Shared Physical Random Access Channel (PRACH) configuration to avoid conflicts in PRACH communications

Abstract

In summary, various aspects of the present disclosure relate to wireless communications. In some aspects, a first base station determines conflict avoidance information for avoiding conflicts in physical random access channel communications from one or more user devices. The conflict avoidance information may include subcarrier spacing information and / or beam correspondence information. The first base station may send the conflict avoidance information to a second base station. Many other aspects are also provided.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This patent application claims the benefit of priority of U.S. Provisional Patent Application No. 62 / 928,186, filed on October 30, 2019, entitled “SHARING A PHYSICAL RANDOM ACCESS CHANNEL (PRACH) CONFIGURATION FOR AVOIDING COLLISIONS OF PRACH COMMUNICATIONS,” and U.S. Non-Provisional Patent Application No. 17 / 021,667, filed on September 15, 2020, entitled “SHARING A PHYSICAL RANDOM ACCESS CHANNEL (PRACH) CONFIGURATION FOR AVOIDING COLLISIONS OF PRACH COMMUNICATIONS,” and the above applications are hereby expressly incorporated herein by reference. Technical Field

[0003]

[0006] Generally speaking, aspects of the disclosure relate to wireless communications and to techniques and apparatus for sharing physical random access channel (PRACH) configurations to avoid collisions of PRACH communications. Background Art

[0004] Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcasting. Typical wireless communication systems may employ multiple access technologies that can support communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power, etc.). Examples of such multiple access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single carrier frequency division multiple access (SC-FDMA) systems, time division synchronous code division multiple access (TD-SCDMA) systems, and long term evolution (LTE). LTE / LTE-Advanced is a collection of enhancements to the Universal Mobile Telecommunications System (UMTS) mobile standard released by the Third Generation Partnership Project (3GPP).

[0005] A wireless communication network may include multiple base stations (BSs) that can support communications for multiple user equipments (UEs). User equipments (UEs) may communicate with base stations (BSs) via downlinks and uplinks. A downlink (or forward link) refers to a communication link from a BS to a UE, and an uplink (or reverse link) refers to a communication link from a UE to a BS. As will be described in more detail herein, a BS may be referred to as a Node B, gNB, access point (AP), radio head, transmit receive point (TRP), new radio (NR) BS, 5G Node B, etc.

[0006] The above multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different user equipment to communicate at the city, country, region, and even global level. New Radio (NR) (which may also be referred to as 5G) is a set of enhancements to the LTE mobile standard released by the Third Generation Partnership Project (3GPP). NR is designed to better integrate with other open standards by improving spectrum efficiency, reducing costs, improving services, utilizing new spectrum, and using orthogonal frequency division multiplexing (OFDM) (CP-OFDM) with cyclic prefix (CP) on the downlink (DL), using CP-OFDM and / or SC-FDM (e.g., also referred to as discrete Fourier transform spread OFDM (DFT-s-OFDM)) on the uplink (UL), and supporting beamforming, multiple input multiple output (MIMO) antenna technology and carrier aggregation, so as to better support mobile broadband Internet access. However, as the demand for mobile broadband access continues to grow, there is a need for further improvements in LTE and NR technologies. Preferably, these improvements should be applicable to other multiple access technologies and telecommunication standards that adopt these technologies. Summary of the invention

[0007] In some aspects, a method of wireless communication performed by a first base station may include determining collision avoidance information for avoiding collisions of physical random access channel (PRACH) communications from one or more user equipments (UEs), the collision avoidance information including one or more of subcarrier spacing information or beam correspondence information. The method may include sending the collision avoidance information to a second base station.

[0008] In some aspects, a method of wireless communication performed by a first base station may include: receiving collision avoidance information from a second base station for avoiding collision of PRACH communications from one or more UEs, the collision avoidance information including one or more of subcarrier spacing information or beam correspondence information. The method may include: determining a PRACH configuration for PRACH communications performed by the one or more UEs based at least in part on the collision avoidance information; and sending the PRACH configuration to the one or more UEs.

[0009] In some aspects, a first base station for wireless communication may include: a memory; and one or more processors operatively coupled to the memory. The memory and the one or more processors may be configured to: determine collision avoidance information for avoiding collision of PRACH communications from one or more UEs, the collision avoidance information including one or more of subcarrier spacing information or beam correspondence information. The memory and the one or more processors may be configured to: send the collision avoidance information to a second base station.

[0010] In some aspects, a first base station for wireless communication may include: a memory; and one or more processors operatively coupled to the memory. The memory and the one or more processors may be configured to: receive collision avoidance information for avoiding collision of PRACH communications from one or more UEs from a second base station, the collision avoidance information including one or more of subcarrier spacing information or beam correspondence information. The memory and the one or more processors may be configured to: determine a PRACH configuration for PRACH communications performed by the one or more UEs based at least in part on the collision avoidance information; and send the PRACH configuration to the one or more UEs.

[0011] In some aspects, a non-transitory computer-readable medium may store one or more instructions for wireless communication. The one or more instructions, when executed by one or more processors of a first base station, may cause the one or more processors to perform the following operations: determine conflict avoidance information for avoiding conflicts of PRACH communications from one or more UEs, the conflict avoidance information including one or more of subcarrier spacing information or beam correspondence information. The one or more instructions, when executed by the one or more processors of the first base station, may cause the one or more processors to perform the following operations: send the conflict avoidance information to a second base station.

[0012] In some aspects, a non-transitory computer-readable medium may store one or more instructions for wireless communication. The one or more instructions, when executed by one or more processors of a first base station, may cause the one or more processors to perform the following operations: receiving conflict avoidance information for avoiding conflicts of PRACH communications from one or more UEs from a second base station, the conflict avoidance information including one or more of subcarrier spacing information or beam correspondence information. The one or more instructions, when executed by the one or more processors of the first base station, may cause the one or more processors to perform the following operations: determining a PRACH configuration for PRACH communications performed by the one or more UEs based at least in part on the conflict avoidance information; and sending the PRACH configuration to the one or more UEs.

[0013] In some aspects, a first device for wireless communication may include: a unit for determining conflict avoidance information for avoiding conflicts in PRACH communications from one or more UEs, the conflict avoidance information including one or more of subcarrier spacing information or beam correspondence information; and a unit for sending the conflict avoidance information to a second device.

[0014] In some aspects, a first apparatus for wireless communication may include: a unit for receiving, from a second apparatus, collision avoidance information for avoiding collisions of PRACH communications from one or more UEs, the collision avoidance information including one or more of subcarrier spacing information or beam correspondence information. The first apparatus may include: a unit for determining a PRACH configuration for PRACH communications by the one or more UEs based at least in part on the collision avoidance information; and a unit for sending the PRACH configuration to the one or more UEs.

[0015] In summary, various aspects include methods, apparatus, systems, computer program products, non-transitory computer-readable media, user equipment, base stations, wireless communication devices, and / or processing systems as fully described herein with reference to the accompanying drawings and description and as illustrated by the accompanying drawings and description.

[0016] The foregoing has been fairly extensively summarized according to the features and technical advantages of the examples of the present disclosure, so that the detailed description below can be better understood. Additional features and advantages will be described below. The disclosed concepts and specific examples can be easily used as the basis for modifying or designing other structures for the same purpose of performing the present disclosure. Such equivalent constructions do not depart from the scope of the attached claims. When considered in conjunction with the accompanying drawings, the characteristics of the concepts disclosed herein (both their organization and method of operation) and the associated advantages will be better understood according to the description below. Each of the figures in the accompanying drawings is provided for the purpose of illustration and description, and is not intended to be a definition of the limitations of the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] A more detailed description of the above brief summary may be obtained by reference to various aspects (some of which are shown in the accompanying drawings) so that the above-mentioned features of the present disclosure may be understood in detail. However, it is to be noted that the accompanying drawings only illustrate certain typical aspects of the present disclosure and are therefore not to be considered as limiting the scope of the present disclosure, as the description may recognize other equally effective aspects. The same reference numerals in different drawings may identify the same or similar elements.

[0018] Figure 1 is a block diagram conceptually illustrating an example of a wireless communication network in accordance with various aspects of the present disclosure.

[0019] Figure 2 is a block diagram conceptually illustrating an example of a base station communicating with a UE in a wireless communication network according to various aspects of the present disclosure.

[0020] Figure 3 is a diagram conceptually illustrating an example of a 4-step random access channel (RACH) procedure and an example of a 2-step RACH procedure.

[0021] Figure 4 is a diagram conceptually illustrating an example table of physical RACH (PRACH) configuration information elements.

[0022] Figure 5 is a diagram conceptually illustrating an example in which base stations share PRACH configuration information through an Xn interface according to various aspects of the present disclosure.

[0023] Figure 6 is a diagram further illustrating an example in which base stations share PRACH configuration information through an Xn interface according to various aspects of the present disclosure.

[0024] Figure 7 is a diagram further illustrating an example in which base stations share PRACH configuration information through an Xn interface according to various aspects of the present disclosure.

[0025] Figure 8 is a diagram illustrating example processes performed, for example, by a base station in accordance with various aspects of the present disclosure.

[0026] Fig. 9 is a diagram illustrating example processes performed, for example, by a base station in accordance with various aspects of the present disclosure. DETAILED DESCRIPTION

[0027] The various aspects of the present disclosure are described more fully below with reference to the accompanying drawings. However, the present disclosure can be embodied in many different forms, and should not be interpreted as being limited to any specific structure or function given throughout the present disclosure. Instead, these aspects are provided so that the present disclosure will be comprehensive and complete, and the scope of the present disclosure will be fully conveyed to those skilled in the art. Based on the teachings of this article, it should be appreciated by those skilled in the art that the scope of the present disclosure is intended to cover any aspect of the present disclosure disclosed herein, whether the aspect is implemented independently of any other aspect of the present disclosure or implemented in combination with any other aspect. For example, using any number of aspects set forth herein, a device can be implemented or a method can be practiced. In addition, the scope of the present disclosure is intended to cover such a device or method that is practiced using other structures, functions, or structures and functions other than the various aspects of the present disclosure set forth herein or different from the various aspects of the present disclosure set forth herein. It should be understood that any aspect of the present disclosure disclosed herein can be embodied by one or more elements of the claims.

[0028] Several aspects of telecommunication systems will now be presented with reference to various devices and techniques. These devices and techniques will be described in the detailed description below by various blocks, modules, components, circuits, steps, processes, algorithms, etc. (collectively referred to as "elements") and illustrated in the accompanying drawings. These elements may be implemented using hardware, software, or a combination thereof. Whether such elements are implemented as hardware or software depends on the specific application and the design constraints imposed on the overall system.

[0029] It should be noted that although various aspects may be described herein using terms commonly associated with 3G and / or 4G wireless technologies, various aspects of the present disclosure may be applied to communication systems based on other generations, such as 5G and beyond (including NR technologies).

[0030] Figure 11 is a schematic diagram showing a wireless network 100 in which various aspects of the present disclosure may be implemented. The wireless network 100 may be an LTE network or some other wireless network (such as a 5G or NR network). The wireless network 100 may include a plurality of BSs 110 (shown as BS 110a, BS 110b, BS 110c, and BS 110d) and other network entities. A BS is an entity that communicates with a user equipment (UE) and may also be referred to as a base station, NR BS, Node B, gNB, 5G Node B (NB), access point, transmit receive point (TRP), etc. Each BS may provide communication coverage for a particular geographic area. In 3GPP, the term "cell" may refer to a coverage area of ​​a BS and / or a BS subsystem serving the coverage area, depending on the context in which the term is used.

[0031] A BS may provide communication coverage for a macro cell, a pico cell, a femto cell, and / or another type of cell. A macro cell may cover a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access by UEs with service subscription. A pico cell may cover a relatively small geographic area and may allow unrestricted access by UEs with service subscription. A femto cell may cover a relatively small geographic area (e.g., a residence) and may allow restricted access by UEs associated with the femto cell (e.g., UEs in a closed subscriber group (CSG)). A BS for a macro cell may be referred to as a macro BS. A BS for a pico cell may be referred to as a pico BS. A BS for a femto cell may be referred to as a femto BS or a home BS. In Figure 1 In the example shown in , BS 110a may be a macro BS for macro cell 102a, BS 110b may be a pico BS for pico cell 102b, and BS 110c may be a femto BS for femto cell 102c. A BS may support one or more (e.g., three) cells. The terms "eNB", "base station", "NR BS", "gNB", "TRP", "AP", "Node B", "5G NB", and "cell" may be used interchangeably herein.

[0032] In some aspects, the cells may not necessarily be stationary, and the geographic area of ​​the cells may move depending on the location of the mobile BS. In some aspects, the BSs may be interconnected with each other and / or with one or more other BSs or network nodes (not shown) in the wireless network 100 via various types of backhaul interfaces, such as direct physical connections, virtual networks, and / or similar interfaces using any suitable transport networks.

[0033] The wireless network 100 may also include a relay station. A relay station is an entity that can receive data transmissions from an upstream station (e.g., a BS or a UE) and send data transmissions to a downstream station (e.g., a UE or a BS). A relay station may also be a UE that is capable of relaying transmissions for other UEs. Figure 1 In the example shown in , a relay BS 110d may communicate with a macro BS 110a and a UE 120d to facilitate communication between the BS 110a and the UE 120d. A relay BS may also be referred to as a relay station, a relay base station, a relay, or the like.

[0034] The wireless network 100 may be a heterogeneous network including different types of BSs (e.g., macro BSs, pico BSs, femto BSs, relay BSs, etc.). These different types of BSs may have different transmit power levels, different coverage areas, and different effects on interference in the wireless network 100. For example, a macro BS may have a high transmit power level (e.g., 5 to 40 watts), while a pico BS, a femto BS, and a relay BS may have a lower transmit power level (e.g., 0.1 to 2 watts).

[0035] The network controller 130 may be coupled to a set of BSs and may provide coordination and control for these BSs. The network controller 130 may communicate with the BSs via a backhaul. The BSs may also communicate with each other via a wireless or wired backhaul (eg, directly or indirectly).

[0036] UE 120 (e.g., 120a, 120b, 120c) can be dispersed throughout the wireless network 100, and each UE can be stationary or mobile. UE can also be referred to as an access terminal, terminal, mobile station, subscriber unit, station, etc. UE can be a cellular phone (e.g., a smart phone), a personal digital assistant (PDA), a wireless modem, a wireless communication device, a handheld device, a laptop computer, a cordless phone, a wireless local loop (WLL) station, a tablet device, a camera, a gaming device, a netbook, a smartbook, an ultrabook, a medical device or apparatus, a biometric sensor / device, a wearable device (smart watch, smart clothing, smart glasses, smart wristband, smart jewelry (e.g., smart ring, smart bracelet, etc.)), an entertainment device (e.g., a music or video device, or a satellite radio unit, etc.), a vehicle component or sensor, a smart meter / sensor, an industrial manufacturing device, a global positioning system device, or any other suitable device configured to communicate via a wireless or wired medium.

[0037] Some UEs may be considered as machine type communication (MTC) or evolved or enhanced machine type communication (eMTC) UEs. MTC and eMTC UEs include, for example, robots, drones, remote devices, sensors, meters, monitors, location tags, etc., which may communicate with a base station, another device (e.g., a remote device), or some other entity. A wireless node may provide a connection to or to a network (e.g., a wide area network such as the Internet or a cellular network) via, for example, a wired or wireless communication link. Some UEs may be considered as Internet of Things (IoT) devices, and / or may be implemented as NB-IoT (narrowband Internet of Things) devices. Some UEs may be considered as user premises equipment (CPE). UE 120 may be included inside a housing that houses components of UE 120 (such as a processor component, a memory component, etc.).

[0038] Generally, any number of wireless networks can be deployed in a given geographic area. Each wireless network can support a specific radio access technology (RAT) and can operate on one or more frequencies. RAT can also be referred to as radio technology, air interface, etc. Frequency can also be referred to as carrier, frequency channel, etc. Each frequency can support a single RAT in a given geographic area to avoid interference between wireless networks of different RATs. In some cases, NR or 5G RAT networks can be deployed.

[0039] In some aspects, two or more UEs 120 (e.g., illustrated as UE 120a and UE 120e) may communicate directly using one or more sidelink channels (e.g., without using base station 110 as an intermediary to communicate with each other). For example, UE 120 may communicate using peer-to-peer (P2P) communication, device-to-device (D2D) communication, vehicle-to-everything (V2X) protocols (e.g., which may include vehicle-to-vehicle (V2V) protocols, vehicle-to-infrastructure (V2I) protocols, etc.), mesh networks, etc. In such cases, UE 120 may perform scheduling operations, resource selection operations, and / or other operations described elsewhere herein as being performed by base station 110.

[0040] As noted above, Figure 1 is provided as an example. Other examples may differ from those described above. Figure 1 Examples described.

[0041] Figure 2 Base station 110 and UE 120 (which may be Figure 11. Block diagram of a design 200 of a base station 110 and a UE 120. Base station 110 may be equipped with T antennas 234a through 234t, and UE 120 may be equipped with R antennas 252a through 252r, where in general, T≥1 and R≥1.

[0042] At the base station 110, the transmit processor 220 may receive data for one or more UEs from the data source 212, select one or more modulation and coding schemes (MCS) for each UE based at least in part on a channel quality indicator (CQI) received from the UE, process (e.g., encode and modulate) the data for the UE based at least in part on the MCS selected for each UE, and provide data symbols for all UEs. The transmit processor 220 may also process system information (e.g., for semi-static resource partitioning information (SRPI), etc.) and control information (e.g., CQI requests, grants, upper layer signaling, etc.), and provide overhead symbols and control symbols. The transmit processor 220 may also generate reference symbols for reference signals (e.g., cell-specific reference signals (CRS)) and synchronization signals (e.g., primary synchronization signals (PSS) and secondary synchronization signals (SSS)). The transmit (TX) multiple-input multiple-output (MIMO) processor 230 may perform spatial processing (e.g., precoding) on ​​data symbols, control symbols, overhead symbols, and / or reference symbols, if applicable, and may provide T output symbol streams to T modulators (MOD) 232a to 232t. Each modulator 232 may process a corresponding output symbol stream (e.g., for OFDM, etc.) to obtain an output sample stream. Each modulator 232 may further process (e.g., convert to analog, amplify, filter, and up-convert) the output sample stream to obtain a downlink signal. T downlink signals from modulators 232a to 232t may be transmitted via T antennas 234a to 234t, respectively. According to various aspects described in more detail below, a synchronization signal may be generated using position coding to convey additional information.

[0043] At UE 120, antennas 252a to 252r may receive downlink signals from base station 110 and / or other base stations, and may provide received signals to demodulators (DEMODs) 254a to 254r, respectively. Each demodulator 254 may condition (e.g., filter, amplify, downconvert, and digitize) the received signal to obtain input samples. Each demodulator 254 may further process the input samples (e.g., for OFDM, etc.) to obtain received symbols. MIMO detector 256 may obtain received symbols from all R demodulators 254a to 254r, perform MIMO detection on the received symbols (if applicable), and provide detected symbols. Receive processor 258 may process (e.g., demodulate and decode) the detected symbols, provide decoded data for UE 120 to data sink 260, and provide decoded control information and system information to controller / processor 280. The channel processor may determine reference signal received power (RSRP), received signal strength indicator (RSSI), reference signal received quality (RSRQ), channel quality indicator (CQI), etc. In some aspects, one or more components of UE 120 may be included in a housing.

[0044] On the uplink, at the UE 120, a transmit processor 264 may receive and process data from a data source 262 and control information from a controller / processor 280 (e.g., for reports including RSRP, RSSI, RSRQ, CQI, etc.). The transmit processor 264 may also generate reference symbols for one or more reference signals. The symbols from the transmit processor 264 may be precoded by a TX MIMO processor 266 (if applicable), further processed by modulators 254a through 254r (e.g., for DFT-s-OFDM, CP-OFDM, etc.), and transmitted to the base station 110. At the base station 110, uplink signals from the UE 120 and other UEs may be received by the antenna 234, processed by the demodulator 232, detected by the MIMO detector 236 (if applicable), and further processed by the receive processor 238 to obtain decoded data and control information transmitted by the UE 120. The receive processor 238 may provide decoded data to a data sink 239 and decoded control information to a controller / processor 240. The base station 110 may include a communication unit 244 and communicate with the network controller 130 via the communication unit 244. The network controller 130 may include a communication unit 294, a controller / processor 290, and a memory 292.

[0045] The controller / processor 240 of the base station 110, the controller / processor 280 of the UE 120, and / or Figure 2Any other components in the base station 110 may perform one or more techniques associated with sharing a physical random access channel (PRACH) configuration to avoid conflicts in PRACH communications, as described in more detail elsewhere herein. For example, the controller / processor 240 of the base station 110, the controller / processor 280 of the UE 120, and / or Figure 2 Any other component in may perform or direct e.g. Figure 8 The process of 800 Fig. 9 The operations of process 900 and / or other processes as described herein. Memories 242 and 282 may store data and program codes for base station 110 and UE 120, respectively. In some aspects, memory 242 and / or memory 282 may include a non-transitory computer-readable medium storing one or more instructions for wireless communication. For example, one or more instructions, when executed by one or more processors of base station 110 and / or UE 120, may perform or direct, for example, Figure 8 The process of 800 Fig. 9 The process 900 and / or operations of other processes as described herein. The scheduler 246 can schedule UEs for data transmission on the downlink and / or uplink.

[0046] In some aspects, UE 120 may include: means for determining collision avoidance information for avoiding collision of PRACH communications from one or more UEs, the collision avoidance information including one or more of subcarrier spacing information or beam correspondence information; means for sending the collision avoidance information to the second base station; and so on. In some aspects, such means may include combining Figure 2 One or more components of base station 110 are depicted, such as antenna 234, DEMOD 232, MIMO detector 236, receive processor 238, controller / processor 240, transmit processor 220, TX MIMO processor 230, MOD 232, antenna 234, and the like.

[0047] In some aspects, the base station 110 may include: a unit for receiving, from a second base station, collision avoidance information for avoiding collisions of PRACH communications from one or more UEs, the collision avoidance information including one or more of subcarrier spacing information or beam correspondence information; a unit for determining a PRACH configuration for PRACH communications by the one or more UEs based at least in part on the collision avoidance information; a unit for sending the PRACH configuration to the one or more UEs; and the like. In some aspects, such a unit may include a unit for combining Figure 2One or more components of the base station 110 are depicted, such as antenna 234, DEMOD 232, MIMO detector 236, receive processor 238, controller / processor 240, transmit processor 220, TX MIMO processor 230, MOD 232, antenna 234, and the like.

[0048] As pointed out above, Figure 2 is provided as an example. Other examples may differ from those described above. Figure 2 Examples described.

[0049] The UE may send a random access channel (RACH) message to the base station to initiate communication with the base station. The RACH message may be the first message sent by the UE when the UE is powered on. The RACH message may be sent on a physical random access channel (PRACH) and may be more generally referred to as a PRACH communication. The UE may request an uplink allocation from the base station using PRACH communication.

[0050] The PRACH communication may include a PRACH sequence (also referred to as a PRACH preamble or PRACH preamble sequence) that may be used to distinguish UEs. The UE may use the PRACH format to determine the PRACH sequence and / or transmission characteristics of the PRACH sequence. The UE may receive an initial PRACH configuration in a transmission from a base station and send the PRACH communication using the initial PRACH configuration. The PRACH communication may initiate a RACH procedure to obtain an uplink allocation.

[0051] Figure 3 is a diagram conceptually illustrating an example 300 of a 4-step RACH procedure and an example 302 of a 2-step RACH procedure. In each example, a UE is performing a RACH procedure with a base station.

[0052] In LTE and NR, the 4-step RACH process can be a RACH process with a four-message (msg1, msg2, msg3, msg4) handshake between the UE and the base station. The UE can send msg1 with a PRACH preamble to the base station on the PRACH. The base station can send msg2 to the UE on the physical downlink control channel (PDCCH) and the physical downlink shared channel (PDSCH). Msg2 can include a random access response. The UE can send msg 3 on the physical uplink shared channel (PUSCH). msg3 can include contention request and device information. The base station can send msg4 on the PDCCH and PDSCH. msg4 can include contention resolution. Contention request and contention resolution involve resolving contention from multiple UEs that happen to use the same PRACH preamble.

[0053] In NR, the 2-step RACH procedure is another RACH procedure. In the 2-step procedure, the base station broadcasts system information and synchronization signal block (SSB) information to the UE. The UE can send the PRACH preamble as part of the msgA message to the base station. msgA can also include a payload. The base station can process the preamble, detect the preamble, and process the payload. The base station can send a response in msgB. msg1 and msg 3 of the 4-step RACH can be considered to be folded into msgA, and msg 2 and msg4 can be considered to be folded into msgB.

[0054] As noted above, Figure 3 are provided as two examples of RACH procedures. Other examples may differ from those regarding Figure 3 Examples described.

[0055] When two or more UEs send the same PRACH preamble to the base station in the same PRACH slot, a collision of PRACH communications (PRACH collision) may occur during the RACH procedure. A RACH procedure that allows possible collision (contention) of PRACH communications may be referred to as a contention-based random access (CBRA) procedure. A 4-step RACH procedure and a 2-step RACH procedure are examples of a CBRA procedure. A RACH procedure in which the network allocates PRACH preambles so that there is no collision is referred to as a contention-free random access (CFRA) procedure.

[0056] In LTE networks, conflicts in PRACH communications may deteriorate PRACH detection performance and have a direct impact on initial UE access, beam failure rate, handover performance, etc. To mitigate potential conflicts in PRACH communications, neighboring base stations in LTE can share their respective PRACH configurations.

[0057] Figure 4 is a diagram conceptually illustrating an example table 400 of PRACH configuration information elements (IEs) that may be shared in LTE.

[0058] Some of the IEs shown in Table 400 may include, for example, RootSequenceIndex, which is the root sequence index for PRACH sequence generation. ZeroCorrelationZoneConfiguration is used to set the number of root sequences required per cell for the selected PRACH. HighSpeedFlag indicates whether a restricted sequence set or an unrestricted sequence set can be used to calculate the cyclic shift interval used to generate the sequence. PRACH-FrequencyOffset defines the frequency position of the preamble. PRACH-ConfigurationIndex is used to determine the preamble format.

[0059] The UE may include frequency domain resources in the RACH procedure messaging. For example, Msg1-FDM (Frequency Division Multiplexing) may indicate the number of PRACH transmission opportunities multiplexed in one time instance. Msg1-FrequencyStart may indicate the offset in the frequency domain relative to the lowest PRACH transmission opportunity of physical resource block 0. The offset may be configured such that the corresponding RACH resource is completely within the bandwidth of the uplink bandwidth portion.

[0060] As noted above, Figure 4 is provided as an example. Other examples may differ from those described above. Figure 4 Examples described.

[0061] Base stations in LTE can use parameters from neighboring base stations to optimize PRACH configurations. However, NR involves NR features that do not exist in LTE. NR features do not take into account PRACH collision avoidance. NR features may include, for example, multiple subcarrier spacings for sequence lengths and multi-beam transmissions. Base stations that do not take these NR features into account may experience collisions in PRACH communications. Conflicts in PRACH communications may waste power, processing (e.g., memory, processor), and signaling resources.

[0062] According to some aspects described herein, a first base station may share PRACH configuration information with a second base station. The PRACH configuration information may include conflict avoidance information related to NR features. For example, multiple subcarrier spacings (SCS) for different sequence lengths are part of NR. For a sequence length of 839, the UE may be configured with an SCS of a PRACH sequence from {1.25, 5} kHz. For a sequence length of 139, the UE may be configured with an SCS from {15, 30, 60, 120} kHz. In some aspects, given the same frequency resources and the same root sequence index, the base station may use different PRACH SCSs to help reduce conflicts in PRACH communications. In this way, the base station can reduce conflicts in PRACH communications in NR by sharing conflict avoidance information that takes into account multiple SCSs in NR.

[0063] Additionally or alternatively, the base station may share collision avoidance information including beam correspondence information. The beam correspondence information may indicate an SSB and / or corresponding SSB to RACH opportunity (time / frequency resource) (RO) mapping. The SSB may correspond to a beam and is an SS / physical broadcast channel (SS / PBCH) block and a master information block (MIB) that carries a synchronization signal. The base station may use the SSB and / or SSB to RO mapping in the beam correspondence information to select an SSB and / or RO different from the SSB and / or RO indicated in the beam correspondence information for PRACH communication.

[0064] Thus, a base station and a UE sending PRACH communications may avoid collisions of PRACH communications and save power, processing (eg, memory, processor), and signaling resources that may otherwise be wasted due to collisions of PRACH communications.

[0065] Figure 5 is a diagram conceptually illustrating an example 500 of base stations sharing PRACH configuration information over an Xn interface according to various aspects of the present disclosure. Figure 5 A first base station 510 (e.g., a gNB) is shown that can communicate with a second base station 520 (e.g., a gNB) via an interface (e.g., an Xn interface). The first base station 510 and the second base station 520 can both receive PRACH communications for RACH procedures from a UE 530. The UE 530 can represent one or more UEs.

[0066] As indicated by reference numeral 540, the first base station 510 may determine collision avoidance information for avoiding collision of PRACH communications from a UE, such as UE 530. The collision avoidance information may include subcarrier spacing information and / or beam correspondence information, which corresponds to a new feature in NR. The first base station 510 may prepare the collision avoidance information for sharing with other base stations for optimizing the PRACH configuration for the UE.

[0067] The subcarrier spacing information may indicate a first subcarrier spacing (SCS) from among a plurality of subcarrier spacings (SCSs) for PRACH, which is used by the first base station 510 to configure PRACH communications by the UE. In some aspects, the collision avoidance information indicates a frequency resource and a root sequence index for PRACH sequence generation, which is used by the first base station 510 to configure PRACH communications by the UE.

[0068] Because NR supports multi-beam operation, the collision avoidance information may include beam correspondence information. The beam correspondence information may include SSB transmission information. For example, the SSB transmission information may include information about what SSB (and corresponding beam) the first base station 510 configures the UE to use for PRACH communication. The SSB is relevant because the UE can send PRACH communication using a transmit beam (uplink spatial filter) corresponding to the receive beam that the UE uses to successfully receive the SSB. In some aspects, the UE can send multiple SSBs, such as up to N=8 SSBs for frequency range 1 (FR1) and up to N=64 SSBs for FR2. Therefore, the first base station 510 can send SSB information using multiple SSBs. The first base station 510 can send a bitmap ssb-PositionsInBurst to indicate which SSBs of the N SSBs are being sent by the UE associated with the first base station 510.

[0069] Additionally or alternatively, the beam correspondence information includes an SSB to RO mapping used by the first base station 510 to configure PRACH communications performed by the UE. In some aspects, there is one RO for one SSB. In some aspects, there are multiple ROs for one SSB. Based at least in part on the time slot and frequency resources, there may be up to 128 ROs that can be selected for PRACH configuration.

[0070] As indicated by reference numeral 550, the first base station 510 may send collision avoidance information to the second base station 520 in a defined message type. In some aspects, the first base station 510 may send subcarrier spacing information in a msg1-SubcarrierSpacing message. In some aspects, the first base station 510 may send beam correspondence information including SSB transmission information and / or SSB-RO mapping. The first base station 510 may send SSB transmission information in a ssb-PositionsInBurst message. The first base station 510 may send SSB-RO mapping in a ssb-perRACH-OccasionAndCB-PreamblesPerSSB message.

[0071] The ssb-PositionsInBurst message may indicate the time domain position of the transmitted SSB (also referred to as an SS / PBCH (Physical Broadcast Channel) block) in the half-frame with the SS / PBCH block. The first (leftmost) bit corresponds to SS / PBCH block index 0, the second bit corresponds to SS / PBCH block index 1, and so on. A value of 0 indicates that the corresponding SS / PBCH block is not transmitted, while a value of 1 indicates that the corresponding SS / PBCH block is transmitted. In some aspects, different bits and / or different values ​​may be used.

[0072] The ssb-perRACH-OccasionAndCB-PreamblesPerSSB message may include a CHOICE field and an ENUMERATED field. The CHOICE field may indicate the number of SSBs per RO. A value of one-eighth corresponds to one SSB associated with 8 ROs, a value of one-quarter corresponds to one SSB associated with 4 ROs, and so on. The ENUMERATED field may indicate the number of contention-based preambles per SSB. A value of n4 corresponds to 4 contention-based preambles per SSB, a value of n8 corresponds to 8 contention-based preambles per SSB, and so on. The total number of CB preambles in a RO may be given by CB-preambles-per-SSB*max(1,SSB-per-rach-occasion).

[0073] For the CFRA process, the first base station 510 may send an SSB index or a channel state information reference signal (CSI-RS) resource that the first base station 510 may indicate to the UE. Each of these UEs may send a PRACH communication in a transmit beam corresponding to a receive beam for receiving an SSB or CSI-RS. The first base station 510 may send an SSB and / or CSI-RS resource in an information element (IE) of a RACH-ConfigDedicated message. The first base station 510 may send an identifier for a CSI-RS resource in conflict avoidance information. The CSI-RS resource may be defined in a measurement object associated with a serving cell. The first base station 510 may send an identifier of an SSB in conflict avoidance information, which may be an SSB sent by a serving cell. The SSB and / or CSI-RS resources may be used for handover scenarios, beam failure detection, recovery, and the like. Other base stations (such as the second base station 520) may use the conflict avoidance information sent by the first base station 510 to optimize the PRACH configuration for a UE (e.g., UE 530) so that conflicts in PRACH communications performed by the UE may be reduced.

[0074] As noted above, Figure 5 is provided as an example. Other examples may differ from those described above. Figure 5 Examples described.

[0075] Figure 6 is a diagram further illustrating an example of base stations sharing PRACH configuration information through an Xn interface according to various aspects of the present disclosure. Figure 6 The first base station 510 and the second base station 520 are shown again in FIG. 5 , but the figure shows that the second base station 520 uses the collision avoidance information received by the second base station 520 from the first base station 510 via the Xn interface. Figure 6 In the embodiment, the collision avoidance information may include subcarrier spacing information.

[0076] The second base station 520 may determine a PRACH configuration for PRACH communication by one or more UEs based at least in part on the collision avoidance information (or more specifically, based on the subcarrier spacing information of the first base station 510). As shown in reference numeral 610, after receiving the collision avoidance information from the first base station 510, the second base station 520 may identify the SCS of the first base station 510 based at least in part on the collision avoidance information. For a sequence length of 839, the SCS of the PRACH sequence may be configured from {1.25, 5} kHz. For a sequence length of 139, the SCS of the PRACH sequence may be configured from {15, 30, 60, 120} kHz. The second base station 520 may identify the SCS that the first base station 510 is using for the PRACH configuration from the possible SCSs for the PRACH.

[0077] As indicated by reference numeral 620, the second base station 520 may determine the PRACH configuration for one or more UEs associated with the second base station 520 by selecting an SCS for the PRACH configuration that is different from the SCS identified as being used by the first base station 510. In some aspects, the collision avoidance information may also indicate the frequency resources and root sequence index used by the first base station 510 for PRACH sequence generation. That is, even if the first base station 510 and the second base station 520 use the same frequency resources and the same root sequence index, the first base station 510 and the second base station 520 may use different SCSs. For example, given the same frequency resources and the same root sequence index, the second base station 520 may identify that the first base station 510 is using a 15kHz SCS for the PRACH configuration of the UE associated with the first base station 510. Therefore, the second base station 520 may select a 60kHz SCS for the PRACH configuration of one or more UEs associated with the second base station 520.

[0078] In some aspects, the second base station 520 may implement a first detector for a given PRACH SCS (e.g., 60 kHz), which may not be able to detect a PRACH SCS of the same sequence length (e.g., 139) but a different SCS (e.g., 15 kHz). The second base station 520 may implement a second detector for a 15 kHz SCS, a 120 kHz SCS, etc. In some aspects, the collision avoidance information may include sequence length information.

[0079] As indicated by reference numeral 630, the second base station 520 may send a PRACH configuration to one or more UEs, including the UE 530. In some aspects, the second base station 520 may broadcast the PRACH configuration to the one or more UEs as an update following the initial PRACH configuration. Each UE receiving the broadcast may update the UE's PRACH configuration and use the PRACH configuration to send PRACH communications.

[0080] As noted above, Figure 6 is provided as an example. Other examples may differ from those described above. Figure 6 Examples described.

[0081] Figure 7 5 is a diagram further illustrating an example 500 of a base station sharing PRACH configuration information via an Xn interface according to various aspects of the present disclosure. Figure 7 The first base station 510 and the second base station 520 are shown again in FIG. 5 , but the figure shows that the second base station 520 uses the collision avoidance information received by the second base station 520 from the first base station 510 via the Xn interface. Figure 7In the embodiment, the conflict avoidance information may include beam correspondence information.

[0082] The beam correspondence information may include SSB transmission information. As indicated by reference numeral 710, the second base station 520 may identify the SSB used by the first base station 510 for the PRACH configuration based at least in part on the SSB transmission information in the beam correspondence information. As indicated by reference numeral 720, the second base station 520 may determine the PRACH configuration for one or more UEs by selecting an SSB different from the SSB indicated by the SSB transmission information for the PRACH configuration.

[0083] Additionally or alternatively, the beam correspondence information may include an SSB to RO mapping. As indicated by reference numeral 710, the second base station 520 may identify a first RO of the first base station 510 based at least in part on the SSB transmission information and / or the SSB to RO mapping in the beam correspondence information. As indicated by reference numeral 720, the second base station 520 may determine a PRACH configuration for one or more UEs by selecting a second RO different from the first RO for the PRACH configuration.

[0084] In some aspects, for the CFRA process, the second base station 520 may provide a serving cell, and the collision avoidance information may include beam correspondence information indicating the first CSI-RS resource. The second base station 520 may determine the PRACH configuration by selecting a CSI-RS resource different from the first CSI-RS resource for the PRACH configuration. Additionally or alternatively, the beam correspondence information may indicate a first SSB identifier. The second base station 520 may determine the PRACH configuration by selecting an SSB identifier different from the first SSB identifier for the PRACH configuration.

[0085] As indicated by reference numeral 730, the second base station 520 may send a PRACH configuration to one or more UEs. In some aspects, the second base station 520 may broadcast the PRACH configuration as an update following the initial PRACH configuration. Each UE receiving the broadcast may update the UE's PRACH configuration and use the PRACH configuration to send PRACH communications.

[0086] As noted above, Figure 7 is provided as an example. Other examples may differ from those described above. Figure 7 Examples described.

[0087] Figure 5-7Used to describe that the first base station 510 shares collision avoidance information with the second base station 520. In some aspects, the second base station 520 may share collision avoidance information with the first base station 510. In some aspects, the first base station 510 may share first collision avoidance information with the second base station 520, and the second base station 520 may share second collision avoidance information with the first base station 510.

[0088] The first base station 510 and the second base station 520 can operate more efficiently by optimizing the PRACH configuration to avoid conflicts in PRACH communications in the NR network. Even if the first base station 510 and the second base station 520 can use the same root and the same SCS, the second base station 520 can also optimize the PRACH communication of the UE. In some aspects, the optimized PRACH configuration can correspond to the UE's transmission of messages associated with a 4-step RACH process. In some aspects, the optimized PRACH configuration can correspond to the communication of messages associated with a two-step RACH process (e.g., msgA preamble).

[0089] Figure 8 8 is a diagram illustrating an example process 800 performed, for example, by a first base station in accordance with various aspects of the present disclosure. Example process 800 is an example of operations in which a first base station (e.g., base station 110, first base station 510, etc.) performs operations associated with sharing PRACH configuration information to avoid collisions in PRACH communications.

[0090] like Figure 8 As shown, in some aspects, process 800 may include: determining collision avoidance information for avoiding collisions of PRACH communications from one or more UEs (block 810). In some aspects, the collision avoidance information includes one or more of subcarrier spacing information or beam correspondence information. For example, the first base station (e.g., using transmit processor 220, receive processor 238, controller / processor 240, memory 242, etc.) may determine collision avoidance information for avoiding collisions of PRACH communications from one or more UEs, as described above. In some aspects, the collision avoidance information includes one or more of subcarrier spacing information or beam correspondence information.

[0091] like Figure 8 As further shown in FIG. 8 , in some aspects, process 800 may include sending collision avoidance information to a second base station (block 820). For example, the first base station (e.g., using transmit processor 220, receive processor 238, controller / processor 240, memory 242, etc.) may send collision avoidance information to the second base station, as described above.

[0092] Process 900 may include additional aspects, such as any single aspect or any combination of aspects described below and / or in conjunction with one or more other processes described elsewhere herein.

[0093] In the first aspect, sending the conflict avoidance information includes: sending the conflict avoidance information to the second base station via an Xn interface.

[0094] In a second aspect, alone or in combination with the first aspect, the collision avoidance information includes subcarrier spacing information. In some aspects, the subcarrier spacing information indicates a first subcarrier spacing from a plurality of subcarrier spacings for PRACH used by the first base station to configure PRACH communications by the UE.

[0095] In a third aspect, alone or in combination with one or more of the first and second aspects, the collision avoidance information indicates frequency resources and root sequence indexes used by the first base station for configuring PRACH communication by the UE for PRACH sequence generation.

[0096] In a fourth aspect, alone or in combination with one or more of the first to third aspects, the collision avoidance information includes beam correspondence information. In some aspects, the beam correspondence information includes SSB transmission information.

[0097] In a fifth aspect, alone or in combination with one or more of the first to fourth aspects, the beam correspondence information further includes an SSB to RO mapping used by the first base station to configure PRACH communication performed by the UE.

[0098] In a sixth aspect, alone or in combination with one or more of the first to fifth aspects, the first base station provides a serving cell, and the conflict avoidance information includes beam correspondence information. In some aspects, the beam correspondence information indicates one of a CSI-RS resource in a measurement object for the serving cell or an SSB identifier for the serving cell.

[0099] Although Figure 8 Example blocks of process 800 are shown, but in some aspects, process 800 may include Figure 8 The blocks depicted in the process 800 may be additional blocks, fewer blocks, different blocks, or blocks arranged in a different manner than those depicted in the process 800. Additionally or alternatively, two or more blocks in the blocks of process 800 may be executed in parallel.

[0100] Fig. 9900 is a diagram illustrating an example process 900 performed, for example, by a first base station in accordance with various aspects of the present disclosure. Example process 900 is an example of operations in which a first base station (e.g., base station 110, first base station 510, etc.) performs operations associated with sharing PRACH configuration information to avoid collisions in PRACH communications.

[0101] like Fig. 9 As shown, in some aspects, process 900 may include: receiving collision avoidance information from a second base station for avoiding collisions of PRACH communications from one or more UEs (block 910). In some aspects, the collision avoidance information includes one or more of subcarrier spacing information or beam correspondence information. For example, a first base station (e.g., using transmit processor 220, receive processor 238, controller / processor 240, memory 242, etc.) may receive collision avoidance information from a second base station for avoiding collisions of PRACH communications from one or more UEs, as described above. In some aspects, the collision avoidance information includes one or more of subcarrier spacing information or beam correspondence information.

[0102] like Fig. 9 As further shown in FIG. 9 , in some aspects, process 900 may include determining a PRACH configuration for PRACH communications by one or more UEs based at least in part on the collision avoidance information (block 920). For example, the first base station (e.g., using transmit processor 220, receive processor 238, controller / processor 240, memory 242, etc.) may determine a PRACH configuration for PRACH communications by one or more UEs based at least in part on the collision avoidance information, as described above.

[0103] like Fig. 9 As further shown in FIG. 9 , in some aspects, process 900 may include sending a PRACH configuration to one or more UEs (block 930). For example, the first base station (e.g., using transmit processor 220, receive processor 238, controller / processor 240, memory 242, etc.) may send a PRACH configuration to one or more UEs, as described above.

[0104] Process 900 may include additional aspects, such as any single aspect or any combination of aspects described below and / or in conjunction with one or more other processes described elsewhere herein.

[0105] In the first aspect, receiving the collision avoidance information includes: receiving the collision avoidance information via an Xn interface.

[0106] In a second aspect, either alone or in combination with the first aspect, the collision avoidance information includes subcarrier spacing information. In some aspects, the subcarrier spacing information indicates a first subcarrier spacing from a plurality of subcarrier spacings for the PRACH. In some aspects, determining the PRACH configuration includes selecting a second subcarrier spacing for the PRACH configuration that is different from the first subcarrier spacing.

[0107] In a third aspect, alone or in combination with one or more of the first and second aspects, the collision avoidance information indicates frequency resources and root sequence indexes for PRACH sequence generation. In some aspects, determining the PRACH configuration includes: selecting frequency resources and root sequence indexes for PRACH sequence generation for the PRACH configuration.

[0108] In a fourth aspect, alone or in combination with one or more of aspects 1 to 3, the collision avoidance information includes beam correspondence information. In some aspects, the beam correspondence information includes SSB transmission information. In some aspects, determining the PRACH configuration includes: selecting an SSB different from the SSB indicated by the SSB transmission information for the PRACH configuration.

[0109] In a fifth aspect, alone or in combination with one or more of the first to fourth aspects, the collision avoidance information includes beam correspondence information. In some aspects, the beam correspondence information includes SSB transmission information and SSB to RO mapping. In some aspects, determining the PRACH configuration includes: identifying a first RO based at least in part on the SSB transmission information and the SSB to RO mapping; and selecting a second RO different from the first RO for the PRACH configuration.

[0110] In a sixth aspect, alone or in combination with one or more of aspects 1 to 5, the second base station provides a serving cell, and the conflict avoidance information includes beam correspondence information. In some aspects, the beam correspondence information indicates a first CSI-RS resource in a measurement object for the serving cell. In some aspects, determining the PRACH configuration includes: selecting a CSI-RS resource different from the first CSI-RS resource for the PRACH configuration.

[0111] In a seventh aspect, alone or in combination with one or more of aspects 1 to 6, the second base station provides a serving cell, and the conflict avoidance information includes beam correspondence information. In some aspects, the beam correspondence information indicates a first SSB identifier for the serving cell. In some aspects, determining the PRACH configuration includes: selecting an SSB identifier different from the first SSB identifier for the PRACH configuration.

[0112] In an eighth aspect, alone or in combination with one or more of the first to seventh aspects, the PRACH configuration corresponds to transmission of a message associated with a 4-step RACH procedure.

[0113] In a ninth aspect, alone or in combination with one or more of the first to eighth aspects, the PRACH configuration corresponds to transmission of a message associated with a 2-step RACH procedure.

[0114] Although Fig. 9 Example blocks of process 900 are shown, but in some aspects process 900 may include Fig. 9 The blocks depicted in the process 900 may be additional blocks, fewer blocks, different blocks, or blocks arranged in a different manner than those depicted in the process 900. Additionally or alternatively, two or more blocks in the blocks of process 900 may be executed in parallel.

[0115] The foregoing disclosure provides illustration and description, but is not intended to be exhaustive or to limit the aspects to the precise forms disclosed. Modifications and variations may be made in light of the above disclosure or may be acquired from practice of the various aspects.

[0116] As used herein, the term "component" is intended to be broadly interpreted as hardware, firmware, or / or a combination of hardware and software. As used herein, a processor is implemented in hardware, firmware, or / or a combination of hardware and software.

[0117] It will be apparent that the systems and / or methods described herein can be implemented in various forms of hardware, firmware, or / or a combination of hardware and software. The actual specialized control hardware or software code used to implement these systems and / or methods is not limiting in any respect. Therefore, the operation and behavior of the systems and / or methods are described herein without reference to specific software code, it being understood that software and hardware can be designed to implement the systems and / or methods based, at least in part, on the description herein.

[0118] Even if a specific combination of features is recorded in the claims and / or disclosed in the specification, these combinations are not intended to limit the disclosure of various aspects. In fact, many of these features can be combined in a manner that is not specifically recorded in the claims and / or specifically disclosed in the specification. Although each dependent claim listed below may only be directly subordinate to one claim, the disclosure of various aspects includes each dependent claim combined with each other claim in the claim set. The phrase "at least one of" the list of items refers to any combination of those items, including a single member. For example, "at least one of a, b or c" is intended to cover a, b, c, ab, ac, bc and abc, and any combination of identical elements in multiples (e.g., aa, aaa, aab, aac, abb, acc, bb, bbb, bbc, cc and ccc or any other ordering of a, b and c).

[0119] Any element, action or instruction used herein should not be interpreted as critical or necessary, unless clearly described as such. In addition, as used herein, the articles "a" and "an" are intended to include one or more projects, and can be used interchangeably with "one or more". In addition, as used herein, the terms "set" and "group" are intended to include one or more projects (e.g., related projects, unrelated projects, combinations of related projects and unrelated projects, etc.), and can be used interchangeably with "one or more". In the case of only expecting one project, the phrase "only one" or similar language is used. In addition, as used herein, the terms "has", "have", "having" and / or similar terms are intended to be open terms. In addition, unless otherwise clearly stated, the phrase "based on" is intended to mean "based at least in part on".

Claims

1. A method of wireless communication performed by a first base station, comprising: determining collision avoidance information for avoiding collision of physical random access channel (PRACH) communications from one or more user equipments (UEs), the collision avoidance information comprising subcarrier spacing information indicating a first subcarrier spacing of a plurality of subcarrier spacings for the PRACH used by the first base station to configure the PRACH communications by the UEs; as well as The conflict avoidance information is sent to the second base station.

2. The method according to claim 1, wherein: Sending the conflict avoidance information includes: sending the conflict avoidance information to the second base station through an Xn interface.

3. The method according to claim 1, wherein: The conflict avoidance information includes beam correspondence information.

4. The method according to claim 1, wherein: The collision avoidance information indicates frequency resources and root sequence indexes used by the first base station for configuring PRACH communication by the UE for PRACH sequence generation.

5. The method according to claim 3, wherein: The beam corresponding information includes synchronization signal block (SSB) transmission information.

6. The method according to claim 3, wherein: The beam correspondence information also includes a SSB to RACH opportunity (RO) mapping used by the first base station to configure PRACH communication by the UE.

7. The method according to claim 3, wherein: The first base station provides a serving cell, and the beam corresponding information indicates one of a channel state information resource signal (CSI-RS) resource in a measurement object used for the serving cell or a synchronization signal block (SSB) identifier used for the serving cell.

8. A method of wireless communication performed by a first base station, comprising: receiving, from a second base station, collision avoidance information for avoiding collisions of physical random access channel (PRACH) communications from one or more user equipments (UEs), the collision avoidance information comprising subcarrier spacing information indicating a first subcarrier spacing of a plurality of subcarrier spacings for the PRACH; determining, based at least in part on the collision avoidance information, a PRACH configuration for PRACH communications by the one or more UEs, comprising selecting a second subcarrier spacing for the PRACH configuration that is different from the first subcarrier spacing; and The PRACH configuration is sent to the one or more UEs.

9. The method according to claim 8, wherein: Receiving the conflict avoidance information includes: receiving the conflict avoidance information through an Xn interface.

10. The method according to claim 8, wherein: The conflict avoidance information includes beam correspondence information.

11. The method according to claim 8, wherein: The collision avoidance information indicates frequency resources and root sequence indexes used for PRACH sequence generation, and wherein determining the PRACH configuration comprises: selecting the frequency resources and the root sequence indexes used for PRACH sequence generation for the PRACH configuration.

12. The method according to claim 10, wherein: The beam correspondence information includes synchronization signal block (SSB) transmission information, and wherein determining the PRACH configuration includes: selecting an SSB different from the SSB indicated by the SSB transmission information for the PRACH configuration.

13. The method according to claim 10, wherein: The beam correspondence information includes synchronization signal block (SSB) transmission information and SSB to RACH opportunity (RO) mapping, and wherein determining the PRACH configuration includes: identifying a first RO based at least in part on the SSB transmission information and the SSB to RO mapping; and selecting a second RO different from the first RO for the PRACH configuration.

14. The method according to claim 10, wherein: The second base station provides a service cell, the beam corresponding information indicates a first channel state information resource signal (CSI-RS) resource in a measurement object used for the service cell, and wherein determining the PRACH configuration includes: selecting a CSI-RS resource different from the first CSI-RS resource for the PRACH configuration.

15. The method according to claim 10, wherein: The second base station provides a serving cell, the beam correspondence information indicates a first synchronization signal block (SSB) identifier for the serving cell, and wherein determining the PRACH configuration comprises: selecting an SSB identifier different from the first SSB identifier for the PRACH configuration.

16. The method according to claim 8, wherein: The PRACH configuration corresponds to the transmission of messages associated with the 4-step RACH procedure.

17. The method according to claim 8, wherein: The PRACH configuration corresponds to the transmission of messages associated with a 2-step RACH procedure.

18. A first base station for wireless communication, comprising: Memory; as well as one or more processors operatively coupled to the memory, the memory and the one or more processors being configured to: determining collision avoidance information for avoiding collision of physical random access channel (PRACH) communications from one or more user equipments (UEs), the collision avoidance information comprising subcarrier spacing information indicating a first subcarrier spacing of a plurality of subcarrier spacings for the PRACH used by the first base station to configure the PRACH communications by the UEs; as well as The conflict avoidance information is sent to the second base station.

19. The first base station according to claim 18, wherein: When sending the conflict avoidance information, the one or more processors are configured to: send the conflict avoidance information to the second base station via an Xn interface.

20. The first base station according to claim 18, wherein: The conflict avoidance information includes beam correspondence information.

21. The first base station according to claim 18, wherein: The collision avoidance information indicates frequency resources and root sequence indexes used by the first base station for configuring PRACH communication by the UE for PRACH sequence generation.

22. The first base station according to claim 20, wherein: The beam correspondence information also includes a SSB to RACH opportunity (RO) mapping used by the first base station to configure PRACH communication by the UE.

23. A first base station for wireless communication, comprising: Memory; as well as one or more processors operatively coupled to the memory, the memory and the one or more processors being configured to: receiving, from a second base station, collision avoidance information for avoiding collisions of physical random access channel (PRACH) communications from one or more user equipments (UEs), the collision avoidance information comprising subcarrier spacing information indicating a first subcarrier spacing of a plurality of subcarrier spacings for the PRACH; determining, based at least in part on the collision avoidance information, a PRACH configuration for PRACH communications by the one or more UEs, comprising selecting a second subcarrier spacing for the PRACH configuration that is different from the first subcarrier spacing; and The PRACH configuration is sent to the one or more UEs.

24. The first base station according to claim 23, wherein: When receiving the collision avoidance information, the one or more processors are configured to: receive the collision avoidance information via an Xn interface.

25. The first base station according to claim 23, wherein: The conflict avoidance information includes beam correspondence information.

26. The first base station according to claim 23, wherein: The collision avoidance information indicates frequency resources and root sequence indexes for PRACH sequence generation, and wherein, when determining the PRACH configuration, the one or more processors are configured to: select the frequency resources and the root sequence indexes for PRACH sequence generation for the PRACH configuration.

27. The first base station according to claim 25, wherein: The beam correspondence information includes synchronization signal block (SSB) transmission information, and wherein, when determining the PRACH configuration, the one or more processors are configured to: select an SSB different from the SSB indicated by the SSB transmission information for the PRACH configuration.

28. The first base station according to claim 25, wherein: The beam correspondence information includes synchronization signal block (SSB) transmission information and SSB to RACH opportunity (RO) mapping, and wherein, when determining the PRACH configuration, the one or more processors are configured to: identify a first RO based at least in part on the SSB transmission information and the SSB to RO mapping; and select a second RO different from the first RO for the PRACH configuration.

29. The first base station according to claim 23, wherein: The PRACH configuration corresponds to the transmission of messages associated with the 4-step RACH procedure.

30. The first base station according to claim 23, wherein: The PRACH configuration corresponds to the transmission of messages associated with a 2-step RACH procedure.

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