Capability design for ssc-free carrier aggregation operation

Abstract

A user equipment (UE) configured to determine one or more band combinations that support a synchronization signal block (SSB)-free carrier aggregation (CA) operation, wherein, for the SSB-free carrier aggregation (CA) operation, the UE is configured to receive a first component carrier (CC) of the CA combination with a synchronization signal block (SSB) from a first serving cell and a second CC of the CA combination without an SSB from a second serving cell, and transmit capability information to a network, the capability information including an indication of the one or more band combinations that support the SSB-free CA operation.

Description

Technical Field

[0001] This application relates generally to wireless communication systems, and more particularly to the design of capabilities for SSB-free carrier aggregation operation. Background Technology

[0002] A synchronization signal block (SSB) is a reference (RS) sent by the base station and used by the user equipment (UE) for time and frequency synchronization with the cell. Therefore, silencing such an RS can cause the UE to become out of sync with the cell. However, when the UE and the network are communicating using carrier aggregation (CA), it may be beneficial if the secondary cell (SCell) could silence the SSB without the UE becoming out of sync with the SCell, for example, to save power. When one or more SCells have silenced the SSB during CA operation, this is referred to as SSB-free CA. Summary of the Invention

[0003] Some example implementations relate to an apparatus for a user equipment (UE) including processing circuitry configured to: determine one or more frequency band combinations that support SSB-free carrier aggregation (CA) operation, wherein, for the SSB-free carrier aggregation (CA) operation, the UE is configured to receive a first component carrier (CC) of the CA combination having a synchronization signal block (SSB) from a first serving cell and a second CC of the CA combination without an SSB from a second serving cell; and configure transceiver circuitry to transmit capability information to the network, the capability information including an indication of one or more frequency band combinations that support SSB-free CA operation.

[0004] Other example implementations relate to an apparatus for a base station, the apparatus including processing circuitry configured to: determine, for a user equipment (UE), reference information including a reference component carrier (CC), a frequency band of the reference CC, a reference synchronization signal block (SSB) frequency, or a reference SSB for performing SSB-free carrier aggregation (CA) operation; and decode capability information including an indication of one or more frequency band combinations supporting SSB-free CA operation based on signals received from the UE.

[0005] A further example embodiment relates to an apparatus for a base station, the apparatus including processing circuitry configured to: decode reference information, including a reference component carrier (CC), a frequency band of the reference CC, a reference synchronization block (SSB) frequency, or a reference SSB, based on a signal received from a user equipment (UE) to perform SSB-free carrier aggregation (CA) operation for the UE; and decode capability information, including an indication of one or more frequency band combinations supporting SSB-free CA operation, based on a signal received from the UE.

[0006] The additional example implementation relates to an apparatus for a base station, the apparatus including processing circuitry configured to: decode capability information, including indications of one or more frequency band combinations supporting asynchronous signal block (SSB) (SSB-free) carrier aggregation (CA) operation, based on signals received from a user equipment (UE), wherein during the SSB-free CA operation, a first serving cell transmits a first component carrier (CC) of the CA combination having an SSB and a second serving cell transmits a second CC of the CA combination without an SSB, wherein the capability information further includes a frequency domain (FD) separation threshold, the FD separation threshold indicating a value in the FD that is a distance from the SSB-free CC of the UE supporting the SSB-free CA operation; and determine, based on the capability information, a CC combination within one or more frequency band combinations that supports the SSB-free CA operation. Attached Figure Description

[0007] Figure 1 Example network layouts based on various example implementation schemes are shown.

[0008] Figure 2 Example user equipment (UE) based on various example implementation schemes is shown.

[0009] Figure 3 Example base stations based on various example implementation schemes are shown.

[0010] Figure 4 Example two-band combinations for SSB-free CA operation are shown according to various example implementations.

[0011] Figure 5 Example three-band combinations for SSB-free CA operation are shown according to various example implementations.

[0012] Figure 6A and Figure 6B An example three-band combination according to various example implementations is shown, wherein the UE can report a frequency domain (FD) separation threshold when reporting UE capabilities for operation without SSB CA.

[0013] Figure 7 Example methods for UE operation without SSB CA operation are shown according to various example implementations.

[0014] Figure 8 Example methods for base station operation without SSB CA are shown according to various example implementations. Detailed Implementation

[0015] The example implementation can be further understood by referring to the following description and related figures, in which similar elements have the same reference numerals. The example implementation involves one or more secondary cells (SCells) of a carrier aggregation (CA) combination silencing the synchronization signal block (SSB) when transmitting to the UE. More specifically, the example implementation involves the UE reporting capability information for SSB-free CA operation to the network on a per-band basis, and the network using this capability information to configure SSB-free CA operation for the UE.

[0016] The example implementation is described with reference to a UE. However, reference to the UE is provided for illustrative purposes only. The example implementation can be used with any electronic component capable of establishing a connection with an accessory device and configured with hardware, software, and / or firmware for exchanging information and data with the accessory device. Therefore, the UE described herein is used to represent any electronic component.

[0017] Example implementations are also described with reference to 5G New Radio (NR) networks. These example implementations can also be implemented in other types of networks, including but not limited to LTE networks, future evolutions of cellular protocols (e.g., 5G Advanced networks, 6G networks), or any other type of network.

[0018] The example implementation is also described with reference to carrier aggregation (CA). In CA, the UE can communicate with multiple cells of the network in the downlink (DL) or uplink (UL) to increase throughput. CA includes the UE being associated with a primary cell (PCell) and one or more secondary cells (SCells). Different frequency band combinations of CA can be served by the PCell and SCell. For example, the PCell can supply the UE with a first component carrier (CC) (e.g., CC1) of the CA frequency band combination, and the SCell can supply the UE with a second CC (e.g., CC2) of the CA frequency band combination. Therefore, in CA, both the PCell and the SCell are considered serving cells.

[0019] The example implementations provide a manner for a UE to report UE capability information for SSB-less CA operation on a per-band basis. The example implementations provide the UE and the network with sufficient information about the reported frequency band combinations so that both the UE and the network understand the component carrier (CC) combinations within the reported frequency band combinations that support SSB-less CA operation for this UE. Each of these example implementations will be described in more detail below.

[0020] Figure 1An example network arrangement 100 according to various example implementations is shown. Example network arrangement 100 includes a UE 110. UE 110 can be any type of electronic component configured to communicate via a network, such as a mobile phone, tablet computer, desktop computer, smartphone, embedded device, wearable device, Internet of Things (IoT) device, etc. A real network arrangement may include any number of UEs used by any number of users. Therefore, for illustrative purposes, only an example of UE 110 is provided.

[0021] UE 110 can be configured to communicate with one or more networks. In the example of network deployment 100, the network with which UE 110 can wirelessly communicate is the 5G NR Radio Access Network (RAN) 120. However, UE 110 can also communicate with other types of networks (e.g., 5G cloud RAN, next-generation RAN (NG-RAN), legacy cellular networks, etc.), and UE 110 can also communicate with the network via a wired connection. Referring to the example implementation, UE 110 can establish a connection with 5G NR RAN 120. Therefore, UE 110 may have a 5G NR chipset to communicate with NR RAN 120.

[0022] 5G NR RAN 120 can be part of a cellular network that can be deployed by network operators (e.g., Verizon, AT&T, T-Mobile, etc.). RAN 120 can include cells or base stations configured to transmit and receive services from UEs equipped with appropriate cellular chipsets. In this example, 5G NR RAN 120 includes gNB 120A and gNB 120B. However, the reference to gNB is provided merely for illustrative purposes, and any appropriate base station or cell can be deployed (e.g., Node B, eNodeB, HeNB, eNB, gNB, gNodeB, macro cell, micro cell, small cell, femtocell, etc.).

[0023] Any association procedure can be performed to connect UE 110 to 5G NR RAN 120. For example, as described above, 5G NR RAN 120 can be associated with a specific network operator, where UE 110 and / or its user have contract and credential information (e.g., stored on a Subscriber Identity Module (SIM) card or an embedded SIM (eSIM)). Upon detecting the presence of 5G NR RAN 120, UE 110 can send the corresponding credential information to associate with 5G NR RAN 120. More specifically, UE 110 can be associated with a specific cell (e.g., gNB 120A).

[0024] In this example, UE 110 can be considered to be operating in CA mode, where gNB 120A is the PCell and gNB 120B is the SCell that will operate in SSB-less mode. As mentioned above, CA mode can include multiple SCells, but for descriptive purposes, only a single SCell is shown. In the example implementation, the PCell and SCell can be considered to be co-located, for example, in the same general physical location (e.g., on the same cell tower). However, it is not required that the PCell and SCell be co-located. Furthermore, although the PCell and SCell are shown as different gNBs, a single gNB can include multiple cells. Therefore, the PCell and SCell can be cells of the same gNB.

[0025] Network deployment 100 also includes a cellular core network 130, an Internet 140, an IP Multimedia Subsystem (IMS) 150, and a network services backbone 160. The cellular core network 130 manages traffic flowing between the cellular network and the Internet 140. The IMS 150 can generally be described as an architecture for delivering multimedia services to the UE 110 using IP protocols. The IMS 150 can communicate with the cellular core network 130 and the Internet 140 to provide multimedia services to the UE 110. The network services backbone 160 communicates directly or indirectly with the Internet 140 and the cellular core network 130. The network services backbone 160 can generally be described as a collection of components (e.g., servers, network storage deployments, etc.) that implement a set of services that can be used to extend the functionality of the UE 110 in communicating with various networks.

[0026] Figure 2 Example UE 110 according to various example implementations is shown. (Refer to...) Figure 1 The network layout 100 is used to describe UE 110. UE 110 can represent any electronic device and may include processor 205, memory layout 210, display device 215, input / output (I / O) device 220, transceiver 225, and other components 230. Other components 230 may include, for example, audio input devices, audio output devices, batteries providing limited power, data acquisition devices, ports for electrically connecting UE 110 to other electronic devices, sensors for detecting the status of UE 110, etc.

[0027] Processor 205 may be configured to execute multiple engines of UE 110. For example, an engine may include an SSB-less CA capability engine 235 for performing operations related to SSB-less CA operation. These operations include, but are not limited to, determining reference information related to SCells for SSB-less CA operation, determining the frequency band combination and / or CC combination that supports SSB-less CA operation for this UE, and reporting SSB-less CA capability information to the network on a per-frequency band basis. Each of these example operations, as well as others, will be described in more detail below.

[0028] The engines described above, as applications (e.g., programs) executed by processor 205, are merely exemplary. The functionality associated with these engines can also be represented as separate, combined components of UE 110, or as modular components coupled to UE 110, such as integrated circuits with or without firmware. For example, the integrated circuit may include input circuitry for receiving signals and processing circuitry for processing signals and other information. The engine can also be embodied as one or more separate applications. Furthermore, in some UEs, the functionality described for processor 205 is split between two or more processors, such as a baseband processor and an application processor. Example implementations can be implemented according to any of these or other configurations of the UE.

[0029] Memory arrangement 210 may be a hardware component configured to store data related to operations performed by UE 110. Display device 215 may be a hardware component configured to display data to a user, while I / O device 220 may be a hardware component enabling a user to input data. Display device 215 and I / O device 220 may be separate components or may be integrated together (such as a touchscreen).

[0030] Transceiver 225 may be a hardware component configured to establish a connection with 5G-NR RAN 120. Therefore, transceiver 225 may operate on a variety of different frequencies or channels (e.g., a continuous set of frequencies). Transceiver 225 includes circuitry configured to transmit and / or receive signals (e.g., control signals, data signals). Such signals may be encoded using information used to implement any of the methods described herein. Processor 205 may be operatively coupled to transceiver 225 and configured to receive signals from and / or transmit signals to transceiver 225. Processor 205 may be configured to encode and / or decode signals (e.g., signaling from a base station in the network) for use in implementing any of the methods described herein.

[0031] Figure 3An example base station 300 is shown according to various example implementations. Base station 300 may represent a gNB 120A, gNB 120B, or any other access node that UE 110 can use to establish connections and manage network operations.

[0032] Base station 300 may include processor 305, memory arrangement 310, input / output (I / O) devices 315, transceiver 320, and other components 325. These other components 325 may include, for example, audio input devices, audio output devices, batteries, data acquisition devices, ports for electrically connecting base station 300 to other electronic devices and / or power sources, etc.

[0033] Processor 305 may be configured to execute multiple engines of UE 110. For example, an engine may include an SSB-free CA engine 330 for performing operations related to configuring the UE for SSB-free CA operation. These operations include, but are not limited to, determining reference information for the UE related to SCells used for SSB-free CA operation, receiving SSB-free CA capability information from the UE on a per-band basis, and determining CC combinations within a band combination that support SSB-free CA operation for this UE. Each of these example operations, as well as others, will be described in more detail below.

[0034] The memory arrangement 310 may be a hardware component configured to store data related to operations performed by the base station 300. The I / O device 315 may be a hardware component or port that enables a user to interact with the base station 300.

[0035] Transceiver 320 may be a hardware component configured to exchange data with UE 110 and any other UE in network arrangement 100. Transceiver 320 may operate on a variety of different frequencies or channels (e.g., a continuous set of frequencies). Therefore, transceiver 320 may include one or more components (e.g., radio components) to enable data exchange with various networks and UEs. Transceiver 320 includes circuitry configured to transmit and / or receive signals (e.g., control signals, data signals). Such signals may be encoded using information used to implement any of the methods described herein. Processor 305 may be operatively coupled to transceiver 320 and configured to receive signals from and / or transmit signals to transceiver 320. Processor 305 may be configured to encode and / or decode signals (e.g., signaling from a UE) for use in implementing any of the methods described herein.

[0036] Before describing the example implementation, a general overview of SCell operation in the presence of a silent SSB (e.g., operation without an SSB) is provided. The SSB is used by the UE to maintain time and frequency synchronization with the cell, including downlink automatic gain control (AGC). Therefore, by making the SSB silent, the SCell may risk the UE becoming out of sync with the SCell.

[0037] When the SCell is operating in SSB-free mode, UE 110 can reuse synchronization information from the serving cell serving CC for the CA band combination. Specifically, in the provided examples, PCell 120A is assumed to be serving CC1, and SCell 120B is assumed to be serving CC2 in the CA band combination CC1+CC2. Therefore, in these examples, SCell 120B is assumed to be operating in SSB-free mode, and when UE 110 reuses synchronization information from the serving cell, the serving cell is PCell 120A.

[0038] The PCell serving cell in an inter-band configuration is merely an example. As mentioned above, when operating in a CA, the PCell and one or more SCells are considered serving cells. For example, consider a 3 CC band combination where PCell serves CC1, SCell 1 serves CC2, and SCell 2 serves CC3. When SCell 1 operates in SSB-free mode, the UE can reuse synchronization information from either PCell or SCell 2 (e.g., a reference to an inter-band serving cell could be a reference to either PCell or SCell 2). Therefore, while the example implementation describes the PCell as a serving cell, it does not require the serving cell to be a PCell.

[0039] As described above, UE 110 can report its ability to support SSB-less CA operation. In some example implementations, this UE capability can be reported on a per-band combination basis. For example, UE 110 can report the frequency bands on which UE 110 is capable of supporting SSB-less CA operation. Reporting this capability on a per-band basis can have certain advantages, such as reduced signaling overhead compared to reporting UE capabilities on a more granular basis (e.g., per CC combination). However, some problems may arise when reporting UE capabilities for SSB-less CA operation on a per-band basis. (Reference) Figure 4 and Figure 5 Describe some example problems that may occur.

[0040] Figure 4An example two-band combination 400 for SSB-free CA operation is illustrated according to various example embodiments. In this example, the band combination can be considered as band 1 410 + band 2 440. Each band can have a large frequency range, for example, up to 1 GHz. Within this band combination, one or more CC combinations can exist as CA CC combinations. In this example, the band combination of band 1 410 + band 2 440 can be considered to include the following CC combinations: CC1 420 + CC4 460 and CC2 430 + CC3 450.

[0041] Therefore, when UE 110 is determining whether it supports SSB-free CA operation on a per-band basis, UE 110 can identify different CC combinations supported by the band combinations. In this example, UE 110 can determine that the frequency domain (FD) separation between CC2 420 + CC3 450 is small enough that UE 110 can support SSB-free SCell operation for this CC combination. On the other hand, UE 110 can determine that the FD separation between CC1 420 + CC4 460 is too large to support SSB-free CA operation for this CC combination. In this scenario, UE 110 can report that it does not support SSB-free CA operation for the band combination of band 1 410 + band 2 440 because there are one or more CC combinations that do not support SSB-free CA operation, such as CC1 420 + CC4 460. Therefore, even if there are one or more supported CC combinations (e.g., CC2 420 + CC3 450) within the band 1 410 + band 2 440 combination, UE 110 will report that it does not support SSB-free CA operation for the entire band 1 410 + band 2 440 combination.

[0042] Figure 5 An example three-band combination for SSB-free CA operation is shown according to various example embodiments. In this example, the band combination can be considered as band 1 510 + band 2 520 + band 3 530. Within this band combination, one or more CC combinations as CA CC combinations may exist. In this example, band combination 500 can be considered to include the following CC combination: CC1 515 + CC2 525 + CC3 535.

[0043] In the first example of band combination 500, for the CC combination CC1 515 + CC2 525 + CC3 535, CC2 525 can be considered as the reference CC. For example, the serving cell serving CC2 is transmitting an SSB, while CC1 515 and CC3 535 are transmitted by an SSB-free SCell. In this example, UE 110 can determine that the FD separation between CC2 525 and CC1 515, and between CC2 and CC3 535, is small enough that UE 110 can support SSB-free CA operation for this CC combination. However, in the second example of band combination 500, for the CC combination CC1 515 + CC2 525 + CC3 535, CC1 515 can be considered as the reference CC. For example, the serving cell serving CC1 is transmitting an SSB, while CC2 525 and CC3 535 are transmitted by an SSB-free SCell. In this example, UE 110 may determine that the FD separation between CC1 515 and CC2 525 is small enough that UE 110 can support SSB-less CA operation for these CCs, but the FD separation between CC1 515 and CC3 535 is too large to support SSB-less CA operation. Therefore, UE 110 may again report that UE 110 does not support band combination 500 because there is a CC combination and / or reference CC within the CC combination that does not support SSBCA operation.

[0044] The example implementation provides a UE capability reporting design that supports SSB-less CA operation on a per-band basis, addressing the example issues mentioned above and others. The example implementation takes into account both signaling overhead and indication accuracy associated with UE capability reporting. These exemplary implementations will be described in more detail below.

[0045] In some example implementations, a CC or frequency band can be used as a reference CC, and UE capability reports can be made on a per-band basis, with that CC then used as the reference CC. The CC used as the reference CC can be defined by the UE 110, defined by the network, or predefined in standard documents (e.g., 3GPP technical specifications TS 38.331, 38.306).

[0046] The network may indicate a reference CC, reference band, reference SSB frequency, or reference SSB to UE 110. This indication may be provided to UE 110 by a base station (e.g., PCell, such as gNB 120A) before or during SSB-free CA configuration. SSB-free CA configuration can be performed using Radio Resource Control (RRC) signaling, and therefore, the reference indication may also be provided via RRC signaling. However, in some example implementations, the reference indication (e.g., reference CC, reference band, reference SSB frequency, or reference SSB) may be provided via other types of signaling such as Medium Access Control Element (MAC-CE) signaling, Downlink Control Information (DCI) signaling, etc.

[0047] UE 110 receives this reference information (e.g., reference CC, reference frequency band, reference SSB frequency, or reference SSB), and can then determine which frequency bands are available for SSB-free CA operation, and UE 110 can then report this capability to the network. Figure 5 For example, the reference information may have indicated that CC2 525, band 2 520, the SSB frequency associated with CC2 525, or the SSB associated with CC2 525 is a reference. Therefore, UE 110 understands that... Figure 5 In the example, CC2 525 is the reference CC for the CC combination CC1 515 + CC2 525 + CC3 535. In this example, when CC2 525 is the reference CC, UE 110 supports SSB-less CA operation for this combination. Therefore, in this example, when reporting UE capabilities, UE 110 can report that the UE supports SSB-less CA operation for band combination 500 (e.g., band 1 510 + band 2 520 + band 3 530) because UE 110 understands that CC2 525 is the reference CC.

[0048] To provide another example, UE 110 may support five (5) frequency bands, for example, frequency bands 1 / 2 / 3 / 4 / 5. UE 110 may receive reference information indicating that frequency band 1 is a reference CC or frequency band for SSB-free CA operation. UE 110 may use this information to determine which supported frequency bands are available for SSB-free CA operation. For example, based on this information, UE 110 may determine that frequency bands 2 and 3 are available for SSB-free CA operation with frequency band 1 as the reference frequency band. Therefore, UE 110 may report the UE capabilities for SSB-free CA operation on a per-band basis as, for example, frequency band 1 + frequency band 2, frequency band 1 + frequency band 3, and frequency band 1 + frequency band 2 + frequency band 3.

[0049] In the second example of the UE using the reference information, the network may or may not request UE 110 to report its ability to operate without SSBCA. For example, the network may explicitly request UE 110 to provide UE capability information related to operating without SSBCA. On the other hand, UE 110 may provide UE capability information related to operating without SSBCA without an explicit request from the network (e.g., when connected to the network).

[0050] In this example, UE 110 may select and / or indicate a reference frequency band, CC, SSB frequency, or SSB. Based on the indicated reference information, UE 110 may then report UE capability information on a per-band basis for SSB-free CA operation. The example provided above for network provisioning reference information will also apply to the reference information selected / indicated by this UE, provided that UE 110 selects / indicates the same reference information as described in the example.

[0051] In these example implementations, UE 110 may indicate multiple combinations based on the selection of different reference information. For example, consider the example provided above where UE 110 may support five (5) frequency bands (e.g., bands 1 / 2 / 3 / 4 / 5). UE 110 may indicate reference information indicating that CC1 of band 1 or band 1 is a reference CC or band for SSB-free CA operation. As described above, when CC1 of band 1 or band 1 is reference information, UE 110 may report UE capabilities for SSB-free CA operation on a per-band basis as, for example, band 1 + band 2, band 1 + band 3, and band 1 + band 2 + band 3. On the other hand, UE 110 may also indicate that CC3 of band 3 or band 3 is a reference CC or band for SSB-free CA operation. In this scenario, UE 110 may determine that bands 2 and 5 are available for SSB-free CA operation with band 3 as the reference band. Therefore, UE 110 can report UE capabilities for SSB-free CA operation on a per-band basis as, for example, band 3 + band 2, band 3 + band 5, and band 3 + band 2 + band 5. In this example, UE 110 can report two capabilities, for example, with band 1 as the reference band and with band 3 as the reference band.

[0052] In the third example of UE using reference information, the reference information may be based on predefined rules provided, for example, by standards such as 3GPP technical specifications (e.g., TS 38.331, 38.306). These predefined rules may indicate to the UE and network which cell, CC, or frequency band is the reference band for the purpose of reporting on the UE's capabilities without SSBCA operation.

[0053] The first example rule could be that the primary component carrier (PCC) or the PCC band is a reference CC or band. The second example rule could be that the secondary component carrier (PSCC) or the PSCC band is a reference CC or band. When the UE is able to perform EUTRA NR dual connectivity (ENDC) operation, the PSCC can be the strongest NR cell.

[0054] A third example rule could be that the active SCC that transmits with an SSB and has the highest signal strength / quality within the active secondary component carrier (SCC) or its frequency band is the reference CC or frequency band. A fourth example rule could be that the closest active SCC with an SSB in the frequency domain is the reference CC or frequency band. For example, if only one active SCC with an SSB exists, that SCC is defined as the closest active SCC with an SSB in the frequency domain. On the other hand, if multiple active SCCs with SSBs exist, the UE 110 can select the SCC closest to the target SCC in the frequency domain as the reference CC or frequency band. For example, the network can provide the center frequency of each SCC (e.g., active, target), and the UE can use this information to select the closest active SCC with an SSB in the frequency domain.

[0055] The rules above are merely examples, and other rules can be defined for selecting a reference CC or frequency band. Furthermore, these rules can be applied individually or in combination (e.g., in a hierarchical manner) when used to select a reference CC or frequency band.

[0056] UE 110 can apply these rules to determine the reference CC or frequency band, and then determine the per-band combination that supports SSB-free CA operation. UE 110 can then indicate to the network, on a per-band basis, the UE's capabilities regarding SSB-free operation.

[0057] Continuing with the example provided above, UE 110 can support five (5) frequency bands (e.g., bands 1 / 2 / 3 / 4 / 5). UE 110 can determine, based on predefined rules, that CC1 of band 1 or band 1 is a reference CC or band for SSB-free CA operation, for example, CC1 or band 1 is a PCC or PCC band. UE 110 can use this information to determine which supported frequency bands are available for SSB-free CA operation. For example, based on this information, UE 110 can determine that bands 2 and 3 are available for SSB-free CA operation with band 1 as a reference band. Therefore, UE 110 can report the UE capabilities for SSB-free CA operation on a per-band basis as, for example, band 1 + band 2, band 1 + band 3, and band 1 + band 2 + band 3.

[0058] In an example scenario where only one serving CC with an SSB exists for UE 110 (e.g., only one CC is transmitted with an SSB), UE 110 can select that CC or frequency band as the reference CC because it is the only CC with an SSB. In this scenario, if the example of the network providing reference information is implemented, the network does not need to provide any signaling to UE 110 because UE 110 will implicitly understand that there is only a single possibility for the reference CC or frequency band. Similarly, if UE 110 is selecting and indicating reference information, UE 110 does not need to provide any signaling to the network because both UE 110 and the network will implicitly understand that there is only a single possibility for the reference CC or frequency band. This implies a third example of applying UE use of reference information in this scenario.

[0059] In the example scenario where UE 110 has multiple serving CCs with SSBs, the signaling solutions of the first or second example using reference information can be used. In one case of this example scenario, the network can provide reference information as described in the first example above. In another case of this example scenario, UE 110 can send reference information to the network by signaling as described in the second example above.

[0060] In other example implementations, UE 110 may report to the network the maximum set of frequency bands or CC combinations and frequency domain (FD) separation. The maximum set of frequency bands or CC combinations means that UE 110 supports SSB-free CA operation using at least a subset or the entire set of that frequency band / CC combination. For example, refer to... Figure 4 and Figure 5 If UE 110 is deemed to support at least a subset of CC combinations for band combination 400 and band combination 500, then UE 110 may report band combination 500, as it represents the maximum set of bands or CC combinations, for example, 3 bands instead of 2 bands of band combination 400.

[0061] Figure 6A and Figure 6B Example tri-band combinations 600 and 650 according to various example implementation schemes are shown, wherein the UE can report the FD separation threshold when reporting UE capabilities for SSB CA operation. Figure 6A and Figure 6B Similar to Figure 5 .exist Figure 6AIn the example, the frequency band combination can be considered as frequency band 1 610 + frequency band 2 620 + frequency band 3 630. Within this frequency band combination, there can be one or more CC combinations as CA CC combinations. In this example, frequency band combination 600 can be considered to include the following CC combination: CC1 615 + CC2 625 + CC3 635. In this example, CC1 615 and CC3 635 are also shown to be transmitted without SSB, while CC2 625 is transmitted with SSB.

[0062] As described above, in these example implementations, UE 110 can be considered to have identified band combination 600 as the largest band or CC combination set, and therefore, band combination 600 can be reported by UE 110 to the network. As described above, in these example implementations, UE 110 will also report FD separation thresholds, such as FD separation 640. The FD separation threshold indicates to the network the separation in the FD for which the UE will support SSB-free CA operation. For example, if the distance of a CC that does not include an SSB and the distance of a CC that transmits an SSB are within the FD separation threshold, then the UE will support SSB-free CA operation for these CCs. If the distance of a CC that does not include an SSB and the distance of a CC that transmits an SSB are outside the FD separation threshold, then the UE will not support SSB-free CA operation for these CCs. Therefore, in these example implementations, the network will understand which CC combinations are supported by UE 110 based on the reported SSB-free CA operation combinations and FD separations per band.

[0063] refer to Figure 6A UE 110 reports frequency band combinations 600 (e.g., the maximum frequency band or CC combination set) and FD separation threshold 640 to the network. The network can use this information to understand the different CC combinations within the frequency band combinations 600 supported by the UE. Figure 6A As shown, CC2 625 is transmitted with an SSB. CC1 615, transmitted without an SSB, is within the FD separation threshold 640 of CC2 625, and therefore, the network understands that UE 110 supports the CA combination of CC2 625 + CC1 615. Additionally, CC3 635, transmitted without an SSB, is also within the FD separation threshold 640 of CC2 625, and therefore, the network understands that UE 110 also supports the CA combination of CC2 625 + CC3 635. Furthermore, this also implies that UE 110 will support the CA combination of CC1 615 + CC2 625 + CC3 635.

[0064] exist Figure 6BIn the example, the frequency band combination can be considered as frequency band 1 660 + frequency band 2 670 + frequency band 3 680. Within this frequency band combination, there can be one or more CC combinations as CA CC combinations. In this example, frequency band combination 650 can be considered to include the following CC combination: CC1 665 + CC2 675 + CC3 685. In this example, CC2 675 and CC3 685 are also shown to be transmitted without SSB, however, CC1 665 is transmitted with SSB.

[0065] Similar to Figure 6A ,exist Figure 6B In the example, UE 110 reports band combination 650 (e.g., the maximum band or CC combination set) and FD separation threshold 690 to the network. The network can use this information to understand the different CC combinations within the band combination 600 supported by the UE. Figure 6A As shown, CC1 665 is transmitted with an SSB. CC2 675, transmitted without an SSB, is within the FD separation threshold 690 of CC1 665, and therefore, the Network Understanding UE 110 supports the CA combination of CC1 665 + CC2 675. In contrast, CC3 685, transmitted without an SSB, is outside the FD separation threshold 690 of CC1 665, and therefore, the Network Understanding UE 110 does not support any CA combination including CC1 665 and CC3 685.

[0066] As can be seen from the examples above, even when some CC combinations within a band combination are not supported, the use of the FD separation threshold allows UE 110 to report the band combination as a combination that supports SSB CA operation. Figure 6B In the example, even if a specific CC combination of CC1 665 + CC3 685 is not supported, UE 110 can still report band combination 650 as a band combination that supports CA operation without SSB. This is because the network can determine the CC combination within band combination 650 that supports CA operation without SSB by using the CA capability information provided by UE 110 and an understanding of which CCs are transmitted with and without SSB.

[0067] Figure 7 An example method 700 for UE 110 operation without SSB CA is illustrated according to various example embodiments. In 710, UE 110 may determine one or more frequency band combinations that UE 110 supports without SSB CA on a per-band basis. As mentioned above, in some example embodiments, this determination is made based on reference information (e.g., a reference CC, the frequency band of the reference CC, a reference SSB frequency, or a reference SSB).

[0068] In some examples, reference information may be provided to UE 110 by the network (e.g., by BS 300, components of core network 130, etc.). In other examples, reference information may be selected by UE 110 and reported to the network. In still other examples, the UE and the network may determine the reference information based on one or more predefined rules (e.g., as encoded in standard documents such as 3GPP technical specifications).

[0069] In 720, UE 110 uses UE capability information reports for SSB-free CA operation to report one or more frequency band combinations to the network. In some example implementations, UE 110 may include an FD separation threshold along with the UE capability information. The FD separation threshold indicates to the network the separation of the FD from the CCs that include the SSBs within which UE 110 supports SSB-free CA operation, for example, supporting CA using CCs that do not include the SSBs.

[0070] In 730, it is assumed that UE 110 has provided a UE capability information report including at least one supported frequency band combination. When the network configures UE 110 to operate in such a way, UE 110 and the network can communicate using SSB-free CA operation.

[0071] Figure 8 An example method 800 for base station 300 operation without SSB CA is illustrated according to various example embodiments. In 810, base station 300 may determine reference information for UE 110, such as a reference CC, the frequency band of the reference CC, a reference SSB frequency, or a reference SSB, to perform SSB-free CA operation.

[0072] In some examples, the reference information may be determined by base station 300 and provided to UE 110, for example, via RRC signaling. In other examples, the reference information may be selected by UE 110 and reported to base station 300. In still other examples, base station 300 and UE 110 may determine the reference information based on one or more predefined rules (e.g., as encoded in standard documents such as 3GPP technical specifications).

[0073] In 820, base station 300 receives a UE capability information report from UE 110, including one or more frequency band combinations in which UE 110 supports CA operation without SSB. In some example implementations, UE 110 may include an FD separation threshold along with the UE capability information. The FD separation threshold indicates to base station 300 the separation of a CC within an FD that includes an SSB, within which UE 110 supports CA operation without SSB, for example, by supporting CA using a CC that does not include an SSB. The base station may use reference information and / or the UE capability information to determine the CC combinations within one or more frequency band combinations that support CA operation without SSB for this UE 110.

[0074] In 830, assuming that UE 110 has provided a UE capability information report including at least one supported frequency band combination, when base station 300 configures UE 110 to operate in such a way, base station 300 and UE 110 can communicate using SSB-free CA operation.

[0075] Example In a first embodiment, a method performed by a user equipment (UE) includes: determining one or more frequency band combinations that support SSB-free carrier aggregation (CA) operation, wherein, for the SSB-free carrier aggregation (CA) operation, the UE is configured to receive a first component carrier (CC) of the CA combination having a synchronization signal block (SSB) from a first serving cell and a second CC of the CA combination without an SSB from a second serving cell; and transmitting capability information to a network, the capability information including an indication of the one or more frequency band combinations that support the SSB-free CA operation.

[0076] In the second embodiment, according to the method of the first embodiment, the one or more frequency band combinations supporting the SSB-free CA operation are determined based on reference information including a reference CC, a frequency band of the reference CC, a reference SSB frequency, or a reference SSB.

[0077] In a third embodiment, according to the method described in the second embodiment, the method further includes: decoding the reference information based on signals received from the network.

[0078] In the fourth embodiment, according to the method of the third embodiment, the reference information is received from the network before or during the SSB CA configuration.

[0079] In the fifth embodiment, according to the method of the third embodiment, the reference information is received via Radio Resource Control (RRC) signaling.

[0080] In a sixth embodiment, according to the method described in the second embodiment, the method further includes: determining the reference information; and sending the reference information to the network.

[0081] In the seventh embodiment, according to the method of the sixth embodiment, the reference information includes first reference information for determining a first frequency band combination that supports the SSB-free CA operation and second reference information for determining a second frequency band combination that supports the SSB-free CA operation, wherein the first frequency band combination and the second frequency band combination are different frequency band combinations.

[0082] In the eighth embodiment, according to the method described in the second embodiment, the method further includes: determining the reference information based on predefined rules.

[0083] In the ninth embodiment, according to the method of the eighth embodiment, the predefined rule includes determining the reference information based on the following: (i) the primary CC (PCC), (ii) the frequency band of the PCC, (iii) the primary secondary CC (PSCC), (iv) the frequency band of the PSCC, (v) the active SCC with SSB that has the highest signal strength or quality among the secondary CCs (SCCs), (vi) the frequency band of the active SCC with SSB that has the highest signal strength or quality among the SCCs, or (vii) the active SCC with SSB that has a frequency closest to the frequency of the target SCC.

[0084] In the tenth embodiment, according to the method of the first embodiment, the capability information further includes a frequency domain (FD) separation threshold, the FD separation threshold indicating the value of the CC with SSB in the FD that the UE supports the SSB-free CA operation.

[0085] In the eleventh embodiment, according to the method of the tenth embodiment, the capability information includes one or more frequency band combinations that support the SSB-free CA operation for the maximum frequency band or CC combination set.

[0086] In the twelfth embodiment, a processor is configured to perform any one of the methods described according to the first to eleventh embodiments.

[0087] In a thirteenth embodiment, a user equipment (UE) includes: a transceiver configured to communicate with a network; and a processor communicatively coupled to the transceiver and configured to perform any one of the methods described according to the first to eleventh embodiments.

[0088] In a fourteenth embodiment, a method performed by a base station includes: determining, for a user equipment (UE), reference information including a reference component carrier (CC), a frequency band of the reference CC, a reference synchronization block (SSB) frequency, or a reference SSB for performing SSB-free carrier aggregation (CA) operation; and decoding, based on signals received from the UE, capability information including an indication of one or more frequency band combinations supporting the SSB-free CA operation.

[0089] In the fifteenth embodiment, according to the method of the fourteenth embodiment, the method further includes: sending the reference information to the UE.

[0090] In the sixteenth embodiment, according to the method of the fifteenth embodiment, the reference information is sent before or during the SSBCA-free configuration.

[0091] In the seventeenth embodiment, according to the method described in the fourteenth embodiment, the method further includes: determining the reference information based on predefined rules.

[0092] In the eighteenth embodiment, according to the method of the seventeenth embodiment, the predefined rule includes determining the reference information based on the following: (i) the primary CC (PCC), (ii) the frequency band of the PCC, (iii) the primary secondary CC (PSCC), (iv) the frequency band of the PSCC, (v) the active SCC with SSB that has the highest signal strength or quality among the secondary CCs (SCCs), (vi) the frequency band of the active SCC with SSB that has the highest signal strength or quality among the SCCs, or (vii) the active SCC with SSB that has a frequency closest to the frequency of the target SCC.

[0093] In the nineteenth embodiment, a processor is configured to perform any one of the methods described according to the fourteenth to eighteenth embodiments.

[0094] In a twentieth embodiment, a base station includes: a transceiver configured to communicate with a user equipment (UE); and a processor communicatively coupled to the transceiver and configured to perform any one of the methods described in embodiments fourteen through eighteen.

[0095] In a twenty-first embodiment, a method performed by a base station includes: decoding reference information, including a reference component carrier (CC), a frequency band of a reference CC, a reference synchronization block (SSB) frequency, or a reference SSB, based on a signal received from a user equipment (UE) to perform SSB-free carrier aggregation (CA) operation for the UE; and decoding capability information, including an indication of one or more frequency band combinations supporting the SSB-free CA operation, based on a signal received from the UE.

[0096] In the twenty-second embodiment, a processor is configured to perform the method according to the twenty-first embodiment.

[0097] In a twenty-third embodiment, a base station includes: a transceiver that communicates with a user equipment (UE); and a processor communicatively coupled to the transceiver and configured to perform the method according to the twenty-first embodiment.

[0098] In a twenty-fourth embodiment, a method performed by a base station includes: decoding capability information, based on a signal received from a user equipment (UE), including indications of one or more frequency band combinations supporting asynchronous signal block (SSB) (SSB-free) carrier aggregation (CA) operation, wherein during the SSB-free CA operation, a first serving cell transmits a first component carrier (CC) of the CA combination having an SSB and a second serving cell transmits a second CC of the CA combination without an SSB, wherein the capability information further includes a frequency domain (FD) separation threshold, the FD separation threshold indicating a value in the FD that is distance from the SSB-free CC of the UE supporting the SSB-free CA operation; and determining, based on the capability information, CC combinations within the one or more frequency band combinations that support the SSB-free CA operation.

[0099] In the twenty-fifth embodiment, according to the method of the twenty-fourth embodiment, the capability information includes support for one or more frequency band combinations without SSB CA for the maximum frequency band or CC combination set.

[0100] In the twenty-sixth embodiment, a processor is configured to perform any one of the methods described according to the twenty-fourth to twenty-fifth embodiments.

[0101] In the twenty-seventh embodiment, a base station includes: a transceiver configured to communicate with a user equipment (UE); and a processor communicatively coupled to the transceiver and configured to perform any one of the methods described according to the twenty-fourth to twenty-fifth embodiments.

[0102] Those skilled in the art will understand that the example embodiments described above can be implemented with any suitable software or hardware configuration or combination thereof. Example hardware platforms for implementing the example embodiments may include, for example, Intel x86-based platforms with compatible operating systems, Windows OS, Mac platforms and MAC OS, and mobile devices with operating systems such as iOS, Android, etc. Example embodiments of the methods described above may be embodied as programs containing lines of code stored on a non-transitory computer-readable storage medium, which, at compile time, can be executed on a processor or microprocessor.

[0103] Although this application describes various embodiments that have different features in various combinations, those skilled in the art will understand that any feature of one embodiment can be combined with features of other embodiments in any way that is not expressly denied or that is not functionally or logically inconsistent with the operation of the device or the specified function of the disclosed embodiment.

[0104] As is widely recognized, the use of personally identifiable information should comply with privacy policies and practices that are generally accepted to meet or exceed industry or governmental requirements for protecting user privacy. Specifically, personally identifiable information data should be managed and processed to minimize the risk of unintentional or unauthorized access or use, and the nature of authorized use should be clearly explained to users.

[0105] It will be apparent to those skilled in the art that various modifications can be made to this disclosure without departing from its spirit or scope. Therefore, this disclosure is intended to cover modifications and variations thereof, provided they fall within the scope of the appended claims and their equivalents.

Claims

1. An apparatus for a user equipment (UE), the apparatus comprising processing circuitry configured to: Identify one or more frequency band combinations that support SSB-free carrier aggregation (CA) operation, wherein, For the SSB-free carrier aggregation (CA) operation, the UE is configured to receive a first component carrier (CC) with a synchronization signal block (SSB) of the CA combination from a first serving cell and a second CC without an SSB of the CA combination from a second serving cell; as well as The transceiver circuitry is configured to send capability information to the network, the capability information including indications of one or more frequency band combinations that support the SSB-free CA operation.

2. The apparatus of claim 1, wherein the one or more frequency band combinations supporting the SSB-free CA operation are determined based on reference information including a reference CC, a frequency band of the reference CC, a reference SSB frequency, or a reference SSB.

3. The apparatus of claim 2, wherein the processing circuit is further configured to: The reference information is decoded based on signals received from the network.

4. The apparatus of claim 3, wherein the reference information is received from the network before or during the absence of an SSB CA configuration.

5. The apparatus of claim 3, wherein the reference information is received via Radio Resource Control (RRC) signaling.

6. The apparatus of claim 2, wherein the processing circuit is further configured to: Determine the reference information; and Configure the transceiver circuitry to send the reference information to the network.

7. The apparatus of claim 6, wherein the reference information includes first reference information for determining a first frequency band combination supporting the SSB-free CA operation and second reference information for determining a second frequency band combination supporting the SSB-free CA operation, wherein the first frequency band combination and the second frequency band combination are different frequency band combinations.

8. The apparatus of claim 2, wherein the processing circuit is further configured to: The reference information is determined based on predefined rules.

9. The apparatus of claim 8, wherein the predefined rule comprises determining the reference information based on: (i) the primary CC (PCC), (ii) the frequency band of the PCC, (iii) the primary secondary CC (PSCC), (iv) the frequency band of the PSCC, (v) the active SCC with SSB that has the highest signal strength or quality among the secondary CCs (SCCs), (vi) the frequency band of the active SCC with SSB that has the highest signal strength or quality among the SCCs, or (vii) the active SCC with SSB that has a frequency closest to the frequency of the target SCC.

10. The apparatus of claim 1, wherein the capability information further includes a frequency domain (FD) separation threshold, the FD separation threshold indicating a value in the FD of the distance between the UE and the CC with SSB supporting the SSB-free CA operation.

11. The apparatus of claim 10, wherein the capability information includes the one or more frequency band combinations that support the SSB-free CA operation for the maximum frequency band or CC combination set.

12. An apparatus for a base station, the apparatus comprising processing circuitry configured to: Determine reference information, including the reference component carrier (CC), the frequency band of the reference CC, the frequency of the reference synchronization signal block (SSB), or the reference SSB, for use in SSB-free carrier aggregation (CA) operations for user equipment (UE); and Based on the signals received from the UE, capability information is decoded, the capability information including an indication of one or more frequency band combinations that support the SSB-free CA operation.

13. The apparatus of claim 12, wherein the processing circuit is further configured to: The transceiver circuit is configured to send the reference information to the UE.

14. The apparatus of claim 13, wherein the reference information is transmitted before or during the SSBCA configuration.

15. The apparatus of claim 12, wherein the processing circuit is further configured to: The reference information is determined based on predefined rules.

16. The apparatus of claim 15, wherein the predefined rule comprises determining the reference information based on: (i) the primary CC (PCC), (ii) the frequency band of the PCC, (iii) the primary secondary CC (PSCC), (iv) the frequency band of the PSCC, (v) the active SCC with SSB that has the highest signal strength or quality among the secondary CCs (SCCs), (vi) the frequency band of the active SCC with SSB that has the highest signal strength or quality among the SCCs, or (vii) the active SCC with SSB that has a frequency closest to the frequency of the target SCC.

17. An apparatus for a base station, the apparatus comprising processing circuitry configured to: Based on signals received from the User Equipment (UE), the system decodes reference information including the Reference Component Carrier (CC), the frequency band of the Reference CC, the Reference Synchronization Block (SSB) frequency, or the reference information of the Reference SSB to perform SSB-free carrier aggregation (CA) operation for the UE; and Based on the signals received from the UE, capability information is decoded, the capability information including an indication of one or more frequency band combinations that support the SSB-free CA operation.

18. An apparatus for a base station, the apparatus comprising processing circuitry configured to: Based on signals received from the user equipment (UE), capability information is decoded, wherein the capability information includes an indication of one or more frequency band combinations supporting asynchronous signal block (SSB) (SSB-free) carrier aggregation (CA) operation, wherein, During the SSB-free CA operation, the first serving cell transmits a first component carrier (CC) with an SSB in the CA combination and the second serving cell transmits a second CC without an SSB in the CA combination, wherein the capability information further includes a frequency domain (FD) separation threshold, the FD separation threshold indicating the value in the FD that is far from the CC with an SSB that the UE supports the SSB-free CA operation; as well as Based on the capability information, determine the CC combination within the one or more frequency band combinations that supports the SSB-free CA operation.

19. The apparatus of claim 18, wherein the capability information includes support for one or more frequency band combinations without SSB CA for the maximum frequency band or CC combination set.

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