Multicast and Broadcast Service Management Technology

Abstract

A technique for performing a wireless communication method is disclosed, and the method comprises: receiving first information instructing a communication node to operate in a point-to-multipoint (PTM) mode to receive multicast and broadcast service (MBS) data by a communication node; receiving second information instructing a communication node not to operate in a point-to-point (PTP) mode to receive MBS data by a communication node; and receiving MBS data by operating the communication node in a PTM mode rather than a PTP mode in response to the first information and the second information.

Description

Technology Field

[0001] This specification generally relates to digital wireless communication. Background Technology

[0002] Mobile communication technology is driving the world toward an increasingly connected and networked society. Compared to existing wireless networks, next-generation systems and wireless communication technologies must support a much wider range of use case characteristics and provide flexibility along with a more complex and sophisticated range of access requirements.

[0003] LTE (Long-Term Evolution) is a wireless communication standard for mobile devices and data terminals developed by the 3GPP (3rd Generation Partnership Project). LTE-A (LTE Advanced) is a wireless communication standard that enhances the LTE standard. The 5th generation wireless system, known as 5G, is dedicated to advancing the LTE and LTE-A wireless standards and supporting higher data speeds, a large number of connections, ultra-low latency, high reliability, and other new business requirements.

[0004] In some embodiments, a technique for managing multicast and broadcast services is disclosed so that packet loss can be minimized or prevented during switching between modes.

[0005] A first wireless communication method comprises: receiving first information instructing a communication node to operate in a point-to-multipoint (PTM) mode to receive multicast and broadcast service (MBS) data; receiving second information instructing a communication node not to operate in a point-to-point (PTP) mode to receive MBS data; and receiving MBS data by operating the communication node in a PTM mode rather than a PTP mode in response to the first information and the second information.

[0006] In some embodiments, the communication node receives first information while operating in PTP mode. In some embodiments, the first information instructs the communication node to operate in PTM mode and not to operate in PTP mode to receive MBS data. In some embodiments, the second information indicates that there is no transmission of data to the communication node via PTP mode. In some embodiments, the second information is indicated by a flag contained in a packet data convergence protocol (PDCP) protocol data unit (PDU) or a radio link control (RLC) PDU. In some embodiments, in response to receiving the first information, the communication node transmits a packet data convergence protocol (PDCP) status report to the network node, and the PDCP status report indicates whether one or more packets have been successfully received by the communication node. In some embodiments, the second information is included in a wireless resource control (RRC) signal, a packet data convergence protocol (PDCP) protocol data unit (PDU), a wireless link control (RLC) PDU, or a medium access control-control element (MAC CE).

[0007] A second wireless communication method comprises: receiving first information instructing a communication node to operate in point-to-point (PTP) mode to receive multicast and broadcast service (MBS) data and not to operate in point-to-multipoint (PTM) mode to receive MBS data; determining by the communication node to operate in PTP mode and not to operate in PTM mode to receive MBS data based on a rule associated with the first information; and receiving an MBS data set by a communication node that operates in PTP mode and not to operate in PTM mode.

[0008] In some embodiments, the communication node receives the first information while operating in PTM mode. In some embodiments, the rule specifies that in response to the reception of the first information, the communication node determines to operate in PTP mode and not to operate in PTM mode. In some embodiments, the rule specifies that after a length of time following the reception of the first information, the communication node determines to operate in PTP mode and not to operate in PTM mode.

[0009] A third wireless communication method comprises: transmitting information indicating that there is no data in a radio bearer for a multicast and broadcast service (MBS) for point-to-point (PTP) transmission by a user plane (UP) of a centralized unit (CU) of a network node to a distributed unit (DU) of a network node; and receiving information by the DU of the network node, wherein the information includes a flag indicating whether the frame containing the information also contains a last packet data convergence protocol (PDCP) protocol data unit (PDU) for PTP transmission.

[0010] In some embodiments, the information includes the number of one or more communication nodes and the identity of each communication node in response to a flag indicating that the frame contains the last PDCP PDU for PTP transmission to one or more communication nodes. In some embodiments, the frame is transmitted in an F1-U tunnel associated with one or more communication nodes using a single radio bearer associated with the MBS. In some embodiments, the frame is transmitted in an F1-U tunnel associated with a specific communication node operating in PTP mode. In some embodiments, the frame is transmitted in an F1-U tunnel carrying packets associated with a single radio bearer associated with the MBS.

[0011] The fourth wireless communication method includes the step of receiving information indicating the absence of expected data through point-to-point (PTP) communication technology between the DU of the network node and one or more communication nodes by the user plane (UP) of the centralized unit (CU) of the network node from the distributed unit (DU) of the network node, and the information is received in a frame by the UP of the CU of the network node.

[0012] In some embodiments, the frame further includes any one or more of a flag indicating which of the information pertains to one or more communication nodes, the number of one or more communication nodes, and the identity of each communication node.

[0013] The fifth wireless communication method comprises the step of receiving information indicating the absence of expected data through point-to-point (PTP) communication technology between the DU of the network node and one or more communication nodes from a distributed unit (DU) of the network node by a centralized unit (CU) of the network node, wherein the information includes any one or more of a wireless bearer identifier, a flag indicating whether the information is applicable to one or more communication nodes, a number of one or more communication nodes, an identity of each communication node, and a multicast session identifier.

[0014] In another exemplary embodiment, the above-described method is implemented in the form of processor-executable code and stored in a non-transient computer-readable storage medium. The code contained in the computer-readable storage medium enables the processor to implement the method disclosed in this patent specification when executed by the processor.

[0015] In another exemplary embodiment, a device configured or operable to perform the above-described method is disclosed.

[0016] The above and other embodiments and their implementations are described in more detail in the drawings, detailed description, and claims. Brief explanation of the drawing

[0017] Figure 1 shows an exemplary technique for lossless switching from point-to-point (PTP) mode to point-to-multipoint (PTM) mode. Figure 2 shows an exemplary technique for performing lossless switching from PTM mode to PTP mode. Figure 3 shows an exemplary technique for performing lossless switching from a combination of PTM mode and PTP mode to PTP mode or PTM mode. Figure 4 shows an exemplary block diagram of a centralized unit (CU)-distributed unit (DU) partitioning architecture of a base station. FIG. 5 shows an exemplary block diagram of a hardware platform (500) that may be part of a network node or user equipment. FIG. 6 shows an example of wireless communication including user equipment (UE) and a base station (BS), based on some embodiments of the disclosed technology. Figure 7 shows an exemplary flowchart for operating a communication node in PTM mode or PTP mode. Figure 8 shows an exemplary flowchart for operating a communication node in PTM mode or PTP mode. FIGS. 9 to 11 show three exemplary flowcharts for operating network nodes in a partitioned architecture. Specific details for implementing the invention

[0018] A UE can receive multicast broadcast sessions (MBS) through various modes, such as point-to-point (PTP) mode or point-to-multipoint (PTM) mode. When the mode is changed to another mode, a technique is required to minimize packet loss or enable lossless mode switching. The exemplary method proposed in this patent specification is designed, among other things, to minimize or avoid packet loss during mode switching between PTP and PTM.

[0019] The exemplary headings for the various sections below are used to facilitate understanding of the subject matter disclosed and do not limit the scope of the claimed subject matter in any way. Accordingly, one or more features of one exemplary section may be combined with one or more features of another exemplary section. Additionally, while the term 5G has been used for clarity of description, the technology disclosed herein is not limited to 5G technology and may be used in wireless systems implementing other protocols.

[0020] I. Exemplary technique for avoiding or reducing packet loss during mode switching.

[0021] In the following methods and embodiments, the meaning of "not using PTP to receive MBS data" or "not operating in PTP mode to receive MBS data" may include at least one of the following descriptions.

[0022] ● Release the PTP Wireless Link Control (RLC) bearer from the MBS wireless bearer.

[0023] ● Disable PTP, disable reception of the RLC bearer for PTP from the wireless bearer for MBS, or reset the status variables and / or timers of the RLC entity for PTP from the wireless bearer for MBS to their initial values.

[0024] The meaning of "using PTM to receive MBS data" or "operating in PTM mode to receive MBS data" may include at least one of the following descriptions.

[0025] ● Add the RLC bearer for PTM to the wireless bearer for MBS.

[0026] ● Activate PTM, enable reception of the RLC bearer for PTM from the wireless bearer for MBS, or resume monitoring of G-RNTI (e.g., wireless network temporary identifier for the MBS group).

[0027] The meaning of "does not use PTM to receive MBS data" or "does not operate in PTM mode to receive MBS data" may include at least one of the following descriptions.

[0028] ● Release the RLC bearer for PTM from the wireless bearer for MBS.

[0029] ● Disable PTM, for example, pause G-RNTI monitoring, or disable reception of the RLC bearer for PTM from the wireless bearer for MBS.

[0030] The meaning of "using PTP to receive MBS data" or "operating in PTP mode to receive MBS data" may include at least one of the following descriptions.

[0031] ● Add an RLC bearer for PTP to the wireless bearer for MBS.

[0032] ● Activate PTP, or enable reception of the RLC bearer for PTP from the wireless bearer for MBS.

[0033] I.(a). Scenario 1: The UE must be switched from PTP to PTM.

[0034] Method 1-1: After the UE receives first information from the base station, the UE uses PTM to receive MBS data, while the UE continues to receive MBS data from PTP until it receives second information from the base station. After the UE receives second information, the UE no longer uses PTP to receive MBS data.

[0035] Example 1-1-1. A UE receives first information from a gNB, and the first information instructs the UE to use PTM to receive MBS data and not to use PTP to receive MBS data.

[0036] After receiving the first information, the UE uses PTM to receive MBS data, and the UE continues to use PTP to receive MBS data until it receives the second information. Upon receiving the first information, the UE transmits a Packet Data Convergence Protocol (PDCP) status report to the base station via PTP. The UE includes information within the PDCP status report to indicate to the base station which data packet(s) were successfully received and which data packet(s) were lost during transmission. If the UE has not received the second information, the UE continues to use PTP to receive MBS data.

[0037] After receiving the second information, the UE no longer uses PTP to receive MBS data. In some embodiments, after the UE transmits PDCP status information to the base station, the UE receives the second information. The second information may include at least one of the following descriptions.

[0038] ● For example, the second information may be an end marker or flag of a PDCP PDU or RLC PDU, and the end marker or flag indicates that there is no more data to be transmitted via PTP. The PDCP PDU may be a PDCP Data PDU or a PDCP Control PDU. The RLC PDU may be an RLC Data PDU or an RLC Control PDU.

[0039] ● In another embodiment, the second information may be included in a MAC CE indicating that the PTP can now be released or deactivated.

[0040] Example 1-2-1. A UE receiving MBS data via PTP receives first information from gNB, and the first information instructs the UE to use PTM to receive MBS data.

[0041] Upon receiving the first information, the UE can perform at least one of the operations of receiving MBS data using PTM and transmitting a PDCP status report to the base station via PTP.

[0042] Subsequently, the UE receives second information instructing it not to use PTP to receive MBS data. The second information may be included in RRC signaling, PDCP PDU, RLC PDU, MAC CE. In some embodiments, the second information may be received by the UE after receiving first information instructing the UE to use PTM to receive MBS data.

[0043] Method 1-2: After receiving first information instructing the UE to use PTM to receive MBS data and not to use PTP to receive MBS data, the UE continues to receive MBS data from PTP for a time period. In some embodiments, the UE continues to receive MBS data from PTP for a predetermined time period.

[0044] Upon receiving the first information, the UE transmits the PDCP status report to the base station via PTP.

[0045] After transmitting a PDCP status report to the gNB, the UE determines for itself the timing (e.g., a certain length of time) when not using PTP to receive MBS data. For example, the timing may vary depending on the implementation. In another embodiment, the timing may be based on the UE successfully receiving a lost PDCP SN that was included in the PDCP status report triggered by the first information.

[0046] FIG. 1 illustrates an exemplary technique for lossless switching from point-to-point (PTP) mode to point-to-multipoint (PTM) mode. A RAN node can determine the forwarding mode for a set of UEs associated with an MBS session based on the UE context, the MBS session context, and the network resource state. If the gNB determines that a UE must be switched from PTP to PTM and that lossless mode switching must be supported, the UE and the gNB can perform exemplary operations as illustrated in FIG. 1. Operations 0 through 8 illustrated in FIG. 1 are described below and in this patent specification.

[0047] 0. The UE uses PTP to receive MBS.

[0048] 1. The UE and the RAN can perform network (NW) interactions in which the UE can provide feedback on the MBS reception status or channel status.

[0049] 2. The RAN decides to switch from PTP to PTM for the UE.

[0050] 3. The RAN instructs the UE to use PTM to receive MBS.

[0051] 4-5. After operation 3, the UE uses both PTM and PTP to receive MBS, and the UE sends a PDCP status report to the RAN.

[0052] 6. Based on the PDCP status report, the RAN knows which packets were lost by the UE and resends these packets to the UE through the PTP leg.

[0053] 7. After successfully transmitting the lost packet via PTP, the RAN instructs the UE not to use PTP.

[0054] 8. The UE uses PTM only for MBS reception, and now the UE does not use PTP. If lossless mode switching must be guaranteed by protocol means, operation 8 may be triggered by operation 7. Only when the goal is to minimize non-lossless data loss, operation 7 may also be omitted, in which case operation 8 is triggered by the UE implementation, and then operation 4 is performed for a certain period of time (e.g., for a predetermined period of time).

[0055] I.(b). Scenario 2: The UE must be switched from PTM to PTP.

[0056] Method 2: After receiving third information, the UE uses PTP to receive MBS data and the UE transmits a PDCP status report to the base station.

[0057] Example 2-1: The third information instructs the UE to use PTP to receive MBS data and not to use PTM to receive MBS data.

[0058] After receiving third information, the UE uses PTP to receive MBS data, and the UE transmits a PDCP status report to the base station.

[0059] Timings during which the UE does not use PTM to receive MBS data may include at least one of the following.

[0060] ● When third information is received (e.g., the UE stops receiving MBS data from the PTM in response to receiving third information).

[0061] ● After receiving third information during a time period (e.g., during a predetermined time period).

[0062] Example 2-2: The third information instructs the UE to receive MBS data using PTP.

[0063] Timings during which the UE does not use PTM to receive MBS data may include at least one of the following.

[0064] ● When the UE receives fourth information instructing it not to use the PTM to receive MBS data (e.g., the UE stops receiving MBS data from the PTM in response to the UE receiving the fourth information). In some embodiments, the fourth information may be received by the UE after receiving third information instructing the UE to use the PTP to receive MBS data.

[0065] In some embodiments, the wireless communication method for Example 2-2 may include: receiving first information instructing the communication node to operate in point-to-point (PTP) mode to receive multicast and broadcast service (MBS) data by the communication node; receiving second information instructing the communication node to operate in point-to-multipoint (PTM) mode to receive MBS data by the communication node; determining by the communication node not to operate in PTM mode to receive MBS data in response to receiving the second information; and receiving a set of MBS data by the communication node that operates in PTP mode and not in PTM mode. In some embodiments, the communication node receives the first information while operating in PTM mode.

[0066] FIG. 2 illustrates an exemplary technique for performing lossless switching from PTM mode to PTP mode. When gNB determines that the UE must be switched from PTM to PTP and that lossless mode switching must be supported, the UE and gNB can perform exemplary operations as illustrated in FIG. 2. Operations 0 through 7 illustrated in FIG. 2 are described below and in this patent specification.

[0067] 0. The UE uses PTM to receive MBS.

[0068] 1. The UE and the RAN can perform network (NW) interactions in which the UE can provide feedback on the MBS reception status or channel status.

[0069] 2. The RAN decides to switch from PTM to PTP for the UE.

[0070] 3. The RAN instructs the UE to use PTM for MBS reception and not to use PTP.

[0071] 4-5. After operation 3, the UE uses only PTP to receive MBS, and the UE sends a PDCP status report to the RAN.

[0072] 6. Based on the PDCP status report, the RAN knows which packets were lost by the UE and resends these packets to the UE through the PTP leg.

[0073] 7. After successfully transmitting the lost packet via PTP, the RAN transmits a new packet to the UE via PTP.

[0074] I.(c). Scenario 3: The UE must be switched from PTP+PTM to PTP, or from PTP+PTM to PTM.

[0075] The UE receives ninth information from the base station, and the ninth information triggers the UE to perform a PDCP status report. The ninth information may be a polling indication included in a PDCP PDU. In another embodiment, the ninth information may be included in an RRC message.

[0076] The UE receives tenth information instructing the UE not to use PTP or PTM to receive MBS data. The tenth information may be included in an RRC message, or a MAC CE, or a PDCP PDU, or an RLC PDU.

[0077] Upon receiving the 10th information, the UE does not use PTP or PTM to receive MBS data immediately or after a time period (e.g., after a predetermined time period).

[0078] The base station may transmit the 10th information after transmitting one or more lost packets as directed by the PDCP status report triggered by the 9th information.

[0079] FIG. 3 illustrates an exemplary technique for performing lossless switching from a combination of PTM mode and PTP mode to PTP mode or PTM mode. If gNB determines that the UE must be switched from PTM+PTP to PTP or PTM and that lossless mode switching must be supported, the UE and gNB can perform exemplary operations as illustrated in FIG. 3. Operations 0 through 7 illustrated in FIG. 3 are described below and in this patent specification.

[0080] 0. The UE uses PTM+PTP for MBS reception.

[0081] 1. The UE and the RAN can perform network (NW) interactions in which the UE can provide feedback on the MBS reception status or channel status.

[0082] 2. RAN from PTM+PTP for the UE<PTP 또는 PTM> Decide to switch to.

[0083] 3. The RAN instructs the UE to transmit PDCP status reports.

[0084] 4. The UE transmits PDCP status reports to the RAN via the PTP leg.

[0085] 5. Based on the PDCP status report, the RAN knows which packets were lost by the UE and resends these packets to the UE through the PTP leg.

[0086] 6. After successfully transmitting the lost packet via PTP, the RAN [receives] MBS from the UE<PTM 또는 PTP> Instruct not to use .

[0087] 7. The UE is only for MBS reception<PTP 또는 PTM> Uses

[0088] In some embodiments, a wireless communication method for scenario 3 comprises: transmitting a packet data convergence protocol (PDCP) status report by a communication node indicating whether one or more packets have been successfully received by the communication node; receiving information by the communication node and in response to the PDCP status report instructing the communication node not to operate in point-to-multipoint (PTM) mode and point-to-point (PTP) mode to receive multicast and broadcast service (MBS) data; and receiving MBS data by the communication node while not operating in PTP mode and PTM mode based on a rule. In some embodiments, the rule specifies that the communication node receives MBS data while not operating in PTP mode and PTM mode in response to receiving the information. In some embodiments, the rule specifies that the communication node receives MBS data while not operating in PTP mode and PTM mode after a certain length of time after receiving the information.

[0089] II. Description of when a base station is expected to transmit instructions regarding the timing for not using the previous mode in a CU-DU partitioned architecture.

[0090] FIG. 4 shows an exemplary block diagram of a CU-DU partitioning architecture of a base station. In 5G technology, the CU can perform operations related to the PDCP layer, and the DU can perform operations related to the RLC and MAC layers. When data packet processing (which may be a retransmitted data packet) is completed, the CU and the DU must inform each other so that the base station can transmit information (e.g., the fourth information in Example 2-2 or the second information in Method 1-1) to the UE to inform the UE not to use the previous mode.

[0091] If the command sender is CU-UP, the command sender can determine the timing of the PTP release through the following method: CU-UP can notify the DU that the PDCP entity has successfully delivered all PDCP PDUs to be transmitted via PTP, and the DU can feed back the downlink data delivery status to CU-UP. Then, CU-UP knows the time to send a command to the UE to not operate in PTP mode.

[0092] If the command sender is CU-CP, the command sender can determine the timing of the PTP release through the following method: CU-UP can notify the DU that the PDCP entity has successfully delivered all PDCP PDUs to be transmitted via PTP, and after the DU feeds back the downlink data delivery status to CU-UP, CU-UP informs CU-CP that it is time to send a command to the UE not to operate in PTP mode.

[0093] If the command sender is a DU, the command sender can determine the timing of the PTP release through the following method: the CU-UP can notify the DU that the PDCP entity has successfully delivered all PDCP PDUs to be transmitted via PTP, and the DU can determine for itself the appropriate time to send a command to the UE to not operate in PTP mode based on the RLC ACK or packet delivery status.

[0094] Method 3: The CU-UP of the base station transmits a fifth information to the DU of the same base station to indicate that there is no more data to the radio bearer of the MBS for PTP transmission. In some embodiments, after the CU-UP transmits the fifth information to the DU, the base station may transmit information to the UE(s) to instruct the UE not to use PTP mode or not to operate in PTP mode, as described in Section 1 of this patent specification.

[0095] Example 3-1:

[0096] The fifth information includes a first flag for indicating whether the frame carrying the fifth information delivers the last PDCP PDU via PTP to one or more UEs. The frame carrying the fifth information may be an F1-U packet transmitted from the CU-UP of the DU, the frame header may be within the F1-U protocol, and the frame load may be a PDCP PDU. In some embodiments, the PDCP PDU (e.g., load) may be processed by an RLC / MAC entity within the DU and transmitted to the UE.

[0097] Fifth information further includes the number of the UE and the identity of each UE if the first flag indicates that this frame contains the last PDCP PDU through PTP for one or more UEs. Thus, the F1-U tunnel in Example 3-1 may be a group common tunnel.

[0098] The fifth piece of information is included in the first frame.

[0099] The first frame is used to transmit a downlink NR PDCP PDU for the MBS from the CU-UP to the DU. The first frame is transmitted in a procedure associated with a single radio bearer for the MBS and associated with a group of UEs that are joining or have joined to the MBS.

[0100] Example 3-2:

[0101] The fifth information includes a first flag for indicating whether the frame conveying the fifth information conveys the last PDCP PDU to the UE via PTP.

[0102] The fifth piece of information is included in the second frame.

[0103] The second frame is used to transmit the downlink NR PDCP PDU for the MBS from the CU-UP to the DU. The second frame is transmitted as a procedure associated with a single radio bearer for the MBS and associated with a specific UE receiving the radio bearer via PTP mode. Thus, the F1-U tunnel in Example 3-2 may be a UE-specific tunnel.

[0104] Method 4: CU-UP sets the DL report NR PDCP PDU SN as the last PDCP SN associated with the last packet to be transmitted via PTP to one or more UE(s) in the third frame.

[0105] The third frame is used to transmit downlink NR PDCP PDUs for MBS from the base station's CU-UP to the same base station's DU. When the DU receives the third frame, it determines the SN of the last PDCP PDU, so the DU can check whether one or more PDCP PDUs received by the DU have the same SN as the last PDCP PDU. If the DU determines that a PDCP PDU has the same SN as the last PDCP PDU, the base station can transmit information to the UE(s) to not use PTP mode or not operate in PTP mode.

[0106] The third frame is transmitted as a procedure associated with a single wireless bearer for the MBS. In one embodiment, the procedure is associated with a specific UE receiving the wireless bearer via PTP mode.

[0107] In another embodiment, the procedure is associated with MBS or a group of combined UEs. The third frame further includes a PDCP PDU for PTP for one or more UEs, the number of the UE receiving this PDCP PDU via PTP, and a second flag indicating whether the frame conveys the identity of each UE.

[0108] In some embodiments, the wireless communication method of method 4 comprises the steps of: transmitting, by a user plane (UP) of a centralized unit (CU) of a network node to a distributed unit (DU) of a network node, a serial number of the last packet data convergence protocol (PDCP) protocol data unit (PDU) to be transmitted in a wireless frame via point-to-point transmission; receiving, by a DU of the network node, the serial number of the last PDCP PDU for the PTP transmission; and transmitting information to one or more communication nodes in response to receiving the serial number by the network node and by the DU, wherein the information instructs one or more communication nodes whether to operate in PTP mode. In some embodiments, the frame is transmitted in an FI-1 tunnel associated with one or more communication nodes using a single wireless bearer associated with an MBS. In some embodiments, the frame is transmitted in an F1-U tunnel associated with a specific communication node operating in PTP mode. In some embodiments, the frame further includes any one or more of a flag indicating which of the information pertains to one or more communication nodes, the number of one or more communication nodes, and the identity of each communication node.

[0109] Method 5: The DU transmits sixth information to the CU-UP to indicate that one or more UL or DL ​​data are expected to be transmitted between the DU and the UE(s) via PTP. In some embodiments, after the DU transmits the sixth information to the CU-UP or after the CU-UP receives the sixth information, the gNB transmits other information instructing one or more communication nodes whether to operate in PTP mode, as described in Section I of this patent specification.

[0110] Sixth information may be included in the fourth frame. The fourth frame is used to provide feedback from the DU to the CU-UP to enable the CU-UP to control the downlink user data flow for individual radio bearers of the MBS. In some embodiments, the CU-UP may control the data transmission rate based on information from the fourth frame. The fourth frame is transmitted as a procedure associated with a single radio bearer for the MBS.

[0111] In one embodiment, the procedure is associated with a specific UE that receives a wireless bearer via PTP mode.

[0112] In another embodiment, the procedure is associated with MBS or a group of combined UEs. The fourth frame further includes at least one of a third flag indicating whether this feedback is for one or more specific UEs, the number of the specific UE, or the identity of each UE.

[0113] Method 6: The DU transmits seventh information to the CU-CP to indicate that no further UL or DL ​​data is expected to be transmitted between the DU and the UE(s) via PTP. In some embodiments, if the CU-CP determines that the seventh information is an RRC message, the CU-CP may transmit the seventh information as described in Section I of this patent specification after receiving the seventh information.

[0114] The seventh piece of information may be included in the F1AP message. The F1AP message is transmitted via the F1AP procedure.

[0115] In one embodiment, the procedure is associated with a multicast session. The fourth frame further includes at least one of a third flag indicating whether this feedback is for one or more specific UEs, the number of the specific UE, or the identity of each UE.

[0116] In another embodiment, the procedure is associated with a specific UE. The seventh information further includes a multicast session ID and a wireless bearer ID.

[0117] Method 7: CU-UP transmits eighth information to CU-CP to indicate that no further UL or DL ​​data is expected to be transmitted between the DU and the UE(s) via PTP. In some embodiments, if CU-CP determines that the eighth information is an RRC message, after receiving the eighth information, CU-CP may transmit second information as described in Section I of this patent specification.

[0118] The eighth piece of information may be included in the E1AP message. The E1AP message is transmitted via the E1AP procedure.

[0119] In one embodiment, the procedure is associated with a multicast session. The fourth frame further includes at least one of a third flag indicating whether this feedback is for one or more specific UEs, the number of the specific UE, or the identity of each UE.

[0120] In another embodiment, the procedure is associated with a specific UE. The eighth information further includes a multicast session ID and a wireless bearer ID.

[0121] III. A technology that enables the UE of the MBS to move the receiving window under the control of the base station.

[0122] Method 8: This section describes a technique to address the issue of whether it is necessary for a UE of an MBS to move its receive window under the control of a base station. In some embodiments, the base station may be able to dynamically control the UE to lose some packets in order to keep up with the rate of packet transmission. The base station may transmit a special PDCP PDU to all UEs containing a specific PDCP SN or COUNT. Upon receiving this PDCP PDU, the UE moves the lower boundary of its receive window to the specific PDCP SN or COUNT. The specific COUNT refers to the COUNT associated with the specific PDCP SN included in the special PDCP PDU, or the specific COUNT included in the special PDCP PDU.

[0123] After receiving a special PDCP PDU, the UE's PDCP entity performs at least one (or any one or more) of the following actions:

[0124] ● In the following cases, if the files have not been decompressed previously, perform header decompression and then pass them to the upper layer in ascending order of the associated COUNT values.

[0125] ■ All stored PDCP SDU(s) with associated COUNT value(s) < specific COUNT.

[0126] ■ All stored PDCP SDU(s) with consecutively associated COUNT value(s) start from a specific COUNT.

[0127] ● Update RX_DELIV with the COUNT value of the 1st PDCP SDU that was not passed to the upper layer (COUNT value >= specific COUNT).

[0128] ● If RX_DELIV < RX_NEXT:

[0129] ■ Updated RX_REORD to RX_NEXT.

[0130] ■ Start t-Reordering.

[0131] Method 9: The base station may send a special RLC packet to a group of UEs receiving through a PTM that includes a specific SN. After receiving this RLC packet, the UE will move the lower boundary of the receiving window to the specific SN.

[0132] After receiving a special RLC packet, the receiving side of the AM RLC entity performs at least one of the following operations:

[0133] ● Discard all segments where SN < a specific SN that are not reassembled and passed to the upper layer.

[0134] ● Update RX_Next to a specific SN.

[0135] ● Update RX_Highest_Status to the SN of the first RLC SDU with SN >= RX_Next_Status_Trigger where all bytes were not received.

[0136] ● If RX_Next_Highest > RX_Highest_Status + 1: or if RX_Next_Highest = RX_Highest_Status + 1 and there is at least one missing byte segment of the SDU associated with SN = RX_Highest_Status before the last byte of all received segments of this SDU:

[0137] ■ Start t-Reassembly.

[0138] ■ Set RX_Next_Status_Trigger to RX_Next_Highest.

[0139] In some embodiments of the technology described in Section III, a wireless communication method comprises: receiving by a communication node a first number of a packet data convergence protocol (PDCP) protocol data unit (PDU) to be received by the communication node or a serial number of a last PDCP PDU; and determining by the communication node a lower boundary of a reception time period for receiving one or more PDCP PDUs, wherein one of the one or more PDCP PDUs has the serial number of the last PDCP PDU, or the second number of one or more PDCP PDUs is the same as the first number of the PDCP PDU to be received by the communication node.

[0140] FIG. 5 illustrates an exemplary block diagram of a hardware platform (500) that may be part of a network node or user equipment. The hardware platform (500) includes at least one processor (510) and a memory (505) in which instructions are stored. When executed by the processor (510), the instructions configure the hardware platform (500) to perform operations in a number of embodiments described with respect to FIGS. 1 through 4 and FIGS. 7 through 15 and described herein. A transmitter (515) transmits or sends information or data to another node. For example, a network node transmitter may transmit a message to user equipment. A receiver (520) receives information or data transmitted or sent by other modes. For example, user equipment may receive a message from a network node.

[0141] An embodiment as discussed above will be applied to wireless communication. FIG. 6 illustrates an example of a wireless communication system (e.g., a 5G or NR cellular network) comprising a base station (620) and one or more user equipment (UE) (611, 612, and 613). In some embodiments, the UE accesses a BS (e.g., a network) using a communication link to the network [sometimes referred to as the uplink direction, as indicated by dashed arrows (631, 632, 633)], which enables subsequent communication from the BS to the UE [sometimes referred to as the downlink direction, as indicated by arrows (641, 642, 643)]. In some embodiments, the BS transmits information to the UE [sometimes referred to as the downlink direction, as illustrated by arrows (641, 642, 643)], which enables subsequent communication from the UE to the BS [e.g., shown as the direction from the UE to the BS, sometimes referred to as the uplink direction, as illustrated by dashed arrows (631, 632, 633)]. The UE may be, for example, a smartphone, tablet, mobile computer, machine-to-machine (M2M) device, IoT (Internet of Things) device, etc.

[0142] UEs can be, for example, smartphones, tablets, mobile computers, machine-to-machine (M2M) devices, IoT (Internet of Things) devices, etc.

[0143] FIG. 7 illustrates an exemplary flowchart for operating a communication node (e.g., a communication device or user equipment) in PTM mode or PTP mode. Operation 702 includes receiving first information instructing the communication node to operate in point-to-multipoint (PTM) mode to receive multicast and broadcast service (MBS) data. Operation 704 includes receiving second information instructing the communication node to operate in point-to-point (PTP) mode to receive multicast and broadcast service (MBS) data. Operation 706 includes receiving MBS data by operating the communication node in PTM mode rather than PTP mode in response to the first and second information.

[0144] In some embodiments, the communication node receives first information while operating in PTP mode. In some embodiments, the first information instructs the communication node to operate in PTM mode and not to operate in PTP mode to receive MBS data. In some embodiments, the second information indicates that there is no transmission of data to the communication node via PTP mode. In some embodiments, the second information is indicated by a flag contained in a packet data convergence protocol (PDCP) protocol data unit (PDU) or a radio link control (RLC) PDU. In some embodiments, in response to receiving the first information, the communication node transmits a packet data convergence protocol (PDCP) status report to the network node, and the PDCP status report indicates whether one or more packets have been successfully received by the communication node. In some embodiments, the second information is included in a wireless resource control (RRC) signal, a packet data convergence protocol (PDCP) protocol data unit (PDU), a wireless link control (RLC) PDU, or a medium access control-control element (MAC CE).

[0145] In some embodiments, another wireless communication method comprises: receiving first information instructing a communication node to operate in point-to-multipoint (PTM) mode to receive multicast and broadcast service (MBS) data by a communication node; determining that the communication node operates simultaneously in point-to-point (PTP) mode and PTM mode in response to the first information; and receiving a first set of MBS data by a communication node operating in PTP mode and PTM mode.

[0146] In some embodiments, a communication node receives first information while operating in PTP mode. In some embodiments, the first information instructs the communication node to operate in PTM mode and not to operate in PTP mode to receive MBS data. In some embodiments, the method further comprises: receiving second information indicating the absence of data transmission to the communication node via PTP mode by the communication node; determining that the communication node does not operate in PTP mode in response to the second information; and receiving a second set of MBS data by the communication node operating in PTM mode and not operating in PTP mode. In some embodiments, the second information is indicated by a flag contained in a packet data convergence protocol (PDCP) protocol data unit (PDU) or a radio link control (RLC) PDU. In some embodiments, the method comprises: receiving second information indicating the release or deactivation of PTP mode by the communication node; determining that the communication node does not operate in PTP mode in response to the second information; and further includes the step of receiving a second set of MBS data by a communication node that operates in PTM mode and does not operate in PTP mode.

[0147] In some embodiments, the communication node transmits a packet data convergence protocol (PDCP) status report to a network node in response to receiving the first information, and the PDCP status report indicates whether one or more packets have been successfully received by the communication node. In some embodiments, the method further comprises the steps of: receiving second information instructing the communication node not to operate in PTP mode to receive MBS data; determining that the communication node does not operate in PTP mode in response to the second information; and receiving a second set of MBS data by the communication node that operates in PTM mode and does not operate in PTP mode.

[0148] In some embodiments, the second information is contained in a wireless resource control (RRC) signal, a packet data convergence protocol (PDCP) protocol data unit (PDU), a wireless link control (RLC) PDU, or a medium access control-control element (MAC CE). In some embodiments, after the communication node transmits a packet data convergence protocol (PDCP) status report to the network node, the communication node determines not to operate in PTP mode for a period of time, and the PDCP status report indicates whether one or more packets have been successfully received by the communication node.

[0149] FIG. 8 illustrates an exemplary flowchart for operating a communication node (e.g., a communication device or user equipment) in PTM mode or PTP mode. Operation 802 includes receiving first information instructing the communication node to operate in point-to-point (PTP) mode to receive multicast and broadcast service (MBS) data and not to operate in point-to-multipoint (PTM) mode to receive MBS data. Operation 804 includes determining, based on a rule associated with the first information, that the communication node should operate in PTP mode to receive MBS data and not operate in PTM mode. Operation 806 includes receiving a set of MBS data by the communication node that operates in PTP mode and not in PTM mode.

[0150] In some embodiments, the communication node receives the first information while operating in PTM mode. In some embodiments, the rule specifies that in response to the reception of the first information, the communication node determines to operate in PTP mode and not to operate in PTM mode. In some embodiments, the rule specifies that after a length of time following the reception of the first information, the communication node determines to operate in PTP mode and not to operate in PTM mode.

[0151] FIG. 9 illustrates an exemplary flowchart for operating a network node in a partitioned architecture. Operation 902 includes an operation in which the user plane (UP) of the centralized unit (CU) of the network node transmits information to the distributed unit (DU) of the network node indicating that there is no data in the wireless bearer for the multicast and broadcast service (MBS) for point-to-point (PTP) transmission. Operation 904 includes an operation in which the DU of the network node receives information including a flag indicating whether the frame containing the information also includes the last packet data convergence protocol (PDCP) protocol data unit (PDU) for PTP transmission.

[0152] In some embodiments, the information includes the number of one or more communication nodes and the identity of each communication node in response to a flag indicating that the frame contains the last PDCP PDU for PTP transmission to one or more communication nodes. In some embodiments, the frame is transmitted in an F1-U tunnel associated with one or more communication nodes using a single radio bearer associated with the MBS. In some embodiments, the frame is transmitted in an F1-U tunnel associated with a specific communication node operating in PTP mode. In some embodiments, the frame is transmitted in an F1-U tunnel carrying packets associated with a single radio bearer associated with the MBS.

[0153] FIG. 10 illustrates another exemplary flowchart for operating a network node in a partitioned architecture. Operation 1002 includes receiving information indicating the absence of expected data through point-to-point (PTP) communication technology between the network node's DU and one or more communication nodes, by the user plane (UP) of the centralized unit (CU) of the network node from the distributed unit (DU) of the network node, and the information is received in a frame by the UP of the network node's CU.

[0154] In some embodiments, the frame further includes any one or more of a flag indicating which of the information pertains to one or more communication nodes, the number of one or more communication nodes, and the identity of each communication node.

[0155] FIG. 11 illustrates another exemplary flowchart for operating a network node in a partitioned architecture. Operation 1102 includes receiving information from a distributed unit (DU) of a network node by a centralized unit (CU) of a network node, indicating the absence of expected data through point-to-point (PTP) communication technology between the DU of the network node and one or more communication nodes, wherein the information includes any one or more of a wireless bearer identifier, a flag indicating whether the information is applicable to one or more communication nodes, the number of one or more communication nodes, the identity of each communication node, and a multicast session identifier.

[0156] In some embodiments, information is received by the control plane (CP) of the CU. In some embodiments, information is received by the user plane (UP) of the CU.

[0157] In some embodiments, a device for wireless communication includes a processor configured to implement the operations described in FIGS. 1 through 11 and in a number of related embodiments. In some embodiments, code is stored in a non-transient computer-readable program storage medium, and when executed by the processor, this code causes the processor to implement the operations described in FIGS. 1 through 11 and various related embodiments.

[0158] In this specification, the term "exemplary" is used to mean "an example of" and does not imply an ideal or preferred embodiment unless otherwise specified. In this specification, terms such as the first, second, third...ninth, etc., do not imply a specific order unless otherwise specified.

[0159] Some of the actual forms disclosed herein are implemented as an embodiment by a computer program product and are described in the general context of a method or processor that can be executed by a computer in a networked environment, and are implemented on a computer-readable medium containing computer-executable instructions such as program code. Computer-readable media may include removable and non-removable storage devices, including but not limited to ROM (Read Only Memory), RAM (Random Access Memory), CD (Compact Disc), DVD (Digital Versatile Disc), etc. Accordingly, computer-readable media may include non-transient storage media. Generally, a program module may include routines, programs, objects, components, data structures, etc., that perform specific tasks or implement specific abstract data types. Computer or processor-executable instructions, related data structures, and program modules represent examples of program code for executing the steps of the method disclosed herein. Specific sequences of such executable instructions or related data structures represent examples of corresponding operations for implementing the functions described in these steps or processes.

[0160] Some of the disclosed embodiments may be implemented as devices or modules using hardware circuits, software, or a combination thereof. For example, a hardware circuit implementation may include individual analog and / or digital components integrated, for example, as part of a printed circuit board. Alternatively or additionally, the disclosed components or modules may be implemented as Application Specific Integrated Circuit (ASIC) and / or Field Programmable Gate Array (FPGA) devices. Some embodiments may additionally or alternatively include a Digital Signal Processor (DSP), which is a specialized microprocessor having an architecture optimized for the operational requirements of digital signal processing related to the functions disclosed in this application. Likewise, various components or sub-components within each module may be implemented in software, hardware, or firmware. Connections between modules and / or components within modules may be provided using any one of connection methods and media known in the art, including but not limited to communication over the Internet, wired, or wireless networks using suitable protocols.

[0161] Although this document contains many details, they should not be interpreted as limitations on the scope of the claimed invention or the scope that may be claimed, but rather as descriptions of features specific to specific embodiments. Specific features described in this document in relation to separate embodiments may be implemented in combination in a single embodiment. Conversely, various features disclosed in the context of a single embodiment may be implemented in each of multiple embodiments or any suitable sub-combination. Furthermore, even if a feature may be described above as operating in a specific combination and even initially claimed as such, one or more features from the claimed combination may, in some cases, be removed from the combination and the claimed combination may be directed to a sub-combination or / or a variation of a sub-combination. Likewise, although operations are depicted in a specific order in the drawings, these operations should not be understood as needing to be performed in the specific order depicted or in a sequential order, or that all depicted operations must be performed, in order to achieve the desired result.

[0162] Only a few embodiments and examples are described, and other embodiments, improvements, and modifications may be made based on the description and examples provided in this disclosure.

Claims

Claim 1 A wireless communication method comprising: receiving first information by a communication node that instructs the communication node to operate in a point-to-multipoint (PTM) mode to receive MBS (multicast and broadcast service) data, wherein the first information instructs the communication node to operate in the PTM mode to receive MBS data and not to operate in a point-to-point (PTP) mode; receiving second information by the communication node that instructs the communication node not to operate in the PTP mode to receive MBS data, wherein the second information instructs the communication node to not operate in the PTP mode to receive MBS data, wherein the second information instructs the communication node to have no transmission of data to the communication node through the PTP mode; and receiving MBS data by operating in the PTM mode other than the PTP mode in response to the first information and the second information by the communication node. Claim 2 A wireless communication method according to claim 1, wherein the communication node receives the first information while operating in the PTP mode. Claim 3 A wireless communication method according to claim 1, wherein the second information is indicated by a flag included in a PDCP (packet data convergence protocol) PDU (protocol data unit) or RLC (radio link control) PDU. Claim 4 A wireless communication method according to claim 1, wherein the communication node transmits a PDCP (packet data convergence protocol) status report to a network node in response to receiving the first information, and the PDCP status report indicates whether one or more packets have been successfully received by the communication node. Claim 5 A wireless communication method according to claim 1, wherein the second information is included in an RRC (radio resource control) signal, a PDCP (packet data convergence protocol) PDU (protocol data unit), an RLC (radio link control) PDU, or a MAC CE (medium access control-control element). Claim 6 A communication node for wireless communication comprising a processor, configured to implement a method, wherein the method comprises: receiving first information instructing the communication node to operate in a point-to-multipoint (PTM) mode to receive MBS (multicast and broadcast service) data, wherein the first information instructs the communication node to operate in the PTM mode to receive MBS data and not to operate in a point-to-point (PTP) mode; receiving second information instructing the communication node not to operate in the PTP mode to receive MBS data, wherein the second information instructs the communication node not to operate in the PTP mode to receive MBS data; and receiving second information in which the communication node instructs the communication node not to operate in the PTP mode to receive MBS data, wherein the second information instructs the communication node to have no transmission of data to the communication node through the PTP mode; and receiving MBS data by operating in the PTM mode other than the PTP mode in response to the first information and the second information. Claim 7 In paragraph 6, the communication node is a communication node that receives the first information while operating in the PTP mode. Claim 8 In paragraph 6, the communication node, wherein the second information is indicated by a flag included in a PDCP (packet data convergence protocol) PDU (protocol data unit) or RLC (radio link control) PDU. Claim 9 In paragraph 6, the communication node transmits a PDCP (packet data convergence protocol) status report to a network node in response to receiving the first information, and the PDCP status report indicates whether one or more packets have been successfully received by the communication node. Claim 10 In paragraph 6, the communication node, wherein the second information is included in an RRC (radio resource control) signal, a PDCP (packet data convergence protocol) PDU (protocol data unit), an RLC (radio link control) PDU, or a MAC CE (medium access control-control element). Claim 11 A non-transient computer-readable program storage medium in which code is stored, said code, when executed by a processor, causes said processor to implement the method described in any one of claims 1 to 10. Claim 12 delete Claim 13 delete Claim 14 delete Claim 15 delete Claim 16 delete Claim 17 delete Claim 18 delete Claim 19 delete Claim 20 delete Claim 21 delete Claim 22 delete Claim 23 delete

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