claim 6.

Description

Technical Field The present disclosure relates to a terminal, a radio communication method, a base station and a system (formed by the terminal and the base station) in next-generation mobile communication systems. Background Art In a Universal Mobile Telecommunications System (UMTS) network, the specifications of Long-Term Evolution (LTE) have been drafted for the purpose of further increasing high speed data rates, providing lower latency and so on (see Non-Patent Literature 1). In addition, for the purpose of further high capacity, advancement and the like of the LTE (Third Generation Partnership Project (3GPP) Release (Rel.) 8 and Rel. 9), the specifications of LTE-Advanced (3GPP Rel. 10 to Rel. 14) have been drafted. Successor systems of LTE (for example, also referred to as "5th generation mobile communication system (5G)," "5G+ (plus)," "6th generation mobile communication system (6G)," "New Radio (NR)," "3GPP Rel. 15 (or later versions)," and so on) are also under study. In existing LTE systems (for example, 3GPP Rel. 8 to Rel. 14), a user terminal (User Equipment (UE)) transmits uplink control information (UCI) by using at least one of a UL data channel (for example, a Physical Uplink Shared Channel (PUSCH)) and a UL control channel (for example, a Physical Uplink Control Channel (PUCCH)). Citation List Non-Patent Literature Non-Patent Literature 1: 3GPP TS 36.300 V8.12.0 "Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access Network (E-UTRAN); Overall description; Stage 2 (Release 8)," April, 2010 OPPO: "Enhancements on Multi-Beam Operation", 3GPP DRAFT; R1-2100118 relates to unified TCI state and common beam operation, inter-cell mobility, UL beam selection and MPE. MODERATOR (SAMSUNG): "Moderator summary#6 for multi-beam enhancement: Round 3B", 3GPP DRAFT; R1-2102112 relates to multi-beam enhancement. Summary of Invention Technical Problem For future radio communication systems (for example, NR), layer 1 / layer 2 (L1/L2) inter-cell mobility that facilitates more efficient DL/UL beam management (that achieves lower latency and overhead) is studied. In L1/L2 inter-cell mobility, serving cell change is possible by using a function such as beam control without performing radio resource control (RRC) reconfiguration. In other words, transmission to / reception from a non-serving cell is possible without performing handover. For handover, a period in which data communication is not possible occurs due to the necessity of RRC reconfiguration, for example. For this reason, L1/L2 inter-cell mobility without necessity of handover is preferable. However, a cell radio network temporary identifier (C-RNTI) used in the serving cell may not be able to be used directly in transmission to / reception from a non-serving cell. This is because the C-RNTI used in the serving cell may be already used for another user terminal (User Equipment (UE)) in the non-serving cell, for example. When the same C-RNTI is used between UEs in the same cell, an issue is, for example, one UE can erroneously read downlink control information destined to another UE. Thus, an object of the present disclosure is to provide a terminal, a radio communication method, a base station and a system that can appropriately select a C-RNTI. Solution to Problem The object of the invention is achieved by the subject-matter of the independent claims. Advantageous embodiments are defined in the dependent claims. Further examples are provided for facilitating the understanding of the invention. A terminal according to one aspect of the present disclosure includes: a receiving section that receives an indication related to a beam; and a control section that selects, when a serving cell is updated by the indication, one cell radio network temporary identifier (C-RNTI) from among a plurality of C-RNTIs, based on the indication. Advantageous Effects of Invention According to one aspect of the present disclosure, a C-RNTI can be appropriately selected. Brief Description of Drawings [FIG. 1] FIGS. 1A to 1D are diagrams to show examples of a multi-TRP scenario.[FIG. 2] FIGS. 2A and 2B are diagrams to show examples of intra-cell mobility.[FIG. 3] FIG. 3 is a diagram to show an example of joint common TCI indication for UL/DL.[FIG. 4] FIG. 4 is a diagram to show an example of an example of separate common TCI indication for UL/DL.[FIG. 5] FIG. 5 is a diagram to show an example of switching of a TCI state.[FIG. 6] FIG. 6 is a diagram to show an example of C-RNTI assumption in Aspect 1-1.[FIG. 7] FIG. 7 is a diagram to show an example of C-RNTI assumption in Aspect 1-2.[FIG. 8] FIG. 8 is a diagram to show an example of a TCI framework in Option 1 of Aspect 2-1.[FIG. 9] FIG. 9 is a diagram to show an example of a TCI framework in Option 2 of Aspects 2-1 and 2-2.[FIG. 10] FIG. 10 is a diagram to show an example of a TCI framework in Option 1 of Aspect 2-2.[FIG. 11] FIG. 11 is a diagram to show an example of a TCI framew