Timing adjustment instructions for multiple inter-cell transmission / reception points

Abstract

Certain aspects of the present disclosure generally provide a method for wireless communication by a user equipment (UE) that includes receiving a physical downlink control channel (PDCCH) command to trigger a PRACH transmission associated with an additional PCI different from a first PCI associated with a serving cell, transmitting the PRACH associated with the additional PCI, receiving an indication of a timing advance (TA) associated with the additional PCI via a MAC-CE, and applying the TA for an uplink transmission associated with the additional PCI.

Description

[Technical Field]

[0001] Field of Disclosure Aspects of the present disclosure relate to wireless communications, and more particularly, to techniques for random access procedures. [Background technology]

[0002] 2. Description of Related Art

[0002] Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, broadcast, or other similar types of services. These wireless communication systems may employ multiple access technologies capable of supporting communication with multiple users by sharing available wireless communication system resources with those users.

[0003]

[0003] Although wireless communication systems have made great technological advances over the years, challenges still exist. For example, complex and dynamic environments can still attenuate or block signals between wireless transmitters and wireless receivers. Therefore, there is a continuing desire to improve the technical performance of wireless communication systems, including, for example, improving the speed and data-carrying capacity of communication, improving the efficiency of use of shared communication media, reducing the power used by transmitters and receivers while performing communication, improving the reliability of wireless communication, avoiding redundant transmissions and / or receptions and associated processing, improving the coverage area of ​​wireless communication, increasing the number and types of devices that can access a wireless communication system, improving the ability of different types of devices to communicate with each other, and increasing the number and types of wireless communication media available for use. Therefore, further improvements in wireless communication systems are needed to overcome the aforementioned technical challenges and others. Summary of the Invention

[0004] One aspect provides a method of wireless communication by a user equipment (UE), the method including receiving a physical downlink control channel (PDCCH) command to trigger a physical random access channel (PRACH) transmission associated with an additional physical cell identifier (PCI) different from a first PCI associated with a serving cell, transmitting the PRACH associated with the additional PCI, receiving, via a medium access control (MAC) control element (MAC-CE), an indication of a timing advance (TA) associated with the additional PCI, and applying the TA for an uplink transmission associated with the additional PCI.

[0005] Another aspect provides a method of wireless communication by a network entity, the method including: transmitting a PDCCH command to a UE to trigger a PRACH transmission associated with an additional PCI different from a first PCI associated with a serving cell; receiving a PRACH associated with the additional PCI; and transmitting, via a MAC-CE to the UE, an indication of a TA associated with the additional PCI.

[0006]

[0006] Other aspects provide an apparatus operable, configured, or otherwise adapted to perform any one or more of the aforementioned methods and / or methods described elsewhere herein; a non-transitory computer-readable medium comprising instructions that, when executed by a processor of the apparatus, cause the apparatus to perform the aforementioned methods and methods described elsewhere herein; a computer program product embodied on a computer-readable storage medium comprising code for performing the aforementioned methods and methods described elsewhere herein; and / or an apparatus comprising means for performing the aforementioned methods and methods described elsewhere herein. By way of example, the apparatus may comprise a processing system, a device having a processing system, or processing systems that cooperate via one or more networks.

[0007]

[0007] The following description and the accompanying drawings set forth certain features for purposes of illustration. [Brief explanation of the drawings]

[0008]

[0008] The accompanying drawings illustrate some features of the various aspects described herein and should not be considered as limiting the scope of the present disclosure. [Figure 1]

[0009] 1 illustrates an exemplary wireless communication network. [Figure 2]

[0010] FIG. 1 illustrates an exemplary split base station architecture. [Figure 3]

[0011] FIG. 1 illustrates aspects of an exemplary base station and exemplary user equipment. [Figure 4A]

[0012] 1A-1C illustrate various exemplary aspects of data structures for wireless communication networks. [Figure 4B] 1A-1C illustrate various exemplary aspects of data structures for wireless communication networks. [Figure 4C] 1A-1C illustrate various exemplary aspects of data structures for wireless communication networks. [Figure 4D] 1A-1C illustrate various exemplary aspects of data structures for wireless communication networks. [Figure 5A]

[0013] 1 illustrates exemplary downlink control information (DCI) and multiple transmission / reception point (mTRP) operations, as well as an exemplary control resource set (CORESET) pool configuration. [Figure 5B] 1 illustrates exemplary downlink control information (DCI) and multiple transmission / reception point (mTRP) operations, as well as an exemplary control resource set (CORESET) pool configuration. [Figure 6]

[0014] 1 illustrates the association between active transmission configuration indicator (TCI) states and physical cell IDs (PCIs). [Figure 7A]

[0015] 1 illustrates an exemplary random access channel (RACH) configuration. [Figure 7B] 1 illustrates an exemplary random access channel (RACH) configuration. [Figure 8A]

[0016] 1 shows timing advance values ​​for a first TRP and a second TRP in a multi-TRP network. [Figure 8B] 1 shows timing advance values ​​for a first TRP and a second TRP in a multi-TRP network. [Figure 8C] 1 shows timing advance values ​​for a first TRP and a second TRP in a multi-TRP network. [Figure 9]

[0017] 1 illustrates an example RACH configuration according to various aspects of the present disclosure. [Figure 10]

[0018] 1 illustrates a call flow diagram for timing adjustment in a multiple transmission / reception point (mTRP) scenario, according to an aspect of the present disclosure. [Figure 11]

[0019] 1 illustrates a call flow diagram for timing adjustment in an mTRP scenario in accordance with certain aspects of the present disclosure. [Figure 12]

[0020] 1 illustrates a call flow diagram for timing adjustment in an mTRP scenario in accordance with certain aspects of the present disclosure. [Figure 13]

[0021] 1 illustrates a call flow diagram for timing adjustment in an mTRP scenario in accordance with certain aspects of the present disclosure. [Figure 14A]

[0022] 1 illustrates a call flow diagram for timing adjustment in an mTRP scenario, according to an aspect of the present disclosure. [Figure 14B] 1 illustrates a call flow diagram for timing adjustment in an mTRP scenario, according to an aspect of the present disclosure. [Figure 15]

[0023] SUMMARY OF THE INVENTION A method for wireless communication is presented. [Figure 16]

[0024] SUMMARY OF THE INVENTION A method for wireless communication is presented. [Figure 17]

[0025] 1 illustrates aspects of an exemplary communications device. [Figure 18]

[0026] 1 illustrates aspects of an exemplary communications device. DETAILED DESCRIPTION OF THE INVENTION

[0009]

[0027] Aspects of the present disclosure provide an apparatus, method, processing system, and computer-readable medium for physical random access channel (PRACH) enhancement for inter-cell multiple transmission / reception points (mTRP).

[0010]

[0028] In current wireless systems, a user equipment (UE) may be scheduled to transmit signaling to more than one TRP. In some cases, the UE may be configured with a timing advance (TA) for each scheduled transmission. The TA is used for time synchronization and determines when the UE sends an uplink transmission. The TA allows the UE to adjust the timing of an UL transmission to align it with a future transmission in the time domain. In other words, the TA value is designed to ensure that an uplink transmission arrives at a TRP that is aligned with a time slot boundary.

[0011]

[0029] The TA value is typically determined via a random access channel (RACH) procedure, in which the UE sends a first message called a physical RACH (PRACH) preamble to a network entity (e.g., a base station), which responds with a random access response (RAR) message (MSG2) that may include the TA value.

[0012]

[0030] For inter-cell mTRP operation, the UE and gNB may need to know the UL TA value for UL transmissions associated with TRPs associated with PCIs different from that of the serving cell. However, since PRACH transmissions are typically not supported in non-serving cells, it is unclear how to measure TA for PCIs different from that of the serving cell.

[0013]

[0031] However, aspects of the present disclosure provide techniques for determining a TA associated with an additional PCI that is different from the PCI associated with the serving cell. For example, according to some aspects, a UE may receive an instruction (or command) from a serving cell to trigger a PRACH transmission for the additional PCI. In response, the UE may transmit a PRACH for the additional PCI. The UE may then receive an indication of a TA value to apply to uplink transmissions associated with the additional PCI.

[0014]

[0032] Utilizing the techniques disclosed herein can help enable PRACH for non-serving cells. Thus, the techniques can enable a UE to efficiently acquire a TA value to apply at a non-serving cell before or when an additional PCI (e.g., a non-serving cell) is activated. Thus, the UE can synchronize to the non-serving cell faster, improving overall system performance and user experience.

[0015] Introduction to Wireless Communication Networks

[0033] The techniques and methods described herein can be used in various wireless communication networks. Although aspects may be described herein using terminology commonly associated with 3G, 4G, and / or 5G wireless technologies, aspects of the present disclosure may be equally applicable to other communication systems and standards not explicitly mentioned herein.

[0016]

[0034] FIG. 1 illustrates an example of a wireless communication network 100 in which aspects described herein can be implemented.

[0017]

[0035] Generally, wireless communication network 100 includes various network entities (alternatively, network elements or network nodes). A network entity is generally a communication device and / or a communication function performed by a communication device (e.g., user equipment (UE), base station (BS), components of a BS, server, etc.). For example, various functions of the network and various devices associated with and interacting with the network can be considered network entities. Furthermore, wireless communication network 100 includes terrestrial aspects, such as a ground-based network entity (e.g., BS 102), and non-terrestrial aspects, such as satellites 140 and aircraft 145, which can include on-board network entities (e.g., one or more BSs) capable of communicating with other network elements (e.g., terrestrial BSs) and user equipment.

[0018]

[0036] In the illustrated embodiment, wireless communication network 100 includes a BS 102, a UE 104, and one or more core networks, such as an Evolved Packet Core (EPC) 160 and a 5G Core (5GC) network 190, which interoperate to provide communication services over various communication links, including wired and wireless links.

[0019]

[0037] 1 illustrates various exemplary UEs 104, which may more generally include a cellular phone, a smartphone, a session initiation protocol (SIP) phone, a laptop, a personal digital assistant (PDA), a satellite radio, a global positioning system, a multimedia device, a video device, a digital audio player, a camera, a game console, a tablet, a smart device, a wearable device, a vehicle, an electric meter, a gas pump, a large or small kitchen appliance, a healthcare device, an implant, a sensor / actuator, a display, an internet of things (IoT) device, an always on (AON) device, an edge processing device, or other similar devices. The UEs 104 may also be more generally referred to as a mobile device, a wireless device, a wireless communication 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, etc.

[0020]

[0038] The BS 102 wirelessly communicates with the UE 104 (e.g., transmits signals to the UE 104 or receives signals from the UE 104) via a communication link 120. The communication link 120 between the BS 102 and the UE 104 may include uplink (UL) (also called a reverse link) transmissions from the UE 104 to the BS 102 and / or downlink (DL) (also called a forward link) transmissions from the BS 102 to the UE 104. The communication link 120 may use multiple-input multiple-output (MIMO) antenna technology, including spatial multiplexing, beamforming, and / or transmit diversity in various aspects.

[0021]

[0039] The BSs 102 may generally include a NodeB, an enhanced NodeB (eNB), a next generation enhanced NodeB (ng-eNB), a next generation NodeB (gNB or gNodeB), an access point, a base transceiver station, a radio base station, a radio transceiver, a transceiver function, a transmit / receive point, and / or others. Each of the BSs 102 may provide communication coverage for a respective geographic coverage area 110, which may be referred to as a cell and may in some cases overlap (e.g., a small cell 102′ may have a coverage area 110′ that overlaps with the coverage area 110 of a macro cell). The BSs may provide communication coverage for, for example, a macrocell (covering a relatively large geographic area), a picocell (covering a relatively smaller geographic area, such as a sports stadium), a femtocell (covering a relatively smaller geographic area (e.g., a home)), and / or other types of cells.

[0022]

[0040] Although the BS 102 is shown in various aspects as a single communications device, the BS 102 may be implemented in various configurations. For example, one or more components of a base station may be separated and include a central unit (CU), one or more distributed units (DUs), one or more radio units (RUs), a Near-Real Time (NRT) RAN Intelligent Controller (RIC), or a Non-Real Time (Non-RT) RIC, to name a few. In another example, various aspects of a base station may be virtualized. More generally, a base station (e.g., the BS 102) may include components located in a single physical location or components located in various physical locations. In examples where a base station includes components located in various physical locations, the various components may each perform functions such that the various components collectively achieve similar functionality as a base station located in a single physical location. In some aspects, a base station that includes components located at different 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. Figure 2 illustrates and describes an exemplary disaggregated base station architecture.

[0023]

[0041] Different BSs 102 in the wireless communication network 100 may also be configured to support different radio access technologies, such as 3G, 4G, and / or 5G. For example, a BS 102 configured for 4G LTE (collectively referred to as the Evolved Universal Mobile Telecommunications System Terrestrial Radio Access Network (E-UTRAN)) may interface with the EPC 160 via a first backhaul link 132 (e.g., an S1 interface). A BS 102 configured for 5G (e.g., 5G NR or Next Generation RAN (NG-RAN)) may interface with the 5GC 190 via a second backhaul link 184. The BSs 102 may communicate with each other directly or indirectly (e.g., via the EPC 160 or the 5GC 190) via a third backhaul link 134 (e.g., an X2 interface), which may be wired or wireless.

[0024]

[0042] The wireless communication network 100 may subdivide the electromagnetic spectrum into various classes, bands, channels, or other characteristics. In some aspects, the subdivision is based on wavelength and frequency, which may also be referred to as carriers, subcarriers, frequency channels, tones, or subbands. For example, 3GPP currently defines Frequency Range 1 (FR1) as including 410 MHz to 7125 MHz, which is often (interchangeably) referred to as "sub-6 GHz." Similarly, 3GPP currently defines Frequency Range 2 (FR2) as including 24,250 MHz to 52,600 MHz, which may (interchangeably) be referred to as "millimeter wave" ("mmW" or "mm-wave"). A base station configured to communicate using mm-wave / quasi-mm-wave radio frequency bands (e.g., an mm-wave base station such as BS180) can utilize beamforming (e.g., 182) with a UE (e.g., 104) to improve path loss and range.

[0025]

[0043] The communication link 120 between the BS 102 and, for example, the UE 104, may be via one or more carriers that may have different bandwidths (e.g., 5, 10, 15, 20, 100, 400, and / or other MHz) and may be aggregated in various manners. The carriers may or may not be adjacent to one another. The allocation of carriers may also be asymmetric for the DL and UL (e.g., more or fewer carriers may be allocated for the DL than for the UL).

[0026]

[0044] Communications using higher frequency bands may have higher path loss and shorter range compared to lower frequency communications. Therefore, some base stations (e.g., 180 in FIG. 1) may utilize beamforming 182 with the UE 104 to improve path loss and range. For example, the BS 180 and the UE 104 may each include multiple antennas, such as antenna elements, antenna panels, and / or antenna arrays, to facilitate beamforming. In some cases, the BS 180 may transmit beamformed signals to the UE 104 in one or more transmit directions 182′. The UE 104 may receive beamformed signals from the BS 180 in one or more receive directions 182″. The UE 104 may also transmit beamformed signals to the BS 180 in one or more transmit directions 182″. The BS 180 may also receive beamformed signals from the UE 104 in one or more receive directions 182′. The BS 180 and the UE 104 may then perform beam training to determine the best receive and transmit directions for each of the BS 180 and the UE 104. In particular, the transmit and receive directions for the BS 180 may or may not be the same. Similarly, the transmit and receive directions for the UE 104 may or may not be the same.

[0027]

[0045] The wireless communication network 100 further includes a Wi-Fi AP 150 in communication with Wi-Fi stations (STAs) 152 via communication links 154, for example, in the 2.4 GHz and / or 5 GHz unlicensed frequency spectrum.

[0028]

[0046] Several UEs 104 may communicate with each other using a device-to-device (D2D) communication link 158. The D2D communication 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).

[0029]

[0047] The EPC 160 may include various functional components, including, for example, in the illustrated example, 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. The MME 162 may be in communication with a Home Subscriber Server (HSS) 174. The MME 162 is a control node that handles signaling between the UE 104 and the EPC 160. Generally, the MME 162 provides bearer and connection management.

[0030]

[0048] Generally, user Internet protocol (IP) packets are forwarded through a serving gateway 166, which itself is connected to a PDN gateway 172. The PDN gateway 172 provides UE IP address allocation and other functions. The 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), Packet Switched (PS) streaming services, and / or other IP services.

[0031]

[0049] The BM-SC 170 may provide MBMS user service provisioning and distribution functionality. The BM-SC 170 may serve as the entry point for content provider MBMS transmissions, may be used to authorize and initiate MBMS bearer services within the public land mobile network (PLMN), and / or may be used to schedule MBMS transmissions. The MBMS Gateway 168 may be used to deliver MBMS traffic to BSs 102 that belong to a Multicast Broadcast Single Frequency Network (MBSFN) area that broadcasts a particular service, and / or may be responsible for session management (start / stop) and collecting eMBMS-related charging information.

[0032]

[0050] The 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. The AMF 192 may be in communication with a Unified Data Management (UDM) 196.

[0033]

[0051] The AMF 192 is a control node that handles signaling between the UE 104 and the 5GC 190. The AMF 192 provides, for example, quality of service (QoS), flow and session management.

[0034]

[0052] Internet Protocol (IP) packets are forwarded through UPF 195, which connects to IP services 197 and provides UE IP address allocation and other functions for 5GC 190. IP services 197 may include, for example, Internet, Intranet, IMS, PS streaming services, and / or other IP services.

[0035]

[0053] In various aspects, a network entity or network node may be implemented as an aggregated base station, as a separate base station, as a component of a base station, as an integrated access and backhaul (IAB) node, as a relay node, as a sidelink node, to name a few.

[0036]

[0054] 2 illustrates the architecture of an exemplary separated base station 200. The separated 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 via one or more separated base station units (e.g., 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). The CUs 210 can communicate with one or more distributed units (DUs) 230 via respective midhaul links, such as an F1 interface. The DUs 230 can communicate with one or more radio units (RUs) 240 via respective fronthaul links. The RUs 240 can communicate with respective UEs 104 via one or more radio frequency (RF) access links. In some implementations, a UE 104 may be served by multiple RUs 240 simultaneously.

[0037]

[0055] Each of the units, e.g., CU 210, DU 230, RU 240, and quasi-RT RIC 225, non-RT RIC 215, and SMO framework 205, may include 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 that provides instructions to the unit's communication interface, may be configured to communicate with one or more of the other units via a transmission medium. For example, a unit may include a wired interface configured to receive signals from or transmit signals to one or more of the other units via a wired transmission medium. Additionally or alternatively, a unit may include a wireless interface, which may include a receiver, transmitter, or transceiver (e.g., a radio frequency (RF) transceiver) configured to receive, transmit, or transmit signals via a wireless transmission medium to one or more of the other units.

[0038]

[0056] In some aspects, the CU 210 can host one or more higher-layer control functions. Such control functions may include Radio Resource Control (RRC), Packet Data Convergence Protocol (PDCP), Service Data Adaptation Protocol (SDAP), etc. Each control function may implement 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 functions (e.g., Central Unit-User Plane (CU-UP)), control plane functions (e.g., Central Unit-Control Plane (CU-CP)), or a combination thereof. In some implementations, the CU 210 may be logically divided into one or more CU-UP units and one or more CU-CP units. The CU-UP units, when implemented in an O-RAN configuration, may communicate bidirectionally with the CU-CP units via an interface, such as an E1 interface. The CU 210 may be implemented to communicate with the DU 230 as needed for network control and signaling.

[0039]

[0057] The DU 230 may correspond to a logical unit including one or more base station functions for controlling 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 upper physical (PHY) layers (e.g., modules for forward error correction (FEC) encoding and decoding, scrambling, modulation and demodulation, etc.) at least in part according to a functional division such as that defined by the 3rd Generation Partnership Project (3GPP). In some aspects, the DU 230 may further host one or more lower PHY layers. Each layer (or module) may implement an interface configured to communicate signals with other layers (and modules) hosted by the DU 230 or with control functions hosted by the CU 210.

[0040]

[0058] The lower layer functions may be implemented by one or more RUs 240. In some deployments, the RUs 240 controlled by the DU 230 may correspond to logical nodes hosting RF processing functions, lower PHY layer functions (such as performing fast Fourier transforms (FFTs), inverse FFTs (iFFTs), digital beamforming, physical random access channel (PRACH) extraction and filtering, and the like), or both, based at least in part on a functional division, such as a lower layer functional division. In such an architecture, the RU(s) 240 may 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 may be controlled by the corresponding DU 230. In some scenarios, this configuration may enable the DU(s) 230 and CU 210 to be implemented in a cloud-based RAN architecture, such as a vRAN architecture.

[0041]

[0059] 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 deployment of dedicated physical resources for RAN coverage requirements, which may be managed via an operations and maintenance interface (e.g., an O1 interface). For virtualized network elements, the SMO framework 205 may be configured to interact with a cloud computing platform (e.g., an open cloud (O-cloud) 290) via a cloud computing platform interface (e.g., an O2 interface) to perform network element lifecycle management (e.g., instantiate virtualized network elements). Such virtualized network elements may include, but are not limited to, the CU 210, the DU 230, the RU 240, and the quasi-RT RIC 225. In some implementations, the SMO framework 205 may communicate with hardware aspects of a 4G RAN, such as the open eNB (O-eNB) 211, via the O1 interface. Additionally, in some implementations, the SMO framework 205 can communicate directly with one or more RUs 240 via an O1 interface. The SMO framework 205 can also include a non-RT RIC 215 configured to support the functionality of the SMO framework 205.

[0042]

[0060] The non-RT RIC 215 can be configured to include logic functions that enable 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 / functions in the quasi-RT RIC 225. The non-RT RIC 215 can be coupled to or communicate with the quasi-RT RIC 225 (e.g., via an A1 interface). The quasi-RT RIC 225 can be configured to include logic functions that enable near-real-time control and optimization of RAN elements and resources through data collection and action via interfaces (e.g., via an E2 interface) that connect one or more CUs 210, one or more DUs 230, or both, and the O-eNB to the quasi-RT RIC 225.

[0043]

[0061] In some implementations, the non-RT RIC 215 can receive parameters or external enrichment information from an external server to generate AI / ML models to be deployed in the quasi-RT RIC 225. Such information can be utilized by the quasi-RT RIC 225 and can be received at the SMO framework 205 or the non-RT RIC 215 from non-network data sources or from network functions. In some embodiments, the non-RT RIC 215 or the quasi-RT RIC 225 can be configured to adjust RAN behavior or performance. For example, the non-RT RIC 215 may employ AI / ML models to monitor long-term trends and patterns in performance and take corrective action via the SMO framework 205 (e.g., reconfiguration via O1) or through the creation of RAN management policies (e.g., A1 policies).

[0044]

[0062] FIG. 3 illustrates an exemplary BS 102 and UE 104 aspect.

[0045]

[0063] Generally, the BS 102 includes various processors (e.g., 320, 330, 338, and 340), antennas 334a-t (collectively 334), transceivers 332a-t (collectively 332) including modulators and demodulators, and other aspects that enable wireless transmission of data (e.g., data source 312) and wireless reception of data (e.g., data sink 339). For example, the BS 102 can transmit and receive data between the BS 102 and the UE 104. The BS 102 includes a controller / processor 340 that can be configured to implement various functions described herein related to wireless communication.

[0046]

[0064] Generally, the UE 104 includes various processors (e.g., 358, 364, 366, and 380), antennas 352a-r (collectively 352), transceivers 354a-r (collectively 354) including modulators and demodulators, and other aspects that enable wireless transmission of data (e.g., received from a data source 362) and wireless reception of data (e.g., provided to a data sink 360). The UE 104 includes a controller / processor 380 that can be configured to implement various functions described herein related to wireless communication.

[0047]

[0065] For an exemplary downlink transmission, BS 102 includes a transmit processor 320 that can receive data from a data source 312 and control information from a controller / processor 340. The control information may be for a physical broadcast channel (PBCH), a physical control format indicator channel (PCFICH), a physical HARQ indicator channel (PHICH), a physical downlink control channel (PDCCH), a group common PDCCH (GC PDCCH), and / or others. In some examples, the data may be for a physical downlink shared channel (PDSCH).

[0048]

[0066] The transmit processor 320 may process (e.g., encode and symbol map) the data and control information to obtain data symbols and control symbols, respectively. The transmit processor 320 may also generate reference symbols, such as for a primary synchronization signal (PSS), a secondary synchronization signal (SSS), a PBCH demodulation reference signal (DMRS), and a channel state information reference signal (CSI-RS).

[0049]

[0067] The transmit (TX) multiple-input multiple-output (MIMO) processor 330 may perform spatial processing (e.g., precoding) on ​​the data symbols, control symbols, and / or reference symbols, if applicable, and may provide output symbol streams to modulators (MODs) in transceivers 332a through 332t. Each modulator in transceiver 332a through 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. The downlink signals from the modulators in transceivers 332a through 332t may be transmitted via antennas 334a through 334t, respectively.

[0050]

[0068] To receive downlink transmissions, the UE 104 includes antennas 352a through 352r, which can receive downlink signals from the BS 102 and can provide received signals to demodulators (DEMODs) within transceivers 354a through 354r, respectively. Each demodulator within the transceivers 354a through 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.

[0051]

[0069] The MIMO detector 356 may obtain received symbols from all demodulators in the transceivers 354a-354r, perform MIMO detection on the received symbols if applicable, and provide detected symbols. The receive processor 358 may process (e.g., demodulate, deinterleave, and decode) the detected symbols and provide decoded data for the UE 104 to a data sink 360 and decoded control information to the controller / processor 380.

[0052]

[0070] For an exemplary uplink transmission, the UE 104 further includes a transmit processor 364 that can receive and process data (e.g., for a PUSCH) from a data source 362 and control information (e.g., for a physical uplink control channel (PUCCH)) from a controller / processor 380. The transmit processor 364 can also generate reference symbols for a reference signal (e.g., for a 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 a modulator in the transceiver 354a-354r (e.g., for SC-FDM, etc.), and transmitted to the BS 102.

[0053]

[0071] At BS 102, the uplink signals from UE 104 may be received by antennas 334a-t, processed by demodulators in transceivers 332a-t, 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 a controller / processor 340.

[0054]

[0072] Memories 342 and 382 may store data and program codes for BS 102 and UE 104, respectively.

[0055]

[0073] A scheduler 344 may schedule UEs for data transmission on the downlink and / or uplink.

[0056]

[0074] In various aspects, the 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 for outputting data, such as outputting data from the data source 312, the scheduler 344, the memory 342, the transmit processor 320, the controller / processor 340, the TX MIMO processor 330, the transceivers 332a-t, the antennas 334a-t, and / or other aspects described herein. Similarly, "receiving" may refer to various mechanisms for obtaining data, such as obtaining data from the antennas 334a-t, the transceivers 332a-t, the RX MIMO detector 336, the controller / processor 340, the receive processor 338, the scheduler 344, the memory 342, and / or other aspects described herein.

[0057]

[0075] In various aspects, the UE 104 may similarly 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 for outputting data, such as outputting data from the data source 362, memory 382, ​​transmit processor 364, controller / processor 380, TX MIMO processor 366, transceivers 354a-t, antennas 352a-t, and / or other aspects described herein. Similarly, "receiving" may refer to various mechanisms for obtaining data, such as obtaining data from the antennas 352a-t, transceivers 354a-t, RX MIMO detector 356, controller / processor 380, receive processor 358, memory 382, ​​and / or other aspects described herein.

[0058]

[0076] In some aspects, the processor may be configured to perform various operations, such as those associated with the methods described herein, to transmit (output) data to or receive (obtain) data from another interface configured to transmit or receive data, respectively.

[0059]

[0077] 4A, 4B, 4C, and 4D illustrate aspects of data structures for a wireless communication network, such as wireless communication network 100 of FIG.

[0060]

[0078] In particular, FIG. 4A is a diagram 400 illustrating an example of a first subframe in a 5G (e.g., 5G NR) frame structure, FIG. 4B is a diagram 430 illustrating an example of a DL channel in a 5G subframe, FIG. 4C is a diagram 450 illustrating an example of a second subframe in a 5G frame structure, and FIG. 4D is a diagram 480 illustrating an example of a UL channel in a 5G subframe.

[0061]

[0079] Wireless communication 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 into multiple orthogonal subcarriers (e.g., as shown in FIGS. 4B and 4D). 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.

[0062]

[0080] The wireless communication frame structure may be frequency division duplex (FDD) where, for a particular set of subcarriers, subframes within the set of subcarriers are dedicated to either DL or UL. The wireless communication frame structure may also be time division duplex (TDD) where, for a particular set of subcarriers, subframes within the set of subcarriers are dedicated to both DL and UL.

[0063]

[0081] In Figures 4A and 4C, the wireless communication frame structure is TDD, where D is DL, U is UL, and X is flexible for use between DL and UL. The UE can be configured with the slot format via a received slot format indicator (SFI) (dynamically via DL control information (DCI) or semi-statically / statically via radio resource control (RRC) signaling). In the illustrated example, a 10 ms frame is divided into ten equally sized 1 ms subframes. Each subframe may contain one or more time slots. In some examples, each slot may contain 7 or 14 symbols, depending on the slot format. A subframe may also contain a minislot, which generally has fewer symbols than an entire slot. Other wireless communication technologies may have different frame structures and / or different channels.

[0064]

[0082] In some aspects, the number of slots in a subframe is based on the slot configuration and numerology. For example, for slot configuration 0, different numerologies (μ) 0-5 allow 1, 2, 4, 8, 16, and 32 slots per subframe, respectively. For slot configuration 1, different numerologies 0-2 allow 2, 4, and 8 slots per subframe, respectively. Thus, for slot configuration 0 and numerology μ, there are 14 symbols / slot and 2μ slots / subframe. Subcarrier spacing and symbol length / duration are functions of numerology. Subcarrier spacing is 2 μThe symbol length / duration may be equal to 15 kHz × 15 kHz, where μ is a numerology between 0 and 5. Thus, numerology μ=0 has a subcarrier spacing of 15 kHz, and numerology μ=5 has a subcarrier spacing of 480 kHz. The symbol length / duration is inversely proportional to the subcarrier spacing. Figures 4A, 4B, 4C, and 4D provide an example of slot configuration 0 with 14 symbols per slot and numerology μ=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 μs.

[0065]

[0083] A resource grid can be used to represent the frame structure, as shown in Figures 4A, 4B, 4C, and 4D. Each time slot includes resource blocks (RBs) (also called physical RBs (PRBs)), for example, spanning 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.

[0066]

[0084] As shown in Figure 4A, some of the REs carry reference (pilot) signals (RSs) for the UE (e.g., the UE 104 in Figures 1 and 3). The RSs may include demodulation RSs (DMRSs) and / or channel state information reference signals (CSI-RSs) for channel estimation at the UE. The RSs may also include beam measurement RSs (BRSs), beam refinement RSs (BRRSs), and / or phase tracking RSs (PT-RSs).

[0067]

[0085] 4B shows an example of various DL channels within a subframe of a frame. The physical downlink control channel (PDCCH) carries DCI in one or more control channel elements (CCEs), each CCE including, for example, 9 RE groups (REGs), each REG including, for example, 4 consecutive REs within an OFDM symbol.

[0068]

[0086] A primary synchronization signal (PSS) may be present in symbol 2 of a particular subframe of a frame. The PSS is used by the UE (e.g., 104 in Figures 1 and 3) to determine subframe / symbol timing and physical layer identification information.

[0069]

[0087] A secondary synchronization signal (SSS) may be present in symbol 4 of a particular subframe of a frame. The SSS is used by the UE to determine the group number of the physical layer cell identity and the timing of the radio frame.

[0070]

[0088] Based on the physical layer identity and the group number of the physical layer cell identity, the UE can determine the physical cell identifier (PCI). Based on the PCI, the UE can determine the location of the above-mentioned DMRS. The physical broadcast channel (PBCH), which carries the master information block (MIB), may be logically grouped with the PSS and SSS to form a synchronization signal (SS) / PBCH block. The MIB provides the number of RBs in the system bandwidth and the system frame number (SFN). The physical downlink shared channel (PDSCH) carries user data, broadcast system information not transmitted over the PBCH, such as system information blocks (SIBs), and / or paging messages.

[0071]

[0089] As shown in FIG. 4C , some of the REs carry DMRS (denoted as R for one particular configuration, but other DMRS configurations are possible) for channel estimation at the base station. The UE can transmit DMRS for PUCCH and DMRS for PUSCH. The PUSCH DMRS can be transmitted, for example, within the first one or two symbols of the PUSCH. The PUCCH DMRS can be transmitted in different configurations depending on whether a short or long PUCCH is transmitted and the specific PUCCH format used. The UE 104 can transmit a sounding reference signal (SRS). The SRS can be transmitted, for example, within the last symbol of a subframe. The SRS can have comb configurations, and the UE can transmit the SRS in one of the combs. The SRS can be used by the base station for channel quality estimation to enable frequency-dependent scheduling on the UL.

[0072]

[0090] 4D shows an example of various UL channels within a subframe of a frame. The PUCCH, in one configuration, may be arranged as shown. The PUCCH carries uplink control information (UCI), such as scheduling requests, channel quality indicators (CQI), precoding matrix indicators (PMI), rank indicators (RI), and HARQ ACK / NACK feedback. The PUSCH carries data and, in addition, may be used to carry buffer status reports (BSR), power headroom reports (PHR), and / or UCI.

[0073] Overview of mTRPs

[0091] Current wireless systems support multiple transmission / reception point (mTRP) signaling based on single or multiple downlink control information (DCI) transmissions. In a single DCI scenario, a single DCI is sent to schedule mTRP transmissions. In a multiple DCI scenario, each TRP sends a separate DCI.

[0074]

[0092] As illustrated in the mTRP scenario shown in FIG. 5A, a first DCI transmitted from a first TRP (TRP1) (carried via PDCCH1) may schedule a first physical downlink shared channel (PDSCH1) transmitted from TRP1. A second DCI transmitted from a second TRP (TRP2) (carried via PDCCH2) may schedule a second PDSCH (PDSCH2) transmitted from TRP2. For uplink mDCI mTRP, a first DCI transmitted from a first TRP (TRP1) (carried via PDCCH1) may schedule a first physical uplink shared channel (PUSCH1) transmitted to TRP1. A second DCI transmitted from a second TRP (TRP2) (carried via PDCCH2) may schedule a second PUSCH (PUSCH2) transmitted to TRP2.

[0075]

[0093] The differentiation of TRPs can be performed by the user equipment (UE) based on a pool index value (e.g., CORESETPoolIndex) defined within a control resource set (CORESET) for each TRP. In many cases, a UE is configured with multiple DCI-based TRPs on a given component carrier (CC). Each CORESET can be configured with a CORESETPoolIndex value. In many cases, up to five CORESETs can be configured.

[0076]

[0094] As shown in FIG. 5B, the value of CORESETPoolIndex may be assigned an ID of 0 or 1. The CORESETPoolIndex value can group CORESETs into two groups. For example, CORESETs with CORESET IDs 1 and 2 may be grouped when CORESETPoolIndex is equal to 0. CORESETs with CORESET IDs 3 and 4 may be grouped when CORESETPoolIndex is equal to 1. In many cases, a UE may be able to distinguish TRPs from each other. In some cases, a UE may be configured by higher layer parameters (e.g., PDCCH-Config) that include two different values ​​of CORESETPoolIndex in each CORESET for the active bandwidth part (BWP) of the serving cell. In many cases, the CORESETPoolIndex of the CORESET in which DCI is received may be used for different purposes. For example, CORESETPoolIndex may be used for hybrid automatic repeat request (HARQ) acknowledgment (ACK) feedback.

[0077]

[0095] Different TRPs may have the same physical cell identifier (PCI) (inter-cell mTRP) but different panels or remote radio heads (RRHs) of the same cell or base station. In some cases, different TRPs may have different PCIs (inter-cell mTRPs). In such cases, from the UE's perspective, an mTRP may still be defined in a given serving cell, but the UE may only recognize one PCI (e.g., the PCI for the cell the UE acquired during cell search).

[0078] Overview of TCI conditions

[0096] A user equipment (UE) may be RRC configured with a list of up to M (e.g., M=128) candidate transmission configuration indication (TCI) states, at least for the purpose of quasi-co-location (QCL) indication. In such cases, the TCI states may be configured / defined in the PDSCH configuration, but the "TCI-StateId" may be used to configure TCI states for other purposes, such as CORESET, non-zero-power channel state information reference signal (NZP-CSI-RS) resources, physical uplink control channel (PUCCH) resources, and sounding reference signal (SRS) resources.

[0079]

[0097] A medium access control (MAC) control element (MAC-CE) is used to activate a subset (e.g., up to two) of the M TCI states configured for the PDSCH QCL indication for a given CORESETPoolIndex. For the PDCCH, the MAC-CE activates one TCI state. N bits in the DCI can dynamically indicate one of the activated TCI states (e.g., N=3 to indicate one of eight activated TCI states) for the PDSCH transmission. For multi-DCI-based mTRP (e.g., in Rel. 16), the PDSCH is associated with the CORESETPoolIndex value of the CORESET in which the DCI is received.

[0080] Overview of intercellular mTRPs

[0098] For inter-cell mTRP, the maximum number of additional RRC-configured PCIs per CC may be denoted as X and may be reported as a UE capability. In some cases, a UE may support two independent X values ​​(X1, X2), which may be reported as a UE capability. Different values ​​may be selected for two different assumptions regarding the additional SSB time-domain location and periodicity with respect to the serving cell SSB. For example, in the first case (e.g., Case A), X1 may represent the maximum number of configured additional PCIs when the SSB time-domain location and periodicity configurations of the additional PCIs are the same as those of the serving cell PCI. In the second case (e.g., Case B), X2 may represent the maximum number of configured additional PCIs when the SSB time-domain location and periodicity configurations of the additional PCIs do not follow Case A. By definition, Case A and Case B may not be allowed to be enabled simultaneously. From an RRC signaling perspective, the number of configured additional PCIs may be selected from the group {1, 2, 3, 4, 5, 6, 7}. In some cases, this UE capability may depend on the frequency range (for example, there may be a distinction between FR1 and FR2).

[0081]

[0099] Various parameters, such as center frequency, subcarrier spacing (SCS), and system frame number (SFN) offset, may be assumed to be the same for SSBs from a serving cell and SSBs with a PCI different from the serving cell configured for inter-cell multi-TRP operation.

[0082]

[0100] In some cases, an RRC indicator / signaling (e.g., re-indexing the non-serving cell) may be used to indicate the non-serving cell information with which the TCI state / QCL information is associated, where the new indicator / signaling is not the exact PCI value.

[0083]

[0101] Generally, there is an association between PCI and CORESETPoolIndex. Generally, a serving cell PCI is associated with an active TCI state, and only one additional PCI may be associated with an active TCI state. In the case of inter-cell mTRP, one PCI associated with one or more activated TCI states for PDSCH / PDCCH is associated with one CORESETPoolIndex. Another PCI associated with one or more activated TCI states for PDSCH / PDCCH may be associated with another CORESETPoolIndex.

[0084]

[0102] 6 shows an example of an association between active TCI states and PCIs. As illustrated, a first MAC CE may activate a first subset 612 of TCI states (from a set 610 of RRC-configured TCI states) for CORESETPoolIndex 0. This first subset of TCI states may be associated with a first PCI, PCI x. In this example, PCI x is associated with CORESETPoolIndex 0. A second MAC CE may activate a second subset 614 of TCI states for CORESETPoolIndex 1. This second subset of TCI states may be associated with a second PCI, PCI y. In this example, PCI y is associated with CORESETPoolIndex y. At least one of PCI x and PCI y may be assumed to be a serving cell PCI, while at most one of PCI x and PCI y may be a non-serving cell PCI.

[0085] Aspects Relating to PRACH Extensions for Inter-Cell mTRP

[0103] As explained above, the TA value is typically determined via a RACH procedure, in which the UE sends a first message called a PRACH preamble to a network entity (e.g., a base station), which responds with a Random Access Response (RAR) message (MSG2) that may include the TA value.

[0086]

[0104] In some systems (e.g., NR Rel.16 / Rel.17), PRACH resources can be configured for each BWP of the serving cell (e.g., via a common RACH configuration rach-ConfigCommon). Except in the case of handover, the UE can be configured with a dedicated RACH configuration (rach-ConfigDedicated, e.g., by reconfigurationWithSync) to perform random access toward neighboring cells (non-serving cells). Figures 7A and 7B show example RACH configurations for the serving cell and SpCell (the primary cell of the master or secondary cell group). As shown, the RACH configuration can be per BWP.

[0087]

[0105] In an mTRP scenario, such as that shown in FIG. 8A, where a UE transmits uplink transmissions to a first TRP and a second TRP according to dynamic or configured scheduling, it may be desirable to allow each TRP to belong to a different TA group (TAG). As mentioned above, a UE may be configured with two TAs for UL multi-DCI transmissions for multi-TRP operation. To account for different propagation delays from various TRPs, the UE may apply different TAs for UL transmissions to different TRPs. Each different TA may be associated with several TRPs.

[0088]

[0106] Therefore, different TRPs may have different TA values ​​for UL transmissions, as shown in Figures 8B and 8C, where TA1 is used for transmissions to TRP1 and TA2 is used for transmissions to TRP2. As a result, scheduled UL transmissions may overlap in time.

[0089]

[0107] For inter-cell mTRP operation, the UE and gNB may need to know the UL TA value for UL transmissions associated with TRPs associated with PCIs different from that of the serving cell. However, since PRACH transmissions are typically not supported in non-serving cells, it is unclear how to measure TA for PCIs different from that of the serving cell.

[0090]

[0108] However, aspects of the present disclosure provide techniques for determining a TA associated with an additional PCI that is different from the PCI associated with the serving cell.

[0091]

[0109] For example, according to some aspects, a UE may receive a PDCCH command (or instruction) from a serving cell to trigger a PRACH transmission for an additional PCI. In some cases, the PDCCH command may be transmitted from the serving cell, e.g., when the additional PCI is not associated with any active TCI state (e.g., when the additional PCI is not activated). In other cases, the PDCCH command may be transmitted from a non-serving cell having the additional PCI, e.g., when the additional PCI is associated with one or more active TCI states (e.g., when the additional PCI is activated). In response, the UE may transmit a PRACH for the additional PCI. The UE may then receive an indication of a TA value to apply to uplink transmissions associated with the additional PCI.

[0092]

[0110] In some cases, a list of PRACH configurations associated with additional PCIs (different from the serving cell PCI) may be configured to support TA measurements for PCIs different from the serving cell. In other words, the UE may receive signaling indicating a set of Physical Random Access Channel (PRACH) configurations.

[0093]

[0111] A list of PRACH configurations may be configured for each serving cell, as shown in Figure 9. For each non-serving cell PRACH configuration in the list, various parameters may be configured. For example, these parameters may include an additional PCI (different from the serving cell PCI), which may be configured explicitly (e.g., by an additional PCI) or implicitly (e.g., based on an additional PCI index).

[0094]

[0112] Also, as shown in FIG. 9, for each non-serving cell PRACH configuration in the list, a general RACH configuration may be included in addition to several SSBs per RACH occasion (RO).

[0095]

[0113] Each generic RACH configuration may include one or more of a time domain location, a frequency domain location, a number of frequency division multiplexed (FDMed) RACH occasions (ROs) (e.g., msg1-FDM), a PRACH transmit (Tx) power configuration, and a maximum number of RA preamble transmissions. The time domain location may be indicated by a parameter prach-ConfigurationIndex, where the table indicates an entry from a predefined table that defines the time domain pattern of the PRACH preamble. The frequency domain location may be indicated by a starting physical resource block (PRB) msg1-FrequencyStart. The PRACH Tx power configuration may include preambleReceivedTargetPower and powerRampingStep. The maximum number of RA preamble transmissions may be indicated by a parameter preambleTransMax.

[0096]

[0114] The general procedure proposed herein for triggering a PRACH in a non-serving cell having an additional PCI to obtain a UL TA for the additional PCI different from the serving cell PCI can be understood with reference to the call flow diagram 1000 of FIG. 10.

[0097]

[0115] The example of Figure 10 shows a first case (Case 1) in which the triggered PRACH is associated with an additional PCI that is already associated with an active TCI state (e.g., the additional PCI is active). In the second case (Case 2) shown in Figure 11, the PRACH is associated with an additional PCI that is not associated with an active TCI state (e.g., the additional PCI is not active).

[0098]

[0116] In the example shown in Figure 10, the TRP of the serving cell may have a first PCI, while additional PCIs may be associated with the TRPs of non-serving cells. The operation of the serving and non-serving cells may be directed by a network entity (e.g., a gNB or a node such as a CU of a separate base station). The following description refers to a gNB, with the understanding that other network entities may perform the same or similar operations.

[0099]

[0117] As shown, in a first step (1), after RRC configuration, the UE may perform SSB measurements based on SSB configurations associated with the serving cell and non-serving cells and report the measurement results to the serving cell TRP. For example, the reported measurement results may include physical layer (Layer 1 or L1)-Reference Signal Received Power (L1-RSRP) measurements.

[0100]

[0118] In a second step (2), the gNB may trigger contention-free random access (CFRA) for additional PCIs by transmitting a PDCCH command after receiving a measurement report of a non-serving cell. For example, the gNB may select which non-serving cell to instruct the UE to transmit a PRACH on based on the measurement results received in the report. In the example shown in FIG. 10, the PDCCH command is transmitted from the serving cell. In some cases, the PDCCH command may be transmitted from additional PCIs (e.g., non-serving cells), which is not shown in FIG. 10.

[0101]

[0119] The PDCCH order may carry DCI format 1_0 scrambled by a Cell Radio Network Temporary Identifier (C-RNTI) with the Frequency Domain Resource Allocation (FDRA) field set to all ones. The PDCCH order may indicate various parameters for the PRACH transmission. For example, the parameters may include a random access preamble index, an SSB index, and a PRACH mask index.

[0102]

[0120] Additionally, to distinguish which PRACH configuration is used for PRACH transmission, additional fields may be included in the PDCCH order to indicate a PRACH configuration from the list of PRACH configurations described above. Some of the reserved fields in the PDCCH order may be reused to indicate additional PCIs of the PRACH configuration.

[0103]

[0121] A conventional (e.g., legacy) PDCCH order may not include a PRACH configuration-related indication because the PRACH configuration for the serving cell is used. However, in the case of inter-cell mTRP, it may be necessary to indicate in the PDCCH order which PRACH configuration should be used.

[0104]

[0122] In a third step (3), upon receiving the PDCCH command, the UE transmits the PRACH based on the instruction in the PDCCH command. In some cases, a related parameter (e.g., preambleReceivedTargetPower, powerRampingStep, or preambleTransMax) in the PRACH configuration associated with the additional PCI indicated in the PDCCH command may be used to determine the PRACH transmit power.

[0105]

[0123] As shown in the call flow diagram 1100 of Figure 11, a PRACH transmission may also be triggered if the PRACH is associated with an additional PCI that is not associated with an active TCI state (Case 2). In this case, the additional PCI indicated in the PDCCH command may be activated after the PRACH transmission.

[0106]

[0124] From the network (gNB) perspective, after receiving the PRACH, the TRP associated with the additional PCI (different from the serving cell) may measure the TA for the additional PCI. The TRP may then indicate the TA to the UE once the TCI state associated with the additional PCI is activated. From the UE perspective, the UE may only send the PRACH and transmit on the UL based on the TA indication from the gNB.

[0107]

[0125] According to some aspects, in the case of multiple TAs for inter-cell mTRPs, a UE capability may be defined, which may be reported to indicate the UE's ability to support multiple TAs.

[0108]

[0126] In some cases, the reported capability may indicate that the UE is able to maintain at least two TAs for intercell mTRPs. This may be an optional UE capability that may be signaled separately from the two TAs for intercell mTRPs. The UE may also indicate various capabilities, such as the ability to support (at least) two TAs for intracell mTRPs only, or the ability to support (at least) two TAs for both intracell and intercell mTRPs.

[0109]

[0127] In some cases, the maximum number of PRACH configurations associated with the additional PCI may be defined as a UE capability. For example, a UE may report that it supports two independent Y values ​​(Y1, Y2) due to two different assumptions regarding the additional SSB time-domain location and periodicity for the serving cell SSB. For example, Y1 (e.g., for case A) may represent the maximum number of PRACH configurations associated with the additional PCI when the SSB time-domain location and periodicity configurations of the additional PCI are the same as those of the serving cell PCI. Y2 (e.g., for case B) may represent the maximum number of PRACH configurations associated with the additional PCI when the SSB time-domain location and periodicity configurations of the additional PCI do not follow case A.

[0110] Aspects of how to indicate TA for additional PCI

[0128] Aspects of the present disclosure provide various options for how to indicate a TA for additional PCI without traditional random access response (RAR) monitoring.

[0111]

[0129] To indicate a TA for an additional PCI different from the serving cell, the cases where the PRACH is associated with an additional PCI that is already associated with an active TCI state (Case 1) as well as the case where the PRACH is associated with an active TCI state and an additional PCI that is not associated with an active TCI state (Case 2) may be considered.

[0112]

[0130] In case 1, when the UE receives a TA command MAC CE, the UE may apply the TA command after a certain time period from the reception of the MAC CE. The time period may follow the conventional processing time of the existing TA command MAC CE.

[0113]

[0131] In case 2, the UE may need to save the TA and start using it only after an active TCI state associated with the additional PCI is indicated in the MAC CE (e.g., via a TCI Activation MAC CE).

[0114]

[0132] To ensure that a stored TA does not expire, a time window can be defined, as shown in call flow diagram 1200 of Figure 12. This time window can define the period during which the stored TA is valid.

[0115]

[0133] The window may start from the end of PRACH transmission or from the end of TA command MAC CE reception, as shown in Figure 12. The duration of the window may be predefined or configurable.

[0116]

[0134] If an additional PCI is activated during the window, the UE may apply the TA saved for the additional PCI, as in the example shown in Figure 12. Otherwise, the UE may drop the TA saved for the additional PCI.

[0117]

[0135] In some cases, the maximum number of TAs that the UE can store may be reported as a UE capability. The reported value may indicate the maximum number of TAs within a serving cell or the maximum number of TAs across all serving cells.

[0118]

[0136] There are various options for how to indicate the TA using the TA command MAC CE.

[0119]

[0137] For example, according to the first option, the TA command may indicate a TA adjustment value for a previous TA associated with the same CORESETPoolIndex as the additional PCI, in which case the TA associated with the additional PCI may be obtained by applying the TA adjustment value on the previous TA.

[0120]

[0138] According to a second option, the TA command indicates a TA offset relative to a reference initial TA. The TA associated with the additional PCI is obtained by applying a TA offset on top of the reference initial TA. The reference initial TA can be the latest initial TA of the serving cell. If the serving cell PCI is associated with two CORESETPoolIndex values, the initial TA associated with a fixed CORESETPoolIndex value (e.g., the lowest or highest CORESETPoolIndex value) can be used as the reference initial TA.

[0121]

[0139] These different options may require different inter-TRP coordination and may be applicable in different cases.

[0122]

[0140] For the first option, inter-TRP coordination without UE involvement may be required to obtain the previous TA associated with the same CORESETPoolIndex as the additional PCIs. For example, the TRPs associated with the serving cell PCI and the additional PCIs may need to communicate with each other to obtain the TAs associated with each of the additional PCIs.

[0123]

[0141] One potential advantage of the first option is that TA updates across additional PCIs may be transparent to the UE. The first option may not be optimal in some cases because the TRP may not know the absolute UL TA value. Additionally, if the CORESETPoolIndex associated with the additional PCI has not previously been associated with any PCI, there may be no previous TA associated with the CORESETPoolIndex (e.g., there is no reference TA for the TA adjustment value).

[0124]

[0142] As shown in the call flow diagram 1300 of FIG. 13, in the first option, some inter-TRP coordination without UE involvement may be required to obtain the TA offset between the TA of the activated additional PCI and the current TA of the second additional PCI associated with the same CORESETPoolIndex value as the activated additional PCI (e.g., the first additional PCI requests the current TA associated with the second additional PCI).

[0125]

[0143] As shown in call flow diagram 1400A of FIG. 14A, according to a first alternative, a TRP associated with an activated additional PCI can request an initial TA associated with a serving cell PCI, and the TRP associated with the serving cell PCI can send the initial TA to the TRP associated with the activated additional PCI in response to the request.

[0126]

[0144] As shown in call flow diagram 1400B of FIG. 14B, according to a second alternative, a TRP associated with a serving cell PCI can proactively send an initial TA associated with the serving cell PCI without a request associated with an additional PCI.

[0127]

[0145] For the second option, the TRP may not need to know the absolute UL TA, but the UE may need to be able to distinguish whether the TA command should indicate a TA offset relative to a reference initial TA or a TA adjustment relative to a previous TA (e.g., a legacy TA command).

[0128]

[0146] To address this, various options can be used. For example, the conventional (legacy) TA command MAC CE can be used, and some type of rule can be defined to distinguish it from the legacy TA command MAC CE. For example, the time window can be predefined or configured. The start position and duration of the time window can be predefined or configured. For example, the start position can be the end of the PRACH transmission or X symbols / slots after the PRACH transmission. The duration can be a predefined or configured value.

[0129]

[0147] In some cases, the first MAC CE after a PRACH transmission that corresponds to an additional PCI and indicates the same TAG ID associated with the same CORESETPoolIndex as the additional PCI may be used to indicate a TA offset relative to the reference initial TA. For case 1, the TAG ID associated with the additional PCI may be pre-configured or determined based on the CORESETPoolIndex value associated with the additional PCI. For case 2, the TAG ID associated with the additional PCI may need to be pre-configured. For example, this may be because the CORESETPoolIndex associated with the additional PCI based on the TCI-activating MAC CE is not yet known.

[0130]

[0148] In some cases, a new TA command MAC CE may be defined to indicate a TA offset relative to a reference initial TA, in which case the new TA command MAC CE may include additional PCI information.

[0131] Exemplary Operation of User Equipment

[0149] FIG. 15 illustrates an example method 1500 for wireless communication by a UE, such as the UE 104 of FIGS. 1 and 3.

[0132]

[0150] Method 1500 begins with receiving a PDCCH command to trigger a PRACH transmission associated with an additional PCI different from a first PCI associated with a serving cell in step 1505. In some cases, the operations of this step may refer to or be performed by circuitry and / or code for receiving, such as those described with reference to FIG.

[0133]

[0151] Method 1500 then proceeds to step 1510, where the PRACH associated with the additional PCI is transmitted. In some cases, the operations of this step may refer to or be performed by transmitting circuitry and / or code such as those described with reference to FIG. 17.

[0134]

[0152] Method 1500 then proceeds to step 1515, where method 1500 receives, via the MAC-CE, an indication of a TA associated with the additional PCI. In some cases, the operations of this step may refer to or be performed by receiving circuitry and / or code such as those described with reference to FIG.

[0135]

[0153] Method 1500 then proceeds to step 1520 and applies the TA for uplink transmissions associated with the additional PCI. In some cases, the operations of this step may refer to or be performed by applying circuitry and / or applying code such as those described with reference to FIG.

[0136]

[0154] In some aspects, the additional PCI is associated with one or more active TCI states.

[0137]

[0155] In some aspects, the UE applies the TA a period of time after receiving the indication.

[0138]

[0156] In some aspects, the time period corresponds to a processing time associated with the received instruction.

[0139]

[0157] In some aspects, the additional PCI is not associated with any active TCI state.

[0140]

[0158] In some aspects, method 1500 further includes storing the TA for a duration, the end of which defines when the stored TA expires. In some cases, the operations of this step may refer to or be performed by storing circuitry and / or code, such as those described with reference to FIG. 17.

[0141]

[0159] In some aspects, the duration is predefined.

[0142]

[0160] In some aspects, the duration begins at the end of the PRACH transmission or at the end of the MAC-CE reception.

[0143]

[0161] In some aspects, method 1500 further includes receiving an indication of activation of one or more TCI states associated with the additional PCI. In some cases, the operations of this step may refer to or be performed by receiving circuitry and / or code such as those described with reference to FIG.

[0144]

[0162] In some aspects, the indication of activation of one or more TCI states is received via the MAC-CE.

[0145]

[0163] In some aspects, an indication of activation of one or more TCI states is received within a duration, and applying the TA includes applying a TA saved for uplink transmissions associated with additional PCIs after the indication of activation of the one or more TCI states is received.

[0146]

[0164] In some aspects, method 1500 further includes transmitting, to the serving cell, UE capability information indicating at least one maximum number of TAs the UE is capable of storing. In some cases, operations of this step may refer to or be performed by circuitry and / or code for transmitting, such as those described with reference to FIG. 17 .

[0147]

[0165] In some aspects, the at least one maximum number of TAs indicates a maximum number of TAs that the UE may store in a serving cell.

[0148]

[0166] In some aspects, the received indication of the TA indicates a TA adjustment value for a previous TA associated with the same CORESET pool index as the additional PCI.

[0149]

[0167] In some aspects, the received indication of the TA indicates a TA offset value relative to a reference initial TA, the reference initial TA comprising at least one of the most recent initial TA of the serving cell or the most recent initial TA associated with a fixed CORESET pool index value.

[0150]

[0168] In some aspects, the first MAC-CE received within a time window after a PRACH transmission indicates a TA offset relative to a reference initial TA and a TAG ID, where the TAG ID is associated with an additional PCI and associated with a CORESET pool index value associated with the additional PCI.

[0151]

[0169] In some embodiments, the association between the TAG ID and the additional PCI is pre-configured.

[0152]

[0170] In some aspects, the association between the TAG ID and the additional PCI is determined based on an association between the TAG ID and a CORESET pool index associated with the additional PCI.

[0153]

[0171] In some aspects, the time window begins a time period after the PRACH transmission, and the duration of the time window is predefined or configured by the RRC.

[0154]

[0172] In some aspects, the MAC-CE is in the same format as the previous TA command MAC-CE.

[0155]

[0173] In some aspects, the MAC-CE includes information regarding the additional PCI.

[0156]

[0174] In one aspect, method 1500, or any aspect related thereto, may be performed by an apparatus such as communications device 1700 of Figure 17 that includes various components operable, configured, or adapted to perform method 1500. Communications device 1700 is described in further detail below.

[0157]

[0175] It should be noted that FIG. 15 is merely one example of a method, and that other methods including fewer, additional, or alternative steps are possible consistent with this disclosure.

[0158] Exemplary Operation of a Network Entity

[0176] FIG. 16 illustrates an example method 1600 for wireless communication by a network entity, such as the BS 102 of FIGS. 1 and 3, or a separate base station as described with respect to FIG.

[0159]

[0177] Method 1600 begins with transmitting a PDCCH command to a UE to trigger a PRACH transmission associated with an additional PCI different from a first PCI associated with the serving cell in step 1605. In some cases, operations in this step may refer to or be performed by circuitry and / or code for transmitting, such as those described with reference to FIG.

[0160]

[0178] Method 1600 then proceeds to step 1610, where a PRACH associated with the additional PCI is received. In some cases, the operations of this step may refer to or be performed by receiving circuitry and / or code such as those described with reference to FIG.

[0161]

[0179] Method 1600 then proceeds to step 1615, where method 1600 transmits an indication of the TA associated with the additional PCI to the UE via the MAC-CE. In some cases, operations at this step may refer to or be performed by circuitry and / or code for transmitting, such as those described with reference to FIG. 18.

[0162]

[0180] In some aspects, the additional PCI is associated with one or more active TCI states.

[0163]

[0181] In some aspects, the additional PCI is not associated with any active TCI state.

[0164]

[0182] In some aspects, the method 1600 further includes transmitting to the UE an indication of activation of one or more TCI states associated with the additional PCI. In some cases, operations of this step may refer to or be performed by circuitry and / or code for transmitting, such as those described with reference to FIG. 18 .

[0165]

[0183] In some aspects, the indication of activation of one or more TCI states is transmitted via the MAC-CE.

[0166]

[0184] In some aspects, the method 1600 further includes receiving, from the UE, UE capability information indicating at least one maximum number of TAs that the UE can store. In some cases, operations of this step may refer to or be performed by circuitry and / or code for receiving, such as those described with reference to FIG. 18 .

[0167]

[0185] In some aspects, the at least one maximum number of TAs indicates a maximum number of TAs that the UE may store in a serving cell.

[0168]

[0186] In some aspects, the transmitted indication of the TA indicates a TA adjustment value for a previous TA associated with the same CORESET pool index as the additional PCI.

[0169]

[0187] In some aspects, the transmitted indication of the TA indicates a TA offset value relative to a reference initial TA, the reference initial TA comprising at least one of the most recent initial TA of the serving cell or the most recent initial TA associated with a fixed CORESET pool index value.

[0170]

[0188] In some aspects, the MAC-CE is in the same format as the previous TA command MAC-CE.

[0171]

[0189] In some aspects, the first MAC-CE transmitted within a time window after the PRACH transmission indicates a TA offset relative to a reference initial TA and a TAG ID, where the TAG ID is associated with an additional PCI and associated with a CORESET pool index value associated with the additional PCI.

[0172]

[0190] In some embodiments, the association between the TAG ID and the additional PCI is pre-configured.

[0173]

[0191] In some aspects, the association between the TAG ID and the additional PCI is determined based on an association between the TAG ID and a CORESET pool index associated with the additional PCI.

[0174]

[0192] In some aspects, the time window begins a time period after the PRACH transmission, and the duration of the time window is predefined or configured by the RRC.

[0175]

[0193] In some aspects, the MAC-CE includes information regarding the additional PCI.

[0176]

[0194] In one aspect, method 1600, or any aspect related thereto, may be performed by an apparatus such as communications device 1800 of Figure 18 that includes various components operable, configured, or adapted to perform method 1600. Communications device 1800 is described in further detail below.

[0177]

[0195] It should be noted that FIG. 16 is merely one example of a method, and that other methods including fewer, additional, or alternative steps are possible consistent with this disclosure.

[0178] Exemplary Communication Devices

[0196] 17 illustrates an aspect of an exemplary communications device 1700. In some aspects, the communications device 1700 is user equipment, such as the UE 104 described above with respect to FIGS.

[0179]

[0197] Communications device 1700 includes a processing system 1705 coupled to a transceiver 1765 (e.g., a transmitter and / or a receiver). The transceiver 1765 is configured to transmit and receive signals for communications device 1700, such as various signals as described herein, via an antenna 1770. Processing system 1705 may be configured to perform processing functions for communications device 1700, including processing signals received by and / or to be transmitted by communications device 1700.

[0180]

[0198] The processing system 1705 includes one or more processors 1710. In various aspects, the one or more processors 1710 may represent one or more of the receive processor 358, the transmit processor 364, the TX MIMO processor 366, and / or the controller / processor 380, as described with respect to FIG. 3. The one or more processors 1710 are coupled to a computer-readable medium / memory 1735 via a bus 1760. In some aspects, the computer-readable medium / memory 1735 is configured to store instructions (e.g., computer-executable code) that, when executed by the one or more processors 1710, cause the one or more processors 1710 to perform the method 1500 described with respect to FIG. 15, or any aspects related thereto. It should be noted that reference to a processor performing a function of the communications device 1700 may include one or more processors 1710 performing that function of the communications device 1700.

[0181]

[0199] In the depicted example, computer-readable medium / memory 1735 stores code (e.g., executable instructions), such as code for receiving 1740, code for sending 1745, code for applying 1750, and code for storing 1755. Processing of code for receiving 1740, code for sending 1745, code for applying 1750, and code for storing 1755 may cause communications device 1700 to perform method 1500, or any aspect related thereto, as described with respect to FIG.

[0182]

[0200] The one or more processors 1710 include circuitry configured to implement (e.g., execute) code stored on a computer-readable medium / memory 1735, including circuitry such as a circuit for receiving 1715, a circuit for transmitting 1720, a circuit for applying 1725, and a circuit for storing 1730. Processing by the circuit for receiving 1715, the circuit for transmitting 1720, the circuit for applying 1725, and the circuit for storing 1730 may cause the communications device 1700 to perform the method 1500 described with respect to FIG. 15, or any aspect related thereto.

[0183]

[0201] Various components of the communications device 1700 may provide means for performing the method 1500 described with respect to Figure 15, or any aspects related thereto. For example, the means for transmitting, sending, or outputting for transmission may include the transceiver 354 and / or the antenna(s) 352 of the UE 104 shown in Figure 3 and / or the transceiver 1765 and antenna 1770 of the communications device 1700 of Figure 17. The means for receiving or obtaining may include the transceiver 354 and / or the antenna(s) 352 of the UE 104 shown in Figure 3 and / or the transceiver 1765 and antenna 1770 of the communications device 1700 of Figure 17.

[0184]

[0202] 18 illustrates aspects of an exemplary communications device 1800. In some aspects, the communications device 1800 is a network entity, such as the BS 102 of FIGS. 1 and 3, or a separate base station as described with respect to FIG.

[0185]

[0203] Communications device 1800 includes a processing system 1805 coupled to a transceiver 1840 (e.g., a transmitter and / or receiver) and / or a network interface 1850. The transceiver 1840 is configured to transmit and receive signals for communications device 1800, such as various signals as described herein, via an antenna 1845. The network interface 1850 is configured to obtain and send signals for communications device 1800 via communication link(s), such as a backhaul link, a midhaul link, and / or a fronthaul link described herein, such as with respect to FIG. 2. The processing system 1805 may be configured to perform processing functions for communications device 1800, including processing signals received by and / or to be transmitted by communications device 1800.

[0186]

[0204] The processing system 1805 includes one or more processors 1810. In various aspects, the one or more processors 1810 may represent one or more of the receive processor 338, the transmit processor 320, the TX MIMO processor 330, and / or the controller / processor 340, as described with respect to FIG. 3. The one or more processors 1810 are coupled to a computer-readable medium / memory 1825 via a bus 1835. In some aspects, the computer-readable medium / memory 1825 is configured to store instructions (e.g., computer-executable code) that, when executed by the one or more processors 1810, cause the one or more processors 1810 to perform the method 1600 described with respect to FIG. 16, or any aspects related thereto. It should be noted that reference to a processor of the communications device 1800 performing a function may include the one or more processors 1810 of the communications device 1800 performing that function.

[0187]

[0205] In the depicted example, computer-readable medium / memory 1825 stores code (e.g., executable instructions), such as code for transmitting 1830 and code for receiving 1835. Processing of code for transmitting 1830 and code for receiving 1835 may cause communications device 1800 to perform method 1600, or any aspect related thereto, described with respect to FIG.

[0188]

[0206] The one or more processors 1810 include circuitry configured to implement (e.g., execute) code stored on a computer-readable medium / memory 1825, including circuitry such as a circuit for transmitting 1815 and a circuit for receiving 1820. Processing by the circuit for transmitting 1815 and the circuit for receiving 1820 may cause the communications device 1800 to perform the method 1600 described with respect to FIG.

[0189]

[0207] Various components of the communications device 1800 may provide means for performing the method 1600 described with respect to Figure 16, or any aspects related thereto. The means for transmitting, sending, or outputting for transmission may include the transceiver 332 and / or the antenna(s) 334 of the BS 102 shown in Figure 3, and / or the transceiver 1840 and antenna 1845 of the communications device 1800 of Figure 18. The means for receiving or acquiring may include the transceiver 332 and / or the antenna(s) 334 of the BS 102 shown in Figure 3, and / or the transceiver 1840 and antenna 1845 of the communications device 1800 of Figure 18.

[0190] Example clauses

[0208] Example implementations are described in the following numbered clauses.

[0191]

[0209] Clause 1: A method for wireless communication by a UE, comprising: receiving a PDCCH command for triggering a PRACH transmission associated with an additional PCI different from a first PCI associated with a serving cell; transmitting the PRACH associated with the additional PCI; receiving, via a MAC-CE, an indication of a TA associated with the additional PCI; and applying the TA for an uplink transmission associated with the additional PCI.

[0192]

[0210] Clause 2: The method of clause 1, wherein the additional PCI is associated with one or more active TCI states.

[0193]

[0211] Clause 3: The method of clause 2, wherein the UE applies the TA for a period of time after receiving the instruction.

[0194]

[0212] Clause 4: The method of clause 3, wherein the time period corresponds to a processing time associated with the received instruction.

[0195]

[0213] Clause 5: The method of any one of clauses 1 to 4, wherein the additional PCI is not associated with any active TCI state.

[0196]

[0214] Clause 6: The method of clause 5, further comprising storing the TA for a duration, the end of the duration defining when the stored TA expires.

[0197]

[0215] Clause 7: The method of clause 6, wherein the duration is predefined.

[0198]

[0216] Clause 8: The method of clause 6, wherein the duration starts at the end of the PRACH transmission or at the end of the MAC-CE reception.

[0199]

[0217] Clause 9: The method of clause 6, further comprising receiving an indication of activation of one or more TCI states associated with the additional PCI.

[0200]

[0218] Clause 10: The method of clause 9, wherein the indication of activation of one or more TCI states is received via a MAC-CE.

[0201]

[0219] Clause 11: The method of clause 9, wherein an indication of activation of one or more TCI states is received within a duration, and applying the TA includes applying a TA saved for uplink transmissions associated with additional PCIs after the indication of activation of one or more TCI states is received.

[0202]

[0220] Clause 12: The method of clause 6, further comprising: transmitting UE capability information to the serving cell, the UE capability information indicating at least one maximum number of TAs that the UE can store.

[0203]

[0221] Clause 13: The method of clause 12, wherein the at least one maximum number of TAs indicates a maximum number of TAs that the UE can store in one serving cell.

[0204]

[0222] Clause 14: The method of any one of clauses 1 to 13, wherein the received indication of the TA indicates a TA adjustment value with respect to a previous TA associated with the same CORESET pool index as the additional PCI.

[0205]

[0223] Clause 15: A method according to any one of clauses 1 to 14, wherein the received indication of the TA indicates a TA offset value relative to a reference initial TA, the reference initial TA comprising at least one of the latest initial TA of the serving cell or the latest initial TA associated with a fixed CORESET pool index value.

[0206]

[0224] Clause 16: The method described in clause 15, wherein the first MAC-CE received within a time window after a PRACH transmission indicates a TA offset relative to a reference initial TA and a TAG ID, the TAG ID being associated with an additional PCI and a CORESET pool index value associated with the additional PCI.

[0207]

[0225] Clause 17: The method of clause 16, wherein the association between the TAG ID and the additional PCI is preconfigured.

[0208]

[0226] Clause 18: The method of clause 16, wherein the association between the TAG ID and the additional PCI is determined based on an association between the TAG ID and a CORESET pool index associated with the additional PCI.

[0209]

[0227] Clause 19: The method according to clause 16, wherein the time window starts a time period after a PRACH transmission, the duration of the time window being predefined or configured by the RRC.

[0210]

[0228] Clause 20: The method according to any one of clauses 1 to 19, wherein the MAC-CE is in the same format as the previous TA command MAC-CE.

[0211]

[0229] Clause 21: The method of any one of clauses 1 to 20, wherein the MAC-CE includes information regarding additional PCI.

[0212]

[0230] Clause 22: A method for wireless communication by a network entity, the method comprising: sending a PDCCH command to a UE to trigger a PRACH transmission associated with an additional PCI different from a first PCI associated with a serving cell; receiving a PRACH associated with the additional PCI; and sending an indication of a TA associated with the additional PCI to the UE via a MAC-CE.

[0213]

[0231] Clause 23: The method of clause 22, wherein the additional PCI is associated with one or more active TCI states.

[0214]

[0232] Clause 24: The method of any one of clauses 22 and 23, wherein the additional PCI is not associated with any active TCI state.

[0215]

[0233] Clause 25: The method of any one of clauses 22 to 24, further comprising sending to the UE an indication of activation of one or more TCI states associated with the additional PCI.

[0216]

[0234] Clause 26: The method of clause 25, wherein the indication of activation of one or more TCI states is sent via MAC-CE.

[0217]

[0235] Clause 27: The method of any one of clauses 22 to 26, further comprising receiving, from the UE, UE capability information indicating at least one maximum number of TAs that the UE can store.

[0218]

[0236] Clause 28: The method of clause 27, wherein the at least one maximum number of TAs indicates a maximum number of TAs that the UE can store in one serving cell.

[0219]

[0237] Clause 29: The method of any one of clauses 22 to 28, wherein the transmitted instruction of the TA indicates a TA adjustment value with respect to a previous TA associated with the same CORESET pool index as the additional PCI.

[0220]

[0238] Clause 30: A method according to any one of clauses 22 to 29, wherein the transmitted indication of the TA indicates a TA offset value relative to a reference initial TA, the reference initial TA comprising at least one of the latest initial TA of the serving cell or the latest initial TA associated with a fixed CORESET pool index value.

[0221]

[0239] Clause 31: The method according to any one of clauses 22 to 30, wherein the MAC-CE is in the same format as the previous TA command MAC-CE.

[0222]

[0240] Clause 32: A method according to any one of clauses 22 to 31, wherein the first MAC-CE transmitted within a time window after the PRACH transmission indicates a TA offset relative to a reference initial TA and a TAG ID, the TAG ID being associated with an additional PCI and associated with a CORESET pool index value associated with the additional PCI.

[0223]

[0241] Clause 33: The method of clause 32, wherein the association between the TAG ID and the additional PCI is preconfigured.

[0224]

[0242] Clause 34: The method of clause 32, wherein the association between the TAG ID and the additional PCI is determined based on an association between the TAG ID and a CORESET pool index associated with the additional PCI.

[0225]

[0243] Clause 35: The method according to clause 32, wherein the time window starts a time period after a PRACH transmission, the duration of the time window being predefined or configured by the RRC.

[0226]

[0244] Clause 36: The method of any one of clauses 22 to 35, wherein the MAC-CE includes information regarding additional PCI.

[0227]

[0245] Clause 37: An apparatus comprising: a memory containing executable instructions; and a processor configured to execute the executable instructions to cause the apparatus to perform a method according to any one of clauses 1 to 36.

[0228]

[0246] Clause 38: An apparatus comprising means for carrying out the method according to any one of clauses 1 to 36.

[0229]

[0247] Clause 39: A non-transitory computer-readable medium comprising executable instructions that, when executed by a processor of a device, cause the device to perform a method according to any one of clauses 1 to 36.

[0230]

[0248] Clause 40: A computer program product embodied on a computer-readable storage medium comprising code for performing the method of any one of clauses 1 to 36.

[0231] Additional Considerations

[0249] The foregoing description is provided to enable any person skilled in the art to practice the various aspects described herein. The examples described herein do not limit the scope, applicability, or aspects described 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 described without departing from the scope of the disclosure. Various embodiments may omit, substitute, or add various steps or components as appropriate. For example, described methods may be performed in an order different from that described, or various actions may be added, omitted, or combined. Also, features described with respect to some embodiments may be combined in some other embodiments. For example, an apparatus may be implemented or a method may be practiced using any number of the aspects described herein. Additionally, the scope of the disclosure is intended to encompass apparatuses or methods that are practiced using other structure, functions, or structure and functions in addition to or other than the various aspects of the disclosure described herein. It should be understood that any aspect of the disclosure disclosed herein may be embodied by one or more elements of a claim.

[0232]

[0250] The various example logic blocks, modules, and circuits described in connection with this disclosure may be implemented or performed using a general-purpose processor, 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 alternatively, 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, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, a system on a chip (SoC), or any other such configuration.

[0233]

[0251] As used herein, phrases referring to "at least one of" a list of items refer to any combination of those items, including single members. By way of example, "at least one of a, b, or c" is intended to encompass a, b, c, ab, ac, bc, and abc, as well as any combination having multiples of the same element (e.g., aa, aaa, aab, aac, abb, acc, bb, bbb, bbc, cc, and ccc, or any other permutation of a, b, and c).

[0234]

[0252] 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, database, or another data structure), ascertaining, etc. Also, "determining" may include receiving (e.g., receiving information), accessing (e.g., accessing data in a memory), etc. Also, "determining" may include resolving, selecting, choosing, establishing, etc.

[0235]

[0253] The methods disclosed herein include one or more actions that achieve the method. The actions of those methods 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. Furthermore, the various operations of the methods described above may be performed by any suitable means capable of performing the corresponding functions. These means may include various hardware and / or software component(s) and / or various hardware and / or software module(s), including, but not limited to, circuits, application specific integrated circuits (ASICs), or processors.

[0236]

[0254] The following claims are not intended to be limited to the embodiments set forth herein, but are to be accorded the full scope consistent with the language of the claims. Within the claims, reference to an element by the singular is intended to mean "one and only one," unless expressly stated otherwise, and rather "one or more." The term "some" refers to one or more, unless expressly stated otherwise. Claim elements are not 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 of the elements of the various embodiments described throughout this disclosure that are known or later become known to those skilled in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Furthermore, nothing disclosed herein is intended to be made available to the public, regardless of whether such disclosure is expressly recited in the claims.

Claims

1. 1. A method of wireless communication by a user equipment (UE), comprising: receiving a physical downlink control channel (PDCCH) command to trigger a physical random access channel (PRACH) transmission associated with an additional physical cell identifier (PCI) different from a first physical cell identifier (PCI) associated with the serving cell; transmitting a PRACH associated with the additional PCI; receiving, via a Medium Access Control (MAC) Control Element (MAC-CE), an indication of a timing advance (TA) associated with the additional PCI; and applying the TA for uplink transmissions associated with the additional PCI.

2. The method of claim 1 , wherein the additional PCI is associated with one or more active TCI states.

3. The method of claim 2 , wherein the UE applies the TA for a period of time after receiving the indication.

4. The method of claim 3 , wherein the time period corresponds to a processing time associated with the received instruction.

5. The method of claim 1 , wherein the additional PCI is not associated with any active TCI state.

6. The method of claim 5 , further comprising storing the TA for a duration, the end of the duration defining when the stored TA expires.

7. The method of claim 6 , wherein the duration is predefined.

8. The method of claim 6 , wherein the duration starts at the end of the PRACH transmission or at the end of reception of the MAC-CE.

9. The method of claim 6 , further comprising receiving an indication of activation of one or more TCI states associated with the additional PCI.

10. 10. The method of claim 9, wherein the indication of the activation of one or more TCI states is received via a MAC-CE.

11. the indication of the activation of one or more TCI states is received within the duration; 10. The method of claim 9, wherein applying the TA comprises applying the saved TA for uplink transmissions associated with the additional PCI after the indication of the activation of one or more TCI states is received.

12. The method of claim 6 , further comprising: transmitting UE capability information to a serving cell indicating at least one maximum number of TAs that the UE can store.

13. The method of claim 12 , wherein the maximum number of the at least one TA indicates a maximum number of TAs that the UE can store in one serving cell.

14. 2. The method of claim 1, wherein the received indication of the TA indicates a TA adjustment value with respect to a previous TA associated with the same control resource set (CORESET) pool index as the additional PCI.

15. The received indication of the TA indicates a TA offset value relative to a reference initial TA, and the reference initial TA is: the most recent initial TA of the serving cell; or a most recent initial TA associated with a fixed control resource set (CORESET) pool index value.

16. The method of claim 1 , wherein the MAC-CE is in the same format as a previous TA command MAC-CE.

17. a first MAC-CE received within a time window after the PRACH transmission; The TA offset relative to a reference initial TA; and a TA Group (TAG) Identifier (ID), the TAG ID being associated with the additional PCI and associated with a CORESET Pool Index value associated with the additional PCI.

18. The method of claim 17 , wherein the association between the TAG ID and the additional PCI is preconfigured.

19. 18. The method of claim 17, wherein the association between the TAG ID and the additional PCI is determined based on the association between the TAG ID and the CORESET pool index associated with the additional PCI.

20. the time window begins a time period after the PRACH transmission; 18. The method of claim 17, wherein the duration of the time window is predefined or configured by RRC.

21. The method of claim 1 , wherein the MAC-CE includes information regarding the additional PCI.

22. 1. A method of wireless communication by a network entity, comprising: transmitting a physical downlink control channel (PDCCH) command to a user equipment (UE) to trigger a physical random access channel (PRACH) transmission associated with an additional physical cell identifier (PCI), the additional physical cell identifier being different from a first physical cell identifier (PCI) associated with the serving cell; receiving a PRACH associated with the additional PCI; and transmitting an indication of a timing advance (TA) associated with the additional PCI to the UE via a medium access control (MAC) control element (MAC-CE).

23. 23. The method of claim 22, wherein the additional PCI is associated with one or more active TCI states.

24. 23. The method of claim 22, wherein the additional PCI is not associated with any active TCI state.

25. 23. The method of claim 22, further comprising: sending to the UE an indication of activation of one or more TCI states associated with the additional PCI.

26. 26. The method of claim 25, wherein the indication of the activation of one or more TCI states is sent via MAC-CE.

27. 23. The method of claim 22, further comprising receiving UE capability information from the UE indicating at least one maximum number of TAs the UE can store.

28. 28. The method of claim 27, wherein the maximum number of the at least one TA indicates a maximum number of TAs that the UE can store in one serving cell.

29. 23. The method of claim 22, wherein the transmitted indication of the TA indicates a TA adjustment value with respect to a previous TA associated with the same control resource set (CORESET) pool index as the additional PCI.

30. The transmitted indication of the TA indicates a TA offset value relative to a reference initial TA, and the reference initial TA is: the most recent initial TA of the serving cell; or 23. The method of claim 22, wherein the at least one of: a most recent initial TA associated with a fixed control resource set (CORESET) pool index value;

31. 23. The method of claim 22, wherein the MAC-CE is in the same format as a previous TA command MAC-CE.

32. a first MAC-CE transmitted within a time window after transmitting the PRACH; The TA offset relative to a reference initial TA; and a TA Group (TAG) Identifier (ID), the TAG ID being associated with the additional PCI and associated with a CORESET Pool Index value associated with the additional PCI.

33. 33. The method of claim 32, wherein the association between the TAG ID and the additional PCI is preconfigured.

34. 33. The method of claim 32, wherein the association between the TAG ID and the additional PCI is determined based on the association between the TAG ID and the CORESET pool index associated with the additional PCI.

35. the time window begins a time period after the PRACH transmission; 33. The method of claim 32, wherein the duration of the time window is predefined or configured by RRC.

36. The method of claim 22, wherein the MAC-CE includes information regarding the additional PCI.

37. 37. An apparatus comprising: a memory containing executable instructions; and a processor configured to execute the executable instructions to cause the apparatus to perform a method according to any one of claims 1 to 36.

38. 37. Apparatus comprising means for carrying out the method of any one of claims 1 to 36.

39. 37. A non-transitory computer-readable medium comprising executable instructions that, when executed by a processor of a device, cause the device to perform the method of any one of claims 1 to 36.

40. 37. A computer program product embodied on a computer readable storage medium comprising code for performing the method of any one of claims 1 to 36.

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