User equipment and method thereof, base station and method thereof

Abstract

The present disclosure provides a user equipment and a method thereof, a base station and a method thereof. The method performed by the user equipment comprises: receiving, from the base station, a medium access control control element (MAC CE) used for indicating an activation configuration of a packet data convergence protocol (PDCP) duplication of a data radio bearer (DRB) and / or an associated radio link control (RLC) entity; and performing, based on the MAC CE, the activation configuration of the PDCP duplication and / or the associated RLC entity. In this way, the communication efficiency and reliability of the wireless communication system can be improved.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of wireless communication, and more particularly, to a user equipment and a method thereof, a base station and a method thereof. BACKGROUND

[0002] In September 2018, at the 3rd Generation Partnership Project (3GPP) RAN #81 plenary meeting, Nokia proposed a study item on 5G (or called NR) Industrial Internet of Things (IIOT) (see Non-Patent Literature: RP-182090: Revised SID: Study on NR Industrial Internet of Things (IIoT)), and it was approved. One of the goals of this study item is to improve the reliability and reduce the latency of data transmission through data duplication, including: (1) resource-efficient PDCP duplication, such as avoiding unnecessary duplicate transmissions; (2) more than two times of PDCP duplication using dual connectivity (DC) or carrier aggregation (CA).

[0003] In Release 15, a bearer supporting PDCP duplication can be configured with at most two RLC entities. The initial state of a bearer configured with PDCP duplication is indicated by the pdcp-Duplication information element (see 3GPP TS 38.331 for the detailed description of the information element) whether the PDCP duplication function is activated or not at the initial time. In carrier aggregation, for a bearer whose initial PDCP duplication function is not activated, its data is transmitted through the logical channel indicated by the primaryPath information element (see 3GPP TS 38.331 for the detailed description of the information element). In dual connectivity, for a bearer whose initial PDCP duplication function is not activated, it is determined whether its data is transmitted through the logical channel indicated by the primaryPath information element (see 3GPP TS 38.331 for the detailed description of the information element) or transmitted in a split bearer manner according to the amount of data to be transmitted.

[0004] In NR IIOT, to achieve the goal of more than two times of PDCP duplication using dual connectivity or carrier aggregation, some vendors propose to configure multiple RLC entities for a bearer supporting PDCP duplication, but only activate some of the RLC entities each time. The network can indicate whether to activate PDCP duplication and the activated RLC entities through RRC signaling or medium access control control element (MAC CE). The present disclosure discusses related issues involved in configuring and / or activating / deactivating PDCP duplication and / or RLC entities. SUMMARY

[0005] To solve the above problems in the prior art, the disclosure provides a user equipment and a method thereof, a base station and a method thereof, which can perform appropriate PDCP repetition and / or activation configuration of RLC entity based on information indicating the activation configuration of PDCP repetition and / or RLC entity, thereby improving the communication efficiency and reliability of the wireless communication system.

[0006] According to a first aspect of the disclosure, a method performed by a user equipment is provided, comprising: receiving a medium access control control element (MAC CE) from a base station, the MAC CE being used to indicate an activation configuration of a packet data convergence protocol (PDCP) repetition and / or an associated radio link control (RLC) entity of a data radio bearer (DRB); and based on the MAC CE, performing the activation configuration of the PDCP repetition and / or the associated RLC entity.

[0007] In the above method, the MAC CE can include a first field and a second field, the first field indicating a DRB to which the MAC CE is applied, and the second field indicating activation or deactivation of a corresponding RLC entity or indicating an activation / deactivation state of PDCP repetition of a corresponding RLC entity.

[0008] In the above method, the MAC CE can further include a third field, the third field indicating an activation / deactivation state of PDCP repetition of the DRB indicated by the first field.

[0009] In the above method, in a case where the MAC CE indicates that all RLC entities or secondary RLC entities associated with a DRB are deactivated, the upper layer is instructed to deactivate PDCP repetition of the DRB; in a case where the MAC CE indicates that at least one RLC entity or at least one secondary RLC entity associated with a DRB is activated, the upper layer is instructed to activate PDCP repetition of the DRB and / or the activated RLC entity.

[0010] In the above method, in a case where the MAC CE indicates that PDCP repetition of a DRB is deactivated, the upper layer is instructed to deactivate PDCP repetition of the DRB; in a case where the MAC CE indicates that PDCP repetition of a DRB is activated, the upper layer is instructed to activate PDCP repetition of the DRB and / or the activated RLC entity.

[0011] In the method, the MAC CE can be used to indicate an activation configuration of PDCP duplication of a DRB, in a case that the MAC CE indicates deactivation of PDCP duplication of a DRB, instructing a higher layer to deactivate PDCP duplication of the DRB; in a case that the MAC CE indicates activation of PDCP duplication of a DRB, instructing the higher layer to activate PDCP duplication of the DRB only when a number of RLC entities associated with the DRB is less than two.

[0012] In the method, the MAC CE can be used to indicate an activation configuration of PDCP duplication of a DRB, in a case that the MAC CE indicates deactivation of PDCP duplication of a DRB, instructing a higher layer to deactivate PDCP duplication of the DRB; in a case that the MAC CE indicates activation of PDCP duplication of a DRB, instructing the higher layer to activate PDCP duplication of the DRB only when a number of RLC entities associated with the DRB is less than two.

[0013] According to a second aspect of the present disclosure, a user equipment is provided, comprising: a processor; and a memory storing instructions; wherein the instructions, when executed by the processor, perform the above method.

[0014] According to a third aspect of the present disclosure, a method performed by a base station is provided, comprising: generating a medium access control control element (MAC CE) used to indicate an activation configuration of packet data convergence protocol (PDCP) duplication and / or associated radio link control (RLC) entity of a data radio bearer (DRB); and transmitting the MAC CE to a user equipment, based on which the user equipment configures the PDCP duplication and / or associated RLC entity.

[0015] According to a fourth aspect of the present disclosure, a base station is provided, comprising: a processor; and a memory storing instructions; wherein the instructions, when executed by the processor, perform the above method.

[0016] Inventive Effects

[0017] According to the user equipment and the method thereof, the base station and the method thereof of the present disclosure, appropriate PDCP duplication and / or RLC entity activation configuration can be performed based on information indicating the PDCP duplication and / or RLC entity activation configuration, thereby improving the communication efficiency and reliability of the wireless communication system. BRIEF DESCRIPTION OF DRAWINGS

[0018] The above and other features of the present disclosure will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings, in which:

[0019] Figure 1 A flow chart representing a method 100 in a user equipment (UE) based on an embodiment of the present disclosure.

[0020] Figure 2 A schematic diagram representing a first MAC CE.

[0021] Figure 3 A schematic diagram representing a second MAC CE.

[0022] Figure 4 A block diagram representing a user equipment 40 based on embodiments of the disclosure.

[0023] Figure 5 A flowchart representing a method 500 in a base station based on embodiments of the disclosure.

[0024] Figure 6 A block diagram representing a base station 60 based on embodiments of the disclosure.

[0025] Figure 7 A schematic diagram representing a correspondence between PDCP entities, RLC entities, logical channels, MAC entities. DETAILED DESCRIPTION

[0026] The present disclosure will be described in detail below with reference to the attached drawings and specific embodiments. It should be noted that the present disclosure should not be limited to the specific embodiments described below. In addition, for the sake of simplicity, detailed descriptions of well-known technology related to the present disclosure will be omitted so as not to obscure the understanding of the present disclosure.

[0027] Some terms related to the present disclosure will be described below. Unless specifically stated, the terms related to the present disclosure are defined as follows.

[0028] RRC: Radio Resource Control

[0029] PDCP: Packet Data Convergence Protocol

[0030] RLC: Radio Link Control. The transmission mode of the RLC entity can be configured as one of a transparent mode TM, an unacknowledged mode UM, or an acknowledged mode AM.

[0031] MAC: Medium Access Control

[0032] MAC CE: MAC Control Element

[0033] PDU: Protocol Data Unit

[0034] SDU: Service Data Unit

[0035] In the present disclosure, data received from or sent to upper layers is referred to as SDU, and data sent to or received from lower layers is referred to as PDU. For example, data received from or sent to upper layers by a PDCP entity is referred to as PDCP SDU, and data received from or sent to an RLC entity by a PDCP entity is referred to as PDCP PDU (i.e., RLC SDU). A PDCP PDU can be a PDCP control PDU or a PDCP data PDU.

[0036] PDCP-Config information element: The information element PDCP-Config is used to configure the configurable PDCP parameters for a signaling bearer and / or a data bearer.

[0037] RLC-BearerConfig information element: The information element RLC-BearerConfig is used to configure an RLC entity, a corresponding logical channel in MAC and the linking to a PDCP entity (served radio bearer).

[0038] MCG: Master Cell Group

[0039] PCell: Primary Cell. An MCG cell operating on a primary frequency on which a UE performs an initial connection establishment procedure or initiates a connection re-establishment procedure.

[0040] PSCell: Primary SCG Cell. In dual connectivity, an SCG cell used by a UE to perform random access in a synchronous reconfiguration.

[0041] SCell: Secondary Cell. A cell providing additional radio resources on top of a special cell for a UE configured with CA.

[0042] SCG: Secondary Cell Group. For a UE configured with dual connectivity, a subset of serving cell groups, which contains a PSCell and zero or more secondary cells.

[0043] Special Cell: Special Cell, SPCell. In dual connectivity, Special Cell refers to the PCell of the MCG or the PSCell of the SCG, otherwise (i.e. in carrier aggregation), Special Cell refers to the PCell of the MCG.

[0044] Dual Connectivity: dual Connectivity, DC.

[0045] Carrier Aggregation: carrier aggregation, CA.

[0046] DRB: Data Radio Bearer carrying user plane data, Data Radio Bearer or simply Data Radio Bearer.

[0047] SRB: Signalling Radio Bearer.

[0048] As not specifically stated, the bearer or radio bearer described in the present disclosure can be: SRB, DRB, split DRB, split SRB.

[0049] PDCP duplication: also referred to as duplication or packet duplication or data duplication, SRB, DRB, split SRB, split DRB can be configured with PDCP duplication. When a radio bearer is configured with PDCP duplication, an auxiliary RLC entity and an auxiliary logical channel are added for the radio bearer to handle the duplicated PDCP PDUs. PDCP duplication refers to the same PDCP PDU being sent twice or more times, the twice or more times sent PDCP PDUs being sent through RLC entities and / or logical channels associated to different carriers or carrier groups. In dual connectivity mode, the RLC entities and / or logical channels of the radio bearer configured with PDCP duplication belong to different MAC entities.

[0050] Duplication Activation / Deactivation MAC CE: Duplication Activation / Deactivation MAC CE, used to activate or deactivate PDCP duplication of a radio bearer.

[0051] Primary path: Primary path, also referred to as primary RLC entity, used to send PDCP control PDUs and PDCP data PDUs, the primary path being configured through RRC message and cannot be deactivated.

[0052] In 3GPP Release 15, in carrier aggregation, when PDCP duplication is deactivated, the PDCP entity delivers PDCP PDUs to the primary path. In dual connectivity, when PDCP duplication is deactivated, if the total amount of data is less than the configured data split threshold, the PDCP entity delivers PDCP PDUs to the primary path. But in 3GPP Release 16, for dual connectivity scenario with more than 2 RLC entities associated to a DRB configured with PDCP duplication, the data delivery way after PDCP duplication deactivation can be different from Release 15. In carrier aggregation scenario, the data delivery way after PDCP duplication deactivation can be the same as Release 15.

[0053] Secondary path: secondary path, other RLC entities associated to a DRB configured with PDCP duplication except the primary path.

[0054] In the following, the method in a user equipment UE in the disclosure is explained, in particular, the control method related to PDCP duplication of a bearer in a user equipment UE is explained. As an example, Figure 1 Figure 1 shows a flow chart of a method 100 in a user equipment UE according to an embodiment of the disclosure.

[0055] In step S101, the user equipment UE (i.e. the MAC entity in the UE) receives a single data radio bearer duplication activation or deactivation medium access control control element (single DRB Duplication Activation / Deactivation MAC CE, referred to as first MAC CE or enhanced duplication activation / deactivation MAC CE) from a base station. The single data radio bearer duplication activation or deactivation MAC CE is used to indicate to activate or deactivate PDCP duplication of one DRB and / or to activate or deactivate associated RLC entities (i.e. to indicate whether the corresponding RLC entities are activated or not).

[0056] The following describes an example implementation of the first MAC CE.

[0057] In one embodiment, the first MAC CE contains a DRB dup Index field and an Ri field. Wherein, the DRB dup Index field indicates the DRB for which the MAC CE applies); preferably, the DRB dup Index field indicates the DRB for which the MAC CE applies); preferably, the DRB dupThe value of the index field is the ascending order of the DRB ID among the DRBs configured with PDCP duplication and with RLC entity(ies) associated with this MAC entity. In other words, the DRBs configured with PDCP duplication and with RLC entity(ies) associated with this MAC entity are arranged in ascending order of the DRB ID, and the value of the index field is the sequence number of the DRB ID. The starting sequence number is 0 or 1. dup The value of the index field is the ascending order of the DRB ID among the DRBs configured with PDCP duplication and with RLC entity(ies) associated with this MAC entity. In other words, the DRBs configured with PDCP duplication and with RLC entity(ies) associated with this MAC entity are arranged in ascending order of the DRB ID, and the value of the index field is the sequence number of the DRB ID. The starting sequence number is 0 or 1. For example, DRB1, DRB3, DRB4 are configured with PDCP duplication and all of them have RLC entity(ies) associated with the current MAC entity, then the sequence numbers (i.e. the value of the index field) corresponding to DRB1, DRB3, DRB4 are 0, 1, 2 (or 1, 2, 3) respectively. dup The value of the index field is the ascending order of the DRB ID among the DRBs configured with PDCP duplication and with RLC entity(ies) associated with this MAC entity. In other words, the DRBs configured with PDCP duplication and with RLC entity(ies) associated with this MAC entity are arranged in ascending order of the DRB ID, and the value of the index field is the sequence number of the DRB ID. The starting sequence number is 0 or 1. dup The value of the index field is the ascending order of the DRB ID among the DRBs configured with PDCP duplication and with RLC entity(ies) associated with this MAC entity. In other words, the DRBs configured with PDCP duplication and with RLC entity(ies) associated with this MAC entity are arranged in ascending order of the DRB ID, and the value of the index field is the sequence number of the DRB ID. The starting sequence number is 0 or 1. For example, assume that DRB1 (or its PDCP entity) configured with PDCP duplication has RLC1, RLC2, RLC3 associated with it and RLC1 is the primary path, then RLC2 and RLC3 are mapped to R0 and R1 respectively, while R2 is not mapped to any RLC entity. Figure 2 An example format of the first MAC CE is given.

[0058] Optionally, the first MAC CE further comprises an A / D field, which is used to indicate whether the DRB dupThe activation / deactivation status of the PDCP duplication of the DRB indicated by the index field is indicated by the A / D field, and the A / D field is set to 1 to indicate that the PDCP duplication of the corresponding DRB is activated, and the A / D field is set to 0 to indicate that the PDCP duplication of the corresponding DRB is deactivated. Conversely, if the A / D field is set to 0, all Ri fields are set to 0 (if the first MAC CE contains the Ri corresponding to the primary path, the Ri corresponding to the primary path is 1, but the other Ri is 0).

[0059] It should be noted that, since there is a one-to-one mapping relationship between the RLC entity and the logical channel, the RLC entity in the embodiments of the present disclosure can also be replaced by the logical channel, and the RLC entity identifier is replaced by the logical channel identifier.

[0060] In the embodiments of the present disclosure, if the base station configures a unique RLC identifier for each RLC entity associated with the DRB configured with PDCP duplication in the RRC message sent to the UE, the Ri field in the first MAC CE can directly correspond to the RLC identifier, but if the RLC identifier is not configured, the correspondence between the Ri field and the RLC entity can be indicated according to the logical channel identifier of the logical channel associated with the RLC entity. Since the logical channel identifier is unique to the MAC, in the DC case, the UE is configured with two MAC entities, and the logical channel corresponding to the DRB configured with PDCP duplication may take the same value in the two MACs, at this time, the logical channel identifier is arranged in ascending order (or descending order or ascending order or descending order) from small to large (or from large to small) and in the order of MCG first and SCG second (or MCG first or SCG) (if present). For example, DRB1 is associated with logical channel LCID 2, LCID 3 in MCG, and logical channel LCID 1, LCID 3 in SCG, and the RLC entity corresponding to MCG LCID 2 is the primary RLC entity, then it is arranged in the order of MCG LCID 3, SCG LCID 1, SCG LCID 3 in the order of MCG first and SCG second and in ascending order, which correspond to R0, R1, R2 respectively.

[0061] Figure 7 The correspondence between the PDCP entity, the RLC entity, the logical channel, and the MAC entity is shown.

[0062] In step S102, the user equipment UE (i.e. the MAC entity in the UE) instructs the upper layer (e.g. the PDCP layer / entity) to activate or deactivate the PDCP duplication of the corresponding DRB and / or the associated RLC entity based on the first MAC CE. Specifically, for each DRB configured with PDCP duplication, the MAC entity performs the following operations:

[0063] In one embodiment, if the first MAC CE is received for the RLC entities associated with the DRB configured with PDCP duplication, if all Rls are 0 (all RLC entities or secondary RLC entities are deactivated), the upper layer is instructed to deactivate the PDCP duplication of the DRB; otherwise, the upper layer is instructed to activate the PDCP duplication of the DRB and / or the activated RLC entities (i.e. the RLC entities corresponding to the bits with Ri = 1).

[0064] In one embodiment, if the first MAC CE is received for the RLC entities associated with the DRB configured with PDCP duplication, if at least one Ri is 1 (at least one RLC entity or at least one secondary RLC entity is activated), the upper layer is instructed to activate the PDCP duplication of the DRB and / or the activated RLC entities (i.e. the RLC entities corresponding to the bits with Ri = 1); otherwise, the upper layer is instructed to deactivate the PDCP duplication of the DRB.

[0065] In one embodiment, if the first MAC CE is received for the RLC entities associated with the DRB configured with PDCP duplication, if the PDCP duplication of the DRB is deactivated, the upper layer is instructed to deactivate the PDCP duplication of the DRB and / or the activated RLC entities (if any); otherwise (i.e. if the PDCP duplication of the DRB is activated), the upper layer is instructed to activate the PDCP duplication of the DRB and / or the activated RLC entities (i.e. the RLC entities corresponding to the bits with Ri = 1).

[0066] In the embodiments of the present disclosure, the operation of the MAC in receiving the first MAC CE and indicating the activated RLC entities to the upper layer can be replaced by indicating the deactivated RLC entities to the upper layer. Deactivating an RLC entity means that the PDCP entity does not submit PDCP data PDUs to the RLC entity after the RLC entity is deactivated.

[0067] In the present disclosure, the activated RLC entity can also be referred to as the PDCP duplication activated RLC entity, which means that among the multiple RLC entities associated with the PDCP entity, the RLC entity that is activated for transmitting PDCP data PDUs. When the PDCP duplication is activated, the PDCP entity duplicates the PDCP data PDUs and submits the PDCP data PDUs to the associated PDCP duplication activated RLC entity. It should be noted that in dual connectivity, if the split bearer data transmission mode is adopted after the PDCP duplication is deactivated, there are two activated RLC entities (the primary RLC entity and one secondary RLC entity), but at this time the activated secondary RLC entity is not for the purpose of PDCP duplication.

[0068] The following describes embodiments of operations performed by a UE when it receives a repetition activation / deactivation medium access control control element, MAC CE (hereinafter referred to as second MAC CE) defined in 3GPP Release 15.

[0069] It can be specified or predefined that the second MAC CE is only used for deactivating PDCP duplication, but not for activating PDCP duplication, or, for a PDCP entity with more than 2 associated RLC entities, the UE ignores the value corresponding to Di = 1; for a PDCP entity with 2 associated RLC entities, if Di = 1, the MAC entity indicates to the upper layer to activate PDCP duplication for the corresponding DRB; for a PDCP entity with 2 associated RLC entities, if Di = 0, the MAC entity indicates to the upper layer to deactivate PDCP duplication for the corresponding DRB. Figure 3 An example format of the second MAC CE is given. Wherein, the Di field indicates the PDCP duplication activation / deactivation status of DRB i, where i is the ascending order of the DRB ID among the DRBs configured with PDCP duplication and with RLC entity(ies) associated with this MAC entity (This field indicates the activation / deactivation status of the PDCP duplication of DRB i where i is the ascending order of the DRB ID among the DRBs configured with PDCP duplication and with RLC entity(ies) associated with this MAC entity). The Di field is set to 0 to indicate that the PDCP duplication of DRB i shall be deactivated, and the Di field is set to 1 to indicate that the PDCP duplication of DRB i shall be activated (The D i field is set to 1 to indicate that the PDCP duplication of DRB ishall be activated.The D i field is set to 0 to indicate that the PDCPduplication of DRB i shall be deactivated)。

[0070] Specifically, for each DRB configured with PDCP duplication, the MAC entity performs the following operations:

[0071] In one embodiment, when Di=0 (i.e. the received second MAC CE deactivates the PDCP duplication for the DRB corresponding to Di), the MAC entity indicates to the upper layer to deactivate the PDCP duplication for the DRB; when Di=l (i.e. the received second MAC CE activates the PDCP duplication for the DRB corresponding to Di), if the associated RLC entities (the RLC entities associated with the DRB or the RLC entities associated with the PDCP entity corresponding to the DRB) are not more than two or are two, the MAC entity indicates to the upper layer to activate the PDCP duplication for the DRB; otherwise (i.e. if the associated RLC entities (the RLC entities associated with the DRB or the RLC entities associated with the PDCP entity corresponding to the DRB) are more than two), the UE does not indicate to the upper layer (i.e. the DRB corresponding to Di=l does not perform any operation, in other words, the Di is ignored).

[0072] In one embodiment, when Di=0 (i.e. the received second MAC CE deactivates the PDCP duplication for the DRB corresponding to Di), the MAC entity indicates to the upper layer to deactivate the PDCP duplication for the DRB; when Di=l (i.e. the received second MAC CE activates the PDCP duplication for the DRB corresponding to Di) and the PDCP duplication for the corresponding DRB is currently activated, the MAC entity indicates to the upper layer to activate the PDCP duplication for the DRB and / or indicates to the upper layer to keep the currently activated RLC entities; if Di=l and the corresponding DRB is associated with two RLC entities or the associated RLC entities are not more than two, the MAC entity indicates to the upper layer to activate the PDCP duplication for the DRB.

[0073] In one embodiment, when Di=0 (i.e. the received second MAC CE deactivates the PDCP duplication for the DRB corresponding to Di), the MAC entity indicates to the upper layer to deactivate the PDCP duplication for the DRB; when Di=l (i.e. the received second MAC CE activates the PDCP duplication for the DRB corresponding to Di), the UE does not indicate to the upper layer to activate the PDCP duplication for the DRB (i.e. the DRB corresponding to Di=l does not perform any operation, in other words, the Di is ignored).

[0074] It can also be specified or predefined that if a DRB configured with PDCP duplication is configured (or associated) with only two RLCs, the second MAC CE is used to activate or deactivate the PDCP duplication; if configured (or associated) with 3 or more RLC entities, the first MAC CE is used to activate or deactivate the PDCP duplication for the DRB and / or the associated RLC entities.

[0075] It can also be specified or predefined that for the DRB corresponding to Di = 1 in the received second MAC CE, no matter whether the PDCP duplication of the DRB is currently in the activated state or the deactivated state, the PDCP duplication of the corresponding DRB will be activated and the RLC in the activated state configured in the RRC message will be used for the PDCP duplication of the DRB, that is, the RLC entity configured in the RRC message as the activated state will be activated to send the PDCP PDU when the PDCP duplication of the DRB is activated.

[0076] In the embodiments of the present disclosure, the MAC entity instructing the upper layer refers to the MAC entity instructing the PDCP layer or the PDCP entity if not specifically stated.

[0077] The following describes embodiments in which a base station configures a PDCP duplication bearer for a user equipment.

[0078] In the first step, the user equipment UE receives an RRC message, for example, an RRC reconfiguration message, from the base station. The RRC message contains an information element (IE) secondaryFallbackPath, which indicates the secondary RLC entity or the activated secondary RLC entity or the fallback RLC entity that can be used or can send the PDCP PDU after the PDCP duplication is deactivated (see the operation embodiment performed by the transmitting PDCP entity for details). The value of the secondaryFallbackPath information element can be the logical channel identifier of the secondary RLC entity or the LCID of the secondary RLC entity or the identifier of the logical channel associated with the secondary RLC entity or the identifier (denoted as RLC ID) of the secondary RLC entity, and the logical channel identifier or LCID corresponds to a cell group different from the cell group corresponding to the primary path. Since the current 3GPP system only supports the case of configuring two cell groups, MCG and SCG, for the UE, the cell group identifier CellGroupId corresponding to the MCG is 0, and the cell group identifier CellGroupId corresponding to the SCG is 1. The information element primaryPath contained in the RRC message for indicating the primary path contains two information elements, cellGroup IE and logicalChannel IE, the cellGroup IE is used to indicate the cell group where the primary path is located, and the logicalChannel IE is used to indicate the logical channel or the logical channel identifier in the cell group indicated by the cellGroup IE. The logical channel identifier of the logical channel indicated by the secondaryFallbackPath is in a cell group different from the cell group of the primary path. If the primary path is in the MCG, then the logical channel indicated by the secondaryFallbackPath is in the SCG, and vice versa.

[0079] It can be specified or predefined that in DC, if the RLC entity configured / associated for the DRB configured with PDCP duplication contains more than one RLC entity in a cell group different from the cell group where the primary path is located, the secondaryFallbackPath must be configured.

[0080] The following is an example description of secondaryFallbackPath included in PDCP-Config IE for configuring PDCP parameters for DRB or SRB:

[0081]

[0082]

[0083] In the above example description, the logicalChannel information element or the RLC entity identification information element (the RLC entity identification information element is used to indicate the fallback RLC entity) is included in the secondaryFallbackPath information element, or the value of the secondaryFallbackPath information element is the logical channel identifier LogicalChannelIdentity or the RLC entity identifier.

[0084] The secondaryFallbackPath information element (hereinafter referred to as information element) can also be included in the RLC-BearerConfig information element, which is configured by the base station for the UE through the RRC message. Preferably, the value of secondaryFallbackPath can be TRUE or False or 1 or 0. When the value is TRUE or 1 or the secondaryFallbackPath appears, after deactivating PDCP duplication, the secondaryFallbackPath indicated by the primary RLC entity is used as the data transmission path of the DRB, and the PDCP PDU is transmitted according to the method defined in the embodiment of the operation performed by the sending PDCP entity. Alternatively, the value of secondaryFallbackPath can be one of the values used to indicate that the corresponding RLC entity is in the activated state (denoted as Activated), the value used to indicate that the corresponding RLC entity is in the deactivated state (denoted as Deactivated), and the value used to indicate whether the corresponding RLC entity is used as a fallback path (denoted as FallbackPath) after deactivating PDCP duplication. The fallback path is the secondary RLC entity used when transmitting the PDCP PDU according to the method defined in the embodiment of the operation performed by the sending PDCP entity after deactivating PDCP duplication.

[0085] It can be specified or predefined that in a DC configured with carrier aggregation, if there are more than one RLC entity in a cell group different from the cell group where the primary RLC entity is located, one secondaryFallbackPath must be configured in the cell group different from the cell group where the primary RLC entity is located.

[0086] In a second step, the user equipment UE establishes / adds / reconfigures the corresponding DRB based on the RRC message.

[0087] The following describes the operation performed by the transmitting PDCP entity.

[0088] The transmitting PDCP entity performs the following operations when submitting a PDCP PDU to lower layers:

[0089] If the transmitting PDCP entity is associated with one RLC entity, the PDCP PDU is submitted to the associated RLC entity;

[0090] If the transmitting PDCP entity is associated with at least two RLC entities and if PDCP duplication is activated and if the PDCP PDU is a PDCP data PDU, the PDCP data PDU is duplicated and submitted to the activated RLC entities;

[0091] If the transmitting PDCP entity is associated with at least two RLC entities and if PDCP duplication is activated and if the PDCP PDU is a PDCP control PDU, the PDCP control PDU is submitted to the primary RLC entity;

[0092] If the transmitting PDCP entity is associated with at least two RLC entities and if PDCP duplication is deactivated, and if the transmitting PDCP entity is associated with two RLC entities and the two RLC entities belong to different cell groups, and the total amount of PDCP data volume and RLC data volume pending for initial transmission in these two RLC entities is equal to or larger than ul-DataSplitThreshold, the PDCP PDU is submitted to the primary RLC entity or the secondary RLC entity; wherein ul-DataSplitThreshold is a parameter configured through an RRC message.

[0093] If the transmitting PDCP entity is associated with at least 2 RLC entities and if PDCP duplication is deactivated, and if the transmitting PDCP entity is associated with two RLC entities, and the two RLC entities belong to different cell groups, and the total of the PDCP number and the amount of data pending initial transmission in the two associated RLCs is less than ul-DataSplitThreshold, then this PDCP PDU is submitted to the primary RLC entity;

[0094] If PDCP duplication is deactivated, and if the transmitting PDCP entity is associated with more than 2 RLC entities, and if secondaryFallbackPath is configured, and the total of the PDCP number and the amount of data pending initial transmission in the primary RLC entity and the RLC entity indicated by secondaryFallbackPath is greater than or equal to ul-DataSplitThreshold, then this PDCP PDU is submitted to the primary RLC entity or the RLC entity indicated by secondaryFallbackPath;

[0095] If PDCP duplication is deactivated, and if the transmitting PDCP entity is associated with more than 2 RLC entities, and if secondaryFallbackPath is configured, and the total of the PDCP number and the amount of data pending initial transmission in the primary RLC entity and the RLC entity indicated by secondaryFallbackPath is less than ul-DataSplitThreshold, then this PDCP PDU is submitted to the primary RLC entity;

[0096] If PDCP duplication is deactivated, and if the transmitting PDCP entity is associated with more than 2 RLC entities, and if secondaryFallbackPath is not configured, then this PDCP PDU is submitted to the primary RLC entity.

[0097] It can also be specified or predefined that if PDCP duplication is deactivated, and if the transmitting PDCP entity is associated with more than 2 RLC entities, and secondaryFallbackPath is not configured, if an activated secondary RLC entity is received as indicated by the MAC layer, and the total of the PDCP number and the amount of data pending initial transmission in the primary RLC entity and the activated secondary RLC entity indicated by the MAC layer is greater than or equal to ul-DataSplitThreshold, then this PDCP PDU is submitted to the primary RLC entity or the activated secondary RLC entity indicated by the MAC layer;

[0098] It can also be specified or predefined that if a PDCP is repeatedly deactivated, and if there are more than two RLC entities associated with the sending PDCP entity, and no secondaryFallbackPath is configured, if an activated secondary RLC entity is received as indicated by the MAC layer, and the total number of PDCPs and the amount of data waiting for initial transmission in the main RLC entity and the activated secondary RLC entity indicated by the MAC layer is less than ul-DataSplitThreshold, then this PDCP PDU will be delivered to the main RLC entity.

[0099] It can also be specified or predefined that if the PDCP is repeatedly deactivated, and if there are more than two RLC entities associated with the sending PDCP entity, and no secondaryFallbackPath is configured, the PDCP PDU will be handed over to the primary RLC entity if no secondary RLC entity is activated as indicated by the MAC layer.

[0100] According to the method performed by the user equipment described above, appropriate PDCP repetition and / or RLC entity activation configuration can be performed based on information received from the base station indicating the activation configuration of PDCP repetition and / or RLC entities, thereby improving the communication efficiency and reliability of the wireless communication system.

[0101] also, Figure 4 A block diagram of a user equipment 40 according to an embodiment of the present disclosure is shown. Figure 4 As shown, the user equipment 40 includes a processor 401 and a memory 402. The processor 401 may include, for example, a microprocessor, a microcontroller, an embedded processor, etc. The memory 402 may include, for example, volatile memory (such as I2R random access memory RAM), a hard disk drive (HDD), non-volatile memory (such as flash memory), or other memory systems. Program instructions are stored on the memory 402. When executed by the processor 401, these instructions can perform the methods described in detail in this disclosure within the user equipment.

[0102] Furthermore, as an example, Figure 5 The diagram below illustrates a flowchart of method 500 in a base station based on an embodiment of the present disclosure. In step S501, a MAC CE is generated, which is used to indicate the PDCP repetition of the DRB and / or the activation configuration of associated RLC entities. In step S502, the MAC CE is sent to the user equipment, and the activation configuration of the user equipment's PDCP repetition and / or associated RLC entities is performed based on the MAC CE.

[0103] According to the method performed by the base station described above, appropriate PDCP repetition and / or RLC entity activation configuration can be performed based on information sent to the user equipment indicating the activation configuration of PDCP repetition and / or RLC entities, thereby improving the communication efficiency and reliability of the wireless communication system.

[0104] also, Figure 6 A block diagram of a base station 60 according to an embodiment of the present disclosure is shown. Figure 6 As shown, the base station 60 includes a processor 601 and a memory 602. As described above, the base station 60 in this disclosure can be any type of base station, including but not limited to: Node B, enhanced base station eNB, 5G communication system base station gNB, or micro base station, pico base station, macro base station, home base station, etc. The processor 601 may include, for example, a microprocessor, microcontroller, embedded processor, etc. The memory 602 may include, for example, volatile memory (such as random access memory RAM), hard disk drive (HDD), non-volatile memory (such as flash memory), or other memory systems. Program instructions are stored on the memory 602. When executed by the processor 601, these instructions can perform the methods described in detail in this disclosure within the base station.

[0105] Computer-executable instructions or programs running on a device according to this disclosure may be programs that enable a computer to perform the functions of embodiments of this disclosure by controlling a central processing unit (CPU). The program or information processed by the program may be temporarily stored in volatile memory (such as random access memory, RAM), hard disk drive (HDD), non-volatile memory (such as flash memory), or other memory systems.

[0106] Computer-executable instructions or programs for implementing the functions of the embodiments of this disclosure can be recorded on a computer-readable storage medium. The corresponding functions can be implemented by causing a computer system to read and execute the programs recorded on the recording medium. The term "computer system" herein can refer to a computer system embedded in the device, and may include an operating system or hardware (such as peripheral devices). "Computer-readable storage medium" can be a semiconductor recording medium, an optical recording medium, a magnetic recording medium, a short-time dynamic program storage medium, or any other computer-readable recording medium.

[0107] Various features or function modules of the apparatus used in the above-described embodiments can be implemented or performed by a circuit (e.g., a single- or multi-chip integrated circuit). The circuit designed to perform the functions described in the present specification can include 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 devices, discrete gates or transistor logic, discrete hardware components, or any combination thereof. The general-purpose processor can be a microprocessor, but implementation is not limited thereto. The general-purpose processor can be any controller or a state machine deviced to perform a certain function thereon. The above circuit can be implemented or performed with a digital circuit, or it can be implemented or performed with an analogue circuit. If a new integrated circuit technology replaces the existing integrated circuit technology, one or more embodiments of the present disclosure can use the new integrated circuit technology as a substitute.

[0108] Furthermore, the present disclosure is not limited to the above-described embodiments. Although various examples of the embodiments have been described, the present disclosure is not limited thereto. Fixed or non-mobile electronic devices installed indoors or outdoors can be used as terminal devices or communication devices, such as AV devices, kitchen devices, cleaning devices, air conditioners, office devices, vending machines, and other home appliances.

[0109] As described above, the embodiments of the present disclosure have been described in detail with reference to the accompanying drawings. However, the specific configuration is not limited to the above-described embodiments, and the present disclosure includes any design modification without departing from the spirit of the present disclosure. In addition, various modifications can be made to the present disclosure within the scope of the claims, and embodiments obtained by appropriately combining the technical means disclosed in the various embodiments are also included in the technical scope of the present disclosure. Furthermore, components described in the above-described embodiments as having the same effect can be replaced with each other.

Claims

1.A user equipment, comprising: receiving circuitry configured to receive an RRC message, the RRC message comprising: (i) a first indication for indicating a first logical channel identity of a first cell group and a primary RLC entity, (ii) a second indication for indicating a second logical channel identity of a secondary RLC entity, and (iii) an ul-DataSplitThreshold parameter, wherein the secondary RLC entity belongs to a second cell group different from the first cell group, the secondary RLC entity is an RLC entity for a fallback path; the receiving circuitry is configured to receive a third indication and a fourth indication, wherein the third indication indicates whether PDCP duplication is activated, and the fourth indication indicates whether PDCP duplication is activated for the secondary RLC entity; and transmitting circuitry configured to deliver a PDCP PDU to the primary RLC entity or the secondary RLC entity if the PDCP duplication is deactivated and a total amount of PDCP data amount and RLC data amount pending initial transmission in the primary RLC entity and the secondary RLC entity is equal to or larger than the ul-DataSplitThreshold parameter. 2.A method performed by a user equipment, comprising: receiving an RRC message, the RRC message comprising: (i) a first indication for indicating a first logical channel identity of a first cell group and a primary RLC entity, (ii) a second indication for indicating a second logical channel identity of a secondary RLC entity, and (iii) an ul-DataSplitThreshold parameter, wherein the secondary RLC entity belongs to a second cell group different from the first cell group, and the secondary RLC entity is an RLC entity for a fallback path; receiving a third indication and a fourth indication, wherein the third indication indicates whether PDCP duplication is activated, and the fourth indication indicates whether PDCP duplication is activated for the secondary RLC entity; and delivering a PDCP PDU to the primary RLC entity or the secondary RLC entity if the PDCP duplication is deactivated and a total amount of PDCP data amount and RLC data amount pending initial transmission in the primary RLC entity and the secondary RLC entity is equal to or larger than the ul-DataSplitThreshold parameter. 3.A base station, comprising: transmitting circuitry configured to transmit an RRC message to a user equipment, UE, the RRC message comprising: (i) a first indication for indicating a first logical channel identity of a first cell group and a primary RLC entity, (ii) a second indication for indicating a second logical channel identity of a secondary RLC entity, and (iii) an ul-DataSplitThreshold parameter, wherein the secondary RLC entity belongs to a second cell group different from the first cell group, and the secondary RLC entity is an RLC entity for a fallback path; the transmitting circuitry is configured to transmit a third indication and a fourth indication, wherein the third indication indicates whether PDCP duplication is activated, and the fourth indication indicates whether PDCP duplication is activated for the secondary RLC entity. the third indication indicates whether PDCP duplication is activated or not, and the fourth indication indicates whether PDCP duplication is activated or not for the secondary RLC entity; and the RRC message causes the UE to deliver a PDCP PDU to the primary RLC entity or the secondary RLC entity if the PDCP duplication is deactivated and a total of a PDCP data volume and a RLC data volume pending initial transmission in the primary RLC entity and the secondary RLC entity is equal to or larger than the ul-DataSplitThreshold parameter.

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