U.S. patent application number 17/219578 was filed with the patent office on 2021-10-14 for method and apparatus for downlink communication in communication system.
This patent application is currently assigned to ELECTRONICS AND TELECOMMUNICATIONS RESEARCH INSTITUTE. The applicant listed for this patent is ELECTRONICS AND TELECOMMUNICATIONS RESEARCH INSTITUTE. Invention is credited to Jae Heung KIM.
Application Number | 20210321276 17/219578 |
Document ID | / |
Family ID | 1000005565655 |
Filed Date | 2021-10-14 |
United States Patent
Application |
20210321276 |
Kind Code |
A1 |
KIM; Jae Heung |
October 14, 2021 |
METHOD AND APPARATUS FOR DOWNLINK COMMUNICATION IN COMMUNICATION
SYSTEM
Abstract
An operation method of a terminal in a communication system may
comprise receiving, from a base station, first information
indication suspension of a physical downlink control channel
(PDCCH) monitoring operation; in response to the first information,
suspending the PDCCH monitoring operation in a first period; and
restarting the PDCCH monitoring operation after the first period
ends.
Inventors: |
KIM; Jae Heung; (Sejong-si,
KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
ELECTRONICS AND TELECOMMUNICATIONS RESEARCH INSTITUTE |
Daejeon |
|
KR |
|
|
Assignee: |
ELECTRONICS AND TELECOMMUNICATIONS
RESEARCH INSTITUTE
Daejeon
KR
|
Family ID: |
1000005565655 |
Appl. No.: |
17/219578 |
Filed: |
March 31, 2021 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04W 24/08 20130101;
H04W 76/11 20180201; H04W 72/042 20130101; H04W 72/0453 20130101;
H04W 72/0493 20130101; H04L 1/0061 20130101; H04W 68/005 20130101;
H04W 72/0446 20130101 |
International
Class: |
H04W 24/08 20060101
H04W024/08; H04W 72/04 20060101 H04W072/04; H04W 68/00 20060101
H04W068/00; H04W 76/11 20060101 H04W076/11; H04L 1/00 20060101
H04L001/00 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 10, 2020 |
KR |
10-2020-0044096 |
Jul 8, 2020 |
KR |
10-2020-0084157 |
Jul 22, 2020 |
KR |
10-2020-0091044 |
Mar 25, 2021 |
KR |
10-2021-0038455 |
Claims
1. An operation method of a terminal in a communication system, the
operation method comprising: receiving, from a base station, first
information indication suspension of a physical downlink control
channel (PDCCH) monitoring operation; in response to the first
information, suspending the PDCCH monitoring operation in a first
period; and restarting the PDCCH monitoring operation after the
first period ends.
2. The operation method according to claim 1, further comprising
receiving configuration information for controlling the PDCCH
monitoring operation from the base station, wherein the first
period is indicated by the configuration information.
3. The operation method according to claim 2, wherein the
configuration information includes one or more of a start time of
the first period, a duration of the first period, an end time of
the first period, a restart time of the PDCCH monitoring operation,
information of a signaling occasion in which the first information
is transmitted and received, information of a control resource set
(CORESET) in which the first information is transmitted and
received, and information of a search space in which the first
information is transmitted and received.
4. The operation method according to claim 3, wherein the duration
of the first period is a multiple of a periodicity of the signaling
occasion.
5. The operation method according to claim 1, wherein the first
information is received through one or more of a radio resource
control (RRC) message, a medium access control (MAC) message, and a
physical (PHY) message.
6. The operation method according to claim 1, wherein the first
information is received using a radio network temporary identifier
(RNTI) configured for transmission and reception of the first
information.
7. The operation method according to claim 6, wherein the RNTI is a
terminal-specific RNTI allocated for the terminal or a common RNTI
allocated for a group including the terminal, and a cyclic
redundancy check (CRC) of downlink control information (DCI)
including the first information is scrambled by the RNTI.
8. An operation method of a terminal in a communication system, the
operation method comprising: receiving, from a base station, first
information indication execution of a physical downlink control
channel (PDCCH) monitoring operation; in response to the first
information, performing the PDCCH monitoring operation in a first
period; and suspending the PDCCH monitoring operation after the
first period ends.
9. The operation method according to claim 8, further comprising
receiving configuration information for controlling the PDCCH
monitoring operation from the base station, wherein the first
period is indicated by the configuration information.
10. The operation method according to claim 9, wherein the
configuration information includes one or more of a transmission
time of the first information, an offset between the transmission
time of the first information and the first period, a start time of
the first period, a duration of the first period, an end time of
the first period, information of a signaling occasion in which the
first information is transmitted and received, information of a
control resource set (CORESET) in which the first information is
transmitted and received, and information of a search space in
which the first information is transmitted and received.
11. The operation method according to claim 8, wherein the first
information is received through one or more of a radio resource
control (RRC) message, a medium access control (MAC) message, and a
physical (PHY) message.
12. The operation method according to claim 8, wherein the first
information is received using a radio network temporary identifier
(RNTI) configured for transmission and reception of the first
information.
13. The operation method according to claim 12, wherein the RNTI is
a terminal-specific RNTI allocated for the terminal or a common
RNTI allocated for a group including the terminal, and a cyclic
redundancy check (CRC) of downlink control information (DCI)
including the first information is scrambled by the RNTI.
14. The operation method according to claim 8, wherein the first
information is received before an offset from a start time of the
first period or in the first period, and the PDCCH monitoring
operation is performed to receive a paging message.
15. The operation method according to claim 8, wherein the first
information indicates execution of the PDCCH monitoring operation
for reception of a paging message, and the first information is
received according to a signaling occasion periodicity.
16. An operation method of a base station in a communication
system, the operation method comprising: generating configuration
information for controlling a physical downlink control channel
(PDCCH) monitoring operation; transmitting a radio resource control
(RRC) message including the configuration information to a
terminal; and transmitting first information indicating of a
control of the PDCCH monitoring operation to the terminal.
17. The operation method according to claim 16, wherein the first
information indicates suspension or execution of the PDCCH
monitoring operation.
18. The operation method according to claim 16, wherein the first
information is transmitted using a radio network temporary
identifier (RNTI) configured for transmission and reception of the
first information, and the RNTI is a terminal-specific RNTI
allocated for the terminal or a common RNTI allocated for a group
including the terminal.
19. The operation method according to claim 16, wherein the first
information is transmitted before an offset from a start time of an
execution period of the PDCCH monitoring operation or in the
execution period of the PDCCH monitoring operation, and the PDCCH
monitoring operation is performed by the terminal to receive a
paging message.
20. The operation method according to claim 16, wherein the
configuration information includes one or more of a start time of
an execution period of the PDCCH monitoring operation, a duration
of the execution period, an end time of the execution period, a
restart time of the PDCCH monitoring operation, a transmission time
of the first information, an offset between the first information
and the execution period, information of a signaling occasion in
which the first information is transmitted and received,
information of a control resource set (CORESET) in which the first
information is transmitted and received, and information of a
search space in which the first information is transmitted and
received.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to Korean Patent
Applications No. 10-2020-0044096 filed on Apr. 10, 2020, No.
10-2020-0084157 filed on Jul. 8, 2020, No. 10-2020-0091044 filed on
Jul. 22, 2020, and No. 10-2021-0038455 filed on Mar. 25, 2021 with
the Korean Intellectual Property Office (KIPO), the entire contents
of which are hereby incorporated by reference.
BACKGROUND
1. Technical Field
[0002] The present disclosure relates to a downlink communication
technique, and more specifically, to a technique of monitoring a
downlink control channel for reducing power consumption of a
terminal.
2. Related Art
[0003] With the development of information and communication
technology, various wireless communication technologies have been
developed. Typical wireless communication technologies include long
term evolution (LTE) and new radio (NR), which are defined in the
3rd generation partnership project (3GPP) standards. The LTE may be
one of 4th generation (4G) wireless communication technologies, and
the NR may be one of 5th generation (5G) wireless communication
technologies.
[0004] The communication system (hereinafter, a new radio (NR)
communication system) using a higher frequency band (e.g., a
frequency band of 6 GHz or above) than a frequency band (e.g., a
frequency band of 6 GHz or below) of the long term evolution (LTE)
(or, LTE-A) is being considered for processing of soaring wireless
data. The 5G communication system can support enhanced mobile
broadband (eMBB), ultra-reliable low-latency communication (URLLC),
massive machine type communication (mMTC), and the like.
[0005] Meanwhile, a millimeter frequency band (e.g., a frequency
band of 6 to 90 GHz) may be used to process rapidly increasing
data. A small base station may be used to overcome deterioration of
received signal performance due to path attenuation and reflection
of radio waves in a high frequency band (e.g., millimeter frequency
band). In a communication system supporting the millimeter
frequency band, instead of a small base station supporting all
functions of a radio protocol, a plurality of remote radio
transmission/reception blocks (e.g., remote radio heads (RRHs)) and
a centralized baseband processing function block may be
deployed.
[0006] That is, all functions of a radio protocol can be
distributedly supported in the remote radio transmission/reception
blocks and the baseband processing function block in a functional
split scheme. When the functional split technique is used, the
communication system may be configured by a plurality of
transmission and reception points (TRPs). The plurality of TRPs may
perform communications using a carrier aggregation scheme, a dual
connectivity scheme, a duplication transmission scheme, or the
like. In the communication system supporting the functional split
scheme, the carrier aggregation scheme, the dual connectivity
scheme, a bi-casting scheme, the duplication transmission scheme,
or the like, methods for reducing power consumption of a terminal
by controlling a monitoring operation on a downlink control channel
are required.
SUMMARY
[0007] Accordingly, exemplary embodiments of the present disclosure
are directed to providing methods and apparatuses for monitoring a
downlink control channel in a communication system.
[0008] According to a first exemplary embodiment of the present
disclosure, an operation method of a terminal in a communication
system may comprise: receiving, from a base station, first
information indication suspension of a physical downlink control
channel (PDCCH) monitoring operation; in response to the first
information, suspending the PDCCH monitoring operation in a first
period; and restarting the PDCCH monitoring operation after the
first period ends.
[0009] The operation method may further comprise receiving
configuration information for controlling the PDCCH monitoring
operation from the base station, wherein the first period is
indicated by the configuration information.
[0010] The configuration information may include one or more of a
start time of the first period, a duration of the first period, an
end time of the first period, a restart time of the PDCCH
monitoring operation, information of a signaling occasion in which
the first information is transmitted and received, information of a
control resource set (CORESET) in which the first information is
transmitted and received, and information of a search space in
which the first information is transmitted and received.
[0011] The duration of the first period may be a multiple of a
periodicity of the signaling occasion.
[0012] The first information may be received through one or more of
a radio resource control (RRC) message, a medium access control
(MAC) message, and a physical (PHY) message.
[0013] The first information may be received using a radio network
temporary identifier (RNTI) configured for transmission and
reception of the first information.
[0014] The RNTI may be a terminal-specific RNTI allocated for the
terminal or a common RNTI allocated for a group including the
terminal, and a cyclic redundancy check (CRC) of downlink control
information (DCI) including the first information may be scrambled
by the RNTI.
[0015] According to a second exemplary embodiment of the present
disclosure, an operation method of a terminal in a communication
system may comprise: receiving, from a base station, first
information indication execution of a physical downlink control
channel (PDCCH) monitoring operation; in response to the first
information, performing the PDCCH monitoring operation in a first
period; and suspending the PDCCH monitoring operation after the
first period ends.
[0016] The operation method may further comprise receiving
configuration information for controlling the PDCCH monitoring
operation from the base station, wherein the first period is
indicated by the configuration information.
[0017] The configuration information may include one or more of a
transmission time of the first information, an offset between the
transmission time of the first information and the first period, a
start time of the first period, a duration of the first period, an
end time of the first period, information of a signaling occasion
in which the first information is transmitted and received,
information of a control resource set (CORESET) in which the first
information is transmitted and received, and information of a
search space in which the first information is transmitted and
received.
[0018] The first information may be received through one or more of
a radio resource control (RRC) message, a medium access control
(MAC) message, and a physical (PHY) message.
[0019] The first information may be received using a radio network
temporary identifier (RNTI) configured for transmission and
reception of the first information.
[0020] The RNTI may be a terminal-specific RNTI allocated for the
terminal or a common RNTI allocated for a group including the
terminal, and a cyclic redundancy check (CRC) of downlink control
information (DCI) including the first information may be scrambled
by the RNTI.
[0021] The first information may be received before an offset from
a start time of the first period or in the first period, and the
PDCCH monitoring operation may be performed to receive a paging
message.
[0022] The first information may indicate execution of the PDCCH
monitoring operation for reception of a paging message, and the
first information may be received according to a signaling occasion
periodicity.
[0023] According to a third exemplary embodiment of the present
disclosure, an operation method of a base station in a
communication system may comprise: generating configuration
information for controlling a physical downlink control channel
(PDCCH) monitoring operation; transmitting a radio resource control
(RRC) message including the configuration information to a
terminal; and transmitting first information indicating of a
control of the PDCCH monitoring operation to the terminal.
[0024] The first information may indicate suspension or execution
of the PDCCH monitoring operation.
[0025] The first information may be transmitted using a radio
network temporary identifier (RNTI) configured for transmission and
reception of the first information, and the RNTI may be a
terminal-specific RNTI allocated for the terminal or a common RNTI
allocated for a group including the terminal.
[0026] The first information may be transmitted before an offset
from a start time of an execution period of the PDCCH monitoring
operation or in the execution period of the PDCCH monitoring
operation, and the PDCCH monitoring operation may be performed by
the terminal to receive a paging message.
[0027] The configuration information may include one or more of a
start time of an execution period of the PDCCH monitoring
operation, a duration of the execution period, an end time of the
execution period, a restart time of the PDCCH monitoring operation,
a transmission time of the first information, an offset between the
first information and the execution period, information of a
signaling occasion in which the first information is transmitted
and received, information of a control resource set (CORESET) in
which the first information is transmitted and received, and
information of a search space in which the first information is
transmitted and received.
[0028] According to the exemplary embodiments of the present
disclosure, a downlink control channel monitoring operation may be
controlled in consideration of the operation state of the terminal
(e.g., terminal mounted on a mobile means). For example, the base
station may transmit information indicating suspension of the
downlink control channel monitoring operation to the terminal, and
the terminal may suspend the downlink control channel monitoring
operation according to the indication of the base station. In
addition, the base station may transmit information indicating
execution of the downlink control channel monitoring operation to
the terminal, and the terminal may perform the downlink control
channel monitoring operation according to the indication of the
base station. In this case, the power consumption of the terminal
can be reduced, and the performance of the terminal can be
improved. Therefore, the performance of the communication system
can be improved.
BRIEF DESCRIPTION OF DRAWINGS
[0029] Exemplary embodiments of the present disclosure will become
more apparent by describing in detail embodiments of the present
disclosure with reference to the accompanying drawings, in
which:
[0030] FIG. 1 is a conceptual diagram illustrating a first
exemplary embodiment of a communication system;
[0031] FIG. 2 is a block diagram illustrating a first embodiment of
a communication node constituting a communication system;
[0032] FIG. 3 is a conceptual diagram illustrating a second
exemplary embodiment of a communication system;
[0033] FIG. 4 is a conceptual diagram illustrating a first
exemplary embodiment of a method for configuring bandwidth parts
(BWPs) in a communication system;
[0034] FIG. 5 is a conceptual diagram illustrating a first
exemplary embodiment of operation states of a terminal in a
communication system;
[0035] FIG. 6 is a timing diagram illustrating a first exemplary
embodiment of a PDCCH monitoring operation based on DL-SkipSig in a
communication system.
[0036] FIG. 7 is a timing diagram illustrating a first exemplary
embodiment of a PDCCH monitoring operation based on DL-MonitSig in
a communication system.
[0037] FIG. 8 is a timing diagram illustrating a first exemplary
embodiment of a PagingIndSig signaling method in a communication
system.
[0038] It should be understood that the above-referenced drawings
are not necessarily to scale, presenting a somewhat simplified
representation of various preferred features illustrative of the
basic principles of the disclosure. The specific design features of
the present disclosure, including, for example, specific
dimensions, orientations, locations, and shapes, will be determined
in part by the particular intended application and use
environment.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0039] Embodiments of the present disclosure are disclosed herein.
However, specific structural and functional details disclosed
herein are merely representative for purposes of describing
embodiments of the present disclosure. Thus, embodiments of the
present disclosure may be embodied in many alternate forms and
should not be construed as limited to embodiments of the present
disclosure set forth herein.
[0040] Accordingly, while the present disclosure is capable of
various modifications and alternative forms, specific embodiments
thereof are shown by way of example in the drawings and will herein
be described in detail. It should be understood, however, that
there is no intent to limit the present disclosure to the
particular forms disclosed, but on the contrary, the present
disclosure is to cover all modifications, equivalents, and
alternatives falling within the spirit and scope of the present
disclosure. Like numbers refer to like elements throughout the
description of the figures.
[0041] It will be understood that, although the terms first,
second, etc. may be used herein to describe various elements, these
elements should not be limited by these terms. These terms are only
used to distinguish one element from another. For example, a first
element could be termed a second element, and, similarly, a second
element could be termed a first element, without departing from the
scope of the present disclosure. As used herein, the term "and/or"
includes any and all combinations of one or more of the associated
listed items.
[0042] It will be understood that when an element is referred to as
being "connected" or "coupled" to another element, it can be
directly connected or coupled to the other element or intervening
elements may be present. In contrast, when an element is referred
to as being "directly connected" or "directly coupled" to another
element, there are no intervening elements present. Other words
used to describe the relationship between elements should be
interpreted in a like fashion (i.e., "between" versus "directly
between," "adjacent" versus "directly adjacent," etc.).
[0043] The terminology used herein is for the purpose of describing
particular embodiments only and is not intended to be limiting of
the present disclosure. As used herein, the singular forms "a,"
"an" and "the" are intended to include the plural forms as well,
unless the context clearly indicates otherwise. It will be further
understood that the terms "comprises," "comprising," "includes"
and/or "including," when used herein, specify the presence of
stated features, integers, steps, operations, elements, and/or
components, but do not preclude the presence or addition of one or
more other features, integers, steps, operations, elements,
components, and/or groups thereof.
[0044] Unless otherwise defined, all terms (including technical and
scientific terms) used herein have the same meaning as commonly
understood by one of ordinary skill in the art to which this
present disclosure belongs. It will be further understood that
terms, such as those defined in commonly used dictionaries, should
be interpreted as having a meaning that is consistent with their
meaning in the context of the relevant art and will not be
interpreted in an idealized or overly formal sense unless expressly
so defined herein.
[0045] Hereinafter, exemplary embodiments of the present disclosure
will be described in greater detail with reference to the
accompanying drawings. In order to facilitate general understanding
in describing the present disclosure, the same components in the
drawings are denoted with the same reference signs, and repeated
description thereof will be omitted.
[0046] A communication system to which exemplary embodiments
according to the present disclosure are applied will be described.
The communication system to which the exemplary embodiments
according to the present disclosure are applied is not limited to
the contents described below, and the exemplary embodiments
according to the present disclosure may be applied to various
communication networks. Here, the communication system may be used
in the same sense as a communication network.
[0047] FIG. 1 is a conceptual diagram illustrating a first
exemplary embodiment of a communication system.
[0048] Referring to FIG. 1, a communication system 100 may comprise
a plurality of communication nodes 110-1, 110-2, 110-3, 120-1,
120-2, 130-1, 130-2, 130-3, 130-4, 130-5, and 130-6. The plurality
of communication nodes may support 4th generation (4G)
communication (e.g., long term evolution (LTE), LTE-advanced
(LTE-A)), 5th generation (5G) communication (e.g., new radio (NR)),
or the like. The 4G communication may be performed in a frequency
band of 6 gigahertz (GHz) or below, and the 5G communication may be
performed in a frequency band of 6 GHz or above.
[0049] For example, for the 4G and 5G communications, the plurality
of communication nodes may support a code division multiple access
(CDMA) based communication protocol, a wideband CDMA (WCDMA) based
communication protocol, a time division multiple access (TDMA)
based communication protocol, a frequency division multiple access
(FDMA) based communication protocol, an orthogonal frequency
division multiplexing (OFDM) based communication protocol, a
filtered OFDM based communication protocol, a cyclic prefix OFDM
(CP-OFDM) based communication protocol, a discrete Fourier
transform spread OFDM (DFT-s-OFDM) based communication protocol, an
orthogonal frequency division multiple access (OFDMA) based
communication protocol, a single carrier FDMA (SC-FDMA) based
communication protocol, a non-orthogonal multiple access (NOMA)
based communication protocol, a generalized frequency division
multiplexing (GFDM) based communication protocol, a filter bank
multi-carrier (FBMC) based communication protocol, a universal
filtered multi-carrier (UFMC) based communication protocol, a space
division multiple access (SDMA) based communication protocol, or
the like.
[0050] Also, the communication system 100 may further include a
core network. When the communication system 100 supports the 4G
communication, the core network may comprise a serving gateway
(S-GW), a packet data network (PDN) gateway (P-GW), a mobility
management entity (MME), and the like. When the communication
system 100 supports the 5G communication, the core network may
comprise a user plane function (UPF), a session management function
(SMF), an access and mobility management function (AMF), and the
like.
[0051] Meanwhile, each of the plurality of communication nodes
110-1, 110-2, 110-3, 120-1, 120-2, 130-1, 130-2, 130-3, 130-4,
130-5, and 130-6 constituting the communication system 100 may have
the following structure.
[0052] FIG. 2 is a block diagram illustrating a first embodiment of
a communication node constituting a communication system.
[0053] Referring to FIG. 2, a communication node 200 may comprise
at least one processor 210, a memory 220, and a transceiver 230
connected to the network for performing communications. Also, the
communication node 200 may further comprise an input interface
device 240, an output interface device 250, a storage device 260,
and the like. Each component included in the communication node 200
may communicate with each other as connected through a bus 270.
[0054] However, each component included in the communication node
200 may be connected to the processor 210 via an individual
interface or a separate bus, rather than the common bus 270. For
example, the processor 210 may be connected to at least one of the
memory 220, the transceiver 230, the input interface device 240,
the output interface device 250, and the storage device 260 via a
dedicated interface.
[0055] The processor 210 may execute a program stored in at least
one of the memory 220 and the storage device 260. The processor 210
may refer to a central processing unit (CPU), a graphics processing
unit (GPU), or a dedicated processor on which methods in accordance
with embodiments of the present disclosure are performed. Each of
the memory 220 and the storage device 260 may be constituted by at
least one of a volatile storage medium and a non-volatile storage
medium. For example, the memory 220 may comprise at least one of
read-only memory (ROM) and random access memory (RAM).
[0056] Referring again to FIG. 1, the communication system 100 may
comprise a plurality of base stations 110-1, 110-2, 110-3, 120-1,
and 120-2, and a plurality of terminals 130-1, 130-2, 130-3, 130-4,
130-5, and 130-6. The communication system 100 including the base
stations 110-1, 110-2, 110-3, 120-1, and 120-2 and the terminals
130-1, 130-2, 130-3, 130-4, 130-5, and 130-6 may be referred to as
an `access network`. Each of the first base station 110-1, the
second base station 110-2, and the third base station 110-3 may
form a macro cell, and each of the fourth base station 120-1 and
the fifth base station 120-2 may form a small cell. The fourth base
station 120-1, the third terminal 130-3, and the fourth terminal
130-4 may belong to cell coverage of the first base station 110-1.
Also, the second terminal 130-2, the fourth terminal 130-4, and the
fifth terminal 130-5 may belong to cell coverage of the second base
station 110-2. Also, the fifth base station 120-2, the fourth
terminal 130-4, the fifth terminal 130-5, and the sixth terminal
130-6 may belong to cell coverage of the third base station 110-3.
Also, the first terminal 130-1 may belong to cell coverage of the
fourth base station 120-1, and the sixth terminal 130-6 may belong
to cell coverage of the fifth base station 120-2.
[0057] Here, each of the plurality of base stations 110-1, 110-2,
110-3, 120-1, and 120-2 may refer to a Node-B, a evolved Node-B
(eNB), a base transceiver station (BTS), a radio base station, a
radio transceiver, an access point, an access node, a road side
unit (RSU), a radio remote head (RRH), a transmission point (TP), a
transmission and reception point (TRP), an eNB, a gNB, or the
like.
[0058] Here, each of the plurality of terminals 130-1, 130-2,
130-3, 130-4, 130-5, and 130-6 may refer to a user equipment (UE),
a terminal, an access terminal, a mobile terminal, a station, a
subscriber station, a mobile station, a portable subscriber
station, a node, a device, an Internet of things (IoT) device, a
mounted apparatus (e.g., a mounted module/device/terminal or an
on-board device/terminal, etc.), or the like.
[0059] Meanwhile, each of the plurality of base stations 110-1,
110-2, 110-3, 120-1, and 120-2 may operate in the same frequency
band or in different frequency bands. The plurality of base
stations 110-1, 110-2, 110-3, 120-1, and 120-2 may be connected to
each other via an ideal backhaul or a non-ideal backhaul, and
exchange information with each other via the ideal or non-ideal
backhaul. Also, each of the plurality of base stations 110-1,
110-2, 110-3, 120-1, and 120-2 may be connected to the core network
through the ideal or non-ideal backhaul. Each of the plurality of
base stations 110-1, 110-2, 110-3, 120-1, and 120-2 may transmit a
signal received from the core network to the corresponding terminal
130-1, 130-2, 130-3, 130-4, 130-5, or 130-6, and transmit a signal
received from the corresponding terminal 130-1, 130-2, 130-3,
130-4, 130-5, or 130-6 to the core network.
[0060] Also, each of the plurality of base stations 110-1, 110-2,
110-3, 120-1, and 120-2 may support multi-input multi-output (MIMO)
transmission (e.g., a single-user MIMO (SU-MIMO), multi-user MIMO
(MU-MIMO), massive MIMO, or the like), coordinated multipoint
(CoMP) transmission, carrier aggregation (CA) transmission,
transmission in an unlicensed band, device-to-device (D2D)
communications (or, proximity services (ProSe)), or the like. Here,
each of the plurality of terminals 130-1, 130-2, 130-3, 130-4,
130-5, and 130-6 may perform operations corresponding to the
operations of the plurality of base stations 110-1, 110-2, 110-3,
120-1, and 120-2, and operations supported by the plurality of base
stations 110-1, 110-2, 110-3, 120-1, and 120-2. For example, the
second base station 110-2 may transmit a signal to the fourth
terminal 130-4 in the SU-MIMO manner, and the fourth terminal 130-4
may receive the signal from the second base station 110-2 in the
SU-MIMO manner. Alternatively, the second base station 110-2 may
transmit a signal to the fourth terminal 130-4 and fifth terminal
130-5 in the MU-MIMO manner, and the fourth terminal 130-4 and
fifth terminal 130-5 may receive the signal from the second base
station 110-2 in the MU-MIMO manner.
[0061] The first base station 110-1, the second base station 110-2,
and the third base station 110-3 may transmit a signal to the
fourth terminal 130-4 in the CoMP transmission manner, and the
fourth terminal 130-4 may receive the signal from the first base
station 110-1, the second base station 110-2, and the third base
station 110-3 in the CoMP manner. Also, each of the plurality of
base stations 110-1, 110-2, 110-3, 120-1, and 120-2 may exchange
signals with the corresponding terminals 130-1, 130-2, 130-3,
130-4, 130-5, or 130-6 which belongs to its cell coverage in the CA
manner. Each of the base stations 110-1, 110-2, and 110-3 may
control D2D communications between the fourth terminal 130-4 and
the fifth terminal 130-5, and thus the fourth terminal 130-4 and
the fifth terminal 130-5 may perform the D2D communications under
control of the second base station 110-2 and the third base station
110-3.
[0062] Hereinafter, operation methods of a communication node in a
communication system will be described. Even when a method (e.g.,
transmission or reception of a data packet) performed at a first
communication node among communication nodes is described, the
corresponding second communication node may perform a method (e.g.,
reception or transmission of the data packet) corresponding to the
method performed at the first communication node. That is, when an
operation of a terminal is described, the corresponding base
station may perform an operation corresponding to the operation of
the terminal. Conversely, when an operation of the base station is
described, the corresponding terminal may perform an operation
corresponding to the operation of the base station.
[0063] In the following exemplary embodiments, a signaling message
may be a signaling message including system information, an RRC
signaling message, a MAC signaling message (e.g., MAC control
element (CE)), and/or a PHY signaling message (e.g., downlink
control information (DCI), uplink control information (UCI),
sidelink control information (SCI)). The signaling message may be
referred to as a `control message`. In this case, the control
message may be a control message including system information, an
RRC control message, a MAC control message, and/or a PHY control
message.
[0064] Meanwhile, in a communication system, a base station may
perform all functions (e.g., remote radio transmission and
reception function, baseband processing function, and the like) of
a communication protocol. Alternatively, the remote radio
transmission and reception function among all the functions of the
communication protocol may be performed by a transmission reception
point (TRP) (e.g., flexible TRP (f-TRP)), and the baseband
processing function among all the functions of the communication
protocol may be performed by a baseband unit (BBU) block. The TRP
may be a remote radio head (RRH), a radio unit (RU), a transmission
point (TP), or the like. The BBU block may include at least one BBU
or at least one digital unit (DU). The BBU block may be referred to
as a `BBU pool`, a `centralized BBU`, or the like. The TRP may be
connected to the BBU block via a wired fronthaul link or a wireless
fronthaul link. A communication system composed of a backhaul link
and a fronthaul link may be as follows. When a functional-split
technique of the communication protocol is applied, the TRP may
selectively perform some functions of the BBU or some functions of
a medium access control (MAC) layer or a radio link control (RLC)
layer.
[0065] FIG. 3 is a conceptual diagram illustrating a second
exemplary embodiment of a communication system.
[0066] Referring to FIG. 3, a communication system may include a
core network and an access network. The core network supporting the
4G communication may include an MME, an S-GW, a P-GW, and the like.
The core network supporting the 5G communication may include an AMF
310-1, an UPF 310-2, a PDN-GW 310-3, and the like. The access
network may include a macro base station 320, a small base station
330, TRPs 350-1 and 350-2, terminals 360-1, 360-2, 360-3, 360-4,
and 360-5, and the like. The macro base station 320 or the small
base station 330 may be connected to a termination node of the core
network via a wired backhaul. The TRPs 350-1 and 350-2 may support
the remote radio transmission and reception function among all the
functions of the communication protocol, and the baseband
processing function for the TRPs 350-1 and 350-2 may be performed
by the BBU block 340. The BBU block 340 may belong to the access
network or the core network. The communication nodes (e.g., MME,
S-GW, P-GW, AMF, UPF, PDN-GW, macro base station, small base
station, TRPs, terminals, and BBU block) belonging to the
communication system may be configured identically or similarly to
the communication node 200 shown in FIG. 2.
[0067] The macro base station 320 may be connected to the core
network (e.g., AMF 310-1, UPF 310-2, MME, S-GW) using a wired
backhaul link or a wireless backhaul link, and may provide
communication services to the terminals 360-3 and 360-4 based on a
communication protocol (e.g., 4G communication protocol, 5G
communication protocol). The small base station 330 may be
connected to the core network (e.g., AMF 310-1, UPF 310-2, MME,
S-GW) using a wired backhaul link or a wireless backhaul link, and
may provide communication services to the terminal 360-5 based on a
communication protocol (e.g., 4G communication protocol, 5G
communication protocol).
[0068] The BBU block 340 may be located in the AMF 310-1, the UPF
310-2, the MME, the S-GW, or the macro base station 320.
Alternatively, the BBU block 340 may be located independently of
each the AMF 310-1, the UPF 310-2, the MME, the S-GW, and the macro
base station 320. For example, the BBU block 340 may be configured
as a logical function block between the macro base station 320 and
the AMF 310-1 (or UPF 310-2). The BBU block 340 may support the
plurality of TRPs 350-1 and 350-2, and may be connected to each of
the plurality of TRPs 350-1 and 350-2 using a wired fronthaul link
or a wireless fronthaul link. That is, the link between the BBU
block 340 and the TRPs 350-1 and 350-2 may be referred to as a
`fronthaul link`.
[0069] The first TRP 350-1 may be connected to the BBU block 340
via a wired fronthaul link or a wireless fronthaul link, and
provide communication services to the first terminal 360-1 based on
a communication protocol (e.g., 4G communication protocol, 5G
communication protocol). The second TRP 350-2 may be connected to
the BBU block 340 via a wired fronthaul link or a wireless
fronthaul link, and provide communication services to the second
terminal 360-2 based on a communication protocol (e.g., 4G
communication protocol, 5G communication protocol).
[0070] The communication system including the access network, the
Xhaul network, and the core network may be referred to as an
`integrated communication system`. The communication nodes (e.g.,
MME, S-GW, P-GW, AMF, UPF, BBU block, distributed unit (DU),
central unit (CU), base station, TRP, terminal, and the like)
belonging to the integrated communication system may be configured
identically or similarly to the communication node 200 shown in
FIG. 2. The communication nodes belonging to the Xhaul network may
be connected using Xhaul links, and the Xhaul link may be a
backhaul link or a fronthaul link.
[0071] Also, the UPF (or, S-GW) of the integrated communication
system may refer to a termination communication node of the core
network that exchanges packets (e.g., control information, data)
with the base station, and the AMF (or, MME) of the integrated
communication system may refer to a communication node in the core
network, which performs control functions in a radio access section
(or, interface) of the terminal. Here, each of the backhaul link,
fronthaul link, Xhaul link, DU, CU, BBU block, S-GW, MME, AMF, and
UPF may be referred to as a different term according to a function
(e.g., function of the Xhaul network, function of the core network)
of a communication protocol depending on a radio access technology
(RAT).
[0072] In order to perform a mobility support function and a radio
resource management function, the base station may transmit a
synchronization signal (e.g., a synchronization signal/physical
broadcast channel (SS/PBCH) block) and/or a reference signal. In
order to support multiple numerologies, frame formats supporting
symbols having different lengths may be configured. In this case,
the terminal may perform a monitoring operation on the
synchronization signal and/or reference signal in a frame according
to an initial numerology, a default numerology, or a default symbol
length. Each of the initial numerology and the default numerology
may be applied to a frame format applied to radio resources in
which a UE-common search space is configured, a frame format
applied to radio resources in which a control resource set
(CORESET) #0 of the NR communication system is configured, and/or a
frame format applied to radio resources in which a synchronization
symbol burst capable of identifying a cell in the NR communication
system is transmitted.
[0073] The frame format may refer to information of configuration
parameters (e.g., values of the configuration parameters, offset,
index, identifier, range, periodicity, interval, duration, etc.)
for a subcarrier spacing, control channel (e.g., CORESET), symbol,
slot, and/or reference signal. The base station may inform the
frame format to the terminal using system information and/or a
control message (e.g., dedicated control message).
[0074] The terminal connected to the base station may transmit a
reference signal (e.g., uplink dedicated reference signal) to the
base station using resources configured by the corresponding base
station. For example, the uplink dedicated reference signal may
include a sounding reference signal (SRS). In addition, the
terminal connected to the base station may receive a reference
signal (e.g., downlink dedicated reference signal) from the base
station in resources configured by the corresponding base station.
The downlink dedicated reference signal may be a channel state
information-reference signal (CSI-RS), a phase tracking-reference
signal (PT-RS), a demodulation-reference signal (DM-RS), or the
like. Each of the base station and the terminal may perform a beam
management operation through monitoring on a configured beam or an
active beam based on the reference signal.
[0075] For example, the base station 320 may transmit a
synchronization signal and/or a reference signal so that the first
terminal 360-3 located within its service area can search for
itself to perform downlink synchronization maintenance, beam
configuration, or link monitoring operations. The first terminal
360-3 connected to the base station 320 (e.g., serving base
station) may receive physical layer radio resource configuration
information for connection configuration and radio resource
management from the base station 320. The physical layer radio
resource configuration information may mean configuration
parameters included in RRC control messages of the LTE
communication system or the NR communication system. For example,
the resource configuration information may include
PhysicalConfigDedicated, PhysicalCellGroupConfig,
PDCCH-Config(Common), PDSCH-Config(Common), PDCCH-ConfigSIB1,
ConfigCommon, PUCCH-Config(Common), PUSCH-Config(Common),
BWP-DownlinkCommon, BWP-UplinkCommon, ControlResourceSet,
RACH-ConfigCommon, RACH-ConfigDedicated, RadioResourceConfigCommon,
RadioResourceConfigDedicated, ServingCellConfig,
ServingCellConfigCommon, and the like.
[0076] The radio resource configuration information may include
parameter values such as a configuration (or allocation)
periodicity of a signal (or radio resource) according to a frame
format of the base station (or transmission frequency), time
resource allocation information for transmission, frequency
resource allocation information for transmission, a transmission
(or allocation) time, or the like. In order to support multiple
numerologies, the frame format of the base station (or transmission
frequency) may mean a frame format having different symbol lengths
according to a plurality of subcarrier spacings within one radio
frame. For example, the number of symbols constituting each of a
mini-slot, slot, and subframe that exist within one radio frame
(e.g., a frame of 10 ms) may be configured differently. [0077]
Configuration information of transmission a frequency and a frame
format of a base station [0078] Transmission frequency
configuration information: information on all transmission carriers
(i.e., cell-specific transmission frequency) in the base station,
information on bandwidth parts (BWPs) in the base station,
information on a transmission reference time or time difference
between transmission frequencies of the base station (e.g., a
transmission periodicity or offset parameter indicating the
transmission reference time (or time difference) of the
synchronization signal), etc. [0079] Frame format configuration
information: configuration parameters of a mini-slot, slot, and
subframe having a different symbol length according to a subcarrier
spacing [0080] Configuration information of a downlink reference
signal (e.g., channel state information-reference signal (CSI-RS),
common reference signal (Common-RS), etc.) [0081] Configuration
parameters such as a transmission periodicity, transmission
position, code sequence, or masking (or scrambling) sequence for a
reference signal, which are commonly applied within the coverage of
the base station (or beam). [0082] Configuration information of an
uplink control signal [0083] Configuration parameters such as a
sounding reference signal (SRS), uplink beam sweeping (or beam
monitoring) reference signal, uplink grant-free radio resources
(or, preambles), etc. [0084] Configuration information of a
physical downlink control channel (e.g., PDCCH) [0085]
Configuration parameters such as a reference signal for PDCCH
demodulation, beam common reference signal (e.g., reference signal
that can be received by all terminals within a beam coverage), beam
sweeping (or beam monitoring) reference signal, reference signal
for channel estimation, etc. [0086] Configuration information of a
physical uplink control channel (e.g., PUCCH) [0087] Scheduling
request signal configuration information [0088] Configuration
information for a feedback (acknowledgement (ACK) or negative ACK
(NACK)) transmission resource in a hybrid automatic repeat request
(HARD) procedure [0089] Number of antenna ports, antenna array
information, beam configuration or beam index mapping information
for application of beamforming techniques [0090] Configuration
information of a downlink signal and/or an uplink signal (or uplink
access channel resource) for beam sweeping (or beam monitoring)
[0091] Configuration information of parameters for beam
configuration, beam recovery, beam reconfiguration, or radio link
re-establishment operation, beam change operation within the same
base station, reception signal of a beam triggering handover
execution to another base station, timers controlling the
above-described operations, etc.
[0092] In case of a radio frame format that supports a plurality of
symbol lengths for supporting multi-numerology, the configuration
(or allocation) periodicity of the parameter, the time resource
allocation information, the frequency resource allocation
information, the transmission time, and/or the allocation time,
which constitute the above-described information, may be
information configured for each corresponding symbol length (or
subcarrier spacing).
[0093] In the following exemplary embodiments, `Resource-Config
information` may be a control message including one or more
parameters of the physical layer radio resource configuration
information. In addition, the `Resource-Config information` may
mean attributes and/or configuration values (or range) of
information elements (or parameters) delivered by the control
message. The information elements (or parameters) delivered by the
control message may be radio resource configuration information
applied commonly to the entire coverage of the base station (or,
beam) or radio resource configuration information allocated
dedicatedly to a specific terminal (or, specific terminal group). A
terminal group may include one or more terminals.
[0094] The configuration information included in the
`Resource-Config information` may be transmitted through one
control message or different control messages according to the
attributes of the configuration information. The beam index
information may not express the index of the transmission beam and
the index of the reception beam explicitly. For example, the beam
index information may be expressed using a reference signal mapped
or associated with the corresponding beam index or an index (or
identifier) of a transmission configuration indicator (TCI) state
for beam management.
[0095] Therefore, the terminal operating in the RRC connected state
may receive a communication service through a beam (e.g., beam
pair) configured between the terminal and the base station. For
example, when a communication service is provided using beam
configuration (e.g., beam pairing) between the base station and the
terminal, the terminal may perform a search operation or a
monitoring operation of a radio channel by using a synchronization
signal (e.g., SS/PBCH block) and/or a reference signal (e.g.,
CSI-RS) of a beam configured with the base station, or a beam that
can be received. Here, the expression that a communication service
is provided through a beam may mean that a packet is transmitted
and received through an active beam among one or more configured
beams. In the NR communication system, the expression that a beam
is activated may mean that a configured TCI state is activated.
[0096] The terminal may operate in the RRC idle state or the RRC
inactive state. In this case, the terminal may perform a search
operation (e.g., monitoring operation) of a downlink channel by
using parameter(s) obtained from system information or common
Resource-Config information. In addition, the terminal operating in
the RRC idle state or the RRC inactive state may attempt to access
by using an uplink channel (e.g., a random access channel or a
physical layer uplink control channel). Alternatively, the terminal
may transmit control information by using an uplink channel.
[0097] The terminal may recognize or detect a radio link problem by
performing a radio link monitoring (RLM) operation. Here, the
expression that a radio link problem is detected may mean that
physical layer synchronization configuration or maintenance for a
radio link has a problem. For example, the expression that a radio
link problem is detected may mean that it is detected that the
physical layer synchronization between the base station and the
terminal is not maintained during a preconfigured time. When a
radio link problem is detected, the terminal may perform a recovery
operation of the radio link. When the radio link is not recovered,
the terminal may declare a radio link failure (RLF) and perform a
re-establishment procedure of the radio link.
[0098] The procedure for detecting a physical layer problem of a
radio link, procedure for recovering a radio link, procedure for
detecting (or declaring) a radio link failure, and procedure for
re-establishing a radio link according to the RLM operation may be
performed by functions of a layer 1 (e.g., physical layer), a layer
2 (e.g., MAC layer, RLC layer, PDCP layer, etc.), and/or a layer 3
(e.g., RRC layer) of the radio protocol.
[0099] The physical layer of the terminal may monitor a radio link
by receiving a downlink synchronization signal (e.g., primary
synchronization signal (PSS), secondary synchronization signal
(SSS), SS/PBCH block) and/or a reference signal. In this case, the
reference signal may be a base station common reference signal,
beam common reference signal, or terminal (or terminal group)
specific reference signal (e.g., dedicated reference signal
allocated to a terminal (or terminal group)). Here, the common
reference signal may be used for channel estimation operations of
all terminals located within the corresponding base station or beam
coverage (or service area). The dedicated reference signal may be
used for a channel estimation operation of a specific terminal or a
specific terminal group located within the base station or beam
coverage.
[0100] Accordingly, when the base station or the beam (e.g.,
configured beam between the base station and the terminal) is
changed, the dedicated reference signal for beam management may be
changed. The beam may be changed based on the configuration
parameter(s) between the base station and the terminal. A procedure
for changing the configured beam may be required. The expression
that a beam is changed in the NR communication system may mean that
an index (or identifier) of a TCI state is changed to an index of
another TCI state, that a TCI state is newly configured, or that a
TCI state is changed to an active state. The base station may
transmit system information including configuration information of
the common reference signal to the terminal. The terminal may
obtain the common reference signal based on the system information.
In a handover procedure, synchronization reconfiguration procedure,
or connection reconfiguration procedure, the base station may
transmit a dedicated control message including the configuration
information of the common reference signal to the terminal.
[0101] The configured beam information may include at least one of
a configured beam index (or identifier), configured TCI state index
(or identifier), configuration information of each beam (e.g.,
transmission power, beam width, vertical angle, horizontal angle),
transmission and/or reception timing information of each beam
(e.g., subframe index, slot index, mini-slot index, symbol index,
offset), reference signal information corresponding to each beam,
and reference signal identifier.
[0102] In the exemplary embodiments, the base station may be a base
station installed in the air. For example, the base station may be
installed on an unmanned aerial vehicle (e.g., drone), a manned
aircraft, or a satellite.
[0103] The terminal may receive configuration information of the
base station (e.g., identification information of the base station)
from the base station through one or more of an RRC message, MAC
message, and PHY message, and may identify a base station with
which the terminal performs a beam monitoring operation, radio
access operation, and/or control (or data) packet transmission and
reception operation.
[0104] The result of the measurement operation (e.g., beam
monitoring operation) for the beam may be reported through a
physical layer control channel (e.g., PUCCH) and/or a MAC message
(e.g., MAC CE, control PDU). Here, the result of the beam
monitoring operation may be a measurement result for one or more
beams (or beam groups). For example, the result of the beam
monitoring operation may be a measurement result for beams (or beam
groups) according to a beam sweeping operation of the base
station.
[0105] The base station may obtain the result of the beam
measurement operation or the beam monitoring operation from the
terminal, and may change the properties of the beam or the
properties of the TCI state based on the result of the beam
measurement operation or the beam monitoring operation. The beam
may be classified into a primary beam, a secondary beam, a reserved
(or candidate) beam, an active beam, and a deactivated beam
according to its properties. The TCI state may be classified into a
primary TCI state, a secondary TCI state, a reserved (or candidate)
TCI state, a serving TCI state, a configured TCI state, an active
TCI state, and a deactivated TCI state according to its properties.
Each of the primary TCI state and the secondary TCI state may be
assumed to be an active TCI state and a serving TCI state. The
reserved (or candidate) TCI state may be assumed to be a
deactivated TCI state or a configured TCI state.
[0106] A procedure for changing the beam (or TCI state) property
may be controlled by the RRC layer and/or the MAC layer. When the
procedure for changing the beam (or TCI state) property is
controlled by the MAC layer, the MAC layer may inform the higher
layer of information regarding a change in the beam (or TCI state)
property. The information regarding the change in the beam (or TCI
state) property may be transmitted to the terminal through a MAC
message and/or a physical layer control channel (e.g., PDCCH). The
information regarding the change in the beam (or TCI state)
property may be included in downlink control information (DCI) or
uplink control information (UCI). The information regarding the
change in the beam (or TCI state) property may be expressed as a
separate indicator or field.
[0107] The terminal may request to change the property of the TCI
state based on the result of the beam measurement operation or the
beam monitoring operation. The terminal may transmit control
information (or feedback information) requesting to change the
property of the TCI state to the base station by using one or more
of a PHY message, a MAC message, and an RRC message. The control
information (or feedback information, control message, control
channel) requesting to change the property of the TCI state may be
configured using one or more of the configured beam information
described above.
[0108] The change in the property of the beam (or TCI state) may
mean a change from the active beam to the deactivated beam, a
change from the deactivated beam to the active beam, a change from
the primary beam to the secondary beam, a change from the secondary
beam to the primary beam, a change from the primary beam to the
reserved (or candidate) beam, or a change from the reserved (or
candidate) beam to the primary beam. The procedure for changing the
property of the beam (or TCI state) may be controlled by the RRC
layer and/or the MAC layer. The procedure for changing the property
of the beam (or TCI state) may be performed through partial
cooperation between the RRC layer and the MAC layer.
[0109] When a plurality of beams are allocated, one or more beams
among the plurality of beams may be configured as beam(s) for
transmitting physical layer control channels. For example, the
primary beam and/or the secondary beam may be used for transmission
and reception of a physical layer control channel (e.g., PHY
message). Here, the physical layer control channel may be a PDCCH
or a PUCCH. The physical layer control channel may be used for
transmission of one or more among scheduling information (e.g.,
radio resource allocation information, modulation and coding scheme
(MCS) information), feedback information (e.g., channel quality
indication (CQI), preceding matrix indicator (PMI), HARQ ACK, HARQ
NACK), resource request information (e.g., scheduling request
(SR)), result of the beam monitoring operation for supporting
beamforming functions, TCI state ID, and measurement information
for the active beam (or deactivated beam).
[0110] The physical layer control channel may be configured to be
transmitted through the primary beam of downlink. In this case, the
feedback information may be transmitted and received through the
primary beam, and data scheduled by the control information may be
transmitted and received through the secondary beam. The physical
layer control channel may be configured to be transmitted through
the primary beam of uplink. In this case, the resource request
information (e.g., SR) and/or the feedback information may be
transmitted and received through the primary beam.
[0111] In the procedure of allocating the plurality of beams (or
the procedure of configuring the TCI states), the allocated (or
configured) beam indexes, information indicating a spacing between
the beams, and/or information indicating whether contiguous beams
are allocated may be transmitted and received through a signaling
procedure between the base station and the terminal. The signaling
procedure of the beam allocation information may be performed
differently according to status information (e.g., movement speed,
movement direction, location information) of the terminal and/or
the quality of the radio channel. The base station may obtain the
status information of the terminal from the terminal.
Alternatively, the base station may obtain the status information
of the terminal through another method.
[0112] The radio resource information may include parameter(s)
indicating frequency domain resources (e.g., center frequency,
system bandwidth, PRB index, number of PRBs, CRB index, number of
CRBs, subcarrier index, frequency offset, etc.) and parameter(s)
indicating time domain resources (e.g., radio frame index, subframe
index, transmission time interval (TTI), slot index, mini-slot
index, symbol index, time offset, and periodicity, length, or
window of transmission period (or reception period)). In addition,
the radio resource information may further include a hopping
pattern of radio resources, information for beamforming (e.g., beam
shaping) operations (e.g., beam configuration information, beam
index), and information on resources occupied according to
characteristics of a code sequence (or bit sequence, signal
sequence).
[0113] The name of the physical layer channel and/or the name of
the transport channel may vary according to the type (or attribute)
of data, the type (or attribute) of control information, a
transmission direction (e.g., uplink, downlink, sidelink), and the
like.
[0114] The reference signal for beam (or TCI state) or radio link
management may be a synchronization signal (e.g., PSS, SSS, SS/PBCH
block), CSI-RS, PT-RS, SRS, DM-RS, or the like. The reference
parameter(s) for reception quality of the reference signal for beam
(or TCI state) or radio link management may include a measurement
time unit, a measurement time interval, a reference value
indicating an improvement in reception quality, a reference value
indicating a deterioration in reception quality, or the like. Each
of the measurement time unit and the measurement time interval may
be configured in units of an absolute time (e.g., millisecond,
second), TTI, symbol, slot, frame, subframe, scheduling
periodicity, operation periodicity of the base station, or
operation periodicity of the terminal.
[0115] The reference value indicating the change in reception
quality may be configured as an absolute value (dBm) or a relative
value (dB). In addition, the reception quality of the reference
signal for beam (or TCI state) or radio link management may be
expressed as a reference signal received power (RSRP), a reference
signal received quality (RSRQ), a received signal strength
indicator (RSSI), a signal-to-noise ratio (SNR), a
signal-to-interference ratio (SIR), or the like.
[0116] Meanwhile, in the NR communication system using a millimeter
frequency band, flexibility for a channel bandwidth operation for
packet transmission may be secured based on a bandwidth part (BWP)
concept. The base station may configure up to 4 BWPs having
different bandwidths to the terminal. The BWPs may be independently
configured for downlink and uplink. That is, downlink BWPs may be
distinguished from uplink BWPs. Each of the BWPs may have a
different subcarrier spacing as well as a different bandwidth. For
example, BWPs may be configured as follows.
[0117] FIG. 4 is a conceptual diagram illustrating a first
exemplary embodiment of a method for configuring bandwidth parts
(BWPs) in a communication system.
[0118] As shown in FIG. 4, a plurality of bandwidth parts (e.g.,
BWPs #1 to #4) may be configured within a system bandwidth of the
base station. The BWPs #1 to #4 may be configured not to be larger
than the system bandwidth of the base station. The bandwidths of
the BWPs #1 to #4 may be different, and different subcarrier
spacings may be applied to the BWPs #1 to #4. For example, the
bandwidth of the BWP #1 may be 10 MHz, and the BWP #1 may have a 15
kHz subcarrier spacing. The bandwidth of the BWP #2 may be 40 MHz,
and the BWP #2 may have a 15 kHz subcarrier spacing. The bandwidth
of the BWP #3 may be 10 MHz, and the BWP #3 may have a 30 kHz
subcarrier spacing. The bandwidth of the BWP #4 may be 20 MHz, and
the BWP #4 may have a 60 kHz subcarrier spacing.
[0119] The BWPs may be classified into an initial BWP (e.g., first
BWP), an active BWP (e.g., activated BWP), and a default BWP. The
terminal may perform an initial access procedure (e.g., access
procedure) with the base station in the initial BWP. One or more
BWPs may be configured through an RRC connection configuration
message, and one BWP among the one or more BWPs may be configured
as the active BWP. Each of the terminal and the base station may
transmit and receive packets in the active BWP among the configured
BWPs. Therefore, the terminal may perform a monitoring operation on
control channels for packet transmission and reception in the
active BWP.
[0120] The terminal may switch the operating BWP from the initial
BWP to the active BWP or the default BWP. Alternatively, the
terminal may switch the operating BWP from the active BWP to the
initial BWP or the default BWP. The BWP switching operation may be
performed based on an indication of the base station or a timer.
The base station may transmit information indicating the BWP
switching to the terminal using one or more of an RRC message, a
MAC message (e.g., MAC control element (CE)), and a PHY message
(e.g., DCI). The terminal may receive the information indicating
the BWP switching from the base station, and may switch the
operating BWP of the terminal to a BWP indicated by the received
information.
[0121] When a random access (RA) resource is not configured in the
active uplink (UL) BWP in the NR communication system, the terminal
may switch the operating BWP of the terminal from the active UL BWP
to the initial UL BWP in order to perform a random access
procedure. The operating BWP may be a BWP in which the terminal
performs communication (e.g., transmission and reception operation
of a signal and/or channel).
[0122] Measurement operations (e.g., monitoring operations) for
beam (or TCI state) or radio link management may be performed at
the base station and/or the terminal. The base station and/or the
terminal may perform the measurement operations (e.g., monitoring
operations) according to parameter(s) configured for the
measurement operations (e.g., monitoring operations). The terminal
may report a measurement result according to parameter(s)
configured for measurement reporting.
[0123] When a reception quality of a reference signal according to
the measurement result meets a preconfigured reference value and/or
a preconfigured timer condition, the base station may determine
whether to perform a beam (or, radio link) management operation, a
beam switching operation, or a beam deactivation (or, activation)
operation according to a beam blockage situation. When it is
determined to perform a specific operation, the base station may
transmit a message triggering execution of the specific operation
to the terminal. For example, the base station may transmit a
control message for instructing the terminal to execute the
specific operation to the terminal. The control message may include
configuration information of the specific operation.
[0124] When a reception quality of a reference signal according to
the measurement result meets a preconfigured reference value and/or
a preconfigured timer condition, the terminal may report the
measurement result to the base station. Alternatively, the terminal
may transmit to the base station a control message triggering a
beam (or, radio link) management operation, a beam switching
operation (or a TCI state ID change operation, a property change
operation), or a beam deactivation operation (or a beam activation
operation) according to a beam blockage situation. The control
message may request to perform a specific operation.
[0125] A basic procedure for beam (or TCI state) management through
the radio link monitoring may include a beam failure detection
(BFD) procedure, a beam recovery (BR) request procedure, and the
like for a radio link. An operation of determining whether to
perform the beam failure detection procedure and/or the beam
recovery request procedure, an operation triggering execution of
the beam failure detection procedure and/or the beam recovery
request procedure, and a control signaling operation for the beam
failure detection procedure and/or the beam recovery request
procedure may be performed by one or more of the PHY layer, the MAC
layer, and the RRC layer.
[0126] FIG. 5 is a conceptual diagram illustrating a first
exemplary embodiment of operation states of a terminal in a
communication system.
[0127] As shown in FIG. 5, operation states of the terminal may be
classified into an RRC connected state, an RRC inactive state, and
an RRC idle state. When the terminal operates in the RRC connected
state or the RRC inactive state, a radio access network (RAN)
(e.g., a control function block of the RAN) and the base station
may store and manage RRC connection configuration information
and/or context information (e.g., RRC context information, AS
context information) of the corresponding terminal.
[0128] The terminal operating in the RRC connected state may
receive configuration information of physical layer control
channels and/or reference signals required for maintaining
connection configuration and transmission/reception of data from
the base station. The reference signal may be a reference signal
for demodulating the data. Alternatively, the reference signal may
be a reference signal for channel quality measurement or
beamforming. Therefore, the terminal operating in the RRC connected
state may transmit and receive the data without delay.
[0129] When the terminal operates in the RRC inactive state,
mobility management functions/operations identical or similar to
mobility management functions/operations supported in the RRC idle
state may be supported for the corresponding terminal. That is,
when the terminal operates in the RRC inactive state, a data bearer
for transmitting and receiving data may not be configured, and
functions of the MAC layer may be deactivated. Accordingly, the
terminal operating in the RRC inactive state may transition the
operation state of the terminal from the RRC inactive state to the
RRC connected state by performing the non-initial access procedure
to transmit data. Alternatively, the terminal operating in the RRC
inactive state may transmit data having a limited size, data having
a limited quality of service, and/or data associated with a limited
service.
[0130] When the terminal operates in the RRC idle state, there may
be no connection configuration between the terminal and the base
station, and the RRC connection configuration information and/or
context information (e.g., RRC context information, AS context
information) of the terminal may not be stored in the RAN (e.g., a
control function block of the RAN) and the base station. In order
to transition the operation state of the terminal from the RRC idle
state to the RRC connected state, the terminal may perform the
initial access procedure. Alternatively, when the initial access
procedure is performed, the operation state of the terminal may
transition from the RRC idle state to the RRC inactive state
according to determination of the base station.
[0131] The terminal may transition from the RRC idle state to the
RRC inactive state by performing the initial access procedure or a
separate access procedure defined for the RRC inactive state. When
a limited service is provided to the terminal, the operation state
of the terminal may transition from the RRC idle state to the RRC
inactive state. Alternatively, depending on capability of the
terminal, the operation state of the terminal may transition from
the RRC idle state to the RRC inactive state.
[0132] The base station and/or the control function block of the
RAN may configure condition(s) for transitioning to the RRC
inactive sate by considering one or more of the type, capability,
and service (e.g., a service currently being provided and a service
to be provided) of the terminal, and may control the operation for
transitioning to the RRC inactive state based on the configured
condition(s). When the base station allows the transition to the
RRC inactive state or when the transition to the RRC inactive state
is configured to be allowed, the operation state of the terminal
may be transitioned from the RRC connected state or the RRC idle
state to the RRC inactive state.
[0133] A control function block of the base station and/or RAN may
configure a condition(s) of transitioning to the RRC inactive state
in consideration of one or more of the type, capability, and
service (e.g., service currently being provided, service to be
provided) of the terminal, and may control an operation of
transition to the RRC inactive state based on the configured
condition(s). When the base station allows the operation of
transition to the RRC inactive state or when the terminal is
configured to be able to transition to the RRC inactive state, the
operation state of the terminal may be transitioned from the RRC
connected state or the RRC idle state to the RRC inactive
state.
[0134] The base station may transmit a DCI (hereinafter referred to
as `scheduling DCI`) including scheduling information of a downlink
resource (e.g., PDSCH) and/or an uplink resource (e.g., PUSCH) on a
PDCCH. In addition, the DCI may further include slot format
information, a transmit power control (TPC) command, and the like.
A terminal (e.g., terminal operating in the RRC connected state)
may perform a monitoring operation on a PDCCH in order to receive
the scheduling DCI. The terminal may perform a PDCCH monitoring
operation using a radio network temporary identifier (RNTI)
allocated (or, configured) to the terminal. When a DCI masked by
the RNTI (e.g., scheduling identifier) is detected, the terminal
may identify information element(s) included in the DCI by
performing a decoding operation on the corresponding DCI. That is,
the terminal may obtain control information from the DCI. The
terminal may receive downlink data from the base station based on
information element(s) included in the DCI. Alternatively, the
terminal may transmit uplink data to the base station based on the
information element(s) included in the DCI.
[0135] Here, the RNTI (e.g., scheduling identifier) may be a cell
(C)-RNTI, a temporary cell (TC)-RNTI, a configured scheduling
(CS)-RNTI, a slot format indication (SFI)-RNTI, a semi-persistent
channel state information (SP-CSI)-RNTI, a modulation and coding
scheme (MCS)-C-RNTI, a transmit power control sounding reference
signal (TPC-SRS)-RNTI, a TPC-PUSCH-RNTI, a TPC-PUCCH-RNTI, a system
information (SI)-RNTI, a paging (P)-RNTI, a random access
(RA)-RNTI, a MSGB-RNTI, an interruption (INT)-RNTI, a power saving
(PS)-RNTI, a cancellation indication (CI)-RNTI, a sidelink
(SL)-RNTI, an SL configured scheduling (SLCS)-RNTI, a predefined
uplink resource (PUR)-RNTI, or the like.
[0136] If a DCI is not received by the PDCCH monitoring operation,
the terminal may not perform a transmission/reception operation
until a next PDCCH monitoring time. If a DCI (e.g., effective DCI)
is not received, the terminal may continuously perform the PDCCH
monitoring operation. In this case, power consumption of the
terminal may increase due to the unnecessary PDCCH monitoring
operations. In order to reduce the power consumption of the
terminal, the PDCCH monitoring operation may be controlled.
[0137] A signaling for controlling the PDCCH monitoring operation
(e.g., DL-SkipSig) may indicate suspension of the PDCCH monitoring
operation to the terminal (or terminal group). In exemplary
embodiments, `suspension` may have a meaning including `stop`.
Alternatively, `stop` may have a meaning including `suspension`.
The base station may transmit a DL-SkipSig to the terminal. When
the DL-SkipSig is received from the base station, the terminal may
not perform a PDCCH monitoring operation in a preconfigured
period.
[0138] The base station may transmit, to the terminal,
configuration information of signaling (e.g., DL-SkipSig) for
controlling the PDCCH monitoring operation through one or a
combination of two or more of a higher layer message (e.g., RRC
message), a MAC message (e.g., MAC control element (CE)), and a PHY
message (e.g., DCI). The configuration information of DL-SkipSig
may include one or more parameters described in Table 1 below.
TABLE-US-00001 TABLE 1 DL-SkipSig configuration information A time
at which the PDCCH monitoring operation is suspended (e.g., a start
time of a period (i.e., suspension period) in which the PDCCH
monitoring operation is stopped (i.e., suspended)) A suspension
period in which the PDCCH monitoring operation is suspended (e.g.,
a duration of the period in which the PDCCH monitoring operation is
stopped). The suspension period may be configured with a window
and/or a timer. A time at which the suspension of the PDCCH
monitoring operation ends (e.g., an end time of the period (i.e.,
suspension period) in which the PDCCH monitoring operation is
stopped (i.e., suspended)) A restart time of the PDCCH monitoring
operation DL-SkipSig signaling occasion (or, occasion periodicity)
Offset(s) for parameter(s) for DL-SkipSig signaling Information of
a control resource set (CORESET) and/or a search space in which the
DL- SkipSig signaling is transmitted Information indicating a
target (e.g., BWP, terminal, and/or terminal group) of the
suspension and/or restart of the PDCCH monitoring operation
[0139] The parameter(s) defined in Table 1 may be set in units of
radio frames, subframes, slots, minislots, or symbols. The
suspension period (e.g., time window, period corresponding to the
timer, duration) of the PDCCH monitoring operation may be set as a
multiple of a DL-SkipSig signaling occasion (or periodicity).
[0140] The DL-SkipSig configuration information may be configured
for each terminal or each terminal group. When the DL-SkipSig
configuration information is configured for each terminal group, a
parameter indicating a specific terminal group may be included in
the DL-SkipSig configuration information.
[0141] A radio resource in which the information (e.g., DL-SkipSig
information) indicating suspension and/or restart of the PDCCH
monitoring operation is transmitted may be predefined (or fixed).
In this case, the DL-SkipSig configuration information may include
configuration parameter(s) for the radio resource in which the
DL-SkipSig information is transmitted in the time domain and/or the
frequency domain. That is, the signaling for controlling the PDCCH
monitoring operation (e.g., DL-SkipSig) may be transmitted in the
resource (e.g., downlink radio resource) predefined in the time
domain and/or the frequency domain. Accordingly, the terminal may
detect the DL-SkipSig from the predefined resource (e.g.,
configured resource), and may suspend or restart the PDCCH
monitoring according to the detected DL-SkipSig.
[0142] The signaling (e.g., DL-SkipSig) for controlling suspension
and restart of the PDCCH monitoring operation may be transmitted
and received using an RNTI (e.g., scheduling identifier). The
DL-SkipSig may be transmitted using one or a combination of two or
more of the RNTI, system information, an RRC message, a MAC
message, and a PHY message.
[0143] When the DL-SkipSig is transmitted and received using the
RNTI, a scheduling identifier (e.g., SkipSig-RNTI) for the
DL-SkipSig may be configured. The SkipSig-RNTI may be uniquely
allocated to a specific terminal to support the function of
suspending the PDCCH monitoring operation. Alternatively, an RNTI
uniquely allocated to a specific terminal may be configured as the
SkipSig-RNTI. That is, a terminal-specific RNTI may be configured
as the RNTI for transmission and reception of the DL-SkipSig. A DCI
(e.g., PDCCH) itself having a cyclic redundancy check (CRC)
scrambled by the SkipSig-RNTI may mean the DL-SkipSig. The
SkipSig-RNTI may be configured as a scheduling identifier (e.g.,
common RNTI) commonly applied to one or more terminal groups within
the base station. Accordingly, the base station may transmit
control information for suspension and/or restart the PDCCH
monitoring in units of a terminal or a terminal group by using the
SkipSig-RNTI.
[0144] When the SkipSig-RNTI is received (e.g., detected), the
terminal may temporarily suspend (i.e., stop) the PDCCH monitoring
operation in a suspension period (e.g., window, period
corresponding to the timer, duration) according to the DL-SkipSig
configuration information. Alternatively, the terminal may
temporarily suspend (i.e., stop) the PDCCH monitoring operation
until an end time or a restart time of the suspension period
according to the DL-SkipSig configuration information. When the
suspension period of the PDCCH monitoring operation ends or when
the restart time of the PDCCH monitoring operation arrives, the
terminal may perform the PDCCH monitoring operation again. The
terminal may receive a DCI by performing the PDCCH monitoring
operation, and may perform an operation (e.g., downlink reception
operation, uplink transmission operation) based on information
element(s) included in the DCI.
[0145] When the DL-SkipSig, which controls suspension and restart
of the PDCCH monitoring operation, is transmitted and received
using an RNTI (e.g., scheduling identifier), a scheduling
identifier indicating suspension of the PDCCH monitoring operation
may be configured differently from a scheduling identifier
indicating restart of the PDCCH monitoring operation. In this case,
when a scheduling identifier of the DL-SkipSig received in the
DL-SkipSig signaling occasion (or period) indicates suspension of
the PDCCH monitoring operation, the terminal may suspend the PDCCH
monitoring operation. When a scheduling identifier of the
DL-SkipSig received in the DL-SkipSig signaling occasion (or
period) indicates restart of the PDCCH monitoring operation, the
terminal may perform the PDCCH monitoring operation again.
[0146] The signaling operation of the DL-SkipSig for controlling
suspension and restart of the PDCCH monitoring operation may be
performed based on a DCI. For example, a specific field in the DCI
may indicate suspension and/or restart of the PDCCH monitoring
operation.
[0147] When control information in the DCI indicates that the PDCCH
monitoring operation is to be suspended, the terminal may suspend
the PDCCH monitoring operation after the DCI is received. When the
DCI includes information indicating a time point for the suspension
of the PDCCH monitoring operation, the terminal may suspend the
PDCCH monitoring operation at the time point indicated by the
corresponding DCI.
[0148] The DL-SkipSig configuration information may be
preconfigured using system information and/or a control message
(e.g., RRC message, MAC message, PHY message). In this case, the
terminal may suspend the PDCCH monitoring operation during a
suspension period (e.g., period corresponding to the window and/or
the timer) according to the DL-SkipSig configuration information.
Alternatively, the terminal may suspend the PDCCH monitoring
operation until an end time or a restart time according to the
DL-SkipSig configuration information. When the suspension period of
the PDCCH monitoring operation ends or when the restart time of the
PDCCH monitoring operation arrives, the terminal may perform the
PDCCH monitoring operation again. The terminal may receive a DCI by
performing the PDCCH monitoring operation, and may perform an
operation (e.g., downlink reception operation, uplink transmission
operation) according information element(s) included in the
DCI.
[0149] Alternatively, suspension and restart of the PDCCH
monitoring operation may be indicated by a DCI. In this case, the
DCI may include one or more parameters defined in Table 1. Each
parameter included in the DCI may be set in units of radio frames,
subframes, slots, minislots, or symbols. The suspension period
(e.g., period corresponding to the window and/or the timer) of the
PDCCH monitoring operation may be set as a multiple of the
DL-SkipSig signaling occasion (or periodicity).
[0150] The terminal may receive the DCI from the base station, and
may suspend and/or restart the PDCCH monitoring operation according
to DL-SkipSig information included in the DCI. For example, the
terminal may suspend the PDCCH monitoring operation at a suspension
time according to the DL-SkipSig information included in the DCI.
The terminal may perform the PDCCH monitoring operation again at a
restart time according to the DL-SkipSig information included in
the DCI. The terminal may receive a DCI by performing the PDCCH
monitoring operation, and may perform an operation (e.g., downlink
reception operation, uplink transmission operation) according to
information element(s) included in the DCI.
[0151] When the DL-SkipSig signaling operation is performed based
on a DCI, a specific bit in the DCI may be used to control the
PDCCH monitoring operation. For example, a specific bit set to a
first value (e.g., 1) may indicate suspension of the PDCCH
monitoring operation. In addition, the specific bit set to the
first value may indicate that data (e.g., packet) to be transmitted
to the terminal (or terminal group) through a PDSCH does not exist
in a scheduling period to which the specific bit is applied (e.g.,
resource scheduled by the corresponding DCI). Therefore, when the
specific bit in the DCI is set to the first value, the terminal (or
terminal group) may not perform a reception operation (e.g.,
demodulation operation, decoding operation) in a PDSCH radio
resource (e.g., resource scheduled by the corresponding DCI) within
the corresponding scheduling period. The specific bit set to a
second value (e.g., 0) in the DCI may indicate execution of the
PDCCH monitoring operation without suspension. Alternatively, the
specific bit set to the second value in the DCI may indicate
restart of the PDCCH monitoring operation.
[0152] When suspension and/or restart of the PDCCH monitoring
operation is indicated using the control information (e.g.,
specific field, specific bit) in the DCI, the DCI may include
information indicating a terminal group. In this case, all
terminals belonging to the terminal group indicated by the DCI may
suspend and/or restart the PDCCH monitoring operation according to
the control information included in the DCI.
[0153] The base station may transmit the DCI for controlling
suspension and/or restart of the PDCCH monitoring operation to the
terminal by using the SkipSig-RNTI. In this case, the terminal (or
terminal group) may control (e.g., suspend and/or restart) the
PDCCH monitoring operation based on the SkipSig-RNTI and/or the
DCI.
[0154] Alternatively, the signaling operation of the DL-SkipSig for
controlling suspension and/or restart of the PDCCH monitoring
operation may be performed based on a MAC control message (e.g.,
MAC subheader, MAC (sub)PDU, etc.). In this case, the base station
may instruct the terminal to perform a suspension operation and/or
a restart operation of the PDCCH monitoring operation by using the
MAC control message. When the MAC control message indicates
suspension of the PDCCH monitoring operation, the MAC layer of the
terminal may transmit an internal signal (e.g., primitive or
triggering signal) indicating suspension of the PDCCH monitoring
operation to the PHY layer of the terminal.
[0155] When the internal signal indicating suspension of the PDCCH
monitoring operation is received from the MAC layer, the PHY layer
of the terminal may suspend the PDCCH monitoring operation in a
suspension period (e.g., period corresponding to the window and/or
the timer) according to the DL-SkipSig configuration information.
Alternatively, the PHY layer of the terminal may suspend the PDCCH
monitoring operation until a suspension end time or a restart time
according to the DL-SkipSig configuration information. Here, the
DL-SkipSig configuration information may be transmitted from the
MAC layer to the PHY layer. Alternatively, the DL-SkipSig
configuration information may be preconfigured in the PHY layer.
When the suspension period of the monitoring operation ends or when
the restart time of the PDCCH monitoring operation arrives, the
terminal may perform the PDCCH monitoring operation again. The
terminal may receive a DCI by performing the PDCCH monitoring
operation, and may perform an operation (e.g., downlink reception
operation, uplink transmission operation) according to information
element(s) included in the DCI.
[0156] FIG. 6 is a timing diagram illustrating a first exemplary
embodiment of a PDCCH monitoring operation based on DL-SkipSig in a
communication system.
[0157] As shown in FIG. 6, terminals 601-1 and 601-2 may receive
DCI(s) (e.g., PDCCH(s)) including scheduling information and/or
control information from a base station (S602-1 to S602-6). When a
DL-SkipSig 604 is received, the terminals 601-1 and 601-2 may
suspend DL monitoring operations. In exemplary embodiments, the DL
monitoring operation may refer to a PDCCH monitoring operation
and/or a DCI monitoring operation. The terminals 601-1 and 601-2
may receive the DL-SkipSig 604 in an active DL BWP, a radio
resource region configured for the DL-SkipSig signaling operation
or a CORESET/search space configured for the DL-SkipSig signaling
operation.
[0158] The terminal may obtain DL-SkipSig configuration information
through system information and/or a separate control message. Each
of the system information and the separate control message may
include the DL-SkipSig configuration information (e.g.,
parameter(s) defined in Table 1), DL-MonitSig configuration
information (e.g., parameter(s) defined in Table 2), and/or
PagingIndSig configuration information (e.g., parameter(s) defined
in Table 3). The terminal may suspend the DL monitoring operation
during a suspension period (e.g., 603-1 to 603-5; period
corresponding to the window and/or the timer) indicated by the
DL-SkipSig configuration information or the DL-SkipSig 604. The
suspension period may be referred to as `DL monitoring skip
duration`. When the suspension period (e.g., DL monitoring skip
duration) ends or when a restart time of the DL monitoring
operation arrives, the terminal may perform the DL monitoring
operation again (S602-2, S602-3, S602-5, S602-6).
[0159] As another method for reducing the power consumption of the
terminal by reducing unnecessary PDCCH monitoring operations,
signaling (e.g., DL-MonitSig) that controls the PDCCH monitoring
operation of the terminal by instructing the terminal (or terminal
group) to receive a DCI may be used. The base station may transmit
a DL-MonitSig to a terminal (or terminal group). When the
DL-MonitSig is received from the base station, the terminal (or
terminal group) may perform the PDCCH monitoring operation during a
preconfigured period or until a next PDCCH monitoring occasion.
When the MonitSig is not received from the base station, the
terminal (or terminal group) may not perform the PDCCH monitoring
operation during a preconfigured period, until a timer ends, or
until a next PDCCH monitoring occasion.
[0160] The base station may transmit DL-MonitSig configuration
information for controlling the PDCCH monitoring operation of the
terminal to the terminal using system information and/or a control
message (e.g., RRC message, MAC message, PHY message). The
DL-MonitSig configuration information may include one or more
parameters defined in Table 2 below.
TABLE-US-00002 TABLE 2 DL-MonitSig configuration information A
start time of the PDCCH monitoring operation An execution period of
the PDCCH monitoring operation (e.g., duration of the execution
period). The execution period may be configured with a window
and/or a timer. An end time of the PDCCH monitoring operation
DL-MonitSig signaling occasion (or, occasion periodicity) Offset(s)
for parameter(s) for DL-MonitSig signaling Information of a control
resource set (CORESET) and/or a search space in which the DL-
MonitSig signaling is transmitted Information indicating a target
(e.g., BWP, terminal, and/or terminal group) of the execution of
the PDCCH monitoring operation
[0161] Each of the parameters defined in Table 2 may be set in
units of radio frames, subframes, slots, minislots, or symbols. The
execution period of the PDCCH monitoring operation (e.g., period
corresponding to a window and/or the timer) may be set as a
multiple of the DL-MonitSig signaling occasion (or periodicity).
The DL-MonitSig configuration information may be configured for
each terminal or each terminal group. When the DL-MonitSig
configuration information is configured for each terminal group, a
parameter indicating a specific terminal group may be included in
the DL-MonitSig configuration information.
[0162] A radio resource in which a DL-MonitSig indicating execution
of the PDCCH monitoring operation is transmitted may be predefined
(or fixed). In this case, the DL-MonitSig configuration information
may include configuration parameter(s) for the radio resource in
which the DL-MonitSig is transmitted in the time domain and/or the
frequency domain. That is, the Dl-MonitSig for indicating execution
of the PDCCH monitoring operation may be transmitted in the
downlink radio resource preconfigured in the time domain and/or the
frequency domain. Accordingly, the terminal (or, terminal group)
may detect the DL-MonitSig from the preconfigured resource, and may
determine whether to perform the PDCCH monitoring according to the
detected DL-MonitSig.
[0163] The signaling operation of the DL-MonitSig for controlling
execution of the PDCCH monitoring operation may be performed using
one or a combination of two or more of an RNTI (e.g., scheduling
identifier), a DCI (e.g., a control field included in the DCI), a
MAC control message (e.g., MAC subheader or MAC (sub)PDU), and an
RRC control message.
[0164] When the signaling operation of DL-MonitSig is performed
based on an RNTI (e.g., scheduling identifier), a scheduling
identifier (e.g., MonitSig-RNTI) may be configured for the
signaling operation of DL-MonitSig. Here, the scheduling identifier
(e.g., MonitSig-RNTI) for the signaling operation of DL-MonitSig
may refer to a scheduling identifier uniquely allocated to a
specific terminal to support the DL-MonitSig signaling function.
One scheduling identifier among the terminal-specific scheduling
identifiers may be configured as the MonitSig-RNTI. That is, a
terminal-specific RNTI may be configured as the RNTI for the
signaling operation of DL-MonitSig. Accordingly, a DCI (e.g.,
PDCCH) itself having a CRC scrambled by the above-described
scheduling identifier (e.g., MonitSig-RNTI) may be used for the
signaling operation of DL-MonitSig. The MonitSig-RNTI for the
DL-MonitSig signaling operation may be configured as a scheduling
identifier commonly applied to one or more terminal groups in the
base station. Accordingly, the base station may transmit control
information (e.g., DL-MonitSig) indicating whether to perform the
PDCCH monitoring operation in units of a terminal or a terminal
group by using the MonitSig-RNTI.
[0165] When the MonitSig-RNTI is received (e.g., detected), the
terminal may perform the PDCCH monitoring operation during a
preconfigured execution period (e.g., period corresponding to the
window and/or the timer), until an end time of the PDCCH monitoring
operation, or until a next PDCCH monitoring occasion according to
the DL-MonitSig configuration information. When the execution
period of the PDCCH monitoring operation ends or when the next
PDCCH monitoring occasion arrives, the terminal may identify
whether a DL-MonitSig exists by performing the PDCCH monitoring
operation. If a DL-MonitSig for the terminal or terminal group
(e.g., terminal group to which the terminal belongs) is not
detected, the terminal may not perform the PDCCH monitoring
operation until a next PDCCH monitoring occasion.
[0166] Alternatively, the signaling operation of DL-MonitSig may be
performed based on a DCI. A control field (e.g., information
element, control information) in the DCI may indicate whether to
perform the PDCCH monitoring operation.
[0167] The DL-MonitSig configuration information may be
preconfigured using system information and/or a control message. In
this case, according to the DL-MonitSig configuration information,
the terminal may perform the PDCCH monitoring operation during an
execution period (e.g., period corresponding to the window and/or
the timer), until an end time of the PDCCH monitoring operation, or
until a next PDCCH monitoring occasion. When the execution period
of the PDCCH monitoring operation ends or when the next PDCCH
monitoring occasion arrives, the terminal may identify whether a
DL-MonitSig exists by performing the PDCCH monitoring
operation.
[0168] Alternatively, the execution of the PDCCH monitoring
operation may be indicated based on a DCI. In this case, the DCI
may include one or more parameters defined in Table 2 above. Each
parameter (e.g., configuration information) may be set in units of
radio frames, subframes, slots, minislots, or symbols. The
execution period of the PDCCH monitoring operation (e.g., period
corresponding to the window and/or the timer) may be set as a
multiple of the DL-MonitSig signaling occasion (or
periodicity).
[0169] The terminal may receive the DCI from the base station, and
may determine whether to perform the PDCCH monitoring operation
according to DL-MonitSig information included in the DCI. For
example, the terminal may start a PDCCH monitoring operation at a
start time according to the DL-MonitSig information included in the
DCI. The terminal may perform the PDCCH monitoring operation during
an execution period (e.g., period corresponding to the window
and/or the timer), until an end time of the PDCCH monitoring
operation, or until a next PDCCH monitoring occasion by using a
preconfigured parameter or a parameter (e.g., DL-MonitSig
parameter) in the DCI. When the execution period of the PDCCH
monitoring operation ends or when the next PDCCH monitoring
occasion arrives, the terminal may identify whether a DL-MonitSig
exists.
[0170] When the DL-MonitSig signaling operation is performed based
on a DCI, a specific bit in the DCI may be used to control the
PDCCH monitoring operation. For example, a specific bit set to a
first value (e.g., 1) may indicate execution of the PDCCH
monitoring operation, and a specific bit set to a second value
(e.g., 0) may indication suspension of the PDCCH monitoring
operation. In addition, the specific bit set to the second value
may indicate that data (e.g., packet) to be transmitted to the
terminal (or terminal group) through a PDSCH radio resource does
not exist in a corresponding scheduling period. Therefore, when the
specific bit in the DCI is set to the second value, the terminal
(or terminal group) may not perform a reception operation (e.g.,
demodulation operation, decoding operation) in a PDSCH radio
resource in the corresponding scheduling period.
[0171] When execution of the PDCCH monitoring operation is
indicated using the control information in the DCI, the DCI may
further include information indicating a specific terminal group.
All terminals belonging to the terminal group indicated by the DCI
may determine whether to perform the PDCCH monitoring operation
based on the DCI, and may perform the operation according to the
determination result.
[0172] The base station may transmit a DCI indication execution of
the PDCCH monitoring operation to the terminal using the
above-described MonitSig-RNTI. In this case, the terminal (or
terminal group) may determine whether to perform the PDCCH
monitoring operation using the MonitSig-RNTI and/or the control
information included in the DCI.
[0173] Alternatively, the DL-MonitSig signaling operation may be
performed based on a MAC control message (e.g., MAC subheader or
MAC (sub)PDU). The base station may indicate to the terminal
whether to perform the PDCCH monitoring operation by using the MAC
control message. When the MAC control message indicates execution
of the PDCCH monitoring operation, the MAC layer of the terminal
may transmit an internal signal (e.g., primitive or triggering
signal) indicating execution of the PDCCH monitoring operation to
the PHY layer of the terminal. When the internal signal indicating
execution of the PDCCH monitoring operation is received from the
MAC layer, the PHY layer of the terminal may perform the PDCCH
monitoring operation during an execution period (e.g., period
corresponding to the window and/or the timer) of the PDCCH
monitoring operation, until an end time of the PDCCH monitoring
operation, or until a next PDCCH monitoring occasion according to
the DL-MonitSig configuration information. Here, the DL-MonitSig
configuration information may be preconfigured in the PHY layer.
Alternatively, the DL-MonitSig configuration information may be
transmitted from the MAC layer to the PHY layer. When the execution
period of the PDCCH monitoring operation ends or when the next
PDCCH monitoring occasion arrives, the terminal may identify
whether a DL-MonitSig signaling exists by receiving a DCI.
[0174] FIG. 7 is a timing diagram illustrating a first exemplary
embodiment of a PDCCH monitoring operation based on DL-MonitSig in
a communication system.
[0175] As shown in FIG. 7, terminals 701-1 and 701-2 may receive a
DL-MonitSig 704 indicating execution of the DL monitoring operation
from a base station, and receive DCI(s) (e.g., PDCCH(s)) including
scheduling information and/or control information from the base
station (S702-1 to S702-5). The terminals may receive the
DL-MonitSig 704 from the base station in an active DL BWP, a radio
resource region configured for the DL-MonitSig signaling operation,
and/or a CORESET/search space configured for the DL-MonitSig
signaling operation.
[0176] When the DL-MonitSig 704 is received, the terminal may
perform the PDCCH monitoring operation (e.g., DL monitoring
operation) in an execution period of the PDCCH monitoring operation
(e.g., DL monitoring duration in FIG. 7) indicated by DL-MonitSig
configuration information configured by system information and/or a
separate control message or the DL-MonitSig. Each of the system
information and the separate control message may include the
DL-SkipSig configuration information (e.g., parameter(s) defined in
Table 1), the DL-MonitSig configuration information (e.g.,
parameter(s) defined in Table 2), and/or PagingIndSig configuration
information (e.g., parameter(s) defined in Table 3). When the DL
monitoring duration ends or when an end time of the DL monitoring
operation arrives, the terminal may suspend the downlink monitoring
operation until a next DL-MonitSig signaling occasion (or,
reception period, reception time) (703-1 to 703-5). The period in
which the downlink monitoring operation is suspended may be a DL
monitoring skip duration.
[0177] The signaling information of DL-SkipSig or DL-MonitSig that
controls execution of the PDCCH monitoring operation may be
transmitted in a specific radio resource (e.g., specific resource
region) for PDCCH transmission. Here, `signaling information is
transmitted in a specific resource region` may mean `a radio
resource for PDCCH transmission is configured in the frequency
domain and/or time domain`, `a search space and/or CORESET in which
the PDCCH is transmitted is configured`, and/or `signaling
information of DL-SkipSig or DL-MonitSig (e.g., DCI including the
signaling information of DL-SkipSig or DL-MonitSig is first
transmitted and detected in a step of receiving (e.g., demodulating
and decoding) a DCI`. For example, in order to configure a search
space in which the PDCCH is transmitted, an index of the search
space in which the DL-SkipSig or DL-MonitSig is transmitted may be
allocated. The index of the search space in which the DL-SkipSig or
DL-MonitSig is transmitted may be included in the DL-SkipSig
configuration information or the DL-MonitSig configuration
information.
[0178] As a method for allowing the DCI including the signaling
information DL-SkipSig or DL-MonitSig to be detected first, an
aggregation level of control channel elements (CCEs) constituting
the DCI may be set to the lowest (e.g., level=1). Alternatively,
the signaling information of DL-SkipSig or DL-MonitSig may include
information of the aggregation level of the corresponding DCI. In
this case, in the step of receiving the DCI, the terminal may
preferentially identify the signaling information of DL-SkipSig or
DL-MonitSig.
[0179] Meanwhile, the terminal may receive the DL-SkipSig (604
shown in FIG. 6) or the DL-MonitSig (704 shown in FIG. 7) from the
base station. In this case, the terminal may apply an offset from a
reception time of the DL-SkipSig 604 or the DL-MonitSig 704 to an
execution time of the operation according to the DL-SkipSig 604 or
the DL-MonitSig 704. For example, the terminal may suspend
execution of the DL monitoring operation (e.g., PDCCH monitoring
operation) after the offset from the reception time of the
DL-SkipSig 604. In addition, the terminal may perform the DL
monitoring operation after the offset from the reception time of
the DL-MonitSig 704.
[0180] Each of the DL-SkipSig and DL-MonitSig controlling the PDCCH
monitoring operation may be indicated as `DL-Sig`. That is, the
DL-Sig may mean DL-SkipSig and/or DL-MonitSig. A specific field
(e.g., specific bit(s)) included in the DCI may be set to the
DL-Sig. Information indicating an application time of a DL-Sig
signaling operation may be configured by a field (e.g., bit(s),
parameter(s)) in the DCI, a MAC subheader, a MAC CE, or system
information.
[0181] The monitoring operation for a downlink channel (e.g.,
PDCCH) may be performed according to the DL-Sig. During the
execution of the monitoring operation, an operation according to an
inactivity timer may be selectively performed as follows. [0182]
Option 1: The inactivity timer may be operated according to the
conventional operation. That is, the inactivity timer may be reset
and (re)started regardless of the DL-Sig. [0183] Option 2: If an
operation timer according to the DL-Sig expires after the
inactivity timer is stopped, the inactivity timer may be reset and
(re)started. [0184] Option 3: If an operation timer according to
the DL-Sig expires after the inactivity timer is stopped, the
inactivity timer may be (re)started without being reset.
[0185] In the period in which the monitoring operation for a
downlink channel is not performed according to the DL-Sig, the
existing configuration according to a semi-persistent scheduling
(SPS) or a configured grant (CG) is maintained, and thus an uplink
transmission operation according to the SPS or CG (e.g., PUSCH
transmission operation, PUCCH transmission operation, scheduling
request (SR) transmission operation) may be performed.
[0186] When a carrier aggregation (CA) function is applied, DL-Sig
signaling information that controls execution of the PDCCH
monitoring operation may be transmitted in a primary cell (or,
SpCell of the 3GPP NR system). A method of indicating whether to
perform the PDCCH monitoring operation based on a cross carrier
scheduling scheme may be excluded.
[0187] When the method of indicating whether to perform the PDCCH
monitoring operation based on a cross-carrier scheduling scheme is
allowed, an identifier (e.g., cell identifier, BWP identifier) for
identifying a target (e.g., cell, BWP) of the DL-Sig signaling for
controlling the PDCCH monitoring operation or information
indicating the corresponding target may be included in
cross-carrier scheduling information transmitted to the terminal
(or terminal group).
[0188] [Method of Controlling a PDCCH Monitoring Operation for
Paging Message Reception]
[0189] The base station may transmit paging information (e.g.,
paging message) according to a discontinuous reception (DRX) cycle
of the terminal in order to notify reception of downlink data or a
change of system information. The terminal may perform a DRX
operation to reduce power consumption. In this case, the terminal
may perform a monitoring operation for a downlink channel in a
specific period according to a DRX cycle.
[0190] The terminal may identify a paging occasion (PO) of a paging
frame (PF) based on the DRX cycle, a terminal identifier (e.g., UE
ID), and/or a system frame number (SFN). The terminal may receive a
DCI (e.g., paging DCI) masked with a scheduling identifier (e.g.,
P-RNTI) for transmission of paging information in the paging
occasion of the paging frame, thereby identifying whether paging
information exists or not or whether system information is changed
or not. The PF and/or PO for transmission of the paging DCI may be
configured differently for each terminal. The paging DCI may
selectively include Short Message information indicating whether
the system information is changed. The paging DCI may include a
Short Messages Indicator indicating presence of the Short Message
information and/or presence of paging scheduling information. The
size of the Short Message Indicator may be 1 bit or 2 bits.
[0191] As an additional method for reducing power consumption of
the terminal, a method of controlling the PDCCH monitoring
operation for receiving paging information may be proposed. For
example, based on the signaling concept of DL-SkipSig or
DL-MonitSig described above, the terminal may be controlled to
determine whether to receive paging information at a specific time
(e.g., PF and/or PO). The terminal may perform an operation of
receiving paging information (e.g., paging message) in a PO
according to the DRX cycle. For example, the terminal may receive a
PagingIndSig (or, paging wake up signaling (P-WUS)) at a
preconfigured time based on the PF and/or PO or in the PF and/or PO
of the corresponding terminal. When the terminal receives the
PagingIndSig (or P-WUS), the terminal may perform an operation of
receiving paging information.
[0192] The base station may control whether to perform the PDCCH
monitoring operation for reception of paging information by using
the PagingIndSig. To support the signaling operation of
PagingIndSig, or for signaling of PagingIndSig, the base station
may deliver one or more parameters defined in Table 3 below to the
terminal. One or more parameters defined in Table 3 may be
transmitted using one or a combination of two or more of system
information, an RRC control message, a MAC control message, and a
PHY control message (e.g., PDCCH, DCI).
TABLE-US-00003 TABLE 3 PagingIndSig configuration information A
signaling time of PagingIndSig An offset between the signaling time
of PagingIndSig and a PF and/or PO An execution period of the PDCCH
monitoring operation according to PagingIndSig signaling (e.g.,
duration of the execution period). The execution period may be
configured with a window and/or a timer. A start time of the PDCCH
monitoring operation according to PagingIndSig signaling An end
time of the PDCCH monitoring operation according to PagingIndSig
signaling PagingIndSig signaling occasion (or, occasion
periodicity) A start offset of the PDCCH monitoring operation
according to PagingIndSig signaling Information of a CORESET and/or
a search space in which the PagingIndSig signaling is transmitted
Information indicating a target (e.g., BWP, terminal, and/or
terminal group) of the execution of the PDCCH monitoring operation
for paging information reception
[0193] The offset (hereinafter referred to as `PagingIndSig
signaling offset` or `P-WUS offset`) between the PagingIndSig
signaling time and the PF and/or PO may refer to a time domain
offset (or difference) between the PF and/or PO configured for each
terminal or terminal group and the signaling time of the
PagingIndSig. The PagingIndSig may be transmitted to the terminal
before the PagingIndSig signaling offset (or P-WUS offset) from the
PF and/or PO configured for each terminal or terminal group.
[0194] Each of the parameters defined in Table 3 may be set in
units of radio frames, subframes, slots, minislots, or symbols. The
execution period (or, window, period corresponding to the window,
or duration) of the PDCCH monitoring operation according to the
PagingIndSig signaling may be set as a multiple of a PagingIndSig
signaling occasion periodicity, the DRX cycle, or a PO periodicity
of the terminal.
[0195] The execution period (e.g., window, period corresponding to
the timer, duration) of the PDCCH monitoring operation according to
the PagingIndSig signaling may be configured based on a timer
indicating the execution time of the PDCCH monitoring operation,
the number of POs to be monitored, the start time of the PDCCH
monitoring operation according to the PagingIndSig signaling and/or
the end time of the PDCCH monitoring operation according to the
PagingIndSig signaling.
[0196] FIG. 8 is a timing diagram illustrating a first exemplary
embodiment of a PagingIndSig signaling method in a communication
system.
[0197] As shown in FIG. 8, a method 1 and/or a method 2 may be used
for the PagingIndSig signaling. In exemplary embodiments, a PO may
mean a PF, and a PagingIndSig signaling offset may mean a P-WUS
offset. [0198] Method 1: PagingIndSig 802-1 may be transmitted
before a PagingIndSig signaling offset 804 from a reference time of
a PO 803-1 for a terminal or terminal group. [0199] Method 2:
PagingIndSig 802-1 may be transmitted in the PO 803-1 for the
terminal or terminal group.
[0200] The base station may control the PDCCH monitoring operation
for reception of paging information (e.g., paging message)
according to the method 1 or method 2. The terminal 801 may receive
PagingIndSig 802-1 and 802-2 from the base station according to the
method 1 or method 2. When the PagingIndSig 802-1 and 802-2 are
received, the terminal may perform a paging information reception
operation in the PDCCH monitoring operation periods 807-1, 807-2,
and/or 807-3.
[0201] The execution period 807-1 of the first PDCCH monitoring
operation may be an execution period of the monitoring operation
according to the PagingIndSig 802-1 when the method 1 is used. The
execution period 807-2 of the second PDCCH monitoring operation may
be an execution period of the monitoring operation according to the
PagingIndSig 802-2 when the method 2 is used. The execution period
807-3 of the third PDCCH monitoring operation may be an execution
period of the monitoring operation according to the PagingIndSig
802-2 when a monitoring start offset 806 is applied in the method
2.
[0202] The base station may configure the monitoring start offset
806 indicating the start time of the PDCCH monitoring operation,
and may inform the terminal 801 of the monitoring start offset 806.
The monitoring start offset 806 may be applied from the reception
time of the PagingIndSig 802-1 and 802-2. The above-described
operation may be applied to the method 1 and/or the method 2. In
this case, the terminal 801 may perform the PDCCH monitoring
operation after the monitoring start offset 806 from the reception
time of the PagingIndSig 802-1.
[0203] On the other hand, the terminal may not be able to receive
the PagingIndSig. In this case, the terminal may not perform the
PDCCH monitoring operation for reception of paging information in
the PO within the PDCCH monitoring operation execution period
and/or the PDCCH monitoring operation for reception of paging
information until a next PagingIndSig signaling occasion according
to a PagingIndSig signaling occasion periodicity 805-1 and
805-2.
[0204] The signaling operation of PagingIndSig may be performed
using a separate DCI format and/or the existing DCI format. When
the existing DCI format is used for PagingIndSig signaling, `Short
Message`, `Short Messages Indicator`, and/or `reserved` bits
included in the existing DCI format may be used for the
PagingIndSig signaling.
[0205] The terminal may perform the PDCCH monitoring operation for
receiving PagingIndSig and/or paging information according to the
DRX cycle. Alternatively, the terminal may be controlled to perform
the PDCCH monitoring operation according to a periodicity longer
than the DRX cycle or a periodicity shorter than the DRX cycle.
[0206] In order to control the PDCCH monitoring operation for
reception of paging information, control information included in
the DCI may be used. To support this operation, the Short Messages
Indicator included in the DCI may be used. Also, to support this
operation, the DCI may include the PagingIndSig.
[0207] When using the Short Message Indicator to control the PDCCH
monitoring operation (e.g., DCI monitoring operation) for reception
of paging information, the Short Messages Indicator set to a
specific pattern (e.g., specific value) may indicate execution of
the PDCCH monitoring operation for reception of paging information.
For example, when the Short Message Indicator has a length of 2
bits, the specific pattern may be `00`. When the PagingIndSig
indicates execution of the PDCCH monitoring operation, and the
Short Message Indicator in the DCI is set to `00`, the terminal may
perform the PDCCH monitoring operation for reception of paging
information during an execution period (e.g., period corresponding
to the window and/or the timer) or until a next PagingIndSig
signaling occasion according to a PagingIndSig signaling occasion
periodicity. When the PagingIndSig indicates suspension of the
PDCCH monitoring operation, and the Short Message Indicator in the
DCI is set to `00`, the terminal may not perform the PDCCH
monitoring operation for reception of paging information during the
execution period (e.g., period corresponding to the window and/or
the timer) or until a next PagingIndSig signaling occasion
according to the PagingIndSig signaling occasion periodicity.
[0208] Alternatively, the base station may transmit a paging DCI
including the PagingIndSig. In this case, reserved bits in the
paging DCI may be used to indicate the PagingIndSig. Alternatively,
the PagingIndSig may be expressed as a logical operation (e.g.,
exclusive OR (XOR)) with short message information included in the
paging DCI. For example, when the PagingIndSig (or PagingIndSig in
the DCI) indicates execution of the PDCCH monitoring operation, the
terminal may perform the PDCCH monitoring operation for reception
of paging information during an execution period (e.g., period
corresponding to the window and/or the timer) or until a next
PagingIndSig signaling occasion.
[0209] When the PagingIndSig (or PagingIndSig in the DCI) indicates
suspension (or stop or skip) of the PDCCH monitoring operation or
when the PagingIndSig is not received, the terminal may not perform
the PDCCH monitoring operation for reception of paging information
during the execution period (e.g., period corresponding to the
window and/or the timer) or until a next PagingIndSig signaling
occasion.
[0210] When the PagingIndSig signaling operation is performed
according to the above-described method, the DCI including the
PagingIndSig may further include the following information
element(s). [0211] Information indicating the execution period of
the PDCCH monitoring operation [0212] Information indicating a
terminal group for the PagingIndSig signaling
[0213] The information indicating the execution period of the PDCCH
monitoring operation may be information of a time period in which
the PDCCH monitoring operation is performed in order to receive the
paging information. The information indicating the execution period
of the PDCCH monitoring operation may include a time window, a
timer, the number of POs, the start time of the PDCCH monitoring
operation according to the PagingIndSig signaling, and/or the end
time of the PDCCH monitoring operation according to the
PagingIndSig signaling.
[0214] The terminal receiving the PagingIndSig signaling may
identify the execution period of the PDCCH monitoring operation for
reception of paging information, based on the time window, the
timer, the number of POs, the start time of the PDCCH monitoring
operation according to the PagingIndSig signaling, and/or the end
time of the PDCCH monitoring operation according to the
PagingIndSig signaling.
[0215] When the PagingIndSig signaling is not received or when a
paging message is not received in a PO within the execution period
of the PDCCH monitoring operation according to the PagingIndSig
signaling, the terminal may not perform the PDCCH monitoring
operation for reception of paging information until a next
PagingIndSig signaling occasion.
[0216] The information indicating the terminal group for the
PagingIndSig signaling may be an identifier or indicator indicating
the terminal group to which the corresponding PagingIndSig
signaling is applied. The information indicating the terminal group
for the PagingIndSig signaling may be configured in form of a
bitmap. In this case, each bit included in the bitmap may
correspond to one or more terminal groups. Information indicating
the correspondence between each bit and a terminal group(s) may be
delivered to the terminal through system information and/or a
control message. For example, a terminal group corresponding to a
bit set to a first value (e.g., 0 or 1) in the bitmap may perform
the operation of receiving paging information according to the
above-described method. A terminal belonging to the terminal group
corresponding to the bit set to the first value may be a terminal
receiving the PagingIndSig. A terminal group corresponding to the
bit set to a second value (e.g., 1 or 0) in the bitmap may not
perform the PDCCH monitoring operation. The bitmap may indicate the
PagingIndSig signaling to one or more terminal groups.
[0217] A scheduling identifier (e.g., PagingInd-RNTI) for the
PagingIndSig transmission may be configured. The PagingInd-RNTI
(i.e., P-RNTI) may be configured for a terminal or a terminal
group. Alternatively, one or more P-RNTIs may be configured for a
terminal group. The base station may transmit the PagingIndSig to a
terminal or terminal group using the PagingInd-RNTI or P-RNTI. The
terminal or the terminal group may receive the PagingIndSig from
the base station, and may determine whether to perform the PDCCH
monitoring operation for reception of paging information based on
the PagingIndSig.
[0218] The PagingIndSig information (e.g., PagingIndSig) included
in the paging DCI may indicate whether to perform the PDCCH
monitoring operation for reception of paging information. In this
case, the terminal may perform or suspend (or skip) the PDCCH
monitoring operation for reception of paging information according
to the PagingIndSig included in the paging DCI.
[0219] PagingIndSig configuration information (e.g., some
parameters included in the configuration information) may be
configured for a base station (or cell), a radio access network
(RAN)-based notification area (RNA), or a system information (SI)
area (e.g., area identified by systemInformationAreaID). When the
base station (or cell), RNA, or SI area is changed, the terminal
may update the PagingIndSig configuration information by performing
a system information update procedure or an SI area update
procedure. When the base station (or cell), RNA, or SI area changes
according to the movement of the terminal, the terminal may
determine whether or not the PagingIndSig configuration information
(e.g., some parameters included in the configuration information)
is changed or valid. For example, the terminal may determine
whether each of the time point of the PagingIndSig signaling, the
time point of the PDCCH monitoring operation by the PagingIndSig
signaling, the PagingIndSig signaling offset (or P-WUS offset), and
the execution period of the PDCCH monitoring operation by the
PagingIndSig signaling is changed or not, or determine whether each
of them is valid or not. When a specific parameter is changed or
when a specific parameter is invalid, the terminal may perform a
procedure of updating the specific parameter (e.g., procedure of
changing or resetting the specific parameter).
[0220] A radio resource for the PagingIndSig signaling may be
preconfigured. A BWP, CORESET, and/or search space in which the
PagingIndSig is transmitted may be preconfigured. For example, the
BWP in which the PagingIndSig is transmitted may be limited to an
initial BWP or a preconfigured BWP. The CORESET in which the
PagingIndSig is transmitted may be limited to a CORESET #0 or a
CORESET #1. The search space in which the PagingIndSig is
transmitted may be limited to a common search space, a
terminal-specific (i.e., UE-specific) search space, a specific
resource within a common search space, and/or a specific resource
within a terminal-specific search space.
[0221] The terminal may not receive the PagingIndSig signaling at
the time point of receiving the PagingIndSig signaling according to
the method 1 (e.g., the time point before the PagingIndSig
signaling offset (or P-WUS offset) from the reference point of the
PF/PO for the terminal or terminal group) or at the time point of
receiving the PagingIndSig signaling according to the method 1. In
this case, the terminal may not perform the PDCCH monitoring
operation for reception of paging information in the PO within the
execution period of the PDCCH monitoring operation and/or the PDCCH
monitoring operation for reception of paging information until a
next PagingIndSig signaling occasion.
[0222] When the PagingIndSig signaling is not received, the
terminal may not be able to perform the PDCCH monitoring operation.
The system information may be changed according to a system
information modification periodicity in the period in which the
terminal does not perform the PDCCH monitoring operation. The
terminal may identify whether the system information is changed (or
valid). When the system information is changed or when the system
information stored in the terminal is invalid, the terminal may
perform a system information acquisition procedure.
[0223] That is, in the period in which the terminal not receiving
the PagingIndSig signaling does not perform the PDCCH monitoring
operation, when a boundary of the system information change period
is located or when a new system information change period starts,
the terminal may identify whether the system information is changed
(or valid) regardless of whether the information notifying the
change of the system information is received. When the system
information is changed or when the system information stored in the
terminal is invalid, the terminal may perform a system information
acquisition procedure.
[0224] The PagingIndSig configuration information may be configured
in order to prevent the above-described system information update
procedure (e.g., the procedure for identify whether system
information is changed (or valid), the procedure system information
acquisition procedure). The PO for receiving the information
notifying the change of the system information may be guaranteed.
For example, the execution period of the PDCCH monitoring operation
may be configured to include the PO in which the information
notifying the change of the system information is transmitted and
received. The parameter(s) for the PagingIndSig signaling occasion
periodicity and/or the execution period of the PDCCH monitoring
operation may be configured such that the PO in which the
information notifying the change of the system information is
transmitted and received and the execution period of the PDCCH
monitoring operation are aligned with each other.
[0225] In the present disclosure, the radio channel quality may be
a channel state indicator (CSI), a received signal strength
indicator (RSSI), a reference signal received power (RSRP), a
reference signal received quality (RSRQ), or a signal to
interference and noise ratio (SINR). With respect to the operation
of the timer defined or described in the present disclosure,
although operations such as start, stop, reset, restart, or expire
of the defined timer are not separately described, they mean or
include the operations of the corresponding timer or a counter for
the corresponding timer.
[0226] In the present disclosure, the base station (or cell) may
refer to a node B (NodeB), an evolved NodeB, a base transceiver
station (BTS), a radio base station, a radio transceiver, an access
point, an access node, a road side unit (RSU), a radio remote head
(RRH), a transmission point (TP), a transmission and reception
point (TRP), or a gNB. In addition, the base station (or, cell) may
a CU node or a DU node to which the functional split is
applied.
[0227] In the present disclosure, the terminal may refer to a UE, a
terminal, an access terminal, a mobile terminal, a station, a
subscriber station, a mobile station, a portable subscriber
station, a node, a device), an Internet of Thing (IoT) device, or a
mounted apparatus (e.g., a mounted module/device/terminal or an
on-board device/terminal).
[0228] The exemplary embodiments of the present disclosure may be
implemented as program instructions executable by a variety of
computers and recorded on a computer readable medium. The computer
readable medium may include a program instruction, a data file, a
data structure, or a combination thereof. The program instructions
recorded on the computer readable medium may be designed and
configured specifically for the present disclosure or can be
publicly known and available to those who are skilled in the field
of computer software.
[0229] Examples of the computer readable medium may include a
hardware device such as ROM, RAM, and flash memory, which are
specifically configured to store and execute the program
instructions. Examples of the program instructions include machine
codes made by, for example, a compiler, as well as high-level
language codes executable by a computer, using an interpreter. The
above exemplary hardware device can be configured to operate as at
least one software module in order to perform the embodiments of
the present disclosure, and vice versa.
[0230] While the embodiments of the present disclosure and their
advantages have been described in detail, it should be understood
that various changes, substitutions and alterations may be made
herein without departing from the scope of the present
disclosure.
* * * * *