METHOD AND NODES FOR L1 / L2-CENTRIC MOBILITY FOR SCELLS - Patent application

Abstract

A method is provided that is performed by a user equipment (UE) configured with carrier aggregation to handle L1 (Layer 1) / L2 (Layer 2) mobility for secondary cells associated with a cell group, where a first cell is configured on the UE as a secondary cell on a first frequency. The method may include receiving configuration of at least one second cell on the first frequency, where the at least one second cell is a candidate to become the secondary cell, receiving L1 / L2 signaling including an indication to change the secondary cell from the first cell to the second cell, and changing the secondary cell on the first frequency from the first cell to the second cell.

Description

[Technical field]

[0001] Related Applications This application claims the benefit of and priority to U.S. Provisional Patent Application No. 63 / 185,171, entitled "Codebook Subset Restriction for NR Type II Port-Selection Codebooks," filed May 6, 2021, and U.S. Provisional Patent Application No. 63 / 327,596, entitled "L1 / L2 centric mobility for SCell(s)," filed April 5, 2022, the disclosures of which are incorporated herein by reference in their entireties.

[0002] The present disclosure relates to wireless communications, and more particularly, to Layer 1 (L1) / Layer 2 (L2) mobility for secondary cells. [Background technology]

[0003] Beam indication, Quasi-Co-Location (QCL) source and Transmission Configuration Indicator (TCI) status

[0004] Multiple signals may be transmitted from the same base station antenna from different antenna ports that may have the same large-scale characteristics, e.g., in terms of Doppler shift / spread, average delay spread, or average delay, as measured at the receiver, and these antenna ports are said to be quasi-colocated (QCL).

[0005] The network may also signal to the user equipment (UE) that the two antenna ports are QCLs so that the UE interprets that the signals from the two antenna ports will have some similar characteristics. If the UE knows that the two antenna ports are QCLs with respect to a certain parameter (e.g., Doppler spread), the UE may estimate that parameter based on a reference signal transmitted from one of the antenna ports and use that estimate when receiving another reference signal or physical channel from the other antenna port. Typically, the first antenna port is represented by a measurement reference signal, such as a channel state information reference signal (CSI-RS), known as a source RS, and the second antenna port is a demodulation reference signal (DMRS), known as a target RS, for Physical Downlink Shared Channel (PDSCH) or Physical Downlink Control Channel (PDCCH) reception.

[0006] QCL type D was introduced to facilitate beam management procedures using analog beamforming and is known as spatial QCL. Spatial QCL can be understood as if two transmitted antenna ports are spatially QCLs and the UE can use the same receive (RX) beam to receive signals related to them. This is useful for UEs that use analog beamforming to receive signals because the UE needs to adjust its RX beam in a certain direction before reception of a particular signal. If the UE knows that a signal is spatially QCL with some other signal that the UE has received before, the UE can also receive this signal using the same RX beam. Note that while the discussion of beam management is mainly centered around QCL type D, it is also necessary to convey the type A QCL relationship for RS to the UE so that all the relevant large-scale parameters can be estimated. In other words, if two signals are QCL type D, it can be said that the two signals are transmitted in the same direction or via the same downlink beam. The network may therefore provide this relationship between the channel being decoded (e.g., PDCCH / PDSCH) and signals known to be transmitted in a given direction, such as CSI-RS, Synchronization Signal Blocks (SSBs), etc., that may be used as a reference by the UE.

[0007] Along with the concept of QLC sources, there is the concept of TCI states. Each of the M states in the list of TCI states can be interpreted as a list of M possible beams transmitted in the downlink from the network and / or a list of M possible transmission points (TRPs) used by the network to communicate with the UE. The M TCI states can be further interpreted as a combination of one or more beams transmitted from one or more TRPs. To introduce dynamics in beam and TRP selection / switching, the UE can be configured with M TCI states (e.g., during connection setup, resumption, reconfiguration, handover, etc.) through Radio Resource Control (RRC) signaling, where M is up to 128 in Frequency Range 2 (FR2) and up to 8 in FR1 for PDSCH reception, depending on the UE capabilities.

[0008] With regard to RRC signaling, the TCI state is currently configured as part of the so-called CellGroupConfig, which is a Distributed Unit (DU) configuration (i.e. determined by the baseband unit) in a Central Unit (CU)-DU split architecture, and is conveyed to the UE, e.g. via RRCResume (i.e. during the transition from Inactive to Connected) or RRCReconfiguration (e.g. during handover, intra-cell reconfiguration, or during the transition from Idle to Connected).

[0009] The TCI state configuration is signaled as part of the PDSCH configuration, which is configured per downlink (DL) bandwidth portion (BWP) of a Special Cell (SpCell) (i.e., a Primary Cell (PCell) or a Primary Secondary Cell Group (SCG) cell (PSCell), where an SpCell may consist of one or more DL BWPs or Supplementary / Secondary Cells (SCells). Figure 1 shows an example structure of the CellGroupConfig for signaling (e.g., for an initial DL BWP).

[0010] Each TCI state configuration contains a pointer, known as TCI-StateId, that points to the TCI state. This pointer can be used, for example, to reference the TCI configuration in a Control resource set (CORESET) configuration. In other words, the TCI configuration is provided in a PDSCH configuration for a given DL BWP. And in case of PDCCH, the CORESET configuration contains a TCI state pointer to the configured TCI state in the PDSCH.

[0011] Each TCI state includes the aforementioned QCL information, i.e., one or two source DL RSs, where each source RS is associated with a QCL type. For example, a TCI state includes a pair of reference signals, each associated with a QCL type, e.g., two different CSI-RSs {CSI-RS1, CSI-RS2} are configured as {qcl-Type1, qcl-Type2}={Type A, Type D} in a TCI state. This means that the UE can derive Doppler shift, Doppler spread, mean delay, delay spread from CSI-RS1, and spatial RX parameters (i.e., RX beam to use) from CSI-RS2. With regard to RRC signaling, the TCI state is represented by an information element (IE) called TCI-State, as indicated in 3GPP TS 38.331.

[0012] In the definition of the TCI-State IE, there is a field called cell. According to the definition in 3GPP TS 38.331, the field called cell in the QCL configuration (i.e. the cell field of the IE ServCellIndex) is the serving cell of the UE for which the RS is configured as QCL. If the field is not present, it applies to the serving cell for which the TCI-State is configured (i.e. the SpCell of the cell group, not the indexed SCell). The RS can be located in a serving cell other than the serving cell for which the TCI-State is configured only if the qcl-Type is configured as type D (see TS 38.214 section 5.1.5). In other words, for a given spCellConfig, the RS for a given TCI state is associated with a serving cell in the cell group, which can be a PCell / PScell ​​or associated SCell(s). This is indicated by the field cell in the TCI state configuration. And if the field is not present, it points to the cell for which the TCI state is configured.

[0013] L1 / L2 Centric Mobility in Release 17 (Rel-17)

[0014] Rel-16 manages to provide some reduction in overhead and / or latency, but high speed vehicular scenarios in FR2 (e.g. UE moving at high speed on a highway) require more aggressive reduction in latency and overhead, not only for intra-cell but also for L1 / L2-centric inter-cell mobility. Rel-16 manages to provide some reduction in overhead and / or latency, but high speed vehicular scenarios in FR2 (e.g. UE moving at high speed on a highway) require more aggressive reduction in latency and overhead, not only for intra-cell but also for L1 / L2-centric inter-cell mobility. Thus, work item description RP-193133, while primarily targeting FR2, had the objective of extending multi-beam operation applicable to FR1 as well.

[0015] Although 3GPP has not determined how L1 / L2 inter-cell centric mobility should be standardized, the understanding for purposes of this disclosure is that the UE receives L1 / L2 signaling (instead of RRC signaling) indicating a TCI status (e.g., for a PDCCH) that may be associated with an SSB whose PCI is not necessarily the same as the PCI of the cell to which the UE is connected, e.g., via connection resumption or connection establishment. In other words, the L1 / L2-centric inter-cell mobility procedure may be interpreted as a beam management operation that extends the coverage of multiple SSBs associated with multiple PCIs (e.g., that may be associated with the same cell or different cells).

[0016] In Rel-16, L1 mobility including multiple PCIs is already discussed, but nothing is specified. RAN2 discussed in an email how to enable mPDCCH mTRP support in higher layers (see 107#39][NR] Multi PDCCH multi TRP impact to RAN2 (Ericsson)).

[0017] It was proposed to add a list of additional SSBs (including PCIs) to ServingCellConfig, and to add a reference to one entry in that list to QCL-Info (included only if the reference is an SSB).

[0018] In Rel-17, it is highly likely that one of the above can be considered as the baseline. Furthermore, in patent application WO2021 / 064494, multiple sets of SSBs were considered in the serving cell configuration, each set having its independent PCI configured for the UE. One aspect here is that a unique SSB can be indicated by the pair {SSB index and PCI}, compared to Rel-15, where only the SSB index was used to address a unique SSB under the serving cell.

[0019] Carrier Aggregation (CA) and configuration of (one or more) SCells

[0020] In CA, two or more Component Carriers (CCs) are aggregated. Depending on its capabilities, a UE may simultaneously receive or transmit on one or more CCs. When CA is configured, the UE has only one RRC connection with the network. For RRC connection establishment / re-establishment / handover, one serving cell provides Non-Access Stratum (NAS) mobility information and security input. This cell is called Primary Cell (PCell). Depending on the UE capabilities, a Secondary Cell (SCell) may be configured to form a set of serving cells together with the PCell. Thus, the configured set of serving cells for a UE always consists of one PCell and one or more SCells.

[0021] Reconfiguration / modification, addition, and removal of an SCell can be performed via RRC signaling (e.g., an RRC reconfiguration procedure) via an RRCReconfiguration message. In an intra-NR handover, for example, the RRC may add, remove, or reconfigure / modify (one or more) SCells for use with the target PCell. When adding a new SCell, dedicated RRC signaling is used to transmit all necessary system information for the SCell, i.e., the UE does not need to obtain broadcast system information directly from the SCell while in connected mode.

[0022] When a UE transitions from IDLE to CONNECTED or from INACTIVE to CONNECTED state in a cell (e.g., PCell), a so-called SCell may be configured for the UE (e.g., in an RRCReconfiguration or RRCResume message) and the UE is said to be in the same cell group (Master Cell Group - MCG) as the PCell. These SCells are configured as part of the MCG configuration in the IE CellGroupConfig. They may be added to the sCellToAddModList in which each SCell is configured.

[0023] Similar reasoning can be applied for SCells associated to a Secondary Cell Group (SCG): when an SCG is added to a UE, SCells can be added for the SCG, and these SCells are said to be part of the SCG.

[0024] State of (one or more) SCells: Activation / deactivation of SCells (and dormant SCells)

[0025] To enable reasonable UE battery consumption when CA is configured, an activation / deactivation mechanism for SCells is supported. If an SCell is deactivated, the UE does not need to receive the corresponding PDCCH or PDSCH, cannot transmit in the corresponding uplink, and does not need to perform channel quality information (CQI) measurements. However, this does not preclude the need to perform radio resource management (RRM) measurements for these SCells. Conversely, if an SCell is active, the UE should be able to receive the PDSCH and PDCCH (if the UE is configured to monitor the PDCCH from this SCell) and perform CQI measurements.

[0026] To reconfigure the set of serving cells:

[0027] -SCells added to the set are first activated or deactivated;

[0028] - The remaining SCells in the set (either unchanged or reconfigured) do not change their activation status (activated or deactivated).

[0029] Upon handover or connection resumption from RRC_INACTIVE, the SCell is activated or deactivated.

[0030] To enable reasonable UE battery consumption when Bandwidth Adaptation (BA) is configured, only one uplink (UL) BWP per uplink carrier and one DL BWP or one DL / UL BWP pair may be active at a time in the active serving cell, and all other BWPs configured for the UE are deactivated. In a deactivated BWP, the UE does not monitor the PDCCH and does not transmit on the PUCCH, PRACH, and UL-SCH. To enable fast SCell activation when CA is configured, one dormant BWP may be configured for the SCell. If the active BWP of an activated SCell is a dormant BWP, the UE stops monitoring the PDCCH and transmitting the Sounding Reference Signal (SRS) / PUSCH / PUCCH on the SCell, but continues to perform CSI measurements, automatic gain control (AGC), and beam management (if configured). Downlink control information (DCI) is used to control entering / exiting the dormant BWP for one or more SCells or one or more SCell groups. The dormant BWP is one of the dedicated BWPs of the UE, which is configured by the network via dedicated RRC signaling. The dormant BWP cannot be configured for the SpCell and PUCCH SCell.

[0031] (One or more) SCells, TCI state and QCL source

[0032] Part of the SCell configuration is the sCellConfigDedicated of the IE ServingCellConfig, which is used to configure (add or modify) an Scell ​​of the MCG or SCG for the UE. The parameters here are mostly UE specific, but also partly cell specific (e.g. in the additional configured bandwidth part). As part of the initial BWP configuration (of the IE BWP-DownlinkDedicated), the UE is configured with PDCCH and PDSCH configuration (for that BWP and similarly for additional DL BWPs, if configured).

[0033] Within the PDSCH-Config, there is a list of TCI states for each BWP, indicating the transmission configuration including the QCL relationship between DL RSs in an RS set and the PDSCH demodulation reference signal (DMRS) ports.

[0034] Each TCI state in tci-StatesToAddModList is defined as above. Briefly, for a given SCell, a list of TCI states is configured in the UE per BWP. Each TCI state has a QCL source (i.e., RS in DL, e.g., SSB of a given PCI) associated with it. Since the UE needs to know how to find its RS (e.g., PCI and SSB frequency / absolute radio-frequency channel number (ARFCN)), each QCL source configuration of a TCI state indicates the BWP (bwp-Id) where the RS is transmitted, the UE's serving cell (e.g., its exact same SCell or another serving cell) where the RS is configured, and the RS index (e.g., SSB index or CSI-RS index).

[0035] Similar to the case of the SpCell, based on the RRC configured TCI state, the UE may receive a Medium Access Control (MAC) Control Element (CE) indicating which TCI state should be activated / deactivated for the UE-specific PDCCH. The network may inform the UE of the TCI state for PDCCH reception for the CORESET of the serving cell (or the set of serving cells configured in simultaneousTCI-UpdateList1 or simultaneousTCI-UpdateList2) by sending a TCI state indication for the UE-specific PDCCH MAC CE (see 6.1.3.15 of TS 38.321). If the MAC entity receives a TCI state indication for the UE-specific PDCCH MAC CE on the serving cell, the UE informs the lower layers about the TCI state indication for the UE-specific PDCCH MAC CE.

[0036] The TCI status indication for a UE specific PDCCH MAC CE is identified by a MAC subheader with a Logical Channel ID (LCID), which has a fixed size of 16 bits and contains the following fields:

[0037] - Serving Cell ID: This field indicates the identity of the serving cell to which the MAC CE applies. The field length is 5 bits. If the indicated serving cell is configured as part of simultaneousTCI-UpdateList1 or simultaneousTCI-UpdateList2 as specified in TS 38.331 [5], this MAC CE applies to all serving cells in the set simultaneousTCI-UpdateList1 or simultaneousTCI-UpdateList2, respectively;

[0038] - CORESET ID: This field indicates the control resource set identified by ControlResourceSetId as specified in TS 38.331 [5] for which the TCI status is indicated. If the value of this field is 0, it refers to the control resource set set by controlResourceSetZero as specified in TS 38.331 [5]. The field length is 4 bits.

[0039] -TCIStateID: This field indicates the TCI state identified by the TCI-StateId specified in TS 38.331 [5] applicable to the control resource set identified by the CORESET ID field. If the CORESET ID field is set to 0, this field indicates the TCI-StateId for the TCI state among the first 64 TCI states set by tci-States-ToAddModList and tci-States-ToReleaseList in the PDSCH-Config of the active BWP. If the CORESET ID field is set to a value other than 0, this field indicates the TCI-StateId set by tci-StatesPDCCH-ToAddList and tci-StatesPDCCH-ToReleaseList in the controlResourceSet identified by the indicated CORESET ID. The field length is 7 bits.

[0040] For example, Figure 2 shows a TCI status indication for a UE-specific PDCCH MAC CE, and Table 1 below shows example code points corresponding to LCID values. TIFF0007671862000001.tif34143 Summary of the Invention

[0041] Currently, certain challenges exist: With the introduction of L1 / L2 centric mobility in Release 17, a UE should be able to perform inter-cell mobility upon receipt of L1 or L2 signaling. For example, a MAC CE indicating a TCI state having as QCL source an RS associated with a cell (not the current PCell, but possibly within the frequency of the PCell) may possibly indicate (directly or indirectly) a new cell that the UE needs to access.

[0042] 3GPP RAN1 uses the term "Serving Cell" in the agreement for L1 mobility, but the details of how it can be applied to SCell are not discussed. One problem is that there is no concept of inter-cell mobility for SCell in 3GPP specifications and 3GPP systems (only PCell / PSCell mobility exists). And all procedures for SCell, such as adding, modifying, and / or releasing SCell, require RRC Reconfiguration.

[0043] Another issue is that for PCell / PSCell, a single SpCell is configured in the UE for each cell group with a given frequency (e.g., SSB frequency, Point A frequency), e.g., PCell for MCG at SSB frequency f0, PSCell for SCG at SSB frequency f1. On the other hand, in the case of SCell, the UE may be configured with multiple SCells for a given cell group (one SCell for each serving frequency that is not a SpCell frequency), e.g., SCell(1) at SSB frequency f2, SCell(2) at SSB frequency f3 for MCG, and SCell(3) at SSB frequency f4, SCell(4) at SSB frequency f5 for SCG. In this example, the UE will have f0, f1, f2, f3, f4, f5 as serving frequencies and one serving cell for each serving frequency.

[0044] In FIG. 3, one of the scenarios addressed by the present disclosure is shown, in which the UE is within the coverage area of ​​a PCell (or PSCell, more generally SpCell), but the coverage of the SCell(s) changes as the UE moves. For example, assume that a Pcell-A in a low band (frequency lower than 6 GHz) is configured in the UE, while a SCell-x in a high band (so that as the UE moves, the UE stays in the PCell coverage for frequency 2, but not in the Scell ​​coverage). As a result, if L1 mobility may be supported between Pcells (assuming that Pcell-B is also controlled by the same DU), the handling of the Scell(s) may require RRC signaling for SCell release and addition (SCell-x and cell-y and cell-z are in the same frequency, and the UE cannot be configured with multiple Scells of the same frequency).

[0045] Certain aspects of the present disclosure and its embodiments may provide solutions to these and other problems.

[0046] An embodiment includes a method implemented in a UE for handling L1 / L2 mobility for a SCell associated with a cell group, the UE being configured with a first cell as a SCell in a first frequency and configured with CA, the method including receiving a configuration of at least a second cell in the first frequency, the second cell being a candidate for the SCell, receiving L1 / L2 signaling indicating a change of a secondary cell from the first cell to the second cell, and changing the SCell in the first frequency from the first cell to the second cell.

[0047] That is, the UE stops considering a first cell in a first frequency as an SCell and starts considering a second cell in a first frequency as an SCell. This "Start / Stop Considering an Scell" is a new procedure that will be described in detail below.

[0048] The method further includes configuration of cells in SCell frequencies (i.e. serving frequencies that are not SpCell frequencies) that are candidates for L1 based mobility (such as a second cell) and different ways to reference / identify these cells, e.g. indices associated with cell groups and / or serving frequencies.

[0049] There is no procedure in the NR or LTE specifications for a UE to "change" its SCell in a first frequency from a first cell to a second cell (in the first frequency). Thus, actions corresponding to this "change" may include any combination of the following:

[0050] A) setting the SCell state of the first cell and / or the state of the second cell;

[0051] B) Handling the deactivation timer;

[0052] C) Handling cell-specific and UE-specific configurations.

[0053] Embodiments further include a method implemented in a network node (e.g., a gNB, or a DU-gNB) for handling L1 / L2 mobility for a SCell associated with a cell group of a UE served by an NG-RAN, where a network entity configures a first cell as an SCell in a first frequency for the UE, the method including sending a configuration of at least a second cell in the first frequency to the UE, the second cell being a candidate for the SCell, sending L1 / L2 signaling to the UE indicating a change of the SCell from the first cell to the second cell, and changing the SCell in the first frequency for the UE from the first cell to the second cell.

[0054] That is, similar to the UE, the network also stops considering a first cell on a first frequency as a SCell and starts considering a second cell on the first frequency as a SCell. The network node may further configure the UE with cells on SCell frequencies (i.e. serving frequencies that are not SpCell frequencies) that are candidates for L1-based mobility (such as the second cell) and different ways to index / identify these cells, e.g. indexes associated with cell groups and / or serving frequencies.

[0055] There is no procedure in the NR or LTE specifications for a network node to "change" a SCell in a first frequency from a first cell to a second cell (also in the first frequency). Thus, actions corresponding to this "change" may include one or any combination of the following:

[0056] A) setting the SCell state of the first cell and / or the state of the second cell;

[0057] B) Handling the deactivation timer;

[0058] C) Handling cell-specific and UE-specific configurations.

[0059] Certain embodiments may provide one or more of the following technical advantages.

[0060] With these embodiments, it is possible to configure multiple SCells in the same serving frequency and select an SCell based on L1 / L2 signaling such as MAC CE without needing to add, modify and / or release SCells while the UE is moving towards a new SCell area. For example, Figure 4 shows such an example, where the UE considers different cells as Scells in frequency 2 at different times while the UE is moving. [Brief description of the drawings]

[0061] Exemplary embodiments are described in more detail with reference to the following drawings:

[0062] [Figure 1] FIG. 1 shows an example structure of a CellGroupConfig.

[0063] [Diagram 2] FIG. 2 shows an example of a TCI status indication for a UE-specific PDCCH MAC CE.

[0064] [Diagram 3] FIG. 3 shows an example scenario in which several Scells are configured for a UE and the UE moves within the coverage of the Scells.

[0065] [Figure 4] FIG. 4 illustrates an example solution to the scenario of FIG. 3, according to one embodiment.

[0066] [Diagram 5] FIG. 5 illustrates an example set of Scells associated with the nth cell group and configured for a UE.

[0067] [Figure 6]FIG. 6 shows an example of TCI state setting for a cell.

[0068] [Figure 7] FIG. 7 illustrates an exemplary MAC CE for TCI state setting, according to one embodiment.

[0069] [Figure 8] FIG. 8 shows an example of a MAC PDU that includes two MAC sub-PDUs.

[0070] [Figure 9] FIG. 9 shows an example MAC CE for indicating cell activation / deactivation.

[0071] [Figure 10] FIG. 10 shows an example MAC CE for indicating cell activation / deactivation.

[0072] [Figure 11] FIG. 11 illustrates a flowchart of a method in a UE according to one embodiment.

[0073] [Figure 12] FIG. 12 shows a flowchart of a method in a network node according to one embodiment.

[0074] [Figure 13] FIG. 13 illustrates an example of a communication system, according to one embodiment.

[0075] [Figure 14] FIG. 14 illustrates a schematic diagram of a UE according to one embodiment.

[0076] [Figure 15] FIG. 15 shows a schematic diagram of a network node according to one embodiment.

[0077] [Figure 16]FIG. 16 shows a block diagram of the host.

[0078] [Figure 17] FIG. 17 is a block diagram illustrating a virtualization environment.

[0079] [Figure 18] FIG. 18 shows a communication diagram of the host. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0080] Some of the embodiments discussed herein are described more fully below with reference to the accompanying drawings, in which: The embodiments are provided as examples to convey the scope of the subject matter to those skilled in the art.

[0081] This disclosure refers to a "cell" or a "set of cells" or secondary cells for which a UE may be configured to perform L1 / L2-centric mobility. These sets of cells may be referred to as a set of intra-frequency neighboring cells for which the UE may perform measurements or change SCells, or a set of intra-frequency non-serving cells, or simply a set of non-serving cells (in addition to the serving cell). Alternatively, the cells that the UE may use to perform L1-based mobility may be referred to as candidate SCells, additional SCells, SCells, non-serving SCells, non-serving cells (SCell candidates configured for L1-based mobility), etc.

[0082] With regard to Abstract Syntax Notation one (ASN.1) encoding (for examples showing signaling), consider TS 38.331 Rel-16 specification for RRC as a reference for omitted information elements (IEs) and fields in messages and / or IEs that are proposed to be extended to implement the methods / embodiments disclosed herein.

[0083] The term "secondary cell" refers to a cell configured in a UE for CA (i.e., configured to be used as a component carrier). This term is used in NR (e.g., in TS 38.331) and EUTRA (see, e.g., TS 36.331). However, the embodiments herein are applicable to any type of cell configured in a UE for CA or for a UE configured with CA, a cell providing additional radio resources on a Special Cell / PCell, a PSCell, or any kind of cell considered as a main cell or a higher layer cell, although with different terminology. The term "secondary serving frequency" refers to a carrier frequency (e.g., SSB frequency and / or Point A frequency, both defined in TS 38.331) for a secondary cell (i.e., a cell that is not an SpCell (i.e., not a PCell or a PSCell).

[0084] When this disclosure describes a "UE receiving" a message (e.g., a MAC CE) from a network node, which may correspond to the UE receiving the message from a network node, a network function such as a DU or CU of a gNB in ​​a next generation radio access network, or a node performing a baseband function.

[0085] This disclosure describes a solution for configuring the TCI state(s) and its QCL source, i.e., RS, associated with a cell (not a serving cell) using terminology in NR specifications (e.g., TS 38.211, TS 38.212, TS 38.213, TS 38.331, TS 38.321). However, this disclosure should not be limited to one aspect where a beam indication (e.g., TCI state) associated with a physical channel (e.g., PDCCH) whose beam is associated with a cell that is not a secondary serving cell (e.g., not a SCell) is configured in the UE via higher layer signaling (e.g., RRC). The UE also receives an L1 / L2 indication (e.g., MAC CE) including an identifier of the beam indication (e.g., a TCI status identifier), and upon receipt, the UE determines the beam indication and its associated cell, and the UE determines that the cell of the indicated beam is in the serving frequency but is not the serving cell, and performs a change of serving cell from the current serving cell to the cell associated with the indicated beam in the serving frequency.

[0086] Potential Solutions in 3GPP for L1 / L2 Centric Mobility

[0087] This disclosure refers to the term “L1 / L2 inter-cell centric mobility,” which may be used interchangeably with the terms L1 / L2 mobility, L1 mobility, L1-based mobility, L1 / L2-centric inter-cell mobility, or L1 / L2 inter-cell mobility. The objective of L1 / L2 inter-cell-centric mobility is for a UE in RRC_connected to be connected to (i.e. served by) a serving cell (SpCell), which is considered as a PCell after the UE performs connection setup, for example when transitioning from RRC_IDLE to RRC_connected, or when transitioning from RRC_INACTIVE to RRC_connected, and in that case the UE has the first PCI associated with that PCell (i.e. the PCI in ServingCellConfigCommon / SIB1 for the cell on which the UE was camped when it performed random access for transition to RRC_connected). In a multi-beam scenario, a cell may be associated with multiple SSBs, and different SSBs may be transmitted in different spatial directions (i.e. using different beams across the coverage area of ​​the cell) during a half frame.

[0088] Although the term "L1 / L2 inter-cell centric mobility" has the term "inter-cell", one aspect is that a serving cell configuration has two or more physical cell identities (PCIs) associated with it, and there are at least two approaches to creating that association:

[0089] 1) Intra-cell multi-PCI L1 / L2-centric mobility: The same serving cell configuration is associated with more than one PCI (e.g., a TCI state configuration in ServingCellConfig may be associated with a PCI, which may be different from the PCI in ServingCellConfigCommon). For example, this means that a UE may have an SCell associated with one or more PCIs, and that the UE may receive L1 / L2 signaling (e.g., MAC CE, as defined in TS 38.321) that informs the UE that the PCI of the SCell needs to be changed (e.g., from PCI-1 to PCI-2). This can be done by associating the SSB of PCI-2, which is configured as a QCL source for the TCI state (indicated by TCI State Id-X) indicated in the MAC CE in the RRC signaling. Thereafter, upon receiving that MAC CE with TCI State Id-X, the UE knows that it needs to change to PCI-2 and perform the actions associated with the SCell(s) as described in this disclosure.

[0090] 2) Inter-cell multi-PCI L1 / L2-centric mobility: The UE has several cell configurations with associated individual PCIs, but the TCI state may point to the PCIs of other cells (e.g., other serving cells or even non-serving cells to which the UE can move using L1 / L2-centric mobility). For example, this means that the UE is configured with multiple cells (e.g., SCells), each with its own PCI, and the UE may receive L1 / L2 signaling (e.g., MAC CE) that informs the UE that the SCell needs to be changed (e.g., from the cell associated with PCI-1 to the cell associated with PCI-2) in its given secondary serving frequency. This can be done by associating the SSB of the cell associated with PCI-2, which is configured as the QCL source for the TCI state (indicated by TCI State Id-X) indicated in the MAC CE in the RRC signaling. Thereafter, upon receiving that MAC CE with TCI State Id-X, the UE knows that it needs to change to the SCell associated with PCI-2 and perform actions related to the change of SCell(s), as described in this disclosure.

[0091] When this disclosure describes L1 / L2 signaling for L1 mobility, it may refer to "TCI status indication for UE-specific PDCCH MAC CE" including one or more indications of TCI configuration (e.g., serving cell ID and / or serving frequency ID), CORESET ID, and TCI status ID. The MAC CE may be identified by a MAC subheader with LCID as specified / defined in TS 38.321.

[0092] Next, a method in a UE is described. For example, the UE may be configured in CA and move around as shown in the scenario of FIG. 4. As the UE moves around, the UE needs to change the Scell ​​(e.g., from cell-x to cell-y to cell-z). First, the UE is configured with a first cell as a SCell in a first frequency. That means that the UE is configured with a secondary cell in the first frequency (which may be represented by an SSB frequency, defined by an ARFCN and / or a point A frequency, as defined in TS 38.331). For example, the UE may receive its SCell configuration in the IE CellGroupConfig as part of the MCG or SCG configuration. Then, the UE receives the configuration of at least a candidate second cell in the first frequency (e.g., frequency 2). The candidate second cell is a candidate to become a SCell via L1 / L2-centric mobility. After receiving L1 / L2 signaling (L1 mobility) containing an indication of a candidate second cell for the Scell, the UE changes the Scell ​​to the candidate second cell and takes some actions accordingly. These different steps are explained in more detail below.

[0093] There are various ways on how to configure cells in SCell frequencies (i.e., serving frequencies that are not SpCell frequencies), including the first cell and the candidate second cell for L1-based mobility, and various ways to refer to or identify these cells, for example, via an index associated with a cell group and / or a serving frequency. For example, cells for Scell ​​candidates may be configured as a common list for all SCell serving frequencies or may be configured per serving frequency.

[0094] A) A common list for cells in all SCell serving frequencies.

[0095] In one example, a UE is configured with multiple cells (e.g., cell (1,1),..., cell (1,K1)) in the same serving frequency (first frequency, e.g., referred to as frequency 1) and for one of the cells in that frequency, it is indicated which cell is the so-called initial SCell (or first Scell). It is needed so that the UE knows which of the configured cells in that serving frequency (e.g., cell (1,k1)) should be considered first as the SCell in that serving frequency to be considered when receiving an RRC message (e.g., RRCReconfiguration). This is important because the method assumes that the UE may be configured with multiple cell configurations for a given serving frequency (although a single cell may be the SCell in that serving frequency).

[0096] In one example, a list, set or group (e.g., list sCellToAddModList in CellGroupConfig) defines two or more cells per serving frequency. Figure 5 shows a set of Scells for a cell group. If there is only one cell considered as an SCell per frequency, the UE may receive a parameter in the RRC signaling to indicate that a given cell should be considered as an SCell at that frequency when the UE receives the RRC message (e.g., the parameter may be an initial SCell, which may be a Boolean IE, or its inclusion may indicate that the configured cell is the initial SCell at that frequency). When cells (e.g., cells (1,1),..., cells (1,K1)) are configured in sCellToAddModList, they are configured as if they were all (one or more) SCells, although the initial SCell is indicated (per serving frequency). In this case, each cell of the first frequency is identified / indexed by its cell index / identifier (e.g., sCellIndex of IE SCellIndex), and the configuration of candidate cells may be identified later by its index. An example of ANS.1 is: TIFF0007671862000002.tif35154

[0097] The cell index (e.g., sCellIndex in IE SCellIndex) may be used as an indication that the configured cell should be considered as the initial SCell in its associated frequency. In one example, the UE considers the cell with the smallest cell index / identifier among the cells in the same frequency as the initial SCell. For example, if the following secondary frequency cells are configured in the UE, with cell indices / identifiers / identities of 1, 2, 3, 4, 5, 6 (and fk refers to frequency k), [cell(1,f1), cell(2,f1), cell(3,f1), cell(4,f2), cell(5,f2), cell(6,f3)], the UE considers the following as the SCell(s) in each fk frequency:

[0098] - The initial Scell ​​in serving frequency f1 is the cell whose cell index = 1 (the smallest index in that frequency), therefore, cells with index equal to 2 and 3 are candidates for L1 mobility in f1;

[0099] - The initial Scell ​​in serving frequency f2 has its cell index = 4, therefore cells with index equal to 5 are candidates for L1 mobility in f2;

[0100] - The initial Scell ​​in serving frequency f3 is the cell with cell index = 6, and no other candidates are configured for L1 mobility in f3.

[0101] Compared to the previous example, the advantage of this example is that no additional signaling needs to be introduced (e.g., no need to introduce the parameter initialSCell), but the cell index used in the RRC signaling needs to be signaled again.

[0102] Note that since candidate cells are configured as SCells, in principle they may have the same configuration as SCells. However, the configuration of the candidate SCell(s) may be limited to cell(s) specific configuration, such as information in the IE ServingCellConfigCommon, such as PCI. The UE may receive an indication to modify or release a candidate cell for L1 mobility in the first frequency, as it may receive for the SCell.

[0103] In an example, the cell index of the second cell (configured as a SCell candidate for L1 mobility) can be used to inform the UE that the RS configured as the QCL for the TCI state is for the second cell. The following shows an example for the configuration of the TCI state for tci-StateId=3, cell index cell=4 (to indicate that the RS refers to the candidate cell configured with sCellIndex=4): TIFF0007671862000003.tif86154

[0104] Assuming the above configured TCI state is in the SCellConfig with index sCellIndex and set to 2, it means that the UE knows that it needs to look at that TCI state if it receives a MAC CE with serving cell ID equal to 2. Furthermore, upon receiving a MAC CE indicating tci-StateId=3, the UE determines that the configured RS (e.g., SSB 12) is for cell index cell=4, which is one of the configured candidates for L1 mobility, and performs a change from its current SCell (e.g., the cell with sCellIndex=2) to the candidate cell with cell index sCellIndex=4.

[0105] Further details about this SCell change operation are provided later in this disclosure. In mobility scenarios (synchronization, handover, reconfiguration with PSCell change), the initial SCell (in the list of candidates) may be set by the target network node (eg, target gNodeB) in response to a handover request message.

[0106] B) List of cells per serving frequency (for SCell).

[0107] In one example, the UE is configured with one SCell in a first frequency that is considered to be the initial SCell when the UE receives RRC signaling. The additional cells configured (e.g., in each SCellConfig) can be considered as candidate cells for L1 mobility in that frequency. Each candidate can become an SCell via L1 / L2 signaling (MAC CE). These candidates can be configured in a new list (e.g., sCellCandidatesToAddModList) in each SCellConfig, e.g., in the SCellConfig for the first frequency. Note that the SCellConfig is more like a per-frequency configuration, not just per-SCell. The configuration of the initial SCell is the configuration in the SCellConfig that is not present in the list / set of configurations for the additional cells (i.e., not present in sCellCandidatesToAddModList), such as the UE-specific configuration, SCellConfigCommon for the initial SCell.

[0108] The first index / identifier may be used as a serving frequency index (e.g., sCellIndex in SCellConfig), and at least each additional candidate for L1 mobility in that serving frequency is further identified by a second index (e.g., sCellCandIndex for identifying a candidate cell in that first frequency). The second index is important when the UE needs to identify a candidate cell for L1 mobility in the first frequency, and the second index / identifier may be used (together with the first index for the serving frequency) to indicate, for example, that the RS configured as a QCL source for the TCI state is the RS of the candidate cell with the second index. An example of this signaling is shown below: TIFF0007671862000004.tif54154

[0109] The advantage of this example is that it does not change the legacy signaling and the meaning of the parameters for the secondary serving frequency until the UE is reconfigured when there is only one cell (i.e., SCell). If there are no L1 mobility candidates for a given secondary serving frequency, the first index / identifier is both the serving frequency index and the serving cell index.

[0110] In some examples, the second index / identifier is used by the UE as an indication that the RS configured as the QCL in the TCI state is of a second cell (i.e., a candidate cell that is a SCell that is not the initial SCell), and may be combined with the first index / identifier indicating the serving frequency of the second cell.

[0111] The following is an example of the TCI state setting for tci-StateId=3, cell index cell=4, and sCellCandIndex=2 (the candidate cell for which the TCI state is to be set): TIFF0007671862000005.tif108154

[0112] Under the assumption that the TCI state configuration is part of the initial SCell configuration (i.e., in the SCellConfig), upon reception of the MAC CE including the serving cell ID, the UE knows that the TCI state to look at is in the initial SCell configuration for the SCell in the serving frequency indicated by the received serving cell ID. Thus, the UE receives the MAC CE including the serving cell ID=2 and the TCI state ID=3, and determines the new QCL source and the new SCell based on the stored RRC configuration for the serving frequency with the first index / identifier=2 (i.e., sCellCandIndex=2) and tci-StateId=3 (for the indicated CORESET). Regardless of the new nested RRC structure for the serving frequency, the initial SCell, and the candidate cell that becomes the SCell via L1 mobility, the MAC CE only needs to indicate the TCI state that is configured to the UE, and an indication of the SCell serving frequency. In summary, under this assumption, the serving cell ID in the MAC CE indicates the identity of the initial serving cell to which the MAC CE applies, which includes UE-specific configuration (including TCI state configuration) for that UE for any cell in that serving frequency. Figure 6 shows such configuration as an example.

[0113] In this example, the initial SCell configuration (i.e., list of SCells) is compared to what is included as the configuration of each candidate cell that becomes a SCell via L1 mobility (i.e., the configuration included in each instance of SCellCandidateConfig). sCellCandidatesToAddModList There may be various alternatives for what is included in the IEs (and other IEs and parameters).

[0114] For example, the configuration of a candidate cell for L1 mobility, which is changed to a SCell(s), may be limited to cell(s) specific configuration, such as information in the IE ServingCellConfigCommon including PCI. TIFF0007671862000006.tif58154

[0115] In another example, the configuration of a candidate cell for L1 mobility to be changed to a SCell(s) may include UE specific configuration, such as information in the IE ServingCellConfig, such as the TCI state configuration as shown below: TIFF0007671862000007.tif68154

[0116] If a candidate cell (e.g., one of the cells in sCellCandidatesToAddModList), which may be a SCell via L1 mobility, may contain UE-specific configurations that may include TCI state settings (or CSI settings), the use of current systems (e.g., prior art) for MAC CE design for TCI state indication may be ambiguous. The UE needs to be able to determine in which cell configuration to find the specific TCI state configuration indicated with MAC CE, and the current interpretation of the Serving Cell ID states that the field indicates the identity of the serving cell to which the MAC CE applies. However, if there may be more than one cell with TCI state settings in a given serving frequency, it is not clear which configuration (i.e., which cell's configuration) the UE should consider for the TCI state. There may be different solutions for this:

[0117] In one example, the UE assumes that the serving cell ID field in the MAC CE indicates the current cell that the UE considers as a SCell on the serving frequency indicated by the serving cell ID, which could be the initial SCell or any candidate cell that has become a SCell (via L1 mobility).

[0118] In a second example, the UE assumes that the serving cell ID field in the MAC CE indicates the configuration of the initial SCell.

[0119] In a third example, the UE assumes that the serving cell ID field in the MAC CE indicates the serving frequency and that an additional identifier in the same MAC CE indicates a candidate cell in that serving frequency for which the TCI state is set.

[0120] In a fourth example, the UE assumes that the serving cell ID field in the MAC CE indicates a candidate cell in the serving frequency for which the TCI state is set, and an additional identifier (e.g., serving frequency ID) is included in the MAC CE to indicate the serving frequency for which the candidate cell is configured. Figure 7 shows such an example.

[0121] In a fifth example, the UE receives a second type of initial MAC CE indicating serving frequencies (for the SCell) that the UE considers to find candidate cells and their configuration, which may correspond to a MAC sub-PDU including MAC CE 1, which includes a serving frequency ID corresponding to a serving cell index (e.g., sCellIndex) configured in the SCellConfig. The MAC CE for TCI status indication including the serving cell ID may correspond to a MAC sub-PDU including MAC CE 2 to indicate which candidate cell (within the indicated serving frequency) is the indicated TCI configuration. The two MAC sub-PDUs may be received by the UE (sent by the network) in the same MAC PDU. Figure 8 illustrates such an example.

[0122] Some additional options related to any of the above examples are now described. In a first version / option, the MAC CE does not include a core set ID, but the BWP ID and the same TCI state is updated for all CORESETs of the indicated BWP. In another option, the MAC CE does not include a BWP ID or a CORESET ID, but the same TCI state is applied to all CORESETs in all BWPs of the indicated Scell. In yet another option, the MAC CE does not include a BWP ID or a CORESET ID, but includes a list of TCI states giving the TCI states for the CORESETs configured in all BWPs. In this case, the order of TCI state mapping to CORESETs is fixed, e.g., the mapping starts with the CORESET configured for BWP ID 1, then the CORESET configured for BWP ID 2, etc. Note that in these examples / options, the MAC CE may further include an additional field indicating the type of the MAC CE. For example, an n-bit field (e.g., field F) may indicate in which of the possible formats the MAC CE is configured. That is, for example, whether it contains a list of TCI states, or whether a BWP ID is present, etc.

[0123] In any of the cases and examples described above, when the UE receives the MAC CE for L1 mobility for the SCell, it determines a new candidate cell to become the SCell in its serving frequency, which may be considered as changing the SCell. Details regarding UE actions in changing the SCell (i.e., changing the SCell from a first cell to a second cell in a given serving frequency) are described below.

[0124] UE Actions when Changing SCell with L1 Mobility

[0125] As mentioned above, there is no procedure in the NR or LTE specifications for a UE to "change" its SCell on a first frequency from a first cell to a second cell (also on the first frequency). Therefore, an action corresponding to this "change" is defined as part of a method, such as one of the following, or any combination of the following:

[0126] A) Set the SCell state of the first cell and / or the state of the second cell

[0127] In some embodiments, the state of the initial SCell is set via RRC and may be inactive, active, or dormant.

[0128] For example, when changing the SCell from a first cell to a second cell, the UE sets the SCell state of the first cell and / or sets the state of the second cell (which becomes the Scell ​​in its serving frequency) according to the rule(s) and / or the RRC configuration and / or the indication received in the MAC CE.

[0129] In one embodiment, the UE sets the state of the first cell to deactivated, suspended (new states defined later) or dormant, while the state of the second cell (which will be the SCell in its serving frequency) is set to be activated. This is done as a UE autonomous action upon receiving a MAC CE for L1 mobility when the UE decides to change from the first cell to the second cell.

[0130] In another embodiment, the UE sets the state of the first cell to a new state (e.g., suspended), which means that the UE does not perform lower layer procedures for that cell (e.g., no CSI measurements, no CSI reporting, no PDCCH monitoring, no PUCCH / PUSCH transmission, no RACH, etc.) unless CSI measurements are configured for the suspended cell in the configuration of the other cell. The cell is simply a cell whose configuration is stored in the UE's RRC configuration and whose configuration may be activated at any time, e.g., by the RRC or MAC CE.

[0131] In one embodiment, the state of the second cell is set to a value that is set (e.g., activated) via RRC when the second cell (configured as a candidate) is informed to become a SCell via reception of L1 / L2 signaling, such as MAC CE for L1-based mobility, indicating a TCI state whose QCL source has the RS of the second cell. This is done as a UE autonomous action upon reception of MAC CE for L1 mobility when the UE decides to change from the first cell to the second cell based on the stored RRC configuration for the first and second cells. In one example, this embodiment is applicable when a candidate cell for L1 / L2 mobility in the first frequency is configured as a SCell, such as the second cell. Furthermore, according to the method, "changing" the SCell may be equivalent to deactivating (or moving to a dormant state) the first SCell and activating the second SCell.

[0132] A first example of how this can be implemented in the MAC specification (TS 38.321) is shown below. In this example, the actions for activation / deactivation of the SCell on SCell change are performed as part of the procedure on receipt of the MAC CE for L1 mobility of the SCell, as follows: ******************************************************************************** 5.18.5 TCI status indication for UE specific PDCCH The network shall determine the TCI state for PDCCH reception for a CORESET of serving cells or the set of serving cells configured in simultaneousTCI-UpdateList1 or simultaneousTCI-UpdateList2 by sending a TCI state indication for the UE specific PDCCH MAC CE as described in subclause 6.1.3.15. or a candidate cell for L1 mobility in the serving frequency can be informed. The MAC entity: 1> If the MAC entity receives a TCI status indication for a UE specific PDCCH MAC CE on the serving cell: 2> Inform lower layers about TCI status indication for UE-specific PDCCH MAC CE. 2> If the indicated TCI state ID has a QCL source and the RS is in a candidate cell in a serving frequency that is not a SCell in the serving frequency: 3>Suspend SCell; 3> Consider the candidate cell as a SCell in its serving frequency; 3> If the candidate cell has sCellStateUponChange set to active: 4> Perform actions upon SCell activation as defined in clause 5.9 (activate / deactivate SCell); 3> If the candidate cell has sCellStateUponChange set to inactive: 4> Perform actions upon SCell deactivation as defined in clause 5.9 (SCell activation / deactivation); ********************************************************************************

[0133] A second example of how it can be implemented in the MAC specification (TS 38.321) is shown below, where in response to receiving an indication of which TCI state is indicated, the lower layer determines that the new TCI state has an RS of a different cell (second cell) than the SCell in its serving frequency as a QCL source, and informs the new SCell to the upper layer, such that the MAC entity takes action according to the SCell change, as follows: ******************************************************************************** 5.18.5 TCI status indication for UE specific PDCCH [...] The MAC entity: 1> If the MAC entity receives a TCI status indication for a UE specific PDCCH MAC CE on the serving cell: 2> Inform lower layers about TCI status indication for UE-specific PDCCH MAC CE. The MAC entity: 1> Upon receiving an indication from lower layers for SCell change to a configured candidate cell in the serving frequency: 2> suspend SCell; 2> Consider the candidate cell as a SCell in its serving frequency; 2> If the candidate cell has sCellStateUponChange set to active: 3> Perform actions upon SCell activation as defined in clause 5.9 (Activate / Deactivate SCell) 3> If the candidate cell has sCellStateUponChange set to inactive: 4> Perform actions upon SCell deactivation as defined in clause 5.9 (SCell activation / deactivation); ********************************************************************************

[0134] In some embodiments, the UE receives an explicit indication that a first cell (i.e., a SCell in a first frequency) should be set to a first state (e.g., inactive or suspended) and an indication that a second cell should be set to a second state (e.g., active), where the first cell may be a SCell in the first frequency and the second cell may be a candidate cell for L1 mobility (in the same serving frequency). As mentioned above, there may be an operational method for identifying for which cell (SCell or candidate cell) in a given serving frequency the UE should set the state according to the received indication(s).

[0135] In one embodiment, the UE receives both cell state indications included in the first type MAC CE to set the cell state. If the UE is configured with a single list of cells (initial SCell and candidate cells) and a common pool of cell indices / identifiers is used (e.g., as described in "Common List for Cells in All SCell Serving Frequencies"), the first type MAC CE may refer to the index of the first cell to indicate the state the UE should set for the first cell and may refer to the index of the second cell to indicate the state the UE should set for the second cell. The first type MAC CE may be multiplexed with the second type MAC CE (for TCI state indication), so that the UE may receive the first type MAC CE and the second type MAC CE in the same MAC PDU. The second type MAC CE is used to indicate the TCI state ID for the TCI state for which the QCL is configured with the RS of the second cell and the second cell in the serving frequency is not a SCell.

[0136] In the example of Fig. 9, the SCell of the first serving frequency (f1) is cell 50, whose serving cell index is set to 4 (configuration sCellIndex = 4), and the candidate cell 52 is one whose index is set to 3 (configuration sCellIndex = 3). Ci indicates whether there is a SCell configured for the MAC entity or a candidate cell in the serving frequency of the SCell with SCell index i, and this field indicates the activation / deactivation status of the SCell or the candidate cell with SCell index i, otherwise the MAC entity ignores the Ci field. The Ci field is set to 1 to indicate that the SCell with SCell index i should be activated. The Ci field is set to 0 to indicate that the SCell with SCell index i should be deactivated.

[0137] In another embodiment, when the initial SCell and the candidate cells to be SCells in L1 mobility are configured in the RRC configuration (SCellConfig) as described in "List per serving frequency (for SCell)", if L1 mobility is configured for the SCell, a first index / identifier is used to indicate the serving frequency (sCellIndex) and a second index is used to indicate a cell within that serving frequency (sCellCandIndex), which may be the initial SCell and / or the candidate cell (which becomes a SCell via L1 mobility). Also, under such configuration, the first type of MAC CE may result in ambiguity regarding the cell state that the UE should set (except for the case where there is a serving frequency with a single configured cell and it is a SCell). To resolve this ambiguity, one of the alternatives may be considered (instead of considering the first type of MAC CE):

[0138] In one alternative, the UE receives a first type MAC CE and a second type MAC CE in the same MAC PDU, where a TCI state ID for a configured TCI state is indicated in the second type MAC CE, where the RS of the second cell has a configured QCL and the cell in the serving frequency is not a SCell. Upon processing the second type MAC CE and receiving the serving cell ID, the UE determines which candidate cell and / or Scell ​​the first type MAC CE received in the same MAC PDU refers to. In other words, if the first type MAC CE indicates a SCell change, it also indicates the serving frequency for the SCell / candidate cell of the first type MAC CE.

[0139] In another alternative, a new MAC CE of the first type is defined (possibly with its own logical channel identity / identifier, as defined in the tables in TS 38.321). An example of a new MAC CE is shown in Figure 10 and may include:

[0140] - Serving Cell ID field 60, indicating the serving frequency according to which the UE determines to configure the state of the SCell and / or candidate cell(s) in that serving frequency (i.e., sCellIndex is indicated by the serving cell ID received at the MAC CE).

[0141] - Per-cell indication, indicating the state that the UE should set per cell upon receipt of a MAC CE. In one example, it is the field Ci 62: if there is a SCell or candidate cell configured for the MAC entity for the serving frequency indicated by the serving cell ID with SCell index i, this field indicates the activation / deactivation status of the SCell or candidate cell with SCell index i in that serving frequency, otherwise the MAC entity shall ignore the Ci field. The Ci field is set to 1 to indicate that the SCell with SCell index i should be activated. The Ci field is set to 0 to indicate that the SCell with SCell index i should be deactivated (or suspended). The exemplary MAC CE in Fig. 10 shows up to 11 candidate cells for a given serving frequency whose state can be set upon receipt of a MAC CE.

[0142] Please note that any of the above examples / embodiments shown for the second type of MAC CE (for TCI status indication with SCell change) are applicable in this section ("UE actions when changing SCell with L1 mobility").

[0143] Actions (performed by the UE) related to the cell state to be set

[0144] Depending on the SCell state set for the Scell ​​and / or the candidate cell becoming the SCell via L1 mobility, different actions for the first cell and the second cell may be performed.

[0145] If a candidate cell becomes an SCell (via L1 mobility) and the SCell state (for the initial SCell / first cell) is set to inactive, at least one of the following actions (or a combination of these actions) is performed to reference the SCell to the first cell: - Deactivating the SCell according to the timing defined in TS 38.213; - Stopping the SCell deactivation timer (e.g. sCellDeactivationTimer) associated with the SCell; - Stop the bwp-InactivityTimer associated with the SCell; - Deactivating any active BWP associated with the SCell; - clearing any configured downlink assignments and any configured uplink grant type 2 each associated with the SCell; - Clear any PUSCH resources for semi-persistent CSI reporting associated with the SCell; - suspend any configured uplink grant type 1 associated with the SCell; - Flushing all HARQ buffers associated with the SCell; - Cancel if a triggered consistent LBT failure for a SCell occurs. - Stop SRS transmission on the SCell; - Stop CSI reporting for SCells; - Stop UL-SCH transmission on the SCell; - Stop performing transmissions on the RACH on the SCell; - Stop PDCCH monitoring on the SCell; - Stop PUCCH transmission on the SCell. - Inform higher layers in the UE about the changes in the SCell, which results in at least one of the following actions: o Changes in the RRM measurements associated with the serving cell on that frequency, e.g. the UE considers a newly announced cell on that frequency as the serving cell for purposes of performing serving cell measurements (defined in TS 38.331, 5.5). o Changes in RRM measurements associated with candidate serving cells on that frequency. o Resetting of ongoing event evaluation on that frequency based on the previous serving cell on that frequency. o Resetting of ongoing event evaluation on that frequency based on the previous candidate cell that became the serving cell on that frequency.

[0146] When the first cell that the UE is changing from (the SCell on the first frequency before the second cell becomes the SCell on the first frequency) is set to Suspend (via L1 mobility), a very limited set of actions is performed. Thus, the UE stops performing actions in the inactive state, but in addition, the UE performs the following: - The UE stops performing RRM measurements on the first cell (which is suspended) since there is a new SCell in that same serving frequency (unless a specific RRM configuration indicates otherwise). - The UE stops performing CSI measurements / reporting according to the configuration for the first cell, but may perform CSI measurements for the(one or more) RS of the first cell (if configured to do so in another configured cell that is not suspended, e.g. the second cell). - If the UE has a UE-specific configuration configured for each serving frequency (when CSI is configured) that is not suspended, since this is valid regardless of which cell is the SCell on that frequency. - In one example, if a first cell is suspended, it means that its configuration is preserved (e.g., ServingCellConfigCommon), but the UE does nothing related to it unless it is later resumed (e.g., by setting the cell's state to inactive, dormant or active). The suspension of a cell candidate may not result in UE actions based on UE-specific configurations if the candidate cells mainly contain cell-specific configurations (as described in "Per Serving Frequency List (for SCell)").

[0147] When a candidate cell becomes an SCell (via L1 mobility) and the SCell state is set to active, at least one of the following actions (or a combination of these actions) is performed and the SCell is a candidate cell: SRS transmission on the SCell; CSI reporting for the SCell; PDCCH monitoring on the SCell; and / or PUCCH transmission on the SCell, if configured.

[0148] B) Processing of the inactivation timer(s)

[0149] In legacy, the SCell deactivation timer (represented as sCellDeactivationTimer in TS 38.33) can be configured in the UE. The timer is configured in the IE ServingCellConfig, which is configured for the SCell in the UE-specific / dedicated part (i.e., it is not a cell-specific configuration). The legacy timer is started when the cell is activated.

[0150] A new behavior for this timer is introduced in this disclosure.

[0151] In one example, the timer is defined per serving frequency and not per serving cell, e.g., when the UE is configured with multiple cells (initial SCell and candidate cells) on the same serving frequency, the timer is not defined per serving cell.

[0152] In another example, the UE starts a timer when an initial SCell is configured and its state is set to active.

[0153] In another example, the UE starts or restarts a timer (sCellDeactivationTimer) upon receiving a MAC CE for L1 mobility for a candidate cell in its serving frequency.

[0154] C) Handling cell-specific and UE-specific settings

[0155] As mentioned above, for a given serving frequency, there may be different cell configurations for the initial SCell and the candidate cell(s). The following approaches are considered:

[0156] Approach i) The UE-specific configuration is frequency-specific, and the initial SCell and each candidate cell in the serving frequency have their own cell-specific configuration.

[0157] Approach ii) A UE-specific configuration is defined for each cell in the serving frequency, and the initial SCell and each candidate cell in the serving frequency have their own UE-specific configuration and their own cell-specific configuration.

[0158] For approach i), the configuration of candidate cells for L1 mobility, which are changed to SCell(s), may be limited to cell(s) specific configuration, such as information in the IE ServingCellConfigCommon, including PCI. In this case, due to a change of SCell in serving frequency f1 (with serving frequency index sCellIndex=1) from SCell with sCellCandIndex=3 to SCell with sCellCandIndex=5, the UE stops using the ServingCellConfigCommon associated with sCellCandIndex=3 and starts using the ServingCellConfigCommon associated with sCellCandIndex=5. This means, for example, that the PCI considered as the PCI of the SCell is the PCI in the new ServingCellConfigCommon, which may be required if the UE performs RRM measurements for the SCell. Thus, upon "SCell change" via L1 mobility, the UE starts using its active UE-specific configuration(s), i.e. the new sCellConfigCommon (configuration for the cell candidate to become the SCell) while the sCellConfigDedicated in the IE ServingCellConfig remains the same. Since the UE-specific configuration remains the same, this includes the CSI configuration for the UE to perform measurements on the initial SCell as well as on candidates in its serving frequency, and the TCI state configuration, whose QCL source may refer to an RS on the initial SCell or / and any configured candidate cell (e.g. in its serving frequency).

[0159] For approach ii), in addition to changing the cell-specific configuration, when the SCell is changed, the UE also changes its UE-specific configuration. In this case, due to a change of SCell in serving frequency f1 (with serving frequency index sCellIndex=1) from SCell with sCellCandIndex=3 to SCell with sCellCandIndex=5, the UE stops using sCellConfigDedicated in the IE ServingCellConfig associated with sCellCandIndex=3 and starts using sCellConfigDedicated in the IE ServingCellConfig associated with sCellCandIndex=5. That means, for example, that a new set of TCI state configurations may be applied and / or a new set of CSI configurations may be applied. Thus, in response to a "SCell change" via L1 mobility, the UE may update / modify / add / release (one or more) UE-specific configurations.

[0160] In any of the above approaches, there may be different ways to handle the change in configuration(s) upon SCell change, such as at least one of the following schemes:

[0161] - Delta signaling on latest configuration: In this first scheme, the UE applies a new configuration (e.g. UE specific, like sCellConfigDedicated in IE ServingCellConfig) on ​​top of a previous configuration of the same type (like sCellConfigDedicated). Since there can be changes from different pairs of candidate cells (e.g. cell A to cell B, cell A to cell C, cell C to cell A), there can be different versions of the configuration applied depending on the current UE configuration.

[0162] - Delta signaling on a reference configuration: In this second scheme, the UE applies a new configuration (e.g. a UE-specific one, such as sCellConfigDedicated in the IE ServingCellConfig) on ​​top of a previous configuration of the same type, such as an equivalent configuration for the initial SCell. For example, upon a change of SCell, the UE first considers the configuration of the initial SCell, applies the new configuration (of the candidate cell that will become the SCell) on top of its reference configuration, and then starts to operate according to the new applied configuration.

[0163] - Configuration replacement: In this third scheme, the UE replaces the previous configuration with a new configuration (e.g. UE specific, like sCellConfigDedicated in IE ServingCellConfig). This requires more signaling than the previous options / schemes, but may be simpler for the UE.

[0164] The present disclosure further includes a method implemented in a network entity / node, such as an NG-RAN function, for handling L1 / L2 mobility for an SCell associated with a cell group of a UE served by the NG-RAN, where the network node configures the UE with a first cell in a first frequency as the SCell. For example, the network node may send to the UE a configuration of at least a second cell in the first frequency, which is a candidate to become the SCell (e.g., via L1 / L2-centric mobility). The network node may send to the UE L1 / L2 signaling, such as a MAC CE, indicating a change of cell for the SCell (through a TCI state whose QCL source has the RS of the second cell). The network node may then "change" the SCell in the first frequency from the first cell to the second cell for the UE.

[0165] That is, similar to the UE, the network also stops considering a first cell in a first frequency as a SCell and starts considering a second cell in the first frequency as a SCell. Furthermore, the network node may configure the UE with cells in SCell frequencies (i.e., serving frequencies that are not SpCell frequencies) that are candidates for L1-based mobility (such as the second cell) and different ways to index / identify these cells, e.g., indexes associated with cell groups and / or serving frequencies.

[0166] There is no procedure in the NR or LTE specifications for a network node to "change" a SCell in a first frequency from a first cell to a second cell (also in the first frequency). Therefore, the actions corresponding to this "change" are defined as part of a method, such as the one defined for a UE. It should be noted that the embodiments described with respect to a UE may also apply to a method in a network node or to actions performed by a network node.

[0167] 11 illustrates a flowchart of a method 100 in a UE / wireless device for handling L1 / L2 mobility for a secondary cell (Scell) associated with a cell group, where the UE is configured with a first cell as a secondary cell in a first frequency. The method 100 may include:

[0168] Step 110: Receive a configuration of at least one second cell in a first frequency, where the at least one second cell is a candidate to become a secondary cell.

[0169] Step 120: Receive L1 / L2 signaling including an indication to change the secondary cell from the first cell to the second cell.

[0170] Step 130: Change the candidate cell on the first frequency from the first cell to the second cell.

[0171] For example, the indication to change the Scell ​​from the first cell to the second cell may include a first TCI state whose QCL source has the RS of the second cell, and the received signal (L1 / L2 signaling) may be a MAC CE or a DCI.

[0172] In one example, a UE is configured with multiple cells on a first frequency, the multiple cells having different indices, and the first cell may be designated as an initial Scell ​​(using a parameter or by selecting a smallest index). For example, at least one of the second cell and the first cell may be identified by an index.

[0173] In some examples, the configuration may be received in RRC signaling (there may be one or more configurations). The RRC signaling may include a list of second cells associated with the first frequency. The list of second cells may further include a cell associated with the first frequency and a cell associated with the second frequency. For example, the first frequency may be a serving frequency.

[0174] In some examples, the configuration may include an indication to set the second list of cells to an inactive state.

[0175] In some examples, the indication to change the Scell ​​from the first cell to the second cell is an indication of a TCI state whose QCL source has an RS of the second cell.

[0176] In some examples, changing the Scell ​​in the first frequency from a first cell to a second cell may be performed by setting the state of the first cell to inactive, suspended or dormant, and setting the state of the second cell to active.

[0177] In some examples, the UE may receive one or more MAC CEs indicating to set a first cell to inactive, suspended, or dormant and to set a second cell to active.

[0178] In some examples, setting the state of the first cell to inactive or suspended or dormant may include performing one or more of: stopping a deactivation timer, stopping transmitting SRS on the Scell, stopping reporting CSI for the Scell, stopping performing RACH transmissions on the SCell, stopping monitoring a PDCCH on the SCell, stopping monitoring a PDCCH on the SCell, stopping transmitting a PUCCH on the SCell, stopping performing RRM measurements, etc.

[0179] In some examples, activating the state of the second cell may include performing one or more of SRS transmission on the SCell, CSI reporting for the SCell, PDCCH monitoring on the SCell, PUCCH transmission on the SCell, etc., if configured.

[0180] In some examples, the UE may start a timer associated with the secondary cell when the UE is configured with the first cell, or the UE may start or restart a timer associated with the secondary cell when the UE receives L1 / L2 signaling.

[0181] In some examples, changing the secondary cell in the first frequency from the first cell to the second cell may include applying a configuration associated with the second cell over a configuration associated with the first cell, or applying a configuration associated with the second cell over a reference configuration, or replacing a configuration associated with the first cell with a configuration configuration associated with the second cell.

[0182] The present disclosure further includes a method in a UE, the method including receiving a beam configuration associated with a physical channel, receiving L1 / L2 signaling (e.g., MAC CE) including an indication of the beam and a cell associated with the beam, and in response to determining that the cell associated with the indicated beam is on a serving frequency but is not the serving cell, performing a serving cell change from a current serving cell to the cell associated with the indicated beam.

[0183] Further, the present disclosure includes a method in a UE, the method including receiving a MAC CE indicating a TCI state, determining that the indicated TCI state has a QCL source, the RS of which is in a candidate cell in a serving frequency that is not an SCell in the serving frequency, suspending an Scell ​​(e.g., a first cell), and considering the candidate cell as an Scell ​​in the serving frequency.

[0184] 12, a flow chart of a method 200 performed by a network node for handling L1 / L2 mobility for a secondary cell (Scell) associated with a cell group of a UE in which the first cell is configured as the Scell ​​in a first frequency is illustrated. The method may include:

[0185] Step 210: Send a configuration of at least a second cell in a first frequency to the UE, where the second cell is a candidate to become a secondary cell.

[0186] Step 220: Send L1 / L2 signaling to the UE, the L1 / L2 signaling including an indication to change the secondary cell from the first cell to the second cell.

[0187] Step 230: Change the candial cell on the first frequency from the first cell to the second cell.

[0188] In some examples, the configuration may be transmitted in RRC signaling.

[0189] In some examples, the configuration includes a list of second cells. For example, the list of second cells may include cells associated with the first frequency and cells associated with the second frequency, or only cells associated with the first frequency. The first frequency may be a serving frequency. There may be one or more transmitted configurations.

[0190] In some examples, the configuration may include an indication to set the second list of cells to an inactive state.

[0191] In some examples, the at least one second cell and the first cell can be identified by an index, and the first cell can be identified as an initial cell for the secondary cell.

[0192] In some examples, the L1 / L2 signaling is a MAC CE or a DCI.

[0193] In some examples, the indication to change the secondary cell from the first cell to the second cell may be an indication of a TCI state whose QCL source has an RS of the second cell.

[0194] In some examples, changing the Scell ​​in the first frequency from a first cell to a second cell may include setting a state of the first cell to inactive, suspended, or dormant, and setting a state of the second cell to active.

[0195] In some examples, the network node may transmit one or more MAC CEs indicating setting a first cell to inactive, suspended, or dormant, and setting a second cell to active.

[0196] In some examples, setting the state of the first cell to inactive, suspended, or dormant includes performing one or more of: stopping receiving SRS on the first cell, stopping receiving CSI for the first cell, stopping receiving RACH on the first cell, stopping receiving PUCCH on the first cell, and stopping performing RRM measurements.

[0197] In some examples, setting the state of the second cell to active includes performing one or more of: receiving an SRS transmission on the second cell, receiving a CSI report for the second cell, and receiving a PUCCH transmission on the second cell.

[0198] In some examples, changing the secondary cell in the first frequency from the first cell to the second cell may include applying a configuration associated with the second cell over a configuration associated with the first cell, or applying a configuration associated with the second cell over a reference configuration, or replacing a configuration associated with the first cell with a configuration configuration associated with the second cell.

[0199] FIG. 13 illustrates an example of a communication system 1400 according to some embodiments.

[0200] In this example, the communications system 1400 includes a communications network 1402 including an access network 1404, such as a radio access network (RAN), and a core network 1406 including one or more core network nodes 1408. The access network 1404 includes one or more access network nodes, such as network nodes 1410a and 1410b (one or more of which may be generally referred to as network node 1410), or any other similar Third Generation Partnership Project (3GPP) access node or non-3GPP access point. The network nodes 1410 enable direct or indirect connectivity of UEs 1412a, 1412b, 1412c, and 1412d (one or more of which may be generally referred to as UEs 1412) to the core network 1406 via one or more wireless connections.

[0201] Exemplary wireless communication over wireless connections includes transmitting and / or receiving wireless signals using electromagnetic waves, radio waves, infrared, and / or other types of signals suitable for carrying information without the use of wires, cables, or other conductors. Additionally, in various embodiments, communications system 1400 may include any number of wired or wireless networks, network nodes, UEs, and / or any other components or systems that may potentially facilitate or be involved in the communication of data and / or signals, whether via wired or wireless connections. Communications system 1400 may include and / or interface with any type of communications, telecommunications, data, cellular, wireless networks, and / or other similar types of systems.

[0202] The UE 1412 may be any of a wide variety of communications devices, including a wireless device configured, configured, and / or operable to wirelessly communicate with the network node 1410 and other communications devices. Similarly, the network node 1410 may be configured, capable, configured, and / or operable to communicate directly or indirectly with the UE 1412 and / or other network nodes or apparatuses in the communications network 1402 to enable and / or provide network access, such as wireless network access, and / or to perform other functions, such as management within the communications network 1402.

[0203] In the depicted example, the core network 1406 connects the network node 1410 to one or more hosts, such as the host 1416. These connections may be direct or indirect via one or more intermediate networks or devices. In other examples, the network nodes may be directly coupled to the hosts. The core network 1406 includes one or more core network nodes (e.g., the core network node 1408) comprised of hardware and software components. The functionality of these components may be substantially similar to that described with respect to the UEs, network nodes, and / or hosts, and therefore those descriptions are generally applicable to the corresponding components of the core network node 1408. Exemplary core network nodes include one or more of the following functions: a Mobile Switching Center (MSC), a Mobility Management Entity (MME), a Home Subscriber Server (HSS), an Access and Mobility Management Function (AMF), a Session Management Function (SMF), an Authentication Server Function (AUSF), a Subscription Identifier De-concealing function (SIDF), a Unified Data Management (UDM), a Security Edge Protection Proxy (SEPP), a Network Exposure Function (NEF), and / or a User Plane Function (UPF).

[0204] The host 1416 may be owned or under the control of, and operated by or on behalf of, a service provider other than an operator or provider of the access network 1404 and / or the communication network 1402. The host 1416 may host various applications for providing one or more services. Examples of such applications include live and pre-recorded audio / video content, data collection services such as searching and compiling data regarding various ambient conditions detected by multiple UEs, analytics functions, social media, functions for controlling or otherwise interacting with remote devices, functions for alarm and monitoring centers, or any other such functions performed by a server.

[0205] In general, the communication system 1400 of Figure 14 provides connectivity between UEs, network nodes, and hosts. In that sense, the communication system may be configured to operate according to predetermined rules or procedures, such as a particular standard, including, but not limited to, Global System for Mobile Communications (GSM), Universal Mobile Telecommunications System (UMTS), Long Term Evolution (LTE), and / or 4G, 5G standards, or any applicable future generation standard (e.g., 6G), a wireless local area network (WLAN) standard, such as the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard (WiFi), and / or Worldwide Interoperability for Microwave Access (WiMax), Bluetooth, Z-Wave, Near Field Communication (NFC), ZigBee, LiFi, and / or any low-power wide-area network (LPWAN).

[0206] In some examples, the communication network 1402 is a cellular network implementing 3GPP standardized features. Thus, the communication network 1402 may support network slicing to provide different logical networks to different devices connected to the communication network 1402. For example, the communication network 1402 may provide Ultra Reliable Low Latency Communication (URLLC) services to some UEs, while providing Enhanced Mobile Broadband (eMBB) services to other UEs and / or Massive Machine Type Communication (mMTC) / Massive IoT services to additional UEs.

[0207] In some examples, the UE 1412 is configured to transmit and / or receive information without direct human interaction. For example, the UE may be designed to transmit information to the access network 1404 on a predefined schedule, when triggered by an internal or external event, or in response to a request from the access network 1404. Furthermore, the UE may be configured to operate in a single-RAT mode, a multi-RAT mode, or a multi-standard mode. For example, the UE may operate in any one or combination of Wi-Fi, NR, and LTE, i.e., configured for Evolved-UMTS Terrestrial Radio Access Network (E-UTRAN) New Radio-Dual Connectivity (EN-DC).

[0208] In this example, the hub 1414 communicates with the access network 1404 to enable indirect communication between one or more UEs (e.g., UEs 1412c and / or 1412d) and a network node (e.g., network node 1410b). In some examples, the hub 1414 may be a controller, a router, a content source, and analytics, or any of the other communication devices described herein with respect to a UE. For example, the hub 1414 may be a broadband router that enables access to the core network 1406 for the UE. As another example, the hub 1414 may be a controller that sends commands or instructions to one or more actuators in the UE. The commands or instructions may be received from the UE, the network node 1410, or by executable code, scripts, processes, or other instructions in the hub 1414. As another example, the hub 1414 may be a data collector that acts as a temporary storage for UE data and, in some embodiments, may perform analysis or other processing of the data. As another example, the hub 1414 may be a content source. For example, in the case of a UE that is a VR headset, display, loudspeaker, or other media distribution device, the hub 1414 may retrieve, via a network node, VR assets, video, audio, or other media or data related to sensory information, which the hub 1414 then provides directly to the UE, either after performing local processing and / or adding additional local content. In yet another example, the hub 1414 acts as a proxy server or orchestrator for the UEs, particularly if one or more of the UEs are low energy IoT devices.

[0209] Hub 1414 may have a constant / permanent connection or an intermittent connection to network node 1410b.

[0210] 14 illustrates a UE 1500 according to some embodiments. As used herein, a UE refers to a device capable of, configured to, and / or operable to communicate wirelessly with a network node and / or other UEs. Examples of UEs include, but are not limited to, smartphones, mobile phones, cell phones, voice over IP (VoIP) phones, wireless local loop phones, desktop computers, personal digital assistants (PDAs), wireless cameras, game consoles or devices, music storage devices, playback devices, wearable terminal devices, wireless endpoints, mobile stations, tablets, laptops, laptop-embedded equipment (LEE), laptop-mounted equipment (LME), smart devices, wireless customer-premise equipment (CPE), vehicle-mounted or embedded / integrated wireless devices, and the like. Other examples include any UE identified by 3GPP, including narrow band internet of things (NB-IoT) UE, machine type communication (MTC) UE, and / or enhanced MTC (eMTC) UE.

[0211] A UE may support device-to-device (D2D) communications, for example by implementing 3GPP standards for sidelink communications, Dedicated Short Range Communications (DSRC), vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), or vehicle-to-everything (V2X). In other examples, a UE may not necessarily have a user in the sense of a human user that owns and / or operates the associated device. As an alternative, a UE may represent a device that is not intended for sale to or operation by an end user, but may be associated with or operated for the benefit of a user (e.g., a smart electricity meter).

[0212] The UE 1500 includes a processing circuit 1502 operatively coupled to an input / output interface 1506, a power source 1508, a memory 1510, a communication interface 1512, and / or any other components, or any combination thereof, via a bus 1504. A particular UE may utilize all or a subset of the components shown in FIG. 14. The level of integration between the components may vary from UE to UE. Additionally, a particular UE may include multiple instances of a component, such as multiple processors, memories, transceivers, transmitters, receivers, etc.

[0213] The processing circuit 1502 is configured to process instructions and data, and may be configured to implement any sequential state machine operable to execute instructions stored as a machine-readable computer program in the memory 1510. The processing circuit 1502 may be implemented as one or more hardware-implemented state machines (e.g., discrete logic, a field programmable gate array (FPGA), an application specific integrated circuit (ASIC), etc.), programmable logic in conjunction with appropriate firmware, one or more stored computer programs, such as a microprocessor or digital signal processor (DSP), in conjunction with appropriate software, a general-purpose processor, or any combination of the above. For example, the processing circuit 1502 may include multiple central processing units (CPUs).

[0214] In this example, the input / output interface 1506 may be configured to provide an interface to an input device, an output device, or one or more input devices and / or output devices. Examples of output devices include a speaker, a sound card, a video card, a display, a monitor, a printer, an actuator, an emitter, a smart card, another output device, or any combination thereof. An input device may enable a user to capture information to the UE 1500. Examples of input devices include a touch-sensitive or presence-sensitive display, a camera (e.g., a digital camera, a digital video camera, a webcam, etc.), a microphone, a sensor, a mouse, a trackball, directional keys, a trackpad, a scroll wheel, a smart card, etc. A presence-sensitive display may include a capacitive or resistive touch sensor to sense input from a user. The sensor may be, for example, an accelerometer, a gyroscope, a tilt sensor, a force sensor, a magnetometer, a light sensor, a proximity sensor, a biometric sensor, etc., or any combination thereof. An output device may use the same type of interface port as an input device. For example, a Universal Serial Bus (USB) port may be used to provide input and output devices.

[0215] In some embodiments, the power source 1508 is configured as a battery or battery pack. Other types of power sources may be used, such as an external power source (e.g., an electrical outlet), a photovoltaic device, or a power cell. The power source 1508 may further include power circuitry for sending power from the power source 1508 itself and / or from the external power source through an interface, such as an input circuit or a power cable, to various parts of the UE 1500. Sending power may be for charging the power source 1508, for example. The power circuitry may perform any formatting, conversion, or other modification of the power from the power source 1508 to make the power suitable for the individual components of the UE 1500 being powered.

[0216] The memory 1510 may be or may be configured to include memory such as random access memory (RAM), read only memory (ROM), programmable gate array read only memory (PROM), erasable programmable gate array read only memory (EPROM), electrically erasable programmable gate array read only memory (EEPROM), magnetic disk, optical disk, hard disk, removable cartridge, flash drive, etc. In one example, the memory 1510 includes one or more application programs 1514, such as an operating system, a web browser application, widgets, gadget engine, or other applications, and corresponding data 1516. The memory 1510 may store any of a variety of operating systems or combinations of operating systems for use by the UE 1500.

[0217] The memory 1510 may be configured to include a number of physical drive units, such as a redundant array of independent disks (RAID), flash memory, a USB flash drive, an external hard disk drive, a thumb drive, a pen drive, a key drive, a high density digital versatile disk (HD-DVD) optical disk drive, an internal hard disk drive, a Blu-ray optical disk drive, a Holographic Digital Data Storage (HDDS) optical disk drive, an external mini dual in-line memory module (DIMM), a synchronous dynamic random access memory (SDRAM), an external micro-DIMM SDRAM, a smart card memory, such as a tamper-resistant module in the form of a Universal Integrated Circuit Card (UICC) including one or more Subscriber Identity Modules (SIMs), such as a USIM and / or ISIM, other memory, or any combination thereof. The memory 1510 may enable the UE 1500 to access instructions, application programs, etc. stored in a temporary or non-transitory memory medium, offload data, or upload data. An article of manufacture, such as one that utilizes a communications system, may be tangibly embodied as or within memory 1510, which may be or comprise a device readable storage medium.

[0218] The processing circuit 1502 may be configured to communicate with an access network or other network using a communication interface 1512. The communication interface 1512 may comprise one or more communication subsystems and may include or be communicatively coupled to an antenna 1522. The communication interface 1512 may include one or more transceivers used to communicate, such as by communicating with one or more remote transceivers of another device capable of wireless communication (e.g., another UE or a network node in the access network). Each transceiver may include a transmitter 1518 and / or a receiver 1520 suitable for providing network communication (e.g., optical, electrical, frequency allocation, etc.). Furthermore, the transmitter 1518 and the receiver 1520 may be coupled to one or more antennas (e.g., antenna 1522) and may share circuit components, software or firmware or may be implemented separately. Furthermore, the processing circuit 1502 may be configured to perform any of the steps of the method 100 of FIG. 11.

[0219] In the illustrated embodiment, the communication capabilities of communication interface 1512 may include cellular / Wi-Fi / LPWAN / data / voice / multimedia / short-range (Bluetooth) / near-field communications, and location-based communications such as using a Global Positioning System (GPS) to determine location, or any combination thereof. Communications may be implemented according to one or more communications protocols and / or standards, such as IEEE 802.11, Code Division Multiple Access (CDMA), Wideband Code Division Multiple Access (WCDMA), GSM, LTE, NR, UMTS, WiMax, Ethernet, Transmission Control Protocol / Internet Protocol (TCP / IP), Synchronous Optical Networking (SONET), Asynchronous Transfer Mode (ATM), QUIC, Hypertext Transfer Protocol (HTTP), etc.

[0220] Regardless of the type of sensor, the UE may provide an output of data captured by its sensor through its communication interface 1512 via a wireless connection to a network node. Data captured by a UE's sensor may be communicated through another UE via a wireless connection to a network node. The output may be periodic (e.g., once every 15 minutes when reporting sensed temperature), random (e.g., to even out the load from reporting from several sensors), in response to a trigger event (e.g., when moisture is detected, an alert is sent), on request (e.g., a user-initiated request), or a continuous stream (e.g., a live video feed of a patient).

[0221] As another example, the UE may include an actuator, motor, or switch associated with a communication interface configured to receive wireless input from a network node over a wireless connection, and in response to the received wireless input, the actuator, motor, or switch may change state.

[0222] When the UE is in the form of an Internet of Things (IoT) device, it may be a device for use in one or more application domains, such as urban wearable technology, augmented industry applications, and healthcare. Non-limiting examples of such IoT devices are devices that are or are embedded in a connected refrigerator, a TV, a connected lighting device, an electric meter, a robotic vacuum cleaner, a smart watch, a fitness tracker, a head mounted display for augmented reality (AR) or virtual reality, a heart rate monitor, or a remote controlled surgical robot. A UE in the form of an IoT device may comprise, in addition to other components, circuitry and / or software depending on the intended application of the IoT device, as described in relation to UE 1500 shown in FIG. 14.

[0223] As yet another specific example, in an IoT scenario, a UE may represent a machine or other device that performs monitoring and / or measurements and transmits results of such monitoring and / or measurements to another UE and / or network node. The UE may be an M2M device or an MTC device in this case. The UE may implement the 3GPP NT-IoT standard. In other scenarios, the UE may represent a vehicle such as a car, a bus, a truck, a ship, and an aircraft, or other equipment capable of monitoring and / or reporting an operating state or other functionality associated with its operation.

[0224] In practice, any number of UEs may be used together for a single use case, for example, a first UE may be a drone or may be integrated into a drone and may provide speed information of the drone (obtained through a speed sensor) to a second UE that is a remote controller that operates the drone.

[0225] 15 illustrates a network node 1600 according to some embodiments. As used herein, a network node refers to a device capable of, configured to, configured to, and / or operable to communicate, directly or indirectly, with UEs and / or other network nodes or devices in a communications network. Examples of network nodes include, but are not limited to, access points (APs) (e.g., wireless access points), base stations (BSs) (e.g., radio base stations, Node Bs, evolved Node Bs (eNBs), and NR Node Bs (gNBs)).

[0226] Base stations may be classified based on the amount of coverage they provide (or, stated differently, their transmit power levels) and may therefore be referred to as femto, pico, micro, or macro base stations depending on the amount of coverage provided. A base station may be a relay node or a relay donor node that controls a relay. A network node may further include one or more (or all) parts of a distributed radio base station, such as a centralized digital unit, sometimes referred to as a remote radio head (RRH), and / or a remote radio unit (RRU). Such remote radio units may or may not be integrated with an antenna as an antenna-integrated radio. Some of the distributed radio base stations may also be referred to as nodes in a distributed antenna system (DAS).

[0227] Other examples of network nodes include multiple transmission / reception point (multi-TRP) 5G access nodes, multi-standard radio (MSR) equipment such as an MSR BS, a network controller such as a radio network controller (RNC) or a base station controller (BSC), a base transceiver station (BTS), a transmission point, a transmitting node, a multi-cell / multicast coordination entity (MCE), an Operation and Maintenance (O&M) node, an Operations Support System (OSS) node, a Self-Organizing Network (SON) node, a positioning node (e.g., an Evolved Serving Mobile Location Center (E-SMLC)), and / or a Minimization of Drive Test (MDT).

[0228] The network node 1600 comprises a processing circuit 1602, a memory 1604, a communication interface 1606, and a power source 1608. The network node 1600 may be comprised of multiple physically separate components (e.g., a Node B component and an RNC component, or a BTS component and a BSC component, etc.), each of which may have its own separate components. In some scenarios where the network node 1600 comprises multiple separate components (e.g., a BTS and a BSC component), one or more of the separate components may be shared among several network nodes. For example, a single RNC may control several Node Bs. In such scenarios, each unique Node B and RNC pair may be considered as a single separate network node in some instances. In some embodiments, the network node 1600 may be configured to support several radio access technologies (RATs). In such embodiments, some components may overlap (e.g., separate memories 1604 for different RATs) and some components may be reused (e.g., the same antenna 1610 may be shared by different RATs). Network node 1600 may further include multiple sets of the various illustrated components for different wireless technologies (e.g., GSM, WCDMA, LTE, NR, WiFi, Zigbee, Z-wave, LoRaWAN, Radio Frequency Identification (RFID) or Bluetooth wireless technologies) integrated into network node 1600. These wireless technologies may be integrated in the same or different chips or sets of chips and other components within network node 1600.

[0229] The processing circuitry 1602 may include one or more combinations of a microprocessor, controller, microcontroller, central processing unit, digital signal processor, application specific integrated circuit, field programmable gate array, or any other suitable computing device, resource, or combination of hardware, software, and / or coded logic that are operable, alone or in conjunction with other network node 1600 components, such as memory 1604, to provide the functionality of the network node 1600.

[0230] In some embodiments, the processing circuit 1602 comprises a system on a chip (SOC). In some embodiments, the processing circuit 1602 includes one or more of a radio frequency (RF) transceiver circuit 1612 and a baseband processing circuit 1614. In some embodiments, the RF transceiver circuit 1612 and the baseband processing circuit 1614 may be on separate chips (or sets of chips), boards, or units, such as a radio unit and a digital unit. In some embodiments, some or all of the RF transceiver circuit 1612 and the baseband processing circuit 1614 may be on the same chip or set of chips, board, or unit. Additionally, the processing circuit 1602 may be configured to perform any step of the method 200 of FIG. 12.

[0231] The memory 1604 may include any form of volatile or non-volatile computer readable memory, including, without limitation, persistent storage, solid state memory, remotely mounted memory, magnetic media, optical media, RAM, ROM, mass storage media (e.g., hard disks), removable storage media (e.g., flash drives, compact disks (CDs) or digital video disks (DVDs)), and / or any other volatile or non-volatile, non-transitory device readable and / or computer executable memory devices that store information, data, and / or instructions that may be used by the processing circuitry 1602. The memory 1604 may store any suitable instructions, data, or information, including applications, computer programs, software, including one or more of logic, rules, codes, tables, and / or other instructions that may be executed by the processing circuitry 1602 and utilized by the network node 1600. The memory 1604 may be used to store any operations performed by the processing circuitry 1602 and / or any data received via the communication interface 1606. In some embodiments, the processing circuit 1602 and the memory 1604 are integrated.

[0232] The communication interface 1606 is used in wired or wireless communication of signaling and / or data between network nodes, access networks, and / or UEs. As shown, the communication interface 1606 comprises port(s) / terminal(s) 1616 for transmitting and receiving data to and from a network via a wired connection, for example. The communication interface 1606 further comprises a radio front-end circuit 1618, which may be coupled to an antenna 1610 or may be part of the antenna 1610 in some embodiments. The radio front-end circuit 1618 comprises a filter 1620 and an amplifier 1622. The radio front-end circuit 1618 may be connected to the antenna 1610 and the processing circuit 1602. The radio front-end circuit may be configured to condition signals communicated between the antenna 1610 and the processing circuit 1602. The radio front-end circuit 1618 may receive digital data to be sent to other network nodes or UEs via a wireless connection. The radio front-end circuitry 1618 may convert the digital data into a radio signal having appropriate channel and bandwidth parameters using a combination of filters 1620 and / or amplifiers 1622. The radio signal may then be transmitted via the antenna 1610. Similarly, in receiving data, the antenna 1610 may collect a radio signal that is converted into digital data by the radio front-end circuitry 1618. The digital data may be passed to the processing circuitry 1602. In other embodiments, the communication interface may include different components and / or different combinations of components.

[0233] In certain alternative embodiments, the network node 1600 does not include a separate radio front-end circuit 1618, and instead the processing circuit 1602 includes the radio front-end circuitry and is connected to the antenna 1610. Similarly, in some embodiments, all or a portion of the RF transceiver circuitry 1612 is part of the communications interface 1606. In yet other embodiments, the communications interface 1606 includes one or more ports or terminals 1616, the radio front-end circuitry 1618, and the RF transceiver circuitry 1612 as part of a radio unit (not shown), and the communications interface 1606 communicates with baseband processing circuitry 1614 that is part of a digital unit (not shown).

[0234] The antenna 1610 may include one or more antennas or an antenna array configured to transmit and / or receive wireless signals. The antenna 1610 may be coupled to a radio front-end circuit 1618 and may be any type of antenna capable of transmitting and receiving data and / or signals wirelessly. In an embodiment, the antenna 1610 is separate from the network node 1600 and connectable to the network node 1600 via an interface or port.

[0235] The antenna 1610, the communication interface 1606, and / or the processing circuit 1602 may be configured to perform any receiving operation and / or certain acquisition operations described herein as being performed by a network node. Any information, data, and / or signals may be received from a UE, another network node, and / or any other network equipment. Similarly, the antenna 1610, the communication interface 1606, and / or the processing circuit 1602 may be configured to perform any transmitting operation described herein as being performed by a network node. Any information, data, and / or signals may be transmitted to a UE, another network node, and / or any other network equipment.

[0236] The power source 1608 provides power to the various components of the network node 1600 in a form suitable for the individual components (e.g., at voltage and current levels required by the individual components). The power source 1608 may further comprise or be coupled to a power management circuit for providing power to the components of the network node 1600 to perform the functions described herein. For example, the network node 1600 may be connectable to an external power source (e.g., a power grid, an electrical outlet) via an input circuit or interface, such as an electrical cable, whereby the external power source provides power to the power circuit of the power source 1608. As a further example, the power source 1608 may comprise a power source in the form of a battery or battery pack connected to or integrated into the power circuit. In the event that the external power source fails, the battery may provide back-up power.

[0237] Embodiments of network node 1600 may include additional components beyond those shown in FIG. 15 to provide certain aspects of the network node's functionality, including any of the functionality described herein and / or any functionality necessary to support the subject matter described herein.

[0238] 16 is a block diagram of a host 1700, which may be an embodiment of the host 1416 of FIG. 13 in accordance with various aspects described herein. As used herein, the host 1700 may be or comprise various combinations of hardware and / or software, including a standalone server, a blade server, a cloud-implemented server, a distributed server, a virtual machine, a container, or a processing resource within a server farm. The host 1700 may provide one or more services to one or more UEs.

[0239] The host 1700 includes a processing circuit 1702 operably coupled to an input / output interface 1706, a network interface 1708, a power source 1710, and a memory 1712 via a bus 1704. Other components may be included in other embodiments. The functionality of these components may be substantially similar to those described with respect to the devices of the previous figures (e.g., Figures 14 and 15), such that the descriptions are generally applicable to the corresponding components of the host 1700.

[0240] Memory 1712 may include one or more computer programs, including one or more host application programs 1714 and data 1716, which may include user data (e.g., data generated by a UE for host 1700 or data generated by host 1700 for a UE). An embodiment of host 1700 may utilize only a subset or all of the components shown. Host application programs 1714 may be implemented in a container-based architecture and may provide support for video codecs (e.g., Versatile Video Coding (VVC), High Efficiency Video Coding (HEVC), Advanced Video Coding (AVC), MPEG, VP9) and audio codecs (e.g., FLAC, Advanced Audio Coding (AAC), MPEG, G.711), including transcoding for multiple different classes, types, or implementations of UE (e.g., handsets, desktop computers, wearable display systems, heads-up display systems). The host application program 1714 may further provide user authentication and licensing checks and may periodically report health, route, and content availability to a central node, such as a device in the core network or on the edge of the core network. Thus, the host 1700 may select and / or indicate different hosts for over-the-top services for the UE. The host application program 1714 may support various protocols, such as HTTP Live Streaming (HLS) protocol, Real-Time Messaging Protocol (RTMP), Real-Time Streaming Protocol (RTSP), Dynamic Adaptation Streaming over HTTP (MPEG-DASH), etc.

[0241] FIG. 17 is a block diagram illustrating a virtualization environment 1800 in which functionality implemented by some embodiments may be virtualized. In this context, virtualization means creating a virtual version of an apparatus or device, which may include virtualized hardware platforms, storage devices, and network resources. As used herein, virtualization may apply to any device described herein, or components thereof, and relates to implementations in which at least a portion of functionality is implemented as one or more virtual components. Some or all of the functionality described herein may be implemented as virtual components executed by one or more virtual machines (VMs) implemented in one or more virtualization environments 1800 hosted by one or more of the hardware nodes, such as a network node, a UE, a core network node, or a hardware computing device acting as a host. Furthermore, in embodiments in which the virtual node does not require wireless connectivity (e.g., a core network node or a host), the node may be fully virtualized.

[0242] An application 1802 (which may alternatively be referred to as a software instance, a virtual appliance, a network function, a virtual node, a virtual network function, etc.) executes in the virtualized environment 1800 to implement some of the features, functions, and / or advantages of some of the embodiments disclosed herein.

[0243] Hardware 1804 includes processing circuitry, memory storing software and / or instructions executable by the hardware processing circuitry, and / or other hardware devices described herein, such as network interfaces, input / output interfaces, etc. Software executed by the processing circuitry may instantiate one or more virtualization layers 1806 (also referred to as a hypervisor or virtual machine monitor (VMM)), provide VMs 1808a and 1808b (one or more of which may be generally referred to as VMs 1808), and / or perform any of the functions, features and / or benefits described in connection with some embodiments described herein. Virtualization layer 1806 may present a virtual operating platform to VMs 1808 that appears to be networking hardware.

[0244] The VMs 1808 may include virtual processing, virtual memory, virtual networking or interfaces, and virtual storage, and may be executed by a corresponding virtualization layer 1806. Various embodiments of an instance of a virtual appliance 1802 may be implemented in one or more of the VMs 1808, and may be implemented in a variety of ways. Hardware virtualization is referred to in some contexts as network function virtualization (NFV). NFV may be used to consolidate many network equipment types with industry-standard high-volume server hardware, physical switches, and physical storage (which may be located in a data center), and customer premises equipment.

[0245] In the context of NFV, VMs 1808 may be software implementations of physical machines that execute programs as if they were running on a physical, non-virtualized machine. Each of the VMs 1808, and the portion of the hardware 1804 on which it runs, may be hardware dedicated to that VM and / or hardware shared by that VM with others of the VMs, forming a separate virtual network element. Furthermore, in the context of NFV, a virtual network function may run in one or more VMs 1808 on the hardware 1804 and be responsible for handling a particular network function corresponding to an application 1802.

[0246] The hardware 1804 may be implemented in a standalone network node with generic or specific components. The hardware 1804 may implement some functions via virtualization. Alternatively, the hardware 1804 may be part of a larger cluster of hardware (e.g., in a data center or CPE) where many hardware nodes work together and are managed via a management and orchestration 1810 that oversees, among other things, the lifecycle management of the applications 1802. In some embodiments, the hardware 1804 is coupled to one or more radio units, each of which includes one or more transmitters and one or more receivers that may be coupled to one or more antennas. The radio units may communicate directly with other hardware nodes via one or more appropriate network interfaces or may be used in combination with virtual components to provide radio functions to the virtual nodes, such as a radio access node or base station. In some embodiments, some signaling may be provided with the use of a control system 1812, which may alternatively be used for communication between the hardware nodes and the radio units.

[0247] Figure 18 illustrates a communication diagram of a host 1902 communicating over a partial wireless connection with a UE 1906 via a network node 1904, according to some embodiments. Exemplary implementations of UEs (such as UE 1412a of Figure 13 and / or UE 1500 of Figure 14), network nodes (such as network node 1410a of Figure 13 and / or network node 1600 of Figure 15), and hosts (such as host 1416 of Figure 13 and / or host 1700 of Figure 16), according to various embodiments, will now be described with reference to Figure 18.

[0248] Similar to the host 1700, an embodiment of the host 1902 includes hardware such as a communications interface, processing circuitry, and memory. The host 1902 further includes software stored on or accessible by the host 1902 and executable by the processing circuitry. The software includes a host application that may be operable to provide services to a remote user, such as a UE 1906 connecting via an over-the-top (OTT) connection 1950 extending between the UE 1906 and the host 1902. In providing services to the remote user, the host application may provide user data that is transmitted using the OTT connection 1950.

[0249] The network node 1904 includes hardware that enables it to communicate with the host 1902 and the UE 1906. The connection 1960 may be direct or may pass through a core network (such as the core network 1406 of FIG. 14) and / or one or more other intermediate networks, such as one or more public, private, or hosted networks. For example, the intermediate network may be a backbone network or the Internet.

[0250] The UE 1906 includes hardware and software that is stored on or accessible by the UE 1906 and executable by the processing circuitry of the UE. The software includes a client application, such as a web browser or an operator-specific "app," that may be operable to provide services to a human or non-human user via the UE 1906 with the support of the host 1902. An executing host application on the host 1902 may communicate with an executing client application via an OTT connection 1950 that terminates on the UE 1906 and the host 1902. In providing services to a user, the client application on the UE may receive request data from the host application on the host and provide user data in response to the request data. The OTT connection 1950 may transport both the request data and the user data. The client application on the UE may interact with the user to generate user data to provide to the host application via the OTT connection 1950.

[0251] The OTT connection 1950 may extend via a connection 1960 between the host 1902 and a network node 1904, and via a wireless connection 1970 between the network node 1904 and the UE 1906, thereby providing a connection between the host 1902 and the UE 1906. The connections 1960 and wireless connections 1970 over which the OTT connection 1950 may be provided are depicted abstractly to illustrate communication between the host 1902 and the UE 1906 via the network node 1904, without explicit reference to any intermediate devices and the precise routing of messages through these devices.

[0252] As an example of transmitting data over the OTT connection 1950, in step 1908, the host 1902 provides user data, which may be performed by executing a host application. In some embodiments, the user data is associated with a particular human user interacting with the UE 1906. In other embodiments, the user data is associated with a UE 1906 that shares data with the host 1902 without explicit human interaction. In step 1910, the host 1902 initiates a transmission conveying the user data toward the UE 1906. The host 1902 may initiate the transmission in response to a request transmitted by the UE 1906. The request may result from human interaction with the UE 1906 or from the operation of a client application executing on the UE 1906. The transmission may pass through the network node 1904 in accordance with the teachings of the embodiments described throughout this disclosure. Thus, in step 1912, the network node 1904 transmits user data carried in the transmission initiated by the host 1902 to the UE 1906, in accordance with the teachings of the embodiments described throughout this disclosure. In step 1914, the UE 1906 receives the user data carried in the transmission, which may be executed by a client application executing on the UE 1906 that is associated with the host application executed by the host 1902.

[0253] In some examples, the UE 1906 executes a client application that provides user data to the host 1902. The user data may be provided in reaction or response to data received from the host 1902. Thus, in step 1916, the UE 1906 may provide the user data. This may be performed by executing the client application. In providing the user data, the client application may further take into account user input received from a user via an input / output interface of the UE 1906. Regardless of the particular manner in which the user data is provided, the UE 1906, in step 1918, initiates transmission of the user data to the host 1902 via the network node 1904. In step 1920, the network node 1904 receives the user data from the UE 1906 and initiates transmission of the received user data towards the host 1902, in accordance with the teachings of the embodiments described throughout this disclosure. In step 1922, the host 1902 receives the user data carried in the transmission initiated by the UE 1906.

[0254] One or more of the various embodiments improve the performance of the OTT service provided to the UE 1906 using the OTT connection 1950, of which the radio connection 1970 forms the final segment. More precisely, the teachings of these embodiments may improve the data rate or latency, thereby providing benefits such as reduced user latency and better responsiveness.

[0255] In an example scenario, factory status information may be collected and analyzed by the host 1902. As another example, the host 1902 may process audio and video data that may have been retrieved from UEs for use in creating maps. As another example, the host 1902 may collect and analyze real-time data to assist in controlling vehicle congestion (e.g., controlling traffic lights). As another example, the host 1902 may store surveillance video uploaded by UEs. As another example, the host 1902 may store or control access to media content, such as video, audio, VR, or AR, that may be broadcast, multicast, or unicast to UEs. As another example, the host 1902 may be used for energy pricing, remote control of non-time-critical electrical loads to balance power generation needs, location services, presentation services (such as compiling diagrams, etc. from data collected from remote devices), or any other function that collects, extracts, stores, analyzes, and / or transmits data.

[0256] In some examples, measurement procedures may be provided for the purpose of monitoring data rates, latency, and other factors that one or more embodiments improve upon. There may further be optional network functionality to reconfigure the OTT connection 1950 between the host 1902 and the UE 1906 in response to changes in the measurement results. The measurement procedures and / or network functionality to reconfigure the OTT connection may be implemented in software and hardware of the host 1902 and / or the UE 1906. In some embodiments, sensors (not shown) may be located in or associated with other devices through which the OTT connection 1950 passes. The sensors may participate in the measurement procedures by providing values ​​of monitored quantities, as exemplified above, or other physical quantities from which software may compute or estimate the monitored quantities. The reconfiguration of the OTT connection 1950 may include message formats, retransmission configurations, preferred routing, etc. Such reconfiguration need not directly change the operation of the network node 1904. Such procedures and functionality are known and may be implemented in the art. In one embodiment, the measurements may involve proprietary UE signaling to facilitate measurements by the host 1902 of throughput, propagation time, latency, etc. The measurements may be performed in having the software send messages (particularly null or "dummy" messages) using the OTT connection 1950 while monitoring propagation time, errors, etc.

[0257] Although the computing devices (e.g., UEs, network nodes, hosts) described herein may include the illustrated combination of hardware components, other embodiments may include computing devices with different combinations of components. It should be understood that these computing devices may include any suitable combination of hardware and / or software required to perform the tasks, features, functions, and methods disclosed herein. Furthermore, while a component is depicted as a single box located within a larger box or nested within multiple boxes, in reality the computing device may comprise multiple different physical components that make up a single illustrated component, and functionality may be distributed among the separate components. For example, a communication interface may be configured to include any of the components described herein, and / or functionality of a component may be distributed between a processing circuit and a communication interface. In another example, non-computationally intensive functionality of any such component may be implemented in software or firmware, and computationally intensive functionality may be implemented in hardware.

[0258] In certain embodiments, some or all of the functionality described herein may be provided by a processing circuit executing instructions stored in a memory, which in certain embodiments may be a computer program product in the form of a non-transitory computer-readable storage medium. In alternative embodiments, some or all of the functionality may be provided by a processing circuit without executing instructions stored in a separate or distinct device-readable storage medium, such as in a hardwired manner. In any of these particular embodiments, the processing circuit may be configured to perform the described functionality, whether or not it executes instructions stored in a non-transitory computer-readable storage medium. Benefits provided by such functionality are not limited to just the processing circuit, or to other components of the computing device, but are enjoyed by the entire computing device and / or by end users and the wireless network as a whole.

[0259] The embodiments described above are intended to be examples only. Alterations, modifications, and variations may be made by those of skill in the art to the particular embodiments without departing from the scope of the description, which is defined solely by the appended claims.

Claims

1. 1. A method performed by a user equipment (UE) configured with carrier aggregation to handle Layer 1 (L1) / Layer 2 (L2) mobility for a secondary cell associated with a cell group, the UE being configured with a first cell as a secondary cell in a first frequency, the method comprising: receiving a configuration of at least one second cell in the first frequency, the at least one second cell being a candidate to become the secondary cell; and receiving L1 / L2 signaling including an indication to change the secondary cell from the first cell to the second cell, the secondary cell being not a special cell (SpCell); and changing the secondary cell in the first frequency from the first cell to the second cell; A method comprising:

2. 2. The method of claim 1, wherein receiving the configuration comprises receiving radio resource control (RRC) signaling.

3. The method of claim 1 , wherein receiving the configuration includes receiving a list of second cells.

4. The method of claim 3 , wherein the list of second cells includes cells associated with only the first frequency.

5. The method of claim 3 , wherein the setting includes an indication to set the list of second cells to an inactive state.

6. The method of claim 1 , wherein the at least one second cell and the first cell are identified by an index.

7. The method of claim 1 , wherein the first cell is identified as an initial cell for the secondary cell.

8. 2. The method of claim 1, wherein the L1 / L2 signaling is a medium access control (MAC) control element (CE).

9. The method of claim 1 , wherein the L1 / L2 signaling is DCI (Downlink Control Information) signaling.

10. 2. The method of claim 1, wherein the indication to change the secondary cell from the first cell to the second cell is a transmission configuration indicator (TCI) state, and a quasi-colocated (QCL) source of the TCI state has an RS (reference signal) associated with the second cell.

11. 2. The method of claim 1, wherein changing the secondary cell in the first frequency from the first cell to the second cell includes setting a state of the first cell to inactive, suspend or dormant, and setting a state of the second cell to active.

12. 12. The method of claim 11, further comprising receiving one or more MAC CEs indicating setting the first cell to an inactive, suspend or dormant state and indicating setting the second cell to an active state.

13. 12. The method of claim 11, wherein setting the state of the first cell to inactive, suspended, or dormant comprises: Stopping the inactivation timer; Stopping transmission of a sounding reference signal (SRS) in the first cell; Stopping reporting channel state information (CSI) for the first cell; ceasing transmission on a random access channel (RACH) in the first cell; Stopping monitoring a physical downlink control channel (PDCCH) in the first cell; Stopping transmission on a physical uplink control channel (PUCCH) in the first cell; and Stopping the performance of RRM (Radio Resource Management) measurements; The method includes performing one or more of the following:

14. 12. The method of claim 11, wherein setting the state of the second cell to active comprises: SRS transmission in the second cell; a CSI report for the second cell; PDCCH monitoring in the second cell; transmitting a PUCCH on the second cell; The method includes performing one or more of the following:

15. The method of claim 1 , further comprising starting a timer associated with the secondary cell when the UE is configured with the first cell.

16. The method of claim 1 , further comprising starting or restarting a timer associated with the secondary cell when the UE receives the L1 / L2 signaling.

17. 2. The method of claim 1, wherein changing the secondary cell in the first frequency from the first cell to the second cell includes replacing a configuration associated with the first cell with a configuration associated with the second cell.

18. 2. The method of claim 1, wherein the first frequency is a serving frequency of the UE.

19. 19. A UE (User Equipment) comprising a processing circuit and a network interface coupled to said processing circuit, said processing circuit being configured to perform the steps of the method according to any one of claims 1 to 18.

20. 1. A method performed by a network node for handling L1 (Layer 1) / L2 (Layer 2) mobility for a secondary cell associated with a cell group for a user equipment (UE) configured with carrier aggregation and having a first cell configured as a secondary cell in a first frequency, the method comprising: transmitting a configuration of at least a second cell in the first frequency to the UE, the second cell being a candidate to become the secondary cell; and sending L1 / L2 signaling to the UE including an indication to change the secondary cell from the first cell to the second cell, where the secondary cell is not a special cell (SpCell); and changing the secondary cell in the first frequency from the first cell to the second cell; A method comprising:

21. 21. The method of claim 20, wherein transmitting the configuration includes transmitting radio resource control (RRC) signaling.

22. 21. The method of claim 20, wherein transmitting the configuration includes transmitting a list of second cells.

23. 23. The method of claim 22, wherein the list of second cells includes cells associated with only the first frequency.

24. 23. The method of claim 22, wherein the setting includes an indication to set the list of second cells to an inactive state.

25. 21. The method of claim 20, wherein the second cell and the first cell are identified by an index.

26. 21. The method of claim 20, wherein the first cell is identified as an initial cell for the secondary cell.

27. 21. The method of claim 20, wherein the L1 / L2 signaling is a medium access control (MAC) control element (CE).

28. 21. The method of claim 20, wherein the L1 / L2 signaling is DCI (Downlink Control Information) signaling.

29. 21. The method of claim 20, wherein the indication to change the secondary cell from the first cell to the second cell is a transmission configuration indicator (TCI) state, and a quasi-colocated (QCL) source of the TCI state has an RS (reference signal) associated with the second cell.

30. 21. The method of claim 20, wherein changing the secondary cell in the first frequency from the first cell to the second cell includes setting a state of the first cell to inactive, suspend or dormant, and setting a state of the second cell to active.

31. 31. The method of claim 30, further comprising: transmitting one or more MAC CEs indicating setting the first cell to an inactive, suspend or dormant state and indicating setting the second cell to an active state.

32. 31. The method of claim 30, wherein setting the state of the first cell to inactive, suspended, or dormant comprises: Stopping reception of a sounding reference signal (SRS) in the first cell; Stopping receiving channel state information (CSI) for the first cell; ceasing reception on a Random Access Channel (RACH) in the first cell; Stopping reception on a physical uplink control channel (PUCCH) in the first cell; and Stopping the performance of RRM (Radio Resource Management) measurements; The method includes performing one or more of the following:

33. 31. The method of claim 30, wherein setting the state of the second cell to active comprises: receiving an SRS transmission in the second cell; receiving a CSI report for the second cell; transmitting a PUCCH on the second cell; The method includes performing one or more of the following:

34. 21. The method of claim 20, wherein changing the secondary cell in the first frequency from the first cell to the second cell includes replacing a configuration associated with the first cell with a configuration associated with the second cell.

35. 21. The method of claim 20, wherein the first frequency is a serving frequency of the UE.

36. A network node comprising a processing circuit and a network interface coupled to said processing circuit, said processing circuit being configured to perform the steps of the method according to any one of claims 20 to 35.

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