Base stations, communication methods, and communication systems

Abstract

To make it possible to transmit and receive essential information between network nodes in wireless communication systems.SOLUTION: A base station includes a receiving unit that receives an inter-base station message from another base station, and a control unit that maintains a value notified by a message sent from another base station prior to receiving the inter-base station message, if the inter-base station message does not contain a measGapConfig field.SELECTED DRAWING: Figure 7

Description

Technical Field

[0001] The present invention relates to a base station, a communication method executed by the base station, and a communication system.

Background Art

[0002] In NR (New Radio), which is a successor system to LTE (Long Term Evolution) (also referred to as "5G"), technologies that satisfy requirements such as a large-capacity system, high data transmission speed, low latency, simultaneous connection of a large number of terminals, low cost, and power saving are being studied (for example, Non-Patent Document 1).

[0003] In the NR system, similar to dual connectivity in the LTE system, technologies called LTE-NR dual connectivity, NR-NR dual connectivity, or multi-RAT (Multi Radio Access Technology) dual connectivity (hereinafter referred to as "MR-DC") are introduced, in which data is split between a base station (eNB) of the LTE system and a base station (gNB) of the NR system, and the data is simultaneously transmitted and received by these base stations (for example, Non-Patent Document 2).

Prior Art Documents

Non-Patent Documents

[0004]

Non-Patent Document 1

Non-Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] In NR wireless communication systems, although RRC messages between user equipment and base station equipment are optional, internode RRC messages between base station equipment related to those RRC messages were sometimes mandatory.

[0006] This invention has been made in view of the above points, and aims to transmit and receive essential information between network nodes in a wireless communication system. [Means for solving the problem]

[0007] The base station in this embodiment includes a receiving unit that receives interbase station messages from other base stations, and the interbase station messages Delta signaling was applied. The system includes, if the measGapConfig field is not included, a control unit that maintains a value notified by a message sent from the other base station before receiving the inter-base station message. [Effects of the Invention]

[0008] According to the disclosed technology, essential information can be sent and received between network nodes in a wireless communication system. [Brief explanation of the drawing]

[0009] [Figure 1] This figure shows an example of the network architecture configuration in an embodiment of the present invention. [Figure 2] This figure shows an example configuration of a wireless communication system according to an embodiment of the present invention. [Figure 3] This is a sequence diagram illustrating a first example of operation in an embodiment of the present invention. [Figure 4] This figure illustrates the information elements used in the first operational example in an embodiment of the present invention. [Figure 5] This is a sequence diagram illustrating a second example of operation in an embodiment of the present invention. [Figure 6]This figure illustrates the information elements used in a second operational example in an embodiment of the present invention. [Figure 7] This is an example of a specification change relating to an example of operation in an embodiment of the present invention. [Figure 8] This figure shows an example of the functional configuration of the base station device 10 in an embodiment of the present invention. [Figure 9] This figure shows an example of the functional configuration of the user device 20 in an embodiment of the present invention. [Figure 10] This figure shows an example of the hardware configuration of a base station device 10 or user device 20 in an embodiment of the present invention. [Modes for carrying out the invention]

[0010] Embodiments of the present invention will be described below with reference to the drawings. Note that the embodiments described below are examples, and the embodiments to which the present invention applies are not limited to those described below.

[0011] In the operation of the wireless communication system according to the embodiments of the present invention, existing technologies may be used as appropriate. However, such existing technologies include, for example, existing LTE, but are not limited to existing LTE. Furthermore, the term "LTE" as used herein has a broad meaning that includes LTE-Advanced and LTE-Advanced and later methods (e.g., NR), unless otherwise specified.

[0012] Also, in the embodiments of the present invention described below, terms such as SS (Synchronization signal), PSS (Primary SS), SSS (Secondary SS), PBCH (Physical broadcast channel), PRACH (Physical random access channel), etc. that are used in existing LTE are used. This is for the convenience of description, and signals, functions, etc. similar to these may be called by other names. Also, the above-mentioned terms in NR correspond to NR-SS, NR-PSS, NR-SSS, NR-PBCH, NR-PRACH, etc. However, even for signals used in NR, it is not always necessary to clearly write "NR-".

[0013] Also, in the embodiments of the present invention, the duplex mode may be a TDD (Time Division Duplex) mode, an FDD (Frequency Division Duplex) mode, or another mode (for example, Flexible Duplex, etc.).

[0014] Also, in the embodiments of the present invention, that a radio parameter or the like is "configured" may mean that a predetermined value is pre-configured, or that a radio parameter notified from the base station device 10 or the user device 20 is configured.

[0015] FIG. 1 is a diagram showing a configuration example of a network architecture in an embodiment of the present invention. As shown in FIG. 1, the radio network architecture in the embodiment of the present invention includes, on the LTE-Advanced side, 4G-CU, 4G-RU (Remote Unit, remote radio station), EPC (Evolved Packet Core), etc. The radio network architecture in the embodiment of the present invention includes, on the 5G side, 5G-CU, 5G-DU, etc.

[0016] As shown in FIG. 1, the 4G-CU includes layers up to RRC (Radio Resource Control), PDCP (Packet Data Convergence Protocol), RLC (Radio Link Control), MAC (Medium Access Control), and L1 (layer 1, PHY layer or physical layer), and is connected to the 4G-RU via CPRI (Common Public Radio Interface). A network node including the 4G-CU and the 4G-RU is called an eNB.

[0017] On the other hand, on the 5G side, as shown in FIG. 1, the 5G-CU includes the RRC layer, is connected to the 5G-DU via the FH (Flonthaul) interface, and is connected to the 5GC (5G Core Network) via the NG interface (NG interface). Also, the 5G-CU is connected to the 4G-CU via the X2 interface. The PDCP layer in the 4G-CU becomes the combination or separation point when 4G-5G DC (Dual Connectivity), that is, EN-DC (E-UTRA-NR Dual Connectivity) is performed. A network node including the 5G-CU and the 5G-DU is called a gNB. Also, the 5G-CU may be called gNB-CU and the 5G-DU may be called gNB-DU.

[0018] Also, as shown in FIG. 1, carrier aggregation (CA) is performed between 4G-RUs, and DC is performed between the 4G-RU and the 5G-DU. Although not shown, the UE (User Equipment) is wirelessly connected via the RF of the 4G-RU or the 5G-DU to transmit and receive packets.

[0019] Figure 1 shows the wireless network architecture for LTE-NR DC, i.e., EN-DC (E-UTRA-NR Dual Connectivity). However, the same wireless network architecture may be used when separating 4G-CU into CU-DU, or when operating NR standalone. When separating 4G-CU into CU-DU, the functions related to the RRC layer and PDCP layer may be moved to 4G-CU, and the RLC layer and below may be included in 4G-DU. Note that the CPRI data rate may be reduced by separating CU-DU.

[0020] Furthermore, multiple 5G-DUs may be connected to a 5G-CU. Also, NR-DC (NR-NR Dual Connectivity) may be performed by connecting UEs to multiple 5G-CUs, or by connecting UEs to multiple 5G-DUs and a single 5G-CU.

[0021] Figure 2 shows an example configuration of a wireless communication system according to an embodiment of the present invention. Figure 2 is a schematic diagram showing a wireless communication system in MR-DC (Multi-RAT Dual Connectivity) mode.

[0022] As shown in Figure 2, the user device 20 communicates with base station device 10A and base station device 10B provided by the NR system (hereinafter, when base station device 10A and base station device 10B are not distinguished, they may be referred to as "base station device 10"). Furthermore, the user device 20 supports NR-NR dual connectivity, i.e., NR-DC, with base station device 10A as the master node (hereinafter also referred to as "MN") and base station device 10B as the secondary node (hereinafter also referred to as "SN"). The user device 20 can simultaneously transmit or receive with base station device 10A and base station device 10B by simultaneously utilizing multiple component carriers provided by base station device 10A, the master node, and base station device 10B, the secondary node.

[0023] Furthermore, as shown in Figure 2, the user device 20 communicates with the base station device 10A provided by the LTE system and the base station device 10B provided by the NR system. In addition, the user device 20 supports LTE-NR dual connectivity, i.e., EN-DC, with base station device 10A as the MN and base station device 10B as the SN. The user device 20 can simultaneously transmit or receive with base station device 10A, the master node, and base station device 10B, the secondary node, by simultaneously utilizing multiple component carriers provided by base station device 10A, the master node, and base station device 10B, the secondary node.

[0024] Although the following embodiments describe NR-NR dual connectivity, the user device 20 according to the embodiments of the present invention is not limited to NR-NR dual connectivity, but is applicable to dual connectivity between multiple wireless communication systems using different RATs, i.e., MR-DC.

[0025] Figure 3 is a sequence diagram illustrating a first operational example in an embodiment of the present invention. The base station device 10A shown in Figure 3 is the source NG-RAN node for the handover, and the base station device 10B is the target NG-RAN node for the handover. The user device 20 initiates a handover from base station device 10A to base station device 10B.

[0026] In step S11, base station device 10A sends a "HANDOVER REQUEST" to base station device 10B. The "HANDOVER REQUEST" includes an internode RRC message "HandoverPreparationInformation". Through "HandoverPreparationInformation", the AS-Config (Access Stratum-Config), which is the radio access layer configuration, is transferred from base station device 10A to base station device 10B. The AS-Config has all the fields necessary to describe the AS context regarding the function to be configured. Therefore, "need" or "cond", which apply to the fields of the RRC message between user device 20 and base station device 10, may not apply to the fields of the RRC message between base station devices 10. In the interpretation of the fields, "need" means to specify, maintain, no action, or release, etc., and "cond" means the condition of the configuration or the condition of the message. Some fields of the RRC message between base station devices 10 are always included, regardless of whether they are "need" or "cond". For example, the information element "discardTimer" is a field that must be included. In step S12, the base station device 10B, which is the target NG-RAN node, sends "HANDOVER REQUEST ACKNOWLEDGE" to the base station device 10A, which is the source NG-RAN node, and the handover process begins.

[0027] Figure 4 is a diagram illustrating the information elements used in a first operational example in an embodiment of the present invention. Figure 4 shows an example of an internode RRC message, "HandoverPreparationInformation." "HandoverPreparationInformation" is sent from a source NG-RAN node or another RAN to a target NG-RAN node.

[0028] As shown in Figure 4, "HandoverPreparationInformation" contains the information element "HandoverPreparationInformation-IEs". "HandoverPreparationInformation-IEs" contains the information element "AS-Config". "AS-Config" contains the information element "RRCReconfiguration". "RRCReconfiguration" contains the information element "RRCReconfiguration-IEs". "RRCReconfiguration-IEs" contains the information element "RadioBearerConfig". "RadioBearerConfig" contains the information element "DRB-ToAddModList". "DRB-ToAddModList" contains the information element "DRB-ToAddMod". "DRB-ToAddMod" contains the information element "PDCPConfig". "PDCPConfig" contains the information element "discardTimer".

[0029] As shown in Figure 4, "discardTimer" is an information element to which a timer value is set. "discardTimer" is activated in the PDCP layer when a PDCP SDU (Service Data Unit) is acquired from a higher layer, and when it expires, the PDCP SDU is discarded.

[0030] As shown in Figure 4, "discardTimer" is an option that requires setup, such as "OPTIONAL, -- Cond Setup," between the user device 20 and the base station device 10. However, "discardTimer" may also be sent as a required field in internode RRC messages from the source NG-RAN node to the target NG-RAN node via "HandoverPreparationInformation." In other words, information required between network nodes is sent as a required field regardless of the settings for the corresponding fields between the user device 20 and the base station device 10, thereby ensuring the network functions properly.

[0031] Figure 5 is a sequence diagram illustrating a second operational example in an embodiment of the present invention. The base station device 10A shown in Figure 5 is an NG-RAN master node, and the base station device 10B is an NG-RAN secondary node.

[0032] In step S21, base station device 10A sends "S-NODE ADDITION REQUEST" to base station device B. "S-NODE ADDITION REQUEST" includes the internode RRC message "CG-ConfigInfo". Through "CG-ConfigInfo", a request to establish, modify, or release a connection in the secondary cell group is forwarded from base station device 10A to base station device 10B. In step S22, base station device 10B, which is the NG-RAN secondary node, sends "S-NODE ADDITION REQUEST ACKNOWLEDGE" to base station device 10A, which is the NG-RAN master node, and allocates resources for the DC to user device 20.

[0033] Note that "S-NODE ADDITION REQUEST" may be replaced with, for example, "S-NODE MODIFICATION REQUEST" or "S-NODE RELEASE REQUEST". "S-NODE MODIFICATION REQUEST" is a message requesting a change in the NG-RAN secondary node, and "S-NODE RELEASE REQUEST" is a message requesting a release in the NG-RAN secondary node.

[0034] Figure 6 is a diagram illustrating information elements used in a second operational example in an embodiment of the present invention. Figure 6 is an example of an internode RRC message "CG-ConfigInfo". "CG-ConfigInfo" is transmitted from an NG-RAN master node or LTE-RAN master node to an NG-RAN secondary node. "CG-ConfigInfo" is an information element for performing actions such as establishing, changing, or releasing connections in a secondary cell group.

[0035] As shown in Figure 6, "CG-ConfigInfo" contains the information element "CG-ConfigInfo-IEs". "CG-ConfigInfo-IEs" contains the information element "MeasConfigMN". The information element "measGapConfig" in "MeasConfigMN" is set to "GapConfig" using the data type "SetupRelease". The data type "SetupRelease" is a data type in which NULL is set during Release and the information element is set during Setup. In other words, "GapConfig" is set in "measGapConfig" during Setup.

[0036] Here, when the data type "SetupRelease" is used in the information element "CG-Config" and the aforementioned "CG-ConfigInfo" for configuring the wireless settings of the secondary cell group, delta configuration is supported. If the data type "SetupRelease" is not used in "CG-Config" and "CG-ConfigInfo", the transmitter must include all fields related to the functions set on the user device in the configuration. In other words, if a field is not included in the configuration, it means that the function corresponding to that field is not set on the user device 20 unless "SetupRelease" is used.

[0037] As described above, delta configuration is supported when the data type is SetupRelease. Regarding the various configurations set on the user device 20 during communication, the information set on the user device 20, such as wireless bearer or secondary cell settings, may change depending on the communication status, etc. The network can maintain stable communication by changing the settings on the user device 20 appropriately each time. Configuration refers to the information for performing communication that is set on the user device 20.

[0038] In delta configuration, when a setting is changed on the user device 20 or a network node, only the difference from the previously set value is notified. It is desirable to apply delta configuration when possible from the perspective of wireless resource consumption or terminal power consumption. Various settings configured on the user device 20 can be carried over between network nodes; for example, delta configuration can be continued when moving between network nodes due to mobility.

[0039] On the other hand, when changing configuration values, a full configuration is known, in which all configuration values ​​are communicated. For example, a full configuration is applied when there is incompatibility between network nodes.

[0040] Figure 7 shows an example of specification changes relating to an example of operation in an embodiment of the present invention. As shown in Figure 7, the AS-Config, which is the setting of the radio access layer, is transferred from the source gNB to the target gNB via "HandoverPreparationInformation". The AS-Config has all the fields necessary to describe the AS context regarding the function to be set. Therefore, "need" or "cond" which are applied to the fields of the RRC message between the user device 20 and the base station device 10 may not be applied to the fields of the RRC message between the base station devices 10. In the interpretation of the fields, "need" means specific, maintain, no action or release, etc., and "cond" means the condition of the setting or the condition of the message. Some fields of the RRC message between the base station devices 10 are always included, regardless of "need" or "cond". For example, the information element "discardTimer" is a field that is always included.

[0041] In short, information essential between network nodes is transmitted as an essential field, regardless of the settings for the corresponding fields between the user device 20 and the base station device 10, thereby ensuring the network functions properly.

[0042] Furthermore, as shown in Figure 7, "CG-Config" and "CG-ConfigInfo," used to notify the setting parameters of the user device 20, may include all fields if delta configuration is not performed. Based on the full CG configuration obtained from the source gNB, the target gNB can create a delta CG configuration. The "need" or "cond" set in the fields does not necessarily have to be applied to "CG-Config" and "CG-ConfigInfo."

[0043] Here, the information element "measGapConfig" may support delta signaling. If the "measGapConfig" field is not included in an internode RRC message, it may mean that the value notified in the previous message is maintained. Also, if a new field introduced in "CG-Config" or "CG-ConfigInfo" supports delta signaling, the field may be defined using the data type "SetupRelease" in the message containing "CG-Config" or "CG-ConfigInfo".

[0044] Furthermore, delta configuration may be supported when the data type "SetupRelease" is used in "CG-Config" and "CG-ConfigInfo". If the data type "SetupRelease" is not used in "CG-Config" and "CG-ConfigInfo", the sender may include all fields related to the functions set on the user device in the configuration. In other words, the absence of a field in the configuration may mean that the function corresponding to that field is not set on the user device 20, unless "SetupRelease" is used.

[0045] In other words, if the data type "SetupRelease" is not used, all fields related to the functions set on the user device 20 are included in the configuration as required and sent to ensure the network functions properly.

[0046] As described above, the network can function properly by sending network node messages as required fields, regardless of the settings for the corresponding fields between the user device 20 and the base station device 10, for information that is essential between network nodes. Furthermore, if the data type "SetupRelease" is not used, the base station device 10 can send network node messages by including all fields related to the functions set on the user device 20 as required in the configuration.

[0047] In other words, it can send and receive essential information between network nodes in a wireless communication system.

[0048] (Device configuration) Next, we will describe an example of the functional configuration of the base station device 10 and user device 20 that perform the processes and operations described above. The base station device 10 and user device 20 include functions to implement the embodiments described above. However, the base station device 10 and user device 20 may each have only some of the functions in the embodiments.

[0049] <Base station device 10> Figure 8 shows an example of the functional configuration of a base station device 10 in an embodiment of the present invention. As shown in Figure 8, the base station device 10 has a transmitting unit 110, a receiving unit 120, a setting unit 130, and a control unit 140. The functional configuration shown in Figure 8 is merely an example. The names of the functional categories and functional units can be anything as long as they can perform the operations according to the embodiment of the present invention.

[0050] The transmitting unit 110 includes the function of generating a signal to be transmitted to the user device 20 and transmitting the signal wirelessly. The transmitting unit 110 also transmits inter-network node messages to other network nodes. The receiving unit 120 includes the function of receiving various signals transmitted from the user device 20 and obtaining information from the received signals, for example, higher layer information. The transmitting unit 110 also has the function of transmitting NR-PSS, NR-SSS, NR-PBCH, DL / UL control signals, etc. to the user device 20. The receiving unit 120 also receives inter-network node messages from other network nodes.

[0051] The setting unit 130 stores pre-configured setting information and various setting information to be transmitted to the user device 20 in a storage device, and reads it from the storage device as needed. The contents of the setting information include, for example, setting information related to communication of the user device 20, such as the settings for wireless bearers or secondary cells.

[0052] As described in the embodiment, the control unit 140 controls the communication between the user device 20 and the NR-DC-enabled communication. The control unit 140 also obtains or notifies other network nodes of the user device 20's communication configuration. Furthermore, the control unit 140 performs delta configuration or full configuration of the user device 20's communication configuration. The signal transmission function in the control unit 140 may be included in the transmission unit 110, and the signal reception function in the control unit 140 may be included in the reception unit 120.

[0053] <User device 20> Figure 9 shows an example of the functional configuration of the user device 20 in an embodiment of the present invention. As shown in Figure 9, the user device 20 has a transmitting unit 210, a receiving unit 220, a setting unit 230, and a control unit 240. The functional configuration shown in Figure 9 is merely an example. The names of the functional categories and functional units can be anything as long as they can perform the operations according to the embodiment of the present invention.

[0054] The transmitting unit 210 creates a transmission signal from the transmission data and transmits the transmission signal wirelessly. The receiving unit 220 wirelessly receives various signals and acquires signals from higher layers from the received physical layer signals. The receiving unit 220 also has the function of receiving NR-PSS, NR-SSS, NR-PBCH, DL / UL / SL control signals, etc. transmitted from the base station equipment 10. For example, the transmitting unit 210 transmits PSCCH (Physical Sidelink Control Channel), PSSCH (Physical Sidelink Shared Channel), PSDCH (Physical Sidelink Discovery Channel), PSBCH (Physical Sidelink Broadcast Channel), etc. as D2D communication to other user equipment 20, and the receiving unit 120 receives PSCCH, PSSCH, PSDCH or PSBCH, etc. from other user equipment 20.

[0055] The setting unit 230 stores various setting information received from the base station device 10 or user device 20 by the receiving unit 220 in its storage device and reads it from the storage device as needed. The setting unit 230 also stores pre-configured setting information. The content of the setting information includes, for example, setting information related to communication of the user device 20, such as the settings for wireless bearers or secondary cells.

[0056] As described in the embodiment, the control unit 240 performs wireless communication to which NR-DC is applied. The control unit 240 also receives information related to wireless communication from the base station device 10, controls the wireless communication of the user device 20 based on that information, and reports necessary information to the base station device 10. The signal transmission function in the control unit 240 may be included in the transmission unit 210, and the signal reception function in the control unit 240 may be included in the reception unit 220.

[0057] (Hardware configuration) The block diagrams (Figures 8 and 9) used in the description of the above embodiments show functional units. These functional blocks (components) are realized by any combination of at least one of hardware and software. Furthermore, the method of realizing each functional block is not particularly limited. That is, each functional block may be realized using one device that is physically or logically coupled, or it may be realized using two or more physically or logically separated devices that are directly or indirectly connected (for example, using wired or wireless connections). A functional block may be realized by combining the above one device or the above multiple devices with software.

[0058] Functions include, but are not limited to, judgment, decision, judgment, calculation, calculation, processing, derivation, investigation, exploration, confirmation, reception, transmission, output, access, resolution, selection, selection, establishment, comparison, assumption, expectation, assumption, broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating (mapping), and assigning. For example, a functional block (configuration part) that enables transmission is called a transmitting unit or transmitter. As mentioned above, the method of implementation is not particularly limited.

[0059] For example, the base station device 10, user device 20, etc. in one embodiment of the present disclosure may function as a computer that processes the wireless communication method of the present disclosure. Figure 10 is a diagram showing an example of the hardware configuration of the base station device 10 and user device 20 according to one embodiment of the present disclosure. The above-mentioned base station device 10 and user device 20 may be physically configured as a computer device including a processor 1001, a storage device 1002, an auxiliary storage device 1003, a communication device 1004, an input device 1005, an output device 1006, a bus 1007, etc.

[0060] In the following explanation, the term "device" can be replaced with "circuit," "device," "unit," etc. The hardware configuration of the base station device 10 and the user device 20 may include one or more of the devices shown in the figure, or it may be configured to omit some of the devices.

[0061] Each function in the base station device 10 and the user device 20 is realized by loading predetermined software (programs) onto hardware such as the processor 1001 and the storage device 1002, which allows the processor 1001 to perform calculations, control communication by the communication device 1004, and control at least one of the reading and writing of data in the storage device 1002 and the auxiliary storage device 1003.

[0062] The processor 1001 controls the entire computer, for example, by running an operating system. The processor 1001 may consist of a central processing unit (CPU) that includes interfaces with peripheral devices, control devices, arithmetic units, registers, etc. For example, the control unit 140, control unit 240, etc., described above may be implemented by the processor 1001.

[0063] Furthermore, the processor 1001 reads programs (program code), software modules, or data from at least one of the auxiliary storage device 1003 and the communication device 1004 into the storage device 1002, and executes various processes accordingly. The program used is one that causes the computer to execute at least a part of the operations described in the above embodiment. For example, the control unit 140 of the base station device 10 shown in Figure 8 may be implemented by a control program stored in the storage device 1002 and operated by the processor 1001. Also, for example, the control unit 240 of the user device 20 shown in Figure 9 may be implemented by a control program stored in the storage device 1002 and operated by the processor 1001. Although the above processes have been described as being executed by one processor 1001, they may be executed simultaneously or sequentially by two or more processors 1001. The processor 1001 may be implemented by one or more chips. The program may be transmitted from the network via a telecommunications line.

[0064] The storage device 1002 is a computer-readable recording medium and may consist of at least one of the following: ROM (Read Only Memory), EPROM (Erasable Programmable ROM), EEPROM (Electrically Erasable Programmable ROM), RAM (Random Access Memory), etc. The storage device 1002 may also be called a register, cache, main memory, etc. The storage device 1002 can store executable programs (program code), software modules, etc., for implementing a communication method according to one embodiment of this disclosure.

[0065] The auxiliary storage device 1003 is a computer-readable recording medium and may consist of at least one of the following: an optical disc such as a CD-ROM (Compact Disc ROM), a hard disk drive, a flexible disk, a magneto-optical disk (e.g., a compact disc, a digital multipurpose disc, a Blu-ray® disc), a smart card, flash memory (e.g., a card, a stick, a key drive), a floppy® disk, a magnetic strip, etc. The above-mentioned storage medium may also be a database, server, or other suitable medium that includes at least one of the storage device 1002 and the auxiliary storage device 1003.

[0066] The communication device 1004 is hardware (transmitting / receiving device) for communicating between computers via at least one of a wired network and a wireless network, and is also referred to as a network device, network controller, network card, communication module, etc. The communication device 1004 may be configured to include high-frequency switches, duplexers, filters, frequency synthesizers, etc., in order to implement at least one of frequency division duplex (FDD) and time division duplex (TDD). For example, the transmitting and receiving antennas, amplifier section, transmitting and receiving section, transmission path interface, etc., may be implemented by the communication device 1004. The transmitting and receiving section may be implemented in a physically or logically separated manner, with a transmitting section and a receiving section.

[0067] The input device 1005 is an input device that accepts input from an external source (e.g., a keyboard, mouse, microphone, switch, button, sensor, etc.). The output device 1006 is an output device that outputs to an external source (e.g., a display, speaker, LED lamp, etc.). The input device 1005 and the output device 1006 may be configured as an integrated unit (e.g., a touch panel).

[0068] Furthermore, each device, such as the processor 1001 and the storage device 1002, is connected by a bus 1007 for communicating information. The bus 1007 may be configured using a single bus, or different buses may be configured for each device.

[0069] Furthermore, the base station device 10 and the user device 20 may be configured to include hardware such as a microprocessor, a digital signal processor (DSP), an ASIC (Application Specific Integrated Circuit), a PLD (Programmable Logic Device), and an FPGA (Field Programmable Gate Array), and some or all of each functional block may be realized by such hardware. For example, the processor 1001 may be implemented using at least one of these hardware components.

[0070] (Summary of the embodiments) According to this embodiment, the following base station, communication method, and communication system are provided.

[0071] The base station in this embodiment includes a receiving unit that receives inter-base station messages from other base stations, and a control unit that maintains a value notified by a message sent from the other base station before receiving the inter-base station message, if the inter-base station message does not include the measGapConfig field.

[0072] In the base station of this embodiment, delta signaling is applied to the measGapConfig field.

[0073] In this embodiment, the base station is an inter-base station RRC message.

[0074] The communication method performed by the base station in this embodiment includes the steps of receiving an inter-base station message from another base station, and, if the inter-base station message does not include the measGapConfig field, maintaining the value notified by a message sent from the other base station before receiving the inter-base station message.

[0075] The communication system in this embodiment comprises a first base station and a second base station. The first base station transmits an interbase station message to the second base station. The second base station receives the interbase station message from the first base station, and if the interbase station message does not contain the measGapConfig field, it maintains the value notified by a message transmitted from the first base station before receiving the interbase station message.

[0076] (Supplement to the embodiment) While embodiments of the present invention have been described above, the disclosed invention is not limited to such embodiments, and those skilled in the art will understand various modifications, alterations, alternatives, substitutions, etc. Specific numerical examples have been used to facilitate understanding of the invention, but unless otherwise specified, these numerical values ​​are merely examples, and any appropriate values ​​may be used. The division of items in the above description is not essential to the present invention, and matters described in two or more items may be combined as needed, and matters described in one item may be applied to matters described in another item (as long as they do not contradict each other). The boundaries of functional units or processing units in the functional block diagram do not necessarily correspond to the boundaries of physical parts. The operation of multiple functional units may be physically performed by one part, or the operation of one functional unit may be physically performed by multiple parts. Regarding the processing procedures described in the embodiments, the order of processing may be changed as long as it does not contradict each other. For the convenience of explaining the processing, the base station device 10 and the user device 20 have been described using functional block diagrams, but such devices may be implemented in hardware, software, or a combination thereof. The software operated by the processor of the base station device 10 according to an embodiment of the present invention and the software operated by the processor of the user device 20 according to an embodiment of the present invention may be stored in random access memory (RAM), flash memory, read-only memory (ROM), EPROM, EEPROM, registers, hard disk (HDD), removable disk, CD-ROM, database, server, or any other suitable storage medium.

[0077] Furthermore, the notification of information is not limited to the embodiments / models described herein and may be carried out by other methods. For example, the notification of information may be carried out by physical layer signaling (e.g., DCI (Downlink Control Information), UCI (Uplink Control Information)), upper layer signaling (e.g., RRC (Radio Resource Control) signaling, MAC (Medium Access Control) signaling, broadcast information (MIB (Master Information Block), SIB (System Information Block))), other signals, or combinations thereof. Also, RRC signaling may be called RRC messages, and may be, for example, RRC Connection Setup messages, RRC Connection Reconfiguration messages, etc.

[0078] Each aspect / embodiment described in this disclosure may be applied to at least one of the following systems: LTE (Long Term Evolution), LTE-A (LTE-Advanced), SUPER 3G, IMT-Advanced, 4G (4th generation mobile communication system), 5G (5th generation mobile communication system), FRA (Future Radio Access), NR (new Radio), W-CDMA (registered trademark), GSM (registered trademark), CDMA2000, UMB (Ultra Mobile Broadband), IEEE 802.11 (Wi-Fi (registered trademark)), IEEE 802.16 (WiMAX (registered trademark)), IEEE 802.20, UWB (Ultra-WideBand), Bluetooth (registered trademark), and other appropriate systems, as well as next-generation systems extended based thereon. Furthermore, multiple systems may be applied in combination (for example, a combination of at least one of LTE and LTE-A with 5G).

[0079] The processing procedures, sequences, flowcharts, etc., of each aspect / embodiment described herein may be reordered, provided they are consistent with each other. For example, the methods described herein present various step elements in an exemplary order and are not limited to that specific order.

[0080] In this specification, specific operations performed by the base station device 10 may, in some cases, be performed by its upper node. In a network consisting of one or more network nodes having a base station device 10, it is clear that various operations performed for communication with the user device 20 can be performed by the base station device 10 and at least one of the other network nodes (for example, an MME or S-GW, but not limited to these). Although the above example illustrates the case where there is one other network node besides the base station device 10, the other network node may be a combination of multiple other network nodes (for example, an MME and an S-GW).

[0081] The information or signals described in this disclosure may be output from a higher layer (or lower layer) to a lower layer (or higher layer). They may also be input and output via multiple network nodes.

[0082] Input and output information may be stored in a specific location (e.g., memory) or managed using a management table. Input and output information may be overwritten, updated, or appended to. Output information may be deleted. Input information may be transmitted to other devices.

[0083] The determination in this disclosure may be made by a value represented by one bit (0 or 1), by a boolean value (true or false), or by a numerical comparison (for example, a comparison with a predetermined value).

[0084] Software should be broadly interpreted to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, execution threads, procedures, functions, and so on, whether they are called software, firmware, middleware, microcode, hardware description languages, or by any other name.

[0085] Furthermore, software, instructions, information, etc., may be transmitted and received via a transmission medium. For example, if software is transmitted from a website, server, or other remote source using at least one of wired technology (such as coaxial cable, fiber optic cable, twisted pair, or digital subscriber line (DSL)) and wireless technology (such as infrared or microwave), then at least one of these wired and wireless technologies is included in the definition of a transmission medium.

[0086] The information, signals, etc. described in this disclosure may be represented using any of the various different techniques. For example, the data, instructions, commands, information, signals, bits, symbols, chips, etc. that may be referred to throughout the above description may be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, optical fields or photons, or any combination thereof.

[0087] In addition, terms used in this disclosure and terms necessary for understanding this disclosure may be replaced with terms having the same or similar meanings. For example, at least one of the channel and symbol may be a signal (signaling). Also, a signal may be a message. Furthermore, a component carrier (CC) may be called a carrier frequency, cell, frequency carrier, etc.

[0088] The terms “system” and “network” as used in this disclosure are interchangeable.

[0089] Furthermore, the information, parameters, etc., described in this disclosure may be expressed using absolute values, relative values ​​from a given value, or other corresponding information. For example, wireless resources may be indicated by an index.

[0090] The names used for the parameters described above are not restrictive in any way. Furthermore, the formulas and other expressions using these parameters may differ from those expressly disclosed in this disclosure. Various channels (e.g., PUCCH, PDCCH, etc.) and information elements can be identified by any suitable name, and therefore, the various names assigned to these various channels and information elements are not restrictive in any way.

[0091] In this disclosure, terms such as "base station (BS)", "wireless base station", "base station equipment", "fixed station", "NodeB", "eNodeB (eNB)", "gNodeB (gNB)", "access point", "transmission point", "reception point", "transmission / reception point", "cell", "sector", "cell group", "carrier", and "component carrier" may be used interchangeably. Base stations may also be referred to by terms such as macrocell, small cell, femtocell, and picocell.

[0092] A base station can accommodate one or more (e.g., three) cells. If a base station accommodates multiple cells, the entire coverage area of ​​the base station can be divided into several smaller areas, each of which may also be provided with communication services by a base station subsystem (e.g., a Remote Radio Head (RRH)). The terms “cell” or “sector” refer to part or all of the coverage area of ​​at least one of the base station and / or base station subsystems that provide communication services in that coverage.

[0093] In this disclosure, terms such as "Mobile Station (MS)," "user terminal," "User Equipment (UE)," and "terminal" may be used interchangeably.

[0094] A mobile station may also be referred to by those skilled in the art as a subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, mobile device, wireless device, wireless communication device, remote device, mobile subscriber station, access terminal, mobile terminal, wireless terminal, remote terminal, handset, user agent, mobile client, client, or several other appropriate terms.

[0095] At least one of the base station and the mobile station may be called a transmitting device, a receiving device, a communication device, etc. At least one of the base station and the mobile station may be a device mounted on a mobile body, the mobile body itself, etc. The mobile body may be a vehicle (e.g., a car, an airplane, etc.), an unmanned mobile body (e.g., a drone, an autonomous vehicle, etc.), or a robot (manned or unmanned). At least one of the base station and the mobile station may be a device that does not necessarily move during communication operation. For example, at least one of the base station and the mobile station may be an IoT (Internet of Things) device such as a sensor.

[0096] Furthermore, the term "base station" in this disclosure may be interpreted as "user terminal." For example, the various aspects / embodiments of this disclosure may be applied to a configuration in which communication between a base station and a user terminal is replaced with communication between multiple user devices 20 (which may be called, for example, D2D (Device-to-Device), V2X (Vehicle-to-Everything), etc.). In this case, the user devices 20 may have the functions that the base station device 10 has. Also, terms such as "uplink" and "downlink" may be interpreted as terms corresponding to terminal-to-terminal communication (for example, "side"). For example, uplink channel, downlink channel, etc., may be interpreted as side channel.

[0097] Similarly, the term "user terminal" in this disclosure may be replaced with "base station." In this case, the base station may be configured to have the same functions as the user terminal described above.

[0098] As used in this disclosure, the terms “determining” and “determining” may encompass a wide variety of actions. “Determining” may include, for example, judging, calculating, computing, processing, deriving, investigating, looking up, searching, inquiry (e.g., searching in a table, database, or other data structure), and ascertaining. “Determining” may also include, for example, receiving (e.g., receiving information), transmitting (e.g., sending information), input, output, and accessing (e.g., accessing data in memory). Furthermore, "judgment" and "decision" can include considering something as having been "judged" or "decided" after resolving, selecting, choosing, establishing, comparing, etc. In other words, "judgment" and "decision" can include considering something as having been "judged" or "decided" after some action. Also, "judgment (decision)" can be reinterpreted as "assuming," "expecting," or "considering."

[0099] The terms “connected,” “coupled,” or any variation thereof, mean any direct or indirect connection or coupling between two or more elements, and may include the presence of one or more intermediate elements between two elements that are “connected” or “coupled” with each other. The coupling or connection between elements may be physical, logical, or a combination thereof. For example, “connection” may be reinterpreted as “access.” As used in this disclosure, two elements may be considered to be “connected” or “coupled” with each other using at least one of one or more wires, cables, and printed electrical connections, and, in some non-limiting and non-exclusive examples, electromagnetic energy having wavelengths in the radio frequency domain, microwave domain, and optical (both visible and invisible) domain.

[0100] The reference signal can also be abbreviated as RS (Reference Signal), and may be called a pilot depending on the applicable standard.

[0101] In this disclosure, the phrase "based on" does not mean "based solely on" unless otherwise specified. In other words, the phrase "based on" means both "based solely on" and "based at least on."

[0102] Any reference to elements using the designations “first,” “second,” etc., as used in this disclosure does not generally limit the quantity or order of those elements. These designations may be used in this disclosure as a convenient way to distinguish between two or more elements. Accordingly, references to the first and second elements do not imply that only two elements may be employed, or that the first element must precede the second element in any way.

[0103] In the configuration of each of the above devices, "means" may be replaced with "part," "circuit," "device," etc.

[0104] Where the terms “include,” “including,” and variations thereof are used in this disclosure, these terms are intended to be inclusive, as is the term “comprising.” Furthermore, the term “or” as used in this disclosure is not intended to mean exclusive OR.

[0105] A wireless frame may consist of one or more frames in the time domain. Each of these frames in the time domain may be called a subframe. A subframe may further consist of one or more slots in the time domain. A subframe may have a fixed time length (e.g., 1 ms) that is independent of numerology.

[0106] Numerical logic may be communication parameters applied to at least one of the transmission and reception of a signal or channel. Numerical logic may include, for example, at least one of the following: subcarrier spacing (SCS), bandwidth, symbol length, cyclic prefix length, transmission time interval (TTI), number of symbols per TTI, radio frame configuration, specific filtering processes performed by the transceiver in the frequency domain, and specific windowing processes performed by the transceiver in the time domain.

[0107] A slot may consist of one or more symbols in the time domain (such as OFDM (Orthogonal Frequency Division Multiplexing) symbols, SC-FDMA (Single Carrier Frequency Division Multiple Access) symbols, etc.). A slot may also be a time unit based on neurology.

[0108] A slot may include multiple minislots. Each minislot may consist of one or more symbols in the time domain. Minislots may also be called subslots. Minislots may consist of fewer symbols than a slot. A PDSCH (or PUSCH) transmitted in a time unit larger than a minislot may be called PDSCH (or PUSCH) mapping type A. A PDSCH (or PUSCH) transmitted using a minislot may be called PDSCH (or PUSCH) mapping type B.

[0109] Wireless frames, subframes, slots, minislots, and symbols all represent units of time when transmitting a signal. Different names may be used for each of these terms.

[0110] For example, one subframe may be called a Transmission Time Interval (TTI), multiple consecutive subframes may be called a TTI, or one slot or one mini-slot may be called a TTI. In other words, at least one of a subframe and a TTI may be a subframe (1 ms) in existing LTE, a period shorter than 1 ms (e.g., 1-13 symbols), or a period longer than 1 ms. Note that the unit representing the TTI may be called a slot, mini-slot, etc., instead of a subframe.

[0111] Here, TTI refers to, for example, the smallest unit of time for scheduling in wireless communication. For example, in an LTE system, the base station schedules each user device 20 to allocate wireless resources (such as the frequency bandwidth and transmission power available to each user device 20) in TTI units. However, the definition of TTI is not limited to this.

[0112] TTI may be a transmission time unit for channel-encoded data packets (transport blocks), code blocks, code words, etc., or it may be a processing unit for scheduling, link adaptation, etc. Given a TTI, the actual time interval (e.g., number of symbols) to which the transport block, code block, code word, etc. are mapped may be shorter than the given TTI.

[0113] Furthermore, if one slot or one mini-slot is referred to as TTI, then one or more TTIs (i.e., one or more slots or one or more mini-slots) may constitute the minimum time unit of scheduling. In addition, the number of slots (number of mini-slots) that constitute the minimum time unit of scheduling may be controlled.

[0114] A TTI with a time length of 1ms may also be called a normal TTI, long TTI, normal subframe, long subframe, slot, etc. A TTI shorter than a normal TTI may also be called a shortened TTI, short TTI, partial or fractional TTI, shortened subframe, short subframe, mini slot, sub slot, slot, etc.

[0115] Furthermore, long TTIs (e.g., normal TTIs, subframes, etc.) may be interpreted as TTIs with a time length exceeding 1 ms, and short TTIs (e.g., shortened TTIs, etc.) may be interpreted as TTIs with a TTI length less than that of a long TTI but 1 ms or more.

[0116] A resource block (RB) is a resource allocation unit in the time domain and frequency domain, and in the frequency domain, it may contain one or more consecutive subcarriers. The number of subcarriers in an RB may be the same regardless of the neurology, for example, 12. The number of subcarriers in an RB may be determined based on the neurology.

[0117] Furthermore, the time domain of the RB may contain one or more symbols and may be the length of one slot, one minislot, one subframe, or one TTI. Each TTI, subframe, etc., may consist of one or more resource blocks.

[0118] One or more RBs may also be called a Physical RB (PRB), Sub-Carrier Group (SCG), Resource Element Group (REG), PRB pair, RB pair, etc.

[0119] Furthermore, a resource block may consist of one or more resource elements (REs). For example, one RE may be a radio resource area comprising one subcarrier and one symbol.

[0120] A Bandwidth Part (BWP), also known as a partial bandwidth, may represent a subset of consecutive common resource blocks (RBs) for a particular neurology system in a given carrier. These common RBs may be identified by an index of the RBs relative to a common reference point of the carrier. A Bandwidth Part (PRB) may be defined and numbered within a given BWP.

[0121] A BWP may include BWPs for UL (UL BWP) and BWPs for DL ​​(DL BWP). One or more BWPs may be configured within a single carrier for a UE.

[0122] At least one of the configured BWPs may be active, and the UE does not need to assume that it will send or receive a given signal / channel outside of the active BWP. In this disclosure, terms such as "cell" and "carrier" may be read as "BWP".

[0123] The structures described above, such as wireless frames, subframes, slots, minislots, and symbols, are merely illustrative. For example, the number of subframes included in a wireless frame, the number of slots per subframe or wireless frame, the number of minislots included in a slot, the number of symbols and RBs included in a slot or minislot, the number of subcarriers included in an RB, and the number of symbols, symbol length, and cyclic prefix (CP) length within a TTI can be varied in various ways.

[0124] In this disclosure, if articles are added through translation, such as a, an, and the in English, this disclosure may include the fact that the noun following these articles is plural.

[0125] In this disclosure, the term "A and B are different" may mean "A and B are different from each other." The term may also mean "A and B are each different from C." Terms such as "separate" and "combine" may be interpreted similarly to "different."

[0126] Each aspect / embodiment described herein may be used individually, in combination, or switched between as needed during implementation. Furthermore, notification of specific information (e.g., notification that "X is") is not limited to explicit notification, but may also be implicit (e.g., by not providing such notification).

[0127] In this disclosure, AS-Config, CG-Config, or CG-ConfigInfo are examples of communication settings related to user equipment. discardTimer is an example of a timer used for data discarding. HANDOVER REQUEST is an example of a handover request. S-NODE ADDITION REQUEST is an example of a secondary node addition request. The data type "SetupRelease" is an example of a data type to which setup or release is specified.

[0128] Although the present disclosure has been described in detail above, it will be clear to those skilled in the art that the present disclosure is not limited to the embodiments described herein. The present disclosure can be implemented in modified and altered forms without departing from the intent and scope of the present disclosure as defined by the claims. Therefore, the descriptions in the present disclosure are illustrative and not intended to be restrictive in any way. [Explanation of Symbols]

[0129] 10 Base station equipment 110 Transmitter 120 Receiver 130 Setting section 140 Control Unit 20 User devices 210 Transmitter 220 Receiver 230 Setting section 240 Control Unit 1001 Processor 1002 Storage device 1003 Auxiliary storage device 1004 Communication device 1005 Input device 1006 Output device

Claims

1. A receiving unit that receives inter-base station messages from other base stations, If the inter-base station message does not include a measGapConfig field to which delta signaling has been applied, the control unit maintains a value notified by a message sent from the other base station before the inter-base station message is received. The control unit updates the value based on the information contained in the measGapConfig field if the inter-base station message includes the measGapConfig field to which the delta signaling is applied.

2. The base station according to claim 1, wherein the inter-base station message is an inter-base station RRC message.

3. A communication method performed by a base station, The steps include receiving inter-base station messages from other base stations, If the inter-base station message does not include a measGapConfig field to which delta signaling has been applied, the steps include maintaining the value notified by a message sent from the other base station before receiving the inter-base station message, A communication method comprising the step of updating the value based on the information contained in the measGapConfig field if the interbase station message includes the measGapConfig field to which the delta signaling is applied.

4. A communication system comprising a first base station and a second base station, The first base station transmits an interbase station message to the second base station. The second base station is, The inter-base station message is received from the first base station. If the inter-base station message does not include the measGapConfig field to which delta signaling has been applied, the value notified by the message sent from the first base station before receiving the inter-base station message is maintained. A communication system that updates the value based on the information contained in the measGapConfig field if the interbase station message includes the measGapConfig field to which the delta signaling is applied.

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