Technical Field
The present invention relates to a communication system. The invention has
particular but not exclusive relevance to wireless communication systems and devices
thereof operating according to the 3rd Generation Partnership Project (3GPP) standards
or equivalents or derivatives thereof (including LTE-Advanced and Next Generation or
5G networks). The invention has particular, although not necessarily exclusive
relevance to, improved apparatus and methods that support flexible monitoring for the
transmission of control information in a downlink control channel (e.g., a physical
downlink control channel (PDCCH)).
Background Art
[0002] Recent developments of the 3GPP standards are referred to as the Long Term
[0003]
Evolution (LTE) of Evolved Packet Core (EPC) network and Evolved UMTS Terrestrial
Radio Access Network (E-UTRAN), also commonly referred as '4G'. In
addition, the term '5G' and 'new radio' (NR) refer to an evolving communication
technology that is expected to support a variety of applications and services. Various
details of 5G networks are described in, for example, the 'NGMN 5G White Paper'
Vl.O by the Next Generation Mobile Networks (NGMN) Alliance, which document is
available from https://www.ngmn.org/5g-white-paper.html. 3GPP intends to support
5G by way of the so-called 3GPP Next Generation (NextGen) radio access network
(RAN) and the 3GPP NextGen core network.
Under the 3GPP standards, a NodeB (or an eNB in LTE, gNB in 5G) is the base
station via which communication devices (user equipment or 'UE') connect to a core
network and communicate to other communication devices or remote servers. For
simplicity, the present application will use the term base station to refer to any such
base stations.
[0004] In the current 5G architecture, for example, the gNB structure may be split into two
parts known as the Central Unit (CU) and the Distributed Unit (DU), connected by an
Fl interface. This enables the use of a 'split' architecture, whereby the, typically
'higher', CU layers (for example, but not necessarily or exclusively), PDCP) and the,
typically 'lower', DU layers (for example, but not necessarily or exclusively, RLC/
MAC/PHY) to be implemented separately. Thus, for example, the higher layer CU
functionality for a number of gNBs may be implemented centrally (for example, by a
single processing unit, or in a cloud-based or virtualised system), whilst retaining the
lower layer DU functionality locally, in each of the gNB.
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[0005] For simplicity, the present application will use the term mobile device, user device,
or UE to refer to any communication device that is able to connect to the core network
via one or more base stations. Although the present application often refers to mobile
devices in the description, it will be appreciated that the technology described can be
implemented on any communication devices (mobile and/or generally stationary) that
can connect to a communications network for sending/receiving data, regardless of
whether such communication devices are controlled by human input or software Instructions
stored in memory.
[0006] In 5G, the concept of a control resource set (CORESET) has been introduced. A
CORESET is a set of time-frequency resources with which a UE can search for
downlink control information (DCI) transmitted by a base station on a PDCCH. A
CORESET is analogous to the control region at the start LTE subframes. However,
unlike LTE, in which the frequency domain of the control region corresponds to the
total system bandwidth, the frequency domain location for CORESET is localised to a
specific region in frequency domain and has a variable width can be set to any suitable
value (in the multiples of 6 resource blocks where each resource block comprises 12
subcarriers in the frequency domain).
[0007] A base station may transmit control information for a specific UE in a PDCCH that
uses the resources of a UE specific CORESET defined for that UE. The PDCCH is
made up of a number of control channel elements (CCEs) depending on the required
aggregation level (L). Each CCE comprises a set of time/frequency resource
comprising bundles of resource element groups, each group comprising a number of
resource elements.
[0008] Allowing different UEs to be assigned different resource sets for their dedicated
PDCCH signalling reduces but does not eliminate the probability of PDCCH blocking
events in which there are no CCEs free for scheduling a given UE, at a particular aggregation
level, in that UEs search space.
[0009] A number of different DCI formats can be used for transmission on a PDCCH and
[0010]
the transmitted format is unknown to the UE in advance. Accordingly, the UE typically
needs to make multiple blind attempts to detect a DCI format. Whilst the CCE and
CO RESET structure helps in reducing the number of blind decoding attempts required
this is not sufficient to reduce the number of blind decoding attempts to a practical
level. To alleviate this issue, whilst still providing the base station with scheduling
flexibility, a discrete number of search spaces are defined in which a UE is to search
possible PDCCH resource locations (PDCCH 'candidates') for DCI. Each search space
is a set of candidate PDCCHs formed by CCEs at a given aggregation level, which the
UE can attempt to decode.
As there are a number of different possible aggregation levels there can be several
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search spaces for a given CORESET and, as there can be a number of CORESETs, the
number of blind decoding attempts can still be relatively high. Thus, the respective
number of PDCCH candidates for each PDCCH search space set is also configurable
to allow blind decoding attempts to be spread across the search spaces for different aggregation
levels.
[0011] Each PDCCH search space set can form a DE specific search space (DSS) configured
[0012]
[0013]
[0014]
for a single DE, or a common search space (CSS), which is similar in structure to a
DSS but which has a set of CCEs that are predefined and hence known to all DEs.
Typically, at least the following five PDCCH search space sets are configured to
support of the basic communication functionalities:
A common search space set for system information block type 1 (SIB 1 ),
A common search space set for other system information,
A common search space set for RACH,
A common search space set for paging, and
A DE-specific search space set for data transmission and reception.
Before a DE can attempt to decode a PDCCH candidate the DE must first perform
channel estimation needs to be performed based on demodulation reference signals
(DMRS) transmitted in the CCEs forming the PDCCH candidate. The number of
PDCCH DMRS used to perform channel estimation depends on the number of CCEs
forming the PDCCH candidate.
In order to reduce device complexity both the maximum number of blind decoding
attempts that a DE is permitted to perform, and the number of CCEs on which channel
estimation is performed, are limited depending on the subcarrier spacing and hence the
slot duration. When a DE is searching for control information any unsearched PDCCH
candidates will be skipped (or 'dropped') when either the number of blind decodes, or
the number of CCEs, exceeds the maximum defined for the DE. This means that in
some circumstances not all search spaces will be searched and so a rule is used to
determine which search spaces should be searched first. According to this rule,
common search space sets are prioritised over DE-specific search space sets, and DEspecific
search space sets are prioritised based on their identities, with a DSS having a
smaller index being prioritised over a DSS having a larger index.
[0015] At 3GPP Technical Standards Group (TSG) RAN Meeting #86, a new study was
[0016]
initiated for developing so called reduced capability ('RedCap' or 'REDCAP') DEs for
a number of specific use cases including, but not limited to, industrial wireless sensing,
video surveillance and wearable devices.
REDCAP DEs will typically: have a significantly reduced device complexity,
compared to the high-end enhanced mobile broadband (eMBB) and ultra-reliable lowlatency
communication (DRLLC) devices of earlier releases (especially for industrial
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[0017]
[0018]
sensors); support a reduced device size since most use cases require the capability for a
device design with compact form factor; and support all the frequency bands of both
5G frequency ranges (i.e., FRl and FR2) for both frequency division duplex (FDD)
and time division duplex (TDD).
Each of the different use cases for REDCAP UEs has differing technical requirements
making the design of communication protocols and apparatus that support
REDCAP UEs more challenging. For example, the requirements for some of the key
use cases may be summarised as follows:
Industrial wireless sensors
Communication service availability should ideally be at least 99.99% and end-to-end
latency less than lOOms. The reference bit rate should ideally be less than 2 Mbps
(potentially uplink/downlink asymmetric e.g., because of uplink (UL) heavy traffic) for
all use cases and the device is stationary. The battery should ideally last at least few
years. For safety related sensors, the latency requirement may be lower, for example
5-10 ms.
Video Surveillance
Reference economic video bitrate capability would ideally be in the range 2-4 Mbps.
Latency should ideally be less than 500 ms. Reliability should ideally be 99%-99.9%.
High-end video, e.g., for farming, could require higher video bitrate capability in the
range 7.5-25 Mbps. Traffic pattern dominated by UL transmissions should be
supported.
Wearables
Reference bitrate for smart wearable application capability would ideally be in the
range 5-50 Mbps in downlink (DL) and 2-5 Mbps in UL. Peak bit rate capability of the
device should ideally be higher- in the range 10-150 Mbps forDLand 5-50 Mbps for
UL. The battery of the device should last multiple days (up to 1-2 weeks).
It can be seen that, for REDCAP UEs, power saving is an important design aspect,
for example due to the smaller form factor and longer battery lifetime requirements. To
help support such power saving, therefore, REDCAP UEs will typically have a reduced
capability to monitor for control information on the PDCCH with tighter limits on the
number of allowed blind decoding attempts and the maximum number of CCEs that
can be subject to channel estimation.
[0019] Some REDCAP UEs may not support the usage of small aggregation levels, such as
[0020]
L=l or L=2, while others may not be able to support high aggregation levels, e.g.,
L=16 due to bandwidth limitations.
Moreover, the PDCCH blocking probability may increase due to the potentially
reduced bandwidth, potentially larger aggregation levels and/or potentially reduced
number of CCEs that may be used for REDCAP UEs.
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Summary of Invention
[0021] The invention aims to provide improved apparatus and methods that overcome or at
least partially ameliorates the above issues.
[0022] Example aspects of the invention are set out in the appended independent claims.
[0023]
[0024]
[0025]
Optional but beneficial features are set out in the appended dependent claims.
According to one example aspect there is provided a method performed by a user
equipment (UE) that communicates with a radio access network in a communication
system, the method comprising: receiving, from the radio access network, first information
for configuring at least one set of control resources in which the radio access
network may transmit control information, and second information for configuring at
least one search space within the set of control resources within which to search for
control information; monitoring for downlink control information (DCI) transmitted by
the radio access network within the at least one search space within the at least one set
of control resources; receiving, from the radio access network, DCI comprising third
information for reconfiguring the at least one set of control resources configured by the
first information, or the at least one search space configured by the second information;
and monitoring for DCI transmitted by the radio access network within the at least one
search space within the set of control resources as reconfigured by the third information;
wherein the third information is configured to provide an indication of at
least one set of control resources configured by the first information, or of at least one
search space configured by the second information, within which the UE is to stop
monitoring for DCI, start monitoring for DCI, or continue monitoring for DCI.
According to one example aspect there is provided a method performed by a user
equipment (UE) that communicates with a radio access network in a communication
system, the method comprising: obtaining information for mapping each of a plurality
of possible power saving configurations to a set of parameters that characterise that
power configuration; and providing, to the radio access network, UE assistance information
comprising an indication of at least one power saving configuration, of the
plurality of power saving configurations, that represents a configuration or capability
of the UE.
According to one example aspect there is provided a method performed by a user
equipment (UE) that communicates with a radio access network in a communication
system, the method comprising: monitoring, during a monitoring occasion, for
downlink control information (DCI) transmitted by the radio access network within a
plurality of search spaces, comprising at least one common search space (CSS) and at
least on UE specific search space (USS), within at least one set of control resources;
wherein the set of control resources comprise at least one control channel element and
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[0026]
each search space comprises a respective set of physical downlink control channel
(PDCCH) candidates within which to search for DCI; wherein the monitoring
comprises, during a current slot of the monitoring occasion: (a) treating a first search
space of the plurality of search spaces that has not been searched in the current slot as a
current search space and attempting to blind decode each PDCCH candidate of the
current search space in tum until an end to searching of the current search space is
triggered; (b) when the current search space has been fully searched, and the plurality
of search spaces include at least one remaining search space that has not been searched
in the current slot, selecting a remaining search space that has not been searched in the
current slot to be searched next and repeating steps (a) and (b) with the selected search
space as the current search space, unless an end to searching in the current slot is
triggered; and (c) when an end to searching in the current slot is triggered, repeating
steps (a) to (c) during a subsequent slot of a monitoring occasion as the current slot,
until an end to searching in the monitoring occasion is triggered; wherein, before
performing step (b), at least one USS is assigned to be a highest priority USS for the
current slot; wherein, when selecting a search space to be searched next in step (b) the
UE prioritises the remaining search spaces that have not been searched in the current
slot based on based on a prioritisation scheme that requires that USSs are prioritised
starting from a USS having a highest priority; and wherein the method further
comprises, before repeating steps (a) to (c) during a subsequent slot of the monitoring
occasion, reassigning a different USS to be highest priority USS.
According to one example aspect there is provided a method performed by a user
equipment (UE) that communicates with a radio access network in a communication
system, the method comprising: monitoring, during a monitoring occasion, for
downlink control information (DCI) transmitted by the radio access network within a
plurality of search spaces, comprising at least one common search space (CSS) and at
least on UE specific search space (USS), within at least one set of control resources;
wherein the set of control resources comprise at least one control channel element
(CCE) and each search space comprises a respective set of physical downlink control
channel (PDCCH) candidates within which to search for DCI, each PDCCH candidate
comprising at least one CCE; wherein the monitoring comprises, during a current slot
of the monitoring occasion: (a) treating a first search space of the plurality of search
spaces that has not been searched in the current slot as a current search space and attempting
to blind decode each PDCCH candidate of the current search space in tum
until an end to searching of the current search space is triggered; (b) when the current
search space has been fully searched, and the plurality of search spaces include at least
one remaining search space that has not been searched in the current slot, selecting a
remaining search space that has not been searched in the current slot to be searched
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[0027]
next and repeating steps (a) and (b) with the selected search space as the current search
space, unless an end to searching in the current slot is triggered; and (c) when an end to
searching in the current slot is triggered, repeating steps (a) to (c) during a subsequent
slot of a monitoring occasion as the current slot, until an end to searching in the
monitoring occasion is triggered; wherein, the UE is configured with a maximum
number of blind decode attempts, and an end to searching in the current slot is
triggered when the maximum number of blind decode attempts will be exceeded if
searching continues; wherein, the UE is configured with a maximum share of the
maximum number of blind decode attempts that can be used for searching CSSs; and
wherein, when selecting a search space to be searched next in step (b) the UE prioritises
the remaining search spaces that have not been searched in the current slot
based on a prioritisation scheme that requires that CSSs that have not been searched in
the current slot are prioritised until further searching in a CSS will cause the maximum
share of the maximum number of blind decode attempts to be exceeded, after which
USSs that have not been searched in the current slot are prioritised.

Claims
A method performed by a user equipment (UE) that communicates
with a radio access network in a communication system, the method
compnsmg:
receiving, from the radio access network, first information for configuring
at least one set of control resources in which the radio access
network may transmit control information, and second information for
configuring at least one search space within the set of control resources
within which to search for control information;
monitoring for downlink control information (DCI) transmitted by
the radio access network within the at least one search space within the
at least one set of control resources;
receiving, from the radio access network, DCI comprising third Information
for reconfiguring the at least one set of control resources
configured by the first information, or the at least one search space
configured by the second information; and
monitoring for DCI transmitted by the radio access network within
the at least one search space within the set of control resources as reconfigured
by the third information;
wherein the third information is configured to provide an indication
of at least one set of control resources configured by the first information,
or of at least one search space configured by the second Information,
within which the UE is to stop monitoring for DCI, start
monitoring for DCI, or continue monitoring for DCI.
A method as claimed in claim 1 wherein the indication the third Information
comprises a bitmap wherein each bit of the bitmap represents
a respective set of control resources configured by the first information
or at least one respective search space configured by the second information,
optionally where a bit of a bitmap is set to '0' to indicate
that the UE is to stop monitoring for DCI, and to '1' to indicate that the
UE is start monitoring for DCI, or continue monitoring for DCI.
A method as claimed in claim 1 or 2 wherein the UE is operating in a
discontinuous reception (DRX) mode and receives the third information
during whilst in an inactive state during a DRX cycle.
A method as claimed in claim 3 wherein the UE receives the third Information,
whilst in an inactive state during an OFF period of the DRX
cycle, in a field of a DCI format that is receivable during the OFF
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[Claim 5]
[Claim 6]
[Claim 7]
[Claim 8]
[Claim 9]
[Claim 10]
[Claim 11]
[Claim 12]
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period of the DRX cycle.
A method as claimed in claim 4 wherein the third information is
received in a field of DCI format 2_6, optionally a wake-up signal
(WUS) field of DCI format 2_6.
A method as claimed in claim 3 wherein the UE receives the third Information
during whilst in an inactive state during an ON period of the
DRX cycle.
A method as claimed in claim 3 or 6 wherein the third information is
received in a field of DCI format 0_1 or DCI format 1_1, optionally a
code block group (CBG) transmission information (CBGTI) field of
DCI format 0_1 or DCI format 1_1.
A method as claimed in any of claims 1 to 7 wherein the UE stores
information identifying a maximum number of search space sets that
can be simultaneously monitored by the UE, wherein the information is
configurable to any of a plurality of different values.
A method as claimed in any of claims 1 to 8 wherein the first Information
for configuring at least one set of resources for receiving
and/or the second information for configuring at least one is received
using radio resource control (RRC) signalling.
A method performed by a user equipment (UE) that communicates
with a radio access network in a communication system, the method
compnsmg:
obtaining information for mapping each of a plurality of possible
power saving configurations to a set of parameters that characterise that
power configuration; and
providing, to the radio access network, UE assistance information
comprising an indication of at least one power saving configuration, of
the plurality of power saving configurations, that represents a configuration
or capability of the UE.
A method as claimed in claim 10 wherein the information for
mapping each of a plurality of possible power saving configurations to
a set of parameters that characterise that power configuration respectively
comprises at least one index representing each power saving
configuration, and wherein the indication of at least one power saving
configuration comprises the respective at least one index corresponding
to each of the at least one power saving configuration.
A method as claimed in claim 10 or 11, wherein the information for
mapping each of a plurality of possible power saving configurations to
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[Claim 13]
[Claim 14]
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a set of parameters that characterise that power configuration comprises
at least one table.
A method as claimed in any of claims 10 to 12, wherein the set of
parameters that characterise that power configuration comprises at least
one parameter from the following list of parameters: at least one
parameter for use in configuring a search space; at least one parameter
for use in configuring a monitoring occasion within which the UE is to
monitor for control information; at least one parameter indicating a
maximum number of blind decoding attempts supported by the UE; at
least one parameter indicating a maximum number of physical
downlink control channel (PDCCH) candidates per aggregation level
supported at the UE; at least one parameter indicating a maximum
number of control channel elements (CCEs) for channel estimation
supported at the UE; at least one parameter indicating a corresponding
aggregation level supported at the UE; at least one parameter indicating
a maximum number of configurable search space sets supported at the
UE; at least one parameter indicating a maximum number of simultaneously
monitored search space sets supported at the UE; at least one
parameter representing an expected UE battery life; at least one
parameter representing a reference bit rate requirement for the UE; at
least one parameter representing a peak bit rate requirement for the UE;
and at least one parameter representing a latency requirement for the
UE.
A method performed by a user equipment (UE) that communicates
with a radio access network in a communication system, the method
compnsmg:
monitoring, during a monitoring occasion, for downlink control Information
(DCI) transmitted by the radio access network within a
plurality of search spaces, comprising at least one common search
space (CSS) and at least on UE specific search space (USS), within at
least one set of control resources;
wherein the set of control resources comprise at least one control
channel element and each search space comprises a respective set of
physical downlink control channel (PDCCH) candidates within which
to search for DCI;
wherein the monitoring comprises, during a current slot of the
monitoring occasion:
(a) treating a first search space of the plurality of search spaces
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[Claim 15]
[Claim 16]
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that has not been searched in the current slot as a current search space
and attempting to blind decode each PDCCH candidate of the current
search space in turn until an end to searching of the current search
space is triggered;
(b) when the current search space has been fully searched, and the
plurality of search spaces include at least one remaining search space
that has not been searched in the current slot, selecting a remaining
search space that has not been searched in the current slot to be
searched next and repeating steps (a) and (b) with the selected search
space as the current search space, unless an end to searching in the
current slot is triggered; and
(c) when an end to searching in the current slot is triggered,
repeating steps (a) to (c) during a subsequent slot of a monitoring
occasion as the current slot, until an end to searching in the monitoring
occasion is triggered;
wherein, before performing step (b), at least one USS is assigned to
be a highest priority USS for the current slot;
wherein, when selecting a search space to be searched next in step
(b) the UE prioritises the remaining search spaces that have not been
searched in the current slot based on based on a prioritisation scheme
that requires that USSs are prioritised starting from a USS having a
highest priority; and
wherein the method further comprises, before repeating steps (a) to
(c) during a subsequent slot of the monitoring occasion, reassigning a
different USS to be highest priority USS.
A method as claimed in claim 14 wherein, when selecting a search
space to be searched next in step (b), after prioritising USS having a
highest priority, the USSs are prioritised in ascending order of USS
index until the USS having the highest USS index is reached, and then
in ascending order of USS index from the USS having the lowest USS
index if not already searched in the current slot.
A method as claimed in claim 14 or 15 wherein, when reassigning a
different USS to be the highest priority USS, the UE: reassigns the
highest priority to the USS that has the next USS index, in ascending
order, to the USS index of the current highest priority USS when a
higher index USS has not been searched in the current slot; and
reassigns the highest priority to the USS to the USS having the lowest
USS index, if not already searched in the current slot, when the current
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[Claim 17]
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highest priority USS is the highest index USS.
A method performed by a user equipment (UE) that communicates
with a radio access network in a communication system, the method
compnsmg:
monitoring, during a monitoring occasion, for downlink control Illformation
(DCI) transmitted by the radio access network within a
plurality of search spaces, comprising at least one common search
space (CSS) and at least on UE specific search space (USS), within at
least one set of control resources;
wherein the set of control resources comprise at least one control
channel element (CCE) and each search space comprises a respective
set of physical downlink control channel (PDCCH) candidates within
which to search for DCI, each PDCCH candidate comprising at least
one CCE;
wherein the monitoring comprises, during a current slot of the
monitoring occasion:
(a) treating a first search space of the plurality of search spaces
that has not been searched in the current slot as a current search space
and attempting to blind decode each PDCCH candidate of the current
search space in turn until an end to searching of the current search
space is triggered;
(b) when the current search space has been fully searched, and the
plurality of search spaces include at least one remaining search space
that has not been searched in the current slot, selecting a remaining
search space that has not been searched in the current slot to be
searched next and repeating steps (a) and (b) with the selected search
space as the current search space, unless an end to searching in the
current slot is triggered; and
(c) when an end to searching in the current slot is triggered,
repeating steps (a) to (c) during a subsequent slot of a monitoring
occasion as the current slot, until an end to searching in the monitoring
occasion is triggered;
wherein, the UE is configured with a maximum number of blind
decode attempts, and an end to searching in the current slot is triggered
when the maximum number of blind decode attempts will be exceeded
if searching continues;
wherein, the UE is configured with a maximum share of the
maximum number of blind decode attempts that can be used for
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[Claim 18]
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searching CSSs; and
wherein, when selecting a search space to be searched next in step
(b) the UE prioritises the remaining search spaces that have not been
searched in the current slot based on a prioritisation scheme that
requires that CSSs that have not been searched in the current slot are
prioritised until further searching in a CSS will cause the maximum
share of the maximum number of blind decode attempts to be
exceeded, after which USSs that have not been searched in the current
slot are prioritised.
A method performed by a user equipment (UE) that communicates
with a radio access network in a communication system, the method
compnsmg:
monitoring, during a monitoring occasion, for downlink control Information
(DCI) transmitted by the radio access network within a
plurality of search spaces, comprising at least one common search
space (CSS) and at least on UE specific search space (USS), within at
least one set of control resources;
wherein the set of control resources comprise at least one control
channel element (CCE) and each search space comprises a respective
set of physical downlink control channel (PDCCH) candidates within
which to search for DCI, each PDCCH candidate comprising at least
one CCE;
wherein the monitoring comprises, during a current slot of the
monitoring occasion:
(a) treating a first search space of the plurality of search spaces
that has not been searched in the current slot as a current search space
and attempting to blind decode each PDCCH candidate of the current
search space in turn until an end to searching of the current search
space is triggered;
(b) when the current search space has been fully searched, and the
plurality of search spaces include at least one remaining search space
that has not been searched in the current slot, selecting a remaining
search space that has not been searched in the current slot to be
searched next and repeating steps (a) and (b) with the selected search
space as the current search space, unless an end to searching in the
current slot is triggered; and
(c) when an end to searching in the current slot is triggered,
repeating steps (a) to (c) during a subsequent slot of a monitoring
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[Claim 19]
[Claim 20]
[Claim 21]
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occasion as the current slot, until an end to searching in the monitoring
occasion is triggered;
wherein, the UE is configured with a maximum number of blind
decode attempts, and an end to searching in the current search space
and the current slot is triggered when the maximum number of blind
decode attempts will be exceeded if searching continues, even when the
current search space has not been fully searched.
A method performed by a user equipment (UE) that communicates
with a radio access network in a communication system, the method
compnsmg:
identifying a sequence of consecutive slots for forming a
monitoring occasion; and
monitoring, during the monitoring occasion, for downlink control
information (DCI) transmitted by the radio access network within a
plurality of search spaces, within at least one set of control resources;
wherein, when performing the monitoring, the UE monitors for
control information in slots of the sequence of consecutive slots that are
spaced apart by an unmonitored interval of at least one other slot of the
sequence of consecutive slots.
A method as claimed in claim 19 wherein the communication system
has a plurality of different numerologies that can be used for communication,
each numerology having a different respective subcarrier
spacing and slot length, and wherein the unmonitored interval is determined
based on at least one configuration parameter that is determined
based on the numerology of the communications system that
is being used for communication.
A user equipment (UE) for communicating with a radio access
network in a communication system, the UE comprising:
a controller and a transceiver, wherein the controller is configured to
control the transceiver to:
receive, from the radio access network, first information for configuring
at least one set of control resources in which the radio access
network may transmit control information, and second information for
configuring at least one search space within the set of control resources
within which to search for control information;
monitor for downlink control information (DCI) transmitted by the
radio access network within the at least one search space within the at
least one set of control resources;
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[Claim 22]
[Claim 23]
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receive, from the radio access network, DCI comprising third information
for reconfiguring the at least one set of control resources
configured by the first information, or the at least one search space
configured by the second information; and
monitor for DCI transmitted by the radio access network within
the at least one search space within the set of control resources as reconfigured
by the third information;
wherein the third information is configured to provide an indication
of at least one set of control resources configured by the first information,
or of at least one search space configured by the second Information,
within which the UE is to stop monitoring for DCI, start
monitoring for DCI, or continue monitoring for DCI.
A user equipment (UE) for communicating with a radio access
network in a communication system, the UE comprising:
a controller and a transceiver, wherein the controller is configured:
to obtain information for mapping each of a plurality of possible
power saving configurations to a set of parameters that characterise that
power configuration; and
to control the transceiver to provide, to the radio access network,
UE assistance information comprising an indication of at least one
power saving configuration, of the plurality of power saving configurations,
that represents a configuration or capability of the UE.
A user equipment (UE) for communicating with a radio access
network in a communication system, the UE comprising:
a controller and a transceiver, wherein the controller is configured to
control the transceiver to:
monitor, during a monitoring occasion, for downlink control Information
(DCI) transmitted by the radio access network within a
plurality of search spaces, comprising at least one common search
space (CSS) and at least on UE specific search space (USS), within at
least one set of control resources;
wherein the set of control resources comprise at least one control
channel element and each search space comprises a respective set of
physical downlink control channel (PDCCH) candidates within which
to search for DCI;
wherein the controller is configured to control the UE, during a
current slot of the monitoring occasion, to:
(a) treat a first search space of the plurality of search spaces that
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[Claim 24]
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has not been searched in the current slot as a current search space and
attempt to blind decode each PDCCH candidate of the current search
space in turn until an end to searching of the current search space is
triggered;
(b) when the current search space has been fully searched, and the
plurality of search spaces include at least one remaining search space
that has not been searched in the current slot, select a remaining search
space that has not been searched in the current slot to be searched next
and repeat steps (a) and (b) with the selected search space as the current
search space, unless an end to searching in the current slot is triggered;
and
(c) when an end to searching in the current slot is triggered, repeat
steps (a) to (c) during a subsequent slot of a monitoring occasion as the
current slot, until an end to searching in the monitoring occasion is
triggered;
wherein, before performing step (b), at least one USS is assigned to
be a highest priority USS for the current slot;
wherein the controller is configured to control the UE to, when
selecting a search space to be searched next in step (b), prioritise the
remaining search spaces that have not been searched in the current slot
based on based on a prioritisation scheme that requires that USSs are
prioritised starting from a USS having a highest priority; and
wherein the controller is configured to control the UE to, before
repeating steps (a) to (c) during a subsequent slot of the monitoring
occasion, reassign a different USS to be highest priority USS.
A user equipment (UE) for communicating with a radio access
network in a communication system, the UE comprising:
a controller and a transceiver, wherein the controller is configured to
control the transceiver to:
monitor, during a monitoring occasion, for downlink control Information
(DCI) transmitted by the radio access network within a
plurality of search spaces, comprising at least one common search
space (CSS) and at least on UE specific search space (USS), within at
least one set of control resources;
wherein the set of control resources comprise at least one control
channel element and each search space comprises a respective set of
physical downlink control channel (PDCCH) candidates within which
to search for DCI;
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[Claim 25]
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wherein the controller is configured to control the UE, during a
current slot of the monitoring occasion, to:
(a) treat a first search space of the plurality of search spaces that
has not been searched in the current slot as a current search space and
attempt to blind decode each PDCCH candidate of the current search
space in turn until an end to searching of the current search space is
triggered;
(b) when the current search space has been fully searched, and the
plurality of search spaces include at least one remaining search space
that has not been searched in the current slot, select a remaining search
space that has not been searched in the current slot to be searched next
and repeat steps (a) and (b) with the selected search space as the current
search space, unless an end to searching in the current slot is triggered;
and
(c) when an end to searching in the current slot is triggered, repeat
steps (a) to (c) during a subsequent slot of a monitoring occasion as the
current slot, until an end to searching in the monitoring occasion is
triggered;
wherein, the UE is configured with a maximum number of blind
decode attempts, and an end to searching in the current slot is triggered
when the maximum number of blind decode attempts will be exceeded
if searching continues;
wherein, the UE is configured with a maximum share of the
maximum number of blind decode attempts that can be used for
searching CSSs; and
wherein the controller is configured to control the UE to, when
selecting a search space to be searched next in step (b), UE prioritise
the remaining search spaces that have not been searched in the current
slot based on a prioritisation scheme that requires that CSSs that have
not been searched in the current slot are prioritised until further
searching in a CSS will cause the maximum share of the maximum
number of blind decode attempts to be exceeded, after which USSs that
have not been searched in the current slot are prioritised.
A user equipment (UE) for communicating with a radio access
network in a communication system, the UE comprising:
a controller and a transceiver, wherein the controller is configured to
control the transceiver to:
monitor, during a monitoring occasion, for downlink control mwo
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[Claim 26]
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formation (DCI) transmitted by the radio access network within a
plurality of search spaces, comprising at least one common search
space (CSS) and at least on UE specific search space (USS), within at
least one set of control resources;
wherein the set of control resources comprise at least one control
channel element and each search space comprises a respective set of
physical downlink control channel (PDCCH) candidates within which
to search for DCI;
wherein the controller is configured to control the UE, during a
current slot of the monitoring occasion, to:
(a) treat a first search space of the plurality of search spaces that
has not been searched in the current slot as a current search space and
attempt to blind decode each PDCCH candidate of the current search
space in turn until an end to searching of the current search space is
triggered;
(b) when the current search space has been fully searched, and the
plurality of search spaces include at least one remaining search space
that has not been searched in the current slot, select a remaining search
space that has not been searched in the current slot to be searched next
and repeat steps (a) and (b) with the selected search space as the current
search space, unless an end to searching in the current slot is triggered;
and
(c) when an end to searching in the current slot is triggered, repeat
steps (a) to (c) during a subsequent slot of a monitoring occasion as the
current slot, until an end to searching in the monitoring occasion is
triggered;
wherein, the UE is configured with a maximum number of blind
decode attempts, and an end to searching in the current search space
and the current slot is triggered when the maximum number of blind
decode attempts will be exceeded if searching continues, even when the
current search space has not been fully searched.
A user equipment (UE) for communicating with a radio access
network in a communication system, the UE comprising:
a controller and a transceiver, wherein the controller is configured to
identify a sequence of consecutive slots for forming a monitoring
occasion, and to control the transceiver to monitor, during the
monitoring occasion, for downlink control information (DCI)
transmitted by the radio access network within a plurality of search
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[Claim 27]
[Claim 28]
[Claim 29]
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spaces, within at least one set of control resources;
wherein the controller is configured to control the UE to monitor for
control information in slots of the sequence of consecutive slots that are
spaced apart by an unmonitored interval of at least one other slot of the
sequence of consecutive slots.
A method performed by a radio access network that communicates
with a user equipment (UE) in a communication system, the method
compnsmg:
transmitting, to the UE, first information for configuring at least one
set of control resources in which the radio access network may transmit
control information, and second information for configuring at least
one search space within the set of control resources within which to
search for control information; and
transmitting, to the UE, from the radio access network, DCI
comprising third information for reconfiguring the at least one set of
control resources configured by the first information, or the at least one
search space configured by the second information;
wherein the third information is configured to provide an indication
of at least one set of control resources configured by the first information,
or of at least one search space configured by the second Information,
within which the UE is to stop monitoring for DCI, start
monitoring for DCI, or continue monitoring for DCI.
A method performed by a radio access network that communicates
with a user equipment (UE) in a communication system, the method
compnsmg:
obtaining information for mapping each of a plurality of possible
power saving configurations to a set of parameters that characterise that
power configuration;
receiving, from the UE, UE assistance information comprising an Indication
of at least one power saving configuration, of the plurality of
power saving configurations, that represents a configuration or capability
of the UE; and
configuring communication with the UE based on the received UE
assistance information.
A method performed by a radio access network that communicates
with a user equipment (UE) in a communication system, the method
compnsmg:
transmitting, to the UE, information for configuring at least one set
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[Claim 30]
[Claim 31]
[Claim 32]
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of control resources in which the radio access network may transmit
control information, and second information for configuring a plurality
of search spaces, comprising at least on UE specific search space
(USS), within at least one set of control resources, wherein the information
comprises information for configuring a maximum share of a
maximum number of blind decode attempts that can be used by the UE
for searching a common search space (CSSs).
A method performed by a radio access network that communicates
with a user equipment (UE) in a communication system, the method
compnsmg:
transmitting, to the UE, information indicating a sequence of consecutive
slots for forming a monitoring occasion, wherein the information
comprises information for indicating an interval between
slots of the sequence of consecutive slots that is to remain unmonitored
by the UE.
A radio access network node for communicating with a user
equipment (UE) in a communication system, the radio access network
node comprising:
a controller and a transceiver, wherein the controller is configured to
control the transceiver to:
transmit, to the UE, first information for configuring at least one set
of control resources in which the radio access network may transmit
control information, and second information for configuring at least
one search space within the set of control resources within which to
search for control information; and
transmit, to the UE, from the radio access network, DCI comprising
third information for reconfiguring the at least one set of control
resources configured by the first information, or the at least one search
space configured by the second information;
wherein the third information is configured to provide an indication
of at least one set of control resources configured by the first information,
or of at least one search space configured by the second Information,
within which the UE is to stop monitoring for DCI, start
monitoring for DCI, or continue monitoring for DCI.
A radio access network node for communicating with a user
equipment (UE) in a communication system, the radio access network
node comprising:
a controller and a transceiver, wherein the controller is configured: to