Patent Description:
In September <NUM>, Nokia proposed a study item on the <NUM> (or NR) industrial internet of things (IIoT) (see non-patent literature: RP-<NUM>: Revised SID: Study on NR Industrial Internet of Things (IoT)) at the 3rd Generation Partnership Project (3GPP) RAN#<NUM> plenary meeting, and the study item was approved. One of the goals of this study item is to improve the reliability of data transmission and reduce the time delay of data transmission by means of data duplication, specifically including: (<NUM>) resource-efficient PDCP duplication, such as avoiding unnecessary duplicate transmissions; and (<NUM>) more than two PDCP duplications implemented by dual connectivity or carrier aggregation.

"<NPL>) discusses potential issues with pdcp-Duplication and its field description.

In Release <NUM>, a bearer that supports PDCP duplication can be configured with two RLC entities at most. The initial state of the bearer configured with PDCP duplication indicates whether the PDCP duplication function is initially activated by means of a pdcp-Duplication information element (see 3GPP TS38. <NUM> for a detailed description of the information element). In carrier aggregation, for a bearer in which an initial PDCP duplication function is not activated, data of the bearer is transmitted by means of a logical channel indicated by a primaryPath information element (see 3GPP TS38. <NUM> for a detailed description of the information element). In dual connectivity, for a bearer in which an initial PDCP duplication function is not activated, it is determined, according to the amount of data to be transmitted, whether the data is to be transmitted by means of a logical channel indicated by a primaryPath information element (see 3GPP TS38. <NUM> for a detailed description of the information element) or by using a split bearer.

In NR IIoT, in order to achieve the goal of more than two PDCP duplications by means of dual connectivity or carrier aggregation, some manufacturers propose to configure a plurality of RLC entities for a bearer that supports PDCP duplication, but only activate a number of RLC entities thereamong each time. If a plurality of (more than two) RLC entities can be configured for a bearer that supports PDCP duplication, a problem to be resolved is how to set an initial state for the bearer configured with a plurality of RLC entities.

In order to resolve the above problem in the prior art, provided in the present invention are a method performed by a user equipment, a user equipment, and a base according to independent claims <NUM>-<NUM>. In the following the description of <FIG> in combination with the embodiments <NUM>, <NUM> and <NUM> and the definitions of the terms PDCP-Config information element, DRB and PDCP duplication as given in the term definitions part at the beginning of the detailed description are according to the invention. The rest of the following description and figures (even if named embodiment(s)) does not or does not fully correspond to the invention as defined in the claims and is therefore not according to the invention as defined in the claims but is considered as useful for understanding the invention.

The above and other features of the present disclosure will become more apparent with the following detailed description in conjunction with the accompanying drawings.

The following describes the present disclosure in detail with reference to the accompanying 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 simplicity, detailed description of the prior art not directly related to the present disclosure is omitted to prevent confusion in understanding the present disclosure.

Some terms involved in the present disclosure are described below. If not specifically indicated, the terms involved in the present disclosure use the definitions herein. The terms given in the present disclosure may be named differently in NR, LTE, and eLTE, but unified terms are used in the present disclosure. When applied to a specific system, the terms may be replaced with terms used in the corresponding system.

RLC: radio link control. The transmission mode of an RLC entity can be configured as one of a transparent mode (TM), an unacknowledged mode (UM), or an acknowledged mode (AM).

In the present disclosure, data received from or transmitted to an upper layer is referred to as an SDU, and data transmitted to or received from a lower layer is referred to as a PDU. For example, data received from or transmitted to an upper layer by a PDCP entity is referred to as a PDCP SDU; and data received from or transmitted to an RLC entity by the PDCP entity is referred to as a PDCP PDU (i.e., an RLC SDU).

PDCP-Config information element: the information element PDCP-Config is used to set configurable PDCP parameters for a signaling bearer and a data bearer.

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).

Master base station: master eNB or master gNB, denoted as MeNB (a base station corresponding to E-UTRAN or LTE or eLTE) or MgNB (a base station corresponding to <NUM>-RAN or NR). The master base station is an eNB that at least terminates at a control node mobility management entity (which can be denoted as S <NUM>-MME) for processing interaction between UE and a core network in dual-connectivity; or a gNB that at least terminates at an NG-C, wherein the NG-C is a control plane interface between an NG-RAN and a 5GC.

Secondary base station: secondary eNB or secondary gNB, denoted as SeNB (a base station corresponding to E-UTRAN or LTE or eLTE) or SgNB (a base station corresponding to <NUM>-RAN or NR). In dual connectivity, the secondary base station is a base station that is not a primary base station but provides additional radio resources for UE.

Primary Cell: PCell. The PCell is a cell that operates at a primary frequency, and may be a cell on which UE performs an initial connection establishment procedure or initiates a connection re-establishment procedure or which is designated as a primary cell during a handover procedure. The cell in the present disclosure may also be referred to as a carrier or a set of beams.

Primary Secondary Cell: PSCell. The PSCell is an SCG cell used to instruct UE to perform random access during an SCG switching procedure.

Secondary Cell: SCell. The SCell is a cell that operates at a secondary frequency. The cell can be configured after an RRC connection is established and can be used to provide additional radio resources.

Cell group: CG. In dual-connectivity or multi-connectivity, the cell group is a group of serving cells or carriers associated with a primary base station or a secondary base station, which may be an MCG or an SCG.

Master cell group: MCG. For UE that is not configured with dual connectivity, the MCG consists of all serving cells; for UE that is configured with dual connectivity, the MCG consists of a subset of the serving cells (i.e., a group of serving cells associated with a primary base station), which includes a PCell and <NUM>, <NUM> or a plurality of SCells.

Secondary cell group: SCG. The SCG is a group of serving cells associated with an SeNB or an SgNB in dual-connectivity. The SCG may comprise one PSCell, and may further comprise one or a plurality SCells.

DRB: data radio bearer carrying user plane data, or is briefly referred to as a data radio bearer.

Unless otherwise stated, the bearer or radio bearer described in the present disclosure may be: an SRB, a DRB, a split DRB (for example, an MCG split DRB or an SCG split DRB), or a split SRB (for example, an MCG split SRB or an SCG split SRB).

PDCP duplication: it may also be referred to as duplication, packet duplication or data duplication. An SRB, a DRB, a split SRB, and a split DRB may all be configured with the PDCP duplication. When a radio bearer is configured with the PDCP duplication, a secondary RLC entity and a secondary logical channel are added to the radio bearer to process duplicate PDCP PDUs. The PDCP duplication means that the same PDCP PDU is transmitted twice or many times, and the PDCP PDU transmitted twice or many times is transmitted by means of RLC entities and logical channels associated with different carriers or carrier groups. In a dual connectivity manner, the RLC entities and logical channels of radio bearers configured with the PDCP duplication belong to different MAC entities.

Duplication activation/deactivation MAC CE: duplication activation/deactivation MAC CE used to activate or deactivate PDCP duplication of a radio bearer.

Total data volume: the total amount of a PDCP data volume and a data volume of two or more associated RLC entities (or activated RLC entities) (RLC data volume pending for initial transmission) (the total amount of PDCP data volume and RLC data volume pending for initial transmission in the activated RLC entities).

Primary path: in carrier aggregation, when PDCP duplication is deactivated, a PDCP entity transmits PDCP PDUs to the primary path. In dual connectivity, when PDCP duplication is deactivated, if a total data volume is less than a data split threshold, the PDCP entity transmits PDCP PDUs to the primary path.

Secondary path: in carrier aggregation and dual connectivity, when PDCP duplication is activated, the secondary path is an RLC entity and/or a logical channel and/or an RLC bearer used to transmit PDCP PDUs. Specifically, when PDCP duplication is activated, a PDCP entity duplicates a PDCP PDU and transmit the PDCP PDU to an activated RLC entity and/or logical channel and/or RLC bearer (also referred to as a primary path and a secondary path). The embodiments in the present disclosure specifically describe those RLC entities and/or logical channels and/or RLC bearers that are considered to be activated. Among the activated RLC entities and/or logical channels and/or RLC bearers, RLC entities and/or logical channels and/or RLC bearers except for the primary path can all be referred to as secondary paths.

A method in user equipment (UE) in the present disclosure is described below. Specifically, a control method involved in PDCP duplication of a bearer in the UE is described. As an example, <FIG> shows a flowchart of a method <NUM> in user equipment (UE) based on an embodiment of the present disclosure.

In step S101, the user equipment (UE) receives from a base station a radio resource control (RRC) message comprising packet data convergence protocol (PDCP) duplication configuration information of a bearer.

In step S102, the user equipment (UE) performs activation configuration of packet data convergence protocol (PDCP) duplication on the basis of the PDCP duplication configuration information of the bearer. Specifically, if the bearer is based on a carrier aggregation manner (that is, RLC entities associated therewith belong to the same cell group), a PDCP entity transmits a PDCP PDU according to a PDCP duplication activated or deactivated manner in the carrier aggregation manner. If the bearer is based on a dual connectivity manner (that is, the RLC entities associated therewith belong to different cell groups), the PDCP entity transmits a PDCP PDU according to a PDCP duplication activated or deactivated manner in the dual connectivity manner.

In addition, the PDCP duplication configuration information of the bearer comprises, according to the invention, an activation indicator for indicating an activation or deactivation status of a radio link control (RLC) entities for PDCP duplication.

The activation indicator may comprise a primary path indicator and a secondary path indicator. The primary path indicator may comprise a cell group identity for indicating a cell group of a primary path, and/or a logical channel identity for indicating a logical channel of the primary path. The secondary path indicator may comprise a cell group identity for indicating a cell group of a secondary path, and/or a logical channel identity for indicating a logical channel of the secondary path.

The activation indicator may also comprise a cell group indicator for indicating a master cell group (MCG) and a secondary cell group (SCG).

The activation indicator may comprise a first indicator for indicating an activated RLC entity in a master cell group (MCG), and a second indicator for indicating an activated RLC entity in a secondary cell group (SCG).

In addition, <FIG> shows a block diagram of user equipment <NUM> according to an embodiment of the present disclosure. As shown in <FIG>, the user equipment <NUM> includes a processor <NUM> and a memory <NUM>. The processor <NUM> may include, for example, a microprocessor, a microcontroller, an embedded processor, and the like. The memory <NUM> may include, for example, a volatile memory (for example, a random access memory (RAM)), a hard disk drive (HDD), a non-volatile memory (for example, a flash memory), or other memory systems. The memory <NUM> stores program instructions. The instructions, when run by the processor <NUM>, can execute the method in user equipment described in detail in the present disclosure.

Furthermore, as an example, <FIG> shows a flowchart of a method <NUM> in a base station based on an embodiment of the present disclosure.

In step S301, the base station device generates a radio resource control (RRC) message comprising packet data convergence protocol (PDCP) duplication configuration information of a bearer.

In step S302, the base station device transmits the PDCP duplication configuration information of the bearer to user equipment (UE), and configures PDCP duplication of the user equipment (UE) by means of the PDCP duplication configuration information of the bearer.

Regarding the aforementioned "the PDCP duplication configuration information of the bearer," reference may be made to the content described in the method in user equipment above.

In addition, <FIG> shows a block diagram of a base station <NUM> according to an embodiment of the present disclosure. As shown in <FIG>, the base station <NUM> includes a processor <NUM> and a memory <NUM>. As mentioned above, the base station <NUM> in the present disclosure may be any type of base station, including but not limited to: a Node B or an enhanced base station eNB, or may be a base station gNB in a <NUM> communication system, or a micro base station, a pico base station, a macro base station, a home base station, and the like. The processor <NUM> may include, for example, a microprocessor, a microcontroller, an embedded processor, and the like. The memory <NUM> may include, for example, a volatile memory (for example, a random access memory (RAM)), a hard disk drive (HDD), a non-volatile memory (for example, a flash memory), or other memory systems. The memory <NUM> stores program instructions. The instructions, when run by the processor <NUM>, can execute the method in a base station described in detail in the present disclosure.

Hereinafter, specific examples and embodiments related to the present disclosure are described in detail. In addition, as described above, the examples and embodiments described in the present disclosure are illustrative descriptions for facilitating understanding of the present invention, rather than limiting the present invention.

First, an embodiment in which a base station configures a bearer that supports PDCP duplication for user equipment and sets an initial state of the bearer is described hereinafter.

The user equipment receives an RRC message from the base station (the RRC message in the embodiment of the present disclosure may be an RRC reconfiguration message), and the message comprises an activation indicator (denoted as a first indicator, for example, represented by an information element activatedPath). The activation indicator is used for indicating whether RLC entities are in an activated or deactivated state for PDCP duplication.

Optionally, the RRC message also includes an information element (denoted as maxNrofActivatedLCH) for indicating a maximum number of activatable RLC entities and/or logical channels and/or RLC bearers when PDCP duplication is activated. The value of the information element is an integer and does not exceed a maximum number of RLC entities and/or logical channels and/or RLC bearers that can be configured for one bearer or a maximum value maxLC-ID of a logical channel identity.

Optionally, not according to the invention, the RRC message further comprises an information element (denoted as releaseAllowedServingCells) for indicating whether to remove a restriction on a serving cell after deactivation of PDCP duplication (the restriction on the serving cell can be configured by an information element allowedServingCells, and if the information element appears, a UL MAC SDU corresponding to a logical channel can only be mapped to a serving cell in a cell list specified by the information element). In other words, after deactivation of PDCP duplication, the uplink UL MAC SDU from the logical channel can be mapped to any (or all) serving cells configured in the cell group. The information element may be configured in PDCP-config, in which case the information element is applied to all RLC entities or logical channels. The information element may also be configured in LogicalChannelConfig, in which case the information element is applied to only the corresponding logical channel or an RLC entity associated with the logical channel. For example, if the information element has the value of <NUM> or true or the information element appears, it indicates that the restriction on the serving cell is removed after deactivation of PDCP duplication.

Optionally, not according to the invention, in carrier aggregation, if the number of activated RLC entities and/or logical channels and/or RLC bearers indicated by the activation indicator is larger than two, PDCP duplication is activated. The PDCP entity will duplicate a PDCP PDU and transmit the PDCP PDU to an activated RLC entity and/or logical channel and/or RLC bearer associated therewith. Not according to the invention, if the number of activated RLC entity and/or logical channel and/or RLC bearer indicated by the activation indicator is only one, PDCP duplication is deactivated. The PDCP entity transmits the PDCP PDU to the activated RLC entity and/or logical channel and/or RLC bearer.

Optionally, the RRC message further comprises a PDCP duplication indicator (denoted as pdcp-Duplication) for indicating that an uplink duplication status is configured and activated when this information element is received. In carrier aggregation, if the value of the PDCP duplication indicator is true, the PDCP entity duplicates a PDCP PDU and transmits the PDCP PDU to a plurality of activated RLC entities. Not according to the invention, if the value of the PDCP duplication indicator is false, the PDCP entity transmits the PDCP PDU to an activated RLC entity (or primary path) or the PDCP entity transmits the PDCP PDU to one activated RLC entity (the RLC entity is an RLC entity among activated RLC entities that is associated with a logical channel having the smallest (or smaller or largest or larger) logical channel identity). If the value of the PDCP duplication indicator is false and there is no primary path configured in the RRC message, only one RLC entity and/or logical channel and/or RLC bearer is activated (that is, the value of the activation indicator thereof is true). In dual connectivity, if the value of pdcp-Duplication is true, the PDCP entity duplicates a PDCP PDU and transmits the PDCP PDU to a plurality of activated RLC entities. Not according to the invention, if the value of pdcp-Duplication is false, the PDCP entity transmits the PDCP PDU in a split bearer data transmission manner. Specifically, in this case, the RRC message further comprises a configuration of a primary path and/or a data split threshold (denoted as ul-DataSplitThreshold in the present disclosure). If a total data volume is equal to or larger than the data split threshold, the PDCP entity transmits the PDCP PDU to one of two or more activated RLC entities. If the total data volume is less than the data split threshold, the PDCP entity transmits the PDCP PDU to an RLC entity specified by the primary path. The value of the primary path may be a cell group identity or an MCG or an SCG. In this case, when the total data volume is less than the data split threshold, the PDCP entity transmits the PDCP PDU to an RLC entity and/or logical channel and/or RLC bearer that is activated and belongs to (or is associated with) a cell group indicated by the primary path. Not according to the invention, in carrier aggregation, for a PDCP control PDU, when PDCP duplication is activated, it may be predefined to transmit the PDCP control PDU to an RLC entity that is activated and associated with a logical channel having the smallest (or smaller or largest or larger) logical channel identity. In other words, in this case, the RLC entity that is activated and associated with the logical channel having the smallest (or smaller or largest or larger) logical channel identity serves as the primary path.

The activation indicator is comprised in PDCP-config for indicating that a plurality of RLC entities are activated or deactivated for PDCP duplication. The activation indicator (denoted as ActivatedPath) may include a cell group indicator (for example, represented by an information element cellGroup) and includes, according to the invention, a logical channel indicator (not according to the invention, represented by an information element logicalHChannelList). The cell group indicator is used for indicating a cell group. A cell group identity (denoted as CellGroupld) of a master cell group (MCG) may be <NUM>, and other values indicate a secondary cell group. The value of the logical channel indicator is a logical channel identity LogicalChannelIdentity (i.e., LCH ID) bitmap. Each bit in the bitmap corresponds to one logical channel. Logical channel identities of logical channels associated with the bearer or a PDCP entity thereof sequentially correspond to respective bits in the bitmap (from left to right) in increasing order. An RLC entity corresponding to a bit with a value of <NUM> in the bitmap is deactivated (or activated); and an RLC entity corresponding to a bit with a value of <NUM> in the bitmap is activated (or deactivated). In carrier aggregation, the activation indicator may comprise only a logical channel indicator. In dual connectivity, the length of the bitmap may be set to a configurable maximum number of RLC entities or maximum number of logical channels for a bearer that supports PDCP duplication minus <NUM>.

The activation indicator is comprised in PDCP-config. The activation indicator has two information elements. One information element (denoted as MCGActivatedPath) is used for indicating an activated RLC entity in a master cell group (MCG). Another information element (denoted as SCGActivatedPath) is used for indicating an activated RLC entity in a secondary cell group (SCG). The value of the MCGActivatedPath (or SCGActivatedPath) is a logical channel identity LogicalChannelIdentity (i.e., LCH ID) bitmap. Each bit in the bitmap corresponds to one logical channel. Logical channel identities of logical channels associated with the bearer or a PDCP entity thereof and located in the MCG (or SCG) sequentially correspond to respective bits in the bitmap (from left to right) in increasing order. An RLC entity corresponding to a bit with a value of <NUM> in the bitmap is deactivated (or activated); and an RLC entity and/or logical channel and/or RLC bearer corresponding to a bit with a value of <NUM> in the bitmap is activated (or deactivated). In dual connectivity, the number of elements in the logical channel identity list or the length of the bitmap may be set to a configurable maximum number of RLC entities or maximum number of logical channels for a bearer that supports PDCP duplication minus <NUM>.

Optionally, the MCGActivatedPath and/or SCGActivatedPath comprises a primary path indicating information element for indicating whether a corresponding cell group or an RLC entity (or logical channel) belonging to the corresponding cell group or an activated RLC entity (or logical channel) belonging to the corresponding cell group serves as a primary path. If the primary path indicating information element has the value of true or <NUM> or the primary path indicating information element appears, the corresponding cell group or the RLC entity (or logical channel) belonging to the corresponding cell group or the activated RLC entity (or logical channel) belonging to the corresponding cell group serves as the primary path, otherwise, does not serve as the primary path; vice versa. <IMG>
<IMG>.

The activation indicator (denoted as initialActivated) may be comprised in RLC-BearerConfig for indicating whether a corresponding RLC entity and/or logical channel and/or RLC bearer is in an activated state, or for indicating whether the corresponding RLC entity and/or logical channel and/or RLC bearer is in an activated state when the information element is received.

If the activation indicator initial Activated has the value of true or <NUM> or the indicator appears, it indicates that the corresponding RLC entity and/or logical channel and/or RLC bearer is in an activated state; and if the value of the activation indicator initialActivated is false or <NUM> or the indicator does not appear, it indicates that the corresponding RLC entity and/or logical channel and/or RLC bearer is in a deactivated state. Vice versa.

Optionally, the RLC-BearerConfig may further comprise a primary path information element, which has the value of true or false, or <NUM> or <NUM>, or is determined depending on presence or absence of the primary path information element. If the primary path information element has the value of true or <NUM> or appears, an RLC entity associated therewith serves as a primary path, otherwise does not serve as the primary path. Vice versa.

Optionally, in an initial state of carrier aggregation, if PDCP duplication is deactivated (for example, pdcp-Duplication does not appear or is set to false), only one RLC entity is in an activated state, that is, the activation indicator initialActivated of only one RLC entity has the value of true or <NUM> or the indicator appears; if PDCP duplication is activated, at least two RLC entities are in an activated state, that is, the activation indicators Initial Activated of at least two RLC entities have the value of true or <NUM> or the indicators appear. <IMG>
<IMG>.

In carrier aggregation, in an initial state, if PDCP duplication is activated, a PDCP entity transmits a PDCP PDU to RLC entities associated with logical channels having the smallest and second smallest (or largest and second largest) logical channel identities (herein two logical channels are used as an example, and so forth if there are a plurality of logical channels). If PDCP duplication is deactivated, the PDCP entity transmits the PDCP PDU to an RLC entity associated with a logical channel having the smallest (or largest) logical channel identity.

In dual connectivity, in an initial state, if PDCP duplication is activated, the PDCP entity transmits a PDCP PDU to an RLC entity associated with a logical channel having the smallest (or largest) logical channel identity in each cell group. If PDCP duplication is deactivated and a total data volume is greater than or equal to a data split threshold, the PDCP entity transmits the PDCP PDU to one of RLC entities associated with a logical channel having the smallest (or largest) logical channel identity in two cell groups, respectively. If PDCP duplication is deactivated and the total data volume is less than the data split threshold, the PDCP entity transmits the PDCP PDU to a primary path. A cell group to which the primary path belongs may be configured by RRC, and then an RLC entity associated with a logical channel having the smallest (or largest) logical channel identity in the cell group is predefined as the primary path.

Alternatively, the initial state of PDCP duplication is always deactivated. In carrier aggregation, the PDCP entity transmits a PDCP PDU to an RLC entity associated with a logical channel having the smallest (or largest) logical channel identity. In dual connectivity, if the total data volume is greater than or equal to the data split threshold, the PDCP entity transmits a PDCP PDU to one of RLC entities associated with a logical channel having the smallest (or largest) logical channel identity in two cell groups, respectively. If the total data volume is less than the data split threshold, the PDCP entity transmits the PDCP PDU to a primary path. A cell group to which the primary path belongs may be configured by RRC, and then an RLC entity associated with a logical channel having the smallest (or largest) logical channel identity in the cell group is predefined as the primary path.

The activation indicator is comprised in PDCP-config, and the activation indicator comprises two information elements, namely, a primary path indicator (denoted as PrimaryPath) and a secondary path indicator (denoted as SecondaryPath). The primary path indicator further comprises a logical channel identity bitmap of the primary path. The secondary path indicator identity comprises a logical channel identity bitmap of the secondary path. Each bit in the bitmap corresponds to one logical channel. Logical channel identities of logical channels associated with the bearer or a PDCP entity thereof and located in the cell group indicated by the cell group identity sequentially correspond to bits in the bitmap (from left to right) in increasing order. An RLC entity corresponding to a bit with a value of <NUM> in the bitmap is deactivated (or activated); and an RLC entity corresponding to a bit with a value of <NUM> in the bitmap is activated (or deactivated). In dual connectivity, the number of elements in the logical channel identity list or the length of the bitmap may be set to a configurable maximum number of RLC entities or maximum number of logical channels for a bearer that supports PDCP duplication minus <NUM>. Not according to the invention, after deactivation of PDCP duplication, if the primary path comprises a plurality of logical channels or RLC entities or RLC logical channels, a logical channel or RLC entity or RLC logical channel thereamong with the largest or smallest logical channel identity may be predefined as a logical channel or RLC entity or RLC logical channel for transmitting a PDCP PDU (that is, the PDCP entity transmits the PDCP PDU to the logical channel or RLC entity or RLC logical channel), or one of the logical channels or RLC entities or RLC logical channels may be configured by RRC (for example, indicated by an indicator) to transmit the PDCP PDU.

It should be noted that in the present disclosure, corresponding to PDCP duplication based on carrier aggregation, since RLC entities or logical channels associated with the same bearer (or PDCP entity) that supports PDCP duplication belongs to one cell group, the activation indicator in this case may not comprise cell group identity. In other words, the activation indicator only comprises the logical channel identification bitmap.

The following describes an embodiment not according to the present invention of dynamically switching an RLC entity when PDCP duplication is activated.

User equipment (UE) receives an RRC message from a base station. The RRC message configures a plurality of RLC entities and/or logical channels for a bearer that supports PDCP duplication.

The user equipment receives a switching MAC CE from the base station. The switching MAC CE is used to activate and/or deactivate the RLC entities and/or logical channels associated with the bearer that supports PDCP duplication. The switching MAC CE comprises a field (may be denoted as Di) for indicating the bearer that supports PDCP duplication, and a field (may be denoted as Lij) for indicating the RLC entities or logical channels associated with the bearer (or a PDCP entity of the bearer). The switching MAC CE is related to a MAC entity. A switching MAC CE from a specific MAC entity only indicates an RLC entity (or logical channel) associated with this MAC entity and a DRB or SRB that supports duplication corresponding thereto.

<FIG> shows a schematic diagram of the switching MAC CE. In <FIG>, Di corresponds to DRBi or SRBi, where i is a corresponding serial number in ascending or descending order of DRB identities (or SRB identities) of DRBs (or SRBs) configured with PDCP duplication, and RLC entities (or some of associated RLC entities) associated with the DRBs (or SRBs) are located in this MAC entity. The SRBs can also support dynamic switching of an RLC entity or logical channel for data transmission. If the SRBs support dynamic switching of an RLC entity or logical channel for data transmission, the SRBs and DRBs can use different switching MAC CEs; or the switching MAC CE comprises a field for indicating whether the corresponding switching MAC CE is used for an SRB or a DRB (a MAC CE used for an SRB and a MAC CE used for a DRB when distinguished according to different values of the field), for example, if the value of the field is <NUM> (or <NUM>), the corresponding switching MAC CE is used for an SRB (or DRB), that is, Di corresponds to an SRB (or DRB), and vice versa; or mapped to Di in a manner of SRB first and then DRB, or DRB first and then SRB. Furthermore, each SRB (or DRB) may be mapped to each Di in the switching MAC CE in increasing or decreasing order (mapping may be performed in an order from left to right or from right to left, for example, D0 corresponds to a DRB or SRB with the smallest or largest bearer identity).

In <FIG>, the field Lij is used for indicating activating or deactivating the j-th RLC entity and/or logical channel of the bearer corresponding to Di, where j is a serial number in ascending or descending order of logical channel identities of RLC entities and/or logical channels of the bearer corresponding to Di associated with this MAC entity. If the value of the field is <NUM>, the corresponding RLC entity and/or logical channel is deactivated; if the value of the field is <NUM>, the corresponding RLC entity and/or logical channel is activated. Vice versa.

Preferably, when Di = <NUM>, the corresponding field Lij is not comprised in the switching MAC CE. Alternatively, when Di = <NUM>, at most only one field Lij has the value of <NUM>. Alternatively, when Di = <NUM>, the corresponding field Lij is not comprised in the switching MAC CE, but the switching MAC CE comprises a field for indicating an RLC entity and/or logical channel in an activated state after deactivation of PDCP duplication. The value of the field may be a logical channel identity of the activated logical channel or a logical channel identity of a logical channel associated with the activated RLC entity, or the value of the field is <NUM> or <NUM>, indicating deactivation of other RLC entities other than an RLC entity associated with a logical channel having the smallest logical channel identity, or the value of the field is <NUM> or <NUM>, indicating deactivation of other RLC entities other than an RLC entity associated with a logical channel having the largest logical channel identity.

If the switching MAC CE is further used for activating or deactivating PDCP duplication, Di is used for indicating whether PDCP duplication of SRBi or DRBi is in an activated state or a deactivated state. If Di = <NUM>, it indicates that the PDCP duplication of SRBi or DRBi is deactivated; if Di = <NUM>, it indicates that the PDCP duplication of SRBi or DRBi is activated. Vice versa. Optionally, Di is further used for indicating whether Lij appears in the switching MAC CE. When Di = <NUM>, the corresponding field Lij is not comprised in the switching MAC CE; when Di = <NUM>, the corresponding field Lij is comprised in the switching MAC CE.

If the switching MAC CE is not used for duplication activation/deactivation, the switching MAC CE may only comprise a logical channel corresponding to an activated bearer (which may be a logical channel only belonging to this MAC entity). In this case, the field Di in <FIG> may not be carried, and the switching MAC CE only carries fields Lij corresponding to those activated bearers. The arrangement of the fields Lij is consistent with that shown in <FIG>, and the fields Lij may be arranged in ascending or descending order according to bearer identity sizes of corresponding Di, and Lij corresponding to each activated bearer may be arranged in ascending or descending order according to logical channel identity sizes.

Alternatively, the switching MAC CE may further instruct only one bearer to switch an RLC entity and/or a logical channel at a time. In this case, the switching MAC CE carries a bearer identity and a field Lij (used for indicating an activated logical channel of the corresponding bearer).

After receiving the switching MAC CE, the user equipment performs one of the following operations:.

User equipment receives an RRC message (for example, an RRC reconfiguration message) from a base station, and the message comprises an RLC entity group or logical channel group or RLC bearer group that can be used after activation of PDCP duplication. Specifically, RLC entities and/or logical channels associated with the same bearer are divided into several groups, and a group number can be configured for each group in the RRC message. For example, one group number indicator is used to indicate the group number, and another group indicator is used to indicate RLC entities or logical channels comprised in the group. The group may be represented by using a logical channel identity list or a bitmap. In the case of grouping according to a bitmap, each bit in the bitmap corresponds to each RLC entity and/or logical channel (which can be mapped in increasing or decreasing order) of this bearer, and RLC entities and/or logical channels corresponding to bits of <NUM> in the bitmap are divided into the same group. Alternatively, RLC entities and/or logical channel groups are numbered according to a sequential order of the RLC entity and/or logical channel groups. The first group number is <NUM> (or <NUM>), the second group number is <NUM> (or <NUM>), and so on.

The user receives a switching MAC CE from the base station. The switching MAC CE is used to instruct to switch a PDCP duplication RLC entity or logical channel to an RLC entity or logical channel indicated by the MAC CE. Preferably, a field value of the switching MAC CE is a number of the RLC entity and/or logical channel group. Alternatively, the switching MAC CE is a bitmap. Bits in the bitmap have a one-to-one correspondence in ascending or descending order of group numbers. A bit with a value of <NUM> in the bitmap indicates that an RLC entity and/or logical channel in the group is activated, and a bit with a value of <NUM> in the bitmap indicates that an RLC entity and/or logical channel in the group is deactivated. Only one bit in the MAC CE at most can be set to <NUM>. Optionally, if all bits in the bitmap are set to <NUM>, PDCP duplication of corresponding bearers is deactivated.

Embodiments regarding how to determine an RLC entity to which a PDCP entity transmits a PDCP PDU after PDCP duplication is deactivated (carrier aggregation and dual connectivity scenarios are discussed separately) are described below.

Embodiment <NUM> to Embodiment are used as examples to describe processing in the case of carrier aggregation. In carrier aggregation, RLC entities and/or logical channels and/or RLC bearers associated with the same bearer that supports PDCP duplication or a PDCP entity thereof belong to the same cell group.

In this embodiment, UE receives an RRC message from a base station, and the RRC message carries a primary path indicating information element (denoted as primaryPath). The primary path indicating information element may include a cell group indicating information element cellGroup for indicating a cell group identity and/or a logical channel indicating information element logicalChannel) for indicating a logical channel identity. If PDCP duplication is deactivated (for example, a duplication activation/deactivation MAC CE is received), a PDCP entity transmits a PDCP PDU to a primary path. In other words, even if the primary path is deactivated before PDCP duplication is deactivated, when the PDCP duplication is deactivated, the primary path is activated and used by the PDCP entity to transmit the PDCP PDU. For example, when a MAC entity receives a duplication activation/deactivation MAC CE (or switching MAC CE), if the primary path or an RLC entity or logical channel or RLC bearer indicated by the primary path is deactivated, the MAC layer (the MAC layer instructs an upper layer to) activates the primary path or the RLC entity or logical channel or RLC bearer indicated by the primary path, and indicates to the upper layer that PDCP duplication is deactivated; or, the MAC layer indicates to the upper layer that PDCP duplication is deactivated, and the upper layer activates the primary path or the RLC entity or logical channel or RLC bearer indicated by the primary path; or, when the MAC entity receives the duplication activation/deactivation MAC CE (or switching MAC CE), the MAC entity instructs the upper layer to deactivate PDCP duplication and/or the RLC entity defined by the primary path or the RLC entity corresponding to the logical channel identity or the logical channel or the logical channel identity.

In this embodiment, UE receives a switching MAC CE from a base station. For example, the switching MAC CE indicates that the value of Di corresponding to a bearer DRB i (or SRB i) is <NUM>, that is, PDCP duplication is deactivated.

Preferably, a MAC entity activates an RLC entity and/or logical channel and/or RLC bearer corresponding to Lij with a value of <NUM> corresponding to the bearer DRB i (or SRB i), and instructs an upper layer to deactivate PDCP duplication of the corresponding bearer; or, at the same time, indicates to the upper layer the activated RLC entity and/or logical channel and/or RLC bearer and/or logical channel identity; or, instructs the upper layer to activate PDCP duplication and/or indicates the upper layer the activated RLC entity and/or logical channel. In this case, corresponding to Di with a value of <NUM>, there is only one corresponding Lij with a value of <NUM>.

Alternatively, when Di = <NUM>, the corresponding field Lij is not comprised in the switching MAC CE, but the switching MAC CE comprises a field for indicating an RLC entity and/or logical channel in an activated state after deactivation of PDCP duplication. The value of the field is an identity of the activated logical channel or a logical channel identity of a logical channel associated with the activated RLC entity.

In this embodiment, when a MAC CE (for example, a duplication activation/deactivation MAC CE or a switching MAC CE) for deactivating PDCP duplication is received, if PDCP duplication of a specific bearer is deactivated, a MAC entity performs at least one of the following operations when the MAC CE is received:.

In this embodiment, after it is predefined to deactivate PDCP duplication of the bearer, the PDCP entity transmits a PDCP PDU to the RLC entity associated with the logical channel having the smallest (or largest) logical channel identity. The largest or smallest is only in consideration of the largest or smallest one of the logical channel identities corresponding to activated logical channels (or RLC entities). In this embodiment of the present disclosure, activating an RLC entity means that the PDCP entity transmits a PDCP PDU to the RLC entity. Deactivating an RLC entity means that the PDCP entity no longer transmits a PDCP PDU to the RLC entity.

Next, Embodiment <NUM> to Embodiment <NUM> are used as examples to describe the processing in the case of dual connectivity.

In dual connectivity, RLC entities and/or logical channels and/or RLC bearers associated with the same bearer that supports PDCP duplication or a PDCP entity thereof belong to different cell groups. For a bearer configured with PDCP duplication (for example, a base station configures PDCP duplication for user equipment by an RRC message), if PDCP duplication is in an activated state, a PDCP entity will duplicate a PDCP PDU and transmit the PDCP PDU to an RLC entity that is associated with the PDCP entity and activated; if PDCP duplication is in a deactivated state and activated RLC entities belong to different cell groups and a total data volume is equal to or greater than a data split threshold configured in the RRC message (for example, indicated by an information element ulDataSplitThreshold), the data (i.e., the PDCP PDU) is transmitted to a primary path (in the present disclosure, the primary path may also be referred to as a primary RLC entity) or a secondary RLC entity (or an activated secondary RLC entity); if PDCP duplication is in a deactivated state and the activated RLC entities belong to different cell groups and if the total data volume is less than the data split threshold configured in the RRC message (for example, indicated by the information element ulDataSplitThreshold), the data (i.e., the PDCP PDU) is transmitted to the primary path. This data transmission manner in which the total data volume is compared with the data split threshold, and the PDCP entity only transmits the PDCP PDU to the primary path if the total data volume is less than the data split threshold, and the PDCP entity transmits the PDCP PDU to one of the primary path and other activated RLC entities if the total data volume is greater than or equal to the data split threshold is called data splitting. The primary path can be defined in the manner described in other embodiments of the present disclosure.

In this embodiment, UE receives an RRC message from a base station, and the RRC message comprises a configuration of a bearer that supports PDCP duplication. Specifically, the RRC message comprises a configuration of a primary path, the configuration of the primary path may include a cell group indicator (or include a cell group indicator and a logical channel indicator), and the cell group indicator is used for indicating which cell group where an RLC entity and/or logical channel can serve as the primary path. If the primary path configuration includes both a cell group indicator and a logical channel indicator, only an RLC entity that is located in a cell indicated by the cell group indicator and is associated with a logical channel indicated by the logical channel indicator (or a logical channel whose logical channel identity is of the value of the logical channel indicator) can serve as the primary path.

When the UE receives from the base station a MAC CE for deactivating PDCP duplication of a specific bearer (for example, a duplication activation/deactivation MAC CE or a switching MAC CE), the UE performs one of the following operations:.

In this embodiment, a MAC CE for deactivating PDCP duplication of a bearer carries logical channel identity indicating information, which is used to instruct a PDCP entity, after PDCP duplication is deactivated, to transmit a PDCP PDU to an RLC entity associated with a logical channel indicated by the logical channel identity indicating information. For example, when the UE receives from the base station a MAC CE for deactivating PDCP duplication of a specific bearer (for example, a duplication activation/deactivation MAC CE or a switching MAC CE), and the value of Di corresponding to the bearer is <NUM> in the MAC CE, a MAC entity activates an RLC entity corresponding to Lij with a value of <NUM> or an RLC entity and/or logical channel associated with a logical channel indicated by a logical channel identity indicator, and/or instructs an upper layer to deactivate PDCP duplication and/or indicates to the upper layer the logical channel identity corresponding to Lij with the value of <NUM> (or the logical channel or the RLC entity associated with the logical channel having the logical channel identity).

In this embodiment, when a MAC CE for deactivating PDCP duplication (for example, a duplication activation/deactivation MAC CE or a switching MAC CE) is received, if there are only two RLC entities in an activated state, a PDCP entity transmits, according to a manner of data splitting, a PDCP PDU to the RLC entity in an activated state (i.e., the RLC entity in an activated state when the MAC CE of deactivating PDCP duplication is received); if there are more than two RLC entities in an activated state in a specific cell group, it is predefined that the PDCP entity transmits the PDCP PDU according to a manner of data splitting by using a logical channel in the cell group that has the smallest (or largest) logical channel identity or an RLC entity associated with the logical channel having the smallest (or largest) logical channel identity. The largest or smallest is only in consideration of the largest or smallest one of the logical channel identities corresponding to activated logical channels (or RLC entities).

Specifically, when the UE receives from the base station a MAC CE for deactivating PDCP duplication of a specific bearer, a MAC entity performs at least one of the following operations:.

The larger or smaller or largest or smallest in this embodiment is only in consideration of the larger or smaller or largest or smallest one of the logical channel identities corresponding to activated logical channels (or RLC entities).

In the embodiments not being part of the present invention, the RLC entity and/or logical channel and/or RLC bearer in an activated state may also be referred to as an RLC entity and/or logical channel and/or RLC bearer that is activated or used to transmit data. If PDCP duplication is activated, an uplink UL MAC SDU from an activated RLC entity or logical channel can only be transmitted on a serving cell configured therefor. The RLC entity and/or logical channel and/or RLC bearer in an activated state may be an RLC entity and/or logical channel and/or RLC bearer that is used to transmit a PDCP PDU after PDCP duplication is activated or deactivated. The activated RLC entity and/or logical channel and/or RLC bearer refers to an RLC entity indicated in an RRC message (or an RLC entity in an activated state indicated in the RRC message) or an RLC entity indicated by a lower layer (or an RLC entity in an activated state indicated by the lower layer). In carrier aggregation, for a specific bearer, the primary path described in the present disclosure refers to an RLC entity to which the PDCP entity transmits a PDCP PDU (or an RLC entity used to transmit a PDCP PDU) after PDCP duplication is deactivated. In dual connectivity, for a specific bearer, the primary path described in the present disclosure refers to an RLC entity to which the PDCP entity transmits data (or an entity used to transmit a PDCP PDU) when the sum of a PDCP data volume and an RLC data volume to be initially transmitted of an associated (or associated and activated) RLC is less than a data split threshold configured in an RRC message. The indicated upper-layer RLC entity in the embodiments of the present disclosure may also be expressed as an indicated upper-layer logical channel or logical channel identity. In the present disclosure, the activated RLC entity refers to an entity used to transmit a PDCP PDU. After an RLC entity is activated, a PDCP entity can transmit a PDCP PDU to the RLC entity. The deactivated RLC entity described in the present disclosure can also be replaced with a deactivated logical channel.

UE receives a capability query message from a base station. The UE transmits a capability report message to the base station. The capability report message carries an information element used for indicating a maximum number of supportable RLC entities and/or logical channels; or the information element is used for indicating a maximum number of RLC entities and/or logical channels that can be simultaneously activated; or the information element is used for indicating how many RLC entities at most to which the PDCP entity can transmit the duplicated PDCP PDU.

For a PDCP entity configured with PDCP duplication, a PDCP transmitting entity performs the following operations:
If an associated RLC entity is switched (or an instruction from a lower layer to switch an RLC entity is received or a switching instruction from the lower layer is received), instruct a deactivated RLC entity to delete all duplicated PDCP data PDUs.

The deactivated RLC entity or logical channel or RLC bearer in the present disclosure means that the PDCP entity no longer transmits PDCP PDUs to the deactivated RLC entity.

The computer-executable instructions or program running on the device according to the present invention may be a program that enables the computer to implement the functions of the embodiments of the present invention by controlling the central processing unit (CPU). The program or information processed by the program can be stored temporarily in a volatile memory (e.g., Random Access Memory (RAM)), a Hard Disk Drive (HDD), a non-volatile memory (e.g., flash memory), or other memory systems.

The computer-executable instructions or program for implementing the functions of the embodiments of the present invention may be recorded on a computer-readable storage medium. The corresponding functions can be achieved by reading programs recorded on the recording medium and executing these programs by the computer system. The so-called "computer system" may be a computer system embedded in the device, which may include operating systems or hardware (e.g., peripherals). The "computer-readable storage medium" may be a semiconductor recording medium, an optical recording medium, a magnetic recording medium, a short-time dynamic memory program recording medium, or any other recording medium readable by a computer.

Various features or functional modules of the device used in the foregoing embodiments may be implemented or executed by circuits (e.g., monolithic or multi-chip integrated circuits). Circuits designed to execute the functions described in this description may include general-purpose processors, Digital Signal Processors (DSPs), Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs) or other programmable logic devices, discrete gates or transistor logic, or discrete hardware components, or any combination of the above. The general-purpose processor may be a microprocessor, or may be any existing processor, controller, microcontroller, or state machine. The circuit may be a digital circuit or an analog circuit. When new integrated circuit technologies that replace existing integrated circuits emerge because of the advances in semiconductor technology, one or a plurality of embodiments of the present invention may also be implemented using these new integrated circuit technologies.

Furthermore, the present invention is not limited to the embodiments described above. Although various examples of the described embodiments have been described, the present invention is not limited thereto. Fixed or non-mobile electronic devices mounted indoors or outdoors, such as AV equipment, kitchen equipment, cleaning equipment, air conditioner, office equipment, vending machines, and other household appliances, may be used as terminal devices or communications devices.

Claim 1:
User equipment (<NUM>) comprising:
a processor (<NUM>); and
a memory (<NUM>) storing program instructions, wherein
the processor (<NUM>) is configured to run the program instructions to cause the user equipment (<NUM>) to:
receive a radio resource control, RRC, message which includes an indication in a PDCP-Config information element, IE, the indication being used to indicate whether each of radio link control, RLC, entities associated with a data radio bearer, DRB, is activated or deactivated for packet data convergence protocol, PDCP, duplication;
duplicate a PDCP protocol data unit, PDU; and
transmit the PDCP PDU to more than one of the RLC entities which is activated for the PDCP duplication, if the PDCP duplication is activated for the DRB, wherein
the PDCP-Config IE is used to set configurable PDCP parameters for the DRB,
characterized in that
the indication is constituted by more than one bit associated with the RLC entities, and
bit positions in the more than one bit which are associated with the RLC entities are based on ascending order of logical channel IDs associated with the RLC entities.