CN113038632A

CN113038632A - Control method of PDCP entity and PDCP entity

Info

Publication number: CN113038632A
Application number: CN201911352409.9A
Authority: CN
Inventors: 肖芳英; 刘仁茂; 堀贵子
Original assignee: Sharp Corp
Current assignee: Sharp Corp
Priority date: 2019-12-24
Filing date: 2019-12-24
Publication date: 2021-06-25
Also published as: WO2021129701A1

Abstract

The present disclosure provides a control method of a PDCP entity and a PDCP entity, wherein the PDCP entity associates two or more RLC entities including a main RLC entity and a secondary RLC entity, and performs the following operations when receiving an instruction to activate PDCP duplication, an instruction to change the secondary RLC entity, or an instruction to activate the RLC entity: activating PDCP repetition; PDCP repetition is activated for the indicated RLC entity.

Description

Control method of PDCP entity and PDCP entity

Technical Field

The present disclosure relates to the field of wireless communications. More particularly, the present disclosure relates to a control method of a PDCP entity and the PDCP entity.

Background

At the third Generation Partnership Project (3 GPP) RAN #71 Congress, 3rd Generation Partnership Project: 3GPP, year 2016, NTT DOCOMO proposed a New research Project on the 5G technical standard (see non-patent document: RP-160671: New SID Proposal: Study on New Radio Access Technology) and was approved. The purpose of the research project is to develop a New wireless (New Radio: NR) access technology to meet all application scenarios, requirements and deployment environments of 5G.

Currently, a network may configure a PDCP duplication function of a packet data convergence protocol PDCP entity, where the sending PDCP entity function supports PDCP duplication (i.e., delivers one PDCP data PDU to a lower layer two or more times), and the receiving PDCP entity function supports deletion of duplicate PDCP PDUs. Both uplink and downlink support PDCP repetition, which is transmitted on two or more RLC entities/logical channels using PDCP Protocol Data Units (PDUs) and/or Service Data Units (SDUs) and enables the repeated PDCP PDUs to be transmitted over different carriers/cells. In the existing system, a PDCP entity with PDCP duplication is configured, and if an indication that the sending of a PDCP data PDU from one AM RLC entity of its associated AM RLC entities is successful is received, other AM RLC entities (or other active AM RLC entities) are instructed to delete the duplicated PDCP data PDU; if the PDCP duplication is deactivated, indicating the auxiliary RLC entity to delete all the duplicated PDCP data PDUs; if the secondary RLC entity is deactivated, instructing the deactivated secondary RLC entity to delete all the repeated PDCP data PDUs. In the industrial internet of things (IIoT) project under discussion in 3GPP release 16, one bearer configuration or associated RLC entities supporting PDCP duplication can be up to 4, which RLC entities are indicated for transmitting PDCP data PDUs by RRC messages or medium access control elements.

The present disclosure discusses problems involved in switching/changing the RLC entity for transmitting PDCP data PDUs after PDCP repetitions are deactivated or activated by the PDCP entity and/or the RLC entity.

Disclosure of Invention

The present disclosure is made in view of the above problems, and it is an object of the present disclosure to provide a control method of a PDCP entity and a PDCP entity capable of solving problems involved in a PDCP entity and/or an RLC entity that switches/changes an RLC entity for transmitting PDCP data PDUs after PDCP repetition is deactivated or activated.

According to a first aspect of the present disclosure, a method for controlling a PDCP entity is provided, where the PDCP entity associates two or more RLC entities including a primary RLC entity and a secondary RLC entity, and the PDCP entity performs the following operations when receiving an instruction to activate PDCP duplication, an instruction to change the secondary RLC entity, or an instruction to activate the RLC entity: activating PDCP repetition; PDCP repetition is activated for the indicated RLC entity.

In the control method of the PDCP entity of the first aspect, in a process in which the PDCP repetition is activated, the PDCP entity may perform the following operations when receiving an indication of deactivation of the PDCP repetition: deactivating PDCP repetition; the PDCP repetition is deactivated for the indicated RLC entity.

In the control method of the PDCP entity of the first aspect, in a process in which the PDCP entity is repeatedly activated, the PDCP entity may perform the following operations when receiving an indication of changing a secondary RLC entity, or an indication of activating an RLC entity that is not activated, or an indication of deactivating an RLC entity that is activated: sending a first indication to the associated RLC entities indicated as deactivated, wherein the first indication is used for indicating that the corresponding RLC entities are no longer used for PDCP repetition or deactivate PDCP repetition or indicating that the corresponding RLC entities are deactivated.

In the control method of the PDCP entity of the first aspect, in a process in which the PDCP repetition is activated, the PDCP entity may instruct the deactivated RLC entity or the deactivated secondary RLC entity to delete all the repeated PDCP data PDUs when receiving an instruction to deactivate the PDCP repetition, an instruction to change the secondary RLC entity, or an instruction to deactivate the activated RLC entity.

In the control method of the PDCP entity of the first aspect, in a process in which the PDCP repetition is activated, the PDCP entity may perform at least one of the following operations when receiving an indication to deactivate the PDCP repetition, or an indication to change a secondary RLC entity, or an indication to activate an RLC entity that is not activated, or an indication to deactivate an RLC entity that is activated: instructing the associated RLC entity to deactivate PDCP duplication; and instructing the deactivated RLC entity or the deactivated secondary RLC entity to delete all the repeated PDCP data PDUs.

In the control method of the PDCP entity of the first aspect, in a process in which the PDCP repetition is activated, when the PDCP entity receives an instruction to deactivate the PDCP repetition, or an instruction to change a secondary RLC entity, or an instruction to activate an RLC that is not activated, or an instruction to deactivate an RLC that is already activated, the PDCP entity performs any one of the following operations: sending a first indication to the associated RLC entity indicated as deactivated; transmitting a first indication to an RLC entity indicating repeated deactivation of PDCP; sending a first indication to a lower layer; sending a first indication to the deactivated RLC entity; sending a first indication to an RLC entity that is repeatedly deactivated for PDCP; wherein the first indication indicates that the corresponding RLC entity is no longer used for PDCP repetition or deactivates PDCP repetition or indicates that the corresponding RLC entity is deactivated.

In the control method of the PDCP entity of the first aspect, when one secondary RLC entity is switched from a first type RLC entity to a second type RLC entity in a case where there are more than two RLC entities associated with the PDCP entity, the PDCP entity may send an indication or a first indication of changing the secondary RLC entity to the RLC entity, where the first indication is used to indicate that the corresponding RLC entity is no longer used for PDCP repetition or to deactivate PDCP repetition or to indicate that the corresponding RLC entity is deactivated.

In the above control method of the PDCP entity of the first aspect, when the RLC entity receives an instruction from an upper layer to delete a radio link control service data unit, RLC SDU, or an instruction from the upper layer to deactivate the RLC entity, or a first instruction, or an instruction to deactivate PDCP duplication of the RLC entity, or an instruction to deactivate a secondary RLC entity, the following operations are performed: retransmitting the (radio link control service data unit) RLC SDU having the largest sequence number of the delivered lower layer; a challenge is included in the corresponding AMD PDU.

In the above-mentioned control method of the PDCP entity of the first aspect, the AMD PDU corresponding to the RLC SDU or the RLC SDU segment includes an inquiry indicating that an inquiry bit field of the AMD PDU is set to 1, a variable PDU _ WITHOUT _ POLL value is set to 0, and a variable BYTE _ WITHOUT _ POLL value is set to 0.

According to a second aspect of the present disclosure, there is provided a PDCP entity performing the control method of the PDCP entity according to the context under the control of an upper layer.

Drawings

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:

FIG. 1 shows a packet repetition diagram;

fig. 2a shows a schematic diagram of a protocol architecture for packet repetition bearer in carrier aggregation;

fig. 2b shows a schematic diagram of the protocol architecture of packet repetition bearers in dual connectivity;

Detailed Description

The present disclosure is described in detail below with reference to the attached drawings and detailed description. It should be noted that the present disclosure should not be limited to the specific embodiments described below. In addition, for the sake of brevity, detailed descriptions of well-known technologies not directly related to the present disclosure are omitted to prevent confusion of understanding of the present disclosure. The embodiments of the present disclosure may be applied not only to LTE, NR, but also to other communication systems, for example, 6G.

Some of the terms to which the present disclosure relates are briefly described below, and are described in more detail in 3 GPP-related documents. Terms referred to in this disclosure are defined herein, unless otherwise specified.

RRC: radio Resource Control, Radio Resource Control.

PDCP: packet Data Convergence Protocol, Packet Data Convergence Protocol.

RLC: radio Link Control, Radio Link Control.

The RLC entity may be an Unacknowledged Mode (UM) RLC entity or an Acknowledged Mode (AM) RLC entity. The AM RLC entity includes an AM RLC entity transmitting end and an AM RLC entity receiving end, the AM RLC entity transmitting end of one AM RLC entity transmits an RLC PDU (also referred to as AMD PDU) to the AM RLC entity receiving end of the other AM RLC entity, and the AM RLC entity receiving end transmits a STATUS report (also referred to as STATUS PDU) to the AM RLC entity transmitting end. The AMD PDU may contain one complete RLC SDU or segment (segment) of an RLC SDU. The AM RLC entity or the AM RLC entity transmitting end of the AM RLC entity and the another AM RLC entity or the AM RLC entity receiving end of the another AM RLC entity are mutually called peer AM RLC entities (peer RLC entities). An AM RLC entity sending end submits an RLC PDU of a lower layer to be called an AMD PDU; the RLC PDU received by the receiving end of the AM RLC entity from the lower layer is called AMD PDU.

MAC: medium Access Control, Medium Access Control.

SDU: service Data Unit.

PDU: protocol Data Unit, Protocol Data Unit. In the present disclosure, the PDU may be a data PDU and/or a control PDU, as not specifically illustrated. For example, the RLC PDU may be an RLC data PDU and/or an RLC control PDU (e.g., a STATUS report or STATUS PDU). The STATUS PDU is used by the AM RLC entity receiving end to report its correctly received RLC data PDU and RLC data PDU detected as missing to its peer AM RLC entity (STATUS PDU is used by the receiving side of the AM RLC entity to the peer AM RLC entity about RLC data PDUs which are received by the peer AM RLC entity.

In the present disclosure, data received or carried (transmitter) from an upper layer is referred to as SDU, and data delivered (submit) or received from a lower layer is referred to as PDU. At the transmitting end, each layer (e.g., PDCP or RLC) packages SDUs into PDUs according to predefined rules after receiving the SDUs, and the SDUs or SDU segments serve as the payload of the PDUs. For example, data received by the PDCP entity from an upper layer or data carrying the upper layer is referred to as PDCP SDU; data received by the PDCP entity from the RLC entity or data delivered to the RLC entity is referred to as PDCP PDU (i.e., RLC SDU).

The main RLC entity: primary RLC entity, RLC entity for at least transmitting PDCP control PDU (whether PDCP repetition is activated or deactivated) among RLC entities configured for PDCP repetition. In case of carrier aggregation, the PDCP entity after deactivation of packet repetition sends PDCP data PDUs to the primary RLC entity, which is one of the associated RLC entities. The primary RLC entity may be configured through RRC signaling.

The base station may configure a primary RLC entity for the user equipment UE or the DRB or PDCP entity supporting PDCP duplication by using a cell primarypath (the detailed description of the cell is shown in 3GPP TS38.331) carried in the RRC signaling and a cell cellGroup and/or a cell logiocalchannel of a logical channel identifier included in the cell. The present disclosure refers to an RLC entity that is not designated as a primary RLC entity as a secondary RLC entity (secondary RLC entity) in order to facilitate description of the disclosed embodiments.

In the case of dual connectivity, the base station sets a data separation threshold for separating bearers, for example, by using ul-DataSplitThreshold (the specific description of the cell is shown in 3GPP TS38.331 and TS 38.323). In the existing system, when PDCP duplication is deactivated or PDCP duplication is not configured, if the sum of the total PDCP data amount and the data amount waiting for initial transmission in two RLC entities associated therewith is greater than or equal to a set data separation threshold, the PDCP entity submits the PDCP PDU to the associated primary RLC entity or secondary RLC entity; if the data separation threshold is not configured or if the sum of the total amount of PDCP data and the amount of data waiting for initial transmission in the two RLC entities related to the total amount of PDCP data is less than the set data separation threshold, the PDCP entity submits the PDCP PDUs to the main RLC entity. In release 16, which is being discussed by 3GPP, since one PDCP entity can be configured to associate up to 4 RLC entities, the PDCP entity submits PDCP PDUs to the master RLC entity for a carrier aggregation scenario when PDCP duplication is deactivated; for a dual-connection scenario, if the total amount of PDCP data and the sum of the amounts of data waiting for initial transmission in the associated primary RLC entity and activated secondary RLC entity are greater than or equal to a set data separation threshold, the PDCP entity submits the PDCP PDU to the associated primary RLC entity or activated secondary RLC entity; if the data separation threshold is not configured or if the sum of the total amount of PDCP data and the amount of data waiting for initial transmission in the associated primary RLC entity and the activated secondary RLC entity is less than the set data separation threshold, the PDCP entity submits the PDCP PDUs to the primary RLC entity. Here, the activated RLC entity refers to an RLC entity configured or indicated as available for separate bearer data transmission after PDCP repetition is deactivated.

Grouping and repeating: packet duplication or PDCP duplication, also referred to as PDCP duplication or duplication, refers to a PDCP entity delivering the same PDCP PDU to a lower layer twice (or multiple times), one of which is delivered to a primary RLC entity (also referred to as a primary path) and the other is delivered to an active secondary RLC entity (also referred to as a secondary path).

In 3GPP current protocol release 15 (TS38.323, TS38.300, and TS38.331), RRC re-configures two RLC entities for PDCP. Fig. 1 shows a packet repetition diagram, and as shown in fig. 1, RRC may repeatedly configure two RLC entities for PDCP. When PDCP repetition is activated, the PDCP entity transmits the same PDCP PDU to the associated two lower layer entities (i.e., RLC entities), in other words, the PDCP entity delivers one PDCP PDU to the lower layer twice, once to the primary RLC entity and once to the secondary RLC entity. To enhance reliability of URLLC, 3GPP will support a scenario where one PDCP entity is associated to at most 4 RLC entities in release 16. In this case, when PDCP repetition is activated, the PDCP entity delivers the same PDCP PDU to the activated RLC entity. For example, assuming that the RRC configures 4 RLC entities for one PDCP entity, of which only 3 RLC entities are activated (which may be indicated by RRC configuration or by a MAC control element), the PDCP entity sends the same PDCP PDU to the associated and three activated lower layer entities (i.e., RLC entities), in other words, the PDCP entity delivers one PDCP PDU to the lower layer three times, respectively to the three activated RLC entities. It should be noted that, if the primary RLC entity cannot be deactivated, the active RLC entity is referred to as the primary RLC entity and other active secondary RLC entities in this disclosure. If one PDCP entity is associated with only two RLC entities, when PDCP repetition is activated, both of the associated RLC entities are activated.

In the embodiments of the present disclosure, as not particularly illustrated, an activated RLC entity (which may also be referred to as an RLC entity activated for PDCP repetition or an RLC entity activated for PDCP repetition) refers to that the PDCP repetition of the RLC entity is activated, that is, the RLC entity is used to transmit PDCP data PDUs (the PDCP entity delivers the PDCP data PDUs to the activated RLC entity). In other words, in case that PDCP is repeatedly activated, after activating the RLC entity, the PDCP entity will deliver PDCP data PDUs to it until this RLC entity is deactivated. A deactivated RLC entity (which may also be referred to as an RLC entity deactivating or deactivated for PDCP repetition or an RLC entity deactivated for PDCP repetition) means that the RLC entity is no longer being used for transmission of PDCP data PDUs. In other words, after deactivating the RLC entity, the PDCP entity no longer delivers PDCP data PDUs to it until this RLC entity is activated.

The present disclosure takes as an example the operations involved in the AM RLC entity. However, the embodiments of the present disclosure are also applicable to the UM RLC entity.

In the present disclosure, the "lower layer entity" and "lower layer" are equivalent descriptions and may be used interchangeably.

Retransmission query timer t-polretransfmit: the timer is used by the sending end of the AM RLC entity for the purpose of retransmitting the query (This timer is used by the transmitting side of an AM RLC entity in order to retransmit a poll).

Taking the example of PDCP PDU or SDU being repeatedly sent twice (i.e. one PDCP entity is associated with two RLC entities and/or two logical channels), as an example, fig. 2a shows a protocol architecture diagram of packet repetition bearer in a carrier aggregation scenario, and fig. 2b shows a protocol architecture diagram of packet repetition in a dual connectivity scenario. In the schematic diagram shown in fig. 2a, a PDCP entity of one bearer is associated with two RLC entities and two logical channels, one MAC entity. In the schematic diagram shown in fig. 2b, a PDCP entity of a split bearer is associated with two RLC entities and two logical channels, two MAC entities. However, the technical solution described in the present disclosure is not limited to the scenario that the PDCP PDU or SDU is repeatedly transmitted twice, and those skilled in the art can easily extend to the scenario that the transmission is repeated multiple times (i.e. one PDCP entity is associated with multiple RLC entities and/or multiple logical channels).

An information element PDCP-duplexing is carried in the PDCP-Config to indicate whether the status of uplink repetition is configured and activated when this information element (abbreviated as cell) is received. This information element appears indicating that a duplicate is configured and the value TRUE of this information element indicates that a duplicate is activated. The PDCP-Config for setting the configurable PDCP parameters for the SRBs and/or DRBs is included in an RRC message sent by the base station or the network to the UE, the RRC message being used to configure the DRBs supporting PDCP duplication for the UE.

The following describes operations (for a data radio bearer DRB) performed by a PDCP entity (i.e., a transmitting PDCP entity) configured with PDCP repetition or with PDCP-duplexing set to TRUE, the transmitting PDCP entity (i.e., the PDCP entity configured with PDCP repetition) performing at least one of the following:

(one) if an indication to activate PDCP duplication is received (the activation of PDCP duplication is indicated) or an indication to change a secondary RLC entity is received or an indication to activate an RLC entity is received or an indication to deactivate an RLC entity is received, activating PDCP duplication or activating PDCP duplication for the indicated RLC entity associated with the indication, the RLC entity being the RLC entity that is activated for PDCP duplication, e.g., the RLC entity indicated as activated in an RRC message or the RLC entity indicated as activated in a MAC CE;

(ii) if an indication to activate PDCP duplication or if an indication to deactivate PDCP duplication or an indication to change a secondary RLC entity or an indication to activate an RLC entity or an indication to deactivate an RLC entity is received, sending a first indication to the associated RLC entity indicated as deactivated or sending a first indication to a lower layer or sending a first indication to a deactivated RLC entity or sending a first indication to an RLC entity deactivated for PDCP duplication (the indication being sent if such an RLC entity exists). The first indication is used to indicate that the corresponding RLC entity is no longer used for PDCP repetition or to deactivate PDCP repetition or to indicate that the corresponding RLC entity is deactivated;

(iii) if an indication to activate a PDCP repetition is received or an indication to change a secondary RLC entity is received or an indication to activate an RLC entity is received or an indication to deactivate an RLC entity is received, indicating to a lower layer to deactivate an associated RLC entity (if such an RLC entity exists to send the indication) or indicating to the lower layer that a PDCP repetition of the associated RLC entity is deactivated (if such an RLC entity exists to send the indication);

(IV) if an indication of deactivating PDCP duplication is received (if the deactivation of PDCP duplication is indicated), deactivating PDCP duplication or deactivating PDCP duplication for the indicated RLC entity;

(V) if an indication to deactivate PDCP duplication or an indication to change the secondary RLC entity is received (e.g., the MAC layer of the UE receives a media access control element (MAC CE)) from the base station to indicate a change of PDCP duplication status of one DRB and/or an activated RLC entity or an indication to deactivate the RLC entity, instructing the secondary RLC entity or the deactivated secondary RLC entity to delete all duplicated PDCP data PDUs.

(six) if an indication to deactivate PDCP duplication or an indication to change a secondary RLC entity or an indication to activate RLC or an indication to deactivate RLC is received, indicating that an associated RLC entity deactivates PDCP duplication or indicating that PDCP duplication of a lower associated RLC entity is deactivated; and/or instructing the secondary RLC entity or the deactivated secondary RLC entity to delete all the repeated PDCP data PDUs.

(seventhly) if an indication to deactivate PDCP duplication or an indication to change a secondary RLC entity or an indication to activate RLC or an indication to deactivate RLC is received, sending a first indication to the associated RLC entity indicated as deactivated or an indication to the RLC entity indicated as deactivating PDCP duplication or sending a first indication to a lower layer or an indication to the deactivated RLC entity or an indication to the RLC entity for PDCP duplication deactivation (if such an RLC entity exists).

(eight) if an indication to activate PDCP duplication is received (or an indication to change a secondary RLC entity is received or an indication to activate an RLC entity is received or an indication to deactivate an RLC entity is received) and more than two RLC entities with which the PDCP entity is associated are received, the PDCP entity sends the indication to change the secondary RLC entity or the first indication to one of the RLC entities if the one secondary RLC entity is switched from the first type of RLC entity to the second type of RLC entity. The first type of RLC entity is an activated RLC entity, and the second type of RLC entity is a deactivated RLC entity;

(nine) if an indication to activate PDCP duplication is received and for a deactivated RLC entity associated with the PDCP entity, the PDCP entity sending an indication to the RLC entity to change a secondary RLC entity.

Optionally, the operation performed when the indication of activating or deactivating the PDCP repetition (or the indication of changing the secondary RLC entity) is received is performed only when the PDCP entity is associated with more than two RLC entities. It may be provided that if the PDCP entity is associated with only two RLC entities, the following is performed: activating PDCP duplication if an indication to activate PDCP duplication is received; deactivating the PDCP duplication if an indication to deactivate the PDCP duplication is received.

Optionally, as not specifically illustrated, the indications received by the PDCP entity in the above embodiments are all from a lower layer (e.g., MAC layer) or RRC layer.

Alternatively, the indication of changing the secondary RLC entity and the indication of activating the RLC entity and the indication of deactivating the RLC entity may be that the MAC layer indicates to the PDCP layer (i.e., an upper layer of the MAC) when a MAC control element indicating that the DRB activates or deactivates PDCP repetition and/or an activated RLC entity (i.e., a lower layer of the PDCP) is received.

In the embodiment of the present disclosure, the indication to change the secondary RLC entity is an indication to change an activated (or deactivated) secondary RLC entity, or an indication to convert the state of the secondary RLC entity, or an indication to activate the secondary RLC entity, or an indication to deactivate the secondary RLC entity. The secondary RLC entity may also be replaced with an RLC entity and vice versa.

An embodiment of operations performed by the RLC entity is described below.

Receiving an instruction of deactivating an RLC entity or a first instruction or an instruction of deactivating a PDCP duplication of an RLC entity or an instruction of deactivating a secondary RLC entity or an instruction of deactivating a PDCP duplication from an upper layer, an AM RLC entity transmitting end or an UM RLC transmitting entity deletes all RLC SDUs, and the RLC SDUs and segments thereof are not delivered to a lower layer (a neighbor of a sequence of not transmitted candidates to the lower layer).

After receiving an instruction of deleting an RLC SDU from an upper layer or receiving an instruction of deactivating an RLC entity or a first instruction or an instruction of deactivating PDCP duplication of an RLC entity or an instruction of deactivating a secondary RLC entity or an instruction of deactivating PDCP duplication, from the upper layer, an AM RLC entity transmitting end performs one of the operations defined in embodiments 1 to 7 below:

in embodiment 1, if the transmission buffer and the retransmission buffer are empty (except for RLC SDU or RLC SDU segments that have been transmitted and waiting for acknowledgement), in other words, the AM RLC entity transmitting end (or the AM RLC entity transmitting end in the transmission buffer and the retransmission buffer) contains (or contains and contains) only RLC SDU or RLC SDU segments that have been transmitted (transmitted) and wait for acknowledgement (acknowledgement), the RLC SDU with the highest sequence number of the submitted lower layer is retransmitted (the RLC SDU with the highest sequence number, the RLC SDUs with the lowest transmitted sequence number for retransmission) and a query is contained in the corresponding AMD PDU. The corresponding AMD PDU is the AMD PDU corresponding to the RLC SDU or RLC SDU segment, i.e. the payload (also called data field) of the AMD PDU is the RLC SDU or RLC SDU segment.

In the embodiment of the present disclosure, including a query in an AMD PDU means setting a Polling bit field (Polling bit field) of the AMD PDU to 1 (indicating that an AM RLC entity sending end requests a status report to its peer AM RLC entity), setting a variable PDU _ WITHOUT _ POLL value to 0 and setting a variable BYTE _ WITHOUT _ POLL value to 0, where the variable BYTE _ WITHOUT _ POLL value is set to 0

PDU _ WITHOUT _ POLL is a counter that records the number of AMD PDUs sent (send) since the last transmission (transmit) challenge bit, with an initial value of 0;

BYTE _ WITHOUT _ POLL is a counter that records the number of data BYTEs sent (send) since the last transmission (transmit) challenge bit, with an initial value of 0. In addition, the AM RLC entity sending end performs the following operations when delivering an AMD PDU containing an inquiry to the lower layer: setting the value of POLL _ SN to the maximum sequence number of AMD PDU submitted to the lower layer (i.e. setting the value of POLL _ SN to the sequence number of AMD PDU with the maximum sequence number among AMD PDUs submitted to the lower layer, set POLL _ SN to the highest SN of the AMD PDUs ampoules of the AMD PDUs, and transmitting to lower layer), if t-PollRetransmit is not running, starting t-PollRetransmit, otherwise restarting t-PollRetransmit. See 3GPP TS38.3225.3.3.2 for a more detailed description of setting the challenge bit.

In embodiment 2, if both the send buffer and the retransmit buffer are empty but there is (or at least one) RLC SDU or RLC SDU segment that has been sent and waiting for acknowledgement, the RLC SDU with the largest sequence number of the submitted lower layer is retransmitted and a query is included in the corresponding AMD PDU. And the corresponding AMD PDU is the AMD PDU corresponding to the RLC SDU or the RLC SDU segmentation, namely the data field of the AMD PDU is the RLC SDU or the RLC SDU segmentation.

In embodiment 3, if both the send buffer and the retransmit buffer are empty and/or there is (or at least one) RLC SDU or RLC SDU segment that has been sent and waiting for acknowledgement and the retransmission-query timer t-polretransfmit is not running, the RLC SDU with the largest sequence number of the submitted lower layer is retransmitted with one query included in the corresponding AMD PDU. And the corresponding AMD PDU is the AMD PDU corresponding to the RLC SDU or the RLC SDU segmentation, namely the data field of the AMD PDU is the RLC SDU or the RLC SDU segmentation.

In embodiment 4, if both the transmission buffer and the retransmission buffer are empty (except for RLC SDU or RLC SDU segments that have been transmitted and waiting for acknowledgement) and/or there is (or at least there is one) RLC SDU or RLC SDU segment that has been transmitted and waiting for acknowledgement and the retransmission-interrogation timer t-poll is not running, the RLC SDU with the largest sequence number of the submitted lower layer is retransmitted and an interrogation is included in the corresponding AMD PDU. And the corresponding AMD PDU is the AMD PDU corresponding to the RLC SDU or the RLC SDU segmentation, namely the data field of the AMD PDU is the RLC SDU or the RLC SDU segmentation.

In embodiment 5, if both the transmission buffer and the retransmission buffer are empty (except for RLC SDUs or RLC SDU segments that have been transmitted and waiting for acknowledgement) and/or there is or is at least one RLC SDU or RLC SDU segment that has been transmitted and waiting for acknowledgement that has not yet been interrogated, the RLC SDU with the largest sequence number of the submitted lower layer is retransmitted, with one interrogation included in the corresponding AMD PDU. And the corresponding AMD PDU is the AMD PDU corresponding to the RLC SDU or the RLC SDU segmentation, namely the data field of the AMD PDU is the RLC SDU or the RLC SDU segmentation. The existence of a transmitted and awaiting acknowledgement RLC SDU or RLC SDU segment that has not yet been interrogated means that the transmitted interrogation is not used (or does not include) to request the peer AM RLC entity to acknowledge whether the RLC SDU or RLC SDU segment was successfully received (or a positive or negative acknowledgement of the RLC SDU or RLC SDU segment must be included in a status report sent by the peer AM RLC entity).

In embodiment 6, if both the transmission buffer and the retransmission buffer are empty (except for RLC SDUs or RLC SDU segments that have been transmitted and waiting for acknowledgement) and/or there is (or there is at least one) RLC SDU or RLC SDU segment that has been transmitted and waiting for acknowledgement, and POLL _ SN is less than the maximum sequence number of an AMD PDU that has been delivered to the lower layer, the RLC SDU with the maximum sequence number of the delivered lower layer is retransmitted, with a query included in the corresponding AMD PDU. And the corresponding AMD PDU is the AMD PDU corresponding to the RLC SDU or the RLC SDU segmentation, namely the data field of the AMD PDU is the RLC SDU or the RLC SDU segmentation.

In embodiment 7, if both the send buffer and the retransmit buffer are empty and/or there is (or there is at least one) RLC SDU or RLC SDU segment that has been sent and waiting for acknowledgement and POLL _ SN is smaller than the maximum sequence number of AMD PDU that has been delivered to the lower layer, the RLC SDU with the maximum sequence number of the delivered lower layer is retransmitted and a query is included in the corresponding AMD PDU. And the corresponding AMD PDU is the AMD PDU corresponding to the RLC SDU or the RLC SDU segmentation, namely the data field of the AMD PDU is the RLC SDU or the RLC SDU segmentation.

In embodiments 1-7 above, it can be further limited that if there is data waiting for transmission in the upper layer, the transmission buffer and retransmission buffer are empty (except for RLC SDU or RLC SDU segments that have been transmitted and waiting for acknowledgement) and should not cause unnecessary retransmissions. However, if PDCP duplication is deactivated or the current RLC entity (or the secondary RLC entity) is deactivated, even if the upper layer has data waiting for transmission (data accesses in the upper layer), retransmission is performed, that is, the RLC SDU having the largest sequence number of the delivered lower layer is retransmitted, and a query is included in the corresponding AMD PDU. And the corresponding AMD PDU is the AMD PDU corresponding to the RLC SDU or the RLC SDU segmentation, namely the load of the AMD PDU is the RLC SDU or the RLC SDU segmentation. Because, in this case, although the upper layer has data waiting for transmission, the PDCP entity does not transmit the data to the current RLC entity because the PDCP repetition has been deactivated or the current RLC entity is deactivated.

In the embodiment of the present disclosure, a new embodiment may be formed by replacing the condition "if both the transmission buffer and the retransmission buffer are empty and/or there is (or there is at least one) RLC SDU or RLC SDU segment that has been transmitted and waits for acknowledgement" with the condition "if both the transmission buffer and the retransmission buffer are empty (except for RLC SDU or RLC SDU segment that has been transmitted and waits for acknowledgement)", which is also an implementation scope of the present disclosure. In the embodiment of the present disclosure, the sending buffer and the retransmission buffer are empty (except for RLC SDU or RLC SDU segments that have been sent and wait for acknowledgement), which means that the AM RLC entity sending end (or in the sending buffer and the retransmission buffer of the AM RLC entity sending end) does not contain other RLC SDU or RLC SDU segments except for RLC SDU or RLC SDU segments that have been sent and wait for acknowledgement.

Furthermore, in the embodiment of the present disclosure, retransmitting the RLC SDU with the largest sequence number of the submitted lower layer means that the RLC SDU with the largest sequence number of the submitted lower layer is used for retransmission or the RLC SDU with the largest sequence number of the submitted lower layer is used for retransmission, but when constructing the corresponding AMD PDU, a data field of the AMD PDU that needs to be constructed according to the transmittable data amount indicated by the lower layer may contain the RLC SDU or its segment (i.e. the constructed AMD PDU should fit the total size of the AMD PDU indicated by the lower layer in a specific transmission opportunity). In addition, an embodiment formed by replacing the operation of "retransmitting the RLC SDU having the largest sequence number of the delivered lower layer" with "retransmitting any one of the RLC SDUs having not been positively acknowledged (subsequent and RLC SDU having not been positively acknowledged for retransmission)" or "retransmitting the RLC SDU having the largest sequence number of the delivered lower layer, or retransmitting any one of the RLC SDUs having not been positively acknowledged" is also within the scope of the present disclosure.

The maximum sequence number of the RLC SDU or RLC SDU segment of the lower layer waiting for acknowledgement or delivered to the present disclosure refers to the sequence number of the RLC SDU or RLC SDU segment of the lower layer waiting for acknowledgement or delivered to the highest sequence number in the RLC SDU or RLC SDU segment of the lower layer waiting for acknowledgement or delivered to the highest sequence number.

In the embodiment of the present disclosure, the query status variable POLL _ SN is used to store (hold) the maximum value of the sequence number of the AMD PDU that has been submitted to the lower layer when the query is set (specifically, set according to section 3GPP TS38.3225.3.3.2) (This state variable hold of the value of the high SN of the AMD PDU assembling the AMD PDUs sub-transmitted to lower layer POLL _ SN set accessing to sub-close 5.3.3.2).

According to the method of the above embodiment, an appropriate operation can be performed upon receiving a status report from the receiving end of the AM RLC entity, so that the communication efficiency and reliability of the wireless communication system can be improved.

It is noted that embodiments of the present disclosure performed at the UE may also be performed at the base station.

As not specifically illustrated, the buffers in the present disclosure may be transmit buffers and/or retransmit buffers.

In addition, "deactivate packet repetition", "configure packet repetition but in deactivated state", and "receive an indication of deactivated packet repetition from an upper layer (e.g., PDCP) or a lower layer (e.g., MAC)" in this disclosure may be used interchangeably.

It should be understood that the above-described embodiments of the present disclosure may be implemented by software, hardware, or a combination of both software and hardware. For example, various components within the base station and user equipment in the above embodiments may be implemented by various devices or circuits, including but not limited to: analog circuit devices, Digital Signal Processing (DSP) circuits, programmable processors, Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs), programmable logic devices (CPLDs), and the like.

Furthermore, embodiments of the present disclosure disclosed herein may be implemented on a computer program product. More specifically, the computer program product is one of the following: there is a computer readable medium having computer program logic encoded thereon that, when executed on a computing device, provides related operations to implement the above-described aspects of the present disclosure. When executed on at least one processor of a computing system, the computer program logic causes the processor to perform the operations (methods) described in the embodiments of the disclosure. Such arrangements of the present disclosure are typically provided as downloadable software images, shared databases, etc. arranged or encoded in software, code and/or other data structures on a computer readable medium such as an optical medium (e.g., CD-ROM), floppy or hard disk or other media such as firmware or microcode on one or more ROM or RAM or PROM chips or in one or more modules. The software or firmware or such configurations may be installed on a computing device to cause one or more processors in the computing device to perform the techniques described in the embodiments of the present disclosure.

Embodiments of the present disclosure disclosed herein may be implemented as a program running on a device according to the present disclosure. The program running on the apparatus according to the present disclosure may be a program that causes a computer to realize the functions of the embodiments of the present disclosure by controlling a Central Processing Unit (CPU). The program or information processed by the program may be temporarily stored in a volatile memory (such as a random access memory RAM), a Hard Disk Drive (HDD), a nonvolatile memory (such as a flash memory), or other memory system.

Although the present disclosure has been shown in connection with the preferred embodiments of the present disclosure, those skilled in the art will appreciate that various modifications, substitutions and alterations can be made to the present disclosure without departing from the spirit and scope of the present disclosure. Accordingly, the present disclosure should not be limited by the above-described embodiments, but should be defined by the appended claims and their equivalents.

Claims

1. A control method of a packet data convergence protocol PDCP entity, the PDCP entity associates more than two radio link control RLC entities, the more than two RLC entities comprise a main RLC entity and a secondary RLC entity,

the PDCP entity performs the following operations when receiving an instruction of activating PDCP duplication, or an instruction of changing a secondary RLC entity, or an instruction of activating an RLC entity:

activating PDCP repetition;

PDCP repetition is activated for the indicated RLC entity.

2. The control method according to claim 1,

in the process that the PDCP repetition is activated, the PDCP entity performs the following operations under the condition that an indication of deactivating the PDCP repetition is received:

deactivating PDCP repetition;

the PDCP repetition is deactivated for the indicated RLC entity.

3. The control method according to claim 1 or 2, wherein,

in the PDCP repeatedly activated procedure, the PDCP entity performs the following operations when receiving an indication of changing a secondary RLC entity, or an indication of activating an RLC entity that is not activated, or an indication of deactivating an RLC entity that is activated: sending a first indication to the associated RLC entity indicated as deactivated,

wherein the first indication indicates that the corresponding RLC entity is no longer used for PDCP repetition or deactivates PDCP repetition or indicates that the corresponding RLC entity is deactivated.

4. The control method according to claim 1 or 2, wherein,

in the PDCP repetition activated procedure, the PDCP entity instructs the deactivated RLC entity or the deactivated secondary RLC entity to delete all the repeated PDCP data PDUs when receiving an instruction to deactivate PDCP repetition, or an instruction to change the secondary RLC entity, or an instruction to deactivate the activated RLC entity.

5. The control method according to claim 1 or 2, wherein,

in the PDCP repetition activated procedure, the PDCP entity performs at least one of the following operations when receiving an instruction to deactivate PDCP repetition, or an instruction to change a secondary RLC entity, or an instruction to activate an RLC entity that is not activated, or an instruction to deactivate an RLC entity that is activated:

instructing the associated RLC entity to deactivate PDCP duplication; and

instructing the deactivated RLC entity or the deactivated secondary RLC entity to delete all the repeated PDCP data PDUs.

6. The control method according to claim 1 or 2, wherein,

in the PDCP repetition activated procedure, when the PDCP entity receives an instruction to deactivate PDCP repetition, or an instruction to change a secondary RLC entity, or an instruction to activate an RLC that is not activated, or an instruction to deactivate an RLC that is activated, the PDCP entity performs any one of the following operations:

sending a first indication to the associated RLC entity indicated as deactivated;

transmitting a first indication to an RLC entity indicating repeated deactivation of PDCP;

sending a first indication to a lower layer;

sending a first indication to the deactivated RLC entity;

sending a first indication to an RLC entity that is repeatedly deactivated for PDCP;

7. The control method according to claim 1,

in case that there are more than two RLC entities with which the PDCP entity is associated, the PDCP entity transmits an indication or a first indication of changing a secondary RLC entity to one secondary RLC entity when the one secondary RLC entity is converted from a first type RLC entity to a second type RLC entity,

wherein the first indication is to indicate that the corresponding RLC entity is no longer used for PDCP repetition or to deactivate PDCP repetition or to indicate that the corresponding RLC entity is deactivated.

8. The control method according to claim 1 or 2, wherein,

the RLC entity performs the following operations when receiving an instruction of deleting a radio link control service data unit, RLC SDU, from an upper layer, or receiving an instruction of deactivating the RLC entity, or receiving a first instruction, or an instruction of deactivating PDCP duplication of the RLC entity, or an instruction of deactivating a secondary RLC entity, from the upper layer:

retransmitting the (radio link control service data unit) RLC SDU having the largest sequence number of the delivered lower layer;

a challenge is included in the corresponding AMD PDU.

9. The control method according to claim 8,

the corresponding AMD PDU is the RLC SDU or an AMD PDU corresponding to the RLC SDU segment,

the AMD PDU comprises a query, namely setting a query bit field of the AMD PDU to be 1, setting a variable PDU _ WITHOUT _ POLL value to be 0 and setting a variable BYTE _ WITHOUT _ POLL value to be 0.

10. A PDCP entity performing the control method of any one of claims 1 to 9 under control of an upper layer.