Communication method and communication device

Abstract

The present application discloses a communication method and a communication device. The method includes: determining whether an operation performed during a current handover is an initial operation, where the initial operation includes a radio link control (RLC) maintenance operation and a media access control (MAC) reset or partial reset operation; and, if it is determined that the operation performed during the current handover is an initial operation, sending an RLC status report to a second device, where the RLC status report indicates the reception status of data packets. According to the present application, the timeliness of sending the RLC status report can be improved, the continuity of service transmission during handover can be ensured, and data transmission efficiency can be improved.

Description

[Technical Field]

[0001] The present application relates to the field of communication technologies, and in particular to communication methods and devices. [Background technology]

[0002] This application claims priority to Chinese Patent Application No. 202211695101.6, entitled "Communication Method and Communication Apparatus," filed with the State Intellectual Property Office of the People's Republic of China on December 28, 2022, which is incorporated herein by reference in its entirety.

[0003] In a mobile communication system, as the location of a terminal device changes, the communication link between the terminal device and an access network device changes. The access network device instructs the terminal device to perform a cell handover based on the movement status of the terminal device. However, during handover, a problem may occur in which a radio link control (RLC) status report is not generated in time. This affects service transmission efficiency and makes it impossible to ensure the continuity of service transmission during handover. Summary of the Invention

[0004] The embodiments of the present application provide a communication method and a communication device for improving the timeliness of RLC status report transmission, ensuring continuity of service transmission during handover, and improving data transmission efficiency.

[0005] According to a first aspect, an embodiment of the present application provides a communication method, including: determining whether an operation performed during the current handover is an initial operation, where the initial operation includes a radio link control (RLC) maintenance operation and a media access control (MAC) reset operation or partial reset operation; and, if it is determined that the operation performed during the current handover is an initial operation, sending an RLC status report to the second device, where the RLC status report indicates a reception status of data packets. The step of sending the RLC status report is immediately activated if it is determined that the operation performed during the current handover is an RLC maintenance operation and a MAC reset operation or partial reset operation. This improves the timeliness of sending the RLC status report, ensures continuity of service transmission during handover, and improves data transmission efficiency.

[0006] In a possible design, when it is determined that an initial operation is to be performed on at least one radio bearer RB, the RLC status report is sent to the second device. In other words, the step of sending the RLC status report is directly triggered on the condition that an initial operation is performed on any RB. This improves the timeliness of sending the RLC status report, ensures the continuity of service transmission during handover, and improves data transmission efficiency.

[0007] In another possible design, a first operation is determined to be performed on at least one RB. It is determined on the at least one RB whether discontinuous data packets exist among received data packets transmitted using the first RB. If discontinuous data packets exist among received data packets transmitted using the first RB, an RLC status report is transmitted to the second device. In other words, the step of transmitting an RLC status report is activated only when discontinuous data packets exist among received data packets transmitted using the RB, thereby reducing the number of RLC status reports and signaling overhead.

[0008] In another possible design, a first sequence number of a data packet with the largest sequence number and a second sequence number of a last received data packet among all received data packets transmitted using the first RB are obtained. If the first sequence number exceeds the second sequence number, it is determined that discontinuous data packets exist among the received data packets transmitted using the first RB. The first sequence number and the second sequence number are obtained to determine whether discontinuous data packets exist among the data packets transmitted using the RB, thereby ensuring accuracy of the determination that discontinuous data packets exist among the data packets transmitted using the RB.

[0009] In another possible design, first indication information transmitted by the second device is received. The first indication information includes a poll bit in an RLC protocol data unit (PDU) transmitted using at least one RB being 1. The first indication information instructs transmission of an RLC status report, and the first indication information is transmitted by the second device when it is determined that an initial operation is to be performed on at least one RB. When it is determined that the operation performed during the current handover is an initial operation, it is determined to activate transmission of the RLC status report by referring to the first indication information. This improves the timeliness of transmission of the RLC status report, ensures continuity of service transmission during handover, and improves data transmission efficiency.

[0010] In another possible design, all of the first indication information is carried in a first message, and the first message includes one common bit indicating that a poll bit in an RLC PDU transmitted using at least one RB is 1. The first message is a handover command or a target cell access message. The one common bit indicates that a poll bit in an RLC PDU transmitted using at least one RB is 1, thereby reducing signaling overhead.

[0011] In another possible design, the first message includes at least one bit and at least one RB ID field, one bit corresponding to one RB ID field, and each bit indicating whether to start polling for an RLC status report on the RB corresponding to the RB ID field.

[0012] In another possible design, the first indication information includes a first information portion and a second information portion. The first information portion includes a poll bit being 1 in an RLC PDU transmitted using some of the at least one RBs, and the second information portion includes a poll bit being 1 in an RLC PDU transmitted using RBs other than the some of the at least one RBs. The first information portion is carried in a first message, or the first information portion and the first message are included in the same message. The second information portion is transmitted after the handover is completed. The first message is a handover command or a target cell access message.

[0013] In another possible design, if it is determined that the operation performed during the current handover is the first operation, a status report prohibit timer is stopped. The status report prohibit timer indicates that transmission of an RLC status report is prohibited while it is running. The status report prohibit timer is stopped, thereby allowing the UE to send an RLC status report to the access network equipment as soon as possible.

[0014] In another possible design, the handover is an L1 and / or L2 activated mobility LTM handover.

[0015] According to a second aspect, an embodiment of the present application provides a communication method, including: receiving a radio link control (RLC) status report sent by the first device, where the RLC status report is sent by the first device if it is determined that an operation performed during the current handover is an initial operation, and the initial operation includes an RLC maintenance operation and a media access control (MAC) reset operation or a partial reset operation; and determining a reception status of data packets based on the RLC status report, where the sending of the RLC status report is immediately activated if it is determined that the operation performed during the current handover is an RLC maintenance operation and a MAC reset operation or a partial reset operation. This improves the timeliness of sending the RLC status report, ensures continuity of service transmission during the handover, and improves data transmission efficiency.

[0016] In one possible design, when it is determined that a first operation is to be performed on at least one radio bearer RB, first indication information is sent to the first device. The first indication information includes a poll bit being 1 in an RLC protocol data unit (PDU) transmitted using the at least one RB. The first indication information instructs the first device to transmit an RLC status report. When it is determined that the operation performed during the current handover is a first operation, the first indication information is sent to instruct the first device to activate the transmission of the RLC status report. This improves the timeliness of the transmission of the RLC status report, ensures continuity of service transmission during the handover, and improves data transmission efficiency.

[0017] In another possible design, all of the first indication information is carried in a first message, and the first message includes one common bit indicating that a poll bit in an RLC protocol data unit (PDU) transmitted using at least one RB is 1. The first message is a handover command or a target cell access message. The one common bit indicates that a poll bit in an RLC PDU transmitted using at least one RB is 1, thereby reducing signaling overhead.

[0018] In another possible design, the first message includes at least one bit and at least one RB ID field, one bit corresponding to one RB ID field, each bit indicating whether to start polling for an RLC status report on the RB corresponding to the RB ID field.

[0019] In another possible design, the first indication information includes a first information portion and a second information portion. The first information portion includes a poll bit in an RLC PDU transmitted using some of the at least one RBs being 1, and the second information portion includes a poll bit in an RLC PDU transmitted using RBs other than the some of the at least one RBs being 1. The first information portion is carried in a first message, or the first information portion and the first message are included in the same message. The second information portion is transmitted after the handover is completed. The first message is a handover command or a target cell access message.

[0020] In another possible design, the handover is a mobility LTM handover triggered by L1 and / or L2.

[0021] According to a third aspect, an embodiment of the present application provides a communication method, including: determining whether an operation performed during the current handover is an initial operation, where the initial operation includes a radio link control (RLC) maintenance operation and a media access control (MAC) reset operation or a partial reset operation; and, if it is determined that the operation performed during the current handover is an initial operation, sending first indication information to the second device, where the first indication information includes a poll bit in an RLC protocol data unit (PDU) transmitted using at least one radio bearer (RB) being 1, and the first indication information instructs the second device to transmit an RLC status report. If it is determined that the operation performed during the current handover is an RLC maintenance operation and a MAC reset operation or a partial reset operation, the first indication information instructs the second device to activate the transmission of the RLC status report. This improves the timeliness of the transmission of the RLC status report, ensures the continuity of service transmission during the handover, and improves data transmission efficiency.

[0022] In a possible design, the first instruction information is sent to the second device when it is determined to perform the first action on at least one RB.

[0023] In another possible design, all of the first indication information is carried in a first message, and the first message includes one common bit indicating that a poll bit in an RLC PDU transmitted using at least one RB is 1. The first message is a handover command or a target cell access message. The one common bit indicates that a poll bit in an RLC PDU transmitted using at least one RB is 1, thereby reducing signaling overhead.

[0024] In another possible design, the first message includes at least one bit and at least one RB ID field, one bit corresponding to one RB ID field, each bit indicating whether to start polling for an RLC status report on the RB corresponding to the RB ID field.

[0025] In another possible design, the first indication information includes a first information portion and a second information portion. The first information portion includes a poll bit being 1 in an RLC PDU transmitted using some of the at least one RBs, and the second information portion includes a poll bit being 1 in an RLC PDU transmitted using RBs other than the some of the at least one RBs. The first information portion is carried in a first message, or the first information portion and the first message are included in the same message. The second information portion is transmitted after the handover is completed. The first message is a handover command or a target cell access message.

[0026] In another possible design, the handover is an L1 and / or L2 activated mobility LTM handover.

[0027] According to a fourth aspect, an embodiment of the present application provides a communication method, including: receiving first indication information transmitted by the first device, where the first indication information is transmitted by the first device when it is determined that the operation performed during the current handover is the first operation; the first indication information includes a poll bit being 1 in a radio link control (RLC) protocol data unit (PDU) transmitted using at least one radio bearer (RB); and the first operation includes an RLC maintenance operation and a media access control (MAC) reset or partial reset operation; and transmitting an RLC status report to the first device based on the first indication information; where the first indication information indicates that the operation performed during the current handover is an RLC maintenance operation and a MAC reset or partial reset operation, the first indication information instructs activation of transmission of the RLC status report; thereby improving the timeliness of the transmission of the RLC status report, ensuring continuity of service transmission during the handover, and improving data transmission efficiency.

[0028] In a possible design, first indication information is transmitted by the first device when a first operation is performed on at least one RB.

[0029] In another possible design, all of the first indication information is carried in a first message, and the first message includes one common bit indicating that a poll bit in an RLC protocol data unit (PDU) transmitted using at least one RB is 1. The first message is a handover command or a target cell access message. The one common bit indicates that a poll bit in an RLC PDU transmitted using at least one RB is 1, thereby reducing signaling overhead.

[0030] In another possible design, the first message includes at least one bit and at least one RB ID field, one bit corresponding to one RB ID field, each bit indicating whether to start polling for an RLC status report on the RB corresponding to the RB ID field.

[0031] In another possible design, the first indication information includes a first information portion and a second information portion. The first information portion includes a poll bit being 1 in an RLC PDU transmitted using some of the at least one RBs, and the second information portion includes a poll bit being 1 in an RLC PDU transmitted using RBs other than the some of the at least one RBs. The first information portion is carried in a first message, or the first information portion and the first message are included in the same message. The second information portion is transmitted after the handover is completed. The first message is a handover command or a target cell access message.

[0032] In another possible design, the handover is a mobility LTM handover triggered by L1 and / or L2.

[0033] According to a fifth aspect, an embodiment of the present application provides a communication method, including: determining data discarded during handover if it is determined that the operation performed during the current handover is the initial operation, where the initial operation includes a radio link control (RLC) maintenance operation and a media access control (MAC) reset operation or partial reset operation; and transmitting the discarded data to a second device in the target cell after the handover to the target cell is performed and before an RLC status report is received. If it is determined that the operation performed during the current handover is an RLC maintenance operation and a MAC reset operation or partial reset operation, the data discarded during handover is obtained, and a new HARQ transmission is scheduled to transmit the discarded data once, without waiting for an RLC status report to be received to retransmit data packets that were not successfully received. This improves the continuity of data transmission and improves data transmission efficiency.

[0034] According to a sixth aspect, an embodiment of the present application provides a communication device, including: a processing module configured to determine whether an operation performed during a current handover is an initial operation, where the initial operation includes a radio link control (RLC) maintenance operation and a media access control (MAC) reset operation or a partial reset operation, and a transmitting module configured to transmit an RLC status report to the second device if the operation performed during the current handover is determined to be an initial operation, where the RLC status report indicates a reception status of the data packet.

[0035] In a possible design, the transmitting module is configured to transmit an RLC status report to the second device when it is determined to perform a first operation on at least one radio bearer RB.

[0036] In another possible design, the processing module is further configured to determine execution of the first operation on the at least one RB and to determine whether discontinuous data packets are present among the received data packets transmitted using the first RB on the at least one RB. The transmitting module is further configured to transmit an RLC status report to the second device if discontinuous data packets are present among the received data packets transmitted using the first RB.

[0037] In another possible design, the processing module is further configured to obtain a first sequence number of a data packet having a highest sequence number and a second sequence number of a last received data packet among all of the received data packets transmitted using the first RB, and determine that discontinuous data packets exist among the received data packets transmitted using the first RB if the first sequence number exceeds the second sequence number.

[0038] In another possible design, the device further comprises: a receiving module configured to receive first indication information transmitted by the second device, where the first indication information includes a poll bit in an RLC protocol data unit (PDU) transmitted using at least one RB being 1, the first indication information instructing transmission of an RLC status report, and the first indication information is transmitted by the second device when it is determined to perform a first operation on the at least one RB;

[0039] In another possible design, all of the first indication information is carried in a first message, the first message includes one common bit indicating that a poll bit in an RLC PDU transmitted using at least one RB is 1, and the first message is a handover command or a target cell access message.

[0040] In another possible design, the first indication information includes a first information portion and a second information portion. The first information portion includes a poll bit in an RLC PDU transmitted using some of the at least one RBs being 1, and the second information portion includes a poll bit in an RLC PDU transmitted using RBs other than the some of the at least one RBs being 1. The first information portion is carried in a first message, and the second information portion is transmitted after the handover is completed. The first message is a handover command or a target cell access message.

[0041] In another possible design, the processing module is further configured to stop running a status report prohibit timer when it is determined that a first operation has been performed during the current handover, where the status report prohibit timer, while running, indicates prohibiting transmission of an RLC status report.

[0042] In another possible design, the handover is an L1 and / or L2 activated mobility LTM handover.

[0043] For the operations performed by the communication device and their beneficial effects, please refer to the method in the first aspect and its beneficial effects, and overlapping parts will not be described again.

[0044] According to a seventh aspect, an embodiment of the present application provides a communication device, including: a receiving module configured to receive a radio link control (RLC) status report sent by the first device, where the RLC status report is sent by the first device when it is determined that an operation performed during the current handover is an initial operation, and the initial operation includes an RLC maintenance operation and a media access control (MAC) reset operation or a partial reset operation; and A processing module configured to determine a reception status of the data packet based on the RLC status report.

[0045] In a possible design, the transmitting module is configured to, when it is determined to perform a first operation on the at least one radio bearer RB, transmit first indication information to the first device, where the first indication information includes a poll bit in an RLC protocol data unit PDU transmitted using the at least one RB being 1, and the first indication information instructs transmission of an RLC status report.

[0046] In another possible design, all of the first indication information is carried in a first message, the first message includes one common bit, the common bit indicates that a poll bit in an RLC protocol data unit (PDU) transmitted using at least one RB is 1, and the first message is a handover command or a target cell access message.

[0047] In another possible design, the first indication information includes a first information portion and a second information portion. The first information portion includes a poll bit in an RLC PDU transmitted using some of the at least one RBs being 1, and the second information portion includes a poll bit in an RLC PDU transmitted using RBs other than the some of the at least one RBs being 1. The first information portion is carried in a first message, and the second information portion is transmitted after the handover is completed. The first message is a handover command or a target cell access message.

[0048] In another possible design, the handover is an L1 and / or L2 activated mobility LTM handover.

[0049] For the operations performed by the communication device and their beneficial effects, please refer to the method in the second aspect and its beneficial effects, and overlapping parts will not be described again.

[0050] According to an eighth aspect, an embodiment of the present application provides a communication device, including: a processing module configured to determine whether an operation performed during a current handover is an initial operation, where the initial operation includes a radio link control (RLC) maintenance operation and a media access control (MAC) reset or partial reset operation; and a transmitting module configured to transmit first indication information to the second device when it is determined that the operation performed during the current handover is an initial operation, where the first indication information includes a poll bit in an RLC protocol data unit (PDU) transmitted by using at least one radio bearer (RB) being 1, and the first indication information instructs transmission of an RLC status report.

[0051] In another possible design, the sending module is further configured to send first indication information to the second device when it is determined to perform the first operation on the at least one RB.

[0052] In another possible design, all of the first indication information is carried in a first message, the first message includes one common bit indicating that a poll bit in an RLC PDU transmitted using at least one RB is 1, and the first message is a handover command or a target cell access message.

[0053] In another possible design, the first indication information includes a first information portion and a second information portion. The first information portion includes a poll bit in an RLC PDU transmitted using some of the at least one RBs being 1, and the second information portion includes a poll bit in an RLC PDU transmitted using RBs other than the some of the at least one RBs being 1. The first information portion is carried in a first message, and the second information portion is transmitted after the handover is completed. The first message is a handover command or a target cell access message.

[0054] In another possible design, the handover is an L1 and / or L2 activated mobility LTM handover.

[0055] For the operations performed by the communication device and their beneficial effects, please refer to the method in the third aspect and its beneficial effects, and overlapping parts will not be described again.

[0056] According to a ninth aspect, an embodiment of the present application provides a communication device, including: a receiving module configured to receive first indication information sent by the first device, where the first indication information is sent by the first device when it is determined that the operation performed during the current handover is an initial operation, where the first indication information includes a poll bit being 1 in a radio link control (RLC) protocol data unit (PDU) sent using at least one radio bearer (RB), and the initial operation includes an RLC maintenance operation and a media access control (MAC) reset operation or a partial reset operation; and a transmitting module configured to transmit an RLC status report to the first device based on the first indication information;

[0057] In another possible design, the first indication information is sent by the first device when the first operation is performed on at least one RB.

[0058] In another possible design, all of the first indication information is carried in a first message, the first message includes one common bit indicating that a poll bit in an RLC protocol data unit (PDU) transmitted using at least one RB is 1, and the first message is a handover command or a target cell access message.

[0059] In another possible design, the first indication information includes a first information portion and a second information portion. The first information portion includes a poll bit in an RLC PDU transmitted using some of the at least one RBs being 1, and the second information portion includes a poll bit in an RLC PDU transmitted using RBs other than the some of the at least one RBs being 1. The first information portion is carried in a first message, and the second information portion is transmitted after the handover is completed. The first message is a handover command or a target cell access message.

[0060] In another possible design, the handover is an L1 and / or L2 activated mobility LTM handover.

[0061] For the operations performed by the communication device and their beneficial effects, please refer to the method in the fourth aspect and its beneficial effects, and overlapping parts will not be described again.

[0062] According to a tenth aspect, an embodiment of the present application provides a communication device, including: a processing module configured to determine data discarded during the handover if it is determined that the operation performed during the current handover is an initial operation, where the initial operation includes a radio link control (RLC) maintenance operation and a media access control (MAC) reset or partial reset operation; and a transmitting module configured to transmit the discarded data to a second device in the target cell after a handover to the target cell is performed and before an RLC status report is received;

[0063] For the operations performed by the communication device and their beneficial effects, please refer to the method in the fifth aspect and its beneficial effects, and overlapping parts will not be described again.

[0064] According to an eleventh aspect, the present application provides a communication device. The device may be a terminal device, a device within a terminal device, or a device usable in combination with a terminal device. Alternatively, the communication device may be a chip system. The communication device may perform the method of the first aspect. The functions of the communication device may be implemented by hardware, or by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the functions. The modules may be software and / or hardware. For operations performed by the communication device and their beneficial effects, please refer to the methods of the first to fifth aspects and their beneficial effects. Repeated descriptions will not be repeated.

[0065] According to a twelfth aspect, the present application provides a communication device. The device may be an access network device, a device within the access network device, or a device usable in combination with the access network device. The communication device may be a chip system. The communication device may perform the method of the second aspect. The functions of the communication device may be implemented by hardware, or by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the functions. The modules may be software and / or hardware. For operations performed by the communication device and their beneficial effects, please refer to the methods of the first to fifth aspects and their beneficial effects. Repeated descriptions will not be repeated.

[0066] According to a thirteenth aspect, the present application provides a communications device, the communications device including a processor and a memory, the memory configured to store computer-executable instructions, and the processor configured to execute the computer-executable instructions stored in the memory, to enable the communications device to perform a method according to any one of the first to fifth aspects.

[0067] According to a fourteenth aspect, the present application provides a computer-readable storage medium configured to store a computer program which, when executed, implements a method according to any one of the first to fifth aspects.

[0068] According to a fifteenth aspect, the present application provides a computer program product comprising a computer program which, when executed, implements a method according to any one of the first to fifth aspects.

[0069] According to a sixteenth aspect, an embodiment of the present application provides a communication system, the communication system including at least one terminal device and at least one access network device, the terminal device being configured to perform the steps in the first to fifth aspects, and the access network device being configured to perform the steps in the first to fifth aspects. [Brief explanation of the drawings]

[0070] In order to more clearly describe the technical solutions in the embodiments of the present application or the background art, the accompanying drawings for illustrating the embodiments of the present application or the background art are described below.

[0071] [Figure 1] 1 illustrates an architecture of a communication system according to an embodiment of the present application; [Figure 2] FIG. 1 illustrates a CU-DU split architecture. [Figure 3] FIG. 1 illustrates an LTM handover. [Figure 4] 1 is a schematic flow chart illustrating a communication method according to an embodiment of the present application; [Figure 5] 4 is a schematic flow chart illustrating another communication method according to an embodiment of the present application; [Figure 6] 4 is a schematic flow chart illustrating another communication method according to an embodiment of the present application; [Figure 7] 1 is a diagram illustrating a configuration of a communication device according to an embodiment of the present application. [Figure 8] FIG. 2 is a diagram illustrating a configuration of a terminal device according to an embodiment of the present application. [Figure 9] FIG. 2 is a diagram illustrating the configuration of an access network device according to an embodiment of the present application. DETAILED DESCRIPTION OF THE INVENTION

[0072] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the present application will be described below with reference to the accompanying drawings in which the embodiments of the present application are described.

[0073] FIG. 1 illustrates a communication system architecture according to an embodiment of the present application. The communication system includes access network equipment and terminal equipment. The access network equipment may include a primary base station and a secondary base station, and the coverage of serving cells (carriers) of one or more secondary base stations is located within the coverage of the primary base station. The terminal equipment may be located within the coverage of one or more serving cells provided by the access network equipment. If there are multiple cells serving the terminal equipment, the terminal equipment may operate in carrier aggregation (CA), dual connectivity (DC), or coordinated multipoint transmission mode. The one or more serving cells provide at least one parameter set (numerology) and simultaneously provide radio resources to the terminal equipment.

[0074] Terminal equipment, also referred to as user equipment (UE), mobile station (MS), mobile terminal (MT), or the like, is equipment that provides a user with voice and / or data connectivity, such as a handheld device or in-vehicle device with wireless connectivity. Currently, some examples of terminal equipment include mobile phones, tablet computers, laptops, handheld computers, mobile internet devices (MIDs), wearable devices, virtual reality (VR) devices, augmented reality (AR) devices, wireless terminals in industrial control, wireless terminals in self-driving, wireless terminals in remote medical surgery, wireless terminals in smart grids, wireless terminals in transportation safety, wireless terminals in smart cities, wireless terminals in smart homes, and the like. The following description uses an example in which the terminal equipment is a UE.

[0075] An access network device is a radio access network (RAN) node (or device) that connects terminal devices to a wireless network and is sometimes called a base station. Currently, some examples of RAN nodes include a continuously evolved NodeB (gNB), a transmission reception point (TRP), an evolved NodeB (eNB), a radio network controller (RNC), a NodeB (NodeB, NB), a base station controller (BSC), a base transceiver station (BTS), a home base station (e.g., a home evolved NodeB or home NodeB, HNB), a baseband unit (BBU), a wireless fidelity (Wi-Fi) access point (AP), and the like. In a network structure, the access network device may include a central unit (CU) node, a distributed unit (DU) node, or RAN devices including a CU node and a DU node. The RAN equipment, including the CU node and the DU node, divides the protocol layers of the eNB in ​​a long term evolution (LTE) system. Some protocol layer functions are centrally controlled by the CU, and some or all of the remaining protocol layer functions are distributed to the DUs, and the CU centrally controls the DUs.

[0076] The communication system may be a long term evolution (LTE) system, a universal mobile telecommunications system (UMTS), a code division multiple access (CDMA) system, a wireless local area network (WLAN), a fifth generation mobile communication system (5G), a next generation wireless communication system, or the like.

[0077] Figure 2 shows the CU-DU split architecture. A 5G base station is logically divided into one CU and one or more DUs. Each DU is connected to the CU through an F1 logical interface. Operations related to the radio link control (RLC) layer, medium access control (MAC) layer, and physical layer (PHY) layer are processed by the DU. Operations related to the service data adaptation protocol (SDAP) layer, radio resource control (RRC) layer, and packet data convergence protocol (PDCP) layer are processed by the CU.

[0078] L1 / L2 triggered mobility (LTM) handover mainly involves L1 and / or L2, and handover-related operations are mainly performed in L1 and L2. L1 is the physical layer, and L2 is one or more of the MAC layer, RLC layer, PDCP layer, and SDAP layer. L1 / L2 may alternatively be understood as L1 and / or L2. For example, a terminal device transmits L1 measurement results to an access network device by using physical layer control signaling. The physical layer control signaling is carried on a physical uplink control channel (PUCCH). The access network device reads the L1 measurement results, makes a handover decision based on the L1 measurement results, and transmits the handover decision to the terminal device by using L1 / L2 signaling. The L1 / L2 signaling may be transmitted on a physical downlink control channel (PDCCH) or may be a media access control element (MAC CE).

[0079] LTM handover means that handover-related operations are primarily performed at the physical and MAC layers. However, it should be understood that LTM handover also includes involvement and processing at other protocol layers, such as the RRC layer (sometimes referred to as L3). The document of this application does not limit the specific names of handover techniques. L1 / L2 handover may also be referred to as lowest layer handover, lower layer handover, or the like.

[0080] Figure 3 shows a diagram illustrating an LTM handover. In a cell handover scenario within the same DU in a CU-DU split architecture, a UE is handed over from a source cell (cell 1) to a target cell (cell 2) through an LTM handover. This process mainly includes the following steps:

[0081] S301: The CU sends configuration information of an LTM candidate cell to the UE. It should be understood that the CU sends the configuration information to the UE via the DU.

[0082] S302: The UE transmits the measurement result to the access network device (DU in the figure) to which the source cell belongs.

[0083] Specifically, the UE measures the reference signal of the source cell and / or the reference signal of the candidate cell based on the configuration information, obtains the measurement result, and then reports the measurement result to the DU.

[0084] The measurement results include at least one of the following: L1 measurement results of the source cell and L1 measurement results of at least one candidate cell. The L1 measurement results of the source cell and / or the L1 measurement results of the candidate cell may be cell-level measurement results, such as cell-level reference signal received power (RSRP), or beam-level measurement results, such as beam-level RSRP.

[0085] S303: The DU sends a handover command to the UE.

[0086] Specifically, after receiving the measurement result, the DU determines whether to perform handover based on the measurement result, and if it decides to perform handover, it sends a handover command to the UE.

[0087] For example, if the signal quality of a particular candidate cell is better than that of the source cell, it is determined that a handover to the candidate cell is to be performed. In this case, the candidate cell is also called the target cell. The DU sends a handover command to the UE. This handover command is an LTM handover command, and the LTM handover command is L1 / L2 signaling.

[0088] The handover command may include an identification of the target cell or an identification associated with the target cell, and may further include an indication of beam direction information that the UE should use when communicating with the target cell.

[0089] S304: The UE sends a target cell access message to the DU.

[0090] Specifically, the UE performs handover based on the configuration information of the target cell received in S301, accesses the target cell, and starts uplink and downlink data transmission to the target cell after successful access.

[0091] In the text of this application, communication between a UE and a target cell may be understood as communication between the UE and an access network device to which the target cell belongs.

[0092] Furthermore, the UE may access the target cell in a random access channel (RACH) manner or in a random access-less (RACH-less) manner.

[0093] S305: The DU sends notification information to the CU, where the notification information indicates that the UE has successfully completed the LTM handover.

[0094] The notification information may include identification information associated with an identifier of the target cell.

[0095] During an L3 handover, the radio link control (RLC) layer performs a re-establishment procedure, and the media access control (MAC) layer performs a reset procedure. Data currently being processed in the RLC and MAC layers is flushed, and the data is restored by the packet data convergence protocol (PDCP) layer. During an LTM handover, L2 processing operations may be continuously maintained to maintain service continuity during the handover. For example, the RLC layer may continue to perform a maintenance procedure instead of a reset or re-establishment procedure. However, the MAC layer may still perform a reset or partial reset procedure. For example, in a cell handover scenario within the same DU, the RLC layer operations of the access network equipment and the UE are continuously performed or maintained. The MAC layer performs a reset or partial reset procedure, and the contents of some of the data packets currently being processed in the MAC layer are flushed. For example, operations such as discarding MAC PDUs or clearing / flushing Hybrid Automatic Repeat Request (HARQ) buffers may be performed.

[0096] The RLC layer can perform the maintenance procedure because it processes data at the data radio bearer (DRB) level without relying directly on the cell. The MAC layer does not perform the complete maintenance procedure and needs to perform a reset or partial reset procedure because some of the processing operations of the MAC layer are performed at a cell-level granularity. The MAC layer needs to perform a reset or partial reset procedure because the source cell and the target cell usually have different cell-level configurations.

[0097] RLC Automatic Repeat Request (ARQ) is described below.

[0098] The RLC layer may use an acknowledged mode (AM). In AM, the data receiver sends an RLC status report to the data sender, which indicates the reception status of data packets. The data sender retransmits data packets that were not successfully received to ensure the reliability of data transmission.

[0099] The RLC status report may be triggered by the data sender or by the data receiver. The two triggering methods are described separately below.

[0100] (1) Triggered by the data sender: The data sender instructs the data receiver to send an RLC status report by setting the poll bit (Poll) in the RLC protocol data unit (PDU) to 1. For example, the data sender triggers the data receiver to send an RLC status report by setting the poll bit in the RLC PDU to 1 in the following cases:

[0101] a: When the send buffer of the data sender becomes empty, the data sender starts actively polling.

[0102] b: If the send window of the data sender is stopped (paused), the data sender will start actively polling. The stopped send window indicates that the data sender is temporarily unable to send subsequent data packets.

[0103] For example, a data sender maintains a transmission window (e.g., 0 is the lower limit of the window and 100 is the upper limit of the window) and can only transmit data packets with sequence numbers between 0 and 100. When the data receiver feedbacks that data packet #0, data packet #1, and data packet #2 have all been successfully received, the lower limit of the transmission window is raised to 3 and the upper limit is raised to 103. However, since the data receiver has not subsequently fed back the RLC ACK for data packet #3, the lower limit of the window cannot be updated and the data sender cannot transmit any data packets with sequence numbers greater than 103, resulting in transmission stall.

[0104] (2) Trigger executed by the data receiver: After the reassembly timer (t-Reassembly) of the data receiver expires, an RLC status report is sent. If discontinuous data exists in the received data packets (a gap exists in the sequence numbers), the data receiver starts t-Reassembly. If discontinuous data packets are received successfully during t-Reassembly, the data receiver stops t-Reassembly. If t-Reassembly expires, the data receiver triggers an RLC status report once. Here, the RLC status report instructs the data sender to perform data retransmission. After the RLC entity of the data receiver sends an RLC status report once, the status report prohibit timer (t-StatusProhibit) starts. While t-StatusProhibit is running, the RLC entity of the data receiver will not generate or send an RLC status report. After t-StatusProhibit expires, the RLC entity of the data receiver can send an RLC status report again. t-StatusProhibit is used, which can effectively prevent the data receiver from sending RLC status reports frequently, thereby reducing unnecessary transmission overhead.

[0105] However, during LTM handover, if the RLC layer maintenance process and the MAC layer reset process or partial reset process are performed, the RLC status report will not be activated in time, which will affect the service transmission experience during handover. A detailed explanation is provided below using two examples.

[0106] Example 1: In the polling method, when a data sender triggers a data receiver to send an RLC status report, the RLC PDU (with the polling bit set to 1) for packet assembly may be discarded at the MAC layer because the data sender performs a MAC reset or partial reset. As a result, the data receiver cannot receive the poll in time and cannot send the RLC status report. In this case, the transmission window of the data sender may be stopped. Because the data sender cannot receive the RLC status report in time, it cannot continue sending other data, resulting in a decrease in transmission efficiency.

[0107] Example 2: The data sender performs a MAC reset or partial reset, resulting in the loss of some data packets. Upon detecting gaps in data reception, the data receiver initiates t-Reassembly and attempts to wait for Hybrid Automatic Repeat Request (HARQ) retransmissions on the air interface to fill these gaps. In reality, these data packets are discarded by the data sender, and no HARQ retransmissions are performed. After t-Reassembly expires, the data receiver sends an RLC status report to instruct the data sender to perform RLC retransmissions for the data packets that were not successfully received. This entire process delays the time at which the data receiver receives data, reducing the timeliness of the data and potentially causing data invalidation.

[0108] To solve the above technical problems, the embodiments of the present application provide the following solutions:

[0109] 4 is a schematic flowchart illustrating a communication method according to an embodiment of the present invention. This embodiment of the present application mainly includes the following steps:

[0110] S401: The CU sends configuration information of an LTM candidate cell to the UE.

[0111] S402: The UE reports the measurement result to the access network device (DU in the figure) to which the source cell belongs.

[0112] S403: The DU sends a handover command to the UE.

[0113] S404: The UE sends a target cell access message to the DU.

[0114] The specific implementation of S401 to S404 is the same as the specific implementation of S301 to S304 in Fig. 3. For S401 to S404, please refer to S301 to S304. The details will not be described again in this specification.

[0115] For downlink transmission, the first device is a UE and the second device is an access network device. The UE activates the transmission of an RLC status report, and S405a and S406a are performed. For uplink transmission, the first device is an access network device and the second device is a UE. The access network device activates the transmission of an RLC status report, and S405b and S406b are performed.

[0116] S405a: The UE determines whether the operation performed during the current handover is the first operation, where the first operation includes a radio link control (RLC) maintenance operation and a media access control (MAC) reset operation or partial reset operation.

[0117] In one embodiment, the configuration information in S401 may include second indication information, where the second indication information indicates an operation to be performed during the current handover. For example, when a handover is performed from a source cell (cell 1) to a target cell (cell 2), the second indication information indicates whether an RLC maintenance procedure and a MAC reset procedure should be performed, or an RLC maintenance procedure and a partial MAC reset procedure should be performed. After receiving the handover command, the UE determines the target cell and determines that the operation performed during the current handover is the first operation based on the second indication information in the configuration information.

[0118] In another embodiment, the handover command in S403 may include third indication information, where the third indication information indicates operations to be performed during the current handover, for example, the third indication information indicates that an RLC maintenance procedure and a MAC reset procedure, or an RLC maintenance procedure and a partial MAC reset procedure, need to be performed during the current handover.

[0119] The MAC reset or partial MAC reset process includes at least one of the following: clearing / flushing a transmit data buffer (e.g., HARQ buffer, etc.) at the MAC layer, clearing a receive data buffer (e.g., HARQ buffer, etc.) at the MAC layer, or clearing PDUs that are currently being processed at the MAC layer.

[0120] It should be understood that the second and third indication information may perform instructions at the granularity of a UE. In other words, a first operation is performed on all radio bearers (RBs) between the terminal device and the access network device during the current handover. Alternatively, the second and third indication information may perform instructions at the granularity of an RB. For example, for RB1, it indicates that an RLC maintenance procedure and a MAC reset procedure or a partial reset procedure are to be performed, and for RB2, it indicates that an RLC reestablishment procedure and a MAC reset procedure are to be performed.

[0121] An RB may be a Data Radio Bearer (DRB) or a Signaling Radio Bearer (SRB), or alternatively, an RLC bearer, a corresponding RLC channel, or a logical channel.

[0122] The handover may be an LTM handover, a lowest layer handover, a lower layer handover, or another type of cell handover. The RLC maintenance procedure may also be called an RLC non-reestablishment procedure. The MAC reset procedure or partial reset procedure may also be called a MAC re-establishment procedure or partial re-establishment procedure.

[0123] S406a: When the UE determines that the action performed during the current handover is the first action, it sends an RLC status report to the access network equipment, where the RLC status report indicates the reception status of the data packet.

[0124] In a possible implementation, the UE transmits an RLC status report to the access network device when it determines that an initial operation is to be performed on at least one RB, in other words, the UE directly triggers the transmission of the RLC status report on the condition that an initial operation is to be performed on any RB.

[0125] For example, if the UE decides to perform initial operations on RB1 and RB2, but not on RB3, the RLC status report may be sent in the following two ways:

[0126] In a first optional scheme, the UE sends an RLC status report to the access network equipment by using RB1, where the RLC status report includes the reception status of the data packets transmitted by using RB1. Furthermore, the UE sends another RLC status report to the access network equipment by using RB2, where the RLC status report includes the reception status of the data packets transmitted by using RB2. Because the first operation is not performed on RB3, there is no need to send an RLC status report for the data packets carried by RB3.

[0127] In a second option, the UE sends an RLC status report to the access network equipment. The RLC status report includes the reception status of the data packets transmitted using RB1 and the reception status of the data packets transmitted using RB2. Because the first operation is not performed on RB3, the RLC status report does not include the reception status of the data packets transmitted using RB3.

[0128] In another possible implementation, the UE determines to perform a first operation on at least one RB, determines whether discontinuous data packets exist among received data packets transmitted using a first RB on the at least one RB, and transmits an RLC status report to a second device if discontinuous data packets exist among received data packets transmitted using the first RB. The first RB is any RB or a specific RB on the at least one RB. In other words, the transmission of the RLC status report is activated only when discontinuous data packets exist among received data packets transmitted using an RB, thereby reducing the number of RLC status reports and reducing signaling overhead.

[0129] Discontinuous data packets can be understood as a gap in sequence numbers in received data packets. For example, an access network device transmits five data packets to a UE by using RB1, and the sequence numbers of the five data packets are 1, 2, 3, 4, and 5, respectively. However, the UE only receives the data packets with sequence numbers 1, 2, 4, and 5, but does not receive the data packet with sequence number 3. Therefore, there is a gap in sequence numbers in the data packets received by the UE that are transmitted by using RBs.

[0130] Furthermore, the UE may obtain a first sequence number of a data packet with the highest sequence number among all received data packets transmitted using the first RB and a second sequence number of the last received data packet, and if the first sequence number exceeds the second sequence number, determine that discontinuous data packets exist among the received data packets transmitted using the first RB.

[0131] For example, if the UE decides to perform an initial operation on RB1, RB2, and RB3, the RLC status report may be sent in the following two ways: the data packets received by the UE and transmitted using RB3 are consecutive data packets, and there are discontinuous data packets among the received data packets transmitted using RB1 and RB2.

[0132] In a first optional scheme, the UE sends an RLC status report to the access network equipment by using RB1, where the RLC status report includes the reception status of the data packets transmitted by using RB1. Furthermore, the UE sends another RLC status report to the access network equipment by using RB2, where the RLC status report includes the reception status of the data packets transmitted by using RB2. The first operation is also performed on RB3, but because the received data packets transmitted by using RB3 are consecutive data packets, there is no need to send an RLC status report for the data packets carried by RB3.

[0133] In a second option, the UE sends an RLC status report to the access network equipment. The RLC status report includes the reception status of the data packets transmitted using RB1 and the reception status of the data packets transmitted using RB2. Although the first operation is also performed on RB3, the RLC status report does not include the reception status of the data packets transmitted using RB3 because the received data packets transmitted using RB3 are consecutive data packets.

[0134] Optionally, when the UE determines that the first operation has been performed during the current handover, the UE stops running a status report prohibit timer, where the status report prohibit timer indicates that transmission of an RLC status report is prohibited during its execution. The status report prohibit timer stops running, thereby allowing the UE to transmit an RLC status report to the access network equipment as soon as possible.

[0135] Optionally, when the access network device determines to perform a first operation on at least one radio bearer RB, the access network device sends first indication information to the UE, where the first indication information includes that a poll bit in the RLC PDU transmitted using the at least one RB is 1. After receiving the first indication information, the UE decides to transmit an RLC status report. In other words, when the UE determines that the operation performed during the current handover is a first operation, the UE decides to transmit an RLC status report by referring to the first indication information. The first indication information may be instructed in the following manner:

[0136] In a first optional scheme, after the UE successfully hands over to the target cell, the access network equipment transmits downlink data to the UE by using resources of the target cell. During the handover, an initial operation is performed on a first DRB. After the handover is completed, the access network equipment sets the poll bit in the RLC PDU transmitted using the first DRB to 1. For example, during an LTM handover, the UE performs an initial operation on DRB1 and DRB2. After the LTM handover is completed, the access network equipment sets the poll bit in the first RLC PDU transmitted using DRB1 to 1 and sets the poll bit in the first RLC PDU transmitted using DRB2 to 1.

[0137] In a second optional scheme, all of the first indication information is carried in a first message, and the first message includes one common bit, which indicates whether to start polling for an RLC status report on at least one RB. The first indication information does not need to be carried in a packet header of an RLC PDU transmitted using each DRB, thereby reducing signaling overhead. Alternatively, the first message includes at least one bit and at least one RB ID field, one bit corresponding to one RB ID field, and each bit indicating whether to start polling for an RLC status report on an RB corresponding to the RB ID field. The first message is a handover command.

[0138] For example, if the handover command is a MAC CE, the MAC CE may include two bits and two RB ID fields. Bit 1 corresponds to the RB ID field of RB1, and bit 2 corresponds to the RB ID field of RB2. Bit 1 indicates whether to start polling for RLC status reports on RB1. When bit 1 is set to 1, it indicates that polling for RLC status reports on RB1 is started. When bit 1 is set to 0, it indicates that polling for RLC status reports on RB1 is not started. Bit 2 indicates whether to start polling for RLC status reports on RB2. When bit 2 is set to 1, it indicates that polling for RLC status reports on RB2 is started. When bit 2 is set to 0, it indicates that polling for RLC status reports on RB2 is not started. Alternatively, the MAC CE may include one common bit, where only one bit indicates whether to start polling for RLC status reports on at least one RB. When that bit is set to 1, it indicates that polling for RLC status reports on at least one RB is started.

[0139] In a third optional scheme, the first indication information includes a first information portion and a second information portion. The first information portion includes a poll bit being 1 in an RLC PDU transmitted using some of the at least one RBs, and the second information portion includes a poll bit being 1 in an RLC PDU transmitted using RBs other than the part of the at least one RBs. The first information portion is carried in a first message, or the first information portion and the handover command are included in the same message. The second information portion is transmitted after the handover is completed. The first message is the handover command.

[0140] S405b: The access network device determines whether the operation performed during the current handover is the first operation, where the first operation includes a radio link control (RLC) maintenance operation and a media access control (MAC) reset operation or partial reset operation.

[0141] During handover, the access network equipment decides whether to perform handover and what actions to perform during handover, so that the access network equipment can know whether the action performed during the current handover is the first action or not.

[0142] S406b: If the access network device determines that the action performed during the current handover is the first action, send an RLC status report to the UE, where the RLC status report indicates the reception status of the data packet.

[0143] The specific implementation of S406b is the same as that of S406a. For S406b, please refer to S406a. The details will not be described again in this specification.

[0144] Optionally, the access network equipment may send a first message to the UE, where the first message includes an RLC status report and a handover command. In other words, the RLC status report and the handover command are sent to the UE in the same message to reduce signaling overhead.

[0145] It should be understood that during the current handover, the initial operations (RLC maintenance operation and MAC reset or partial reset operation) are not performed on the RB, and the above-mentioned process of activating the transmission of an RLC status report does not need to be performed. For example, if the operation performed during the current handover is an RLC reestablishment operation, there is no need to activate the transmission of an RLC status report.

[0146] It should be noted that the execution order of the above steps is not limited, and these steps may be combined or divided. S405a and S406a, and S405b and S406b may coexist. In this case, the order of S405a and S406a and the order of S405b and S406b are not limited. S405a and S406a, and S405b and S406b may alternatively exist separately. This is not limited in this solution.

[0147] In this embodiment of the present application, if it is determined that the operations performed during the current handover are an RLC maintenance procedure and a MAC reset procedure or a partial reset procedure, the transmission of an RLC status report is immediately activated, thereby improving the timeliness of the transmission of the RLC status report, ensuring the continuity of service transmission during handover, and improving data transmission efficiency.

[0148] 5 is a schematic flowchart illustrating a communication method according to an embodiment of the present invention. This embodiment of the present application mainly includes the following steps:

[0149] S501: The CU sends configuration information of an LTM candidate cell to the UE.

[0150] S502: The UE reports the measurement result to the access network device (DU in the figure) to which the source cell belongs.

[0151] S503: The DU sends a handover command to the UE.

[0152] S504: The UE sends a target cell access message to the DU.

[0153] The specific implementation of S501 to S504 is the same as the specific implementation of S301 to S304 in Fig. 3. For S501 to S504, please refer to S301 to S304. The details will not be described again in this specification.

[0154] For downlink transmission, the first device is an access network device and the second device is a UE. The access network device sends first indication information to instruct the UE to send an RLC status report, and S505a and S506a are executed. For uplink transmission, the first device is a UE and the second device is an access network device. The UE sends first indication information to instruct the access network device to send an RLC status report, and S505b and S506b are executed.

[0155] S505a: The access network device determines whether the operation performed during the current handover is the first operation, where the first operation includes an RLC maintenance procedure and a MAC reset procedure or a partial reset procedure.

[0156] During handover, the access network equipment decides whether to perform handover and what actions to perform during handover, so that the access network equipment can know whether the action performed during the current handover is the first action or not.

[0157] S506a: When the access network device determines that the action performed during the current handover is a first action, it sends first indication information to the UE, where the first indication information includes: a poll bit in an RLC protocol data unit (PDU) transmitted using at least one radio bearer (RB) is 1, and the first indication information instructs the UE to transmit an RLC status report.

[0158] In a possible implementation, after the UE successfully hands over to the target cell, the access network equipment transmits downlink data to the UE by using resources of the target cell. During the handover, the initial operation is performed on the first DRB. After the handover is completed, the access network equipment sets the poll bit in the RLC PDU transmitted using the first DRB to 1. For example, during an LTM handover, the UE performs the initial operation on DRB1 and DRB2. After the LTM handover is completed, the access network equipment sets the poll bit in the first RLC PDU transmitted using DRB1 to 1 and sets the poll bit in the first RLC PDU transmitted using DRB2 to 1.

[0159] In another possible implementation, all of the first indication information is carried in a first message, and the first message includes one common bit indicating whether to start polling for an RLC status report on at least one RB. The first indication information does not need to be carried in a packet header of an RLC PDU transmitted using each DRB, thereby reducing signaling overhead. Alternatively, the first message includes at least one bit and at least one RB ID field, one bit corresponding to one RB ID field, and each bit indicating whether to start polling for an RLC status report on an RB corresponding to the RB ID field. The first message is a handover command.

[0160] For example, if the handover command is a MAC CE, the MAC CE may include two bits and two RB ID fields. Bit 1 corresponds to the RB ID field of RB1, and bit 2 corresponds to the RB ID field of RB2. Bit 1 indicates whether to start polling for RLC status reports on RB1. When bit 1 is set to 1, it indicates that polling for RLC status reports on RB1 is started. When bit 1 is set to 0, it indicates that polling for RLC status reports on RB1 is not started. Bit 2 indicates whether to start polling for RLC status reports on RB2. When bit 2 is set to 1, it indicates that polling for RLC status reports on RB2 is started. When bit 2 is set to 0, it indicates that polling for RLC status reports on RB2 is not started. Alternatively, the MAC CE may include one common bit, where only one bit indicates whether to start polling for RLC status reports on at least one RB. When that bit is set to 1, it indicates that polling for RLC status reports on at least one RB is started.

[0161] In another possible implementation, the first indication information includes a first information portion and a second information portion. The first information portion includes a poll bit being 1 in an RLC PDU transmitted using some of the at least one RBs, and the second information portion includes a poll bit being 1 in an RLC PDU transmitted using RBs other than the part of the at least one RBs. The first information portion is carried in a first message, or the first information portion and the handover command are included in the same message. The second information portion is transmitted after the handover is completed. The first message is the handover command.

[0162] S505b: The UE determines whether the operation performed during the current handover is the first operation, where the first operation includes an RLC maintenance procedure and a MAC reset procedure or a partial reset procedure.

[0163] The specific implementation of S505b is the same as that of S405a. For S505b, please refer to S405a. The details will not be described again in this specification.

[0164] S506b: When the UE determines that the action performed during the current handover is a first action, it sends first indication information to the access network device, where the first indication information includes that a poll bit in an RLC protocol data unit (PDU) transmitted by using at least one radio bearer (RB) is 1, and the first indication information instructs the UE to transmit an RLC status report.

[0165] The entire first indication information may be carried in the target cell access message. Alternatively, a part of the first indication information may be carried in the target cell access message, and the remaining part may be transmitted after the handover is completed. For specific implementation, refer to S506a. Details will not be described again in this specification.

[0166] It should be understood that during the current handover, the first operation (RLC maintenance operation, and MAC reset operation or partial reset operation) is not performed on the RB, and the above-mentioned process of activating the transmission of an RLC status report does not need to be performed. For example, if the operation performed during the current handover is an RLC reestablishment operation, there is no need to activate the transmission of an RLC status report.

[0167] It should be noted that the execution order of the above steps is not limited, and these steps may be combined or divided. S505a and S506a, and S505b and S506b may coexist. In this case, the order of S505a and S506a and the order of S505b and S506b are not limited. S505a and S506a, and S505b and S506b may alternatively exist separately. This is not limited in this solution.

[0168] It should be noted that S405a and S406a in the foregoing embodiments may be combined with S506b. For downlink transmission, the UE actively sends an RLC status report (S405a and S406a) based on the fact that the operation performed during the current handover is the first operation. For uplink transmission, the UE may also actively activate the base station to send an RLC status report once (S506b). Similarly, S405b and S406b in the foregoing embodiments may also be combined with S506a.

[0169] In this embodiment of the present application, if it is determined that the operations performed during the current handover are an RLC maintenance procedure and a MAC reset procedure or a partial reset procedure, the first indication information is sent to instruct to activate the sending of an RLC status report, thereby improving the timeliness of the sending of the RLC status report, ensuring the continuity of service transmission during the handover, and improving data transmission efficiency.

[0170] 6 is a schematic flowchart illustrating a communication method according to an embodiment of the present invention. This embodiment of the present application mainly includes the following steps:

[0171] S601: The CU sends configuration information of an LTM candidate cell to the UE.

[0172] S602: The UE reports the measurement result to the access network device (DU in the figure) to which the source cell belongs.

[0173] S603: The DU sends a handover command to the UE.

[0174] S604: The UE sends a target cell access message to the DU.

[0175] The specific implementation of S601 to S604 is the same as the specific implementation of S301 to S304 in Fig. 3. For S601 to S604, please refer to S301 to S304. The details will not be described again in this specification.

[0176] For downlink transmission, the first device is an access network device and the second device is a UE. The access network device transmits data discarded during handover, and steps S605a and S606a are performed. For uplink transmission, the first device is a UE and the second device is an access network device. The UE transmits data discarded during handover, and steps S605b and S606b are performed.

[0177] S605a: If it is determined that the operation performed during the current handover is an initial operation, the access network device identifies data discarded during the handover, where the initial operation includes a radio link control (RLC) maintenance operation and a media access control (MAC) reset operation or partial reset operation.

[0178] During handover, the access network equipment decides whether to perform handover and what actions to perform during handover, so that the access network equipment can know whether the action performed during the current handover is the first action or not.

[0179] S606a: The access network equipment sends the discard data to the UE in the target cell after the handover to the target cell is performed and before the RLC status report is received.

[0180] During handover, if the operation performed during the current handover is the first operation, some of the data being processed in the downlink transmission is discarded at the MAC layer. For example, the downlink HARQ buffer is cleared and / or flushed. The access network equipment may obtain the discarded data at the MAC layer and retransmit the discarded data to the target cell after the handover. It should be understood that in the process of retransmitting the discarded data, the UE does not feed back an RLC status report and request the access network equipment to perform a retransmission. Therefore, the retransmission may be considered as a new HARQ transmission sent by the access network equipment to the UE in the target cell, rather than an RLC retransmission.

[0181] For example, if the access network equipment is transmitting RLC PDU#1 and RLC PDU#2 in the downlink transmission direction, the MAC layer packetizes RLC PDU#1 and RLC PDU#2 into the same transport block (TB) for transmission. Because the UE fails to successfully decode TB, the UE feeds back a HARQ NACK to the access network equipment, expecting the access network equipment to perform a HARQ retransmission procedure for TB. However, in this case, the access network equipment triggers a one-time LTM handover based on the UE's channel change status, and both the UE and the access network equipment perform the initial operation of clearing / flushing the HARQ buffer. In this case, the HARQ retransmission procedure cannot be performed. The access network equipment recognizes that RLC PDU#1 and RLC PDU#2 have not been successfully received by the UE. Therefore, the access network equipment still transmits RLC PDU#1 and RLC PDU#2 in the target cell. In this case, a new HARQ transmission is scheduled only once. In this way, the access network equipment does not need to wait to receive an RLC status report fed back by the UE to retransmit data packets that were not successfully received by the UE.

[0182] S605b: If it is determined that the operation performed during the current handover is an initial operation, the UE identifies data discarded during the handover, where the initial operation includes a radio link control (RLC) maintenance operation and a media access control (MAC) reset operation or partial reset operation.

[0183] For how the UE determines that the action performed during the current handover is the first action, please refer to S405a, and the details will not be described again in this specification.

[0184] S606b: After the handover to the target cell is performed and before the RLC status report is received, the UE sends the discard data to the access network equipment in the target cell.

[0185] The specific implementation of S606b is the same as that of S606a. For S606b, please refer to S606a. The details will not be described again in this specification.

[0186] It should be noted that S605a and S606a, and S605b and S606b may coexist or may be used independently.

[0187] In the embodiment of the present application, if it is determined that the operations performed during the current handover are an RLC maintenance procedure and a MAC reset procedure or a partial reset procedure, data discarded during the handover is retrieved, and a new HARQ transmission procedure is scheduled only once to transmit the discarded data without waiting for the reception of an RLC status report, thereby improving the continuity of data transmission and improving data transmission efficiency.

[0188] In the method embodiments described above, it may be understood that the methods and operations implemented by the terminal equipment may alternatively be implemented by components (e.g., chips or circuits, etc.) that may be used in the terminal equipment, and that the methods and operations implemented by the access network equipment may alternatively be implemented by components (e.g., chips or circuits, etc.) that may be used in the access network equipment.

[0189] The solutions provided in the embodiments of the present application have been described above mainly from the perspective of interactions between devices. To implement the above-described functions, each network element, such as a sending device or a receiving device, may be understood to include a corresponding hardware structure and / or software module for performing each function. By referring to the examples described in the embodiments disclosed herein, those skilled in the art may understand that the units and algorithm steps in the present application can be implemented by hardware or a combination of computer software and hardware. Whether a function is performed by hardware or by hardware driven by computer software depends on the specific application and the design constraints of the technical solution. Those skilled in the art may implement the described functions using various methods for each specific application, but such implementation should not be deemed to go beyond the scope of the present application.

[0190] In the embodiments of the present application, the functional modules of the terminal equipment or the access network equipment may be obtained by division based on the above-mentioned method example. For example, each functional module may be obtained by division based on each corresponding function, or two or more functions may be integrated into one processing module. The integrated module may be implemented in the form of hardware or in the form of a software functional module. It should be noted that in the embodiments of the present application, the module division is an example and is merely a logical functional division. In actual implementation, other division methods may be used. The following provides an explanation using an example in which each functional module is obtained by division corresponding to each function.

[0191] The method provided in the embodiment of the present application has been described in detail above with reference to Figures 4 to 6. The communication device provided in the embodiment of the present application will be described in detail below with reference to Figure 7. It should be understood that the description of the device embodiment corresponds to the description of the method embodiment. Therefore, for the contents not described in detail, please refer to the method embodiment. For the sake of brevity, the details will not be described again in this specification.

[0192] 7 is a diagram illustrating a configuration of a communication device according to an embodiment of the present application. The communication device may include a receiving module 701, a processing module 702, and a transmitting module 703. The receiving module 701 and the transmitting module 703 may communicate with the outside, and the processing module 702 may be configured to perform processing, such as determining whether the current handover is an initial operation. The receiving module 701 may also be referred to as a communication interface, a transceiver unit, or a transceiver module. The receiving module 701 and the processing module 702 may be configured to perform operations performed by a UE or an access network device in the above-described method embodiments.

[0193] In a possible design, the communication device may implement steps or procedures performed by a UE or access network equipment in the above-described method embodiments. For example, the communication device may be a UE or a chip or circuit configured within a UE. Alternatively, the communication device may be access network equipment or a chip or circuit configured within the access network equipment. The receiving module 701 is configured to perform operations related to reception and transmission by the UE or access network equipment in the above-described method embodiments. The processing module 702 is configured to perform operations related to processing by the UE or access network equipment in the above-described method embodiments.

[0194] In one embodiment, The processing module 702 is configured to determine whether the operation performed during the current handover is the first operation, where the first operation includes a radio link control (RLC) maintenance operation and a media access control (MAC) reset operation or partial reset operation; and The sending module 703 is configured to send an RLC status report to the second device when it is determined that the action performed during the current handover is an initial action, where the RLC status report indicates a reception status of the data packet.

[0195] Optionally, the sending module 703 is further configured to send an RLC status report to the second device when it is determined to perform a first operation on the at least one radio bearer RB.

[0196] Optionally, the processing module 702 is further configured to determine to perform a first operation on the at least one RB, and determine whether discontinuous data packets exist among the received data packets transmitted using the first RB in the at least one RB. The transmitting module is further configured to transmit an RLC status report to the second device if discontinuous data packets exist among the received data packets transmitted using the first RB.

[0197] Optionally, the processing module 702 is further configured to obtain a first sequence number of a data packet having a highest sequence number and a second sequence number of a last received data packet among all of the received data packets transmitted by using the first RB, and determine that discontinuous data packets exist among the received data packets transmitted by using the first RB if the first sequence number exceeds the second sequence number.

[0198] Optionally, the receiving module 701 is configured to receive first indication information sent by the second device, where the first indication information includes: a poll bit in an RLC protocol data unit PDU sent using the at least one RB is 1, the first indication information instructs sending an RLC status report, and the first indication information is sent by the second device when it is determined to perform a first operation on the at least one RB.

[0199] Optionally, all of the first indication information is carried in a first message, and the first message includes one common bit, which indicates that a poll bit in an RLC PDU transmitted using at least one RB is 1, and the first message is a handover command or a target cell access message.

[0200] Optionally, the first indication information includes a first information portion and a second information portion. The first information portion includes a poll bit in an RLC PDU transmitted using some of the at least one RBs being 1, and the second information portion includes a poll bit in an RLC PDU transmitted using RBs other than the some of the at least one RBs being 1. The first information portion is carried in a first message, and the second information portion is transmitted after the handover is completed. The first message is a handover command or a target cell access message.

[0201] Optionally, the processing module 702 is further configured to stop running a status report prohibit timer if it is determined that the initial operation is during a current handover, where the status report prohibit timer indicates prohibiting transmission of an RLC status report during its execution.

[0202] Optionally, the handover is a mobility LTM handover activated by L1 and / or L2.

[0203] In another embodiment, The receiving module 701 is configured to receive a radio link control (RLC) status report sent by a first device, where the RLC status report is sent by the first device when it is determined that an operation performed during the current handover is an initial operation, and the initial operation includes an RLC maintenance operation and a media access control (MAC) reset operation or partial reset operation; and The processing module 702 is configured to determine a reception status of the data packet based on the RLC status report.

[0204] Optionally, the sending module 703 is configured to, when it is determined to perform a first operation on the at least one radio bearer RB, send first indication information to the first device, where the first indication information includes: a poll bit in an RLC protocol data unit PDU transmitted using the at least one RB is 1, and the first indication information instructs the first device to transmit an RLC status report.

[0205] Optionally, all of the first indication information is carried in a first message, and the first message includes one common bit, which indicates that a poll bit in an RLC protocol data unit (PDU) transmitted using at least one RB is 1, and the first message is a handover command or a target cell access message.

[0206] Optionally, the first indication information includes a first information portion and a second information portion. The first information portion includes a poll bit in an RLC PDU transmitted using some of the at least one RBs being 1, and the second information portion includes a poll bit in an RLC PDU transmitted using RBs other than the some of the at least one RBs being 1. The first information portion is carried in a first message, and the second information portion is transmitted after the handover is completed. The first message is a handover command or a target cell access message.

[0207] Optionally, the handover is a mobility LTM handover activated by L1 and / or L2.

[0208] In another embodiment, The processing module 702 is configured to determine whether the operation performed during the current handover is the first operation, where the first operation includes a radio link control (RLC) maintenance operation and a media access control (MAC) reset operation or partial reset operation; and The sending module 703 is configured to send first indication information to the second device when it is determined that the action performed during the current handover is a first action, where the first indication information includes a poll bit in an RLC protocol data unit PDU transmitted by using at least one radio bearer RB being 1, and the first indication information instructs the second device to transmit an RLC status report.

[0209] Optionally, the sending module 703 is further configured to send first indication information to the second device when it is determined to perform the first operation on the at least one RB.

[0210] Optionally, all of the first indication information is carried in a first message, and the first message includes one common bit, which indicates that a poll bit in an RLC PDU transmitted using at least one RB is 1, and the first message is a handover command or a target cell access message.

[0211] Optionally, the first indication information includes a first information portion and a second information portion. The first information portion includes a poll bit in an RLC PDU transmitted using some of the at least one RBs being 1, and the second information portion includes a poll bit in an RLC PDU transmitted using RBs other than the some of the at least one RBs being 1. The first information portion is carried in a first message, and the second information portion is transmitted after the handover is completed. The first message is a handover command or a target cell access message.

[0212] Optionally, the handover is a mobility LTM handover activated by L1 and / or L2.

[0213] In another embodiment, The receiving module 701 is configured to receive first indication information sent by the first device, where the first indication information is sent by the first device when it is determined that the operation performed during the current handover is a first operation, the first indication information includes a poll bit in a radio link control (RLC) protocol data unit (PDU) sent by using at least one radio bearer (RB) being 1, and the first operation includes an RLC maintenance operation and a media access control (MAC) reset operation or partial reset operation; and The sending module 703 is configured to send an RLC status report to the first device based on the first indication information.

[0214] Optionally, the first indication information is sent by the first device when a first operation is performed on at least one RB.

[0215] Optionally, all of the first indication information is carried in a first message, and the first message includes one common bit, which indicates that a poll bit in an RLC protocol data unit (PDU) transmitted using at least one RB is 1, and the first message is a handover command or a target cell access message.

[0216] Optionally, the first indication information includes a first information portion and a second information portion. The first information portion includes a poll bit in an RLC PDU transmitted using some of the at least one RBs being 1, and the second information portion includes a poll bit in an RLC PDU transmitted using RBs other than the some of the at least one RBs being 1. The first information portion is carried in a first message, and the second information portion is transmitted after the handover is completed. The first message is a handover command or a target cell access message.

[0217] Optionally, the handover is a mobility LTM handover activated by L1 and / or L2.

[0218] It should be noted that for the implementation of each module, please refer to the corresponding description in the method embodiments shown in Figures 4 to 6 to perform the methods and functions performed by the UE or access network equipment in the above-mentioned embodiments.

[0219] 8 is a diagram illustrating the configuration of a terminal device according to an embodiment of the present application, which can be used in the system illustrated in FIG. 1 or FIG. 2 to perform the functions of the terminal device in the above-described method embodiments, or to perform the steps or procedures performed by the terminal device in the above-described method embodiments.

[0220] As shown in FIG. 8 , the terminal equipment includes a processor 801 and a transceiver 802. Optionally, the terminal equipment further includes a memory 803. The processor 801, the transceiver 802, and the memory 803 communicate with each other via an internal connection path to transfer control signals and / or data signals. The memory 803 is configured to store a computer program. The processor 801 is configured to call the computer program from the memory 803 and execute the computer program to control the transceiver 802 to receive / transmit signals. Optionally, the terminal equipment may further include an antenna configured to transmit the uplink data or uplink control signal output by the transceiver 802 via a wireless signal.

[0221] The processor 801 may correspond to the processing module in Figure 7. The processor 801 and the memory 803 may be integrated into one processing device. The processor 801 is configured to execute program code stored in the memory 803 to implement the above-described functions. In a specific implementation, the memory 803 may alternatively be integrated into the processor 801 or may be separate from the processor 801.

[0222] The transceiver 802 may correspond to the receiving module and transmitting module in Figure 7 and may also be referred to as a transceiver unit or a transceiver module. The transceiver 802 includes a receiver (also referred to as a receiver or receiving circuit) and a transmitter (also referred to as a transmitter or transmitting circuit). The receiver is configured to receive signals, and the transmitter is configured to transmit signals.

[0223] It should be understood that the terminal device shown in Figure 8 can implement the processes related to the terminal device in the method embodiments in Figures 4 to 6. The operations and / or functions of the modules in this terminal device are intended to individually implement the corresponding procedures in the above-mentioned method embodiments. For details, please refer to the descriptions in the above-mentioned method embodiments. To avoid repetition, detailed descriptions will be omitted in this specification as appropriate.

[0224] The processor 801 may be configured to perform the operations implemented in the terminal device and described in the above-mentioned method embodiments, and the transceiver 802 may be configured to perform the operations transmitted by the terminal device to or received from the access network device and described in the above-mentioned method embodiments. For details, please refer to the descriptions in the above-mentioned method embodiments. Details will not be described again in this specification.

[0225] The processor 801 may be a central processing unit, a general-purpose processor, a digital signal processor, an application-specific integrated circuit, a field programmable gate array (FPGA) or other programmable logic device, a transistor logic device, a hardware component, or any combination thereof. The processor 801 may implement or execute various exemplary logic blocks, modules, and circuits described with reference to the disclosure herein. Alternatively, the processor 801 may be a combination that implements computing functions, such as a combination including one or more microprocessors, or a combination of a digital signal processor and a microprocessor. The communication bus 804 may be a peripheral component interconnect (PCI) bus, an extended industry standard architecture (EISA) bus, or the like. Buses may be categorized as address buses, data buses, control buses, and the like. In FIG. 8, for ease of illustration, only one bold line is present to represent a bus, but this does not imply that there is only one bus or only one type of bus. The communication bus 804 is configured to implement communication connections between these components. The transceiver 802 in this embodiment of the present application is configured to perform signaling or data communication to another node device.The memory 803 may include volatile memory, such as nonvolatile random access memory (NVRAM), phase change random access memory (PRAM), or magnetoresistive random access memory (MRAM), or may include nonvolatile memory, such as at least one magnetic disk storage device, electrically erasable programmable read-only memory (EEPROM), flash memory, such as NOR flash memory or NAND flash memory, or a semiconductor device, such as a solid state drive (SSD). Optionally, the memory 803 may alternatively be at least one storage device remote from the processor 801. Optionally, the memory 803 may further store groups of computer program code or configuration information. Optionally, the processor 801 may further execute programs stored in the memory 803. The processor, in cooperation with the memory and the transceiver, may execute any of the methods and functions of the terminal device in the above-mentioned embodiments of the present application.

[0226] 9 is a diagram illustrating the configuration of an access network device according to an embodiment of the present application, which can be used in the system illustrated in FIG. 1 or FIG. 2 to perform the functions of the access network device in the above-described method embodiments, or to implement the steps or procedures performed by the access network device in the above-described method embodiments.

[0227] As shown in Figure 9, the access network equipment includes a processor 901 and a transceiver 902. Optionally, the access network equipment further includes a memory 903. The processor 901, the transceiver 902, and the memory 903 communicate with each other via an internal connection path to transfer control signals and / or data signals. The memory 903 is configured to store a computer program. The processor 901 is configured to call the computer program from the memory 903 and execute the computer program to control the transceiver 902 to receive / transmit signals. Optionally, the access network equipment may further include an antenna configured to transmit the uplink data or uplink control signals output by the transceiver 902 via a wireless signal.

[0228] The processor 901 corresponds to the processing module in Fig. 7. The processor 901 and the memory 903 may be integrated into one processing device. The processor 901 is configured to execute program code stored in the memory 903 to implement the above-described functions. In a specific implementation, the memory 903 may be integrated into the processor 901 or may be separate from the processor 901.

[0229] The transceiver 902 may correspond to the transmitting module and receiving module in FIG. 7 and may also be referred to as a transceiver unit or a transceiver module. The transceiver 902 may include a receiver (also referred to as a receiver or receiving circuit) and a transmitter (also referred to as a transmitter or transmitting circuit). The receiver is configured to receive signals, and the transmitter is configured to transmit signals.

[0230] It should be understood that the access network equipment shown in Figure 9 can perform the processes related to the access network equipment in the method embodiments in Figures 4 to 6. The operations and / or functions of the modules in the access network equipment are intended to separately perform the corresponding procedures in the above-mentioned method embodiments. For details, please refer to the descriptions in the above-mentioned method embodiments. To avoid repetition, detailed descriptions will be omitted in this specification as appropriate.

[0231] The processor 901 may be configured to perform operations implemented within the access network equipment and described in the above-mentioned method embodiments, and the transceiver 902 may be configured to perform operations transmitted by the access network equipment to or received from the terminal equipment and described in the above-mentioned method embodiments. For details, please refer to the descriptions in the above-mentioned method embodiments. Details will not be described again herein.

[0232] The processor 901 may be any of the various types of processors described above. The communication bus 904 may be a Peripheral Component Interconnect (PCI) bus, an Extended Industry Standard Architecture (EISA) bus, or the like. Buses may be classified as address buses, data buses, control buses, and the like. In FIG. 9, for ease of illustration, only one bold line is used to represent a bus, but this does not imply that there is only one bus or only one type of bus. The communication bus 904 is configured to implement communication connections between these components. The transceiver 902 in the device in this embodiment of the present application is configured to perform signaling or data communication with another device. The memory 903 may be any of the various types of memory described above. Optionally, the memory 903 may alternatively be at least one storage device separate from the processor 901. The memory 903 stores groups of computer program code or configuration information, and the processor 901 executes the programs in the memory 903. The processor, in cooperation with the memory and the transceiver, may perform any of the methods and functions of the access network equipment in the above-mentioned embodiments of the present application.

[0233] An embodiment of the present application further provides a chip system. The chip system includes a processor configured to support a terminal device or an access network device in performing functions in any one of the above-described embodiments, such as generating or processing a first message in the above-described method. In a possible design, the chip system may further include a memory configured to store program instructions and data required by the terminal device or the access network device. The chip system may include a chip, or may include a chip and another individual component. Inputs and outputs of the chip system correspond to receiving and transmitting operations, respectively, of the terminal device or the access network device in the method embodiments.

[0234] An embodiment of the present application further provides a processing device including a processor and a communication interface, the processor being configured to perform the method in the method embodiments described above.

[0235] It should be noted that the processor in this embodiment of the present application may be an integrated circuit chip and have signal processing functions. In the implementation process, the steps in the above-mentioned method embodiments can be implemented by using hardware integrated logic circuits in the processor or by using instructions in the form of software. The processor may be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic device, a discrete gate or transistor logic device, or a discrete hardware component. The processor may implement or execute the methods, steps, and logical block diagrams disclosed in the embodiments of the present application. The general-purpose processor may be a microprocessor, or the processor may be any conventional processor or the like. The operations of the methods disclosed with reference to the embodiments of the present application may be performed and completed directly by using a hardware decode processor, or may be performed and completed by using a combination of hardware modules and software modules in the decode processor. The software modules may be located in mature storage media in the art, such as random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, or registers. The storage medium is located in a memory, and the processor reads the information in the memory and completes the steps in the above-described method in combination with the processor's hardware.

[0236] According to the method provided in the embodiments of the present application, the present application further provides a computer program product, which includes a computer program that, when executed on a computer, enables the computer to perform the method according to any one of the embodiments shown in Figures 4 to 6.

[0237] According to the method provided in the embodiments of the present application, the present application further provides a computer-readable medium, which stores a computer program, which, when executed on a computer, enables the computer to perform the method according to any one of the embodiments shown in Figures 4 to 6.

[0238] According to the method provided in the embodiment of the present application, the present application further provides a communication system, which includes one or more terminal devices as described above and one or more access network devices as described above.

[0239] All or part of the above-described embodiments may be implemented using software, hardware, firmware, or any combination thereof. When software is used to implement the embodiments, all or part of the embodiments may be implemented in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer instructions are loaded and executed on a computer, the procedures or functions according to the embodiments of the present application are generated in whole or in part. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or another programmable device. The computer instructions may be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions may be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via a wired connection (e.g., coaxial cable, optical fiber, or digital subscriber line (DSL)) or a wireless connection (e.g., infrared, radio, or microwave). The computer-readable storage medium may be any available medium that can be accessed by a computer, or may be a data storage device that integrates one or more available media, such as a server or a data center. The available medium may be a magnetic medium (such as a floppy disk, a hard disk drive, or a magnetic tape), an optical medium (such as a high-density digital video disk (digital subscriber line, DVD)), a semiconductor medium (such as a solid state drive (SSD)), or the like.

[0240] The above description is merely a specific embodiment of the present application, but is not intended to limit the scope of protection of the present application. Any modifications or replacements that can be easily thought of by those skilled in the art within the technical scope disclosed in the present application shall be included in the scope of protection of the present application. Therefore, the scope of protection of the present application shall be subject to the scope of protection of the claims.

Claims

1. 1. A communication method comprising: determining whether an operation performed during the current handover is an initial operation, said initial operation including a radio link control (RLC) maintenance operation and a media access control (MAC) reset or partial reset operation; sending an RLC status report to a second device if it is determined that the action performed during the current handover is the initial action, the RLC status report indicating a reception status of a data packet; A method comprising:

2. sending the RLC status report to the second device if it is determined to perform the first operation on at least one radio bearer RB; The method of claim 1 further comprising:

3. determining to perform the first operation on at least one RB; determining whether there are discontinuous data packets among received data packets transmitted using a first RB on the at least one RB; sending the RLC status report to the second device if the discontinuous data packets are present among the received data packets transmitted using the first RB; The method of claim 1 further comprising:

4. The step of determining whether the discontinuous data packets are present in the received data packets transmitted using the first RB on the at least one RB, comprises: obtaining a first sequence number of a data packet having a maximum sequence number and a second sequence number of a last received data packet among all of the received data packets transmitted using the first RB; determining that the non-consecutive data packets are present in the received data packets transmitted using the first RB if the first sequence number is greater than the second sequence number; The method of claim 3, comprising:

5. receiving first indication information transmitted by the second device, the first indication information including a poll bit in an RLC protocol data unit PDU transmitted using the at least one RB being 1, the first indication information instructing transmission of the RLC status report, the first indication information being transmitted by the second device when it is determined to perform the first operation on the at least one RB; The method of any one of claims 1 to 4, further comprising:

6. 6. The method of claim 5, wherein all of the first indication information is carried in a first message, the first message includes one common bit, the common bit indicates that a poll bit in the RLC PDU transmitted using the at least one RB is 1, and the first message is a handover command or a target cell access message.

7. 6. The method of claim 5, wherein the first indication information includes a first information portion and a second information portion, the first information portion including a poll bit in an RLC PDU transmitted using some of the at least one RBs being 1, the second information portion including a poll bit in an RLC PDU transmitted using RBs other than the some of the at least one RBs being 1, the first information portion being carried in a first message, the second information portion being transmitted after the handover is completed, and the first message being a handover command or a target cell access message.

8. 8. The method of claim 1, further comprising the step of stopping a status report prohibit timer if it is determined that the first action has been performed during the current handover, the status report prohibit timer indicating, when running, that transmission of the RLC status report is prohibited.

9. The method according to any one of claims 1 to 8, wherein the handover is a mobility LTM handover triggered by L1 and / or L2.

10. 1. A communication method comprising: receiving a radio link control (RLC) status report sent by a first device, the RLC status report being sent by the first device when it is determined that an operation performed during the current handover is an initial operation, the initial operation including an RLC maintenance operation and a media access control (MAC) reset or partial reset operation; determining a reception status of the data packet based on the RLC status report; A method comprising:

11. sending first indication information to the first device when it is determined to perform the first operation on at least one radio bearer RB, the first indication information including a poll bit being 1 in an RLC protocol data unit PDU transmitted using the at least one RB, the first indication information being used to activate the second device to transmit the RLC status report; The method of claim 10, comprising:

12. 12. The method of claim 11, wherein all of the first indication information is carried in a first message, the first message includes one common bit, the common bit indicates that a poll bit in the RLC protocol data unit (PDU) transmitted using the at least one RB is 1, and the first message is a handover command or a target cell access message.

13. 12. The method of claim 11, wherein the first instruction information includes a first information portion and a second information portion, the first information portion including a poll bit in an RLC PDU transmitted using some of the at least one RBs being 1, the second information portion including a poll bit in an RLC PDU transmitted using RBs other than the some of the at least one RBs being 1, the first information portion being carried in a first message, the second information portion being transmitted after the handover is completed, and the first message being a handover command or a target cell access message.

14. 14. The method of any one of claims 10 to 13, wherein the handover is a mobility LTM handover triggered by L1 and / or L2.

15. 1. A communication method comprising: determining whether an operation performed during the current handover is an initial operation, said initial operation including a radio link control (RLC) maintenance operation and a media access control (MAC) reset or partial reset operation; sending first indication information to a second device when it is determined that the operation performed during the current handover is the first operation, the first indication information including a poll bit being 1 in an RLC protocol data unit (PDU) transmitted using at least one radio bearer (RB), the first indication information being used to activate the second device to transmit an RLC status report; A method comprising:

16. When it is determined that the operation performed during the current handover is the first operation, the step of sending the first instruction information to the second device includes: transmitting the first instruction information to the second device when it is determined that the first operation is to be performed on the at least one RB; 16. The method of claim 15, comprising:

17. 17. The method according to claim 15 or 16, wherein all of the first indication information is carried in a first message, the first message includes one common bit, the common bit indicates that a poll bit in the RLC PDU transmitted using at least one RB is 1, and the first message is a handover command or a target cell access message.

18. 17. The method of claim 15 or 16, wherein the first indication information includes a first information portion and a second information portion, the first information portion including a poll bit in an RLC PDU transmitted using some RBs of at least one RB being 1, the second information portion including a poll bit in an RLC PDU transmitted using RBs other than the some RBs of the at least one RB being 1, the first information portion being carried in a first message, the second information portion being transmitted after the handover is completed, and the first message being a handover command or a target cell access message.

19. 19. The method of any one of claims 15 to 18, wherein the handover is a mobility LTM handover triggered by L1 and / or L2.

20. 1. A communication method comprising: receiving first indication information sent by a first device, the first indication information being sent by the first device when it is determined that the operation performed during the current handover is an initial operation, the first indication information including a poll bit being 1 in a radio link control (RLC) protocol data unit (PDU) sent using at least one radio bearer (RB), and the initial operation including a RLC maintenance operation and a media access control (MAC) reset operation or partial reset operation; sending an RLC status report to the first device based on the first indication information; A method comprising:

21. The method of claim 20 , wherein the first indication information is transmitted by the first device when the initial operation is to be performed on the at least one RB.

22. 22. The method according to claim 20 or 21, wherein all of the first indication information is carried in a first message, the first message includes one common bit, the common bit indicates that a poll bit in the RLC protocol data unit (PDU) transmitted using the at least one RB is 1, and the first message is a handover command or a target cell access message.

23. 22. The method of claim 20 or 21, wherein the first instruction information includes a first information portion and a second information portion, the first information portion including a poll bit in an RLC PDU transmitted using some of the at least one RBs being 1, the second information portion including a poll bit in an RLC PDU transmitted using RBs other than the some of the at least one RBs being 1, the first information portion being carried in a first message, the second information portion being transmitted after handover is completed, and the first message being a handover command or a target cell access message.

24. 24. The method of any one of claims 20 to 23, wherein the handover is a mobility LTM handover triggered by L1 and / or L2.

25. A communication device comprising a memory and a processor, wherein the memory is configured to store a computer program and the processor executes the computer program, thereby causing the communication device to perform a method according to any one of claims 1 to 9 or any one of claims 20 to 24.

26. A communication device comprising a memory and a processor, wherein the memory is configured to store a computer program and the processor is configured to execute the computer program, thereby causing the communication device to perform a method according to any one of claims 10 to 14 or any one of claims 15 to 19.

27. 25. A computer-readable storage medium storing a computer program which, when executed on a processor, implements the method of any one of claims 1 to 24.

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