JP7801430B2 - Terminal and communication method - Google Patents

Description

The present invention relates to a terminal, a base station, and a communication method in a wireless communication system.

For NR (New Radio) (also known as "5G"), the successor system to LTE (Long Term Evolution), technologies are being considered that meet the requirements of a large-capacity system, high data transmission speeds, low latency, simultaneous connection of a large number of terminals, low cost, and low power consumption (for example, non-patent document 1).

NR Release 18 considers energy saving specifications for base stations. Details are a topic for further study.

3GPP TS 38.300 V16.8.0 (2021-12)

In order to achieve carbon neutrality and the SDGs, it is becoming increasingly important to reduce the power consumption of base stations. However, in conventional technology, there is no standardized and appropriate method for reducing the power consumption of base stations.

The present invention has been made in consideration of the above points, and aims to provide technology for achieving power consumption savings in base stations in wireless communication systems.

According to the disclosed technology, a control unit assumes that a synchronization signal block is transmitted from a base station at a period longer than a predetermined period of 20 ms at the time of initial access;
a receiving unit for receiving the synchronization signal block ,
When the control unit detects that spare of MIB included in at least one synchronization signal block has a specific value, it assumes that the synchronization signal block is being transmitted from the base station at a period longer than the predetermined period.
A terminal is provided.

The disclosed technology provides a technology for achieving power consumption savings in base stations in wireless communication systems.

1 is a diagram illustrating a wireless communication system according to an embodiment of the present invention. 1 is a diagram illustrating a wireless communication system according to an embodiment of the present invention. A diagram showing each piece of information in PBCH and its role. FIG. 1 illustrates the contents of the PBCH. FIG. 10 is a diagram illustrating an example of an SSB period. FIG. 10 is a diagram for explaining an operation for notifying capability information. FIG. 1 is a diagram for explaining an overview of an embodiment. FIG. 10 is a diagram for explaining an outline of an operation using a timer. FIG. 10 is a diagram for explaining an example of an operation using a timer. FIG. 10 is a diagram for explaining an outline of an operation using a pause period. FIG. 10 is a diagram illustrating an example of an operation using a pause period. FIG. 2 is a diagram illustrating an example of the configuration of a base station 10. FIG. 2 is a diagram illustrating an example of the configuration of a terminal 20. 2 is a diagram illustrating an example of a hardware configuration of a base station 10 or a terminal 20 according to an embodiment of the present invention. FIG. FIG. 1 is a diagram illustrating an example of the configuration of a vehicle.

The following describes an embodiment of the present invention with reference to the drawings. Note that the embodiment described below is an example, and the embodiments to which the present invention can be applied are not limited to the following embodiment.

Existing technologies are used as appropriate when operating the wireless communication system of an embodiment of the present invention. However, such existing technologies may be, for example, existing LTE or existing NR, but are not limited to existing LTE or NR.

In addition, in the embodiments of the present invention described below, terms used in existing LTE or NR, such as SS (Synchronization signal), PSS (Primary SS), SSS (Secondary SS), PBCH (Physical broadcast channel), PRACH (Physical random access channel), PDCCH (Physical Downlink Control Channel), PDSCH (Physical Downlink Shared Channel), PUCCH (Physical Uplink Control Channel), and PUSCH (Physical Uplink Shared Channel), are used. This is for convenience of description, and similar signals, functions, etc. may be referred to by other names. Furthermore, the above-mentioned terms in NR correspond to NR-SS, NR-PSS, NR-SSS, NR-PBCH, NR-PRACH, etc. However, even signals used in NR are not necessarily referred to as "NR-".

Furthermore, in an embodiment of the present invention, the duplex method may be a TDD (Time Division Duplex) method, an FDD (Frequency Division Duplex) method, or another method (e.g., Flexible Duplex, etc.).

Furthermore, in an embodiment of the present invention, "configuring" radio parameters, etc. may mean that predetermined values are pre-configured, or that radio parameters notified from the base station 10 or terminal 20 are set.

Figure 1 is a diagram showing an example configuration (1) of a wireless communication system in an embodiment of the present invention. As shown in Figure 1, the wireless communication system in an embodiment of the present invention includes a base station 10 and a terminal 20. Although Figure 1 shows one base station 10 and one terminal 20, this is an example, and there may be multiple base stations 10 and multiple terminals 20 of each.

The base station 10 is a communication device that provides one or more cells and performs wireless communication with the terminal 20. The physical resources of a wireless signal are defined in the time domain and the frequency domain. The time domain may be defined by the number of Orthogonal Frequency Division Multiplexing (OFDM) symbols, and the frequency domain may be defined by the number of subcarriers or resource blocks. The base station 10 transmits synchronization signals and system information to the terminal 20. The synchronization signals are, for example, NR-PSS and NR-SSS. The system information is transmitted, for example, via NR-PBCH and is also referred to as broadcast information. The synchronization signals and system information may also be referred to as SSB (SS/PBCH block). As shown in FIG. 1, the base station 10 transmits control signals or data to the terminal 20 via DL (Downlink) and receives control signals or data from the terminal 20 via UL (Uplink). Both the base station 10 and the terminal 20 are capable of transmitting and receiving signals using beamforming. Furthermore, both the base station 10 and the terminal 20 can apply MIMO (Multiple Input Multiple Output) communication to DL or UL. Furthermore, both the base station 10 and the terminal 20 may communicate via a secondary cell (SCell: Secondary Cell) and a primary cell (PCell: Primary Cell) using CA (Carrier Aggregation). Furthermore, the terminal 20 may communicate via a primary cell of the base station 10 and a primary secondary cell group cell (PSCell: Primary SCG Cell) of another base station 10 using DC (Dual Connectivity).

The terminal 20 is a communication device equipped with wireless communication capabilities, such as a smartphone, mobile phone, tablet, wearable device, or M2M (Machine-to-Machine) communication module. As shown in FIG. 1, the terminal 20 receives control signals or data from the base station 10 via DL and transmits control signals or data to the base station 10 via UL, thereby utilizing various communication services provided by the wireless communication system. The terminal 20 also receives various reference signals transmitted from the base station 10 and performs measurement of propagation path quality based on the reception results of the reference signals.

The terminal 20 is capable of performing carrier aggregation, which aggregates multiple cells (multiple CCs (Component Carriers)) to communicate with the base station 10. In carrier aggregation, one PCell (Primary cell) and one or more SCells (Secondary cells) are used. A PUCCH-SCell having a PUCCH may also be used.

Figure 2 is a diagram illustrating an example (2) of a wireless communication system in an embodiment of the present invention. Figure 2 shows an example configuration of a wireless communication system when DC (Dual connectivity) is implemented. As shown in Figure 2, a base station 10A serving as an MN (Master Node) and a base station 10B serving as an SN (Secondary Node) are provided. Base station 10A and base station 10B are each connected to a core network. Terminal 20 can communicate with both base station 10A and base station 10B.

The cell group provided by base station 10A, which is an MN, is called the MCG (Master Cell Group), and the cell group provided by base station 10B, which is an SN, is called the SCG (Secondary Cell Group). In addition, in DC, the MCG consists of one PCell and one or more SCells, and the SCG consists of one PSCell (Primary SCG Cell) and one or more SCells.

The processing operations in this embodiment may be performed using the system configuration shown in Figure 1, the system configuration shown in Figure 2, or any other system configuration.

(Regarding power saving)
Next, we will explain the status of discussion on base station power saving in NR Release 18. Techniques for base stations and terminals to improve network energy saving from both the base station transmission and reception perspectives are being considered. For example, it is being considered that a base station can use support/feedback and assistance information from terminals to save network energy in one or more of the time, frequency, space, and power domains.

In order to achieve carbon neutrality and the SDGs, it is becoming increasingly important to reduce the power consumption of base stations. However, until now, no appropriate methods have been proposed for reducing the power consumption of base stations.

In particular, in wireless communication systems, periodic downlink (DL) transmissions such as SSB constantly consume power from the base station 10. Therefore, it is important to reduce SSB transmission opportunities in order to reduce the power consumption of the base station 10. However, conventional technology has the problem that reducing SSB transmission opportunities can cause unexpected events in the terminal 20, which can prevent the terminal 20 (and the base station 10) from operating properly.

Note that SSB is an abbreviation for Synchronization Signal Block. SSB is also sometimes called Synchronization/PBCH block or SS/PBCH block.

In the following explanation, we will use SSB as an example to explain the mechanism for solving the above problems, but SSB is an example of a DL signal (which may also be called DL information) that is periodically transmitted by base station 10, and the technology described below may also be applied to DL signals other than SSB.

(Basic operations related to SSB)
First, the basic operation related to the SSB (especially its transmission periodicity) in this embodiment will be described. The SSB is used by the terminal 20 to measure the received power or the received quality. The terminal 20 also obtains basic information about a cell by reading information contained in the PBCH in the SSB of that cell. Figure 3 shows each piece of information in the PBCH (MIB) contained in the SSB and its role. Figure 4 shows the contents of the PBCH.

NR SSBs are basically transmitted periodically within the time resource of the first or second half of a frame (10 ms). Figure 5 shows a case in which four SSBs are transmitted per period in a certain cell (cell A) at a period of X ms. One SSB is, for example, four symbols long, and each SSB starts at a specified position. One SSB includes the PBCH and synchronization signals (PSS, SSS).

The operation of the terminal 20 in relation to the SSB period can be classified into the following three cases: Case 1, Case 2, and Case 3. The existence of Cases 1 to 3 is also true in the embodiments of the present invention. However, in the present embodiments (first to third embodiments and variations described below), it is assumed that the base station 10 can transmit SSB at a longer period than that in conventional technology. The periods shown in the explanations of the cases here are existing periods.

<Case 1: Initial cell selection>
At the time of initial cell selection (initial access) in Case 1, terminal 20 assumes that half frames of the SS/PBCH block occur at a two-frame cycle. In other words, at the time of initial access, terminal 20 monitors SSB assuming that the SSB has a 20 ms cycle.

<Case 2: From SIB1 reception to RRC connected state>
After initial access to a cell, the terminal 20 receives SIB1 from that cell and establishes an RRC connection. During this period, the SSB transmission periodicity is notified to the terminal 20 by the base station 10 using ssb-periodicityServingCell in the ServingCellConfigCommonSIB. The terminal 20 monitors the SSB based on the notified periodicity. The periodicity is a required parameter, and a value selected from {ms5, ms10, ms20, ms40, ms80, ms160} is notified to the terminal 20 by the base station 10.

<Case 3: During RRC connected state>
The SSB periodicity during the RRC connected state is notified from the base station 10 to the terminal 20 by ssb-periodicityServingCell in ServingCellConfigCommon. The notified value is in the range of {ms5, ms10, ms20, ms40, ms80, ms160, spare2, spare1}. If ssb-periodicityServingCell does not exist in ServingCellConfigCommon, the terminal 20 assumes that the SSB periodicity is 5 ms.

(About capability information notification operations)
In this embodiment, in the RRC connected state, the base station 10 can set parameters related to the SSB period and the like in the terminal 20 based on the capability information of the terminal 20. Fig. 6 shows the basic operation related to the capability information notification.

First, in S1, the base station 10 sends a capability inquiry (UE Capability Enquiry) to the terminal 20. In S2, the terminal 20 sends capability information (UE Capability Information) to the base station 10.

(Outline of the embodiment)
In this embodiment, the proposed contents will be described separately for the above-mentioned cases 1, 2, and 3. That is, as shown in FIG. 7 , an embodiment in case 1, which corresponds to the time of initial access, will be described as a first embodiment. Also, an embodiment in case 2, from SIB1 reception shown in S101 until the RRC connected state is established, will be described as a second embodiment. Furthermore, an embodiment in case 3, which corresponds to the period during the RRC connected state, will be described as a third embodiment. As shown in FIG. 7 , in case 3, the terminal 20 notifies the base station 10 of capability information (S102), and the base station 10 notifies the terminal 20 of setting information (which may also be called instruction information) (S103).

Each embodiment will be described below. In all of the following embodiments, it is assumed that the base station 10 can transmit SSB at a longer period than that in conventional technology in order to reduce power consumption. In each of the following embodiments, the operation of the base station 10 and the terminal 20 will be described so that the terminal 20 can properly receive SSB even when the base station 10 transmits SSB at a longer period.

(First embodiment)
In the first embodiment, which is an embodiment for Case 1 (at the time of initial access), the terminal 20 assumes that the period of the SSB transmitted from the base station 10 is X ms, which is longer than a predetermined value (for example, 20 ms). More specifically, the operations related to this assumption include the following Option 1 and Option 2.

Option 1 is an operation based on the judgment of terminal 20, and includes options 1-1 and 1-2 below.

<First embodiment: Option 1-1>
In option 1-1, an SSB period longer than the period in the prior art (called an "extended SSB period") is applied only to terminals 20 that support the extended SSB period.

For example, a terminal 20 that supports an extended SSB periodicity may assume that half frames having SS/PBCH blocks occur at a periodicity of Y frames, where Y is X/10. For example, if X = 320 ms, then Y is 32.

The base station 10 transmits SS/PBCH blocks at a period of Y frames. At that time, the base station 10 assumes that terminals 20 that support an extended SSB period will monitor the SSB at that period (Y frame period). The base station 10 also assumes that terminals 20 that do not support an extended SSB period will monitor the SSB at a period of a specific value (e.g., 2 frames).

The value of Y mentioned above may be, for example, a fixed value specified in the specifications. The value of Y may also be 4, 8, 16, 32, or 64. However, these values are examples, and the value of Y may be a value other than these. Furthermore, the value of Y may differ for each cell (each base station).

Note that a terminal 20 that supports an extended SSB period may be interpreted as a terminal 20 that supports the terminal capability (UE capability) for the extended SSB period. Furthermore, the terminal capability (UE capability) may be defined to distinguish the SSB period that can be monitored. Note that the terminal capability is reported from the terminal 20 to the base station 10 after initial access.

<First embodiment: Option 1-2>
In Option 1-2, the extended SSB period is applied to all terminals 20 (any terminal 20). In Option 1-2, terminal capabilities such as the terminal capabilities (UE capability) in Option 1-1 are not defined.

The terminal 20 assumes that half frames having SS/PBCH blocks occur in a period of Y frames (Y number of frames). There may also be a terminal 20 that assumes that half frames having SS/PBCH blocks occur in a period of two frames.

<First embodiment: Option 2>
In option 2, the terminal 20 operates based on a notification from the base station 10. Specifically, for example, after the terminal 20 receives at least one SSB from the base station 10, if the terminal 20 detects that the MIB (PBCH) spare (shown in FIG. 3 ) in the SSB is a specific value (e.g., 1), the terminal 20 assumes that half frames having SS/PBCH blocks occur at a period of Y frames (Y frames). Here, Y is X/10. For example, if X=320 ms, Y is 32.

The value of Y may be, for example, a fixed value specified in the specifications. The value of Y may also be 4, 8, 16, 32, or 64. However, these values are examples, and the value of Y may be a value other than these. Furthermore, the value of Y may differ for each cell (each base station).

From the perspective of base station 10, when base station 10 transmits SSB at a Y frame period, base station 10 sets the spare bit of the MIB to a specific value.

In option 2, before terminal 20 receives SSB, terminal 20 monitors SSB assuming that the SSB period is, for example, 20 ms (i.e., the existing period).

The first embodiment described above enables the terminal 20 to properly receive the SSB during initial access when the base station 10 transmits the SSB at an extended SSB period.

Second Embodiment
Next, a second embodiment in case 2, which is an operation during the period from reception of SIB1 until the RRC connection state is established, will be described.

In the second embodiment, the base station 10 transmits a ServingCellConfigCommonSIB including new parameters (e.g., ssb-periodicityServingCell-r18) in SIB1.

Candidate periods notified in ssb-periodicityServingCell-r18 are, for example, {ms5, ms10, ms20, ms40, ms80, ms160, ms320, ms640}. For example, a base station 10 of a cell that transmits SSB at a period (e.g., 320 ms) longer than a predetermined value (e.g., the existing value of 160 ms) transmits ssb-periodicityServingCell-r18 with that period set.

A terminal 20 that receives ssb-periodicityServingCell-r18 with a period set longer than a specified value (e.g., the existing value of 160 ms) can monitor SSB at a period longer than the specified value based on the setting information.

The base station 10 can operate under the assumption that SSB will be monitored at a period set by the base station 10. For example, the base station 10 can determine that the terminal 20 is capable of receiving signals or data other than SSB because the terminal 20 does not monitor SSB at times that do not correspond to the SSB transmission timing.

The second embodiment described above enables the terminal 20 to properly receive SSB when the base station 10 transmits SSB at a period longer than a specified period.

(Third embodiment)
In the third embodiment, an operation in Case 3, which is a period during the RRC connected state, will be described. Option 1, Option 2, and Option 3 will be described below.

<Third embodiment: Option 1>
In option 1, the base station 10 can notify the terminal 20 of a period for transmitting SSBs that is longer than the predetermined period (e.g., 160 ms) in the prior art (which may be called an "extended SSB period").

For example, the base station 10 notifies (sets) the terminal 20 of the SSB periodicity using ssb-periodicityServingCell in ServingCellConfigCommon. The base station 10 may also notify (set) the terminal 20 of the extended SSB periodicity using a new parameter (e.g., ssb-periodicityServingCell-r18) in ServingCellConfigCommon.

For example, a value selected from {ms5, ms10, ms20, ms40, ms80, ms160, ms320, ms640} is set to ssb-periodicityServingCell or ssb-periodicityServingCell-r18. Note that the value range {ms5, ms10, ms20, ms40, ms80, ms160, ms320, ms640} is an example. A value other than these (for example, a value greater than 640 ms) may also be notified from base station 10 to terminal 20.

A terminal 20 that receives an SSB period via ssb-periodicityServingCell or ssb-periodicityServingCell-r18 can monitor the SSB at that period.

If there is no field in ServingCellConfigCommon (ssb-periodicityServingCell, ssb-periodicityServingCell-r18) that can notify an extended SSB periodicity, the terminal 20 may assume that the SSB periodicity is a specific value (e.g., 5 ms).

Also, if the above field is not present, a terminal 20 that supports an extended SSB periodicity may assume that half frames having SS/PBCH blocks occur at a period of Y frames (Y number of frames). The value of Y may be, for example, a fixed value specified in the specifications. The value of Y may be 4, 8, 16, 32, or 64. However, these values are examples, and the value of Y may be a value other than these. The value of Y may also differ for each cell (each base station).

A terminal 20 that receives ssb-periodicityServingCell-r18 with a period set longer than a specified value (e.g., the existing value of 160 ms) can monitor SSB at a period longer than the specified value based on the setting information.

The base station 10 can operate under the assumption that SSB will be monitored at a period set by the base station 10. For example, the base station 10 can determine that the terminal 20 is capable of receiving signals or data other than SSB because the terminal 20 does not monitor SSB at times that do not correspond to the SSB transmission timing.

<Third embodiment: Option 2>
In option 2 of the third embodiment, the terminal 20 performs an operation using a timer. The basic operation will be described with reference to FIG.

In S201, a certain timer value is set (or notified) from the base station 10 to the terminal 20. In S202, the terminal 20 performs operations related to SSB monitoring based on the state (operating, expired, etc.) of the timer that has that timer value as its initial value.

The timer value may be in units of ms, symbols, slots, subframes, or frames. Other units may also be used as the timer value unit. The setting/notification in S201 of FIG. 8 may be performed by any of RRC, MAC CE, and DCI. The setting/notification in S201 of FIG. 8 may be performed by a combination of any two or three of RRC, MAC CE, and DCI.

As an example of a combination of the two, the base station 10 sets multiple timer values to the terminal 20 via RRC and notifies the terminal 20 of information specifying one of the multiple timer values via DCI. The terminal 20 uses the timer value specified in the DCI.

Also, for example, the base station 10 may set a timer value in RRC or MAC CE to the terminal 20, and instruct the terminal 20 in MAC CE or DCI to start a timer with the timer value as its initial value. If the timer subsequently expires and another start instruction is given, the timer may start from its initial value.

Also, for example, notifying the terminal 20 of a timer value via MAC CE or DCI from the base station 10 may be an instruction to start the timer with that value as the initial value.

As specific examples of the operation of terminal 20 in option 2, options 2-1 and 2-2 will be explained.

<Third embodiment: Option 2-1>
In option 2-1, the terminal 20 does not assume that an SSB will be transmitted from the base station 10 while the timer is running. Even if an SSB period (e.g., ssb-periodicityServingCell in ServingCellConfigCommon) is set by the base station 10, the terminal 20 does not assume that an SSB will be transmitted from the base station 10 while the timer is running. The base station 10 may not transmit an SSB while the timer is running.

When the timer expires, the terminal 20 assumes that the base station 10 is transmitting SSB at the SSB period set by the base station 10 (e.g., ssb-periodicityServingCell in ServingCellConfigCommon). Under this assumption, the terminal 20 can monitor the SSB at the set SSB period. If the SSB period is not set by the base station 10, the terminal 20 may assume that the SSB period is a specific value (e.g., 5 ms).

An example of operation in option 2-1 will be explained with reference to Figure 9. At the time indicated by A, the terminal 20 starts the timer by receiving a timer start instruction from the base station 10, and the timer expires at the time indicated by B. During the period from A to B, the terminal 20 assumes that no SSB is being transmitted from the base station 10. During this period, the terminal 20 does not need to perform SSB monitoring operations. Furthermore, the base station 10 does not need to transmit SSB during this period. The same applies to the periods from C to D.

During the period B to C, the terminal 20 assumes that SSB is being transmitted from the base station 10 at the set period and monitors the SSB.

Note that the operation of the terminal 20/base station 10 during the timer operation described above and the operation of the terminal 20/base station 10 after the timer expires may be reversed. In this case, for example, in the example of Figure 9, during periods A to B and C to D, the terminal 20 assumes that SSB is being transmitted at the set cycle, and during period B to C, the terminal 20 assumes that SSB is not being transmitted.

<Third embodiment: Option 2-2>
In option 2-2, while the timer is running, the terminal 20 assumes that half a frame of SS/PBCH blocks arrives at a period of Y frames. The value of Y may be, for example, a fixed value defined in the specifications. The value of Y may be 4, 8, 16, 32, or 64. However, these values are examples, and the value of Y may be a value other than these. Furthermore, the value of Y may differ for each cell (each base station).

When the timer expires, the terminal 20 assumes that the base station 10 is transmitting SSB at the SSB period set by the base station 10 (e.g., ssb-periodicityServingCell in ServingCellConfigCommon). Under this assumption, the terminal 20 can monitor the SSB at the set SSB period. If the SSB period is not set by the base station 10, the terminal 20 may assume that the SSB period is a specific value (e.g., 5 ms).

An example of operation in option 2-2 will also be described with reference to Figure 9. At the time indicated by A, the terminal 20 receives a timer start instruction from the base station 10, thereby starting the timer, and the timer expires at the time indicated by B. During the period from A to B, the terminal 20 assumes that the SSB is being transmitted from the base station 10 at a cycle of Y frames, and monitors the SSB. The same applies to the period from C to D.

During the period B to C, the terminal 20 assumes that SSB is being transmitted from the base station 10 at the set period and monitors the SSB.

Note that the operation of the terminal 20/base station 10 during the timer operation described above and the operation of the terminal 20/base station 10 after the timer expires may be reversed. In this case, for example, in the example of Figure 9, during periods A to B and C to D, the terminal 20 assumes that SSB is being transmitted at the set cycle, and during period B to C, the terminal 20 assumes that SSB is being transmitted at a cycle of Y frames.

<Third embodiment: Option 3>
In option 3 of the third embodiment, the base station 10 sets or notifies the terminal 20 of a pause period, and the terminal 20 performs an operation using the pause period. The pause period may be rephrased as any one of an interruption period, a stop period, a temporary suspension period, and a pause period. The basic operation will be described with reference to FIG. 10 .

In S301, the base station 10 sets (or notifies) the terminal 20 of a certain sleep period value. In S302, the terminal 20 performs operations related to SSB monitoring based on the sleep period.

The unit of the idle period may be any of ms, symbols, slots, subframes, and frames. Other units may also be used as the unit of the idle period. Furthermore, the setting/notification in S301 of FIG. 10 may be performed by any of RRC, MAC CE, and DCI. Furthermore, the setting/notification in S301 of FIG. 10 may be performed by a combination of any two or three of RRC, MAC CE, and DCI.

As an example of a combination of the two, the base station 10 sets multiple idle periods to the terminal 20 via RRC and notifies the terminal 20 of information specifying one of the multiple idle periods via MAC CE or DCI. The terminal 20 uses the specified idle period.

Also, for example, the base station 10 may set a sleep period for the terminal 20 using RRC or MAC CE, and instruct the terminal 20 to start the sleep period using MAC CE or DCI.

Also, for example, the base station 10 may notify the terminal 20 of the dormant period using MAC CE or DCI, which may be an instruction to start the dormant period.

As specific examples of the operation of terminal 20 in option 3, options 3-1 and 3-2 will be explained.

<Third embodiment: Option 3-1>
In option 3-1, the terminal 20 does not assume that SSB will be transmitted from the base station 10 during the idle period. In other words, the terminal 20 does not assume (expect) to monitor or receive SSB during the idle period. Even if an SSB periodicity (e.g., ssb-periodicityServingCell in ServingCellConfigCommon) is configured by the base station 10, the terminal 20 does not assume that SSB will be transmitted from the base station 10 during the idle period.

The base station 10 does not transmit SSB during the idle period. However, there may be cases where the base station 10 transmits SSB during the idle period.

After the end of the idle period, for example, the terminal 20 assumes that SSB is being transmitted at a period of a specific value (e.g., 2 frames). Furthermore, after the end of the idle period, the terminal 20 may assume that SSB is being transmitted from the base station 10 at the SSB period set by the base station 10 (e.g., ssb-periodicityServingCell in ServingCellConfigCommon). Under this assumption, the terminal 20 can monitor SSB at the set SSB period. If the SSB period is not set by the base station 10, the terminal 20 may assume that the SSB period is a specific value (e.g., 5 ms).

An example of operation in option 3-1 will be described with reference to Figure 11. At the time indicated by A, the terminal 20 starts the sleep period by receiving a sleep period start instruction from the base station 10, and the sleep period ends at the time indicated by B. During the period from A to B, the terminal 20 assumes that no SSB is being transmitted from the base station 10. During this period, the terminal 20 does not need to perform SSB monitoring operations. Furthermore, the base station 10 does not need to transmit SSB during this period. The same applies to the periods from C to D.

During the period B to C, the terminal 20 assumes that SSB is being transmitted from the base station 10, for example at a set period, and monitors the SSB.

<Third embodiment: Option 3-2>
In option 3-2, terminal 20 assumes that half frames of SS/PBCH blocks arrive at a cycle of Y frames during idle periods. The value of Y may be, for example, a fixed value defined in the specifications. The value of Y may be 4, 8, 16, 32, or 64. However, these values are examples, and the value of Y may be a value other than these. Furthermore, the value of Y may differ for each cell (each base station).

When the idle period ends, the terminal 20 assumes that the base station 10 is transmitting SSBs at the SSB period set by the base station 10 (e.g., ssb-periodicityServingCell in ServingCellConfigCommon). Under this assumption, the terminal 20 can monitor SSBs at the set SSB period. If the base station 10 has not set an SSB period, the terminal 20 may assume that the SSB period is a specific value (e.g., 5 ms).

An example of operation for option 3-2 will also be described with reference to Figure 11. At the time indicated by A, the terminal 20 receives a sleep period start instruction from the base station 10, thereby starting the sleep period, and at the time indicated by B, the sleep period ends. During the period from A to B, the terminal 20 assumes that SSB is being transmitted from the base station 10 at a cycle of Y frames, and monitors the SSB. The same applies to the period from C to D.

During the period B to C, the terminal 20 assumes that SSB is being transmitted from the base station 10, for example at a set period, and monitors the SSB.

The third embodiment described above enables the terminal 20 to properly receive SSB when there is a period during which the base station 10 does not transmit SSB, or when the base station 10 transmits SSB at a period longer than a specified period.

(Variation 1)
In the first to third embodiments described above, an operation has been described that enables the use of a longer SSB period than in conventional techniques. In this way, in addition to using a longer period (or independently of using a longer period), a shorter transmission time length per SSB period (or fewer SSBs per period) than in conventional techniques may be used. For ease of explanation, SSBs with a shorter transmission time length per period than in conventional techniques or fewer SSBs than in conventional techniques will be referred to as shortened SSBs. Here, the number of SSBs per shortened SSB period may be one. Furthermore, the time length per shortened SSB period may be less than four symbols.

In case 1, the terminal 20 performs monitoring assuming that the base station 10 will transmit an SSB with a shortened time length/number of SSBs as specified in the specifications. In case 2, for example, the terminal 20 performs monitoring assuming that the base station 10 will transmit an SSB with a shortened time length/number of SSBs notified by the base station 10 in SIB1. In case 3, for example, the terminal 20 performs monitoring assuming that the base station 10 will transmit an SSB with a shortened time length/number of SSBs received from the base station 10 in an RRC message after RRC connection.

(Variation 2)
Variation 2 will be described as an example applicable to any of the first to third embodiments and variation 1.

The value of Y described in the first to third embodiments may be a value that the terminal 20 receives from the base station 10. The base station 10 may transmit the value of Y to the terminal 20 in any of an RRC message, MAC CE, or DCI.

Furthermore, "ssb-periodicityServingCell-r18" used in the second and third embodiments is a message (which may also be called an information element, parameter, etc.) indicating the SSB periodicity in the serving cell. A message with a name other than "ssb-periodicityServingCell-r18" may also be used as this message.

Which of the multiple operations (each option, etc.) described in the first to third embodiments and Variation 1 will be performed by the terminal 20 may be determined by RRC settings from the base station 10 to the terminal 20, by notification/instruction of MAC CE, DCI, UCI, etc., or based on the capabilities of the terminal 20.

In addition, capability information (UE capability) shown in (1) to (3) below may be specified and reported from the terminal 20 to the base station 10.

(1) Capability information indicating whether or not an extended SSB period (a longer SSB period than the conventional technology) is supported. (2) Capability information indicating whether or not a timer described in option 2 of the third embodiment is supported. (3) Capability information indicating whether or not a pause described in option 3 of the third embodiment is supported.

(Device configuration)
Next, an example of the functional configuration of the base station 10 and the terminal 20 that execute the processes and operations described above will be described.

<Base station 10>
FIG. 12 is a diagram showing an example of the functional configuration of the base station 10. As shown in FIG. 12, the base station 10 has a transmitting unit 110, a receiving unit 120, a setting unit 130, and a control unit 140. The functional configuration shown in FIG. 12 is merely an example. The names of the functional divisions and functional units may be any as long as they can perform the operations related to the embodiment of the present invention. Furthermore, the transmitting unit 110 and the receiving unit 120 may be collectively referred to as a communication unit.

The transmitter 110 has the function of generating signals to be transmitted to the terminal 20 and transmitting these signals wirelessly. The receiver 120 has the function of receiving various signals transmitted from the terminal 20 and obtaining, for example, information of higher layers from the received signals. The transmitter 110 also has the function of transmitting NR-PSS, NR-SSS, NR-PBCH, DL/UL control signals, DCI via PDCCH, data via PDSCH, etc. to the terminal 20.

The setting unit 130 stores pre-set setting information and various setting information to be transmitted to the terminal 20 in a storage device provided in the setting unit 130, and reads it from the storage device as needed.

The control unit 140 schedules DL reception or UL transmission of the terminal 20 via the transmission unit 110. The control unit 140 also includes a function for performing LBT. The control unit 140 also includes a timer function. The functional unit related to signal transmission in the control unit 140 may be included in the transmission unit 110, and the functional unit related to signal reception in the control unit 140 may be included in the reception unit 120. The transmission unit 110 may also be called a transmitter, and the reception unit 120 may also be called a receiver.

<Terminal 20>
Fig. 13 is a diagram showing an example of the functional configuration of the terminal 20. As shown in Fig. 13, the terminal 20 has a transmitting unit 210, a receiving unit 220, a setting unit 230, and a control unit 240. The functional configuration shown in Fig. 13 is merely an example. As long as the operations related to the embodiment of the present invention can be performed, the names of the functional divisions and functional units may be any. The transmitting unit 210 and the receiving unit 220 may be collectively referred to as a communication unit.

The transmitter 210 creates a transmission signal from the transmission data and transmits the transmission signal wirelessly. The receiver 220 receives various signals wirelessly and obtains higher layer signals from the received physical layer signals. The receiver 220 also has the function of receiving NR-PSS, NR-SSS, NR-PBCH, DL/UL/SL control signals, DCI via PDCCH, data via PDSCH, etc. transmitted from the base station 10. Furthermore, for example, the transmitter 210 may transmit a PSCCH (Physical Sidelink Control Channel), a PSSCH (Physical Sidelink Shared Channel), a PSDCH (Physical Sidelink Discovery Channel), a PSBCH (Physical Sidelink Broadcast Channel), or the like to another terminal 20 as D2D communication, and the receiver 220 may receive the PSCCH, the PSSCH, the PSDCH, or the PSBCH, or the like, from the other terminal 20. Furthermore, the transmitter 210 includes the antenna port described in this embodiment.

The setting unit 230 stores various setting information received by the receiving unit 220 from the base station 10 or other terminals in a storage device provided in the setting unit 230, and reads it from the storage device as needed. The setting unit 230 also stores setting information that is set in advance.

The control unit 240 controls the terminal 20. The control unit 240 also includes a timer function. The functional unit in the control unit 240 related to signal transmission may be included in the transmitting unit 210, and the functional unit in the control unit 240 related to signal reception may be included in the receiving unit 220. The transmitting unit 210 may also be called a transmitter, and the receiving unit 220 may also be called a receiver.

This embodiment provides at least the terminal, base station, and communication method described in Supplementary Notes 1 and 2 below.

<Appendix 1>
(Additional note 1)
a control unit that assumes that a synchronization signal block is transmitted from a base station at a period longer than a predetermined period during initial access;
a receiving unit that receives the synchronization signal block.
(Additional note 2)
The terminal according to claim 1, wherein the predetermined period is 20 ms.
(Additional note 3)
The terminal described in Supplementary Item 1 or 2, wherein the control unit assumes that the synchronization signal block is being transmitted from the base station at a period longer than the predetermined period when it detects that at least one synchronization signal block contains a specific value.
(Additional note 4)
a control unit that assumes that the synchronization signal block is transmitted from the base station at a period longer than a predetermined period based on setting information received from the base station;
a receiving unit that receives the synchronization signal block.
(Additional note 5)
a transmitter that transmits setting information indicating a period for transmitting synchronization signal blocks to a terminal;
a control unit that assumes that the synchronization signal block is being received in the terminal based on the setting information.
(Additional note 6)
At the time of initial access, it is assumed that the synchronization signal block is transmitted from the base station at a period longer than a predetermined period,
A communication method performed by a terminal that receives the synchronization signal block.

All of paragraphs 1 through 6 provide techniques for reducing the power consumption of base stations in wireless communication systems. According to supplementary paragraph 2, SSB can be monitored at a period longer than the existing period of 20 ms. According to supplementary paragraph 3, even during initial access, it is possible to know that SSB is being transmitted at a period longer than the specified period.

<Appendix 2>
(Additional note 1)
a receiver for receiving a timer value from a base station;
a control unit that, after a timer having the timer value has started, assumes that no synchronization signal block is being transmitted from the base station while the timer is running.
(Additional note 2)
The terminal according to Supplementary Item 1, wherein the control unit assumes that the synchronization signal block is being transmitted from the base station at a period set by the base station after the timer expires.
(Additional note 3)
a receiver for receiving a timer value from a base station;
and a control unit that, after a timer having the timer value has started, assumes that a synchronization signal block is being transmitted from the base station at a period longer than a predetermined period while the timer is operating.
(Additional note 4)
a receiver for receiving a value of the idle period from a base station;
a control unit that assumes that no synchronization signal block is transmitted from the base station during the idle period.
(Additional note 5)
a transmitter for transmitting a timer value to a terminal;
a control unit that performs control in the terminal so that after a timer having the timer value starts, the terminal does not transmit a synchronization signal block while the timer is running.
(Additional note 6)
receiving a timer value from the base station;
A communication method performed by a terminal, wherein after a timer having the timer value starts, the terminal assumes that no synchronization signal block is transmitted from the base station while the timer is running.

All of paragraphs 1 to 6 provide techniques for saving power consumption in base stations in wireless communication systems. According to supplementary paragraph 2, SSB can be properly received after the timer expires.

(Hardware configuration)
The block diagrams (FIGS. 12 and 13) used to explain the above embodiments show functional blocks. These functional blocks (components) are realized by any combination of at least one of hardware and software. Furthermore, the method for realizing each functional block is not particularly limited. That is, each functional block may be realized using a single device that is physically or logically coupled, or may be realized using two or more physically or logically separated devices that are directly or indirectly connected (e.g., wired, wireless, etc.) and these multiple devices. The functional block may also be realized by combining software with the single device or multiple devices.

Functions include, but are not limited to, judgment, determination, assessment, calculation, computation, processing, derivation, investigation, search, confirmation, reception, transmission, output, access, resolution, selection, election, establishment, comparison, assumption, expectation, regard, broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating, mapping, and assignment. For example, a functional block (component) that performs transmission functions is called a transmitting unit or transmitter. As mentioned above, there are no particular limitations on how these functions are implemented.

For example, the base station 10, terminal 20, etc. in one embodiment of the present disclosure may function as a computer that performs processing of the wireless communication method of the present disclosure. Figure 14 is a diagram showing an example of the hardware configuration of the base station 10 and terminal 20 in one embodiment of the present disclosure. The above-mentioned base station 10 and terminal 20 may be physically configured as a computer device including a processor 1001, a memory device 1002, an auxiliary memory device 1003, a communication device 1004, an input device 1005, an output device 1006, a bus 1007, etc.

In the following description, the term "apparatus" can be interpreted as a circuit, device, unit, etc. The hardware configuration of the base station 10 and terminal 20 may be configured to include one or more of the devices shown in the figure, or may be configured to exclude some of the devices.

Each function in the base station 10 and the terminal 20 is realized by loading specified software (programs) onto hardware such as the processor 1001 and the memory device 1002, causing the processor 1001 to perform calculations, control communication by the communication device 1004, and control at least one of reading and writing data in the memory device 1002 and the auxiliary memory device 1003.

The processor 1001, for example, runs an operating system to control the entire computer. The processor 1001 may be configured as a central processing unit (CPU) including an interface with peripheral devices, a control unit, an arithmetic unit, registers, etc. For example, the above-mentioned control unit 140, control unit 240, etc. may be realized by the processor 1001.

The processor 1001 also reads programs (program code), software modules, data, etc. from at least one of the auxiliary storage device 1003 and the communication device 1004 into the storage device 1002, and executes various processes in accordance with these. The program used is a program that causes a computer to execute at least some of the operations described in the above-mentioned embodiments. For example, the control unit 140 of the base station 10 shown in FIG. 12 may be stored in the storage device 1002 and implemented by a control program running on the processor 1001. For example, the control unit 240 of the terminal 20 shown in FIG. 13 may be stored in the storage device 1002 and implemented by a control program running on the processor 1001. While the various processes described above have been described as being executed by one processor 1001, they may also be executed simultaneously or sequentially by two or more processors 1001. The processor 1001 may be implemented on one or more chips. The program may also be transmitted from a network via a telecommunications line.

The storage device 1002 is a computer-readable recording medium and may be composed of, for example, at least one of 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 the present disclosure.

The auxiliary storage device 1003 is a computer-readable recording medium, and may be composed of, for example, at least one of an optical disk such as a CD-ROM (Compact Disc ROM), a hard disk drive, a flexible disk, a magneto-optical disk (e.g., a compact disk, a digital versatile disk, a Blu-ray (registered trademark) disk), a smart card, a flash memory (e.g., a card, a stick, a key drive), a floppy (registered trademark) disk, a magnetic strip, etc. The above-mentioned storage medium may be, for example, a database, a server, or other suitable medium that includes at least one of the storage device 1002 and the auxiliary storage device 1003.

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, for example, a network device, network controller, network card, or communication module. The communication device 1004 may be configured to include a high-frequency switch, duplexer, filter, frequency synthesizer, etc. to realize at least one of frequency division duplex (FDD) and time division duplex (TDD). For example, a transmitting/receiving antenna, an amplifier unit, a transmitting/receiving unit, a transmission path interface, etc. may be realized by the communication device 1004. The transmitting/receiving unit may be implemented as a physically or logically separated transmitting unit and receiving unit.

The input device 1005 is an input device (e.g., a keyboard, mouse, microphone, switch, button, sensor, etc.) that accepts input from the outside. The output device 1006 is an output device (e.g., a display, speaker, LED lamp, etc.) that outputs to the outside. Note that the input device 1005 and the output device 1006 may be integrated into one structure (e.g., a touch panel).

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 may be configured using different buses between each device.

Furthermore, the base station 10 and the terminal 20 may be configured to include hardware such as a microprocessor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a programmable logic device (PLD), or a field programmable gate array (FPGA), and some or all of the functional blocks may be realized by such hardware. For example, the processor 1001 may be implemented using at least one of these pieces of hardware.

The terminal 20 or base station 10 may also be provided in the vehicle 2001. Figure 15 shows an example configuration of the vehicle 2001. As shown in Figure 15, the vehicle 2001 is provided with a drive unit 2002, a steering unit 2003, an accelerator pedal 2004, a brake pedal 2005, a shift lever 2006, front wheels 2007, rear wheels 2008, an axle 2009, an electronic control unit 2010, various sensors 2021 to 2029, an information service unit 2012, and a communication module 2013. Each aspect/embodiment described in this disclosure may be applied to a communication device mounted on the vehicle 2001, and may be applied to the communication module 2013, for example. The functions of the terminal 20 may be mounted on the communication module 2013.

The drive unit 2002 is composed of, for example, an engine, a motor, or a hybrid of an engine and a motor. The steering unit 2003 includes at least a steering wheel (also called a handle) and is configured to steer at least one of the front wheels and rear wheels based on the operation of the steering wheel operated by the user.

The electronic control unit 2010 is composed of a microprocessor 2031, memory (ROM, RAM) 2032, and a communication port (IO port) 2033. Signals are input to the electronic control unit 2010 from various sensors 2021 to 2029 provided in the vehicle 2001. The electronic control unit 2010 may also be called an ECU (Electronic Control Unit).

Signals from the various sensors 2021 to 2029 include a current signal from a current sensor 2021 that senses the motor current, a front and rear wheel rotation speed signal obtained by a rotation speed sensor 2022, a front and rear wheel air pressure signal obtained by an air pressure sensor 2023, a vehicle speed signal obtained by a vehicle speed sensor 2024, an acceleration signal obtained by an acceleration sensor 2025, an accelerator pedal depression amount signal obtained by an accelerator pedal sensor 2029, a brake pedal depression amount signal obtained by a brake pedal sensor 2026, a shift lever operation signal obtained by a shift lever sensor 2027, and a detection signal for detecting obstacles, vehicles, pedestrians, etc. obtained by an object detection sensor 2028.

The information service unit 2012 is composed of various devices, such as a car navigation system, audio system, speakers, television, and radio, for providing various types of information such as driving information, traffic information, and entertainment information, as well as one or more ECUs that control these devices. The information service unit 2012 uses information obtained from external devices via the communication module 2013, etc., to provide various types of multimedia information and multimedia services to the occupants of the vehicle 2001.

The driving assistance system unit 2030 is composed of various devices that provide functions to prevent accidents and reduce the driver's driving burden, such as millimeter-wave radar, LiDAR (Light Detection and Ranging), cameras, positioning locators (e.g., GNSS, etc.), map information (e.g., high-definition (HD) maps, autonomous vehicle (AV) maps, etc.), gyro systems (e.g., IMU (Inertial Measurement Unit), INS (Inertial Navigation System), etc.), AI (Artificial Intelligence) chips, and AI processors, as well as one or more ECUs that control these devices. The driving assistance system unit 2030 also transmits and receives various information via the communication module 2013 to realize driving assistance functions or autonomous driving functions.

The communication module 2013 can communicate with the microprocessor 2031 and components of the vehicle 2001 via the communication port. For example, the communication module 2013 transmits and receives data via the communication port 2033 between the drive unit 2002, steering unit 2003, accelerator pedal 2004, brake pedal 2005, shift lever 2006, front wheels 2007, rear wheels 2008, axle 2009, microprocessor 2031 and memory (ROM, RAM) 2032 in the electronic control unit 2010, and sensors 2021-29, all of which are provided on the vehicle 2001.

The communication module 2013 is a communication device that can be controlled by the microprocessor 2031 of the electronic control unit 2010 and can communicate with an external device. For example, it transmits and receives various information to and from the external device via wireless communication. The communication module 2013 may be located either inside or outside the electronic control unit 2010. The external device may be, for example, a base station, a mobile station, etc.

The communication module 2013 transmits current signals from the current sensors input to the electronic control unit 2010 to external devices via wireless communication. The communication module 2013 also transmits to external devices via wireless communication the following signals input to the electronic control unit 2010: front and rear wheel rotation speed signals acquired by the rotation speed sensor 2022, front and rear wheel air pressure signals acquired by the air pressure sensor 2023, vehicle speed signals acquired by the vehicle speed sensor 2024, acceleration signals acquired by the acceleration sensor 2025, accelerator pedal depression amount signals acquired by the accelerator pedal sensor 2029, brake pedal depression amount signals acquired by the brake pedal sensor 2026, shift lever operation signals acquired by the shift lever sensor 2027, and detection signals for detecting obstacles, vehicles, pedestrians, etc. acquired by the object detection sensor 2028.

The communication module 2013 receives various information (traffic information, traffic signal information, vehicle distance information, etc.) transmitted from external devices and displays it on the information service unit 2012 provided in the vehicle 2001. The communication module 2013 also stores the various information received from external devices in memory 2032 that can be used by the microprocessor 2031. Based on the information stored in memory 2032, the microprocessor 2031 may control the drive unit 2002, steering unit 2003, accelerator pedal 2004, brake pedal 2005, shift lever 2006, front wheels 2007, rear wheels 2008, axles 2009, sensors 2021-2029, etc. provided in the vehicle 2001.

(Supplementary explanation of the embodiment)
Although the 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, and substitutions. While specific numerical examples have been used to facilitate understanding of the invention, 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; matters described in two or more items may be used in combination as needed, and matters described in one item may apply to matters described in another item (unless inconsistent). Boundaries between functional units or processing units in functional block diagrams do not necessarily correspond to boundaries between physical components. The operations of multiple functional units may be performed by a single physical component, or the operations of a single functional unit may be performed by multiple physical components. The order of processing steps described in the embodiments may be reversed as long as there is no contradiction. For convenience of processing description, the base station 10 and terminal 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 10 in accordance with an embodiment of the present invention and the software operated by the processor of the terminal 20 in accordance with an embodiment of the present invention may each be stored in random access memory (RAM), flash memory, read-only memory (ROM), EPROM, EEPROM, register, hard disk (HDD), removable disk, CD-ROM, database, server, or any other suitable storage medium.

Furthermore, the notification of information is not limited to the aspects/embodiments described in the present disclosure, and may be performed using other methods. For example, the notification of information may be performed by physical layer signaling (e.g., Downlink Control Information (DCI), Uplink Control Information (UCI)), higher layer signaling (e.g., Radio Resource Control (RRC) signaling, Medium Access Control (MAC) signaling), broadcast information (Master Information Block (MIB), System Information Block (SIB)), other signals, or a combination thereof. Furthermore, RRC signaling may be referred to as an RRC message, and may be, for example, an RRC Connection Setup message, an RRC Connection Reconfiguration message, etc.

Each aspect/embodiment described in this disclosure may be applied to at least one of systems utilizing LTE (Long Term Evolution), LTE-Advanced (LTE-A), 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), or other suitable systems, and next generation systems enhanced based on these. In addition, multiple systems may be combined (for example, a combination of at least one of LTE and LTE-A with 5G, etc.).

The order of the procedures, sequences, flowcharts, etc. of each aspect/embodiment described herein may be rearranged unless inconsistent. For example, the methods described in this disclosure present elements of various steps using an example order and are not limited to the particular order presented.

Specific operations described herein as being performed by the base station 10 may also be performed by its upper node in some cases. In a network consisting of one or more network nodes including a base station 10, it is clear that various operations performed for communication with a terminal 20 may be performed by at least one of the base station 10 and other network nodes other than the base station 10 (such as, but not limited to, an MME or S-GW). While the above example illustrates a case where there is one other network node other than the base station 10, the other network node may also be a combination of multiple other network nodes (for example, an MME and an S-GW).

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

Input and output information may be stored in a specific location (e.g., memory) or may be managed using a management table. Input and output information may be overwritten, updated, or added to. Output information may be deleted. Input information may be sent to another device.

In this disclosure, the determination may be made based on a value represented by one bit (0 or 1), a Boolean value (true or false), or a numerical comparison (e.g., comparison with a predetermined value).

Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise.

Software, instructions, information, etc. may also be transmitted and received via a transmission medium. For example, if software is transmitted from a website, server, or other remote source using wired technologies (such as coaxial cable, fiber optic cable, twisted pair, Digital Subscriber Line (DSL)), and/or wireless technologies (such as infrared, microwave), these wired and/or wireless technologies are included within the definition of transmission media.

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

Note that terms explained 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 a channel and a symbol may be a signal (signaling). Furthermore, a signal may be a message. Furthermore, a component carrier (CC) may be called a carrier frequency, a cell, a frequency carrier, etc.

As used in this disclosure, the terms "system" and "network" are used interchangeably.

Furthermore, the information, parameters, etc. described in this disclosure may be expressed using absolute values, relative values from a predetermined value, or other corresponding information. For example, radio resources may be indicated by an index.

The names used for the above-described parameters are not intended to be limiting in any way. Furthermore, the mathematical formulas, etc. using these parameters may differ from those explicitly disclosed in this disclosure. The various channels (e.g., PUCCH, PDCCH, etc.) and information elements may be identified by any suitable names, and therefore the various names assigned to these various channels and information elements are not intended to be limiting in any way.

In this disclosure, terms such as "base station (BS)," "radio base station," "base station," "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.

A base station can accommodate one or more (e.g., three) cells. When a base station accommodates multiple cells, the entire coverage area of the base station can be divided into multiple smaller areas, and each smaller area can also be provided with communication services by a base station subsystem (e.g., a small indoor base station (RRH: Remote Radio Head)). The terms "cell" or "sector" refer to part or all of the coverage area of a base station and/or base station subsystem that provides communication services within this coverage area.

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

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 some other suitable terminology.

At least one of the base station and the mobile station may be referred to as 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, or the mobile body itself. 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 also include devices that do not necessarily move during communication operations. 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.

Furthermore, the term "base station" in the present disclosure may be read as "terminal." For example, each aspect/embodiment of the present disclosure may be applied to a configuration in which communication between a base station and a terminal is replaced with communication between multiple terminals 20 (which may be referred to as, for example, D2D (Device-to-Device) or V2X (Vehicle-to-Everything)). In this case, the terminal 20 may be configured to have the functions possessed by the base station 10 described above. Furthermore, terms such as "uplink" and "downlink" may be read as terms corresponding to communication between terminals (for example, "side"). For example, terms such as "uplink channel" and "downlink channel" may be read as "side channel."

Similarly, the term "terminal" in this disclosure may be interpreted as "base station." In this case, the base station may be configured to have the functions of the terminal described above.

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

The terms "connected," "coupled," or any variation thereof, refer to 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" to each other. The coupling or connection between elements may be physical, logical, or a combination thereof. For example, "connected" may be read as "access." As used in this disclosure, two elements may be considered to be "connected" or "coupled" to each other using one or more wires, cables, and/or printed electrical connections, as well as electromagnetic energy having wavelengths in the radio frequency range, microwave range, and optical (both visible and invisible) range, as some non-limiting and non-exhaustive examples.

The reference signal may also be abbreviated as RS (Reference Signal) or may be called a pilot depending on the applicable standard.

As used in this disclosure, the phrase "based on" does not mean "based only on," unless expressly stated otherwise. In other words, the phrase "based on" means both "based only on" and "based at least on."

As used in this disclosure, any reference to an element using a designation such as "first," "second," etc. does not generally limit the quantity or order of those elements. These designations may be used in this disclosure as a convenient method of distinguishing between two or more elements. Thus, a reference to a first and a second element does not imply that only two elements may be employed or that the first element must in some way precede the second element.

The "means" in the configuration of each of the above devices may be replaced with "part," "circuit," "device," etc.

When the terms "include," "including," and variations thereof are used in this disclosure, these terms are intended to be inclusive, similar to the term "comprising." Furthermore, when the term "or" is used in this disclosure, it is not intended to be an exclusive or.

A radio frame may be composed of one or more frames in the time domain. Each of the one or more frames in the time domain may be called a subframe. A subframe may further be composed 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.

Numerology may be a communication parameter that applies to at least one of the transmission and reception of a signal or channel. Numerology may indicate, 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 structure, specific filtering operations performed by the transceiver in the frequency domain, and specific windowing operations performed by the transceiver in the time domain.

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

A slot may include multiple minislots. Each minislot may consist of one or more symbols in the time domain. A minislot may also be called a subslot. A minislot 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.

Radio frame, subframe, slot, minislot, and symbol all represent time units for transmitting signals. Other names may also be used for radio frame, subframe, slot, minislot, and symbol.

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 minislot may be called a TTI. In other words, at least one of the subframe and the 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, minislot, etc. instead of a subframe. One slot may also be called a unit time. The unit time may differ for each cell depending on the numerology.

Here, TTI refers to, for example, the smallest time unit for scheduling in wireless communication. For example, in an LTE system, a base station schedules each terminal 20 by allocating radio resources (such as frequency bandwidth and transmission power that can be used by each terminal 20) in TTI units. Note that the definition of TTI is not limited to this.

A TTI may be a transmission time unit for a channel-coded data packet (transport block), code block, code word, etc., or may be a processing unit for scheduling, link adaptation, etc. Note that when a TTI is given, the time interval (e.g., the number of symbols) to which a transport block, code block, code word, etc. is actually mapped may be shorter than the TTI.

Note that when one slot or one minislot is referred to as a TTI, one or more TTIs (i.e., one or more slots or one or more minislots) may be the smallest time unit for scheduling. Furthermore, the number of slots (minislots) that constitute the smallest time unit for scheduling may be controlled.

A TTI with a time length of 1 ms may be referred to as a regular TTI (TTI in LTE Rel. 8-12), normal TTI, long TTI, regular subframe, normal subframe, long subframe, slot, etc. A TTI shorter than a regular TTI may be referred to as a shortened TTI, short TTI, partial TTI (partial or fractional TTI), shortened subframe, short subframe, minislot, subslot, slot, etc.

Note that a long TTI (e.g., a normal TTI, a subframe, etc.) may be interpreted as a TTI having a time length of more than 1 ms, and a short TTI (e.g., a shortened TTI, etc.) may be interpreted as a TTI having a TTI length shorter than that of a long TTI and greater than or equal to 1 ms.

A resource block (RB) is a resource allocation unit in the time and frequency domains, and may include one or more consecutive subcarriers in the frequency domain. The number of subcarriers included in an RB may be the same regardless of numerology, for example, 12. The number of subcarriers included in an RB may also be determined based on numerology.

Furthermore, the time domain of an RB may include one or more symbols and may be one slot, one minislot, one subframe, or one TTI in length. One TTI, one subframe, etc. may each consist of one or more resource blocks.

In addition, one or more RBs may also be referred to as a physical resource block (PRB), a sub-carrier group (SCG), a resource element group (REG), a PRB pair, an RB pair, etc.

A resource block may also be composed of one or more resource elements (REs). For example, one RE may be a radio resource region of one subcarrier and one symbol.

A Bandwidth Part (BWP) (which may also be referred to as a partial bandwidth) may represent a subset of contiguous common resource blocks (RBs) for a given numerology on a given carrier, where the common RBs may be identified by their index relative to a Common Reference Point of the carrier. PRBs may be defined in a BWP and numbered within that BWP.

BWPs may include a BWP for the UL (UL BWP) and a BWP for the DL (DL BWP). One or more BWPs may be configured for a UE within one carrier.

At least one of the configured BWPs may be active, and the UE may not expect to transmit or receive a given signal/channel outside the active BWP. Note that the terms "cell," "carrier," etc. in this disclosure may be read as "BWP."

The above-described structures of radio frames, subframes, slots, minislots, and symbols are merely examples. For example, the number of subframes included in a radio frame, the number of slots per subframe or radio 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, as well as the number of symbols in a TTI, symbol length, and cyclic prefix (CP) length can be varied in various ways.

In this disclosure, where articles are added by translation, such as a, an, and the in English, this disclosure may include the noun following these articles being plural.

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 "combined" may also be interpreted in the same way as "different."

Each aspect/embodiment described in this disclosure may be used alone, in combination, or switched between depending on the implementation. Furthermore, notification of specified information (e.g., notification that "X is true") is not limited to being done explicitly, but may also be done implicitly (e.g., not notifying the specified information).

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 spirit and scope of the present disclosure as defined by the claims. Therefore, the description of the present disclosure is intended to be illustrative and does not have any limiting meaning on the present disclosure.

10 Base station 110 Transmitter 120 Receiver 130 Setting unit 140 Control unit 20 Terminal 210 Transmitter 220 Receiver 230 Setting unit 240 Control unit 1001 Processor 1002 Storage device 1003 Auxiliary storage device 1004 Communication device 1005 Input device 1006 Output device 2001 Vehicle 2002 Drive unit 2003 Steering unit 2004 Accelerator pedal 2005 Brake pedal 2006 Shift lever 2007 Front wheels 2008 Rear wheels 2009 Axle 2010 Electronic control unit 2012 Information service unit 2013 Communication module 2021 Current sensor 2022 Rotation speed sensor 2023 Air pressure sensor 2024 Vehicle speed sensor 2025 Acceleration sensor 2026 Brake pedal sensor 2027 Shift lever sensor 2028 Object detection sensor 2029 Accelerator pedal sensor 2030: Driving assistance system unit 2031: Microprocessor 2032: Memory (ROM, RAM)
2033 Communication port (IO port)

Claims (2)

a control unit that assumes that a synchronization signal block is transmitted from a base station at a period longer than a predetermined period of 20 ms during initial access;
a receiving unit for receiving the synchronization signal block ,
When the control unit detects that spare of MIB included in at least one synchronization signal block has a specific value, it assumes that the synchronization signal block is being transmitted from the base station at a period longer than the predetermined period.
Terminal. Assume that, at the time of initial access, the synchronization signal block is transmitted from the base station at a period longer than the predetermined period of 20 ms .
A communication method executed by a terminal receiving the synchronization signal block, comprising:
When the terminal detects that spare of an MIB included in at least one synchronization signal block has a specific value, the terminal assumes that the synchronization signal block is being transmitted from the base station at a period longer than the predetermined period.
Communication method.