SSB-less mobility for network energy conservation

Abstract

A method, a system, an apparatus, and a computer program product for performing the method for performing an RRM operation using an SSB-less SCell are disclosed. In one aspect, the method may include determining, by a UE, that a target SCell is an SSB-less SCell, determining, by the UE, a reference serving cell for the target SCell, and performing, by the UE, an RRM operation on the target SCell based on a reference signal of the reference serving cell.

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application claims priority to U.S. Provisional Patent Application No. 63 / 446,410, filed February 17, 2023, entitled "SSB-LESS MOBILITY FOR NETWORK ENERGY SAVING," which is incorporated herein by reference in its entirety. [Background technology]

[0002] Wireless communication networks provide an integrated communications platform and telecommunications services to wireless user devices. Exemplary telecommunications services include telephony, data (e.g., voice, audio, and / or video data), messaging, and / or other services. Wireless communication networks have radio access nodes that exchange wireless signals with wireless user devices using radio network protocols, such as those described in various telecommunications standards promulgated by the 3rd Generation Partnership Project (3GPP®). Exemplary wireless communication networks include time division multiple access (TDMA) networks, frequency division multiple access (FDMA) networks, orthogonal frequency division multiple access (OFDMA) networks, Long Term Evolution (LTE), and Fifth Generation New Radio (5G NR). Wireless communication networks facilitate mobile broadband services using technologies such as OFDM, multiple input multiple output (MIMO), advanced channel coding, massive MIMO, beamforming, and / or other features. Summary of the Invention

[0003] According to one aspect of the present disclosure, a method for performing radio resource management (RRM) operations using an SSB-less SCell is disclosed. In one aspect, the method may include: determining, by a UE, that a target SCell is an SSB-less SCell; determining, by the UE, a reference serving cell for the target SCell; and performing, by the UE, an RRM operation on the target SCell based on a reference signal of the reference serving cell. In general, RRM operations may rely on the reference signal for various purposes, including power control, scheduling, cell search, cell reselection, handover, radio link or connection monitoring, and connection establishment and re-establishment. RRM operations are particularly important for carrier aggregation (CA) use cases where component carriers (CCs) are from different frequency bands and from different serving cells. This disclosure describes activation of an inter-band SSB-less SCell based on substitution of the SCell's SSB for RRM operations.

[0004] Other aspects include apparatuses, systems, and computer programs for performing the actions of the aforementioned methods.

[0005] The innovative method may include other optional features. For example, in some implementations, determining a reference serving cell for the target SSB-less SCell may include selecting, by the UE, a reference serving cell on a band or carrier that is closest to the band or carrier of the SSB-less SCell.

[0006] In some implementations, the closest band to the band or carrier of the SSB-less SCell is a reference serving cell on a band or carrier adjacent to the SSB-less SCell.

[0007] In some implementations, the method further includes receiving, by the UE, signaling from the access node configuring a reference serving cell index for the SSB-less SCell when adding the SSB-less SCell to the UE. In such implementations, determining a reference serving cell for the target SSB-less SCell can include selecting, by the UE, the reference serving cell based on the reference serving cell index.

[0008] In some implementations, the method may further include determining, by the UE, a type of reference signal used by the reference serving cell.

[0009] In some implementations, the method may further include selecting, by the UE, the SSB reference signal as a reference signal for use in performing RRM operations in the SSB-less SCell based on a determination by the UE that the reference signal used by the reference serving cell is an SSB reference signal.

[0010] In some implementations, the method may further include receiving, by the UE, signaling from the access node configuring one or more SSB indices of a reference serving cell for use with the SSB-less SCell when adding the SSB-less SCell to the UE. In such implementations, determining a reference serving cell for the target SSB-less SCell may include selecting, by the UE, one or more SSBs of the reference serving cell indicated by the SSB indices as reference signals for use in performing RRM operations on the SSB-less SCell.

[0011] In some implementations, the method may further include, based on a determination by the UE that the reference signal used by the reference serving cell is a tracking reference signal (TRS) or a channel state information reference signal (CSI-RS), selecting, by the UE, a TRS or a CSI-RS as a reference signal for use in performing RRM operations in the SSB-less SCell.

[0012] In some implementations, the selected TRS is an active TRS and the selected CSI-RS is a semi-persistent (SP) or periodic CSI-RS.

[0013] In some implementations, the method may further include receiving, by the UE, signaling from the access node when adding the SSB-less SCell to the UE, that configures one or more CSI-RS indices of a reference serving cell for the SSB-less SCell. In such implementations, determining a reference serving cell for the target SSB-less SCell may include selecting, by the UE, a CSI-RS as a reference signal for use in performing RRM operations on the SSB-less SCell based on the CSI-RS index.

[0014] In some implementations, the selected CSI-RS is a semi-persistent (SP) or periodic CSI-RS.

[0015] In some implementations, the RRM operations may include (i) L3 measurements for the target SSB-less SCell, (ii) activation of the target SSB-less SCell, (iii) time and frequency tracking (T / F tracking), or (iv) (AGC) estimation.

[0016] According to another inventive aspect of the present disclosure, a method for performing RRM operations using an SSB-less SCell is disclosed. In one aspect, the method may include receiving, by a UE, a channel state information reference signal (CSI-RS) from an access node of a target SSB-less SCell, and performing, by the UE, an RRM operation on the target SSB-less SCell using the received CSI-RS.

[0017] Other aspects include apparatuses, systems, and computer programs for performing the actions of the aforementioned methods.

[0018] This innovative method may include other optional features, for example, in some implementations, the CSI-RS is within the active bandwidth of the target SSB-less SCell.

[0019] In some implementations, receiving, by the UE, the CSI-RS from the access node of the target SSB-less SCell may include receiving, by the UE, the CSI-RS time offset, periodicity, and signal bandwidth from the access node of the active serving cell.

[0020] In some implementations, the CSI-RS is associated with an SSB from a reference serving cell.

[0021] In some implementations, the CSI-RS is associated with a reference serving cell.

[0022] In some implementations, the reference serving cell is determined by the UE selecting a reference serving cell on a band or carrier that is closest to the band or carrier of the SSB-less SCell.

[0023] In some implementations, the closest band to the band or carrier of the SSB-less SCell is a reference serving cell on a band or carrier adjacent to the SSB-less SCell.

[0024] In some implementations, the reference serving cell is determined by the UE receiving signaling from the access node that configures a reference serving cell index for the SSB-less SCell when adding the SSB-less SCell to the UE.

[0025] In some implementations, the RRM operation includes (i) L3 measurements for the target SSB-less SCell, or (ii) Includes activation of the target SSB-less SCell.

[0026] In some implementations, the CSI-RS is quasi-colocated (QCLed) with another reference signal from a reference serving cell.

[0027] In some implementations, the QCLed is QCLed Type A.

[0028] In some implementations, QCLed Type A includes Doppler shift, Doppler spread, mean delay, delay spread, and receive absolute timing for inter-band CA.

[0029] In some implementations, the QCLed is QCLed Type C.

[0030] In some implementations, QCLed Type C includes Doppler shift, mean delay, and receive absolute timing for inter-band CA.

[0031] According to another inventive aspect of the present disclosure, a method for performing RRM operations using an SSB-less SCell is disclosed. In one aspect, the method can include determining, by a UE, a measurement of a reference signal of a target SSB-less SCell based on (i) a reference signal received power (RSRP) of a reference signal at a reference serving cell and (ii) a reference signal strength indicator (RSSI) or an interference measurement of a serving cell different from the reference serving cell, and performing, by the UE, an RRM operation on the target SSB-less SCell using the determined measurement of the reference signal of the target SSB-less SCell.

[0032] Other aspects include apparatuses, systems, and computer programs for performing the actions of the aforementioned methods.

[0033] The innovative method may include other optional features. For example, in some implementations, the measurement of the reference signal of the target SSB-less SCell is a Reference Signal Received Quality (RSRQ) measurement or a SINR measurement of the SSB-less SCell.

[0034] In some implementations, the different serving cells are SSB-less SCells.

[0035] In some implementations, the method may further include determining, by the UE, a type of reference signal used by the reference serving cell.

[0036] In some implementations, (i) determining by the UE a measurement value of a reference signal of the target SSB-less SCell based on a reference signal received power (RSRP) of the reference signal at the reference serving cell may include determining by the UE the RSRP of the SSB reference signal at the reference serving cell based on a determination by the UE that the reference signal used by the reference serving cell is an SSB reference signal.

[0037] In some implementations, (i) determining by the UE a measurement value of a reference signal of the target SSB-less SCell based on a reference signal received power (RSRP) of a reference signal at a reference serving cell may include determining by the UE an RSRP measurement value of a TRS reference signal at the reference serving cell or a CSI-RS reference signal at the reference serving cell based on a determination by the UE that the reference signal used by the reference serving cell is a tracking reference signal (TRS) or a channel state information reference signal (CSI-RS).

[0038] In some implementations, the method may further include receiving, by the UE, signaling from the access node that configured the UE with an interference measurement resource (IMR) or a channel measurement resource (CMR) for the SSB-less SCell.

[0039] In some implementations, the IMR and CMR may be configured as reference signals on the SSB-less SCell and other active serving cells.

[0040] According to another inventive aspect of the present disclosure, a method for performing RRM operations on an SSB-less SCell is disclosed. In one aspect, the method can include receiving, by a UE, signaling from an access node for an SSB-less SCell, the received signaling pre-configuring the UE with SSB periodicity and SSB in-bursts for the SSB-less SCell, and receiving, by the UE, different signaling that triggers performance of RRM operations on the SSB-less SCell.

[0041] Other aspects include apparatuses, systems, and computer programs for performing the actions of the aforementioned methods.

[0042] This innovative method can include other optional features, for example, in some implementations, the received signaling is SP-SSB and the received different signaling is MAC-CE activating or deactivating the SSB.

[0043] In some implementations, the received signaling is AP-SSB and the received different signaling is downlink control information (DCI) that aperiodically indicates to the UE to perform RRM operations.

[0044] In some implementations, the RRM operation is T / F tracking.

[0045] In some implementations, the RRM operation is an AGC estimation.

[0046] In some implementations, the AGC is an RSSI-based AGC on an SSB-less SCell.

[0047] In some implementations, the RSSI is measured based on the total power within the initial bandwidth portion of the SSB-less SCell, the total power within the active bandwidth portion of the SSB-less SCell, or the total power within the first active bandwidth portion of the SSB-less SCell.

[0048] The details of one or more embodiments of these systems and methods are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of these systems and methods will be apparent from the description and drawings, and from the claims. [Brief explanation of the drawings]

[0049] [Figure 1] 1 illustrates a wireless network according to some implementations.

[0050] [Figure 2] 1 illustrates a flowchart of an example process for performing radio resource management (RRM) operations on an SSB-less SCell, according to some implementations.

[0051] [Figure 3] 10 illustrates an example of an information element that may be used to configure a reference serving cell index for an SSB-less SCell, according to some implementations.

[0052] [Figure 4] 10 illustrates a flowchart of another example process for performing RRM operations on an SSB-less SCell based on a channel state information reference signal (CSI-RS) associated with the SSB-less SCell, according to some implementations.

[0053] [Figure 5] 1 illustrates a flowchart of an example of another process for performing RRM operations in an SSB-less SCell based on measuring the SSB-less SCell Reference Signal Received Quality (RSRQ) or Signal-to-Interference-and-Noise Ratio (SINR) using Reference Signal Received Power (RSRP) and Reference Signal Strength Indicator (RSSI) from different serving cells, according to some implementations.

[0054] [Figure 6] 10 illustrates a flowchart of an example of another process for performing RRM operations in an SSB-less SCell using a UE (pre-) configured by an access node for an SSB-less SCell with SSB periodicity and SSB inbursts, according to some implementations.

[0055] [Figure 7] 1 illustrates an exemplary user equipment (UE) according to some implementations.

[0056] [Figure 8] 1 illustrates an exemplary access node according to some implementations. DETAILED DESCRIPTION OF THE INVENTION

[0057] The present disclosure is directed to SSB-less radio resource management (RRM) for network energy conservation. In an SSB-less SCell, an access node is not broadcasting synchronization signal blocks (SSBs) that can be used by a user equipment (UE) to perform measurements for mobility operations such as cell selection, cell reselection, power control calculations, mobility procedures, and beam management. When an access node is not broadcasting SSB blocks, less power is consumed, thereby achieving power savings in an SSB-less serving cell. The present disclosure provides systems, methods, devices, and computer programs for enabling a UE to perform RRM operations, including mobility operations, in the absence of SSB transmissions in an SSB-less SCell.

[0058] In some implementations, methods for L3 measurements on an SSB-less SCell are disclosed. Generally, when operating in an SSB-less SCell, a UE can use an SSB alternative to at least partially determine measurements for mobility operations, including measurements related to time or frequency synchronization, L1 or L3 measurements, for automatic gain control. By using an SSB alternative, the UE can perform inter-band carrier aggregation using an SSB-less SCell with at least some indication of channel quality and synchronization. These methods can include, for example, (i) using an SSB for L3 or mobility measurements on another serving cell for the SSB-less SCell, (ii) using CSI-RS for L3 or mobility measurements on the SSB-less SCell, and (iii) using RSRQ together with RSRP and RSSI on a different cell, or using an interference resource concept for L3 measurements. In some implementations, methods for timing and frequency (T / F) tracking on an SSB-less SCell are disclosed. These methods may include, for example, (i) using a tracking reference signal (TRS) or SSB or CSI-RS from another serving cell for T / F tracking in an SSB-less SCell, or (ii) using aperiodic (AP)-SSB for the SSB-less SCell or using CSI-RS / TRS on the SSB-less SCell. In some implementations, methods for automatic gain control (AGC) on an SSB-less SCell are disclosed. These methods may include, for example, (i) using SSB or CSI-RS from another serving cell, (ii) using RSSI-based AGC on the SSB-less SCell, and (iii) using AP-SSB for the SSB-less SCell or CSI-RS / TRS on the SSB-less SCell.

[0059] For purposes of this disclosure, a SCell is a secondary cell in carrier aggregation (CA) or dual connectivity (DC). More generally, a serving cell, such as a reference serving cell, can be a PCell, a PSCell (in DC), or a SCell (in CA or DC).

[0060] 1 illustrates a wireless network 100 according to some implementations. The wireless network 100 includes a UE 102 and a base station 104 connected via one or more channels 106A, 106B over an air interface 108. The UE 102 and the base station 104 communicate using a system that supports control for managing access of the UE 102 to the network via the base station 104.

[0061] In some implementations, wireless network 100 may be a non-standalone (NSA) network incorporating Long Term Evolution (LTE) and Fifth Generation (5G) New Radio (NR) communication standards defined by the 3rd Generation Partnership Project (3GPP) technical specifications. For example, wireless network 100 may be an Evolved Universal Terrestrial Radio Access (E-UTRA)-NR dual connectivity (EN-DC) network or an NR-EUTRA dual connectivity (NE-DC) network. In other implementations, wireless network 100 may be a standalone (SA) network incorporating only 5G NR. Additionally, other types of communication standards are possible, including future 3GPP systems (e.g., sixth generation (6G)), Institute of Electrical and Electronics Engineers (IEEE) 802.11 technologies (e.g., IEEE 802.11a, IEEE 802.11b, IEEE 802.11g, IEEE 802.11-2007, IEEE 802.11n, IEEE 802.11-2012, IEEE 802.11ac, or other current or future developed IEEE 802.11 technologies), IEEE 802.16 protocols (e.g., WMAN, WiMAX, etc.), etc. Although aspects may be described herein using terminology generally associated with 5G NR, aspects of the present disclosure may apply to other systems, such as systems subsequent to 3G, 4G, and / or 5G (e.g., 6G).

[0062] In wireless network 100, UE 102 and any other UEs in the system may be, for example, a laptop computer, a smartphone, a tablet computer, a machine-type device such as a smart meter or a dedicated device for healthcare, an intelligent transportation system, or any other wireless device. In network 100, base stations 104 provide UE 102 with network connectivity to a wider network (not shown). This UE 102 connectivity is provided over an air interface 108 within a base station service area provided by base station 104. In some implementations, such a wider network may be a wide area network operated by a cellular network provider or may be the Internet. Each base station service area associated with a base station 104 is supported by one or more antennas integrated with the base station 104. The service area may be divided into multiple sectors associated with one or more specific antennas. Such sectors may be physically associated with one or more fixed antennas and may be assigned to a physical area using one or more adjustable tunable antennas or antenna settings in a beamforming process used to direct signals to specific sectors.

[0063] The UE 102 includes a control circuit 110 coupled to a transmit circuit 112 and a receive circuit 114. The transmit circuit 112 and the receive circuit 114 may each be coupled to one or more antennas. The control circuit 110 may include various combinations of application-specific and baseband circuitry. The transmit circuit 112 and the receive circuit 114 may be adapted to transmit and receive data, respectively, and may include radio frequency (RF) circuitry and / or front-end module (FEM) circuitry.

[0064] In various implementations, aspects of the transmit circuitry 112, the receive circuitry 114, and the control circuitry 110 may be integrated in various ways to implement the operations described herein. The control circuitry 110 may be adapted or configured to perform various operations, such as those described elsewhere in this disclosure in connection with a UE. For example, the control circuitry 110 may include performing operations such as operations 210, 220, and 230 of FIG. 2, operation 420 of FIG. 4, operations 510 and 520 of FIG. 5, and operations 610 and 620 of FIG. 6.

[0065] The transmit circuitry 112 may perform various operations described herein. Additionally, the transmit circuitry 112 may transmit using multiple multiplexed uplink physical channels. The multiple uplink physical channels may be multiplexed by time division multiplexing (TDM) or frequency division multiplexing (FDM), for example, with carrier aggregation. The transmit circuitry 112 may be configured to receive block data from the control circuitry 110 for transmission over the air interface 108.

[0066] The receive circuitry 114 may perform various operations described herein. For example, the receive circuitry 114 may perform receive operations such as operation 410 of FIG. 4 and receive operations 610, 620 of FIG. 6. Additionally, the receive circuitry 114 may receive multiple multiplexed downlink physical channels from the air interface 108 and relay the physical channels to the control circuitry 110. The multiple downlink physical channels may be multiplexed using, for example, TDM or FDM with carrier aggregation. The transmit circuitry 112 and the receive circuitry 114 may transmit and receive both control data and content data (e.g., messages, images, videos, etc.) structured within data blocks carried by the physical channels.

[0067] 1 also shows a base station 104. In some implementations, the base station 104 may be a 5G radio access network (RAN), an Next Generation RAN, an E-UTRAN, a non-terrestrial cell, or a legacy RAN such as a UTRAN. As used herein, terms such as "5G RAN" may refer to a base station 104 operating in an NR or 5G wireless network 100, and terms such as "E-UTRAN" may refer to a base station 104 operating in an LTE or 4G wireless network 100. The UE 102 utilizes connections (or channels) 106A, 106B, each of which includes a physical communication interface or layer.

[0068] The base station 104 circuitry may include control circuitry 116 coupled to transmit circuitry 118 and receive circuitry 120. The transmit circuitry 118 and receive circuitry 120 may each be coupled to one or more antennas that may be used to facilitate communication over the air interface 108. The transmit circuitry 118 and receive circuitry 120 may be adapted to transmit and receive data, respectively, to any UE connected to the base station 104. The receive circuitry 120 may receive multiple uplink physical channels from one or more UEs, including the UE 102.

[0069] 1, one or more channels 106A, 106B are depicted as an air interface enabling a communicative coupling and may conform to a cellular communication protocol such as a UMTS protocol, a 3GPP LTE protocol, an Advanced Long Term Evolution (LTE-A) protocol, an LTE-based access to unlicensed spectrum (LTE-U), a 5G protocol, an NR protocol, an NR-based access to unlicensed spectrum (NR-U) protocol, and / or any other communication protocol(s). In implementations, the UE 102 may directly exchange communication data over the ProSe interface. The ProSe interface may alternatively be referred to as a sidelink (SL) interface and may include one or more logical channels, including, but not limited to, a physical sidelink control channel (PSCCH), a physical sidelink discovery channel (PSDCH), and a physical sidelink broadcast channel (PSBCH). Radio Resource Management (RRM) Operation for SSB-less SCell

[0070] Systems, methods, devices, and computer programs for L3 measurements and SCell activation for inter-band SSB-less SCells are disclosed. This disclosure describes how L3 measurements can be performed when attempting to activate an SCell for carrier aggregation using an inter-band component carrier in situations where the SCell is an SSB-less SCell.

[0071] In some implementations, the UE is configured to use reference signals (RS) of another serving cell (e.g., a reference serving cell) for L3 or mobility measurements or SCell activation for an SSB-less SCell, and the UE can determine which RS of which serving cell can be used for such purposes based on the following method:

[0072] The UE can determine the "reference serving cell" for the target SSB-less SCell in several different ways: In a first implementation, the UE can select a reference serving cell on the closest or adjacent band / carrier compared to the band / carrier of the SSB-less SCell.

[0073] Alternatively, in other implementations, the network (e.g., the access node of the SSB-less SCell) can configure a reference serving cell index for the SSB-less SCell when adding this SSB-less SCell to a UE. The reference serving cell index indicates which serving cell the UE can use as a reference serving cell. An example of an information element IE 300 that can be used to configure a reference serving cell index for an SSB-less SCell is shown in FIG. 3. The IE 300 includes a parameter "refCellIndex" 310 that can be used to indicate to the UE the reference serving cell index for the SSB-less SCell, for example, when SMTC and SSB are not configured for this SCell.

[0074] The UE can determine the reference signal (RS) of the reference serving cell in several different ways. For example, in some implementations, if SSB is used for RS, the UE can select the SSB of the reference serving cell specifically for L3 measurements. In such a case, the measurement configuration of the SSB for the reference serving cell can be retained for the target SSB-less SCell. That is, the measurement configuration of the SSB for the identified or selected reference serving cell is used for the SSB-less SCell to which the UE will connect. Measurement configuration parameters for the SSB can include, for example, nrofSS-BlocksToAverage and measurements / reports with / without SSB index.

[0075] In some implementations, if an SSB of a reference serving cell is used for the RS, the network may indicate one or more SSB indices of the selected or identified reference serving cell when adding an SSB-less SCell to the UE. The UE uses these indicated SSBs of the reference cell for L3 measurements and SCell activation to connect to and use the target SSB-less SCell.

[0076] In some implementations, if TRS or CSI-RS is used for reference signals (RS), the UE selects the TRS of the selected or identified reference serving cell for target SSB-less SCell activation and / or operation if the TRS is configured on that reference serving cell and the active TRS is always preferred for use.

[0077] In some implementations, if TRS or CSI-RS is used, the network (e.g., the access node of the reference cell) may indicate one or more CSI-RS indices of the reference serving cell when adding the target SSB-less SCell to the UE. In such implementations, only semi-persistent (SP) and / or periodic CSI-RS may be used in this case.

[0078] 2 shows a flowchart of an example process 200 for performing RRM operations on an SSB-less SCell, according to some implementations. For convenience, the process 200 is described as being performed by a UE, such as UE 102 or UE 700.

[0079] The UE may begin execution of process 200 by determining 210 that the target SCell is an SSB-less SCell.

[0080] The UE may continue execution of process 200 by determining a reference serving cell for the target SSB-less SCell (220). In some implementations, determining a reference serving cell for the target SSB-less SCell in stage 220 may include the UE selecting a reference serving cell on a band or carrier that is closest to the band or carrier of the SSB-less SCell. In some implementations, the band that is closest to the band or carrier of the SSB-less SCell is a reference serving cell on a band or carrier that is adjacent to the SSB-less SCell.

[0081] Alternatively, in some implementations, performing process 200 may include the UE receiving signaling from the access node configuring a reference serving cell index that identifies a reference serving cell that may be used for one or more RRM measurements with the SSB-less SCell when adding the SSB-less SCell to the UE. In such implementations, determining a reference serving cell for the target SSB-less SCell in stage 220 may include the UE selecting the reference serving cell based on the reference serving cell index.

[0082] The UE may continue execution of process 200 by performing RRM operations on the target SSB-less SCell based on the reference signal of the reference serving cell. In some implementations, the RRM operations may include (i) L3 measurements for the target SSB-less SCell, (ii) activation of the target SSB-less SCell, (iii) time and frequency tracking (T / F tracking), or (iv) (AGC) estimation.

[0083] In some implementations, the UE may continue execution of process 200 by determining, by the UE, the type of reference signal used by the reference serving cell. In some implementations, based on a determination by the UE that the reference signal used by the reference serving cell is an SSB reference signal, the UE may continue execution of process 200 by selecting the SSB reference signal as the reference signal for use in performing RRM operations in an SSB-less SCell.

[0084] In some implementations, the UE may receive signaling from the access node configuring one or more SSB indices of a reference serving cell for use by the UE when adding an SSB-less SCell to the UE. In such implementations, determining a reference serving cell for the target SSB-less SCell in stage 220 may include the UE selecting, based on the CSI-RS index, one or more SSBs of the reference service indicated by the SSB index as reference signals for use in performing RRM operations on the SSB-less SCell.

[0085] In some implementations, based on a determination by the UE that the reference signal used by the reference serving cell is a tracking reference signal (TRS) or a channel state information reference signal (CSI-RS), the UE may continue performing process 200 by selecting the TRS or the CSI-RS as the reference signal for use in performing RRM operations in the SSB-less SCell. In some implementations, priority may be given to selecting a TRS reference signal over a CSI-RS reference signal.

[0086] In some implementations, the selected TRS is an active TRS and the selected CSI-RS is a semi-persistent (SP) or periodic CSI-RS.

[0087] In some implementations, the UE may receive signaling from the access node configuring one or more CSI-RS indices of reference serving cells for the SSB-less SCell when adding the SSB-less SCell to the UE. In such implementations, determining a reference serving cell for the target SSB-less SCell in step 220 may include the UE selecting a CSI-RS as a reference signal based on the CSI-RS index to use in performing RRM operations on the SSB-less SCell. In such implementations, the selected CSI-RS is a semi-persistent (SP) or periodic CSI-RS.

[0088] 3 illustrates an example of an information element 300 that may be used to configure a reference serving cell index for an SSB-less SCell, according to some implementations. For convenience, the process 300 is described as being performed by a UE, such as UE 102 or UE 700.

[0089] RRM Operation for SSB-less SCell Using CSI-RS

[0090] A system, method, device, and computer program for L3 measurements and SCell activation for inter-band SSB-less SCell are disclosed.

[0091] In some implementations, for L3 or other RRM measurements only, the UE can use CSI-RS for L3 or mobility measurements of the reference serving cell for the SSB-less SCell, where the CSI-RS is within the bandwidth (BW) of the target SSB-less SCell and the CSI-RS information is configured for the UE when adding this SSB-less SCell, such as CSI-RS time offset, periodicity, and signal BW.

[0092] In some implementations, the CSI-RS may have an associated SSB on a reference serving cell, and the reference serving cell selection may be based on a reference serving cell that has a closest or adjacent band compared to the band of the SSB-less SCell, and the associated SSB index of the reference serving cell is configured by the network; or

[0093] In some implementations, the CSI-RS may be directly associated with the reference serving cell, and the reference serving cell selection may be based on a refCellIndex information element configured to indicate the reference serving cell, or

[0094] In some implementations, a CSI-RS may be QCLed with another RS ​​on a reference serving cell, for example, QCLed Type A or C. The legacy QCLed Type A or C is extended in this case to reflect the absolute time difference.

[0095] For example, legacy "Type A" can include {Doppler shift, Doppler spread, mean delay, delay spread} -> new Type A {Doppler shift, Doppler spread, mean delay, delay spread, receive absolute timing for inter-band CA}, and legacy "Type C" can include {Doppler shift, mean delay} -> new Type C {Doppler shift, mean delay, receive absolute timing for inter-band CA}.

[0096] 4 illustrates a flowchart of an example of another method 400 for performing RRM operations on an SSB-less SCell based on a channel state information reference signal (CSI-RS) associated with the SSB-less SCell, according to some implementations. For convenience, the process 400 is described as being performed by a UE, such as UE 102 or UE 700.

[0097] The UE may begin execution of process 400 by receiving 410 a channel state information reference signal (CSI-RS) from an access node of the target SSB-less SCell. In some implementations, receiving CSI-RS from an access node of the target SSB-less SCell at stage 410 may include the UE receiving a CSI-RS time offset, periodicity, and signal bandwidth from the access node of the active serving cell.

[0098] The UE may continue execution of process 400 by performing 420 RRM operations on the target SSB-less SCell using the received CSI-RS.

[0099] In some implementations, the CSI-RS is within the active bandwidth of the target SSB-less SCell.

[0100] In some implementations, the CSI-RS is associated with an SSB from a reference serving cell. In some implementations, the CSI-RS is associated with an SSB if the CSI-RS timing can be referenced to the SSB timing of the reference serving cell. When the UE detects this association, the UE can directly use the SSB timing to locate the symbols of the CSI-RS and then perform measurements on the CSI-RS.

[0101] In some implementations, the CSI-RS is associated with a reference serving cell, in which case the CSI-RS timing may be referenced to the timing of the reference serving cell.

[0102] In some implementations, the reference serving cell is determined by the UE selecting a reference serving cell on a band or carrier that is closest to the band or carrier of the SSB-less SCell.

[0103] In some implementations, the closest band to the band or carrier of the SSB-less SCell is a reference serving cell on a band or carrier adjacent to the SSB-less SCell.

[0104] In some implementations, the reference serving cell is determined by the UE receiving signaling from the access node that configures a reference serving cell index for the SSB-less SCell when adding the SSB-less SCell to the UE.

[0105] In some implementations, the RRM operation includes (i) L3 measurements for the target SSB-less SCell, or (ii) activation of the target SSB-less SCell.

[0106] In some implementations, the CSI-RS is quasi-colocated (QCLed) with another reference signal from a reference serving cell. In some implementations, the QCLed is QCLed Type A. In such implementations, the QCLed Type A may include Doppler shift, Doppler spread, mean delay, delay spread, and receive absolute timing for inter-band CA. In some implementations, the QCLed is QCLed Type C. In such implementations, the QCLed Type C may include Doppler shift, mean delay, and receive absolute timing for inter-band CA.

[0107] RRM behavior for SSB-less SCell based on measurements of SSB-less SCell RSRP

[0108] In some implementations, for RSRQ or SINR measurements of a target SSB-less SCell, RSRP is measured based on an RS on a reference serving cell, and RSSI / interference measurements are on this target SSB-less SCell without any specific RS. The selection of RS and reference serving cell is based on Option 1.

[0109] In some implementations, for L3 RSRQ or SINR measurement, the UE measures the target SSB-less SCell RSRQ or SINR using RSRP and RSSI on different serving cells, or uses the interference resource concept for L3.

[0110] In some implementations, the network configures CMR and IMR for SSB-less SCell RSRQ or SINR measurements. CMR is a channel measurement resource and IMR is an interference measurement resource. CMR and IMR may be configured on different serving cells and different RSs.

[0111] 5 shows a flowchart of an example of another method 500 for performing RRM operations on an SSB-less SCell based on measuring an SSB-less SCell Reference Signal Received Quality (RSRQ) or Signal-to-Interference-and-Noise Ratio (SINR) using Reference Signal Received Power (RSRP) and Reference Signal Strength Indicator (RSSI) from different serving cells, according to some implementations. For convenience, the process 500 is described as being performed by a UE, such as UE 102 or UE 700.

[0112] The UE may begin execution of process 500 by determining (510) a measurement of a reference signal of a target SSB-less SCell based on (i) a reference signal received power (RSRP) of a reference signal at a reference serving cell and (ii) a reference signal strength indicator (RSSI) or interference measurement of a serving cell different from the reference serving cell.

[0113] The UE may continue performing process s500 by performing RRM operations on the target SSB-less SCell using the determined measurements of the reference signal of the target SSB-less SCell.

[0114] In some implementations, the measurement of the reference signal of the target SSB-less SCell is an RSRQ measurement or an SINR measurement of the SSB-less SCell.

[0115] In some implementations, the different serving cells are SSB-less SCells.

[0116] In some implementations, the UE may continue execution of process 500 by determining the type of reference signal used by the reference serving cell.

[0117] In some implementations, (i) determining by the UE a measurement value of a reference signal of the target SSB-less SCell based on a reference signal received power (RSRP) of the reference signal at the reference serving cell may include determining by the UE the RSRP of the SSB reference signal at the reference serving cell based on a determination by the UE that the reference signal used by the reference serving cell is an SSB reference signal.

[0118] In some implementations, (i) determining, by the UE, a measurement value of a reference signal of the target SSB-less SCell based on a reference signal received power (RSRP) of a reference signal at a reference serving cell may include determining, by the UE, an RSRP measurement value of a TRS reference signal at the reference serving cell or a CSI-RS reference signal at the reference serving cell based on a determination by the UE that the reference signal used by the reference serving cell is a tracking reference signal (TRS) or a channel state information reference signal (CSI-RS). In some implementations, priority may be given to selecting a TRS reference signal over a CSI-RS reference signal.

[0119] In some implementations, the UE may continue performing process 500 by receiving signaling from an access node that has configured the UE with an interference measurement resource (IMR) or a channel measurement resource (CMR) for the SSB-less SCell.

[0120] In some implementations, the IMR and CMR may be configured as reference signals on the SSB-less SCell and other active serving cells.

[0121] RRM Operation for SSB-less SCell Using UEs (Pre-)Configured with SSB Periodicity and SSB Inburst

[0122] In some implementations, time and frequency (T / F) tracking for inter-band SSB-less SCell. In some implementations, the UE does not have an in-band serving CC of the target SSB-less SCell.

[0123] In some implementations, the UE can perform T / F tracking on an SSB-less SCell using an implementation of process 200 described with reference to FIG. 2. In other implementations, the network configures semi-persistent (SP) or AP-SSB on the SSB-less SCell. In such implementations, SP-SSB means that the network pre-configures the UE with SSB periodicity and SSB inbursts for the SSB-less SCell and uses MAC-CE to activate and deactivate SSB for the UE to perform T / F tracking. Alternatively, AP-SSB means that the network pre-configures the UE with SSB periodicity and SSB inbursts for the SSB-less SCell and uses DCI to aperiodically instruct the UE to perform T / F tracking.

[0124] The UE will use the next available AP-SSB occasion after the DCI for T / F tracking. If the time interval between the DCI and the next closest SSB occasion is less than a threshold, the UE will use the SSB occasion after the next closest SSB occasion as the AP-SSB.

[0125] In some implementations, the AGC estimation may be implemented on an inter-band SSB-less SCell. In some implementations, the UE does not have an in-band serving CC of the target SSB-less SCell.

[0126] In some implementations, the UE may perform ACG estimation using an RS from another serving cell, such as the implementation described with reference to process 200 of FIG. 2 above for L3 measurements.

[0127] In some implementations, the network can configure the UE with SP / AP-SSB on the SSB-less SCell in the same way as described for T / F tracking above. In other implementations, the UE can use RSSI-based AGC on the SSB-less SCell. In some implementations, the RSSI is measured based on the total power in the initial BWP or active BWP or first active BWP.

[0128] 6 shows a flowchart of an example of another method 600 of performing RRM operations on an SSB-less SCell using a UE that has been (pre-)configured by an access node for an SSB-less SCell with SSB periodicity and SSB inbursts, according to some implementations. For convenience, the process 600 is described as being performed by a UE, such as UE 102 or UE 700.

[0129] The UE may begin execution of process 600 by receiving signaling from an access node for an SSB-less SCell, where the received signaling pre-configures the UE with SSB periodicity and SSB inbursts for the SSB-less SCell (610).

[0130] The UE may continue execution of process 600 by receiving 610 different signaling that triggers execution of an RRM operation on the SSB-less SCell.

[0131] In some implementations, the received signaling is an SP-SSB and the different signaling received is a MAC-CE activating or deactivating the SSB.

[0132] In some implementations, the received signaling is AP-SSB and the received different signaling is downlink control information (DCI) that aperiodically indicates to the UE to perform RRM operations.

[0133] In some implementations, the RRM operation is T / F tracking. In some implementations, the RRM operation is AGC estimation. In such implementations, the AGC may be an RSSI-based AGC on an SSB-less SCell.

[0134] In some implementations, the RSSI is measured based on the total power within the initial bandwidth portion of the SSB-less SCell, the total power within the active bandwidth portion of the SSB-less SCell, or the total power within the first active bandwidth portion of the SSB-less SCell.

[0135] 7 illustrates an exemplary UE 700, according to some implementations. The UE 700 may be similar to and substantially interchangeable with the UE 102 of FIG.

[0136] The UE 700 may be any mobile or non-mobile computing device, such as a mobile phone, a computer, a tablet, an industrial wireless sensor (e.g., a microphone, a pressure sensor, a thermometer, a motion sensor, an accelerometer, an inventory sensor, a voltage / current meter, etc.), a video device (e.g., a camera, a video camera, etc.), a wearable device (e.g., a smart watch), a relaxed-IoT device, etc.

[0137] The UE 700 may include a processor 702, an RF interface circuit 704, memory / storage 706, a user interface 708, sensors 710, driver circuitry 712, a power management integrated circuit (PMIC) 714, one or more antenna(s) 716, and a battery 718. The components of the UE 700 may be implemented as an integrated circuit (IC), portions thereof, discrete electronic devices, or other modules, logic, hardware, software, firmware, or combinations thereof. The block diagram of FIG. 7 is intended to show a high-level view of some of the components of the UE 700. However, some of the components shown may be omitted, additional components may be present, and different arrangements of the components shown may occur in other embodiments.

[0138] The components of UE 700 may be coupled to various other components via one or more interconnects 720, which may represent any type of interface, input / output, bus (local, system, or expansion), transmission line, trace, optical connection, etc. that may allow various circuit components (on a common or different chips or chipsets) to interact with one another.

[0139] The processor 702 may include processor circuitry such as, for example, a baseband processor circuit (BB) 722A, a central processing unit circuit (CPU) 722B, and a graphics processing unit circuit (GPU) 722C. The processor 702 may include any type of circuitry or processor circuitry that executes or otherwise operates computer-executable instructions, such as program code, software modules, or functional processes from memory / storage 706 to cause the UE 700 to perform the operations described herein.

[0140] In some implementations, the baseband processor circuit 722A may access a communications protocol stack 724 in the memory / storage 706 to communicate over a 3GPP-compliant network. Generally, the baseband processor circuit 722A may access the communications protocol stack to perform user plane functions at the physical (PHY), medium access control (MAC), radio link control (RLC), packet data convergence protocol (PDCP), service data adaptation protocol (SDAP), and PDU layers, and control plane functions at the PHY, MAC, RLC, PDCP, RRC, and non-access layers. In some implementations, PHY layer operations may additionally or alternatively be performed by components of the RF interface circuit 704. The baseband processor circuit 722A may generate or process baseband signals or waveforms that carry information within a 3GPP-compliant network. In some implementations, waveforms for NR may be based on cyclic prefix orthogonal frequency division multiplexing (OFDM) "CP-OFDM" in the uplink or downlink and discrete Fourier transform spread OFDM "DFT-S-OFDM" in the uplink.

[0141] The memory / storage 706 may include one or more non-transitory computer-readable media (e.g., communication protocol stack 724) that include instructions that may be executed by one or more of the processors 702 to cause the UE 700 to perform various operations described herein. The memory / storage 706 includes any type of volatile or non-volatile memory that may be distributed throughout the UE 700. In some implementations, some of the memory / storage 706 may be located within the processor 702 itself (e.g., L1 and L2 caches), while other memory / storage 706 is external to the processor 702 but accessible via a memory interface. Memory / storage 706 may include any suitable volatile or non-volatile memory, such as, but not limited to, dynamic random access memory (DRAM), static random access memory (SRAM), erasable programmable read only memory (EPROM), electrically erasable programmable read only memory (EEPROM), flash memory, solid state memory, or any other type of memory device technology.

[0142] The RF interface circuitry 704 may include transceiver circuitry and a radio frequency front end module (RFEM) that enable the UE 700 to communicate with other devices over a radio access network. The RF interface circuitry 704 may include various elements disposed in the transmit or receive paths. These elements may include, for example, switches, mixers, amplifiers, filters, combiner circuits, control circuits, etc.

[0143] In the receive path, the RFEM receives radiated signals from the air interface via antenna(s) 716 and may proceed to filter and amplify the signals (using a low noise amplifier). The signals may be provided to a receiver in the transceiver, which downconverts the RF signals to baseband signals, which are provided to a baseband processor in the processor 702.

[0144] In the transmit path, the transmitter of the transceiver upconverts baseband signals received from the baseband processor and provides RF signals to the RFEM. The RFEM may amplify the RF signals using a power amplifier before radiating the signals over the air interface via antenna(s) 716. In various implementations, the RF interface circuitry 704 may be configured to transmit and receive signals to comply with NR access technologies.

[0145] The antenna(s) 716 may include one or more antenna elements that convert electrical signals into radio waves for transmission through the air and convert received radio waves into electrical signals. The antenna elements may be arranged in one or more antenna panels. The antenna(s) 716 may have antenna panels that are omnidirectional, directional, or a combination thereof, enabling beamforming and multiple-input multiple-output communications. The antenna(s) 716 may include microstrip antennas, printed antennas fabricated on the surface of one or more printed circuit boards, patch antennas, phased array antennas, etc. The antenna(s) 716 may have one or more panels designed for a specific frequency band, including the FR1 or FR2 bands.

[0146] User interface circuitry 708 includes various input / output (I / O) devices designed to enable user interaction with UE 700. User interface 708 includes input device circuitry and output device circuitry. Input device circuitry includes any physical or virtual means for accepting input, including, among others, one or more physical or virtual buttons (e.g., a reset button), a physical keyboard, a keypad, a mouse, a touchpad, a touchscreen, a microphone, a scanner, a headset, etc. Output device circuitry includes any physical or virtual means for displaying or otherwise communicating information, such as sensor readings, actuator position(s), or other similar information. The output device circuitry may include any number or combination of audio or visual displays, including, among other things, one or more simple visual outputs / indicators (e.g., binary status indicators such as light emitting diodes "LEDs" and multi-character visual outputs), or more complex outputs such as display devices or touch screens (e.g., liquid crystal displays "LCDs," LED displays, quantum dot displays, projectors, etc.), and output such as text, graphics, multimedia objects, etc. generated or created from operation of the UE700.

[0147] The sensors 710 may include devices, modules, or subsystems designed to detect events or changes in their environment and transmit information about the detected events (sensor data) to some other device, module, subsystem, etc. Examples of such sensors include, among others, inertial measurement units including accelerometers, gyroscopes, or magnetometers, microelectromechanical or nanoelectromechanical systems including 3-axis accelerometers, 3-axis gyroscopes, or magnetometers, level sensors, temperature sensors (e.g., thermistors), pressure sensors, image capture devices (e.g., cameras or lensless apertures), light detection and ranging sensors; proximity sensors (e.g., infrared detectors, etc.); depth sensors; ambient light sensors; ultrasonic transceivers; microphones or other similar audio capture devices; and the like.

[0148] The driver circuitry 712 may include software and hardware elements that operate to control particular devices embedded in, attached to, or otherwise communicatively coupled to the UE 700. The driver circuitry 712 may include individual drivers that enable other components to interact with or control various input / output (I / O) devices that may be present in or connected to the UE 700. For example, the driver circuitry 712 may include a display driver for controlling and allowing access to a display device, a touchscreen driver for controlling and allowing access to a touchscreen interface, a sensor driver for obtaining sensor readings of and controlling and allowing access to the sensors 710, a driver for obtaining actuator positions of or controlling and allowing access to electromechanical components, a camera driver for controlling and allowing access to an embedded image capture device, and an audio driver for controlling and allowing access to one or more audio devices.

[0149] The PMIC 714 may manage the power supplied to various components of the UE 700. In particular, with respect to the processor 702, the PMIC 714 may control power source selection, voltage scaling, battery charging, or DC-DC conversion.

[0150] In some implementations, the PMIC 714 may control or otherwise be a part of various power saving mechanisms of the UE 700. The battery 718 may power the UE 700, although in some examples, the UE 700 may be mounted and deployed at a fixed location and may have a power source coupled to a power grid. The battery 718 may be a lithium-ion battery, a metal-air battery such as a zinc-air battery, an aluminum-air battery, a lithium-air battery, or the like. In some implementations, such as in vehicle-based applications, the battery 718 may be a typical automotive lead-acid battery.

[0151] 8 illustrates an exemplary access node 800 (e.g., a base station or a gNB) according to some implementations. The access node 800 may be similar to, and substantially interchangeable with, the base station 104. The access node 800 may include a processor 802, RF interface circuitry 804, a core network (CN) interface circuitry 806, memory / storage circuitry 808, and one or more antenna(s) 810.

[0152] The components of the access node 800 may be coupled to various other components via one or more interconnects 812. The processor 802, RF interface circuitry 804, memory / storage circuitry 808 (including a communications protocol stack 814), antenna(s) 810, and interconnects 812 may be similar to the like-named elements shown and described with respect to Figure 7. For example, the processor 802 may include processor circuits such as a baseband processor circuit (BB) 816A, a central processing unit circuit (CPU) 816B, and a graphics processing unit circuit (GPU) 816C.

[0153] The CN interface circuitry 806 may provide connectivity to a core network, e.g., a 5th Generation Core network (5GC), using a 5GC-compliant network interface protocol, such as a Carrier Ethernet protocol or some other suitable protocol. Network connectivity may be provided to / from the access node 800 via optical fiber or wireless backhaul. The CN interface circuitry 806 may include one or more dedicated processors or FPGAs for communicating using one or more of the aforementioned protocols. In some implementations, the CN interface circuitry 806 may include multiple controllers to provide connectivity to other networks using the same or different protocols.

[0154] As used herein, terms such as "access node," "access point," and the like may describe equipment that provides wireless baseband functionality for data and / or voice connectivity between a network and one or more users. These access nodes may be referred to as BSs, gNBs, RAN nodes, eNBs, NodeBs, RSUs, TRxPs, or TRPs, and may include terrestrial stations (e.g., terrestrial access points) or satellite stations that provide coverage within a geographic area (e.g., a cell). As used herein, terms such as "NG RAN node" may refer to an access node 800 operating in an NR or 5G system (e.g., gNB), and terms such as "E-UTRAN node" may refer to an access node 800 operating in an LTE or 4G system (e.g., eNB). According to various implementations, access node 800 may be implemented as one or more of dedicated physical devices, such as a macrocell base station, and / or a low power (LP) base station for providing a femtocell, picocell, or other similar cell having a smaller coverage area, lower user capacity, or higher bandwidth compared to a macrocell.

[0155] In some implementations, all or a portion of the access node 800 may be implemented as one or more software entities running on a server computer as part of a virtual network, which may be referred to as a CRAN and / or a virtual baseband unit pool (vBBUP). In a V2X scenario, the access node 800 may be or operate as a “roadside unit.” The term “roadside unit” or “RSU” may refer to any transportation infrastructure entity used for V2X communications. The RSU may be implemented in or by an appropriate RAN node or a stationary (or relatively stationary) UE; an RSU implemented in or by a UE may be referred to as a “UE-type RSU,” an RSU implemented in or by an eNB may be referred to as an “eNB-type RSU,” an RSU implemented in or by a gNB may be referred to as a “gNB-type RSU,” etc.

[0156] In the description herein, for convenience, various components may be described as performing a task or tasks. Such descriptions should be construed to include the phrase "configured to." It is expressly intended that a description of a component being configured to perform one or more tasks does not invoke 35 U.S.C. 112(f) interpretation with respect to that component.

[0157] For one or more embodiments, at least one of the components depicted in one or more of the foregoing figures may be configured to perform one or more operations, techniques, processes, or methods as described in the example section below. For example, the baseband circuitry described above in connection with one or more of the foregoing figures may be configured to operate according to one or more of the examples described below. As another example, circuitry associated with a UE, a base station, a network element, etc., as described above in connection with one or more of the foregoing figures, may be configured to operate according to one or more of the examples described below in the example section.

[0158] It is understood that use of personally identifiable information should comply with generally recognized privacy policies and practices that meet or exceed industry or government requirements for maintaining user privacy. In particular, personally identifiable information data should be managed and handled in a manner that minimizes the risk of unintended or unauthorized access or use, and the nature of permitted uses should be clearly indicated to users.

Claims

1. 1. A method for performing radio resource management (RRM) operations using a system synchronization block-less secondary cell (SSB-less SCell), comprising: Determining, by a user equipment (UE), that the target SCell is an SSB-less SCell; determining, by the UE and based on the target SCell being an SSB-less SCell, a reference serving cell for the target SCell; performing, by the UE, an RRM operation in the target SCell based on a reference signal of the reference serving cell.

2. determining a reference serving cell for the target SSB-less SCell; The method of claim 1 , comprising selecting, by the UE, a reference serving cell on a band or carrier that is closest to the band or carrier of the SSB-less SCell.

3. The method of claim 2 , wherein the closest band to the band or carrier of the SSB-less SCell is a reference serving cell on a band or carrier adjacent to the SSB-less SCell.

4. The method comprises: and receiving, by the UE from an access node, signaling to configure a reference serving cell index for an SSB-less SCell when adding the SSB-less SCell to the UE; determining a reference serving cell for the target SSB-less SCell; The method of claim 1 , comprising selecting, by the UE, a reference serving cell based on the reference serving cell index.

5. The method comprises: The method of claim 1 , further comprising determining, by the UE, a type of the reference signal used by the reference serving cell.

6. The method comprises:

6. The method of claim 5, further comprising: selecting, by the UE, the SSB reference signal as a reference signal for use in performing the RRM operation in the SSB-less SCell based on a determination by the UE that the reference signal used by the reference serving cell is an SSB reference signal.

7. The method comprises: receiving, by the UE from an access node, signaling that configures one or more SSB indices of reference serving cells for the SSB-less SCell when adding the SSB-less SCell to the UE; determining a reference serving cell for the target SSB-less SCell; 2. The method of claim 1, comprising selecting, by the UE, the one or more SSBs of the reference serving cell indicated by the SSB index as reference signals for use in performing the RRM operation in the SSB-less SCell.

8. The method comprises:

6. The method of claim 5, further comprising: based on a determination by the UE that the reference signal used by the reference serving cell is a tracking reference signal (TRS) or a channel state information reference signal (CSI-RS), selecting, by the UE, the TRS or the CSI-RS as the reference signal for use in performing the RRM operations in the SSB-less SCell.

9. The method of claim 8 , wherein the selected TRS is an active TRS, and the selected CSI-RS is a semi-persistent (SP) or periodic CSI-RS.

10. The method of claim 8 , wherein selection of the TRS as the reference signal takes priority over selection of the CSI-RS as the reference signal.

11. The method of claim 8 , wherein the CSI-RS is quasi-colocated (QCL) with another reference signal from the reference serving cell.

12. The method comprises: receiving, by the UE from an access node, signaling that configures one or more CSI-RS indices of reference serving cells for the SSB-less SCell when adding the SSB-less SCell to the UE; determining a reference serving cell for the target SSB-less SCell; 2. The method of claim 1, comprising selecting, by the UE, the CSI-RS as a reference signal for use in performing the RRM operation in the SSB-less SCell based on the CSI-RS index.

13. The RRM operation comprises: (i) L3 measurements for the target SSB-less SCell; 2. The method of claim 1, comprising: (ii) activating the target SSB-less SCell; (iii) time and frequency tracking (T / F tracking); or (iv) (AGC) estimation.

14. One or more processors comprising circuitry for executing one or more instructions that, when executed, cause a user equipment (UE) to perform an operation, the operation comprising: determining that the target SCell is an SSB-less SCell; determining a reference serving cell for the target SCell based on the target SCell being an SSB-less SCell; and performing an RRM operation in the target SCell based on a reference signal of the reference serving cell.

15. determining a reference serving cell for the target SSB-less SCell; The one or more processors of claim 14 , further comprising selecting a reference serving cell on a closest band or carrier to the band or carrier of the SSB-less SCell.

16. 16. The one or more processors of claim 15, wherein a closest band to the band or carrier of the SSB-less SCell is a reference serving cell on a band or carrier adjacent to the SSB-less SCell.

17. The operation is receiving signaling from an access node to configure a reference serving cell index for an SSB-less SCell when adding the SSB-less SCell to the UE; determining a reference serving cell for the target SSB-less SCell; The one or more processors of claim 14 , further comprising selecting a reference serving cell based on the reference serving cell index.

18. The operation is The one or more processors of claim 14 , further comprising determining a type of the reference signal used by the reference serving cell.

19. The operation is 20. The one or more processors of claim 18, further comprising: selecting the SSB reference signal as a reference signal for use in the performing the RRM operation in the SSB-less SCell based on a determination that the reference signal used by the reference serving cell is an SSB reference signal.

20. The operation is receiving signaling from an access node configuring one or more SSB indices of a reference serving cell for the SSB-less SCell when adding the SSB-less SCell to the UE; determining a reference serving cell for the target SSB-less SCell; 15. The one or more processors of claim 14, further comprising: selecting the one or more SSBs of the reference serving cell indicated by the SSB index as reference signals for use in performing the RRM operation in the SSB-less SCell.

21. The operation is 19. The one or more processors of claim 18, further comprising: based on a determination that the reference signal used by the reference serving cell is a tracking reference signal (TRS) or a channel state information reference signal (CSI-RS), selecting, by the UE, the TRS or the CSI-RS as the reference signal for use in performing the RRM operation in the SSB-less SCell.

22. 22. The one or more processors of claim 21, wherein the selected TRS is an active TRS and the selected CSI-RS is a semi-persistent (SP) or periodic CSI-RS.

23. 22. The one or more processors of claim 21, wherein selection of the TRS as the reference signal takes priority over selection of the CSI-RS as the reference signal.

24. 22. The one or more processors of claim 21, wherein the CSI-RS is quasi-colocated (QCL) with another reference signal from the reference serving cell.

25. The operation is receiving signaling from an access node configuring one or more CSI-RS indices of reference serving cells for the SSB-less SCell when adding the SSB-less SCell to the UE; determining a reference serving cell for the target SSB-less SCell; 15. The one or more processors of claim 14, comprising selecting the CSI-RS as a reference signal for use in the performance of the RRM operation in the SSB-less SCell based on the CSI-RS index.

26. 26. The one or more processors of claim 25, wherein the selected CSI-RS is a semi-persistent (SP) or periodic CSI-RS.

27. 15. The one or more processors of claim 14, wherein the RRM operation includes: (i) L3 measurements for the target SSB-less SCell; (ii) activation of the target SSB-less SCell; (iii) time and frequency tracking (T / F tracking); or (iv) (AGC) estimation.

Images