JP2022046876A - Terminal apparatus, base station apparatus, metho and integrated circuit - Google Patents

Abstract

To provide a terminal apparatus, a base station apparatus, a method and an integrated circuit capable of efficiently controlling mobility.SOLUTION: A process by a terminal apparatus is as follows: S1000, receiving the RRC message from a base station apparatus and configuring the settings according to the RRC message; S1002, initiating the handover procedure according to the RRC message received from the base station apparatus; and S1004, processing the handover failure based on the expiration of the first timer of the terminal apparatus, and in the handover failure process, based on the fact that the first condition is met, for each SRB, the settings of the terminal apparatus other than the state variables of the PDCP entity are returned to the settings used by the source PCell.SELECTED DRAWING: Figure 10

Description

The present invention relates to terminal devices, base station devices, methods, and integrated circuits.

In the 3rd Generation Partnership Project (3GPP), which is a standardization project for cellular mobile communication systems, technical studies and standardization of cellular mobile communication systems including wireless access, core networks, services, etc. were carried out. There is.

For example, E-UTRA (Evolved Universal Terrestrial Radio Access) is a radio access technology (Radio Access Technology: RAT) for 3.9th and 4th generation cellular mobile communication systems in 3GPP. It was started. At 3GPP, technical studies and standardization of extended technology for E-UTRA are still underway. In addition, E-UTRA is also referred to as Long Term Evolution (LTE: registered trademark), and the extended technology may be referred to as LTE-Advanced (LTE-A) or LTE-Advanced Pro (LTE-A Pro).

In addition, NR (New Radio, or NR Radio access) has been studied and standardized as a radio access technology (Radio Access Technology: RAT) for cellular mobile communication systems for the 5th generation (5th Generation: 5G) in 3GPP. It was started. At 3GPP, technical studies and standardization of NR extended technology are still underway.

3GPP TS 38.300v 16.2.0, “NR; NR and NG-RAN Overall description; Stage 2” pp10-134 3GPP TS 36.300 v16.2.0, “Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access Network (E-UTRAN); Overall description; Stage 2” pp19-361 3GPP TS 38.331 v16.1.0, “NR; Radio Resource Control (RRC); Protocol specifications” pp21-861 3GPP TS 36.331 v16.1.0, “Evolved Universal Terrestrial Radio Access (E-UTRA); Radio Resource Control (RRC); Protocol specifications” pp25-1012 3GPP TS 37.340v 16.2.0, “EvolvedUniversal Terrestrial Radio Access (E-UTRA) and NR; Multi-Connectivity; Stage 2” pp6-67

As one of the NR expansion technologies, a mechanism for expanding the existing NR mobility technology is being studied. One of the extensions of NR's mobility technology is conditional handover. Conditional handover is a technique for improving the robustness of handover by executing a handover procedure by a terminal device when one or a plurality of handover execution conditions are satisfied.

The operation of conditional handover is being standardized, but further study is required for detailed operation.

One aspect of the present invention has been made in view of the above circumstances, and one of the objects of the present invention is to provide a terminal device, a base station device, a method, and an integrated circuit capable of efficiently controlling mobility.

In order to achieve the above object, one aspect of the present invention has taken the following measures. That is, one aspect of the present invention is a terminal device that communicates with the base station device, and the terminal device includes a receiving unit and a processing unit that receive an RRC message from the base station device, and the processing unit includes a processing unit. , The terminal device is set according to the RRC message, the handover failure process is performed based on the fact that the first timer of the terminal device has expired, and the first condition is satisfied in the handover failure process. Based on the fact that each SRB is set, the settings of the terminal device other than the state variables of the PDCP entity are returned to the settings used in the source PCell, and the settings of the terminal device are set for each DRB. A process of returning to the setting used in the source PCell was performed, and the setting of the terminal device was used in the source PCell based on the fact that the first condition was not satisfied in the handover failure process. The process of returning to the setting is performed, and the first condition includes at least that the first setting is made in the terminal device and that the conditional handover performed by the terminal device does not involve key update. The conditional handover is a handover in which the terminal device executes a handover procedure when the conditional handover execution condition set in the terminal device is satisfied.

Further, one aspect of the present invention is a base station device that communicates with a terminal device, wherein the base station device includes a transmission unit and a processing unit that transmit an RRC message to the terminal device, and the processing unit is provided. , The terminal device is made to set according to the RRC message, and the terminal device is made to perform the handover failure process based on the fact that the first timer of the terminal device has expired. Based on the fact that the condition of 1 is satisfied, the setting of the terminal device other than the state variable of the PDCP entity is returned to the setting used in the source PCell for each SRB, and each DRB is subjected to a process. The processing of returning the setting of the terminal device to the setting used in the source PCell is performed, and the setting of the terminal device is set based on the fact that the first condition is not satisfied in the processing of the handover failure. The process of returning to the setting used in the source PCell is performed, and the key to the first condition is that the first setting is made in the terminal device and the conditional handover performed by the terminal device. The conditional handover is a handover in which the terminal device executes the handover procedure when the conditional handover execution condition set in the terminal device is satisfied, at least including the fact that the update is not involved.

Further, one aspect of the present invention is a method of a terminal device that communicates with a base station device, wherein the terminal device receives an RRC message from the base station device, sets the terminal device according to the RRC message, and sets the terminal device. Based on the fact that the first timer of the terminal device has expired, the handover failure process is performed, and based on the fact that the first condition is satisfied in the handover failure process, the PDCP entity is assigned to each SRB. A process of returning the settings of the terminal device other than the state variable of to the settings used in the source PCell, and a process of returning the settings of the terminal device to the settings used in the source PCell for each DRB. Then, in the processing of the handover failure, based on the fact that the first condition is not satisfied, the setting of the terminal device is returned to the setting used in the source PCell, and the first condition is satisfied. At least includes that the first setting is made in the terminal device and that the conditional handover performed by the terminal device does not involve key update, and the conditional handover is set in the terminal device. This is a handover in which the terminal device executes the handover procedure when the conditional handover execution condition is satisfied.

Further, one aspect of the present invention is a method of a base station device that communicates with a terminal device, in which the base station device transmits an RRC message to the terminal device and causes the terminal device to make settings according to the RRC message. Based on the fact that the first timer of the terminal device has expired, the terminal device is made to perform the handover failure processing, and each of the above is based on the fact that the first condition is satisfied in the handover failure processing. The SRB is processed to return the settings of the terminal device other than the state variable of the PDCP entity to the settings used in the source PCell, and the settings of the terminal device are used in the source PCell for each DRB. In the processing of the handover failure, the processing of returning the setting of the terminal device to the setting used in the source PCell is performed based on the fact that the first condition is not satisfied. The first condition includes at least that the first setting is made in the terminal device and that the conditional handover performed by the terminal device does not involve key update, and the conditional handover is performed. Is a handover in which the terminal device executes the handover procedure when the conditional handover execution condition set in the terminal device is satisfied.

It should be noted that these comprehensive or specific embodiments may be realized in a system, an apparatus, a method, an integrated circuit, a computer program, or a recording medium, and the system, an apparatus, a method, an integrated circuit, a computer program, and a recording medium may be realized. It may be realized by any combination of.

According to one aspect of the present invention, the terminal device can realize efficient mobility processing.

The schematic diagram of the communication system which concerns on embodiment of this invention. The figure of an example of the E-UTRA protocol configuration which concerns on embodiment of this invention. The figure of an example of the NR protocol composition which concerns on embodiment of this invention. The figure which shows an example of the flow of the procedure for various setting in RRC which concerns on embodiment of this invention. The block diagram which shows the structure of the terminal apparatus in embodiment of this invention. The block diagram which shows the structure of the base station apparatus in embodiment of this invention. The ASN. An example of one description. The ASN. An example of one description. ASN. Representing a field and / or an information element relating to the setting of a conditional handover in an embodiment of the present invention. An example of one description. The figure which shows an example of the processing of the terminal apparatus in embodiment of this invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

LTE (and LTE-A, LTE-A Pro) and NR may be defined as different radio access technologies (Radio Access Technology: RAT). NR may also be defined as a technique included in LTE. LTE may also be defined as a technique included in NR. In addition, LTE that can be connected to NR by MultiRadio Dual connectivity (MR-DC) may be distinguished from conventional LTE. Further, LTE using 5GC for the core network may be distinguished from conventional LTE using EPC for the core network. The conventional LTE may be an LTE that does not implement the technology standardized after the release 15 in 3GPP. Embodiments of the present invention may be applied to NR, LTE and other RATs. In the following description, terms related to LTE and NR will be used, but embodiments of the present invention may be applied in other techniques using other terms. Further, the term E-UTRA in the embodiment of the present invention may be replaced with the term LTE, and the term LTE may be replaced with the term E-UTRA.

In the embodiment of the present invention, the name of each node or entity when the wireless access technology is E-UTRA or NR, processing in each node or entity, and the like will be described, but the embodiment of the present invention is described. It may be used for other wireless access technologies. The name of each node or entity in the embodiment of the present invention may be another name.

FIG. 1 is a schematic diagram of a communication system according to an embodiment of the present invention. The functions of each node, wireless access technology, core network, interface, etc. described with reference to FIG. 1 are some functions closely related to the embodiment of the present invention, and are non-patent documents 1 to 5 and the like. May have other features listed in. Further, it may have other functions not described in Non-Patent Documents 1 to 5 and the like.

The E-UTRA100 may be the wireless access technology described in Non-Patent Document 2 and the like. Further, the E-UTRA 100 may be an air interface between the UE 122 and the eNB 102. The air interface between the UE 122 and the eNB 102 may be referred to as a Uu interface. The eNB (E-UTRAN Node B) 102 may be a base station device of the E-UTRA 100. The eNB 102 may have the E-UTRA protocol described later. The E-UTRA protocol may be composed of an E-UTRA user plane (UP) protocol described later and an E-UTRA control plane (CP) protocol described later. The eNB 102 may terminate the E-UTRA user plane (User Plane: UP) protocol and the E-UTRA control plane (Control Plane: CP) protocol for the UE 122.

The EPC (Evolved Packet Core) 104 may be the core network described in Non-Patent Document 2 and the like. 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 (and / or) user data passes. The control plane interface of the interface 112 may be terminated by the Mobility Management Entry (MME: not shown) in the EPC 104. The user plane interface of the interface 112 may be terminated by a serving gateway (S-GW: not shown) in the EPC 104. The control plane interface of the interface 112 may be referred to as an S1-MME interface. The user plane interface of the interface 112 may be referred to as an S1-U interface.

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

NR106 may be the wireless access technology described in Non-Patent Document 1 and the like. Also NR106
May be an air interface between the UE 122 and the 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 NR106. The gNB 108 may have the NR protocol described below. The NR protocol may be composed of the NR user plane (UP) protocol described later and the NR control plane (CP) protocol described later. The gNB 108 may terminate the NR user plane (UP) protocol and the NR control plane (CP) protocol for the UE 122.

The 5GC110 may be the core network described in Non-Patent Document 1 and the like. The interface 116 is an interface between the gNB 108 and the 5GC110, and may be referred to as an NG interface. The interface 116 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 the interface 116 may be terminated by the Access and mobility Management Function (AMF: not shown) in the 5GC110. The user plane interface of the interface 116 may be terminated by the User Plane Connection (UPF: not shown) in the 5GC110. The control plane interface of the interface 116 may be referred to as an NG-C interface. The user plane interface of the interface 116 may be referred to as an NG-U interface.

It should be noted that one or more gNB 108s may be connected to the 5GC 110 via the interface 116. An interface may exist between the plurality of gNBs 108 connected to the 5GC110 (not shown). The interface between a plurality of gNB 108s connected to the 5GC110 may be referred to as an Xn interface.

The eNB 102 may have a function of connecting to the 5GC110. The eNB 102 having a function of connecting to the 5GC110 may be referred to as an ng-eNB. The interface 114 is an interface between the eNB 102 and the 5GC110 and may be referred to as an NG interface. The interface 114 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 the interface 114 may be terminated by the Access and mobility Management Function (AMF: not shown) within the 5GC110. The user plane interface of the interface 114 may be terminated by the User Plane Connection (UPF: not shown) in the 5GC110. The control plane interface of the interface 114 may be referred to as an NG-C interface. The user plane interface of the interface 114 may be referred to as an NG-U interface.

It should be noted that one or more eNBs 102 may be connected to the 5GC110 via the interface 114. An interface may exist between the plurality of eNBs 102 connected to the 5GC110 (not shown). The interface between the plurality of eNBs 102 connected to the 5GC110 may be referred to as an Xn interface. Further, the eNB 102 connected to the 5GC110 and the gNB108 connected to the 5GC110 may be connected by the interface 120. The interface 120 between the eNB 102 connected to the 5GC110 and the gNB108 connected to the 5GC110 may be referred to as an Xn interface.

The gNB 108 may have a function of connecting to the EPC 104. The gNB 108 having a function of connecting to the EPC 104 may be referred to as an en-gNB. Interface 118 is an interface between gNB 108 and EPC 104 and may be referred to as an S1 interface. The interface 118 may have a user plane interface through which user data passes. The user plane interface of the interface 118 may be terminated by S-GW (not shown) in the EPC 104. The user plane interface of the interface 118 may be referred to as an S1-U interface. Further, the eNB 102 connected to the EPC 104 and the gNB 108 connected to the EPC 104 may be connected by the interface 120. The interface 120 between the eNB 102 connected to the EPC 104 and the gNB 108 connected to the EPC 104 may be referred to as an X2 interface.

The interface 124 is an interface between the EPC 104 and the 5GC 110, and may be an interface through CP only, UP only, or both CP and UP. Further, some or all of the interfaces 114, the interface 116, the interface 118, the interface 120, the interface 124, and the like may not exist depending on the communication system provided by the telecommunications carrier or the like.

The UE 122 may be a terminal device capable of receiving broadcast information and paging messages transmitted from the eNB and / or gNB. Further, the UE 122 may be a terminal device capable of wireless connection with the eNB 102 and / or the gNB 108. Further, the UE 122 may be a terminal device capable of making a wireless connection with the eNB 102 and a wireless connection with the gNB 108 at the same time. 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 described in Non-Patent Document 3, Non-Patent Document 4, and the like.

As described in Non-Patent Document 3, Non-Patent Document 4, etc., when the UE 122 communicates with the eNB 102 and / or the gNB 108, a radio bearer (RB: Radio Bearer) is provided between the UE 122 and the eNB 102 and / or the gNB 108. You may make a wireless connection by establishing. The radio bearer used for CP may be referred to as a signaling radio bearer (SRB: Signaling Radio Bearer). Further, the radio bearer used for UP may be referred to as a data radio bearer (DRB Data Radio Bearer). A radio bearer identifier (ID) may be assigned to each radio bearer. The radio bearer identifier for SRB may be referred to as an SRB identifier (SRB Identity or SRB ID). The radio bearer identifier for DRB is a DRB identifier (DRB).
It may be called Identity, or DRB ID).

Further, the UE 122 may be a terminal device capable of being connected to the EPC 104 and / or the 5GC 110 via the eNB 102 and / or the gNB. When the connection destination core network of the eNB 102 and / or the gNB 108 with which the UE 122 communicates is the EPC 104, each DRB established between the UE 122 and the eNB 102 and / or the gNB 108 further goes through each EPS within the EPC 104. (Evolved Packet System) It may be uniquely associated with the bearer. Each EPS bearer may be identified by an EPS bearer identifier (Identity or ID). Further, the same QoS may be guaranteed for data such as IP packets passing through the same EPS bearer and Ethernet (registered trademark) frames.

Further, when the connection destination core network of the eNB 102 and / or the gNB 108 with which the UE 122 communicates is 5GC110, each DRB established between the UE 122 and the eNB 102 and / or the gNB 108 is further established in the 5GC110. It may be associated with one of the PDU (Packet Data Unit) sessions. There may be one or more QoS flows in each PDU session. Each DRB may be associated (mapped) with one or more QoS flows and may not be associated with any QoS flow. Each PDU session may be identified by a PDU session identifier (Identity, Identity, or ID). In addition, each QoS flow has a QoS flow identifier Identi.
It may be identified by ty, Identifier, or ID). Further, the same QoS may be guaranteed for data such as IP packets and Ethernet frames that pass through the same QoS flow.

The EPC 104 does not have to have a PDU session and / or a QoS flow. Further, the EPS bearer does not have to exist in the 5GC110. When the UE 122 is connected to the EPC 104, the UE 122 has information on the EPS bearer, but does not have to have the information in the PDU session and / or the QoS flow. Further, when the UE 122 is connected to the 5GC110, the UE 122 has the information in the PDU session and / or the QoS flow, but does not have to have the information of the EPS bearer.

In the following description, the eNB 102 and / or the gNB 108 are also simply referred to as a base station device, and the UE 122 is also simply referred to as a terminal device.

FIG. 2 is a diagram of an example of an E-UTRA protocol configuration (protocol architecture) according to an embodiment of the present invention. Further, FIG. 3 is a diagram of an example of the NR protocol configuration according to the embodiment of the present invention. The functions of each protocol described with reference to FIGS. 2 and / or 3 are some functions closely related to the embodiment of the present invention, and as shown in Non-Patent Documents 1 to 4, etc. You may have the function of. Further, it may have other functions not described in Non-Patent Documents 1 to 4 and the like. In the embodiment of the present invention, the uplink (UL) may be a link from the terminal device to the base station device. Further, in each embodiment of the present invention, the downlink (downlink: DL) may be a link from the base station device to the terminal device.

FIG. 2A is a diagram of the E-UTRA user plane (UP) protocol stack. As shown in FIG. 2A, the E-UTRAN UP protocol may be a protocol between the UE 122 and the eNB 102. That is, the E-UTRAN UP protocol may be a protocol terminated by eNB 102 on the network side. As shown in FIG. 2A, the E-UTRA user plane protocol stack is described in PHY (Physical layer) 200, non-patent document 2 and the like, which is the radio physical layer (radio physical layer) described in non-patent document 2 and the like. MAC (Media Access Control) 202, which is a medium access control layer (medium access control layer), RLC (Radio Link Control) 204, which is a wireless link control layer (radio link control layer) described in Non-Patent Document 2 and the like, and It may be composed of PDCP (Packet Data Convergence Protocol) 206, which is a packet data convergence protocol layer (packet data convergence protocol layer) described in Non-Patent Document 2 and the like.

FIG. 3A is a diagram of the NR user plane (UP) protocol stack. As shown in FIG. 3A, the NR UP protocol may be a protocol between UE 122 and gNB 108. That is, the NR UP protocol may be a protocol terminated by gNB108 on the network side. As shown in FIG. 3A, the E-UTRA user plane protocol stack includes PHY300, which is a radiophysical layer described in Non-Patent Document 1, etc., and MAC302, which is a medium access control layer described in Non-Patent Document 1, etc. RLC304 which is a wireless link control layer described in Patent Document 1 and the like, PDCP306 which is a packet data convergence protocol layer described in Non-Patent Document 1 and the like, and service data adaptation protocol layer (service data) described in Non-Patent Document 1 and the like. It may be composed of an adaptive protocol layer (SDAP (Service Data Adapter Protocol) 310).

FIG. 2B is a diagram of the E-UTRA control plane (CP) protocol configuration. As shown in FIG. 2 (B), in the E-UTRAN CP protocol, Non-Patent Document 2 and Non-Patent Document 4
The RRC (Radio Resource Control) 208, which is the radio resource control layer (radio resource control layer) described in the above, may be a protocol between the UE 122 and the eNB 102. That is, RRC208 may be a protocol terminated by eNB 102 on the network side. Further, in the E-UTRAN CP protocol, the NAS (Non Access Stratum) 210, which is a non-AS (Access Stratum) layer (non-AS layer), may be a protocol between the UE 122 and the MME. That is, NAS210 may be a protocol terminated by MME on the network side.

FIG. 3B is a diagram of the NR control plane (CP) protocol configuration. As shown in FIG. 3B, in the NR CP protocol, the RRC308, which is the radio resource control layer described in Non-Patent Document 1, Non-Patent Document 3, etc., may be a protocol between UE 122 and gNB 108. That is, RRC308 may be a protocol terminated by gNB108 on the network side. Further, in the E-UTRAN CP protocol, NAS312, which is a non-AS layer, may be a protocol between UE 122 and AMF. That is, NAS312 may be a protocol terminated by AMF on the network side.

The AS (Access Stratum) layer may be a layer terminated between the UE 122 and the eNB 102 and / or the gNB 108. That is, the AS layer is a layer containing a part or all of PHY200, MAC202, RLC204, PDCP206, and RRC208, and / or a layer containing a part or all of PHY300, MAC302, RLC304, PDCP306, SDAP310, and RRC308. Good.

In the embodiment of the present invention, the protocol of E-UTRA and the protocol of NR are not distinguished below, and PHY (PHY layer), MAC (MAC layer), RLC (RLC layer), PDCP (PDCP layer), RRC ( The terms RRC layer) and NAS (NAS layer) may be used. In this case, the PHY (PHY layer), MAC (MAC layer), RLC (RLC layer), PDCP (PDCP layer), RRC (RRC layer), and NAS (NAS layer) are each the PHY (PHY layer) of the E-UTRA protocol. ), MAC (MAC layer), RLC (RLC layer), PDCP (PDCP layer), RRC (RRC layer), NAS (NAS layer), or NR protocol, PHY (PHY layer), MAC (MAC). Layer), RLC (RLC layer), PDCP (PDCP layer), RRC (RRC layer), NAS (NAS layer). Further, the SDAP (SDAP layer) may be the SDAP (SDAP layer) of the NR protocol.

Further, in the embodiment of the present invention, when the E-UTRA protocol and the NR protocol are distinguished below, the PHY200, MAC202, RLC204, PDCP206, and RRC208 are referred to as PHY for E-UTRA or PHY for LTE, E-UTRA, respectively. MAC or LTE MAC, E-UTRA RLC or LTE RLC, E-UTRA PDCP or LTE PDCP, and E-UTRA RRC or LTE RRC. In addition, PHY200, MAC202, RLC204, PDCP206, and RRC208 are used 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, E-UTRA RRC, respectively. Alternatively, it may be described using a space such as LTE RRC. When distinguishing between the E-UTRA protocol and the NR protocol, the PHY300, MAC302, RLC304, PDCP306, and RRC308 are referred to as PHY for NT, MAC for NR, RLC for NR, RLC for NR, and RRC for NR, respectively. There are also things. Further, PHY200, MAC302, RLC304, PDCP306, and RRC308 may be described by using spaces as NR PHY, NR MAC, NR RLC, NR PDCP, NR RRC, etc., respectively.

The entity in the AS layer of E-UTRA and / or NR will be described. 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. An entity that has some or all of the functions of the PDCP 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. An entity that has some or all of the functions of the RRC layer may be called an RRC entity. The MAC entity, RLC entity, PDCP entity, SDAP entity, and RRC entity may be paraphrased as MAC, RLC, PDCP, SDAP, and RRC, respectively.

The data provided from the lower layer to MAC, RLC, PDCP, and SDAP, and / or the data provided to MAC, RLC, PDCP, and SDAP from the lower layer are referred to as MAC PDU (Protocol Data Unit) and RLC, respectively. PDU, PDCP
It may be called PDU or PDU PDU. In addition, the data provided from the upper layer to MAC, RLC, PDU, and SDAP, and / or the data provided to the upper layer from MAC, RLC, PDU, and SDAP are referred to as MAC SDU (Service Data Unit) and RLC SDU, respectively. , PDCP SDU, SDAP SDU. Further, the divided RLC SDU may be referred to as an RLC SDU segment.

An example of the PHY function will be described. The PHY of the terminal device may have a function of receiving data transmitted from the PHY of the base station device via a downlink (DL) physical channel (Physical Channel). The PHY of the terminal device may have a function of transmitting data to the PHY of the base station device via the uplink (UL) physical channel. The PHY may be connected to the upper MAC by a transport channel (Transport Channel). The PHY may pass data to the MAC via the transport channel. Further, the PHY may be provided with data from the MAC via the transport channel. In PHY, RNTI (Radio Network Temporary Identifier) may be used to identify various control information.

Here, the physical channel will be described.

The physical channels used for wireless communication between the terminal device and the base station device may include the following physical channels.

PBCH (Physical Broadcast Channel)
PDCCH (Physical Downlink Control Channel: Physical Downlink Control Channel)
PDSCH (Physical Downlink Shared Channel)
PUCCH (Physical Uplink Control Channel: Physical Uplink Control Channel)
PUSCH (Physical Uplink Shared Channel)
PRACH (Physical Random Access Channel)

The PBCH may be used to inform the system information required by the terminal device.

Further, in NR, the PBCH may be used to notify the time index (SSB-Index) within the period of the block of the synchronization signal (also referred to as the SS / PBCH block).

The PDCCH may be used to transmit (or carry) downlink control information (Downlink Control Information: DCI) in downlink wireless communication (wireless communication from a base station device to a terminal device). Here, one or more DCIs (which may be referred to as DCI format) may be defined for the transmission of downlink control information. That is, the field for the downlink control information may be defined as DCI and mapped to the information bit. The PDCCH may be transmitted in the PDCCH candidate (candide). The terminal device may monitor the set of PDCCH candidates in the serving cell. Monitoring a set of PDCCH candidates may mean attempting to decode the PDCCH according to a certain DCI format. The DCI format may be used for scheduling PUSCH in the serving cell. The PUSCH may be used for transmitting user data, transmitting an RRC message described later, and the like.

The PUCCH may be used to transmit uplink control information (Uplink Control Information: UCI) in uplink wireless communication (wireless communication from a terminal device to a base station device). Here, the uplink control information may include channel state information (CSI: Channel State Information) used to indicate the status of the downlink channel. Further, the uplink control information may include a scheduling request (SR: Scheduling Request) used for requesting a UL-SCH (UL-SCH: Uplink Shared Channel) resource. Further, the uplink control information may include HARQ-ACK (Hybrid Automatic Repeat ACKnowledgement).

The PDSCH may be used for transmission of downlink data (DL-SCH: Downlink Shared Channel) from the MAC layer. Further, in the case of a downlink, it may be used for transmission of system information (SI: System Information), random access response (RAR: Random Access Response), and the like.

The PUSCH may be used to transmit HARQ-ACK and / or CSI along with uplink data (UL-SCH: Uplink Shared Channel) or uplink data from the MAC layer. PUSCH may also be used to transmit CSI only, or HARQ-ACK and CSI only. That is, the PUSCH may be used to transmit only the UCI. The PDSCH or PUSCH may also be used to transmit RRC signaling (also referred to as RRC message), and MAC control elements. Here, in PDSCH, the RRC signaling transmitted from the base station device may be a signal common to a plurality of terminal devices in the cell. Further, the RRC signaling transmitted from the base station device may be dedicated signaling (also referred to as directed signaling) to a certain terminal device. That is, the information unique to the terminal device (UE specific) may be transmitted to a certain terminal device using a dedicated signaling. The PUSCH may also be used to transmit the UE capacity on the uplink.

PRACH may be used to send a random access preamble. PRACH is an initial connection esta.
It may be used to indicate a brushment procedure, a handover procedure, a connection re-station procedure, synchronization (timing adjustment) for uplink transmission, and a request for PUSCH (UL-SCH) resources.

An example of the MAC function will be described. MAC may be referred to as a MAC sublayer. The MAC may have a function of mapping various logical channels (logical channels) to corresponding transport channels. The logical channel may be identified by a logical channel identifier (Logical Channel Identity, or Logical Channel ID). The MAC may be connected to the upper RLC by a logical channel (logical channel). The logical channel may be divided into a control channel for transmitting control information and a traffic channel for transmitting user information, depending on the type of information to be transmitted. Further, the logical channel may be divided into an uplink logical channel and a downlink logical channel. The MAC may have a function of multiplexing MAC SDUs belonging to one or a plurality of different logical channels and providing them to the PHY. Further, the MAC may have a function of demultiplexing the MAC PDU provided by the PHY and providing it to the upper layer via the logical channel to which each MAC SDU belongs. Further, the MAC may have a function of performing error correction through HARQ (Hybrid Automatic Repeat request). Further, the MAC may have a scheduling report (SR) function that reports scheduling information (scheduling information). The MAC may have a function of performing priority processing between terminal devices by using dynamic scheduling. Further, the MAC may have a function of performing priority processing between logical channels in one terminal device. The MAC may have a function of prioritizing overlapping resources in one terminal device. The E-UTRA MAC may have a function of identifying Multicast Broadcast Multicast Services (MBMS). Further, the NR MAC may have a function of identifying a multicast / broadcast service (Multicast Broadcast Service: MBS). The MAC may have the ability to select a transport format. The MAC has a function of performing intermittent reception (DRX: Discontinuus Reception) and / or intermittent transmission (DTX: Discontinous Transmission), a function of executing a random access (Random Access: RA) procedure, and a power of notifying information on transmittable power. It may have a headroom report (Power Headroom Report: PHR) function, a buffer status report (BSR) function for notifying data amount information of a transmission buffer, and the like. The NR MAC may have a Bandwidth Adaptation (BA) function. Further, the MAC PDU format used in the E-UTRA MAC and the MAC PDU format used in the NR MAC may be different. Further, the MAC PDU may include a MAC control element (MAC control element: MAC CE), which is an element for performing control in MAC.

A logical channel for uplink (UL: Uplink) and / or downlink (DL: Downlink) used in E-UTRA and / or NR will be described.

The BCCH (Broadcast Control Channel) may be a downlink logical channel for broadcasting control information (SI: System Information) or the like.

The PCCH (Paging Control Channel) may be a downlink logical channel for carrying a paging message.

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

DCCH (Dedicated Control Channel) is a logical channel for transmitting dedicated control information in a one-to-one (point-to-point) bi-directional manner between a terminal device and a base station device. It's okay to have it. 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.

The DTCH (Processed Traffic Channel) may be a logical channel for transmitting user data on a one-to-one basis (point-to-point) between a terminal device and a base station device. The DTCH may be a logical channel for transmitting dedicated user data. The dedicated user data may be user data dedicated to each terminal device. DTCH may exist on both the uplink and the downlink.

The MTCH (Multicast Traffic Channel) may be a one-to-multipoint downlink channel for transmitting data from a base station device to a terminal device. MTCH may be a logical channel for multicast. The MTCH may be used by the terminal device only if the terminal device receives the MBMS.

The MCCH (Multicast Control Channel) may be a point-to-multipoint downlink channel for sending MBMS control information for one or more MTCHs from a base station device to a terminal device. The MCCH may be a logical channel for multicast. The MCCH may be used by the terminal device only when the terminal device receives the MBMS or is interested in the terminal device receiving the MBMS.

SC-MTCH (Single Cell Multicast Traffic Channel) is a one-to-multipoint downlink channel for transmitting data from a base station device to a terminal device using SC-PTM. good. The SC-MTCH may be a logical channel for multicast. SC-MTCH may be used by the terminal device only when the terminal device receives MBMS using SC-PTM (Single Cell Point-To-Multipoint).

SC-MCCH (Single Cell Multicast Control Channel) is a one-to-multipoint downlink for sending MBMS control information for one or more SC-MTCHs from a base station device to a terminal device. It can be a channel. The SC-MCCH may be a logical channel for multicast. The SC-MCCH may be used by the terminal device only when the terminal device receives MBMS using SC-PTM or the terminal device is interested in receiving MBMS using SC-PTM.

The mapping of the logical channel and the transport channel of the uplink in E-UTRA and / or NR will be described.

CCCH is a UL-SCH (Uplink), which is an uplink transport channel.
It may be mapped to Shared Channel).

DCCH is a UL-SCH (Uplink), which is an uplink transport channel.
It may be mapped to Shared Channel).

DTCH is a UL-SCH (Uplink), which is an uplink transport channel.
It may be mapped to Shared Channel).

The mapping of the logical channel and the transport channel of the downlink in E-UTRA and / or NR will be described.

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

The PCCH may be mapped to a PCH (Paging Channel) which is a downlink transport channel.

The CCCH may be mapped to a DL-SCH (Downlink Shared Channel) which is a downlink transport channel.

The DCCH may be mapped to a DL-SCH (Downlink Shared Channel) which is a downlink transport channel.

The DTCH may be mapped to a DL-SCH (Downlink Shared Channel) which is a downlink transport channel.

The MTCH may be mapped to an MCH (Multicast Channel) which is a downlink transport channel.

The MCCH may be mapped to an MCH (Multicast Channel) which is a downlink transport channel.

The SC-MTCH may be mapped to a DL-SCH (Downlink Shared Channel) which is a downlink transport channel.

The SC-MTCH may be mapped to a DL-SCH (Downlink Shared Channel) which is a downlink transport channel.

An example of the function of RLC will be described. RLC may be referred to as an RLC sublayer. The E-UTRA RLC may have a function of segmenting and / or concatenating the data provided from the PDCP of the upper layer and providing the data to the lower layer (lower layer). The E-UTRA RLC may have a function of reassembling and reordering the data provided from the lower layer and providing the data to the upper layer. The NR RLC may have a function of adding a sequence number independent of the sequence number added by the PDCP to the data provided by the PDCP of the upper layer. Further, NR RLC may have a function of segmenting data provided by PDCP and providing it to a lower layer. Further, the NR RLC may have a function of reassembling the data provided from the lower layer and providing the data to the upper layer. In addition, RLC has a data retransmission function and / or an automatic repeat function (Automatic Repeat).
You may have reQuest: ARQ). Further, RLC may have a function of performing error correction by ARQ. The control information indicating the data that needs to be retransmitted, which is sent from the receiving side of the RLC to the transmitting side in order to perform the ARQ, may be referred to as a status report. Further, the status report transmission instruction sent from the transmitting side of RLC to the receiving side may be called a pole. Further, RLC may have a function of detecting data duplication. In addition, RLC may have a function of discarding data. The RLC may have three modes: a transparent mode (TM: Transient Mode), a non-response mode (UM: Supported Mode), and a response mode (AM: Acknowledged Mode). In TM, the data received from the upper layer is not divided, and the RLC header need not be added. The TM RLC entity is a uni-directional entity and may be configured as a transmitting TM RLC entity or as a receiving TM RLC entity. In the UM, the data received from the upper layer is divided and / or combined, the RLC header is added, and the like, but the data retransmission control may not be performed. The UM RLC entity may be a unidirectional entity or a bi-directional entity. If the UM RLC entity is a unidirectional entity, the UM RLC entity may be configured as a transmit UM RLC entity or as a receive UM RLC entity. If the UMRLC entity is a bidirectional entity, the UM RLC entity may be configured as a UM RLC entity consisting of a transmitting side and a receiving side. In AM, data received from the upper layer may be divided and / or combined, an RLC header may be added, data retransmission control may be performed, and the like. The AM RLC entity is a bidirectional entity and may be configured as an AM RLC composed of a transmitting side and a receiving side. The data provided to the lower layer by TM and / or the data provided from the lower layer may be referred to as TMD PDU. Further, the data provided to the lower layer by the UM and / or the data provided from the lower layer may be referred to as a UMD PDU. Further, the data provided to the lower layer by AM or the data provided from the lower layer may be referred to as AMD PDU. The RLC PDU format used in E-UTRA RLC and the RLC PDU format used in NR RLC may be different. Further, the RLC PDU may include an RLC PDU for data and an RLC PDU for control. The RLC PDU for data may be referred to as an RLC DATA PDU (RLC Data PDU, RLC data PDU). Further, the control RLC PDU may be referred to as an RLC CONTROL PDU (RLC Control PDU, RLC control PDU, RLC control PDU).

An example of the function of PDCP will be described. PDCP may be referred to as a PDCP sublayer. The PDCP may have a function of performing sequence number maintenance. Further, the PDCP may have a header compression / decompression function for efficiently transmitting user data such as an IP packet (IP Packet) and an Ethernet frame in a wireless section. The protocol used for header compression / decompression of IP packets may be called ROHC (Robust Header Compression) protocol. Further, the protocol used for Ethernet frame header compression / decompression may be called an EHC (Ethernet (registered trademark) Header Compression) protocol. Further, the PDCP may have a function of encrypting / decrypting data. In addition, the PDCP may have a function of data integrity protection / integrity verification. The PDCP may also have a re-ordering function. Further, the PDCP may have a retransmission function of the PDCP SDU. Further, the PDCP may have a function of discarding data using a discard timer (discard timer). The PDCP may also have a multiplexing function. Further, the PDCP may have a function of discarding duplicately received data. The PDCP entity is a bidirectional entity and may consist of a transmitting PDCP entity and a receiving PDCP entity. Further, the PDCP PDU format used in E-UTRA PDCP and the PDCP PDU format used in NR PDCP may be different. Further, the PDCP PDU may include a PDCP PDU for data and a PDCP PDU for control. The PDCP PDU for data may be referred to as a PDCP DATA PDU (PDUC Data PDU, PDU Data PDU). Further, the control PDCP PDU may be referred to as a PDCP CONTROL PDU (PDCP Control PDU, PDCP control PDU, PDCP control PDU).

An example of the function of SDAP will be described. SDAP is a service data adaptation protocol layer (service data adaptation protocol layer). SDAP maps the downlink QoS flow sent from the 5GC110 to the terminal device via the base station device and the data radio bearer (DRB) (mapping), and / or from the terminal device via the base station device. It may have a function of mapping the uplink QoS flow sent to the 5GC110 with the DRB. In addition, SDAP may have a function of storing mapping rule information. Further, SDAP may have a function of marking a QoS flow identifier (QOS Flow ID: QFI). The SDAP PDU may include a SDAP PDU for data and a SDAP PDU for control. The SDAP PDU for data may be referred to as SDAP DATA PDU (SDAP Data PDU, SDAP data PDU). Further, the SDAP PDU for control may be referred to as a SDAP CONTROL PDU (SDAP Control PDU, SDAP control PDU, SDAP control PDU). It should be noted that there may be one SDAP entity of the terminal device for the PDU session.

An example of the function of RRC will be described. The RRC may have a broadcast (broadcast) function. The RRC may have a calling (paging) function from the EPC104 and / or 5GC110. The RRC may have a calling (paging) function from the eNB 102 connected to the gNB 108 or the 5GC100. Further, the RRC may have an RRC connection management function. Further, the RRC may have a wireless bearer control function. Further, the RRC may have a cell group control function. Further, the RRC may have a mobility control function. Further, the RRC may have a terminal device measurement reporting and a terminal device measurement reporting control function. The RRC may also have a QoS management function. The RRC may also have a function of detecting and recovering a wireless link failure. RRC uses RRC messages for notification, paging, RRC connection management, wireless bearer control, cell group control, mobility control, terminal device measurement reporting and terminal device measurement reporting control, QoS management, wireless link failure detection and recovery, etc. You may go. The RRC message or parameter used in the E-UTRA RRC may be different from the RRC message or parameter used in the NR RRC.

The RRC message may be sent using the BCCH of the logical channel, the PCCH of the logical channel, the CCCH of the logical channel, or the DCCH of the logical channel. It may be sent or it may be sent using the MCCH of the logical channel.

The RRC message sent using BCCH may include, for example, the Master Information Block (MIB) described in Non-Patent Document 3 and / or Non-Patent Document 4, and each type of system information block (MIB) may be included. System Information Block: SIB) may be included, or other RRC messages may be included. The RRC message sent using the PCCH may include, for example, the paging message described in Non-Patent Document 3 and / or Non-Patent Document 4, and may include other RRC messages.

The RRC messages sent in the uplink (UL) direction using CCCH include, for example, the RRC setup request message (RRC Setup Request), the RRC restart request message (RRC Resource Request), and the RRC reestablishment request message described in Non-Patent Document 3. (RRC Recovery Request), RRC system information request message (RRC System Info Request), and the like may be included. Further, for example, the RRC connection request message (RRC Connection Request), the RRC connection restart request message (RRC Connection Request Request), the RRC connection reestablishment request message (RRC Connection Request Request) described in Non-Patent Document 4 may be included. Other RRC messages may also be included.

The RRC messages sent in the downlink (DL) direction using the CCCH include, for example, the RRC connection rejection message (RRC Connection Reject), the RRC connection setup message (RRC Connection Setup), and the RRC connection reestablishment message described in Non-Patent Document 4. (RRC Connection Restriction), RRC connection reestablishment refusal message (RRC Connection Reestability Reject), and the like may be included. Further, for example, the RRC rejection message (RRC Reject) and the RRC setup message (RRC Setup) described in Non-Patent Document 3 may be included. Other RRC messages may also be included.

The RRC messages sent in the uplink (UL) direction using the DCCH include, for example, the measurement report message (Measurement Report) described in Non-Patent Document 4, the RRC connection resetting completion message (RRC Connection Reconfiguration Complete), and the RRC connection setup completion. A message (RRC Connection Setup Complete), an RRC connection reestablishment completion message (RRC Connection Restoration Complete), a security mode completion message (Security Mode Compact), a UE capability information message (UE Capability Information, etc.), etc. are included. Further, for example, the measurement report message (Measurement Report) described in Non-Patent Document 3, the RRC resetting completion message (RRC Reconfiguration Complete), the RRC setup completion message (RRC Setup Complete), the RRC reestablishment completion message (RRC Restabrishment Complex). A restart completion message (RRC Measurement Complete), a security mode completion message (Security Mode Complete), a UE capability information message (UE Capability Information), and the like may be included. Other RRC messages may also be included.

The RRC messages sent in the downlink (DL) direction using the DCCH include, for example, the RRC connection reconfiguration message (RRC Connection Reconnection), the RRC connection release message (RRC Connection Release), and the security mode command message described in Non-Patent Document 4. (Security Mode Command), UE capability inquiry message (UE Capacity Energy), and the like may be included. Further, for example, the RRC reconfiguration message (RRC Reconfiguration), the RRC restart message (RRC Resume), the RRC release message (RRC Release), the RRC reestablishment message (RRC Recovery), and the security mode command message (Security Mode) described in Non-Patent Document 3. Command), UE capability inquiry message (UE Capacity Energy), and the like may be included. Other RRC messages may also be included.

An example of the NAS function will be described. NAS may have an authentication function. In addition, NAS may have a function of performing mobility management. In addition, NAS may have a security control function.

The above-mentioned PHY, MAC, RLC, PDCP, SDAP, RRC, and NAS functions are examples, and some or all of the functions may not be implemented. Further, a part or all of the functions of each layer (each layer) may be included in another layer (layer).

The upper layer (not shown) of the AS layer of the terminal device may include an IP layer, a TCP (Transmission Control Protocol) layer above the IP layer, a UDP (User Datagram Protocol) layer, and the like. Further, an Ethernet layer may exist in the upper layer of the AS layer of the terminal device. It may be called an upper layer PDU layer (PDU layer) of the AS layer of the terminal device. The PDU layer may include an IP layer, a TCP layer, a UDP layer, an Ethernet layer, and the like. An application layer may exist in an upper layer such as an IP layer, a TCP layer, a UDP layer, an Ethernet layer, and a PDU layer. The application layer may include SIP (Session Initiation Protocol) and SDP (Session Description Protocol) used in IMS (IP Multimedia Subsystem), which is one of the service networks standardized in 3GPP. Further, the application layer may include RTP (Real-time Transport Protocol) used for media communication, and / or protocols such as RTCP (Real-time Transport Protocol) and HTTP (HyperText Transfer Protocol) for media communication control. .. Further, the application layer may include codecs of various media and the like. Further, the RRC layer may be a higher layer of the SDAP layer.

Next, the state transition of the UE 122 in LTE and NR will be described. The UE 122 connected to the EPC, or 5GC, may be in the RRC_CONNECTED state when the RRC connection is established (RRC connection has been established). The state in which the RRC connection is established may include a state in which the UE 122 holds a part or all of the UE context described later. Further, the state in which the RRC connection is established may include a state in which the UE 122 can transmit and / or receive unicast data. Further, the UE 122 may be in the RRC_INACTIVE state when the RRC connection is suspended (suspended). Further, the UE 122 may be in the RRC_INACTIVE state when the UE 122 is connected to the 5GC and the RRC connection is suspended. The UE 122 may be in the RRC_IDLE state when the UE is neither in the RRC_CONNECTED state nor in the RRC_INACTIVE state.

When the UE 122 is connected to the EPC, it does not have the RRC_INACTIVE state, but the E-UTRAN may start the suspension of the RRC connection. When the UE 122 is connected to the EPC, when the RRC connection is suspended, the UE 122 may change to the RRC_IDLE state by holding the AS context of the UE and the identifier (resume Identity) used for the resume. In the upper layer of the RRC layer of the UE 122 (for example, the NAS layer), the UE 122 holds the AS context of the UE, the return of the RRC connection is permitted by E-UTRAN (Permit), and the UE 122 is from the RRC_IDLE state. When it is necessary to transition to the RRC_CONNECTED state, the restoration of the suspended RRC connection may be started.

The definition of pause may be different between the UE 122 connected to the EPC 104 and the UE 122 connected to the 5GC110. Further, when the UE 122 is connected to the EPC (when it is paused in the RRC_IDLE state) and when the UE 122 is connected to the 5GC (when it is paused in the RRC_INACTIVE state), the UE 122 returns from the pause. All or part of the procedure may be different.

The RRC_CONNECTED state, RRC_INACTIVE state, and RRC_IDLE state may be referred to as a connected state (connected mode), an inactive state (inactive mode), and an idle state (idle mode), respectively, and the RRC connected state (RRC connected mode). , RRC inactive state (RRC inactive mode), RRC idle state (RRC idle mode) may be called.

The AS context of the UE held by the UE 122 is the current RRC setting, the current security context, the PDCP state including the ROHC (RObust Header Compression) state, and the C-RNTI (Cell Radio) used in the PCell of the connection source (Source). Information may be information including all or a part of a Network Frequency Identity), a cell identifier, and a physical cell identifier of the PCell of the connection source. The AS context of the UE held by any or all of the eNB 102 and the gNB 108 may include the same information as the AS context of the UE held by the UE 122, or the information included in the AS context of the UE held by the UE 122. May contain different information.

The security context is an encryption key at the AS level, NH (Next Hop).
Parameter), NCC (Next Hop Chaining Counter parameter) used to derive the access key for the next hop, identifier of the selected AS level encryption algorithm, counter used for replay protection, all or part of the information. May be.

A cell group (Cell Group) set from the base station device to the terminal device will be described. The cell group may be composed of one special cell (Special Cell: SpCell). Further, the cell group may be composed of one SpCell and one or a plurality of secondary cells (Secondary Cell: SCell). That is, the cell group may be composed of one SpCell and, optionally, one or more SCells. The SpCell in the master cell group (MCG) described later may be referred to as a primary cell (Primary Cell: PCell). Further, the SpCell of the secondary cell group (Secondary Cell Group: SCG) described later may be referred to as a primary SCG cell (Primary SCG Cell: PSCell). The PCell may be a cell used in the RRC connection establishment procedure when the terminal device in the RRC idle state transitions to the RRC connection state. Further, the PCell may be a cell used in the RRC connection reestablishment procedure in which the terminal device reestablishes the RRC connection. Further, the PCell may be a cell used for a random access procedure at the time of handover. The PSCell may be a cell used for a random access procedure when a secondary node (Secondary Node: SN), which will be described later, is added. Further, the SpCell may be a cell used for an application other than the above-mentioned applications. When a cell group is composed of SpCell and one or more SCells, it can be said that carrier aggregation (CA) is set in this cell group.

Further, when the Dual Conductivity (DC) described in Non-Patent Document 4 or the like or the Multi-Radio Dual Connectivity (MR-DC) described in Non-Patent Document 5 or the like is performed, a cell group is added from the base station device to the terminal device. May be done. DC is a technology for performing data communication using the radio resources of the cell group configured by the first base station device (first node) and the second base station device (second node). good. MR-DC may be a technique included in DC. In order to perform DC, the first base station device may add a second base station device. The first base station device may be called a master node (Master Node: MN). Further, the cell group composed of the master node may be called a master cell group (MCG). The second base station device may be referred to as a secondary node (Secondary Node: SN). Further, the cell group composed of the secondary node may be referred to as a secondary cell group (Secondary Cell Group: SCG). The master node and the secondary node may be configured in the same base station device.

Further, when DC is not set, the cell group set in the terminal device may be called MCG. Further, when DC is not set, the SpCell set in the terminal device may be a PCell.

As described in Non-Patent Document 5, MR-DC may be a technique for performing DC using E-UTRA for MCG and NR for SCG. Further, MR-DC may be a technique for performing DC using NR for MCG and E-UTRA for SCG. Further, MR-DC may be a technique for performing DC using NR for both MCG and SCG. As an example of MR-DC using E-UTRA for MCG and NR for SCG, there may be EN-DC (E-UTRA-NR Dual Conductivity) using EPC in the core network, and NGEN- using 5GC in the core network. There may be a DC (NG-RAN E-UTRA-NR Dual Connectivity). As an example of MR-DC using NR for MCG and E-UTRA for SCG, NE-DC (NR-E-UTRA Dual) using 5GC for the core network
There may be a connection). Further, as an example of MR-DC using NR for both MCG and SCG, there may be NR-DC (NR-NR Dual Conductivity) using 5GC for the core network.

In the terminal device, one MAC entity may exist for each cell group. For example, when DC or MR-DC is set in the terminal device, one MAC entity for MCG and one MAC entity for SCG may exist. The MAC entity for MCG in the terminal device may always be established in the terminal device in all states (RRC idle state, RRC connected state, RRC inactive state, etc.). Further, the MAC entity for the SCG in the terminal device may be created by the terminal device when the SCG is set in the terminal device. Further, the MAC entity for each cell group of the terminal device may be set by receiving the RRC message from the base station device. In EN-DC and NGEN-DC, the MAC entity for MCG may be an E-UTRA MAC entity, and the MAC entity for SCG may be an NR MAC entity. Further, in NE-DC, the MAC entity for MCG may be an NR MAC entity, and the MAC entity for SCG may be an E-UTRA MAC entity. Further, in NR-DC, the MAC entity for MCG and SCG may be both NR MAC entity. In addition, the fact that one MAC entity exists for each cell group may be rephrased as one MAC entity exists for each SpCell. Further, one MAC entity for each cell group may be paraphrased as one MAC entity for each SpCell.

The wireless bearer will be described. SRB0 to SRB2 may be defined in the SRB of E-UTRA, or other SRBs may be defined. SRB0 to SRB3 may be defined for the SRB of NR, or other SRBs may be defined. SRB0 may be an SRB for RRC messages transmitted and / or received using the CCCH of the logical channel. SRB1 may be an SRB for RRC messages and for NAS messages before SRB2 is established. The RRC message transmitted and / or received using the SRB1 may include a piggybacked NAS message. The DCCH of the logical channel may be used for all RRC messages and NAS messages transmitted and / or received using SRB1. SRB2 may be an SRB for NAS messages and for RRC messages containing logged measurement information. The DCCH of the logical channel may be used for all RRC messages and NAS messages transmitted and / or received using SRB2. Further, SRB2 may have a lower priority than SRB1. The SRB 3 may be an SRB for transmitting and / or receiving a specific RRC message when EN-DC, NGEN-DC, NR-DC, or the like is set in the terminal device. The DCCH of the logical channel may be used for all RRC messages and NAS messages transmitted and / or received using the SRB3. In addition, other SRBs may be prepared for other uses. The DRB may be a wireless bearer for user data. The DTCH of the logical channel may be used for the RRC message transmitted and / or received using the DRB.

A wireless bearer in a terminal device will be described. The radio bearer may include an RLC bearer. The RLC bearer may consist of one or two RLC entities and a logical channel. When there are two RLC entities in the RLC bearer, the RLC entity may be a TM RLC entity and / or a transmit RLC entity and a receive RLC entity in the RLC entity in unidirectional UM mode. SRB0 may be composed of one RLC bearer. The RLC bearer of SRB0 may be composed of an RLC entity of TM and a logical channel. SRB0 may always be established in the terminal device in all states (RRC idle state, RRC connected state, RRC inactive state, etc.). One SRB1 may be established and / or set in the terminal device by the RRC message received from the base station device when the terminal device transitions from the RRC idle state to the RRC connection state. SRB1 may consist of one PDCP entity and one or more RLC bearers. The RLC bearer of SRB1 may be composed of an RLC entity of AM and a logical channel. One SRB2 may be established and / or set in the terminal device by the RRC message received from the base station device by the terminal device in the RRC connected state in which AS security is activated. SRB2 may consist of one PDCP entity and one or more RLC bearers. The RLC bearer of SRB2 may be composed 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. In SRB3, when a secondary node in EN-DC, NGEN-DC, or NR-DC is added, or when the secondary node is changed, the terminal device in the RRC connection state with AS security activated is the base station. One may be established and / or set in the terminal device by the RRC message received from the device. The SRB 3 may be a direct SRB between the terminal device and the secondary node. SRB3 may consist of one PDCP entity and one or more RLC bearers. The RLC bearer of SRB3 may be composed of an RLC entity of AM and a logical channel. The PDCP on the base station device side of the SRB3 may be placed on the secondary node. The DRB may be established and / or set in the terminal device by the RRC message received from the base station device by the terminal device in the RRC connected state in which AS security is activated. The DRB may consist of one PDCP entity and one or more RLC bearers. The DRB RLC bearer may consist of an AM or UM RLC entity and a logical channel.

In MR-DC, a radio bearer in which a PDCP is placed on a master node may be referred to as an MN-terminated bearer. Further, in MR-DC, a wireless bearer in which a PDCP is placed on a secondary node may be referred to as an SN-terminated bearer. In MR-DC, a radio bearer in which the RLC bearer exists only in the MCG may be referred to as an MCG bearer. Further, in MR-DC, a radio bearer in which the RLC bearer exists only in the SCG may be referred to as an SCG bearer. Further, in DC, a radio bearer in which RLC bearers are present in both MCG and SCG may be referred to as split bearers.

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

For the RLC bearer established and / or set in the cell group composed of E-UTRA, the RLC entity established and / or set may be E-UTRA RLC. Further, for the RLC bearer established and / or set in the cell group composed of NR, the RLC entity established and / or set may be NR RLC. When EN-DC is set for the terminal device, the PDCP entity established and / or set for the MN-terminated MCG bearer may be either E-UTRA PDCP or NR PDCP. When EN-DC is set in the terminal device, for other bearer type wireless bearers, that is, MN-terminated split bearer, MN-terminated SCG bearer, SN-terminated MCG bearer, SN-terminated split bearer, and SN-terminated SCG bearer. The PDCP established and / or set may be NR PDCP. Further, when NGEN-DC, NE-DC, or NR-DC is set in the terminal device, the PDCP entity established and / or set for the radio bearer in all bearer types may be NR PDCP. ..

In NR, the DRB established and / or set in the terminal device may be associated with one PDU session. One SDAP entity may be established and / or set for one PDU session in the terminal device. Established and / or set in the terminal device The SDAP entity, PDCP entity, RLC entity, and logical channel may be established and / or set by the RRC message received by the terminal device from the base station device.

Regardless of whether MR-DC is set or not, a network configuration in which the master node is eNB 102 and the EPC 104 is the core network may be referred to as E-UTRA / EPC. Further, a network configuration in which the master node is an eNB 102 and the 5GC110 is a core network may be called E-UTRA / 5GC. Further, a network configuration in which the master node is gNB108 and the 5GC110 is the core network may be referred to as NR or NR / 5GC. When MR-DC is not set, the above-mentioned master node may refer to a base station device that communicates with a terminal device.

Next, the handover in LTE and NR will be described. The handover may be a process in which the UE 122 in the RRC connected state changes the serving cell. The handover may be performed when the UE 122 receives an RRC message instructing the handover from the eNB 102 and / or the gNB 108. The RRC message instructing the handover is an RRC connection including a parameter instructing the handover (for example, an information element named MobilityControlInfo described in Non-Patent Document 4 or an information element named ReconnectionWithSync described in Non-Patent Document 3). It may be a message about resetting. The above-mentioned information element named MobilityControlInfo may be paraphrased as a mobility control setting information element, a mobility control setting, or a mobility control information. The above-mentioned information element named ReconnectionWithSync may be paraphrased as a reconfiguration information element with synchronization or a reconfiguration with synchronization. Further, the RRC message instructing the handover may be a message indicating the movement of another RAT to a cell (for example, the MobilityFromEUTRACommand described in Non-Patent Document 4 or the MobilityFromNRComand described in Non-Patent Document 3). Further, the handover may be paraphrased as reconfiguration with synchronization. Further, the conditions under which the UE 122 can perform the handover include a part or all of the fact that the AS security is activated, the SRB2 is established, and at least one DRB is established. good.

The flow of RRC messages sent and received between the terminal device and the base station device will be described. FIG. 4 is a diagram showing an example of a flow of procedures for various settings in the RRC according to the embodiment of the present invention. FIG. 4 is an example of a flow in which an RRC message is sent from the base station device (eNB 102 and / or gNB 108) to the terminal device (UE 122).

In FIG. 4, the base station apparatus creates an RRC message (step S400). When creating an RRC message in a base station device, the base station device provides notification information (SI: System).
Information) and paging information may be distributed. Further, the RRC message may be created in the base station device so that the base station device can perform processing on a specific terminal device. The process to be performed on a specific terminal device may include, for example, security-related settings, RRC connection resetting, handover to a different RAT, suspension of RRC connection, release of RRC connection, and the like. The RRC connection resetting process includes, for example, wireless bearer control (establishment, change, release, etc.), cell group control (establishment, addition, change, release, etc.), measurement setting, handover, security key update, and the like. May be included. Further, the creation of the RRC message in the base station device may be performed in order to respond to the RRC message transmitted from the terminal device. The response to the RRC message 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 restart request, and the like. The RRC message includes information (parameters) for various information notifications and settings. As described in Non-Patent Document 3 or Non-Patent Document 4, these parameters may be referred to as fields and / or information elements, and ASN. It may be described using the description method of 1 (Abstract Synchronization Notation One).

In FIG. 4, the base station apparatus then transmits the created RRC message to the terminal apparatus (step S402). Next, the terminal device performs processing when processing such as setting is required according to the received RRC message (step S404). The processed terminal device may send an RRC message for response to the base station device (not shown).

The RRC message is not limited to the above example, and may be used for other purposes as described in Non-Patent Document 3 and Non-Patent Document 4.

In MR-DC, the RRC on the master node side is used to transfer RRC messages for SCG side settings (cell group setting, wireless bearer setting, measurement setting, etc.) to and from the terminal device. good. For example, in EN-DC or NGEN-DC, the RRC message of E-UTRA transmitted and received between the eNB 102 and the UE 122 may include the RRC message of NR in the form of a container. Further, in NE-DC, the RRC message of NR transmitted and received between gNB 108 and UE 122 may include the RRC message of E-UTRA in the form of a container. The RRC message for the setting on the SCG side may be sent and received between the master node and the secondary node.

Not limited to the case of using MR-DC, the RRC message for E-UTRA transmitted from eNB 102 to UE 122 may include the RRC message for NR, and the RRC for NR transmitted from gNB 108 to UE 122 may be included. The message may include an RRC message for E-UTRA.

An example of the parameter included in the RRC message regarding the resetting of the RRC connection will be described. FIG. 7 is an ASN. It is an example of one description. Further, FIG. 8 is an ASN. It is an example of one description. Not limited to FIGS. 7 and 8, the ASN. In the example of 1, <omitted> and <omitted> are ASN. It indicates that other information is omitted, not a part of the notation of 1. Information elements may be omitted even in places where there is no description of <omitted> or <omitted>. In the embodiment of the present invention, ASN. An example of 1 is ASN. 1 It does not follow the notation method correctly. In embodiments of the present invention, ASN. The example 1 describes an example of the parameter of the RRC message in the embodiment of the present invention, and other names and other notations may be used. Also, ASN. The first example shows only an example relating to the main information closely related to one embodiment of the present invention, in order to avoid complicating the explanation. In addition, ASN. The parameters described in 1 may be referred to as information elements without distinguishing them into fields, information elements, and the like. Further, in the embodiment of the present invention, the ASN. The field, information element, etc. described in 1 may be paraphrased as information or may be paraphrased as a parameter. The message regarding the resetting of the RRC connection may be an RRC resetting message in NR or an RRC connection resetting message in E-UTRA.

The information element represented by RadioBearerConfig in FIG. 7 may be an information element used for setting, changing, releasing, or the like of a radio bearer such as SRB or DRB. The information element represented by RadioBearerConfig may include a PDCP setting information element described later and an SDAP setting information element. The information element represented by RadioBearerConfig may be paraphrased as a radio bearer setting information element or a radio bearer setting. The information element represented by SRB-ToAddMod included in the information element represented by RadioBearerConfig may be an information element indicating an SRB (signaling radio bearer) setting. The information element represented by SRB-ToAddMod may be paraphrased as an SRB setting information element or an SRB setting. The information element represented by SRB-ToAdModList may be a list of SRB settings. The information element represented by DRB-ToAddMod included in the information element represented by RadioBearerConfig may be an information element indicating a DRB (data radio bearer) setting. The information element represented by DRB-ToAddMod may be paraphrased as a DRB setting information element or a DRB setting. The information element represented by DRB-ToAddModList may be a list of DRB settings. The SRB setting and the DRB setting may be paraphrased as a wireless bearer setting.

The field represented by srb-Identity in the SRB setting information element is information on the SRB identifier (SRB Identity) of the SRB to be added or changed, and may be an identifier that uniquely identifies the SRB in each terminal device. .. The field represented by srb-Identity in the SRB setting information element may be paraphrased as an SRB identifier field or an SRB identifier. Further, the SRB identifier may be paraphrased as a wireless bearer identifier.

The field represented by drb-Identity in the DRB setting information element is the information of the DRB identifier (DRB Identity) of the DRB to be added or changed, and may be an identifier that uniquely identifies the DRB in each terminal device. .. The field represented by drb-Identity in the DRB setting information element may be paraphrased as a DRB identifier field or a DRB identifier. The value of the DRB identifier is an integer value from 1 to 32 in the example of FIG. 7, but another value may be taken. For DCs, the DRB identifier may be unique within the scope of UE 122. Further, the DRB identifier may be paraphrased as a wireless bearer identifier.

In the DRB setting information element, whether the field represented by cnAssociation is associated with the field represented by eps-bearerIdentity described later or the information element represented by SDAP-Config described later. It may be the field shown. The field represented by cnAssociation may be paraphrased as a core network association field or a core network association. The field represented by cnAscation may include an EPS bearer identifier field (eps-bearerIdentity) described later when the terminal device is connected to the EPC104. Further, the field represented by cnAscation may include an information element (SDAP-Config) indicating the SDAP setting described later when the terminal device is connected to the core network 5GC110. The field indicated by eps-bearerIdentity may be a field indicating an EPS bearer identifier that identifies the EPS bearer. The field indicated by eps-bearerIdentity may be paraphrased as an EPS bearer identifier field or an EPS bearer identifier field.

The information element represented by SDAP-Config may be information regarding the setting or resetting of the SDAP entity. The information element represented by SDAP-Config may be paraphrased as the SDAP setting information element or the SDAP setting.

The field indicated by pdu-session included in the SDAP setting information element may be the PDU session identifier of the PDU session to which the QoS flow mapped to the corresponding radio bearer belongs. The field indicated by pdu-cession may be paraphrased as a PDU session identifier field or a PDU session identifier. The PDU session identifier may be the PDU session identifier of the PDU session described in Non-Patent Document 1. Further, the corresponding radio bearer may be a DRB associated with a DRB identifier in the DRB setting including the SDAP setting field.

The field indicated by mappedQoS-FlowsToAdd included in the SDAP setting information element is information indicating a list of QoS flow identifier (QFI: QoS) fields of the uplink QoS flow to be additionally mapped to the corresponding radio bearer. Good. The field indicated by mappedQoS-FlowsToAdd may be paraphrased as an additional QoS flow field or an additional QoS flow. The above-mentioned QoS flow may be the QoS flow of the PDU session indicated by the PDU session included in the SDAP setting information element. Further, the corresponding radio bearer may be a DRB associated with a DRB identifier in the DRB setting including the SDAP setting field.

Further, the field indicated by mappedQoS-FlowsToReleases included in the SDAP setting information element indicates a list of QoS flow identifier information elements of the QoS flows that release the correspondence among the QoS flows mapped to the corresponding radio bearer. It may be information. The field indicated by mappedQoS-FlowsToRelease may be paraphrased as a QoS flow field to be released or a QoS flow to be released. The above-mentioned QoS flow may be the QoS flow of the PDU session indicated by the PDU session included in the SDAP setting information element. Further, the corresponding radio bearer may be a DRB associated with a DRB identifier in the DRB setting including the SDAP setting field.

In addition to this, the SDAP setting information element includes a field indicating whether or not the uplink SDAP header exists in the uplink data transmitted via the corresponding wireless bearer, and the downlink data received via the corresponding wireless bearer. May include a field indicating whether or not the downlink SDAP header exists, a field indicating whether or not the corresponding radio bearer is the default radio bearer (default DRB), and the like. Further, the corresponding radio bearer may be a DRB associated with a DRB identifier in the DRB setting including the SDAP setting field.

Further, the information element represented by PDCP-Config in the SRB setting information element and the DRB setting information element may be an information element related to the setting of the NR PDCP entity. The information element represented by PDCP-Config may be paraphrased as a PDCP setting information element or a PDCP setting. The information elements related to the setting of the NR PDCP entity include a field indicating the size of the sequence number for uplink, a field indicating the size of the sequence number for downlink, a field indicating the profile of header compression (RoHC), and reordering. (Re-ordering) A field indicating the value of the timer may be included.

The information element represented by DRB-ToReleaseList included in the information element represented by RadioBearerConfig may include information indicating one or more DRB identifiers to be released.

In FIG. 8, the information element represented by RadioRelocationControlProcessed may be an information element used for setting, changing, releasing, and the like of the radio bearer. The information element represented by SRB-ToAddMod, which is included in the information element represented by RadioResolutionControlProcessed, may be information indicating the SRB (signaling radio bearer) setting. The information element represented by SRB-ToAddMod may be paraphrased as an SRB setting information element or an SRB setting. The information element represented by SRB-ToAdModList may be a list of information indicating the SRB setting. The information element represented by DRB-ToAddMod, which is included in the information element represented by RadioResolutionControlProcessed, may be information indicating a DRB (data radio bearer) setting. The information element represented by DRB-ToAddMod may be paraphrased as a DRB setting information element or a DRB setting. The information element represented by DRB-ToAddModList may be a list of information indicating the DRB setting. In addition, any one or all of SRB setting and DRB setting may be paraphrased as wireless bearer setting.

The field represented by srb-Identity in the SRB setting information element is information on the SRB identifier (SRB Identity) of the SRB to be added or changed, and may be an identifier that uniquely identifies the SRB in each terminal device. .. In the SRB setting information element,
The field represented by srb-Identity may be paraphrased as an SRB identifier field or an SRB identifier. Further, the SRB identifier may be paraphrased as a wireless bearer identifier. The SRB identifier in FIG. 8 may have the same role as the SRB identifier in FIG. 7.

The field represented by drb-Identity in the DRB setting is the information of the DRB identifier (DRB Identity) of the DRB to be added or changed, and may be an identifier uniquely identifying the DRB in each terminal device. The field represented by drb-Identity in the DRB setting information element may be paraphrased as a DRB identifier field or a DRB identifier. The value of the DRB identifier is an integer value from 1 to 32 in the example of FIG. 8, but another value may be taken. Further, the DRB identifier may be paraphrased as a wireless bearer identifier. The DRB identifier of FIG. 8 may have the same role as the DRB identifier of FIG. 7.

The field represented by eps-BearerIdentity in the DRB setting information element may be an EPS bearer identifier that uniquely identifies the EPS bearer in each terminal device. The field represented by eps-BearerIdentity may be paraphrased as an EPS bearer identifier field or an EPS bearer identifier field. The value of the EPS bearer identifier is an integer value from 1 to 15 in the example of FIG. 8, but another value may be taken. The EPS bearer identifier of FIG. 8 may have the same role as the EPS bearer identifier of FIG. 7. Further, the EPS bearer identifier and the DRB identifier may have a one-to-one correspondence in each terminal device.

Further, among the SRB setting information element and the DRB setting information element, the information element represented by PDCP-Config may be an information element related to the setting of the E-UTRA PDCP entity. The information element represented by PDCP-Config may be paraphrased as a PDCP setting information element or a PDCP setting. The information element related to the setting of the E-UTRA PDCP entity includes a field indicating the size of the sequence number and header compression (RoHC: RObust).
A field indicating the profile of Header Compression), a field indicating the value of the reordering timer, and the like may be included.

Further, the SRB setting information element shown in FIG. 8 may further include a field related to the E-UTRA RLC entity setting (not shown). The field related to the E-UTRA RLC entity setting may be paraphrased as an RLC setting field or an RLC setting. Further, the SRB setting information element shown in FIG. 8 may include an information element related to the logical channel setting (not shown). The information element related to the logical channel setting may be paraphrased as the logical channel setting information element or the logical channel setting.

Further, the DRB setting information element shown in FIG. 8 may further include an information element related to the E-UTRA RLC entity setting (not shown). The information element related to the E-UTRA RLC entity setting may be paraphrased as the RLC setting information element or the RLC setting. Further, the DRB setting information element shown in FIG. 8 may include a field indicating logical channel identifier (identity: ID) information. A field indicating logical channel identifier (identity: ID) information may be paraphrased as a logical channel identifier field or a logical channel identifier. Further, the DRB setting information element shown in FIG. 8 may include an information element related to the logical channel setting (not shown). The information element related to the logical channel setting may be paraphrased as the logical channel setting information element or the logical channel setting. The logical channel identifier may be associated with the wireless bearer identifier.

The information element represented by DRB-ToReleaseList, which is included in the information element represented by RadioResolutionConfigProcessed, may include information indicating one or more DRB identifiers to be released.

In the NR, the information element related to the RLC bearer setting such as the information element related to the NR RLC entity setting for each radio bearer, the information element indicating the logical channel identifier (identity: ID) information, and the information element related to the logical channel setting is the RadioBearerConfig in FIG. It may be included in the information element related to the cell group setting instead of the information element represented by (not shown). The information element regarding the cell group setting may be included in the message regarding the resetting of the RRC connection. The information element related to the cell group setting may be paraphrased as a cell group setting information element or a cell group setting. The information element related to the NR RLC entity setting may be paraphrased as an RLC setting information element or an RLC setting. The information element indicating the logical channel identifier information may be paraphrased as a logical channel identifier information element or a logical channel identifier. The information element related to the logical channel setting may be paraphrased as the logical channel setting information element or the logical channel identifier. The logical channel identifier may be associated with the wireless bearer identifier.

Further, some or all fields and information elements described with reference to FIG. 7 or 8 may be optional. That is, the fields and information elements described with reference to FIG. 7 or FIG. 8 may be included in the message regarding the resetting of the RRC connection, if necessary or conditional. Further, the message regarding the resetting of the RRC connection may include a field or the like indicating that the full setting is applied, in addition to the information element regarding the setting of the wireless bearer. The field meaning that the full setting is applied may be represented by an information element name such as fullConfig, and the full setting may be indicated by using true, enable, or the like.

Based on the above description, various embodiments of the present invention will be described. In addition, each process described above may be applied to each process omitted in the following description.

FIG. 5 is a block diagram showing a configuration of a terminal device (UE122) according to an embodiment of the present invention. In order to avoid complicated explanation, FIG. 5 shows only the main components closely related to one embodiment of the present invention.

The UE 122 shown in FIG. 5 has a receiving unit 500 that receives an RRC message or the like from a base station device, a processing unit 502 that performs processing according to parameters included in the received message, and a transmitting unit that transmits an RRC message or the like to the base station device. It consists of 504. The above-mentioned base station apparatus may be eNB 102 or gNB 108. In addition, the processing unit 502 may include some or all of the functions of various layers (for example, physical layer, MAC layer, RLC layer, PDCP layer, SDAP layer, RRC layer, and NAS layer). That is, the processing unit 502 includes a physical layer processing unit, a MAC layer processing unit, an RLC layer processing unit, a PDCP layer processing unit, a SDAP processing unit, an RRC layer processing unit, and a part or all of the NAS layer processing unit. It's okay.

FIG. 6 is a block diagram showing a configuration of a base station device according to an embodiment of the present invention. In order to avoid complicated explanation, FIG. 6 shows only the main components closely related to one embodiment of the present invention. The above-mentioned base station apparatus may be eNB 102 or gNB 108.

The base station apparatus shown in FIG. 6 has a transmission unit 600 for transmitting an RRC message or the like to the UE 122, and a processing unit for creating an RRC message including parameters and transmitting the RRC message to the UE 122 to cause the processing unit 502 of the UE 122 to perform processing. It consists of a receiving unit 604 that receives an RRC message or the like from the 602 and the UE 122. In addition, the processing unit 602 may include some or all of the functions of various layers (for example, physical layer, MAC layer, RLC layer, PDCP layer, SDAP layer, RRC layer, and NAS layer). That is, the processing unit 602 includes a physical layer processing unit, a MAC layer processing unit, an RLC layer processing unit, a PDCP layer processing unit, a SDAP processing unit, an RRC layer processing unit, and a part or all of the NAS layer processing unit. It's okay.

Conditional Handover (CHO) in the embodiment of the present invention will be described. The conditional handover may be the conditional handover described in Non-Patent Document 1, Non-Patent Document 3, and the like. The terminal device may set the conditional handover by receiving the RRC message including the parameter of the conditional handover setting from the base station device. The parameter of the conditional handover setting may include a setting parameter of the target candidate SpCell and an execution condition parameter for applying the setting to the target candidate SpCell to execute the handover. The conditional handover may be a handover in which the terminal device executes the handover procedure when one or more execution conditions are satisfied. It should be noted that conditional handover may be paraphrased as conditional reconfiguration. Further, the conditional handover may be paraphrased as a handover. The RRC message including the conditional handover setting information element may be a message related to resetting the RRC connection or an RRC resetting message.

FIG. 9 shows an ASN. Representing a field and / or an information element relating to the setting of a conditional handover in the embodiment of the present invention. 1 This is an example of description. The information element represented by the Conditional Recognition in FIG. 9 may be an information element indicating the target candidate (candidate) SpCell in the conditional handover and the setting of the conditional handover execution condition. The information element represented by the Conditional Recognition may be paraphrased as a conditional handover setting information element or a conditional handover setting. The conditional handover setting information element may also be used to change the conditional PSCell.

In FIG. 9, in the field represented by the conductCondReconfig included in the conditional handover setting information element, when this field exists, the first cell selected after the conditional handover fails is the conditional handover setting information element. When it is one of the candidate SpCells included in, it may be a setting indicating that the candidate SpCell is to be conditionally reset. The field represented by attemptCondReconfig may be paraphrased as an attempt conditional reset field or an attempt conditional reset.

In FIG. 9, the information element represented by the CondReconfigToRemoveList included in the conditional handover setting information element may be a list of candidate SpCells to be deleted. The information element represented by CondReconfigToRemoveList may be paraphrased as a conditional reset list information element to be deleted or a conditional reset list to be deleted. The conditional reset list information element to be deleted may be a list of information elements represented by CondReconfid, which will be described later.

In FIG. 9, the information element represented by the CondReconfigToAdModList included in the conditional handover setting information element may be a list of the settings of the candidate SpCell to be added or changed. The information element represented by CondReconfigToAdModList may be paraphrased as a conditional reset list information element or a conditional reset list. Further, the conditional reset list information element may be a list of information elements represented by CondReconfigitToAdMod. The information element represented by the CondReconfigToAddMod may be paraphrased as a conditional reset information element or a conditional reset.

In FIG. 9, the field represented by condReconfid contained in the conditional reset information element may be an identifier that identifies the setting of the conditional handover or the conditional PSCell change. The field represented by condReconfigId may be paraphrased as a conditional reset identifier field or a conditional reset identifier field.

In FIG. 9, the field represented by the conditionExcutionCond included in the conditional reset information element may be an execution condition that must be satisfied in order to trigger the execution of the conditional reset. The field represented by the codeExcutionCond may be paraphrased as a conditional reset execution condition field or a conditional reset execution condition. The reset execution condition field may contain one or more identifiers that identify the measurement setting.

In FIG. 9, the information element represented by the condRRCReconfi contained in the conditional reset information element is applied when the conditional reset execution condition shown in the above-mentioned conditional reset execution condition field is satisfied. It may be an RRC reset message. That is, the information element represented by the condRRCReconfi may include a part or all of the information element and / or the field included in the RRC reset message described in Non-Patent Document 3. The information element represented by the condRRCReconfi may be paraphrased as a conditional reset information element or a conditional reset. Further, it may be prohibited to include the conditional reset information element in the information element and / or the field of the RRC reset message included in the conditional reset information element.

The conditional reset information element described above may include, for example, a part or all of the following settings (A) to (F).
(A) Cell group setting (may be an information element represented by CellGroupConfig described in Non-Patent Document 3).
(B) Information indicating whether or not the setting is full (may be a field represented by fullConfig described in Non-Patent Document 3).
(C) Message of NAS layer (may be an information element represented by Distributed NAS-message described in Non-Patent Document 3).
(D) Key update setting (may be an information element represented by MasterKeyUpdate described in Non-Patent Document 3).
(E) Measurement setting (may be an information element represented by MeasConfig described in Non-Patent Document 3).
(F) Wireless bearer setting.

Further, the above-mentioned cell group setting information may include, for example, a part or all of the following settings (1) to (6).
(1) Cell group identifier (may be an information element represented by CellGroupId described in Non-Patent Document 3).
(2) RLC bearer setting (may be an information element represented by RLC-BearerConfig described in Non-Patent Document 3).
(3) MAC layer setting of cell group (may be an information element represented by MAC-CellGroupConfig described in Non-Patent Document 3).
(4) Physical (PHY) layer setting of cell group (may be an information element represented by PhysicalCellGroupConfig described in Non-Patent Document 3).
(5) SpCell setting (may be an information element represented by SpCellConfig described in Non-Patent Document 3).
(6) SCell information (may be an information element represented by SCellConfig described in Non-Patent Document 3).
The SpCell setting in (5) may include a reset information element with synchronization. (5) S
The reset information element with synchronization included in the pCell setting may include the physical cell identifier of the target candidate SpCell (the information element represented by PhysCellId described in Non-Patent Document 3 may be used).

Further, the above-mentioned wireless bearer setting may include a part or all of the following settings (1) to (3).
(1) SRB setting (2) DRB setting (3) Security setting (may be an information element represented by SecurityConfig described in Non-Patent Document 3).
The security setting of (3) is information on the consistency protection algorithm and the encryption algorithm for SRB and / or DRB (may be an information element represented by the SecurityAlgorithmConfig described in Non-Patent Document 3), and /. Alternatively, it may include information indicating which key to use, the MCG key or the SCG key (the field may be the field indicated by keyTouse described in Non-Patent Document 3).

The above-mentioned candidate SpCell may be paraphrased as a target candidate SpCell. Further, SpCell may be paraphrased as Cell, PCell or PSCell.

An example of the processing of the terminal device in the embodiment of the present invention will be described with reference to FIG. An example of the processing of the terminal device according to the embodiment of the present invention described with reference to FIG. 10 is a contention-based protocol described in Non-Patent Document 1 and the like for a conditional handover without security key update executed by the terminal device. This is an example of solving a security problem that may occur when the above-mentioned conditional handover is used and the above-mentioned conditional handover fails.

FIG. 10 is a diagram showing an example of processing of a terminal device according to an embodiment of the present invention. The receiving unit 500 of the UE 122 may receive an RRC message from the base station device. The processing unit 502 of the UE 122 may set the UE 122 according to the RRC message received from the base station device. (Step S1000)

An example of starting the handover procedure in step S1002 will be described. In step S1000, for example, when the RRC message received from the base station apparatus includes the first synchronized reset information element, the above-mentioned first synchronized reset information element is the conditional handover setting information. When the information element is not included in the element, the processing unit 502 of the UE 122 applies the above-mentioned first synchronized reset information element to the first SpCell according to the above-mentioned first synchronized reset information element. On the other hand, the handover procedure may be started. When the above-mentioned RRC message received from the base station apparatus includes the first synchronized reset information element, the above-mentioned first synchronized reset information element is included in the conditional handover setting information element. The case where it is not an information element may be a case of unconditional handover or a case of normal handover. If the RRC message received from the base station device does not include the above-mentioned first synchronization reset information element, it is not necessary to start the handover procedure for the above-mentioned first SpCell. (Step S1002)

Another example of starting the handover procedure in step S1002 will be described. In step S1000, for example, when the RRC message received from the base station apparatus includes a conditional handover setting information element, the processing unit 502 of the UE 122 sets the UE 122 according to the above-mentioned conditional handover setting information element. You can go. Here, the above-mentioned handover setting information element may include a conditional reset list information element. Further, the above-mentioned conditional reset list information element may include the first to Nth conditional reset information elements (where N is a positive number). At a certain point in time, when the Nth conditional resetting execution condition included in the Nth conditional resetting information element set in the UE 122 is satisfied, the processing unit 502 of the UE 122 has the following (A). Processing including the above may be performed.
(A) The Nth synchronization included in the above-mentioned Nth conditional resetting information element by applying the Nth conditional resetting information element contained in the above-mentioned Nth conditional resetting information element. The handover procedure may be started for the Nth SpCell according to the additional reset information element.
The above-mentioned handover for the Nth SpCell may be rephrased as the above-mentioned conditional handover for the Nth SpCell. Further, when the above-mentioned Nth conditional resetting execution condition is not satisfied, the processing unit 502 of the UE 122 does not have to perform the above-mentioned processing (A). (Step S1002)

In step S1002, the above-mentioned first SpCell and the above-mentioned Nth SpCell may be the same cell. Further, in step S1002, the processing unit 502 of the UE 122 may activate the first timer for the first SpCell described above when performing a handover with respect to the first SpCell described above. Further, in step S1002, the processing unit 502 of the UE 122 may activate the above-mentioned first timer for the above-mentioned Nth SpCell when performing a handover with respect to the above-mentioned Nth SpCell. The processing unit 502 of the UE 122 applies to the above-mentioned first timer included in the above-mentioned first synchronized resetting information element when activating the above-mentioned first timer for the above-mentioned first SpCell. The value may be applied to the first timer described above. Further, the processing unit 502 of the UE 122 is applied to the above-mentioned first timer included in the above-mentioned Nth synchronized resetting information element when the above-mentioned first timer for the above-mentioned Nth SpCell is activated. The value to be applied may be applied to the first timer described above. The above-mentioned first timer may be a timer used for detecting a handover failure or the like. Further, the above-mentioned first timer is a timer that starts when an RRC message instructing a handover is received and stops when a random access to the corresponding (handover destination) SpCell is successful. Is also good. Further, when the above-mentioned first timer expires, it may be considered that the handover has failed. Further, the above-mentioned first timer may be a timer named T304 described in Non-Patent Document 3.

When the above-mentioned first timer expires, the processing unit 502 of the UE 122 may perform a handover failure procedure. It should be noted that the handover failure may be paraphrased as the synchronization reset setting failure. (Step S1004)

In the handover failure procedure of step S1004, the processing unit 502 of the UE 122 confirms whether the first setting has been made to the UE 112. The above-mentioned first setting may be the above-mentioned attempt conditional resetting. That is, the first setting described above is conditional on the candidate SpCell when the first selected cell after the conditional handover fails is one of the candidate SpCells included in the conditional handover setting information element. It may be a setting indicating that the setting is to be performed again. Further, the RRC message received in step S1000 that the above-mentioned first setting is performed includes (or includes) a conditional handover setting information element including an attempt conditional reset field. In other words. Further, the processing unit 502 of the UE 122 may confirm whether the handover of the UE 122 in step S1002 is accompanied by the security key update. It is said that the handover of the UE 122 in step S1002 was accompanied by the security key update, and that the above-mentioned Nth conditional reset information element contained (or contained) the parameter related to the above-mentioned key update setting. In other words. Further, the above-mentioned Nth conditional reset information element did not include (or does not include) the parameter related to the key update setting that the handover of the UE 122 in step S1002 did not involve the security key update. ) May be paraphrased. Further, the handover of the UE 122 in step S1002 may be paraphrased as the previous handover, the handover, or the resetting with synchronization. Further, the handover of the UE 122 in step S1002 may be paraphrased into another term as long as it is a term meaning the handover that caused the expiration of the first timer in step 1002. The above-mentioned parameter related to the key update setting may be an information element represented by MasterKeyUpdate described in Non-Patent Document 3 or the like, and / or a field represented by masterKeyUpdate. Note that security key update may be paraphrased as key update.

In the handover failure procedure of step S1004, the processing unit 502 of the UE 122 may perform processing including a part or all of the following (A) to (B) based on the fact that the first condition is satisfied.
(A) For some or all of the radio bearers established and / or set in the UE 122, the settings of the UE 122 other than the state variables of the PDCP entity are returned to the settings used in the source PCell (revert back). ).
(B) In the above-mentioned (A), the wireless bearer established and / or set in the UE 122 is not processed to return the setting of the UE 122 other than the state variable of the PDCP entity to the setting used in the source PCell. For some or all of them, the setting of UE 122 is returned to the setting used in the source PCell.
In the above (A), a part or all of the radio bearers established and / or set in the UE 122 is a part or all of the SRB established and / or set in the UE 122. It's okay to have it. Further, in (B) above, the wireless bearer established and / or set in the UE 122 is not processed to return the setting of the UE 122 other than the state variable of the PDCP entity to the setting used in the source PCell. A part or all of them may be a part or all of the DRBs established and / or set in the UE 122. That is, the above-mentioned processes (A) and (B) may be paraphrased as follows.
(A) For some or all of the SRBs established and / or set in the UE 122, the settings of the UE 122 other than the state variables of the PDCP entity are returned to the settings used in the source PCell.
(B) For some or all of the DRBs established and / or set in the UE 122, the settings of the UE 122 are returned to the settings used in the source PCell.

The above-mentioned first condition in the handover failure procedure in step S1004 is that the above-mentioned first setting is made in the UE 122, and / or the handover of the UE 122 in the step S1002 is accompanied by a security key update. The conditions may include things that were not done. Further, the above-mentioned first condition is at least a condition that the above-mentioned first setting is made in the UE 122 and that the handover of the UE 122 in step S1002 is not accompanied by the security key update. There may be.

Further, in the handover failure procedure of step S1004, for some or all of the radio bearers established and / or set in the UE 122 of (A) above, other than the state variables of the PDCP entity are used in the source PCell. The process of returning to the setting of the UE 122 that has been performed is a part of the following processes (1) to (2) or a part of the wireless bearers established and / or set in the UE 122. It may be a process including all.
(1) Return the setting of UE 122 to the setting used in the source PCell.
(2) Set the state variable of the PDCP entity of the target PCell (or used in the target PCell) to the state variable of the PDCP entity.

Further, in the handover failure procedure in step S1004, the processing unit 502 of the UE 122 performs a process of returning the setting of the UE 122 to the setting used in the source PCell based on the fact that the above-mentioned first condition is not satisfied. Is also good. The fact that the above-mentioned first condition is not satisfied means that the above-mentioned first setting is made in the UE 122, and that the handover of the UE 122 in step S1002 is not accompanied by the key update. Some or all may not be applicable.

Further, in the handover failure procedure of step S1004, the processing unit 502 of the UE 122 returns the setting of the UE 122 to the setting used in the source PCell, and then, based on the condition of the first condition described above, the following ( A process including a part or all of the processes from C) to (D) may be performed.
(C) For some or all of the radio bearers established and / or configured in the UE 122, the settings of the UE 122 other than the state variables of the PDCP entity are returned to the settings used in the source PCell.
(D) For some or all of the radio bearers established and / or configured in UE 122, the state variable of the PDCP entity is the state variable of the PDCP entity of the target PCell (or used by the target PCell). To set.
In the above (C) and / or (D), some or all of the radio bearers established and / or set in the UE 122 are established and / or set in the UE 122 of the SRB. It may be paraphrased as a part or all of them.

Further, in the handover failure procedure in step S1004, the processing unit 502 of the UE 122 returns the setting of the UE 122 to the setting used in the source PCell, and then, based on the fact that the first condition described above is not satisfied, the following Processing including the processing of (E) may be performed.
(E) Return the setting of UE 122 to the setting used in the source PCell.

Further, in the handover failure procedure of step S1004, the PDCP entity for a part or all of the radio bearers established and / or set in the UE 122 in the above-mentioned processing (A) and (C). "Return the settings of the UE 122 other than the state variables of the to the settings used in the source PCell." To "Return the settings of the UE 122 other than the state variables of the PDCP entity to the settings used in the source PCell." In other words. Further, in the handover failure procedure of step S1004, the target PCell is set to the state variable of the PDCP entity for some or all of the wireless bearers established and / or set in the UE 122 in the process (D) described above. Set the state variable of the PDCP entity (or used by the target PCell) to "Set the state variable of the PDCP entity (or used by the target PCell) to the state variable of the PDCP entity." You can paraphrase it. "

Further, in the handover failure procedure in step S1004, the fact that the above-mentioned first condition is not satisfied may be rephrased as another (else) condition for satisfying the above-mentioned first condition.

In the handover failure process of step S1004, the processing unit 502 of the UE 122 may further perform a process including a part or all of the following processes (F) to (G).
(F) The above-mentioned information regarding the handover failure is stored in the variable related to the wireless link failure of the UE 122.
(G) Invokes the procedure for reestablishing the RRC connection.
The variable related to the wireless link failure in (F) described above may be a variable named VarRLF-Report described in Non-Patent Document 3 and the like. Further, the above-mentioned procedure for reestablishing the RRC connection in (G) may be the procedure for reestablishing the RRC described in Non-Patent Document 3 and the like. The RRC reestablishment procedure may include a procedure in which the terminal device selects a cell for reestablishing the RRC connection, sends an RRC reestablishment request message to the base station device, and receives an RRC reestablishment message from the base station device. ..

In the above-mentioned RRC reconnection procedure after the handover failure process (not shown) in step S1004, the processing unit 502 of the UE 122 is set to a condition including a part or all of the following conditions (1) to (4). PDCP of the target PCell (or used by the target PCell) in the state variable of the PDCP entity for some or all of the radio bearers established and / or configured in the UE 122 based on the applicable. You may set the state variable of the entity.
(1) The above-mentioned first setting is made to the UE 122.
(2) The handover of the UE 122 in step S1002 was not accompanied by the key update.
(3) The selected cell is one of the candidate SpCells for conditional handover.
(4) The conditional handover for the selected cell described above does not involve key update.
In addition, a part or all of the radio bearers established and / or set in the UE 122 may be a part or all of the SRB established and / or set in the UE 122. Also, for some or all of the wireless bearers established and / or configured in UE 122, the state variable of the PDCP entity is the state of the PDCP entity (or used by the target PCell) in the state variable of the PDCP entity. "Set variable" may be rephrased as "set the state variable of the PDCP entity of the target PCell (or used in the target PCell) to the state variable of the PDCP entity".

The handover failure process in step S1004 may be performed based on the fact that the conditions including some or all of the following conditions (H) to (I) are not satisfied.
(H) A DAPS (Dual Active Protocol Stack) bearer is set.
(I) No radio link failure has been detected in the source PCell.
The DAPS bearer in (H) described above may be the DAPS bearer described in Non-Patent Document 3 and the like. A DAPS bearer may be a radio bearer that has some or all of the radio (AS) protocol on both the source and target because it uses both source and target resources during the DAPS handover. The above-mentioned source may be a source PCell. Further, the above-mentioned source may be a source base station device. Further, the above-mentioned target may be a target PCell. Further, the above-mentioned target may be a target base station device.

In an embodiment of the invention, the "UE 122 configuration" for returning the UE 122 configuration to the configuration used in the source PCell may be said to include the state variables and parameters of each radio bearer. Further, in the embodiment of the invention, even if the "setting of UE 122" in the case of returning the setting of UE 122 to the setting used in the source PCell includes the state variables and parameters of each radio bearer unless otherwise specified. good.

In embodiments of the invention, Cell, PCell, SpCell, PSCell, MCG, SCG, and cell groups may be paraphrased with each other.

As described above, in the embodiment of the present invention, efficient communication can be performed at the time of handover of the terminal device.

The radio bearers in the above description may be DRBs, SRBs, DRBs and SRBs, respectively.

Further, in the above explanation, expressions such as "associate", "associate", and "associate" are used.
They may be paraphrased to each other.

Further, in the example of each process in the above description or the example of the flow of each process, some or all of the steps may not be executed. Further, in the example of each process in the above description or the example of the flow of each process, the order of the steps may be different. Further, in the example of each process in the above description or the example of the flow of each process, some or all the processes in each step may not be executed. Further, in the example of each process in the above description or the example of the flow of each process, the order of the processes in each step may be different. Further, in the above description, "performing B based on the fact that it is A" may be paraphrased as "performing B". That is, "doing B" may be executed independently of "being A".

In the above description, "A may be paraphrased as B" may include the meaning of paraphrasing B as A in addition to paraphrasing A as B. Further, in the above description, when "C may be D" and "C may be E" are described, "D may be E" may be included. Further, in the above description, when "F may be G" and "G may be H" are described, "F may be H" may be included.

Further, in the above description, when the condition "A" and the condition "B" are contradictory, the condition "B" may be expressed as the "other" condition of the condition "A". good.

Hereinafter, various aspects of the terminal device, the base station device, and the method according to the embodiment of the present invention will be described.

(1) A terminal device that communicates with a base station device, wherein the terminal device includes a receiving unit and a processing unit that receive an RRC message from the base station device, and the processing unit follows the RRC message. The setting is made in the terminal device, the handover failure process is performed based on the fact that the first timer of the terminal device has expired, and the handover failure process is based on the fact that the first condition is satisfied. For each SRB, the setting of the terminal device other than the state variable of the PDCP entity is returned to the setting used in the source PCell, and the setting of the terminal device is used in the source PCell for each DRB. A process of returning to the set setting is performed, and a process of returning the setting of the terminal device to the setting used in the source PCell based on the fact that the first condition is not satisfied in the handover failure process is performed. The first condition includes at least that the terminal device has the first setting and that the conditional handover performed by the terminal device does not involve a key update, and the conditional handover is performed. Is a handover in which the terminal device executes the handover procedure when the conditional handover execution condition set in the terminal device is satisfied.

(2) A base station device that communicates with a terminal device, wherein the base station device includes a transmission unit and a processing unit that transmit an RRC message to the terminal device, and the processing unit follows the RRC message. The terminal device is made to set, and based on the fact that the first timer of the terminal device has expired, the terminal device is made to perform the handover failure process, and the first condition is satisfied in the handover failure process. Based on the above, the settings of the terminal device other than the state variables of the PDCP entity are returned to the settings used in the source PCell for each SRB, and the settings of the terminal device are set for each DRB. Is returned to the setting used in the source PCell, and the setting of the terminal device is used in the source PCell based on the fact that the first condition is not satisfied in the handover failure processing. The process of returning to the set setting is performed, and the first condition is that the terminal device has the first setting and that the conditional handover performed by the terminal device does not involve key update. The conditional handover is a handover in which the terminal device executes a handover procedure when the conditional handover execution condition set in the terminal device is satisfied.

(3) A method of a terminal device that communicates with a base station device, wherein the terminal device receives an RRC message from the base station device, sets the terminal device according to the RRC message, and sets the terminal device according to the RRC message. Based on the fact that the timer of 1 has expired, the handover failure process is performed, and based on the fact that the first condition is satisfied in the handover failure process, for each SRB, other than the state variables of the PDCP entity. The processing of returning the setting of the terminal device to the setting used in the source PCell is performed, and the processing of returning the setting of the terminal device to the setting used in the source PCell is performed for each DRB, and the handover fails. In the process of, based on the fact that the first condition is not satisfied, the process of returning the setting of the terminal device to the setting used in the source PCell is performed, and the first condition is the terminal device. The first setting is made at least, and the conditional handover performed by the terminal device does not involve key update, and the conditional handover is the conditional handover set in the terminal device. This is a handover in which the terminal device executes the handover procedure when the handover execution condition is satisfied.

(4) A method of a base station device that communicates with a terminal device, wherein the base station device transmits an RRC message to the terminal device, causes the terminal device to make settings according to the RRC message, and causes the terminal device to perform settings. Based on the fact that the first timer has expired, the terminal device is made to perform the handover failure processing, and based on the fact that the first condition is satisfied in the handover failure processing, PDCP is applied to each SRB. A process of returning the settings of the terminal device other than the state variable of the entity to the settings used in the source PCell, and a process of returning the settings of the terminal device to the settings used in the source PCell for each DRB. In the handover failure process, based on the fact that the first condition is not satisfied, the terminal device setting is returned to the setting used in the source PCell, and the first condition is performed. The condition of includes at least that the first setting is made in the terminal device and that the conditional handover performed by the terminal device does not involve key update, and the conditional handover means the terminal. This is a handover in which the terminal device executes the handover procedure when the conditional handover execution condition set in the device is satisfied.

(5) The first setting according to (1) to (4) is that the cell first selected after the conditional handover fails is one of the target candidate SpCells included in the conditional handover setting. If it is, it is a setting indicating that conditional resetting is performed for the target candidate SpCell.

The program that operates in the apparatus according to the present invention may be a program that controls the Central Processing Unit (CPU) or the like to operate the computer so as to realize the functions of the above-described embodiment according to the present invention. .. The program or the information handled by the program is temporarily read into volatile memory such as Random Access Memory (RAM) at the time of processing, or stored in non-volatile memory such as flash memory or Hard Disk Drive (HDD), and is required. The CPU reads, corrects, and writes accordingly.

In addition, a part of the apparatus in the above-described embodiment may be realized by a computer. In that case, the program for realizing this control function is recorded on a recording medium that can be read by the computer, and the program recorded on this recording medium is read by the computer system and executed. May be good. The "computer system" as used herein is a computer system built into the device, and includes hardware such as an operating system and peripheral devices. Further, the "recording medium that can be read by a computer" may be any of a semiconductor recording medium, an optical recording medium, a magnetic recording medium, and the like.

Furthermore, a "recording medium that can be read by a computer" is a communication line that dynamically holds a program for a short time, like a communication line when a program is transmitted via a network such as the Internet or a communication line such as a telephone line. It may also include a program that holds a program for a certain period of time, such as a volatile memory inside a computer system that is a server or a client in that case. Further, the above program may be for realizing a part of the above-mentioned functions, and may be further realized by combining the above-mentioned functions with a program already recorded in the computer system. ..

Also, each functional block, or feature of the device used in the embodiments described above, may be implemented or implemented in an electric circuit, i.e., typically an integrated circuit or a plurality of integrated circuits. Electrical circuits designed to perform the functions described herein are general purpose processors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), or others. Programmable Logic Devices, Discrete Gate or Transistor Logic, Discrete Hardware Components, or Combinations thereof. The general purpose processor may be a microprocessor or instead the processor may be a conventional processor, controller, microprocessor, or steady machine. The general-purpose processor or each of the above-mentioned circuits may be composed of a digital circuit or an analog circuit. In addition, when an integrated circuit technology that replaces the current integrated circuit appears due to advances in semiconductor technology, it is also possible to use an integrated circuit based on this technology.

The invention of the present application is not limited to the above-described embodiment. In the embodiment, an example of the device has been described, but the present invention is not limited to this, and the present invention is not limited to this, and the stationary or non-movable electronic device installed indoors and outdoors, for example, an AV device, a kitchen device, and the like. It can be applied to terminal devices or communication devices such as cleaning / washing equipment, air conditioning equipment, office equipment, vending machines, and other living equipment.

Although the embodiment of the present invention has been described in detail with reference to the drawings, the specific configuration is not limited to this embodiment and includes design changes and the like within a range not deviating from the gist of the present invention. Further, the present invention can be variously modified within the scope of the claims, and embodiments obtained by appropriately combining the technical means disclosed in the different embodiments are also included in the technical scope of the present invention. Will be. Further, the elements described in the above-described embodiment include a configuration in which elements having the same effect are replaced with each other.

100 E-UTRA
102 eNB
104 EPC
106 NR
108 gNB
110 5GC
112, 114, 116, 118, 120, 124 Interface 122 UE
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 504,600 Transmitter

Claims (8)

A terminal device that communicates with a base station device.
The terminal device includes a receiving unit for receiving an RRC message from the base station device and a processing unit.
The processing unit sets the terminal device according to the RRC message, and sets the terminal device.
Based on the fact that the first timer of the terminal device has expired, the handover failure process is performed.
In the handover failure process, the process of returning the settings of the terminal device other than the state variables of the PDCP entity to the settings used in the source PCell for each SRB based on the fact that the first condition is satisfied. To return the settings of the terminal device to the settings used in the source PCell for each DRB.
In the handover failure process, based on the fact that the first condition is not satisfied, a process of returning the setting of the terminal device to the setting used in the source PCell is performed.
The first condition includes at least that the first setting is made in the terminal device and that the conditional handover performed by the terminal device does not involve key update.
The conditional handover is a handover in which the terminal device executes a handover procedure when the conditional handover execution condition set in the terminal device is satisfied.
Terminal device. The first setting is a condition for the target candidate SpCell when the first cell selected after the conditional handover fails is one of the target candidate SpCells included in the conditional handover setting. It is a setting indicating that the setting is to be performed again.
The terminal device according to claim 1. A base station device that communicates with a terminal device.
The base station device includes a transmission unit for transmitting an RRC message to the terminal device and a processing unit.
The processing unit causes the terminal device to make settings according to the RRC message.
Based on the fact that the first timer of the terminal device has expired, the terminal device is made to process the handover failure.
In the handover failure process, the process of returning the settings of the terminal device other than the state variables of the PDCP entity to the settings used in the source PCell for each SRB based on the fact that the first condition is satisfied. Is performed, and each DRB is made to perform a process of returning the setting of the terminal device to the setting used in the source PCell.
In the processing of the handover failure, based on the fact that the first condition is not satisfied, the processing of returning the setting of the terminal device to the setting used in the source PCell is performed.
The first condition includes at least that the first setting is made in the terminal device and that the conditional handover performed by the terminal device does not involve key update.
The conditional handover is a handover in which the terminal device executes a handover procedure when the conditional handover execution condition set in the terminal device is satisfied.
Base station equipment. The first setting is a condition for the target candidate SpCell when the first cell selected after the conditional handover fails is one of the target candidate SpCells included in the conditional handover setting. It is a setting indicating that the setting is to be performed again.
The base station apparatus according to claim 3. It is a method of a terminal device that communicates with a base station device.
The terminal device receives an RRC message from the base station device and receives an RRC message.
Set the terminal device according to the RRC message, and set it.
Based on the fact that the first timer of the terminal device has expired, the handover failure process is performed.
In the handover failure process, the process of returning the settings of the terminal device other than the state variables of the PDCP entity to the settings used in the source PCell for each SRB based on the fact that the first condition is satisfied. To return the settings of the terminal device to the settings used in the source PCell for each DRB.
In the handover failure process, based on the fact that the first condition is not satisfied, a process of returning the setting of the terminal device to the setting used in the source PCell is performed.
The first condition includes at least that the first setting is made in the terminal device and that the conditional handover performed by the terminal device does not involve key update.
The conditional handover is a handover in which the terminal device executes a handover procedure when the conditional handover execution condition set in the terminal device is satisfied.
Method. The first setting is a condition for the target candidate SpCell when the first cell selected after the conditional handover fails is one of the target candidate SpCells included in the conditional handover setting. It is a setting indicating that the setting is to be performed again.
The method according to claim 5. It is a method of base station equipment that communicates with terminal equipment.
The base station device sends an RRC message to the terminal device,
Have the terminal device make settings according to the RRC message.
Based on the fact that the first timer of the terminal device has expired, the terminal device is made to process the handover failure.
In the handover failure process, the process of returning the settings of the terminal device other than the state variables of the PDCP entity to the settings used in the source PCell for each SRB based on the fact that the first condition is satisfied. Is performed, and each DRB is made to perform a process of returning the setting of the terminal device to the setting used in the source PCell.
In the processing of the handover failure, based on the fact that the first condition is not satisfied, the processing of returning the setting of the terminal device to the setting used in the source PCell is performed.
The first condition includes at least that the first setting is made in the terminal device and that the conditional handover performed by the terminal device does not involve key update.
The conditional handover is a handover in which the terminal device executes a handover procedure when the conditional handover execution condition set in the terminal device is satisfied.
Method. The first setting is a condition for the target candidate SpCell when the first cell selected after the conditional handover fails is one of the target candidate SpCells included in the conditional handover setting. It is a setting indicating that the setting is to be performed again.
The method according to claim 7.

Images