WO2020230222A1

WO2020230222A1 - Communication device

Info

Publication number: WO2020230222A1
Application number: PCT/JP2019/018841
Authority: WO
Inventors: 徹内野; 高橋　秀明
Original assignee: 株式会社Ｎｔｔドコモ
Priority date: 2019-05-10
Filing date: 2019-05-10
Publication date: 2020-11-19

Abstract

A UE (200) receives an RLC data PDU that includes a PDCP PDU from a gNB (100) via an RLC entity and also receives an RLC data PDU in which the PDCP PDU is replicated from the gNB (100) via an RLC entity (205). The UE 200 selects an RLC entity other than the RLC entity (205) and transmits an RLC status report via the selected RLC entity.

Description

Communication device

The present invention relates to a communication device that supports duplicate transmission control of data units.

The 3rd Generation Partnership Project (3GPP) is a specification of Long Term Evolution (LTE), LTE-Advanced (hereinafter referred to as LTE including LTE-Advanced), and 5th generation mobile communication system for the purpose of further speeding up LTE. Specifications (also called 5G, New Radio (NR) or Next Generation (NG)) are also underway.

In 5G, in order to realize communication that requires high reliability such as Ultra-Reliable and Low Latency Communications (URLCC), a method of redundant data packets and / or control signals and double (duplicate) transmission is being studied. ing. For example, PDCP duplication that improves reliability by using frequency diversity is defined (Non-Patent Document 1). PDCP duplication is a control for duplicate transmission of packets (data units) at the packet data convergence protocol layer (PDCP).

Specifically, in PDCP duplication, one PDCP entity is associated with a plurality of wireless link control layer entities (RLC entities), and the duplicated data unit is transmitted via different component carriers (CC) or serving cells. In addition, the mapping between the logical channel (LCH) and the CC (which may be a serving cell, the same applies hereinafter) is set so that the original data unit and the duplicated data unit are not transmitted via the same CC (the same applies hereinafter). Non-Patent Document 2).

Also, in the 3GPP Release 16 specifications, extended control of PDCP duplication is being considered. Specifically, it is being considered that the number of RLC entities associated with PDCP entities is 3 or more (that is, the number of data units that can be duplicated is 2 or more).

Furthermore, in such an examination, a configuration in which the number of RLC entities associated with PDCP entities differs between downlink (DL) and uplink (UL) is also being examined (Non-Patent Document 3). It is relatively easy to increase the number of CCs in DL, but increasing the number of CCs in UL is a result of considering that there are many implementation issues.

However, when the number of RLC entities associated with PDCP entities as described above is different between DL and UL, there are the following problems.

Specifically, in the case of RLC-Acknowledged Mode (AM), for example, the feedback information (RLC status report) via UL is the RLC data PDU for the transmission of the data unit (RLC data PDU) via DL. It will be returned to the sender.

So, for example, if the number of RLC entities associated with PDCP entities in DL is greater than the number of RLC entities associated with PDCP entities in UL, in other words, the number of CCs in DL is greater than the number of CCs in UL. , The following conditions can occur.

Specifically, due to the above-mentioned restrictions on the mapping between LCH and CC, the upstream direction for returning the RLC status report for the RLC data PDU transmitted via either the downstream CC (LCH). CC (LCH) does not exist and RLC status report cannot be returned.

Therefore, the present invention has been made in view of such a situation, and even when the duplication control (PDCP duplication) of the data unit is extended, the response such as feedback information for the transmission of the data unit is surely returned. The purpose is to provide a possible communication device.

One aspect of the present invention is a communication device (for example, UE200), which receives a first data unit (RLC data PDU 320) via a first entity of a wireless link control layer and also receives the wireless link control layer. The receiving unit (RLC processing unit 230) that receives the second data unit and the feedback information (RLC status report) for the received second data unit are controlled by wireless links other than the second entity. It includes a transmission unit (RLC processing unit 230) that transmits using the radio resource associated with the first entity of the layer.

One aspect of the present invention is a communication device (for example, UE200), which receives a first data unit (PDCP PDU 310) via a first entity of the wireless link control layer and a first of the wireless link control layer. The receiving unit (RLC processing unit 230) that receives the second data unit (RLC data PDU 320) to which the first data unit is duplicated and the feedback information for the received second data unit are transmitted via the two entities. A control unit (control unit 250) that handles the wireless link used for transmission of the second data unit as a one-way link (um-Uni-Directional-DL) that does not require transmission of the feedback information when there is no capable wireless link. And.

FIG. 1 is an overall schematic configuration diagram of the wireless communication system 10. FIG. 2 is a diagram showing a configuration example of a main protocol stack, a logical channel, and a component carrier in the wireless communication system 10. FIG. 3 is a functional block configuration diagram of the UE 200. FIG. 4 is a functional block configuration diagram of the gNB 100. FIG. 5 is a diagram showing a setting example of Asymmetric PDCP duplication. FIG. 6 is a diagram showing an operation flow (operation example 1) of the UE 200 when Asymmetric PDCP duplication is set. FIG. 7 is a diagram showing a state of transmission / reception of RLC data PDU and RLC status report by gNB100 and UE200 according to the operation example 1. FIG. 8 is a diagram showing an operation flow (operation example 2) of the UE 200 when Asymmetric PDCP duplication is set. FIG. 9 is a diagram showing a state of transmission / reception of RLC data PDU and RLC status report by gNB100 and UE200 according to the operation example 2. FIG. 10 is a diagram showing an example of the hardware configuration of gNB100, gNB101 and UE200.

Hereinafter, embodiments will be described based on the drawings. The same functions and configurations are designated by the same or similar reference numerals, and the description thereof will be omitted as appropriate.

(1) Overall Schematic Configuration of Wireless Communication System FIG. 1 is an overall schematic configuration diagram of the wireless communication system 10 according to the present embodiment. The wireless communication system 10 is a wireless communication system according to 5G (NR).

As shown in FIG. 1, the wireless communication system 10 includes the Next Generation-Radio Access Network 20 (hereinafter, NG-RAN20) and the user terminal 200 (hereinafter, UE200).

NG-RAN20 includes a radio base station 100 (hereinafter, gNB100) and a radio base station 110 (hereinafter, gNB101). The specific configuration of the wireless communication system 10 including the number of gNBs and UEs is not limited to the example shown in FIG.

The NG-RAN20 actually includes multiple NG-RANNodes, specifically gNB (or ng-eNB), and is connected to a core network (5GC, not shown) according to 5G. In addition, NG-RAN20 and 5GC may be simply expressed as "network".

GNB100 and gNB101 are radio base stations according to 5G, and execute wireless communication according to UE200 and 5G. The gNB100 (gNB101) and UE200 are Massive MIMO that generates a beam with higher directivity by controlling radio signals transmitted from multiple antenna elements, and carrier aggregation (CA) that uses multiple component carriers (CC). , And dual connectivity (DC), which simultaneously transmits component carriers between multiple NG-RAN Nodes and UEs, can be supported. In this embodiment, gNB100 (gNB101) and UE200 may be generically referred to as communication devices.

Further, in the present embodiment, in order to satisfy the communication requirements such as URLCC that require high reliability, duplicate transmission control of packets (data units) at the packet data convergence protocol layer (PDCP) is performed. PDCP duplication can be executed. Note that PDCP duplication may be called Packet duplication because it can be interpreted as a replication of packets handled by PDCP.

FIG. 2 shows a configuration example of a main protocol stack, a logical channel, and a component carrier in the wireless communication system 10.

As shown in FIG. 2, the wireless communication system 10 according to the present embodiment corresponds to the extended control of PDCP duplication studied in Release 16 of 3GPP.

First, in 3GPP Release 15, it is possible to associate multiple RLC entities with one PDCP entity, but it is limited to two RLC entities. The data unit (PDCP PDU 310) replicated by the PDCP entity is sent and received via different serving cells (which may be referred to as different CCs). CA-based and DC-based are defined as architectures that realize such PDCP duplication.

The primary RLC entity and the secondary RLC entity receive the duplicated PDCP PDU 310 from the PDCP entity, and receive the RLC data PDU 320 including the PDCP PDU 310 from the medium access control layer entity (MAC entity) and the physical channel (LCH #). It is transmitted via A to #C) and each CC (CC # 1 to # 3).

PDCP duplication can be dynamically turned ON / OFF (Activate / Deactivate) according to the instructions from the network (specifically, gNB100, gNB101). When PDCP duplication is deactivated, PDCP PDU 310 is transmitted only by the primary RLC entity (for example, RLC corresponding to LCH # A in FIG. 2).

In PDCP duplication, the logical channel (LCH) and CC (LCH) and CC (to prevent the original data unit (PDCP PDU 310) and the replicated data unit (PDCP PDU 310) from being transmitted via the same CC. Mapping with the serving cell) is set. Such mapping is specified in 3GPP TS38.300 and TS38.321, and is also called LCH restriction.

In 3GPP Release 16, such PDCP duplication is extended to allow the setting of three or more RLC entities (that is, the setting of two or more secondary RLC entities). Support for three or more RLC entities is demanding on a DC basis, but it is desirable to support at least three RLC entities on a CA basis as well.

(2) Functional Block Configuration of Wireless Communication System Next, the functional block configuration of the wireless communication system 10 will be described. Specifically, the functional block configuration of gNB100 and UE200 will be described. For convenience of explanation, the functional block configuration of UE200 will be described first.

(2.1) UE200
FIG. 3 is a functional block configuration diagram of the UE 200. As shown in FIG. 3, the UE 200 includes a wireless communication unit 210, a MAC processing unit 220, an RLC processing unit 230, a PDCP processing unit 240, a control unit 250, and a user IF unit 260. Although not shown, the UE 200 also executes processing of other layers such as a radio resource control layer (RRC) and a service data adaptation protocol (SDAP) layer.

The wireless communication unit 210 executes wireless communication with gNB100 (and gNB101, the same applies hereinafter). Specifically, the wireless communication unit 210 executes wireless communication with the gNB 100 according to the 5G specifications. As mentioned above, UE200 can support Massive MIMO, Carrier Aggregation (CA), Dual Connectivity (DC), and the like.

The wireless communication unit 210 generally corresponds to the physical layer (PHY / L1), and has coding / decoding, modulation / demodulation, multi-antenna mapping, and other general physical layer functions. The wireless communication unit 210 (physical layer) provides a service to the MAC processing unit 120 in the form of a transport channel.

The MAC processing unit 220 executes processing in the medium access control (MAC) layer. The MAC processing unit 220 has logical channel (LCH) multiplexing, hybrid ARQ retransmission, and scheduling and scheduling-related functions.

Scheduling related functions are provided for both uplinks and downlinks. The MAC processing unit 220 provides a service to the RLC processing unit 130 in the form of LCH. The header structure of the MAC layer in 5G (NR) has been modified to support lower latency processing more efficiently than LTE.

The RLC processing unit 230 executes processing in the wireless link control layer (RLC). RLC is responsible for the split and retransmission process.

Specifically, the RLC processing unit 230 provides a service to the PDCP processing unit 240 in the form of an RLC channel. One RLC entity is set for each RLC channel (that is, for each radio bearer (RAB)) set in the device (UE200).

RLC processing unit 230 does not support sequential distribution of data to higher layers compared to LTE. This is intended to reduce the delay.

The RLC processing unit 230 supports the PDCP duplication described above in cooperation with the PDCP processing unit 240. Specifically, the RLC processing unit 230 receives the RLC data PDU 320 (first data unit) via any RLC entity (first entity) of the wireless link control layer, and also receives the RLC data PDU 320 (first data unit) of the wireless link control layer. Receives RLC data PDU 320 (second data unit) via another RLC entity (second entity).

More specifically, the RLC processing unit 230 gNB100 (first data unit) the RLC data PDU 320 (first data unit) including the PDCP PDU 310 via any RLC entity (first entity) of the wireless link control layer. Received from the destination communication device).

Further, the RLC processing unit 230 receives RLC data in which the RLC data PDU 320 (first data unit) including the original PDCP PDU 310 is duplicated via any RLC entity (second entity) in the wireless link control layer. Receive PDU 320 (second data unit) from gNB100. In the present embodiment, the RLC processing unit 230 constitutes a receiving unit.

Further, the RLC processing unit 230 transmits the feedback information for the received RLC data PDU 320 using the radio resource associated with the RLC entity other than the RLC entity (second entity). In the present embodiment, the RLC processing unit 230 constitutes a transmission unit.

Specifically, the RLC processing unit 230 transmits feedback information via any RLC entity (first entity) of the wireless link control layer selected by the control unit 250.

Specifically, the RLC processing unit 230 operates as an RLC-Acknowledged Mode (AM), and a response indicating the reception status (status) of the received RLC data PDU 320 via the RLC entity selected by the control unit 250. RLC status report is sent as feedback information. The feedback information is not limited to the RLC status report, and may be an RLC control PDU containing the same information as the RLC status report or the RLC status report.

The PDCP processing unit 240 executes processing in the packet data convergence protocol layer (PDCP). PDCP performs IP header compression, encryption, and integrity protection.

The PDCP processing unit 240 also executes data unit retransmission, ordered distribution, and duplicate deletion when the UE 200 executes a handover.

Further, the PDCP processing unit 240 provides a data unit routing and replication function in the case of a split bearer in DC. One PDCP entity is configured for each wireless bearer configured on the device (UE200).

Furthermore, the PDCP processing unit 240 supports PDCP duplication. PDCP duplication is specified in 3GPP TS38.323. For PDCP entities configured by pdcp-Duplication, the sending PDCP entity can behave as follows:

Specifically, in the case of Signaling Radio Bearer (SRB), the PDCP processing unit 240 enables PDCP duplication based on the control of the control unit 250 (the same applies hereinafter).

Also, in the case of DataRadioBearer (DRB), if PDCP replication is instructed to be activated, PDCP replication is enabled. On the other hand, when the invalidation of PDCP replication is instructed, the PDCP processing unit 240 invalidates PDCP replication.

Furthermore, in the case of PDCP entity set by pdcp-Duplication, the sending PDCP entity can operate as follows. Specifically, if one of the two related AM (Acknowledged Mode) RLC entities confirms that the PDCP PDU 310 (specifically, PDCP data PDU) has been successfully delivered, it is duplicated. Instruct other AMRLC entities to discard PDCP data PDUs.

On the other hand, if PDCP replication is instructed to be disabled, PDCP processing unit 240 instructs the secondary RLC entity to discard all duplicate PDCP data PDUs.

The control unit 250 controls the operations of the wireless communication unit 210, the MAC processing unit 220, the RLC processing unit 230, and the PDCP processing unit 240.

In particular, in the present embodiment, the control unit 250 is a radio resource capable of transmitting the RLC status report (feedback information) to the RLC data PDU 320 (second data unit) duplicated by the PDCP duplication received by the RLC processing unit 230 to the gNB 100. If there is no, select an RLC entity (first entity) other than the RLC entity (second entity) that received the duplicated RLC data PDU 320.

In other words, in PDCP duplication, the logical channel (LCH) and CC (to prevent the original data unit (PDCP PDU 310) and the duplicated data unit (PDCP PDU 310) from being transmitted via the same CC. Since the mapping (LCH restriction) with the serving cell) is set, if the number of RLC entities (may be secondary RLC entities) associated by PDCP duplication is in the downlink> uplink status, the RLC status report is sent. There can be no available RLC entities, i.e. LCH / CC.

In such a case, the control unit 250 excludes the application of the restriction by the LCH restriction so that the RLC status report can be transmitted via the RLC entity other than the RLC entity that received the duplicated RLC data PDU 320. Instruct RLC processing unit 230. That is, the control unit 250 is used for transmitting the RLC data PDU 320 including the original PDCP PDU 310 (first data unit) and the RLC data PDU 320 (second data unit) in which the original PDCP PDU 310 is duplicated. By excluding the application of the mapping constraint (LCH restriction) regarding LCH, an RLC entity other than the RLC entity (second entity) that received the duplicated RLC data PDU 320 is selected.

That is, when the control unit 250 selects such an RLC entity, the RLC processing unit 230 receives the duplicated RLC data PDU 320 by excluding the application of the mapping constraint (LCH restriction). The RLC status report is transmitted using the radio resource associated with the RLC entity (first entity) other than the RLC entity (second entity).

The original PDCP PDU 310 and the duplicated PDCP PDU 310 may have some differences in the header information, but the actual contents of the PDU (SDU) are the same, and the original and the duplicate ( It should be noted that (copy) is only a difference for convenience of explanation. Further, in the present embodiment, as described above, the PDCP duplication is in the Deactivate state, that is, the RLC entity that sends and receives only the original PDCP PDU 310 is called the primary RLC entity.

Further, the above-mentioned radio resource is specifically at least one of CC, serving cell, uplink carrier (carrier) or BWP (BandWidth Part, band information).

That is, when the control unit 250 selects such an RLC entity, the RLC processing unit 230 receives the duplicated RLC data PDU if there is no component carrier, serving cell, carrier or bandwidth information capable of transmitting feedback information. The RLC status report is transmitted using the radio resource associated with the RLC entity (first entity) other than the RLC entity (second entity) that received 320.

In 5G, the maximum bandwidth per carrier is 100MHz at frequencies below 6GHz and 400MHz above that, which is significantly larger than LTE. BWP is supported so that a user terminal that supports a bandwidth smaller than the bandwidth can communicate with the carrier operated with such a wide bandwidth using the carrier.

The gNB100 sets the BWP information (bandwidth, frequency position, subcarrier interval) that the UE200 should use for communication in the UE200 using the signaling of the upper layer (RRC). It is also possible to set different BWP information for each user terminal. BWP information can be modified by higher layer signaling or L1 signaling.

In addition, the control unit 250 has a wireless link (uplink) capable of transmitting the RLC status report (feedback information) to the RLC data PDU 320 (second data unit) duplicated by the PDCP duplication received by the RLC processing unit 230 to the gNB 100. If not, the duplicated wireless link (downlink) used for transmission of the RLC data PDU 320 may be treated as a one-way link that does not require transmission of the RLC status report.

Specifically, the control unit 250 may handle the downlink used for transmitting the duplicated RLC data PDU 320 as um-Uni-Directional-DL. More specifically, the control unit 250 operates the RLC processing unit 230 as RLC-UM (Unacknowledged Mode) instead of RLC-AM, and sets it as um-Uni-Directional-DL that does not require transmission of RLC status report. To do.

In um-Uni-Directional-DL, the RLC processing unit 230 only receives downlinks and does not provide feedback on uplinks.

In addition, when the control unit 250 handles the downlink used for transmission of the duplicated RLC data PDU 320 as um-Uni-Directional-DL, the original data unit (PDCP PDU 310) and the duplicated data unit The setting of the mapping related to the logical channel (LCH) used for the transmission of (PDCP PDU 310) may be omitted.

The user IF unit 260 provides an interface for UE200 users. Specifically, the user IF unit 260 is realized by hardware and software that realize various types of input / output. The hardware configuration of UE200 will be described later.

(2.2) gNB100
FIG. 4 is a functional block configuration diagram of the gNB 100. The gNB 101 also has a similar functional block configuration.

As shown in FIG. 4, the gNB100 includes a wireless communication unit 110, a MAC processing unit 120, an RLC processing unit 130, a PDCP processing unit 140, a control unit 150, and a network IF unit 160.

The wireless communication unit 110 executes wireless communication with the UE 200. Specifically, the wireless communication unit 110 executes wireless communication with the UE 200 according to the 5G specifications. Like UE200, gNB100 can support Massive MIMO, Carrier Aggregation (CA), Dual Connectivity (DC), and so on.

The functions of the MAC processing unit 120, RLC processing unit 130, and PDCP processing unit 140 are the same as those of the UE200 MAC processing unit 220, RLC processing unit 230, and PDCP processing unit 240, although the uplink and downlink are reversed.

The control unit 150 controls the operations of the wireless communication unit 110, the MAC processing unit 120, the RLC processing unit 130, and the PDCP processing unit 140. The function of the control unit 150 is the same as that of the control unit 250 of the UE 200, although the uplink and the downlink are reversed.

The network IF unit 160 provides a NW interface for connecting to the NG-RAN20 (and 5GC). Specifically, the network IF unit 160 provides an interface with gNB101 (X2, Xn, etc.) and an interface with 5GC (N2, N3, etc.).

(3) Operation of Wireless Communication System Next, the operation of the wireless communication system 10 will be described. Specifically, gNB100 when an asymmetric number of PDCP duplication (hereinafter referred to as Asymmetric PDCP duplication, but the term is not limited to this) is set between the downlink (DL) and the uplink (UL). And the operation of UE200 will be described.

(3.1) Asymmetric PDCP duplication setting example FIG. 5 shows a setting example of Asymmetric PDCP duplication. In the example shown in FIG. 5, four RLC entities associated with one PDCP entity are set in both gNB100 and UE200.

On the other hand, as shown in FIG. 5, DL is set for each RLC entity, that is, 4 DLs are set, but UL is set for only 3 RLC entities, that is, 3 ULs are set. It is asymmetrical between DL and UL. The number of DLs and ULs may be read as the number of CCs.

Therefore, in the DL direction, four RLC data PDUs are transmitted in duplicate, but in the UL direction, three RLC data PDUs are transmitted in duplicate.

In the example shown in FIG. 5, DL and UL are 4: 3, but if they are asymmetric, the ratio of DL and UL is not particularly limited. Further, an example in which the RLC data PDU is transmitted in the DL will be described below, but the same operation can be performed when the RLC data PDU is transmitted in the UL.

As mentioned above, RLC-AM defines feedback information sent and received via UL for RLC data PDU transmitted via DL, specifically, RLC status report (3GPP TS38). See .322).

Therefore, if there is a difference between the number of DLs and the number of ULs (that is, the number of CCs in the downlink and uplink directions), there will be a problem that the RLC status report cannot be sent due to LCH restriction. As a result, an RLC abnormality is detected on the gNB100 side, and normal communication cannot be continued. In this embodiment, such a problem is solved.

(3.2) Operation example 1
FIG. 6 shows the operation flow (operation example 1) of the UE 200 when Asymmetric PDCP duplication is set. FIG. 7 shows the transmission / reception status of the RLC data PDU and the RLC status report by the gNB100 and UE200 according to the operation example 1.

In this operation example, UE200 operates so that RLC status report can be returned for all RLC data PDUs even when Asymmetric PDCP duplication is set. As described above, the RLC status report may be an RLC control PDU.

As shown in FIG. 6, the UE 200 receives the duplicated RLC data PDU 320 (see FIG. 5) (S10). Specifically, the UE 200 receives RLC data PDUs via four RLC entities (one primary RLC entity and three secondary RLC entities).

UE200 has a CC, serving cell, UL carrier or BWP capable of transmitting RLC status report (RLC control PDU, the same applies hereinafter) in the corresponding RLC entity, specifically, the RLC entity that received the RLC data PDU. Is determined (S20).

Note that UE200 may be determined to have no CC, serving cell, UL carrier or BWP if any of the following applies.

-No CC, serving cell, UL carrier or BWP to be mapped-No CC, serving cell, UL carrier or BWP in Activated state-UL time alignment is established (that is, the TA timer of the TAG to which it belongs is running) No CC, Serving Cell, UL Carrier or BWP • Received instructions from the network that there is no CC, Serving Cell, UL Carrier or BWP (eg IE such as "UL absence" or "Asym config" by RRC layer signaling When applied to LCH (or RLC bearer))
Note that the UE 200 may simply determine whether or not the UL associated with the RLC entity that received the RLC data PDU is set.

Further, the CC, serving cell, UL carrier or BWP used for transmitting the RLC status report may be determined based on any of the following criteria.

-Random selection-Select other CC (LCH, RLC entity) for round robin-Select the target with the largest bandwidth-Select the target with the smallest number of HARQ retransmissions-The smallest Modulation and Coding Scheme (MCS) (most) Select the target that can guarantee the quality ・ Select the target with the largest number of assigned Physical Resource Blocks (PRBs) ・ Select the target with the most scheduling opportunities ・ Target with the largest (or first) or smallest (or last) identifier value -Select the target specified by the network-Select the target for which the most recent RLC status report can be sent-Select the primary cell (PCell) -Select the target with which the primary RLC entity is associated-Send the RLC status report Select a target with possible surplus space (transport block, MAC PDU) The UE200, if there is a CC, serving cell, UL carrier or BWP capable of sending an RLC status report, at least the CC, serving cell, UL carry and BWP. Send an RLC status report to gNB100 using either (S30).

On the other hand, UE200 decides not to apply the mapping constraint between LCH and CC (serving cell), specifically the above-mentioned LCH restriction, when there is no CC, serving cell, UL carrier and BWP capable of transmitting RLC status report. (S40).

Note that the UE200 may realize such a decision by deactivating PDCP duplication. This is because it is stipulated that when PDCP duplication is deactivated, the above-mentioned mapping is automatically deactivated (see 3GPP TS38.300).

In addition, PDCP duplication deactivation may be explicitly instructed by the network to UE200 (for example, RRC or MAC layer signaling). Alternatively, the UE 200 may execute it implicitly without such explicit instruction. At this time, the UE 200 may be determined to be inactivated based on the setting of the mapping between LCH and CC. The network (gNB100 side) must deactivate PDCP duplication.

The UE200 uses at least one of the CC, serving cell, UL carrier and BWP associated with another RLC entity, that is, an RLC entity that is different from the RLC entity that received the RLC data PDU, to set the RLC status report to gNB100. Send (S50).

When the RLC status report is transmitted using at least one of CC, serving cell, UL carrier and BWP associated with the RLC entity in this way, the RLC status report is any RLC entity (or LCH, LCH,). Identification information that identifies whether it corresponds to CC) may be given. For example, the identifier of the RLC entity, the identifier of the RLC bearer, the identifier of the LCH ID, the identifier of the DL serving cell, and the like can be mentioned.

As shown in FIG. 7, the four RLC entities are operating in AM, but only DL is set and UL is not set between RLC entity 105 and RLC entity 205. When PDCP duplication is executed in this state, it becomes the state of Asymmetric PDCP duplication (DL: UL = 4: 3).

Therefore, the RLC entity 205 cannot directly return the RLC status report for the RLC data PDU sent from the RLC entity 105 to the RLC entity 105.

Therefore, the UE200 corresponds to the UL (specifically, CC, serving cell, UL carrier, BWP) associated with other RLC entities via the MAC entity (not shown in FIG. 7, see FIG. 2). Turn the RLC status report (see the alternate long and short dash line in the figure). As a result, the RLC status report for the RLC data PDU sent from the RLC entity 105 is returned to the gNB 100 even in the state of Asymmetric PDCP duplication.

It should be noted that the configuration of up to four RLC entities for duplicate bearers per UE200 is preferably supported by multiple RLC-Bearer Configs with the same radio bearer ID. Also, the configuration of up to four RLC entities for replicated bearers per cell group is preferably supported by multiple RLC-Bearer Configs with the same radio bearer ID.

In addition, the RRC preferably sets whether or not each RLC bearer is used for uplink replication, and when PDCP duplication is activated, PDCP will be applied to all RLC bearers for which replication is configured. It is preferable to transmit the duplicated data unit (PDCP PDU).

(3.3) Operation example 2
FIG. 8 shows the operation flow (operation example 2) of the UE 200 when Asymmetric PDCP duplication is set. FIG. 9 shows the transmission / reception status of the RLC data PDU and the RLC status report by the gNB100 and UE200 according to the operation example 2.

In this operation example, if there is no uplink (UL) for sending RLC status report by Asymmetric PDCP duplication, the downlink (DL) to which RLC data PDU was sent is a one-way link that does not require sending RLC status report. Avoid sending RLC status report by treating it as (um-Uni-Directional-DL).

As shown in FIG. 8, the UE 200 receives the duplicated RLC data PDU 320 (see FIG. 5) (S110). Specifically, the UE 200 receives the RLC data PDU 320 via four RLC entities (one primary RLC entity and three secondary RLC entities) as in the operation example 1.

The UE200 determines whether or not there is a UL capable of transmitting the RLC status report returned in response to the reception of the RLC data PDU (S120). Specifically, the UE 200 determines whether the UL (CC, serving cell, UL carrier or BWP) associated with the RLC entity that received the RLC data PDU is set.

If there is a UL that can send the RLC status report, the UE200 sends the RLC status report to the gNB100 via the UL (S130).

On the other hand, UE200 decides to use um-Uni-Directional-DL when there is no UL that can send RLC status report (S140).

Um-Uni-Directional-DL is specified in 3GPP TS38.322, etc. In um-Uni-Directional-DL, the UE200 only receives RLC data PDUs via DL and does not send feedback information via UL, that is, RLC status report.

As shown in FIG. 9, when the UE200 decides to use um-Uni-Directional-DL, the RLC entity 205 operates as Unacknowledged Mode (UM) instead of Acknowledged Mode (AM). Correspondingly, RLC entity 105 also acts as a UM.

In addition, UE200 has decided to use um-Uni-Directional-DL, and DL only CC / Cell / Carrier composed of DLs for which the corresponding valid UL (UL CC, UL carrier, UL serving cell) is not set. If is set, the mapping settings for the logical channel (LCH), specifically the mapping between the LCH and the serving cell, may be omitted.

In addition, UE200 is a DL only Cell that does not have a corresponding valid UL (UL CC, UL carrier, UL serving cell) set when um-Uni-Directional-DL is set for the RLC bearer with PDCP duplication set. / CC / Carrier may implicitly recognize that it is associated with the RLC bearer.

Furthermore, the above-mentioned um-Uni-Directional-DL may be realized by modeling to disable (disable, omit, suppress) the RLC status report for the RLC entity of AM.

(4) Action / Effect According to the above-described embodiment, the following action / effect can be obtained. Specifically, the UE 200 is other than the RLC entity that received the RLC data PDU 320 if there is no CC, serving cell, UL carrier and BWP capable of sending an RLC status report to the gNB 100 for the RLC data PDU 320 replicated by PDCP duplication. Select the RLC entity for. In addition, UE200 sends an RLC status report for the RLC data PDU 320 to gNB100 via the selected RLC entity.

Therefore, even if Asymmetric PDCP duplication is set, the RLC status report for the RLC data PDU can be reliably returned. That is, according to UE200, even when PDCP duplication is extended and Asymmetric PDCP duplication is set, it is possible to reliably return a response such as feedback information for the transmission of RLC data PDU.

In this embodiment, the UE 200 selects an RLC entity other than the RLC entity that received the RLC data PDU 320 based on the presence or absence of at least one of CC, serving cell, UL carrier or BWP capable of transmitting the RLC status report to the gNB 100. You can decide whether or not to do it. Therefore, the UE200 can determine whether or not the RLC status report can be transmitted from multiple aspects. As a result, it is possible to more reliably return a response such as feedback information to the transmission of the RLC data PDU.

In the present embodiment, the UE 200 can select an RLC entity other than the RLC entity that received the duplicated RLC data PDU 320 by excluding the application of the mapping constraint (LCH restriction) regarding LCH. Therefore, it is possible to send feedback information when Asymmetric PDCP duplication is set while utilizing the existing UE200 operation without defining a new operation.

In the present embodiment, when there is no uplink that can be transmitted to the RLC status report gNB100 for the RLC data PDU 320 replicated by PDCP duplication, the UE 200 transmits the downlink used for transmitting the RLC data PDU 320 to the RLC status report. Can be treated as unnecessary um-Uni-Directional-DL. Therefore, even if Asymmetric PDCP duplication is set, it is possible to avoid sending RLC status report by changing to UM for RLC entities that cannot send RLC status report. As a result, even when Asymmetric PDCP duplication is set, it is possible to reliably return a response such as feedback information that can be transmitted while avoiding a state in which the RLC status report cannot be transmitted normally and terminates abnormally.

In the present embodiment, when the UE 200 treats the downlink used for transmitting the duplicated RLC data PDU 320 as um-Uni-Directional-DL, the UE 200 has the original data unit (PDCP PDU 310) and the duplicated data. You can omit the mapping settings for the logical channel (LCH) used to transmit the unit. Therefore, unnecessary operations in the UE 200 can be reduced, which can contribute to the performance improvement of the UE 200.

(5) Other Embodiments Although the contents of the present invention have been described above with reference to Examples, the present invention is not limited to these descriptions, and various modifications and improvements are possible. It is obvious to the trader.

For example, in the above-described embodiment, the operation of the UE200 has been mainly described, but the gNB100 (and gNB101) can also perform an operation corresponding to Asymmetric PDCP duplication in the same manner as the UE200.

Further, in the above-described embodiment, the example of aggregation in gNB100 has been described, but Asymmetric PDCP duplication may be set (that is, the state of DC) across a plurality of gNBs. Similarly, for UEs, Asymmetric PDCP duplication may be set using a plurality of UEs. In such a case, the PDCP entity may be arranged in any UE, and a plurality of RLC entities may be arranged so as to be distributed and straddled in different UEs. Further, a device belonging to Time Sensitive Networking (TSN) may be connected to the plurality of UEs, or a relationship such as a master unit and a slave unit may be used.

Furthermore, the UE200 may notify the network that it has the capability to support Asymmetric PDCP duplication. For example, for each band combination, each band, each CC, and each resource block (RB) type (Signalling Radio Bearer (SRB), Data Radio Bearer (DRB)), the presence or absence of the ability or the number of RLC entities that can be supported is notified. You may. The notification may be independent of DL and UL.

In addition, UE200 may apply the above-mentioned support for Asymmetric PDCP duplication only to a specific bearer. This makes it easy to implement the function corresponding to Asymmetric PDCP duplication of UE200. For example, only DRBs or SRBs, or only bearers that have a specific identifier or are associated with quality of service (QoS).

Furthermore, in the above-described embodiment, the case where the number of PDCP duplications is 4: 3 between DL and UL has been described. Considering the implementation of UE200, such a case is typical, but the above-mentioned operation example can of course be applied to a case where DL <UL.

Further, the block configuration diagrams (FIGS. 3 and 4) used in the description of the above-described embodiment show blocks of functional units. These functional blocks (components) are realized by any combination of at least one of hardware and software. Further, the method of realizing each functional block is not particularly limited. That is, each functional block may be realized by using one device that is physically or logically connected, or directly or indirectly (for example, by using two or more physically or logically separated devices). , Wired, wireless, etc.) and may be realized using these plurality of devices. The functional block may be realized by combining the software with the one device or the plurality of devices.

Functions include judgment, decision, judgment, calculation, calculation, processing, derivation, investigation, search, confirmation, reception, transmission, output, access, solution, selection, selection, establishment, comparison, assumption, expectation, and assumption. There are broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating, mapping, assigning, etc., but only these. I can't. For example, a functional block (constituent unit) that makes transmission function is called a transmitting unit or a transmitter. As described above, the method of realizing each is not particularly limited.

Further, the above-mentioned gNB100, gNB101 and UE200 (the device) may function as a computer for processing the wireless communication method of the present disclosure. FIG. 10 is a diagram showing an example of the hardware configuration of the device. As shown in FIG. 10, the device may be configured as a computer device including a processor 1001, a memory 1002, a storage 1003, a communication device 1004, an input device 1005, an output device 1006, a bus 1007, and the like.

In the following explanation, the word "device" can be read as a circuit, device, unit, etc. The hardware configuration of the device may be configured to include one or more of each of the devices shown in the figure, or may be configured not to include some of the devices.

Each functional block of the device (see FIGS. 3 and 4) is realized by any hardware element of the computer device or a combination of the hardware elements.

Further, for each function in the device, by loading predetermined software (program) on the hardware such as the processor 1001 and the memory 1002, the processor 1001 performs the calculation, controls the communication by the communication device 1004, and the memory. It is realized by controlling at least one of reading and writing of data in 1002 and storage 1003.

Processor 1001 operates, for example, an operating system to control the entire computer. The processor 1001 may be composed of a central processing unit (CPU) including an interface with peripheral devices, a control device, an arithmetic unit, registers, and the like.

Further, the processor 1001 reads a program (program code), a software module, data, etc. from at least one of the storage 1003 and the communication device 1004 into the memory 1002, and executes various processes according to these. As the program, a program that causes a computer to execute at least a part of the operations described in the above-described embodiment is used. Further, the various processes described above may be executed by one processor 1001 or may be executed simultaneously or sequentially by two or more processors 1001. Processor 1001 may be implemented by one or more chips. The program may be transmitted from the network via a telecommunication line.

The memory 1002 is a computer-readable recording medium, and is composed of at least one of, for example, ReadOnlyMemory (ROM), ErasableProgrammableROM (EPROM), Electrically ErasableProgrammableROM (EEPROM), RandomAccessMemory (RAM), and the like. May be done. The memory 1002 may be called a register, a cache, a main memory (main storage device), or the like. The memory 1002 can store a program (program code), a software module, or the like that can execute the method according to the embodiment of the present disclosure.

The storage 1003 is a computer-readable recording medium, for example, an optical disk such as a Compact Disc ROM (CD-ROM), a hard disk drive, a flexible disk, a photomagnetic disk (for example, a compact disk, a digital versatile disk, or a Blu-ray). It may consist of at least one (registered trademark) disk), smart card, flash memory (eg, card, stick, key drive), floppy (registered trademark) disk, magnetic strip, and the like. Storage 1003 may be referred to as auxiliary storage. The recording medium described above may be, for example, a database, server or other suitable medium containing at least one of memory 1002 and storage 1003.

The communication device 1004 is hardware (transmission / reception device) for communicating between computers via at least one of a wired network and a wireless network, and is also referred to as, for example, a network device, a network controller, a network card, a communication module, or the like.

Communication device 1004 includes, for example, a high frequency switch, a duplexer, a filter, a frequency synthesizer, etc. in order to realize at least one of frequency division duplex (FDD) and time division duplex (TDD). It may be composed of.

The input device 1005 is an input device (for example, keyboard, mouse, microphone, switch, button, sensor, etc.) that accepts input from the outside. The output device 1006 is an output device (for example, a display, a speaker, an LED lamp, etc.) that outputs to the outside. The input device 1005 and the output device 1006 may have an integrated configuration (for example, a touch panel).

In addition, each device such as the processor 1001 and the memory 1002 is connected by the bus 1007 for communicating information. The bus 1007 may be configured by using a single bus, or may be configured by using a different bus for each device.

Further, the device includes hardware such as a microprocessor, a digital signal processor (Digital Signal Processor: DSP), an Application Specific Integrated Circuit (ASIC), a Programmable Logic Device (PLD), and a Field Programmable Gate Array (FPGA). The hardware may implement some or all of each functional block. For example, processor 1001 may be implemented using at least one of these hardware.

Further, the notification of information is not limited to the mode / embodiment described in the present disclosure, and may be performed by using another method. For example, information notification includes physical layer signaling (for example, Downlink Control Information (DCI), Uplink Control Information (UCI), upper layer signaling (eg, RRC signaling, Medium Access Control (MAC) signaling, broadcast information (Master Information Block)). (MIB), System Information Block (SIB)), other signals or combinations thereof. RRC signaling may also be referred to as an RRC message, for example, RRC Connection Setup. ) Message, RRC Connection Reconfiguration message, etc. may be used.

Each aspect / embodiment described in this disclosure, Long Term Evolution (LTE), LTE-Advanced (LTE-A), SUPER 3G, IMT-Advanced, 4th generation mobile communication system (4G), 5 th generation mobile communication system (5G), Future Radio Access (FRA), New Radio (NR), W-CDMA (registered trademark), GSM (registered trademark), CDMA2000, Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi (registered trademark)) ), IEEE 802.16 (WiMAX®), IEEE 802.20, Ultra-WideBand (UWB), Bluetooth®, and other systems that utilize suitable systems and at least next-generation systems extended based on them. It may be applied to one. In addition, a plurality of systems may be applied in combination (for example, a combination of at least one of LTE and LTE-A and 5G).

The order of the processing procedures, sequences, flowcharts, etc. of each aspect / embodiment described in the present disclosure may be changed as long as there is no contradiction. For example, the methods described in the present disclosure present elements of various steps using exemplary order, and are not limited to the particular order presented.

In some cases, the specific operation performed by the base station in the present disclosure may be performed by its upper node (upper node). In a network consisting of one or more network nodes having a base station, various operations performed for communication with a terminal are performed by the base station and other network nodes other than the base station (for example, MME or). It is clear that it can be done by at least one of (but not limited to, S-GW, etc.). Although the case where there is one network node other than the base station is illustrated above, it may be a combination of a plurality of other network nodes (for example, MME and S-GW).

Information and signals (information, etc.) can be output from the upper layer (or lower layer) to the lower layer (or upper layer). Input / output may be performed via a plurality of network nodes.

The input / output information may be stored in a specific location (for example, memory) or may be managed using a management table. The input / output information can be overwritten, updated, or added. The output information may be deleted. The input information may be transmitted to another device.

The determination may be made by a value represented by 1 bit (0 or 1), by a boolean value (Boolean: true or false), or by comparing numerical values (for example, a predetermined value). It may be done by comparison with the value).

Each aspect / embodiment described in the present disclosure may be used alone, in combination, or switched with execution. Further, the notification of predetermined information (for example, the notification of "being X") is not limited to the explicit one, but is performed implicitly (for example, the notification of the predetermined information is not performed). May be good.

Software is an instruction, instruction set, code, code segment, program code, program, subprogram, software module, whether called software, firmware, middleware, microcode, hardware description language, or another name. , Applications, software applications, software packages, routines, subroutines, objects, executable files, execution threads, procedures, functions, etc. should be broadly interpreted to mean.

In addition, software, instructions, information, etc. may be transmitted and received via a transmission medium. For example, a website, where the software uses at least one of wired technology (coaxial cable, fiber optic cable, twist pair, Digital Subscriber Line (DSL), etc.) and wireless technology (infrared, microwave, etc.). When transmitted from a server, or other remote source, at least one of these wired and wireless technologies is included within the definition of transmission medium.

The information, signals, etc. described in this disclosure may be represented using any of a variety of different techniques. For example, data, instructions, commands, information, signals, bits, symbols, chips, etc. that may be referred to throughout the above description are voltages, currents, electromagnetic waves, magnetic fields or magnetic particles, light fields or photons, or any of these. It may be represented by a combination of.

Note that the terms explained in the present disclosure and the terms necessary for understanding the present disclosure may be replaced with terms having the same or similar meanings. For example, at least one of a channel and a symbol may be a signal (signaling). Also, the signal may be a message. Further, the component carrier (CC) may be referred to as a carrier frequency, a cell, a frequency carrier, or the like.

The terms "system" and "network" used in this disclosure are used interchangeably.

In addition, the information, parameters, etc. described in the present disclosure may be expressed using absolute values, relative values from predetermined values, or using other corresponding information. It may be represented. For example, the radio resource may be one indicated by an index.

The names used for the above parameters are not limited in any respect. Further, mathematical formulas and the like using these parameters may differ from those explicitly disclosed in this disclosure. Since the various channels (eg PUCCH, PDCCH, etc.) and information elements can be identified by any suitable name, the various names assigned to these various channels and information elements are in any respect limited names. is not.

In this disclosure, "Base Station (BS)", "Wireless Base Station", "Fixed Station", "NodeB", "eNodeB (eNB)", "gNodeB (gNB)", " "Access point", "transmission point", "reception point", "transmission / reception point", "cell", "sector", "cell group", "cell group" Terms such as "carrier" and "component carrier" can be used interchangeably. Base stations are sometimes referred to by terms such as macrocells, small cells, femtocells, and picocells.

The base station can accommodate one or more (for example, three) cells (also called sectors). When a base station accommodates multiple cells, the entire coverage area of the base station can be divided into multiple smaller areas, each smaller area being a base station subsystem (eg, a small indoor base station (Remote Radio)). Communication services can also be provided by Head: RRH).

The term "cell" or "sector" refers to a part or all of the coverage area of at least one of the base station providing communication services in this coverage and the base station subsystem.

In the present disclosure, terms such as "mobile station (MS)", "user terminal", "user equipment (UE)", and "terminal" may be used interchangeably. ..

Mobile stations can be subscriber stations, mobile units, subscriber units, wireless units, remote units, mobile devices, wireless devices, wireless communication devices, remote devices, mobile subscriber stations, access terminals, mobile terminals, wireless, depending on the trader. It may also be referred to as a terminal, remote terminal, handset, user agent, mobile client, client, or some other suitable term.

At least one of the base station and the mobile station may be called a transmitting device, a receiving device, a communication device, or the like. At least one of the base station and the mobile station may be a device mounted on the mobile body, the mobile body itself, or the like. The moving body may be a vehicle (eg, car, airplane, etc.), an unmanned moving body (eg, drone, self-driving car, etc.), or a robot (manned or unmanned). ) May be. It should be noted that at least one of the base station and the mobile station includes a device that does not necessarily move during communication operation. For example, at least one of a base station and a mobile station may be an Internet of Things (IoT) device such as a sensor.

Further, the base station in the present disclosure may be read as a mobile station (user terminal, the same applies hereinafter). For example, communication between a base station and a mobile station has been replaced with communication between a plurality of mobile stations (for example, it may be called Device-to-Device (D2D), Vehicle-to-Everything (V2X), etc.). Each aspect / embodiment of the present disclosure may be applied to the configuration. In this case, the mobile station may have the function of the base station. In addition, words such as "up" and "down" may be read as words corresponding to inter-terminal communication (for example, "side"). For example, the uplink, downlink, and the like may be read as side channels.

Similarly, the mobile station in the present disclosure may be read as a base station. In this case, the base station may have the functions of the mobile station.

The terms "connected", "coupled", or any variation thereof, mean any direct or indirect connection or connection between two or more elements, and each other. It can include the presence of one or more intermediate elements between two "connected" or "combined" elements. The connection or connection between the elements may be physical, logical, or a combination thereof. For example, "connection" may be read as "access". As used in the present disclosure, the two elements use at least one of one or more wires, cables and printed electrical connections, and, as some non-limiting and non-comprehensive examples, the radio frequency domain. , Electromagnetic energies with wavelengths in the microwave and light (both visible and invisible) regions can be considered to be "connected" or "coupled" to each other.

The reference signal can also be abbreviated as Reference Signal (RS), and may be called a pilot (Pilot) depending on the applicable standard.

The phrase "based on" as used in this disclosure does not mean "based on" unless otherwise stated. In other words, the statement "based on" means both "based only" and "at least based on".

Any reference to elements using designations such as "first", "second" as used in this disclosure does not generally limit the quantity or order of those elements. These designations can be used in the present disclosure as a convenient way to distinguish between two or more elements. Thus, references to the first and second elements do not mean that only two elements can be adopted there, or that the first element must somehow precede the second element.

When "include", "including" and variations thereof are used in the present disclosure, these terms are as comprehensive as the term "comprising". Is intended. Moreover, the term "or" used in the present disclosure is intended not to be an exclusive OR.

In the present disclosure, if articles are added by translation, for example, a, an and the in English, the disclosure may include that the nouns following these articles are in the plural.

In the present disclosure, the term "A and B are different" may mean "A and B are different from each other". The term may mean that "A and B are different from C". Terms such as "separate" and "combined" may be interpreted in the same way as "different".

Although the present disclosure has been described in detail above, it is clear to those skilled in the art that the present disclosure is not limited to the embodiments described in the present disclosure. The present disclosure may be implemented as an amendment or modification without departing from the purpose and scope of the present disclosure, which is determined by the description of the scope of claims. Therefore, the description of this disclosure is for purposes of illustration only and does not have any restrictive meaning to this disclosure.

10 Radio communication system 20 NG-RAN
100, 101 gNB
105 RLC entity 110 Wireless communication unit 120 MAC processing unit 130 RLC processing unit 140 PDCP processing unit 150 Control unit 160 Network IF unit 200 UE
205 RLC entity 210 Wireless communication unit 220 MAC processing unit 230 RLC processing unit 240 PDCP processing unit 250 Control unit 260 User IF unit 310 PDCP PDU
320 RLC data PDU
1001 Processor 1002 Memory 1003 Storage 1004 Communication Device 1005 Input Device 1006 Output Device 1007 Bus

Claims

A receiving unit that receives the first data unit via the first entity of the wireless link control layer and receives the second data unit via the second entity of the wireless link control layer.
A communication device including a transmission unit that transmits received feedback information to the second data unit using radio resources associated with the first entity of the wireless link control layer other than the second entity.
The transmitter uses radio resources associated with the first entity of the radio link control layer other than the second entity if there is no component carrier, serving cell, carrier or band information capable of transmitting the feedback information. The communication device according to claim 1, wherein the feedback information is transmitted.
The transmitting unit becomes a first entity of the radio link control layer other than the second entity by excluding the application of the mapping constraint regarding the logical channel used for transmitting the first data unit and the second data unit. The communication device according to claim 1, wherein the feedback information is transmitted using the associated radio resource.
A receiver that receives the first data unit via the first entity of the wireless link control layer and receives the second data unit via the second entity of the wireless link control layer.
When there is no wireless link capable of transmitting the received feedback information to the second data unit, the control unit that treats the wireless link used for transmitting the second data unit as a one-way link that does not require the transmission of the feedback information. Communication device to be equipped.
When the control unit handles the wireless link used for transmission of the second data unit as the one-way link, the control unit omits the setting of mapping regarding the logical channel used for transmission of the first data unit and the second data unit. The communication device according to claim 4.