RO discarding and RA-RNTI calculation

Abstract

Embodiments of this disclosure relate to methods, devices, apparatus, and computer-readable storage media for discarding random access channel (RACH) opportunities (ROs). In the method, the apparatus determines a set of valid random access channel opportunities (ROs) for a physical random access channel (PRACH) transmission with a repeating preamble. The apparatus determines that, in the set of valid ROs, a PRACH transmission should be discarded at least one RO. The apparatus determines one or more ROs from the set of valid ROs for the calculation of a random access radio network temporary identifier (RA-RNTI). The one or more ROs for the calculation of the RA-RNTI are independent of whether the corresponding PRACH transmission through one or more ROs is discarded. The apparatus then calculates the RA-RNTI based on one or more ROs from the determined set of valid ROs.

Description

Technical Field

[0001] Reference to Related Applications This application claims priority to U.S. Provisional Application No. 63 / 494,291, filed on April 5, 2023. The entire contents of the above application are incorporated herein by reference.

[0002] Various embodiments of the present disclosure generally relate to the field of telecommunications, and more particularly, to methods, devices, apparatuses, and computer-readable storage media for discarding random access channel (RACH) opportunities (ROs) and calculating random access radio network temporary identifiers (RA-RNTIs).

Background Art

[0003] In the 5th generation (5G) new radio (NR), multiple collisional random access (CBRA) procedures are supported, such as the 4-step RACH in Release 15 (Rel-15) and the 2-step RACH in Rel-16. The time-domain resources of the RACH opportunity (RO) may be set by the RRC. With this setting, the user equipment (UE) determines the preamble format of the physical random access channel (PRACH) and applies a predefined or specified procedure to identify the RO within the time domain. In the frequency domain, the offset of the lowest RO and the number of multiplexed ROs at each time instance may be indicated. The number of resource blocks occupied by each RO is represented by the number of resource blocks (RBs) in the physical uplink shared channel (PUSCH), and is predefined or specified according to the set preamble length and subcarrier spacing of the PRACH and PUSCH.

[0004] The mapping between the Synchronization Signal Block (SSB) index and the determined RO is derived so that the UE can recognize the RO associated with the SSB index selected before the start of the RACH procedure. Since various SSB indices beamform in different directions within the cell, selecting the wrong SSB index can lead to the failure of the RACH procedure. [Overview of the project]

[0005] A method is provided in a first aspect of this disclosure. The method includes, in a first device, determining that a first physical random access channel (PRACH) transmission should be discarded at a first random access channel (RACH) opportunity (RO) of an RO group, based on that at least one condition is met, and transmitting at least one second PRACH transmission other than the first PRACH transmission to be discarded at the RO of the RO group.

[0006] A second aspect of this disclosure provides a method. The method includes, in a second device, determining that a first physical random access channel (PRACH) transmission is to be discarded at a first random access channel (RACH) opportunity (RO) of an RO group, based on that at least one condition is met, and receiving from the first device at least one second PRACH transmission other than the first PRACH transmission that is discarded at the RO of the RO group.

[0007] A third aspect of this disclosure provides a method. The method includes determining a set of valid random access channel opportunities (ROs) for a physical random access channel (PRACH) transmission with a repeating preamble; determining that a PRACH transmission should be discarded in at least one RO of the set of valid ROs; determining one or more ROs of the set of valid ROs for the calculation of a random access radio network temporary identifier (RA-RNTI), wherein the one or more ROs for the calculation of the RA-RNTI are not conditioned on whether a corresponding PRACH transmission through one or more ROs is discarded; and calculating the RA-RNTI based on the determined one or more ROs of the set of valid ROs.

[0008] A fourth aspect of this disclosure provides an apparatus, comprising at least one processor and at least one memory that stores instructions, when executed by the at least one processor, causing the apparatus to perform a method according to the first, second, or third aspect.

[0009] A fifth aspect of this disclosure provides an apparatus. The first apparatus comprises means for performing a method according to the first, second, or third aspect.

[0010] In a sixth aspect of this disclosure, a computer-readable medium is provided which stores instructions for causing a device to perform a method according to the first, second, or third aspect.

[0011] It should be understood that the abstract does not identify any important or essential features of the embodiments of this disclosure, nor is it intended to limit the scope of this disclosure. Other features of this disclosure will be readily apparent through the following description. [Brief explanation of the drawing]

[0012] Several embodiments will be described with reference to the attached drawings. [Figure 1] Figure 1 shows an example of a communication environment in which the embodiments of this specification can be implemented. [Figure 2A] Figure 2A shows a four-step random access channel (RACH) procedure. [Figure 2B] Figure 2B shows an example of how time-domain resources are determined when RACH occurs. [Figure 2C] Figure 2C shows an example of mapping from the Synchronization Signal / Physical Broadcast Channel Block (SSB) to the RACH opportunity (RO). [Figure 2D] Figure 2D shows an example of RO disposal in the RO group. [Figure 3] Figure 3 shows a flowchart of a method implemented in the first apparatus according to some embodiments of the present disclosure. [Figure 4] Figure 4 shows signaling diagrams for RO discarding and Random Access Radio Network Temporary Identifier (RA-RNTI) calculation according to some embodiments of the present disclosure. [Figure 5] Figure 5 shows a flowchart of a method implemented in a second apparatus according to some embodiments of the present disclosure. [Figure 6] Figure 6 shows a simplified block diagram of an apparatus suitable for carrying out an embodiment of the present disclosure. [Figure 7] Figure 7 is a block diagram showing examples of computer-readable media according to some embodiments of the present disclosure. Throughout the drawings, the same or similar reference numerals indicate the same or similar elements. [Modes for carrying out the invention]

[0013] The principles of this specification will be explained with reference to several examples. These examples are not intended to limit the scope of this specification, but are provided solely for illustrative purposes to help those skilled in the art understand and implement this specification. The examples described herein can be implemented in various ways other than those described below.

[0014] In the following description and claims, unless otherwise defined, all technical and scientific terms used herein have the same meanings as those generally understood by a person ordinary in the art to which this disclosure belongs.

[0015] In this specification, descriptions such as “one embodiment,” “embodiment,” and “exemplary embodiment” indicate that the described embodiment may include a particular function, structure, or feature, but not all embodiments are required to include such a particular function, structure, or feature. Furthermore, these expressions do not necessarily refer to the same embodiment. Also, if a particular function, structure, or characteristic is described in relation to an embodiment, it is assumed that the influence of that function, structure, or characteristic in relation to other embodiments, whether explicitly stated or not, is within the knowledge of those skilled in the art.

[0016] While terms such as "first," "second," etc., may be used to describe various elements, these elements are not limited by these terms. These terms are simply used to distinguish one element from another. For example, referring to the first element as the second element, or similarly referring to the second element as the first element, does not deviate from the scope of the examples. In this specification, the term "and / or" encompasses any combination of one or more of the terms described.

[0017] In this specification, when "at least one of the following: <list of two or more elements>" and "list of at least one or more elements" and similar expressions refer to lists of two or more elements connected by "and" or "or", it means at least one of any two elements, at least two or more elements, or at least all of the elements.

[0018] In this specification, unless expressly stated otherwise, performing a step "in response to A" does not mean that the step is performed immediately after the occurrence of "A," and that one or more steps may be included in between.

[0019] The terms used in this specification are for the sole purpose of describing particular embodiments and are not intended to limit the exemplary embodiments. Unless otherwise clearly indicated from the context, the singular forms "a", "an", and "the" used in this specification are intended to include the plural forms as well. Furthermore, the terms "comprise", "comprising", "include", "including", and / or "having" as used herein identify the presence of the described features, elements, and / or components, etc., but do not preclude the presence or addition of one or more other features, elements, components, and / or combinations thereof.

[0020] In the present application, the term "circuit" refers to (a) a circuit implementation consisting only of hardware (such as an implementation by only analog circuits and / or digital circuits), (b) a combination of a hardware circuit and software. For example (where applicable), (i) a combination of analog and / or digital hardware circuits and software / firmware, and (ii) a combination of a part of a hardware processor and software (including a digital signal processor), software, and memory, which cooperate to cause a device such as a mobile phone or a server to execute various functions, (c) a hardware circuit and / or processor (such as a microprocessor or a part of a microprocessor) that requires software (such as firmware) to operate, and in which the software may not be present when not required for operation, may refer to any one or more or all of the above.

[0021] This definition of "circuit" applies to all uses of this term in this application, i.e., to all claims. For further example, the term "circuit" as used in this application includes not only a hardware circuit or processor (or more processors), but also a part of a hardware circuit or processor and its associated software and / or firmware implementation. The term "circuit" also includes, for example, a baseband integrated circuit or processor integrated circuit for a mobile device, or a similar integrated circuit in a server, cellular network device, or other computing or network device, as applicable to the elements of a particular claim.

[0022] In this specification, “communication network” refers to a network conforming to an appropriate communication standard such as New Radio (NR), Long-Term Evolution (LTE), LTE-Advanced (LTE-A), Wideband Code Division Multiple Access (WCDMA®), High-Speed ​​Packet Access (HSPA), and Narrowband Internet of Things (NB-IoT). Furthermore, communication between terminal devices and network devices in a communication network includes, but is not limited to, first-generation (1G), second-generation (2G), 2.5G, 2.75G, third-generation (3G), fourth-generation (4G), 4.5G, fifth-generation (5G) communication protocols, and / or other protocols currently known or to be developed in the future. Embodiments of this disclosure are applicable to a variety of communication systems. Given the rapid development of communication technology, there will naturally be future communication technologies and systems to which this disclosure will be embodied. The scope of this disclosure is not limited to the aforementioned systems.

[0023] In this specification, “Network equipment” refers to a node on a communication network from which terminal devices access the network and receive services. Network equipment may also refer to, for example, base stations (BS), access points (AP), node B (NodeB, or NB), evolved node B (eNodeB, or eNB), NR node B (also called gNB), remote radio units (RRU), radio headers (RH), remote radio heads (RRH), relays, integrated access backhaul (IAB) nodes, low-power nodes such as femto and pico, satellite network equipment, non-terrestrial network (NTN) or non-terrestrial network equipment such as low orbit (LEO) satellites and geostationary (GEO) satellites, aircraft network equipment, etc., depending on the terminology and technology applied. In some embodiments, the radio access network (RAN) partitioning architecture includes centralized units (CUs) and distributed units (DUs) in an IAB donor node. An IAB node includes a mobile terminal (IAB-MT) portion that behaves like a UE to the parent node and a DU portion that behaves like a base station to the next IAB node.

[0024] The term "terminal device" refers to any end device capable of wireless communication. While these are merely examples, terminal devices may also be called communication devices, user equipment (UE), subscriber stations (SS), mobile subscriber stations, mobile stations (MS), or access terminals (AT). Terminal devices include, but are not limited to, mobile phones, mobile phone terminals, smartphones, VoIP phones, wireless local loop phones, tablet devices, wearable devices, PDAs, portable computers, desktop computers, image capture terminals such as digital cameras, game terminals, music storage and playback devices, in-vehicle wireless terminals, wireless endpoints, mobile stations, laptop embedded devices (LEEs), laptop mounted devices (LMEs), USB dongles, smart devices, wireless customer premises equipment (CPEs), Internet of Things (IoT) devices, watches and other wearables, head-mounted displays (HMDs), vehicles, drones, medical devices and applications (e.g., remote surgery), industrial devices and applications (e.g., robots and / or other wireless devices operating in industrial and / or automated processing chain environments), consumer electronics, devices operating on commercial and / or industrial wireless networks, and other similar devices. Terminal devices may also correspond to the mobile terminal (MT) portion of an IAB node (such as a relay node). In the following description, the terms “terminal device,” “communication device,” “terminal,” “user device,” and “UE” may be used interchangeably.

[0025] In this specification, “resource,” “transmit resource,” “resource block,” “physical resource block” (PRB), “uplink resource,” or “downlink resource” may refer to any resource for performing communication, such as resources for performing communication between a terminal device and a network device, and including resources in the time domain, resources in the frequency domain, resources in the spatial domain, resources in the code domain, or other resources that enable communication. Hereinafter, unless otherwise specified, resources in both the frequency domain and the time domain will be used as examples of transmit resources in some embodiments of this specification. Note that the embodiments of this specification are similarly applicable to other resources in other domains.

[0026] In CBRA procedures supported by 5G NR, time-domain resources for ROs may be RRC-configured, for example, by prach-ConfigurationIndex (within rach-ConfigGeneric). prach-ConfigurationIndex acts as an indicator of a row in a predefined or specified table. The terminal device uses the parameters indicated by prach-ConfigurationIndex to determine the PRACH preamble format and apply the predefined or specified procedure to discover ROs within the time domain.

[0027] In the frequency domain, the parameters msg1-FrequencyStart and msg1-FDM, configured in RACH-ConfigGeneric, indicate the offset of the lowest RO in the frequency domain and the number of ROs multiplexed in the frequency domain for each time instance, respectively. The number of resource blocks occupied per RO (expressed as the number of RBs in PUSCH) is predefined or specified depending on the configured preamble length and subcarrier interval of PRACH and PUSCH.

[0028] In some mechanisms, the terminal device derives a mapping between the SSB index and the determined RO, and understands the RO associated with the SSB index selected in a preliminary stage before the start of the RACH procedure. Because various SSB indices beamform in different directions within the cell, selecting the wrong SSB index can lead to the failure of the RACH procedure.

[0029] In some mechanisms, the parameter ssb-perRACH-OccasionAndCB-PreamblesPerSSB is set within RACH-ConfigCommon, providing two pieces of information: (i) the number of SSB indices per RO, and (ii) the number of collision preambles per SSB index. When a terminal device obtains this information, it sequentially maps the SSB indices to the time-frequency grid of the RO (determined in the aforementioned manner) in ascending order of frequency resource index and time resource index for ROs in a single PRACH slot and for ROs in multiple PRACH slots.

[0030] In some mechanisms, a terminal device attempting access selects one of the one or more ROs associated with a selected SSB beam and either sends a Msg1 message or transmits its preamble. When a preamble is detected, the network device obtains two elements: a preamble identifier (ID), such as a Random Access Preamble ID (RAPID), and the RO from which the preamble was transmitted. The network device uses these two elements to determine that an access attempt has occurred and to design a corresponding response to the preamble detection. This response is transmitted in the form of a Msg2 RA response (RAR).

[0031] The Msg2 RAR contains an uplink (UL) grant that schedules the Msg3 transmission and is transmitted over a physical downlink shared channel (PDSCH) scheduled by downlink control information (DCI) that is cyclically redundancy checked (CRC) scrambled by a bit string called a Random Access Radio Network Temporary Identifier (RA-RNTI). The RA-RNTI is generated according to a predefined specification. More precisely, the RA-RNTI value is calculated as a function of the PRACH opportunities in which the network device correctly detects one or more preambles, as shown in (1) below. RA-RNTI=1 + s_id + 14×t_id + 14×80×f_id + 14×80×8×ul_carrier_id (1) Here, s_id is the index of the first orthogonal frequency division multiplexing (OFDM) symbol of the physical random access channel (PRACH) opportunity (0 ≤ s_id < 14), and t_id is the index of the first slot of the PRACH opportunity in the system frame (0 ≤ t_id < 80). The subcarrier interval that determines t_id is based on a predefined or specified value of μ, where μ can be μ = {0, 1, 2, 3} and μ = {5, 6}. f_id is the index of the PRACH opportunity in the frequency domain (0 ≤ f_id < 8), and ul_carrier_id is the UL carrier used for random access preamble transmission (normal uplink (NUL) carriers are 0, auxiliary uplink (SUL) carriers are 1).

[0032] In other words, RA-RNTI is an indicator for determining whether a terminal device is interested in the contents of the Msg2 RAR. If the contents of the Msg2 RAR are of interest, the terminal device recognizes the contents of the RAR. The contents of the RAR include a Media Access Control (MAC) protocol data unit (PDU), which transmits a number of sub-PDUs equal to or greater than the number of correctly detected preambles via the RO associated with RA-RNTI. In fact, if a network device scrambles the CRC of a physical downlink control channel (PDCCH) with RA-RNTI and schedules the transmission of a PDSCH carrying the RAR, RA-RNTI may be addressed to multiple terminal devices. For example, multiple terminal devices may decode a PDCCH scrambled with the same RA-RNTI. In this specification, each sub-PDU of a MAC PDU transmits the RAP ID of the corresponding correctly detected preamble and, via the RO associated with RA-RNTI, the actual RAR contents (e.g., the UL grant of Msg3) for the terminal device that transmitted that preamble.

[0033] PRACH repetitions (also referred to in this application as multiple PRACH transmissions) are specified for 5G NR. As an example, a single RO group may be defined as a set of valid ROs used to perform multiple PRACH repetitions. Whether an RO is valid may be determined using predefined rules.

[0034] For multiple PRACH transmissions, an "RO group" is assumed for multiple PRACH transmissions with separate preambles via a shared RO, and / or for multiple PRACH transmissions via separate ROs. One RO group consists of ROs that are valid for a certain number of multiple PRACH transmissions.

[0035] For example, all ROs within a single RO group are associated with the same SSB. Another example is shared or separated RO / preamble, which means whether the RO / preamble is shared or separated with respect to a single PRACH transmission.

[0036] Furthermore, how to address conflicts between valid ROs for multiple PRACH transmissions and existing ROs for legacy single PRACH transmissions, as well as other features such as 2-step RACH, will be discussed.

[0037] Based on the definition of a valid RO, additional verification rules can be applied to ROs used for PRACH repetitions. These additional verification rules address conflicts between valid ROs for multiple PRACH transmissions and existing ROs for legacy single PRACH transmissions, as well as features such as 2-step RACH. In particular, if one RO in a group of ROs for PRACH repetitions occurs in the same time instance (but at a different frequency) as at least one RO reserved for other applications, and the two ROs are mapped to different SSB indices (i.e., different gNB beams), and the gNB can only activate one beam per time instance (e.g., some FR2 implementations using gNBs that only support analog beamforming), then in this situation the gNB will not be able to receive the preamble transmitted on both ROs. This is also referred to here as an SSB index conflict. Specifically, if the gNB prioritizes at least one other RO, the PRACH transmission on the RO for PRACH repetitions is lost. Therefore, as an additional validation rule, a PRACH transmission from one RO in a group of ROs for PRACH repetitions occurring in the same time instance as at least one other RO can be discarded, and the UE can send fewer PRACH repetitions.

[0038] In some mechanisms, the calculation of RA-RNTI for multiple PRACH transmissions is related to the design of the RAR window. For example, some options for RA-RNTI calculation are as follows: Option 1: If there are multiple RA-RNTI candidates within a single RAR window, i.e., the UE attempts to detect DCI format 1_0 with a scrambled CRC in any of the multiple RA-RNTI candidates during the RAR window period. Option 2: If there is a single RA-RNTI within a single RAR window, i.e., the UE attempts to detect DCI format 1_0 with the CRC scrambled by the corresponding RA-RNTI during the RAR window period. Option 2-1: The corresponding RA-RNTI is calculated based on RO for the last PRACH iteration. Option 2-2: The corresponding RA-RNTI is calculated based on RO for the first PRACH iteration. • Option 2-3: The corresponding RA-RNTI is calculated based on RO for predefined PRACH iterations, excluding the first and last ones. • Option 2-4: The corresponding RA-RNTI is calculated as a function of the sequence of ROs used in multiple PRACH transmissions.

[0039] Option 1 indicates that the UE should assume that multiple RA-RNTI candidates exist within a single RAR window. This can occur when multiple RAR windows are used and there is overlap between them.

[0040] Option 2 indicates that the UE expects only one RA-RNTI candidate within a single RAR window, eliminating the need for the UE to anticipate multiple RA-RNTI candidates and thus avoiding increased complexity during RAR reception. Option 2 is valid for single-RAR window designs.

[0041] In particular, Option 2 aims to define a single RA-RNTI for an RO group. However, there remains an unresolved issue, even when applicable, regarding whether ROs discarded due to SSB index collisions should be considered in the RA-RNTI evaluation. For example, in Option 2-1, if the last repeat of PRACH is discarded in a group with four repeats, the last PRACH of the repeat becomes the third repeat of PRACH within that group, and it is necessary to decide whether the RA-RNTI should be calculated based on the third RO or the fourth RO. Similar examples can be seen in Options 2-2, 2-3, and 2-4.

[0042] Several mechanisms related to the CBRA procedure are described. However, these mechanisms need improvement. On the one hand, conditions are needed for discarding PRACH transmissions in the event of an SSB index collision, particularly conditions regarding the allocation of the time / frequency domain of the colliding ROs and conditions regarding the colliding SSB indices. On the other hand, a method for calculating RA-RNTI when one or more ROs in an RO group that should be used for RA-RNTI calculation are discarded needs to be provided.

[0043] The embodiments herein propose a method for RO discarding and RA-RNTI calculation in the presence of multiple PRACH transmissions. In this method, a device such as a UE determines that a PRACH transmission should be discarded at the first RO of an RO group if at least one condition is met. The device then transmits at least one PRACH transmission other than the one to be discarded at the RO of the RO group. In the context herein, when an RO is discarded, it means that no transmissions are made through that RO. When a PRACH transmission is discarded or is subject to discarding, it means that no PRACH is transmitted.

[0044] In this way, multiple PRACH transmissions and single PRACH transmissions can be received correctly, even if they occur in the same time instance and are mapped to different SSB indices. As mentioned earlier, SSB indices are typically beamformed in different directions, and therefore, if a gNB can beamform in only one direction in a single time instance, discarding PRACH transmissions by a UE performing multiple PRACH transmissions allows the gNB to beamform towards a UE performing a single PRACH transmission.

[0045] Figure 1 shows an example of a communication environment 100 in which an embodiment of the present disclosure can be implemented. In the communication environment 100, multiple communication devices, including the first device 110 and the second device 120, can communicate with each other.

[0046] In the example in Figure 1, the first device 110 includes a terminal device, and the second device 120 includes a network device that provides services to the terminal device. The serving area of ​​the second device 120 is called cell 102.

[0047] Please understand that the number of devices and their connections shown in Figure 1 are illustrative for illustrative purposes only and do not imply any limitation. The communication environment 100 may include any appropriate number of devices configured to carry out the embodiments described herein. Please understand that one or more additional devices may be located within cell 102, and one or more additional cells may be deployed within the communication environment 100, although these are not shown. Please note that the second device 120 is shown as a network device, but it may be a device other than a network device. The first device 110 is shown as a terminal device, but it may be a device other than a terminal device.

[0048] In the following, for the sake of clarity, we will describe several embodiments in which the first device 110 operates as a terminal device and the second device 120 operates as a network device. However, in some embodiments, the operations described in relation to the terminal device may be implemented in the network device or other devices, and the operations described in relation to the network device may be implemented in the terminal device or other devices.

[0049] In some embodiments, when the first device 110 is a terminal device and the second device 120 is a network device, the link from the second device 120 to the first device 110 is called a downlink (DL), and the link from the first device 110 to the second device 120 is called an uplink (UL). In a DL, the second device 120 is a transmitting (TX) device (or transmitter), and the first device 110 is a receiving (RX) device (or receiver). In a UL, the first device 110 is a TX device (transmitter), and the second device 120 is an RX device (receiver).

[0050] Communication in communication environment 100 is implemented according to an appropriate communication protocol, which includes, but is not limited to, cellular communication protocols such as first generation (1G), second generation (2G), third generation (3G), fourth generation (4G), fifth generation (5G), and sixth generation (6G), wireless local network communication protocols such as the Institute of Electrical and Electronics Engineers (IEEE) 802.11, and / or other protocols currently known or to be developed in the future. Furthermore, communication may optionally utilize appropriate wireless communication technologies, which include, but is not limited to, code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), frequency division duplexing (FDD), time division duplexing (TDD), multiple input multiple output (MIMO), orthogonal frequency division multiplexing (OFDM), discrete Fourier transform spread OFDM (DFT-s-OFDM), and other technologies currently known or to be developed in the future.

[0051] As mentioned above, 5G NR supports multiple CBRA procedures. Figure 2A shows an example of a signaling diagram for a 4-step RACH procedure. As shown in the figure, terminal devices such as UEs send a first message (called Msg1) to network devices such as gNBs. The first message includes a specific preamble. This first message is sent by the UE via a physical random access channel (PRACH) using a specific resource called a RACH opportunity (RO).

[0052] For example, the gNB sends a second message (called Msg2) to the UE. The second message contains a Random Access Response (RAR) message, such as a MAC RAR. The RAR contains the detected preamble ID, a time advance command, a temporal cell (TC)-RNTI, and a UL grant for sending a third message (called Msg3) over the physical uplink shared channel (PUSCH).

[0053] The UE can send a third message (e.g., Msg3) to the gNB. The third message may be an RRC request. For example, the UE might add a collision resolution ID and send Msg3 as a response to Msg2 via a scheduled PUSCH.

[0054] As an example, gNB sends a fourth message (called Msg4) to the UE. The fourth message may be the RRC setup. The fourth message contains a collision resolution message that includes a collision resolution ID. In this way, gNB sends a collision resolution message with a collision resolution ID.

[0055] Upon receiving Msg4, the UE may send an acknowledgment (ACK) on the physical uplink control channel (PUCCH) if the collision resolution ID is included in Msg4. Sending the ACK completes the four-step RACH. Note that there is a preliminary step before Msg1, which involves sending and receiving a synchronization signal block (SSB), i.e., a DL beam sweep, but this is not part of the formal RACH procedure. As a result of this preliminary step, the UE selects the index of the preferred SSB beam and decodes the associated physical broadcast channel (PBCH) to obtain the master information block (MIB), system information block (SIB), etc. This index is also used by the UE to identify a suitable RO for preamble transmission (Msg1), according to the SSB-RO mapping implicitly communicated by the system information block type 1 (SIB1).

[0056] Similar to the four-step RACH described above, the UE and gNB can perform a two-step RACH. In a two-step RACH, Msg1 and Msg3 are merged into MsgA, and sent without waiting for feedback from the UE (traditionally Msg2) in the meantime. Similarly, the gNB merges Msg2 and Msg4 into MsgB.

[0057] As mentioned above, Msg1 is sent by the UE via PRACH using RO. In some embodiments, time-domain resources are configured for RO using RRC. Figure 2B shows an example of determining the time-domain resources for RO. In the embodiment described in Figure 2B, we assume that the prac-ConfigurationIndex is 251. As shown in the figure, this specified index allows the UE to determine that preamble format C2 should be used. The UE may further determine that RO is assigned to a system frame number (SFN), such as n_SFN, where n_SFN mod1 is equal to 0 (i.e., all SFN numbers are valid). Alternatively, or additionally, in some embodiments, the UE determines that within each determined SFN, RO is assigned to subframe numbers 2 and 7.

[0058] Furthermore, in some embodiments, the UE determines that within each determined subframe, the remaining parameters of the row under consideration indicate that the RO starts with symbol numbers 0, 6, 14, and 20. The symbol numbers are counted sequentially regardless of the number of slots within the subframe, which depends on the subcarrier interval set for PRACH.

[0059] UE may also determine that the duration of RO is 6 symbols (although the actual duration in preamble form may be shorter).

[0060] In some embodiments, it is necessary to verify the validity of the determined RO. An RO may be determined to be valid if it is located within a UL symbol, or if it is located within a flexible symbol, if there is a sufficient interval after the last SSB / DL symbol.

[0061] In some embodiments, the mapping of SSB indices to determined ROs can be configured. Figure 2C shows an example of SSB-to-RO mapping. In the example in Figure 2C, the SSB-to-RO mapping is configured with Prach-ConfigurationIndex251 and the UL / DL setting DDDSU. As shown in the figure, the valid ROs within a single frame are determined. Additional settings can also be configured. Examples of additional settings include, but are not limited to, the DDDSU slot structure, Msg1 frequency division multiplexing (FDM) being equal to 2, and ssb-perRACH-OccasionAndCB-PreamblesPerSSB being 1 / 2. Based on the settings, two ROs are multiplexed in the frequency domain (Msg1-FDM is equal to 2), and any two FDM ROs are mapped to the same SSB index (ssb-perRACH-OccasionAndCB-PreamblesPerSSB is equal to 1 / 2).

[0062] In some embodiments, enhanced UL coverage is provided. For example, multiple PRACH transmissions are performed on the same beam in a four-step procedure, or PRACH transmissions are performed on different beams in a four-step RACH procedure. As an example, PRACH enhancement targets frequency band 2 (FR2), and may also be applied to frequency band 1 (FR1) where applicable. As another example, PRACH enhancement targets short PRACH formats, and may also be applied to other formats where applicable.

[0063] Figure 2D shows an example of discarding an RO within an RO group. In the example in Figure 2D, the second RO in the RO group is discarded because its SSB index is different from the SSB index of the second RO in the RO group intended for single PRACH transmission. The SSB indices in Figure 2D are distinguished by different patterns.

[0064] As shown in the diagram, a PRACH transmission from the second RO in an RO group for repeated PRACH transmissions is discarded because the SSB index of that RO is different from the SSB index of the second RO for a single PRACH transmission performed in the same time instance. The problem in Figure 2D should be understood as occurring when two higher-level ROs are configured with different RACH settings (e.g., 4-step and 2-step RACH, or additional RACH and legacy RACH).

[0065] As described later, some embodiments of this disclosure propose solutions for RO discarding and RA-RNTI calculation in terminal devices. The proposed solutions are applicable to multiple PRACH transmissions. They are also applicable when at least one RO in an RO group occurs in the same time instance, but at least one of the other ROs is at a different frequency position. At least one of the other ROs does not belong to that RO group and is mapped to a different SSB index than the SSB index to which the ROs in that RO group are mapped.

[0066] Several embodiments will be described in detail with reference to Figures 3 to 5.

[0067] Figure 3 shows a flowchart of Method 300 as implemented in the First Apparatus according to some embodiments of the present disclosure. For convenience of explanation, Method 300 will be described in terms of the First Apparatus 110 in Figure 1.

[0068] In block 310, the first device 110 determines that the first PRACH transmission should be discarded in the first RACH opportunity (RO) of the RO group, based on the fulfillment of at least one condition. The terms “first,” “second,” etc., used herein are used solely to distinguish different elements and are not intended to specify their order. In this specification, the term “RO group” may refer to the set of ROs that the first device 110 uses to transmit a repetition of PRACH.

[0069] In this specification, if the first device 110 determines that a PRACH transmission in the RO should be discarded, the corresponding RO may be referred to as a "discarded RO." The corresponding PRACH transmission may also be referred to as a "discarded PRACH transmission." For example, the term "discarded RO" may refer to an RO whose corresponding PRACH transmission the first device 110 has determined to discard.

[0070] In some embodiments, RO groups may be configured as RRCs. For example, the time resources of an RO group can be determined or configured based on the procedure described with respect to Figure 2B. Furthermore, the mapping between the SSB index and the determined ROs within the RO group can be determined in a similar manner to the illustrative mapping in Figure 2C.

[0071] In some embodiments, at least one condition may include the first condition that the first RO completely overlaps in time with the second RO. The first RO and the second RO may be associated with different RACH settings and located at different frequency positions. In some embodiments, the first RO and the second RO may be mapped to different SSB indices. If the second RO and the first RO completely overlap in time with different RACH settings (e.g., for single PRACH transmission), then the first condition is satisfied for the first RO and the second RO mapped to different SSB indices.

[0072] In some embodiments, at least one condition may include a second condition that the first RO partially overlaps in time with the second RO. The second condition is satisfied if the first RO partially overlaps in time with the second RO (and the first and second ROs are mapped to different SSB indices).

[0073] For example, if two settings, the first RO and the second RO, use two different PRACH setting indices, and the number of ROs per slot in the two "parallel" settings is not the same, the first RO may partially overlap with the second RO in time for multiple OFDM symbols.

[0074] In some embodiments, the second condition may be met if the first RO temporally overlaps with the second RO in at least several OFDM symbols. For example, if the first device 110 determines that several OFDM symbols are shared by the first and second ROs, the first device 110 may determine that the second condition is met. For example, several OFDM symbols shared by two ROs are considered to be a partial overlap between the two ROs. For example, if several OFDM symbols are shared by two ROs, the second condition is met.

[0075] The number of OFDM symbols is predetermined by the first device or set by the second device. For example, the second device 120 can notify the amount of overlap in the number of OFDM symbols that the first RO is considered to partially overlap with the second RO.

[0076] In some embodiments, the second device 120 may notify of a partial overlap between two ROs. For example, the second device 120 sends a notification to the first device 110 indicating that the first RO partially overlaps with the second RO in time. For example, if there is a number of OFDM symbols shared by the two ROs that are considered to partially overlap, the second device 120 notifies the first device 110 of such a partial overlap. When the first device 110 receives a notification from the second device 120 indicating a partial overlap, the first device 110 determines that the second condition is met.

[0077] In some embodiments, at least one condition may include a third condition, that the first RO occurs in the same slot as the second RO. For example, if the first RO occurs in the same slot as the second RO, the third condition is satisfied even if the first and second ROs do not actually overlap in time (and the first and second ROs are mapped to different SSB indices).

[0078] In some embodiments, if the first, second, or third condition is met, the first device 110 determines whether the first RO has a lower priority than the second RO. If the first RO has a lower priority, the first device 110 determines that the PRACH transmission should be discarded at the first RO. For example, ROs with different RACH settings are assigned different priority indices. In the event of a conflict between the first and second ROs (i.e., if the first, second, or third condition is met), the first device 110 decides to discard based on the priority assignment. For example, the first device 110 discards the PRACH transmission corresponding to the lower priority RO.

[0079] In some embodiments, the first device 110 determines which of the first and second ROs has lower priority based on their priority indices. In some embodiments, the priority indices are predefined or set or notified by the second device 120. For example, the priority indices of the ROs may be explicitly set or specified.

[0080] Alternatively, or additionally, in some embodiments, the priority index may be determined based on the SSB index associated with the first RO and the second RO. For example, the priority index of an RO may be implicitly determined based on a list of prioritized SSB indices, such as a list of prioritized SSB beam indices. The list of prioritized SSB indices or prioritized SSB beam indices may be predefined. Alternatively, the list of prioritized SSB indices or prioritized SSB beam indices may be set or notified by the second instrument 120.

[0081] As an example, the first device 110 determines a list of prioritized SSB indices. Based on the list of prioritized SSB indices, the first device 110 determines the priority levels of the SSB indices associated with the first and second ROs. Based on the priority levels of the SSB indices associated with the first and second ROs, the first device 110 can determine the priority index.

[0082] Alternatively, or additionally, in some embodiments, the first device 110 may determine the priority index of the first and second ROs based on the preamble index associated with the first and second ROs. The associated preamble index may be a list of prioritized preamble indexes having a set or specified preamble format. The list of prioritized preamble indexes may be predefined. Alternatively, the list of prioritized preamble indexes may be set or notified by the second device 120.

[0083] As an example, the first device 110 determines a list of prioritized preamble indices. Based on the list of prioritized preamble indices, the first device 110 determines the priority levels of the preamble indices associated with the first and second ROs. Based on the priority levels of the preamble indices associated with the first and second ROs, the first device 110 determines the priority index.

[0084] In some embodiments, at least one condition may include a fourth condition that the second device 120 cannot receive PRACH transmissions simultaneously at the first and second ROs if the first RO and the second RO are associated with different synchronization signal block indices, and at least one of the first, second, or third conditions is met. For example, the second device 120 may or may not have the capability to process multiple SSB indices within the same time instance. Even if at least one condition is predetermined, discarding may be further conditioned on whether the second device 120 has the capability or not to process multiple SSB indices within the same time instance. Capability information transmitted by the second device 120 to the first device 110 may include a notification that the second device 120 does not have processing capability. Capability information transmitted by the second device 120 to the first device 110 may include a notification regarding the processing capability of the second device 120. In this case, the first device 110 decides to discard the first RO based on the notification regarding processing capability.

[0085] In some embodiments, at least one condition may include a fifth condition relating to the SSB indices associated with the first and second ROs, which is a condition that the first and second ROs overlap in time based on the first, second, or third condition. For example, the fifth condition may include a condition that a predetermined pair of SSB indices is mapped to the first and second ROs. For example, if a particular pair of SSB indices is mapped to the first and second ROs, the first device 110 discards the PRACH transmission. For example, if a particular pair of SSB indices is mapped to the first and second ROs, the fifth condition is satisfied.

[0086] In some embodiments, at least one condition includes a sixth condition relating to the frequency allocation of the first and second ROs, wherein the first and second ROs overlap in time based on the first, second, or third condition. For example, the sixth condition may include a condition that the first and second ROs are frequency-separated by a distance less than or equal to a threshold frequency distance. If the first and second ROs are frequency-separated by a distance less than or equal to the threshold, the fifth condition is met. In such a situation, the first device 110 may discard the PRACH transmission.

[0087] An example of at least one condition has been described. In some embodiments, at least one condition is predetermined. Alternatively, or additionally, in some embodiments, at least one condition is set or instructed from the second device 120. For example, at least one condition may be indicated from the second device 120 to the first device 110 via higher layer signaling. The term “high layer” used here is also called “higher layer.”

[0088] In some embodiments, the second device 120 sends a trigger notification to the first device 110 in which at least one condition is met. The first device 110 receives this trigger notification. For example, the conditions are predetermined, and the second device 120 notifies a trigger in which at least one condition is met.

[0089] At least one example of conditions has already been described. These conditions can be used individually or in any suitable combination. Please understand that the conditions exemplified are for illustrative purposes only and do not imply any limitation. Any other suitable conditions may also be applied, and the scope of this disclosure is not limited in this respect.

[0090] These conditions enable the first device 110 to make more appropriate decisions regarding the discarding of PRACH transmissions in RO. Therefore, PRACH transmissions can be discarded when SSB index collisions occur. In particular, ROs can be discarded in the time domain or frequency domain allocation of colliding ROs and / or colliding SSB indices, thereby discarding PRACH transmissions.

[0091] In block 320, the first device 110 transmits at least one second PRACH transmission in the RO within the RO group, other than the first PRACH transmission that is discarded. This ensures that multiple RACH transmissions and a single RACH transmission are received correctly.

[0092] In one embodiment, the first device 110 calculates RA-RNTI based on one or more ROs within an RO group. For example, the first device 110 determines one or more ROs in an RO group for the calculation of RA-RNTI. As an example, the one or more ROs used to calculate RA-RNTI are predefined. In other examples, the one or more ROs used to calculate RA-RNTI may be set or notified by the second device 120. For example, which one or more ROs in an RO group to use for the calculation of RA-RNTI may be based on a setting or notification from the second device 120 via upper-level signaling.

[0093] In some embodiments, one or more ROs used in the RA-RNTI calculation are independent of the first RO. For example, whether or not one or more ROs are used in the RA-RNTI calculation is independent of whether or not the corresponding PRACH transmission is discarded via one or more ROs, i.e., whether or not at least one condition is met.

[0094] In some embodiments, one or more ROs used in the calculation of RA-RNTI are associated with a first RO. For example, whether one or more ROs are used in the calculation of RA-RNTI is associated with, or conditioned on, whether the corresponding PRACH transmissions via one or more ROs are discarded.

[0095] In some embodiments, one or more ROs used in the RA-RNTI calculation may include a first RO. For example, a single RO, such as the first RO, is used in the RA-RNTI calculation. In one example, the first RO is retained as part of one or more ROs used in the RA-RNTI calculation if at least one condition is met. In other examples, the first RO is not retained as part of one or more ROs used in the RA-RNTI calculation if at least one condition is met.

[0096] Alternatively, in some embodiments, one or more ROs used in the calculation of RA-RNTI may include ROs whose time interval from a first RO is less than or equal to a threshold interval. This threshold interval is predefined or set. For example, an RO that is temporally close to the first RO may be used in the calculation of RA-RNTI if at least one condition is met. If the first distance to an RO prior to the first RO is the same as the second distance to an RO adjacent to the first RO, then either an RO prior to the first RO or an RO adjacent to the first RO may be determined as the RO for calculating RA-RNTI.

[0097] In some embodiments, one or more ROs may include one or more fallback ROs for calculating RA-RNTI. For example, the first device 110 determines the fallback ROs for calculating RA-RNTI within the RO group. Within the RO group, iterations of PRACH may be transmitted. For example, the fallback ROs may be predefined. In another example, the fallback ROs may be set or notified by the second device 120. Specifically, the fallback RO is the first RO in the RO group, while the last RO in the RO group is one or more ROs used for calculating RA-RNTI. If at least one condition is met for the last RO, RA-RNTI is calculated via the fallback ROs; that is, the fallback ROs are used for calculating RA-RNTI.

[0098] Several examples of using a single RO for RA-RNTI calculation have been described above. In some embodiments, multiple ROs may be used for RA-RNTI calculation. For example, the first device 110 determines multiple ROs within an RO group that are available for RA-RNTI calculation. These multiple ROs include the first RO. The first device 110 can then determine other ROs from among the multiple ROs other than the first RO in order to calculate RA-RNTI.

[0099] As another example, one or more ROs for calculating RA-RNTI are all ROs in an RO group that do not satisfy at least one condition. For example, if an RO group consists of four ROs and all four of these ROs are used in calculating RA-RNTI (i.e., four ROs become one or more ROs for calculating RA-RNTI), and the PRACH transmission of the last of the four ROs is discarded (i.e., at least one condition is satisfied in the last RO), then one or more ROs for calculating RA-RNTI will be the first three ROs in the group of four. Please understand that the above figures are for illustrative purposes only and do not imply any limitation.

[0100] In this way, the first device 110 can calculate RA-RNTI using one or more ROs. Therefore, even if the ROs used in the calculation of RA-RNTI are discarded, RA-RNTI can still be calculated. Consequently, the second device 120 can correctly receive multiple PRACH transmissions and single PRACH transmissions. Furthermore, the first device 110 and the second device 120 can calculate RA-RNTI and arrive at the same calculation result. Moreover, the first device 110 and the second device 120 can have a common understanding of which PRACH transmissions were discarded, i.e., which ROs satisfy at least one condition.

[0101] Examples of RO disposal and RA-RNTI calculation are described with reference to Figure 3. Further examples are described in relation to Figure 4, which shows signaling diagram 400 for RO disposal and RA-RNTI calculation according to some examples of the present disclosure. For illustrative purposes, signaling diagram 400 is described with reference to Figure 1.

[0102] In the description of Figure 4, the CBRA procedure is shown as a 4-step RACH procedure. It should be understood that the embodiments described for the 4-step RACH procedure are also applicable to the 2-step RACH procedure. The scope of this application is not limited in this respect.

[0103] As shown in the figure, the second device 120 transmits the resource settings for PRACH repetition to the first device 110 (410). The first device 110 receives the settings (415). For example, the settings are transmitted via a higher layer (410). The settings include parameters for determining or deriving the RACH opportunity and preamble for transmitting PRACH repetitions.

[0104] The second device 120 sends a notification to the first device 110 indicating that it lacks processing capacity (420). The first device 110 receives the notification that it lacks processing capacity (425). This notification of lack of processing capacity indicates that the second device 120 cannot process multiple SSB indexes within the same time instance. Note that this notification of lack of processing capacity is merely an example, and it should be understood that the second device may also have the capacity to process multiple SSB indexes within the same time instance.

[0105] In some embodiments, the notification of insufficient processing capacity may be the capacity information of the second device 120. For example, the capacity information of the second device 120 may indicate that the second device 120 cannot process multiple SSB indexes within the same time instance. By notifying of insufficient processing capacity in the capacity information, the loss of generality of the notification of insufficient processing capacity can be mitigated.

[0106] Alternatively, or additionally, in some embodiments, notification of insufficient processing capacity may be implicitly conveyed by not notifying anything, such as an empty field. The first device 110 assumes that such processing capacity is unavailable as its default behavior when no notification is given or when an empty field is notified.

[0107] Such notifications regarding processing capacity, or notifications indicating a lack of processing capacity, essentially inform the first device 110 whether or not to discard PRACH transmissions within a particular RO if the particular RO is frequency multiplexed in the same time instance as other ROs mapped to other SSB indices, i.e., if at least one condition is met in the particular RO. In this way, the first device 110 can decide whether or not to discard PRACH transmissions in a particular RO based on the notifications regarding processing capacity or notifications indicating a lack of processing capacity.

[0108] In some embodiments, the second device 120 transmits an RO priority notification to the first device 110 (430). The first device 110 receives the RO priority notification (435).

[0109] In the example in Figure 4, assume that the second device 120 notifies the RO for repeated PRACH transmissions of a second priority or lower priority. For RO for single PRACH transmissions, a first priority or higher priority may be assigned. Without loss of generality, RO for repeated PRACH transmissions may be assigned a first priority or higher priority.

[0110] Alternatively, in some embodiments, the second device 120 may not notify the priority via signaling. Instead, the RO priority may be hardcoded into the specification. For example, the RO for PRACH repetitions may be predefined or configured to have a low or high priority.

[0111] The first device 110 determines the RO group (440) based on the settings received (415) from the second device 120. Here, "RO group" refers to a set of ROs that the first device 110 uses to transmit repeated PRACH messages.

[0112] The first device 110 determines that an RO within the RO group (referred to as the first RO) overlaps in time with another RO (referred to as the second RO) that is mapped to a different SSB index than the SSB index to which the first RO is mapped (445).

[0113] In some embodiments, the second RO and the corresponding mapping may be determined by the first device 110 via additional configuration of RACH resources. This additional configuration may be the configuration of a RACH resource for a single PRACH transmission.

[0114] The first device 110 decides to discard the PRACH transmission at the first RO in the RO group if at least one condition is met (450). Therefore, based on this decision, the first device 110 discards the PRACH transmission at the first RO. The at least one condition may be any suitable condition described with respect to Figure 3, or any other suitable condition not described herein.

[0115] In some embodiments, the discarding of a PRACH transmission in the first RO is determined based on a setting or notification from the second device 120. For example, if the second device 120 notifies that the RO for repeating PRACH has a second priority or a lower priority, the first device 110 discards the corresponding PRACH transmission.

[0116] Alternatively, in some exemplary embodiments, the priority of ROs for PRACH repetitions is implicitly or explicitly (hardcoded) in the specification. For example, duplicate ROs for PRACH repetitions are discarded or retained, eliminating the need for configuration or notification. This reduces signaling overhead.

[0117] In some embodiments, the first device 110 sends a PRACH repetition to the second device 120 for ROs in the RO group excluding discarded ROs (455). The second device 120 receives the PRACH repetition (460). Here, the term "discarded RO" refers to an RO for which the first device 110 has determined to discard the corresponding PRACH transmission.

[0118] In some embodiments, the first device 110 calculates RA-RNTI based on one or more ROs (465). For example, the first device 110 calculates RA-RNTI based on discarded ROs from which PRACH transmissions were discarded (465). In another example, the first device 110 calculates RA-RNTI based on multiple ROs from the RO group to which the discarded RO belongs (465).

[0119] In some embodiments, the second device 120 sends a DCI to the first device 110 to schedule the subsequent Msg2 (470). Msg2 is CRC scrambled by the calculated (465)RA-RNTI. The first device 110 can receive the DCI (475). The first device 110 can perform a RACH procedure based on the DCI. The RACH procedure may be a four-step RACH procedure as shown in Figure 2A. Alternatively, the RACH procedure may be a two-step RACH procedure.

[0120] By using the RO discarding and RA-RNTI calculations described herein, the second device 120 can correctly receive multiple PRACH transmissions and single PRACH transmissions.

[0121] Figure 5 is a flowchart showing an example of Method 500 implemented in a second apparatus according to some embodiments of the present disclosure. For convenience of explanation, Method 500 will be described in terms of the second apparatus 120 in Figure 1.

[0122] In block 510, the second device 120 determines that the first PRACH transmission should be discarded by the first device at the first RO of the RO group, based on the fact that at least one condition is met.

[0123] In block 520, the second device 120 receives from the first device 110 at least one second PRACH transmission other than the first PRACH transmission which is to be discarded in the RO of the RO group.

[0124] In some embodiments, at least one condition includes at least one of the following: a first condition that the first RO completely overlaps in time with the second RO; a second condition that the first RO partially overlaps in time with the second RO; or a third condition that the first RO occurs in the same slot as the second RO.

[0125] In some embodiments, the second device 120 determines that the first, second, or third condition is met. Then, based on the determination that the first RO has a lower priority than the second RO, the second device 120 determines that the PRACH transmission should be discarded at the first RO.

[0126] In some embodiments, determining that the first RO has a lower priority than the second RO may be based on the priority index of the first and second ROs.

[0127] In some embodiments, the priority index is either predefined or set or notified by a second device.

[0128] In some embodiments, the second device 120 determines that the first RO temporally overlaps with the second RO in at least several OFDM symbols. Furthermore, the second device 120 determines that the second condition is met.

[0129] In some embodiments, the number of OFDM symbols is predetermined by the first device or set by the second device.

[0130] In some embodiments, at least one condition includes a fourth condition that the second device cannot receive PRACH transmissions at the first and second ROs if the first RO and the second RO are associated with different synchronization signal block indices and at least one of the first, second, or third conditions is met.

[0131] In some embodiments, at least one condition further includes at least one of the following: a fifth condition relating to the synchronization signal block indices associated with the first and second ROs, or a sixth condition relating to the frequency allocation of the first and second ROs, i.e., the first and second ROs overlap in time based on the first, second, or third condition.

[0132] In some embodiments, at least one of the first, second, third, fifth, or sixth conditions further requires that the first and second ROs are mapped to different synchronization signal block indices.

[0133] In some embodiments, the second apparatus 120 can calculate RA-RNTI based on one or more ROs in the RO group.

[0134] In some embodiments, the second apparatus 120 determines one or more ROs in an RO group for the calculation of RA-RNTI, and one or more ROs in the RO group include a first RO.

[0135] In some embodiments, the first RO is retained as part of one or more ROs if at least one condition is met.

[0136] In some embodiments, the first RO is not retained as part of one or more ROs if at least one condition is met.

[0137] In some embodiments, one or more ROs include one or more fallback ROs for RA-RNTI calculations.

[0138] By using method 500, the second device 120 can also calculate RA-RNTI and arrive at the same calculation result as the first device 110. Furthermore, the first device 110 and the second device 120 can have a common understanding of which PRACH transmissions will be discarded.

[0139] [Examples of devices, equipment, and media] In some embodiments, a first apparatus (e.g., first apparatus 110 in Figure 1) capable of performing any of the methods 300 may include means for performing each operation of the methods 300. These means can be implemented in any suitable form. For example, the means can be implemented as a circuit configuration or as a software module. The first apparatus can be implemented as or included within the first apparatus 110 in Figure 1.

[0140] In some embodiments, the first device includes means for determining whether a physical random access channel (PRACH) transmission should be discarded in a group of ROs of a random access channel (RACH) opportunity (RO) based on the satisfaction of at least one condition, and means for transmitting at least one PRACH transmission other than the one to be discarded in the RO of the RO group.

[0141] In some embodiments, at least one condition includes at least one of the following: a first condition that the first RO completely overlaps in time with the second RO; a second condition that the first RO partially overlaps in time with the second RO; or a third condition that the first RO occurs in the same slot as the second RO.

[0142] In some embodiments, the means for determining whether a PRACH transmission should be discarded at the first RO includes means for determining whether a first, second, or third condition is met, and means for determining whether a PRACH transmission should be discarded at the first RO if the first RO is determined to have a lower priority than the second RO.

[0143] In some embodiments, the means for determining that the first RO has a lower priority than the second RO is based on the priority indices of the first and second ROs.

[0144] In some embodiments, the priority index is predefined or set or notified by a second device.

[0145] In some embodiments, the first apparatus further includes means for determining that the second condition is met based on the determination that the first RO temporally overlaps with the second RO in at least a plurality of OFDM symbols.

[0146] In some embodiments, the first device further includes the fact that the number of OFDM symbols is predetermined by the first device or set by the second device.

[0147] In some embodiments, at least one condition includes a fourth condition that the second device cannot receive PRACH transmissions at the first and second ROs if the first RO and the second RO are associated with different synchronization signal block indices and at least one of the first, second, or third conditions is met.

[0148] In some embodiments, the first device further includes means for receiving a notification from the second device that the second device is unable to process multiple synchronization signal block indices in the same time instance, and means for determining, based on the notification, that the fourth condition is met.

[0149] In some embodiments, at least one condition further includes at least one of the following: a fifth condition relating to the synchronization signal block index associated with the first RO and the second RO, i.e., the first RO and the second RO overlap in time based on the first, second, or third condition; or a sixth condition relating to the frequency assignment of the first RO and the second RO, i.e., the first RO and the second RO overlap in time based on the first, second, or third condition.

[0150] In some embodiments, at least one of the first, second, third, fifth, or sixth conditions further requires that the first and second ROs are mapped to different synchronization signal block indices.

[0151] In some embodiments, the first apparatus further includes means for calculating a Random Access Radio Network Temporary Identifier (RA-RNTI) based on one or more ROs in the RO group.

[0152] In some embodiments, the first apparatus further comprises means for determining one or more ROs in an RO group for calculating RA-RNTI, wherein one or more ROs in the RO group include a first RO.

[0153] In some embodiments, the first RO is retained as part of one or more ROs if at least one condition is met.

[0154] In some embodiments, the first RO is not retained as part of one or more ROs if at least one condition is met.

[0155] In some embodiments, one or more ROs include one or more fallback ROs for RA-RNTI calculations.

[0156] In some embodiments, the first apparatus further comprises means for performing other operations in some embodiments of Method 300 or the first apparatus 110. In some embodiments, these means include at least one processor and at least one memory that, when executed by the at least one processor, stores instructions causing the first apparatus to perform an operation.

[0157] In some embodiments, a second apparatus (e.g., second apparatus 120 in Figure 1) capable of performing any of the methods 500 may include means for performing each operation of the methods 500. These means can be implemented in any suitable form. For example, these means may be implemented as a circuit or a software module. The second apparatus may be implemented as second apparatus 120 in Figure 1, or may be included in second apparatus 120.

[0158] In some embodiments, the second device includes means for determining whether a physical random access channel (PRACH) transmission should be discarded by the first device at the first random access channel (RACH) opportunity (RO) of the RO group, based on the satisfaction of at least one condition. It also includes means for receiving from the first device at least one PRACH transmission other than the one discarded at the RO of the RO group.

[0159] In some embodiments, at least one condition includes at least one of the following: a first condition that the first RO completely overlaps in time with the second RO; a second condition that the first RO partially overlaps in time with the second RO; or a third condition that the first RO occurs in the same slot as the second RO.

[0160] In some embodiments, means for determining whether a PRACH transmission should be discarded at the first RO include means for determining whether a first, second, or third condition is met, and means for determining whether a PRACH transmission should be discarded at the first RO based on the determination that the first RO has a lower priority than the second RO.

[0161] In some embodiments, the means for determining that the first RO has a lower priority than the second RO is based on the priority indices of the first and second ROs.

[0162] In some embodiments, the priority index is predefined or set or notified by a second device.

[0163] In some embodiments, the second apparatus further includes means for determining that the second condition is met based on the determination that the first RO temporally overlaps with the second RO in at least a number of OFDM symbols.

[0164] In some embodiments, the second device further includes the fact that a plurality of OFDM symbols are predetermined by the first device or set by the second device.

[0165] In some embodiments, at least one condition includes a fourth condition that the second device cannot receive PRACH transmissions at the first and second ROs if the first RO and the second RO are associated with different synchronization signal block indices and at least one of the first, second, or third conditions is met.

[0166] In some embodiments, the second device further includes means for notifying the first device that the second device cannot process multiple synchronization signal block indices in the same time instance.

[0167] In some embodiments, at least one condition further includes at least one of the following: a fifth condition relating to the synchronization signal block indices associated with the first and second ROs, i.e., the first and second ROs overlap in time based on the first, second, or third condition; or a sixth condition relating to the frequency allocation of the first and second ROs, i.e., the first and second ROs overlap in time based on the first, second, or third condition.

[0168] In some embodiments, at least one of the first, second, third, fifth, or sixth conditions further requires that the first and second ROs are mapped to different synchronization signal block indices.

[0169] In some embodiments, the second device further includes means for calculating a Random Access Radio Network Temporary Identifier (RA-RNTI) based on one or more ROs in the RO group.

[0170] In some embodiments, the second apparatus further comprises means for determining one or more ROs in an RO group for the calculation of RA-RNTI, wherein one or more ROs in an RO group include a first RO.

[0171] In some embodiments, the first RO is retained as part of one or more ROs if at least one condition is met.

[0172] In some embodiments, the first RO is not retained as part of one or more ROs if at least one condition is met.

[0173] In some embodiments, one or more ROs include one or more fallback ROs for RA-RNTI calculations.

[0174] In some embodiments, the second apparatus further includes means for performing other operations in some embodiments of Method 500 or the second apparatus 120. In some embodiments, the means comprises at least one processor and at least one memory that, when executed by the at least one processor, stores instructions causing the second apparatus to perform an operation.

[0175] Figure 6 is a simplified block diagram of an apparatus 600 suitable for carrying out an embodiment of the present disclosure. The apparatus 600 is provided for carrying out, for example, a communication device such as the first apparatus 110 and the second apparatus 120 shown in Figure 1. As shown in the figure, the apparatus 600 comprises one or more processors 610, one or more memories 620 connected to the processors 610, and one or more communication modules 640 connected to the processors 610.

[0176] The communication module 640 is for bidirectional communication. The communication module 640 has one or more communication interfaces to facilitate communication with other modules or devices. The communication interfaces can represent any interfaces necessary for communication with other network elements. In some embodiments, the communication module 640 may include at least one antenna.

[0177] The processor 610 is any type suitable for the local technology network and, in non-limiting examples, may include general-purpose computers, dedicated computers, microprocessors, digital signal processors (DSPs), and processors based on multi-core processor architectures. The device 600 may have multiple processors, such as application-specific integrated circuit chips that are time-dependent to a clock that synchronizes the main processor.

[0178] Memory 620 may include one or more non-volatile memories and one or more volatile memories. Examples of non-volatile memories include, but are not limited to, read-only memory (ROM) 624, electrically rewritable read-only memory (EPROM), flash® memory, hard disks, compact discs (CDs), digital video discs (DVDs), optical discs, laser discs, and other magnetic and / or optical storage devices. Examples of volatile memories include random-access memory (RAM) 622 and other volatile memories that cannot retain data during power-off periods.

[0179] The computer program 630 includes computer-executable instructions that are executed by the associated processor 610. The instructions in program 630 may include instructions for performing operations / actions in some embodiments of this disclosure. Program 630 may be stored in memory, for example, ROM 624. The processor 610 can perform any appropriate operations and processes by loading program 630 into RAM 622.

[0180] Exemplary embodiments of this disclosure may be implemented by program 630, thereby enabling the device 600 to perform any of the operations of this disclosure described with reference to Figures 3 to 5. Exemplary embodiments of this disclosure may also be implemented by hardware, or by a combination of software and hardware.

[0181] In some embodiments, the program 630 may be tangibly stored in a computer-readable medium built into the device 600 (for example, in memory 620) or in another storage device accessible to the device 600. The device 600 can load the program 630 from the computer-readable medium into RAM 622 and execute it. In some embodiments, the computer-readable medium may include any type of non-temporary storage medium, such as ROM, EPROM, flash® memory, hard disk, CD, or DVD. The term “non-temporary” here refers to the medium itself (i.e., a tangible medium rather than a signal) and not to the persistence of data storage (e.g., RAM vs. ROM).

[0182] Figure 7 shows an example of a computer-readable medium 700 that can take the form of a CD, DVD, or other optical storage disc. A program 630 is stored in the computer-readable medium 700.

[0183] Generally, various embodiments of this disclosure can be implemented in hardware or dedicated circuitry, software, logic, or any combination thereof. Some features may be implemented in hardware, while others may be implemented in firmware or software executable by a controller, microprocessor, or other computing device. Various aspects of the embodiments described herein are illustrated using block diagrams, flowcharts, or other graphic representations; however, it should be understood that the blocks, devices, systems, techniques, or methods described herein can be implemented, in non-limiting examples, in hardware, software, firmware, dedicated circuitry or logic, general-purpose hardware or controllers or other computing devices, or any combination thereof.

[0184] Some embodiments of this disclosure also provide at least one computer program product physically recorded on a computer-readable medium, such as a non-temporary computer-readable medium. This computer program product includes computer-executable instructions, such as those contained in a program module, and runs on a device on a target physical or virtual processor, performing one of the methods described above. Generally, a program module includes routines, programs, libraries, objects, classes, components, data structures, etc., that perform a specific task or implement a specific abstract data type. The functionality of program modules may be combined or divided among program modules as needed in various embodiments. The machine-executable instructions for a program module may run on a local or distributed device. On a distributed device, the program module may reside on both local and remote storage media.

[0185] Program code for carrying out the methods of this disclosure is written in any combination of one or more programming languages. The program code is provided to a processor or controller of a general-purpose computer, a dedicated computer, or other programmable data processing device, and is executed by the processor or controller to implement the functions / operations specified in the flowchart and / or block diagrams. The program code may run entirely on the machine, partially on the machine, run as a standalone software package, partially on the machine and partially on a remote machine, or run entirely on a remote machine or server.

[0186] In the context of this disclosure, computer program code or related data may be transmitted by any suitable medium to enable a device, apparatus, or processor to perform various processes and operations as described above. Examples of such mediums include signals and computer-readable media.

[0187] Computer-readable media may be computer-readable signal media or computer-readable storage media. Computer-readable media include, but are not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, devices, or appropriate combinations thereof. More specific examples of computer-readable storage media include electrical connections with one or more wires, portable computer floppy disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM) or flash® memory, optical fibers, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or appropriate combinations thereof.

[0188] Furthermore, while the operations are shown in a specific order, this does not mean that the operations must be performed in a specific or sequential order shown to obtain the desired results, or that all illustrated operations must be performed. In certain situations, multitasking or parallel processing may be advantageous. Similarly, the above description includes some specific implementation details, which should not be interpreted as limitations on the scope of this disclosure, but rather as descriptions of features specific to particular embodiments. Unless expressly stated, certain features described in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, unless expressly stated, various features described in the context of a single embodiment may also be implemented individually or in any suitable partial combination in multiple embodiments.

[0189] While this disclosure is described in a language specific to structural features and / or methodological actions, the disclosure as defined in the attached claims is not necessarily limited to the specific functions or actions described above. Rather, the specific functions or actions described above are disclosed as exemplary forms of implementing the claims.

Claims

1. Determining a set of valid random access channel opportunities (ROs) for physical random access channel (PRACH) transmission with preamble repetition, In at least one of the set of valid ROs, it is determined that the PRACH transmission should be discarded. Determining one or more ROs from the set of valid ROs for calculating a Random Access Radio Network Temporary Identifier (RA-RNTI), wherein the one or more ROs for calculating the RA-RNTI are independent of whether the corresponding PRACH transmission via the one or more ROs is discarded. Based on the determined one or more ROs of the set of valid ROs, the RA-RNTI is calculated, Methods that include...

2. The method according to claim 1, wherein the one or more ROs used in the calculation of RA-RNTI are predefined.

3. The method according to claim 1, wherein the one or more ROs used in the calculation of RA-RNTI are set by upper-layer signaling.

4. The method according to any one of claims 1 to 3, wherein the one or more ROs for calculating RA-RNTI include at least one RO.

5. The method according to any one of claims 1 to 3, wherein the one or more ROs for calculating RA-RNTI include the last RO in the set of valid ROs.

6. The method according to any one of claims 1 to 3, wherein the one or more ROs for calculating RA-RNTI include an RO having a time interval with at least one RO, and the time interval is less than or equal to a threshold interval.

7. The method according to claim 1, wherein the at least one RO is a part of the one or more ROs used for calculating the RA-RNTI, the at least one RO is held.

8. The method according to claim 1, wherein if the at least one RO is part of the one or more ROs for calculating the RA-RNTI, the at least one RO is not retained.

9. The method according to any one of claims 1 to 8, wherein the one or more ROs for calculating RA-RNTI include one or more fallback ROs.

10. The first condition is that at least one RO completely overlaps in time with the other ROs. The second condition is that at least one of the ROs partially overlaps in time with the other ROs, The third condition is that at least one of the ROs occurs in the same slot as the other ROs. The method according to claim 1, wherein it is determined that the PRACH transmission should be discarded in at least one RO if at least one of the following conditions is met.

11. It is a device, At least one processor, When executed by the at least one processor, the device has at least, Determining a set of valid random access channel opportunities (ROs) for physical random access channel (PRACH) transmission with preamble repetition, In at least one of the set of valid ROs, it is determined that the PRACH transmission should be discarded. Determining one or more ROs from the set of valid ROs for calculating a Random Access Radio Network Temporary Identifier (RA-RNTI), wherein the one or more ROs for calculating the RA-RNTI are independent of whether the corresponding PRACH transmission via the one or more ROs is discarded. Based on the determined one or more ROs of the set of valid ROs, the RA-RNTI is calculated, At least one memory to store instructions to execute, A device equipped with the following features.

12. The apparatus according to claim 11, wherein the one or more ROs for calculating the RA-RNTI are predefined.

13. The apparatus according to claim 11, wherein the one or more ROs used in the calculation of RA-RNTI are set by upper layer signaling.

14. The apparatus according to any one of claims 11 to 13, wherein the one or more ROs for calculating RA-RNTI include at least one RO.

15. The apparatus according to any one of claims 11 to 13, wherein the one or more ROs for calculating RA-RNTI include the last RO in the set of valid ROs.

16. The apparatus according to any one of claims 11 to 13, wherein the one or more ROs for calculating RA-RNTI include an RO having a time interval with at least one RO, and the time interval is less than or equal to a threshold interval.

17. The apparatus according to claim 11, wherein the at least one RO is part of the one or more ROs used for calculating the RA-RNTI, the at least one RO is held.

18. The apparatus according to claim 11, wherein if the at least one RO is part of the one or more ROs used for calculating the RA-RNTI, the at least one RO is not retained.

19. The apparatus according to any one of claims 11 to 18, wherein the one or more ROs for calculating RA-RNTI include one or more fallback ROs.

20. The first condition is that at least one RO completely overlaps in time with the other ROs. The second condition is that at least one of the ROs partially overlaps in time with the other ROs, The third condition is that at least one of the ROs occurs in the same slot as the other ROs. The apparatus according to claim 11, wherein if at least one of the following conditions is met, it is determined that the PRACH transmission should be discarded in the at least one RO.

21. The apparatus according to any one of claims 11 to 20, wherein the apparatus includes a terminal device or a network device.

22. A computer-readable medium containing program instructions for causing a device to perform any of the methods of claims 1 to 10.

23. An apparatus comprising means for carrying out any of the methods of claims 1 to 10.

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