CN117063603A - Terminal and wireless communication method - Google Patents

Abstract

And the terminal deactivates the secondary cell group according to the state of the secondary cell group. When a timer associated with the resetting of radio resources expires or when a problem of an initial access procedure occurs in the secondary cell group, the terminal deactivates the secondary cell group.

Description

Terminal and wireless communication method

Technical Field

The present disclosure relates to a terminal supporting dual connection and a wireless communication method.

Background

The third Generation partnership project (3rd Generation Partnership Project:3GPP) standardizes the fifth Generation mobile communication system (also referred to as 5G, new Radio: NR), or Next Generation (NG)), and further, the Next Generation, which is referred to as Beyond 5G, 5G event, or 6G, has been advanced.

For example, in Release-17 of 3GPP, expansion of Multi-RAT dual connectivity (Multi-RAT Dual Connectivity: MR-DC) is being studied, and for example, activation/deactivation mechanisms (which may be referred to as SCG activation/deactivation) of Secondary Cell Groups (SCGs) are being studied for the main purpose of reducing power consumption of terminals (User Equipment) (non-patent document 1).

Further, regarding SCG activation/deactivation, there is proposed a scheme in which, when a failure of SCG (specifically, radio Link Failure (RLF)) occurs, a UE autonomously deactivates SCG (non-patent document 2).

Prior art literature

Non-patent literature

Non-patent document 1: "Revised WID on Further Multi-RAT Dual-Connectivity enhancements", month 6 of RP-201040,3GPP TSG RAN Meeting#88e,3GPP,2020

Non-patent document 2: "Further consideration on SCG activation and deactivation", R2-2101915,3GPP TSG-RAN WG2Meeting #113electronic,3GPP, month 2 of 2021

Disclosure of Invention

Regarding SCG (deactivated SCG) after being deactivated with the failure of the SCG, when considering the case of being reactivated if the failure is recovered, it is assumed that in the case where the UE autonomously deactivates the SCG with the failure of the SCG, the procedure at the time of failure of the SCG (for example, chapter 3GPP TS38.331 5.7.3.2) is not suitable for direct application.

Accordingly, the following disclosure has been made in view of the above circumstances, and an object thereof is to provide a terminal and a wireless communication method capable of appropriately performing autonomous deactivation of an SCG that accompanies failure of the SCG.

One aspect of the present disclosure provides a terminal (UE 200) having: a transmitting/receiving unit (wireless communication unit 210) that transmits/receives wireless signals via the secondary cell group; and a control unit (control unit 240) that deactivates the secondary cell group according to the state of the secondary cell group, wherein the control unit deactivates the secondary cell group when a timer associated with resetting of radio resources expires or when a problem of an initial access procedure occurs in the secondary cell group.

One embodiment of the present disclosure is a terminal (UE 200) including: a transmitting/receiving unit (wireless communication unit 210) that transmits/receives wireless signals via the secondary cell group; and a control unit (control unit 240) that deactivates the secondary cell group according to the state of the secondary cell group, wherein the control unit maintains the setting of the medium access control layer when the secondary cell group is deactivated.

One mode of the present disclosure provides a wireless communication method including the steps of: the terminal receives and transmits wireless signals through the secondary cell group; and the terminal deactivates the secondary cell group according to the state of the secondary cell group, and in the step of deactivating, the secondary cell group is deactivated when a timer related to resetting of radio resources expires or when a problem of an initial access procedure occurs in the secondary cell group.

One mode of the present disclosure provides a wireless communication method including the steps of: the terminal receives and transmits wireless signals through the secondary cell group; and the terminal deactivates the secondary cell group according to the state of the secondary cell group, and in the deactivating step, the setting of the media access control layer is maintained under the condition of deactivating the secondary cell group.

Drawings

Fig. 1 is a schematic overall configuration diagram of a wireless communication system 10.

Fig. 2 is a functional block configuration diagram of the eNB 100A.

Fig. 3 is a functional block configuration diagram of the UE 200.

Fig. 4 is a diagram showing an example of communication timing related to deactivation and reactivation of SCG.

Fig. 5 is a diagram showing an example of operation when SCG failure occurs in UE 200 conforming to the specifications of 3GPP Release-15, 16.

Fig. 6 is a diagram showing an example of the operation in the case where the UE 200 according to the operation example 2 autonomously deactivates the SCG.

Fig. 7 is a diagram showing an example of the operation of the SCG after the autonomous deactivation by the UE 200 according to the operation example 2 of restarting.

Fig. 8 is a diagram showing an example of a hardware configuration of the eNB 100A, gNB B and the UE 200.

Detailed Description

The embodiments are described below based on the drawings. The same or similar functions and structures are denoted by the same reference numerals, and description thereof is omitted as appropriate.

(1) Overall outline structure of radio communication system

Fig. 1 is a schematic overall configuration diagram of a radio communication system 10 according to the present embodiment. The wireless communication system 10 is a wireless communication system according to long term evolution (Long Term Evolution: LTE) and a New air interface (New Radio: NR). In addition, LTE may be referred to as 4G and nr may be referred to as 5G. The wireless communication system 10 may be a wireless communication system according to a scheme called Beyond 5G, 5G event, or 6G.

LTE and NR may be interpreted as Radio Access Technologies (RATs), in this embodiment LTE may be referred to as radio access technology 1 and NR as radio access technology 2.

The wireless communication system 10 includes an evolved universal terrestrial radio access network (Evolved Universal Terrestrial Radio Access Network, hereinafter E-UTRAN 20), and a Next Generation radio access network30 (Next Generation-Radio Access Network, hereinafter NG RAN 30). The wireless communication system 10 includes a terminal 200 (hereinafter referred to as UE 200 and User Equipment).

The E-UTRAN 20 includes a radio base station, eNB 100A, according to LTE. NG RAN 30 includes a radio base station according to 5G (NR), namely, gNB 100B. Further, user Plane Function (hereinafter, referred to as UPF 40) that provides a function of a user plane included in the system architecture of 5G is connected to the NG RAN 30. In addition, the E-UTRAN 20 and the NG RAN 30 (which may also be either eNB 100A or gNB 100B) may be referred to simply as networks.

The eNB 100A, gNB B and the UE 200 can support Carrier Aggregation (CA) using a plurality of Component Carriers (CCs), dual connection in which component carriers are simultaneously transmitted between a plurality of NG-RAN nodes and the UE, and the like.

The eNB 100A, gNB B and the UE 200 perform wireless communication via radio bearers, specifically, signaling radio bearers (Signalling Radio Bearer: SRB) or data radio bearers (Data Radio Bearer: DRB).

In the present embodiment, a Multi-radio dual connection (Multi-Radio Dual Connectivity: MR-DC) in which eNB 100A forms a Master Node (MN) and gNB 100B forms a Slave Node (SN), specifically, an E-UTRA-NR dual connection (E-UTRA-NR Dual Connectivity: EN-DC)), or an NR-E-UTRA dual connection (NR-E-UTRA Dual Connectivity) in which gNB 100B forms MN and eNB 100A forms SN may be performed: NE-DC). Alternatively, an NR-NR dual connection (NR-NR Dual Connectivity: NR-DC) in which gNB constitutes MN and SN may be performed.

Thus, UE 200 supports dual connectivity with eNB 100A and gNB 100B connections.

eNB 100A is included in a primary cell group (MCG), while gNB 100B is included in a Secondary Cell Group (SCG). That is, gNB 100B is SN contained in SCG.

The enbs 100A and gNB 100B may also be referred to as radio base stations or network devices.

In addition, in the wireless communication system 10, addition or change (PSCell addition/change) of a Primary SCell (PSCell) may be supported. The PSCell addition/change may include addition or change of a PSCell condition (conditional PSCell addition/change).

PSCell is one of the secondary cells. PSCell represents a Primary SCell (Secondary Cell) and may be interpreted as an SCell corresponding to any of a plurality of scells.

In addition, the secondary cell may be replaced with a Secondary Node (SN), secondary Cell Group (SCG).

Further, in the wireless communication system 10, a conditional inter-SN PSCell change procedure may be supported. Specifically, MN-initiated conditional inter-SN PScell change and/or SN-initiated conditional inter-SN PScell change may be supported.

(2.1)eNB100A

Fig. 2 is a functional block configuration diagram of the eNB 100A. As shown in fig. 2, eNB 100A includes a radio communication unit 110, an RRC processing unit 120, a DC processing unit 130, and a control unit 140. Further, the gNB 100B is different in that it supports NR, but may have the same function as the eNB 100A.

The wireless communication unit 110 transmits a downlink signal (DL signal) according to LTE. Further, the wireless communication unit 110 receives an uplink signal (UL signal) according to LTE.

Further, the wireless communication section 110 performs assembly/disassembly of PDUs/SDUs in a plurality of layers (medium access control layer (MAC), radio link control layer (RLC), packet data convergence protocol layer (PDCP), and the like.

The RRC processing unit 120 performs various processes in a radio resource control layer (RRC). Specifically, the RRC processing unit 120 can transmit RRC Reconfiguration to the UE 200. The RRC processing unit 120 can receive RRC Reconfiguration Complete (RRC reconfiguration complete) from the UE 200, which is a response to RRC Reconfiguration.

In this embodiment, the eNB 100A supports LTE, but in this case, the name of the RRC message may be RRC Connection Reconfiguration (RRC connection reconfiguration), RRC Connection Reconfiguration Complete (RRC connection reconfiguration complete).

Furthermore, RRC Reconfiguration (and inter-MN-SN RRC message (inter-node RRC messages) may contain a reconfiguration wisync. Reconfiguration wisync, etc. in chapter 3GPP TS38.331 5.3.5.5.2, etc. in connection with the reconfiguration of the cell.

reconfiguration wishsync may be interpreted as a mechanism that is common to cells (NR cells) that are activated (i.e., additional NR cells) in a non-standalone (NSA) that includes other RATs (LTE, etc.). The UE 200 can perform a random access procedure (RA procedure) or the like according to the reconfigurationWithSync.

The DC processing section 130 performs processing related to dual connection, specifically, multi-RAT Dual Connectivity (MR-DC). In the present embodiment, since eNB 100A supports LTE and gNB 100B supports NR, DC processing unit 130 may perform processing related to E-UTRA-NR Dual Connectivity (EN-DC). As described above, the type of DC is not limited, and for example, NR-E-UTRA Dual Connectivity (NE-DC) or NR-NR Dual Connectivity (NR-DC) may be supported.

The DC processing unit 130 can transmit and receive a message specified in 3gpp ts37.340 and the like, and perform processing related to setting and release of DC between the eNB 100A, gNB B and the UE 200.

The control unit 140 controls each functional block constituting the eNB 100A. In particular, in the present embodiment, the control unit 140 performs control related to addition or change of the secondary cell (may be a secondary node).

Specifically, the control unit 140 can perform control related to activation/deactivation (active/de-active) of the Secondary Cell Group (SCG). Specifically, the control unit 140 may activate (may be referred to as activating) or deactivate (may be referred to as deactivating) SCG. More specifically, the control unit 140 may activate or deactivate one or more scells (may include PSCell, hereinafter the same) included in the SCG.

The activated SCG (SCell) may be interpreted as a state in which the UE 200 can immediately utilize the SCG (SCell). An inactive SCG (SCell) may be interpreted as a state in which the UE 200 cannot immediately utilize the SCG (SCell) but maintains the setting information.

In the present embodiment, the channels include control channels and data channels. The control channels include PDCCH (Physical Downlink Control Channel: physical downlink control channel), PUCCH (Physical Uplink Control Channel: physical uplink control channel), PRACH (Physical Random Access Channel: physical random access channel), PBCH (Physical Broadcast Channel: physical broadcast channel), and the like.

The data channel includes PDSCH (Physical Downlink Shared Channel: physical downlink shared channel), PUSCH (Physical Uplink Shared Channel: physical uplink shared channel), and the like.

The Reference signals include demodulation Reference signals (Demodulation Reference Signal: DMRS), sounding Reference signals (Sounding Reference Signal: SRS), phase tracking Reference signals (Phase Tracking Reference Signal: PTRS), channel state information Reference signals (Channel State Information-Reference Signal: CSI-RS), and the like, and the signals include channels and Reference signals. Further, the data may represent data transmitted via a data channel.

(2.2)UE 200

Fig. 3 is a functional block configuration diagram of the UE 200. As shown in fig. 3, the UE 200 includes a radio communication section 210, an RRC processing section 220, a DC processing section 230, and a control section 240.

The wireless communication unit 210 transmits an uplink signal (UL signal) according to LTE or NR. The wireless communication unit 210 receives a downlink signal (DL signal) according to LTE or NR.

That is, the UE 200 can access the eNB 100A (E-UTRAN 20) and the gNB 100B (NG RAN 30) and can support dual connectivity (specifically, EN-DC). Thus, the UE 200 can transmit and receive radio signals via the MCG or the SCG (specifically, via a cell included in the MCG or a cell included in the SCG (SCell including PSCell)). In the present embodiment, the wireless communication unit 210 may constitute a transmitting/receiving unit.

In addition, the radio communication unit 210 performs assembly/disassembly of PDU/SDU among MAC, RLC, PDCP, and the like, similarly to the radio communication unit 110 of the eNB 100A (gNB 100B).

The RRC processing unit 220 performs various processes in a radio resource control layer (RRC). Specifically, the RRC processing unit 220 can transmit and receive a message of the radio resource control layer.

The RRC processing section 220 can receive RRC Reconfiguration from a network, specifically, the E-UTRAN 20 (or NG RAN 30). The RRC processing unit 220 can send a response RRC Reconfiguration Complete to the network RRC Reconfiguration.

The DC processing section 230 performs processing related to dual connection, specifically, processing related to MR-DC. As described above, in the present embodiment, the DC processing unit 230 may perform the processing related to EN-DC, but may support NE-DC and/or NR-DC.

The DC processing unit 230 can access the eNB 100A and the gNB 100B, respectively, to perform settings in a plurality of layers including RRC (medium access control layer (MAC), radio link control layer (RLC), packet data convergence protocol layer (PDCP), and the like).

The DC processing section 230 can transmit a report on the deactivation of SCG. The report related to deactivation may be interpreted broadly, may include settings related to activation or deactivation of the SCG, explicit or implicit indications of the active or de-active status, transition to that status, etc.

The DC processing unit 230 may also transmit failure information of the SCG to the network. Specifically, the DC processing section 230 may transmit the SCG failure information message (SCG failure information message) (or a new RRC message) via the RRC processing section 220.

The control unit 240 controls each functional block constituting the UE 200. In particular, in the present embodiment, the control unit 240 can perform control related to activation/deactivation (active/de-active) of the Secondary Cell Group (SCG).

Specifically, the control unit 240 deactivates the SCG according to the state of the SCG. More specifically, in the SCG, when the timer associated with the resetting of the radio resource expires, the control unit 240 may deactivate the SCG. The timer related to the reset of radio resources may be interpreted as a timer related to the reset of RRC.

As a timer, T304, T310, or T312 specified in 3gpp ts38.331 may be the object. In case that these timers expire (expire) in the SCG, the control section 240 may deactivate the SCG.

The timer T304 may start when an rrcrecnonfiguration message including a reconfiguration wisync is received or when execution of a conditional reset is performed, that is, when an rrcrecnonfiguration message stored including a reconfiguration wisync is applied, and stop at normal completion of random access in the corresponding SpCell.

With respect to the timer T310, it is possible to start when a problem of the physical layer of the specific Cell (SpCell) is detected, that is, when a continuous out-of-sync instruction of N310 is received from a lower layer, when a continuous in-sync instruction of N311 is received from a lower layer of the SpCell, when rrcrecon configuration is received through a reconfigurationWithSync of the Cell group, when mobilityfrommrcommand is received, when a reconfiguration of rlf-timersandcon status, when a reestablishment procedure of a connection is started, when an MCG failure information procedure is started, and when SCG is released.

Regarding T312, when T312 is configured in the MCG, in the course of execution of T310 of the PCell, a measurement report of a measurement ID configured with T312 and "useT312" set to true is triggered, and when T312 is configured in the SCG and "useT312" set to true, in the course of execution of T310 of the PSCell, a measurement report of a measurement ID configured with T312 is triggered.

Further, T312 may stop when an N311 continuous synchronization instruction is received from a lower layer of the SpCell, when rrcrecondonconfiguration is received through the reconfigurationWithSync of the cell group and a connection re-establishment procedure is started, when rlf-timersandcon is reset, when an MCG failure information procedure is started, and when the validity period of T310 in the corresponding SpCell expires.

In addition, in case that a problem of the initial access procedure occurs, the control part 240 may deactivate the SCG. The initial access procedure may be interpreted as a procedure performed by the UE 200 in an idle state for connection with a cell included in the SCG, or may be a Random Access (RA) procedure.

Specifically, the control section 240 may deactivate the SCG in case a problem indication (random access problemindication) of the RA procedure (RACH transmission may also be) is provided from the MAC layer of the SCG.

The inactive state (deactivated state) of the SCG may be at least any one of the following states.

PUSCH is not transmitted in deactivated SCG.

In the PScell of the deactivated SCG, the PDCCH is not monitored.

Regarding scells within deactivated SCG, SCell dormancy is not supported.

The UE 200 maintains the DL synchronization state.

The UE 200 performs measurements related to the restricted radio resource management (Restricted RRM measurement).

Support mobility of PSCell (mobility).

UE 200 performs restricted Radio Link Monitoring (RLM), and/or does not perform beam management (beam failure detection and recovery), SRS (Sounding Reference Signal) transmission, CSI report (CSI report).

In addition, in the SCG, when the number of retransmissions related to radio link control reaches the maximum number, the control unit 240 may deactivate the SCG. Specifically, the control part 240 may deactivate the SCG in case an instruction to reach the maximum number of retransmissions is provided from the RLC layer of the SCG.

The control unit 240 may maintain the setting of the MAC layer when the SCG is deactivated. Specifically, the control unit 240 may deactivate the SCG, depending on the operation when the SCG fails, but may skip the resetting of the MAC of the SCG.

More specifically, when the SCG is deactivated, the control unit 240 may skip the operation of resetting the MAC of the SCG in the procedure of the Initiation of SCG failure information defined in chapter 3GPP TS38.3315.7.3.2, and may maintain the setting of the MAC of the SCG.

In addition, the control unit 240 may restart at least any one of the radio bearer in the SCG and the channel related to the radio link control when the deactivated SCG is reactivated.

Specifically, the control unit 240 maintains the setting of the MAC of the SCG, and thus can restart transmission in the SCG via Signalling Radio Bearer (SRB) and Data Radio Bearer (DRB). Further, the control part 240 may restart the Backhaul (BH) RLC channel in case that the RLC channel exists.

In addition, the BH RLC channel can be interpreted as an RLC channel composed of logical channels of RLC and IAB (Integrated Access and Backhaul) nodes.

(3) Operation of a wireless communication system

Next, an operation of the wireless communication system 10 will be described. Specifically, an operation related to activation/deactivation (active/de-active) of the Secondary Cell Group (SCG) will be described.

(3.1) outline of the action

Fig. 4 shows an example of communication timing related to deactivation and reactivation of SCGs. As shown in fig. 4, the UE 200 autonomously sets Autonomous SCG deactivation (autonomous SCG deactivation) to deactivate the SCG (step 1). Thus, the UE 200 can autonomously deactivate the SCG when a failure of the SCG (for example, a Radio Link Failure (RLF) of the SCG) occurs.

In addition, the purpose of autonomously deactivating SCG is that, in SCG, a higher frequency band (for example, 24.25GHz to 52.6GHz (FR 2) or 52.6GHz or more) is more likely to be used than MCG, and the propagation state of a radio signal (radio wave) is likely to become unstable. In the SCell in which the high frequency band is used, failure and recovery are likely to occur repeatedly, and in the case where the UE 200 cannot autonomously deactivate the SCG, communication related to activation/deactivation of the SCG of the network is required every time failure and recovery occur.

When the failure determination condition of the SCG is satisfied in the state where Autonomous SCG deactivation is set in this way, the UE 200 reports SCG failure information message to the network (steps 2, 3). The failure determination condition of the SCG may be based on the conditions specified in chapter 3GPP TS38.331 5.7.3.2 and chapter 5.7.3.3 (details will be described later).

The UE 200 may cause the SCG to migrate to the deactivation state if SCG failure information message is reported to the network (step 4). Further, the network can detect a failure of the SCG from the received SCG failure information message (step 5).

In addition, the UE 200 may send a report (including SCG failure information message) regarding the deactivation of the SCG (may be almost simultaneous) and cause the SCG to migrate to the inactive state, or may cause the SCG to migrate to the inactive state within a predetermined time after the migration.

Thereafter, the UE 200 detects recovery of SCG (step 6). Specifically, the UE 200 can detect that the failure determination condition satisfied in step 2 is not satisfied.

The UE 200 re-activates the SCG and causes the SCG to migrate (resume) to the activation state (step 7). The UE 200 may also autonomously perform such an action of reactivating the SCG. Such autonomous reactivation of the SCG may be referred to as UE autonomous reactivation (UE autonomous reactivation).

(3.2) working example 1

As described above, the UE 200 can autonomously deactivate SCG. In this operation example, an example of a condition in which the UE 200 autonomously deactivates the SCG will be described.

The UE 200 may autonomously deactivate the SCG if at least any one of the following conditions is satisfied.

Can't be according to RRC Reconfiguration (Inability to comply with RRC Reconfiguration)

Specifically, the UE 200 is shown in a case where it cannot rely on (part of) the settings included in the RRC Reconfiguration message received via the SRB (SRB 3: radio bearer for a specific RRC message in the MR-DC state). Inability to comply with RRC Reconfiguration is specified in chapter TS38.331 5.3.5.8.2.

Expiration of timer T304 in SCG

Occurrence of RLF in SCG

Specifically, at least one of the following conditions may be satisfied.

Expiration of timers T310 and/or T312 in SCG

Case where the MAC layer of the slave SCG is provided with a problem indication (random access problem indication) of the RA procedure

Specifically, there may be a case where there is a problem in RA for beam failure recovery.

The maximum number of RLC retransmissions of SCG

In case the UE 200 constitutes an IAB node, the case where there is an indication of BH RLF in the BAP (Backhaul Adaptation Protocol: backhaul adaptation protocol) entity of the SCG

In case of an indication of a consistent (existence) LBT (list-Before-Talk) failure from the MAC layer of the SCG

LBT may be interpreted as a mechanism that allows transmission for a predetermined time period or less only when it is confirmed that a channel is not used by another system in the vicinity by performing carrier sense (sensing) by a radio base station (e.g., eNB 100A), and may be applied to an unlicensed band usable by a specific communication carrier without requiring an administrative grant allocation. The procedure including such LBT may be referred to as a channel access procedure (channel access procedure).

In addition, in chapter 3GPP TS38.331 5.7.3.2 (Initiation of SCG failure information), there is also specified a case where there is an indication of failure of an Integrity check (SCG) from a lower layer of SCG concerning SRB3, but in the case where there is such an indication, the UE 200 may not autonomously deactivate the SCG. Failure of the integrity check means that there is a security problem and that it is not appropriate to autonomously deactivate the SCG.

(3.3) working example 2

In this operation example, the UE 200 may maintain the MAC of the SCG when autonomously deactivating the SCG. Specifically, the UE 200 may maintain the setting of the MAC layer of the SCG at that time when the SCG is deactivated.

Fig. 5 shows an example of operation when SCG failure occurs in the UE 200 compliant with the specifications of 3GPP Release-15, 16. As shown in fig. 5, in the Initiation process of SCG failure information, the MAC of the SCG is reset (refer to the underlined section).

Fig. 6 shows an example of operation in the case where the UE 200 according to operation 2 autonomously deactivates the SCG. The condition for autonomously deactivating SCG by the UE 200 may be according to the operation example 1 described above.

Specifically, the operation example of the UE 200 shown in fig. 6 may correspond to the Initiation procedure of SCG failure information defined in the chapter 38.331 5.7.3.2 of the GPP TS, but may be added as a procedure for autonomously deactivating the SCG.

As shown in fig. 6, when the SCG is autonomously deactivated, the UE 200 may operate as follows.

Transmission of SCG via SRB and DRB, and transmission suspension of BH RLC channel (in case of existence)

Stop of timer T304 (in the case of operation)

Transmission of SCG failure information

As shown in fig. 6, when autonomous SCG deactivation (autonomous SCG deactivation) is set, the UE 200 may operate as described above. In addition, autonomous SCG deactivation by the UE 200 may also be referred to as autonomous SCG deactivation based on UE triggers (UE triggered SCG deactivation).

Further, the UE 200 may restart (may also be referred to as activation) the SCG after autonomously performing deactivation. Fig. 7 shows an example of the operation of restarting the SCG after the autonomous deactivation by the UE 200 according to the operation example 2.

As shown in fig. 7, when the UE 200 receives an instruction from a lower layer (physical layer or the like) that the lower layer setting is active, the UE may restart the suspended transmission of SCG via SRB and DRB and BH RLC channel (when present).

The lower layer setting may be activated according to an instruction from the network, or may be activated according to an operation within the UE 200 other than an instruction from the network.

(4) Action and Effect

According to the above embodiment, the following operational effects can be obtained. Specifically, in the SCG, the UE 200 may deactivate the SCG in the case where a timer related to the resetting of radio resources expires or in the case where a problem of an initial access procedure occurs. Further, in case of deactivating the SCG, the UE 200 may maintain the setting of the MAC layer.

Accordingly, the UE 200 can appropriately perform autonomous deactivation of the SCG accompanying the failure of the SCG while coping with rapid reactivation of the SCG (autonomous SCG deactivation). Further, since the MAC of the SCG is maintained, rapid reactivation is enabled.

In the present embodiment, when the number of retransmissions related to Radio Link Control (RLC) reaches the maximum number in the SCG, the UE 200 may deactivate the SCG. Accordingly, autonomous deactivation of SCG considering the state of RLC can be appropriately performed.

In the present embodiment, when the deactivated SCG is reactivated, the UE 200 may restart at least one of the radio bearer in the SCG and the channel (BH RLC channel) related to radio link control. As described above, even when the SCG is deactivated, the UE 200 can maintain the MAC of the SCG, and thus can perform rapid reactivation of the SCG by restarting the radio bearer and the channel.

(5) Other embodiments

The embodiments have been described above, but it is obvious to those skilled in the art that various modifications and improvements can be made without limiting the description of the embodiments.

For example, in the above embodiment, the description was given taking EN-DC in which MN is eNB and SN is gNB as an example, but as described above, other DCs may be used. Specifically, it may be NR-DC where MN is gNB and SN is gNB, or NE-DC where MN is gNB and SN is eNB.

The term "deactivation" of SCG may be replaced with another term having the same meaning, for example, the term "deactivation" or "sleep" may be replaced with the term "deactivation".

The block diagrams (fig. 2 and 3) used in the description of the above embodiments show blocks in units of functions. These functional blocks (structures) are realized by any combination of at least one of hardware and software. The implementation method of each functional block is not particularly limited. That is, each functional block may be realized by using one device physically or logically combined, or may be realized by directly or indirectly (for example, by using a wire, a wireless, or the like) connecting two or more devices physically or logically separated from each other, and using these plural devices. The functional blocks may also be implemented by combining software with the above-described device or devices.

Functionally, there are judgment, decision, judgment, calculation, processing, derivation, investigation, search, confirmation, reception, transmission, output, access, resolution, selection, establishment, comparison, assumption, expectation, view, broadcast (broadcasting), notification (notification), communication (communication), forwarding (forwarding), configuration (reconfiguration), reconfiguration (allocating, mapping), assignment (assignment), and the like, but not limited thereto. For example, a functional block (configuration unit) that causes transmission to function is referred to as a transmitter (transmitting unit) or a transmitter (transmitter). In short, the implementation method is not particularly limited as described above.

The eNB 100A, gNB B and the UE 200 (the apparatus) described above may also function as a computer that performs the processing of the wireless communication method of the present disclosure. Fig. 8 is a diagram showing an example of a hardware configuration of the apparatus. As shown in fig. 8, the device may be configured as a computer device including a processor 1001, a memory 1002 (memory), a storage 1003 (storage), a communication device 1004, an input device 1005, an output device 1006, a bus 1007, and the like.

In addition, in the following description, the term "means" may be replaced with "circuit", "device", "unit", or the like. The hardware configuration of the apparatus may be configured to include one or more of the illustrated apparatuses, or may be configured to include no part of the apparatus.

The functional blocks of the apparatus (see fig. 2 and 3) are realized by any hardware elements or a combination of the hardware elements of the computer apparatus.

In addition, each function in the device is realized by the following method: predetermined software (program) is read into hardware such as the processor 1001 and the memory 1002, and the processor 1001 performs an operation to control communication by the communication device 1004 or to control at least one of reading and writing of data in the memory 1002 and the memory 1003.

The processor 1001 controls the entire computer by, for example, operating an operating system. The processor 1001 may be configured by a Central Processing Unit (CPU) including an interface with peripheral devices, a control device, an arithmetic device, a register, and the like.

Further, the processor 1001 reads out a program (program code), a software module, data, or the like from at least one of the memory 1003 and the communication device 1004 to the memory 1002, and executes various processes accordingly. As the program, a program that causes a computer to execute at least a part of the operations described in the above embodiments is used. 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. The processor 1001 may also be installed by more than one chip. In addition, the program may also be transmitted from the network via a telecommunication line.

The Memory 1002 is a computer-readable recording medium, and may be configured by at least one of a Read Only Memory (ROM), an erasable programmable ROM (Erasable Programmable ROM: EPROM), an electrically erasable programmable ROM (Electrically Erasable Programmable ROM: EEPROM), a random access Memory (Random Access Memory: RAM), and the like. The memory 1002 may also be referred to as a register, a cache, a main memory (main storage), or the like. The memory 1002 can store programs (program codes), software modules, and the like capable of executing the methods according to one embodiment of the present disclosure.

The memory 1003 is a computer-readable recording medium, and may be configured of at least one of an optical disk such as a CD-ROM (Compact Disc ROM), a hard disk drive, a Floppy disk, a magneto-optical disk (for example, a compact disk, a digital versatile disk, a Blu-ray (registered trademark) disk, a smart card, a flash memory (for example, a card, a stick, a Key drive), a flowpy (registered trademark) disk, a magnetic stripe, and the like), for example.

The communication device 1004 is hardware (transceiver) for performing communication between computers via at least one of a wired network and a wireless network, and may be referred to as a network device, a network controller, a network card, a communication module, or the like, for example.

The communication device 1004 may be configured to include a high-frequency switch, a duplexer, a filter, a frequency synthesizer, and the like, for example, in order to realize at least one of frequency division duplexing (Frequency Division Duplex: FDD) and time division duplexing (Time Division Duplex: TDD).

The input device 1005 is an input apparatus (for example, a keyboard, a mouse, a microphone, a switch, a key, a sensor, or the like) that receives an input from the outside. The output device 1006 is an output apparatus (for example, a display, a speaker, an LED lamp, or the like) that performs output to the outside. The input device 1005 and the output device 1006 may be integrally formed (for example, a touch panel).

The processor 1001 and the memory 1002 are connected by a bus 1007 for communicating information. The bus 1007 may be configured using a single bus or may be configured using a different bus for each device.

The device may be configured to include hardware such as a microprocessor, a digital signal processor (Digital Signal Processor: DSP), an application specific integrated circuit (Application Specific Integrated Circuit: ASIC), a programmable logic device (Programmable Logic Device: PLD), a field programmable gate array (Field Programmable Gate Array: FPGA), or the like, and part or all of the functional blocks may be realized by the hardware. For example, the processor 1001 may also be installed using at least one of these hardware.

Further, the notification of the information is not limited to the form/embodiment described in the present disclosure, and may be performed using other methods. For example, the notification of the information may be implemented by physical layer signaling (e.g., downlink control information (Downlink Control Information: DCI), uplink control information (Uplink Control Information: UCI)), higher layer signaling (e.g., RRC signaling, medium access control (Medium Access Control: MAC) signaling, broadcast information (master information block (Master Information Block: MIB), system information block (System Information Block: SIB)), other signals, or a combination thereof.

The various forms/embodiments described in the present disclosure may also be applied to at least one of long term evolution (Long Term Evolution: LTE), LTE-Advanced (LTE-a), upper 3G, IMT-Advanced, fourth generation mobile communication system (4th generation mobile communication system:4G), fifth generation mobile communication system (5th generation mobile communication system:5G), future wireless access (Future Radio Access: FRA), new air interface (New Radio: NR), W-CDMA (registered trademark), GSM (registered trademark), CDMA 2000, ultra mobile broadband (Ultra Mobile Broadband: UMB), IEEE 802.11 (Wi-Fi (registered trademark)), IEEE 802.16 (WiMAX (registered trademark)), IEEE 802.20, UWB (Ultra-wide), bluetooth (registered trademark), systems using other suitable systems, and next generation systems extended accordingly. Further, a plurality of systems (for example, a combination of 5G and at least one of LTE and LTE-a) may be applied in combination.

The processing procedure, sequence, flow, and the like of each form/embodiment described in the present disclosure can be replaced without contradiction. For example, for the methods described in this disclosure, elements of the various steps are presented using an illustrated order, but are not limited to the particular order presented.

The specific actions performed by the base station in the present disclosure are sometimes performed by its upper node (upper node) according to circumstances. In a network comprising one or more network nodes (network nodes) having a base station, it is apparent that various operations performed for communication with a terminal may be performed by the base station and at least one of the other network nodes (for example, MME or S-GW, etc. are considered but not limited thereto) other than the base station. In the above, the case where one other network node other than the base station is illustrated, but the other network node may be a combination of a plurality of other network nodes (for example, MME and S-GW).

Information, signals (information, etc.) can be output from a higher layer (or lower layer) to a lower layer (or higher layer). Or may be input or output via a plurality of network nodes.

The input or output information may be stored in a specific location (e.g., a memory), or may be managed using a management table. The input or output information may be overwritten, updated or recorded. The outputted information may also be deleted. The entered information may also be sent to other devices.

The determination may be performed by a value (0 or 1) represented by 1 bit, may be performed by a Boolean value (true or false), or may be performed by a comparison of values (e.g., a comparison with a predetermined value).

The various forms and embodiments described in this disclosure may be used alone, in combination, or switched depending on the implementation. Note that the notification of the predetermined information is not limited to being performed explicitly (for example, notification of "yes" or "X"), and may be performed implicitly (for example, notification of the predetermined information is not performed).

With respect to software, whether referred to as software, firmware, middleware, microcode, hardware description language, or by other names, should be broadly interpreted to refer to a command, a set of commands, code, a code segment, program code, a program (program), a subroutine, a software module, an application, a software package, a routine, a subroutine, an object, an executable, a thread of execution, a procedure, a function, or the like.

In addition, software, commands, information, etc. may be transmitted and received via a transmission medium. For example, in the case where software is transmitted from a web page, server, or other remote source using at least one of a wired technology (coaxial cable, fiber optic cable, twisted pair, digital subscriber line (Digital Subscriber Line: DSL), etc.) and a wireless technology (infrared, microwave, etc.), at least one of the wired and wireless technologies is included within the definition of transmission medium.

Information, signals, etc. described in this disclosure may also be represented using any of a variety of different technologies. For example, data, commands, instructions (commands), information, signals, bits, symbols, chips (chips), and the like may be referenced throughout the above description by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or photons, or any combination thereof.

In addition, the terms described 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 the channel and the symbol may be a signal (signaling). In addition, the signal may also be a message. In addition, the component carrier (Component Carrier: CC) may be referred to as a carrier frequency, a cell, a frequency carrier, etc.

The terms "system" and "network" as used in this disclosure may be used interchangeably.

In addition, information, parameters, and the like described in this disclosure may be expressed using absolute values, relative values to predetermined values, or other information corresponding thereto. For example, radio resources may also be indicated by an index.

The names used for the above parameters are non-limiting in any respect. Further, the numerical formulas and the like using these parameters may also be different from those explicitly disclosed in the present disclosure. The various channels (e.g., PUCCH, PDCCH, etc.) and information elements may be identified by appropriate names, and thus the various names assigned to these various channels and information elements are not limiting in any respect.

In the present disclosure, terms such as "Base Station (BS)", "radio Base Station", "fixed Station", "NodeB", "eNodeB (eNB)", "gndeb (gNB)", "access point", "transmission point (transmission point)", "reception point", "transmission point (transmission/reception point)", "cell", "sector", "cell group", "carrier", "component carrier", and the like may be used interchangeably. A base station is also sometimes referred to as a macrocell, a microcell, a femtocell, a picocell, or the like.

A base station can accommodate one or more (e.g., three) cells (also referred to as sectors). In the case of a base station accommodating multiple cells, the coverage area of the base station can be divided into multiple smaller areas, each of which can also provide communication services through a base station subsystem (e.g., a small base station (Remote Radio Head (remote radio head): RRH) for indoor use).

The term "cell" or "sector" refers to a part or the whole of a coverage area of at least one of a base station and a base station subsystem that perform communication services within the coverage area.

In the present disclosure, terms such as "Mobile Station (MS)", "User terminal (UE)", "User Equipment (UE)", and "terminal" may be used interchangeably.

For mobile stations, those skilled in the art are sometimes referred to by the following terms: a subscriber station, mobile unit (mobile unit), subscriber unit, wireless unit, remote unit, mobile device, wireless communication device, remote device, mobile subscriber station, access terminal, mobile terminal, wireless terminal, remote terminal, handset, user agent, mobile client, or some other suitable terminology.

At least one of the base station and the mobile station may be referred to as a transmitting apparatus, a receiving apparatus, a communication apparatus, 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 mobile body may be a vehicle (e.g., an automobile, an airplane, etc.), a mobile body that moves unmanned (e.g., an unmanned aerial vehicle, an autopilot, etc.), or a robot (manned or unmanned). At least one of the base station and the mobile station also includes a device that does not necessarily move during a communication operation. For example, at least one of the base station and the mobile station may be an internet of things (Internet of Things: ioT) device of a sensor or the like.

In addition, the base station in the present disclosure may be replaced with a mobile station (user terminal, the same applies hereinafter). For example, various forms/embodiments of the present disclosure may also be applied with respect to a structure in which communication between a base station and a mobile station is replaced with communication between a plurality of mobile stations (for example, may also be referred to as Device-to-Device (D2D), vehicle-to-Everything (V2X), or the like). In this case, the mobile station may have a function of the base station. The terms "uplink" and "downlink" may be replaced with terms (e.g., "side") corresponding to the inter-terminal communication. For example, the uplink channel, the downlink channel, and the like may be replaced with side channels.

Likewise, the mobile station in the present disclosure may be replaced with a base station. In this case, the base station may have a function of the mobile station.

A radio frame may be made up of one or more frames in the time domain. In the time domain, one or more of the frames may be referred to as subframes. A subframe may be composed of one or more slots in the time domain. A subframe may be a fixed length of time (e.g., 1 ms) independent of a parameter set (numerology).

The parameter set may be a communication parameter applied to at least one of transmission and reception of a certain signal or channel. The parameter set may represent, for example, at least one of subcarrier spacing (SubCarrier Spacing: SCS), bandwidth, symbol length, cyclic prefix length, transmission time interval (Transmission Time Interval: TTI), number of symbols per TTI, radio frame structure, specific filtering process performed by the transceiver in the frequency domain, specific windowing process performed by the transceiver in the time domain, and the like.

A slot may be formed in the time domain from one or more symbols (orthogonal frequency division multiplexing (Orthogonal Frequency Division Multiplexing: OFDM) symbols, single carrier frequency division multiple access (Single Carrier Frequency Division Multiple Access: SC-FDMA) symbols, etc.). A slot may be a unit of time based on a set of parameters.

A slot may contain multiple mini-slots. Each mini-slot may be made up of one or more symbols in the time domain. In addition, the mini-slots may also be referred to as sub-slots. Mini-slots may be made up of a fewer number of symbols than slots. PDSCH (or PUSCH) transmitted in units of time greater than the mini-slot may be referred to as PDSCH (or PUSCH) mapping type (type) a. PDSCH (or PUSCH) transmitted using mini-slots may be referred to as PDSCH (or PUSCH) mapping type (type) B.

The radio frame, subframe, slot, mini-slot, and symbol each represent a unit of time when a signal is transmitted. The radio frame, subframe, slot, mini-slot, and symbol may each use corresponding other designations.

For example, 1 subframe may be referred to as a Transmission Time Interval (TTI), a plurality of consecutive subframes may also be referred to as a TTI, and 1 slot or 1 mini slot may also be referred to as a TTI. That is, at least one of the subframe and the TTI may be a subframe (1 ms) in the conventional LTE, may be a period (e.g., 1-13 symbols) shorter than 1ms, or may be a period longer than 1 ms. In addition, the unit indicating the TTI may be not a subframe but a slot, a mini slot, or the like.

Here, TTI refers to, for example, a scheduled minimum time unit in wireless communication. For example, in the LTE system, a base station performs scheduling for allocating radio resources (bandwidth, transmission power, and the like that can be used for each user terminal) to each user terminal in TTI units. In addition, the definition of TTI is not limited thereto.

The TTI may be a transmission time unit of a data packet (transport block), a code block, a codeword, or the like after channel coding, or may be a processing unit such as scheduling or link adaptation. In addition, when a TTI is given, a time interval (for example, the number of symbols) in which a transport block, a code block, a codeword, or the like is actually mapped may be shorter than the TTI.

In addition, in the case where 1 slot or 1 mini slot is referred to as a TTI, more than one TTI (i.e., more than one slot or more than one mini slot) may constitute a minimum time unit of scheduling. Further, the number of slots (mini-slots) constituting the minimum time unit of the schedule can be controlled.

TTIs with a time length of 1ms are also referred to as normal TTIs (TTIs in LTE rel.8-12), normal TTI (normal TTI), long TTIs (long TTIs), normal subframes (normal subframes), long (long) subframes, time slots, etc. A TTI that is shorter than a normal TTI may be referred to as a shortened TTI, a short TTI (short TTI), a partial or fractional TTI, a shortened subframe, a short (short) subframe, a mini-slot, a sub-slot, a slot, etc.

In addition, for long TTIs (long TTIs) (e.g., normal TTIs, subframes, etc.), a TTI having a time length exceeding 1ms may be substituted, and for short TTI (short TTI) (e.g., shortened TTI, etc.), a TTI having a TTI length less than the long TTI (long TTI) and having a TTI length greater than 1ms may be substituted.

A Resource Block (RB) is a resource allocation unit of a time domain and a frequency domain, in which one or more consecutive subcarriers (subcarriers) may be included. The number of subcarriers contained in the RB may be the same regardless of the parameter set, for example, 12. The number of subcarriers included in the RB may also be determined according to the parameter set.

Further, the time domain of the RB may contain one or more symbols, which may be 1 slot, 1 mini slot, 1 subframe, or 1TTI in length. A 1TTI, a 1 subframe, etc. may each be composed of one or more resource blocks.

In addition, one or more RBs may be referred to as Physical Resource Blocks (PRBs), subcarrier groups (Sub-Carrier groups: SCGs), resource element groups (Resource Element Group: REGs), PRB pairs, RB peering.

Furthermore, a Resource block may be composed of one or more Resource Elements (REs). For example, 1RE may be a radio resource region of 1 subcarrier and 1 symbol.

The Bandwidth Part (Bandwidth Part: BWP) (also referred to as partial Bandwidth, etc.) represents a subset of consecutive common RBs (common resource blocks: common resource blocks) for a certain parameter set in a certain carrier. Here, the common RB may be determined by an index of the RB with reference to a common reference point of the carrier. PRBs are defined in a certain BWP and are numbered within the BWP.

BWP may include BWP for UL (UL BWP) and BWP for DL (DL BWP). One or more BWP may be set for the UE within the 1 carrier.

At least one of the set BWP may be active, and a case where the UE transmits and receives a predetermined signal/channel outside the active BWP may not be envisaged. In addition, "cell", "carrier", etc. in the present disclosure may be replaced with "BWP".

The above-described structure of the radio frame, subframe, slot, mini-slot, symbol, etc. is merely an example. For example, the number of subframes included in a radio frame, the number of slots per subframe or radio frame, the number of mini-slots included in a slot, the number of symbols and RBs included in a slot or mini-slot, the number of subcarriers included in an RB, the number of symbols in a TTI, the symbol length, the Cyclic Prefix (CP) length, and the like may be variously changed.

The terms "connected," "coupled," or any variation of these terms are intended to refer to any direct or indirect connection or coupling between two or more elements, including the case where one or more intervening elements may be present between two elements that are "connected" or "coupled" to each other. The combination or connection of the elements may be physical, logical, or a combination of these. For example, "connection" may be replaced with "Access". As used in this disclosure, it is considered that for two elements, the interconnection "or" bonding "is made by using at least one of one or more wires, cables, and printed electrical connections, and as some non-limiting and non-inclusive examples, by using electromagnetic energy or the like having wavelengths in the wireless frequency domain, the microwave region, and the optical (including both visible and invisible) region.

The Reference Signal may be simply referred to as Reference Signal (RS) or Pilot (Pilot) depending on the applied standard.

As used in this disclosure, the recitation of "according to" is not intended to mean "according to" unless explicitly recited otherwise. In other words, the term "according to" means "according to only" and "according to at least" both.

The "unit" in the structure of each device described above may be replaced with "part", "circuit", "device", or the like.

Any reference to elements using references such as "first," "second," etc. used in this disclosure, is not intended to limit the number or order of such elements in its entirety. These designations are used in this disclosure as a convenient way of distinguishing between two or more elements. Thus, references to first and second elements do not indicate that only two elements can be taken herein or that in any aspect the first element must precede the second element.

Where the terms "include", "comprising" and variations thereof are used in this disclosure, these terms are intended to be inclusive in the same sense as the term "comprising". Also, the term "or" as used in this disclosure means not exclusive or.

In the present disclosure, for example, where an article is added by translation as in a, an, and the in english, the present disclosure also includes a case where a noun following the article is in plural.

The terms "determining" and "determining" used in the present disclosure may include various operations. The "judgment" and "decision" may include, for example, a matter in which judgment (determination), calculation (calculation), calculation (processing), derivation (development), investigation (investigation), search (registration up) (for example, search in a table, database, or other data structure), confirmation (evaluation), or the like are regarded as a matter in which "judgment" and "decision" are performed. Further, "determining" or "deciding" may include a matter that a reception (e.g., reception of information), transmission (e.g., transmission of information), input (input), output (output), access (e.g., access of data in a memory) is performed as "determining" or "deciding" or the like. Further, "judging" and "deciding" may include matters of solving (resolving), selecting (selecting), selecting (setting), establishing (establishing), comparing (comparing), and the like as matters of "judging" and "deciding". That is, the terms "determine" and "determining" may include terms that "determine" and "determine" any action. The "judgment (decision)" may be replaced by "assumption", "expectation", "consider", or the like.

In the present disclosure, the term "a and B are different" may also mean that "a and B are different from each other". The term "a and B are different from C" may also be used. The terms "separate," coupled, "and the like may also be construed as" different.

The present disclosure has been described in detail above, but it should be 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 can be implemented as modifications and variations without departing from the spirit and scope of the present disclosure as defined by the claims. Accordingly, the description of the present disclosure is intended to be illustrative, and not in any limiting sense

Description of the reference numerals:

10. wireless communication system

20 E-UTRAN

30 NG RAN

40 UPF

100A eNB

100B gNB

110. Wireless communication unit

120 RRC processing part

130 DC processing unit

140. Control unit

200 UE

210. Wireless communication unit

220 RRC processing part

230 DC processing unit

240. Control unit

1001. Processor and method for controlling the same

1002. Memory

1003. Memory device

1004. Communication device

1005. Input device

1006. Output device

1007. Bus line

Claims (6)

1. A terminal, wherein the terminal has:

a transmitting/receiving unit that transmits/receives a radio signal via a secondary cell group; and

a control unit that deactivates the secondary cell group according to the state of the secondary cell group,

The control unit deactivates the secondary cell group when a timer associated with resetting of radio resources expires or when a problem of an initial access procedure occurs in the secondary cell group.

2. The terminal of claim 1, wherein,

the control unit deactivates the secondary cell group when the number of retransmissions for radio link control reaches a maximum number in the secondary cell group.

3. A terminal, wherein the terminal has:

a transmitting/receiving unit that transmits/receives a radio signal via a secondary cell group; and

a control unit that deactivates the secondary cell group according to the state of the secondary cell group,

the control unit maintains the setting of the medium access control layer when the secondary cell group is deactivated.

4. The terminal of claim 3, wherein,

the control unit restarts at least one of a radio bearer in the secondary cell group and a channel related to radio link control when the secondary cell group after being deactivated is reactivated.

5. A wireless communication method, wherein the wireless communication method comprises the steps of:

The terminal receives and transmits wireless signals through the secondary cell group; and

the terminal deactivates the secondary cell group according to the state of the secondary cell group,

in the step of deactivating, the secondary cell group is deactivated when a timer associated with resetting of radio resources expires or when a problem of an initial access procedure occurs in the secondary cell group.

6. A wireless communication method, wherein the wireless communication method comprises the steps of:

the terminal receives and transmits wireless signals through the secondary cell group; and

the terminal deactivates the secondary cell group according to the state of the secondary cell group,

in the deactivating step, when the secondary cell group is deactivated, setting of a medium access control layer is maintained.