WO2023176229A1

WO2023176229A1 - Base station, terminal device, communication system, method, and non-transitory computer-readable medium

Info

Publication number: WO2023176229A1
Application number: PCT/JP2023/004569
Authority: WO
Inventors: 高広笹木
Original assignee: 日本電気株式会社
Priority date: 2022-03-16
Filing date: 2023-02-10
Publication date: 2023-09-21
Also published as: JPWO2023176229A1

Abstract

The present disclosure provides a base station, a terminal device, a communication system, a method, and a program that contribute to reduction of electric power consumption. A base station (11) according to an aspect is provided with a processor and a transceiver. The processor is configured to cause the transceiver to: transmit, to a terminal device (12), a message including information indicating that information indicating an opportunity for receiving control information includes a plurality of sets of parameters indicating the frequency of the opportunity of receiving the control information; and receive from the terminal device (12) a response message with respect to the message.

Description

Base stations, terminal devices, communication systems, methods and non-transitory computer-readable media

The present disclosure relates to a base station, a terminal device, a communication system, a method, and a program.

In wireless communication, data from a base station is intermittently received on the UE (User Equipment) side. For example, Patent Document 1 describes that a terminal device receives a plurality of candidate DRX settings from a base station and changes the DRX settings used for standby depending on the time zone.

JP2019-165328A

One of the objectives of the present disclosure is to provide a base station, a terminal device, a communication system, a method, and a program that contribute to reducing power consumption. It should be noted that this objective is only one of the objectives that the embodiments disclosed herein seek to achieve. Other objects or objects and novel features will become apparent from the description of this specification or the accompanying drawings.

The base station according to one aspect includes a processor and a transceiver, and the processor sends information indicating an opportunity to receive control information to the transceiver, and sets a parameter indicating the frequency of the opportunity to receive the control information. The terminal device is configured to transmit a message including information indicating that the terminal device includes a plurality of , and receive a response message to the message from the terminal device.

A terminal device according to one aspect includes a processor and a transceiver, and the processor sends information indicating an opportunity to receive control information to the transceiver, including a set of parameters indicating the frequency of the opportunity to receive the control information. The base station is configured to receive a message from a base station including information indicating that a plurality of .

A communication system according to one aspect includes a base station and a terminal device, the base station includes a first processor, and a first transceiver, and the first processor is configured to operate on the first transceiver. , configured to cause the terminal device to transmit a message including information indicating that the information indicating the opportunity to receive control information includes a plurality of parameter sets indicating the frequency of the opportunity to receive the control information, The terminal device includes a second processor and a second transceiver, and the second processor causes the second transceiver to receive the message from the base station, and causes the base station to receive the message. is configured to cause a response message to be sent.

The method according to one aspect includes transmitting to a terminal device a message including information indicating that the information indicating the opportunity to receive control information includes a plurality of parameter sets indicating the frequency of the opportunity to receive the control information, The method performed by a base station includes receiving a response message to the message from the terminal device.

A method according to one aspect includes receiving from a base station a message including information indicating that the information indicating the opportunity to receive control information includes a plurality of parameter sets indicating the frequency of the opportunity to receive the control information, The method is performed by a terminal device and includes transmitting a response message to the message to the base station.

The program according to one aspect transmits to a terminal device a message including information indicating that information indicating an opportunity to receive control information includes a plurality of parameter sets indicating the frequency of the opportunity to receive the control information, The program causes a computer to receive a response message to the message from the terminal device.

A program according to one aspect receives from a base station a message including information indicating that information indicating an opportunity to receive control information includes a plurality of parameter sets indicating the frequency of the opportunity to receive the control information, The program causes a computer to transmit a response message to the message to the base station.

According to the present disclosure, it is possible to provide a base station, a terminal device, a communication system, a method, and a program that contribute to reducing power consumption.

1 is a diagram illustrating a configuration example of a communication system according to a first embodiment; FIG. 1 is a block diagram showing a configuration example of a communication device according to a first embodiment; FIG. FIG. 2 is a sequence diagram showing an example of the operation of the communication system according to the first embodiment. FIG. 7 is a diagram illustrating a configuration example of a search space IE according to a second embodiment. FIG. 7 is a diagram illustrating a configuration example of a search space IE according to a second embodiment. FIG. 7 is a diagram showing a first modification example of the search space IE according to the second embodiment. FIG. 7 is a diagram showing a second modification example of the search space IE according to the second embodiment. FIG. 7 is a diagram showing a third modification example of the search space IE according to the second embodiment. FIG. 7 is a diagram showing a fourth modification example of the search space IE according to the second embodiment. FIG. 7 is a diagram showing an example of common reception timing for a plurality of search spaces according to the fourth embodiment. An implementation example of PDCCH-Config IE is shown. In the SearchSpaceExt-v_xy IE shown in FIG. 11, an example is shown in which a plurality of sets of search space parameters of cycle, offset, and duration are added. An example of implementing a PDCCH-Config IE different from that shown in FIG. 11 is shown. An example of adding search space parameters to the SearchSpaceExt-v_xy IE shown in FIG. 13 is shown. An example of SearchSpace IE configuration is shown. An example of SearchSpace IE configuration is shown. 1 is a block diagram illustrating a configuration example of a communication device according to each embodiment. FIG.

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Note that the following description and drawings are omitted and simplified as appropriate for clarity of explanation. Further, in each of the drawings below, the same elements are denoted by the same reference numerals, and redundant explanations will be omitted as necessary. In addition, in this disclosure, unless specified otherwise, "at least one of A or B (A/B)" may mean any one of A or B. However, it may also mean both A and B. Similarly, when "at least one" is used for three or more elements, it may mean any one of these elements, or any plurality of elements (including all elements). It can also mean

Embodiment 1
(Communication system configuration)
FIG. 1 is a diagram illustrating a configuration example of a communication system according to a first embodiment. The communication system 10 is, for example, a fifth generation mobile communication system (5G system). The 5G System is NR (New Radio Access), a fifth generation radio access technology. Note that the communication system 10 is not limited to the 5th generation mobile communication system, and may be a different mobile communication system such as an LTE (Long Term Evolution) system, an LTE-Advanced system, or a 6th generation mobile communication system.

The communication system 10 includes a base station 11 and a terminal device 12. The terminal device 12 is, for example, a user equipment (UE). Although only one base station 11 and one terminal device 12 are illustrated in FIG. 1, the communication system 10 may include a plurality of devices for each of the base station 11 and the terminal device 12. . The base station 11 and the terminal device 12 are capable of wireless communication.

The base station 11 may be, for example, a gNB. The gNB is a node that terminates the NR user plane and control plane protocols for the UE and connects to the 5GC via the NG interface. As another example, the base station 11 may be an ng-eNB (LTE evolved NodeB). ng-eNB is a node that terminates the E-UTRA (Evolved Universal Terrestrial Radio Access) user plane and control plane protocols for the UE, and connects to the 5G core network (5GC) via the NG interface. . The base station 11 may be a CU (Central Unit) in a C-RAN (cloud RAN) configuration, or may be a gNB-CU. The gNB-CU is a logical node that hosts the gNB's RRC (Radio Resource Control) protocol, SDAP (Service Data Adaptation Protocol) protocol, and PDCP (Packet Data Convergence Protocol) protocol. Alternatively, the gNB-CU is a logical node that hosts the RRC protocol and PDCP protocol of the en-gNB that controls the operation of one or more gNB-DUs (gNB-Distributed Units). gNB-CU terminates the F1 interface connected to gNB-DU. Alternatively, the base station 11 may be a CP (Control Plane) Unit or a gNB-CU-CP (gNB-CU-Control Plane). gNB-CU-CP is a logical node that hosts the RRC protocol and the control plane part of the gNB-CU's PDCP protocol for en-gNB or gNB. gNB-CU-CP terminates the E1 interface that connects to gNB-CU-UP (gNB-CU-User Plane) and the F1-C interface that connects to gNB-DU. gNB-CU-UP is a logical node that hosts the user plane part of the gNB-CU's PDCP protocol for en-gNB. gNB-CU-UP terminates the E1 interface that connects to gNB-CU-CP and the F1-U interface that connects to gNB-DU.

Note that the base station 11 may be an eNB or an eNB-CU. Further, the base station 11 may be an EUTRAN (Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network) node or an NG-RAN (Next Generation Radio Access Network) node. The EUTRAN node may be an eNB or en-gNB. The NG-RAN node may be a gNB or ng-eNB. The en-gNB provides NR user plane and control plane protocol termination for the UE, and operates as a secondary node in EN-DC (NR Dual Connectivity).

Also, in FIG. 1, the base station 11 serves at least one cell. The base station 11 operates the cell, connects and communicates with the terminal device 12 located in the cell. Note that the way this cell is operated changes depending on the action performed by the base station 11.

FIG. 2 is a block diagram showing a configuration example of a communication device that constitutes the base station 11 and the terminal device 12. The communication device 100 includes a communication section 101 and a control section 102. The communication unit 101 and the control unit 102 may be software or modules whose processing is executed by a processor executing a program stored in a memory. Furthermore, the communication unit 101 and the control unit 102 may be hardware such as a circuit or a chip.

The communication unit 101 transmits and receives various information by connecting and communicating with other communication devices (for example, base stations or UEs) included in the access network.

The control unit 102 executes various processes of the communication device 100 by reading and executing various information and programs stored in the memory. The control unit 102 performs processing according to any or all of setting information such as various information elements (IEs), various fields, and various conditions included in the message received by the communication unit 101. The control unit 102 is configured to be able to execute processing of multiple layers. The multiple layers may include a physical layer, a MAC (Media Access Control) layer, an RLC (Radio Link Control) layer, a PDCP layer, an RRC layer, a NAS (non Access Stratum) layer, and the like. The configuration example of the communication system shown above is common to Embodiment 1-2.

FIG. 3 is a sequence diagram showing an example of the operation of the communication system according to the first embodiment. Hereinafter, an example of the operation of the communication system 10 will be described using FIG. 3.

In step S1, the base station 11 sends a message to the terminal device 12 including information indicating that the information indicating the opportunity to receive control information includes a plurality of parameter sets indicating the frequency of the opportunity to receive the control information. and send. Terminal device 12 receives this message. This message may or may not further include information on the set of multiple parameters. Further, the terminal device 12 may or may not change the frequency of opportunities to receive control information, which is set within the terminal device 12, using the reception of this message as a trigger. If not changed, the terminal device 12 changes the frequency of opportunities to receive control information based on another trigger. Further, at the stage of receiving the message, information on a plurality of parameter sets may be stored in the terminal device 12 in advance. Alternatively, at the stage of receiving the message, the terminal device 12 may not store information on the plurality of parameter sets, but may internally store information on the plurality of parameter sets included in the message. That is, the message may be an instruction to initialize the parameter set for the terminal device 12, or may be an instruction to update the parameter set settings.

Note that each of the plurality of parameter sets may set a search space, for example. The search space is an interval in which the terminal device 12 receives control information transmitted from the base station 11 to the terminal device 12 (for example, active time of DRX (Discontinuous Reception)), and in which the terminal device 12 receives control information transmitted from the base station 11 to the terminal device 12. Refers to an opportunity to receive control information when there is a possibility of receiving information. For example, the section indicated by the search space includes one or more CORESETs (physical resources for PDCCH (Physical Downlink Control CHannel) transmission), and each CORESET multiplexes and transmits a plurality of PDCCHs. The terminal device 12 detects DCI (Downlink Control Information) by receiving and decoding these PDCCHs in a round-robin manner. By changing the set of parameters set internally by the terminal device 12, the search space is changed. Changing the search space refers to changing at least one parameter that determines the nature of the search space. The parameter determining the nature of the search space may be, for example, a period of the search space, an offset of the search space, or a duration of the search space per period. However, examples of parameters are not limited to this. Further, the trigger for changing the search space may be, for example, the frequency of information transmission from the base station 11 (details are described in Embodiment 2), or may be triggered by other events such as power consumption of the terminal device 12. It may be.

In step S2, the terminal device 12 can transmit a response message to the base station 11 as a response to the received message. Base station 11 receives this response message.

In the first embodiment, the base station 11 sends to the terminal device 12 a message including information indicating that the information indicating the opportunity to receive control information includes a plurality of parameter sets indicating the frequency of the opportunity to receive the control information. Send to. The terminal device 12 can change the opportunity to receive control information based on the information included in the message. As the frequency of receiving control information increases, the power consumption of the terminal device 12 increases. Therefore, in the first embodiment, changing the frequency of opportunities for the terminal device 12 to receive control information contributes to suppressing the power consumption of the terminal device.

Next, Embodiment 2 will be described. Embodiment 5 provides a specific example of the communication system shown in Embodiment 1.

Embodiment 2
The communication system in Embodiment 2 includes a base station 11 and a terminal device 12, as shown in FIG. This base station 11 is a gNB in 5G, and can transmit DCI, which is control information, to the terminal device 12 via the PDCCH. The destination of the DCI can be specified, and the DCI addressed to the terminal device 12 includes control information addressed to the terminal device 12.

The base station 11 can set, as the configuration of the search space IE, a search space cycle _ks , a search space offset O _s , and a search space duration T _s per cycle. Note that k _s and O _s are collectively referred to as monitoringSlotPeriodicityAndOffset, and T _s is also referred to as duration. Note that the description of the search space is as described in paragraph 0026.

FIG. 4 is a diagram showing an example of the configuration of the search space IE. In FIG. 4, one square represents one time slot (hereinafter also simply referred to as a slot), and hatched slots represent PDCCH reception opportunities. In this example, k _s =8, O _s =2, T _s =2.

In the search space IE, the slots (PDCCH reception opportunities) in which the terminal device 12 can receive (monitor) PDCCH in one period are expressed as follows.

...(1)
satisfy,

...(2)
T _s consecutive slots from . However, n _f is the radio frame number (for example, a value from 0 to 1023),

...(3)
is the number of slots per radio frame,

...(4)
is the slot number in the radio frame. Note that this slot number can range from, for example, 0 to

...(5)
Takes the value up to.

Using the parameters shown above, the frequency of PDCCH reception opportunities is the ratio of the search space duration per period to the search space period, and is T _s /k _s . For example, in the example of FIG. 4, the frequency at which PDCCH can be received in one cycle is 2/8. The power consumption related to PDCCH reception by the terminal device 12 is considered to be roughly proportional to this ratio. Therefore, by reducing this ratio, power consumption related to PDCCH reception by the terminal device 12 can be reduced. In addition, the terminal device 12 also starts receiving a PDSCH (Physical Downlink Shared Channel) in parallel with receiving the PDCCH. Therefore, power consumption related to not only PDCCH reception but also PDSCH reception can be reduced.

In the second embodiment, each terminal device 12 can autonomously change the search space so that the frequency of PDCCH reception opportunities (T _s /k _s ) changes. Specifically, multiple sets of monitoringSlotPeriodicityAndOffset ( _ks , _Os ) and duration ( _Ts ) can be set in one search space IE. Each pair is given an index for identification (in this case, it is set as i). The range of i is {0..maximum settable number - 1}. Since the search space is set in this way, the settings of other search spaces set in advance are not affected. Further, the terminal device 12 receives a set of search spaces from the base station 11 in advance using the method shown in paragraphs 0024-0026, and stores it in the storage unit of the terminal device 12.

The above settings can be used for the purpose, range, etc. of each parameter in the search space for each i. Specifically, in monitoringSlotPeriodicityAndOffset_i, the period of the search space is expressed by k _s,i and the offset of the search space is expressed by O _s,i . Further, the duration is expressed as T _s,i .

In this search space IE, the slots (PDCCH reception opportunities) in which the terminal device 12 can receive PDCCH in one cycle are expressed as follows.

...(6)
satisfy,

...(7)
T _{s, t} consecutive slots from . Note that the description of each parameter in (6) is the same as the description of each parameter in (1). When index=i, the frequency of PDCCH reception opportunities in the search space is T _s,i /k _s,i .

FIG. 5 is a diagram showing an example of the configuration of the search space IE. In FIG. 5, one square represents one slot, and hatched slots represent PDCCH reception opportunities. In this example, k _s,i =8, O _s,i =2, and T _s,i =2.

As an example of how to set the index, existing monitoringSlotPeriodicityAndOffset and duration may be set in a search space where index=0, and different monitoringSlotPeriodicityAndOffset and duration may be set in a search space where index is 1 or more. monitoringSlotPeriodicityAndOffset and duration may be initial values when the index is the maximum value or the minimum value (for example, 0).

Two examples of shifting the PDCCH reception frequency will be described below. Note that here, it is assumed that index is set as a search space frequency parameter ID, and that the larger the index, the lower the PDCCH reception frequency. Furthermore, P _i and M _i are further introduced as parameters to be used. P _i represents the length of an interval for measuring the number of DCI detections in a search space where index=i is set. The unit of P _i is the number of slots, and its range is, for example, {1. ．． 2560}. Here, 2560 is an example of the maximum value of k _s,i . Furthermore, M _i represents a threshold value for the number of times DCI is detected in section P _i . In addition, in the implementation example described later, P _i and M _i are also expressed as countPeriod and dciCount, respectively. Furthermore, in the example below, it is assumed that there are two types of search spaces with different T _s,i /k _s,i , but there are three or more types of search spaces with different T _s,i /k _s,i. Spaces may be present. The search space frequency parameters are parameters indicating the frequency of opportunities to receive control information, and include a period k _s,i , an offset O _s,i , a search space duration per period T _s,i , P _i , M In addition to _i , N _i, which will be described later, may be included. The terminal device 12 stores a set of search space frequency parameters for each index.

(1) Example of shifting the PDCCH reception frequency from high frequency to low frequency When the terminal device 12 initially receives PDCCH with a search space setting where index (search space frequency parameter ID) = i, length P _i Count the DCIs addressed to itself detected in that search space during the count interval. The DCIs to be counted may be, for example, only those linked to this search space, but are not limited to this. At this time, if the total number of detected DCIs is less than M _i , the terminal device 12 autonomously shifts its search space setting from index=i to index=j. Here, j=i+1. However, if i is already the maximum value of index, then j=i. At this time, the base station 11, which is a gNB, also autonomously shifts its search space setting to index=j.

FIG. 6 is a diagram showing a first modification example of the search space IE. In this example, the terminal device 12 sets two types of search space frequency parameters: {k _s,0 =2, O _s,0 =0, T _s,0 =1, P ₀ =8, where index=0, M ₀ =1} ₀ and index=1 {k _s,1 =4, O _s,1 =2, T _s,1 =1, P ₁ =16, M ₁ =1} ₁ from the base station 11 Receive in advance from. When index=0, the PDCCH reception frequency is 1/2, and when index=1, the PDCCH reception frequency is 1/4. Also, the numbers attached to each slot are the slot numbers shown in (7).

...(8)
and the number of slots per radio frame

...(9)
is 20.

The terminal device 12 first sets a search space frequency parameter of index=0 in a DCI count period of length P ₀ =8 (n _f =0, period where slot numbers are 0 to 7) {k _s,0 =2 , O _s,0 =0, T _s,0 =1} PDCCH is received using the search space setting of ₀ . The PDCCH reception opportunities in this count period are the timings of

slot numbers

0, 2, 4, and 6, which are the timings indicated by hatching in FIG. 6. If the number of times the terminal device 12 detects a DCI addressed to itself during PDCCH reception opportunities during this counting period is less than M ₀ = 1 time, the terminal device 12 will immediately update the search space frequency parameter when this counting period ends. Automatically migrate the settings to those with index=1. That is, the terminal device 12 autonomously changes the search space frequency parameter setting to {ks _,1 = 4, O _s,1 = 2, T _s,1 = 1, P ₁ = 16, M ₁ = 1} _1. Transition.

In this example, the DCI count interval defined by _P1 starts at the next slot after the last slot of the DCI count interval defined by _P0 . That is, in FIG. 6, the DCI count period defined by _P1 starts from the timing when n _f =0 and the slot number becomes 8. The PDCCH reception opportunities in this count period are at

slot numbers

10, 14, and 18, and the frequency is 1/2 compared to the time immediately before.

In the example shown above, even if there is no DCI transmitted to the search space for the terminal device 12, the frequency of the terminal device 12 receiving the PDCCH can be autonomously reduced to 1/2. Therefore, it is possible to reduce the power consumption of the terminal device involved in PDCCH reception by half.

Note that the length P _i does not have to be an even number as in the example of FIG. 6, but may be an odd number. FIG. 7 is a diagram showing a second modification example of such a search space IE. In this example, the terminal device 12 has two types of search space frequency parameter settings with index=0 {k _s,0 =2, O _s,0 =0, T _s,0 =1, P ₀ = 5, M ₀ = 1} ₀ and index=1 {k _s,1 = 4, O _s,1 = 2, T _s,1 = 1, P ₁ = 10, M ₁ = 1} ₁ as the base It is received from the station 11 in advance. When index=0, the PDCCH reception frequency is 1/2, and when index=1, the PDCCH reception frequency is 1/4. The description of other parameters is the same as the description regarding FIG.

The terminal device 12 first receives a PDCCH in a DCI count interval of length P ₀ =5 using a search space setting based on a search space frequency parameter setting of index=0. The PDCCH reception opportunities in this count period are the timings of

slot numbers

0, 2, and 4, which are the timings indicated by hatching in FIG. 7. If the number of times the terminal device 12 detects a DCI addressed to itself during the PDCCH reception opportunity during this counting period is less than M ₀ = 1 time, the terminal device 12 sets the search space frequency parameter after this counting period ends. Autonomous transition to index=1. The PDCCH reception opportunities in this count period are at

slot numbers

6, 10, and 14, and the frequency is 1/2 compared to the time immediately before.

(2) Example of shifting the PDCCH reception frequency from low frequency to high frequency Next, an example of shifting the PDCCH reception frequency from low frequency to high frequency will be described. In this explanation, a parameter N _i is introduced as a threshold value for the number of times DCI is detected in a DCI count section with a section length P _i . The parameter N _i is used as a threshold instead of M _i .

When the terminal device 12 initially receives PDCCH with a search space setting where index (search space frequency parameter ID) = i, the terminal device 12 receives the DCI addressed to itself detected in the search space in the count interval of length P _i . Count. The DCIs to be counted may be, for example, only those linked to this search space, but are not limited to this. At this time, if the total number of detected DCIs is N _i or more, the terminal device 12 autonomously shifts its search space setting from index=i to index=j. Here, j=i-1. However, if i is already the minimum value of index, then j=i. At this time, the base station 11, which is a gNB, also autonomously shifts its search space setting to index=j.

FIG. 8 is a diagram showing a third modification example of the search space IE. In this example, the terminal device 12 sets two types of search space frequency parameters: {k _s,0 =2, O _s,0 =0, T _s,0 =1, P ₀ =8, where index=0, N ₀ =2} ₀ and index=1 {k _s,1 =4, O _s,1 =2, T _s,1 =1, P ₁ =16, N ₁ =2} ₁ from the base station 11 Receive in advance from. When index=0, the PDCCH reception frequency is 1/2, and when index=1, the PDCCH reception frequency is 1/4. The other explanations in FIG. 8 are the same as those in FIG. 6, so the explanations will be omitted.

The terminal device 12 first uses index=in a DCI count interval of length P ₁ =16 (period from the timing when n _f =0 and slot number 8 to the timing when n _f =1 and slot number 3). Search space frequency parameter setting of 1 {ks _,1 = 4, O _s,1 = 2, T _s,1 = 1} PDCCH is received using the search space setting of ₁ . The PDCCH reception opportunities in this count period are the timings when the slot numbers are 10, 14, and 18 when n _f =0, and the timings when the slot number is 2 when n _f =1. These timings are indicated by hatching in FIG. If the number of times the terminal device 12 detects a DCI addressed to itself is N ₁ = 2 or more times during the PDCCH reception opportunity during this DCI count period, the terminal device 12 will immediately update the search space frequency when this count period ends. Automatically migrate the parameter settings to those with index=0. That is, the terminal device 12 autonomously changes the search space frequency parameter settings to {ks _,0 = 2, O _s,0 = 0, T _s,0 = 1, P ₀ = 8, N ₀ = 2} ₀ . Transition. The PDCCH reception opportunities in this count period are at times when the slot numbers are 4, 6, 8, 10, etc. in n _f =1, and the frequency is twice as high as that immediately before.

In the example shown above, even if there is no DCI transmitted to the search space for the terminal device 12, the opportunity for the terminal device 12 to receive the PDCCH can be autonomously doubled. Therefore, the terminal device 12 can receive data from the base station 11 if necessary.

Note that the DCI count interval defined by P _i may be defined other than the definition shown in the above example. For example, in the search space IE, the DCI count interval defined by P _i may be expressed as follows.

...(10)
satisfy,

...(11)
P _i consecutive slots from .

At this time, the number of DCIs detected in the DCI count interval of length P _i is defined as follows; at the end of this DCI count interval, the search space frequency parameter of which index (search space frequency parameter ID) The number of DCIs detected in all PDCCH reception opportunities during the corresponding DCI count interval of length P _i , regardless of whether PDCCH is enabled or not.

FIG. 9 is a diagram showing a fourth modification example of the search space IE. In this example, the terminal device 12 sets two types of search space frequency parameters: {k _s,0 =2, O _s,0 =0, T _s,0 =1, P ₀ =8, where index=0, N ₀ =2} ₀ and index=1 {k _s,1 =4, O _s,1 =2, T _s,1 =1, P ₁ =16, N ₁ =2} ₁ from the base station 11 Receive in advance from. In addition, since the search space frequency parameter is changed at the timing after the number "8" given to the slot in FIG. Note that the number can be different. The other explanations in FIG. 9 are the same as those in FIG. 6, so the explanations will be omitted.

FIG. 9 shows that after the DCI count interval ₀ (n _f = 0, slot number 0 to 7) defined by length P ₀ = 8 expires, a long period starts from the timing of n _f = 0, slot number 8. An example of transition to section ₁ defined by P ₁ =16 (n _f =0, period with slot numbers 0 to 15 (period corresponding to slots numbered after number "8" in FIG. 9)) is shown.

Here, the PDCCH reception opportunities to be counted for the number of DCI detections in section ₁ (n _f = 0, period where slot number is 0 to 15) are n _f = 0, slot number = {0, 2, 4, 6 ,10,14}. This PDCCH reception opportunity also includes a PDCCH reception opportunity included in section ₀ (n _f =0, period with slot numbers 0 to 7). On the other hand, the PDCCH reception opportunities to be counted for the number of DCI detections in section ₁ (period from the timing when n _f = 0 and slot number 16 to the timing when n _f = 1 and slot number 11) are n _f = There are four slots: 0, slot number = {18}, and n _f =1, slot number = {2, 6, 10}.

Note that the method by which the terminal device 12 shifts the PDCCH reception frequency from high frequency to low frequency as shown in FIG. 9 is as shown in (1) above, and detailed explanation will be omitted.

Note that the base station 11 may count the number of DCI transmissions for each search space to a certain terminal device 12, and compare the number of transmissions with a predetermined threshold. Then, based on the comparison result, parameters related to the frequency of PDCCH reception opportunities of the search space (search space frequency parameter) can be switched autonomously. In other words, the base station 11 uses the number of DCI transmissions for each search space instead of the number of DCI detections for each search space in the processing of the terminal device 12 described above, thereby performing the same processing as that of the terminal device 12 described above. can be executed.

The UE may perform an operation of continuously receiving multiple PDCCHs at a high frequency (for example, every 1 ms) to detect DCI, but the power consumed in this reception process is large, and it is preferable to reduce it. In particular, when receiving a PDCCH that includes a DCI that is not addressed to itself, the power consumption associated with that operation ends up being wasted.

In the second embodiment, the base station 11 transmits the settings of a plurality of search spaces to the terminal device 12, and the terminal device 12 can change the search space using the settings. By changing the search space, the terminal device 12 can reduce its power consumption.

Here, in setting a plurality of search spaces (sets of parameters), T _s /k _s may be different from each other. As a result, the terminal device 12 can switch between a search space with many reception opportunities and a search space with few reception opportunities as necessary, and it is possible to reduce power consumption and achieve smooth communication. .

Additionally, the base station 11 may transmit the settings of multiple search spaces to the terminal device 12. Thereby, even if the terminal device 12 does not have a search space setting in advance, it is possible to determine the setting on the base station 11 side. Further, the base station 11 can also manage search space settings in a unified manner.

Additionally, the terminal device 12 can measure the frequency with which PDCCHs are received from the base station 11, and change the search space settings based on the frequency. As a result, the terminal device 12 can set a search space that can reduce power consumption and perform a search that enables high-frequency communication depending on whether or not frequent communication with the base station 11 is required. Space settings can be selected.

Furthermore, in each of the settings of a plurality of search spaces, at least a period, a duration, and an offset of the search space may be set. This allows detailed settings of the search space.

Furthermore, the terminal device 12 may receive the DCI from the base station 11 during the period in which the terminal device 12 receives control information transmitted from the base station 11. Thereby, the terminal device 12 can receive control information regarding search space settings without performing any special processing.

Note that in the second embodiment, the terminal device 12 receives a set of search spaces from the base station 11 in advance and stores it in the storage unit of the terminal device 12. However, a set of search spaces may be set and stored in both the base station 11 and the terminal device 12 in advance.

Embodiment 3
In the example shown in Embodiment 2, the base station 11 autonomously transmits DCI to a certain terminal device 12 based on the number of DCI transmissions for each search space, and the terminal device 12 autonomously performs the An example of switching a parameter related to the frequency of PDCCH reception opportunities in a search space (search space frequency parameter) was shown. This is an example in which it is possible to migrate the search space frequency parameter without transmitting dynamic and explicit signaling from the base station 11 to the terminal device 12 by DCI.

However, it is also possible to migrate the search space frequency parameter by using dynamic explicit signaling by the DCI from the base station 11. In detail, by adding a field to notify the search space frequency parameter index (search space frequency parameter ID) to the DCI format (for example, DCI format 1_1), dynamic and explicit signaling by DCI can be used together. becomes possible.

As a specific example, a field name "Search space periodicity-offset-duration indication" is set in the DCI format, and this field may contain, for example, 0, 1, . ．． It may be set by the c(maxNrofAddPerOff-r_xy) bit. Here, c indicates a ceiling function. The bit width for this field is determined to be c(log ₂ (I)) bits with I greater than 1. If the upper layer parameter additionalPeridodicityAndOffsetList-r_xy is set, I is the number of entries in the parameter + 1, and if the upper layer parameter is not set, I is 0 bit.

For example, the base station 11 may notify the terminal device 12 of the search space frequency parameter ID applied to the current DCI count interval using the DCI. The terminal device 12 may receive and store each index set of search space frequency parameters from the base station 11 at or before this timing. Alternatively, a set of indexes of search space frequency parameters may be stored in advance inside the terminal device 12. In this state, the terminal device 12 receives the DCI transmitted from the base station 11 via the PDCCH. Then, the terminal device 12 refers to the search space frequency parameters included in the received DCI, and determines whether the search space frequency parameters currently applied by the base station 11 and the search space frequency parameters applied by the terminal device 12 itself are correct. You can check whether they match. If it is determined that the two do not match, the terminal device 12 can modify the search space frequency parameter that it is currently operating based on the search space frequency parameter ID notified in the received DCI.

Embodiment 4
There is a possibility that the timings of the search spaces at each of the base station 11 and the terminal device 12 may deviate. In Embodiment 4, a process that can eliminate the discrepancy between the two in such a case will be described.

FIG. 10 is a diagram illustrating an example of common reception timing for a plurality of search spaces. The upper search space in FIG. 10 is the search space with index=0 in the second embodiment, and the lower search space is the search space with index=1 in the second embodiment. Although both search spaces have different T _s,i /k _s,i, common PDCCH reception opportunities are provided in

slot numbers

2, 6, 10, . . . indicated by hatching in FIG. 10.

The base station 11 transmits DCI etc. using this common PDCCH reception opportunity. Thereby, the terminal device 12 can receive data from the base station 11 regardless of which search space the terminal device 12 is performing the reception operation on. For example, if the base station 11 uses a search space with index=0 and the terminal device 12 uses a search space with index=1, even if the base station 11 transmits the PDCCH at the timing of slot number 4, Terminal device 12 does not receive the data.

If the base station 11 does not receive information from the terminal device 12 indicating that the terminal device 12 has received the PDCCH, it transmits the DCI again at a common PDCCH reception opportunity such as

slot numbers

6 and 10. As a result, the terminal device 12 can receive the DCI, and also shift the search space from index=1 to index=0 based on the frequency of PDCCH reception, as shown in Embodiment 2. This allows the search space to be used to be the same as that used by the base station 11.

Furthermore, even if the base station 11 transmits DCI at a common PDCCH reception opportunity, if the terminal device 12 does not transmit information indicating that it has received the PDCCH, the base station 11 and the terminal device 12 can search for a search space. It is determined that the timings of the two do not match. Thereby, the base station 11 executes control to match either the timing of its own search space or the timing of the search space of the terminal device 12 by shifting the timing of the search space. Therefore, the search spaces in each of the base station 11 and the terminal device 12 can be matched, and smooth communication can be performed.

(Implementation example)
An implementation example of the search space setting shown in Embodiment 2 will be described below using FIGS. 11 to 15B. Note that although the implementation example shown below is assumed to be based on the standard described in Non-Patent Document 1, other implementations may be applied.

Figure 11 shows an implementation example of PDCCH-Config IE. In FIG. 11, the underlined list of SearchSpaceExt-v_xy is the information introduced by the present disclosure.

Here, the PDCCH-Config IE may be included in the RRC Reconfiguration or RRC Setup message transmitted from the base station 11 to the terminal device 12. Here, the RRC Reconfiguration message is a command for modifying the RRC connection, as described in section 6.2.2 of Non-Patent Document 1, and the RRC Setup message is a command for modifying the RRC connection, as described in section 6.2.2 of Non-Patent Document 1. This is a message used to establish SRB1 (Signaling Radio Bearer 1) as described in . However, as another example, the RRC Setup message may be a message used when establishing an RRC connection, as described in section 5.3.3.1 of Non-Patent Document 1.

The RRC Reconfiguration or RRC Setup message has, for example, the following structure. Note that ">" in the structure below indicates a data hierarchy.
＞RRC Reconfiguration or RRC Setup message
＞＞Cell group config IE
＞＞＞Serving cell config IE
＞＞＞＞BWP-downlink Dedicated IE
＞＞＞＞＞PDCCH-Config IE
The PDCCH-Config IE may thus be included within the RRC Reconfiguration or RRC Setup message. Note that the terminal device 12 that has received the RRC Reconfiguration message including the PDCCH-Config IE can transmit the RRC Reconfiguration complete message to the base station 11 as a response message. Furthermore, the terminal device 12 that has received the RRC Setup message including the PDCCH-Config IE can transmit the RRC setup complete message to the base station 11 as a response message.

FIG. 12 shows an example of adding a plurality of sets of search space parameters, such as period, offset, and duration, to the SearchSpaceExt-v_xy IE shown in FIG. 11. AdditionalPeridodicityAndOffsetList-r_xy in FIG. 12 indicates a parameter list after index=1, AdditionalPeridodicityAndOffset-r_xy indicates a parameter for each index, and additionalPeridodicityAndOffsetIdentity indicates i which is the index. Then, countPeriod, dciCount1, and dciCount2 indicate P _i , M _i , and N _i (i≧1) shown in paragraphs 0040 and 0048, respectively. However, dciCount2 can be omitted, and in this case, M _i =N _i . In FIG. 12, underlined dciCount1_0, dciCount2_0, dciCount1, and dciCount2 are information introduced by the present disclosure.

FIG. 13 shows an implementation example of PDCCH-Config IE different from that shown in FIG. 11. In Figure 13, SearchSpaceExt-v_xy is added to the PDCCH-Config IE, but what is added here is not a list, but the parameters period, offset, and duration are added as Period1, offset1, duration1. There is.

FIG. 14 shows an example of adding search space parameters in the SearchSpaceExt-v_xy IE shown in FIG. 13. This example shows an example of defining two sets of parameters in total by adding one set of index = 1 to the first set of parameters, which are period, offset, and duration, with index = 0. . In FIG. 14, countPeriod_0, dciCount1_0, and dciCount2_0 are P ₀ , M ₀ , and N _0, respectively. However, dciCount2_0 can be omitted, and in this case, M ₀ =N ₀ .

Furthermore, monitoringSlotPeriodicityAndOffset_1 and duration_1 indicate period ₁ (ks _,i ), offset ₁ ( _Os,i ), and duration ₁ (Os _,i ), respectively. Further, countPeriod_1, dciCount1_1, and dciCount2_1 are P ₁ , M ₁ , and N ₁ , respectively. However, dciCount2_1 can be omitted, and in this case, M ₁ =N ₁ . Furthermore, initialPeriodicityAndOffsetIdenity indicates the initial value of index, and is 0 if there is no initial value. In FIG. 14, underlined dciCount1_0, dciCount2_0, dciCount1_1, and dciCount2_1 are information introduced by the present disclosure.

15A and 15B show a configuration example of SearchSpace IE according to the implementation example shown above. For example, an existing SearchSpace IE may be used, or a new one may be used.

Note that the present disclosure is not limited to the above embodiments, and can be modified as appropriate without departing from the spirit. For example, in the second embodiment, if the DCI detected by the terminal device 12 in the above-mentioned DCI count interval is 0, the terminal device 12 updates the search space frequency parameter ID to an incremented search space frequency parameter in the next DCI count interval. do. In other cases, the terminal device 12 can perform an operation of switching from the next DCI count period to the search space frequency parameter of the search space frequency parameter ID notified by the DCI. When the terminal device 12 executes such processing, the parameters M _i and N _i used in the second embodiment become unnecessary.

The technology described in the present disclosure is not limited to a dedicated communication device, and can be applied to any device having a communication function.

(Hardware configuration example)
Next, an example of the hardware configuration of a communication device such as a base station, a terminal device, or a UE described in the plurality of embodiments described above will be described below. FIG. 16 is a block diagram showing a configuration example of a communication device according to each embodiment. Referring to FIG. 16, communication device 100 includes an RF (Radio Frequency) transceiver 1001, a network interface 1003, a processor 1004, and a memory 1005. RF transceiver 1001 performs analog RF signal processing to communicate with the UE. RF transceiver 1001 may include multiple transceivers. RF transceiver 1001 is coupled to antenna 1002 and processor 1004. RF transceiver 1001 receives modulation symbol data (or OFDM (Orthogonal Frequency Division Multiplexing) symbol data) from processor 1004, generates a transmit RF signal, and supplies the transmit RF signal to antenna 1002. Further, RF transceiver 1001 generates a baseband reception signal based on the reception RF signal received by antenna 1002 and supplies this to processor 1004.

The network interface 1003 is used to communicate with network nodes (e.g., other core network nodes). The network interface 1003 may include, for example, a network interface card (NIC) compliant with the Institute of Electrical and Electronics Engineers (IEEE) 802.3 series.

The processor 1004 performs data plane processing and control plane processing including digital baseband signal processing for wireless communication. For example, in the case of LTE and 5G, digital baseband signal processing by processor 1004 may include MAC layer and Physical layer signal processing.

The processor 1004 may include multiple processors. For example, the processor 1004 may include a modem processor (e.g., DSP (digital signal processor)) that performs digital baseband signal processing, and a protocol stack processor (e.g., CPU (central processing unit) or MPU (micro processor unit)).

The memory 1005 is configured by a combination of volatile memory and nonvolatile memory. Memory 1005 may include multiple physically independent memory devices. Volatile memory is, for example, Static Random Access Memory (SRAM) or Dynamic RAM (DRAM) or a combination thereof. Non-volatile memory is masked Read Only Memory (MROM), Electrically Erasable Programmable ROM (EEPROM), flash memory, or a hard disk drive, or any combination thereof. Memory 1005 may include storage located remotely from processor 1004. In this case, processor 1004 may access memory 1005 via network interface 1003 or an I/O interface, not shown.

The memory 1005 may store a software module (computer program) including a group of instructions and data for performing processing by the communication device 100 described in the multiple embodiments described above. In some implementations, the processor 1004 may be configured to retrieve and execute the software modules from the memory 1005 to perform the operations of the communication device 100 described in the embodiments above.

As explained above, one or more processors included in each device in the embodiments described above executes one or more programs including a group of instructions for causing a computer to execute the algorithm described using the drawings. . Through this processing, the signal processing method described in each embodiment can be realized.

A program includes a set of instructions (or software code) that, when loaded into a computer, causes the computer to perform one or more of the 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, non-transitory computer-readable or tangible storage media may include random-access memory (RAM), read-only memory (ROM), flash memory, solid-state drive (SSD), or other Memory technology, including CD-ROM, digital versatile disk (DVD), Blu-ray disk or other optical disk storage, magnetic cassette, magnetic tape, magnetic disk storage or other magnetic storage device. The program may be transmitted on a transitory computer-readable medium or a communication medium. By way of example and not limitation, transitory computer-readable or communication media includes electrical, optical, acoustic, or other forms of propagating signals.

In this specification, user equipment (UE) (or mobile station, mobile terminal, mobile device, wireless device, etc.) is a wireless An entity connected to a network via an interface.

Part or all of the above embodiments may be described as in the following additional notes, but are not limited to the following.
(Additional note 1)
a processor;
comprising a transceiver;
The processor, for the transceiver,
causing a terminal device to transmit a message including information indicating that the information indicating the opportunity to receive control information includes a plurality of parameter sets indicating the frequency of the opportunity to receive the control information;
configured to receive a response message to the message from the terminal device;
base station.
(Additional note 2)
The plurality of parameter sets each have a different ratio of the duration of the search space per period to the period of the search space.
The base station described in Appendix 1.
(Additional note 3)
the processor causes the transceiver to transmit information on the sets of the plurality of parameters having the different ratios to the terminal device;
The base station described in Appendix 2.
(Additional note 4)
In each of the plurality of parameter sets, at least the period, the duration, and the search space offset are set;
The base station described in Appendix 3.
(Appendix 5)
The processor causes the transceiver to transmit data to the terminal device at a timing when the terminal device commonly receives data among the plurality of parameter sets.
The base station described in

Appendix

3 or 4.
(Appendix 6)
When the processor does not receive a message indicating that data has been received from the terminal device at the timing, the timing of the search space at the base station and the timing of the search space at the terminal device do not match. It is determined that
The base station described in Appendix 5.
(Appendix 7)
the processor is configured to cause the transceiver to transmit the message to the terminal device during a period in which the terminal device receives the control information transmitted from the base station;
The base station described in

Supplementary note

1 or 2.
(Appendix 8)
a processor;
comprising a transceiver;
The processor, for the transceiver,
receiving from a base station a message including information indicating that the information indicating the opportunity to receive control information includes a plurality of parameter sets indicating the frequency of the opportunity to receive the control information;
causing the base station to send a response message to the message;
Terminal device.
(Appendix 9)
The plurality of parameter sets each have a different ratio of the duration of the search space per period to the period of the search space.
Terminal device according to appendix 8.
(Appendix 10)
the processor causes the transceiver to receive information about the sets of the plurality of parameters having different ratios;
Terminal device according to appendix 9.
(Appendix 11)
The processor measures the frequency with which control information for the terminal device is received from the base station, and based on the frequency, sets the search space of the terminal device according to the first parameter in the set of the plurality of parameters. changing from the settings of the set to the settings of the second set of parameters,
Terminal device according to appendix 10.
(Appendix 12)
The processor measures the frequency with which the control information for the terminal device is received from the base station, regardless of whether a search space setting of the terminal device has been changed within the frequency count interval. , based on the frequency, changing the search space setting of the terminal device from the setting of the first parameter set in the plurality of parameter sets to the setting of the second parameter set;
Terminal device according to appendix 11.
(Appendix 13)
The processor sets the search space of the terminal device to a first search space having the first ratio when the frequency with which the control information for the terminal device is received from the base station is equal to or higher than a predetermined threshold. changing from setting a set of parameters to setting a second set of parameters having a second said ratio greater than said first ratio;
Terminal device according to

supplementary note

11 or 12.
(Appendix 14)
The processor sets the search space of the terminal device to a first search space having a first ratio when the frequency with which the control information for the terminal device is received from the base station is less than a predetermined threshold. changing from setting a set of parameters to setting a second set of parameters having a second said ratio smaller than said first ratio;
Terminal device according to

supplementary note

11 or 12.
(Appendix 15)
In each of the settings of the plurality of parameter sets, at least the period, the duration, and the offset of the search space are set;
Terminal device according to

supplementary note

10 or 11.
(Appendix 16)
The processor is configured to cause the transceiver to receive the message from the base station during a period in which the terminal device receives the control information transmitted from the base station.
Terminal device according to

appendix

8 or 9.
(Appendix 17)
base station;
comprising a terminal device;
The base station is
a first processor;
a first transceiver;
the first processor, for the first transceiver;
configured to cause the terminal device to transmit a message including information indicating that the information indicating the opportunity to receive control information includes a plurality of parameter sets indicating the frequency of the opportunity to receive the control information,
The terminal device is
a second processor;
a second transceiver;
the second processor, for the second transceiver;
receiving the message from the base station;
configured to cause the base station to send a response message to the message;
Communications system.
(Appendix 18)
The plurality of parameter sets each have a different ratio of the duration of the search space per period to the period of the search space.
The communication system according to claim 17.
(Appendix 19)
transmitting to the terminal device a message including information indicating that the information indicating the opportunity to receive the control information includes a plurality of parameter sets indicating the frequency of the opportunity to receive the control information;
receiving a response message to the message from the terminal device;
A method performed by a base station, comprising:
(Additional note 20)
receiving from a base station a message including information indicating that the information indicating the opportunity to receive control information includes a plurality of parameter sets indicating the frequency of the opportunity to receive the control information;
transmitting a response message to the message to the base station;
A method performed by a terminal device, comprising:
(Additional note 21)
transmitting to the terminal device a message including information indicating that the information indicating the opportunity to receive control information includes a plurality of parameter sets indicating the frequency of the opportunity to receive the control information;
receiving a response message to the message from the terminal device;
A program that causes a computer to do something.
(Additional note 22)
receiving from a base station a message including information indicating that the information indicating the opportunity to receive control information includes a plurality of parameter sets indicating the frequency of the opportunity to receive the control information;
transmitting a response message to the message to the base station;
A program that causes a computer to do something.

Although the present disclosure has been described above with reference to the embodiments, the present disclosure is not limited to the above. Various changes can be made to the configuration and details of the present disclosure that can be understood by those skilled in the art within the scope of the disclosure.

This application claims priority based on Japanese Patent Application No. 2022-041939 filed on March 16, 2022, and the entire disclosure thereof is incorporated herein.

10 communication system 11 base station 12 terminal device

Claims

a processor;
comprising a transceiver;
The processor, for the transceiver,
causing a terminal device to transmit a message including information indicating that the information indicating the opportunity to receive control information includes a plurality of parameter sets indicating the frequency of the opportunity to receive the control information;
configured to receive a response message to the message from the terminal device;
base station.
The plurality of parameter sets each have a different ratio of the duration of the search space per period to the period of the search space.
The base station according to claim 1.
the processor causes the transceiver to transmit information on the sets of the plurality of parameters having the different ratios to the terminal device;
The base station according to claim 2.
In each of the plurality of parameter sets, at least the period, the duration, and the search space offset are set;
The base station according to claim 3.
The processor causes the transceiver to transmit data to the terminal device at a timing when the terminal device commonly receives data among the plurality of parameter sets.
The base station according to claim 3 or 4.
When the processor does not receive a message indicating that data has been received from the terminal device at the timing, the timing of the search space at the base station and the timing of the search space at the terminal device do not match. It is determined that
The base station according to claim 5.
the processor is configured to cause the transceiver to transmit the message to the terminal device during a period in which the terminal device receives the control information transmitted from the base station;
The base station according to claim 1 or 2.
a processor;
comprising a transceiver;
The processor, for the transceiver,
receiving from a base station a message including information indicating that the information indicating the opportunity to receive control information includes a plurality of parameter sets indicating the frequency of the opportunity to receive the control information;
causing the base station to send a response message to the message;
Terminal device.
The plurality of parameter sets each have a different ratio of the duration of the search space per period to the period of the search space.
The terminal device according to claim 8.
the processor causes the transceiver to receive information about the sets of the plurality of parameters having different ratios;
The terminal device according to claim 9.
The processor measures the frequency with which control information for the terminal device is received from the base station, and based on the frequency, sets the search space of the terminal device according to the first parameter in the set of the plurality of parameters. changing from the settings of the set to the settings of the second set of parameters,
The terminal device according to claim 10.
The processor measures the frequency with which the control information for the terminal device is received from the base station, regardless of whether a search space setting of the terminal device has been changed within the frequency count interval. , based on the frequency, changing the search space setting of the terminal device from the setting of the first parameter set in the plurality of parameter sets to the setting of the second parameter set;
The terminal device according to claim 11.
The processor sets the search space of the terminal device to a first search space having the first ratio when the frequency with which the control information for the terminal device is received from the base station is equal to or higher than a predetermined threshold. changing from setting a set of parameters to setting a second set of parameters having a second said ratio greater than said first ratio;
The terminal device according to claim 11 or 12.
The processor sets the search space of the terminal device to a first search space having a first ratio when the frequency with which the control information for the terminal device is received from the base station is less than a predetermined threshold. changing from setting a set of parameters to setting a second set of parameters having a second said ratio smaller than said first ratio;
The terminal device according to claim 11 or 12.
In each of the settings of the plurality of parameter sets, at least the period, the duration, and the offset of the search space are set;
The terminal device according to claim 10 or 11.
The processor is configured to cause the transceiver to receive the message from the base station during a period in which the terminal device receives the control information transmitted from the base station.
The terminal device according to claim 8 or 9.
base station;
comprising a terminal device;
The base station is
a first processor;
a first transceiver;
the first processor, for the first transceiver;
configured to cause the terminal device to transmit a message including information indicating that the information indicating the opportunity to receive control information includes a plurality of parameter sets indicating the frequency of the opportunity to receive the control information,
The terminal device is
a second processor;
a second transceiver;
the second processor, for the second transceiver;
receiving the message from the base station;
configured to cause the base station to send a response message to the message;
Communications system.
The plurality of parameter sets each have a different ratio of the duration of the search space per period to the period of the search space.
The communication system according to claim 17.
transmitting to the terminal device a message including information indicating that the information indicating the opportunity to receive the control information includes a plurality of parameter sets indicating the frequency of the opportunity to receive the control information;
receiving a response message to the message from the terminal device;
A method performed by a base station, comprising:
receiving from a base station a message including information indicating that the information indicating the opportunity to receive control information includes a plurality of sets of parameters indicating the frequency of the opportunity to receive the control information;
transmitting a response message to the message to the base station;
A method performed by a terminal device, comprising:
transmitting to the terminal device a message including information indicating that the information indicating the opportunity to receive the control information includes a plurality of parameter sets indicating the frequency of the opportunity to receive the control information;
receiving a response message to the message from the terminal device;
A non-transitory computer-readable medium that stores a program that causes a computer to perform certain tasks.
receiving from a base station a message including information indicating that the information indicating the opportunity to receive control information includes a plurality of sets of parameters indicating the frequency of the opportunity to receive the control information;
transmitting a response message to the message to the base station;
A non-transitory computer-readable medium that stores a program that causes a computer to perform certain tasks.