Terminal device, method, and integrated circuit

Abstract

To provide a serving cell change technique performed by a terminal device that can efficiently perform communication control.SOLUTION: A terminal device UE includes processing units that include a physical layer processing unit, a MAC layer processing unit, an RLC layer processing unit, a PDCP layer processing unit, an SDAP processing unit, an RRC layer processing unit, and an NAS layer processing unit, and communicates with a base station device. When the RRC processing unit receives an instruction from a lower layer (Layer 1 / Layer 2) of a cell group to change a serving cell to a candidate cell, the RRC processing unit determines whether or not to reset a MAC entity during the serving cell change based on the setting of supplementary cells it holds. If the RRC processing unit determines that the MAC entity should be reset during the serving cell change, it resets the MAC entity of the cell group. If the RRC processing unit determines that the MAC entity should not be reset during the serving cell change, it does not reset the MAC entity of the cell group.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a terminal device, a method, and an integrated circuit. [Background technology]

[0002] The 3G Partnership Project, a standardization project for cellular mobile communication systems, In the 3rd Generation Partnership Project (3GPP), Technical studies and standardization of cellular mobile communication systems, including services, are currently underway.

[0003] For example, 3GPP has begun technical studies and standardization of E-UTRA (Evolved Universal Terrestrial Radio Access) as a radio access technology (RAT) for 3.9G and 4G cellular mobile communication systems. 3GPP is currently conducting technical studies and standardization of E-UTRA extension technologies. E-UTRA is also called Long Term Evolution (LTE: registered trademark), and the extension technologies are sometimes called LTE-Advanced (LTE-A) and LTE-Advanced Pro (LTE-A Pro).

[0004] In addition, 3GPP has begun technical studies and standardization of NR (New Radio, or NR Radio access) as a radio access technology (RAT) for cellular mobile communication systems for the 5th generation (5G). Technical studies and standard development are underway. [Prior art documents] [Non-patent literature]

[0005]

Non-licensed literature 1

Non-licensed Document 4

Non-licensed Document 5

Non-licensed Document 6

Non-licensed Document 7

[0006] As an extension technology of NR, there is a serving cell change technology that allows a terminal device to move from the coverage area of ​​one cell to the coverage area of ​​another cell. This serving cell change is triggered by measurements in Layer 3 (also called RRC) and Synchronized reconfiguration for cell change is triggered by RRC signaling. Compared to RRC signaling, Layer 1 or Layer 2 signaling has low latency and overhead. This has the advantage that there is no need to change the serving cell. Therefore, studies have begun on a serving cell change technique triggered by layer 1 or layer 2 signaling (layer 1 / layer 2 mobility optimization (L1 / L2 mobility enhancement) technique).

[0007] Non-Patent Document 7 is an RRC specification that was released before the study of Layer 1 / Layer 2 mobility optimization technology began. However, there remains a problem that unnecessary delays occur due to certain processing when triggering a serving cell change by Layer 1 or Layer 2 signaling.

[0008] One aspect of the present invention has been made in consideration of the above-mentioned circumstances, and one of its objects is to provide a terminal device, a base station device, a communication method, and an integrated circuit that can efficiently perform communication control. [Means for solving the problem]

[0009] In order to achieve the above object, one aspect of the present invention provides the following means: That is, one aspect of the present invention provides a terminal device that communicates with a base station device, the terminal device comprising: an RRC processing unit; When a lower layer (layer 1 / layer 2) of a cell group instructs a serving cell change to a candidate cell, the RRC processing unit determines whether to reset a MAC entity when the serving cell is changed based on the setting of the candidate cell stored in the RRC processing unit. and if it is determined that the MAC entity is to be reset when the serving cell is changed, In this case, the RRC processing unit resets the MAC entity of the cell group, and when it is determined not to reset the MAC entity when the serving cell is changed, the RRC processing unit does not reset the MAC entity of the cell group.

[0010] Another aspect of the present invention is a method for a terminal device communicating with a base station device, wherein, when an RRC entity of the terminal device is instructed by a lower layer (layer 1 / layer 2) of a certain cell group to change a serving cell to a candidate cell, the RRC entity resets a MAC entity at the time of the serving cell change based on a configuration of the candidate cell stored by the RRC entity. determining whether to reset a MAC entity when the serving cell is changed; resetting a MAC entity of the cell group when determining to set the MAC entity; and resetting a MAC entity when the serving cell is changed. and if it is determined that the RRC entity does not reset the MAC entity of the cell group, the RRC entity does not reset the MAC entity of the cell group.

[0011] Another aspect of the present invention is an integrated circuit implemented in a terminal device that communicates with a base station device, wherein, when an RRC entity of the terminal device is instructed by a lower layer (layer 1 / layer 2) of a certain cell group to change a serving cell to a candidate cell, the RRC entity performs a MAC entity change based on a configuration of the candidate cell stored in the RRC entity when the serving cell is changed. A function to determine whether to reset the MAC entity when changing the serving cell. The RRC entity has a function of resetting a MAC entity of the cell group when it determines to reset the MAC entity of the cell group, and a function of resetting a MAC entity when the serving cell is changed. If it is determined not to reset, the RRC entity performs the function of not resetting the MAC entity of the cell group.

[0012] These comprehensive or specific aspects may be realized as a system, an apparatus, a method, an integrated circuit, a computer program, or a recording medium, or may be realized as any combination of a system, an apparatus, a method, an integrated circuit, a computer program, and a recording medium. [Effects of the Invention]

[0013] According to one aspect of the present invention, a terminal device, a method, and an integrated circuit are provided for efficient communication control processing. This can be achieved. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a schematic diagram of a communication system according to an embodiment of the present invention. [Figure 2] FIG. 2 is a diagram illustrating an example of an E-UTRA protocol configuration according to the present embodiment. [Figure 3] FIG. 1 is a diagram illustrating an example of an NR protocol configuration according to this embodiment. [Figure 4] FIG. 10 is a diagram showing an example of a flow of procedures for various settings in RRC according to the present embodiment. [Figure 5]FIG. 2 is a block diagram showing the configuration of a terminal device according to the embodiment. [Figure 6] FIG. 2 is a block diagram showing the configuration of a base station device according to the present embodiment. [Figure 7] An example of an ASN.1 description included in a message regarding re-establishment of an RRC connection in NR in this embodiment. [Figure 8] 10 is an example of an ASN.1 description included in a message related to re-establishment of an RRC connection in E-UTRA in this embodiment. [Figure 9] 10 is an example of an ASN.1 description included in a serving cell common setting in this embodiment. [Figure 10] 10 shows an example of processing of a terminal device in this embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, this embodiment will be described in detail with reference to the drawings.

[0016] LTE (and LTE-A, LTE-A Pro) and NR may be defined as different radio access technologies (RATs), and NR may be defined as a technology included in LTE. LTE may also be defined as a technology included in NR. LTE that can connect to NR via Multi-Radio Dual Connectivity (MR-DC) may be distinguished from conventional LTE. LTE that uses 5GC for the core network (Core Network: CN) may be distinguished from conventional LTE that uses EPC for the core network. Conventional LTE refers to technology standardized in 3GPP Release 15 or later. This embodiment may refer to LTE that does not implement the technology. This embodiment is applicable to NR, LTE, and other RATs. In the following description, terms related to LTE and NR are used, but in this embodiment The above embodiment may be applied to other technologies using other terminology. Furthermore, the term E-UTRA in this embodiment may be replaced with the term LTE, and the term LTE may be replaced with the term E-UTRA.

[0017] In this embodiment, the names of the nodes and entities and the processes performed by the nodes and entities are described when the radio access technology is E-UTRA or NR, but this embodiment may be used for other radio access technologies. The names of the nodes and entities in this embodiment may be different names.

[0018] Fig. 1 is a schematic diagram of a communication system according to this embodiment. Note that the functions of each node, radio access technology, core network, interface, etc. described using Fig. 1 are only some of the functions closely related to this embodiment, and the system may have other functions.

[0019] E-UTRA 100 may be a radio access technology. The air interface between the UE 122 and the eNB 102 may be referred to as the Uu interface. The eNB (E-UTRAN Node B) 102 is the base station of the E-UTRA 100. The eNB 102 may be a base station device. The eNB 102 may have the E-UTRA protocol, which will be described later. The E-UTRA protocol includes an E-UTRA User Plane (UP) protocol, which will be described later, and an E-UTRA control protocol, which will be described later. The eNB 102 may be configured with a Control Plane (CP) protocol for the UE 122. However, the eNB may terminate the E-UTRA User Plane (UP) protocol and the E-UTRA Control Plane (CP) protocol. A radio access network made up of eNBs may be called E-UTRAN.

[0020] The EPC (Evolved Packet Core) 104 may be a core network. The interface 112 is an interface between the eNB 102 and the EPC 104, and may be referred to as an S1 interface. The interface 112 may include a control plane interface through which control signals pass and / or a user plane interface through which user data passes. The control plane interface of interface 112 may terminate at a Mobility Management Entity (MME; not shown) in EPC 104. The user plane interface of interface 112 may terminate at a service management entity (MME; not shown) in EPC 104. The control plane interface of interface 112 may be referred to as the S1-MME interface. The interface may be called the S1-U interface.

[0021] Note that one or more eNBs 102 may be connected to the EPC 104 via an interface 112. An interface (not shown) may exist between the multiple eNBs 102 connected to the EPC 104. The interface between the multiple eNBs 102 connected to the EPC 104 may be referred to as an X2 interface.

[0022] NR 106 may be a radio access technology. NR 106 may also be an air interface between UE 122 and gNB 108. The air interface between the UE 122 and the gNB 108 may be referred to as a Uu interface. The gNB (g Node B) 108 may be a base station device of the NR 106. The gNB 108 may have the NR protocol described below. The NR protocol includes the NR User Plane (UP) protocol described below and the NR Control Plane (CP) protocol described below. The gNB 108 may terminate NR user plane (UP) protocols and NR control plane (CP) protocols for the UE 122.

[0023] The 5GC 110 may be a core network. The interface 116 is an interface between the gNB 108 and the 5GC 110. The interface 116 may be a control plane interface through which control signals pass, and / or a user plane interface through which user data pass. There may be a control plane interface for the interface 116. may terminate in the Access and Mobility Management Function (AMF: not shown) in the 5GC110. The user plane interface of the interface 116 may be terminated by a User Plane Function (UPF: not shown) in the 5GC 110. The user plane interface of the interface 116 is called the NG-U It can be called an interface.

[0024] Note that one or more gNBs 108 may be connected to 5GC 110 via interface 116. An interface (not shown) may exist between multiple gNBs 108 connected to 5GC 110. The interface between multiple gNBs 108 connected to 5GC 110 may be referred to as an Xn interface.

[0025] The eNB 102 may have a function to connect to the 5GC 110. The eNB 102 having a function to connect to the 5GC 110 may be called an ng-eNB. The interface 114 is an interface between the eNB 102 and the 5GC 110, and is an NG The interface 114 may be referred to as a control plane through which control signals pass. There is a user plane interface through which user data passes. The control plane interface of interface 114 may terminate at an AMF in 5GC 110. The user plane interface of interface 114 may terminate at a UPF in 5GC 110. The control plane interface of interface 114 may be referred to as the NG-C interface. The user plane interface of interface 114 may be called the NG-U interface. A radio access network consisting of ng-eNB or gNB may be referred to as NG-RAN. NG-RAN, E-UTRAN, etc. may be simply referred to as a network. , ng-eNB and gNB, etc.

[0026] Note that one or more eNBs 102 may be connected to the 5G GC 110 via an interface 114. An interface (not shown) may exist between the multiple eNBs 102 connected to the 5GC 110. The interface between the multiple eNBs 102 connected to the 5GC 110 may be called an Xn interface. The eNBs 102 connected to the 5GC 110 and the gNBs 108 connected to the 5GC 110 are connected by an interface 120. The interface 120 between the eNB 102 connected to the 5GC 110 and the gNB 108 connected to the 5GC 110 is , may be called the Xn interface.

[0027] The gNB 108 may have a function to connect to the EPC 104. The gNB 108 having a function to connect to the EPC 104 may be called an en-gNB. The interface 118 is an interface between the gNB 108 and the EPC 104, and is an S1 The interface 118 may be referred to as a user program interface through which user data passes. There may be a lane interface. The interface may terminate at an S-GW (not shown) in the EPC 104. The interface may be referred to as an S1-U interface. The eNB 102 connected to the EPC 104 and the gNB 108 connected to the EPC 104 may be connected by an interface 120. The interface 120 between the gNB 108 and the EPC 104 may be referred to as the X2 interface. stomach.

[0028] The interface 124 is an interface between the EPC 104 and the 5GC 110, and can be either CP only or UP only. Alternatively, the interface 114 may be an interface that passes both the CP and the UP. Some or all of the interfaces 116, 118, 120, and 124 may not be present depending on the communication system provided by the communication carrier or the like.

[0029] The UE 122 may be a terminal device capable of receiving system information and paging messages transmitted from the eNB 102 and / or the gNB 108. The UE 122 may also be a terminal device capable of wireless connection with the eNB 102 and / or the gNB 108. The UE 122 may also be a terminal device capable of simultaneously establishing a wireless connection with the eNB 102 and a wireless connection with the gNB 108. The UE 122 may have an E-UTRA protocol and / or an NR protocol. The wireless connection may be a Radio Resource Control (RRC) connection.

[0030] The UE 122 is also connected to the EPC 104 and / or the 5GC 110 via the eNB 102 and / or the gNB 108. The UE 122 may be a terminal device capable of communicating with the eNB 102 and / or gNB 108. When the core network to which the UE 122 communicates with the eNB 102 and / or gNB 108 is connected is the EPC 104, each Data Radio Bearer (DRB) (described later) established between the UE 122 and the eNB 102 and / or gNB 108 may be uniquely associated with each EPS (Evolved Packet System) bearer passing through the EPC 104. Each EPS bearer may be identified by an EPS bearer identifier (identity, or ID). Furthermore, the same QoS may be guaranteed for data such as IP packets and Ethernet frames passing through the same EPS bearer.

[0031] In addition, when the core network to which the eNB102 and / or gNB108 with which the UE122 communicates is connected is the 5GC110, each DRB established between the UE122 and the eNB102 and / or gNB108 is further established in the 5GC110. Each PDU session may have one or more QoS flows. Each DRB corresponds to one or more QoS flows. Each PDU session may or may not be mapped to any QoS flow. Each QoS flow may be identified by a PDU session identifier (Identity, or ID). Each QoS flow may be identified by a QoS flow identifier (Identity, or ID). The same QoS may be guaranteed for data such as IP packets and Ethernet frames that pass through the same QoS flow.

[0032] There may be no PDU sessions and / or QoS flows in the EPC 104, and no EPS bearers in the 5GC 110. When the UE 122 is connected to the EPC 104, the UE 122 receives the EPS bearer information. The UE 122 may have information about the PDU session and / or the QoS flow, but may not have information about the PDU session and / or the QoS flow. However, it does not need to have information about the EPS bearer.

[0033] In the following description, the eNB102 and / or the gNB108 will also be simply referred to as a base station device, and the UE122 will also be simply referred to as a terminal device or a UE.

[0034] FIG. 2 is a diagram illustrating an example of an E-UTRA protocol architecture according to this embodiment. FIG. 3 is a diagram illustrating an example of an NR protocol architecture according to this embodiment. The functions of each protocol described with reference to FIG. 3 are some of the functions closely related to this embodiment. In this embodiment, the uplink (UL) and In this embodiment, a downlink (DL) may be a link from a base station device to a terminal device.

[0035] Figure 2(A) is a diagram of an E-UTRA user plane (UP) protocol stack. As shown in Figure 2(A), the E-UTRA UP protocol may be a protocol between the UE 122 and the eNB 102. That is, the E-UTRA UP protocol may be a protocol that terminates at the eNB 102 on the network side. As shown in FIG. 1, the E-UTRA user plane protocol stack may be composed of a PHY (Physical layer) 200, which is a radio physical layer, a MAC (Medium Access Control) 202, which is a medium access control layer, a RLC (Radio Link Control) 204, which is a radio link control layer, and a PDCP (Packet Data Convergence Protocol) 206, which is a packet data convergence protocol layer.

[0036] Figure 3(A) shows the NR user plane (UP) protocol stack. As shown in Figure 3(A), the NR The UP protocol may be a protocol between the UE 122 and the gNB 108, i.e., the NR UP protocol. On the network side, the NR user plane protocol stack may be a protocol that terminates at the gNB 108. As shown in Figure 3(A), the NR user plane protocol stack may be composed of a radio physical layer PHY 300, a medium access control layer MAC 302, a radio link control layer RLC 304, a packet data convergence protocol layer PDCP 306, and a service data adaptation protocol layer SDAP (Service Data Adaptation Protocol) 310.

[0037] FIG. 2(B) is a diagram of the E-UTRA control plane (CP) protocol configuration. As shown in FIG. 2(B), in the E-UTRA CP protocol, RRC (Radio Resource Control) 208, which is a radio resource control layer, may be a protocol between the UE 122 and the eNB 102. In other words, the RRC 208 may be a protocol that terminates at the eNB 102 on the network side. In addition, the E-UTRA CP protocol In the protocol, a Non Access Stratum (NAS) 210, which is a non-AS (Access Stratum) layer, may be a protocol between the UE 122 and the MME. That is, the NAS 210 may be a protocol that terminates at the MME on the network side.

[0038] Figure 3(B) shows the NR control plane (CP) protocol configuration. As shown in Figure 3(B), the NR CP protocol In the protocol, the radio resource control layer RRC 308 controls the protocol between the UE 122 and the gNB 108. That is, the RRC 308 may be a protocol that terminates at the gNB 108 on the network side. In the NR CP protocol, the NAS 312, which is a non-AS layer, is a protocol between the UE 122 and the AMF. That is, NAS 312 may be a protocol that terminates at AMF on the network side. It's okay.

[0039] The AS (Access Stratum) layer may be a layer that terminates between the UE 122 and the eNB 102 and / or the gNB 108. That is, the AS layer may be a layer that includes the PHY 200, the MAC 202, the RLC 204, the PDCP 206, and a part or all of the RRC 208. Layers including all of and / or any of PHY 300, MAC 302, RLC 304, PDCP 306, SDAP 310, and RRC 308 It may be a layer that includes part or all of the above.

[0040] In the present embodiment, hereinafter, there is no distinction between the E-UTRA protocol and the NR protocol, and the PHY ( The terms PHY layer, MAC (MAC layer), RLC (RLC layer), PDCP (PDCP layer), RRC (RRC layer), and NAS (NAS layer) may be used. In this case, PHY (PHY layer), MAC (MAC layer), RLC (RLC layer), PDCP (PDCP layer), RRC (RRC layer), and NAS (NAS layer) may respectively refer to the PHY (PHY layer), MAC (MAC layer), RLC (RLC layer), PDCP (PDCP layer), RRC (RRC layer), and NAS (NAS layer) of the E-UTRA protocol, or may refer to the PHY (PHY layer), MAC (MAC layer), RLC (RLC layer), PDCP (PDCP layer), RRC (RRC layer), and NAS (NAS layer) of the NR protocol. Furthermore, SDAP (SDAP layer) may refer to the SDAP (SDAP layer) of the NR protocol.

[0041] In this embodiment, when distinguishing between the E-UTRA protocol and the NR protocol, the PHY 200, the MAC 202, the RLC 204, the PDCP 206, and the RRC 208 will be referred to as the PHY for E-UTRA or the PHY for LTE, the MAC for E-UTRA or the MAC for LTE, the RLC for E-UTRA or the RLC for LTE, the PDCP for E-UTRA or the PDCP for LTE ... RLC for E-UTRA or the RLC for LTE, the PDCP The PHY 200, MAC 202, RLC 204, PDCP 206, and RRC 208 may also be referred to as E-UTRA PHY or LTE PHY, E-UTRA MAC or LTE MAC, E-UTRA RLC or LTE RLC, E-UTRA PDCP or LTE PDCP, and E-UTRA RRC or LTE RRC, respectively. Furthermore, when distinguishing between E-UTRA protocols and NR protocols, PHY 300, MAC 302, RLC 304, PDCP 306, and RRC 308 may be referred to as NR PHY, NR MAC, NR RLC, NR RLC, and NR RRC, respectively. Furthermore, PHY 300, MAC 302, RLC 304, PDCP 306, and RRC 308 may be referred to as NR PHY, NR MAC, NR RLC, NR PDCP, and NR RRC, respectively.

[0042] This section describes entities in the AS layer of E-UTRA and / or NR. An entity that has some or all of the functions of the MAC layer may be called a MAC entity. An entity that has some or all of the functions of the RLC layer may be called an RLC entity. PDCP layer functions An entity that has some or all of the functions of the SDAP layer may be called a PDCP entity. An entity that has some or all of the functions of the SDAP layer may be called an SDAP entity. RRC layer functions An entity having some or all of the above may be called an RRC entity. The MAC entity, RLC entity, PDCP entity, SDAP entity, and RRC entity may be referred to as MAC, RLC, PDCP, SDAP, and RRC, respectively.

[0043] Note that data provided from MAC, RLC, PDCP, and SDAP to lower layers, and / or data provided from lower layers to MAC, RLC, PDCP, and SDAP may be called MAC PDU (Protocol Data Unit), RLC PDU, PDCP PDU, and SDAP PDU, respectively. Data provided and / or provided to higher layers by MAC, RLC, PDCP, and SDAP These may be called MAC SDU (Service Data Unit), RLC SDU, PDCP SDU, and SDAP SDU, respectively. Furthermore, a segmented RLC SDU may be referred to as an RLC SDU segment.

[0044] Here, the base station apparatus and the terminal apparatus exchange (transmit and receive) signals in a higher layer. For example, the base station apparatus and the terminal apparatus communicate with each other through radio resource control (RRC). In the Radio Resource Control (RRC) layer, the base station apparatus and the terminal apparatus may transmit and receive RRC messages (also referred to as RRC messages, RRC information, or RRC signaling). In addition, in the Medium Access Control (MAC) layer, the base station apparatus and the terminal apparatus may transmit and receive MAC control elements. In addition, the RRC layer of the terminal device acquires system information broadcast from the base station device. Here, the RRC message, system information, and / or MAC control element are also referred to as higher layer signaling or higher layer parameters. Each of the parameters included in the higher layer signal received by the terminal device may be referred to as a higher layer parameter. In PHY layer processing, the higher layer refers to a higher layer as seen from the PHY layer, and may therefore refer to one or more of the MAC layer, RRC layer, RLC layer, PDCP layer, NAS (Non Access Stratum) layer, etc. For example, in the processing of the MAC layer, the upper layer refers to one or more of the RRC layer, RLC layer, PDCP layer, NAS layer, etc. In the following, the meaning of "A is given (provided) in a higher layer" or "A is given (provided) by a higher layer" is the meaning of the higher layer (mainly the RRC layer) of the terminal device. The base station receives A from the base station device, and the received A is passed to the terminal device from the upper layer. For example, in a terminal device, "being provided with upper layer parameters" may mean receiving an upper layer signal from a base station device, and providing the upper layer parameters included in the received upper layer signal from the upper layer of the terminal device to the physical layer of the terminal device. Setting upper layer parameters in a terminal device may mean providing (providing) the upper layer parameters to the terminal device. For example, setting upper layer parameters in a terminal device may mean that the terminal device receives an upper layer signal from a base station device, and setting the received upper layer parameters in the upper layer. However, setting upper layer parameters in a terminal device may also include setting default parameters that have been provided in advance to the upper layer of the terminal device. This description refers to transmitting an RRC message from a terminal device to a base station device. When explaining this, the expression "submit" may be used, where a message is sent from the RRC entity of the terminal device to a lower layer. In a terminal device, "submitting a message to a lower layer" from the RRC layer may mean submitting a message to a PDCP entity corresponding to each SRB, since RRC messages are transmitted using SRBs (SRB0, SRB1, SRB2, SRB3, etc.). When the RRC entity of the terminal device receives an indication from a lower layer, the lower layer , may refer to one or more of a PHY layer, a MAC layer, an RLC layer, a PDCP layer, etc.

[0045] An example of the function of the PHY is explained below. The PHY of the terminal device receives the downlink from the PHY of the base station device. Receives data transmitted via a Downlink (DL) physical channel. The PHY of the terminal device may have an uplink (UL) object function with respect to the PHY of the base station device. The PHY may have a function to transmit data via a transport channel. The PHY may be connected to the upper MAC via a transport channel. The PHY may pass data to the MAC via the transport channel. The PHY may also receive data from the MAC via the transport channel. In the PHY, a Radio Network Temporary Identifier (RNTI) may be used to identify various control information.

[0046] Here, the physical channels will be described. The physical channels used for wireless communication between a terminal device and a base station device may include the following physical channels.

[0047] PBCH (Physical Broadcast CHannel) PDCCH (Physical Downlink Control CHannel) PDSCH (Physical Downlink Shared CHannel) PUCCH (Physical Uplink Control CHannel) PUSCH (Physical Uplink Shared CHannel) PRACH (Physical Random Access CHannel)

[0048] The PBCH may be used to broadcast system information required by a terminal device.

[0049] In addition, in NR, the PBCH may be used to broadcast a time index (SSB-Index) within a synchronization signal block (SSB) period.

[0050] The PDCCH is used in downlink wireless communication (wireless communication from a base station device to a terminal device). The UE may be used to transmit (or carry) Downlink Control Information (DCI), where one or more DCIs (DCIs) may be used for the transmission of the downlink control information. In other words, a format for the downlink control information may be defined. The fields in the PDCCH are defined as DCI and may be mapped to information bits. The terminal device may monitor a set of PDCCH candidates in the serving cell. Monitoring a set of PDCCH candidates means monitoring a set of PDCCH candidates in a certain DCI format. The DCI format may mean attempting to decode the PDCCH according to the PDCCH. The terminal device may also use a CORESET (Control Resource Set) to monitor a set of PDCCH candidates. The DCI format may be used for scheduling the PUSCH in the serving cell. The PUSCH may be used for transmitting user data and RRC messages (described later). stomach.

[0051] The PUCCH is used in uplink wireless communication (wireless communication from a terminal device to a base station device). The uplink control information may be used to transmit uplink control information (UCI). Here, the uplink control information may include channel state information (CSI) used to indicate the state of the downlink channel. The uplink control information may include a scheduling request (SR) used to request UL-SCH (Uplink Shared CHannel) resources. The link control information includes HARQ-ACK (Hybrid Automatic Repeat reQuest ACKnowledgement). It's okay to be surrounded.

[0052] The PDSCH may be used to transmit downlink data (DL-SCH: Downlink Shared CHannel) from the MAC layer, and may also be used to transmit system information (SI) and random access responses (RAR) in the downlink.

[0053] The PUSCH may be used to transmit uplink data from the MAC layer (UL-SCH: Uplink Shared CHannel) or uplink data together with HARQ-ACK and / or CSI, or may be used to transmit only CSI or only HARQ-ACK and CSI. That is, the PUSCH may be used to transmit only UCI. Furthermore, the PDSCH or the PUSCH may be used to transmit RRC signaling (also referred to as an RRC message) and MAC CE. Here, in the PDSCH, the RRC signaling transmitted from the base station apparatus may be signaling common to a plurality of terminal apparatuses in a cell. Furthermore, the RRC signaling transmitted from the base station apparatus may be signaling dedicated to a certain terminal apparatus (also referred to as dedicated signaling). In other words, the RRC signaling may be terminal apparatus-specific (UE-specific) The information in (c) may be transmitted to a terminal device using dedicated signaling. In addition, the PUSCH may be used to transmit UE capabilities in the uplink.

[0054] The PRACH may be used to transmit a random access preamble. The PRACH is used for initial connection establishment procedures, handover procedures, connection re-establishment procedures, and the above. It may be used to indicate synchronization (timing alignment) for downlink transmissions and a request for UL-SCH resources.

[0055] An example of the functions of MAC will be described. MAC may be called a MAC sublayer. MAC may have the function of mapping various logical channels to corresponding transport channels. A logical channel may be identified by a logical channel identity (or logical channel ID). MAC may be connected to a higher RLC via a logical channel. Depending on the type of information to be transmitted, logical channels may be divided into control channels that transmit control information and traffic channels that transmit user information. Logical channels may also be divided into uplink logical channels and downlink logical channels. MAC may be configured to handle one or more different logical channels. The MAC may have a function to multiplex MAC SDUs belonging to a logical channel and provide them to the PHY. The MAC may also have a function to demultiplex MAC PDUs provided by the PHY and provide them to a higher layer via the logical channel to which each MAC SDU belongs. The MAC may also have a function to perform error correction through HARQ (Hybrid Automatic Repeat reQuest). The MAC may also have a function to report scheduling information. MAC has the function of using dynamic scheduling to perform priority processing among terminal devices. MAC should also have a function to perform priority processing between logical channels within one terminal device. MAC has the function of prioritizing overlapping resources within a single terminal device. E-UTRA MAC has the function to identify Multimedia Broadcast Multicast Services (MBMS). The NR MAC may also have the ability to identify Multicast / Broadcast Services (MBS). The MAC is The MAC may have the functionality to perform discontinuous reception (DRX) and / or discontinuous transmission (DTX), random access (Random Access), and so on. Access (RA) function to execute procedures, notify information on available power, power headroom Report (Power Headroom Report: PHR) function, notifying the amount of data in the transmission buffer. The NR MAC may have a Buffer Status Report (BSR) function, etc. The NR MAC may have a Bandwidth Adaptation (BA) function. The MAC PDU format used in the NR MAC may differ from that used in the NR MAC. The MAC PDU also contains a MAC control element (MAC control element), which is an element for controlling the MAC. Element: MAC CE).

[0056] This section describes logical channels for uplink (UL) and / or downlink (DL) used in E-UTRA and / or NR.

[0057] The BCCH (Broadcast Control Channel) may be a downlink logical channel for broadcasting control information such as system information (SI).

[0058] A PCCH (Paging Control Channel) may be a downlink logical channel for carrying paging messages.

[0059] A CCCH (Common Control Channel) may be a logical channel for transmitting control information between a terminal device and a base station device. The CCCH is used when the terminal device does not have an RRC connection. The CCCH may also be used between a base station device and multiple terminal devices.

[0060] DCCH (Dedicated Control Channel) is a logical channel for transmitting dedicated control information bidirectionally (point-to-point) between a terminal device and a base station device. The dedicated control information may be control information dedicated to each terminal device. The DCCH may be used when the terminal device has an RRC connection.

[0061] A DTCH (Dedicated Traffic Channel) may be a logical channel for transmitting user data point-to-point between a terminal device and a base station device. The DTCH may be a logical channel for transmitting user data. Dedicated user data may be user data dedicated to each terminal device. The DTCH may exist in both the uplink and downlink.

[0062] E-UTRA and / or NR uplink logical and transport channels The mapping will now be described.

[0063] CCCH is an uplink transport channel, UL-SCH (Uplink Shared Channel) may be mapped to

[0064] DCCH is an uplink transport channel, UL-SCH (Uplink Shared Channel) may be mapped to

[0065] DTCH is an uplink transport channel, UL-SCH (Uplink Shared Channel) may be mapped to

[0066] Logical and transport channels for downlink in E-UTRA and / or NR The mapping will now be described.

[0067] BCCH is a downlink transport channel, BCH (Broadcast Channel), and / or may be mapped to a Downlink Shared Channel (DL-SCH).

[0068] The PCCH is mapped to the PCH (Paging Channel), which is a downlink transport channel. That's fine.

[0069] CCCH is a downlink transport channel, DL-SCH (Downlink Shared Channel) may be mapped to

[0070] DCCH is a downlink transport channel, DL-SCH (Downlink Shared Channel) may be mapped to

[0071] DTCH is a downlink transport channel, DL-SCH (Downlink Shared Channel) may be mapped to

[0072] An example of the function of the RLC will be described. The RLC may be called an RLC sublayer. The E-UTRA RLC may have the function of segmenting and / or concatenating data provided from the PDCP of the upper layer and providing it to the lower layer. The E-UTRA RLC is The NR RLC may have the function of reassembling and reordering data provided from a lower layer and providing it to a higher layer. The NR RLC may assign a sequence number independent of the sequence number added by PDCP to the data provided from the higher layer PDCP. The NR RLC may have the function of adding a number to the data provided by the PDCP. The NR RLC may also have the function of segmenting data provided by the PDCP and providing it to a lower layer. The NR RLC may also have the function of reassembling data provided by the lower layer and providing it to a higher layer. The RLC may also have the function of retransmitting data and / or requesting retransmission (Automatic Repeat reQuest: ARQ). The RLC may also have the function of correcting errors using ARQ. ARQ Control information indicating the data that needs to be retransmitted, sent from the receiving side of the RLC to the sending side in order to This can be called a status report. The command to send a task report can be called a poll. RLC also detects data duplication. RLC may have a function to discard data. RLC may also have a function to discard data. RLC has Transparent Mode (TM), Unacknowledged Mode (UM), and ACK mode. There may be three modes: Acknowledged Mode (AM), Acknowledged Mode (AM), and TM. No data division is performed and no RLC header needs to be added. The TM RLC entity is unidirectional. A uni-directional entity that is the transmitting TM RLC entity In UM, the upper layer The UM RLC entity divides and / or combines data received from the UM, adds an RLC header, etc., but does not need to control data retransmission. The UM RLC entity may be a unidirectional entity or a bidirectional entity. When the UM RLC entity is a unidirectional entity, the UM RLC entity acts as a transmitting UM RLC entity or a receiving UM RLC entity. If the UM RLC entity is a bidirectional entity, the UM RRC entity may be configured as a transmitting side and a receiving side. The AM RLC entity may be configured as an UM RLC entity consisting of a transmitting side and a receiving side. The AM may perform operations such as dividing and / or combining data received from the upper layer, adding an RLC header, and controlling data retransmission. The AM RLC entity is a bidirectional entity and may be configured as an AM RLC consisting of a transmitting side and a receiving side. Note that the data provided to the lower layer in the TM may be configured as an AM RLC entity consisting of a transmitting side and a receiving side. Data provided to a lower layer in UM and / or data provided from a lower layer may be called a TMD PDU. Data provided to a lower layer in UM and / or data provided from a lower layer may be called a UMD PDU. Data provided to a lower layer in AM and / or data provided from a lower layer may be called an AMD PDU. The RLC PDU format used in E-UTRA RLC and the RLC PDU format used in NR RLC may be different. RLC PDUs may include data RLC PDUs and control RLC PDUs. Data RLC PDUs are called RLC DATA PDUs (RLC Data PDUs). In addition, the control RLC PDU may be called an RLC CONTROL PDU (RLC Control PDU).

[0073] An example of the function of PDCP will be explained. PDCP may be called a PDCP sublayer. PDCP may have a function to maintain sequence numbers. PDCP also allows efficient transmission of user data such as IP packets and Ethernet frames over wireless sections. The protocol used for header compression and decompression of IP packets may be called ROHC (Robust Header Compression) protocol. The protocol used for Ethernet frame header compression and decompression is EHC (Ethernet (registered trademark) PDCP may be called the PDCP (Data Header Compression Protocol). PDCP may also have a data encryption / decryption function. PDCP may also have a data integrity protection / verification function. PDCP may also have a re-ordering function. PDCP may also have a PDCP SDU retransmission function. PDCP may also have a data discard function using a discard timer. PDCP may also have a duplication function. PDCP may also have a function to discard duplicated received data. The PDCP entity is a bidirectional entity and may consist of a transmitting PDCP entity and a receiving PDCP entity. The PDCP PDU format used in E-UTRA PDCP may differ from that used in NR PDCP. PDCP PDUs may also include There may be data PDCP PDUs and control PDCP PDUs. Data PDCP PDUs may be called PDCP DATA PDUs (PDCP Data PDUs). Control PDCP PDUs may be called PDCP CONTROL PDUs (PDCP Control PDUs).

[0074] An example of the SDAP function is explained below. SDAP is a service data adaptation protocol layer (SDAP). SDAP is a data service adaptation protocol layer (SDAP). Mapping of downlink QoS flows sent to the device with data radio bearers (DRBs) The SDAP may have a function to map the DRB with the uplink QoS flow (mapping), and / or the uplink QoS flow sent from the terminal device to the 5GC 110 via the base station device. The SDAP may also have a function to store mapping rule information. The SDAP may also have a function to mark the QoS flow identifier (QoS Flow ID: QFI). The SDAP PDU may include a data SDAP PDU and a control SDAP PDU. The data SDAP PDU may be called an SDAP DATA PDU (SDAP Data PDU). The control SDAP PDU may be called an SDAP CONTROL PDU (SDAP Control PDU). There may be one SDAP entity in the terminal device for each PDU session.

[0075] An example of the functions of the RRC will be described. The RRC may have a broadcast function. The RRC may have a paging function from the EPC 104 and / or the 5GC 110. The RRC may have a paging function from the eNB 102 connected to the gNB 108 or 5GC 110. The RRC may also have an RRC connection management function. The RRC may also have a radio base station (RBT) function. The RRC may have a cell group control function. The RRC may have a mobility control function. The RRC may also have a terminal device measurement reporting function. The RRC may have a function for controlling terminal device measurement and reporting. The RRC may also have a function for QoS management. The RRC may also have a function for detecting and recovering from radio link failures. The RRC may also have a function for controlling RRC media. Using messages, broadcasting, paging, RRC connection management, radio bearer control, cell group control, Control, mobility control, terminal device measurement reporting and terminal device measurement reporting control QoS management, detection and recovery of radio link failures, etc. The RRC messages and parameters used may differ from the RRC messages and parameters used in NR RRC.

[0076] RRC messages may be sent using the logical channel BCCH, or the logical channel PCCH. The RRC message may be sent using the logical channel CCCH, or may be sent using the logical channel DCCH. The RRC message sent using the DCCH may also be referred to as dedicated RRC signaling or RRC signaling.

[0077] The RRC messages sent using the BCCH may include, for example, a Master Information Block (MIB), various types of System Information Blocks (SIBs), or other RRC messages.The RRC messages sent using the PCCH may include, for example, paging messages or other RRC messages.

[0078] RRC messages sent in the uplink (UL) direction using CCCH include, for example, an RRC Setup Request message, an RRC Resume Request message, an RRC Reestablishment Request message, and an RRC System Information Request message. The RRC message may include an RRC System Info Request message, an RRC Connection Request message, an RRC Connection Resume Request message, an RRC Connection Reestablishment Request message, etc. Alternatively, the RRC message may include other RRC messages.

[0079] RRC messages sent in the downlink (DL) direction using CCCH include, for example, an RRC connection reject message (RRC Connection Reject), an RRC connection setup message (RRC Connection Setup), an RRC connection reestablishment message (RRC Connection Reestablishment Reject), and an RRC connection reestablishment reject message (RRC Connection Reestablishment Reject). For example, an RRC reject message, an RRC setup message, etc. may be included. Other RRC messages may also be included.

[0080] RRC signaling sent in the uplink (UL) direction using DCCH includes, for example, measurement reports. The message may include a Measurement Report, an RRC Connection Reconfiguration Complete message, an RRC Connection Setup Complete message, an RRC Connection Reestablishment Complete message, a Security Mode Complete message, a UE Capability Information message, etc. Also, for example, the message may include a Measurement Report, an RRC Reconfiguration Complete message, an RRC Setup Complete message, an RRC Connection Reestablishment Complete message, a Security Mode Complete message, a UE Capability Information message, etc. RRC Setup Complete, RRC Reestablishment Complete, RRC Resume Complete, Security Mode Complete The RRC signaling may include a Security Mode Complete message, a UE Capability Information message, etc., and may also include other RRC signaling.

[0081] The RRC signaling sent in the downlink (DL) direction using the DCCH may include, for example, an RRC connection reconfiguration message, an RRC connection release message, a security mode command message, a UE capability inquiry message, etc. Also, for example, an RRC reconfiguration message, an RRC resume message, an RRC release message, an RRC reestablishment message, a security mode command message, a UE capability inquiry message, etc. Also, other RRC signaling may be included.

[0082] An example of the NAS function is explained below. The NAS may have an authentication function. The NAS may also have the functionality to perform security control. You can have it.

[0083] The above-mentioned PHY, MAC, RLC, PDCP, SDAP, RRC, and NAS functions are examples, and only a portion of each function is shown. In addition, some or all of the functions of each layer may be included in another layer.

[0084] Next, state transitions of the UE 122 in LTE and NR will be described. When the UE 122 connected to EPC or 5GC has an established RRC connection, the UE 122 may be in an RRC_CONNECTED state. The state in which the RRC connection is established may include a state in which the UE 122 holds some or all of the UE context described below. The state in which the RRC connection is established may also include a state in which the UE 122 can transmit and / or receive unicast data. The UE 122 may be in an RRC_INACTIVE state when the RRC connection is suspended. The UE 122 may be in the RRC_INACTIVE state when the UE 122 is connected to 5GC and the RRC connection is suspended. When the UE 122 is in the RRC_CONNECTED state, When not in the RRC_INACTIVE state or the RRC_INACTIVE state, the UE 122 may be in the RRC_IDLE state.

[0085] Note that when the UE 122 is connected to the EPC, it does not have the RRC_INACTIVE state, but is connected to the E-UTRAN. If the UE 122 is connected to the EPC, when the RRC connection is suspended, the UE 122 may transition to the RRC_IDLE state, retaining the UE AS context and an identifier (resumeIdentity) used for resuming. An upper layer (e.g., NAS layer) of the RRC layer of the UE 122 may initiate the suspension of the suspended RRC connection when the UE 122 retains the UE AS context, the E-UTRAN has permitted the RRC connection to be resumed, and the UE 122 needs to transition from the RRC_IDLE state to the RRC_CONNECTED state. Recovery may be initiated.

[0086] The definition of dormancy may be different for the UE 122 connected to the EPC 104 and the UE 122 connected to the 5GC 110. In addition, when the UE 122 is connected to the EPC (when the UE 122 is dormant in the RRC_IDLE state), and when the UE 122 is connected to the 5GC (when the UE 122 is dormant in the RRC_INACTIVE state), However, all or part of the procedure for returning from sleep may be different.

[0087] The RRC_CONNECTED state, RRC_INACTIVE state, and RRC_IDLE state are referred to as connection states, respectively. The RRC state may be referred to as connected mode, inactive mode, or idle mode, or may be referred to as RRC connected mode, RRC inactive mode, or RRC idle mode.

[0088] The UE AS context held by the UE 122 may be information including all or some of the following: a current RRC configuration, a current security context, a PDCP state including a ROHC (Robust Header Compression) state, a C-RNTI (Cell Radio Network Temporary Identifier) ​​used in the source PCell, a cell identifier (cellIdentity), and a physical cell identifier of the source PCell. Note that the UE AS context held by one or all of the eNB 102 and the gNB 108 may include the same information as the UE AS context held by the UE 122, or may include information different from the information included in the UE AS context held by the UE 122.

[0089] The security context may be information that includes all or part of the following: encryption keys at the AS level, the Next Hop parameter (NH), the Next Hop Chaining Counter parameter (NCC) used to derive the next hop access key, an identifier for the selected AS level encryption algorithm, and a counter used for replay protection.

[0090] Next, we will explain about the serving cell. CA and / or DC, which will be described later, In a terminal device in an unconfigured RRC connected state, the serving cell may be configured as one primary cell (PCell). In a terminal device in an RRC connected state in which the plurality of serving cells is specified, the plurality of serving cells may refer to a set of cells (set of cell(s)) consisting of one or more special cells (SpCells) and one or more secondary cells (SCells). The SpCell may support PUCCH transmission and contention-based random access (CBRA), and the SpCell may be always activated. The PCell may be a cell used in the RRC connection establishment procedure when a terminal device in an RRC idle state transitions to an RRC connected state. The PCell may also be used in the RRC connection re-establishment procedure in which the terminal device re-establishes the RRC connection. The PCell may be the cell used for the random access procedure during handover. The PSCell may be a cell used for a random access procedure when adding a secondary node, which will be described later. The SpCell may be a cell used for purposes other than those described above.

[0091] When a group of serving cells configured for a terminal device is composed of an SpCell and one or more SCells, it may be considered that carrier aggregation (CA) is configured for the terminal device. Also, for a terminal device in which CA is configured, a cell providing additional radio resources to the SpCell may refer to an SCell.

[0092] A group of serving cells configured by RRC, among which the uplink is configured The same timing reference cell and the same time for the cell being A group of serving cells using a Timing Advance value may be called a Timing Advance Group (TAG). A TAG including these may refer to a Primary Timing Advance Group (PTAG). A TAG other than the above PTAG may refer to a Secondary Timing Advance Group. It may refer to one or more Secondary Timing Advance Groups (STAGs). may be configured for each cell group, which will be described later.

[0093] The following describes a cell group configured by a base station device for a terminal device. A cell group may be configured with one SpCell. Alternatively, a cell group may be configured with one SpCell and one or more SCells. In other words, a cell group may be configured with one SpCell and one or more SCells. A cell group may optionally be composed of one or more SCells, and may be expressed as a set of cells.

[0094] Dual Connectivity (DC) is a technology that performs data communication using the radio resources of cell groups that are respectively configured by a first base station device (first node) and a second base station device (second node). When DC or MR-DC (described later) is performed, the base station device A cell group may be added. To perform DC, a first base station device may add a second base station device. The first base station device may be called a master node (MN). The cell group configured by the master node may be called a Master Cell Group (MCG). The second base station device is called a Secondary Node (SN). A cell group configured by a secondary node may be called a secondary cell group (SCG). The master node and the secondary node may be configured within the same base station device.

[0095] Furthermore, when DC is not configured, the cell group configured in the terminal device may be called an MCG. Furthermore, when DC is not configured, the SpCell configured in the terminal device may be a PCell. Furthermore, an NR in which DC is not configured may be called an NR standalone. good.

[0096] Note that Multi-Radio Dual Connectivity (MR-DC) may be a technology that performs DC using E-UTRA for MCG and NR for SCG. MR-DC is also a technology that performs DC using NR for MCG and E-UTRA for SCG. MR-DC is a technique for performing DC using NR in both MCG and SCG. MR-DC may be a technology included in DC. An example of MR-DC using E-UTRA for MCG and NR for SCG is EN-DC (E-UTRA-NR Dual Connectivity) which uses EPC for the core network. An example of MR-DC that uses NR for MCG and E-UTRA for SCG is NGEN-DC (NG-RAN E-UTRA-NR Dual Connectivity), which uses 5GC for the core network. An example of MR-DC that uses NR for MCG and E-UTRA for SCG is NE-DC (NR-E-UTRA Dual Connectivity), which uses 5GC for the core network. An example of MR-DC that uses NR for both MCG and SCG is NE-DC (NR-E-UTRA Dual Connectivity). It would be good to have NR-DC (NR-NR Dual Connectivity) that uses 5GC in the core network.

[0097] In addition, in the terminal device, one MAC entity may exist for each cell group. For example, when DC or MR-DC is configured in the terminal device, one MAC entity for the MCG and one MAC entity for the SCG may exist. The MAC entity for the MCG in the terminal device is used in all states (RRC idle state, RRC connected state, and RRC inactive state). The MAC entity for the SCG in the terminal device may be always established in the terminal device (e.g., in the terminal device state). The MAC entity for the SCG in the terminal device may be created by the terminal device when the SCG is configured in the terminal device. The MAC entity for each cell group in the terminal device may be created by the terminal device. The setting may be performed by receiving RRC signaling from the base station device. If the MAC entity is associated with the MCG, the SpCell may refer to the PCell. If the entity is associated with an SCG, SpCell may refer to the Primary SCG Cell (PSCell). If the MAC entity is not associated with a cell group, SpCell may refer to the PCell. PCell, PSCell, and SCell are serving cells. In EN-DC and NGEN-DC, the MAC entity for the MCG is the E-UTRA MAC entity. In the NE-DC, the MAC entity for the MCG may be an NR MAC entity, and the MAC entity for the SCG may be an E-UTRA MAC entity. In the NR-DC, the MAC entities for the MCG and SCG may both be NR MAC entities. The existence of one MAC entity for each cell group can be rephrased as the existence of one MAC entity for each SpCell. In addition, the existence of one MAC entity for each cell group may be rephrased as the existence of one MAC entity for each SpCell. The entity can be rephrased as one MAC entity for each SpCell.

[0098] When a terminal device communicates with a base station device, a radio bearer (RB) is established between the terminal device and the base station device to establish a radio connection. A radio bearer used for CP may be called a signaling radio bearer (SRB). A radio bearer used for UP may be called a data radio bearer (DRB). Each radio bearer may be assigned a radio bearer identity (ID). A radio bearer identifier for an SRB may be called an SRB identity (SRB ID). A radio bearer identifier for a DRB may be called a DRB identity (DRB ID). SRB0 to SRB2 may be defined for the SRBs of E-UTRA, or other SRBs may be defined. SRB0 to SRB3 may be defined for the SRBs of NR, or other SRBs may be defined. SRB0 may be an SRB for RRC messages, which are transmitted and / or received using the logical channel CCCH. SRB1 is used for RRC signaling and for NAS before the establishment of SRB2. RRC signaling transmitted and / or received using SRB1 may include piggybacked NAS signaling. All RRC and NAS signaling transmitted and / or received using SRB1 includes the logical channel A DCCH may be used for NAS signalling and for logged measurement information. It may be an SRB for RRC signaling including measurement information. All RRC and NAS signalling sent and / or received through the A DCCH of the channel may be used. SRB2 may have a lower priority than SRB1. SRB3 may be an SRB for transmitting and / or receiving specific RRC signaling when EN-DC, NGEN-DC, NR-DC, etc. are configured in the terminal device. Transmission and / or reception using SRB3 All RRC and NAS signaling may be received using the logical channel DCCH. Other SRBs may also be provided for other uses. DRBs may be radio bearers for user data. RRC systems that transmit and / or receive using DRBs The logical channel DTCH may be used for signaling.

[0099] The radio bearer in the terminal device is explained. The radio bearer includes the RLC bearer. An RLC bearer may consist of one or two RLC entities and logical channels. If there are two RLC entities in a bearer, the RLC entity is the TM RLC entity, and / or a transmitting RLC entity and a receiving RLC entity in unidirectional UM mode. SRB0 may consist of one RLC bearer. The RRC may consist of an RLC entity and a logical channel of the TM. SRB0 may be always established in the terminal device in all states (RRC idle state, RRC connected state, RRC inactive state, etc.). When the terminal device transitions from the RRC idle state to the RRC connected state, one SRB1 may be established and / or configured in the terminal device by RRC signaling received from the base station device. SRB1 may consist of one PDCP entity and one or more RLC bearers. The RLC bearers of SRB1 may consist of an RLC entity and logical channels of the AM. SRB2 is an AS One SRB2 may be established and / or configured in a terminal device in an RRC connected state with security activated by RRC signaling received from a base station device. The RLC bearer of SRB2 may consist of an RLC entity of AM and a logical channel. The PDCP on the base station device side of SRB1 and SRB2 may be placed in the master node. SRB3 is a PDCP in EN-DC, NGEN-DC, or NR-DC. When a secondary node is added or changed, one SRB3 may be established and / or configured in the terminal device by RRC signaling received from the base station device by the terminal device in an RRC connected state with AS security activated. SRB3 may be a direct SRB between the terminal device and the secondary node. SRB3 is composed of one PDCP entity and one or more The RLC bearer of the SRB3 may consist of the RLC entity of the AM and the logical The PDCP on the base station side of the SRB3 may be placed in a secondary node. One or more DRBs may be established and / or configured in a terminal device by RRC signaling received from a base station device by a terminal device in an RRC connected state with AS security activated. A DRB may be composed of one PDCP entity and one or more RLC bearers. The RLC bearers of a DRB A RA may consist of an AM or UM RLC entity and logical channels.

[0100] In MR-DC, a radio bearer in which PDCP is placed in the master node may be called an MN terminated bearer. A radio bearer in which a PDCP is placed is called an SN-terminated bearer. In MR-DC, a radio bearer whose RLC bearer exists only in an MCG may be called an MCG bearer. In MR-DC, a radio bearer whose RLC bearer exists only in an SCG may be called an MCG bearer. In DC, a radio bearer whose RLC bearer exists in both the MCG and SCG may be called a split bearer.

[0101] When MR-DC is configured in a terminal device, the bearer type of SRB1 and SRB2 established / and / or configured in the terminal device may be an MN terminated MCG bearer and / or an MN terminated split bearer. Also, when MR-DC is configured in a terminal device, the bearer type of SRB3 established / and / or configured in the terminal device may be an SN terminated SCG bearer. Also, when MR-DC is configured in a terminal device, the bearer type of the DRB established / and / or configured in the terminal device may be any of all bearer types.

[0102] For an RLC bearer established and / or configured in a cell group configured with E-UTRA, the RLC entity established and / or configured may be an E-UTRA RLC. Also, for an RLC bearer established and / or configured in a cell group configured with NR, the RLC entity established and / or configured may be an NR RLC. When an EN-DC is configured in the terminal device, the PDCP entity established and / or configured for an MN-terminated MCG bearer may be either an E-UTRA PDCP or an NR PDCP. In addition, when EN-DC is set in the terminal device, other bearer types of radio The PDCP established and / or configured for the bearers, i.e., MN terminated split bearer, MN terminated SCG bearer, SN terminated MCG bearer, SN terminated split bearer, and SN terminated SCG bearer, may be an NR PDCP. Also, if NGEN-DC, NE-DC, or NR-DC is configured in the terminal device, the PDCP entity established and / or configured for the radio bearers of all bearer types may be an NR PDCP. may be an NR PDCP.

[0103] In NR, a DRB established and / or configured in a terminal device may be associated with one PDU session. The SDAP entity, PDCP entity, RLC entity, and logical channels established and / or configured in the terminal device may be used to establish and / or configure the SDAP entity, PDCP entity, RLC entity, and logical channels that the terminal device receives from the base station device. The RRC signaling may be established and / or configured.

[0104] Regardless of whether MR-DC is configured or not, the master node is the eNB 102 and the EPC 104 A network configuration in which the master node is the eNB 102 and the 5GC 110 is the core network may be called E-UTRA / EPC. A network configuration in which the master node is the gNB 108 and the 5GC 110 is the core network may be called E-UTRA / 5GC. A network configuration in which the master node is the gNB 108 and the 5GC 110 is the core network may be called NR or NR / 5GC. When MR-DC is not set, the above-mentioned master node is the terminal device and It may refer to the base station device that conducts communication.

[0105] Next, we will explain handover in LTE and NR. Handover is a process in which a UE 122 in an RRC connected state changes its serving cell from a source SpCell to a target SpCell. Handover may be part of mobility control performed by RRC. The UE 122 receives RRC signaling from the eNB 102 and / or the gNB 108 instructing handover. The RRC signaling indicating the handover is the RRC signaling indicating the handover. A message regarding reconfiguration of the RRC connection containing a parameter indicating the server (for example, an information element named MobilityControlInfo or an information element named ReconfigurationWithSync) The above information element named MobilityControlInfo can be This information element may be called a mobility control setting information element, a mobility control setting, or mobility control information. This can be called a reconfiguration information element or a synchronized reconfiguration. The signaling may be a message indicating movement to a cell of another RAT (e.g., MobilityFromEUTRACommand or MobilityFromNRCommand). Handover may also be referred to as reconfiguration with sync. Reconfiguration with sync may be triggered by RRC, DCI, or MAC control element. The UE 122 may be able to perform handover when AS security is activated. When SRB2 is established, at least one DRB is established in part or in whole. The above handover may be rephrased as Layer 3 handover, etc. .

[0106] Explains the RRC signaling flow transmitted and received between the terminal device and the base station device FIG. 4 is a flow chart of procedures for various settings in the RRC according to this embodiment. 4 is a diagram illustrating an example of a flow when RRC signaling is sent from a base station device (eNB 102 and / or gNB 108) to a terminal device (UE 122).

[0107] In FIG. 4, the base station device creates an RRC message (step S400). The base station device may create an RRC message in order to deliver system information (SI) or a paging message. The message is created by the base station device sending RRC signaling to a specific terminal device to perform processing. The processing to be performed on a specific terminal device may be, for example, security-related settings, re-establishment of an RRC connection, handover to a different RAT, or RRC connection reset. The re-establishment of the RRC connection may include processes such as radio bearer control (establishment, modification, release, etc.), cell group control (establishment, addition, etc.), etc. addition, modification, release, etc.), measurement settings, handover, security key updates, etc. The base station device may generate an RRC message based on the received RRC message. The RRC message may be sent in response to the RRC signaling transmitted from the terminal device. The response to the RRC signaling transmitted from the terminal device may include, for example, a response to an RRC setup request, a response to an RRC reconnection request, a response to an RRC resume request, etc. The RRC message includes information (parameters) for various information notifications and settings. These parameters are represented by fields and / or information elements. It may be called ASN.1 (Abstract Syntax Notation One) and described using the notation method. It is okay to do so.

[0108] In FIG. 4, the base station device then transmits the created RRC signaling to the terminal device (step (Step S402). Next, the terminal device performs processing such as setting according to the received RRC signaling if necessary (step S404). After performing the processing, the terminal device may transmit RRC signaling in response to the base station device (not shown).

[0109] RRC signaling may be used for other purposes, not limited to the above examples.

[0110] In the MR-DC, the RRC on the master node side may be used to transfer RRC signaling for SCG side configuration (cell group configuration, radio bearer configuration, measurement configuration, etc.) between the terminal device and the UE. For example, in the EN-DC or NGEN-DC, the RRC transmitted and received between the eNB 102 and the UE 122 may be used. The E-UTRA RRC signaling transmitted to the NE-DC may include NR RRC signaling in the form of a container. Also, the E-UTRA RRC signaling may be included in the NR RRC signaling transmitted and received between the gNB 108 and the UE 122 in the NE-DC. The RRC signaling for the SCG side configuration may be transmitted and received between the master node and the secondary node.

[0111] It should be noted that the RRC signal for E-UTRA transmitted from the eNB 102 to the UE 122 is not limited to the case where MR-DC is used. The RRC signaling for NR may be included in the RRC signaling transmitted from the gNB 108 to the UE 122, and the RRC signaling for NR may include the RRC signaling for E-UTRA.

[0112] An example of parameters included in a message related to RRC connection re-establishment is shown below. Figure 7 shows the RRC connection re-establishment message in NR in Figure 4. FIG. 8 shows an example of an ASN.1 description representing fields and / or information elements related to cell group configuration in FIG. 4. 7 and 8 are examples of ASN.1 descriptions representing fields and / or information elements relating to cell group configuration included in the message. indicates that other information is omitted, and is not part of the ASN.1 notation. Note that even if there is no notation such as <Omitted> or <Omitted>, the information element may be omitted. Note that the ASN.1 example in this embodiment does not exactly follow the ASN.1 notation method. The ASN.1 example in this embodiment is an example of a parameter of RRC signaling in this embodiment, and other Names or other notations may be used, and ASN.1 examples are provided to avoid cluttering the explanation. For this reason, only examples of main information closely related to this embodiment are shown. In some cases, the parameters to be used are not distinguished as fields, information elements, etc., but are all referred to as information elements. In this embodiment, fields, information elements, etc. described in ASN.1 that are included in the RRC signaling may be referred to as information or parameters. Note that the message related to the reconfiguration of the RRC connection may be an RRC reconfiguration message in NR or an RRC connection reconfiguration message in E-UTRA.

[0113] In FIG. 7, the information element named CellGroupConfig may be an information element used for setting, changing, releasing, etc., of a cell group of an MCG or an SCG in NR. The information element named SpCellConfig included in the information element named CellGroupConfig is , may be an information element used to configure a special cell (SpCell). An information element named SpCellConfig may be rephrased as an SpCell configuration information element or SpCell configuration. An information element named SCellConfig included in an information element named CellGroupConfig may be an information element used to configure a secondary cell (SCell). An information element named SCellConfig may be rephrased as an SCell configuration information element or SCell configuration. An information element named ReconfigurationWithSync included in an information element named SpCellConfig may be rephrased as an information element used to configure a secondary cell (SCell). This information element may be a reconfiguration with synchronization information element, or a reconfiguration with synchronization information element. The information element named spCellConfigCommon may contain a new UE identifier named newUE-Identity. The element may be an information element indicating common settings configured in the SpCell. The information element named spCellConfigCommon may be rephrased as SpCell common settings. An information element named sCellConfigCommon included in the information elements may be an information element indicating common settings configured in SCells. The information element named sCellConfigCommon may be rephrased as SCell common settings.

[0114] FIG. 9 shows an information element named ServingCellConfigCommon included in the SpCell configuration or SCell configuration in FIG. 7, that is, a field related to the serving cell common configuration, and / or or an example of ASN.1 description representing an information element. An information element named DownlinkConfigCommon included in an information element named ServingCellConfigCommon may be an information element indicating a common configuration set in the downlink. The information element named DownlinkConfigCommon may be rephrased as a downlink common configuration. An information element named BWP-DownlinkCommon included in an information element named DownlinkConfigCommon may be an information element indicating a common configuration set in the downlink BWP. The information element named BWP-DownlinkCommon may be rephrased as downlink BWP common configuration. The information element named PDCCH-ConfigCommon included in this is the common configuration to be set in the PDCCH. An information element named PDCCH-ConfigCommon may be an information element indicating the PDCCH common configuration. The information element named PDCCH-ConfigCommon may include an information element named commonSearchSpaceList, an information element named searchSpaceSIB1, an information element named searchSpaceOtherSystemInformation, and / or an information element named pagingSearchSpace. The information element named commonSearchSpaceList may contain the information element The information element named searchSpaceSIB1 may be information on a search space for receiving system information (SIB1). The information element named searchSpaceOtherSystemInformation may include information on a search space for receiving system information (SIB2 and later). The information element named pagingSearchSpace may be information on a search space for receiving paging messages.

[0115] The RRC reconfiguration procedure is explained below. The RRC reconfiguration procedure is a procedure in which parameters set by RRC are reconfigured. The RRC reconfiguration procedure may be a procedure for reconfiguring data, information elements, etc. The purpose of the RRC reconfiguration procedure may be some or all of the following (A) to (F). (A) Modifying the RRC connection (B) Perform synchronized reconfiguration. (C) Setting, modifying, and / or releasing measurements (D) Adding, modifying, and / or releasing one or more SCells and cell groups. To do (E) Adding, modifying, and / or releasing conditional handover (CHO) settings (F) Adding, modifying, and / or releasing a conditional PSCell change (CPC) or conditional PSCell addition (CPA) configuration.

[0116] A base station device (network) may initiate an RRC reconfiguration procedure for a terminal device in the RRC_CONNECTED state. At this time, the base station device may apply some or all of the following (A) to (F) to the RRC reconfiguration procedure. Note that "a base station device initiates an RRC reconfiguration procedure for a terminal device" means "a base station device initiates an RRC connection reconfiguration procedure for a terminal device." This may be rephrased as "send a message regarding the setting of the (A) Establishment of a radio bearer other than SRB1 (B) Adding an SCG and one or more SCells (C) Synchronous reconfiguration included in cell group configuration of SCG (D) Synchronous reconfiguration included in MCG cell group configuration (E) Conditional Reconfiguration for Conditional PSCell Changes (F) Conditional Reconfiguration for Conditional Handover or Conditional PSCell Addition

[0117] Included in messages related to RRC connection re-establishment, including security key updates Synchronized reconfiguration may include some or all of the following (A) through (E), triggered by an explicit Layer 2 indicator: (A) Random access to PCell and / or PSCell (B) MAC Reset (C) Security Updates (D) Re-establishing RLC (E) Re-establishment of PDCP

[0118] Messages related to RRC connection re-establishment, including security key updates Unsynchronized reconfiguration may include some or all of the following (A) through (D), triggered by an explicit Layer 2 indicator: (A) Random access to PCell and / or PSCell (B) MAC Reset (C) Re-establishing RLC (D)PDCP Data Recovery

[0119] The above-mentioned layer 2 indicators may include layer 2 signaling such as MAC, RLC, and PDCP.

[0120] The terminal device may: When a conditional reset (CHO, CPA, or CPC) is executed, some or all of the following items (A) through (E) may be performed: May be performed. (Processing RRP) (A) If a message regarding re-establishment of the RRC connection is sent at the start of the RRC re-establishment procedure, If applicable, by performing a conditional reset at the time of cell selection while timer T311 is running, all entries in the entry list described below are removed. (B) If the message regarding the re-establishment of the RRC connection includes the cell group configuration of the MCG If so, perform the cell group configuration for the received MCG cell group configuration, If the cell group configuration includes an SpCell configuration accompanied by a synchronized reconfiguration information element, synchronized reconfiguration is performed. (C) If the message regarding the re-establishment of the RRC connection includes the cell group configuration of the SCG If so, configure the cell group for the SCG and verify that the cell group configuration is synchronized. If the SpCell configuration includes a reconfiguration information element, a synchronized reconfiguration is performed. (D) If the message regarding the reconfiguration of the RRC connection includes a conditional reconfiguration, perform the conditional reconfiguration. (E) Submit an RRC reconfiguration complete message to the lower layers (PHY, MAC, etc.) for transmission using the new configuration.

[0121] In order to execute synchronous reconfiguration, the terminal device must: "Perform synchronized reconfiguration" means "Perform synchronized reconfiguration" This may be rephrased as "to trigger a synchronized reconfiguration" or "to trigger a synchronized reconfiguration." (Processing RWS) (A) If timer T310 for the corresponding SpCell is running, it is stopped. (B) If timer T312 for the corresponding SpCell is running, it is stopped. (C) Reset the MAC entity of the corresponding cell group. (D) The value of the new UE identifier (newUE-Identity) included in the synchronization reconfiguration information element is set to the corresponding The C-RNTI is applied as the C-RNTI for the cell group. (E) Configure the lower layers (PHY, etc.) according to the received SpCell common settings.

[0122] Next, conditional reconfiguration will be described. Conditional reconfiguration may refer to conditional handover, conditional PSCell addition, and / or conditional PSCell modification. The network configures one or more target candidate cells for conditional reconfiguration for the terminal device. The terminal device evaluates the status of the configured candidate cells. The terminal device performs the evaluation and applies conditional reconfiguration information elements associated with candidate cells that satisfy an execution condition. Furthermore, the terminal device may retain a list of entries (VarConditionalReconfig) described below for conditional reconfiguration.

[0123] Based on receiving information regarding conditional reconfiguration, the terminal device may perform an operation to erase a target candidate cell for conditional reconfiguration if the information regarding conditional reconfiguration includes an entry deletion list (condReconfigToRemoveList), and may perform an operation to add or modify a target candidate cell for conditional reconfiguration if the information regarding conditional reconfiguration includes an entry addition modification list (condReconfigToAddModList).

[0124] The operation of deleting the target candidate cell for the conditional reconfiguration may be, when an entry identifier (condReconfigId) included in the entry deletion list is included in a list of entries held by the terminal device, the terminal device deleting an entry corresponding to the entry identifier from the list of entries held by the terminal device. In the following description, the list of entries held by the terminal device will also be simply referred to as an entry list. In other words, unless otherwise specified, the "entry list" in the following description refers to a list of entries held by the terminal device. In addition, the entry list may be a variable named VarConditionalReconfig. In addition, the entry identifier will also be simply referred to as an entry identifier.

[0125] The operation of adding or modifying a target candidate cell for the conditional reconfiguration may be that when each entry identifier included in the entry addition / modification list exists in an entry in the entry list, the terminal device performs the following processing (A) and / or (B): (A) If an entry included in the addition / modification list of an entry includes an execution condition (condExecutionCond), the execution condition of the entry in the entry list that matches the entry identifier of this entry is replaced with the execution condition included in the addition / modification list of that entry. (B) If an entry included in the addition modification list of an entry includes a conditional reconfiguration information element (condRRCReconfig), replace the conditional reconfiguration information element in the entry list that matches the entry identifier of this entry with the conditional reconfiguration information element included in the addition modification list of that entry.

[0126] Furthermore, if an entry identifier included in the entry addition / modification list is not included in the entry list, the terminal device may add to the entry list a new entry corresponding to the entry identifier not included in the entry list.

[0127] The entry deletion list may be a list of one or more candidate SpCell settings to be deleted. The entry addition / modification list may be a list of the settings of one or more candidate SpCells to be deleted. The entry list may be a list of one or more candidate SpCell configurations to be added and modified. Each entry included in the entry addition / modification list includes an entry identifier, and may also include an execution condition and / or a conditional reconfiguration information element. Each entry may be associated with one of one or more candidate SpCells. The entry identifier is an identifier used to identify each entry of the CHO, CPA, and CPC. The entry list may be The entry list may include multiple entries. Each entry may include an entry identifier, one or more execution conditions, and one conditional reconfiguration information element. If the entry list held by the terminal device does not include any entries, the terminal device may hold an empty list. The execution condition may be a condition that needs to be met to trigger the execution of the conditional reconfiguration. The conditional reconfiguration information element may be an RRC connection that is applied when the execution condition is met. The message may be a message relating to re-establishment of the RRC connection. The message may be a message used to connect to a candidate SpCell.

[0128] The terminal device may evaluate the execution conditions of the entries included in the entry list held by the terminal device. If the entry list held by the terminal device is empty or if the terminal device does not hold an entry list, it is not necessary to evaluate the execution conditions.

[0129] Performing a conditional reconfiguration may mean, when one or more execution conditions are met, applying a conditional reconfiguration information element included in the same entry as the one or more execution conditions, and performing an RRC reconfiguration procedure based on the conditional reconfiguration information element.

[0130] If there are multiple candidate cells that satisfy the execution conditions, the terminal device may select one cell from the multiple candidate cells that satisfy the execution conditions and apply the conditional reconfiguration information element associated with the selected candidate cell.

[0131] When a MAC entity of a terminal device is requested to reset the MAC entity from an upper layer (such as RRC), the MAC entity may perform some or all of the following steps (A) to (O). The reset of the MAC entity may be referred to as a MAC reset. In addition, the MAC entity of the terminal device performs part of the following processes (A) to (O): This can be rephrased as a partial MAC reset, and is a partial MAC entity reset. This can be rephrased as the process of partially resetting a MAC entity. " may be rephrased as "instruct the MAC entity to perform a partial reset," etc. (Processing MR) (A) The parameter Bj set for each logical channel is initialized to 0. (B) Stop all timers if they are running. (C) Set the New Data Indicator (NDI) value of all uplink HARQ processes to 0. do. (D) Stop any ongoing random access procedures. (E) Discard explicitly signaled contention-free random access (CFRA) resources for 4-step and 2-step RA types, if any. (F) Flush the Msg3 buffer. (G) Flush the MSGA buffer. (H) Cancel any triggered SR procedures, if any. (I) Cancel any triggered BSR procedures, if any. (J) Cancel any triggered PHR procedures, if any. (K) Cancel any triggered confirmation of configured uplink grants, if any. (L) Flushes the soft buffers of all downlink HARQ processes. (M) For each downlink HARQ process, The next received transmission is considered to be the very first transmission. (N) Release the Temporary C-RNTI, if any. (O) Reset all BFI_COUNTERs.

[0132] This section describes multiple Transmit / Receive Point (also referred to as multi-TRP or mTRP) operation.

[0133] In mTRP operation, the serving cell may use the IEEE 802.11a / b / g / n IEEE 802.1 ... It is possible to schedule terminal devices from multiple TRPs (Transmit / Receive Points). stomach.

[0134] There are two different operation modes for scheduling PDSCH transmissions in mTRP: The two operation modes may be single-DCI and multi-DCI. The control of uplink and downlink operation for the mode is configured by the RRC layer. In single-DCI mode, the terminal device may be scheduled for both TRPs by the same DCI. In multi-DCI mode, In this case, a terminal device may be scheduled for each TRP by an independent DCI.

[0135] Each TRP in the mTRP may be identified by TRP information. For example, the TRP information may include one or The TRP information may be information for identifying one of a plurality of TRPs. For example, the TRP information may be For example, a TRP may be determined based on the TRP information. For example, the TRP information may be used to identify one or more TRPs. The TRP information may be information for selecting one TRP. The TRP information may be a CORESET pool index. One CORESET may be associated with one CORESET pool index and one CORESET resource set identifier. The terminal device may transmit a PUSCH in the corresponding TRP based on the CORESET resource set identifier. The TRP information may be associated with an index of a CORESET resource pool. For example, a first CORESET pool index may be associated with a first TRP, and a second CORESET pool index may be associated with a second TRP. The TRP information may be associated with a pool of TCI states (or a pool index of TCI states). For example, a first TCI state pool (or pool index) may be associated with a first TRP, and a second TCI state pool (or pool index) may be associated with a second TRP.

[0136] There are two different operation modes for scheduling PDCCH transmissions in mTRP: Two operation modes may be PDCCH repetition and single frequency network (SFN) based PDCCH transmission. In both modes, the terminal device can receive each of the PDCCH transmissions carrying the same DCI from each TRP. In PDCCH repetition mode, the terminal device can receive two PDCCH transmissions each associated with a different CORESET. In an SFN-based PDCCH transmission mode, the terminal device can receive two PDCCH transmissions carrying the same DCI from linked search spaces / CORESETs using different TCI states.

[0137] In the mTRP PUSCH repetition, the terminal device may select beams associated with different spatial relations corresponding to two TRPs by indication of a single DCI or a configured uplink grant provided by RRC signaling. The PUSCH transmissions of the same content may be performed in both directions.

[0138] In inter-cell mTRP operation, one of the multi-DCI PDSCH transmissions Multiple TCI states may be associated with SSBs of a Physical Cell Identity (PCI) different from the PCI of the serving cell. There can be at most one TCI state associated with a PCI different from the cell.

[0139] Next, we will explain the central unit (CU) and distributed unit (DU). The central unit may be a logical node that hosts the RRC layer, SDAP layer, and PDCP layer of the base station device. The distributed unit may be a logical node that hosts the RLC layer of the base station device. An aggregation unit may be a logical node that hosts the MAC layer and the PHY layer. An aggregation unit may control the operation of one or more distributed units. A distributed unit may support one or more cells, and one cell may be supported by only one distributed unit, i.e., one distributed unit may be associated with one or more cells.

[0140] Next, Layer 1 / Layer 2 mobility (L1 / L2 mobility) in this embodiment will be described. Layer 1 / Layer 2 mobility is a method in which a base station device assigns a target cell to a terminal device. Additionally or alternatively, Layer 1 / Layer 2 mobility may refer to a procedure in which a terminal device changes its serving cell to one or more cells indicated by a DCI or MAC control element received from a base station device that allows the terminal device to specify one or more target cells for the serving cell. The DCI that allows the terminal device to specify one or more target cells for the serving cell may be a DCI or MAC control element received from a base station device that allows the terminal device to specify one or more target cells for the serving cell. DCI indicating one or more target cells of the serving cell of the terminal device to be changed Similarly, the MAC control element that allows the terminal device to specify one or more target cells of the serving cell may be the MAC control element that the base station device changes the serving cell of the terminal device. a MAC control element indicating one or more target cells of the serving cell; The DCI and MAC control elements that allow the terminal device to identify one or more target cells of the serving cell may include other information that indicates a change of serving cell. The terminal device may be instructed to change one or more serving cells through a DCI or MAC control element that allows the terminal device to identify one or more target cells of the serving cell based on one or more received measurement reports. Note that "Layer 1 / Layer 2 mobility" refers to "Layer 1 / Layer 2-based It may be rephrased as "inter-cell mobility (L1 / L2 based inter-cell mobility)," "Layer 1 / Layer 2 inter-cell mobility," "Layer 1 / Layer 2 serving cell change procedure," "Layer 1 / Layer 2 serving cell change," or "Layer 1 / Layer 2 handover." The "DCI that allows a terminal device to identify one or more target cells of the serving cell" may be rephrased as "DCI that allows a terminal device to change the serving cell to one or more target cells." "DCI for instructing a terminal device to change one or more serving cells" or "DCI for changing one or more serving cells of the terminal device" may be rephrased as "MAC control element for causing a terminal device to specify one or more target cells of the serving cell" or "DCI for changing one or more target cells of the serving cell". "MAC control element instructing a change of serving cell" and "one or more terminal devices" This can be rephrased as "MAC control element that changes multiple serving cells" DCI can also be called Layer 1 signaling, and MAC control element. The layer 1 element may be referred to as Layer 2 signaling. Layer 2 may be one of the MAC layer, the RLC layer, the PDCP layer, and the SDAP layer. The above-mentioned measurements may be performed by layer 1 and / or layer 3, i.e., the RRC layer.

[0141] In Layer 1 / Layer 2 mobility, the base station device changes the serving center of the terminal device. One or more candidate cells for the target of a cell may be called a candidate cell, a candidate target cell, or some other name. In Layer 1 / Layer 2 mobility, a candidate cell is a cell that the terminal device is connected to in one or more serving Before changing the candidate cell to one or more target cells, one or more candidate cells may be set in the terminal device by the base station device. The cell may be an SpCell or an SCell. In Layer 1 / Layer 2 mobility, a group (a set of cells) of one or more candidate cells as targets of the serving cell of a terminal device changed by a base station device may be called a candidate cell group (CCG), or may be called a candidate cell set, a configured cell set, or other names. In Layer 1 / Layer 2 mobility, a CCG may be a group of some or all of the cells included in an MCG or an SCG. In Layer 1 / Layer 2 mobility, one or more CCGs may be configured in a terminal device by a base station device before the terminal device changes one or more serving cells to one or more target cells. The candidate target may be the candidate cell described above, or the candidate cell of the CCG described above. Additionally or alternatively, in Layer 1 / Layer 2 mobility In this case, the candidate targets may include both the candidate cells and CCGs mentioned above. In Y2 mobility, one or more target cells are configured in the terminal device. These may be one or more candidate cells and / or one or more cells identified by a DCI or MAC control element that allows the terminal device to identify one or more target cells for the serving cell from among one or more CCGs configured in the terminal device.

[0142] In Layer 1 / Layer 2 mobility, a base station device provides one or more A configuration indicating information about multiple candidate cells and / or one or more CCGs may be referred to as an L1 / L2 inter-cell mobility candidate target configuration, or by other names such as candidate target configuration, candidate cell configuration, CCG configuration, etc. Additionally or alternatively, in Layer 1 / Layer 2 mobility, The inter-cell mobility candidate target setting is a set of candidate targets that a base station device provides to a terminal device. Layer 1 / Layer 2 may refer to a setting that indicates information about multiple candidate targets. In mobility, Layer 1 / Layer 2 inter-cell mobility candidate target configuration can be one or more It may include a set of candidate targets or multiple candidate targets, and may be applied to one or more candidate targets. In Layer 1 / Layer 2 mobility, the base station device prepares one or more candidate cells and provides the terminal device with a Layer 1 / Layer 2 inter-cell mobility candidate target configuration including the configuration of the candidate cells. In this case, the terminal device may Upon receiving the configuration, the base station device may start measuring the candidate cell and reporting the measurements. In this case, the base station device may prepare one or more CCGs and provide the terminal device with a Layer 1 / Layer 2 inter-cell mobility candidate target configuration including the configuration of the CCG. When the terminal device receives the Layer 1 / Layer 2 inter-cell mobility candidate target configuration, and transmits measurements of each candidate cell of the CCG and a report thereof to the base station device. For example, in Layer 1 / Layer 2 mobility, a base station device may start DCI to change one or more serving cells of the By notifying the terminal device of the information indicating which CCG it is, the terminal device can In addition, for example, in Layer 1 / Layer 2 mobility, The base station device performs MAC control to change one or more serving cells of the terminal device. The cell element communicates information indicating which candidate cell or CCG the terminal device is referring to. By notifying the terminal device, the terminal device may change one or more serving cells.

[0143] In Layer 1 / Layer 2 mobility, some or all of the following mobility (A) to (C) In addition, in a terminal device in which a CA is not set, the following mobility scenario (A) may be supported. This may be a scenario in which only the PCell is changed, or the terminal device in which the CA is configured In the above-described configuration, the mobility scenario (A) below may be a scenario in which the PCell and one or more SCells are changed. (A) PCell change (B) Intra-DU mobility and intra-CU-inter-DU mobility (C) Inter-cell beam management

[0144] In Layer 1 / Layer 2 mobility, the following principles (A) and / or (B) are true: may be applied. (A) The base station device configures Layer 1 / Layer 2 inter-cell mobility candidate targets so that dynamic switching can be performed without requiring full configuration. Prepare. (B) The user plane is responsible for avoiding data loss and additional delays for data recovery. Therefore, communication is performed continuously without resetting as much as possible.

[0145] In Layer 1 / Layer 2 mobility, Layer 1 / Layer 2 inter-cell mobility candidate target configuration is performed by the RRC signaling (A) to (C) below or other control information (RRC signaling). The terminal device may be notified in advance by a notification (e.g., a notification message) and may store the layer 1 / layer 2 inter-cell mobility candidate target configuration until receiving a DCI or MAC control element from layer 1 or layer 2 instructing a change of serving cell to one or more target cells. In inter-unit mobility, the Layer 1 / Layer 2 inter-cell mobility candidate target setting is may be common to and part of the Layer 1 / Layer 2 inter-cell mobility candidate targeting; In addition, the layer 1 / layer 2 inter-cell mobility candidate target setting may be It may include some or all of the following: system information (searchSpaceSIB1, searchSpaceOtherSystemInformation, etc.), paging messages (pagingSearchSpace, etc.), and common search spaces (commonSearchSpaceList, etc.). No key update is required. (A) Messages regarding re-establishment of the RRC connection for each candidate target (B) Cell group configuration for each candidate target (C) SpCell or SCell configuration for each candidate target

[0146] Handover interruption time for Layer 1 / Layer 2 mobility and The terminal device receives, from layer 1 or layer 2, a DCI or MAC control element instructing a change of serving cell to one or more target cells, and then first changes downlink / uplink in the beam of the one or more target cells. It may be the time until transmission and reception are performed. The handover interruption time for Layer 1 / Layer 2 mobility may include the time to process some or all of the following (A) to (F). This can be rephrased as "Layer 1 / Layer 2 mobility delay" or "Layer 3 mobility delay." (A) UE reconfiguration (B) Measurements in Layer 1 and / or RRC (C) Downlink Synchronization (D) Uplink Synchronization (E) TRS (Temporary RS) Tracking (F) CSI-RS measurement

[0147] Based on the above description, various embodiments of the present invention will be described. Note that the processes described above may be applied to the processes omitted in the following description.

[0148] 5 is a block diagram showing the configuration of a terminal device (UE 122) in this embodiment. In order to avoid a complicated explanation, FIG. 5 shows only the main components closely related to this embodiment. Show only.

[0149] The UE 122 shown in FIG. 5 includes a receiver 500 that receives control information (DCI, RRC signaling, etc.) from a base station device, a processor 502 that performs processing according to parameters included in the received control information, and a transmitter 504 that transmits the control information (UCI, RRC signaling, etc.) to the base station device. The base station device may be the eNB 102 or the gNB 108. The processing unit 502 includes various layers (for example, a physical layer, a MAC layer, an RLC layer, a PDCP layer, an SDAP layer, an RRC layer, and an NAS layer). That is, the processing unit 502 may include a physical layer processing unit, a MAC layer processing unit, an RLC layer processing unit, a PDCP layer processing unit, an SDAP processing unit, an RRC layer processing unit, and an NAS layer processing unit. may include some or all of the following.

[0150] FIG. 6 is a block diagram showing the configuration of a base station device in this embodiment. To avoid clutter, FIG. 6 shows only the main components closely related to this embodiment. The base station device may be the eNB 102 or the gNB 108.

[0151] The base station apparatus shown in FIG. 6 includes a transmitter 600 that transmits control information (DCI, RRC signaling, etc.) to the UE 122, a processor 602 that creates control information (DCI, RRC signaling including parameters, etc.) and transmits it to the UE 122, causing the processor 502 of the UE 122 to process it, and a receiver 604 that receives the control information (UCI, RRC signaling, etc.) from the UE 122. The processor 602 may include some or all of the functions of various layers (e.g., the physical layer, MAC layer, RLC layer, PDCP layer, SDAP layer, RRC layer, and NAS layer). That is, the processor 602 may include some or all of the functions of the physical layer processor, MAC layer processor, RLC layer processor, PDCP layer processor, SDAP processor, RRC layer processor, and NAS layer processor. may include all of them.

[0152] An example of the processing of the terminal device in this embodiment will be described with reference to FIG.

[0153] 10 is a diagram showing an example of processing by a terminal device in this embodiment. Upon receiving a MAC control element from the transmitter 600 of the gNB 108, the RRC 308 of the processor 502 of the UE 122 determines the conditions (step S1000) and operates based on the determination (step S1002).

[0154] In step S1000, the RRC 308 of the processing unit 502 of the UE 122 selects one of the following (a) to (e): It may be determined whether any one or any combination is satisfied. (a) The MAC control element received from the transmitter 600 of the gNB 108 is one of the targets. In a MAC control element that indicates a change of serving cell to one or more cells be. (b) The MAC control element received from the transmitter 600 of the gNB 108 is It contains information that indicates that the MAC entity should be reset upon change. (c) The MAC control element received from the transmitter 600 of the gNB 108 is It contains information to instruct the MAC entity to perform a partial reset when a change occurs. It can be enjoyed. (d) The MAC control element received from the transmitter 600 of the gNB 108 is It contains information indicating that the RLC entity is to be re-established in the event of a change. (e) The MAC control element received from the transmitter 600 of the gNB 108 is It contains information indicating that the PDCP entity will be re-established upon change.

[0155] If it is determined in step S1000 that the condition (a) is satisfied, the RRC 308 of the processing unit 502 of the UE 122 determines in step S1002 that the serving cell is one of the targets or If it is determined that the condition (a) is not met, the state In step S1002, the serving cell is changed to the one or more target cells. Furthermore, if the RRC 308 of the processing unit 502 of the UE 122 determines in step S1000 that the condition (b) is satisfied, the RRC 308 may reset the MAC entity when the serving cell is changed in step S1002. At this time, the MAC 302 of the processing unit 502 of the UE 122 may perform part or all of the processing shown in the above processing (MR) when the serving cell is changed in step S1002. In addition, the RRC 308 of the processing unit 502 of the UE 122 may perform the following in step S1000: If it is determined that the condition (b) is not satisfied, in step S1002, the MAC entity does not need to be reset when the serving cell is changed. In step S1002, the MAC 302 performs the above process (MR) when changing the serving cell. In addition, if the RRC 308 of the processing unit 502 of the UE 122 determines in step S1000 that the condition (c) is satisfied, the RRC 308 of the processing unit 502 of the UE 122 performs the following process in step S1002: In this case, the MAC entity is configured to perform a partial reset when the serving cell changes. At this time, the MAC 302 of the processing unit 502 of the UE 122 may instruct the server in step S1002. In addition, if the RRC 308 of the processing unit 502 of the UE 122 determines in step S1000 that the condition (c) is not satisfied, the RRC 308 may not instruct the MAC entity to perform a partial reset when the serving cell is changed in step S1002. In this case, the MAC 302 of the processing unit 502 of the UE 122 may not instruct the MAC entity to perform a partial reset when the serving cell is changed in step S1002. Furthermore, if the RRC 308 of the processing unit 502 of the UE 122 determines in step S1000 that the condition (d) is satisfied, the RRC 308 of the processing unit 502 of the UE 122 performs the following in step S1002: If the RRC 308 of the processing unit 502 of the UE 122 determines in step S1000 that the condition (e) is satisfied, the RLC entity may be re-established when the serving cell is changed, or if the RRC 308 determines in step S1002 that the condition (e) is satisfied, the RLC entity may not be re-established when the serving cell is changed. The PDCP entity may be re-established upon a change of the receiving cell, and the condition (e) above is satisfied. If it is determined that the PDCP encoder is not used when changing the serving cell, in step S1002, The MAC control element described in the above conditions (a) to (e) does not need to be re-established. The elements may be common to multiple conditions or may be independent of each other.

[0156] Another example of the processing of the terminal device in this embodiment will be described with reference to FIG. 10. Processing of a UE 122 instructed by a lower layer (layer 1 or layer 2) of a cell group including at least one SpCell to change its serving cell to one or more target cells. The RRC 308 of the control unit 502 judges the conditions (step S1000) and operates based on the judgment ( Step S1002).

[0157] In step S1000, the RRC 308 of the processing unit 502 of the UE 122 determines whether or not the configuration of the candidate targets is stored. If it is determined that the configuration of the candidate targets is stored, the RRC 308 may determine whether or not either or both of the following (a) and (b) are satisfied. If it is determined that the configuration of the candidate targets is not stored, the RRC 308 of the processing unit 502 of the UE 122 may determine whether or not the serving cell is set to one or more of the targets in step S1002. There is no need to change it to the cell. (a) The setting of the candidate target includes information #A. (b) The setting of the candidate target includes information #B.

[0158] The information #A may include any one or any combination of the following (a-1) to (a-4), and other information may also be included in the information #A. (a-1) Information indicating that the MAC entity is reset when the serving cell is changed (a-2) Information for instructing the MAC entity to perform a partial reset when the serving cell is changed (a-3) Information indicating that an RLC entity is re-established when a serving cell is changed (a-4) Information indicating that a PDCP entity is to be re-established when a serving cell is changed

[0159] In step S1000, the RRC 308 of the processing unit 502 of the UE 122 determines that the condition (a) is satisfied, and if the information #A includes the above information (a-1), in step S1002, The RRC 308 of the processing unit 502 may perform the following process (a'-1) and add the above information to the information #A. If the information #A does not include the information (a-1), the RRC 308 of the processing unit 502 of the UE 122 does not need to perform the process of (a'-1) below in step S1002. Also, the RRC 308 of the processing unit 502 of the UE 122 determines in step S1000 that the condition (a) is satisfied, and if the information #A includes the above information (a-2), If so, in step S1002, the RRC 308 of the processing unit 502 of the UE 122 performs the following process (a'-2): If the information #A does not include the above information (a-2), the RRC 308 of the processing unit 502 of the UE 122 does not need to perform the following processing (a'-2) in step S1002. Also, if the RRC 308 of the processing unit 502 of the UE 122 determines in step S1000 that the condition (a) is satisfied and the information #A includes the above information (a-3), the RRC 308 of the processing unit 502 of the UE 122 does not need to perform the following processing (a'-2) in step S1002. The RRC 308 of the processing unit 502 of the UE 122 may perform the process of (a'-3) below, and if the information #A does not include the above information (a-3), the RRC 308 of the processing unit 502 of the UE 122 may not perform the process of (a'-3) below in step S1002. Also, if the RRC 308 of the processing unit 502 of the UE 122 determines in step S1000 that the condition (a) is satisfied and the information #A includes the above information (a-4), the RRC 308 of the processing unit 502 of the UE 122 may perform the process of (a'-4) below in step S1002. If the information #A does not include the above information (a-4), the RRC 308 of the processing unit 502 of the UE 122 does not need to perform the following processing (a'-4) in step S1002. In step S1000, the RRC 308 of the processing unit 502 determines that the condition (a) is satisfied, If the information #A includes other information, in step S1002, the processing unit 502 of the UE 122 The RRC 308 may perform processes other than the following (a'-1) to (a'-4). The following processes (a'-1) to (a'-4) may be combined with each other. Furthermore, the following process (a'-1) may be part or all of the process shown in the above process (MR), and the following process (a'-2) may be part of the process shown in the above process (MR). (a'-1) When the serving cell is changed, the MAC entity of the cell group is reset. do. (a'-2) When a serving cell is changed, a partial link is assigned to the MAC entity of the cell group. Instruct them to perform a set. (a'-3) Re-establishing an RLC entity when the serving cell changes. (a'-4) Re-establishing a PDCP entity when a serving cell is changed.

[0160] The information #B may include any one of the following (b-1) to (b-2), or any combination thereof, and other information may also be included in the information #B. (b-1) Information indicating the group to which each candidate target belongs (b-2) List information of candidate targets

[0161] In step S1000, when the RRC 308 of the processing unit 502 of the UE 122 determines that the condition (b) is satisfied and the information #B includes the above information (b-1), the RRC 308 may determine whether to perform some or all of the processes from (a'-1) to (a'-4) based on the information (b-1). For example, when one or more target cells instructed from a lower layer belong to the same group as some or all of the cells before the serving cell change, the RRC 308 of the processing unit 502 of the UE 122 may determine whether to perform some or all of the processes from (a'-1) to (a'-4) in step S1000. In step S1002, based on the above determination, the above (a'-1) to (a'-4) are performed. In addition, if one or more target cells instructed from the lower layer belong to a group different from some or all of the cells before the serving cell change, the RRC 308 of the processing unit 502 of the UE 122 may not perform some or all of the above processes in step S1000. It is determined that part or all of the processes (a'-1) to (a'-4) are to be performed, and in step S1002 Based on the determination, some or all of the processes from (a'-1) to (a'-4) above may be performed. Note that the information (b-1) above may be, for example, an identifier indicating the group to which each candidate target belongs. Alternatively, the above information (b-1) may be a list of candidate targets belonging to each group. For example, an identifier for identifying each candidate cell is included in list information associated with each group, and the terminal device may determine that candidate cells with identifiers included in list information of the same group belong to the same group. The described groups may be set by gNB108 based on any one or any combination of the following (b-1-1) to (b-1-6): (b-1-1) Distributed units supporting each candidate target within the same aggregation unit (b-1-2) Whether or not it is necessary to reset the MAC entity of the cell group when changing the serving cell (b-1-3) Whether it is necessary to instruct the MAC entity of the cell group to perform a partial reset when changing the serving cell (b-1-4) Whether or not the RLC entity needs to be re-established when the serving cell is changed (b-1-5) Whether or not the PDCP entity needs to be re-established when the serving cell is changed (b-1-6) Other conditions

[0162] In step S1000, the RRC 308 of the processing unit 502 of the UE 122 determines that the condition (b) is satisfied, and if the information #B includes the above information (b-2), the RRC 308 may determine whether to perform some or all of the processes in the above (a'-1) to (a'-4) based on the information (b-2). For example, if the information (b-2) includes settings corresponding to one or more target cells instructed from a lower layer, the RRC 308 of the processing unit 502 of the UE 122 determines in step S1000 not to perform some or all of the processes in the above (a'-1) to (a'-4), and in step S1002 Based on the determination, some or all of the processes (a'-1) to (a'-4) above may not be performed. Also, if the information (b-2) does not include settings corresponding to one or more target cells instructed from a lower layer, the RRC 308 of the processing unit 502 of the UE 122 determines in step S1000 to perform some or all of the processes (a'-1) to (a'-4) above, and in step S1002, based on the determination, performs some or all of the processes (a'-1) to (a'-4) above. The candidate target corresponding to the setting included in the information (b-2) may be, for example, For example, the determination may be made by the gNB 108 based on whether the candidate target supports intra-distributed unit mobility. The candidate target corresponding to the setting is, for example, the PCI of the candidate target is the serving center. This may be determined by gNB108 based on whether the PCI matches a PCI that is different from the rule.

[0163] If the RRC 308 of the processing unit 502 of the UE 122 determines in step S1000 that the condition (a) is not satisfied, the RRC 308 may determine in step S1002 whether to perform part or all of the processes from (a'-1) to (a'-4) described above based on information other than information #A. Also, if the RRC 308 of the processing unit 502 of the UE 122 determines in step S1000 that the condition (b) is not satisfied, If so, in step S1002, it may be determined based on information other than information #B whether to perform some or all of the above processes (a'-1) to (a'-4).

[0164] In each embodiment, when determining whether the configuration of a candidate target includes information #A, if the configuration of the candidate target includes information indicating that the process corresponding to the information #A is not performed or information not indicating that the process corresponding to the information #A is performed, the RRC 308 of the processing unit 502 of the UE 122 may determine that the configuration of the candidate target does not include information #A.

[0165] In each embodiment, information #A and information #B may be included in the following RRC signaling (A) to (D) of the candidate target configuration, or other control information (RRC signaling, etc.). Note that in each embodiment, the list information may be information indicating a list including one or more of the following settings or parameters (A) to (D), and the list may be, for example, an entry list. Also, in each embodiment, information #A and information #B may be common in the candidate target configuration, or may be indicated independently. (A) Messages regarding re-establishment of the RRC connection for each candidate target (B) Cell group configuration for each candidate target (C) SpCell or SCell configuration for each candidate target (D) Conditional resets for each candidate target

[0166] In each embodiment, the terminal device may have one or more candidate target settings. Additionally or alternatively, the one or more target cells indicated by the lower layer in the serving cell change may be one or more candidate cells and / or may be one or more CCGs. Additionally or alternatively, the candidate target The cell group configuration may include the configuration of one or more candidate cells and / or the configuration of one or more CCGs. Also, the cell group configuration described in (B) above may include the SpCell configuration and The CCG configuration may include the SCell configuration and / or the SCell configuration, and the CCG configuration instructed by a lower layer in a serving cell change may be applied to the cell group of the lower layer.

[0167] According to Non-Patent Document 7, in conventional handover, i.e., Layer 3 handover, the UE triggers a synchronized reconfiguration. A scheduled reconfiguration is triggered by the RRC or by the DCI or MAC control element. Regardless of whether it was triggered or not, the MAC entity is reset based on Non-Patent Document 8. At this time, some of the candidate target configurations are cleared and Layer 1 / Layer 2 mobility is In the above embodiments, the UE may need to acquire some of the configurations of the candidate targets again. In the above embodiments, the part of the configurations of the candidate targets is not erased by the synchronized reconfiguration, and in the Layer 1 / Layer 2 mobility, the UE may need to acquire some of the configurations of the candidate targets again. It can be used as is.

[0168] Unless otherwise specified, the radio bearer in the above description may be a DRB, an SRB, or a combination of a DRB and an SRB.

[0169] In the above description, the terms "user plane," "user plane protocol," "user plane interface," etc. may be interchangeable.

[0170] Also, in the above description, "receive a DCI or MAC control element instructing a change of serving cell to one or more target cells" may be rephrased as "be instructed to change the serving cell to one or more target cells."

[0171] In the above explanation, expressions such as "candidate target", "candidate cell", and "CCG" are used interchangeably. This may also be expressed as:

[0172] Furthermore, unless otherwise specified, the serving cell change in the above description may refer to a Layer 1 / Layer 2 serving cell change.

[0173] In the above description, expressions such as "notified" and "indicated" may be interchangeable.

[0174] In the above description, expressions such as "link," "associate," and "link" may be interchangeable.

[0175] In addition, in the above description, expressions such as "included," "included," and "was included" may be used interchangeably.

[0176] In the above description, "the above-mentioned" may be replaced with "the above-mentioned."

[0177] In the above explanation, "confirmed to be...", "set to be...", "includes..." Expressions such as these may be interchangeable.

[0178] Furthermore, in the examples of each process or each process flow in the above description, some or all of the steps may not be executed. Furthermore, in the examples of each process or each process flow in the above description, the order of the steps may be different. Furthermore, in the examples of each process or each process flow in the above description, some or all of the processing within each step may not be executed. Furthermore, in the examples of each process or each process flow in the above description, the order of the processing within each step may be different. Furthermore, in the above description, "doing B based on A being true" may be rephrased as "doing B". In other words, "doing B" means "being true" may be executed independently.

[0179] In the above explanation, "A may be replaced with B" may mean replacing A with B, as well as replacing B with A. Also, in the above explanation, when it is written that "C may be D" and "C may be E", it may also mean that "D may be E". Also, in the above explanation, when it is written that "F may be G" and "G may be H", it may also mean that "F may be H".

[0180] In the above explanation, if the conditions "A" and "B" are contradictory conditions, the condition "B" may be expressed as the "other" condition of the condition "A."

[0181] The program that runs on the device according to this embodiment may be a program that controls a central processing unit (CPU) or the like to make a computer function so as to realize the functions of this embodiment. The program or the information handled by the program may be temporarily stored in a hard disk during processing. It is automatically loaded into volatile memory such as Random Access Memory (RAM) or flash memory. It is stored in non-volatile memory such as memory or a hard disk drive (HDD) and is retrieved by the CPU as needed. Reading, modifying and writing are performed by this.

[0182] Note that a part of the device in the above-described embodiment may be realized by a computer. In this case, a program for realizing this control function may be recorded on a computer-readable recording medium, and the program recorded on the recording medium may be read and executed by a computer system. The "computer system" here refers to a computer system built into the device, including hardware such as an operating system and peripheral devices. Furthermore, the "computer-readable recording medium" may be any of a semiconductor recording medium, an optical recording medium, a magnetic recording medium, etc.

[0183] Furthermore, "computer-readable recording media" includes those that dynamically store programs for a short period of time, such as communication lines when transmitting programs via networks such as the Internet or communication lines such as telephone lines, and those that store programs for a certain period of time, such as volatile memory within computer systems that serve as servers or clients in such cases. The program may be for realizing part of the above-mentioned functions, or may be a program that already has the above-mentioned functions recorded in a computer system. It may be possible to achieve this in combination with

[0184] Furthermore, each functional block or feature of the device used in the above-described embodiments may be implemented or performed by an electric circuit, typically an integrated circuit or a plurality of integrated circuits. The electric circuit designed to perform the functions described herein may be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable logic circuit (FPLC), a microprocessor (MCU), a microcomputer (CPU ... The general-purpose processor may include a field-programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or a combination thereof. The general-purpose processor may be a microprocessor, or alternatively, the processor may be a conventional processor, controller, microcontroller, or state machine. The general-purpose processor or each of the aforementioned circuits may be composed of digital circuits or analog circuits. Additionally, if advances in semiconductor technology result in the emergence of integrated circuit technologies that can replace current integrated circuits, integrated circuits based on those technologies may also be used.

[0185] It should be noted that the present embodiment is not limited to the above-described embodiment. In the embodiment, an example of a device is described, but the present embodiment is not limited to this, and can be applied to terminal devices or communication devices such as stationary or non-movable electronic devices installed indoors or outdoors, for example, AV equipment, kitchen equipment, cleaning / washing equipment, air conditioning equipment, office equipment, vending machines, and other household appliances.

[0186] Although this embodiment has been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment and includes design modifications within the scope of the gist of this embodiment. Furthermore, this embodiment can be modified in various ways within the scope of the claims, and embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of this embodiment. Furthermore, configurations in which elements described in the above embodiment are substituted with elements that achieve the same effect are also included. [Explanation of symbols]

[0187] 100 E-UTRA 102 eNB 104 EPC 106NR 108 gNB 110 5GC 112, 114, 116, 118, 120, 124 interfaces 122UE 200, 300 PHY 202, 302 MAC 204, 304 RLC 206, 306 PDCP 208, 308 RRC 310 SDAP 210, 312 NAS 500, 604 Receiver 502, 602 Processing section 504, 600 Transmitter

Claims

1. A terminal device that communicates with a base station device, an RRC processing unit; Equipped with The RRC processing unit: When a lower layer of a cell group instructs a change of serving cell to a candidate cell, Based on the setting of the candidate cell held by the RRC processing unit, determining whether to reset a MAC entity when the serving cell is changed; When it is determined that a MAC entity is to be reset upon the serving cell change, The RRC processing unit: resetting a MAC entity of said cell group; If it is determined that the MAC entity is not to be reset when the serving cell is changed, The RRC processing unit: not resetting a MAC entity of said cell group; Terminal device.

2. A method for a terminal device communicating with a base station device, comprising: An RRC entity of the terminal device, When a lower layer of a cell group instructs a change of serving cell to a candidate cell, Based on the configuration of the candidate cells maintained by the RRC entity, A step of determining whether to reset the MAC entity when the serving cell is changed. Top and When it is determined that a MAC entity is to be reset upon the serving cell change, The RRC entity: resetting a MAC entity of the cell group; If it is determined that the MAC entity is not to be reset when the serving cell is changed, The RRC entity: not resetting a MAC entity of said cell group; A method comprising:

3. An integrated circuit implemented in a terminal device that communicates with a base station device, An RRC entity of the terminal device, When a lower layer of a cell group instructs a change of serving cell to a candidate cell, Based on the configuration of the candidate cells maintained by the RRC entity, a function for determining whether to reset a MAC entity when the serving cell is changed; and, When it is determined that a MAC entity is to be reset upon the serving cell change, The RRC entity: resetting a MAC entity of said cell group; If it is determined that the MAC entity is not to be reset when the serving cell is changed, The RRC entity: not resetting a MAC entity of said cell group; An integrated circuit that demonstrates this.

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