Switch pattern for lowband carrier aggregation via switching

Abstract

A user equipment, UE, (22) configured to communicate with a network node (16) is provided. The UE (22) is configured with at least one switch pattern for low band carrier aggregation. The UE (22) is configured to determine whether to apply at least one of the at least one switch pattern to at least one slot based on a state of a secondary cell, SCell, adapt at least one operation in the at least one slot associated with the SCell based on the determination, and indicate the at least one adapted operation.

Description

[0001] SWITCH PATTERN FOR LOWBAND CARRIER AGGREGATION VIA SWITCHING

[0002] TECHNICAL FIELD

[0003] The present disclosure relates to wireless communications, and in particular, to low band carrier aggregation switch patterns in wireless communication networks.

[0004] BACKGROUND

[0005] The Third Generation Partnership Project (3GPP) has developed and is developing standards for Fourth Generation (4G) (also referred to as Long Term Evolution (LTE)) and Fifth Generation (5G) (also referred to as New Radio (NR)) wireless communication systems. Such systems provide, among other features, broadband communication between network nodes, such as base stations, and mobile user equipments (UEs), as well as communication between network nodes and between UEs. The 3GPP is also developing standards for Sixth Generation (6G) wireless communication networks.

[0006] Radio Link Monitoring (RLM) handling in NR

[0007] In NR, RLM is also defined for a similar purpose as in LTE, i.e., monitor the downlink (DL) radio link quality of the serving cell (more precisely, the special cell (SpCell), i.e., primary cell (PCell) and PSCell if the UE is configured with Multiple-Radio Dual Connectivity) in RRC CONNECTED state.

[0008] RLM is performed by the lower layers at the UE (e.g., LI - layer 1, physical layer). The UE performs measurements, e.g., SINR (Signal to Interference plus Noise Ratio) in which when the quality of the measurements is poor (according to a hypothetical physical downlink control channel (PDCCH) Block Error Rate (BLER) threshold), the lower layers at the UE generate an out of sync (OOS) indication to higher layer, which maintains a counter. Similarly, when the quality improves (according to another hypothetical PDCCH Block Error Rate threshold), the UE generates an in sync (IS) indication to higher layer, which maintains another counter. These counters are used by higher layer to determine whether or not a radio link failure should be declared.

[0009] To perform these measurements to generate OOS and IS events, the UE uses reference signals. In LTE, these may be referred to as Cell-specific Reference Signals (CRS) defined per cell. Different from LTE, some level of configurability has beenintroduced for RLM in NR in terms of RS (Reference Signal) type / beam / RLM resource configuration and BLER thresholds for IS / OOS generation.

[0010] Explicit RLM configuration

[0011] In NR, two types of reference signals (RS Types) are defined: PBCH (Physical Broadcast Channel) / SS Block (SSB or SS Block), which comprises synchronization signals equivalent to PSS (Primary Synchronization Signal) / SSS (Secondary Synchronization Signal) in LTE and PBCH / DMRS (Demodulation RS), and, CSLRS (Channel State Information RS), more configurable and configured via dedicated signaling. There are different reasons to define the two RS types, one of them being the possibility to transmit SSBs in wide beams while CSLRSs in narrow beams.

[0012] In NR, the RS type used for RLM is also configurable and both CSLRS based RLM and SS block based RLM are supported. In the case of CSLRS, the time / frequency resource and sequence can be used. As there can be multiple beams, the UE needs to know which ones to monitor for RLM and how to generate IS / OOS events. In the case of SSB, each beam can be identified by an SSB index (derived from a time index in PBCH and / or a PBCH / DMRS scrambling). The network (e.g., network node) can configure by RRC (Radio Resource Control) signaling, X RLM resources, either related to SS blocks or CSL RS, as follows:

[0013] One RLM-RS resource can be either one PBCHSS block or one CSLRS resource / port;

[0014] The RLM-RS resources are UE-specifically configured at least in case of CSLRS based RLM;

[0015] When the UE is configured to perform RLM on one or multiple RLM-RS resource(s),

[0016] o Periodic IS is indicated if the estimated link quality corresponding to hypothetical PDCCH BLER based on at least Y RLM-RS resource(s) among all configured X RLM-RS resource(s) is above Q in threshold; o Periodic OOS is indicated if the estimated link quality corresponding to hypothetical PDCCH BLER based on all configured X RLM-RS resource(s) is below Q out threshold;

[0017] ■ That points in the direction that only the quality of best beam really matters at every sample to generate OOS / IS events.RLM is not defined for SCells, only for SpCells, i.e., if the UE is in single connectivity, RLM is performed only on the PCell. If the UE is configured with MR-DC, RLM is performed on both the PCell and the PSCell.

[0018] Resources for RLM can be configured viaRRC, see 3GPP TS 38.331 V18.9.0 (2025-03), as part of the SpCellConfig, within each dedicated BWP configuration - BWP-DownlinkDedicated, in an RRCRe configuration or RRCResume message) within the RadioLinkMonitoringConfig IE, as illustrated in FIG. 1 A.

[0019] Each RLM resource of an SpCell that needs to be monitored is configured in the IE (Information Element) RadioLinkMonitoringRS, wherein the UE is configured either with an SSB index or a CSLRS index. These resources are equivalent to the downlink beams / spatial directions transmitting the reference signals (SSBs) associated with these indexes. And, each of these beams are also used for transmission of control channel(s) for that cell (e.g., PDCCH) so that performing RLM is equivalent to assessing the quality of control channel for that cell.

[0020] The UE can be configured with up to 1VRLMRadioLinkMonitoringRS for radio link monitoring depending on Lmax(maximum number of SSBs and / or downlink beams transmitting SSBs) as shown in table illustrated in FIG. IB.

[0021] Implicit RLM confi uration

[0022] According to 3GPP TS 38.331, if an explicit list of RSs is not configured for RLM, the UE monitors the reference signal(s) configured as Quasi-Co-location (QCL) of currently active TCI (Transmission Configuration Indicator) states configured for the PCell or PSCell. FIG. 1C shows the field description for the RadioLinkMonitoringConfig IE.

[0023] As described in 3GPP TS 38.213 V18.6.0 (2025-03), if the UE is not provided RadioLinkMonitoringRS and the UE is provided for PDCCH receptions TCI states that include one or more of a CSLRS

[0024] the UE uses for radio link monitoring the RS provided for the active TCI state for PDCCH reception if the active TCI state for PDCCH reception includes only one RS

[0025] if the active TCI state for PDCCH reception includes two RS, the UE expects that one RS is configured with qcl-Type set to 'typeD'(see 3GPP TS 38.214 VI 8.6.0 (2025-03)) and the UE uses the RS configured with qcl-Type set to 'typeD'forradio link monitoring,' the UE does not expect both RS to be configured with qcl-Type set to 'typeD'

[0026] the UE is not required to use for radio link monitoring an aperiodic or semi-persistent RS

[0027] For Lmax, the UE selects the NRLMRS provided for active TCI states for PDCCH receptions in CORESETs associated with the search space sets in an order from the shortest monitoring periodicity. If more than one CORESETs are associated with search space sets having same monitoring periodicity, the UE determines the order of the CORESET from the highest CORESET index as described in clause 10.1.

[0028] The RS for a TCI state is configured by TCI-State IE as illustrated in FIG. ID. FIG. IE shows the field description for the QCL-Info field in the TCI-State IE.

[0029] And, the TCI state is considered activated based on reception of one or more MAC (Medium Access Control) Control Elements (CEs) (see 3GPP TS 38.321 V18.5.0 (2025-03) for further details on MAC CE activation of TCI states).

[0030] Out of Sync (QOS) and In Sync (IS) indications based on RLM resources

[0031] For both implicit and explicit RLM configurations, the UE performs monitoring of the resources and evaluates the conditions whether the radio link is suitable for the RRC connection or not.

[0032] In non-DRX (non Discontinuous Reception) mode operation, the physical layer in the UE assesses once per indication period the radio link quality, evaluated over the previous time period defined in 3GPP TS 38.133 V18.8.0 (2024-12) against thresholds (Qout and Qin) configured by rlmlnSyncOutOfSyncThreshold. The UE determines the indication period as the maximum between the shortest periodicity for radio link monitoring resources and 10 msec.

[0033] In DRX (Discontinuous Reception) mode operation, the physical layer in the UE assesses once per indication period the radio link quality, evaluated over the previous time period defined in 3GPP TS 38.133, against thresholds (Qout and Qin) provided by rlmlnSyncOutOfSyncThreshold. The UE determines the indication period as the maximum between the shortest periodicity for radio link monitoring resources and the DRX period.

[0034] The physical layer in the UE indicates, in frames where the radio link quality is assessed, out-of-sync (OOS) to higher layers when the radio link quality is worse than the threshold Qout for all resources in the set of resources for radio link monitoring. When the radio link quality is better than the threshold Qin for any resource in the set of resources forradio link monitoring, the physical layer in the UE indicates, in frames where the radio link quality is assessed, in-sync to higher layers.

[0035] Radio Link Failure due to physical layer problems

[0036] The higher layer (RRC) receives the OOS and IS indications from the lower layers (LI, physical layer), as described above. After a configurable number (N310) of such consecutive OOS indications, a timer (T310) is started. If the link quality is not improved (recovered) while T310 is running (i.e., there are no N311 consecutive "in-sync" indications from the physical layer), a radio link failure is declared in the UE. FIG. 2 is a diagram of an example radio link failure due to physical layer problems.

[0037] Upon declaring RLF (Radio Link Failure) in the PCell, the UE initiates reestablishment or, if configured with MR-DC and if configured with MCG failure reporting, it reports an MCG failure to the PSCell. Upon declaring RLF in the PSCell (also named S-RLF), the UE initiates an SCG Failure Report via the PCell.

[0038] Low band carrier aggregation (CA) via switching

[0039] Operators have mid-band spectrum but limited low-band spectrum, which may be crucial for coverage in both urban and rural areas. In some of the band combinations (BC) of the low band, e.g., n5 plus n29 and nl2 plus n29, low band carrier aggregation is not supported at present. One issue for the lack of support of the low band CA in these BC are listed below.

[0040] • Antenna Bandwidth: Supporting a large antenna bandwidth (BW) with a single antenna for certain band combinations is difficult. This is because the antenna needs to cover a wide range of frequencies, which can be technically challenging.

[0041] • Duplex Gap and Multiplexer Issues: For some band combinations like nl2 and n29, n29 exists in the duplex gap of nl2. This means there is no gap for Tx-Rx (transmit-receive) switching, which may be essential for the UE transmission and reception to operate properly.

[0042] FIG. 2 is a diagram of an example of low-band CA feasibility issues.

[0043] The 3GPP is working to specify a semi-static switching mechanism to support the low band CA via switching. Low band CA via switching may be summarized as follows:

[0044] • when the SCell operation is triggered, the UE needs to switch to an SDL (Supplementary Downlink) carrier (SCell), and during the operation period there isno simultaneous Tx / Rx between the PCell (FDD carrier 1) and the SDL carrier 2 (SCell).

[0045] • UE switches back to the FDD carrier 1 (PCell) after the SCell operation is finished.

[0046] The semi-static switch pattern allows the UE to switch to the PCell and SCell at the specified occasion as per the switch pattern.

[0047] In the low band CA via switching operation, the UE may be provided with switching pattern (e.g., semi-static switching pattern) which indicates the slots or time units during which UE is expected to operate (e.g., receive / transmit signals / channels) on the PCell and slots or time units during which UE is expected to operate on the SCell. However, switch pattern design and the switch pattern to use suffer from various inefficiencies.

[0048] SUMMARY

[0049] Some embodiments advantageously provide methods, systems, and apparatuses for low band carrier aggregation switch patterns.

[0050] One or more embodiments relate to a UE, in which the UE switches between the PCell and SCell based on the switch pattern and / or the rules for staying on the PCell without performing the switching as per the indicated switch pattern.

[0051] According to an embodiment, a method implemented in a UE is provided. The UE is configured to communicate with a network node. The UE is configured with at least one switch pattern for low band carrier aggregation. According to the method, the UE determines whether to apply at least one of the at least one switch pattern to at least one slot based on a state of a secondary cell (SCell). Further, the UE adapts at least one operation in the at least one slot associated with the SCell based on the determination. Further, the UE indicates the at least one adapted operation.

[0052] According to a further embodiment, a UE is provided. The UE is configured to communicate with a network node. The UE is configured with at least one switch pattern for low band carrier aggregation. The UE is configured to determine whether to apply at least one of the at least one switch pattern to at least one slot based on a state of an SCell. Further, the UE is configured to adapt at least one operation in the at least one slot associated with the SCell based on the determination. Further, the UE indicates the at least one adapted operation.

[0053] According to a further embodiment, a UE is provided. The UE is configured to communicate with a network node. The UE is configured with at least one switch patternfor low band carrier aggregation. The UE comprises a radio interface and / or processing circuitry configured to: determine whether to apply at least one of the at least one switch pattern to at least one slot based on a state of an SCell; adapt at least one operation in the at least one slot associated with the SCell based on the determination; and indicate the at least one adapted operation.

[0054] According to a further embodiment, a method implemented by a network node is provided. The network node is configured to communicate with a UE. According to the method, the network node configures the UE with at least one switch pattern for low band carrier aggregation. Further, the network node receives an indication of at least one adapted operation at the UE, the at least one adapted operation being associated with at least one slot associated with an SCell and based on whether the UE applies the at least one switch pattern to the at least one slot based on a state of the SCell. Further, the network node performs at least one action based on the indication.

[0055] According to a further embodiment, a network node is provided. The network node is configured to communicate with a UE. The network node is configured to configure the UE with at least one switch pattern for low band carrier aggregation.

[0056] Further, the network node is configured to receive an indication of at least one adapted operation at the UE, the at least one adapted operation being associated with at least one slot associated with an SCell and based on whether the UE applies the at least one switch pattern to the at least one slot based on a state of the SCell. Further, the network node is configured to perform at least one action based on the indication.

[0057] According to a further embodiment, a network node is provided. The network node is configured to communicate with a UE. The network node comprises a radio interface and / or processing circuitry configured to: configure the UE with at least one switch pattern for low band carrier aggregation; receive an indication of at least one adapted operation at the UE, the at least one adapted operation being associated with at least one slot associated with an SCell and based on whether the UE applies the at least one switch pattern to the at least one slot based on a state of the SCell; and perform at least one action based on the indication.

[0058] BRIEF DESCRIPTION OF THE DRAWINGS

[0059] A more complete understanding of the present embodiments, and the attendant advantages and features thereof, will be more readily understood by reference to thefollowing detailed description when considered in conjunction with the accompanying drawings wherein:

[0060] FIG. 1 A shows a RadioLinkMonitoringConfig IE of RRC signaling in the NR technology;

[0061] FIG. IB is a table showing dependency of a number of configurable RS for radio link monitoring on maximum number of SSBs and / or downlink beams transmitting SSBs;

[0062] FIG. 1C shows field descriptions of the RadioLinkMonitoringConfig IE;

[0063] FIG. ID shows a TCLState IE of the NR technology;

[0064] FIG. IE shows field descriptions of the QCL-Info field of the TCE-State IE;

[0065] FIG. 2 is a diagram of an example radio link failure due to physical layer problems;

[0066] FIG. 3 is a diagram of an example low band CA feasibility issues;

[0067] FIG. 4 is a schematic diagram of an example network architecture illustrating a communication system according to principles disclosed herein;

[0068] FIG. 5 is a block diagram of a network node in communication with a user equipment over a wireless connection according to some embodiments of the present disclosure;

[0069] FIG. 6 is a schematic diagram of another example network architecture illustrating a communication system according to principles disclosed herein;

[0070] FIG. 7 is a flowchart of an example process in a network node according to some embodiments of the present disclosure;

[0071] FIG. 8 is a flowchart of an example process in a user equipment according to some embodiments of the present disclosure; and

[0072] FIG. 9 is a diagram of an example bit map for two component carriers according to some embodiments of the present disclosure.

[0073] DETAILED DESCRIPTION

[0074] As described above, switch pattern design and the switch pattern to use may suffer from various inefficiencies. For example, the switch pattern design and the switch pattern to use may depend on the state of the SCell and conditions on the PCell.

[0075] One or more embodiments described herein addresses one or more problems with existing systems and / or specifications (e.g., 3GPP specification(s) and / or standard(s)). One or more embodiments relate to a User equipment (UE), in which the UE switches betweenthe PCell and SCell based on the switch pattern and / or the rules for staying on the PCell without performing the switching as per the indicated switch pattern.

[0076] One or more embodiments described herein provide one or more advantages including saving radio resources on the SCell when the PCell link is experiencing the problems. Since there is no guarantee whether the ACK (positive acknowledgement) / NACK (negative acknowledgement), e.g., of HARQ (Hybrid Automatic Repeat Request), on the PCell will be received when the PCell radio link is not good.

[0077] Before describing in detail exemplary embodiments, it is noted that the embodiments reside primarily in combinations of apparatus components and processing steps related to low band carrier aggregation switch patterns. 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.

[0078] 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.

[0079] 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.

[0080] 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.

[0081] 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, multistandard radio (MSR) radio node such as MSR BS, multi-cell / multicast coordination entity (MCE), relay node, donor node controlling relay, radio access point (AP), transmission points, transmission-reception points (TRPs), 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 user equipment (UE) such as a wireless device (WD) or a radio network node.

[0082] In some embodiments, the non-limiting terms wireless device (WD) or a user equipment (UE) are used interchangeably. The UE herein can be any type of user equipment capable of communicating with a network node or another UE over radio signals, such as a wireless device (WD). The UE may also be a radio communication device, target device, device to device (D2D) UE, machine type UE or UE capable of machine to machine communication (M2M), low-cost and / or low-complexity UE, a sensor equipped with UE, Tablet, mobile terminals, smart phone, laptop embedded equipped (LEE), laptop mounted equipment (LME), USB dongles, Customer Premises Equipment (CPE), an Internet of Things (loT) device, or a Narrowband loT (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 -cell / multicast Coordination Entity (MCE), relay node, access point, radio access point, Remote Radio Unit (RRU) Remote Radio Head (RRH).

[0083] Note that although terminology from one particular wireless system, such as, for example, 3GPP LTE and / or New Radio (NR) and / or 6G, may be used in this disclosure, this should not be seen as limiting the scope of the disclosure to only the aforementioned system. It is contemplated that other 3GPP systems may make use of the concepts and arrangements disclosed herein. For example, a disclosure relating to NR may also be implementable in a 6G system and / or an LTE system, a disclosure relating to 6G may also be implementable in a NR and / or LTE system, and a disclosure relating to LTE may also be implementable in a NR and / or 6G 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.

[0084] Note further, that functions described herein as being performed by a user equipment or a network node may be distributed over a plurality of UEs and / or network nodes. In other words, it is contemplated that the functions of the network node and user equipment described herein are not limited to performance by a single physical device and, in fact, can be distributed among several physical devices.

[0085] 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.

[0086] Some embodiments are directed to low band carrier aggregation switch patterns. Referring again to the drawing figures, in which like elements are referred to by like reference numerals, there is shown in FIG. 4 a schematic diagram of a communication system 10, according to an embodiment, such as a 3 GPP -type cellular network that may support standards such as LTE and / or NR (5G) and / or 6G, which comprises an accessnetwork 12, such as a radio access network, and a core network 14. The core network 14 includes one or more network nodes 15. The access network 12 comprises a plurality of network nodes 16a, 16b, 16c (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 18a, 18b, 18c (referred to collectively as coverage areas 18). Each network node 16a, 16b, 16c is connectable to the core network 14 over a wired or wireless connection 20. A first user equipment (UE) 22a located in coverage area 18a is configured to wirelessly connect to, or be paged by, the corresponding network node 16a. A second UE 22b in coverage area 18b is wirelessly connectable to the corresponding network node 16b. While a plurality of UEs 22a, 22b (collectively referred to as user equipments 22) are illustrated in this example, the disclosed embodiments are equally applicable to a situation where a sole UE is in the coverage area or where a sole UE is connecting to the corresponding network node 16. Note that although only two UEs 22 and three network nodes 16 are shown for convenience, the communication system may include many more UEs 22 and network nodes 16.

[0087] As one example, in certain embodiments, access network 12 may contain some access network nodes 16 that support 3 GPP radio access technologies (RAT), such as LTE or NR, while other access network nodes 16 support (or the same access network nodes 16 additionally support) non-3GPP RATs, such as Wi-Fi or a proprietary RAT. As another example, communication system 10 may support multiple generations of related communication standards (e.g., 4G, 5G and 6G 3GPP communication standards) and, as a result, may include an access network 12 and / or a core network 14 that supports multiple different standard generations or may include multiple access networks 12 and / or multiple core networks 14 with individual networks supporting different standards generations.

[0088] Also, it is contemplated that a UE 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 UE 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, UE 22 can be in communication with an eNB for LTEZE-UTRAN, a gNB for NR / NG-RAN (i.e. being configured for multiradio dual connectivity (MR-DC), such as E-UTRAN (Evolved-UMTS Terrestrial Radio Access Network) New Radio - Dual Connectivity (EN-DC) and / or Wi-Fi.

[0089] A network node 16 (eNB or gNB) is configured to include a configuration unit 24 which is configured to perform one or more network node 16 functions described herein.A user equipment 22 is configured to include an adaptation unit 26 which is configured to perform one or more UE 22 functions described herein.

[0090] Example implementations, in accordance with an embodiment, of the UE 22 and network node 16 discussed in the preceding paragraphs will now be described with reference to FIG. 5.

[0091] The communication system 10 includes a network node 16 provided in a communication system 10 and including hardware 28 enabling it to communicate with the UE 22. The hardware 28 may include a communication interface 29 comprising a radio interface 30 for setting up and maintaining at least a wireless connection 32 with a UE 22 located in a coverage area 18 served by the network node 16. The radio interface 30 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 radio interface 30 includes an array of antennas 34 to radiate and receive signal(s) carrying electromagnetic waves.

[0092] In the embodiment shown, the hardware 28 of the network node 16 further includes processing circuitry 36. The processing circuitry 36 may include a processor 38 and a memory 40. In particular, in addition to or instead of a processor, such as a central processing unit, and memory, the processing circuitry 36 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 38 may be configured to access (e.g., write to and / or read from) the memory 40, 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).

[0093] Thus, the network node 16 further has software 42 stored internally in, for example, memory 40, 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 42 may be executable by the processing circuitry 36. The processing circuitry 36 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.

[0094] Processor 38 corresponds to one or more processors 38 for performing network node 16 functions described herein. The memory 40 is configured to store data, programmatic software code and / or other information described herein. In some embodiments, the software 42 may include instructions that, when executed by the processor 38 and / orprocessing circuitry 36, causes the processor 38 and / or processing circuitry 36 to perform the processes described herein with respect to network node 16. For example, processing circuitry 36 of the network node 16 may include configuration unit 24 which is configured to perform one or more network node 16 functions as described herein.

[0095] The network node 16 may be composed of multiple distinct network entities (e.g., a NodeB entity and a RNC entity, or a BTS entity and a BSC entity, etc.), which may each have or utilize their own respective physical components. In certain scenarios in which the network node 16 comprises multiple such entities (e.g., BTS and BSC), one or more of the separate entities may be shared among several network nodes. For example, a single RNC may control multiple NodeBs. In such a scenario, each unique NodeB and RNC pair, may in some instances be considered a single separate network node. In some embodiments, the network node 16 may be configured to support multiple radio access technologies (RATs). In such embodiments, some components may be duplicated (e.g., separate memories 40 or portions of memory 40 for different RATs) and some components may be reused (e.g., a same antenna may be shared by different RATs). The network node 16 may also include multiple sets of the various illustrated components for different wireless technologies integrated into network node 16, for example GSM, WCDMA, LTE, NR, Wi-Fi (e.g., according to an IEEE 802.11 family standard), Zigbee, Z-wave, LoRaWAN, Radio Frequency Identification (RFID) or Bluetooth wireless technologies. These wireless technologies may be integrated into the same or different chip or set of chips and other components within network node 16.

[0096] In certain alternative embodiments, network node 16 may be capable of wireless communication but does not include separate radio front-end circuitry, instead, the processing circuitry 36 includes radio front-end circuitry and is connected to the antenna 34. Similarly, in some embodiments, all or some of the RF receivers, transmitters and / or transceivers are part of the radio interface 30. In still other embodiments, the communication interface 29 includes one or more ports or terminals, the radio interface 30, and the RF receiver, transmitter and / or transceiver, and the communication interface 31 communicates with baseband processing circuitry, which is part of a digital unit (not shown).

[0097] The antenna 34 may include one or more antennas, or antenna arrays, configured to send and / or receive wireless signals. The antenna 34 may be coupled to the radio front-end circuitry in radio interface 30 and may be any type of antenna capable of transmitting and receiving data and / or signals wirelessly. In certain embodiments, the antenna 34 isseparate from the network node 16 and connectable to the network node 16 through one or more interfaces or ports.

[0098] Network node 15 can include one or more components described above with respect to network node 16, e.g., communication interface 29, radio interface 30, antenna 34, ports, processing circuitry 36, processor 38, memory 40 and software 42. These elements of network node 15 can be arranged such that network node 15 can perform various core network functions. Network node 15 can communicate wirelessly or via a wired connection with network nodes 16 via communication link 59.

[0099] The communication system 10 further includes the UE 22 already referred to. The UE 22 may have hardware 44 that may include a radio interface 46 configured to set up and maintain a wireless connection 32 with a network node 16 serving a coverage area 18 in which the UE 22 is currently located. The radio interface 46 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 radio interface 46 includes an array of antennas 48 to radiate and receive signal(s) carrying electromagnetic waves.

[0100] Communication functions of the radio interface 46 may include cellular communication, Wi-Fi communication (e.g., according to an IEEE 802.11 family standard), LPWAN communication, data communication, voice communication, multimedia communication, short-range communications such as Bluetooth, near-field communication, location-based communication such as the use of the global positioning system (GPS) to determine a location, another like communication function, or any combination thereof. Communications may be implemented according to one or more communication protocols and / or standards, such as IEEE 802.11, Code Division Multiplexing Access (CDMA), Wideband Code Division Multiple Access (WCDMA), GSM, LTE, New Radio (NR), UMTS, WiMax, Ethernet, transmission control protocol / internet protocol (TCP / IP), synchronous optical networking (SONET), Asynchronous Transfer Mode (ATM), QUIC, Hypertext Transfer Protocol (HTTP), and so forth.

[0101] The hardware 44 of the UE 22 further includes processing circuitry 50. The processing circuitry 50 may include a processor 52 and memory 54. In particular, in addition to or instead of a processor, such as a central processing unit, and memory, the processing circuitry 50 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 executeinstructions. The processor 52 may be configured to access (e.g., write to and / or read from) memory 54, 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).

[0102] Thus, the UE 22 may further comprise software 56, which is stored in, for example, memory 54 at the UE 22, or stored in external memory (e.g., database, storage array, network storage device, etc.) accessible by the UE 22. The software 56 may be executable by the processing circuitry 50. The software 56 may include a client application 58. The client application 58 may be operable to provide a service to a human or non-human user via the UE 22.

[0103] The processing circuitry 50 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 UE 22. The processor 52 corresponds to one or more processors 52 for performing UE 22 functions described herein. The UE 22 includes memory 54 that is configured to store data, programmatic software code and / or other information described herein. In some embodiments, the software 56 and / or the client application 58 may include instructions that, when executed by the processor 52 and / or processing circuitry 50, causes the processor 52 and / or processing circuitry 50 to perform the processes described herein with respect to UE 22. For example, the processing circuitry 50 of the user equipment 22 may include adaptation unit 26 which is configured to perform one or more UE 22 functions as described herein.

[0104] In some embodiments, the inner workings of the network node 16 and UE 22 may be as shown in FIG. 5 and independently, the surrounding network topology may be that of FIG. 4.

[0105] The wireless connection 32 between the UE 22 and the network node 16 is in accordance with the teachings of the embodiments described throughout this disclosure. More precisely, the teachings of some of these embodiments may improve the data rate, latency, and / or power consumption and thereby provide benefits such as reduced user waiting time, relaxed restriction on file size, better responsiveness, extended battery lifetime, etc. In some embodiments, a measurement procedure may be provided for the purpose of monitoring data rate, latency and other factors on which the one or more embodiments improve.

[0106] Although FIGS. 4 and 5 show various “units” such as configuration unit 24 andadaptation unit 26 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.

[0107] FIG. 6 is another example of a communication system 10 according to some embodiments. As used herein, the communication system 10 of FIG. 6 includes multiple access points (APs) 60 (with four example APs 60a, 60b, 60c, and 60d being depicted) and multiple wireless devices, referred to in the context of communication system 10 of FIG. 6 as stations (STAs) 62 (referred to individually as STA 62a, STA 62b, STA 62c, STA 62d, and STA 62e). STA 62a is served by AP 60a in a first basic service set (BSS) 64a. STA 60b and STA 60c are served by AP 60b in a second BSS, BSS 64b. STA 62d is served by AP 60c in a third BSS, BSS 64c. STA 62e is served by AP 60d in a fourth BSS, BSS 64d. Stations 62 may be non-AP STAs and correspond to various kinds of wireless devices, for example, user terminals, such as mobile or stationary computing devices like smartphones, laptop computers, desktop computers, tablet computers, gaming devices, head-mounted displays (HMDs) for Augmented Reality (AR) or Virtual Reality (VR), or the like, including UEs 22 that are shown and described with respect to FIGS. 4 and 5. In other words, in some embodiment, STA 62 is a UE 22. Further, stations 62 could, for example, correspond to other kinds of equipment like smart home devices, printers, multimedia devices, data storage devices, or the like.

[0108] Each of STAs 62 may connect through a radio link to one of APs 60. For example, depending on location or channel conditions experienced by a given STA 62, the STA may select an appropriate AP and BSS for establishing the radio link. The radio link may be based on one or more orthogonal frequency-division multiplexing (OFDM) carriers from a frequency spectrum that is shared on the basis of a contention-based mechanism, e.g., an unlicensed or license exempt band like 2.4 GHz Industrial, Scientific, and Medical (ISM) band, the 5 GHz band, the 6 GHz band, or the 60 GHz band.

[0109] Each AP 60 may provide data connectivity to STAs 62 connected to a particular AP 60. As illustrated, APs 60 may be connected to a data network 66. In this way, APs 60 may also provide data connectivity between STAs 62 and other entities, e.g., to one or more servers, service providers, data sources, data sinks, user terminals, or the like.

[0110] Accordingly, the radio link established between a given STA 62 and its serving AP 60 may be used for providing various kinds of services to STA 62, e.g., a voice service, a multimedia service, or other data service. Such services may be based on applications thatare executed on STA 62 and / or on a device linked to STA 62. By way of example, FIG. 6 illustrates an application service platform 68 provided in data network 66. The application(s) executed on STA 62 and / or on one or more other devices linked to STA 62 may use the radio link for data communication with one or more other STA 62 and / or the application service platform 68, thereby enabling utilization of the corresponding service(s) at STA 62.

[0111] FIG. 7 is a flowchart of an example process in a network node 16 according to some embodiments of the present disclosure. One or more blocks described herein may be performed by one or more elements of network node 16 such as by one or more of processing circuitry 36 (including the configuration unit 24), processor 38, and / or radio interface 30. Network node 16 is configured to configure (Block S100) the UE 22 with at least one switch pattern for low band carrier aggregation, as described herein. As described above, the low band carrier aggregation may involve switching according to a semi-static switch pattern: When the SCell operation is triggered, the UE needs to switch to the SCell, and during the operation period there is no simultaneous Tx / Rx between the PCell and SCell. The PCell may correspond to an FDD (Frequency Division Duplex) carrier (FDD carrier 1), e.g., a DL carrier and paired UL carrier, while the SCell may correspond to an SDL carrier (carrier 2), e.g., a DL carrier without paired UL carrier. After SCell operation is finished, the UE 22 may switch back to the PCell. The semi-static switch pattern allows the UE 22 to switch to the PCell and SCell at the specified occasion as per the switch pattern. In this low band carrier aggregation via switching operation, the UE 22 may be provided with the switch pattern (e.g., semi-static switching pattern) which indicates the slots or time units during which UE 22 is expected to operate (e.g., receive / transmit signals / channels) on the PCell and slots or time units during which UE 22 is expected to operate on the SCell.

[0112] Network node 16 is configured to receive (Block SI 02) an indication of at least one adapted operation at the UE 22, where the at least one adapted operation is: associated with at least one slot associated with a secondary cell, SCell; and based on whether the UE 22 applies the at least one switch pattern to the at least one slot based on a state of the SCell, as described herein. Network node 16 is configured to perform (Block SI 04) at least one action based on the indication, as described herein.

[0113] According to one or more embodiments, the state of the SCell comprising one of: SCell deactivated; SCell activation triggered; or SCell is activated.

[0114] According to one or more embodiments, the at least one adapted operationcomprises one of stopping reception, pausing reception, delaying reception or suspending reception in the at least one slot associated with the SCell.

[0115] According to one or more embodiments, the at least one adapted operation is based on one or more of the following conditions being met: an N1 number of out of sync indications are triggered on a primary cell, PCell; a T310 timer is started; a T311 timer is started; a beam failure has been detected; and a candidate beam detection procedure has been triggered.

[0116] According to one or more embodiments, the at least one adapted operation is associated with communication on the PCell without the UE 22 switching to the SCell.

[0117] According to one or more embodiments, the at least one adapted operation is valid until one of: an indication is transmitted by the network node to resume one of the at least one pattern; an expiration of a predefined time; or another switch pattern is transmitted by the network node 16.

[0118] According to one or more embodiments, the at least one action comprises communicating with the UE 22 based on the at least one adapted operation at the UE 22.

[0119] According to one or more embodiments, the UE 22 receives a configuration from the network node 16, to start carrier aggregation operation using the PCell and the SCell. The configuration may comprise or consist of the at least one switch pattern. The UE 22 can receive the configuration via RRC signaling.

[0120] According to one or more embodiments, the at least one switch pattern consists of a bit map and each bit of the bitmap indicates on which carrier the UE 22 should receive and / or transmit within a given slot. Each bit may indicate whether the UE 22 should receive from the PCell or from the SCell.

[0121] According to one or more embodiments, the SCell corresponds to an SDL carrier. According to one or more embodiments, a time period including a switching time switching time from the PCell to the SCell and / or from the SCell to PCell is configurable, e.g., as part of the configuration of the switch pattern.

[0122] FIG. 8 is a flowchart of an example process in a UE 22 according to some embodiments of the present disclosure. One or more blocks described herein may be performed by one or more elements of UE 22 such as by one or more of processing circuitry 50 (including the Adaptation unit 26), processor 52, and / or radio interface 46. UE 22 is configured with at least one switch pattern for low band carrier aggregation, as described herein. As described above, the low band carrier aggregation may involve switching according to a semi-static switch pattern: When the SCell operation is triggered,the UE needs to switch to the SCell, and during the operation period there is no simultaneous Tx / Rx between the PCell and SCell. The PCell may correspond to an FDD carrier (FDD carrier 1), e.g., a DL carrier and paired UL carrier, while the SCell may correspond to an SDL carrier (carrier 2), e.g., a DL carrier without paired UL carrier. After SCell operation is finished, the UE 22 may switch back to the PCell. The semi-static switch pattern allows the UE 22 to switch to the PCell and SCell at the specified occasion as per the switch pattern. In this low band carrier aggregation via switching operation, the UE 22 may be provided with the switch pattern (e.g., semi-static switching pattern) which indicates the slots or time units during which UE 22 is expected to operate (e.g., receive / transmit signals / channels) on the PCell and slots or time units during which UE 22 is expected to operate on the SCell.

[0123] UE 22 is configured to determine (Block SI 06) whether to apply at least one of the at least one switch pattern to at least one slot based on a state of a secondary cell, SCell, as described herein. UE 22 is configured to adapt (Block SI 08) at least one operation in the at least one slot associated with the SCell based on the determination, as described herein. UE 22 is configured to indicate (Block SI 10) the at least one adapted operation, as described herein.

[0124] According to one or more embodiments, the state of the SCell comprises one of: SCell deactivated; SCell activation triggered; or SCell is activated.

[0125] According to one or more embodiments, the adapting of at least one operation comprises one of stopping reception, pausing reception, delaying reception or suspending reception in the at least one slot associated with the SCell.

[0126] According to one or more embodiments, the adapting of the at least one operation is based on one or more of the following conditions being met: an N1 number of out of sync indications are triggered on a primary cell, PCell; a T310 timer is started; a T311 timer is started; a beam failure has been detected; and a candidate beam detection procedure has been triggered.

[0127] According to one or more embodiments, the indication is transmitted to the network node 16, and the adapted at least one operation is associated with communication on the PCell without the UE 22 switching to the SCell.

[0128] According to one or more embodiments, the adapted at least one operation is valid until one of: an indication is received from the network node 16 to resume one of the at least one pattern; an expiration of a predefined time; or another switch pattern is received from the network node 16.According to one or more embodiments, the network node 16 transmits a configuration to the UE 22, to start carrier aggregation operation using the PCell and the SCell. The configuration may comprise or consist of the at least one switch pattern. The network node 16 can transmit the configuration via RRC signaling.

[0129] According to one or more embodiments, the at least one switch pattern consists of a bit map and each bit of the bitmap indicates on which carrier the UE 22 should receive and / or transmit within a given slot. Each bit may indicate whether the UE 22 should receive from the PCell or from the SCell.

[0130] According to one or more embodiments, the SCell corresponds to an SDL carrier. According to one or more embodiments, a time period including a switching time switching time from the PCell to the SCell and / or from the SCell to PCell is configurable, e.g., as part of the configuration of the switch pattern.

[0131] Having described the general process flow of arrangements of the disclosure and having provided examples of hardware and software arrangements for implementing the processes and functions of the disclosure, the sections below provide details and examples of arrangements for low band carrier aggregation switch patterns.

[0132] Some embodiments provide low band carrier aggregation switch patterns. One or more network node 16 functions described below may be performed by one or more of processing circuitry 36, processor 38, configuration unit 24, radio interface 30, etc. One or more UE 22 functions described below may be performed by one or more of processing circuitry 50, processor 52, adaptation unit 26, radio interface 46, etc.

[0133] Embodiments for the low band CA switch pattern applicability

[0134] Example A. A method at a User equipment (UE 22) configured with one or more switch pattern for the low band CA via switching operation from the network node 16, the method comprising:

[0135] - Determining the pattern(s) applicability based on the state of the SCell, wherein the state of the SCell with respect to the UE can be SCell deactivated, or SCell activation triggered, or SCell is activated.

[0136] - Adapting (e.g., comprises stopping, pausing / delaying, suspending the reception) the operation in the slots corresponding to SCell as indicated in the switch pattern or switching to different pattern which provides access to essential signals on the PCell to maintain the PCell connection when one or more of the following conditions are met:

[0137] o N1 number of out of sync are triggered on PCell;o T310 timer is started;

[0138] o T311 is started;

[0139] o Beam failure has been detected; and

[0140] o Candidate beam detection procedure has been triggered.

[0141] - Transmitting an indication to the network node about the adapted operation of the switch pattern (that means only receiving on the PCell without switching to SCell), wherein the stopping, suspending or pausing / delaying of the pattern is valid till one or more of:

[0142] o An indication to resume a pattern is sent to the network node by the UE 22; o For a predefined time; and

[0143] o Till the new switch pattern is received from the network node. Another example. The method of Example A, further comprising receiving a configuration from the network node 16, to start carrier aggregation operation using CC1 (e.g., PCell) and CC2 (e.g., SCell), wherein the configuration consists of one or more of the switch patterns for communication on CC1 (e.g., component carrier 1), CC2 (component carrier 2):

[0144] The switch pattern consists of one or more of the following:

[0145] • Length of the pattern (i.e., periodicity): which indicates the length (i.e., periodicity) of the pattern, wherein the pattern repeats after the length of the pattern is complete.

[0146] • The pattern: the pattern may consist of bit map and the length of the bit map is equal to the length of the pattern where each bit of the bitmap indicates on which carrier the UE 22 should receive / transmit within a given slot.

[0147] o Each bit of the bitmap corresponds to a time unit (e.g., slot) at the UE 22.

[0148] For example, when the pattern length is 40, the pattern consists of 40 bits and each bit corresponds to one slot. For example, each bit indicates whether the UE 22 should receive from CC1 or CC2.

[0149] ■ In one example, bit 0 indicates that UE 22 should receive from CC1 in the given slot and bit 1 indicates the UE should receive from CC2 (e.g., in the given slot)

[0150] ■ In one example, bit 0 indicates that UE 22 should receive from CC1+CC2 in the given slot and bit 1 indicates the UE 22 should receive from CC2 (e.g., in the given slot)

[0151] ■ In one example, bit 0 indicates that UE 22 should receive fromCC1+CC2 in the given slot and bit 1 indicates the UE 22 should receive from CC1 (e.g., in the given slot)

[0152] • Number of symbols for the switch (N_Symb): number of symbols the UE 22 is allowed to use for the purpose of switching. The switch occurs at the end of the slot and the switch starts N Symb before the end of the slot.

[0153] FIG. 9 is a diagram of a non-limiting example where, if the periodicity is 40 slots, the bit map indicates which slots corresponds to CC1 communication and which slot corresponds to CC2 communication. That is, in FIG. 9, “0” corresponds to the UE communicating with CC1 and “1” corresponds to the UE communicating with CC2.

[0154] When the periodicity is 40 slots, the same pattern is repeated for every 40 slots. In another example, the switch pattern can be specified as the length of the pattern and the number contiguous slots corresponding to CC1; and number contiguous slots corresponding to CC2. This may not be a bit map. For example, if the length of the pattern is 40 slots and if network node 16 indicates the number of contiguous slots to CC1 as 7 and the number of contiguous slots to CC2 as 3, the pattern is: 7 slots to CC1, next 3 slots to CC2, next 7 slots to CC1, next 3 slots to CC2, next 7 slots to CC1, next 3 slots to CC2, next 7 slots to CC1, next 3 slots to CC2.

[0155] In yet another example, the switch pattern can be specified as a list of switch points where the UE 22 stays on a CC in between the switch points. For example, the list could be {3, 8, 3, 10, 3, 5, 3, 5}. The UE 22 would stay on CC1 for 3 slots, then switch to CC2 for 8 slots, then switch back to CC1 for 3 slots, then switch to CC2 for 10 slots, and so-on according to the list or indication of CC ordering. The CC corresponding to the first entry in the list can be either CC1 or CC2 and likewise for the last entry in the list.

[0156] In another example, the pattern may be an index from the predetermined set of patterns. In this example, a number of different patterns (pattern 1, pattern 2, pattern 3, pattern 4, etc.) are specified, and network node 16 informs the UE 22 which pattern (e.g., pattern 2) to use among the predefined set of patterns.

[0157] Example B. The method of Example A, wherein the determining of the pattern(s) applicability is based on predefined set of rules or conditions:

[0158] In some embodiments, when network node 16 configures more than one pattern (e.g., pattern 1 and pattern 2), UE 22 determines the pattern to use based on the state of the SCell, where in the state of the SCell with respect to UE 22 can be one of the following:

[0159] • State 1: SCell is configured (i.e., through SCell addition) to the UE 22 and it is not activated by the network node 16 and the SCell is deemed to be indeactivated state.

[0160] • State 2: SCell activation is triggered (e.g., using SCell activation MAC CE) by the network node 16 but the activation is not completed (e.g., valid CSI / CQI report is not sent) at the UE 22

[0161] • State 3: SCell activation is completed at the UE 22 and the UE 22 communicates with SCell

[0162] • State 4: SCell is released for the UE 22 by the network node 16. When the state of the SCell with respect to UE 22 is state 1 :

[0163] • In one example condition, UE 22 does not use any of the configured pattern (e.g., pattern 1 or pattern 2) when the SCell is in state 1 with respect to UE 22 but UE 22 performs measurements on the SCell on the UE 22 chosen occasion by taking interruption on the PCell transmission / reception.

[0164] • In one example condition, the pattern to use is indicated by the network node 16.

[0165] • In one example condition, UE 22 does not use any of the configured pattern (e.g., pattern 1 or pattern 2) when the SCell is in state 1 with respect to UE 22 but receives from the SCell to make measurements on the SCell

[0166] o based on the value of the measCycleSCell (as stated in 3GPP TS 38.331) o based on DRX periodicity

[0167] o Based on SSB transmission occasion and once in measCycleSCell o Based on SSB transmission occasion and once in DRX periodicity • In one example condition, UE 22 determines one of the configured pattern (e.g., pattern 1 or pattern 2, etc.) when the SCell is in state 1 with respect to UE 22 o based on the value of the measCycleSCell (as stated in 3GPP TS 38.331). If the measCycleSCell is above a certain value (e.g., 640 ms), UE 22 uses pattern 1, otherwise uses pattern 2

[0168] o based on the configured DRX periodicity, if the DRX periodicity is above a certain value (e.g., 640), UE 22 uses pattern 1, otherwise uses pattern 2 In yet another example, the selection of the pattern depends on the frequency relation between the PCell and SCell. In one specific example, if the frequency separation between the carriers of PCell and SCell is smaller than a threshold Hl, then UE 22 suspends the use of the switching pattern. In this case, it is assumed that the radio conditions of PCell and SCell with respect to UE 22 are similar and UE 22 may not need to make or perform measurements on the SCell. Otherwise, the UE 22 operates following the switching pattern as described above.When the state of the SCell with respect to UE 22 is state 2:

[0169] • In one example condition, the pattern to use is indicated by the network node 16.

[0170] • In one example condition, the pattern to use is determined by the UE 22 based on the configured patterns

[0171] • In one example condition, the pattern to use is determined by the UE 22 based on the slots available for the SCell in the configured patterns. In one example, UE 22 choses or selects the pattern which has a lower number of slots allocated to SCell.

[0172] • In one example condition, the pattern to use is determined by the UE 22 based on the availability of the SSB, CSI-RS, TRS on the SCell. UE 22 receives from the SCell in the slots where the SSB or CSI-RS or TRS is available on the SCell. • In one example condition, without choosing any configured pattern, UE 22 switches to the SCell on the slots where the SSB or CSI-RS or TRS are transmitted. This can be defined as an implicit pattern.

[0173] When the state of the SCell with respect to UE 22 is state 3 :

[0174] • In one example condition, the pattern to use is indicated by the network node 16.

[0175] • In one example condition, the pattern to use is determined by the UE 22 based on the configured patterns.

[0176] • In one example condition, the pattern to use is determined by the UE 22 based on the slots available for the SCell in the configured patterns. In one example, UE 22 choses or selects the pattern which has a higher number of slots allocated to SCell. When the state of the SCell with respect to UE 22 is state 4:

[0177] • In one example condition, UE 22 does not use any pattern and always communicates with PCell and does not communicate with SCell.

[0178] Example C. The method of any one of Examples A and B, wherein the determining of the pattern(s) applicability is based on a predefined set of rules or conditions.

[0179] In some embodiments, when network node 16 configures one or more patterns, stopping or pausing the reception in the slots corresponding to SCell as indicated in the switch pattern or switching to different pattern which provides greater number of slots for PCell communication for maintaining the connection to the PCell, when one or more of following conditions has been met:

[0180] o N1 number of out of sync are triggered on PCell;

[0181] o T310 timer is started;

[0182] o T311 is started;

[0183] o Beam failure has been detected;o Candidate beam detection procedure has been triggered;

[0184] o UE 22 is operating critical or high priority signals / channels (such as positioning signals, signals associated with public warning systems etc.) When one or more of the above-mentioned conditions are met, UE 22 performs one or more of the following actions:

[0185] - In a particular slot, receives or transmits on the PCell even though the switch pattern indicates that particular slot corresponds to SCell communication, when one or more of the following conditions occurs:

[0186] o The slot contains SSB on the PCell;

[0187] o The slot contains CSI-RS on the PCell;

[0188] o The slot contains explicitly configured RLM-RS on the PCell; o The slot contains implicitly configured RLM-RS on the PCell; o Once in a predefined amount of time (e.g., every 10 ms or every 10 slots or 20 slots, etc.);

[0189] o Slots contain high-priority signals / channels (e.g., positioning signals, signals associated with public warning systems).

[0190] Suspends or discards operation on a cell indicated by the switching pattern and instead prioritizes and / or performs operation on a cell associated with a radio link procedure during a time period Tl. In one example, the cell associated with radio link procedure is the PCell where the procedure is the radio link monitoring. In another example, the cell associated with radio link procedure is a PCell where the procedure is a link recovery procedure (such as beam management). In yet another example, the cell associated with the radio link procedure is a different SCell. This may indicate that the operation on a cell as indicated by the switching pattern is discarded. As used herein, in one or more embodiments, “Operation” comprises both transmission and reception. Tl can be configurable or predefined. In one specific example, Tl comprises the time resource required for the UE 22 to receive the necessary signals and / or channels required to perform the radio link procedures. In one specific example, Tl is the time required for the UE 22 to perform an out-of-sync evaluation. In another example, Tl is the time required for the UE 22 to perform a candidate beam detection. In yet another example, Tl may correspond to the time the UE 22 needs in order to perform radio link recovery procedures (such as RRC re-establishment). Tl may also include the switching time (from SCell to PCell, one SCell to another SCell, PCell to SCell etc.). AfterTl, UE 22 resumes its operation following the switching pattern. In an alternative embodiment, the operation following the switching pattern is suspended until the UE 22 is explicitly indicated or reconfigured by the network node 16.

[0191] - In another example, Tl may correspond to the time UE 22 needs to switch to stable operation, i.e., when the UE 22 is considered to be in-sync. Examples of indications indicating stable operations are one or more of: hypothetical PDCCH BLELR < 2%, number of out-of-sync indications is less than XI over last Til, number of consecutive in-sync indications are N311 and / or timers (e.g., T310) associated with radio link problems have stopped, no beam failure is detected, one or more candidate beams have been detected, etc.

[0192] - UE 22 starts operating following a different or modified switching pattern. For example, the new (different or modified) pattern may allow the UE 22 to operate signals and / or channels more frequently on the cell associated with radio link procedures than the original switching pattern.

[0193] - UE 22 falls back to single carrier or single cell operation.

[0194] In an alternative embodiment, when one of the conditions about radio link operation is met, the UE 22 continues to operate following the switching pattern, but in this case (1) the UE 22 is not required to meet the requirements associated with the PCell or (2) the UE is allowed to meet the more relaxed requirements, then, for example, the RLM / BFD evaluation period can be longer than the minimum time period it needs to perform evaluations.

[0195] In an alternative embodiment, when the above conditions are met, UE 22 choses or selects a different pattern, where the UE 22 choses or selects the pattern which has a lower number of slots allocated to SCell and a greater number of slots allocated to PCell.

[0196] In some embodiments, the UE 22 may detect that the PCell starts to get in bad radio coverage (e.g., T310 has started due to a number of Out of Sync indications, PCell radio measurements become lower than a threshold): in that case, UE 22 would be at risk to stop monitoring the SCell which may be configured according to the low band CA via switching operation. The UE 22 may have transmitted as measurement report to the network node 16 to indicate that the PCell is bad (e.g., an Example A3 event) and while the network node 16 tries or attempts to send a handover (HO) command (e.g., via the SCell) it may not be suitable for the UE 22 to stop monitoring the SCell.

[0197] Thus, in some embodiments, the UE 22 starts a timer when it sends a Measurement Report (e.g., triggered when the PCell quality is lower than a threshold and / or when aneighbour is an offset better than the PCell) and is configured with the CA switching pattern, and when the timer expires (and the UE 22 has not received a signaling to change the pattern and / or HO command and / or release with redirect) the UE 22 stops monitoring the SCell and / or stops sending HARQ signaling (for the SCell) to the PCell. If the timer is running and UE 22 receives one of these messages, the timer stops. The timer can be configured with the switching configuration and include an indication of a reportConfig associated to it (e.g., ReportConfig for L3 events, or CSI-ReportConfig for CSI, measld for L3 events), or that could be within the reporting configuration (a bit as the T312 timer) Example D: The method of any one of Examples A-C, wherein with respect to the transmitting of the indication to the network node 16 about the stopping or pausing of the switch pattern (that means only receiving on the PCell without switching to SCell), the stopping or pausing (e.g., the adapting or adaptation) of the pattern is valid till:

[0198] o An indication of resuming of the pattern is sent to the network node 16 by the UE 22

[0199] o For a predefined time

[0200] o Till the new switch pattern is received from the network node 16 In response to receiving the indication from the UE 22 about suspending, stopping or pausing at least one operation following the switching pattern, the network node 16 may send a resume command instructing the UE 22 to resume its operations following the switching pattern. In one example, the network node 16 may reconfigure the UE 22 with a different or modified switching pattern.

[0201] In another example, in response to receiving the indication from the UE 22 about suspending, stopping or pausing at least one operation following the switching pattern, the network node 16 may trigger one or more procedures such as initiating the cell change procedure.

[0202] 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 producton 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.

[0203] 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.

[0204] 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.

[0205] 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.

[0206] It is to be understood that the functions / 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 functionality / 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 Python, 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).

[0207] 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.

[0208] 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.

[0209] In view of the above, example embodiments provided in the present disclosure include:

[0210] Embodiment Al . A user equipment, UE, configured to communicate with a network node, the UE being configured with at least one switch pattern for low band carrier aggregation, the UE configured to, and / or comprising a radio interface and / or processing circuitry configured to:

[0211] determine whether to apply at least one of the at least one switch pattern to at least one slot based on a state of a secondary cell, SCell;

[0212] adapt at least one operation in the at least one slot associated with the SCell based on the determination; andindicate the at least one adapted operation.

[0213] Embodiment A2. The UE of Embodiment Al, wherein the state of the SCell comprising one of:

[0214] SCell deactivated;

[0215] SCell activation triggered; or

[0216] SCell is activated.

[0217] Embodiment A3. The UE of any one of Embodiments A1-A2, wherein the adapting of at least one operation comprises one of stopping reception, pausing reception, delaying reception or suspending reception in the at least one slot associated with the SCell.

[0218] Embodiment A4. The UE of any one of Embodiments A1-A3, wherein the adapting of the at least one operation is based on one or more of the following conditions being met:

[0219] an N1 number of out of sync indications are triggered on a primary cell, PCell; a T310 timer is started;

[0220] a T311 timer is started;

[0221] a beam failure has been detected; and

[0222] a candidate beam detection procedure has been triggered.

[0223] Embodiment A5. The UE of any one of Embodiments A1-A4, wherein the indication is transmitted to the network node; and

[0224] the adapted at least one operation being associated with communication on the PCell without the UE switching to the SCell.

[0225] Embodiment A6. The UE of any one of Embodiments A1-A5, wherein the adapted at least one operation is valid until one of:

[0226] an indication is received from the network node to resume one of the at least one pattern;

[0227] an expiration of a predefined time; or

[0228] another switch pattern is received from the network node.Embodiment Bl. A method implemented in a user equipment, UE, that is configured to communicate with a network node, the UE being configured with at least one switch pattern for low band carrier aggregation, the method comprising:

[0229] determining whether to apply at least one of the at least one switch pattern to at least one slot based on a state of a secondary cell, SCell;

[0230] adapting at least one operation in the at least one slot associated with the SCell based on the determination; and

[0231] indicating the at least one adapted operation.

[0232] Embodiment B2. The method of Embodiment Bl, wherein the state of the SCell comprising one of

[0233] SCell deactivated;

[0234] SCell activation triggered; or

[0235] SCell is activated.

[0236] Embodiment B3. The method of any one of Embodiments B1-B2, wherein the adapting of at least one operation comprises one of stopping reception, pausing reception, delaying reception or suspending reception in the at least one slot associated with the SCell.

[0237] Embodiment B4. The method of any one of Embodiments B1-B3, wherein the adapting of the at least one operation is based on one or more of the following conditions being met:

[0238] an N1 number of out of sync indications are triggered on a primary cell, PCell; a T310 timer is started;

[0239] a T311 timer is started;

[0240] a beam failure has been detected; and

[0241] a candidate beam detection procedure has been triggered.

[0242] Embodiment B5. The method of any one of Embodiments B1-B4, wherein the indication is transmitted to the network node; and

[0243] the adapted at least one operation being associated with communication on the PCell without the UE switching to the SCell.Embodiment B6. The method of any one of Embodiments B1-B5, wherein the adapted at least one operation is valid until one of:

[0244] an indication is received from the network node to resume one of the at least one pattern;

[0245] an expiration of a predefined time; or

[0246] another switch pattern is received from the network node.

[0247] Embodiment Cl . A network node configured to communicate with a user equipment, UE, the network node configured to, and / or comprising a radio interface and / or comprising processing circuitry configured to:

[0248] configure the UE with at least one switch pattern for low band carrier aggregation; receive an indication of at least one adapted operation at the UE, the at least one adapted operation being:

[0249] associated with at least one slot associated with a secondary cell, SCell; and based on whether the UE applies the at least one switch pattern to the at least one slot based on a state of the SCell; and

[0250] perform at least one action based on the indication.

[0251] Embodiment C2. The network node of Embodiment Cl, wherein the state of the SCell comprising one of:

[0252] SCell deactivated;

[0253] SCell activation triggered; or

[0254] SCell is activated.

[0255] Embodiment C3. The network node of any one of Embodiments C1-C2, wherein the at least one adapted operation comprises one of stopping reception, pausing reception, delaying reception or suspending reception in the at least one slot associated with the SCell.

[0256] Embodiment C4. The network node of any one of Embodiments C1-C3, wherein the at least one adapted operation is based on one or more of the following conditions being met:

[0257] an N1 number of out of sync indications are triggered on a primary cell, PCell; a T310 timer is started;a T311 timer is started;

[0258] a beam failure has been detected; and

[0259] a candidate beam detection procedure has been triggered.

[0260] Embodiment C5. The network node of any one of Embodiments C1-C4, wherein the at least one adapted operation is associated with communication on the PCell without the UE switching to the SCell.

[0261] Embodiment C6. The network node of any one of Embodiments C1-C5, wherein the at least one adapted operation is valid until one of:

[0262] an indication is transmitted by the network node to resume one of the at least one pattern;

[0263] an expiration of a predefined time; or

[0264] another switch pattern is transmitted by the network node.

[0265] Embodiment C7. The network node of any one of Embodiments C1-C6, wherein the at least one action comprises communicating with the UE based on the at least one adapted operation at the UE.

[0266] Embodiment DI . A method implemented by a network node that is configured to communicate with a user equipment, UE, the method comprising:

[0267] configuring the UE with at least one switch pattern for low band carrier aggregation;

[0268] receiving an indication of at least one adapted operation at the UE, the at least one adapted operation being:

[0269] associated with at least one slot associated with a secondary cell, SCell; and based on whether the UE applies the at least one switch pattern to the at least one slot based on a state of the SCell; and

[0270] performing at least one action based on the indication.

[0271] Embodiment D2. The method of Embodiment DI, wherein the state of the SCell comprising one of:

[0272] SCell deactivated;

[0273] SCell activation triggered; orSCell is activated.

[0274] Embodiment D3. The method of any one of Embodiments D1-D2, wherein the at least one adapted operation comprises one of stopping reception, pausing reception, delaying reception or suspending reception in the at least one slot associated with the SCell.

[0275] Embodiment D4. The method of any one of Embodiments D1-D3, wherein the at least one adapted operation is based on one or more of the following conditions being met:

[0276] an N1 number of out of sync indications are triggered on a primary cell, PCell; a T310 timer is started;

[0277] a T311 timer is started;

[0278] a beam failure has been detected; and

[0279] a candidate beam detection procedure has been triggered.

[0280] Embodiment D5. The method of any one of Embodiments D1-D4, wherein the at least one adapted operation is associated with communication on the PCell without the UE switching to the SCell.

[0281] Embodiment D6. The method of any one of Embodiments D1-D5, wherein the at least one adapted operation is valid until one of:

[0282] an indication is transmitted by the network node to resume one of the at least one pattern;

[0283] an expiration of a predefined time; or

[0284] another switch pattern is transmitted by the network node.

[0285] Embodiment D7. The method of any one of Embodiments D1-D6, wherein the at least one action comprises communicating with the UE based on the at least one adapted operation at the UE.

Claims

36CLAIMS1. A method implemented in a user equipment, UE, (22) that is configured to communicate with a network node (16), the UE (22) being configured with at least one switch pattern for low band carrier aggregation, the method comprising:determining whether to apply at least one of the at least one switch pattern to at least one slot based on a state of a secondary cell, SCell;adapting at least one operation in the at least one slot associated with the SCell based on the determination; andindicating the at least one adapted operation.

2. The method of claim 1,wherein the state of the SCell comprises one ofSCell deactivated;SCell activation triggered; orSCell is activated.

3. The method of claim 1 or 2, wherein the adapting of at least one operation comprises one of stopping reception, pausing reception, delaying reception or suspending reception in the at least one slot associated with the SCell.

4. The method of any one of claims 1-3,wherein the adapting of the at least one operation is based on one or more of the following conditions being met:an N1 number of out of sync indications are triggered on a primary cell, PCell; a T310 timer is started;a T311 timer is started;a beam failure has been detected; anda candidate beam detection procedure has been triggered.

5. The method of any one of claims 1-4,wherein the indication is transmitted to the network node (16), andwherein the adapted at least one operation is associated with communication on a37PCell without the UE (22) switching to the SCell.

6. The method of any one of claims 1-5,wherein the adapted at least one operation is valid until one of:an indication is received from the network node (16) to resume one of the at least one pattern;an expiration of a predefined time; oranother switch pattern is received from the network node (16).

7. The method of any of claims 1-6, comprising:receiving a configuration from the network node (16), to start carrier aggregation operation using the PCell and the SCell, wherein the configuration comprises the at least one switch pattern.

8. The method of any of claims 1-7,wherein the at least one switch pattern consists of a bit map and each bit of the bitmap indicates on which carrier the UE (22) should receive and / or transmit within a given slot.

9. The method of claim 8,wherein each bit indicates whether the UE (22) should receive from the PCell or from the SCell.

10. The method of any of claims 1-9,wherein the SCell corresponds to a supplementary downlink, SDL, carrier.

11. The method according to any of claims 1-10,wherein a time period including a switching time switching time from the PCell to the SCell and / or from the SCell to PCell is configurable.

12. A user equipment, UE, (22) configured to communicate with a network node (16), the UE (22) being configured with at least one switch pattern for low band carrier aggregation, the UE (22) being configured to:determine whether to apply at least one of the at least one switch pattern to at leastone slot based on a state of a secondary cell, SCell;adapt at least one operation in the at least one slot associated with the SCell based on the determination; andindicate the at least one adapted operation.

13. The UE (22) of claim 12,wherein the UE (12) is configured to perform a method according to any of claims 1-11.

14. The UE (22) of claim 12 or 13, comprising a radio interface (46) and / or processing circuitry (50) configured to perform a method according to any of claims 1-11.

15. A method implemented by a network node that (16) is configured to communicate with a user equipment, UE, (22), the method comprising:configuring the UE (22) with at least one switch pattern for low band carrier aggregation;receiving an indication of at least one adapted operation at the UE (22), the at least one adapted operation being:associated with at least one slot associated with a secondary cell, SCell; and based on whether the UE (22) applies the at least one switch pattern to the at least one slot based on a state of the SCell; andperforming at least one action based on the indication.

16. The method of claim 15,wherein the state of the SCell comprises one of:SCell deactivated;SCell activation triggered; orSCell is activated.

17. The method of claim 15 or 16,wherein the at least one adapted operation comprises one of stopping reception, pausing reception, delaying reception or suspending reception in the at least one slot associated with the SCell.

18. The method of any one of claims 15-17,wherein the at least one adapted operation is based on one or more of the following conditions being met:an N1 number of out of sync indications are triggered on a primary cell, PCell; a T310 timer is started;a T311 timer is started;a beam failure has been detected; anda candidate beam detection procedure has been triggered.

19. The method of any one of claims 15-18,wherein the at least one adapted operation is associated with communication on the PCell without the UE switching to the SCell.

20. The method of any one of claims 15-19,wherein the at least one adapted operation is valid until one of:an indication is transmitted by the network node (16) to resume one of the at least one pattern;an expiration of a predefined time; oranother switch pattern is transmitted by the network node (16).

21. The method of any one of claims 15-20,wherein the at least one action comprises communicating with the UE (22) based on the at least one adapted operation at the UE (22).

22. The method of any of claims 15-21, comprising:transmitting a configuration to the UE (22), to start carrier aggregation operation using the PCell and the SCell, wherein the configuration comprises the at least one switch pattern.

23. The method of any of claims 15-22,wherein the at least one switch pattern consists of a bit map and each bit of the bitmap indicates on which carrier the UE (22) should receive and / or transmit within a given slot.

24. The method of claim 23,wherein each bit indicates whether the UE (22) should receive from the PCell or from the SCell.

25. The method of any of claims 15-24,wherein the SCell corresponds to a supplementary downlink, SDL, carrier.

26. The method according to any of claims 15-25,wherein a time period including a switching time switching time from the PCell to the SCell and / or from the SCell to PCell is configurable.

27. A network node (16) configured to communicate with a user equipment, UE, (22), the network node (16) being configured to:configure the UE (22) with at least one switch pattern for low band carrier aggregation;receive an indication of at least one adapted operation at the UE (22), the at least one adapted operation being:associated with at least one slot associated with a secondary cell, SCell; and based on whether the UE (22) applies the at least one switch pattern to the at least one slot based on a state of the SCell; andperform at least one action based on the indication.

28. The network node (16) of claim 27,wherein the network node (16) is configured to perform a method according to any of claims 15-26.

29. The network node (16) of claim 27 or 28, comprising a radio interface (30) and / or processing circuitry (36) configured to perform a method according to any of claims 15-26.

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