Multiple transmission points (m-TRP) connection setup

Abstract

A method, apparatus, and computer readable medium are provided. In the context of a method, the method receives configuration information related to a plurality of transmission-reception points (TRPs) of a cell, wherein the configuration information comprises at least one random access channel (RACH) configuration related to the plurality of TRPs of the cell. The method initiates a state transition to a radio resource control connected state under the cell based on the configuration information. The method initiates a setup or resume operation based on the configuration information prior to connecting to the at least one of the plurality of TRPs of the cell.

Description

MULTIPLE TRANSMISSION POINTS (M-TRP) CONNECTION SETUPTECHNOLOGICAL FIELD

[0001] An example embodiment relates to setting up user equipment connectivity with multipleTRPs (mTRP).BACKGROUND

[0002] Intra-cell TRP operation aims at improving user equipment throughput or robustness using multiple transmission points (m-TRPs) controlled under the same cell. To communicate with two cells in uplink, a user equipment needs to maintain timing advance timers for two TRPs. A user equipment may obtain a timing advance (TA) that the user equipment uses in the same serving cell through a physical downlink control channel (PDCCH) ordered random access channel (RACH). The PDCCH ordered RACH indicates the user equipment to initiate the random access procedure towards the additional TRP. After the user equipment sends the preamble, the network indicates a timing advance command with a mapping to the additional TRP timing advance, which the user equipment stores and uses while sending uplink messages to the second TRP.

[0003] A serving cell (e.g., network node 112 in FIG. 1) can schedule the user equipment from two TRPs, providing better coverage, reliability, and / or data rates for physical downlink shared channel (PDSCH), physical downlink control channel (PDCCH), physical uplink shared channel (PUSCH), and physical uplink control channel (PUCCH). Multi-TRP PDSCH transmissions may be scheduled with single-downlink control information (DCI) and multi-DCI operation modes. For each mode, control of uplink and downlink operation can be done by physical layer and medium access control (MAC) layer within the configuration provided by the radio resource control (RRC) layer. In a single-DCI mode, the user equipment 110 is scheduled by the same DCI for both TRPs. In multi-DCI mode, the user equipment 110 is scheduled by independent DCIs from each TRP.

[0004] There are two different operation modes for multi-TRP PDCCH: PDCCH repetition and single frequency network (SFN) based PDCCH transmission. In both modes, the user equipment 110 can receive two PDCCH transmissions (one from each TRP) carrying the same DCI. In PDCCH repetition mode, the user equipment 110 can receive the two PDCCH transmissionscarrying the same DCI from two linked search spaces each associated with a different control resource set (CORESET). In SFN based PDCCH transition mode, the user equipment 110 can receive two PDCCH transmissions carrying the same DCI from a single search space / CORESET using different TCI states.

[0005] For multi-TRP PUSCH repetition, according to indications in a single DCI or in a semistatic configured grant provided over RRC, the user equipment 110 performs PUSCH transmission of the same contents toward two TRPs with corresponding beam directions associated with different spatial relations. For multi-TRP PUCCH repetition, the user equipment performs PUCCH transmission of the same contents toward two TRPs with corresponding beam directions associated with different spatial relations.

[0006] For inter-cell multi-TRP operation multi-DCI PDSCH transmission, one or more TCI states can be associated with synchronization signal block (SSB) with a physical cell identifier (PCI) different from the serving cell PCI. The activated transmission configuration indicator (TCI) states can be associated with at most one PCI different from the serving cell PCI at a time.

[0007] For inter-cell and intra-cell multi-DCI multi-TRP operation, up to two timing advance groups (TAGs) with associated TAG identifiers can be configured per serving cell. Each uplink / joint TCI state is associated with a TAG identifier and the UE applies the timing advance of the TAG identifier associated with the uplink / joint TCI state utilized for uplink transmission.

[0008] For single-DCI multi-TRP Simultaneous Transmission with Multi-Panel (STxMP) Spatial Domain Multiplexing (SDM) PUSCH transmission, different layers of one PUSCH are separately transmitted towards two TRPs. For single-DCI multi-TRP STxMP SFN PUSCH transmission, same layers of one PUSCH are transmitted towards two TRPs. For multi-DCI based multi-TRP STxMP PUSCH+PUSCH transmission, two PUSCHs are transmitted towards two TRPs. For single-DCI multi-TRP STxMP SFN PUCCH transmission, one PUCCH is transmitted towards two TRPs.BRIEF SUMMARY

[0009] In one or more embodiments, a user equipment (110) is provided for wireless communication, including at least one processor and at least one memory storing instructions thereon that, when executed by the at least one processor, cause the user equipment (110) to receive (408) configuration information related to a plurality of transmission-reception points (TRPs) of a cell, wherein the configuration information includes at least one random accesschannel (RACH) configuration (402) related to the plurality of TRPs (112 / 114) of the cell. The user equipment (110) is further caused to initiate a state transition to a radio resource control connected state under the cell based on the configuration information. The user equipment (110) is further caused to initiate a setup or resume operation based on the configuration information prior to connecting to the at least one of the plurality of TRPs (112 / 114) of the cell.

[0010] In one or more embodiments, a network node (112 / 114) is provided for wireless communication, includes at least one processor and at least one memory storing instructions thereon that, when executed by the at least one processor, cause the network node (112 / 114) to transmit (408) to a user equipment (110), configuration information related to a plurality of transmission-reception points (TRPs) of a cell, wherein the configuration information includes at least one random access channel (RACH) configuration (402) related to the plurality of TRPs (112 / 114) of the cell. The network node (112 / 114) is further caused to receive (506 / 508), from a user equipment (110), at least one preamble (506a / 508a) on a random access channel (RACH) occasion (504) at at least one of the plurality of TRPs (112 / 114) of the cell based on the configuration information. The network node (112 / 114) is further caused to transmit (512 / 514), to the user equipment (110), at least one random access response (RAR) (512a / 514a) corresponding to the at least one preamble (506a / 508a) received from the at least one of the plurality of TRPs (112 / 114) of the cell. The network node (112 / 114) is further caused to receive (518 / 520), from the user equipment (110), at least one message (518a / 520a) to a radio resource control connected state at the at least one of the plurality of TRPs (112 / 114) of the cell based on the at least one random access response (512a / 514a), wherein the at least one message includes at least one of a request message indicating a state transition, a resume message indicating the state transition, or a handover message confirming the user equipment (110) transitioning from the cell to another cell. The network node (112 / 114) is further caused to transmit (522 / 524), to the user equipment (110), at least one response message (522a / 524a) in response to the at least one message (518a / 520a) from the at least one of the plurality of TRPs (112 / 114) of the cell.

[0011] In one or more embodiments, a user equipment (110) is provided includes means for receiving (408) configuration information related to a plurality of transmission-reception points (TRPs) of a cell, wherein the configuration information includes at least one random access channel (RACH) configuration (402) related to the plurality of TRPs (112 / 114) of the cell. The user equipment (110) further includes means for initiating a state transition to a radio resourcecontrol connected state under the cell based on the configuration information. The user equipment (110) further includes means for initiating a setup or resume operation based on the configuration information prior to connecting to the at least one of the plurality of TRPs (112 / 114) of the cell.

[0012] In one or more embodiments, a network node (112 / 114) is provided, includes means for transmitting (408) to a user equipment (110), configuration information related to a plurality of transmission-reception points (TRPs) of a cell, wherein the configuration information includes at least one random access channel (RACH) configuration (402) related to the plurality of TRPs (112 / 114) of the cell. The network node (112 / 114) further includes means for receiving (506 / 508), from a user equipment (110), at least one preamble (506a / 508a) on a random access channel (RACH) occasion (504) at at least one of the plurality of TRPs (112 / 114) of the cell based on the configuration information. The network node (112 / 114) further includes means for transmitting (512 / 514), to the user equipment (110), at least one random access response (RAR) (512a / 514a) corresponding to the at least one preamble (506a / 508a) received from the at least one of the plurality of TRPs (112 / 114) of the cell. The network node (112 / 114) further includes means for receiving (518 / 520), from the user equipment (110), at least one message (518a / 520a) to a radio resource control connected state at the at least one of the plurality of TRPs (112 / 114) of the cell based on the at least one random access response (512a / 514a), wherein the at least one message includes at least one of a request message indicating a state transition, a resume message indicating the state transition, or a handover message confirming the user equipment (110) transitioning from the cell to another cell. The network node (112 / 114) further includes means for transmitting (522 / 524), to the user equipment (110), at least one response message (522a / 524a) in response to the at least one message (518a / 520a) from the at least one of the plurality of TRPs (112 / 114) of the cell.

[0013] In one or more embodiments, a computer-implemented method is provided that is performed by a user equipment (110) and includes receiving (408) configuration information related to a plurality of transmission-reception points (TRPs) of a cell, wherein the configuration information includes at least one random access channel (RACH) configuration (402) related to the plurality of TRPs (112 / 114) of the cell. The method further includes initiating a state transition to a radio resource control connected state under the cell based on the configuration information. The method further includes initiating a setup or resume operation based on theconfiguration information prior to connecting to the at least one of the plurality of TRPs (112 / 114) of the cell.

[0014] In one or more embodiments, a computer-implemented method is provided that is performed by a network node (112 / 114) and includes transmitting (408) to a user equipment (110), configuration information related to a plurality of transmission-reception points (TRPs) of a cell, wherein the configuration information includes at least one random access channel (RACH) configuration (402) related to the plurality of TRPs (112 / 114) of the cell. The method further includes receiving (506 / 508), from a user equipment (110), at least one preamble (506a / 508a) on a random access channel (RACH) occasion (504) at at least one of the plurality of TRPs (112 / 114) of the cell based on the configuration information. The method further includes transmitting (512 / 514), to the user equipment (110), at least one random access response (RAR) (512a / 514a) corresponding to the at least one preamble (506a / 508a) received from the at least one of the plurality of TRPs (112 / 114) of the cell. The method further includes receiving (518 / 520), from the user equipment (110), at least one message (518a / 520a) to a radio resource control connected state at the at least one of the plurality of TRPs (112 / 114) of the cell based on the at least one random access response (512a / 514a), wherein the at least one message includes at least one of a request message indicating a state transition, a resume message indicating the state transition, or a handover message confirming the user equipment (110) transitioning from the cell to another cell. The method further includes transmitting (522 / 524), to the user equipment (110), at least one response message (522a / 524a) in response to the at least one message (518a / 520a) from the at least one of the plurality of TRPs (112 / 114) of the cell.

[0015] In one or more embodiments, a non-transitory computer readable storage medium is provided including computer instructions that, when executed by a user equipment (110), cause the user equipment (110) to receive (408) configuration information related to a plurality of transmission-reception points (TRPs) of a cell, wherein the configuration information includes at least one random access channel (RACH) configuration (402) related to the plurality of TRPs (112 / 114) of the cell. The user equipment (110) is further caused to initiate a state transition to a radio resource control connected state under the cell based on the configuration information. The user equipment (110) is further caused to initiate a setup or resume operation based on the configuration information prior to connecting to the at least one of the plurality of TRPs (112 / 114) of the cell.

[0016] In one or more embodiments, a non-transitory computer readable storage medium is provided including computer instructions that, when executed by a network node (112 / 114), cause the network node (112 / 114) to transmit (408) to a user equipment (110), configuration information related to a plurality of transmission-reception points (TRPs) of a cell, wherein the configuration information includes at least one random access channel (RACH) configuration (402) related to the plurality of TRPs (112 / 114) of the cell. The network node (112 / 114) is further caused to receive (506 / 508), from a user equipment (110), at least one preamble (506a / 508a) on a random access channel (RACH) occasion (504) at at least one of the plurality of TRPs (112 / 114) of the cell based on the configuration information. The network node (112 / 114) is further caused to transmit (512 / 514), to the user equipment (110), at least one random access response (RAR) (512a / 514a) corresponding to the at least one preamble (506a / 508a) received from the at least one of the plurality of TRPs (112 / 114) of the cell. The network node (112 / 114) is further caused to receive (518 / 520), from the user equipment (110), at least one message (518a / 520a) to a radio resource control connected state at the at least one of the plurality of TRPs (112 / 114) of the cell based on the at least one random access response (512a / 514a), wherein the at least one message includes at least one of a request message indicating a state transition, a resume message indicating the state transition, or a handover message confirming the user equipment (110) transitioning from the cell to another cell. The network node (112 / 114) is further caused to transmit (522 / 524), to the user equipment (110), at least one response message (522a / 524a) in response to the at least one message (518a / 520a) from the at least one of the plurality of TRPs (112 / 114) of the cell.BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Having thus described certain example embodiments of the present disclosure in general terms, reference will hereinafter be made to the accompanying drawings, which are not necessarily drawn to scale, and where:

[0018] FIG. 1 is an example block diagram of a system including a user equipment, a first network node transmission-reception point (TRP), and a second network node TRP, configured to communicate via at least one of uplink and downlink transmission;

[0019] FIG. 2 illustrates an example communications device that may include various components configured to perform operations for the techniques disclosed herein;

[0020] FIG. 3 depicts a flow diagram of setting up a multi-TRP operation in accordance with previous embodiments;

[0021] FIG. 4 is an example flow diagram for coordination between TRPs and creating a configuration for a user equipment;

[0022] FIG. 5 is an example flow diagram for multi-TRP operation setup;

[0023] FIG. 6 is an example flow diagram for an alternative multi-TRP operation setup;

[0024] FIG. 7 is an example flow chart illustrating a procedure performed by a user equipment for setting up multi-TRP operation; and

[0025] FIG. 8 is an example flow chart illustrating a procedure performed by a network node for setting up multi-TRP operation.DETAILED DESCRIPTION

[0026] Some embodiments of the present disclosure will now be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all, embodiments are shown. As used herein, the terms “data,” “content,” “information,” and similar terms may be used interchangeably to refer to data capable of being transmitted, received and / or stored in accordance with embodiments of the present disclosure.

[0027] Additionally, as used herein, the term “circuitry” refers to (a) hardware-only circuit implementations; (b) combinations of circuits and computer program product(s) including software and / or firmware instructions stored on one or more computer readable memories that work together to cause an apparatus to perform one or more functions; and (c) circuits, such as, for example, a microprocessor(s) or a portion of a microprocessor(s), that require software or firmware for operation even if the software or firmware is not physically present.

[0028] As used herein, the term “computer-readable medium” refers to non-transitory storage hardware, non-transitory storage device or non-transitory computer system memory that may be accessed by a controller, a microcontroller, a computational system or a module of a computational system to encored thereon computer-executable instructions or software programs.

[0029] As illustrated in FIG. 1, a system 100 is provided in accordance with an example embodiment. Although the system may be configured in various manners, the system of one embodiment is depicted in FIG. 1 and includes user equipment 110, first network nodetransmission-reception point (TRP) 112, and second network node (TRP) 114 configured to communicate via at least one of uplink and downlink transmission and reception beams. Although one user equipment and two TRPs are depicted, the system may include and the user equipment 110, first network node TRP 112, and second network node TRP 114 may communicate with additional user equipment devices and / or network nodes in other embodiments. In some examples, each of the first network node TRP 112 and the second network node TRP 114 may be associated with the same network node 112 / 114.

[0030] The user equipment of FIG. 1 (also called UE, user device, user terminal, terminal device, etc.) illustrates a type of an apparatus to which resources on an air interface are allocated and assigned. The user equipment typically refers to a portable computing device that includes wireless mobile communication devices operating with or without a subscriber identification module (SIM), including, but not limited to, the following types of devices: a mobile station (mobile phone), smartphone, personal digital assistance (PDA), handset, device using a wireless modem (alarm or measurement device, etc.), laptop and / or touch screen computer, tablet, game console, notebook, and multimedia device. User equipment may also be a device having capability to operate in Internet of Things (loT) network which is a scenario in which objects are provided with the ability to transfer data over a network without requiring human-to-human or human-to-computer interaction. The user equipment may also be called a subscriber unit, mobile station, remote terminal, access terminal, user terminal, or just to mention a few apparatuses.

[0031] The first network node TRP 112 and second network node TRP 114 of FIG. 1 may be associated with, for example, base stations such as remote radio heads (RRHs), access points, node Bs (e.g., eNB, gNB) or other transmission sources. In some examples, first network node TRP 112 and / or second network node TRP 114 may be associated with the same network node.

[0032] FIG. 2 depicts an example apparatus 200 that may be configured to function as user equipment 110, first network node TRP 112, second network node TRP 114, and / or the like. As shown in FIG. 2, the apparatus includes, is associated with, or is in communications with processing circuitry 220, a memory 240, and a communication interface 260. The processing circuitry 220 may be in communication with the memory device 240 via a bus for passing information among components of the apparatus. The memory device may be non-transitory and may include, for example, one or more volatile and / or non-volatile memories. For example, the memory device may be an electronic storage device (e.g., a computer readable storage medium)including gates configured to store data (e.g., bits) that may be retrievable by a machine (e.g., a computing device like the processing circuitry). The memory device may be configured to store information, data, content, applications, instructions, or the like for enabling the apparatus to carry out various example functions. For example, the memory device could be configured to buffer input data for processing by processing circuitry. Additionally or alternatively, the memory device could be configured to store instructions for execution by processing circuitry.

[0033] The apparatus 200 may, in some embodiments, be embodied in various computing devices described as above. However, in some embodiments, the apparatus may be embodied as a chip or chip set. In other words, the apparatus may include one or more physical packages (e.g., chips) including materials, components and / or wires on a structural assembly (e.g., a baseboard). The structural assembly may provide physical strength, conservation of size, and / or limitation of electrical interaction for component circuitry included thereon. The apparatus may therefore, in some cases, be configured to implement an embodiment on a single chip or as a single “system on a chip.” As such, in some cases, a chip or chipset may constitute means for performing one or more operations for providing the functionalities described herein.

[0034] The processing circuitry 220, also referenced as a processor, may be embodied in a number of different ways. For example, the processing circuitry may be embodied as one or more of various hardware processing means such as a coprocessor, a microprocessor, a controller, a digital signal processor (DSP), a processing element with or without an accompanying DSP, or various other circuitry including integrated circuits such as, for example, an ASIC (application specific integrated circuit), an FPGA (field programmable gate array), a microcontroller unit (MCU), a hardware accelerator, a special-purpose computer chip, or the like. As such, in some embodiments, the processing circuitry may include one or more processing cores configured to perform independently. A multi-core processing circuitry may enable multiprocessing within a single physical package. Additionally or alternatively, the processing circuitry may include one or more processors configured in tandem via the bus to enable independent execution of instructions, pipelining, and / or multithreading.

[0035] In an example embodiment, the processing circuitry 220 may be configured to execute instructions stored in the memory device 240 or otherwise accessible to the processing circuitry. Alternatively or additionally, the processing circuitry may be configured to execute hardcoded functionality. As such, whether configured by hardware or software methods, or by acombination thereof, the processing circuitry may represent an entity (e.g., physically embodied in circuitry) capable of performing operations according to an embodiment of the present disclosure while configured accordingly. Thus, for example, when the processing circuitry is embodied as an ASIC, FPGA or the like, the processing circuitry may be specifically configured hardware for conducting the operations described herein. Alternatively, as another example, when the processing circuitry is embodied as an executor of instructions, the instructions may specifically configure the processor to perform the algorithms and / or operations described herein when the instructions are executed. However, in some cases, the processing circuitry may be a processor of a specific device (e.g., an image or video processing system) configured to employ an embodiment by further configuration of the processing circuitry by instructions for performing the algorithms and / or operations described herein.

[0036] The communication interface 260 may be any means such as a device or circuitry embodied in either hardware or a combination of hardware and software that is configured to receive and / or transmit data including media content in the form of video or image files, one or more audio tracks or the like. In this regard, the communication interface may include, for example, an antenna (or multiple antennas) and supporting hardware and / or software for enabling communications with a wireless communication network. Additionally or alternatively, the communication interface may include the circuitry for interacting with the antenna(s) to cause transmission of signals or to handle receipt of signals received. In some environments, the communications interface may also support wired communication.

[0037] Turning now to FIG. 3, a flow diagram 300 is provided to illustrate multi-TRP operation setup in accordance with previous embodiments. At operation 302, the user equipment 302 is in an idle mode camping on a cell, and it is paged or a management object call is initiated for radio resource control setup at operation 304. The user equipment 110 transmits, to the network node TRP 112, a random access message at operation 306 and receives a random access response at operation 308. The user equipment 110 transmits a radio resource control (RRC) setup request at operation 310 and receives a RRC setup response at operation 312, with an RRC setup complete message transmitted to the network node TRP 112 at operation 314. Security setup then takes place, with the core network providing the user equipment context and the related protocol data unit (PDU) sessions of the user equipment 110 which can be used to setup data sessions of the user equipment 110. The user equipment 110 receives a PDCCH order from first network nodeTRP 112 to send a preamble towards TRP 114 so that the timing advance for TRP 114 can be calculated, and the user equipment and transmits a random access message to second network node TRP 114 at operation 318. Once the network calculates the timing advance for TRP 114, the network transmits and the user equipment 110 receives a RRC reconfiguration message with a multi-TRP configuration at operation 320 and transmits a RRC reconfiguration complete message at operation 322, before the user equipment starts multi-TRP operation at operation 324. Since obtaining the timing advance value of TRP 114 is a connected mode procedure and can only be initiated after the user equipment 110 has set up connection, this delays the use of advantages of the multi-TRP procedure. Thus, a need exists for a procedure to initiate multi-TRP operation from the connection setup to improve the user equipment robustness (or connection reliability via exploiting multiple links) without delay.

[0038] Turning now to FIG. 4, an example flow diagram is provided for coordination between TRPs and creating a configuration for a user equipment. In some examples, a method is used to use the robustness provided by multi-TRP operation to be enabled for connection setup procedure. This is enabled via sharing a multi-TRP connection setup configuration in the system information to the user equipment, as outlined in FIG. 4. As outlined in FIGS. 5-6, the network then coordinates to send random access response and / or radio resource control setup messages from both TRPs 112 / 114, thus improving the robustness of connection setup for the user equipment 110.

[0039] In one or more embodiments, at operation 402, Step 0a: operations, administration, and maintenance (0AM) configures or network node 112 / 114 signaling enables two TRPs 112 and 114 to create a mTRP specific RACH configuration for robust mTRP operation.

[0040] In one or more embodiments, at operation 404, called single random access radio network temporary identifier (RA-RNTI), network node 112 / 114 and user equipment 110 are configured with a new RA-RNTI calculation to allocate the same RA-RNTI as a result of two different RACH transmission associated with multi-TRP (mTRP) operation. In some examples, called double RA-RNTI, new RA-RNTI calculation is not needed. And the user equipment 110 is required to maintain two RA-RNTIs related to each mTRP transmission.

[0041] In one or more embodiments, at operation 406, user equipment 110 is in idle mode camping an mTRP cell. In one or more embodiments, at operation 408, system information 408a indicates two different RACH configurations for each TRP 112 / 114 for mTRP operation and acondition for mTRP setup operation. In some examples, a SSB configuration for TRP 114 is provided. In some examples, the mTRP condition is a condition where the user equipment 110 monitors beams from two TRPs 112 / 114, and each beam from the TRPs have to be above a specific threshold. In some examples, the condition is a reference signal received power (RSRP) threshold for beams of each TRP 112 / 114. In some examples, called beam paired mTRP RACH, RACH configurations have RACH occasions (ROs) that map to a pair of beams from both TRPs. In some examples, called preamble paired mTRP RACH, RACH configurations are dedicated for mTRP configuration and the user equipment 110 uses the same preamble over the strongest beam for initial transmissions over mTRP RACH configuration to both TRPs 112 / 114. In some examples, two different RACH configurations are provided in RRC Connection Release message when the user equipment 110 moves to the idle / inactive mode from the connected mode. In some examples, the user equipment 110 indicates its capability to perform mTRP based connection setup, and based on the network may determine to provide such mTRP RACH configuration when the user equipment 110 moves to the idle / inactive mode.

[0042] Turning now to FIG. 5, an example flow diagram is provided for multi-TRP operation setup. In one or more embodiments, mobile origination or mobile termination triggers a RRC setup procedure.

[0043] In one or more embodiments, at operation 501, user equipment 110 measures beams from each of TRP 112 and TRP 114. In some examples, user equipment 110 may be keeping the measurements from TRP 112 and TRP 114 before the RRC setup procedure is triggered.

[0044] In one or more embodiments, at operation 502, user equipment 110 detects that at least one beam from each of TRP 112 and TRP 114 fulfills the mTRP operation initiation condition. For example, beam 3 from TRP 112 may be above -80 dBm and beam 7 from TRP 114 may be above -80 dBm. In some examples, the two beams can be received simultaneously by the user equipment 110.

[0045] In one or more embodiments, at operation 504, the user equipment 110 finds the RO on each of TRP 112 and TRP 114 that maps to both beams (e.g., beam 3 from TRP 112 and beam 7 from TRP 114). In some examples where the user equipment 110 can’t detect at least one beam from each TRP to fulfill the mTRP operation initiation condition, the user equipment 110 falls back to a single TRP RRC setup procedure.

[0046] In one or more embodiments, at operations 506 and 508, the user equipment 110 transmits preambles 506a and 508a on a RO to each TRP. In some examples with beam paired mTRP RACH, the preambles 506a-508a indicate initiation of an mTRP setup procedure, indicate to TRP 112 that a preamble is transmitted to beam 7 of TRP 114 at the same time, and indicate to TRP 114 that a preamble is transmitted to beam 3 of TRP 112 at the same time. In some examples with preamble paired mTRP RACH, the preambles 506a-508a indicate initiation of an mTRP setup procedure, indicate to TRP 112 that the UE is transmitting preamble 508a to TRP 114 at the same time, and indicate to TRP 114 that the UE is transmitting preamble 506a to TRP 112 at the same time. In some examples, beam and preamble pairing are combined. In some examples, user equipment 110 may start monitoring a single random access response window for both preamble transmissions. In some examples, after the expiration of the single random access window, the user equipment 110 starts mTRP RACH transmissions to both TRPs 112 / 114. In some examples, the timer for a random access window is stopped when a random access response is received, such as when the network can fall back to single TRP operation or use another enhancement to setup a second TRP using one TRP. In some examples, the timer for a random access window is stopped only when both random access responses are received from each TRP, such as when the network wants to guarantee reception of both preambles 506a and 508a.

[0047] In one or more embodiments, at operation 510, each of TRP 112 and 114 calculates the RA-RNTI and the timing advance (TA) for the user equipment 110. Each TRP 112 / 114 coordinate to build a mTRP configuration for user equipment 110 and a robust random access response transmission for user equipment 110. In some examples, the mTRP configuration includes random access response (RAR) content such as timing advances, uplink grants, and a temporary cell radio network temporary identifier (TC-RNTI). In some examples, a RAR message for the user equipment 110 has PUSCH and TA for both TRPs 112 / 114. In some examples where one of TRPs 112 / 114 do not receive preamble 506a or 508a due to low power, the network finishes the mTRP operation and switches to single TRP operation, and the user equipment 110 stops re-transmitting the preamble. Alternatively, the network in some examples may not try robust RAR transmission but tries to set up mTRP operation for user equipment 110.For example, the user equipment 110 may go on with preamble re-transmissions (e.g., up to a preconfigured amount) and, if successful, the network will indicate the mTRP configurationduring an RRC setup procedure towards the user equipment 110. Such behavior is preconfigured by the user equipment 110 (such that the user equipment receives one random access response and receives another timing advance value on a RRC setup message). For example, an RRC setup going over TRP 112 may indicate a configuration for TRP 114 and related information to the user equipment 110. In some examples, information to receive an RRC setup message from TRP 114 is provided to the user equipment 110 through TRP 112, for example through downlink assignment or through configuration PDCCH to monitor to receive the assignment for RRC setup. In some examples, it is indicated in system information if the cell aims to persist in calculating timing advance for one or both TRPs for the user equipment. In some examples where both preambles 506a-508a are received, network node 112 / 114 determines to switch to single TRP operation and use link diversity (for example, using spatial diversity) to transmit the RAR message successfully. In some examples, the network node 112 / 114 sends a RAR from only one of TRP 112 or 114 and waits for an RRC setup request form user equipment 110. For example, the RAR message may contain TA values for both links that the user equipment may user for a later mTRP operation. In some examples, the RAR message contains an indication that there is no second RAR from another TRP, and the user equipment 110 stops monitoring for another RAR from the other TRP upon reception. In some examples, if the RRC setup request message is not received (due to, for example RAR failure or a setup request failure) within a time duration, the network may transmit the RAR from another TRP along with timing advance values for both TRPs, or the network may decide to use robust RAR transmission and transmit a RAR over both TRPs.

[0048] In one or more embodiments, at operations 512-514, TRPs 112 and 114 transmit robust RARs 512a and 514a to user equipment 110. In some examples, RARs 512a and 5214 have the same content so that user equipment 110 uses combining techniques to improve decoding probability. In some examples, each RAR 512a / 514a is specific to each TRP 112 / 114, respectively, and link diversity is used as robustness improvement, enabling user equipment 110 to decode and continue communicating to each TRP 112 / 114 / For example, each RAR may only indicate the PUSCH for its specific TRP. In some examples, user equipment 110 uses receive beamforming for RAR reception which are associated with transmission beams used for preamble transmission in operations 506-508. In a single RA-RNTI example, the RAR 512a / 514a is scrambled with the single RA-RNTI calculated by the network. An examplecalculation of a single RA-RNTI is done based on a preamble and RO selected for a TRP 112 / 114 indicated as the main TRP. An example calculation of a single RA-RNTI may be a max function taken between an RA-RNTI calculated over both TRPs. In a double RA-RNU example, each RAR is scrambled by the RA-RNU calculated for the TRP. In some examples, a single TC- RNH is included in the RAR message to bind user equipment 110 to a single identity.

[0049] In one or more embodiments, at operation 516, a user equipment 110 uses a mTRP configuration it received inside a RAR configuration to transmit twice the RRC setup request message. In some examples, the user equipment uses the same transmission beams as for the preamble transmissions in 506a and 508a to transmit the RRC setup request message to each TRP 112 and 114. In some examples, the user equipment 110 applies the given timing advance provided in the random access response associated with the TRP 112 / 114.

[0050] In one or more embodiments, at operation 518 and 520, the user equipment 110 transmits RRC setup request messages 518a and 520a to TRPs 112 and 114. The example messages 518a and 520a may have the same content (so the network can use combining to improve decoding probability) or different content (so link diversity is used as a robustness improvement and the network node 112 / 114 can resolve this internally).

[0051] In one or more embodiments, at operation 522-524, the network responds with RRC setup messages 522a and 524a to the user equipment 110, where each message 522a / 524a has the same message content and includes the mTRP configuration towards the user equipment 110. In some examples, the network may instead determine to switch to single TRP operation but use link diversity to transmit an RRC setup message (i.e., TRP 112 sends the user equipment 110 a RRC setup message, and if it does not receive an RRC setup complete message within a time duration, then TRP 114 sends the user equipment 110 the RRC setup message).

[0052] In one or more embodiments, at operation 526, the user equipment 110 operates in connected mode mTRP operation.

[0053] In FIG. 6, an example flow diagram for an alternative multi-TRP operation setup is given. In some examples, user equipment 110 begins in an RRC idle mode.

[0054] In one or more embodiments, at operation 602, user equipment 110 reads from system information and determines which beams are related to separate TRPs (e.g., TRPs 112 / 114). In some examples, user equipment 110 receives a condition 602a for signal strength to initiate robust connection setup.

[0055] In one or more embodiments, at operation 604, user equipment 110 measures beams for each TRP and determines if the condition 602a holds. In some examples, user equipment 110 determines to initiate robust connection setup with respect to quality of service requirements. In some examples, the user equipment determines which RO is related to which TRP using SSB to RO mapping and the information of which SSBs are linked to which TRPs. In some examples, user equipment 110 uses these ROs to transmit preambles.

[0056] In one or more embodiments, at operations 506 and 508, user equipment 110 transmits preambles 506a and 508a to TRPs 112 and 114. In some examples user equipment 110 uses time division multiplexing, i.e., the user equipment 110 aligns the timing of the preambles such that the reception of RARs for separate preambles would not collide (may send the second preamble after reception of first RAR). In examples where the user equipment does simultaneous reception, the user equipment 110 transmits the preambles irrespective of timing.

[0057] In one or more embodiments, TRPs 112 and 114 are not aware if preambles 506a and 508a are related to the same user equipment 110.

[0058] In one or more embodiments, at operations 512 and 514, the network sends two different RARs 512a and 514a to user equipment 110 for each RA-RNTI. In some examples, the user equipment 110 has monitored and received a RAR for each preamble that it has transmitted.

[0059] In one or more embodiments, at operation 608, the user equipment 110 determines to use two uplink grants to initiate robust connection setup. In some examples where the user equipment does not receive one of the RARs, the user equipment may wait a specified time to receive the second RAR before sending a RRC setup request. In some examples, if the user equipment 110 determines to initiate the robust setup procedure the user equipment 110 can send the RRC request setup directly with the robust setup indication. For example, this may be beneficial when the RRC setup request is specific to one of the TRPs 112 or 114, and the indication tells to the network that (i) it should wait for another RRC setup request over another TRP, (ii) the network should keep re-transmitting the RAR over the other TRP 112 or 114, and (iii) the RRC setup request will be sent after the successful reception of the RAR. In some examples, the user equipment 110 may determine that the robust connection setup procedure can’t be initiated and not send the robust setup indication. In some examples, the network may still enforce the robust setup procedure by sending the robust setup indication in a RRC setup message.

[0060] In one or more embodiments, at operations 518-520, the user equipment 110 transmits, to each of TRPs 112-114, a RRC setup request message 518a and 520a. In some examples, each of the messages 518a and 520a indicate the user equipment 110 identity and include a robust connection setup indication. In one or more embodiments, at operation 610, the network uses the robust connection setup indication to receive the RRC setup requests from the user equipment before sending an RRC setup response. In some examples, the network sends RRC setup responses 522a and 524a to the user equipment 110 at operations 522 and 524, from TRPs 112 and 114, respectively. The user equipment 110 then operates in a connected mTRP mode at operation 526.

[0061] In some examples, any of the above solutions may be used with more than two TRPs and may be applicable to both intra-cell and inter-cell mTRP operations.

[0062] Turning now to FIG. 7, an example flowchart is illustrated for a process 700 performed by an apparatus embodied by, associated with or otherwise in communication with (hereinafter generally referenced as being embodied by) a user equipment (110) in order to set up a multi - TRP operation.

[0063] As shown in block 702 of FIG. 7, the apparatus embodied by the user equipment (110) includes means, such as the processing circuitry (220), the communication interface (260), the like, for receiving (408) configuration information related to a plurality of transmission-reception points (TRPs) of a cell, where the configuration information includes at least one random access channel (RACH) configuration (402) related to the plurality of TRPs (112 / 114) of the cell. In one or more embodiments, the configuration information is at least one of: included in a system information (408a), included in a radio resource control release message, or includes a condition (602a) indicating when a multi-TRP operation is initiated. In one or more embodiments, the random access channel configuration (402) related to the plurality of TRPs (112 / 114) of the cell includes at least one of: a particular random access channel configuration (402) for the at least one TRP of the plurality of TRPs (112 / 114) of the cell, where the user equipment (110) determines a random access channel occasion (504) for transmitting the at least one preamble (506a / 508a) based on the random access channel configuration (402), or one or more random access channel occasions (504) that map to a set of beams from the plurality of TRPs (112 / 114) of the cell.

[0064] As shown in block 704 of FIG. 7, the apparatus embodied by the user equipment (110) includes means, such as the processing circuitry (220), the communication interface (260), the like, for initiating a state transition to a radio resource control connected state under the cell based on the configuration information. In one or more embodiments, the initiating of the state transition to the radio resource control connected state causes the user equipment (110) to transmit (506 / 508) at least one preamble (506a / 508a) on a random access channel (RACH) occasion (504) to at least one of the plurality of TRPs (112 / 114) of the cell. In one or more embodiments, the initiating of the state transition to the radio resource control connected state causes the user equipment (110) to receive (512 / 514) at least one random access response (RAR) (512a / 514a) corresponding to the at least one preamble (506a / 508a) from the plurality of TRPs (112 / 114) of the cell. In one or more embodiments, the user equipment (110) initiates the state transition based on at least one of: a condition (602a) indicated in the configuration information is fulfilled, or a quality of service requirement. In one or more embodiments, the received at least one random access response (512a / 514a) includes at least one of at least one timing advance and at least one uplink grant for at least one TRP of the plurality of TRPs (112 / 114) of the cell or a timing advance and an uplink grant for the at least one of the plurality of TRPs (112 / 114) of the cell. In one or more embodiments, the response message (522a / 524a) further includes a multi- TRP configuration that includes configuration of a particular TRP from which the at least one random access response is not sent.

[0065] As shown in block 706 of FIG. 7, the apparatus embodied by the user equipment (110) includes means, such as the processing circuitry (220), the communication interface (260), the like, for initiating a setup or resume operation based on the configuration information prior to connecting to the at least one of the plurality of TRPs (112 / 114) of the cell. In one or more embodiments, the setup operation includes the user equipment (110) transmitting (518 / 520) at least one message (518a / 520a) to at least one of the of the plurality of TRPs (112 / 114) of the cell based on the at least one random access response (512a / 514a) and receiving (522 / 524) at least one response message (522a / 524a) in response to the at least one message (518a / 520a) from the at least one of the plurality of TRPs (112 / 114) of the cell, where the at least one message includes at least one of a request message indicating the state transition, a resume message indicating the state transition, or a handover message confirming the user equipment (110) transitioning from the cell to another cell. In one or more embodiments, the user equipment (110)is further caused to start at least one random access response (512a / 514a) window associated with the at least one preamble (506a / 508a) for receiving at the at least one random access response (512a / 514a) from the plurality of TRPs (112 / 114) of the cell or monitor at least one physical downlink control channel (PDCCH) from the plurality of TRPs (112 / 114) of the cell for at least one random access response (512a / 514a) identified by a random access radio network temporary identifier (RNH) (404) while the random access response (512a / 514a) window is running. In one or more embodiments, the random access radio network temporary identifier (404) includes at least one of a single random access radio network temporary identifier (404) or at least one random access radio network temporary identifier (404) associated with the at least one of the plurality of TRPs (112 / 114) of the cell. In one or more embodiments, the user equipment (110) is further caused to determine which random access channel occasion (504) is related to at least one TRP of the plurality of TRPs (112 / 114) by configuring separate resources or by using a mapping between a synchronization signal block (SSB) and a random access channel occasion and information related to an association between the synchronization signal block and the at least one TRP. In one or more embodiments, the user equipment (110) is further caused to determine which random access channel occasion (504) is related to the at least one TRP of the plurality of TRPs (112 / 114) of the cell by mapping a synchronization signal block with information linked to the at least one TRP to the random access channel occasion (504).

[0066] Turning now to FIG. 8, an example flowchart is illustrated for a process 800 performed by an apparatus embodied by, associated with or otherwise in communication with (hereinafter generally referenced as being embodied by) a network node (112 / 114) in order to set up a multi - TRP operation.

[0067] As shown in block 802 of FIG. 8, the apparatus embodied by the network node (112 / 114) includes means, such as the processing circuitry (220), the communication interface (260), the like, for transmitting (408) to a user equipment (110), configuration information related to a plurality of transmission-reception points (TRPs) of a cell, where the configuration information includes at least one random access channel (RACH) configuration (402) related to the plurality of TRPs (112 / 114) of the cell.

[0068] As shown in block 804 of FIG. 8, the apparatus embodied by the network node (112 / 114) includes means, such as the processing circuitry (220), the communication interface (260), the like, for receiving (506 / 508), from a user equipment (110), at least one preamble (506a / 508a) ona random access channel (RACH) occasion (504) at at least one of the plurality of TRPs (112 / 114) of the cell based on the configuration information.

[0069] As shown in block 806 of FIG. 8, the apparatus embodied by the network node (112 / 114) includes means, such as the processing circuitry (220), the communication interface (260), the like, for transmitting (512 / 514), to the user equipment (110), at least one random access response (RAR) (512a / 514a) corresponding to the at least one preamble (506a / 508a) received from the at least one of the plurality of TRPs (112 / 114) of the cell; receive (518 / 520), from the user equipment (110), at least one message (518a / 520a) to a radio resource control connected state at the at least one of the plurality of TRPs (112 / 114) of the cell based on the at least one random access response (512a / 514a), where the at least one message includes at least one of a request message indicating a state transition, a resume message indicating the state transition, or a handover message confirming the user equipment (110) transitioning from the cell to another cell. In one or more embodiments, the network node (112 / 114) is further caused to transmit the at least one random access response (512a / 514a) within a single random access response (512a / 514a) window associated with the at least one preamble (506a / 508a) and started by the user equipment (110). In one or more embodiments, the at least one random access response (512a / 514a) is transmitted over at least one physical downlink control channel from the plurality of TRPs (112 / 114) and identified by a random access radio network temporary identifier (404) while the random access response (512a / 514a) window is running. In one or more embodiments, if one or more of the plurality of TRPs (112 / 114) of the cell fails to receive one or more preamble (506a / 508a)s from the user equipment (110), the network node (112 / 114) is further caused to stop a multi-TRP operation or transmit the at least one random access response (512a / 514a) to the user equipment (110), where the at least one random access response (512a / 514a) includes a timing advance and an uplink grant from a TRP of the plurality of TRPs (112 / 114) of the cell where the at least one preamble (506a / 508a) is received, where the response message (522a / 524a) indicates a multi-TRP configuration, and where the response message (522a / 524a) includes a radio resource control setup message (522a / 524a).

[0070] As shown in block 808 of FIG. 8, the apparatus embodied by the network node (112 / 114) includes means, such as the processing circuitry (220), the communication interface (260), the like, for transmitting (522 / 524), to the user equipment (110), at least one response message(522a / 524a) in response to the at least one message (518a / 520a) from the at least one of the plurality of TRPs (112 / 114) of the cell.

[0071] In one or more embodiments, a user equipment (110) is provided for wireless communication, including at least one processor and at least one memory storing instructions thereon that, when executed by the at least one processor, cause the user equipment (110) to receive (408) configuration information related to a plurality of transmission-reception points (TRPs) of a cell, where the configuration information includes at least one random access channel (RACH) configuration (402) related to the plurality of TRPs (112 / 114) of the cell. The user equipment (110) is further caused to initiate a state transition to a radio resource control connected state under the cell based on the configuration information. The user equipment (110) is further caused to initiate a setup or resume operation based on the configuration information prior to connecting to the at least one of the plurality of TRPs (112 / 114) of the cell.

[0072] In one or more embodiments, the initiating of the state transition to the radio resource control connected state causes the user equipment to transmit (506 / 508) at least one preamble (506a / 508a) on a random access channel (RACH) occasion (504) to at least one of the plurality of TRPs (112 / 114) of the cell. In one or more embodiments, the user equipment (110) is further caused to receive (512 / 514) at least one random access response (RAR) (512a / 514a) corresponding to the at least one preamble (506a / 508a) from the plurality of TRPs (112 / 114) of the cell.

[0073] In one or more embodiments, the setup operation includes transmitting (518 / 520) at least one message (518a / 520a) to at least one of the plurality of TRPs (112 / 114) of the cell based on the at least one random access response (512a / 514a). In one or more embodiments, the setup operation includes receiving (522 / 524) at least one response message (522a / 524a) in response to the at least one message (518a / 520a) from the at least one of the plurality of TRPs (112 / 114) of the cell, where the at least one message includes at least one of a request message indicating the state transition, a resume message indicating the state transition, or a handover message confirming the user equipment (110) transitioning from the cell to another cell.

[0074] In one or more embodiments, the configuration information is included in a system information (408a). Additionally or alternatively, the configuration information is included in a radio resource control release message. Additionally or alternatively, the configuration information includes a condition (602a) indicating when a multi-TRP operation is initiated.

[0075] In one or more embodiments, the random access channel configuration (402) related to the plurality of TRPs (112 / 114) of the cell includes a particular random access channel configuration (402) for the at least one TRP of the plurality of TRPs (112 / 114) of the cell, where the user equipment (110) determines a random access channel occasion (504) for transmitting the at least one preamble (506a / 508a) based on the random access channel configuration (402). Additionally or alternatively, the random access channel configuration (402) includes one or more random access channel occasions (504)s that map to a set of beams from the plurality of TRPs (112 / 114) of the cell.

[0076] In one or more embodiments, the user equipment (110) initiates the state transition based on at least one of a condition (602a) indicated in the configuration information is fulfilled or a quality of service requirement.

[0077] In one or more embodiments, the user equipment (110) is further caused to start at least one random access response (512a / 514a) window associated with the at least one preamble (506a / 508a) for receiving at the at least one random access response (512a / 514a) from the plurality of TRPs (112 / 114) of the cell. Additionally or alternatively, the user equipment (110) is caused to monitor at least one physical downlink control channel (PDCCH) from the plurality of TRPs (112 / 114) of the cell for at least one random access response (512a / 514a) identified by a random access radio network temporary identifier (RNTI) (404) while the random access response (512a / 514a) window is running.

[0078] In one or more embodiments, the random access radio network temporary identifier (404) includes at least one of a single random access radio network temporary identifier (404 or at least one random access radio network temporary identifier (404) associated with the at least one of the plurality of TRPs (112 / 114) of the cell.

[0079] In one or more embodiments, the received at least one random access response (512a / 514a) includes at least one of at least one timing advance and at least one uplink grant for at least one TRP of the plurality of TRPs (112 / 114) of the cell or a timing advance and an uplink grant for the at least one of the plurality of TRPs (112 / 114) of the cell.

[0080] In one or more embodiments, the response message (522a / 524a) further includes a multi - TRP configuration that includes configuration of a particular TRP from which the at least one random access response is not sent.

[0081] In one or more embodiments, the user equipment (110) is further caused to determine which random access channel occasion (504) is related to at least one TRP of the plurality of TRPs (112 / 114) by configuring separate resources or by using a mapping between a synchronization signal block (SSB) and a random access channel occasion and information related to an association between the synchronization signal block and the at least one TRP.

[0082] In one or more embodiments, the user equipment (110) is further caused to determine which random access channel occasion (504) is related to the at least one TRP of the plurality of TRPs (112 / 114) of the cell by mapping a synchronization signal block with information linked to the at least one TRP to the random access channel occasion (504).

[0083] In one or more embodiments, a network node (112 / 114) is provided for wireless communication, including at least one processor and at least one memory storing instructions thereon that, when executed by the at least one processor, cause the network node (112 / 114) to transmit (408) to a user equipment (110), configuration information related to a plurality of transmission-reception points (TRPs) of a cell, where the configuration information includes at least one random access channel (RACH) configuration (402) related to the plurality of TRPs (112 / 114) of the cell. The network node (112 / 114) is further caused to receive (506 / 508), from a user equipment (110), at least one preamble (506a / 508a) on a random access channel (RACH) occasion (504) at at least one of the plurality of TRPs (112 / 114) of the cell based on the configuration information. The network node (112 / 114) is further caused to transmit (512 / 514), to the user equipment (110), at least one random access response (RAR) (512a / 514a) corresponding to the at least one preamble (506a / 508a) received from the at least one of the plurality of TRPs (112 / 114) of the cell. The network node (112 / 114) is further caused to receive (518 / 520), from the user equipment (110), at least one message (518a / 520a) to a radio resource control connected state at the at least one of the plurality of TRPs (112 / 114) of the cell based on the at least one random access response (512a / 514a), where the at least one message includes at least one of a request message indicating a state transition, a resume message indicating the state transition, or a handover message confirming the user equipment (110) transitioning from the cell to another cell. The network node (112 / 114) is further caused to transmit (522 / 524), to the user equipment (110), at least one response message (522a / 524a) in response to the at least one message (518a / 520a) from the at least one of the plurality of TRPs (112 / 114) of the cell.

[0084] In one or more embodiments, the configuration information is included in a system information (408a). Additionally or alternatively, the configuration information is included in a radio resource control release message. Additionally or alternatively, the configuration information includes a condition (602a) indicating when a multi-TRP operation is initiated.

[0085] In one or more embodiments, the random access channel configuration (402) related to the plurality of TRPs (112 / 114) of the cell includes at least one of a particular random access channel configuration (402) for the at least one TRP of the plurality of TRPs (112 / 114) of the cell, where the user equipment (110) determines a random access channel occasion (504) for transmitting the at least one preamble (506a / 508a) based on the random access channel configuration (402) or one or more random access channel occasion (504)s that map to a set of beams from the plurality of TRPs (112 / 114) of the cell.

[0086] In one or more embodiments, the user equipment (110) is further caused to transmit the at least one random access response (512a / 514a) within a single random access response (512a / 514a) window associated with the at least one preamble (506a / 508a) and started by the user equipment (110).

[0087] In one or more embodiments, the at least one random access response (512a / 514a) is transmitted over at least one physical downlink control channel from the plurality of TRPs (112 / 114) and identified by a random access radio network temporary identifier (404) while the random access response (512a / 514a) window is running.

[0088] In one or more embodiments, the random access radio network temporary identifier (404) includes at least one of a single random access radio network temporary identifier (404) or at least one random access radio network temporary identifier (404) associated with the at least one of the plurality of TRPs (112 / 114) of the cell.

[0089] In one or more embodiments, the at least one random access response (512a / 514a) includes at least one of at least one timing advance and at least one uplink grant for at least one TRP of the plurality of TRPs (112 / 114) of the cell or a timing advance and an uplink grant for the at least one of the plurality of TRPs (112 / 114) of the cell.

[0090] In one or more embodiments, if one or more of the plurality of TRPs (112 / 114) of the cell fails to receive one or more preamble (506a / 508a)s from the user equipment (110), the network node (112 / 114) is further caused to stop a multi-TRP operation; or transmit the at least one random access response (512a / 514a) to the user equipment (110), where the at least one randomaccess response (512a / 514a) includes a timing advance and an uplink grant from a TRP of the plurality of TRPs (112 / 114) of the cell where the at least one preamble (506a / 508a) is received, where the response message (522a / 524a) indicates a multi-TRP configuration, and where the response message (522a / 524a) includes a radio resource control setup message (522a / 524a).

[0091] In one or more embodiments, a user equipment (110) is provided including means for receiving (408) configuration information related to a plurality of transmission-reception points (TRPs) of a cell, where the configuration information includes at least one random access channel (RACH) configuration (402) related to the plurality of TRPs (112 / 114) of the cell. The user equipment (110) further includes means for initiating a state transition to a radio resource control connected state under the cell based on the configuration information. The user equipment (110) further includes means for initiating a setup or resume operation based on the configuration information prior to connecting to the at least one of the plurality of TRPs (112 / 114) of the cell.

[0092] In one or more embodiments, a network node (112 / 114) is provided including means for transmitting (408) to a user equipment (110), configuration information related to a plurality of transmission-reception points (TRPs) of a cell, where the configuration information includes at least one random access channel (RACH) configuration (402) related to the plurality of TRPs (112 / 114) of the cell. The network node (112 / 114) further includes means for receiving (506 / 508), from a user equipment (110), at least one preamble (506a / 508a) on a random access channel (RACH) occasion (504) at at least one of the plurality of TRPs (112 / 114) of the cell based on the configuration information. The network node (112 / 114) further includes means for transmitting (512 / 514), to the user equipment (110), at least one random access response (RAR) (512a / 514a) corresponding to the at least one preamble (506a / 508a) received from the at least one of the plurality of TRPs (112 / 114) of the cell. The network node (112 / 114) further includes means for receiving (518 / 520), from the user equipment (110), at least one message (518a / 520a) to a radio resource control connected state at the at least one of the plurality of TRPs (112 / 114) of the cell based on the at least one random access response (512a / 514a), where the at least one message includes at least one of a request message indicating a state transition, a resume message indicating the state transition, or a handover message confirming the user equipment (110) transitioning from the cell to another cell. The network node (112 / 114) further includes means for transmitting (522 / 524), to the user equipment (110), at least one response message(522a / 524a) in response to the at least one message (518a / 520a) from the at least one of the plurality of TRPs (112 / 114) of the cell.

[0093] In one or more embodiments, a computer-implemented method is provided that is performed by a user equipment (110) and includes receiving (408) configuration information related to a plurality of transmission-reception points (TRPs) of a cell, where the configuration information includes at least one random access channel (RACH) configuration (402) related to the plurality of TRPs (112 / 114) of the cell. The method further includes initiating a state transition to a radio resource control connected state under the cell based on the configuration information. The method further includes initiating a setup or resume operation based on the configuration information prior to connecting to the at least one of the plurality of TRPs (112 / 114) of the cell.

[0094] In one or more embodiments, a computer-implemented method is provided that is performed by a network node (112 / 114) and includes transmitting (408) to a user equipment (110), configuration information related to a plurality of transmission-reception points (TRPs) of a cell, where the configuration information includes at least one random access channel (RACH) configuration (402) related to the plurality of TRPs (112 / 114) of the cell. The method further includes receiving (506 / 508), from a user equipment (110), at least one preamble (506a / 508a) on a random access channel (RACH) occasion (504) at at least one of the plurality of TRPs (112 / 114) of the cell based on the configuration information. The method further includes transmitting (512 / 514), to the user equipment (110), at least one random access response (RAR) (512a / 514a) corresponding to the at least one preamble (506a / 508a) received from the at least one of the plurality of TRPs (112 / 114) of the cell. The method further includes receiving (518 / 520), from the user equipment (110), at least one message (518a / 520a) to a radio resource control connected state at the at least one of the plurality of TRPs (112 / 114) of the cell based on the at least one random access response (512a / 514a), where the at least one message includes at least one of a request message indicating a state transition, a resume message indicating the state transition, or a handover message confirming the user equipment (110) transitioning from the cell to another cell. The method further includes transmitting (522 / 524), to the user equipment (110), at least one response message (522a / 524a) in response to the at least one message (518a / 520a) from the at least one of the plurality of TRPs (112 / 114) of the cell.

[0095] In one or more embodiments, a non-transitory computer readable storage medium is provided including computer instructions that, when executed by a user equipment (110), cause the user equipment (110) to receive (408) configuration information related to a plurality of transmission-reception points (TRPs) of a cell, where the configuration information includes at least one random access channel (RACH) configuration (402) related to the plurality of TRPs (112 / 114) of the cell. The user equipment (110) is further caused to initiate a state transition to a radio resource control connected state under the cell based on the configuration information. The user equipment (110) is further caused to initiate a setup or resume operation based on the configuration information prior to connecting to the at least one of the plurality of TRPs (112 / 114) of the cell.

[0096] In one or more embodiments, a non-transitory computer readable storage medium is provided including computer instructions that, when executed by a network node (112 / 114), cause the network node (112 / 114) to transmit (408) to a user equipment (110), configuration information related to a plurality of transmission-reception points (TRPs) of a cell, where the configuration information includes at least one random access channel (RACH) configuration (402) related to the plurality of TRPs (112 / 114) of the cell. The network node (112 / 114) is further caused to receive (506 / 508), from a user equipment (110), at least one preamble (506a / 508a) on a random access channel (RACH) occasion (504) at at least one of the plurality of TRPs (112 / 114) of the cell based on the configuration information. The network node (112 / 114) is further caused to transmit (512 / 514), to the user equipment (110), at least one random access response (RAR) (512a / 514a) corresponding to the at least one preamble (506a / 508a) received from the at least one of the plurality of TRPs (112 / 114) of the cell. The network node (112 / 114) is further caused to receive (518 / 520), from the user equipment (110), at least one message (518a / 520a) to a radio resource control connected state at the at least one of the plurality of TRPs (112 / 114) of the cell based on the at least one random access response (512a / 514a), where the at least one message includes at least one of a request message indicating a state transition, a resume message indicating the state transition, or a handover message confirming the user equipment (110) transitioning from the cell to another cell. The network node (112 / 114) is further caused to transmit (522 / 524), to the user equipment (110), at least one response message (522a / 524a) in response to the at least one message (518a / 520a) from the at least one of the plurality of TRPs (112 / 114) of the cell.

Claims

What is claimed is:

1. A user equipment for wireless communication, comprising: at least one processor; and at least one memory storing instructions thereon that, when executed by the at least one processor, cause the user equipment to: receive configuration information related to a plurality of transmission-reception points (TRPs) of a cell, wherein the configuration information comprises at least one random access channel (RACH) configuration related to the plurality of TRPs of the cell; initiate a state transition to a radio resource control connected state under the cell based on the configuration information; and initiate a setup or resume operation based on the configuration information prior to connecting to the at least one of the plurality of TRPs of the cell.

2. The user equipment of claim 1 , wherein the initiating of the state transition to the radio resource control connected state causes the user equipment to: transmit at least one preamble on a random access channel (RACH) occasion to at least one of the plurality of TRPs of the cell; and receive at least one random access response (RAR) corresponding to the at least one preamble from the plurality of TRPs of the cell.

3. The user equipment of claim 1, wherein the setup operation comprises: transmit at least one message to at least one of the of the plurality of TRPs of the cell based on the at least one random access response; and receive at least one response message in response to the at least one message from the at least one of the plurality of TRPs of the cell, wherein the at least one message comprises at least one of a request message indicating the state transition, a resume message indicating the state transition, or a handover message confirming the user equipment transitioning from the cell to another cell.

4. The user equipment of claim 1, wherein the configuration information is at least one of:comprised in a system information; comprised in a radio resource control release message; or comprises a condition indicating when a multi-TRP operation is initiated.

5. The user equipment of claim 2, wherein the random access channel configuration related to the plurality of TRPs of the cell comprises at least one of: a particular random access channel configuration for the at least one TRP of the plurality of TRPs of the cell, wherein the user equipment determines a random access channel occasion for transmitting the at least one preamble based on the random access channel configuration; or one or more random access channel occasions that map to a set of beams from the plurality of TRPs of the cell.

6. The user equipment of claim 2, wherein the user equipment initiates the state transition based on at least one of: a condition indicated in the configuration information is fulfilled; or a quality of service requirement.

7. The user equipment of claim 2, further caused to perform one or more of: start at least one random access response window associated with the at least one preamble for receiving at the at least one random access response from the plurality of TRPs of the cell; or monitor at least one physical downlink control channel (PDCCH) from the plurality of TRPs of the cell for at least one random access response identified by a random access radio network temporary identifier (RNTI) while the random access response window is running.

8. The user equipment of claim 7, wherein the random access radio network temporary identifier comprises at least one of: a single random access radio network temporary identifier; or at least one random access radio network temporary identifier associated with the at least one of the plurality of TRPs of the cell.

9. The user equipment of claim 2, wherein the received at least one random access response comprises at least one of: at least one timing advance and at least one uplink grant for at least one TRP of the plurality of TRPs of the cell; or a timing advance and an uplink grant for the at least one of the plurality of TRPs of the cell.

10. The user equipment of claim 2, wherein the response message further comprises a multi-TRP configuration that comprises configuration of a particular TRP from which the at least one random access response is not sent.

11. The user equipment of claim 1 or 2, further caused to determine which random access channel occasion is related to at least one TRP of the plurality of TRPs by configuring separate resources or by using a mapping between a synchronization signal block (SSB) and a random access channel occasion and information related to an association between the synchronization signal block and the at least one TRP.

12. The user equipment of claim 1, further caused to determine which random access channel occasion is related to the at least one TRP of the plurality of TRPs of the cell by mapping a synchronization signal block with information linked to the at least one TRP to the random access channel occasion.

13. A network node for wireless communication, comprising: at least one processor; and at least one memory storing instructions thereon that, when executed by the at least one processor, cause the network node to: transmit to a user equipment, configuration information related to a plurality of transmission-reception points (TRPs) of a cell, wherein the configuration information comprises at least one random access channel (RACH) configuration related to the plurality of TRPs of the cell;receive, from a user equipment, at least one preamble on a random access channel (RACH) occasion at at least one of the plurality of TRPs of the cell based on the configuration information; transmit, to the user equipment, at least one random access response (RAR) corresponding to the at least one preamble received from the at least one of the plurality of TRPs of the cell; receive, from the user equipment, at least one message to a radio resource control connected state at the at least one of the plurality of TRPs of the cell based on the at least one random access response, wherein the at least one message comprises at least one of a request message indicating a state transition, a resume message indicating the state transition, or a handover message confirming the user equipment transitioning from the cell to another cell; and transmit, to the user equipment, at least one response message in response to the at least one message from the at least one of the plurality of TRPs of the cell.

14. The network node of claim 13, wherein the configuration information is at least one of: comprised in a system information; comprised in a radio resource control release message; or comprises a condition indicating when a multi-TRP operation is initiated.

15. The network node of claim 13, wherein the random access channel configuration related to the plurality of TRPs of the cell comprises at least one of: a particular random access channel configuration for the at least one TRP of the plurality of TRPs of the cell, wherein the user equipment determines a random access channel occasion for transmitting the at least one preamble based on the random access channel configuration; or one or more random access channel occasions that map to a set of beams from the plurality of TRPs of the cell.

16. The network node of claim 13, further caused to transmit the at least one random access response within a single random access response window associated with the at least one preamble and started by the user equipment.

17. The network node of claim 16, wherein the at least one random access response is transmitted over at least one physical downlink control channel from the plurality of TRPs and identified by a random access radio network temporary identifier while the random access response window is running.

18. The network node of claim 17, wherein the random access radio network temporary identifier comprises at least one of: a single random access radio network temporary identifier; or at least one random access radio network temporary identifier associated with the at least one of the plurality of TRPs of the cell.

19. The network node of claim 12, wherein the at least one random access response comprises at least one of: at least one timing advance and at least one uplink grant for at least one TRP of the plurality of TRPs of the cell; or a timing advance and an uplink grant for the at least one of the plurality of TRPs of the cell.

20. The network node of claim 12, wherein if one or more of the plurality of TRPs of the cell fails to receive one or more preambles from the user equipment, the network node is further caused to perform at least one of: stop a multi-TRP operation; or transmit the at least one random access response to the user equipment, wherein the at least one random access response comprises a timing advance and an uplink grant from a TRP of the plurality of TRPs of the cell where the at least one preamble is received, wherein the response message indicates a multi-TRP configuration, and wherein the response message comprises a radio resource control setup message.

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