WO2020064908A1

WO2020064908A1 - Adaptive control-resource-set (coreset) and/or search-space configuration

Info

Publication number: WO2020064908A1
Application number: PCT/EP2019/075988
Authority: WO
Inventors: Andres Reial; Ali Nader; Sina MALEKI; Pramod Jacob MATHECKEN
Original assignee: Telefonaktiebolaget Lm Ericsson (Publ)
Priority date: 2018-09-28
Filing date: 2019-09-26
Publication date: 2020-04-02

Abstract

Methods and apparatuses are disclosed for adaptive control resource set and search space configurations. In one embodiment, a method implemented in a wireless device (WD) includes receiving a configuration for a plurality of search space configurations; and as a result of a trigger, switching from a first search space configuration to a second search space configuration of the plurality of search space configurations. In another embodiment, a method implemented in a network node includes configuring a WD with a plurality of search space configurations, at least one of the plurality of search space configurations associated with a trigger; and transmitting a physical downlink control channel (PDCCH) according to one of the plurality of search space configurations.

Description

ADAPTIVE CONTROL-RESOURCE-SET (CORESET) AND/OR SEARCH-SPACE

CONFIGURATION

TECHNICAL FIELD

Wireless communication and in particular, to adaptive control-resource-set and/or search- space configuration in e.g., connected discontinuous reception (DRX).

BACKGROUND

In the 3^rd Generation Partnership Project (3 GPP) series of standards, wireless device (WD) power saving techniques are being considered for New Radio (NR), also referred to as 5G. The energy consumption of a WD device that operates on the NR technology is being assessed. Specifically, from a physical layer perspective, a goal may be to analyze the various layer- 1 (Ll) features that can result in high energy consumption for a WD device and propose solutions for lowering the energy consumption.

Potential areas in NR that might cause bottle-necks for the WD devices have been identified. Possible high-level generic solutions have also been discussed. One of the main areas determined as having a significant potential for power saving is reducing the number of Physical Downlink Control Channel (PDCCH) monitoring occasions in Radio Resource Control (RRC)- Connected mode. In existing systems, this may be performed through the application of

Connected-DRX (C-DRX).

FIG. 1 depicts an example of existing 3GPP behavior of a WD configured to operate in a discontinuous reception manner (DRX) in RRC Connected mode; called C-DRX. In short (some details such as retransmission timers are omitted for ease of understanding), such a configuration tells the WD that it only needs to monitor PDCCH for potential Downlink Control Information (DCI) candidates during certain periods called On-Duration periods. In cases where there are any PDSCH/PUSCH allocations for the WD in the DCIs, the WD goes into a constantly monitoring mode during which time an Inactivity Timer (IAT) is running. Upon expiration of the timer, the WD returns to the DRX operation, waking up during On-Duration periods (On-Duration periods may be either in range [1/32... l]ms or [l..l600]ms) again.

The inactivity timer period, indicated by 1 in FIG. 1, is (re-)started after each allocation and may be a duration between [0.. 2560]ms. In case there is no allocation to the WD during on-Duration period, as indicated by 2 in FIG. 1, the WD returns to DRX. In case there is no allocation to the WD during the period indicated by 3 in FIG. 1, WD enters DRX. In case there is no allocation to the WD during the period indicated by 4 in FIG. 1, the WD enters long DRX. However, if there is an allocation during the period indicated by 4 in FIG. 1, the WD starts the inactivity timer as in the beginning. If the WD stays in long DRX until an allocation causes the WD to start the inactivity timer, as shown by the period indicated by 5 in FIG. 1, the network may reconfigure (e.g., remove C-DRX) or release the WD. Optionally, the network, such as via a network node, may configure the WD with two DRX cycle sets (one with short DRX cycles and one with long DRX cycles) and the WD can transition through short DRX cycles period to long DRX cycles period. The short DRX may optionally be configured by the network. The duration of the complete period, indicated by 6 in FIG. 1, may be a multiplication factor (called DRX- ShortCycleTimer) [1...16] of short CRX cycles. A main assumption behind this scheme is that after a WD activity, there is a high probability that the WD will communicate with its counterpart within a short time. However, as time passes after the WD activity, this probability gets lower. In some releases, there may be only one configuration for the On-Durations. The one configuration applies to both long and short DRX. Furthermore, throughout the whole RRC connected state operating in a so-called bandwidth part (BWP), the WD may monitor the PDCCH according to one Control Resource Set (CORESET)/Search Space configuration (only called“search space” hereinafter for the sake of simplicity) by decoding PDCCH according to the one CORESET/Search Space configuration. This configuration may be applicable to all the monitoring occasions depicted as an example in FIG. 1 with the blocks filled with a diagonal shading pattern.

A WD in NR may monitor (e.g., receive and decode) data on the PDCCH in its search space for potential downlink control information (DCIs) from the network (e.g., gNB, network node). A search space together with a Control Resource Set (CORESET) configuration may indicate out how often (e.g., at which periodicity) the WD should monitor PDCCH in a time- and frequency grid. Furthermore, a search space configuration can define which potential DCI candidates to search for. Generally, it may be considered that the more candidates configured by the network node in a search space, the more bandwidth (e.g., analog/radio frequency (RF) processing) may be required and the more decoding effort (e.g., baseband processing) may be carried out by the WD. This may be based on an assumption that the PDCCH candidates may be equally likely to occur in any part of the CORESET bandwidth. If, however, the search space for a WD in the CORESET is localized to a time- frequency grid then the WD can reduce its RF bandwidth.

It has been observed that WDs waste precious battery power on monitoring PDCCH when in fact no control data may be transmitted by the network node. Therefore, from a power consumption perspective, it may be beneficial for the WD to monitor PDCCH seldomly and search for a few potential DCI candidates in a small bandwidth. However, in contrast, from a latency perspective and furthermore from a network scheduling perspective, it may be desirable to have the WD monitoring PDCCH as often as possible. Thus, there are competing interests related to the design considerations for PDCCH monitoring. Unfortunately, many of the solutions put a large burden on the network-side to reduce WD power consumption, which may imply a large cost from a network-side implementation perspective.

SUMMARY

Some embodiments provide methods and apparatuses for adaptive control resource set and search space configurations based on a DRX state, sub-state or condition that may advantageously reduce WD power consumption as compared with existing solutions.

According to one aspect of this disclosure, a network node is configured to configure the WD with a plurality of Control Resource Set (CORESET) and search space configurations, each of the plurality of CORESET and search space configurations associated with a discontinuous reception (DRX) condition.

According to another aspect of this disclosure, a WD is configured to receive a configuration for a plurality of Control Resource Set (CORESET) and search space

configurations; and switch from a first to a second one of the plurality of CORESET and search space configurations based at least in part on a discontinuous reception (DRX) condition.

According to an aspect of the present disclosure, a method implemented in a wireless device, WD, is provided. The method includes receiving a configuration for a plurality of search space configurations. The method includes, as a result of a trigger, switching from a first search space configuration to a second search space configuration of the plurality of search space configurations.

In some embodiments of this aspect, the method further includes monitoring a physical downlink control channel, PDCCH, according to the second search space configuration. In some embodiments of this aspect, the trigger is an operational mode of the WD. In some embodiments of this aspect, the trigger is a discontinuous reception, DRX, condition of the WD. In some embodiments of this aspect, the trigger is in one of a downlink control information, DCI, message and a Medium Access Control, MAC, Control Element, CE. In some embodiments of this aspect, the method further includes receiving a command from a network node, the command indicating which one of the plurality of search space configurations to switch to.

In some embodiments of this aspect, the trigger is associated with a timer. In some embodiments of this aspect, the trigger is associated with a physical downlink control channel, PDCCH, reception. In some embodiments of this aspect, the first search space configuration is different from the second search space configuration by at least one of: a different periodicity, a different bandwidth and a different amount of downlink control information, DCI, candidates. In another aspect of the present disclosure, a method implemented in a network node is provided. The method includes configuring a wireless device, WD, with a plurality of search space configurations, at least one of the plurality of search space configurations associated with a trigger. The method includes transmitting a physical downlink control channel, PDCCH, according to one of the plurality of search space configurations.

In some embodiments of this aspect, the trigger is in one of a downlink control information, DCI, message and a Medium Access Control, MAC, Control Element, CE. In some embodiments of this aspect, the method further includes transmitting a command to the WD, the command indicating which one of the plurality of search space configurations that the WD is to switch to. In some embodiments of this aspect, the trigger is associated with a physical downlink control channel, PDCCH, transmission. In some embodiments of this aspect, at least one of the plurality of search space configurations is different from at least a second one of the plurality of search space configurations by at least one of: a different periodicity, a different bandwidth and a different amount of downlink control information, DCI, candidates.

According to yet another aspect of the present disclosure, a wireless device, WD, configured to communicate with a network node is provided. The WD includes processing circuitry. The processing circuitry is configured to cause the WD to receive a configuration for a plurality of search space configurations. The processing circuitry is configured to cause the WD to, as a result of a trigger, switch from a first search space configuration to a second search space configuration of the plurality of search space configurations.

In some embodiments of this aspect, the processing circuitry is further configured to cause the WD to monitor a physical downlink control channel, PDCCH, according to the second search space configuration. In some embodiments of this aspect, the trigger is an operational mode of the WD. In some embodiments of this aspect, the trigger is a discontinuous reception, DRX, condition of the WD. In some embodiments of this aspect, the trigger is in one of a downlink control information, DCI, message and a Medium Access Control, MAC, Control Element, CE. In some embodiments of this aspect, the processing circuitry is further configured to cause the WD to receive a command from the network node, the command indicating which one of the plurality of search space configurations to switch to.

In some embodiments of this aspect, the trigger is associated with a timer. In some embodiments of this aspect, the trigger is associated with a physical downlink control channel, PDCCH, reception. In some embodiments of this aspect, the first search space configuration is different from the second search space configuration by at least one of: a different periodicity, a different bandwidth and a different amount of downlink control information, DCI, candidates. According to yet another aspect of the present disclosure, a network node configured to communicate with a wireless device, WD, is provided. The network node includes processing circuitry. The processing circuitry is configured to cause the network node to configure the WD with a plurality of search space configurations, at least one of the plurality of search space configurations associated with a trigger. The processing circuitry is configured to cause the network node to transmit a physical downlink control channel, PDCCH, according to one of the plurality of search space configurations.

In some embodiments of this aspect, the trigger is in one of a downlink control information, DCI, message and a Medium Access Control, MAC, Control Element, CE. In some embodiments of this aspect, the processing circuitry is further configured to cause the network node to transmit a command to the WD, the command indicating which one of the plurality of search space configurations that the WD is to switch to. In some embodiments of this aspect, the trigger is associated with a physical downlink control channel, PDCCH, transmission. In some embodiments of this aspect, at least one of the plurality of search space configurations is different from at least a second one of the plurality of search space configurations by at least one of: a different periodicity, a different bandwidth and a different amount of downlink control information, DCI, candidates.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of the present embodiments, and the attendant advantages and features thereof, will be more readily understood by reference to the following detailed description when considered in conjunction with the accompanying drawings wherein:

FIG. 1 illustrates an example of a Connected-DRX (C-DRX) operation as currently specified in 3GPP;

FIG. 2 is a schematic diagram of an exemplary network architecture illustrating a communication system according to the principles in the present disclosure;

FIG. 3 is a block diagram of a network node in communication with a wireless device according to some embodiments of the present disclosure;

FIG. 4 is a flowchart of an exemplary process in a network node for a search space configuration unit according to some embodiments of the present disclosure;

FIG. 5 is a flowchart of an exemplary process in a wireless device for a search space adaptor unit according to some embodiments of the present disclosure;

FIG. 6 illustrates an example of a C-DRX in which the WD switches between various search space configurations depending on operation state, according to some of the principles of this disclosure; and FIG. 7 illustrates an example of WD switches between CORESETs/Search Spaces of various sizes, according to some of the principles of this disclosure.

DETAILED DESCRIPTION

Even though in NR (as in LTE) there exist DRX schemes in connected mode (C-DRX), there is still be room for more power savings during the wakeup times. This disclosure addresses this issue.

In some embodiments of the disclosure, the problem of power consumption during PDCCH monitoring can be solved by minimizing the number of PDCCH monitoring occasions, blind decode (BD) candidates, and/or bandwidth especially during C-DRX operation mode. One embodiment is that the WD is pre-configured with several CORESETs and search spaces of various periodicities and bandwidths. The WD then switches between these search space configurations during operation. In some embodiments, the WD can switch between these configurations autonomously, according to a predetermined mechanism between the network node and WD, triggered by for example a presence or a lack of certain events, e.g., PDCCH reception. In other embodiments, the WD can switch between these search space configurations based on commands from the network node, e.g., through DCI commands on PDCCH, and/or Medium Access Control (MAC) Control Elements (CEs) on PDSCH.

One potential advantage of the proposed solution is the power savings in the WD without overly compromising the network node scheduler flexibility and latency.

In some aspects of this disclosure, techniques are described with no (or very little) extra signaling for the WD to implement the principles described herein. This can be particularly useful because it does not add much to the network node signaling overhead as compared to existing techniques, and can render the solution more affordable from the network perspective, while still also providing power savings in the WD.

In some embodiments, a DCI format with a certain size may be configured with many CORESETS and search space configurations. In some embodiments, the periodicity parameter indicates or determines how often the PDCCH channel is transmitted by the network.

In some embodiments, both the network node and WD switch between configurations in a coordinated manner, e.g., according to pre-determined rule and/or an agreed trigger. For example, the WD may trigger the change/switch or the network node can trigger the

change/switch.

Before describing in detail exemplary embodiments, it is noted that the embodiments reside primarily in combinations of apparatus components and processing steps related to adaptive control resource set and/or search space configuration in e.g., connected DRX. Accordingly, components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein. Like numbers refer to like elements throughout the description.

As used herein, relational terms, such as“first” and“second,”“top” and“bottom,” and the like, may be used solely to distinguish one entity or element from another entity or element without necessarily requiring or implying any physical or logical relationship or order between such entities or elements. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the concepts described herein. 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.

In embodiments described herein, the joining term,“in communication with” and the like, may be used to indicate electrical or data communication, which may be accomplished by physical contact, induction, electromagnetic radiation, radio signaling, infrared signaling or optical signaling, for example. One having ordinary skill in the art will appreciate that multiple components may interoperate and modifications and variations are possible of achieving the electrical and data communication.

In some embodiments described herein, the term“coupled,”“connected,” and the like, may be used herein to indicate a connection, although not necessarily directly, and may include wired and/or wireless connections.

The term“network node” used herein can be any kind of network node comprised in a radio network which may further comprise any of base station (BS), radio base station, base transceiver station (BTS), base station controller (BSC), radio network controller (RNC), g Node B (gNB), evolved Node B (eNB or eNodeB), Node B, multi- standard radio (MSR) radio node such as MSR BS, multi-cell/multicast coordination entity (MCE), relay node, integrated access and backhaul (IAB) node, donor node controlling relay, radio access point (AP), transmission points, transmission nodes, Remote Radio Unit (RRU) Remote Radio Head (RRH), a core network node (e.g., mobile management entity (MME), self-organizing network (SON) node, a coordinating node, positioning node, MDT node, etc.), an external node (e.g., 3rd party node, a node external to the current network), nodes in distributed antenna system (DAS), a spectrum access system (SAS) node, an element management system (EMS), etc. The network node may also comprise test equipment. The term“radio node” used herein may be used to also denote a wireless device (WD) such as a wireless device (WD) or a radio network node.

In some embodiments, the non-limiting terms wireless device (WD) or a user equipment (UE) are used interchangeably. The WD herein can be any type of wireless device capable of communicating with a network node or another WD over radio signals, such as wireless device (WD). The WD may also be a radio communication device, target device, device to device (D2D) WD, machine type WD or WD capable of machine to machine communication (M2M), low-cost and/or low-complexity WD, a sensor equipped with WD, Tablet, mobile terminals, smart phone, laptop embedded equipped (LEE), laptop mounted equipment (LME), USB dongles, Customer Premises Equipment (CPE), an Internet of Things (IoT) device, or a

Narrowband IoT (NB-IOT) device etc.

Also, in some embodiments the generic term“radio network node” is used. It can be any kind of a radio network node which may comprise any of base station, radio base station, base transceiver station, base station controller, network controller, RNC, evolved Node B (eNB), Node B, gNB, Multi-ccll/multicast Coordination Entity (MCE), relay node, IAB node, access point, radio access point, Remote Radio Unit (RRU) Remote Radio Head (RRH).

Note that although terminology from one particular wireless system, such as, for example, 3GPP LTE and/or New Radio (NR), may be used in this disclosure, this should not be seen as limiting the scope of the disclosure to only the aforementioned system. Other wireless systems, including without limitation Wide Band Code Division Multiple Access (WCDMA), Worldwide Interoperability for Microwave Access (WiMax), Ultra Mobile Broadband (UMB) and Global System for Mobile Communications (GSM), may also benefit from exploiting the ideas covered within this disclosure.

Note further, that functions described herein as being performed by a wireless device or a network node may be distributed over a plurality of wireless devices and/or network nodes. In other words, it is contemplated that the functions of the network node and wireless device described herein are not limited to performance by a single physical device and, in fact, can be distributed among several physical devices.

Even though the descriptions herein may be explained in the context of one of a

Downlink (DL) and an Uplink (UL) communication, it should be understood that the basic principles disclosed may also be applicable to the other of the one of the DL and the UL communication. In some embodiments in this disclosure, the principles may be considered applicable to a transmitter and a receiver. For DL communication, the network node is the transmitter and the receiver is the WD. For the UL communication, the transmitter is the WD and the receiver is the network node.

Although the description herein may be explained in the context of for example monitoring PDCCH channel, it should be understood that the principles may also be applicable to reduce WD power consumption for other channels. Any two or more embodiments described in this disclosure may be combined in any way with each other.

The term“signaling” used herein may comprise any of: high-layer signaling (e.g., via Radio Resource Control (RRC) or a like), lower- layer signaling (e.g., via a physical control channel or a broadcast channel), or a combination thereof. The signaling may be implicit or explicit. The signaling may further be unicast, multicast or broadcast. The signaling may also be directly to another node or via a third node.

In some embodiments, control information on one or more resources may be considered to be transmitted in a message having a specific format. A message may comprise or represent bits representing payload information and coding bits, e.g., for error coding.

Receiving (or obtaining) control information may comprise receiving one or more control information messages (e.g., an RRC monitoring parameter). It may be considered that receiving control signaling comprises demodulating and/or decoding and/or detecting, e.g. blind detection of, one or more messages, in particular a message carried by the control signaling, e.g. based on an assumed set of resources, which may be searched and/or listened for the control information.

It may be assumed that both sides of the communication (e.g., network and WD side) are aware of the configurations, and may determine the set of resources, e.g. based on for example the reference size.

Signaling may generally comprise one or more symbols and/or signals and/or messages. A signal may comprise or represent one or more bits. An indication may represent signaling, and/or be implemented as a signal, or as a plurality of signals. One or more signals may be included in and/or represented by a message. Signaling, in particular control signaling, may comprise a plurality of signals and/or messages, which may be transmitted on different carriers and/or be associated to different signaling processes, e.g. representing and/or pertaining to one or more such processes and/or corresponding information. An indication may comprise signaling, and/or a plurality of signals and/or messages and/or may be comprised therein, which may be transmitted on different carriers and/or be associated to different acknowledgement signaling processes, e.g. representing and/or pertaining to one or more such processes. Signaling associated to a channel may be transmitted such that represents signaling and/or information for that channel, and/or that the signaling is interpreted by the transmitter and/or receiver to belong to that channel. Such signaling may generally comply with transmission parameters and/or format/s for the channel.

An indication generally may explicitly and/or implicitly indicate the information it represents and/or indicates. Implicit indication may for example be based on position and/or resource used for transmission. Explicit indication may for example be based on a

parametrization with one or more parameters, and/or one or more index or indices corresponding to a table, and/or one or more bit patterns representing the information.

Configuring a radio node, in particular a terminal or WD, may refer to the radio node being adapted or caused or set and/or instructed to operate according to the configuration (e.g., to monitor PDCCH according to an adaptable CORESET and search space configuration scheme). Configuring may be done by another device, e.g., a network node (for example, a base station or gNB) or network, in which case it may comprise transmitting configuration data to the radio node to be configured. Such configuration data may represent the configuration to be configured and/or comprise one or more instruction pertaining to a configuration, e.g. a configuration for transmitting and/or receiving on allocated resources, in particular frequency resources. A radio node may configure itself, e.g., based on configuration data received from a network or network node. A network node may utilize, and/or be adapted to utilize, its circuitry/ies for configuring. Allocation information may be considered a form of configuration data. Configuration data may comprise and/or be represented by configuration information, and/or one or more corresponding indications and/or message/s.

A channel may generally be a logical or physical channel. A channel may comprise and/or be arranged on one or more carriers, in particular a plurality of subcarriers. A wireless communication network may comprise at least one network node, in particular a network node as described herein. A terminal connected or communicating with a network may be considered to be connected or communicating with at least one network node, in particular any one of the network nodes described herein.

A channel may generally be a logical, transport or physical channel. A channel may comprise and/or be arranged on one or more carriers, in particular a plurality of subcarriers. A channel carrying and/or for carrying control signaling/control information may be considered a control channel, in particular if it is a physical layer channel and/or if it carries control plane information. Analogously, a channel carrying and/or for carrying data signaling/user information may be considered a data channel, in particular if it is a physical layer channel and/or if it carries user plane information. A channel may be defined for a specific communication direction, or for two complementary communication directions (e.g., UL and DL, or sidelink in two directions), in which case it may be considered to have two component channels, one for each direction. Configuring a terminal or wireless device (WD) or node may involve instructing and/or causing the wireless device or node to change its configuration, e.g., at least one setting and/or register entry and/or operational mode. A terminal or wireless device or node may be adapted to configure itself, e.g., according to information or data in a memory of the terminal or wireless device (e.g., a predetermined rule as discussed above). Configuring a node or terminal or wireless device by another device or node or a network may refer to and/or comprise

transmitting information and/or data and/or instructions to the wireless device or node by the other device or node or the network, e.g., control information (which may also be and/or comprise configuration data) and/or scheduling data and/or scheduling grants. Configuring a terminal may include sending configuration data to the terminal indicating which search space configuration to use. A terminal may be configured with and/or for scheduling data and/or to use, e.g., for transmission, scheduled and/or allocated uplink resources, and/or, e.g., for reception, scheduled and/or allocated downlink resources. Uplink resources and/or downlink resources may be scheduled and/or provided with allocation or configuration data.

Configuring a Radio Node

Configuring a radio node, in particular a terminal or user equipment or the WD, may refer to the radio node being adapted or caused or set and/or instructed to operate according to the configuration. Configuring may be done by another device, e.g., a network node (for example, a radio node of the network like a base station or eNodeB) or network, in which case it may comprise transmitting configuration data to the radio node to be configured. Such configuration data may represent the configuration to be configured and/or comprise one or more instruction pertaining to a configuration, e.g. a configuration for searching for information on a control channel in DRX mode. A radio node may configure itself, e.g., based on configuration data received from a network or network node. A network node may use, and/or be adapted to use, its circuitry/ies for configuring. Allocation information may be considered a form of configuration data. Configuration data may comprise and/or be represented by configuration information, and/or one or more corresponding indications and/or message/s.

Configuring in general

Generally, configuring may include determining configuration data representing the configuration and providing, e.g. transmitting, it to one or more other nodes (parallel and/or sequentially), which may transmit it further to the radio node (or another node, which may be repeated until it reaches the wireless device). Alternatively, or additionally, configuring a radio node, e.g., by a network node or other device, may include receiving configuration data and/or data pertaining to configuration data, e.g., from another node like a network node, which may be a higher-level node of the network, and/or transmitting received configuration data to the radio node. Accordingly, determining a configuration and transmitting the configuration data to the radio node may be performed by different network nodes or entities, which may be able to communicate via a suitable interface, e.g., an X2 interface in the case of LTE or a corresponding interface for NR. Configuring a terminal (e.g. WD 22) may comprise configuring search space parameters or scheduling downlink and/or uplink transmissions for the terminal, e.g. downlink data and/or downlink control signaling and/or DCI and/or uplink control or data or

communication signaling, in particular acknowledgement signaling, and/or configuring resources and/or a resource pool therefore.

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 disclosure belongs. It will be further understood that terms used herein should be interpreted as having a meaning that is consistent with their meaning in the context of this specification and the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

Referring again to the drawing figures, in which like elements are referred to by like reference numerals, there is shown in FIG. 2 a schematic diagram of a communication system 10, according to an embodiment, such as a 3GPP-type cellular network that may support standards such as LTE and/or NR (5G), which comprises an access network 12, such as a radio access network, and a core network 14. The access network 12 comprises a plurality of network nodes l6a, l6b, l6c (referred to collectively as network nodes 16), such as NBs, eNBs, gNBs or other types of wireless access points, each defining a corresponding coverage area l8a, 18b, l8c (referred to collectively as coverage areas 18). Each network node l6a, 16b, l6c is connectable to the core network 14 over a wired or wireless connection 20. A first wireless device (WD) 22a located in coverage area l8a is configured to wirelessly connect to, or be paged by, the corresponding network node l6c. A second WD 22b in coverage area 18b is wirelessly connectable to the corresponding network node l6a. While a plurality of WDs 22a, 22b

(collectively referred to as wireless devices 22) are illustrated in this example, the disclosed embodiments are equally applicable to a situation where a sole WD is in the coverage area or where a sole WD is connecting to the corresponding network node 16. Note that although only two WDs 22 and three network nodes 16 are shown for convenience, the communication system may include many more WDs 22 and network nodes 16.

Also, it is contemplated that a WD 22 can be in simultaneous communication and/or configured to separately communicate with more than one network node 16 and more than one type of network node 16. For example, a WD 22 can have dual connectivity with a network node 16 that supports LTE and the same or a different network node 16 that supports NR. As an example, WD 22 can be in communication with an eNB for LTE/E-UTRAN and a gNB for NR/NG-RAN.

A network node 16 is configured to include a search space configuration unit 32 which is configured to cause the network node 16 to configure the WD 22 with a plurality of search space configurations, at least one of the plurality of search space configurations associated with a trigger; and transmit a physical downlink control channel, PDCCH, according to one of the plurality of search space configurations.

In some embodiments, the search space configuration unit 32 is configured to cause the network node 16 to configure the WD 22 with a plurality of Control Resource Set (CORESET) and search space configurations, each of the plurality of CORESET and search space

configurations associated with a discontinuous reception (DRX) condition.

A wireless device 22 is configured to include a search space adaptor unit 34 which is configured to cause the WD 22 to receive a configuration for a plurality of search space configurations; and as a result of a trigger, switch from a first search space configuration to a second search space configuration of the plurality of search space configurations.

In some embodiments, the search space adaptor unit 34 is configured to cause the WD 22 to receive a configuration for a plurality of Control Resource Set (CORESET) and search space configurations; and switch from a first to a second one of the plurality of CORESET and search space configurations based at least in part on a discontinuous reception (DRX) condition.

Example implementations, in accordance with an embodiment, of the WD 22 and network node 16 discussed in the preceding paragraphs will now be described with reference to FIG. 3. The communication system 10 includes a network node 16 provided in a communication system 10 and including hardware 58 enabling it to communicate with the WD 22. The hardware 58 may include a communication interface 60 for setting up and maintaining a wired or wireless connection with an interface of a different communication device of the communication system 10, as well as a radio interface 62 for setting up and maintaining at least a wireless connection 64 with a WD 22 located in a coverage area 18 served by the network node 16. The radio interface 62 may be formed as or may include, for example, one or more RF transmitters, one or more RF receivers, and/or one or more RF transceivers.

In the embodiment shown, the hardware 58 of the network node 16 further includes processing circuitry 68. The processing circuitry 68 may include a processor 70 and a memory 72. In particular, in addition to or instead of a processor, such as a central processing unit, and memory, the processing circuitry 68 may comprise integrated circuitry for processing and/or control, e.g., one or more processors and/or processor cores and/or FPGAs (Field Programmable Gate Array) and/or ASICs (Application Specific Integrated Circuitry) adapted to execute instructions. The processor 70 may be configured to access (e.g., write to and/or read from) the memory 72, which may comprise any kind of volatile and/or nonvolatile memory, e.g., cache and/or buffer memory and/or RAM (Random Access Memory) and/or ROM (Read-Only

Memory) and/or optical memory and/or EPROM (Erasable Programmable Read-Only Memory).

Thus, the network node 16 further has software 74 stored internally in, for example, memory 72, or stored in external memory (e.g., database, storage array, network storage device, etc.) accessible by the network node 16 via an external connection. The software 74 may be executable by the processing circuitry 68. The processing circuitry 68 may be configured to control any of the methods and/or processes described herein and/or to cause such methods, and/or processes to be performed, e.g., by network node 16. Processor 70 corresponds to one or more processors 70 for performing network node 16 functions described herein. The memory 72 is configured to store data, programmatic software code and/or other information described herein. In some embodiments, the software 74 may include instructions that, when executed by the processor 70 and/or processing circuitry 68, causes the processor 70 and/or processing circuitry 68 to perform the processes described herein with respect to network node 16, such as for example the process described with reference to FIG. 4.

For example, in some embodiments, processing circuitry 68 of the network node 16 may include a search space configuration unit 32 configured to configure the WD 22 with a plurality of Control Resource Set (CORESET) and search space configurations, each of the plurality of CORESET and search space configurations associated with a discontinuous reception (DRX) condition.

In some embodiments, the processing circuitry 68 is further configured to communicate a control signal to the WD 22, the control signal indicating which of the plurality of CORESET and search space configurations to use for physical downlink control channel (PDCCH) monitoring. In some embodiments, the DRX condition includes at least one of a DRX operation mode, a DRX state, a DRX sub-state, and a DRX timer associated with the WD 22. In some embodiments, each of the plurality of CORESET and search space configurations is different from the other ones of the plurality of CORESET and search space configurations by at least one of: a different periodicity, a different bandwidth, and a different amount of downlink control information (DCI) candidates.

The communication system 10 further includes the WD 22 already referred to. The WD 22 may have hardware 80 that may include a radio interface 82 configured to set up and maintain a wireless connection 64 with a network node 16 serving a coverage area 18 in which the WD 22 is currently located. The radio interface 82 may be formed as or may include, for example, one or more RF transmitters, one or more RF receivers, and/or one or more RF transceivers. The hardware 80 of the WD 22 further includes processing circuitry 84. The processing circuitry 84 may include a processor 86 and memory 88. In particular, in addition to or instead of a processor, such as a central processing unit, and memory, the processing circuitry 84 may comprise integrated circuitry for processing and/or control, e.g., one or more processors and/or processor cores and/or FPGAs (Field Programmable Gate Array) and/or ASICs (Application Specific Integrated Circuitry) adapted to execute instructions. The processor 86 may be configured to access (e.g., write to and/or read from) memory 88, which may comprise any kind of volatile and/or nonvolatile memory, e.g., cache and/or buffer memory and/or RAM (Random Access Memory) and/or ROM (Read-Only Memory) and/or optical memory and/or EPROM (Erasable Programmable Read-Only Memory).

Thus, the WD 22 may further comprise software 90, which is stored in, for example, memory 88 at the WD 22, or stored in external memory (e.g., database, storage array, network storage device, etc.) accessible by the WD 22. The software 90 may be executable by the processing circuitry 84. The software 90 may include a client application 92. The client application 92 may be operable to provide a service to a human or non-human user via the WD 22. The client application 92 may interact with the user to generate the user data that it provides.

The processing circuitry 84 may be configured to control any of the methods and/or processes described herein and/or to cause such methods, and/or processes to be performed, e.g., by WD 22. The processor 86 corresponds to one or more processors 86 for performing WD 22 functions described herein. The WD 22 includes memory 88 that is configured to store data, programmatic software code and/or other information described herein. In some embodiments, the software 90 and/or the client application 92 may include instructions that, when executed by the processor 86 and/or processing circuitry 84, causes the processor 86 and/or processing circuitry 84 to perform the processes described herein with respect to WD 22, such as for example the process described with reference to FIG. 5.

For example, in some embodiments, the processing circuitry 84 of the wireless device 22 may include a search space adaptor unit 34 configured to receive a configuration for a plurality of Control Resource Set (CORESET) and search space configurations; and switch from a first to a second one of the plurality of CORESET and search space configurations based at least in part on a discontinuous reception (DRX) condition.

In some embodiments, the processing circuitry 84 is configured to switch from the first to the second one of the plurality of CORESET and search space configurations based at least in part on at least one of: a predefined rule and as a result of a control signal from the network node 16. In some embodiments, the DRX condition includes at least one of a DRX operation mode, a DRX state, a DRX sub-state, and a DRX timer. In some embodiments, each of the plurality of CORESET and search space configurations is different from the other ones of the plurality of CORESET and search space configurations by at least one of: a different periodicity, a different bandwidth, and a different amount of downlink control information (DCI) candidates.

In some embodiments, the inner workings of the network node 16 and WD 22 may be as shown in FIG. 3 and independently, the surrounding network topology may be that of FIG. 2.

The wireless connection 64 between the WD 22 and the network node 16 is in accordance with the teachings of the embodiments described throughout this disclosure.

Although FIGS. 2 and 3 show various“units” such as a search space configuration unit 32, and a search space adaptor unit 34 as being within a respective processor, it is contemplated that these units may be implemented such that a portion of the unit is stored in a corresponding memory within the processing circuitry. In other words, the units may be implemented in hardware or in a combination of hardware and software within the processing circuitry.

FIG. 4 is a flowchart of an exemplary process in a network node 16 according to some embodiments of the present disclosure. One or more Blocks and/or functions and/or methods performed by the network node 16 may be performed by one or more elements of network node 16 such as by search space configuration unit 32 in processing circuitry 68, processor 70, radio interface 62, etc. according to the example method. The example method includes configuring (Block S134), such as via search space configuration unit 32, processing circuitry 68, processor 70 and/or radio interface 62, a wireless device, WD 22, with a plurality of search space configurations, at least one of the plurality of search space configurations associated with a trigger. The method includes transmitting (Block S136), such as via search space configuration unit 32, processing circuitry 68, processor 70 and/or radio interface 62, a physical downlink control channel, PDCCH, according to one of the plurality of search space configurations.

In some embodiments, the trigger is in one of a downlink control information, DCI, message and a Medium Access Control, MAC, Control Element, CE (transmitted, such as via search space configuration unit 32, processing circuitry 68, processor 70 and/or radio interface 62). In some embodiments, the method further includes transmitting, such as via search space configuration unit 32, processing circuitry 68, processor 70 and/or radio interface 62, a command to the WD 22, the command indicating which one of the plurality of search space configurations that the WD 22 is to switch to. In some embodiments, the trigger is associated with a physical downlink control channel, PDCCH, transmission. In some embodiments, at least one of the plurality of search space configurations is different from at least a second one of the plurality of search space configurations by at least one of: a different periodicity, a different bandwidth and a different amount of downlink control information, DCI, candidates. In another embodiment, the method includes configuring, such as via the search space configuration unit 32, a wireless device 22 (WD) with a plurality of Control Resource Set (CORESET) and search space configurations, each of the plurality of CORESET and search space configurations associated with a discontinuous reception (DRX) condition.

In some embodiments, the method further includes communicating, such as via the search space configuration unit 32, a control signal to the WD 22, the control signal indicating which of the plurality of CORESET and search space configurations to use for physical downlink control channel (PDCCH) monitoring. In some embodiments, the DRX condition includes at least one of a DRX operation mode, a DRX state, a DRX sub-state, and a DRX timer associated with the WD 22. In some embodiments, each of the plurality of CORESET and search space configurations is different from the other ones of the plurality of CORESET and search space configurations by at least one of: a different periodicity, a different bandwidth, and a different amount of downlink control information (DCI) candidates.

FIG. 5 is a flowchart of an exemplary process in a wireless device 22 according to some embodiments of the present disclosure. One or more Blocks and/or functions and/or methods performed by WD 22 may be performed by one or more elements of WD 22 such as by search space adaptor unit 34 in processing circuitry 84, processor 86, radio interface 82, etc. The example method includes receiving (Block S138), such as via search space adaptor unit 34, processing circuitry 84, processor 86, and/or radio interface 82, a configuration for a plurality of search space configurations. The method includes, as a result of a trigger, switching (Block S140), such as via search space adaptor unit 34, processing circuitry 84, processor 86, and/or radio interface 82, from a first search space configuration to a second search space configuration of the plurality of search space configurations.

In some embodiments, the method further includes monitoring, such as via search space adaptor unit 34, processing circuitry 84, processor 86, and/or radio interface 82, a physical downlink control channel, PDCCH, according to the second search space configuration. In some embodiments, the trigger is an operational mode of the WD 22. In some embodiments, the trigger is a discontinuous reception, DRX, condition of the WD 22. In some embodiments, the trigger is in one of a downlink control information, DCI, message and a Medium Access Control, MAC, Control Element, CE (received, such as via search space adaptor unit 34, processing circuitry 84, processor 86, and/or radio interface 82). In some embodiments, the method further includes receiving, such as via search space adaptor unit 34, processing circuitry 84, processor 86, and/or radio interface 82, a command from a network node 16, the command indicating which one of the plurality of search space configurations to switch to. In some embodiments, the trigger is associated with a timer. In some embodiments, the trigger is associated with a physical downlink control channel, PDCCH, reception. In some embodiments, the first search space configuration is different from the second search space configuration by at least one of: a different periodicity, a different bandwidth and a different amount of downlink control information, DCI, candidates.

In another embodiment, the method includes receiving, such as via a search space adaptor unit 34, a configuration for a plurality of Control Resource Set (CORESET) and search space configurations. The method includes switching, such as via a search space adaptor unit 34, from a first to a second one of the plurality of CORESET and search space configurations based at least in part on a discontinuous reception (DRX) condition.

In some embodiments, the switching comprises switching from the first to the second one of the plurality of CORESET and search space configurations based at least in part on at least one of: a predefined rule and as a result of a control signal from the network node 16. In some embodiments, the DRX condition includes at least one of a DRX operation mode, a DRX state, a DRX sub-state, and a DRX timer. In some embodiments, each of the plurality of CORESET and search space configurations is different from the other ones of the plurality of CORESET and search space configurations by at least one of: a different periodicity, a different bandwidth, and a different amount of downlink control information (DCI) candidates.

Having described some embodiments for search space configurations in e.g., connected DRX that may advantageously reduce WD power consumption, without overburdening the network side, a more detailed description of some of the embodiments is described below, which may be implemented by the network node 16 and/or wireless device 22.

Even though this disclosure describes embodiments in the context of C-DRX operation, it should be understood that the methods herein may be beneficial for and/or equally applicable to other operational modes. For example, the techniques herein related to switching configuration issued through network node 16 commands can be carried out even when the WD 22 is in constant reception mode (i.e., without a C-DRX configuration); for example, in case the network node 16 during low throughput periods decides to move the WD 22 to a less demanding (in terms of processing and/or power consumption, and/or network node resource utilization) PDCCH monitoring related configuration. The principle may also be used for moving the WD 22 e.g. from C-DRX in RRC CONNECTED to I-DRX in RRC IDLE or RRC INACTIVE.

Generally, the network (e.g., network node 16) prefers to have the WD 22 highly reachable during the time the Inactivity Timer is running. The preferred search space

configuration may indicate very frequent PDCCH monitoring by the WD 22 (e.g., every slot) during reception periods, including On-Duration periods. One way to reduce the accumulated energy consumption impact of frequent monitoring during such On-Periods is to configure the WD 22 with very short On-Duration periods. However, doing so could lead to fewer possibilities for the network node 16 to schedule the WDs 22 when many WDs 22 are active in the network.

Thus, the principles in this disclosure include configuring the WD 22 with

various/different search space configurations, where the WD 22 can switch between the various/different configurations depending for example on the operation mode. An example of this is depicted in FIG. 6, in which the WD 22 in regular RRC CONNECTED mode during the time the Inactivity Timer is running monitors the PDCCH according to one search space (SS) configuration, e.g., a search space with more frequent DCI occasions. On the other hand, during the On-Duration the WD 22 can monitor the PDCCH according to another search space configuration, e.g. a less frequent search space. In other words, during the On-Duration (e.g., as indicated by 150 in FIG. 6), the WD 22 can switch to monitoring the PDCCH according to a search space with low periodicity, thereby, reducing the power consumption for the WD 22 device during the ON-period (as compared to power consumption in regular RRC

CONNECTED mode). In case there is no allocation to the WD 22 during the On-Duration 150, the WD 22 returns to DRX.

Furthermore, to save more power/processing in the WDs 22, the various search space configurations could potentially use CORESETS of different sizes, i.e., different bandwidths and/or configure different amounts of potential DCI candidates, as shown for example in FIG. 7. For example, the WDs 22 can be configured with different CORESETS/SS configurations based on an operation mode that the WD 22 is in. For example, during the WD 22 active time (or running inactivity timer (IAT) as indicated by 152 in FIG. 7), the WD 22 may be configured with wider CORESETS/SSs (as indicated by the larger boxes in FIG. 7 for CORESET/SS under the inactivity Timer duration). Duration/time 152 may be considered a time during the WD 22 operates on a larger CORESET/SS with several potential DCIs configured. On the other hand, during the DRX as indicated by 154 in FIG. 7, the WD 22 may be configured with narrower CORESETS/SSs (as indicated by the smaller, middle box in FIG. 7 for CORESET/SS under the DRX states duration) such that the WD 22 can monitor DRX potential PDCCHs (e.g., wake-up signaling, WUS), with narrower CORESETS/SS. This may, for example, allow for a more power efficient implementation of WUS detection. Duration/time 154 may be considered a time during which the WD 22 enters a pre-configured search space during C-DRX until a wake-up is detected.

In one aspect of this disclosure, there could be even finer granularity with several configurations separately applicable to short DRX cycles and long DRX cycles. In another aspect of this disclosure, the switching between the configurations can happen autonomously based on a predetermined agreement or rule between the network node 16 and the WD 22 regarding e.g., when to transition between operation states. The implicit switching criteria or predefined rule may include, without limitation, one or more of the following: 1) Beginning of a DRX cycle ON phase; 2) Expiration of a timer, e.g., which may be the result of one or more of: lack of reception of a PDCCH addressed to the WD during a predetermined number of search space occasions, lack of reception of a PDCCH addressed to the WD during a predetermined number of DRX cycles, and timer setting after a finished PDSCH reception (or immediately, timer = 0); and/or 3) a changing state (non-DRX, short CDRX, long CDRX, etc.) according to other state control mechanisms.

In another aspect of the present invention, the network node 16 explicitly commands the WD 22 to switch between pre-configured/specified configurations. Such commands could be carried out via: 1) DCIs, either in separate, non-data-scheduling DCIs or in DCIs simultaneously scheduling a PDSCH transmission, and/or 2) Medium Access Control (MAC) Control Elements (CEs) in which the identity of the intended search space may be given. The identity may be an index value used to select a search space option from a list or table or look-up table of multiple options.

The multiple search space options may be configured e.g., via RRC signaling, using existing mechanisms or their extensions.

Some embodiments of this disclosure provide for one or more of the following:

The WD 22 operates in a discontinuous manner during the active part of the DRX activity, e.g., DRX inside DRX. This may be through the use of the periodicity parameter of the search space configuration.

The WD 22 may achieve potential power savings by use of smaller bandwidths and monitoring fewer DCI candidates which in turn may be obtained by switching between different CORESET/search space configurations. The switching between various configurations may be performed during different sub-states of connected mode DRX, thereby, enabling further power savings compared to using a single search space configuration during the sub-states of connected mode DRX. It should be noted that the principles in this disclosure are not limited to the C-DRX operation and may be applicable to other modes, such as the Idle/Inactive mode DRX, as well.

The WD 22 operates in a smaller bandwidth and monitors fewer DCI candidates as a result of CORESET/Search space configuration changing during different sub- states of the connected mode DRX. In addition, some embodiments of the present disclosure may include one or more of the following:

Embodiment Al . A network node configured to communicate with a wireless device

(WD), the network node configured to, and/or comprising a radio interface and/or comprising processing circuitry configured to:

configure the WD with a plurality of Control Resource Set (CORESET) and search space configurations, each of the plurality of CORESET and search space configurations associated with a discontinuous reception (DRX) condition.

Embodiment A2. The network node of Embodiment Al , wherein the processing circuitry is further configured to communicate a control signal to the WD, the control signal indicating which of the plurality of CORESET and search space configurations to use for physical downlink control channel (PDCCH) monitoring.

Embodiment A3. The network node of Embodiment Al , wherein the DRX condition includes at least one of a DRX operation mode, a DRX state, a DRX sub-state, and a DRX timer associated with the WD.

Embodiment A4. The network node of Embodiment Al , wherein each of the plurality of CORESET and search space configurations is different from the other ones of the plurality of CORESET and search space configurations by at least one of: a different periodicity, a different bandwidth, and a different amount of downlink control information (DCI) candidates.

Embodiment Bl . A method implemented in a network node, the method comprising: configuring a wireless device (WD) with a plurality of Control Resource Set (CORESET) and search space configurations, each of the plurality of CORESET and search space

configurations associated with a discontinuous reception (DRX) condition.

Embodiment B2. The method of Embodiment B 1 , further comprising

communicating a control signal to the WD, the control signal indicating which of the plurality of CORESET and search space configurations to use for physical downlink control channel (PDCCH) monitoring.

Embodiment B3. The method of Embodiment B 1 , wherein the DRX condition includes at least one of a DRX operation mode, a DRX state, a DRX sub-state, and a DRX timer associated with the WD.

Embodiment B4. The method of Embodiment B 1 , wherein each of the plurality of CORESET and search space configurations is different from the other ones of the plurality of CORESET and search space configurations by at least one of: a different periodicity, a different bandwidth, and a different amount of downlink control information (DCI) candidates. Embodiment Cl . A wireless device (WD) configured to communicate with a network node, the WD configured to, and/or comprising a radio interface and/or processing circuitry configured to:

receive a configuration for a plurality of Control Resource Set (CORESET) and search space configurations; and

switch from a first to a second one of the plurality of CORESET and search space configurations based at least in part on a discontinuous reception (DRX) condition.

Embodiment C2. The WD of Embodiment Cl, wherein the processing circuitry is configured to switch from the first to the second one of the plurality of CORESET and search space configurations based at least in part on at least one of: a predefined rule and as a result of a control signal from the network node.

Embodiment C3. The WD of Embodiment C 1 , wherein the DRX condition includes at least one of a DRX operation mode, a DRX state, a DRX sub-state, and a DRX timer.

Embodiment C4. The WD of Embodiment Cl, wherein each of the plurality of CORESET and search space configurations is different from the other ones of the plurality of CORESET and search space configurations by at least one of: a different periodicity, a different bandwidth, and a different amount of downlink control information (DCI) candidates.

Embodiment Dl . A method implemented in a wireless device (WD), the method comprising:

receiving a configuration for a plurality of Control Resource Set (CORESET) and search space configurations; and

switching from a first to a second one of the plurality of CORESET and search space configurations based at least in part on a discontinuous reception (DRX) condition.

Embodiment D2. The method of Embodiment Dl, wherein the switching comprises switching from the first to the second one of the plurality of CORESET and search space configurations based at least in part on at least one of: a predefined rule and as a result of a control signal from the network node.

Embodiment D3. The method of Embodiment D 1 , wherein the DRX condition includes at least one of a DRX operation mode, a DRX state, a DRX sub-state, and a DRX timer.

Embodiment D4. The method of Embodiment D 1 , wherein each of the plurality of CORESET and search space configurations is different from the other ones of the plurality of CORESET and search space configurations by at least one of: a different periodicity, a different bandwidth, and a different amount of downlink control information (DCI) candidates.

As will be appreciated by one of skill in the art, the concepts described herein may be embodied as a method, data processing system, computer program product and/or computer storage media storing an executable computer program. Accordingly, the concepts described herein may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects all generally referred to herein as a “circuit” or“module.” Any process, step, action and/or functionality described herein may be performed by, and/or associated to, a corresponding module, which may be implemented in software and/or firmware and/or hardware. Furthermore, the disclosure may take the form of a computer program product on a tangible computer usable storage medium having computer program code embodied in the medium that can be executed by a computer. Any suitable tangible computer readable medium may be utilized including hard disks, CD-ROMs, electronic storage devices, optical storage devices, or magnetic storage devices.

Some embodiments are described herein with reference to flowchart illustrations and/or block diagrams of methods, systems and computer program products. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer (to thereby create a special purpose computer), special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer readable memory or storage medium that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer readable memory produce an article of manufacture including instruction means which implement the function/act specified in the flowchart and/or block diagram block or blocks.

The computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks.

It is to be understood that the funct ions/ acts noted in the blocks may occur out of the order noted in the operational illustrations. For example, two blocks shown in succession may in fact be executed substantially concurrently or the blocks may sometimes be executed in the reverse order, depending upon the funct ionality/acts involved. Although some of the diagrams include arrows on communication paths to show a primary direction of communication, it is to be understood that communication may occur in the opposite direction to the depicted arrows.

Computer program code for carrying out operations of the concepts described herein may be written in an object oriented programming language such as Java® or C++. However, the computer program code for carrying out operations of the disclosure may also be written in conventional procedural programming languages, such as the "C" programming language. The program code may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer. In the latter scenario, the remote computer may be connected to the user's computer through a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider).

Many different embodiments have been disclosed herein, in connection with the above description and the drawings. It will be understood that it would be unduly repetitious and obfuscating to literally describe and illustrate every combination and subcombination of these embodiments. Accordingly, all embodiments can be combined in any way and/or combination, and the present specification, including the drawings, shall be construed to constitute a complete written description of all combinations and subcombinations of the embodiments described herein, and of the manner and process of making and using them, and shall support claims to any such combination or subcombination.

It will be appreciated by persons skilled in the art that the embodiments described herein are not limited to what has been particularly shown and described herein above. In addition, unless mention was made above to the contrary, it should be noted that all of the accompanying drawings are not to scale. A variety of modifications and variations are possible in light of the above teachings without departing from the scope of the following claims.

Claims

CLAIMS:

1. A method implemented in a wireless device, WD (22), the method comprising: receiving (S138) a configuration for a plurality of search space configurations; and as a result of a trigger, switching (S140) from a first search space configuration to a second search space configuration of the plurality of search space configurations.

2. The method of Claim 1, further comprising:

monitoring a physical downlink control channel, PDCCH, according to the second search space configuration.

3. The method of any one of Claims 1 and 2, wherein the trigger is an operational mode of the WD (22).

4. The method of any one of Claims 1 and 2, wherein the trigger is a discontinuous reception, DRX, condition of the WD (22).

5. The method of any one of Claims 1 and 2, wherein the trigger is in one of a downlink control information, DCI, message and a Medium Access Control, MAC, Control Element, CE.

6. The method of any one of Claims 1 and 2, further comprising:

receiving a command from a network node (16), the command indicating which one of the plurality of search space configurations to switch to.

7. The method of any one of Claims 1 and 2, wherein the trigger is associated with a timer.

8. The method of any one of Claims 1 and 2, wherein the trigger is associated with a physical downlink control channel, PDCCH, reception.

9. The method of any one of Claims 1-8, wherein the first search space

configuration is different from the second search space configuration by at least one of: a different periodicity, a different bandwidth and a different amount of downlink control information, DCI, candidates.

10. A method implemented in a network node (16), the method comprising:

configuring (S134) a wireless device, WD (22), with a plurality of search space configurations, at least one of the plurality of search space configurations associated with a trigger; and

transmitting (S136) a physical downlink control channel, PDCCH, according to one of the plurality of search space configurations.

11. The method of Claim 10, wherein the trigger is in one of a downlink control information, DCI, message and a Medium Access Control, MAC, Control Element, CE.

12. The method of Claim 10, further comprising:

transmitting a command to the WD (22), the command indicating which one of the plurality of search space configurations that the WD (22) is to switch to.

13. The method of Claim 10, wherein the trigger is associated with a physical downlink control channel, PDCCH, transmission.

14. The method of any one of Claims 10-13, wherein at least one of the plurality of search space configurations is different from at least a second one of the plurality of search space configurations by at least one of: a different periodicity, a different bandwidth and a different amount of downlink control information, DCI, candidates.

15. A wireless device, WD (22), configured to communicate with a network node (16), the WD (22) comprising processing circuitry (84), the processing circuitry (84) configured to cause the WD (22) to:

receive a configuration for a plurality of search space configurations; and

as a result of a trigger, switch from a first search space configuration to a second search space configuration of the plurality of search space configurations.

16. The wireless device (22) of Claim 15, wherein the processing circuitry (84) is further configured to cause the WD (22) to:

monitor a physical downlink control channel, PDCCH, according to the second search space configuration.

17. The wireless device (22) of any one of Claims 15 and 16, wherein the trigger is an operational mode of the WD (22).

18. The wireless device (22) of any one of Claims 15 and 16, wherein the trigger is a discontinuous reception, DRX, condition of the WD (22).

19. The wireless device (22) of any one of Claims 15 and 16, wherein the trigger is in one of a downlink control information, DCI, message and a Medium Access Control, MAC, Control Element, CE.

20. The wireless device (22) of any one of Claims 15 and 16, wherein the processing circuitry (84) is further configured to cause the WD (22) to:

receive a command from the network node (16), the command indicating which one of the plurality of search space configurations to switch to.

21. The wireless device (22) of any one of Claims 15 and 16, wherein the trigger is associated with a timer.

22. The wireless device (22) of any one of Claims 15 and 16, wherein the trigger is associated with a physical downlink control channel, PDCCH, reception.

23. The wireless device (22) of any one of Claims 15-22, wherein the first search space configuration is different from the second search space configuration by at least one of: a different periodicity, a different bandwidth and a different amount of downlink control information, DCI, candidates.

24. A network node (16) configured to communicate with a wireless device, WD (22), the network node (16) comprising processing circuitry (68), the processing circuitry (68) configured to cause the network node (16) to:

configure the WD (22) with a plurality of search space configurations, at least one of the plurality of search space configurations associated with a trigger; and

transmit a physical downlink control channel, PDCCH, according to one of the plurality of search space configurations.

25. The network node (16) of Claim 24, wherein the trigger is in one of a downlink control information, DCI, message and a Medium Access Control, MAC, Control Element, CE.

26. The network node (16) of Claim 24, wherein the processing circuitry (68) is further configured to cause the network node (16) to:

transmit a command to the WD (22), the command indicating which one of the plurality of search space configurations that the WD (22) is to switch to.

27. The network node (16) of Claim 24, wherein the trigger is associated with a physical downlink control channel, PDCCH, transmission.

28. The network node (16) of any one of Claims 24-27, wherein at least one of the plurality of search space configurations is different from at least a second one of the plurality of search space configurations by at least one of: a different periodicity, a different bandwidth and a different amount of downlink control information, DCI, candidates.