Access node, user device, method, and program

Abstract

The purpose of the present invention is to provide an access node with which a user device can recognize whether the access node supports on-demand SSB SCell operation. An access node according to the present disclosure comprises a transmission means for transmitting, to a user device, an information element indicating whether to transmit synchronization information used for establishing synchronization in cells.

Description

Access node, user device, method and program

[0001] The present disclosure relates to an access node, a user device, a method, and a program.

[0002] 3GPP (3rd Generation Partnership Project) (registered trademark), which defines specifications related to mobile communications, specifies that a base station transmits a broadcast channel that notifies a user device of a synchronization signal and radio parameters for the user device to detect the timing of receiving data. The synchronization signal and the broadcast channel are specified as SSB (Synchronization Signals / Physical Broadcast Channel Block).

[0003] Non-Patent Document 1 also describes a power saving function supported in Carrier Aggregation (CA) implemented using a Primary Cell (PCell) and a Secondary Cell (SCell). Specifically, the power saving function is described as on-demand SSB SCell operation for UEs in connected mode configured with CA (hereinafter referred to as on-demand SSB SCell operation).

[0004] Generally, a base station transmits an SSB within a cell using pre-configured resources. A user equipment establishes synchronization with the base station in the cell by detecting the SSB. On the other hand, in on-demand SSB SCell operation, a base station constituting an SCell transmits an SSB within a cell when it receives a message requesting on-demand SSB transmission from a user equipment. As a result, if the user equipment does not require an SSB, the base station constituting an SCell stops transmitting the SSB. As a result, energy consumption in the network can be reduced.

[0005] Ericsson, “Enhancements of network energy savings for NR”, 3GPP TSG RAN Meeting #102, RP-234065

[0006] On-demand SSB SCell operation is transmitted from the base station when a request is made from the user equipment to the base station. However, there is a problem in that user equipment that has not requested the base station to transmit on-demand SSB cannot recognize whether or not SSB is being transmitted.

[0007] In view of the above-mentioned problems, an object of the present disclosure is to provide an access node, a user device, a method, and a program that enable a user device to recognize whether an SSB is being transmitted.

[0008] The access node according to the present disclosure comprises a transmitting means for transmitting to a user equipment an information element indicating whether or not to transmit synchronization information used to establish synchronization in a cell.

[0009] The user equipment according to the present disclosure comprises a receiving means for receiving an information element indicating whether or not to transmit synchronization information used to establish synchronization in a cell, and a control means for determining, based on the information element, the reception processing of resources pre-configured for the synchronization information.

[0010] The method according to the present disclosure transmits to the user equipment an information element indicating whether or not to transmit synchronization information used to establish synchronization in a cell.

[0011] The program according to the present disclosure causes a computer to transmit, to a user equipment, an information element indicating whether or not to transmit synchronization information used to establish synchronization in a cell.

[0012] The present disclosure provides an access node, a user device, a method, and a program that enable a user device to recognize whether an SSB is being transmitted.

[0013] FIG. 1 shows an example configuration of an access node according to the present disclosure. FIG. 2 shows an example configuration of a user equipment according to the present disclosure. FIG. 3 shows a diagram illustrating a transmission method executed in an access node according to the present disclosure. FIG. 4 shows a diagram illustrating a control method executed in a user equipment according to the present disclosure. FIG. 5 shows an example configuration of a gNB according to the present disclosure. FIG. 6 shows a sequence for adding or changing an SCell according to the present disclosure. FIG. 7 shows the configuration contents of a CellGroupConfigIE according to the present disclosure. FIG. 8 shows a diagram illustrating the transmission timing of an on-demand SSB according to the present disclosure. FIG. 9 shows an example configuration of a UE according to the present disclosure. FIG. 10 shows a sequence between a UE and a gNB according to the present disclosure. FIG. 11 shows a sequence between a UE and a gNB according to the present disclosure. FIG. 12 shows an example configuration of an SCellConfigIE included in a CellGroupConfigIE according to the present disclosure. FIG. 13 shows an example configuration of a ServingCellConfigCommonIE included in a SCellConfigIE according to the present disclosure. FIG. 14 shows an example configuration of a DownlinkConfigCommonIE according to the present disclosure. Fig. 15 is a block diagram showing an example configuration of an access node and a gNB 30 according to the present disclosure. Fig. 16 is a block diagram showing an example configuration of a user equipment and a UE 40 according to the present disclosure.

[0014] (First Embodiment) Fig. 1 illustrates a configuration example of an access node 10 according to the present disclosure. The access node 10 may be a computer device that operates when a processor executes a program stored in a memory. The access node 10 may be, for example, a base station device. Furthermore, the access node 10 may be a gNB (g NodeB), which is a base station device used in 5G (5th Generation) defined as a wireless communication standard by 3GPP.

[0015] The access node 10 includes a transmitter 11. The transmitter 11 may be used as a transmitting means for transmitting information or data. The transmitter 11 may be software or a module that performs processing by a processor executing a program stored in a memory. Alternatively, the transmitter 11 may be hardware such as a circuit or a chip.

[0016] The transmitter 11 transmits an information element indicating whether to transmit synchronization information to a user device. The user device may be a UE (User Equipment) defined in 3GPP. Specifically, the user device may be a smartphone terminal, a tablet terminal, an IoT (Internet of Things) terminal, or the like.

[0017] The synchronization information is information used by a user equipment to establish synchronization in a cell. In other words, the synchronization information may be information used by a user equipment to connect to the access node 10 or to communicate with the access node 10. A cell is a communication area managed or formed by the access node 10. The access node 10 may manage or form multiple cells. Managing may be another way of saying controlling. The synchronization information may be used, for example, by a user equipment to discover a cell formed by the access node 10. Furthermore, the synchronization information may be used to determine the transmission and reception timing of signals, data, or frames transmitted between the access node 10 and the user equipment. Furthermore, the synchronization information may be used by a user equipment to measure downlink radio quality. The synchronization information may be information used by multiple user equipments present in a cell. In other words, the synchronization information may not be information transmitted with a specific user equipment as its destination, but may be information used by any user equipment. Furthermore, synchronization may include, for example, at least one of time synchronization and frequency synchronization. Furthermore, the synchronization information may be used for purposes other than synchronization, such as RRM (Radio Resource Management), beam management, or AGC (Automatic Gain Control).

[0018] The synchronization information may include, for example, two signals, a Primary Synchronization Signal (PSS) and a Secondary Synchronization Signal (SSS). Furthermore, the synchronization information may include a Physical Broadcast Channel (PBCH) and a Demodulation Reference Signal for PBCH (DMRS for PBCH), which are broadcast information broadcast to a cell. The synchronization information including the PSS, SSS, PBCH, and DMRS for PBCH may be an SSB.

[0019] Transmitting the synchronization information may mean including the synchronization information in information transmitted by the access node 10 to the user equipment. For example, transmitting the synchronization information may mean mapping or scheduling the synchronization information to communication resources transmitted by the access node 10 to the user equipment. The communication resources may be radio resources. Transmitting the synchronization information may also be rephrased as broadcasting the synchronization information to multiple user equipments present in the cell. Broadcasting may also be rephrased as distributing.

[0020] The information element may be a parameter, a flag, etc. that is set in a message or a signal. The information element may be represented in binary.

[0021] The information element indicating whether to transmit synchronization information may be, for example, an information element indicating whether the access node 10 transmits synchronization information into a cell, in other words, the information element indicating whether to transmit synchronization information to one or more user equipments present in the cell.

[0022] 2 shows a configuration example of a user device 20 according to the present disclosure. The user device 20 may be a computer device that operates by a processor executing a program stored in a memory. The user device 20 may also be User Equipment (UE) as defined by 3GPP. Specifically, the user device may be a smartphone terminal, a tablet terminal, an IoT (Internet of Things) terminal, or the like.

[0023] The user device 20 has a receiving unit 21 and a control unit 22. The receiving unit 21 may be used as a receiving means for receiving information or data. The control unit 22 may be used as a control means for controlling processing executed in the user device 20. The receiving unit 21 and the control unit 22 may be software or a module in which processing is performed by a processor executing a program stored in a memory. Alternatively, the receiving unit 21 and the control unit 22 may be hardware such as a circuit or a chip.

[0024] The receiving unit 21 receives an information element indicating whether to transmit synchronization information used to establish synchronization in a cell. The synchronization information is transmitted from the access node 10 to any user equipment present in the cell, for example, the user equipment 20 and other user equipment different from the user equipment 20.

[0025] The control unit 22 determines a receiving process for the resource preset for the synchronization information based on the information element. The resource preset for the synchronization information may be a resource preset for transmitting the synchronization information. The resource may be indicated using, for example, time and frequency. In other words, the resource may be specified using time and frequency. The time may be specified using, for example, a symbol, a slot, etc. The resource preset for the synchronization information is mainly allocated with the synchronization information.

[0026] The reception process is, for example, a process for receiving information assigned to a preset resource. For example, when an information element indicates that synchronization information is to be transmitted, the control unit 22 may perform a reception process assuming that no information other than the synchronization information is assigned to the preset resource. Specifically, the control unit 22 may perform a reception process for receiving synchronization information assigned to a preset resource. When an information element indicates that synchronization information is to be transmitted and synchronization information is required, the control unit 22 may perform a reception process for receiving synchronization information assigned to a preset resource. Alternatively, when an information element indicates that synchronization information is to be transmitted, the control unit 22 may perform a reception process for not receiving information from the preset resource. When an information element indicates that synchronization information is to be transmitted and synchronization information is not required, the control unit 22 may perform a reception process for not receiving information from the preset resource.

[0027] The reception process of not receiving information from the preset resource may be to discard the information received from the preset resource, or to skip the preset resource and receive information from another resource.

[0028] The reception process for receiving synchronization information may be, for example, reading information assigned to a preset resource as synchronization information. Reading may be rephrased as extracting, taking out, or the like. Alternatively, the reception process for receiving synchronization information may be treating or processing information read from a preset resource as synchronization information. The reception process for receiving synchronization information may be reception process that assumes that synchronization information has been assigned to a preset resource.

[0029] Furthermore, when the information element indicates that synchronization information will not be transmitted, the control unit 22 may perform reception processing to receive the information assigned to the preset resources as other information different from the synchronization information. Furthermore, when the control unit 22 does not receive the information element, the control unit 22 may perform reception processing to receive the information assigned to the preset resources as other information different from the synchronization information. The reception processing to receive the information as other information may be reception processing that assumes that other information is assigned to some or all of the preset resources. Alternatively, the reception processing to receive the information as other information may be processing that assumes that synchronization information is not assigned to the preset resources.

[0030] 3 is a diagram illustrating a transmission method executed in the access node 10 according to the present disclosure. The transmitter 11 transmits to the user equipment an information element indicating whether or not to transmit synchronization information used to establish synchronization in a cell (S11).

[0031] 4 is a diagram illustrating a control method executed in the user equipment 20 according to the present disclosure. The receiver 21 receives an information element indicating whether or not to transmit synchronization information used to establish synchronization in a cell (S21). Next, the controller 22 determines a reception process for a resource preset for the synchronization information based on the information element (S22).

[0032] As described above, the access node 10 transmits an information element indicating whether or not to transmit synchronization information to the user equipment 20. In addition, the user equipment 20 receives an information element indicating whether or not to transmit synchronization information.

[0033] By receiving the information element, the user equipment 20 can recognize whether synchronization information is to be transmitted. As a result, the user equipment 20 can receive synchronization information when necessary by determining the reception processing of the resources preset for synchronization information based on the information element. Furthermore, the access node transmits synchronization information upon a request from the user equipment, and can transmit other information instead of synchronization information when there is no request from the user equipment. This can improve frequency utilization efficiency.

[0034] (Embodiment 2) Below, configuration examples and operations of a gNB 30 and a UE 40 will be described with reference to the drawings. FIG. 5 is a diagram showing a configuration example of a gNB 30 according to the present disclosure. The gNB 30 is a base station that supports a wireless communication method defined in 3GPP as 5G or NR (New Radio). The gNB 30 has a transmitter 31, a controller 32, and a receiver 33. The gNB 30 corresponds to the access node 10 in FIG. 1. The transmitter 31 corresponds to the transmitter 11 in FIG. 1. Hereinafter, detailed description of the operation and functions of the transmitter 31 that are similar to those of the transmitter 11 will be omitted. The controller 32 may be used as a control unit that controls processing executed in the gNB 30. The receiver 33 may be used as a receiving unit that receives information or data.

[0035] The transmitter 31, the controller 32, and the receiver 33 may be software or modules that are executed by a processor executing a program stored in a memory, or may be hardware such as a circuit or a chip.

[0036] The gNB 30 supports on-demand SSB SCell operation for UEs in connected mode configured with CA (hereinafter referred to as on-demand SSB SCell operation), which is being discussed in 3GPP. The on-demand SSB SCell operation supports both intra-band CA, which uses component carriers (CCs) within the same band, and inter-band CA, which uses CCs of different bands.

[0037] In CA, the UE 40 uses a primary cell (PCell) and a secondary cell (SCell). The PCell is a cell used as a serving cell at the time of starting CA. The SCell is a cell used in addition to the PCell. The gNB 30 may provide the PCell and SCell used in CA.

[0038] The transmitter 31 configures the UE 40 for on-demand SSB operation. Specifically, the transmitter 31 may configure the UE 40 for on-demand SSB operation when configuring an SCell. The configuration of the SCell may be, for example, an addition of an SCell or a modification of an SCell. The addition of an SCell may be adding an SCell to a PCell currently used by the UE 40 as a serving cell in order for the UE 40 to perform CA. Alternatively, the addition of an SCell may be adding an additional SCell to a UE that is performing CA using a PCell and an SCell. The modification of an SCell may be changing the currently used SCell to another SCell by a UE that is performing CA using a PCell and an SCell.

[0039] For example, when adding an SCell in a state in which gNB 30 is providing only a PCell to UE 40, transmitter 31 may perform settings related to on-demand SSB operation on UE 40 via the PCell. When gNB 30 is providing CA using a PCell and an SCell, transmitter 31 may perform settings related to on-demand SSB operation on UE 40 via the PCell or the SCell.

[0040] Here, when a gNB other than gNB 30 manages or controls the PCell, the gNB other than gNB 30 may configure on-demand SSB operation for UE 40. When an eNB or an access point manages or controls the PCell, the eNB or the access point may configure on-demand SSB operation for UE 40.

[0041] In order to configure the UE 40 for on-demand SSB operation, the transmission unit 31 may transmit, for example, an RRC message to the UE 40 as a message for reestablishing RRC (Radio Resource Control) as shown in Fig. 6 (S31). Fig. 6 shows a sequence for adding or changing an SCell according to the present disclosure.

[0042] The RRC message may be an RRCReconfiguration message, an RRCResume message, or an RRCSetup message. The RRCReconfiguration message may be used to change or modify an RRC connection. The RRCResume message may be used to resume a stopped RRC connection. The RRCSetup message may be used to establish an SRB (Signaling Radio Bearer).

[0043] The transmitter 31 may configure the UE 40 for on-demand SSB operation, for example, by including a CellGroupConfig IE (Information Element) in the RRC message. The CellGroupConfig IE may be used to notify the UE 40 of a list of SCells that support on-demand SSB operation. Fig. 7 shows the configuration content of the CellGroupConfig IE. The list of SCells that support on-demand SSB operation may be indicated in sCellOn-demandSSBToAddModList-r19 in Fig. 7.

[0044] Returning to FIG. 5 , the receiver 33 receives a message requesting transmission of on-demand SSBs from the UE 40 or another UE different from the UE 40. The receiver 33 may receive the message requesting transmission of on-demand SSBs via a PCell or another SCell with which synchronization has already been established. For example, the receiver 33 may receive a Medium Access Control Element (MAC CE) indicating a request for transmission of on-demand SSBs. The MAC CE is used as a control signal for performing control in the MAC layer. The MAC CE indicating a request for transmission of on-demand SSBs may include, for example, a Serving Cell ID and the duration of the on-demand SSBs.

[0045] The Serving Cell ID is identification information of the SCell to which the UE requests the gNB 30 to transmit an on-demand SSB. The duration of the on-demand SSB may be indicated, for example, using the number of radio frames. For example, if the duration of the on-demand SSB is set to "2," the duration of the on-demand SSB is twice the length of the radio frame. Alternatively, the duration of the on-demand SSB may be measured in units of the on-demand SSB period, which is set other than the number of radio frames. Alternatively, the duration of the on-demand SSB may be set to one time selected from several predetermined or set times. The duration of the on-demand SSB may be indicated in binary notation or by identification information associated with each predetermined or set time.

[0046] For example, when a 3-bit binary notation is used, a value from 0 to 7 or 1 to 8 may be used for the duration of an on-demand SSB. 0 to 7 or 1 to 8 may indicate the number of radio frames (or the number of periods of an on-demand SSB). Alternatively, when a 3-bit binary notation is used for the duration of an on-demand SSB, some values ​​may be used to specify a semi-static setting. For example, 0 may be used to specify a semi-static setting, and 1 to 7 may indicate the number of radio frames (or the number of periods of an on-demand SSB).

[0047] When the receiver 33 receives a message requesting transmission of on-demand SSBs, the transmitter 31 transmits an information element indicating that on-demand SSBs will be transmitted to the UE 40 and other UEs other than the UE 40. The information element indicating whether to transmit on-demand SSBs may be indicated using a flag. For example, an on-demand SSB indicator field may be provided in a DCI format for scheduling a PDSCH (Physical Downlink Shared Channel), which corresponds to a data channel, to set a flag indicating whether to transmit on-demand SSBs. The DCI format for scheduling the PDSCH may be transmitted in a PDCCH (Physical Downlink Control Channel), for example. The DCI format for scheduling the PDSCH may be DCI format 1_1. The PDSCH may be scheduled in the same slot as the PDCCH, or in a slot different from the slot in which the PDCCH is transmitted.

[0048] For example, when it is indicated that an on-demand SSB is to be transmitted, the on-demand SSB indicator field may be set to "1." When it is indicated that an on-demand SSB is not to be transmitted, the on-demand SSB indicator field may be set to "0."

[0049] For example, when gNB30 transmits a DCI format when it has not received a message from a UE requesting the transmission of an on-demand SSB, the on-demand SSB indicator field may be set to "0".

[0050] When a DCI format in which the on-demand SSB indicator field is set to "1" is transmitted to UE 40 and other UEs other than UE 40, the control unit 32 maps the PDSCH avoiding resources preset for on-demand SSBs. Alternatively, the control unit 32 recognizes that a DCI format in which the on-demand SSB indicator field is set to "1" is transmitted to UE 40 and other UEs other than UE 40 when the receiving unit 33 receives a message requesting transmission of on-demand SSBs. When the control unit 32 recognizes that a DCI format in which the on-demand SSB indicator field is set to "1" is transmitted, the control unit 32 may map the PDSCH avoiding resources preset for on-demand SSBs. Mapping the PDSCH avoiding resources preset for on-demand SSBs may be referred to as rate matching around the on-demand SSBs. Furthermore, the control unit 32 maps the SSBs to resources preset for on-demand SSBs.

[0051] A case will be described in which a DCI format in which the on-demand SSB indicator field is set to "0" is transmitted to UE 40 and other UEs other than UE 40. In this case, the control unit 32 maps the PDSCH to resources that are preset for on-demand SSBs and overlap with resources allocated to the PDSCH. Alternatively, the control unit 32 recognizes that a DCI format in which the on-demand SSB indicator field is set to "0" is transmitted to UE 40 and other UEs other than UE 40 because the receiving unit 33 does not receive a message requesting transmission of on-demand SSBs. When the control unit 32 recognizes that a DCI format in which the on-demand SSB indicator field is set to "0" is transmitted to UE 40 and other UEs other than UE 40, it may map the PDSCH to resources preset for on-demand SSBs. Furthermore, when the control unit 32 recognizes that a DCI format that does not include an on-demand SSB indicator field is transmitted to UE 40 and other UEs other than UE 40, the control unit 32 may map the PDSCH to resources that are pre-configured for on-demand SSB.

[0052] Here, the on-demand SSB transmitted by the gNB 30 will be described using FIG. 8. FIG. 8 is a diagram showing the transmission timing of the on-demand SSB. In FIG. 8, the horizontal axis represents time. The lines drawn vertically on the time axis in FIG. 8 represent radio frame boundaries or the start timing of the on-demand SSB transmission cycle. The downward arrows in FIG. 8 indicate the timing at which the SSB mapped to the resources pre-configured for the on-demand SSB is transmitted within the SCell. T1 to T3 represent periods. T1 represents the period during which the gNB 30 accepts a message requesting transmission of the on-demand SSB in T3. The acceptance period may be referred to as, for example, an acceptance window. T2 represents one radio frame period or one transmission period of the on-demand SSB. The slot period may be the period from the start to the end of the slot, or the period from the start of the slot to the start of the next slot. T3 represents the duration of the on-demand SSB notified by the UE.

[0053] FIG. 8 shows that the duration of an on-demand SSB is two radio frames. T2 can also be said to represent the transmission period of the on-demand SSB. At T1, the control unit 32 may receive a message requesting transmission of an on-demand SSB from UE 40 or another UE other than UE 40. In this case, the control unit 32 starts transmitting the on-demand SSB immediately after the end of T1, or in a radio frame or on-demand SSB transmission period that starts after a time known to the gNB 30 and UE 40. The control unit 32 also repeatedly transmits the on-demand SSB for the duration of the on-demand SSB included in the message requesting transmission of the on-demand SSB.

[0054] Next, the configuration of the UE 40 will be described. Fig. 9 shows an example configuration of the UE 40 according to the present disclosure. The UE 40 corresponds to the user equipment 20 in Fig. 2. It is assumed that the UE 40 supports on-demand SSB operation. It is also assumed that the UE 40 is in a state where communication is possible using the PCell as a serving cell.

[0055] UE 40 has a receiving unit 41, a control unit 42, and a transmitting unit 43. The receiving unit 41 and the control unit 42 correspond to the receiving unit 21 and the control unit 22 in Fig. 2. In the following, detailed description of the operations and functions of the receiving unit 41 and the control unit 42 that are similar to those of the receiving unit 21 and the control unit 22 will be omitted. The transmitting unit 43 may be used as a transmitting means for transmitting information or data.

[0056] The receiving unit 41, the control unit 42, and the transmitting unit 43 may be software or modules that are executed by a processor executing a program stored in a memory, or may be hardware such as a circuit or a chip.

[0057] When configuring an SCell to perform CA, the reception unit 41 receives an RRC message including a CellGroupConfig IE from the gNB 30. By receiving the CellGroupConfig IE, the UE 40 can recognize at least one SCell that supports on-demand SSB operation.

[0058] The transmitter 43 transmits a message requesting transmission of on-demand SSB to the gNB 30 in a cell that supports on-demand SSB operation included in the CellGroupConfig IE. Here, it is assumed that the gNB 30 forms a cell that supports on-demand SSB operation.

[0059] The receiver 41 receives an information element indicating whether to transmit an on-demand SSB from the gNB 30. For example, the receiver 41 receives an information element set in a DCI format for scheduling a PDSCH. The information element may be a flag indicating whether to transmit an on-demand SSB.

[0060] Here, the operation of the control unit 42 when the receiving unit 41 receives an information element (on-demand SSB indicator field) indicating whether or not to transmit on-demand SSB will be described.

[0061] First, a case will be described in which the transmitter 43 transmits a message requesting transmission of an on-demand SSB to the gNB 30 and then receives an on-demand SSB indicator field set to "1." In this case, since the UE 40 needs to acquire synchronization information to establish synchronization in the SCell, the control unit 42 performs reception processing assuming that an SSB is assigned to a resource previously configured for the on-demand SSB. That is, the control unit 42 acquires an SSB from a resource previously configured for the on-demand SSB. In other words, the control unit 42 acquires information assigned to a resource previously configured for the on-demand SSB as an SSB. In further words, the control unit 42 recognizes information acquired from a resource previously configured for the on-demand SSB as an SSB. Furthermore, the reception processing assuming that an SSB is assigned to a resource previously configured for the on-demand SSB may be reception processing assuming that a PDSCH, which is a data channel, is not assigned to the resource.

[0062] Furthermore, when an on-demand SSB indicator field set to "1" is received, the control unit 42 performs PDSCH reception processing while avoiding resources preset for on-demand SSB.

[0063] Next, a case will be described in which the on-demand SSB indicator field is set to "1" before the transmitter 43 transmits a message requesting the transmission of on-demand SSBs to the gNB 30. This situation occurs, for example, when a UE other than UE 40 transmits a message requesting the transmission of on-demand SSBs. "Before the transmitter 43 transmits a message requesting the transmission of on-demand SSBs to the gNB 30" also includes a case in which the UE 40 does not transmit the message after that. In such a case, the UE 40 does not need to acquire synchronization information to establish synchronization in the SCell. Therefore, the controller 42 may perform reception processing assuming that no SSBs are assigned to resources pre-configured for on-demand SSBs. The reception processing assuming that no SSBs are assigned to resources pre-configured for on-demand SSBs may, for example, not acquire information assigned to the pre-configured resources. Alternatively, the reception processing assuming that no SSBs are assigned to resources pre-configured for on-demand SSBs may be to acquire and then discard information assigned to the pre-configured resources. In this case, the reception process that assumes that no SSB is assigned to the resources pre-configured for on-demand SSB may be reception process that assumes that no PDSCH, which is a data channel, is assigned to the resources.

[0064] Next, a case where an on-demand SSB indicator field set to "0" is received will be described. In this case, the control unit 42 performs reception processing assuming that the PDSCH is assigned to resources that are preset for on-demand SSBs and overlap with resources assigned to the PDSCH. That is, the control unit 42 acquires the PDSCH from the resources preset for on-demand SSBs. In other words, the control unit 42 acquires information assigned to resources preset for on-demand SSBs as the PDSCH. In yet another way, the control unit 42 recognizes information acquired from resources preset for on-demand SSBs as the PDSCH. Furthermore, even when a DCI format that does not include an on-demand SSB indicator field is received, the control unit 42 may perform reception processing assuming that the PDSCH is assigned to resources preset for on-demand SSBs.

[0065] Furthermore, when an on-demand SSB indicator field set to "0" is received, the control unit 42 performs reception processing for the PDSCH, including resources that are pre-set for the on-demand SSB and overlap with the resources allocated to the PDSCH.

[0066] Next, the flow of communication processing between the UE 40 and the gNB 30 will be described with reference to Fig. 10. Fig. 10 shows a sequence between the UE 40 and the gNB 30 according to the present disclosure.

[0067] First, the UE 40 transmits a message requesting transmission of an on-demand SSB to the gNB 30 (S41). Next, the gNB 30 transmits DCI including an on-demand SSB indicator field set to "1" (S42). The gNB 30 may transmit a PDCCH with the DCI set. Next, the UE 40 acquires an SSB allocated to a resource pre-configured for the on-demand SSB, and performs reception processing of the PDSCH while avoiding the resource (S43). The processing in S41 and S42 may be performed as independent procedures.

[0068] Next, the flow of communication processing between the UE 40 and the gNB 30 will be described with reference to Fig. 11. Fig. 11 shows a sequence between the UE 40 and the gNB 30 according to the present disclosure.

[0069] 11 , UE 40 receives DCI including an on-demand SSB indicator field from gNB 30 without transmitting a message requesting transmission of on-demand SSB to gNB 30 (S51). The on-demand SSB indicator field is set to "1" or "0".

[0070] Next, UE 40 performs a PDSCH reception process (S52). When UE 40 receives an on-demand SSB indicator field set to "1", it receives the PDSCH avoiding resources preset for on-demand SSBs. When UE 40 receives an on-demand SSB indicator field set to "0", it receives the PDSCH including resources preset for on-demand SSBs. Furthermore, even when UE 40 receives a DCI format that does not include an on-demand SSB indicator field, it may receive the PDSCH including resources preset for on-demand SSBs.

[0071] As described above, in slots where on-demand SSBs are not transmitted, the gNB 30 uses pre-configured resources for on-demand SSBs for PDSCH resource mapping. This increases the resources allocated to the PDSCH. Specifically, the resources allocated to the PDSCH are increased compared to when pre-configured resources for on-demand SSBs must be left unused at all times for on-demand SSBs. A situation where a resource must be left unused at all times for on-demand SSBs may arise, for example, when the UE is not notified of whether or not it will be used for SSB transmission, and the UE assumes that the SSB is being transmitted at all times. As a result, the effect of improving spectral efficiency is achieved.

[0072] Furthermore, by receiving the on-demand SSB indicator field, UE 40 can select an appropriate reception process for the resources preset for on-demand SSB. That is, UE 40 can select a process for receiving SSB or PDSCH allocated to the resources preset for on-demand SSB. Note that a function equivalent to on-demand SSB SCell operation may be applied to the PCell.

[0073] (Variant example of embodiment 2) In Figure 7, it is shown that gNB30 configures UE40 for on-demand SSB operation by including sCellOn-demandSSBToAddModList-r19 in CellGroupConfig IE, but the method of configuring on-demand SSB operation is not limited to this.

[0074] 12 shows a configuration example of the SCellConfig IE included in the CellGroupConfig IE. FIG. 12 shows that the gNB 30 configures the UE 40 for on-demand SSB operation by including sCellConfigon-DemandSSB-r19 in the SCellConfig IE. The SCellConfig is associated with each SCell included in the SCell list. Therefore, the SCell associated with the SCellConfig IE including sCellConfigon-DemandSSB-r19 indicates that it supports on-demand SSB operation.

[0075] Moreover, Figure 13 shows a setting example of the ServingCellConfigCommon IE included in the SCellConfig IE. Figure 13 shows that the ServingCellConfigCommon IE includes On-DemandSsbDuration-r19, indicating that the gNB 30 configures the UE 40 for on-demand SSB operation. On-DemandSsbDuration-r19 indicates the duration of the on-demand SSB. For example, values ​​such as n1 and n2 may be set to On-DemandSsbDuration-r19. For example, n1 may indicate that the duration of the on-demand SSB is one radio frame, and n2 may indicate that the duration of the on-demand SSB is two radio frames.

[0076] Furthermore, the frequency of the resource preset for on-demand SSB may be configured using the DownlinkConfigCommon IE included in the ServingCellConfigCommon IE. Fig. 14 shows an example of the DownlinkConfigCommon IE configuration. The frequency of the resource preset for on-demand SSB may be configured in frequencyInfoDL. Furthermore, the symbol position of the resource preset for on-demand SSB may be predetermined as a specification of on-demand SSB operation.

[0077] As described above, gNB30 may configure on-demand SSB operation for UE40 using any of the settings shown in the modified examples.

[0078] (Embodiment 3) Next, an example will be described in which UE 40 uses an information element indicating whether to transmit an on-demand SSB to avoid collision determination. A UE operating in half-duplex FDD (Frequency Division Duplex) cannot transmit data on the uplink in a slot in which an SSB is transmitted on the downlink. Therefore, when transmitting data on the uplink, a UE operating in half-duplex FDD generally needs to perform collision determination as to whether a collision with an SSB will occur.

[0079] Here, a UE operating in half-duplex frequency division duplex (FDD) receives an information element indicating that it will not transmit on-demand SSBs. In this case, the UE may determine that SSBs will not be transmitted in downlink slots in which pre-configured resources for on-demand SSBs are transmitted. As a result, the UE can determine to transmit data on the uplink in downlink slots in which pre-configured resources for on-demand SSBs are transmitted without performing collision detection processing for SSBs.

[0080] Furthermore, a UE operating in half-duplex frequency division duplex (FDD) receives an information element indicating transmission of an on-demand SSB. In this case, the UE may determine that an SSB is to be transmitted in a downlink slot in which a resource preset for the on-demand SSB is transmitted. As a result, the UE can determine not to transmit data on the uplink in the downlink slot in which a resource preset for the on-demand SSB is transmitted without performing a collision determination process for the SSB.

[0081] FIG. 15 is a block diagram showing an example configuration of an access node 10 and a gNB 30 (hereinafter referred to as the access node 10, etc.). Referring to FIG. 15, the access node 10, etc. includes an RF (Radio Frequency) transceiver 1001, a network interface 1003, a processor 1004, and a memory 1005. The RF transceiver 1001 performs analog RF signal processing to communicate with UEs. The RF transceiver 1001 may include multiple transceivers. The RF transceiver 1001 is coupled to an antenna 1002 and a processor 1004. The RF transceiver 1001 receives modulation symbol data (or OFDM (Orthogonal Frequency Division Multiplexing) symbol data) from the processor 1004, generates a transmit RF signal, and provides the transmit RF signal to the antenna 1002. The RF transceiver 1001 also generates a baseband receive signal based on the receive RF signal received by the antenna 1002 and provides the baseband receive signal to the processor 1004.

[0082] The network interface 1003 is used to communicate with network nodes (e.g., other core network nodes) and may include, for example, a network interface card (NIC) compliant with the IEEE 802.3 series.

[0083] The processor 1004 performs data plane processing and control plane processing, including digital baseband signal processing for wireless communication.

[0084] The processor 1004 may include multiple processors. For example, the processor 1004 may include a modem processor (e.g., a Digital Signal Processor: DSP) that performs digital baseband signal processing and a protocol stack processor (e.g., a Central Processing Unit: CPU or a Micro Processing Unit: MPU) that performs control plane processing.

[0085] The memory 1005 is configured by a combination of volatile memory and nonvolatile memory. The memory 1005 may include multiple physically independent memory devices. The volatile memory may be, for example, static random access memory (SRAM), dynamic RAM (DRAM), or a combination thereof. The nonvolatile memory may be mask read only memory (MROM), electrically erasable programmable ROM (EEPROM), flash memory, a hard disk drive, or any combination thereof. The memory 1005 may include storage located remotely from the processor 1004. In this case, the processor 1004 may access the memory 1005 via the network interface 1003 or an input / output (I / O) interface (not shown).

[0086] The memory 1005 may store software modules (computer programs) including instructions and data for performing processing by the access node 10, etc. In some implementations, the processor 1004 may be configured to read and execute the software modules from the memory 1005 to perform processing by the access node 10, etc.

[0087] FIG. 16 is a block diagram showing an example configuration of a user equipment 20 and a UE 40 (hereinafter referred to as user equipment 20, etc.). A radio frequency (RF) transceiver 1101 performs analog RF signal processing to communicate with an access network node 20 or a gNB 40. The analog RF signal processing performed by the RF transceiver 1101 includes frequency up-conversion, frequency down-conversion, and amplification. The RF transceiver 1101 is coupled to an antenna 1102 and a baseband processor 1103. That is, the RF transceiver 1101 receives modulation symbol data (or OFDM symbol data) from the baseband processor 1103, generates a transmit RF signal, and provides the transmit RF signal to the antenna 1102. The RF transceiver 1101 also generates a baseband receive signal based on the receive RF signal received by the antenna 1102 and provides it to the baseband processor 1103.

[0088] The baseband processor 1103 performs digital baseband signal processing (data plane processing) and control plane processing for wireless communication. Digital baseband signal processing includes (a) data compression / decompression, (b) data segmentation / concatenation, (c) transmission format (transmission frame) generation / decomposition, (d) transmission path coding / decoding, (e) modulation (symbol mapping) / demodulation, and (f) generation of OFDM symbol data (baseband OFDM signal) using Inverse Fast Fourier Transform (IFFT). Meanwhile, control plane processing includes communication management for Layer 1, Layer 2, and Layer 3.

[0089] The baseband processor 1103 may include a modem processor (e.g., a Digital Signal Processor (DSP)) that performs digital baseband signal processing and a protocol stack processor (e.g., a Central Processing Unit (CPU) or a Micro Processing Unit (MPU)) that performs control plane processing. In this case, the protocol stack processor that performs control plane processing may be shared with the application processor 1104, which will be described later.

[0090] The application processor 1104 is also referred to as a CPU, MPU, microprocessor, or processor core. The application processor 1104 may include multiple processors (multiple processor cores). The application processor 1104 executes a system software program (operating system (OS)) and various application programs (e.g., a calling application, a web browser, a mailer, a camera operation application, and a music playback application) read from the memory 1106 or a memory not shown, thereby realizing various functions of the user device 20, etc.

[0091] In some implementations, the baseband processor 1103 and the application processor 1104 may be integrated on a single chip, as indicated by the dashed line (1105) in Figure 16. In other words, the baseband processor 1103 and the application processor 1104 may be implemented as a single System on Chip (SoC) device 1105. An SoC device may also be called a system Large Scale Integration (LSI) or chipset.

[0092] The memory 1106 is volatile memory, nonvolatile memory, or a combination thereof. The memory 1106 may include multiple physically independent memory devices. Volatile memory is, for example, static random access memory (SRAM), dynamic RAM (DRAM), or a combination thereof. Nonvolatile memory is, for example, mask read only memory (MROM), electrically erasable programmable ROM (EEPROM), flash memory, or a hard disk drive, or any combination thereof. For example, the memory 1106 may include an external memory device accessible from the baseband processor 1103, the application processor 1104, and the SoC 1105. The memory 1106 may also include an internal memory device integrated within the baseband processor 1103, the application processor 1104, or the SoC 1105. Furthermore, the memory 1106 may include memory within a Universal Integrated Circuit Card (UICC).

[0093] The memory 1106 may store software modules (computer programs) including instructions and data for performing processing by the user device 20, etc. In some implementations, the baseband processor 1103 or the application processor 1104 may be configured to read and execute the software modules from the memory 1106 to perform processing by the user device 20, etc.

[0094] In the above examples, the program includes instructions (or software code) that, when loaded into a computer, cause the computer to perform one or more functions described in the embodiments. The program may be stored on a non-transitory computer-readable medium or a tangible storage medium. By way of example and not limitation, computer-readable medium or tangible storage medium includes random-access memory (RAM), read-only memory (ROM), flash memory, solid-state drive (SSD) or other memory technology, CD-ROM, digital versatile disc (DVD), Blu-ray disc or other optical disk storage, magnetic cassette, magnetic tape, magnetic disk storage or other magnetic storage device. The program may also be transmitted on a transitory computer-readable medium or communication medium. By way of example and not limitation, transitory computer-readable medium or communication medium includes electrical, optical, acoustic, or other forms of propagated signals.

[0095] Although the present disclosure has been described above with reference to the embodiments, the present disclosure is not limited to the above-described embodiments. Various modifications that can be understood by those skilled in the art can be made to the configuration and details of the present disclosure within the scope of the present disclosure. Furthermore, each embodiment can be combined with other embodiments as appropriate.

[0096] Each drawing is merely an example for describing one or more embodiments. Each drawing may not relate to only one particular embodiment, but may also relate to one or more other embodiments. As will be understood by those skilled in the art, various features or steps described with reference to any one drawing can be combined with features or steps shown in one or more other drawings to create, for example, an embodiment not explicitly shown or described. Not all features or steps shown in any one drawing are necessary to describe an exemplary embodiment, and some features or steps may be omitted. The order of steps described in any drawing may be changed as appropriate.

[0097] Some or all of the above embodiments can be described as, but are not limited to, the following supplementary notes. (Supplementary Note 1) An access node comprising: a transmitting means for transmitting, to a user equipment, an information element indicating whether or not to transmit synchronization information used to establish synchronization in a cell. (Supplementary Note 2) The access node according to Supplementary Note 1, further comprising: control means for allocating a data channel to a resource preset for the synchronization information when the information element indicates not to transmit the synchronization information. (Supplementary Note 3) The access node according to Supplementary Note 2, wherein the control means avoids allocating a data channel to a resource preset for the synchronization information when the information element indicates to transmit the synchronization information. (Supplementary Note 4) The access node according to Supplementary Note 2 or 3, further comprising: receiving means for receiving, from a first user equipment, a request message requesting transmission of the synchronization information to the first user equipment, wherein the transmitting means transmits, to the first user equipment and a second user equipment, the information element indicating transmission of the synchronization information when the request message is received. (Supplementary Note 5) The access node according to Supplementary Note 4, wherein the control means, when the request message is received, allocates the synchronization information to resources preset for the synchronization information. (Supplementary Note 6) The access node according to any one of Supplements 1 to 5, wherein the information element is set in DCI (Data Control Information) including scheduling information for a data channel. (Supplementary Note 7) The access node according to any one of Supplements 1 to 6, wherein the information element is a first flag indicating that the synchronization information is included or a second flag indicating that the synchronization information is not included. (Supplementary Note 8) A user equipment comprising: receiving means for receiving an information element indicating whether or not to transmit synchronization information used to establish synchronization in a cell; and control means for determining a reception process for resources preset for the synchronization information based on the information element.(Supplementary Note 9) The user equipment according to Supplementary Note 8, wherein the control means, if the information element indicates that the synchronization information is to be transmitted, performs reception processing on the assumption that no data channel is allocated to the resources, and, if the information element indicates that the synchronization information is not to be transmitted, performs reception processing on the assumption that a data channel is allocated to some or all of the resources. (Supplementary Note 10) The user equipment according to Supplementary Note 8 or 9, further comprising: transmission means for transmitting a request message requesting transmission of the synchronization information to the user equipment, wherein the control means, if the information element indicating that the synchronization information is to be transmitted is received after the request message is transmitted, performs reception processing on the assumption that the synchronization information is allocated to the resources. (Supplementary Note 11) The user equipment according to Supplementary Note 10, wherein the control means, if the information element indicating that the synchronization information is to be transmitted is received before the request message is transmitted, performs reception processing on the assumption that the synchronization information is not allocated to the resources. (Supplementary Note 12) The user equipment according to any one of Supplements 8 to 11, wherein the information element is set in DCI (Data Control Information) including scheduling information for a data channel. (Supplementary Note 13) The user equipment according to any one of Supplementary Notes 8 to 12, wherein the information element is a first flag indicating that the synchronization information is to be transmitted or a second flag indicating that the synchronization information is not to be transmitted. (Supplementary Note 14) A method, executed in an access node, transmitting to a user equipment an information element indicating whether or not to transmit synchronization information used to establish synchronization in a cell. (Supplementary Note 15) The method of Supplementary Note 14, allocating a data channel to resources pre-configured for the synchronization information if the information element indicates that the synchronization information is not to be transmitted. (Supplementary Note 16) The method of Supplementary Note 15, avoiding allocating a data channel to resources pre-configured for the synchronization information if the information element indicates that the synchronization information is to be transmitted.(Supplementary Note 17) A method executed in a user equipment, receiving an information element indicating whether to transmit synchronization information used to establish synchronization in a cell, and determining, based on the information element, reception processing for resources preset for the synchronization information. (Supplementary Note 18) The method according to Supplementary Note 17, when determining the reception processing, determines to perform reception processing assuming that no data channel is assigned to the resources if the information element indicates that the synchronization information is to be transmitted, and to perform reception processing assuming that data channels are assigned to some or all of the resources if the information element indicates that the synchronization information is not to be transmitted. (Supplementary Note 19) A program causing a computer to transmit, to a user equipment, an information element indicating whether to transmit synchronization information used to establish synchronization in a cell. (Supplementary Note 20) A program causing a computer to receive an information element indicating whether to transmit synchronization information used to establish synchronization in a cell, and determining, based on the information element, reception processing for resources preset for the synchronization information.

[0098] Some or all of the elements (e.g., configurations and functions) described in Supplementary Notes 2 to 7 that are dependent on Supplementary Note 1 may also be dependent on Supplementary Notes 14 and 19 in the same dependency relationship as Supplementary Notes 2 to 7. Some or all of the elements (e.g., configurations and functions) described in Supplementary Notes 9 to 13 that are dependent on Supplementary Note 8 may also be dependent on Supplementary Notes 17 and 20 in the same dependency relationship as Supplementary Notes 9 to 13. Some or all of the elements described in any Supplementary Note may be applicable to various hardware, software, recording means for recording software, systems, and methods.

[0099] This application claims priority based on Japanese Patent Application No. 2024-018266, filed February 9, 2024, the disclosure of which is incorporated herein in its entirety by reference.

[0100] 10 Access node 11 Transmitter 20 User equipment 21 Receiver 22 Control unit 30 gNB 31 Transmitter 32 Control unit 33 Receiver 40 UE 41 Receiver 42 Control unit 43 Transmitter

Claims

1. An access node comprising: transmitting means for transmitting to a user equipment an information element indicating whether or not to transmit synchronization information used to establish synchronization in a cell.

2. The access node according to claim 1, further comprising: control means for allocating a data channel to a resource pre-configured for the synchronization information if the information element indicates that the synchronization information is not to be transmitted.

3. The access node according to claim 2, wherein the control means, if the information element indicates that the synchronization information is to be transmitted, avoids allocating a data channel to resources pre-configured for the synchronization information.

4. An access node as described in claim 2 or 3, further comprising a receiving means for receiving a request message from a first user device requesting that the synchronization information be transmitted to the first user device, wherein the transmitting means, when the request message is received, transmits the information element indicating that the synchronization information will be transmitted to the first user device and the second user device.

5. The access node according to claim 4, wherein said control means, when said request message is received, allocates said synchronization information to resources preset for said synchronization information.

6. An access node according to any one of claims 1 to 3, wherein the information element is set in DCI (Data Control Information) including scheduling information for a data channel.

7. An access node according to any one of claims 1 to 3, wherein the information element is a first flag indicating that the synchronization information is included or a second flag indicating that the synchronization information is not included.

8. A user equipment comprising: a receiving means for receiving an information element indicating whether or not to transmit synchronization information used to establish synchronization in a cell; and a control means for determining a receiving process of a resource preset for the synchronization information based on the information element.

9. The user equipment according to claim 8, wherein the control means, when the information element indicates that the synchronization information is to be transmitted, performs reception processing on the assumption that no data channel is assigned to the resource, and when the information element indicates that the synchronization information is not to be transmitted, performs reception processing on the assumption that a data channel is assigned to some or all of the resource.

10. A user device as described in claim 8 or 9, further comprising a transmitting means for transmitting a request message requesting that the synchronization information be transmitted to the user device, wherein the control means, when receiving an information element indicating that the synchronization information is to be transmitted after the request message has been transmitted, performs a receiving process assuming that the synchronization information has been assigned to the resource.

11. The user equipment according to claim 10, wherein the control means performs a receiving process assuming that the synchronization information is not allocated to the resource when the information element indicating that the synchronization information is to be transmitted is received before the request message is transmitted.

12. The user equipment according to any one of claims 8 to 11, wherein the information element is set in DCI (Data Control Information) including scheduling information for a data channel.

13. A user device according to any one of claims 8 to 12, wherein the information element is a first flag indicating that the synchronization information is to be transmitted or a second flag indicating that the synchronization information is not to be transmitted.

14. A method, performed in an access node, transmitting to a user equipment an information element indicating whether or not to transmit synchronization information used to establish synchronization in a cell.

15. The method of claim 14, further comprising allocating a data channel to a resource pre-configured for the synchronization information if the information element indicates that the synchronization information is not to be transmitted.

16. The method of claim 15, further comprising avoiding allocating a data channel to resources pre-configured for the synchronization information if the information element indicates that the synchronization information is to be transmitted.

17. A method executed in a user equipment, comprising: receiving an information element indicating whether to transmit synchronization information used to establish synchronization in a cell; and determining, based on the information element, a reception process for a resource preset for the synchronization information.

18. The method according to claim 17, wherein, when determining the reception processing, if the information element indicates that the synchronization information is to be transmitted, a reception processing is performed on the assumption that no data channel is assigned to the resource, and if the information element indicates that the synchronization information is not to be transmitted, a reception processing is performed on the assumption that a data channel is assigned to some or all of the resource.

19. A program that causes a computer to transmit, to a user device, an information element that indicates whether or not to transmit synchronization information used to establish synchronization in a cell.

20. A program that causes a computer to receive an information element indicating whether or not to transmit synchronization information used to establish synchronization in a cell, and determine a reception process for a resource that is preset for the synchronization information based on the information element.

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