WO2024064502A1 - Dynamic signaling to release configured cell groups for layer 1 and layer 2 inter-cell mobility - Google Patents

Abstract

Certain aspects of the present disclosure provide a method of wireless communication at a user equipment (UE), generally including receiving a configuration indicating a set of cells that are configured for serving the UE and support mobility signaling via physical (PHY) layer or medium access control (MAC) layer signaling; receiving signaling that indicates a group of cells for the UE to remove from the set of cells; and releasing the indicated group from the set of cells.

Description

DYNAMIC SIGNALING TO RELEASE CONFIGURED CELL GROUPS FOR

LAYER 1 AND LAYER 2 INTER-CELL MOBILITY

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Patent Application No.

18/456,000 filed August 25, 2023, which claims benefit of and priority to U.S. Provisional Patent Application No. 63/409,074, filed on September 22, 2022, which are assigned to the assignee hereof and herein incorporated by reference in their entireties as if fully set forth below and for all applicable purposes.

Field of the Disclosure

[0002] Aspects of the present disclosure relate to wireless communications, and more particularly, to techniques for dynamically signaling a user equipment (UE) to release configured cell groups for cells that support cell changes via dynamic signaling.

Description of Related Art

[0003] Wireless communications systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, broadcasts, or other similar types of services. These wireless communications systems may employ multiple-access technologies capable of supporting communications with multiple users by sharing available wireless communications system resources with those users.

[0004] Although wireless communications systems have made great technological advancements over many years, challenges still exist. For example, complex and dynamic environments can still attenuate or block signals between wireless transmitters and wireless receivers. Accordingly, there is a continuous desire to improve the technical performance of wireless communications systems, including, for example: improving speed and data carrying capacity of communications, improving efficiency of the use of shared communications mediums, reducing power used by transmitters and receivers while performing communications, improving reliability of wireless communications, avoiding redundant transmissions and/or receptions and related processing, improving the coverage area of wireless communications, increasing the number and types of devices that can access wireless communications systems, increasing the ability for different types of devices to intercommunicate, increasing the number and type of wireless communications mediums available for use, and the like. Consequently, there exists a need for further improvements in wireless communications systems to overcome the aforementioned technical challenges and others.

SUMMARY

[0005] One aspect provides a method for wireless communications at a user equipment (UE). The method includes receiving a configuration indicating a set of cells that are configured for serving the UE and support mobility signaling via physical (PHY) layer or medium access control (MAC) layer signaling; receiving signaling that indicates a group of cells for the UE to remove from the set of cells; and releasing the indicated group from the set of cells.

[0006] Another aspect provides a method for wireless communications at a network entity. The method includes transmitting a configuration indicating a set of cells that are configured for serving a user equipment (UE) and support mobility signaling via physical (PHY) layer or medium access control (MAC) layer signaling; transmitting first signaling that indicates a group of cells for the UE to remove from the set of cells; and removing the indicated group from the set of cells.

[0007] Other aspects provide: an apparatus operable, configured, or otherwise adapted to perform any one or more of the aforementioned methods and/or those described elsewhere herein; a non-transitory, computer-readable media comprising instructions that, when executed by a processor of an apparatus, cause the apparatus to perform the aforementioned methods as well as those described elsewhere herein; a computer program product embodied on a computer-readable storage medium comprising code for performing the aforementioned methods as well as those described elsewhere herein; and/or an apparatus comprising means for performing the aforementioned methods as well as those described elsewhere herein. By way of example, an apparatus may comprise a processing system, a device with a processing system, or processing systems cooperating over one or more networks.

[0008] The following description and the appended figures set forth certain features for purposes of illustration. BRIEF DESCRIPTION OF DRAWINGS

[0009] The appended figures depict certain features of the various aspects described herein and are not to be considered limiting of the scope of this disclosure.

[0010] FIG. 1 depicts an example wireless communications network.

[0011] FIG. 2 depicts an example disaggregated base station architecture.

[0012] FIG. 3 depicts aspects of an example base station and an example user equipment.

[0013] FIGS. 4A, 4B, 4C, and 4D depict various example aspects of data structures for a wireless communications network.

[0014] FIG. 5 depicts an example of UE mobility, in accordance with some aspects of the present disclosure.

[0015] FIG. 6 depicts an example of carrier aggregation (CA) configuration, in accordance with some aspects of the present disclosure.

[0016] FIGs. 7 depicts an example call flow diagram for configuring mobility based on dynamic signaling, in accordance with some aspects of the present disclosure.

[0017] FIG. 8 depicts fields of an example medium access control (MAC) control element (MAC-CE), in accordance with aspects of the present disclosure.

[0018] FIG. 9 depicts a method for wireless communications.

[0019] FIG. 10 depicts a method for wireless communications.

[0020] FIG. 11 depicts aspects of an example communications device.

[0021] FIG. 12 depicts aspects of an example communications device.

DETAILED DESCRIPTION

[0022] Aspects of the present disclosure provide apparatuses, methods, processing systems, and computer-readable mediums for dynamically signaling a user equipment (UE) to release configured cell groups for cells that support cell changes via dynamic signaling.

[0023] In advanced wireless systems, mobility management procedures are in place to help maintain network connections for a user equipment (UE) as it moves between the coverage areas of different cells. Mobility procedures generally refer to mechanisms that allow a UE to transition from being served by a source cell to being served by a target cell. Mobility based on dynamic signaling is referred to herein as L1/L2 based inter-cell mobility, because it is typically based on layer 1 (LI) communications (i.e., physical (PHY) layer signaling, such as downlink control information (DCI)) or layer 2 (L2) communications (i.e., medium access control (MAC) layer signaling, such as a MAC control element (MAC-CE)) to direct a LE to transition from being served by a source cell to being served by a target cell.

[0024] As a LE moves, some cells may no longer be suitable for L1/L2 mobility. For example, when a LE moves too far away from some cells, then those cells are no longer suitable for L1/L2 mobility, as the LE will not be able to activate those cells without moving closer to the cells. While cells that are not in use may be stored in a deactivated cell set in the configured L1/L2 mobility cell set, the LE may be configured to perform measurement on the deactivated cell set, resulting in power consumption.

[0025] In such a case, it may be preferable to remove those cells from the L1/L2 mobility cell set of the UE, freeing resources (e.g., memory) of the LE. Even if the LE is configured not to perform measurement on the deactivated cells, the LE may have a capability limit of a maximum number of cells supported in the configured L1/L2 mobility cell set.

[0026] Aspects of the present disclosure provide techniques for using a DCI or MAC- CE signaling to indicate to a UE to release one or more cells or cell groups from L1/L2 mobility configuration. The mechanisms proposed herein may help reduce latency, achieve efficient use of signaling resources, and reduce power consumption by a LE as the LE moves between cells.

Introduction to Wireless Communications Networks

[0027] The techniques and methods described herein may be used for various wireless communications networks. While aspects may be described herein using terminology commonly associated with 3G, 4G, and/or 5G wireless technologies, aspects of the present disclosure may likewise be applicable to other communications systems and standards not explicitly mentioned herein.

[0028] FIG. 1 depicts an example of a wireless communications network 100, in which aspects described herein may be implemented. [0029] Generally, wireless communications network 100 includes various network entities (alternatively, network elements or network nodes). A network entity is generally a communications device and/or a communications function performed by a communications device (e.g., a user equipment (UE), a base station (BS), a component of a BS, a server, etc.). For example, various functions of a network as well as various devices associated with and interacting with a network may be considered network entities. Further, wireless communications network 100 includes terrestrial aspects, such as ground-based network entities (e.g., BSs 102), and non-terrestrial aspects, such as satellite 140 and aircraft 145, which may include network entities on-board (e.g., one or more BSs) capable of communicating with other network elements (e.g., terrestrial BSs) and user equipments.

[0030] In the depicted example, wireless communications network 100 includes BSs 102, UEs 104, and one or more core networks, such as an Evolved Packet Core (EPC) 160 and 5G Core (5GC) network 190, which interoperate to provide communications services over various communications links, including wired and wireless links.

[0031] FIG. 1 depicts various example UEs 104, which may more generally include: a cellular phone, smart phone, session initiation protocol (SIP) phone, laptop, personal digital assistant (PDA), satellite radio, global positioning system, multimedia device, video device, digital audio player, camera, game console, tablet, smart device, wearable device, vehicle, electric meter, gas pump, large or small kitchen appliance, healthcare device, implant, sensor/actuator, display, internet of things (loT) devices, always on (AON) devices, edge processing devices, or other similar devices. UEs 104 may also be referred to more generally as a mobile device, a wireless device, a wireless communications device, a station, a mobile station, a subscriber station, a mobile subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a remote device, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, a handset, and others.

[0032] BSs 102 wirelessly communicate with (e.g., transmit signals to or receive signals from) UEs 104 via communications links 120. The communications links 120 between BSs 102 and UEs 104 may include uplink (UL) (also referred to as reverse link) transmissions from a UE 104 to a BS 102 and/or downlink (DL) (also referred to as forward link) transmissions from a BS 102 to a UE 104. The communications links 120 may use multiple-input and multiple-output (MIMO) antenna technology, including spatial multiplexing, beamforming, and/or transmit diversity in various aspects.

[0033] BSs 102 may generally include: a NodeB, enhanced NodeB (eNB), next generation enhanced NodeB (ng-eNB), next generation NodeB (gNB or gNodeB), access point, base transceiver station, radio base station, radio transceiver, transceiver function, transmission reception point, and/or others. Each of BSs 102 may provide communications coverage for a respective geographic coverage area 110, which may sometimes be referred to as a cell, and which may overlap in some cases (e.g., small cell 102’ may have a coverage area 110’ that overlaps the coverage area 110 of a macro cell). A BS may, for example, provide communications coverage for a macro cell (covering relatively large geographic area), a pico cell (covering relatively smaller geographic area, such as a sports stadium), a femto cell (relatively smaller geographic area (e.g., a home)), and/or other types of cells.

[0034] While BSs 102 are depicted in various aspects as unitary communications devices, BSs 102 may be implemented in various configurations. For example, one or more components of a base station may be disaggregated, including a central unit (CU), one or more distributed units (DUs), one or more radio units (RUs), a Near-Real Time (Near-RT) RAN Intelligent Controller (RIC), or a Non-Real Time (Non-RT) RIC, to name a few examples. In another example, various aspects of a base station may be virtualized. More generally, a base station (e.g., BS 102) may include components that are located at a single physical location or components located at various physical locations. In examples in which a base station includes components that are located at various physical locations, the various components may each perform functions such that, collectively, the various components achieve functionality that is similar to a base station that is located at a single physical location. In some aspects, a base station including components that are located at various physical locations may be referred to as a disaggregated radio access network architecture, such as an Open RAN (O-RAN) or Virtualized RAN (VRAN) architecture. FIG. 2 depicts and describes an example disaggregated base station architecture.

[0035] Different BSs 102 within wireless communications network 100 may also be configured to support different radio access technologies, such as 3G, 4G, and/or 5G. For example, BSs 102 configured for 4G LTE (collectively referred to as Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E- UTRAN)) may interface with the EPC 160 through first backhaul links 132 (e.g., an SI interface). BSs 102 configured for 5G (e.g., 5G NR or Next Generation RAN (NG-RAN)) may interface with 5GC 190 through second backhaul links 184. BSs 102 may communicate directly or indirectly (e.g., through the EPC 160 or 5GC 190) with each other over third backhaul links 134 (e.g., X2 interface), which may be wired or wireless.

[0036] Wireless communications network 100 may subdivide the electromagnetic spectrum into various classes, bands, channels, or other features. In some aspects, the subdivision is provided based on wavelength and frequency, where frequency may also be referred to as a carrier, a subcarrier, a frequency channel, a tone, or a subband. For example, 3GPP currently defines Frequency Range 1 (FR1) as including 410 MHz - 7125 MHz, which is often referred to (interchangeably) as “Sub-6 GHz”. Similarly, 3GPP currently defines Frequency Range 2 (FR2) as including 24,250 MHz - 52,600 MHz, which is sometimes referred to (interchangeably) as a “millimeter wave” (“mmW” or “mmWave”). A base station configured to communicate using mmWave/near mmWave radio frequency bands (e.g., a mmWave base station such as BS 180) may utilize beamforming (e.g., 182) with a UE (e.g., 104) to improve path loss and range.

[0037] The communications links 120 between BSs 102 and, for example, UEs 104, may be through one or more carriers, which may have different bandwidths (e.g., 5, 10, 15, 20, 100, 400, and/or other MHz), and which may be aggregated in various aspects. Carriers may or may not be adjacent to each other. Allocation of carriers may be asymmetric with respect to DL and UL (e.g., more or fewer carriers may be allocated for DL than for UL).

[0038] Communications using higher frequency bands may have higher path loss and a shorter range compared to lower frequency communications. Accordingly, certain base stations (e.g., 180 in FIG. 1) may utilize beamforming 182 with a UE 104 to improve path loss and range. For example, BS 180 and the UE 104 may each include a plurality of antennas, such as antenna elements, antenna panels, and/or antenna arrays to facilitate the beamforming. In some cases, BS 180 may transmit a beamformed signal to UE 104 in one or more transmit directions 182’. UE 104 may receive the beamformed signal from the BS 180 in one or more receive directions 182”. UE 104 may also transmit a beamformed signal to the BS 180 in one or more transmit directions 182”. BS 180 may also receive the beamformed signal from UE 104 in one or more receive directions 182’. BS 180 and UE 104 may then perform beam training to determine the best receive and transmit directions for each of BS 180 and UE 104. Notably, the transmit and receive directions for BS 180 may or may not be the same. Similarly, the transmit and receive directions for UE 104 may or may not be the same.

[0039] Wireless communications network 100 further includes a Wi-Fi AP 150 in communication with Wi-Fi stations (STAs) 152 via communications links 154 in, for example, a 2.4 GHz and/or 5 GHz unlicensed frequency spectrum.

[0040] Certain UEs 104 may communicate with each other using device-to-device (D2D) communications link 158. D2D communications link 158 may use one or more sidelink channels, such as a physical sidelink broadcast channel (PSBCH), a physical sidelink discovery channel (PSDCH), a physical sidelink shared channel (PSSCH), a physical sidelink control channel (PSCCH), and/or a physical sidelink feedback channel (PSFCH).

[0041] EPC 160 may include various functional components, including: a Mobility Management Entity (MME) 162, other MMEs 164, a Serving Gateway 166, a Multimedia Broadcast Multicast Service (MBMS) Gateway 168, a Broadcast Multicast Service Center (BM-SC) 170, and/or a Packet Data Network (PDN) Gateway 172, such as in the depicted example. MME 162 may be in communication with a Home Subscriber Server (HSS) 174. MME 162 is the control node that processes the signaling between the UEs 104 and the EPC 160. Generally, MME 162 provides bearer and connection management.

[0042] Generally, user Internet protocol (IP) packets are transferred through Serving Gateway 166, which itself is connected to PDN Gateway 172. PDN Gateway 172 provides UE IP address allocation as well as other functions. PDN Gateway 172 and the BM-SC 170 are connected to IP Services 176, which may include, for example, the Internet, an intranet, an IP Multimedia Subsystem (IMS), a Packet Switched (PS) streaming service, and/or other IP services.

[0043] BM-SC 170 may provide functions for MBMS user service provisioning and delivery. BM-SC 170 may serve as an entry point for content provider MBMS transmission, may be used to authorize and initiate MBMS Bearer Services within a public land mobile network (PLMN), and/or may be used to schedule MBMS transmissions. MBMS Gateway 168 may be used to distribute MBMS traffic to the BSs 102 belonging to a Multicast Broadcast Single Frequency Network (MBSFN) area broadcasting a particular service, and/or may be responsible for session management (start/stop) and for collecting eMBMS related charging information.

[0044] 5GC 190 may include various functional components, including: an Access and Mobility Management Function (AMF) 192, other AMFs 193, a Session Management Function (SMF) 194, and a User Plane Function (UPF) 195. AMF 192 may be in communication with Unified Data Management (UDM) 196.

[0045] AMF 192 is a control node that processes signaling between UEs 104 and 5GC

190. AMF 192 provides, for example, quality of service (QoS) flow and session management.

[0046] Internet protocol (IP) packets are transferred through UPF 195, which is connected to the IP Services 197, and which provides UE IP address allocation as well as other functions for 5GC 190. IP Services 197 may include, for example, the Internet, an intranet, an IMS, a PS streaming service, and/or other IP services.

[0047] In various aspects, a network entity or network node can be implemented as an aggregated base station, as a disaggregated base station, a component of a base station, an integrated access and backhaul (IAB) node, a relay node, a sidelink node, to name a few examples.

[0048] FIG. 2 depicts an example disaggregated base station 200 architecture. The disaggregated base station 200 architecture may include one or more central units (CUs) 210 that can communicate directly with a core network 220 via a backhaul link, or indirectly with the core network 220 through one or more disaggregated base station units (such as a Near-Real Time (Near-RT) RAN Intelligent Controller (RIC) 225 via an E2 link, or a Non-Real Time (Non-RT) RIC 215 associated with a Service Management and Orchestration (SMO) Framework 205, or both). A CU 210 may communicate with one or more distributed units (DUs) 230 via respective midhaul links, such as an Fl interface. The DUs 230 may communicate with one or more radio units (RUs) 240 via respective fronthaul links. The RUs 240 may communicate with respective UEs 104 via one or more radio frequency (RF) access links. In some implementations, the UE 104 may be simultaneously served by multiple RUs 240.

[0049] Each of the units, e.g., the CUs 210, the DUs 230, the RUs 240, as well as the Near-RT RICs 225, the Non-RT RICs 215 and the SMO Framework 205, may include one or more interfaces or be coupled to one or more interfaces configured to receive or transmit signals, data, or information (collectively, signals) via a wired or wireless transmission medium. Each of the units, or an associated processor or controller providing instructions to the communications interfaces of the units, can be configured to communicate with one or more of the other units via the transmission medium. For example, the units can include a wired interface configured to receive or transmit signals over a wired transmission medium to one or more of the other units. Additionally or alternatively, the units can include a wireless interface, which may include a receiver, a transmitter or transceiver (such as a radio frequency (RF) transceiver), configured to receive or transmit signals, or both, over a wireless transmission medium to one or more of the other units.

[0050] In some aspects, the CU 210 may host one or more higher layer control functions. Such control functions can include radio resource control (RRC), packet data convergence protocol (PDCP), service data adaptation protocol (SDAP), or the like. Each control function can be implemented with an interface configured to communicate signals with other control functions hosted by the CU 210. The CU 210 may be configured to handle user plane functionality (e.g., Central Unit - User Plane (CU-UP)), control plane functionality (e.g., Central Unit - Control Plane (CU-CP)), or a combination thereof. In some implementations, the CU 210 can be logically split into one or more CU-UP units and one or more CU-CP units. The CU-UP unit can communicate bidirectionally with the CU-CP unit via an interface, such as the El interface when implemented in an 0-RAN configuration. The CU 210 can be implemented to communicate with the DU 230, as necessary, for network control and signaling.

[0051] The DU 230 may correspond to a logical unit that includes one or more base station functions to control the operation of one or more RUs 240. In some aspects, the DU 230 may host one or more of a radio link control (RLC) layer, a medium access control (MAC) layer, and one or more high physical (PHY) layers (such as modules for forward error correction (FEC) encoding and decoding, scrambling, modulation and demodulation, or the like) depending, at least in part, on a functional split, such as those defined by the 3^rd Generation Partnership Project (3GPP). In some aspects, the DU 230 may further host one or more low PHY layers. Each layer (or module) can be implemented with an interface configured to communicate signals with other layers (and modules) hosted by the DU 230, or with the control functions hosted by the CU 210. [0052] Lower-layer functionality can be implemented by one or more RUs 240. In some deployments, an RU 240, controlled by a DU 230, may correspond to a logical node that hosts RF processing functions, or low-PHY layer functions (such as performing fast Fourier transform (FFT), inverse FFT (iFFT), digital beamforming, physical random access channel (PRACH) extraction and filtering, or the like), or both, based at least in part on the functional split, such as a lower layer functional split. In such an architecture, the RU(s) 240 can be implemented to handle over the air (OTA) communications with one or more UEs 104. In some implementations, real-time and non-real-time aspects of control and user plane communications with the RU(s) 240 can be controlled by the corresponding DU 230. In some scenarios, this configuration can enable the DU(s) 230 and the CU 210 to be implemented in a cloud-based RAN architecture, such as a vRAN architecture.

[0053] The SMO Framework 205 may be configured to support RAN deployment and provisioning of non-virtualized and virtualized network elements. For non-virtualized network elements, the SMO Framework 205 may be configured to support the deployment of dedicated physical resources for RAN coverage requirements which may be managed via an operations and maintenance interface (such as an 01 interface). For virtualized network elements, the SMO Framework 205 may be configured to interact with a cloud computing platform (such as an open cloud (O-Cloud) 290) to perform network element life cycle management (such as to instantiate virtualized network elements) via a cloud computing platform interface (such as an 02 interface). Such virtualized network elements can include, but are not limited to, CUs 210, DUs 230, RUs 240, and Near-RT RICs 225. In some implementations, the SMO Framework 205 can communicate with a hardware aspect of a 4G RAN, such as an open eNB (O-eNB) 211, via an 01 interface. Additionally, in some implementations, the SMO Framework 205 can communicate directly with one or more RUs 240 via an 01 interface. The SMO Framework 205 also may include a Non-RT RIC 215 configured to support functionality of the SMO Framework 205.

[0054] The Non-RT RIC 215 may be configured to include a logical function that enables non-real-time control and optimization of RAN elements and resources, Artificial Intelligence/Machine Learning (AI/ML) workflows including model training and updates, or policy -based guidance of applications/features in the Near-RT RIC 225. The Non-RT RIC 215 may be coupled to or communicate with (such as via an Al interface) the Near-RT RIC 225. The Near-RT RIC 225 may be configured to include a logical function that enables near-real-time control and optimization of RAN elements and resources via data collection and actions over an interface (such as via an E2 interface) connecting one or more CUs 210, one or more DUs 230, or both, as well as an O-eNB, with the Near-RT RIC 225.

[0055] In some implementations, to generate AI/ML models to be deployed in the Near-RT RIC 225, the Non-RT RIC 215 may receive parameters or external enrichment information from external servers. Such information may be utilized by the Near-RT RIC 225 and may be received at the SMO Framework 205 or the Non-RT RIC 215 from nonnetwork data sources or from network functions. In some examples, the Non-RT RIC 215 or the Near-RT RIC 225 may be configured to tune RAN behavior or performance. For example, the Non-RT RIC 215 may monitor long-term trends and patterns for performance and employ AI/ML models to perform corrective actions through the SMO Framework 205 (such as reconfiguration via 01) or via creation of RAN management policies (such as Al policies).

[0056] FIG. 3 depicts aspects of an example BS 102 and a UE 104.

[0057] Generally, BS 102 includes various processors (e.g., 320, 330, 338, and 340), antennas 334a-t (collectively 334), transceivers 332a-t (collectively 332), which include modulators and demodulators, and other aspects, which enable wireless transmission of data (e.g., data source 312) and wireless reception of data (e.g., data sink 339). For example, BS 102 may send and receive data between BS 102 and UE 104. BS 102 includes controller/processor 340, which may be configured to implement various functions described herein related to wireless communications.

[0058] Generally, UE 104 includes various processors (e.g., 358, 364, 366, and 380), antennas 352a-r (collectively 352), transceivers 354a-r (collectively 354), which include modulators and demodulators, and other aspects, which enable wireless transmission of data (e.g., retrieved from data source 362) and wireless reception of data (e.g., provided to data sink 360). UE 104 includes controller/processor 380, which may be configured to implement various functions described herein related to wireless communications.

[0059] In regards to an example downlink transmission, BS 102 includes a transmit processor 320 that may receive data from a data source 312 and control information from a controller/processor 340. The control information may be for the physical broadcast channel (PBCH), physical control format indicator channel (PCFICH), physical HARQ indicator channel (PHICH), physical downlink control channel (PDCCH), group common PDCCH (GC PDCCH), and/or others. The data may be for the physical downlink shared channel (PDSCH), in some examples.

[0060] Transmit processor 320 may process (e.g., encode and symbol map) the data and control information to obtain data symbols and control symbols, respectively. Transmit processor 320 may also generate reference symbols, such as for the primary synchronization signal (PSS), secondary synchronization signal (SSS), PBCH demodulation reference signal (DMRS), and channel state information reference signal (CSI-RS).

[0061] Transmit (TX) multiple-input multiple-output (MIMO) processor 330 may perform spatial processing (e.g., precoding) on the data symbols, the control symbols, and/or the reference symbols, if applicable, and may provide output symbol streams to the modulators (MODs) in transceivers 332a-332t. Each modulator in transceivers 332a- 332t may process a respective output symbol stream to obtain an output sample stream. Each modulator may further process (e.g., convert to analog, amplify, filter, and upconvert) the output sample stream to obtain a downlink signal. Downlink signals from the modulators in transceivers 332a-332t may be transmitted via the antennas 334a-334t, respectively.

[0062] In order to receive the downlink transmission, UE 104 includes antennas 352a- 352r that may receive the downlink signals from the BS 102 and may provide received signals to the demodulators (DEMODs) in transceivers 354a-354r, respectively. Each demodulator in transceivers 354a-354r may condition (e.g., filter, amplify, downconvert, and digitize) a respective received signal to obtain input samples. Each demodulator may further process the input samples to obtain received symbols.

[0063] MIMO detector 356 may obtain received symbols from all the demodulators in transceivers 354a-354r, perform MIMO detection on the received symbols if applicable, and provide detected symbols. Receive processor 358 may process (e.g., demodulate, deinterleave, and decode) the detected symbols, provide decoded data for the UE 104 to a data sink 360, and provide decoded control information to a controller/processor 380. [0064] In regards to an example uplink transmission, UE 104 further includes a transmit processor 364 that may receive and process data (e.g., for the PUSCH) from a data source 362 and control information (e.g., for the physical uplink control channel (PUCCH)) from the controller/processor 380. Transmit processor 364 may also generate reference symbols for a reference signal (e.g., for the sounding reference signal (SRS)). The symbols from the transmit processor 364 may be precoded by a TX MIMO processor 366 if applicable, further processed by the modulators in transceivers 354a-354r (e.g., for SC-FDM), and transmitted to BS 102.

[0065] At BS 102, the uplink signals from UE 104 may be received by antennas 334a- t, processed by the demodulators in transceivers 332a-332t, detected by a MIMO detector 336 if applicable, and further processed by a receive processor 338 to obtain decoded data and control information sent by UE 104. Receive processor 338 may provide the decoded data to a data sink 339 and the decoded control information to the controller/processor 340.

[0066] Memories 342 and 382 may store data and program codes for BS 102 and UE 104, respectively.

[0067] Scheduler 344 may schedule UEs for data transmission on the downlink and/or uplink.

[0068] In various aspects, BS 102 may be described as transmitting and receiving various types of data associated with the methods described herein. In these contexts, “transmitting” may refer to various mechanisms of outputting data, such as outputting data from data source 312, scheduler 344, memory 342, transmit processor 320, controller/processor 340, TX MIMO processor 330, transceivers 332a-t, antenna 334a-t, and/or other aspects described herein. Similarly, “receiving” may refer to various mechanisms of obtaining data, such as obtaining data from antennas 334a-t, transceivers 332a-t, RX MIMO detector 336, controller/processor 340, receive processor 338, scheduler 344, memory 342, and/or other aspects described herein.

[0069] In various aspects, UE 104 may likewise be described as transmitting and receiving various types of data associated with the methods described herein. In these contexts, “transmitting” may refer to various mechanisms of outputting data, such as outputting data from data source 362, memory 382, transmit processor 364, controller/processor 380, TX MIMO processor 366, transceivers 354a-t, antenna 352a-t, and/or other aspects described herein. Similarly, “receiving” may refer to various mechanisms of obtaining data, such as obtaining data from antennas 352a-t, transceivers 354a-t, RX MIMO detector 356, controller/processor 380, receive processor 358, memory 382, and/or other aspects described herein.

[0070] In some aspects, a processor may be configured to perform various operations, such as those associated with the methods described herein, and transmit (output) to or receive (obtain) data from another interface that is configured to transmit or receive, respectively, the data.

[0071] FIGS. 4A, 4B, 4C, and 4D depict aspects of data structures for a wireless communications network, such as wireless communications network 100 of FIG. 1.

[0072] In particular, FIG. 4A is a diagram 400 illustrating an example of a first subframe within a 5G (e.g., 5GNR) frame structure, FIG. 4B is a diagram 430 illustrating an example of DL channels within a 5G subframe, FIG. 4C is a diagram 450 illustrating an example of a second subframe within a 5G frame structure, and FIG. 4D is a diagram 480 illustrating an example of UL channels within a 5G subframe.

[0073] Wireless communications systems may utilize orthogonal frequency division multiplexing (OFDM) with a cyclic prefix (CP) on the uplink and downlink. Such systems may also support half-duplex operation using time division duplexing (TDD). OFDM and single-carrier frequency division multiplexing (SC-FDM) partition the system bandwidth (e.g., as depicted in FIGS. 4B and 4D) into multiple orthogonal subcarriers. Each subcarrier may be modulated with data. Modulation symbols may be sent in the frequency domain with OFDM and/or in the time domain with SC-FDM.

[0074] A wireless communications frame structure may be frequency division duplex (FDD), in which, for a particular set of subcarriers, subframes within the set of subcarriers are dedicated for either DL or UL. Wireless communications frame structures may also be time division duplex (TDD), in which, for a particular set of subcarriers, subframes within the set of subcarriers are dedicated for both DL and UL.

[0075] In FIG. 4A and 4C, the wireless communications frame structure is TDD where D is DL, U is UL, and X is flexible for use between DL/UL. UEs may be configured with a slot format through a received slot format indicator (SFI) (dynamically through DL control information (DCI), or semi-statically/statically through radio resource control (RRC) signaling). In the depicted examples, a 10 ms frame is divided into 10 equally sized 1 ms subframes. Each subframe may include one or more time slots. In some examples, each slot may include 7 or 14 symbols, depending on the slot format. Subframes may also include mini-slots, which generally have fewer symbols than an entire slot. Other wireless communications technologies may have a different frame structure and/or different channels.

[0076] In certain aspects, the number of slots within a subframe is based on a slot configuration and a numerology. For example, for slot configuration 0, different numerol ogies (p) 0 to 5 allow for 1, 2, 4, 8, 16, and 32 slots, respectively, per subframe. For slot configuration 1, different numerol ogies 0 to 2 allow for 2, 4, and 8 slots, respectively, per subframe. Accordingly, for slot configuration 0 and numerology p, there are 14 symbols/slot and 2p slots/subframe. The subcarrier spacing and symbol length/duration are a function of the numerology. The subcarrier spacing may be equal to 2^ X 15 kHz, where p is the numerology 0 to 5. As such, the numerology p = 0 has a subcarrier spacing of 15 kHz and the numerology p = 5 has a subcarrier spacing of 480 kHz. The symbol length/duration is inversely related to the subcarrier spacing. FIGS. 4A, 4B, 4C, and 4D provide an example of slot configuration 0 with 14 symbols per slot and numerology p = 2 with 4 slots per subframe. The slot duration is 0.25 ms, the subcarrier spacing is 60 kHz, and the symbol duration is approximately 16.67 ps.

[0077] As depicted in FIGS. 4A, 4B, 4C, and 4D, a resource grid may be used to represent the frame structure. Each time slot includes a resource block (RB) (also referred to as physical RBs (PRBs)) that extends, for example, 12 consecutive subcarriers. The resource grid is divided into multiple resource elements (REs). The number of bits carried by each RE depends on the modulation scheme.

[0078] As illustrated in FIG. 4A, some of the REs carry reference (pilot) signals (RS) for a UE (e.g., UE 104 of FIGS. 1 and 3). The RS may include demodulation RS (DMRS) and/or channel state information reference signals (CSI-RS) for channel estimation at the UE. The RS may also include beam measurement RS (BRS), beam refinement RS (BRRS), and/or phase tracking RS (PT-RS).

[0079] FIG. 4B illustrates an example of various DL channels within a subframe of a frame. The physical downlink control channel (PDCCH) carries DCI within one or more control channel elements (CCEs), each CCE including, for example, nine RE groups (REGs), each REG including, for example, four consecutive REs in an OFDM symbol. [0080] A primary synchronization signal (PSS) may be within symbol 2 of particular subframes of a frame. The PSS is used by a UE (e.g., 104 of FIGS. 1 and 3) to determine subframe/symbol timing and a physical layer identity.

[0081] A secondary synchronization signal (SSS) may be within symbol 4 of particular subframes of a frame. The SSS is used by a UE to determine a physical layer cell identity group number and radio frame timing.

[0082] Based on the physical layer identity and the physical layer cell identity group number, the UE can determine a physical cell identifier (PCI). Based on the PCI, the UE can determine the locations of the aforementioned DMRS. The physical broadcast channel (PBCH), which carries a master information block (MIB), may be logically grouped with the PSS and SSS to form a synchronization signal (SS)/PBCH block. The MIB provides a number of RBs in the system bandwidth and a system frame number (SFN). The physical downlink shared channel (PDSCH) carries user data, broadcast system information not transmitted through the PBCH such as system information blocks (SIBs), and/or paging messages.

[0083] As illustrated in FIG. 4C, some of the REs carry DMRS (indicated as R for one particular configuration, but other DMRS configurations are possible) for channel estimation at the base station. The UE may transmit DMRS for the PUCCH and DMRS for the PUSCH. The PUSCH DMRS may be transmitted, for example, in the first one or two symbols of the PUSCH. The PUCCH DMRS may be transmitted in different configurations depending on whether short or long PUCCHs are transmitted and depending on the particular PUCCH format used. UE 104 may transmit sounding reference signals (SRS). The SRS may be transmitted, for example, in the last symbol of a subframe. The SRS may have a comb structure, and a UE may transmit SRS on one of the combs. The SRS may be used by a base station for channel quality estimation to enable frequency-dependent scheduling on the UL.

[0084] FIG. 4D illustrates an example of various UL channels within a subframe of a frame. The PUCCH may be located as indicated in one configuration. The PUCCH carries uplink control information (UCI), such as scheduling requests, a channel quality indicator (CQI), a precoding matrix indicator (PMI), a rank indicator (RI), and HARQ ACK/NACK feedback. The PUSCH carries data, and may additionally be used to carry a buffer status report (BSR), a power headroom report (PHR), and/or UCI. Overview of CA Cell Groups

[0085] In carrier aggregation (CA), cells may be divided into groups referred to as a master cell group (MCG) and a secondary cell group (SCG). A UE that supports dual connectivity (DC) may establish a connection with cells in both the MCG and SCG. The MCG may be a group that includes a cell in which the UE first initiates random access channel (RACH) procedure.

[0086] There may be many different types of cells under the MCG. One cell used for initial access is referred to as a primary cell (PCell). The PCell in the MCG and a secondary cell (SCell) in the MCG are effectively combined using CA. There is also a primary cell in the SCG, referred to as a PSCell, for which initial access is initiated under the SCG. The PSCell and SCell under the SCG may also be effectively combined through CA. Because most signaling messages are sent only on the PCell and PSCell, the protocol also defines a concept of a special cell (SpCell), which refers to the PCell and PSCell.

Overview of Dynamic Signaling-Based Mobility

[0087] Dynamic mobility signaling (e.g., LI and/or L2-centric mobility) may facilitate intra-cell and inter-cell mobility with reduced latency.

[0088] The general concept of L1/L2 based mobility signaling may be understood with reference to FIG. 5. As illustrated, the network may configure (e.g., via RRC signaling), a set of cells for L1/L2 mobility (referred to herein as an L1/L2 Mobility Configured cell set). At any given time, the network may also configure (via L1/L2 signaling) an L1/L2 Mobility Activated cell set, which refers to a group of cells in the configured set that are activated and can be readily used for data and control transfer. The network may also configure (signal) an L1/L2 Mobility Deactivated cell set, which refers to a group of cells in the configured set that are deactivated and can be readily activated by L1/L2 signaling.

[0089] L1/L2 signaling may be used for mobility management of the activated set.

For example, L1/L2 signaling may be used to activate/deactivate cells in the set, select beams within the activated cells, and update/switch a PCell. This dynamic signaling may help provide seamless mobility within the activated cells in the set. In other words, as the UE moves, the cells from the set are deactivated and activated by L1/L2 signaling. The cells to activate and deactivate may be based on various factors, such as signal quality (measurements) and loading. [0090] As in the example illustrated in FIG. 5, in some cases, all cells in the L1/L2 Mobility Configured cell set may belong to the same DU. This may be similar to carrier aggregation (CA), but cells may be on the same carrier frequencies. The size of the cell set configured for L1/L2 mobility signaling may vary. In general, the cell set size may be selected to be large enough to cover a meaningful mobility area.

[0091] In some cases, the UE may be provided with a subset of deactivated cells, as a candidate cell set, from which the UE could autonomously choose to add to the activated cell set. The decision of whether to add a cell from the candidate cell set to the activated cell set may be based on various factors, such as measured channel quality and loading information. In some cases, the ability for the UE to autonomously choose to add to the activated cell set may be similar to a UE decision when configured for Conditional Handover (CHO) for fast and efficient addition of the prepared cells.

[0092] Each cell may be served by an RU. Each of the RUs may have multi-carrier (N CCs) support. In such cases, each CC may be a cell (e.g., Cell 2 and Cell 2’ may be different CCs of the same RU). In such cases, activation/deactivation can be done in groups of carriers (cells).

[0093] For primary cell (PCell) management, L1/L2 signaling may be used to set (select) the PCell out of the preconfigured options within the activated cell set. In some cases, L3 mobility may be used for PCell change (L3 handover) when a new PCell is not from the activated cell set for L1/L2 mobility. In such cases, RRC signaling may update the set of cells for L1/L2 mobility at L3 handover.

[0094] As illustrated in FIG. 5, a group of cells may be configured for a UE with cell activation and/or deactivation and SpCell update for the UE performed on a cell group level. For each cell group eligible for activation for the UE by L1/L2 signaling, a cell group configuration is provided to the UE. L1/L2 signaling sent to the UE by the network determines the activation status of the configured cell group(s). If only one cell group can be active at one time (e.g., because the UE can only have one active cell group), then the L1/L2 signaling may direct the UE to perform a cell group switch. If multiple cell groups can be active at one time (based on UE capability to support this feature), then the L1/L2 signaling may direct the UE to perform a cell group update. [0095] In aspects of the present disclosure, configuration of cell groups may support a cell belonging to multiple groups. In the simplest case, each cell may be restricted to belonging to only a single cell group.

[0096] According to aspects of the present disclosure, cell group configuration for L1/L2 mobility may be provided as a set of changes (e.g., a delta) from a configuration of a reference cell group or reference cell to a new configuration.

[0097] In aspects of the present disclosure, one or more cells in a cell group may be configured to act as a SpCell for the UE. In these aspects, the SpCell for the UE may be changed by L1/L2 signaling while the activated cell group for the UE remains unchanged.

[0098] As a UE moves, some cells may no longer be suitable for L1/L2 mobility. For example, when a UE moves too far away from some cells, then those cells are no longer suitable for L1/L2 mobility, as the UE will not be able to activate those cells without moving closer to the cells. While cells that are not in use may be stored in a deactivated cell set in the configured L1/L2 mobility cell set, the UE may be configured to perform measurement on the deactivated cell set, resulting in power consumption. In such a case, it may be preferable to remove those cells from the L1/L2 mobility cell set, freeing resources (e.g., memory) of the UE. Even if the UE may be configured not to perform measurement on the deactivated cells, the UE may have a capability limit of a maximum number of cells supported in the configured L1/L2 mobility cell set.

[0099] Accordingly, it is desirable to develop L1/L2 signaling to remove cell groups from the configured L1/L2 mobility cell set of a UE.

Aspects Related to Dynamically Signaling a UE to Release Configured Cell Groups

[0100] Aspects of the present disclosure provide apparatuses, methods, processing systems, and computer-readable mediums for L1/L2 signaling to remove cell groups from the configured L1/L2 mobility cell set of a UE.

[0101] In aspects of the present disclosure, techniques are provided for a network entity to signal a UE to utilize a CA configuration with additional configuration elements in order to facilitate L1/L2 Mobility within the configured CA set.

[0102] According to aspects of the present disclosure, a L1/L2 Mobility configured set for a UE may be a subset or may encompass the whole CA set configured at the UE. [0103] In aspects of the present disclosure, cells in the L1/L2 configured cell set may have SpCell and/or SCell configuration.

[0104] According to aspects of the present disclosure, when a UE connects to one cell in the cell group, the UE connects to the whole cell group.

[0105] In aspects of the present disclosure, the configuration of the L1/L2 Mobility configured set, also referred to as the LlL2MobilityConfig, contains an SpCell configuration, an SCell configuration, and a LI measurement configuration for use when the cell is in a deactivated state. More than one SpCell or SCell configuration may be provided for a cell. For example, a list of configurations may be provided for a cell. The actual configuration of the cell to be activated is specified by L1/L2 signaling.

[0106] According to aspects of the present disclosure, an SpCell configuration of a cell may be activated when a cell is updated from an SCell to an SpCell by an L1/L2 mobility procedure.

[0107] In aspects of the present disclosure, an SCell configuration of a cell may be activated when a cell is updated from a PCell to an SCell by L1/L2 mobility procedure.

[0108] FIG. 6 depicts an example set of cell groups configured for a UE, according to aspects of the present disclosure. As illustrated, the set of cell groups includes two cell groups, labeled “Cell group 1” and “Cell group 2.” As described herein, the two cell groups may be included in the CA set for the UE or may encompass the entire CA set for the UE. As described herein, when the UE connects to a cell within a group, the UE connects each cell within the group. For example, when the UE connects to the PCell in the Cell group 1, the UE also connects to SCell 1 and SCell 2 in Cell group 1. As illustrated, each cell is provided with an LlL2MobilityConfig. The LlL2Mobility Config for each cell contains an SCell configuration and an SpCell configuration. And as described herein, each cell could have more than one SCell configuration and more than one SpCell configuration. For example, PCell in Cell group 1 may be provided with a list of SCell configurations and another list of SpCell configurations. If the PCell in Cell group 1 is activated as an SpCell for the UE, then the UE will apply an SpCell configuration for the connection to PCell in Cell group 1. Similarly, if the PCell in Cell group 1 is activated as an SCell for the UE (and, for example, SCell 1 is a new SpCell for the UE), then the UE will apply an SCell configuration for the connection to PCell in Cell group 1. [0109] In aspects of the present disclosure, when a cell group is added to the L1/L2 mobility cell set, a position in a bitmap is assigned to that cell group and then used by a network entity (e.g., a gNB) to activate and deactivate the cells of that cell group. The network entity sets values of bits in a DCI or MAC-CE sent to a UE to activate and deactivate the cells of the cell groups corresponding to the bits.

[0110] According to aspects of the present disclosure, another MAC control element or DCI format may include bits in a bitmap to release a cell group, with each cell group corresponding to a same position in the bitmap as that cell group corresponds to in a bitmap in a MAC-CE or DCI sent to activate and deactivate cells of cell groups. However, instead of being deactivated, the cell group is released and removed from the configured set for the UE.

[0111] FIG. 7 depicts an example call flow 700 between a UE 704 and a network entity 702, according to aspects of the present disclosure. The network entity 702 may an example of the BS 102 depicted and described with respect to FIGs. 1 and 3 or a node of a disaggregated base station depicted and described with respect to FIG. 2. Similarly, the UE 704 may be an example of UE 104 depicted and described with respect to FIGs. 1 and 3. However, in other aspects, UE 104 may be another type of wireless communications device and BS 102 may be another type of network entity or network node, such as those described herein.

[0112] At 710, the network entity transmits and the UE receives a configuration comprising a set of cells that are configured for serving the UE and support mobility signaling via physical (PHY) layer or medium access control (MAC) layer signaling, also referred to herein as an LlL2MobilityConfig.

[0113] At 720, the network entity transmits and the UE receives signaling that indicates a group of cells for the UE to remove from the set of cells (e.g., from the LlL2MobilityConfig of the UE).

[0114] At 730, the UE releases the indicated group of cells from the set of cells (e.g., from the LlL2MobilityConfig of the UE).

[0115] At 740, the network entity removes the group of cells from the set of cells (e.g., from the network record of the LlL2Mobility Config of the UE).

[0116] According to aspects of the present disclosure, a network entity may transmit a separate MAC-CE or DCI to release one or more cell groups from the configured cell set of a UE. Such a separate MAC-CE or DCI may be an example of signaling that indicates a group of cells for the UE to remove from the set of cells, as transmitted by the network entity and received by the UE at 720 in FIG. 7.

[0117] In aspects of the present disclosure, a network entity may transmit a bit (e.g., a bit that is reserved in typical communications systems) in L1/L2 signaling that is intended to activate or deactivate cells or cell groups in an L1/L2 mobility procedure in a typical communications system. Such a bit may be set to a value to indicate the release of a cell.

[0118] FIG. 8 depicts example bitmaps 800 and 850 in a MAC-CE used to indicate release of configured cells using L1/L2 signaling, in accordance with aspects of the present disclosure. As illustrated, a bitmap 800 or 850 in a MAC-CE may include a plurality of octets, labeled Octet 1 through Octet M in bitmap 800. The first octet may include a reserved bit as the lowest order bit, represented as “R,” and a set of C fields. In the example bitmap 800, each C field is a bit corresponding to a cell group index configured in the L1/L2 mobility cell set. In the bitmap 800, Ci = 1 indicates releasing of the cell group having index i. Additionally, there may be additional octets indicating whether to remove the whole cell group from the CA configuration for the UE or to just remove the L1/L2 mobility configuration from the cells in the group. In the additional octets, each bit corresponds to the cell group indicated to be released (in ascending order). In the additional octets, 1 may represent an instruction to remove the whole cell group, while 0 may represent an instruction to only remove the L1/L2 mobility configuration from the cells in the group. The example bitmap 850 has two octets. In the first octet, the C fields Ci, C2, and C5 have values of 1, indicating a receiving UE is to release the cell groups having indices of 1, 2, and 5. The second octet in the example bitmap 850 indicates whether to remove the whole cell group from the CA configuration or to just remove the L1/L2 mobility configuration from the cells. The second octet in the example bitmap 850 does not have any reserved bits, and thus the lowest order bit of the second octet corresponds to the cell group having index 1. The second octet of the example bitmap 850 indicates the receiving UE should release the whole cell group having index 1, and the UE should only release the L1/L2 mobility configuration of the cell groups having indices 2 and 5.

[0119] According to aspects of the present disclosure since a network entity (e.g., a gNB) is in full control when messages are transmitted, any errors in this L1/L2 configuration release signaling described herein will not be catastrophic (i.e., causing loss of user data). For example, if UE does not receive L1/L2 signaling indicating to release one or more cells from the L1/L2 configuration, then in future signaling indicating to release cells the network entity would simply not utilize bits for the cells that were released, even if the UE did not receive the MAC message. In a majority of the time, the signaling is expected to be received by the UE, and the UE can free up the memory that was occupied by information linked to the released cells. When new cells are added, the network entity can utilize positions in the bitmap that were previously released.

[0120] In aspects of the present disclosure, the network entity and the UE do not necessarily need to be in sync with the released cells, but the network entity and the UE will always be in sync regarding configured cells, since those are signaled by RRC.

[0121] According to aspects of the present disclosure, a network entity may use an enhanced cross-layer signaling for error handling. A network entity may record a PDSCH transport block (TB) identifier (ID) of a TB that contains the cell releasing MAC-CE transmitted to the UE. When the UE sends an acknowledgment (ACK) for the corresponding PDSCH TB, the network entity may extract the content acknowledged (ACKed) in that TB and determine that the UE successfully received the MAC-CE. If the UE does not receive (and therefore does not ACK) the MAC CE, the network entity may retransmit the MAC-CE at a later time.

Example Operations

[0122] FIG. 9 shows an example of a method 900 for wireless communications at a UE, such as a UE 104 of FIGs. 1 and 3.

[0123] Method 900 begins at step 905 with receiving a configuration indicating a set of cells that are configured for serving the UE and support mobility signaling via physical (PHY) layer or medium access control (MAC) layer signaling. In some cases, the operations of this step refer to, or may be performed by, circuitry for receiving and/or code for receiving as described with reference to FIG. 11.

[0124] Method 900 then proceeds to step 910 with receiving signaling that indicates a group of cells for the UE to remove from the set of cells. In some cases, the operations of this step refer to, or may be performed by, circuitry for receiving and/or code for receiving as described with reference to FIG. 11. [0125] Method 900 then proceeds to step 915 with releasing the indicated group of cells from the set of cells. In some cases, the operations of this step refer to, or may be performed by, circuitry for releasing and/or code for releasing as described with reference to FIG. 11

[0126] In one aspect, method 900, or any aspect related to it, may be performed by an apparatus, such as communications device 1100 of FIG. 11, which includes various components operable, configured, or adapted to perform the method 900. Communications device 1100 is described below in further detail.

[0127] Note that FIG. 9 is just one example of a method, and other methods including fewer, additional, or alternative steps are possible consistent with this disclosure.

[0128] FIG. 10 shows an example of a method 1000 for wireless communications by a network entity, such as a BS 104 of FIGs. 1 and 3, or a node of a disaggregated base station as discussed with respect to FIG. 2, such as a DU.

[0129] Method 1000 begins at step 1005 with transmitting a configuration indicating a set of cells that are configured for serving a user equipment (UE) and support mobility signaling via physical (PHY) layer or medium access control (MAC) layer signaling. In some cases, the operations of this step refer to, or may be performed by, circuitry for transmitting and/or code for transmitting as described with reference to FIG. 12.

[0130] Method 1000 then proceeds to step 1010 with transmitting first signaling that indicates a group of cells for the UE to remove from the set of cells. In some cases, the operations of this step refer to, or may be performed by, circuitry for transmitting and/or code for transmitting as described with reference to FIG. 12.

[0131] Method 1000 then proceeds to step 1015 with removing the indicated group of cells from the set of cells. In some cases, the operations of this step refer to, or may be performed by, circuitry for removing and/or code for removing as described with reference to FIG. 12.

[0132] In one aspect, method 1000, or any aspect related to it, may be performed by an apparatus, such as communications device 1200 of FIG. 12, which includes various components operable, configured, or adapted to perform the method 1000. Communications device 1200 is described below in further detail. [0133] Note that FIG. 10 is just one example of a method, and other methods including fewer, additional, or alternative steps are possible consistent with this disclosure.

Example Communications Device

[0134] FIG. 11 depicts aspects of an example communications device 1100 configured for wireless communications. In some aspects, communications device 1100 is a user equipment, such as UE 104 described above with respect to FIGS. 1 and 3.

[0135] The communications device 1100 includes a processing system 1102 coupled to a transceiver 1108 (e.g., a transmitter and/or a receiver). The transceiver 1108 is configured to transmit and receive signals for the communications device 1100 via an antenna 1110, such as the various signals as described herein. The processing system 1102 may be configured to perform processing functions for the communications device 1100, including processing signals received and/or to be transmitted by the communications device 1100.

[0136] The processing system 1102 includes one or more processors 1120. In various aspects, the one or more processors 1120 may be representative of one or more of receive processor 358, transmit processor 364, TX MIMO processor 366, and/or controller/processor 380, as described with respect to FIG. 3. The one or more processors 1120 are coupled to a computer-readable medium/memory 1130 via a bus 1106. In certain aspects, the computer-readable medium/memory 1130 is configured to store instructions (e.g., computer-executable code or computer-executable instructions) that when executed by the one or more processors 1120, cause the one or more processors 1120 to perform the method 900 described with respect to FIG. 9, or any aspect related to it. Note that reference to a processor performing a function of communications device 1100 may include one or more processors performing that function of communications device 1100.

[0137] In the depicted example, computer-readable medium/memory 1130 stores code (e.g., executable instructions) for receiving 1131 and code for releasing 1132. Processing of the code 1131-1132 may cause the communications device 1100 to perform the method 900 described with respect to FIG. 9 or any aspect related to it.

[0138] The one or more processors 1120 include circuitry configured to implement (e.g., execute) the code stored in the computer-readable medium/memory 1130, including circuitry for receiving 1121 and circuitry for releasing 1122. Processing with circuitry 1121-1122 may cause the communications device 1100 to perform the method 900 described with respect to FIG. 9 or any aspect related to it.

[0139] Various components of the communications device 1100 may provide means for performing the method 900 described with respect to FIG. 9, or any aspect related to it. For example, means for transmitting, sending, or outputting for transmission may include the transceivers 354 and/or antenna(s) 352 of the UE 104 illustrated in FIG. 3 and/or transceiver 1108 and antenna 1110 of the communications device 1100 in FIG. 11. Means for receiving or obtaining may include the transceivers 354 and/or antenna(s) 352 of the UE 104 illustrated in FIG. 3 and/or transceiver 1108 and antenna 1110 of the communications device 1100 in FIG. 11. Means for releasing may include the receive processor 358, controller/processor 380, and/or memory 382 of the UE 104 illustrated in FIG. 3 and/or processor(s) 1120 and memory 1130 of the communications device 1100 in FIG. 11

[0140] FIG. 12 depicts aspects of an example communications device 1200 configured for wireless communications. In some aspects, communications device 1200 is a network entity, such as BS 102 of FIGs. 1 and 3, or a node of a disaggregated base station as discussed with respect to FIG. 2.

[0141] The communications device 1200 includes a processing system 1205 coupled to a transceiver 1265 (e.g., a transmitter and/or a receiver). In some aspects (e.g., when communications device 1200 is a network entity), processing system 1205 may be coupled to a network interface 1275 that is configured to obtain and send signals for the communications device 1200 via communication link(s), such as a backhaul link, midhaul link, and/or fronthaul link as described herein, such as with respect to FIG. 2. The transceiver 1265 is configured to transmit and receive signals for the communications device 1200 via the antenna 1270, such as the various signals as described herein. The processing system 1205 may be configured to perform processing functions for the communications device 1200, including processing signals received and/or to be transmitted by the communications device 1200.

[0142] The processing system 1205 includes one or more processors 1210. In various aspects, one or more processors 1210 may be representative of one or more of receive processor 338, transmit processor 320, TX MIMO processor 330, and/or controller/processor 340, as described with respect to FIG. 3. The one or more processors 1210 are coupled to a computer-readable medium/memory 1235 via a bus 1260. In certain aspects, the computer-readable medium/memory 1235 is configured to store instructions (e.g., computer-executable code or computer-executable instructions) that when executed by the one or more processors 1210, cause the one or more processors 1210 to perform the method 1000 described with respect to FIG. 10. Note that reference to a processor performing a function of communications device 1200 may include one or more processors 1210 performing that function of communications device 1200.

[0143] In the depicted example, computer-readable medium/memory 1235 stores code (e.g., executable instructions) for transmitting 1240^. code for removing 1245, and code for monitoring 1250. Processing of the code for transmitting 1240, code for removing 1245, and code for monitoring 1250 may cause the communications device 1200 to perform the method 1000 described with respect to FIG. 10 or any aspect related to it.

[0144] The one or more processors 1210 include circuitry configured to implement (e.g., execute) the code stored in the computer-readable medium/memory 1235, including circuitry for transmitting 1215, circuitry for removing 1220, and circuitry for monitoring 1225. Processing with circuitry for transmitting 1215, circuitry for removing 1220, and circuitry for monitoring 1225 may cause the communications device 1200 to perform the method 1000 described with respect to FIG. 10 or any aspect related to it.

[0145] Various components of the communications device 1200 may provide means for performing the method 1000 described with respect to FIG. 10. For example, means for transmitting, sending, or outputting for transmission may include transceivers 332 and/or antenna(s) 334 of the BS 102 illustrated in FIG. 3 and/or the transceiver 1265 and the antenna 1270 of the communications device 1200 in FIG. 12. Means for receiving, monitoring, or obtaining may include transceivers 332 and/or antenna(s) 334 of the BS 102 illustrated in FIG. 3 and/or the transceiver 1265 and the antenna 1270 of the communications device 1200 in FIG. 12. Means for removing may include the receive processor 338, controller/processor 340, memory 342, and/or transmit processor 320 of the BS 102 illustrated in FIG. 3, and/or processor(s) 1210 and memory 1235 of the communications device 1200 illustrated in FIG. 12.

Example Clauses

[0146] Implementation examples are described in the following numbered clauses: [0147] Clause 1 : A method for wireless communications at a user equipment (UE), comprising: receiving a configuration indicating a set of cells that are configured for serving the UE and support mobility signaling via physical (PHY) layer or medium access control (MAC) layer signaling; receiving signaling that indicates a group of cells for the UE to remove from the set of cells; and releasing the indicated group of cells from the set of cells.

[0148] Clause 2: The method of Clause 1, wherein the signaling comprises at least one of a downlink control information (DCI) or a MAC control element (MAC CE).

[0149] Clause 3: The method of any one of Clauses 1-2, wherein the signaling comprises a first set of bits, each bit in the first set indicating whether to release cells of a corresponding group of cells in the set of cells.

[0150] Clause 4: The method of Clause 3, wherein: the signaling further comprises a second set of bits; each bit in the second set corresponds to a group of cells in the set; and each bit in the second set indicates at least one of: to remove the corresponding group of cells from a carrier aggregation (CA) configuration for the UE, or to release the PHY layer or MAC layer mobility signaling configuration for each cell in the corresponding group of cells.

[0151] Clause 5: The method of Clause 4, wherein releasing the corresponding group of cells comprises removing each cell in the group from the configuration for serving the UE.

[0152] Clause 6: The method of Clause 3, wherein: the signaling further comprises a second set of bits; each bit in the second set corresponds to a group of cells in the set; and each bit in the second set indicates to release the PHY layer or MAC layer mobility signaling configuration for each cell in the corresponding group of cells.

[0153] Clause ?: A method for wireless communications at a network entity, comprising: transmitting a configuration indicating a set of cells that are configured for serving a user equipment (UE) and support mobility signaling via physical (PHY) layer or medium access control (MAC) layer signaling; transmitting first signaling that indicates a group of cells for the UE to remove from the set of cells; and removing the indicated group of cells from the set of cells.

[0154] Clause 8: The method of Clause 7, wherein the first signaling comprises at least one of a downlink control information (DCI) or a MAC control element (MAC CE). [0155] Clause 9: The method of any one of Clauses 7-8, wherein the first signaling comprises a first set of bits, each bit in the first set indicating whether to release a corresponding group of cells in the set of cells.

[0156] Clause 10: The method of Clause 9, wherein: the first signaling further comprises a second set of bits; each bit in the second set corresponds to a group of cells in the set; and each bit in the second set indicates at least one of: to remove the corresponding group of cells from a CA configuration for the UE, or to release the PHY layer or MAC layer mobility signaling configuration for each cell in the corresponding group of cells.

[0157] Clause 11 : The method of Clause 9, wherein: the first signaling further comprises a second set of bits; each bit in the second set corresponds to a group of cells in the set; and each bit in the second set indicates to release the PHY layer or MAC layer mobility signaling configuration for each cell in the corresponding group of cells.

[0158] Clause 12: The method any one of Clauses 7-11, further comprising: monitoring, during a period, for an acknowledgment (ACK) from the UE acknowledging a transport block (TB) having a TB identifier (ID) associated with the first signaling; and transmitting second signaling that indicates the group of cells for the UE to remove from the set of cells in response to failing to detect the ACK during the period.

[0159] Clause 13: An apparatus, comprising: a memory comprising executable instructions; and at least one processor configured to execute the executable instructions and cause the apparatus to perform a method in accordance with any one of Clauses 1- 12.

[0160] Clause 14: An apparatus, comprising means for performing a method in accordance with any one of Clauses 1-12.

[0161] Clause 15: A non-transitory computer-readable medium comprising executable instructions that, when executed by a processor of an apparatus, cause the apparatus to perform a method in accordance with any one of Clauses 1-12.

[0162] Clause 16: A computer program product embodied on a computer-readable storage medium comprising code for performing a method in accordance with any one of Clauses 1-12. Additional Considerations

[0163] The preceding description is provided to enable any person skilled in the art to practice the various aspects described herein. The examples discussed herein are not limiting of the scope, applicability, or aspects set forth in the claims. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects. For example, changes may be made in the function and arrangement of elements discussed without departing from the scope of the disclosure. Various examples may omit, substitute, or add various procedures or components as appropriate. For instance, the methods described may be performed in an order different from that described, and various actions may be added, omitted, or combined. Also, features described with respect to some examples may be combined in some other examples. For example, an apparatus may be implemented or a method may be practiced using any number of the aspects set forth herein. In addition, the scope of the disclosure is intended to cover such an apparatus or method that is practiced using other structure, functionality, or structure and functionality in addition to, or other than, the various aspects of the disclosure set forth herein. It should be understood that any aspect of the disclosure disclosed herein may be embodied by one or more elements of a claim.

[0164] The various illustrative logical blocks, modules and circuits described in connection with the present disclosure may be implemented or performed with a general purpose processor, a central processing unit (CPU), a graphics processing unit (GPU), a digital signal processor (DSP), an ASIC, a field programmable gate array (FPGA) or other programmable logic device (PLD), discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but in the alternative, the processor may be any commercially available processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, a system on a chip (SoC), or any other such configuration.

[0165] The functions described herein may be implemented using hardware, software executed by a processor, or any combination thereof. Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, or functions, whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise. If implemented using software executed by a processor, the functions may be stored as or transmitted using one or more instructions or code of a computer-readable medium. Other examples and implementations are within the scope of the disclosure and appended claims. For example, due to the nature of software, functions described herein may be implemented using software executed by a processor, hardware, hardwiring, or combinations of any of these. Features implementing functions may also be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations.

[0166] Computer-readable media includes both non-transitory computer storage media and communication media including any medium that facilitates transfer of a computer program from one location to another. A non-transitory storage medium may be any available medium that may be accessed by a general-purpose or special-purpose computer. By way of example, and not limitation, non-transitory computer-readable media may include RAM, ROM, electrically erasable programmable ROM (EEPROM), flash memory, phase change memory, compact disk (CD) ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other non- transitory medium that may be used to carry or store desired program code means in the form of instructions or data structures and that may be accessed by a general-purpose or special-purpose computer, or a general-purpose or special-purpose processor. Also, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of computer-readable medium. Disk and disc, as used herein, include CD, laser disc, optical disc, digital versatile disc (DVD), floppy disk, and Blu-ray disc. Disks may reproduce data magnetically, and discs may reproduce data optically using lasers. Combinations of the above are also included within the scope of computer-readable media. [0167] As used herein, a phrase referring to “at least one of’ a list of items refers to any combination of those items, including single members. As an example, “at least one of: a, b, or c” is intended to cover a, b, c, a-b, a-c, b-c, and a-b-c, as well as any combination with multiples of the same element (e.g., a-a, a-a-a, a-a-b, a-a-c, a-b-b, a-c-c, b-b, b-b-b, b-b-c, c-c, and c-c-c or any other ordering of a, b, and c).

[0168] As used herein, the term “determining” encompasses a wide variety of actions. For example, “determining” may include calculating, computing, processing, deriving, investigating, looking up (e.g., looking up in a table, a database or another data structure), ascertaining and the like. Also, “determining” may include receiving (e.g., receiving information), accessing (e.g., accessing data in a memory) and the like. Also, “determining” may include resolving, selecting, choosing, establishing, and the like.

[0169] As used herein, “a processor,” “at least one processor” or “one or more processors” generally refers to a single processor configured to perform one or multiple operations or multiple processors configured to collectively perform one or more operations. In the case of multiple processors, performance of the one or more operations could be divided amongst different processors, though one processor may perform multiple operations, and multiple processors could collectively perform a single operation. Similarly, “memory,” “a memory,” “at least one memory” or “one or more memories” generally refers to a single memory configured to store data and/or instructions, or multiple memories configured to collectively store data and/or instructions.

[0170] The methods disclosed herein comprise one or more actions for achieving the methods. The method actions may be interchanged with one another without departing from the scope of the claims. In other words, unless a specific order of actions is specified, the order and/or use of specific actions may be modified without departing from the scope of the claims. Further, the various operations of methods described above may be performed by any suitable means capable of performing the corresponding functions. The means may include various hardware and/or software component(s) and/or module(s), including, but not limited to a circuit, an application specific integrated circuit (ASIC), or processor.

[0171] The following claims are not intended to be limited to the aspects shown herein, but are to be accorded the full scope consistent with the language of the claims. Within a claim, reference to an element in the singular is not intended to mean “one and only one” unless specifically so stated, but rather “one or more.” Unless specifically stated otherwise, the term “some” refers to one or more. No claim element is to be construed under the provisions of 35 U.S.C. §112(f) unless the element is expressly recited using the phrase “means for”. All structural and functional equivalents to the elements of the various aspects described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims.

Claims

WHAT IS CLAIMED IS:

1. A method for wireless communications at a user equipment (UE), comprising: receiving a configuration indicating a set of cells that are configured for serving the UE and support mobility signaling via physical (PHY) layer or medium access control (MAC) layer signaling; receiving signaling that indicates a group of cells for the UE to remove from the set of cells; and releasing the indicated group of cells from the set of cells.

2. The method of claim 1, wherein the signaling comprises at least one of a downlink control information (DCI) or a MAC control element (MAC CE).

3. The method of claim 1, wherein the signaling comprises a first set of bits, each bit in the first set indicating whether to release a corresponding group of cells in the set of cells.

4. The method of claim 3, wherein: the signaling further comprises a second set of bits; each bit in the second set corresponds to a group of cells in the set; and each bit in the second set indicates to remove the corresponding group of cells from a carrier aggregation (CA) configuration for the UE.

5. The method of claim 4, wherein releasing the corresponding group of cells comprises removing each cell in the group from the configuration for serving the UE.

6. The method of claim 3, wherein: the signaling further comprises a second set of bits; each bit in the second set corresponds to a group of cells in the set; and each bit in the second set indicates to release the PHY layer or MAC layer mobility signaling configuration for each cell in the corresponding group of cells.

7. A method for wireless communications at a network entity, comprising: transmitting a configuration indicating a set of cells that are configured for serving a user equipment (UE) and support mobility signaling via physical (PHY) layer or medium access control (MAC) layer signaling; transmitting first signaling that indicates a group of cells for the UE to remove from the set of cells; and removing the indicated group from the set of cells.

8. The method of claim 7, wherein the first signaling comprises at least one of a downlink control information (DCI) or a MAC control element (MAC CE).

9. The method of claim 7, wherein the first signaling comprises a first set of bits, each bit in the first set indicating whether to release a corresponding group of cells in the set of cells.

10. The method of claim 9, wherein: the first signaling further comprises a second set of bits; each bit in the second set corresponds to a group of cells in the set; and each bit in the second set indicates to remove the corresponding group of cells from a carrier aggregation (CA) configuration for the UE.

11. The method of claim 9, wherein: the first signaling further comprises a second set of bits; each bit in the second set corresponds to a group of cells in the set; and each bit in the second set indicates to release the PHY layer or MAC layer mobility signaling configuration for each cell in the corresponding group of cells.

12. The method of claim 7, further comprising: monitoring, during a period, for an acknowledgment (ACK) from the UE acknowledging a transport block (TB) having a TB identifier (ID) associated with the first signaling; and transmitting second signaling that indicates the group of cells for the UE to remove from the set of cells in response to failing to detect the ACK during the period.

13. A user equipment (UE) configured for wireless communications, comprising: a memory comprising computer-executable instructions; and at least one processor configured to execute the computer-executable instructions and cause the UE to: receive a configuration indicating a set of cells that are configured for serving the UE and support mobility signaling via physical (PHY) layer or medium access control (MAC) layer signaling; receive signaling that indicates a group of cells for the UE to remove from the set of cells; and release the indicated group from the set of cells.

14. The UE of claim 13, wherein the at least one processor being configured to execute the computer-executable instructions and cause the UE to receive the signaling comprises the at least one processor being configured to execute the computerexecutable instructions and cause the UE to receive at least one of a downlink control information (DCI) or a MAC control element (MAC CE).

15. The UE of claim 13, wherein the at least one processor being configured to execute the computer-executable instructions and cause the UE to receive the signaling comprises the at least one processor being configured to execute the computerexecutable instructions and cause the UE to receive a first set of bits, each bit in the first set indicating whether to release a corresponding group of cells in the set of cells.

16. The UE of claim 15, wherein: the at least one processor being configured to execute the computer-executable instructions and cause the UE to receive the signaling comprises the at least one processor being configured to execute the computer-executable instructions and further cause the UE to receive a second set of bits; and the at least one processor is configured to execute the computer-executable instructions and further cause the UE to for each bit in the second set, remove a corresponding group of cells from a carrier aggregation (CA) configuration for the UE, wherein each bit in the second set corresponds to a group of cells in the set.

17. The UE of claim 16, wherein the at least one processor being configured to execute the computer-executable instructions and cause the UE to release the corresponding group of cells comprises the at least one processor being configured to execute the computer-executable instructions and cause the UE to deactivate each cell in the group from serving the UE.

18. The UE of claim 15, wherein: the at least one processor being configured to execute the computer-executable instructions and cause the UE to receive the signaling comprises the at least one processor being configured to execute the computer-executable instructions and further cause the UE to receive a second set of bits; and the at least one processor is configured to execute the computer-executable instructions and further cause the UE to for each bit in the second set, release the PHY layer or MAC layer mobility signaling configuration for each cell in the corresponding group of cells, wherein each bit in the second set corresponds to a group of cells in the set.

19. A network entity configured for wireless communications, comprising: a memory comprising computer-executable instructions; and at least one processor configured to execute the computer-executable instructions and cause the network entity to: transmit a configuration indicating a set of cells that are configured for serving a user equipment (UE) and support mobility signaling via physical (PHY) layer or medium access control (MAC) layer signaling; transmit first signaling that indicates a group of cells for the UE to remove from the set of cells; and remove the indicated group from the set of cells.

20. The network entity of claim 19, wherein the at least one processor being configured to execute the computer-executable instructions and cause the network entity to transmit the first signaling comprises the at least one processor being configured to execute the computer-executable instructions and cause the network entity to transmit at least one of a downlink control information (DCI) or a MAC control element (MAC CE).

21. The network entity of claim 19, wherein the at least one processor being configured to execute the computer-executable instructions and cause the network entity to transmit the first signaling comprises the at least one processor being configured to execute the computer-executable instructions and cause the network entity to transmit a first set of bits, each bit in the first set indicating whether to release a corresponding group of cells in the set of cells.

22. The network entity of claim 21, wherein: the at least one processor being configured to execute the computer-executable instructions and cause the network entity to transmit the first signaling comprises the at least one processor being configured to execute the computer-executable instructions and further cause the network entity to transmit a second set of bits; and the at least one processor is configured to execute the computer-executable instructions and further cause the network entity to indicate to the UE to remove a corresponding group of cells from a carrier aggregation (CA) configuration for the UE, wherein each bit in the second set corresponds to a group of cells in the set.

23. The network entity of claim 21, wherein: the at least one processor being configured to execute the computer-executable instructions and cause the network entity to transmit the first signaling comprises the at least one processor being configured to execute the computer-executable instructions and further cause the network entity to transmit a second set of bits; and the at least one processor is configured to execute the computer-executable instructions and further cause the network entity to indicate to the UE to release the PHY layer or MAC layer mobility signaling configuration for each cell in a corresponding group of cells, wherein each bit in the second set corresponds to a group of cells in the set.

24. The network entity of claim 19, wherein the at least one processor is configured to execute the computer-executable instructions and further cause the network entity to: monitor, during a period, for an acknowledgment (ACK) from the UE acknowledging a transport block (TB) having a TB identifier (ID) associated with the first signaling; and transmit second signaling that indicates the group of cells for the UE to remove from the set of cells in response to failing to detect the ACK during the period.