Determination of initial random access channel opportunity for multiple PRACH transmissions for wireless networks

Abstract

In one embodiment, a method includes determining, by a user equipment in a wireless network, at least one initial random access channel occasion (RO), where each of the at least one initial RO is a first active RO of a set of ROs for physical random access (PRACH) transmissions with preamble repetition, where the determining the at least one initial RO is based at least on the active ROs; determining, by the user equipment, a set of ROs for PRACH transmission with preamble repetition based on the determined at least one starting RO, the determined set of ROs comprising one of the at least one starting RO; and transmitting, by the user equipment, the PRACH transmission with the preamble repetition to the network node using the determined RO set.

Description

Cross Reference to Related Applications

[0001] This application claims priority to U.S. Provisional Application No. 63 / 502,406, filed May 15, 2023, and U.S. Provisional Application No. 63 / 580,872, filed September 6, 2023, the entire contents of both of which are incorporated herein by reference. TECHNICAL FIELD

[0002] The present specification relates to wireless communication. BACKGROUND

[0003] A communication system can be a facility that enables communication between two or more nodes or devices such as fixed or mobile communication devices. Signals can be carried on wired or wireless carriers.

[0004] An example of a cellular communication system is the architecture standardized by the Third Generation Partnership Project (3GPP). A recent development in this field is the Long Term Evolution (LTE) of the Universal Mobile Telecommunications System (UMTS) radio access technology. E-UTRA (Evolved UMTS Terrestrial Radio Access) is the air interface of 3GPP's Long Term Evolution (LTE) upgrade path for mobile networks. In LTE, base stations or access points (APs), which are referred to as enhanced Node APs (eNBs), provide wireless access to user equipments (UEs) within a coverage area or cell. LTE is being standardized by 3GPP. LTE includes many improvements over previous generations of mobile networks. Aspects of LTE continue to evolve.

[0005] 5G New Radio (NR) development is part of a continuing process of mobile broadband evolution and is a departure from 3G and 4G wireless networks. In addition to mobile broadband, 5G is also targeted at new emerging use cases including: 1) massive Internet of Things (IoT), 2) mission-critical IoT, 3) wearables, 4) vehicular, 5) augmented reality and virtual reality, 6) private wireless networks, 7) and other use cases. 5G NR is expected to deliver high- performance, low-latency, and high-reliability. SUMMARY

[0006] According to an example embodiment, a method can comprise: determining, by a user equipment in a wireless network, at least one starting random access channel occasion (RO), wherein each of the at least one starting RO is a first valid RO in a set of ROs for physical random access (PRACH) transmission with preamble repetition, wherein determining the at least one starting RO is based on at least a valid RO; determining, by the user equipment, the set of ROs for PRACH transmission with preamble repetition based on the determined at least one starting RO, the determined set of ROs including one of the at least one starting RO; and transmitting, by the user equipment, the PRACH transmission with preamble repetition to a network node using the determined set of ROs.

[0007] An apparatus can comprise at least one processor; and at least one memory including computer program code; the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to determine, by a user equipment in a wireless network, at least one starting random access channel occasion (RO), wherein each of the at least one starting RO is a first valid RO in a set of ROs for physical random access (PRACH) transmission with preamble repetition, wherein determining the at least one starting RO is based on at least a valid RO; determine, by the user equipment, the set of ROs for PRACH transmission with preamble repetition based on the determined at least one starting RO, the determined set of ROs including one of the at least one starting RO; and transmit, by the user equipment, the PRACH transmission with preamble repetition to a network node using the determined set of ROs.

[0008] According to an example embodiment, a method can comprise: receiving, by a user equipment from a network node, configuration information for random access, wherein the configuration information comprises a plurality of synchronization signal blocks (SSBs) and a plurality of random access channel occasions (ROs), the plurality of ROs being divided into a plurality of RO groups; determining, by the user equipment, a set of starting ROs of the plurality of RO groups based on at least a validity of a starting RO; selecting, by the user equipment, a RO group from the plurality of RO groups based on the set of starting ROs; and transmitting, by the user equipment, a plurality of physical random access channel (PRACH) transmissions to the network node during random access using ROs in the selected RO group.

[0009] According to an example embodiment, an apparatus may include: at least one processor; and at least one memory including computer program code; the at least one memory and the computer program code are configured together with the at least one processor such that the apparatus at least: receives configuration information for random access from a network node by a user equipment, wherein the configuration information includes a plurality of synchronization signal blocks (SSBs) and a plurality of random access channel opportunities (ROs), the plurality of ROs being divided into a plurality of RO groups; determines an initial set of ROs for the plurality of RO groups by the user equipment at least based on the validity of the initial ROs; selects an RO group from the plurality of RO groups by the user equipment based on the initial RO set; and transmits a plurality of physical random access channel (PRACH) transmissions to the network node using ROs in the selected RO group during random access.

[0010] Other example embodiments are provided or described for each example method, including: components for performing any example method; a non-transient computer-readable storage medium including instructions stored thereon, which, when executed by at least one processor, are configured to cause a computing system to: perform any example method; and an apparatus including at least one processor and at least one memory including computer program code, the at least one memory and the computer program code being configured, together with the at least one processor, to cause the apparatus to at least perform any example method.

[0011] Details of one or more examples of the embodiments are set forth in the accompanying drawings and the following description. Other features will become apparent from the specification, the drawings, and the claims. Attached Figure Description

[0012] Figure 1 This is a block diagram of a wireless network according to an example embodiment.

[0013] Figure 2A This is a diagram illustrating the operation of a 4-step random access (RACH) procedure according to an example embodiment.

[0014] Figure 2B This is a diagram illustrating the operation of a two-step random access (RACH) procedure according to an example embodiment.

[0015] Figure 3 This is a diagram illustrating an example of time-domain resource determination for RACH timing (RO), where prach-ConfigurationIndex is 251.

[0016] Figure 4 It is from Table 8.1-1 of TS 38.213, which indicates the mapping between PRACH configuration periods and associated periods.

[0017] Figure 5This is a flowchart illustrating the operation of a user equipment (or UE) according to an example embodiment.

[0018] Figure 6 This is a flowchart illustrating the operation of a user equipment (or UE) according to an example embodiment.

[0019] Figure 7 This is a diagram illustrating the initiation RACH timing (RO) for multiple RO groups according to an example embodiment.

[0020] Figure 8 The diagram also illustrates how the timing of the start of RACH (RO) is determined based on network configuration.

[0021] Figure 9 It is a block diagram of a wireless station or node (e.g., a network node, user node or UE, relay node or other node).

[0022] Figure 10 This is a diagram illustrating the initiation RACH timing (RO) for multiple RO groups according to an example embodiment. Detailed Implementation

[0023] Figure 1 This is a block diagram of a wireless network 130 according to an example embodiment. Figure 1 In the wireless network 130, user equipment 131, 132, 133, and 135 (also referred to as mobile stations (MS) or user equipment (UE)) can connect to (and communicate with) a base station (BS) 134, which can also be referred to as an access point (AP), an enhanced node B (eNB), a gNB, or a network node. The terms user equipment and user equipment (UE) are used interchangeably. The BS can also include or be referred to as a RAN (Radio Access Network) node, and can include a portion of the BS or a portion of the RAN node, such as (e.g., a centralized unit (CU) and / or a distributed unit (DU) in the case of splitting the BS or splitting the gNB). At least a portion of the functionality of the BS (e.g., the access point (AP), base station (BS), or (e) node B (eNB), gNB, RAN node) can also be performed by any node, server, or host that can be operatively coupled to a transceiver (such as a remote radio head end). BS (or AP) 134 provides wireless coverage within cell 136, including to user equipment (or UEs) 131, 132, 133, and 135. Although only four user equipment (or UEs) are shown as connected to or attached to BS 134, any number of user equipment can be provided. BS 134 is also connected to core network 150 via S1 interface 151. This is just a simplified example of a wireless network, and other wireless networks can be used.

[0024] A base station (e.g., such as BS 134) is an example of a radio access network (RAN) node within a wireless network. A BS (or RAN node) can be or can include (or may alternatively be referred to as) such as an access point (AP), gNB, eNB, or portions thereof (such as a centralized unit (CU) and / or a distributed unit (DU) in the case of a split BS or a split gNB), or other network nodes.

[0025] According to illustrative examples, a BS node (e.g., BS, eNB, gNB, CU / DU, etc.) or radio access network (RAN) can be part of a mobile telecommunications system. The RAN (Radio Access Network) can include one or more BS or RAN nodes that implement radio access technologies, such as allowing one or more UEs to access the network or core network. Therefore, for example, the RAN (RAN node, such as BS or gNB) can reside between one or more user equipments or UEs and the core network. According to example embodiments, each RAN node (e.g., BS, eNB, gNB, CU / DU, etc.) or BS can provide one or more wireless communication services to one or more UEs or user equipments, such as allowing UEs to wirelessly access the network via the RAN node. Each RAN node or BS can perform or provide wireless communication services, such as allowing UEs or user equipments to establish wireless connections to the RAN node, and sending and / or receiving data from one or more UEs. For example, after establishing a connection to the UE, the RAN node or network node (e.g., BS, eNB, gNB, CU / DU, etc.) can forward data received from the network or core network to the UE, and / or forward data received from the UE to the network or core network. The RAN node or network node (e.g., BS, eNB, gNB, CU / DU, etc.) can perform a variety of other radio functions or services, such as broadcasting control information to the UE (e.g., system information or on-demand system information), paging the UE when data is to be delivered to it, assisting the UE in handover between cells, scheduling resources for uplink data transmission from (multiple) UEs and downlink data transmission to (multiple) UEs, and sending control information to configure one or more UEs. These are some examples of one or more functions that a RAN node or BS can perform.

[0026] User equipment or user nodes (user terminals, user devices (UEs), mobile terminals, handheld wireless devices, etc.) can refer to portable computing devices, including wireless mobile communication devices that operate with or without a subscriber identification module (SIM), such as, but not limited to, devices of the following types: mobile station (MS), mobile phone, cell phone, smartphone, personal digital assistant (PDA), handset, device using a wireless modem (alarm or measuring device, etc.), laptop and / or touchscreen computer, tablet computer, tablet phone, game console, laptop computer, vehicle, sensor, and multimedia device, or any other wireless device. It should be understood that user equipment can also be (or may include) a virtually exclusive uplink-only device, an example of which is a camera or camcorder that loads image or video clips onto the network. Furthermore, user nodes can include user devices (UEs), user equipment, user terminals, mobile terminals, mobile stations, mobile nodes, subscriber equipment, subscriber nodes, subscriber terminals, or other user nodes. For example, regardless of the technology or radio access technology (RAT), a user node can be used to communicate wirelessly with one or more network nodes (e.g., gNB, eNB, BS, AP, CU, DU, CU / DU) and / or with one or more other user nodes.

[0027] In LTE (as an illustrative example), the core network 150 may be referred to as the Evolved Packet Core (EPC), which may include a Mobility Management Entity (MME), one or more gateways, and other control functions or blocks. The MME can handle or assist user equipment in moving / handover between BSs, and the gateways can forward data and control signals between the BS and a packet data network or the Internet. Other types of wireless networks, such as 5G (which may be referred to as New Radio (NR)) and / or 6G, may also include a core network.

[0028] Furthermore, the technologies described in this paper can be applied to various types of user equipment or data service types, or to user equipment that can have multiple applications running on it, which can be different data service types. New 5G (NR) development can support many different applications or many different data service types, such as, for example: Machine-Type Communication (MTC), Enhanced Machine-Type Communication (eMTC), Internet of Things (IoT) and / or Narrowband IoT user equipment, Enhanced Mobile Broadband (eMBB), and Ultra-Reliable Low-Latency Communication (URLLC). Many of these new 5G (NR) related applications may typically require higher performance than previous wireless networks.

[0029] The Internet of Things (IoT) can refer to a growing group of objects that possess internet or network connectivity, enabling them to send and receive information from other network nodes. For example, many sensor-type applications or devices can monitor physical conditions or states and send reports to servers or other network nodes, such as when an event occurs. Machine-type communication (MTC or machine-to-machine communication), for example, can be characterized by fully automated data generation, exchange, processing, and driving between intelligent machines, regardless of human intervention. Enhanced Mobile Broadband (eMBB) can support higher data rates than currently available in LTE.

[0030] Ultra-Reliable Low-Latency Communication (URLLC) is a new type of data service or new use case that new radio (5G) systems can support. This enables emerging new applications and services, such as industrial automation, autonomous driving, vehicle safety, and e-health services. As an illustrative example, 3GPP aims to provide services with 10... -5 The reliability of connectivity corresponds to the block error rate (BLER) and a maximum U-plane (user / data plane) latency of 1 ms. Therefore, for example, URLLC user equipment / UEs may require significantly lower block error rates and lower latency (with or without requirements for simultaneous high reliability) than other types of user equipment / UEs. Thus, for example, URLLC UEs (or URLLC applications on UEs) may require shorter latency compared to eMBB UEs (or eMBB applications running on UEs).

[0031] The technologies described in this document can be applied to a variety of wireless technologies or wireless networks, such as 5G (New Radio (NR)), cmWave and / or mmWave band networks, IoT, MTC, eMTC, eMBB, URLLC, 6G, etc., or any other wireless network or wireless technology. These example networks, technologies, or data service types are provided as illustrative examples only.

[0032] In at least some example scenarios, a UE can be in one of several states relative to a network node or gNB (e.g., one of three Radio Resource Control (RRC) states). In the idle state (RRC idle), the RAN (Radio Access Network) node (e.g., gNB) or network node or UE typically does not (or has limited) store of RRC context (which may include information or parameters required for communication between the UE and the gNB / network node), and the UE does not belong to (or is not connected to) a specific cell. From the core network's perspective, an idle UE is in an idle (CM_Idle) state. When the UE is in the idle state, data transmission typically does not occur between the UE and the network node (e.g., gNB) because the UE spends most of its time sleeping (low-power state) to conserve power. In the idle state, the UE can typically be periodically woken up to receive paging messages from the network.

[0033] By performing a Random Access Transaction (RACH) procedure with a gNB or network node, a UE can transition from an idle state (e.g., RRC idle) to a connected state (e.g., RRC connected state, where the UE is connected to the network node). As part of the RACH procedure, both the UE and the network node (e.g., the gNB) can acquire context, such as communication parameters required to allow UE-gNB communication. As example, as part of the RACH procedure with the gNB or network node, the UE can acquire a timing advance to allow the UE to perform uplink transmissions to the gNB. The UE can also acquire a UE identifier from the network, such as a Cell Radio Network Temporary Identifier (C-RNTI), which the UE can use for communication or signaling with the network or gNB. In a connected state relative to the cell (or gNB or DU) (e.g., RRC connected), the UE is connected to the gNB or network node, and the UE can receive and transmit data (e.g., based on received uplink authorization).

[0034] In 5G NR (for example), two contention-based random access (CBRA) procedures are supported: 4-step random access (4-step RACH) (Rel-15) and 2-step random access (2-step RACH) (Rel-16).

[0035] Figure 2AThis is a diagram illustrating the operation of a 4-step random access (RACH) procedure according to an example embodiment. Each of the four steps of the 4-step RACH procedure will be briefly described: When the RACH procedure is triggered (caused to be executed by the UE), at step 1, the UE sends Msg1 (or message 1) for the random access (RACH) procedure. 1. Msg1 (also referred to as the Physical Random Access Channel, PRACH, or random access preamble): The UE sends a specific random access preamble to the gNB via the Physical Random Access Channel (PRACH) using specific resources called PRACH timing or RACH timing (RO). RO is the set of time-frequency resources used by the UE to send the PRACH (or random access preamble). Different random access preamble groups are defined or configured. The UE obtains information about how to access the RACH channel from System Information Block 1 (SIB1) broadcast from the gNB's System Information (SI).

[0036] about Figure 2A Upon receiving message 1 (PRACH or random access preamble from the UE), the gNB determines the reception timing of the received random access preamble (PRACH). Based on the reception timing of the received preamble (if there is no conflict with other UEs), the gNB determines a timing advance (or TA or timing advance command) to adjust the timing of the UE's uplink frames to align with the downlink frames (and also align the uplink reception timing with other UE uplink frames). Since each UE can be provided in different locations, each UE can have different radio propagation delays, and thus different or specific timing advances relative to the gNB.

[0037] like Figure 2A As shown, at step 2 (Msg2 or message 2), the gNB responds to the UE with a Random Access Response (RAR), which may include the index (or identifier) ​​of the received random access preamble (or PRACH) (index or identifier of the random access preamble resource) (also referred to as RAPID or random access preamble identifier), timing advance (TA or timing advance command), the temporary cell radio network temporary identifier (TC-RNTI) assigned to the UE, and the uplink (UL) grant to be used by the UE for uplink transmission of message 3 (Msg3) (e.g., including scheduling information and / or information indicating the resources to be used for UL transmission). Therefore, at step 2, the gNB sends Msg2 (message 2, also referred to as a Random Access Response (RAR)). Therefore, at step 2, the gNB responds to msg1 with a Random Access Response (RAR) message, which includes the detected preamble ID (or RAPID), timing advance command, TC-RNTI, and UL grant for transmission of Msg3 on PUSCH (Physical Uplink Shared Channel).

[0038] In addition, such as Figure 2A As shown, at step 3, after receiving the RAR message (Msg2), the UE can send a first uplink transmission (Msg3 or message 3) to the network. The size of the Msg3 transmission depends on the grant (Msg2 or message 2) received at step 2. Therefore, at step 3, the UE responds to Msg2 by sending Msg3 (also known as an RRC request) with an ID for contention resolution on the scheduled PUSCH.

[0039] Figure 2A Step 4 (Msg4 or message 4) may include the transmission of a DL message from the gNB to the UE, which involves the contention resolution phase. Therefore, the gNB may send a Msg4 (also known as an RRC establishment message, which may be a contention resolution message) with a contention resolution ID (contention resolution identifier). After the UE is connected to the gNB (e.g., after the random access procedure is completed), the UE may receive an updated timing advance (TA) value or TA command from the serving gNB or serving cell.

[0040] Upon receiving Msg4, if its contention resolution ID is carried by Msg4, the UE sends an ACK (acknowledgment) on the PUCCH (Physical Uplink Control Channel). This completes the 4-step RACH process.

[0041] Furthermore, prior to Msg1, there is a preliminary step where the gNB transmits and the UE receives the Synchronization Signal Block (SSB). This may involve the gNB performing a downlink (DL) beam scan to transmit different SSB beams in different directions (each beam associated with a different SSB index), which is not a formal part of the RACH process. As a result of this preliminary step of SSB transmission and reception by the gNB (and the UE may measure the reference signal received power of one or more SSB beams to select one of these SSB indices), the UE selects the index of the preferred SSB beam and decodes the associated PBCH for the MIB, SIB, etc. Based on the SSB-to-RO mapping implicitly conveyed by SIB1, the UE also uses this index to identify the appropriate RO for preamble transmission (Msg1).

[0042] In addition, as an alternative RACH procedure, a 2-step RACH (random access) procedure can be used to provide a faster random access procedure. Figure 2BThis is a diagram illustrating the operation of a two-step random access (RACH) procedure according to an example embodiment. At message A (MsgA), the UE can send a message including both Msg1 and Msg3 as the first message (MsgA) of the two-step RACH procedure. And, for example, the network node or gNB can send Msg2 and Msg4 as the second message (or MsgB or message B) of the two-step RACH procedure.

[0043] Configuration of RACH timing (RO) (in the time domain):

[0044] The time-domain resources used for RACH timing (RO) are RRCs configured by prach-ConfigurationIndex (in rach-ConfigGeneric), which acts as rows of the table specified in TS 38.211 (Section 6.3.3.2) (see, for example, see...). Figure 3 The indicator (line 330 in the example) is used. Using the parameters indicated by prach-ConfigurationIndex, the UE determines the preamble format for PRACH and finds the RO in the time domain by applying the procedure specified in TS 38.211 (section 5.3.2). Figure 3 This is a diagram illustrating an example of time-domain resource determination for RACH timing (RO), where prach-ConfigurationIndex is 251. For example, in this example, based on this PRACH configuration index (e.g., prach-ConfigurationIndex) = 251, the PRACH configuration index indicates or can be mapped to a set of configuration parameters (e.g., the parameter value indicated at line 330), such as configuration parameters 310, 312, 314, 316, 318, and 320. The indicated index 251 is merely an example, and other PRACH configuration index values ​​can be used to indicate different (or other) configuration parameters for RACH timing (RO).

[0045] like Figure 3 As shown in the example, each system frame (e.g., system frame numbers (SFN) 0 and 1 are shown) comprises 10 subframes, and each subframe comprises 2 time slots (e.g.), and each time slot comprises 14 OFDM (Orthogonal Frequency Division Multiplexing) symbols.

[0046] With PRACH configuration index = 251, this configuration (or indication) is used for the values ​​of various parameters as shown in line 330, and the UE can determine the values ​​for these configuration parameters, such as: PRACH configuration index (310) = 251; preamble format (312) = C2; subframe number (314) = 2, 7; number of PRACH slots within the subframe (316) = 2; number of time-domain ROs (PRACH or RACH timings) within the PRACH slots (318) = 2; PRACH duration (320) = 6. Other parameters can also be indicated based on index = 251. These indicate the ROs configured in the time domain. One or more ROs can be configured in the frequency domain (e.g., multiple ROs can be configured simultaneously using different subcarrier sets).

[0047] Therefore, based on these parameters in row 330 (based on index=251), the following configuration for RO should be used:

[0048] The preamble format C2 should be used.

[0049] RO is allocated at the system frame number (n_SFN) that satisfies n_SFN mod 1=0 (i.e., all SFN numbers are valid).

[0050] Within each defined SFN (system frame number), ROs are allocated at subframe numbers 2 and 7.

[0051] Within each defined subframe, the remaining parameters in the considered row indicate that the RO will begin at symbol numbers 0, 6, 14, and 20. Symbol numbers are counted consecutively regardless of the number of slots within the subframe, depending on the subcarrier spacing configured for PRACH. In this example, the RO duration is 6 symbols (although the actual duration in the preamble format can be less than this value).

[0052] Furthermore, the UE may need to determine or confirm the validity of the RO before it can be used to transmit PRACH. According to TS 38.213 (Article 8.1), the RO is determined to be valid if it is within a UL symbol or has a sufficient (e.g., threshold or minimum) interval after the last SSB (Synchronization Block) / DL (Downlink) symbol.

[0053] RACH timing (RO) configuration (in the frequency domain):

[0054] In the same higher-layer signaling carrying the PRACH configuration, the gNB can also indicate two parameters to convey the frequency resources used for ROs in the UE uplink BWP (bandwidth portion). These frequency-related parameters can include frequency information such as the frequency (or frequency resource) in which the RO begins, and how many ROs are frequency-reused. The parameters msg1-FrequencyStart and msg1-FDM configured in RACH-ConfigGeneric indicate the offset of the lowest RO in the frequency domain from the start of the UE uplink bandwidth portion, and the number of ROs reused in the frequency domain for each time instance, respectively. Such ROs are indexed as n_RA={0, 1, …, M-1}, where M is equal to the higher-layer parameter msg1-FDM, and are numbered in ascending order starting from the lowest frequency within the UE uplink bandwidth portion. Section 6.3.3.2 of TS 38.211 specifies the number of occupied resource blocks per RO, which can be expressed as the number of RBs (resource blocks, where each resource block is a time-frequency resource set) used for PUSCH, depending on the configuration preamble length and subcarrier spacing used for PRACH and PUSCH.

[0055] SSB to RO mapping :

[0056] As described above, the UE can determine the RO (Route of Access) for transmitting PRACH (carrying a random access preamble or Msg1 to perform random access to the gNB) based on the selected (e.g., best or strongest) SSB measured by the UE from the gNB. The UE can map SSB indices to the determined ROs, allowing the UE to determine which ROs are associated with the SSB indices selected by the UE in an initial step before the start of the RACH procedure. Different SSB indices are beamformed in different directions within the cell, so selecting an incorrect SSB index may cause the RACH procedure to fail (e.g., if the random access preamble or PRACH is transmitted via an incorrect SSB, it may not be received). For this purpose, a basic parameter `ssb-perRACH-OccasionAndCB-PreamblesPerSSB` is configured in `RACH-ConfigCommon` and indicates two pieces of information: (i) the number of SSB indices per RO, and (ii) the number of contention-based preambles per SSB index. Multiple consecutive ROs can be mapped to the same SSB index. After this information becomes available to the UE, the UE maps the SSB index to the time-frequency grid of the RO in ascending order of the frequency resource index, the time resource index of the RO within the PRACH slot, and the PRACH slot (as determined above).

[0057] Regarding the mapping from SSB to RO, TS 38.213 defines the associated time period, starting from frame 0, used for mapping the SSB index to the RACH timing (i.e., RO) as configured by the PRACH period according to Table 8.1-1 (e.g., ...). Figure 4 The minimum value in the set determined (as shown in the figure) ensures that all SSB indexes are mapped to the RACH timing at least once during the associated period. Figure 4 This is from Table 8.1-1 of TS38.213, which indicates the mapping between PRACH configuration periods and associated periods. The PRACH configuration period referred to here is determined at the UE based on the configured PRACH configuration index. Furthermore, the associated pattern period includes one or more associated periods and is determined such that the pattern between the RACH timing (RO) and the SS / PBCH block (SSB) index repeats at most once every 160 milliseconds. After an integer number of associated periods (if any), RACH timings (ROs) unrelated to the SS / PBCH (SSB) block index are not used for PRACH transmission. The mapping pattern between the RO and the SSB index repeats. And this mapping (from RO to the SSB index) repeats within a period referred to as the associated pattern period.

[0058] Furthermore, according to the example embodiment, the UE can perform multiple PRACH (Random Access Preamble) transmissions (e.g., PRACH repetition) via multiple ROs (e.g., via the same UE transmit beam), and / or the gNB can receive multiple PRACH transmissions via the same SSB beam. The multiple ROs used by the UE to perform multiple PRACH transmissions can be referred to as an RO group. For multiple PRACH transmissions with the same Tx beam, it is assumed that an "RO group" is used for multiple PRACH transmissions with separate preambles on shared ROs and / or multiple PRACH transmissions on separate ROs, and an RO group consists of (multiple) valid ROs used for a specific number of multiple PRACH transmissions. For example, all ROs in an RO group can be associated with (multiple) the same SSB. Shared or separate ROs / preambles indicate that the RO / preamble is shared or spaced out with a single PRACH transmission.

[0059] According to the example implementation, ROs can be evaluated to determine their validity (see the validity rules above). Furthermore, when determining whether an RO in a RO group can be used for PRACH transmission, the UE can also consider (or base on) whether there is a conflict between the RO in the RO group and ROs used for other configurations, such as for a single PRACH transmission. For example, as an example of RO conflict, the UE can determine whether an RO in the RO group used for PRACH repetition appears in the same time instance (but at a different frequency) of at least one other RO reserved for other configurations (e.g., such as for a single PRACH transmission), and in some implementations where the gNB can only have one beam activity per time instance, the two ROs are mapped to different SSB indices (i.e., different gNB receive beams). This example of RO conflict may cause the gNB to be unable to receive the preamble transmitted in both ROs. Specifically, for example, if the gNB prioritizes other ROs, the PRACH transmission on the RO used for PRACH repetition will be lost (the gNB will not receive it). Therefore, the UE can apply additional verification rules such that PRACH transmissions in one of the ROs in a RO group that occurs in the same time instance as other ROs for PRACH repetition will be dropped or discarded from the RO group, and the UE will send a lower number of PRACH repetitions. However, in another example embodiment, the UE can determine the ROs (such as the starting RO) in the RO group regardless of whether there are RO conflicts for that RO in the RO group. Furthermore, for example, or in some cases, the UE can determine ROs, such as the starting set of ROs for multiple RO groups, regardless of the applied conflict handling rules. The starting ROs of RO groups will be described in more detail below.

[0060] One problem or challenge is defining RO groups; for example, this might involve determining which ROs are part of each RO group. For the UE and gNB, it is important to know the start and end points (or determine the ROs) of RO groups used for multiple PRACH transmissions (PRACH repetitions), for example, allowing the gNB to know which received PRACHs should be combined. According to example embodiments, a starting RO can be determined for each of one or more groups; for example, this RO could be the first RO in the RO group. In some cases, ROs in an RO group may use the same set of frequency resources, where the ROs have different times. In another example, at least some ROs in an RO group may use the same time resources (using the same OFDM symbol or the same time for each RO in the RO group, for example, all ROs in the group appear simultaneously) and are multiplexed onto different frequency resources. Furthermore, ROs in a group may use frequency hopping, meaning that ROs in a group may use different sets of frequency resources at different time instances. Therefore, while there can be different RO group configurations, RO groups can be determined based on the starting RO in the RO group. For example, if the starting RO of the RO group has been determined, the UE and gNB can determine the RO group. For example, once the starting RO of the RO group and the number of ROs in the RO group are known, the UE can determine the ROs of the RO group, for example, based on the configuration.

[0061] Figure 5 This is a flowchart illustrating the operation of a user equipment (or UE) according to an example embodiment. Operation 510 includes the user equipment in the wireless network determining a set of candidate start random access channel timings (ROs) for multiple physical random access (PRACH) transmissions, wherein determining the candidate start RO set is based at least on valid ROs. Operation 520 includes the user equipment determining a group of ROs for the multiple PRACH transmissions based on the candidate start RO set, the RO group including at least one candidate start RO from that set. Furthermore, operation 530 includes the user equipment using the RO group to send multiple PRACH transmissions to network nodes.

[0062] about Figure 5 The method determines the candidate starting RO set regardless of the conflict handling rules applied to the candidate starting RO set, or whether the PRACH transfers in the starting RO are discarded based on a conflict with another RO.

[0063] about Figure 5 The method determines the candidate starting RO set based on at least one of the following: period or reference time.

[0064] about Figure 5The method may include: a first subset of candidate starting ROs, wherein the first subset of candidate starting ROs is determined based on a reference time; and a second subset of candidate starting ROs, wherein the second subset of candidate starting ROs is spaced apart from the first subset of candidate starting ROs by a starting RO period or an RO group period.

[0065] about Figure 5 The method ensures that a valid Return Time (RO) occurs within a reference time period. Furthermore, the reference time may include at least one of the following: a specific time slot or frame at a time offset from time slot 0 of frame 0; the time of the RO closest to the start of the reference time period; or the time of the RO at a time offset from the start of the RO closest to the start of the reference time period.

[0066] about Figure 5 The method for determining the candidate starting list of origins (ROs) can be performed based on the indexes of valid ROs. Furthermore, the index of a valid RO can be equal to 0.

[0067] about Figure 5 The method may further include determining, for each valid RO in the valid ROs, an index of the associated pattern period to which the valid RO belongs; and wherein determining the candidate starting RO set is performed based on the index of the associated pattern period to which each valid RO in the valid ROs belongs.

[0068] about Figure 5 The method allows valid ROs belonging to the associated pattern time period with index 0 to be identified as part of the candidate starting RO set.

[0069] Figure 6 This is a flowchart illustrating the operation of a user equipment (or UE) according to an example embodiment. Operation 610 includes the user equipment (e.g., UE) receiving configuration information for random access from a network node (e.g., gNB), wherein the configuration information includes multiple synchronization signal blocks (SSBs) and multiple random access channel (RACH) timings (ROs), the multiple ROs being divided into multiple RO groups. Operation 620 includes the user equipment determining an initial set of ROs for the multiple RO groups, at least based on the validity of the initial ROs. Operation 630 includes the user equipment selecting an RO group from the multiple RO groups based on the initial RO set. And, operation 640 includes the user equipment sending multiple physical random access channel (PRACH) transmissions to the network node during random access using ROs from the selected RO group.

[0070] about Figure 6The method is such that each starting RO in the starting RO set is valid, wherein if the RO is within one or more flexible symbols, the RO is valid if it is within an uplink symbol to the network node, or if the RO has a predetermined or minimum time interval after the last SSB symbol from the network node.

[0071] about Figure 6 The method is that each starting RO in the starting RO set is valid, and the RO is valid if it is within the uplink symbol to the network node.

[0072] about Figure 6 The method determines the initial RO set regardless of the conflict resolution rules applied to the ROs in the initial RO set.

[0073] about Figure 6 The method allows the initial set of Returning Roots (ROs) to include: a first subset of ROs and one or more additional subsets of ROs spaced apart from the first subset of ROs. Furthermore, for example, the initial set of ROs may occur within a reference time period. Additionally, for example, each RO in the first subset may be located at the same reference time or different reference times associated with multiple Service Subsystems (SSBs). For example, the same or different reference times may be based on time offsets.

[0074] about Figure 6 The method involves a reference time consisting of (or may include) more than one associated time period to which the ROs in the first subset belong.

[0075] about Figure 6 The reference time period can be configured by the network node or determined by the user equipment. For example, the reference time period can be in units of time slots, radio frames, or ROs. Furthermore, in some cases, if only one value is configured for multiple PRACH transmissions, then only one value of the reference time period is configured or determined. Conversely, if more than one value is configured for multiple PRACH transmissions, then one or more values ​​of the reference time period are configured or determined.

[0076] about Figure 6 The method allows the starting RO set to be determined based on the index of the starting RO.

[0077] Figure 6 The method may also include: determining which ROs in the initial RO will be used for multiple PRACH transmissions; and sending multiple PRACH transmissions to network nodes using at least one RO in the initial RO.

[0078] about Figure 6 The method involves at least one RO group being based solely on a subset of the initial RO set that is closest to a specific time instance of at least one RO group.

[0079] about Figure 6 The method may further include selecting an RO group from at least one RO group used for multiple PRACH transmissions.

[0080] about Figure 6 The method allows at least one RO group to be determined based on each subset of the initial RO within the associated reference time period.

[0081] about Figure 6 The method may further include: selecting an RO group from at least one RO group for a plurality of PRACH transmissions to commence after a determined time instance of at least one RO group. Further details and / or other examples will now be described.

[0082] 1) For multiple PRACH (Physical Random Access Channel) / Random Access Preamble transmissions, the UE can determine the starting RO set for multiple RO groups or determine the starting RO set associated with multiple RO groups (e.g., there can be 1 starting RO for each RO group). In some cases, the starting RO of an RO group can be selected from (multiple) valid ROs. Therefore, in some cases, the validity of an RO may be a requirement for selecting an RO as the starting RO of an RO group. Furthermore, in some cases, ROs can be selected as the starting RO of an RO group regardless of whether they are subject to conflict handling rules, i.e., whether they are discarded due to a conflict.

[0083] 1a) The initial RO can be determined using time offset and period. In one embodiment, the UE determines the initial set of ROs for the RO group by including: a first subset of ROs, each RO in the first subset being at the same or different reference time; and an additional subset of one or more ROs spaced apart from the first subset of ROs according to one or more period values. In one implementation, the initial set of ROs for the RO group occurs within a reference time period (i.e., a time interval different from the aforementioned “same or different reference time”), wherein the reference time period is configured by the network, determined by the UE in the case of a given network configuration, or provided by the specification. One or more period values ​​are configured by the network or determined at the UE, for example, as the size of the RO group created from the candidate initial ROs. One or more period values ​​are in units of slots, frames, or ROs. If only one value is configured in the number of PRACH transmissions, then only one period value is configured or determined. If more than one value is configured in the number of PRACH transmissions, then one or more period values ​​are configured or determined. In the case where only one period value is configured or determined, in one embodiment, the period value is large enough to encompass the RO group associated with the maximum number of PRACH transmissions.

[0084] For example, the same or different reference times can be defined based on the time offset / difference from slot 0 of frame 0, or based on the time offset or difference from the start time of the reference time period, or as the time of one or more reference ROs within the reference time period, or as a network configuration value. In one implementation, one or more reference ROs are defined as the RO closest to the start of the reference time period, i.e., the first / earliest RO of the reference time period. A reference RO can be specific to a certain SSB index. In another implementation, one or more reference ROs are defined as the RO at the time offset / distance from the start of the reference time period to the nearest RO. A reference RO can be specific to a certain SSB index. The time offset is configured by the network or predetermined at the UE. In one implementation, a reference RO may include multiple ROs that occur in the same time instance and are multiplexed in the frequency domain.

[0085] 1b) In another embodiment, the UE determines candidate starting ROs for the RO group based on the RO index. In one implementation, the UE determines ROs with indices between 0 and M-1 as candidate starting ROs, where M is the inverse of the CHOICE portion of the field “ssb-perRACH-OccasionAndCB-PreamblesPerSSB” in the RACH-ConfigCommon IE. In another implementation, the UE determines ROs with indices equal to 0 as candidate starting ROs. In another implementation, the UE determines ROs with indices equal to one or more network configuration values ​​as candidate starting ROs. In another implementation, the UE determines ROs with indices equal to one or more determined values ​​as candidate starting ROs. In another implementation, the UE determines ROs with indices satisfying certain constraints, such as mod(RO index, P) = 0, where P is configured by the NW or associated with a reference time period. Details regarding RO indexes are beyond the scope of this invention, but it is assumed that the UE is able to enumerate configured ROs at least within the reference time period.

[0086] 1c) In another embodiment, the UE determines the candidate starting RO of the RO group based on the index of the associated time period to which the RO belongs. In one implementation, the index of the associated time period is an index within the associated time period group belonging to the reference time period. In one implementation, the index of the associated time period containing the candidate starting RO is determined at the UE based on a specification. In another implementation, the index of the associated time period containing the candidate starting RO is determined at the UE based on a network configuration that includes the time offset / distance and / or period of the associated time period, which contains the candidate starting RO. In one implementation, the time offset / difference from slot number 0 in frame number 0 is provided in units of slot, frame, or associated time period. In one implementation, the time offset / difference from a reference time is provided in units of slot, frame, or associated time period, such as the start time of the reference time period. In one implementation, the period is provided in units of slot, frame, or associated time period. In another implementation, the period is provided in units of RO.

[0087] 1d) In another embodiment, the UE further determines which ROs (based on the above embodiments) in the determined set of starting ROs can be used for multiple PRACH transmissions or for a certain number of PRACH transmissions. Further determination is based on the network configuration of a subset of the determined set of starting ROs, which will be used (or not used) for multiple PRACH transmissions or a certain number of PRACH transmissions. In one implementation, this configuration is provided as a bitmap, wherein the size of the bitmap is the number of determined starting ROs (i.e., each bit of the bitmap is relative to a candidate starting RO), and wherein a bit value indicates that a candidate starting RO can be used for multiple PRACH transmissions, while another bit value indicates that a candidate starting RO cannot be used for multiple PRACH transmissions. In one implementation, the configuration is provided as multiple bitmaps, each bitmap associated with a certain number of PRACH transmissions, and wherein a bit value of the bitmap indicates that a candidate starting RO can be used for a specific number of PRACH transmissions, while another bit value indicates that a candidate starting RO cannot be used for a specific number of PRACH transmissions.

[0088] 1e) In another embodiment, based on the number of temporally consecutive subsequent valid ROs associated with the same SS / PBCH block index and using the same frequency resources as the starting RO within a reference time period, the UE determines which ROs in the determined set of starting ROs (according to any of the embodiments described above) are actually the starting valid ROs of a group of ROs for a first number of multiple PRACH transmissions (N). More specifically, if a second number (N-1) of temporally consecutive subsequent valid ROs associated with the same SS / PBCH block index and using the same frequency resources can be determined within the reference time period, the UE determines that the valid ROs within the reference time period are the starting valid ROs of a group of ROs for the first number of PRACH transmissions (N). Alternatively, if, within the reference time period, there is not a second number of subsequent valid ROs (N-1) that are temporally consecutive and associated with the same SS / PBCH block index and use the same frequency resources as the starting RO, and the number of candidate starting ROs and subsequent valid ROs cannot be used to determine the RO group for the first number of multiple PRACH transmissions (N), then the ROs in the candidate starting RO set are not considered as the starting valid ROs of the RO group for the first number of multiple PRACH transmissions (N).

[0089] 1f) In another embodiment, any RO in the determined initial RO set allows the determination of a second number of subsequent valid ROs (N-1) within a reference time period, such that the number of candidate initial ROs and subsequent valid ROs can be used to determine the RO group for transmitting a first number of PRACH transmissions (N), and wherein the subsequent valid RO set is temporally consecutive, associated with the same SS / PBCH block index, and uses the same frequency resources as the initial ROs.

[0090] 2a) In one embodiment, the UE may determine one or more RO groups for transmissions of multiple PRACH transmissions based on a determined set of starting ROs. In one implementation, the determined one or more RO groups may be based on a subset of starting ROs that is closest to (but later than) the determined time, and the UE selects one of the determined one or more RO groups for transmissions of multiple PRACH transmissions. In another implementation, the determined one or more RO groups are based on all subsets of candidate starting ROs within a reference time period, and the UE selects one of the determined one or more RO groups for transmissions of multiple PRACH transmissions that begin after the determined time.

[0091] 2b) In another embodiment, the UE determines one or more RO groups for transmissions of a first number of multiple PRACH transmissions (N) based on a determined set of starting ROs, wherein for any RO in the candidate set of starting ROs, if within a reference time period, the candidate starting RO is followed by a first number of subsequent valid ROs (M-1) less than a second number of subsequent valid ROs (N-1), and wherein the second number of subsequent valid ROs plus 1 is the total number of ROs in the RO groups for the first number of multiple PRACH transmissions, then the candidate starting RO is considered a starting valid RO and is used together with the first number of subsequent valid ROs (M-1) to determine an adaptive RO group (M ROs) for transmissions of a second number of multiple PRACH transmissions (M) less than the first number of multiple PRACH transmissions (N).

[0092] Figure 7 This is a diagram illustrating the initiation RACH timing (RO) for multiple RO groups according to an example embodiment. Figure 7 As shown, each box represents a RO in the time-frequency grid, and each RO in the represented RO is mapped to the same SSB index and is not necessarily continuous in the time and frequency domains (even if shown as continuous for the sake of simplicity). Figure 7 Eight initial ROs (712, 714, 716, 718, 752, 754, 756, and 758) are illustrated. Four RO groups (792, 794, 796, and 798) are shown, each group comprising four ROs. Each RO is shown using a box. The initial ROs are divided into two subsets: a first subset (710) of initial ROs (e.g., including initial ROs 712, 714, 716, and 718) and an additional subset (750) of initial ROs (including initial ROs 752, 754, 756, and 758). Each initial RO is shown as the first RO of a corresponding or related RO group. For example, RO group 792 includes initial RO 712, as well as ROs 722, 732, and 742. RO group 794 includes initial RO 718, as well as ROs 728, 738, and 748. RO group 796 includes starting RO 752, and ROs 762, 772, and 782. RO group 798 includes starting RO 756, and ROs 766, 776, and 786. Starting ROs 712, 714, 716, and 718 are provided in the same time resources (e.g., using the same OFDM symbols), but in different frequency resources (e.g., different subcarrier sets) (or multiplexed across different frequency resources). The same applies to RO groups with additional starting RO sets. RO groups 792 and 796 use the same frequency resources but different time resources. Each row of 8 ROs can use the same SSB index.

[0093] Step 1: The UE determines that a group of ROs (Representative Entities) needs to be established to perform four PRACH transmissions. The determination of the RO group size (i.e., the number of PRACH transmissions) can be based on an SSB-RSRP threshold configured by the network. For example, the lower the RSRP of the selected SSB, the higher or more likely the number of PRACH transmissions may be performed or required, for example, by combining multiple PRACH transmissions via the gNB to increase the probability of a successful RACH procedure.

[0094] Step 2: The UE determines the period of the starting RO based on the size of the RO group it needs to determine, that is, the period of the candidate starting RO is determined and set to 4 ROs that are mapped to the same SSB index.

[0095] Step 3: The UE determines the reference time period based on the network configuration or specification text (in this example, it includes 8 ROs, which are not necessarily consecutive, but map to the same SSB index).

[0096] Step 4: The UE determines the first subset of starting ROs as the ROs closest to the start of the reference time period, i.e., the first RO of the reference time period. In this example, the first subset 710 of starting ROs can be determined because, in this example, these starting ROs can be the ROs closest to the start of the reference time period. In this example, multiple frequency-multiplexed ROs are closest to the start of the reference time period, but in other examples, only one RO can be closest to the start of the reference time period. It should be noted that when referring to the ROs closest to the start of the reference time period, we mean the ROs mapped to a certain SSB index that are closest to the start of the reference time period and are within the reference time period.

[0097] Step 5: The UE determines an additional subset of the candidate starting ROs as all frequency-multiplexed ROs spaced apart by the period determined in Step 2 from the first subset of the candidate starting ROs, i.e., 4 ROs mapped to the same SSB index. In this example, the UE determines an additional subset of starting ROs 750.

[0098] Step 6: The UE determines one or more RO groups based on a first subset and an additional subset of candidate ROs (Example 2.b.), and selects one of the determined RO groups for transmission of multiple PRACH transmissions that begin after a determined time, i.e., the time point at which the UE determines the RO group. In this example, the UE can select RO group 798 (with starting RO 756) because this begins after the determined time.

[0099] Figure 8 This diagram illustrates how the starting RACH timing (RO) is further determined based on network configuration. Figure 8In the example, UE such Figure 7 The example demonstrates how the starting RO set is determined, but the UE also makes the determination of the starting RO set conditional on network configuration, which indicates which ROs in the subset can be used as starting ROs:

[0100] Step 1: The UE determines that it needs to identify RO groups of 4 ROs to perform 4 numbers of multiple PRACH transmissions. The determination of the RO group size (i.e., the number of multiple PRACH transmissions) is based on the SSB-RSRP threshold configured by the network.

[0101] Step 2: The UE determines the period of the candidate starting RO based on the size of the RO group it needs to determine, that is, the period of the candidate starting RO is determined and set to 4 ROs that are mapped to the same SSB index.

[0102] Step 3: The UE determines the reference time period (in this example, it includes 8 ROs, which are not necessarily consecutive, but map to the same SSB index).

[0103] Step 4: The UE determines the first subset of candidate starting ROs as the ROs closest to the start of the reference time period, i.e., the first RO mapped to the same SSB index of the reference time period. In this example, multiple frequency-multiplexed ROs are closest to the start of the reference time period, but in other examples, only one RO can be closest to the start of the reference time period. It should be noted that when referring to the RO closest to the start of the reference time period, we mean the RO mapped to a certain SSB index that is closest to the start of the reference time period and is within the reference time period.

[0104] Step 5: The UE determines an additional subset of the candidate starting ROs as all frequency-multiplexed ROs separated by the period determined in Step 2 from the first subset of the candidate starting ROs, that is, 4 ROs mapped to the same SSB index.

[0105] Step 6: The UE sets the determinations of Steps 5 and 6 to "forbidden" RO ( Figure 8 The network configuration of the RO with X is conditional, and therefore, even if the prohibited RO is initially part of the first subset and additional subset of the candidate starting RO, the UE will not regard it as the starting RO for the determination of the RO group in the next step 7 (Example 1.d.).

[0106] Step 7: The UE determines one or more RO groups based on the first subset and additional subset of candidate ROs and based on the prohibited ROs (based on step 6), and the UE selects one of the determined RO groups for transmission of multiple PRACH transmissions that will begin after a determined time.

[0107] The example embodiments described herein provide a method for a UE to determine the starting ROs for a RO group, which is crucial for ensuring that there is no ambiguity in gNB receiver operation regarding which ROs to combine when receiving multiple PRACH transmissions. The example embodiments allow the gNB to indicate only a subset of the determined candidate starting RO set for creating an RO group with a specific number of PRACH transmissions.

[0108] Now some examples will be described.

[0109] Example 1. A method comprising: determining, by a user equipment in a wireless network, a set of candidate start random access channel timings (ROs) for a plurality of physical random access (PRACH) transmissions, wherein determining the set of candidate start ROs is based at least on valid ROs; determining, by the user equipment, a group of ROs for the plurality of PRACH transmissions based on the set of candidate start ROs, the group of ROs including at least one candidate start RO from the set; and transmitting the plurality of PRACH transmissions to a network node using the group of ROs.

[0110] Example 2. According to the method of Example 1, the determination of the candidate starting RO set is performed regardless of the conflict handling rules applied to the candidate starting RO set, or whether the PRACH transmission in the starting RO is dropped based on a conflict with another RO.

[0111] Example 3. The method of any one of Examples 1 to 2, wherein the determination of the candidate starting RO set is performed based on at least one of the following: period or reference time.

[0112] Example 4. According to the method of Example 1, wherein the candidate starting RO set includes: a first subset of candidate starting ROs, wherein the first subset of candidate starting ROs is determined based on a reference time; and a second subset of candidate starting ROs, wherein the second subset of candidate starting ROs is spaced from the first subset of candidate starting ROs by an starting RO period or an RO group period.

[0113] Example 5. The method of any one of Examples 1 to 4, where the valid RO occurs within the reference time period.

[0114] Example 6. Following the method of Example 5, where the reference time period is given as the number of associated pattern time periods.

[0115] Example 7. According to the method of Example 4, wherein the reference time includes at least one of the following: a specific time slot or frame at a time offset from time slot 0 of frame 0; the time of the RO closest to the start of the reference time period; or the time of the RO at a time offset from the RO closest to the start of the reference time period.

[0116] Example 8. The method of any one of Examples 1 to 7, wherein the determination of the candidate starting RO set is performed based on the index of the valid RO.

[0117] Example 9. Following the method in Example 8, where the index of the valid RO is equal to 0.

[0118] Example 10. The method according to any one of Examples 1 to 9 further includes: determining the index of the associated pattern period to which each valid RO belongs; and wherein determining the candidate starting RO set is performed based on the index of the associated pattern period to which each valid RO belongs.

[0119] Example 11. Following the method of Example 10, valid ROs belonging to the associated pattern time period with index 0 are determined as part of the candidate starting RO set.

[0120] Example 12. According to the method of any one of Examples 5 to 10, wherein if a candidate starting RO is followed by a second number of subsequent valid ROs that are temporally consecutive and associated with the same SS / PBCH block index and use the same frequency resources as the starting RO, such that the candidate starting RO and the number of subsequent valid ROs can be used to determine the RO group for the first number of multiple PRACH transmissions, then any RO in the candidate starting RO set is determined as the starting valid RO of the RO group for the first number of multiple PRACH transmissions within the reference time period.

[0121] Example 13. According to the method of any one of Examples 5 to 10, any RO in the candidate starting RO set of the RO group for a first number of multiple PRACH transmissions allows the determination of a second number of temporally consecutive subsequent valid ROs associated with the same SS / PBCH block index and using the same frequency resources as the starting RO within the reference time period, such that the candidate starting RO and the second number of subsequent valid ROs are used to determine the RO group for transmitting the first number of multiple PRACH transmissions.

[0122] Example 14. According to the method of any one of Examples 5 to 10, wherein for any RO in the candidate starting RO set of RO groups for a first number of multiple PRACH transmissions, if within the reference time period, the candidate starting RO is followed by a first number of subsequent valid ROs less than a second number of subsequent valid ROs, and wherein the second number of subsequent valid ROs plus 1 is the total number of ROs in the RO groups for the first number of multiple PRACH transmissions, then the candidate starting RO is a starting valid RO and can be used together with the first number of subsequent valid ROs to determine an adaptive RO group for a second number of multiple PRACH transmissions less than the first number of PRACH transmissions.

[0123] Example 15. An apparatus comprising: at least one processor; and at least one memory including computer program code; the at least one memory and the computer program code being configured together with the at least one processor such that the apparatus performs at least one of the methods according to Examples 1 to 14.

[0124] Example 16. A non-transient computer-readable storage medium including instructions stored thereon, which, when executed by at least one processor, are configured to cause a computing system to perform a method according to any one of Examples 1 to 14.

[0125] Example 17. A user equipment includes: at least one processor; and at least one memory including computer program code; the at least one memory and the computer program code are configured together with the at least one processor such that the user equipment performs at least: determining a set of candidate start random access channel timings (ROs) for a plurality of physical random access (PRACH) transmissions, wherein determining the set of candidate start ROs is based at least on valid ROs; determining a group of ROs for the plurality of PRACH transmissions based on the set of candidate start ROs, the group of ROs including at least one candidate start RO from the set; and sending the plurality of PRACH transmissions to a network node using the group of ROs.

[0126] Example 18. A user equipment comprising: means for determining a set of candidate start random access channel timings (ROs) for a plurality of physical random access (PRACH) transmissions, wherein determining the set of candidate start ROs is based at least on valid ROs; means for determining a group of ROs for the plurality of PRACH transmissions based on the set of candidate start ROs, the group of ROs including at least one candidate start RO from the set; and means for sending the plurality of PRACH transmissions to a network node using the group of ROs.

[0127] Example 19. A method comprising: receiving configuration information for random access from a network node by a user equipment, wherein the configuration information includes a plurality of synchronization signal blocks (SSBs) and a plurality of random access channel opportunities (ROs), the plurality of ROs being divided into a plurality of RO groups; determining an initial set of ROs for the plurality of RO groups by the user equipment at least based on the validity of an initial RO; selecting an RO group from the plurality of RO groups by the user equipment based on the initial RO set; and transmitting a plurality of physical random access channel (PRACH) transmissions to the network node during random access using ROs from the selected RO group.

[0128] Example 20. According to the method of Example 19, each of the starting ROs in the set of starting ROs is valid, wherein if the RO is within one or more flexible symbols, the RO is valid if the RO is within an uplink symbol to the network node, or if the RO has a predetermined or minimum time interval after the last SSB symbol from the network node.

[0129] Example 21. The method of Example 19, wherein each starting RO in the set of starting ROs is valid, and the RO is valid if it is within the uplink symbol to the network node.

[0130] Example 22. The method of any one of Examples 19 to 21, wherein the initial RO set is determined regardless of the conflict resolution rules applied to the ROs in the initial RO set.

[0131] Example 23. According to any of Examples 19 to 22, wherein the initial RO set includes a first subset of ROs and one or more additional subsets of ROs spaced apart from the first subset of ROs.

[0132] Example 24. The method of any of Examples 19 to 23, wherein the initial RO set appears within the reference time period.

[0133] Example 25. According to the method of Example 23, each of the ROs in the first subset is at the same reference time or a different reference time associated with the plurality of SSBs.

[0134] Example 26. Following the method of Example 25, where the same or different reference time is based on a time offset.

[0135] Example 27. According to the method of any of Examples 24 to 26, the reference time consists of more than one associated time period to which the RO in the first subset belongs.

[0136] Example 28. The method of Example 27, wherein the value of the reference time period is configured by the network node or determined by the user equipment.

[0137] Example 29. The method of any of Examples 27 to 28, wherein the reference time period is in units of time slots, radio frames, or ROs.

[0138] Example 30. According to any one of Examples 26 to 29, wherein if only one value of the plurality of PRACH transmissions is configured, then only one value of the reference time period is configured or determined.

[0139] Example 31. According to any of Examples 26 to 29, wherein if more than one value of the plurality of PRACH transmissions is configured, one or more values ​​of the reference time period are configured or determined.

[0140] Example 32. The method of any one of Examples 19 to 22, wherein the starting RO set is determined based on the index of the starting RO.

[0141] Example 33. The method according to any one of Examples 19 to 22 further includes: determining which ROs in the initial ROs will be used for the plurality of PRACH transmissions; and sending the plurality of PRACH transmissions to the network node using at least one RO in the initial ROs.

[0142] Example 34. The method of any one of Examples 19 to 33, wherein the at least one RO group is based only on a subset of the initial RO set that is closest to a determined time instance of the at least one RO group.

[0143] Example 35. According to the method of Example 34, it further includes selecting an RO group from at least one RO group used for multiple PRACH transmissions.

[0144] Example 36. According to the method of Example 34, wherein the at least one RO group is determined based on each subset of the starting RO within the associated reference time period.

[0145] Example 37. The method according to Example 36 further includes: selecting an RO group from at least one RO group for multiple PRACH transmissions that begin after a determined time instance of at least one RO group.

[0146] Example 38. An apparatus comprising: at least one processor; and at least one memory including computer program code; the at least one memory and the computer program code being configured together with the at least one processor such that the apparatus performs at least one of the methods according to Examples 19 to 37.

[0147] Example 39. A non-transient computer-readable storage medium including instructions stored thereon, which, when executed by at least one processor, are configured to cause a computing system to perform a method according to any one of Examples 19 to 37.

[0148] Example 40. An apparatus comprising a component for performing a method according to any one of Examples 19 to 37.

[0149] Example 41. An apparatus comprising: at least one processor; and at least one memory including computer program code; the at least one memory and the computer program code being configured together with the at least one processor such that the apparatus performs at least: receiving configuration information for random access from a network node by a user equipment, wherein the configuration information includes a plurality of synchronization signal blocks (SSBs) and a plurality of random access channel opportunities (ROs), the plurality of ROs being divided into a plurality of RO groups; determining an initial set of ROs for the plurality of RO groups by the user equipment at least based on the validity of initial ROs; selecting an RO group from the plurality of RO groups by the user equipment based on the initial RO set; and transmitting a plurality of physical random access channel (PRACH) transmissions to the network node by the user equipment during random access using ROs from the selected RO group.

[0150] Figure 9 This is a block diagram of a wireless station or node (e.g., UE, user equipment, AP, BS, eNB, gNB, RAN node, network node, TRP, or other node) 1300 according to an example embodiment. The wireless station 1300 may include, for example, one or more (e.g., such as...) Figure 8 The two RF (radio frequency) or wireless transceivers 1302A and 1302B shown herein include a transmitter for transmitting signals and a receiver for receiving signals. The wireless station also includes a processor or control unit / entity (controller) 1304 for executing instructions or software and controlling the transmission and reception of signals, and a memory 1306 for storing data and / or instructions.

[0151] Processor 1304 may also make decisions or determinations, generate frames, packets, or messages for transmission, decode received frames or messages for further processing, and perform other tasks or functions described herein. For example, processor 1304, which may be a baseband processor, may generate messages, packets, frames, or other signals for transmission via wireless transceiver 1302 (1302A or 1302B). Processor 1304 may control the transmission of signals or messages via a wireless network and may control the reception of signals or messages via a wireless network (e.g., after being down-converted by wireless transceiver 1302). Processor 1304 may be programmable and capable of executing software or other instructions stored in memory or on other computer media to perform the various tasks and functions described above, such as one or more of the tasks or methods described above. For example, processor 1304 may be (or may include) hardware, programmable logic, a programmable processor executing software or firmware, and / or any combination of these. For example, using other terms, processor 1304 and transceiver 1302 may be considered together as a wireless transmitter / receiver system.

[0152] In addition, refer toFigure 9 The controller (or processor) 1308 can execute software and instructions, and can provide overall control for station 1300, and can also be used for... Figure 9 Other systems, not shown, provide control, such as controlling input / output devices (e.g., a display, a keypad), and / or can execute software for one or more applications available on the wireless station 1300, such as, for example, an email program, an audio / video application, a word processor, a VoIP application, or other applications or software.

[0153] In addition, a storage medium may be provided that includes stored instructions, which, when executed by a controller or processor, may cause the processor 1304 or other controller or processor to perform one or more of the functions or tasks described above.

[0154] According to another example embodiment, the RF or (multiple) wireless transceivers 1302A / 1302B can receive signals or data, and / or transmit or emit signals or data. The processor 1304 (and possibly the transceivers 1302A / 1302B) can control the RF or wireless transceivers 1302A or 1302B to receive, transmit, broadcast, or emit signals or data.

[0155] Figure 10 This is a diagram illustrating the initiation RACH timing (RO) for multiple RO groups according to an example embodiment. Figure 10 Each box in the diagram represents a Region of Origin (RO) in the time-frequency grid, and each represented RO is mapped to an SSB index. The first and additional subsets of candidate starting ROs within the reference time period are illustrated using dashed boxes surrounding subsets of frequency-multiplexed ROs spaced at time offsets (e.g., configured by the network). In this example, it is assumed that the PRACH repeats 4 times, i.e., the number of valid ROs within the RO group is N=4, as shown below. Figure 10As shown, for each frequency resource, and within a reference time period, for any candidate starting RO in the first and second subsets of the candidate starting ROs, three (i.e., N-1) temporally consecutive subsequent valid ROs can be found, which are associated with the same SS / PBCH block index and use the same frequency resource as the starting RO. This is not the case for candidate starting ROs in the third subset of the candidate starting ROs; for the third subset, regardless of the mapped SS / PBCH block index and the frequency resource of the considered starting RO, only two such subsequent valid ROs can be found. According to the above embodiment, two alternative solutions can be envisioned for this situation. In one alternative, the determination of the starting RO is also constrained by the condition that only starting RO candidates preceding at least N-1 valid ROs with the same frequency position within the reference time period are considered starting valid ROs. In other words, if N-1 temporally consecutive subsequent valid ROs associated with the same SS / PBCH block index and using the same frequency resource can be determined within the reference time period, then the valid RO is the first valid RO with N preamble repetitions. In other words, each first valid RO allows determining a set of N valid ROs within a reference time period for sending N preamble repetitions. According to these two alternative solutions, in this example, only two groups of 4 valid ROs can be determined within the reference time period. In another alternative, and always referencing... Figure 10 The starting RO candidate preceding M consecutive valid ROs (where M < (N-1)) that are associated with the same SS / PBCH block index and use the same frequency resources within the reference time period is also the first valid RO in the group used for multiple PRACH transmissions, and the RO group size of the RO group starting with the starting RO is applicable to M valid ROs, where M=3 in this example.

[0156] Embodiments of the various technologies described herein can be implemented in digital electronic circuit systems, or in computer hardware, firmware, software, or a combination thereof. Embodiments can be implemented as computer program products, i.e., computer programs tangibly embodied in an information carrier, such as in a machine-readable storage device or in a transmitted signal, for use by a data processing device to execute or control the operation of a data processing device, such as a programmable processor, computer, or multiple computers. Embodiments can also be provided on a computer-readable medium or a computer-readable storage medium, which may be a non-transient medium. Embodiments of the various technologies may also include embodiments provided via transient signals or media, and / or program and / or software embodiments downloadable via the Internet or (multiple) other networks (wired and / or wireless networks). Furthermore, embodiments can be provided via machine-type communication (MTC) or via the Internet of Things (IoT).

[0157] Computer programs can be in the form of source code, object code, or some intermediate form, and can be stored on some carrier, distribution medium, or computer-readable medium, which can be any entity or device capable of carrying the program. Such carriers include recording media, computer memory, read-only memory, optoelectronic and / or electrical carrier signals, telecommunication signals, and software distribution packages. Depending on the required processing power, a computer program can be executed in a single electronic digital computer, or it can be distributed among multiple computers.

[0158] Furthermore, embodiments of the various technologies described herein can utilize cyber-physical systems (CPS) (systems that control collaborative computing elements of physical entities). CPS enables the implementation and development of a large number of interconnected ICT devices (sensors, actuators, processors, microcontrollers, etc.) embedded in physical objects in different locations. Mobile cyber-physical systems (where the physical systems under discussion have inherent mobility) are a subcategory of cyber-physical systems. Examples of mobile physical systems include mobile robots and electronic devices transported by humans or animals. The proliferation of smartphones has increased interest in the field of mobile cyber-physical systems. Therefore, various embodiments of the technologies described herein can be provided via one or more of these technologies.

[0159] Computer programs such as those described above can be written in any programming language, including compiled or interpreted languages, and can be deployed in any form, including as standalone programs, or as modules, components, subroutines, or other units or parts thereof suitable for a computing environment. Computer programs can be deployed to be executed on a single computer, on multiple computers at a single site, or on multiple computers distributed across multiple sites and interconnected via a communication network.

[0160] The method steps can be executed by one or more programmable processors that execute a computer program or portions thereof to perform a function by manipulating input data and generating output. The method steps can also be executed by a dedicated logic circuit system, and the apparatus can be implemented as a dedicated logic circuit system, such as an FPGA (Field-Programmable Gate Array) or an ASIC (Application-Specific Integrated Circuit).

[0161] For example, processors suitable for executing computer programs include both general-purpose and special-purpose microprocessors, as well as any type of digital computer, chip, or chipset, and any one or more processors. Typically, a processor receives instructions and data from read-only memory or random access memory, or both. Computer components may include at least one processor for executing instructions, and one or more memory devices for storing instructions and data. Typically, a computer may also include, or be operatively coupled to, receiving data from or transferring data to one or more mass storage devices (e.g., magneto-optical, magneto-optical, or optical discs) for storing data, or both. Information carriers suitable for embodying computer program instructions and data include all forms of non-volatile memory, including, for example, semiconductor memory devices such as EPROM, EEPROM, and flash memory devices; magnetic disks, such as internal hard disks or removable disks; magneto-optical disks; and CD-ROM and DVD-ROM discs. The processor and memory may be complemented or integrated into a special-purpose logic circuit system.

[0162] To provide interaction with the user, the embodiments can be implemented on a computer having a display device (e.g., a cathode ray tube (CRT) or liquid crystal display (LCD) monitor) for displaying information to the user, and a user interface through which the user can provide input to the computer (such as a keyboard and pointing devices, such as a mouse or trackball). Other types of devices can also be used to provide interaction with the user; for example, the feedback provided to the user can be any form of sensory feedback, such as visual feedback, auditory feedback, or tactile feedback; and input from the user can be received in any form, including sound, speech, or tactile input.

[0163] The embodiments can be implemented in a computing system comprising: a backend component, such as a data server; or a middleware component, such as an application server; or a frontend component, such as a client computer having a graphical user interface or web browser through which a user can interact with the embodiments; or any combination of such backend, middleware, or frontend components. The components can be interconnected via digital data communication of any form or media, such as a communication network. Examples of communication networks include local area networks (LANs) and wide area networks (WANs), such as the Internet.

[0164] While certain features of the described embodiments have been illustrated herein, many modifications, substitutions, alterations, and equivalents will now occur to those skilled in the art. Therefore, it should be understood that the appended claims are intended to cover all such modifications and variations falling within the true spirit of the various embodiments.

Claims

1. A method comprising: A user equipment in a wireless network determines at least one starting random access channel timing (RO), wherein each of the at least one starting RO is the first valid RO in a set of ROs for physical random access (PRACH) transmissions with preamble repetition, and the determination of the at least one starting RO is based at least on valid ROs; The user equipment determines a set of ROs for the PRACH transmission with preamble repetition based on the determined at least one starting RO, the determined set of ROs including one of the at least one starting ROs; as well as The user equipment uses the determined RO set to send the PRACH transmission with preamble repetition to the network node.

2. The method of claim 1, wherein regardless of the conflict handling rules applied to the first valid RO(s), or whether the PRACH transmissions in the first valid RO(s) are dropped based on a conflict with another PRACH transmission, it is determined that the at least one initiating RO is executed.

3. The method according to any one of claims 1 to 2, wherein determining the at least one starting RO is performed based on at least one of the following: time offset between starting ROs, or reference time.

4. The method of claim 3, wherein the at least one initiating RO comprises: The first subset of the starting RO, wherein the first subset of the starting RO is determined based on the reference time; as well as The second subset of the starting RO, wherein the second subset of the starting RO is spaced from the first subset of the starting RO by the time offset between the starting RO and the starting RO.

5. The method of claim 3 or 4, wherein if the preamble is repeated more than once, more than one time offset between the starting ROs is configured.

6. The method according to any one of claims 3 to 5, wherein the reference time includes at least one of the following: A specific time slot or frame at a time offset from time slot 0 of frame 0; The RO time closest to the start of the reference time period; The time of RO at the time offset from the start of the RO closest to the reference time period.

7. The method according to any one of claims 1 to 6, wherein the effective RO occurs within the reference time period.

8. The method of claim 7, wherein the reference time period is given as the number of associated pattern time periods.

9. The method according to claim 7 or 8, further comprising: The reference time period is determined by the user equipment.

10. The method according to any one of claims 1 to 9, wherein determining the at least one starting RO is performed based on the index of the valid RO.

11. The method of claim 10, wherein the index of the valid RO is equal to 0.

12. The method according to any one of claims 1 to 11, further comprising: For each valid RO in the valid RO, determine the index of the associated pattern time period to which the valid RO belongs; and The determination of the at least one starting RO is performed based on the index of the associated pattern period to which each valid RO belongs.

13. The method of claim 12, wherein the valid RO belonging to the associated pattern period having index 0 is determined as part of the at least one starting RO.

14. The method of any one of claims 7 to 13, wherein if any RO of the at least one starting RO is followed by a second number of subsequent valid ROs that are temporally consecutive and associated with the same SS / PBCH block index and use the same frequency resources as the starting RO, such that the starting RO and the number of subsequent valid ROs can be used to determine a set of ROs for a first number of PRACH transmissions with preamble repetition, then within the reference time period, the RO of the at least one starting RO is determined as a starting valid RO in the set of ROs for the first number of PRACH transmissions with preamble repetition.

15. The method of any one of claims 7 to 13, wherein any RO in the at least one starting RO of the RO set for a first number of PRACH transmissions with preamble repetition allows the determination of a second number of temporally consecutive subsequent valid ROs associated with the same SS / PBCH block index and using the same frequency resources as the ROs within the reference time period, such that the starting ROs and the second number of subsequent valid ROs are used to determine the RO set for transmitting the first number of PRACH transmissions with preamble repetition.

16. The method according to any one of claims 7 to 13, wherein for any RO in the at least one starting RO of the RO set for a first number of PRACH transmissions with preamble repetition, if, within the reference time period, the starting RO is followed by a first number of subsequent valid ROs less than a second number of subsequent valid ROs, and wherein the second number of subsequent valid ROs plus 1 is the total number of ROs in the RO set for the first number of PRACH transmissions with preamble repetition, then the starting RO is a starting valid RO and can be used together with the first number of subsequent valid ROs to determine an adaptive RO group for a second number of PRACH transmissions with preamble repetition less than the first number of PRACH transmissions with preamble repetition.

17. The method according to any one of claims 1 to 16, further comprising: Based solely on a subset of the at least one starting RO, a plurality of RO sets are determined for the PRACH transmission with preamble repetition, the subset being closest to the determined time instance of the plurality of RO sets.

18. The method of claim 17, wherein the determined RO set is selected from the plurality of RO sets and begins after the determined time instance of the plurality of RO sets.

19. An apparatus comprising: At least one processor; as well as At least one memory, the at least one memory storing instructions, the instructions, when executed by the at least one processor, cause the apparatus to perform at least the method according to any one of claims 1 to 18.

20. A non-transient computer-readable storage medium comprising instructions stored thereon, the instructions being configured, when executed by at least one processor, to cause a computing system to perform the method according to any one of claims 1 to 18.

21. A user equipment, comprising: At least one processor; as well as At least one memory storing instructions that, when executed by the at least one processor, cause the user equipment to at least: Determine at least one starting random access channel timing (RO), wherein each of the at least one starting RO is the first valid RO in a set of ROs for physical random access (PRACH) transmissions with preamble repetition, wherein the determination of the at least one starting RO is based at least on valid ROs; A set of ROs for the PRACH transmission with preamble repetition is determined based on the determined at least one starting RO, the determined set of ROs including one of the at least one starting ROs; as well as The determined RO set is used to send the PRACH transmission with preamble repetition to the network node.

22. A user equipment, comprising: The component is used to determine at least one starting random access channel timing (RO), wherein each of the at least one starting RO is the first valid RO in a set of ROs for physical random access (PRACH) transmissions with preamble repetition, wherein the determination of the at least one starting RO is based at least on valid ROs; A component for determining a set of ROs for the PRACH transmission with preamble repetition based on the determined at least one starting RO, the determined set of ROs including one of the at least one starting ROs; as well as A component for sending the PRACH transmission with preamble repetition to a network node using the determined RO set.

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