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JP-7856657-B2 - Lossless switching between PTP and PTM transmission/reception in MBS.

JP7856657B2JP 7856657 B2JP7856657 B2JP 7856657B2JP-7856657-B2

Inventors

  • テイェブ、オウメール
  • ナラヤナン タンガラジ、ユゲスワール ディーノー

Assignees

  • インターデイジタル パテント ホールディングス インコーポレイテッド

Dates

Publication Date
20260511
Application Date
20220111
Priority Date
20210111

Claims (20)

  1. A wireless transceiver unit (WTRU), Upon receiving an instruction to switch from the first transmission mode to the second transmission mode, Based on the above instruction, switch from the first transmission mode to the second transmission mode, The data packet reception window is extended by extending the boundary of the data packet reception window, and the boundary is extended by an offset. Receive data packets, The data packet is added to the receive buffer, and the addition is based on the fact that the signal-to-noise ratio (SN) of the data packet is within the extended portion of the extended data packet receive window. A WTRU equipped with a processor configured as such.
  2. The first transmission mode is associated with the first RNTI, the second transmission mode is associated with the second RNTI, and the processor is Based on the switching from the first transmission mode to the second transmission mode, monitoring is performed for PDCCH transmission via the use of the second RNTI. The WTRU according to claim 1, further configured as follows.
  3. The WTRU according to claim 2, wherein the boundary of the data packet reception window is the starting end of the data packet reception window, and extending the boundary of the data packet reception window includes setting the first value of the starting end to a second value that is lower by the offset below the sequence number (SN) associated with the received data.
  4. The WTRU according to claim 3, wherein the extended portion of the extended data packet reception window is the portion of the extended data packet reception window that begins at the second value and ends at the SN.
  5. The WTRU according to claim 1, wherein the first transmission mode is a point-to-point (PTP) transmission mode, and the second transmission mode is a point-to-multipoint (PTM) transmission mode.
  6. The WTRU according to claim 5, wherein the instruction is based on the reception of a radio link control (RLC) data packet via an RLC entity associated with the PTM transmission mode, and the WTRU is operating in the PTP transmission mode.
  7. The aforementioned processor, G-RNTI is received, Based on the reception of the G-RNTI, it is determined that the WTRU is permitted to participate in multicast operation. The WTRU according to claim 2, further configured as follows.
  8. The WTRU according to claim 1, wherein the boundary of the data packet reception window is extended based on state variables, the state variables including RX_next_reassemblely and RX_next_highest.
  9. The WTRU according to claim 8, wherein RX_next_reassemblely and RX_next_highest are received in a message, and the instruction to switch from the first transmission mode to the second transmission mode is indicated via the message.
  10. The WTRU according to claim 9, wherein the message is an RRC reconstruction message.
  11. A method performed by a wireless transceiver unit (WTRU), Receiving an instruction to switch from the first transmission mode to the second transmission mode, Based on the above instruction, the system switches from the first transmission mode to the second transmission mode, Extending the data packet reception window by extending the boundary of the data packet reception window, wherein the boundary is extended based on an offset. Receiving data packets and, The process involves adding the aforementioned data packet to the receive buffer, wherein the addition is based on the fact that the signal-to-noise ratio (SN) of the data packet falls within the extended portion of the extended data packet receive window. A method that includes [a certain feature].
  12. The first transmission mode is associated with a first RNTI, the second transmission mode is associated with a second RNTI, and the method is Based on the switching from the first transmission mode to the second transmission mode, monitoring for PDCCH transmission via the use of the second RNTI, The method according to claim 11, further comprising:
  13. The method according to claim 12, wherein the boundary of the data packet reception window is the starting end of the data packet reception window, and extending the boundary of the data packet reception window includes setting the first value of the starting end to a second value that is lower by the offset below the sequence number (SN) associated with the received data.
  14. The method according to claim 13, wherein the extended portion of the extended data packet reception window is the portion of the extended data packet reception window that begins at the second value and ends at the SN.
  15. The method according to claim 11, wherein the first transmission mode is a point-to-point (PTP) transmission mode, and the second transmission mode is a point-to-multipoint (PTM) transmission mode.
  16. The method according to claim 15, wherein the instruction is based on receiving radio link control (RLC) data packets via an RLC entity associated with the PTM transmission mode, and the WTRU is operating in the PTP transmission mode.
  17. The aforementioned method, Receiving G-RNTI and Based on the reception of the G-RNTI, it is determined that the WTRU is permitted to participate in multicast operation, The method according to claim 11, further comprising:
  18. The method according to claim 11, wherein the boundary of the data packet reception window is extended based on a state variable, the state variable includes RX_next_reassemblely and RX_next_highest.
  19. The method according to claim 18, wherein RX_next_reassemblely and RX_next_highest are received in a message, and the instruction to switch from the first transmission mode to the second transmission mode is indicated via the message.
  20. The method according to claim 19, wherein the message is an RRC reconstruction message.

Description

Cross-reference of related applications This application claims the benefit of U.S. Provisional Patent Application No. 63/135,930, filed on 11 January 2021, the disclosure of which is incorporated herein by reference in its entirety. Mobile communications using wireless communication are constantly evolving. The fifth generation of mobile communication radio access technology (RAT) can be referred to as 5G, or new radio (NR). Previous (conventional) generations of mobile communication RAT could be, for example, the fourth generation (4G) or long-term evolution (LTE). For example, systems, methods, and means relating to lossless switching between point-to-point (PTP) and point-to-multipoint (PTM) transmission and reception in multicast and broadcast services (MBS) are described herein. A wireless transmit-receive unit (WTRU) can receive instructions to switch from the use of point-to-point (PTP) transmission (e.g., from PTP transmission mode) to the use of point-to-multipoint (PTM) transmission (e.g., to PTM transmission mode), or can decide to switch from the use of PTP transmission (e.g., from PTP transmission mode) to the use of PTM transmission (e.g., to PTM transmission mode) based on reliability conditions associated with PTM mode. Based on the instructions or decision, the WTRU can switch from the use of PTP transmission (e.g., from PTP transmission mode) to the use of PTM transmission (e.g., to PTM transmission mode). The WTRU can receive a first data packet. The WTRU can extend the data packet receive window by extending its boundaries. The boundaries may be extended based on the sequence number (SN) and offset of the first data packet. In some examples, the WTRU can receive a second data packet and add it to the receive buffer for processing; this addition may be based on the second SN of the second data packet falling within the extended portion of the extended data packet receive window. In some examples, the boundary of the data packet receive window may be the beginning of the data packet receive window, and extending the boundary of the data packet receive window may involve setting the first value of the beginning to a second value that is offset lower than the SN of the first data packet. In some examples, the extended portion of the extended data packet receive window may be the portion of the extended data packet receive window that begins at the second value and ends at the SN of the first data packet. The WTRU can receive the first data packet. Based on the reliability conditions associated with the PTM transmission mode, the WTRU may decide to switch from using PTM transmission (e.g., from PTM transmission mode) to using PTP transmission (e.g., to PTP transmission mode). Based on this decision, the WTRU may send a request to switch from using PTM transmission (e.g., from PTM transmission mode) to using PTP transmission (e.g., to PTP transmission mode). The WTRU can receive an instruction to switch from using PTM transmission (e.g., from PTM transmission mode) to using PTP transmission (e.g., to PTP transmission mode). Based on the instruction, the WTRU can switch from using PTM transmission (e.g., from PTM transmission mode) to using PTP transmission (e.g., to PTP transmission mode) and send a data packet status report. The data packet status report may indicate that the first data packet was received. The WTRU can trigger MBS mode switching(s) (based on instructions, such as instructions received from the network, or based on decisions made by the WTRU), as shown in the example in Figure 3. The WTRU (see, for example, 304 in Figure 3) may be configured for MBS and may be configured with one or more multicast radio bearers (MRBs) (see, for example, 308 in Figure 3). The WTRU can receive configuration information from the network (see, for example, 306 in Figure 3), which may include parameters/thresholds (to be used, for example) for triggering MBS mode switching. Parameters/thresholds may include recounts of signal levels/thresholds related to the serving cell (e.g., reference signal received power (RSRP) level/threshold, reference signal received quality (RSRQ) level/threshold, received signal to noise indicator (RSNI) level/threshold, etc., HARQ failure/success rate level/threshold, MRB level/threshold). The WTRU can monitor the performance of the MBS operation (according to configuration information or WTRU implementation). The WTRU can decide to switch MBS modes. For example, the WTRU (for example, when operating in PTM mode) may decide to switch to PTP mode if, for example, the serving cell signal level falls below a threshold and/or the HARQ failure rate/retransmission count exceeds a threshold (see, for example, 310 in Figure 3). When the WTRU decides to switch the MBS mode, for example, from PTM to PTP or vice versa, it may send an MBS mode switch request (see, for example, 312 in Figure 3). The request may include information such as a packet data convergence protocol (PDCP)/R