Random access method, apparatus, and communication system

Abstract

To provide a random access method, a device, and a communication system.SOLUTION: A device includes a first processing unit. The first processing unit determines a random access type based on configuration information of a bandwidth part (BWP) for random access selected by a terminal device and a downlink reference signal received power measured by the terminal device, selects a random access resource, and transmits an initial message of random access using the random access resource.SELECTED DRAWING: Figure 14

Description

Technical Field

[0001] Embodiments of the present invention relate to the technical field of wireless communication.

Background Art

[0002] The random access procedure is a very important procedure in mobile communication technology.

[0003] Figure 1(a) is a flowchart of a conventional four-step contention-based random access (CBRA) procedure. As shown in Figure 1(a), in operation 101, the terminal device selects a CBRA preamble and transmits the preamble by Msg1 in a pre-set contention-based random access occasion (RO) of the system; in operation 102, after receiving the preamble, the network device can transmit Msg2, whereby the random access response (RAR) authorizes a dedicated uplink PUSCH resource for the terminal device that transmitted the preamble, assigns a cell radio network temporary identifier (CRNTI), and indicates the uplink advance amount of the physical uplink shared channel (PUSCH); in operation 103, the terminal device transmits Msg3 that carries signaling or data on the PUSCH resource; also, in operation 104, the network device transmits a contention resolution signaling Msg4 for Msg3 to the terminal device.

[0004] Figure 1(b) is a flowchart of a conventional two-step contention-based random access (CBRA) procedure. As shown in Figure 1(b), in operation 105, the terminal device sends MsgA, which includes a two-step random access preamble and payload. The terminal device sends the preamble of MsgA using a contention-based RO and transmits the signaling or service data of MsgA using a contention-based physical uplink shared channel (PUSCH) resource. In operation 106, the network device sends MsgB after receiving MsgA, thereby sending a random access response and a contention resolution message to the terminal device.

[0005] The above-mentioned introduction of background art is intended to clearly and completely explain the proposed technical aspects of the present invention and to facilitate understanding by those skilled in the art. These technical aspects, as described in the background art of the present invention, should not be construed as being well-known to those skilled in the art. [Overview of the project] [Problems that the invention aims to solve]

[0006] The inventors of this invention have discovered the following: With technological advancements, the types of random access continue to increase, and when multiple types of random access exist in a communication standard, one of the problems that needs to be solved is how to select the appropriate random access type and determine the appropriate random access resource.

[0007] Embodiments of the present invention provide a random access method, apparatus, and communication system, which can determine the random access type by determining the random access type based on the setting information of the bandwidth part (BWP, also known as partial bandwidth) for random access selected by the terminal device and the downlink reference signal received power (received power) measured by the terminal device, thereby enabling the method to select an appropriate random access type and determine (determine) an appropriate random access resource. [Means for solving the problem]

[0008] According to a first aspect of the embodiments of the present invention, a random access method for application to a terminal device is provided, and this method is Based on the configuration information for the bandwidth part (BWP) for random access selected by the terminal device and the downlink reference signal reception power measured by the terminal device, the random access type is determined; Select random access resources; and This includes sending an initial random access message to the random access resource.

[0009] According to a second aspect of the embodiments of the present invention, a random access method for application to a network device is provided, the method is: This includes transmitting configuration information for random access of one or more bandwidth parts to a terminal device. Among these, the configuration information includes a two-step random access resource, which includes a synchronization signal block (SSB) for two-step random access, a two-step random access preamble, a preamble access opportunity for two-step random access, and a physical uplink shared channel (PUSCH) resource for two-step random access.

[0010] According to a third aspect of the embodiments of the present invention, a random access method for application to a terminal device is provided, and this method is Receive a two-step non-conflicting random access resource configuration via network device transmission (transmitted by the network device); and This includes sending a first message (MsgA) of a two-step non-conflicting random access procedure to the network device. The aforementioned first message includes a two-step non-conflicting random access preamble and a physical uplink sharing channel.

[0011] According to a fourth aspect of the embodiments of the present invention, a random access method applied to a network device is provided, and this method is Send a two-step non-conflicting random access resource configuration to the terminal device; and This includes receiving the first message (MsgA) of a two-step non-conflicting random access procedure from the terminal device, The aforementioned first message includes a two-step non-conflicting random access preamble and a physical uplink sharing channel.

[0012] According to the fifth aspect of the embodiment of the present invention, a random access device for application in a terminal device is provided, which performs the random access method of the first and third aspects of the embodiment of the present invention.

[0013] According to the sixth aspect of the embodiment of the present invention, a random access device for application in a network device is provided, which performs the random access method of the second and fourth aspects of the embodiment of the present invention.

[0014] According to the seventh aspect of the embodiment of the present invention, a terminal device is provided which has a random access device as described in the fifth aspect of the embodiment of the present invention.

[0015] According to the eighth aspect of the embodiments of the present invention, a network device is provided which has a random access device as described in the sixth aspect of the embodiments of the present invention.

[0016] According to the ninth aspect of the embodiment of the present invention, a communication system is provided which comprises a terminal device described in the seventh aspect of the embodiment of the present invention and a network device described in the eighth aspect.

[0017] According to the tenth aspect of the embodiment of the present invention, a computer-readable program is provided, and when the program is executed on a random access device or terminal device, the program causes the random access device or terminal device to execute the random access method described in the first and third aspects of the embodiment of the present invention.

[0018] According to the eleventh aspect of the embodiment of the present invention, a storage medium storing a computer-readable program is provided. Among them, the computer-readable program causes a random access device or a terminal device to execute the random access method described in the first and third aspects of the embodiment of the present invention.

[0019] According to the twelfth aspect of the embodiment of the present invention, a computer-readable program is provided. Among them, when the program is executed by a random access device or a network device, the program causes the random access device or the network device to execute the random access method described in the second and fourth aspects of the embodiment of the present invention.

[0020] According to the thirteenth aspect of the embodiment of the present invention, a storage medium storing a computer-readable program is provided. Among them, the computer-readable program causes a random access device or a network device to execute the random access method described in the second and fourth aspects of the embodiment of the present invention.

Advantages of the Invention

[0021] The advantageous effects of the embodiments of the present invention are as follows. That is, based on the setting information of the bandwidth part (BWP) for random access selected by the terminal device and the downlink reference signal reception power measured by the terminal device, the random access type is determined. Thereby, an appropriate random access type can be selected to determine an appropriate random access resource.

[0022] By referring to the following description and drawings, specific embodiments of the present invention are disclosed in detail, showing aspects in which the principles of the present invention can be adopted. It should be noted that the embodiments of the present invention are not limited in scope by these. Within the scope of the appended claims, the embodiments of the present invention may include various changes, modifications, and alternatives.

[0023] Also, the features described and / or shown for one embodiment can be used in one or more other embodiments in the same or similar manner, combined with the features in other embodiments, or replace the features in other embodiments.

[0024] Note that terms such as "comprising / including" when used in this specification refer to the presence of features, elements, steps, or assemblies, but also refer to the fact that they do not exclude the presence or addition of one or more other features, elements, steps, or assemblies.

Brief Description of Drawings

[0025] The elements and features described in one drawing or one embodiment of the present invention can be combined with the elements and features shown in one or more other drawings or embodiments. Also, in the drawings, like reference numerals indicate corresponding parts in several drawings and are also used to indicate corresponding parts used in multiple embodiments.

[0026] The included drawings are used to provide a further understanding of the embodiments of the present invention. These drawings form part of this specification, illustrate the embodiments of the present invention, and are used to explain the principles of the present invention together with the written description. Also, as is clear, the drawings described below are only for showing some embodiments of the present invention, and those skilled in the art can obtain other drawings based on these drawings without creative labor. [Figure 1] (a) is a flowchart of a conventional 4-step contention-based random access procedure; (b) is a flowchart of a conventional 2-step contention-based random access procedure. [Figure 2] (a) is a flowchart of a non-contention random access procedure; (b) is a flowchart of a 2-step non-contention random access procedure. [Figure 3] It is a diagram showing a communication system in an embodiment of the present invention. [Figure 4]This figure shows a random access method in the first aspect of an embodiment of the present invention. [Figure 5] This diagram illustrates one implementation method for performing a two-step random access resource selection. [Figure 6] This figure shows another implementation method for performing a two-step random access resource selection. [Figure 7] This diagram shows one implementation method for selecting random access resources in four steps. [Figure 8] This diagram shows another implementation method for performing a 4-step random access resource selection. [Figure 9] This diagram shows a two-step implementation method for selecting non-conflicting random access resources. [Figure 10] This figure shows a random access method in a second aspect of an embodiment of the present invention. [Figure 11] This figure shows a random access method in the third aspect of an embodiment of the present invention. [Figure 12] This diagram shows the method for performing operation 1102. [Figure 13] This figure shows a random access method in the fourth aspect of an embodiment of the present invention. [Figure 14] This figure shows a random access device in the fifth aspect of an embodiment of the present invention. [Figure 15] This figure shows a random access device in the fifth aspect of an embodiment of the present invention. [Figure 16] This figure shows a random access device in the sixth aspect of an embodiment of the present invention. [Figure 17] This figure shows a random access device in the sixth aspect of an embodiment of the present invention. [Figure 18] This figure shows the system configuration of the terminal device 1800 in the seventh aspect of an embodiment of the present invention. [Figure 19] This figure shows the configuration of a network device in an embodiment of the present invention. [Modes for carrying out the invention]

[0027] The aforementioned and other features of the present invention will become clear by referring to the attached drawings and the following description. While the specification and drawings disclose specific embodiments of the present invention, they represent only a limited number of embodiments that may employ the principles of the present invention. It should be understood that the present invention is not limited to the embodiments described, and that it includes all modifications, variations, and substitutions within the scope of the attached claims.

[0028] In embodiments of the present invention, the terms "communication network" or "wireless communication network" may refer to a network conforming to any communication standard such as LTE (Long Term Evolution), LTE-A (LTE-Advanced), WCDMA (Wideband Code Division Multiple Access), HSPA (High-Speed ​​Packet Access), etc.

[0029] Furthermore, communication between devices in a communication system may be carried out according to any stage of communication protocol, and may include, but is not limited to, the following communication protocols: namely, 1G (generation), 2G, 2.5G, 2.75G, 3G, 4G, 4.5G and future 5G, New Radio (NR), and / or other conventional or future-developed communication protocols.

[0030] In embodiments of the present invention, the term "network device" refers, for example, to a device in a communication system that connects terminal devices to a communication network and provides services to said terminal devices. Network devices may include, but are not limited to, the following: base stations (BS), access points (AP), transmission and reception points (TRP), broadcast transmitters, mobile management entities (MME), network gateways, servers, radio network controllers (RNC), base station controllers (BSC), etc.

[0031] Among these, base stations may include, but are not limited to, Node B (NodeB or NB), Evolutionary Node B (eNodeB or eNB), and 5G base stations (gNB), and may also include RRH (Remote Radio Head), RRU (Remote Radio Unit), relay, or low-power nodes (e.g., femto, pico). Furthermore, the term "base station" may include some or all of these functions, and each base station can provide communication coverage to a specific geographic area. The term "cell" may refer to a base station and / or the area it covers, depending on the context of the term.

[0032] In embodiments of the present invention, the terms "User Equipment" (UE) or "Terminal Equipment" (TE) refer to, for example, a device that accesses a communication network via a network device and receives services from the network. User equipment may be fixed or mobile, and may also be referred to as a mobile station (MS), terminal, subscriber station (SS), access terminal (AT), station, etc.

[0033] Among these, user devices may include, but are not limited to, the following: cellular phones, PDAs (Personal Digital Assistants), wireless modems, wireless communication devices, mobile devices, machine-type communication devices, laptop computers, cordless telephones, smartphones, smartwatches, digital cameras, etc.

[0034] Furthermore, in scenarios such as IoT (Internet of Things), the user device may also be a monitoring or measurement device or apparatus, and may include, but is not limited to, the following: machine-type communication (MTC) terminals, in-vehicle communication terminals, D2D (device-to-device) terminals, M2M (machine-to-machine) terminals, etc.

[0035] Embodiments of the present invention include two procedures: a contention-free random access (CFRA) procedure and a two-step contention-free random access (2-step CFRA) procedure. Figure 2(a) is a flowchart of the contention-free random access procedure, and Figure 2(b) is a flowchart of the two-step contention-free random access procedure.

[0036] As shown in Figure 2(a), a non-competitive random access procedure may include the following operations, namely, Operation 201: The network device may set a dedicated preamble for the terminal device using a Radio Resource Control (RRC) message or a Physical Downlink Control Channel (PDCCH) command, and may set a dedicated preamble for each of the multiple Synchronization Signal Blocks / Channel State Information (SSB / CSI) signals; Operation 202: When the terminal device initiates random access, select SSB / CSI and send a dedicated preamble via Mag1; Operation 203: After the network device receives a dedicated preamble, it sends a random access response to the terminal device via Msg2; Operation 204: The terminal device transmits uplink data or signaling in an uplink grant included in the random access response.

[0037] As shown in Figure 2(b), a two-step non-conflicting random access procedure may include the following operations, namely: Operation 205: The network device sets a dedicated two-step random access preamble for the terminal device using a Radio Resource Control (RRC) message or a Physical Downlink Control Channel (PDCCH) command; Operation 206: When the terminal device initiates random access, select SSB / CSI and send a dedicated preamble and physical uplink sharing channel (PUSCH) via MagA; Operation 207: The network device sends a random access response to the terminal device via MsgB.

[0038] In a two-step non-conflicting random access procedure, the transmission latency of PUSCH can be reduced because PUSCH and a dedicated preamble are sent in operation 206.

[0039] In each embodiment of the present invention, a dedicated two-step random access preamble may also be referred to as a two-step non-conflicting random access preamble, but the two terms have the same meaning.

[0040] The following describes a scenario relating to an embodiment of the present invention based on an example, but the present invention is not limited thereto.

[0041] Figure 3 illustrates a communication system according to the present invention, illustrating an example using a terminal device and a network device. As shown in Figure 3, the communication system 300 includes a network device 301 and a terminal device 302. For convenience, Figure 3 uses one terminal device and one network device as examples for the explanation, but the present invention is not limited to this.

[0042] In embodiments of the present invention, conventional traffic (services) or services that may be implemented in the future can be performed between the network device 301 and the terminal device 302. These traffics may include, but are not limited to, eMBB (enhanced Mobile Broadband), mMTC (massive Machine Type Communication), URLLC (Ultra-Reliable and Low-Latency Communication), etc.

[0043] Of these, terminal device 302 can transmit data to network device 301 using, for example, a ground-free transmission method. Network device 301 can receive data transmitted by one or more terminal devices 302 and can also return feedback information (e.g., acknowledgment ACK / negative acknowledgment NACK) to terminal device 202. Based on the feedback information, terminal device 302 can confirm the end of the transmission process, or transmit new data or retransmit data.

[0044] The following explanation will use a network device as the receiving end and a terminal device as the transmitting end in a communication system as an example, but the present invention is not limited to this, and the transmitting end and / or receiving end may be other devices. For example, the present invention can be applied not only to uplink ground-free transmission between a network device and a terminal device, but also to sidelink ground-free transmission between two terminal devices.

[0045] <First aspect of the example> In a first aspect of the embodiments of the present invention, a random access method is provided which is applied to a terminal device, for example, terminal device 302.

[0046] Figure 4 is a diagram illustrating a random access method in the first aspect of an embodiment of the present invention, and as shown in Figure 4, the random access method may include the following operations (steps).

[0047] Operation 401: Determine the random access type based on the configuration information of the bandwidth part (BWP) for random access selected by the terminal device and the downlink reference signal received power measured by the terminal device; Operation 402: Select a random access resource; Operation 403: Send an initial message for random access on a random access resource.

[0048] In one aspect of the embodiment of the present invention, the random access type is determined based on the setting information of the Bandwidth Part (BWP) for random access selected by the terminal device and the downlink reference signal reception power measured by the terminal device, thereby enabling the selection of an appropriate random access type and the determination of an appropriate random access resource.

[0049] In operation 401, if a 2-step random access resource is configured in the bandwidth part (BWP) selected by the terminal device, and the downlink reference signal received power measured by the terminal device is higher than the first threshold, the random access type is determined to be 2-step random access; or if only a 2-step random access resource is configured in the bandwidth part (BWP) selected by the terminal device, the random access type is determined to be 2-step random access; otherwise, the random access type is determined to be 4-step random access.

[0050] In at least one embodiment, operation 401 includes a two-step random access resource configured in a bandwidth part (BWP) selected by the terminal device, which includes a synchronous signal block (SSB) for two-step random access, a two-step random access preamble, a preamble access opportunity for two-step random access, and a physical uplink shared channel (PUSCH) resource for two-step random access.

[0051] In at least one embodiment, the first threshold is a measurement threshold parameter based on a synchronization signal block (SSB), which is set by radio resource control (RRC) signaling.

[0052] In at least one embodiment, when different uplink carriers are configured for a serving cell, the terminal adopts the measurement threshold corresponding to the uplink carrier. That is, when the terminal device selects the serving cell's additional uplink (SUL) carrier for random access, the first threshold is the first threshold for the additional uplink; when the terminal device selects the serving cell's normal uplink (NUL) carrier for random access, the first threshold is the first threshold for the normal uplink. Of these, the first thresholds corresponding to the SUL and NUL carriers are set by radio resource control (RRC) signaling, respectively.

[0053] In at least one embodiment, after determining the random access type as 2-step random access in operation 401, operation 402 performs the selection of a 2-step random access resource, i.e., operation 4021; after determining the random access type as 4-step random access in operation 401, operation 402 performs the selection of a 4-step random access resource, i.e., operation 4022.

[0054] In operation 403, the initial random access message that the terminal device sends with the random access resource is the first message MsgA or Msg1. For example, if the terminal device selects a 2-step random access resource in operation 402, it sends the first message MsgA, and if it selects a 4-step random access resource, it sends Msg1, i.e., the 4-step random access preamble.

[0055] Figure 5 shows one implementation of a two-step random access resource selection, and as shown in Figure 5, the two-step random access resource selection (i.e., operation 4021) may include the following operations.

[0056] Operation 501: Determine whether the selection criteria for non-conflicting random access resources in two steps have been met. If the answer is "yes," proceed to operation 502; otherwise, proceed to operation 503. Operation 502: Select a non-conflicting random access resource in two steps; Operation 503: Select a 2-step contention-based random access resource.

[0057] Figure 6 shows another implementation of a two-step random access resource selection, and as shown in Figure 6, the two-step random access resource selection (i.e., operation 4021) may include the following operations.

[0058] Operation 601: Determine whether the selection criteria for non-conflicting random access resources in two steps have been met. If the answer is "yes," proceed to operation 602; otherwise, proceed to operation 603. Operation 602: Select a non-conflicting random access resource in two steps; Operation 603: Determine if the selection criteria for non-conflicting random access resources are met. If the answer is "yes," proceed to operation 604; otherwise, proceed to operation 605. Operation 604: Select a non-conflicting random access resource; Operation 605: Select a 2-step contention-based random access resource.

[0059] Note that when selecting a two-step random access resource in operation 402, it is not always the case that a two-step random access resource is selected; for example, in operation 604, a non-conflicting random access resource is selected.

[0060] Figure 7 shows one implementation of a four-step random access resource selection, and as shown in Figure 7, the four-step random access resource selection (i.e., operation 4022) may include the following operations:

[0061] Operation 701: Determine if the selection criteria for non-conflicting random access resources are met. If the answer is "yes," proceed to operation 702; otherwise, proceed to operation 703; Operation 702: Select a non-conflicting random access resource; Operation 703: Select a 4-step contention-based random access resource.

[0062] Figure 8 shows another implementation of the four-step random access resource selection, and as shown in Figure 8, the four-step random access resource selection (i.e., operation 4022) may include the following operations. Operation 801: Determine whether the selection criteria for non-conflicting random access resources in two steps have been met. If the answer is "yes," proceed to operation 802; otherwise, proceed to operation 803. Operation 802: Select a non-conflicting random access resource in two steps; Operation 803: Determine if the selection criteria for non-conflicting random access resources are met. If the answer is "yes," proceed to operation 804; otherwise, proceed to operation 805. Operation 804: Select a non-conflicting random access resource; Operation 805: Select a 4-step competition-based random access resource.

[0063] Note that when selecting a 4-step random access resource in operation 402, it is not always the case that a 4-step random access resource is selected. For example, in operation 804, a non-conflicting random access resource is selected, and in operations 702 and 802, a 2-step non-conflicting random access resource is selected.

[0064] In operations 501, 601, and 801 described above, satisfying the selection criteria for a two-step non-conflicting random access resource means that a dedicated two-step random access resource is configured on the terminal device by the network device, and that the reference signal received power (RSRP) of at least one synchronization signal block (SSB) or channel status information reference signal (CSI-RS) in the dedicated two-step random access resource is higher than the second threshold. The dedicated two-step random access resource includes at least one synchronization signal block (SSB) or channel status information reference signal (CSI-RS) and a dedicated two-step random access preamble corresponding to the synchronization signal block (SSB) or channel status information reference signal (CSI-RS).

[0065] Operations 502, 602, and 802 described above select a two-step non-conflicting random access resource. Figure 9 shows one implementation of selecting a two-step non-conflicting random access resource, and as shown in Figure 9, selecting a two-step non-conflicting random access resource involves the following operations.

[0066] Operation 901: Select one synchronization signal block (SSB) or channel status information reference signal (CSI-RS) to transmit a dedicated two-step random access preamble and a physical uplink shared channel (PUSCH); Operation 902: Set the two-step random access preamble to be transmitted as a dedicated two-step random access preamble corresponding to the synchronization signal block (SSB) or channel status information reference signal (CSI-RS); Operation 903: Determine the preamble access opportunity for a two-step random access corresponding to the following one available Synchronization Signal Block (SSB) or Channel State Information Reference Signal (CSI-RS); Operation 904: Determine the uplink grant based on the random access preamble of the two steps and the physical uplink shared channel (PUSCH) corresponding to the preamble access opportunity.

[0067] In operation 901, the terminal device selects a single synchronous signal block (SSB) or channel status information reference signal (CSI-RS) whose reference signal reception power (RSRP) is higher than the second threshold.

[0068] In operation 902, if dedicated two-step random access preambles corresponding to Group A and Group B are set in the Synchronization Signal Block (SSB) or Channel Status Information Reference Signal (CSI-RS), the terminal device selects either the Group A or Group B dedicated two-step random access preamble based on the path loss and / or the transmission block size (TB size) of the first message (MsgA) of the two-step non-conflicting random access procedure, and the modulation and coding schemes (MCS) of the physical uplink shared channels (PUSCH) corresponding to the dedicated two-step random access preambles of Group A and Group B are different. This allows the terminal device to select and transmit from the physical uplink shared channel (PUSCH) with a reasonable modulation and coding scheme (MCS).

[0069] For example, if the path loss measured by terminal device 302 is less than the path loss threshold and the transmission block size (TB Size) of the first message (MsgA) is greater than the transmission block size threshold, terminal device 302 sets the two-step random access preamble to be sent as the dedicated two-step random access preamble for group B; otherwise, it sets the two-step random access preamble to be sent as the dedicated two-step random access preamble for group A.

[0070] Furthermore, for example, if the path loss measured by terminal device 302 is smaller than the path loss threshold, terminal device 302 sets the two-step random access preamble to be transmitted as the dedicated two-step random access preamble for group B; otherwise, it sets the two-step random access preamble to be transmitted as the dedicated two-step random access preamble for group A.

[0071] The transmission block size threshold may be, for example, the following parameter, namely, the size of group A of random access MsgA (ra - MsgASizeGroupA). The path loss threshold can be calculated, for example, using the following formula.

[0072] Path loss threshold = PCMAX-preambleReceivedTargetPower-msgA-DeltaPreamble-messagePowerOffsetGroupB Here, preambleReceivedTargetPower is the target received power of the two-step competition-based random access preamble, msgA-DeltaPreamble is the offset between the target received power of MsgA and the target received power of the preamble, messagePowerOffsetGroupB is the power offset for selecting the preamble group, and PCMAX is the maximum transmit power (Pcmax) for which terminal device 302 performs random access.

[0073] In operation 904, the confirmed uplink grant (UL grant) may include the modulation and coding scheme (MCS), uplink resource (UL), transmission block size (TB size), etc.

[0074] As shown in Figure 4, in at least one embodiment, the method further includes the following operations after operation 403.

[0075] Operation 404: If the random access procedure is incomplete (completed), perform the random access resource selection again (i.e., return to operation 402).

[0076] As shown in Figure 4, operation 404 may include the following operations.

[0077] Operation 4041: Determine if the random access procedure is complete. If the random access procedure is not complete (determined as "no"), the process (flow) returns to operation 402 to select a random access resource again.

[0078] Operation 4041 can determine whether the random access to the random access resource selected in operation 402 is complete. For example, if a two-step non-conflicting random access resource is selected in operation 402, operation 4041 can determine that the random access is incomplete, which includes not receiving the second message (MsgB) after sending the first message (MsgA) of the two-step non-conflicting random access but before the response receiving window (ra-ResponseWindow2-step) for the two-step non-conflicting random access has ended.

[0079] In this invention, when returning from operation 4041 to operation 402, the process may proceed to operation 4021 or operation 4022 of operation 402.

[0080] As shown in Figure 4, operation 404 may further include the following operations.

[0081] Operation 4042: If the terminal device has selected a two-step random access resource, or if the random access type is two-step random access, select a two-step random access resource again (i.e., return to operation 4021 in operation 402).

[0082] Among these, the selection of a two-step random access resource by a terminal device may, for example, mean that terminal device 302 selected a two-step competition-based random access resource or a two-step non-competitive random access resource in operation 402. The random access type being two-step random access may, for example, mean that the random access type determined by terminal device 302 in operation 401 is two-step random access. Thus, the random access resource selected by terminal device 302 in operation 4021 may be a two-step competition-based random access resource, a two-step non-competitive random access resource, or a non-competitive random access resource.

[0083] As shown in Figure 4, after operation 4042, operation 404 may further include the following operations.

[0084] Operation 4043: If the random access procedure is incomplete, determine if the count value of the random access preamble is greater than threshold N. If the count value of the preamble is greater than threshold N (i.e., the result is "yes"), proceed to operation 4044. If the count value of the preamble is less than or equal to threshold N (i.e., the result is "no"), proceed to operation 4021 to perform a two-step random access resource selection; Operation 4044: Set the random access type to 4-step random access, and proceed to operation 4022 to select a 4-step random access resource.

[0085] In operation 4043, the count value is used to record the number of times a two-step random access preamble is transmitted, for example, if the terminal device selects a two-step random access resource or a two-step non-conflicting random access resource, the count value increases; or the count value is used to record the number of times the terminal device transmits a preamble when it confirms the random access type to be two-step random access.

[0086] Operations 4043 and 4044 allow for timely adjustment of the random access type, thereby improving the efficiency of random access.

[0087] As shown in Figure 4, operation 404 may further include the following operations.

[0088] Operation 4045: If the terminal device has selected a 4-step random access resource, or if the random access type is 4-step random access, perform the selection of a 4-step random access resource again.

[0089] Among these, the selection of a 4-step random access resource by a terminal device may, for example, mean that terminal device 302 selected a 4-step conflicted random access resource in operation 402. The random access type being 4-step random access may, for example, mean that the random access type determined by terminal device 302 in operation 401 was 4-step random access, and the random access resource selected by terminal device 302 in operation 4022 may be a 2-step non-conflicting random access resource, a non-conflicting random access resource, or a 4-step conflict-based random access resource.

[0090] As shown in Figure 4, operation 404 may further include operations 4046 and 4047. Operations 4046 and 4047 precede operations 4042 and 4045.

[0091] Operations 4046 and 4047 are as follows:

[0092] Operation 4046: Determine if there are any two-step non-conflicting random access resources that satisfy the selection criteria within the backoff time, or any non-conflicting random access resources. If the result is "yes" (i.e., there are non-conflicting random access resources that satisfy the selection criteria within the backoff time), perform another random access resource selection before the backoff time ends (i.e., perform operation 4042 or operation 4045). If the result is "no" (i.e., there are no non-conflicting random access resources that satisfy the selection criteria within the backoff time), perform another random access resource selection after the backoff time ends (i.e., perform operation 4042 or operation 4045); Operation 4047: Determine if the backoff time has ended. If the result is "yes" (i.e., the backoff time has ended), perform the random access resource selection again (i.e., perform operation 4042 or operation 4045). If the result is "no" (i.e., the backoff time has not ended), return to operation 4046.

[0093] In operation 4046, the selection criteria for a two-step non-conflicting random access resource are satisfied, for example, if a dedicated two-step random access resource is provided to the terminal device, and the reference signal received power (RSRP) of at least one SSB or CSI-RS in the dedicated two-step random access resource is higher than the second threshold.

[0094] In operation 4047, the backoff time is a single value randomly selected from a value between 0 and the backoff parameter, which is, for example, the backoff parameter of a two-step random access preamble (PREAMBLE_BACKOFF_2-step), which may be indicated, for example, by the Backoff Indication (BI) field in MsgB.

[0095] If operations 4046 and 4047 fail to successfully complete random access, the terminal device can attempt random access again after a random backoff period (one period) has elapsed, based on the network's backoff instruction. In this way, the network access load can be effectively controlled, and the efficiency of random access can be improved by allowing the terminal device to preferentially select and access two-step non-conflicting random access resources or non-conflicting random access resources.

[0096] In one aspect of the embodiments of the present invention, the terminal device can select an appropriate random access type and determine an appropriate random access resource, thereby improving the efficiency of random access.

[0097] <Second aspect of the example> A second aspect of the embodiments of the present invention provides a random access method which is applied to a network device, for example, network device 301.

[0098] Figure 10 is a diagram illustrating a random access method in a second aspect of an embodiment of the present invention, and as shown in Figure 10, the random access method may include the following operations.

[0099] Operation 1001: Send configuration information for random access of one or more bandwidth parts to a terminal device, the configuration information of which includes a 2-step random access resource.

[0100] In operation 1001, the two-step random access resource includes a synchronization signal block (SSB) for the two-step random access, a two-step random access preamble, a preamble access opportunity for the two-step random access, and a physical uplink shared channel (PUSCH) resource for the two-step random access. Of these, the two-step random access resource may be transmitted, for example, by a system broadcast message of the RRC.

[0101] As shown in Figure 10, the method further includes the following steps.

[0102] Operation 1002: A first threshold is transmitted to the terminal device, which is used by the terminal device to determine the random access type.

[0103] In operation 1002, the first threshold includes either the first threshold for the additional uplink link (SUL) or the first threshold for the normal uplink link (NUL).

[0104] As shown in Figure 10, the method further includes the following steps.

[0105] Operation 1003: Set up a dedicated two-step random access resource for the terminal device.

[0106] Among these, a dedicated two-step random access resource includes at least one synchronization signal block (SSB) or channel state information reference signal (CSI-RS) and a dedicated two-step random access preamble corresponding to the synchronization signal block (SSB) or channel state information reference signal (CSI-RS). Among these, the network device can configure the dedicated two-step random access preamble corresponding to the SSB or CSI-RS as a preamble for group A or group B, and the MCS of PUSCH corresponding to the group A and group B preambles are different. For example, during switching, the network device configures at least one SSB or CSI-RS for the terminal device to access the target base station based on the power or quality of the measurement signal made by the terminal device to the target base station based on the SSB or CSI-RS; and configures a dedicated two-step random access preamble for the terminal for group A or group B based on the power or quality of the measurement signal made by the terminal device to the SSB or CSI-RS. In this way, since the MCS of the PUSCH corresponding to the preambles of Group A and Group B are different, it is advantageous for the terminal to adopt the appropriate MCS to transmit the PUSCH under different channel quality conditions.

[0107] As shown in Figure 10, the method further includes the following steps.

[0108] Operation 1004: A second threshold is transmitted to the terminal device, which is used for the terminal device to select either a synchronization signal block (SSB) or a channel status information reference signal (CSI-RS).

[0109] In operation 1004, dedicated two-step random access preambles corresponding to Group A and Group B are set in the Synchronization Signal Block (SSB) or Channel State Information Reference Signal (CSI-RS). The modulation and coding schemes (MCS) of the physical uplink shared channel (PUSCH) corresponding to the dedicated two-step random access preambles of Group A and Group B are different. For example, during switching, the network equipment sets up at least one SSB or CSI-RS for access to the target base station for the terminal equipment based on the power or quality of the measurement signal performed by the terminal equipment on the SSB or CSI-RS with respect to the target base station; and simultaneously sets up a dedicated two-step random access preamble of Group A or Group B for the terminal. In this way, the terminal equipment can spontaneously select to use the random access preamble of Group A or Group B based on the situation (e.g., signal quality with respect to the target base station). Since the MCS of the PUSCH corresponding to the preambles of Group A and Group B are different, it is advantageous for the terminal to adopt the appropriate MCS to transmit the PUSCH under different circumstances (e.g., under different channel quality conditions).

[0110] In a second aspect of the embodiment of the present invention, the terminal device can select an appropriate random access type based on the information transmitted by the network device and determine an appropriate random access resource, thereby improving the efficiency of random access.

[0111] <Third aspect of the example> A third aspect of the embodiment of the present invention provides a random access method which is applied to a terminal device, for example, terminal device 302, which initiates a random access request to network device 301 and receives a random access response transmitted by network device 301.

[0112] A third aspect of the embodiment of the present invention relates to a random access method in which a terminal device performs operations in a two-step non-conflicting random access procedure.

[0113] Figure 11 shows a random access method in a third aspect of an embodiment of the present invention, and as shown in Figure 11, the random access method may include the following operations.

[0114] Operation 1101: Receive a two-step non-conflicting random access resource configuration sent by the network device for the first message (MsgA); Operation 1102: Send a first message (MsgA) of a two-step non-conflicting random access procedure to the network device, the first message including a two-step non-conflicting random access preamble and a physical uplink sharing channel.

[0115] According to a third aspect of the embodiment of the present invention, the first message (MsgA) transmitted by the terminal device to the network device includes a two-step non-conflicting random access preamble and a physical uplink sharing channel (PUSCH). This makes it possible to reduce the transmission latency of the physical uplink sharing channel (PUSCH).

[0116] In at least one embodiment, operation 1101 allows the terminal device to receive the two-step non-conflicting random access resource configuration via physical downlink control channel (PDCCH) or radio resource control (RRC) signaling, the two-step non-conflicting random access resource configuration may also be information for configuring two-step non-conflicting random access resources for the terminal device.

[0117] In at least one embodiment, a two-step non-conflicting random access resource includes a dedicated two-step random access resource, of which the dedicated two-step random access resource may include at least one synchronization signal block (SSB) or channel status information reference signal (CSI-RS) and a dedicated two-step random access preamble corresponding to the synchronization signal block (SSB) or channel status information reference signal (CSI-RS). The dedicated two-step random access preamble is the two-step non-conflicting random access preamble included in the first message (MsgA) in operation 1102.

[0118] Figure 12 is a diagram illustrating a method for performing operation 1102, and as shown in Figure 12, operation 1102 may include the following operations.

[0119] Operation 1201: Select one synchronization signal block (SSB) or channel status information reference signal (CSI-RS) to transmit a dedicated two-step random access preamble and a physical uplink shared channel (PUSCH); Operation 1202: Set the two-step random access preamble to be transmitted as a dedicated two-step random access preamble corresponding to the synchronization signal block (SSB) or channel status information reference signal (CSI-RS); Operation 1203: Determine the preamble access opportunity for a two-step random access corresponding to the following one available Synchronization Signal Block (SSB) or Channel State Information Reference Signal (CSI-RS); Operation 1204: Determine the uplink grant based on a two-step random access preamble and the physical uplink shared channel (PUSCH) corresponding to the preamble access opportunity; Operation 1205: Send the first message (MsgA) based on the uplink grant.

[0120] Of these, operations 1201 to 1204 are the same as operations 901 to 904, respectively.

[0121] In at least one embodiment, the random access method may further include the following operations, as shown in Figure 11.

[0122] Operation 1103: When the second message (MsgB) from the network device is received, it is determined that the random access response was received successfully, and this random access is considered to have been completed successfully.

[0123] In at least one embodiment, the second message (MsgB) may be a timing advance instruction medium access layer control element (TAC MAC CE) scheduled by a physical downlink control channel (PDCCH) addressed to a cell radio network temporary identifier (C-RNTI), and / or the second message (MsgB) may be a medium access control layer protocol data unit (MAC PDU) scheduled by a physical downlink control channel (PDCCH) addressed to a second message radio network temporary identifier (MsgB-RNTI).

[0124] In at least one embodiment, the network device may send a second message (MsgB) if it has successfully demodulated a two-step non-conflict random access preamble, or if it has successfully demodulated a two-step non-conflict random access preamble and a physical uplink sharing channel. A terminal device, upon receiving the second message (MsgB) from the network device, can determine that it has successfully received the network device's random access response, i.e., that the reception of the random access response was successful. The terminal device can determine that this random access was successfully completed upon receiving the MsgB because the network device can recognize the terminal device upon receiving the contention-free preamble of MsgA, and can send the MsgB to the terminal device regardless of whether the PUSCH of MsgA was correctly received by the network device.

[0125] As shown in Figure 11, operation 1103 may include the following operations.

[0126] Operation 11031: If a medium access control layer protocol data unit (MAC PDU) scheduled by a physical downlink control channel (PDCCH) addressed to a cell radio network temporary identifier (C-RNTI) has been successfully demodulated, and the medium access control layer protocol data unit contains a timing advance instruction medium access layer control element (TAC MAC CE), then it is determined that a second message (MsgB) has been received and the random access is considered successful.

[0127] In operation 11031, the timing advance instruction medium access layer control element (TAC MAC CE) included in the medium access control layer protocol data unit is, for example, 12 bits.

[0128] In at least one embodiment, after a terminal device has transmitted a first message (MsgA), it can monitor the PDCCH addressed to the C-RNTI within a second message (MsgB-ResponseWindow) and determine that it has successfully demodulated a Medium Access Control Layer Protocol Data Unit (MAC PDU) scheduled by the Physical Downlink Control Channel (PDCCH) addressed to the Cell Radio Network Temporary Identifier (C-RNTI), and that the Medium Access Control Layer Protocol Data Unit contains a Timing Advance Instruction Medium Access Layer Control Element (TAC MAC CE), which means that the second message (MsgB) transmitted by the network device has been received and that this random access has been successfully completed.

[0129] As shown in Figure 11, operation 1103 may include the following operations.

[0130] Operation 11032: Determine that the second message (MsgB) has been received when a medium access control layer protocol data unit (MAC PDU) scheduled by a physical downlink control channel addressed to the second message radio network temporary identifier (MsgB-RNTI) has been successfully demodulated, and a random access preamble indicator (RAPID) in one of the subprotocol data units (subPDU) of the medium access control layer protocol data unit (MAC PDU) matches a two-step non-conflicting random access preamble transmitted by the terminal device.

[0131] In operation 11032, the subprotocol data unit (subPDU) includes at least a timing advance instruction (TAC), which is, for example, 12 bits long.

[0132] In at least one embodiment, after a terminal device has transmitted a first message (MsgA), it can monitor the PDCCH addressed to MsgB-RNTI within a second message (MsgB-ResponseWindow), and if it has successfully demodulated a medium access control layer protocol data unit (MAC PDU) scheduled by a physical downlink control channel addressed to the second message radio network transient identifier (MsgB-RNTI), and if it is determined that a random access preamble indicator (RAPID) in one of the subprotocol data units (subPDU) of the medium access control layer protocol data unit (MAC PDU) matches a two-step non-conflicting random access preamble transmitted by the terminal device, then it means that the second message (MsgB) transmitted by the network device has been received and this random access has been successfully completed.

[0133] In at least one embodiment, operation 1103 may include at least one of operation 11031 and operation 11032. If operation 1103 includes both operation 11031 and operation 11032, the terminal device can, after sending the first message (MsgA), monitor both the PDCCH addressed to C-RNTI and the PDCCH addressed to MsgB-RNTI within the second message (MsgB-ResponseWindow), and determine in operation 11031 and operation 11032, respectively, that the random access response has been successfully received, and thus consider this random access to have been successfully completed. For example, if the network device successfully demodulates MsgA PUSCH, it can send a TAC MAC CE scheduled by a PDCCH addressed to C-RNTI to the terminal device, and if it fails to successfully demodulate MsgA PUSCH, it can send a MAC PDU scheduled by a PDCCH addressed to MsgB-RNTI to the terminal device.

[0134] In at least one embodiment, if a network device successfully demodulates a two-step non-conflicting random access preamble but fails to successfully demodulate a physical uplink sharing channel (PUSCH), the network device can schedule a terminal device to retransmit the PUSCH, for example, by scheduling the retransmission of the PUSCH using a physical downlink control channel (PDCCH) addressed to a cell radio network temporary identifier (C-RNTI), or by scheduling the retransmission of the PUSCH using a physical downlink control channel (PDCCH) addressed to a second message radio network temporary identifier (MsgB-RNTI). In the present invention, the two methods described above for scheduling a terminal device to retransmit the PUSCH can be optionally combined with two methods for determining that the reception of the random access response was successful in operations 11031 and 11032 and that this random access was successfully completed.

[0135] As shown in Figure 11, the random access method may further include the following operations.

[0136] Operation 1104: Receive uplink grant information in a physical downlink control channel (PDCCH) addressed to a cell radio network temporary identifier (C-RNTI), and use the uplink grant information to schedule retransmissions for the Hybrid Automatic Retransmission Request (HARQ) process of the uplink shared channel; Operation 1105: Retransmit (send) HARQ processes on the physical uplink shared channel (PUSCH) based on uplink grants.

[0137] In at least one embodiment, operation 1104 follows operation 11031. In operation 1104, after sending the first message (MsgA), the terminal device can monitor the PDCCH addressed to C-RNTI within the second message (MsgB-ResponseWindow) and receive uplink grant (UL Grant) information in the PDCCH, and if the PDCCH has scheduled a retransmission of the HARQ process for MsgA, it means that the network did not successfully demodulate the PUSCH of MsgA. Of this, the uplink grant information includes the uplink resources and modulation and coding scheme (MCS) used to retransmit the physical uplink shared channel (PUSCH).

[0138] In operation 1105, the terminal device retransmits the HARQ process on the physical uplink shared channel (PUSCH) based on the uplink grant information from operation 1104.

[0139] As shown in Figure 11, the random access method may further include the following operations.

[0140] Operation 1106: Successfully demodulated a Medium Access Control Layer Protocol Data Unit (MAC PDU) scheduled by a physical downlink control channel addressed to a Second Message Radio Network Temporary Identifier (MsgB-RNTI), and determined that the RAPID in one subprotocol data unit (subPDU) of the Medium Access Control Layer Protocol Data Unit (MAC PDU) matches a two-step non-conflicting random access preamble transmitted by the terminal device, and determined that the random access response was successfully received, and that this random access was successfully completed, with the subprotocol data unit (subPDU) containing at least uplink grant information; Operation 1107: Resend the physical uplink shared channel (PUSCH) based on the uplink grant information in the subprotocol data unit (subPDU).

[0141] In at least one embodiment, operation 1106 follows operation 11031. Operation 1106 means that after the terminal device has sent the first message (MsgA), it can monitor the PDCCH addressed to MsgB-RNTI within the second message (MsgB-ResponseWindow), and has successfully demodulated the Media Access Control Layer Protocol Data Unit (MAC PDU) scheduled by the PDCCH addressed to MsgB-RNTI, and the Random Access Preamble Indicator (RAPID) in one subprotocol data unit (subPDU) of the Media Access Control Layer Protocol Data Unit (MAC PDU) matches the two-step non-conflicting random access preamble transmitted by the terminal device, and the subprotocol data unit (subPDU) contains uplink grant (UL Grant) information, then the network device is unable to successfully demodulate the MsgA PUSCH and will schedule a retransmission of the MsgA PUSCH by the MAC PDU. Among these, the uplink grant information includes the uplink resources and modulation and coding scheme (MCS) used for retransmission of the physical uplink shared channel (PUSCH).

[0142] In operation 1107, the terminal device retransmits the physical uplink shared channel (PUSCH) based on the uplink grant information from operation 1106.

[0143] As shown in Figure 11, operation 1104 schedules a retransmission of PUSCH using a physical downlink control channel (PDCCH) addressed to the cell radio network temporary identifier (C-RNTI); operation 1106 schedules a retransmission of PUSCH using a MAC PDU scheduled by a physical downlink control channel (PDCCH) addressed to the second message radio network temporary identifier (MsgB-RNTI). Operations 1104 and 1106 follow operation 11031, meaning that if the terminal device determines that it has successfully received MsgB based on operation 11031, it can further retransmit PUSCH based on operation 1104 or operation 1106.

[0144] In this invention, if the terminal device determines that it has successfully received MsgB based on operation 11032 and considers this random access to have been successfully completed, it can then retransmit PUSCH. This means that even if the PUSCH of the first message (MsgA) is not properly received by the network device, the terminal device can consider this random access to have been successfully completed because the network device recognizes the terminal device by a dedicated preamble.

[0145] As shown in Figure 11, the random access method may further include the following operations.

[0146] Operation 1108: Operation 11032 includes a subprotocol data unit (subPDU) containing a timing advance instruction (TAC), which further includes uplink grant (UL Grant) information, and the physical uplink shared channel (PUSCH) of the first message (MsgA) is retransmitted based on this uplink grant information.

[0147] Operation 1108 follows Operation 11032, and if Operation 11032 further includes uplink grant (UL Grant) information in the subprotocol data unit (subPDU), it means that a retransmission of the PUSCH is scheduled by the MAC PDU successfully demodulated in Operation 11032, in which case the terminal device retransmits the PUSCH. This uplink grant information includes the uplink resources and modulation and coding scheme (MCS) used for retransmitting the physical uplink shared channel (PUSCH).

[0148] As shown in Figure 11, the random access method may further include the following operations.

[0149] Operation 1109: Receive uplink grant information in a physical downlink control channel (PDCCH) addressed to a Cell Radio Network Temporary Identifier (C-RNTI), and use the uplink grant information to schedule retransmissions for the Hybrid Automatic Retransmission Request (HARQ) process of the uplink shared channel; Operation 1110: Retransmit (send) HARQ processes on the physical uplink shared channel (PUSCH) based on uplink grants.

[0150] In at least one embodiment, operation 1109 follows operation 11032. In operation 1109, after sending the first message (MsgA), the terminal device can monitor the PDCCH addressed to C-RNTI within the second message (MsgB-ResponseWindow) and receive uplink grant (UL Grant) information for the PDCCH, and if the PDCCH has scheduled a retransmission of the HARQ process for the PUSCH, it means that the network device did not successfully demodulate the PUSCH. The uplink grant information includes the uplink resources and modulation and coding scheme (MCS) used to retransmit the physical uplink shared channel (PUSCH).

[0151] In operation 1110, the terminal device retransmits the HARQ process on the physical uplink shared channel (PUSCH) based on the uplink grant information from operation 1109.

[0152] In some other embodiments, operations 1104 and 1106 may occur before operation 11031, and operation 1109 may occur before operation 11032. That is, the terminal device may not have received MsgB when it receives a retransmission scheduling instruction for MsgA PUSCH from the network device. In this case, the terminal device does not receive the second message (MsgB) and therefore does not receive the timing advance instruction (TAC) transmitted by the network device. In such cases, the terminal does not retransmit (send) the PUSCH. For example, if the second message (msgB) is not received before operation 1104 or operation 1109, the HARQ process of the physical uplink shared channel (PUSCH) is not retransmitted based on the uplink grant information in the PDCCH; also, for example, if the second message (msgB) is not received before operation 1106, the PUSCH is not retransmitted based on the uplink grant information in the MAC PDU.

[0153] In at least one embodiment, operation 1103 determines that random access is complete when the terminal device receives not only the second message (MsgB) transmitted by the network device, but also the response to the Hybrid Automatic Retransmission Request (HARQ) transmitted by the network device for the uplink shared channel.

[0154] In at least one embodiment, the response to the Hybrid Auto-Retransmission Request (HARQ) is the exact response to the Hybrid Auto-Retransmission Request carried by the Physical Downlink Control Channel (PDCCH); or the response to the Hybrid Auto-Retransmission Request (HARQ) is new data for the Hybrid Auto-Retransmission Request process scheduled by the Physical Downlink Control Channel (PDCCH).

[0155] The following four examples illustrate the random access method of the embodiment of the third aspect of the present invention.

[0156] [Example 1] In Example 1, MsgB is a TAC MAC CE scheduled by a PDCCH addressed to C-RNTI, and the network device schedules the retransmission of MsgA's PUSCH using a PDCCH scrambled by C-RNTI.

[0157] The operation of the terminal device is as follows:

[0158] After sending MsgA, the terminal device monitors the PDCCH, which is addressed to C-RNTI within the MsgB-ResponseWindow.

[0159] If a terminal device receives a PDCCH addressed to C-RNTI, successfully demodulates the MAC PDU scheduled by the PDCCH, and the MAC PDU contains one 12-bit TAC MAC CE, the terminal device determines that it has successfully received a random access response. Of this, the TAC MAC CE contains an uplink time advance instruction (TAC) that the network device sends to the terminal device.

[0160] When a terminal device receives a PDCCH that schedules the retransmission of the MsgA HARQ process (i.e., when the PDCCH addressed to C-RNTI contains uplink grant information), the terminal device retransmits the MsgA PUSCH.

[0161] Furthermore, if a terminal device does not receive MsgB but receives a PDCCH scrambled by C-RNTI for scheduling a retransmission of MsgA PUSCH, the terminal device will drop this retransmission instruction (i.e., will not retransmit MsgA PUSCH). This is because the terminal device has not received the TAC transmitted by the network device.

[0162] The operation of the terminal device is as follows:

[0163] The network device will send MsgB as long as MsgA preamble is successfully demodulated.

[0164] If a network device can successfully demodulate only the MsgA preamble but not the MsgA PUSCH, the network device may need to schedule a retransmission of the MsgA PUSCH using a PDCCH scrambled by C-RNTI. For example, the network device may first send the MsgB, and then send a PDCCH scrambled by C-RNTI to schedule a retransmission of the MsgA PUSCH.

[0165] If the network device successfully demodulates an uplink shared channel (i.e., MsgA PUSCH), it sends a response to the Hybrid Automatic Retransmission Request (HARQ) transmitted for the uplink shared channel to the terminal device, and the response to the Hybrid Automatic Retransmission Request (HARQ) is used to indicate that the network device has successfully demodulated the uplink shared channel.

[0166] [Example 2] In Example 2, MsgB is a TAC MAC CE scheduled by a PDCCH addressed to C-RNTI, and a Random Access Response (RAR) scheduled by a PDCCH scrambled by MsgB-RNTI. The network device uses the Random Access Response scheduled by the PDCCH scrambled by MsgB-RNTI to schedule the retransmission of MsgA PUSCH.

[0167] The operation of the terminal device is as follows:

[0168] After sending MsgA, the terminal device simultaneously monitors the PDCCH addressed to C-RNTI and the PDCCH addressed to MsgB-RNTI within the MsgB-ResponseWindow.

[0169] If a terminal device receives a PDCCH addressed to C-RNTI, successfully demodulates the MAC PDU scheduled by the PDCCH, and the MAC PDU contains one 12-bit TAC MAC CE, the terminal device determines that it has successfully received a random access response and that the random access has been successfully completed. The TAC MAC CE contains an uplink time advance instruction that the network device sends to the terminal device.

[0170] The terminal device receives a PDCCH addressed to MsgB-RNTI, successfully demodulates the MAC PDU scheduled by the PDCCH, and the RAPID in one of the sub-PDUs of the MAC PDU matches the terminal device's two-step non-conflicting random access preamble (i.e., Msg A preamble), of which the RAR in the sub-PDU contains at least 12 bits of TAC and UL Grant information. In this case, the terminal device determines that it has successfully received the random access response. The terminal device then retransmits MsgA PUSCH based on the UL Grant information contained in the RAR in the sub-PDU, in which the UL Grant information is used to indicate the uplink resources and MCS to be used for retransmitting MsgA PUSCH.

[0171] The operation of the network device is as follows:

[0172] If the network device successfully demodulates the MsgA preamble and MsgA PUSCH, it transmits a MAC PDU (i.e., MsgB) that includes a TAC MAC CE and is scheduled by a PDCCH scrambled by C-RNTI, and also transmits a response to a Hybrid Auto Retransmission Request (HARQ) transmitted for the uplink shared channel, the response to which the Hybrid Auto Retransmission Request (HARQ) is used to indicate that the network device has successfully demodulated the uplink shared channel.

[0173] If a network device can successfully demodulate only the MsgA preamble but not the PUSCH, the network device sends a random access response, which is scheduled by a PDCCH scrambled by MsgB-RNTI. The UL Grant information included in the random access response is used by the terminal device to retransmit the MsgA PUSCH.

[0174] [Example 3] In Example 3, MsgB is a random access response scheduled by a PDCCH scrambled by MsgB-RNTI. The network device uses the PDCCH scrambled by C-RNTI to schedule the retransmission of MsgA PUSCH.

[0175] The operation of the terminal device is as follows:

[0176] After sending MsgA, the terminal device monitors the PDCCH, which is addressed to MsgB-RNTI within the MsgB-ResponseWindow.

[0177] If a terminal device receives a PDCCH addressed to MsgB-RNTI, successfully demodulates the MAC PDU scheduled by the PDCCH, and the RAPID in one sub-PDU of the MAC PDU matches a two-step non-conflicting random access preamble (i.e., MsgA preamble) transmitted by the terminal device, the terminal device considers that it has successfully received a random access response, of which the RAR in the sub-PDU includes at least 12 bits of TAC.

[0178] If the terminal device receives a PDCCH that schedules the retransmission of the MsgA HARQ process, which is scrambled by C-RNTI, the terminal device will retransmit the MsgA PUSCH.

[0179] If a terminal device does not receive MsgB but instead receives a PDCCH instruction to schedule a retransmission of MsgA PUSCH, which will be scrambled by C-RNTI, the terminal device will drop this retransmission instruction because it has not received the TAC transmitted by the network device.

[0180] The operation of the network device is as follows:

[0181] The network device will send msgB as long as the MsgA preamble is successfully demodulated.

[0182] If a network device can successfully demodulate only the preamble but not the MsgA PUSCH, the network device must further schedule a retransmission of the MsgA PUSCH using a PDCCH scrambled by C-RNTI. In particular, the network device can send the MsgB first and then schedule a retransmission of the MsgA PUSCH.

[0183] If the network device successfully demodulates the MsgA PUSCH, it further transmits a response to the Hybrid Automatic Retransmission Request (HARQ) sent for the uplink shared channel, and the Hybrid Automatic Retransmission Request (HARQ) response is used to indicate that the network device has successfully demodulated the uplink shared channel.

[0184] [Example 4] In Example 4, MsgB is a random access response scheduled by a PDCCH scrambled by MsgB-RNTI. The network device uses the random access response (RAR) scheduled by the PDCCH scrambled by MsgB-RNTI to schedule the retransmission of MsgA PUSCH.

[0185] The operation of the terminal device is as follows:

[0186] After sending MsgA, the terminal device monitors the PDCCH, which is addressed to MsgB-RNTI within the MsgB-ResponseWindow.

[0187] The terminal device receives a PDCCH addressed to MsgB-RNTI, successfully demodulates the MAC PDU scheduled by the PDCCH, and the RAPID in one sub-PDU of the MAC PDU matches a two-step non-conflicting random access preamble (i.e., MsgA preamble) transmitted by the terminal device, where the RAR in the sub-PDU includes at least 12 bits of TAC, in which case the terminal device considers the reception of the random access response to have been successful. If the RAR in the sub-PDU includes UL Grant information (e.g., the UL Grant field is valid (value)), the terminal device retransmits the MsgA PUSCH based on the UL Grant information, where the UL Grant information is used to indicate the uplink resources and MCS to be used for retransmitting the MsgA PUSCH.

[0188] The operation of the network device is as follows:

[0189] If the network device successfully demodulates the MsgA preamble and MsgA PUSCH, it transmits a MAC PDU (i.e., MsgB) that includes a TAC MAC CE and is scheduled by a PDCCH scrambled by C-RNTI, and also transmits a response to a Hybrid Auto Retransmission Request (HARQ) transmitted for the uplink shared channel, the response to which the Hybrid Auto Retransmission Request (HARQ) is used to indicate that the network device has successfully demodulated the uplink shared channel.

[0190] If the network device can successfully demodulate only the preamble but not the PUSCH, the network device sends a random access response, which is scheduled by a PDCCH scrambled by MsgB-RNTI. The random access response includes TAC and UL Grant information, which the terminal device uses to retransmit MsgA PUSCH.

[0191] According to a third aspect of the embodiment of the present invention, in a two-step non-conflicting random access procedure, the terminal device can receive an appropriate random access response and accurately perform operations such as retransmitting a PUSCH.

[0192] <Fourth aspect of the example> A fourth aspect of the embodiment of the present invention provides a random access method which is applied to a network device, for example, network device 301, which receives a random access request transmitted by terminal device 301 and also transmits a random access response to terminal device 302.

[0193] The random access method in the fourth aspect of the embodiment of the present invention relates to operations performed by a network device in a two-step non-conflicting random access procedure, and corresponds to operations performed by a terminal device in a two-step non-conflicting random access procedure relating to the random access method in the third aspect of the embodiment of the present invention.

[0194] Figure 13 is a diagram illustrating a random access method in the fourth aspect of an embodiment of the present invention, and as shown in Figure 13, the random access method includes the following operations.

[0195] Operation 1301: Send a two-step non-conflicting random access resource configuration to the terminal device; Operation 1302: Receive a first message (MsgA) of a two-step non-conflicting random access procedure from the terminal device, the first message including a two-step non-conflicting random access preamble (MsgA preamble) and a physical uplink sharing channel (MsgA PUSCH).

[0196] In operation 1301, the network device 301 can transmit a two-step non-conflicting random access resource configuration to the terminal device 302 via physical downlink control channel (PDCCH) or radio resource control (RRC) signaling. Of these, the two-step non-conflicting random access resource includes a dedicated two-step random access resource, which includes at least one synchronization signal block (SSB) or channel status information reference signal (CSI-RS) and a dedicated two-step random access preamble corresponding to the synchronization signal block (SSB) or channel status information reference signal (CSI-RS).

[0197] As shown in Figure 13, the random access method further includes the following steps.

[0198] Operation 1303: Successfully demodulated a 2-step non-conflicting random access preamble; Operation 1304: Send a second message (MsgB) to the terminal device.

[0199] As shown in Figure 13, operation 1304 includes the following operations.

[0200] Operation 13041: Transmit a physical downlink control channel (PDCCH) addressed to a cell radio network temporary identifier (C-RNTI) to the terminal device, and also transmit a medium access control layer protocol data unit (MAC PDU) scheduled by the PDCCH, the MAC PDU of which includes a timing advance instruction medium access layer control element (TAC MAC CE).

[0201] As shown in Figure 13, operation 1304 further includes the following operations.

[0202] Operation 13042: Transmit to the terminal device a physical downlink control channel (PDCCH) addressed to a second message radio network temporary identifier (msgB-RNTI), and also transmit a MAC PDU scheduled by the PDCCH, wherein the RAPID in one subprotocol data unit (subPDU) contained in the MAC PDU matches the two-step non-conflicting random access preamble, and the subPDU contains at least a timing advance instruction (TAC).

[0203] In at least one embodiment, the network device may send a second message (MsgB) to the terminal device using at least one of operations 13041 and 13042. The network device may also send a MsgB using both operations 13041 and 13042. For example, if the network device successfully demodulates PUSCH, it sends a MsgB using operation 13041, and if the network device fails to successfully demodulate PUSCH, it sends a MsgB using operation 13042.

[0204] In at least one embodiment, the network device successfully demodulates a two-step non-conflicting random access preamble and sends a MsgB using operation 13041. If the network device was able to successfully demodulate the two-step non-conflicting random access preamble but failed to successfully demodulate the physical uplink shared channel (PUSCH), it can schedule a retransmission of the PUSCH.

[0205] In at least one embodiment, the network device can schedule a retransmission of PUSCH after operation 13041.

[0206] As shown in Figure 13, the random access method further includes the following steps.

[0207] Operation 1305: If a two-step non-conflicting random access preamble is successfully demodulated but the uplink shared channel is not successfully demodulated, a physical downlink control channel (PDCCH) addressed to a cell radio network temporary identifier (C-RNTI) is transmitted to the terminal device, the PDCCH containing uplink grant information, the uplink grant information is used to schedule a retransmission of the HARQ process for the uplink shared channel; Operation 1306: Based on the uplink grant information, receive a retransmission of the uplink shared channel HARQ process performed by the terminal device.

[0208] Operation 1305 allows scheduling of PUSCH retransmissions using a physical downlink control channel (PDCCH) addressed to a cell radio network temporary identifier (C-RNTI). As shown in Figure 13, operation 1305 follows operation 13041, meaning that Msg B is sent first, and then scheduling is performed for the retransmission of Msg A.

[0209] As shown in Figure 13, the random access method further includes the following operations.

[0210] Operation 1307: If the two-step non-conflicting random access preamble is successfully demodulated but the uplink sharing channel is not successfully demodulated, transmit to the terminal device a physical downlink control channel (PDCCH) addressed to a second message radio network temporary identifier (msgB-RNTI), and also transmit a MAC PDU scheduled by the PDCCH, wherein the RAPID in one subprotocol data unit (subPDU) contained in the MAC PDU matches the two-step non-conflicting random access preamble, and the subPDU contains at least uplink grant information; Operation 1308: Based on the uplink grant information in the subPDU, receive the physical uplink shared channel retransmitted by the terminal device.

[0211] Operation 1307 allows scheduling a retransmission of a PUSCH using a MAC PDU scheduled by a physical downlink control channel (PDCCH) addressed to the Second Message Radio Network Temporary Identifier (MsgB-RNTI).

[0212] The network device can schedule a retransmission of PUSCH using any one of operations 1305 and 1307.

[0213] In at least one other embodiment, if the network device has successfully demodulated a two-step non-conflicting random access preamble and has sent a MsgB using operation 13041, and the network device has successfully demodulated the two-step non-conflicting random access preamble but has not successfully demodulated the physical uplink shared channel (PUSCH), the network device may also schedule a retransmission of the PUSCH.

[0214] As shown in Figure 13, the random access method further includes the following steps.

[0215] Operation 1309: Based on the uplink grant information in the subPDU, receive the physical uplink shared channel retransmitted by the terminal device.

[0216] For example, if a network device successfully demodulates a two-step non-conflicting random access preamble but fails to successfully demodulate the uplink shared channel, and in operation 13042 the subPDU containing the Timing Advance Instruction (TAC) further includes uplink grant information for the terminal device to retransmit the uplink shared channel PUSCH, that is, scheduling the retransmission of PUSCH using a MAC PDU scheduled by a physical downlink control channel (PDCCH) addressed to a second message radio network temporary identifier (MsgB-RNTI), in which case the network device can receive the terminal device's retransmission of the physical uplink shared channel (PUSCH) based on the uplink grant information in the subPDU in operation 1309.

[0217] As shown in Figure 13, the random access method further includes the following steps.

[0218] Operation 1310: If the network device successfully demodulates a two-step non-conflicting random access preamble but fails to successfully demodulate the uplink shared channel, it transmits a physical downlink control channel (PDCCH) addressed to a cell radio network temporary identifier (C-RNTI) to the terminal device, the PDCCH containing uplink grant information, which is used to schedule the retransmission of the uplink shared channel's HARQ process; Operation 1311: Based on the uplink grant information, receive a retransmission of the HARQ process on the uplink shared channel transmitted by the terminal device.

[0219] Operation 1310 allows scheduling of PUSCH retransmissions using a physical downlink control channel (PDCCH) addressed to a cell radio network temporary identifier (C-RNTI). As shown in Figure 13, operation 1310 follows operation 13042, meaning that Msg B is sent first, and then scheduling is performed for the retransmission of Msg A.

[0220] In at least one embodiment, operation 1304 sends a second message (MsgB) to the terminal device if the network device successfully demodulates the two-step non-conflicting random access preamble and uplink shared channel.

[0221] In other words, operation 1304 has two implementation methods: one is to send a second message (MsgB) to the terminal device as long as Msg A preamble is successfully demodulated in operation 1303; the other is to send a second message (MsgB) to the terminal device if the network device successfully demodulates not only Msg A preamble but also MsgA PUSCH.

[0222] In some embodiments, if an uplink shared channel is successfully demodulated, the network device may further send a response to the Hybrid Automatic Retransmission Request (HARQ) sent for that uplink shared channel to the terminal device. For example, if operation 1304 sends a second message (MsgB) to the terminal device in operation 1303, provided that Msg A preamble is successfully demodulated, then when the uplink shared channel is successfully demodulated, the network device sends a response to the HARQ sent for that uplink shared channel to the terminal device.

[0223] As shown in Figure 13, the random access method further includes the following steps.

[0224] Operation 1312: If the uplink shared channel is successfully demodulated, the terminal device is sent a response to the Hybrid Automatic Retransmission Request (HARQ) transmitted for the uplink shared channel, and the response to the Hybrid Automatic Retransmission Request (HARQ) is used to indicate that the network device has successfully demodulated the uplink shared channel.

[0225] In operation 1312, the response to the Hybrid Automatic Retransmission Request (HARQ) is the exact response to the Hybrid Automatic Retransmission Request carried by the physical downlink control channel; or, the response to the Hybrid Automatic Retransmission Request (HARQ) is new data for the Hybrid Automatic Retransmission Request process scheduled by the physical downlink control channel.

[0226] According to a fourth aspect of the embodiments of the present invention, a network device can transmit an appropriate random access response in a two-step non-conflicting random access procedure.

[0227] <Fifth aspect of the example> A fifth aspect of the embodiment of the present invention provides a random access device which is applied to a terminal device, for example, terminal device 302.

[0228] Figure 14 shows a random access device in the fifth aspect of an embodiment of the present invention, and as shown in Figure 14, the random access device 1400 includes a first processing unit 1401.

[0229] The first processing unit 1401 can perform the random access method described in the first aspect of the embodiment of the present invention. For a description of how the first processing unit 1401 performs the random access method, refer to the description of the random access method in the first aspect of the embodiment of the present invention.

[0230] Figure 15 shows another random access device in a fifth aspect of an embodiment of the present invention, and as shown in Figure 15, the random access device 1500 includes a third processing unit 1501.

[0231] The third processing unit 1501 can perform the random access method described in the third aspect of the embodiment of the present invention. For a description of how the third processing unit 1501 performs the random access method, refer to the description of the random access method in the third aspect of the embodiment of the present invention.

[0232] <Sixth aspect of the example> In a sixth aspect of the embodiments of the present invention, a random access device is provided which is applied to a network device, for example, a network device 301.

[0233] Figure 16 shows a random access device in the sixth aspect of an embodiment of the present invention, and as shown in Figure 16, the random access device 1600 includes a second processing unit 1601.

[0234] The second processing unit 1601 can perform the random access method described in the second aspect of the embodiment of the present invention. For a description of how the second processing unit 1601 performs the random access method, refer to the description of the random access method in the second aspect of the embodiment of the present invention.

[0235] Figure 17 shows another random access device in a sixth aspect of an embodiment of the present invention, and as shown in Figure 17, the random access device 1700 includes a fourth processing unit 1701.

[0236] The fourth processing unit 1701 can perform the random access method described in the fourth aspect of the embodiment of the present invention. For a description of how the fourth processing unit 1701 performs the random access method, refer to the description of the random access method in the fourth aspect of the embodiment of the present invention.

[0237] <Seventh aspect of the example> The seventh aspect of the embodiment of the present invention provides a terminal device, which includes the random access device 1400 or 1500 described in the third aspect of the embodiment.

[0238] Figure 18 is a system configuration diagram of a terminal device 1800 in the seventh aspect of an embodiment of the present invention. As shown in Figure 18, the terminal device 1800 may include a processor 1810 and a memory device 1818, the memory device 1818 being connected to the processor 1810. Note that this figure is merely illustrative, and telecommunications functions or other functions can be realized by supplementing or substituting this configuration with other types of configurations.

[0239] In one embodiment, the functions of the random access device 1400 or 1500 can be integrated into the processor 1810, which is configured to perform the random access method in the first aspect of the embodiment.

[0240] In another implementation, the random access device 1400 or 1500 may be located separately from the processor 1810. For example, the random access device 1400 or 1500 may be configured as a chip connected to the processor 1810, and the functions of the random access device 1400 or 1500 can be realized by controlling the processor 1810.

[0241] As shown in Figure 18, the terminal device 1800 may further include a communication module 1830, an input unit 1840, a display unit 1850, a power supply 1860, and the like. However, the terminal device 1800 does not need to include all the components shown in Figure 18. Furthermore, the terminal device 1800 may include components not shown in Figure 18, for which prior art can be consulted.

[0242] As shown in Figure 18, the processor 1810 may be referred to as a controller or operation control, and may include a microprocessor or other processing device and / or logic device, and the processor 1810 can receive inputs and control the operation of each component of the terminal device 1800.

[0243] The memory unit 1820 may include, for example, one or more of a buffer, fresh memory, HDD, movable medium, volatile memory, non-volatile memory, or other suitable devices, and can store various types of data, as well as programs for information processing. The processor 1810 can perform information storage and processing by executing the program stored in the memory unit 1818. Since the functions of the other components are similar to those of conventional devices, a detailed explanation of them is omitted here. Furthermore, each component of the terminal device 1800 may be realized by dedicated hardware, firmware, software, or a combination thereof, but all of these fall within the scope of the present invention.

[0244] <Eighth side view of the example> The eighth aspect of the embodiment of the present invention provides a network device, which includes the random access device 1600 or 1700 described in the fourth aspect of the embodiment.

[0245] Figure 19 is a diagram showing the configuration of a network device in the eighth aspect of an embodiment of the present invention. As shown in Figure 19, the network device 1900 may include a processor 1910 and a memory unit 1920. The memory unit 1920 is connected to the processor 1910. The memory unit 1920 can store various types of data, can store a program 1930 for information processing, and can receive various types of information transmitted by a user device and transmit request information and the like to the user device by executing the program 1930 under the control of the processor 1910.

[0246] In one embodiment, the functions of the random access device 1600 or 1700 can be integrated into the processor 1910. The processor 1910 is configured to perform the random access method described in the second aspect of the embodiment of the present invention.

[0247] In another implementation, the random access device 1600 or 1700 may be located separately from the processor 1910. For example, the random access device 1600 or 1700 may be configured as a chip connected to the processor 1910, and the functions of the random access device 1600 or 1700 can be realized by controlling the processor 1910.

[0248] Furthermore, as shown in Figure 19, the network device 1900 may also include a transceiver 1940, an antenna 1950, and the like. Since the functions of these components are similar to those in the prior art, a detailed explanation is omitted here. Note that the network device 1900 does not need to include all the components shown in Figure 19. Also, the network device 1900 may include components not shown in Figure 19; for these, prior art can be referenced.

[0249] <Ninth side view of the example> In the ninth aspect of the embodiment of the present invention, a communication system is further provided, which includes the network device described in the eighth aspect of the embodiment and the terminal device described in the seventh aspect of the embodiment.

[0250] Furthermore, the above-described apparatus and method may be implemented by software or hardware, or by a combination of hardware and software. The present invention further relates to a computer-readable program as described below, that is, the program, when executed by a logic component, causes the logic component to implement the above-described apparatus or component, or to the logic component to implement the above-described various methods or steps. The logic component may be, for example, an FPGA (Field Programmable Gate Array), a microprocessor, or a processor used in a computer. The present invention further relates to a storage medium storing the above-described program, for example, a hard disk, a magnetic disk, an optical hard disk, a DVD, or a flash memory.

[0251] Furthermore, one or more combinations of the functional blocks shown in the drawings and / or one or more combinations of functional blocks may be implemented as a general-purpose processor, digital signal processor (DSP), application-specific integrated circuit (ASIC), field-programmable gate array (FPGA) or other programmable logic component, discrete gate or transistor logic component, discrete hardware assembly or any other suitable combination for performing the functions described herein. Also, one or more combinations of the functional blocks shown in the drawings and / or one or more combinations of functional blocks may further be configured as a combination of computing devices, for example, a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors connected to a DSP by communication or any other combination of any other configuration.

[0252] Although preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and any modification to the present invention falls within the technical scope of the present invention as long as it does not deviate from the spirit of the invention.

[0253] Furthermore, the following additional information is disclosed regarding the above-mentioned embodiments.

[0254] (Note 1) A random access method applied to terminal devices, Based on the configuration information for the bandwidth part (BWP) for random access selected by the terminal device and the downlink reference signal reception power measured by the terminal device, the random access type is determined; Select random access resources; and A method comprising sending an initial message for random access to the random access resource.

[0255] (Note 2) The method described in Appendix 1, Determining a random access type based on the configuration information of the bandwidth part selected by the terminal device and the downlink reference signal reception power measured by the terminal device is where two-step random access resources are configured in the bandwidth part (BWP) selected by the terminal device, and when the downlink reference signal reception power measured by the terminal device is higher than a first threshold, determining the random access type as two-step random access, or when only two-step random access resources are configured in the bandwidth part (BWP) selected by the terminal device, determining the random access type as two-step random access; otherwise, determining the random access type as four-step random access, a method.

[0256] (Appendix 3) The method according to Appendix 2, when the terminal device selects an additional uplink link (SUL) carrier to perform random access, the first threshold is the first threshold of the additional uplink link, when the terminal device selects a normal (usual) uplink link (NUL) carrier to perform random access, the first threshold is the first threshold of the normal uplink link, a method.

[0257] (Appendix 4) The method according to Appendix 2, where the first threshold is a measurement threshold parameter based on a synchronization signal block (SSB) set by radio resource control (RRC) signaling, a method.

[0258] (Appendix 5) The method according to Appendix 2, The method wherein the two-step random access resource includes a synchronous signal block (SSB) for two-step random access, a two-step random access preamble, a two-step random access preamble access opportunity, and a two-step random access physical uplink shared channel (PUSCH) resource.

[0259] (Note 6) The method described in Appendix 2, The step of selecting random access resources is: After determining that the random access type is two-step random access, a two-step random access resource selection is performed; A method comprising determining the random access type to be a four-step random access, and then performing a four-step random access resource selection.

[0260] (Note 7) The method described in Appendix 6, The two-step process for selecting random access resources is as follows: If the two-step non-conflicting random access resource selection criteria are met, select the two-step non-conflicting random access resource. A method comprising selecting a two-step conflicting random access resource if the two-step non-conflicting random access resource selection criteria are not met.

[0261] (Note 8) The method described in Appendix 6, The two-step process for selecting random access resources is as follows: If the two-step non-conflicting random access resource selection criteria are met, select the two-step non-conflicting random access resource. If the two-step selection criteria for non-conflicting random access resources are not met, but the selection criteria for non-conflicting random access resources are met, then the non-conflicting random access resources are selected. A method comprising selecting a two-step conflicting random access resource if the two-step selection criteria for non-conflicting random access resources are not satisfied.

[0262] (Note 9) The method described in Appendix 6, The four steps involved in selecting random access resources are: If the selection criteria for non-conflicting random access resources are met, select the non-conflicting random access resources. A method for selecting a competing random access resource in four steps, if the selection criteria for a non-competing random access resource are not met.

[0263] (Note 10) The method described in Appendix 6, The four steps involved in selecting random access resources are: If the two-step non-conflicting random access resource selection criteria are met, select the two-step non-conflicting random access resource. If the two-step selection criteria for non-conflicting random access resources are not met, but the selection criteria for non-conflicting random access resources are met, then the non-conflicting random access resources are selected. A method for selecting a four-step conflicting random access resource if the two-step non-conflicting random access resource selection criteria are not met, and the other non-conflicting random access resource selection criteria are also not met.

[0264] (Note 11) The method described in Appendix 7, 8, or 10, The two-step selection criteria for non-conflicting random access resources were satisfied. The terminal device is configured with a dedicated two-step random access resource by a network device, and the reference signal reception power (RSRP) of at least one synchronization signal block (SSB) or channel status information reference signal (CSI-RS) in the dedicated two-step random access resource is higher than a second threshold. A method wherein the dedicated two-step random access resource includes at least one synchronization signal block (SSB) or channel status information reference signal (CSI-RS) and a dedicated two-step random access preamble corresponding to the synchronization signal block (SSB) or channel status information reference signal (CSI-RS).

[0265] (Note 12) The method described in Appendix 7, 8, or 10, The two-step process for selecting non-conflicting random access resources is as follows: Select a dedicated two-step random access preamble and one synchronization signal block (SSB) or channel status information reference signal (CSI-RS) to transmit the physical uplink shared channel (PUSCH); Set the two-step random access preamble to be transmitted as a dedicated two-step random access preamble corresponding to the synchronization signal block (SSB) or channel status information reference signal (CSI-RS); Determine the next two-step random access preamble access opportunity corresponding to one available synchronization signal block (SSB) or channel status information reference signal (CSI-RS); and A method comprising determining an uplink grant based on the random access preamble of the two steps and the physical uplink sharing channel (PUSCH) corresponding to the preamble access opportunity.

[0266] (Note 13) The method described in Appendix 12, The step of setting the two-step random access preamble to be transmitted as a dedicated two-step random access preamble corresponding to the synchronization signal block (SSB) or the channel state information reference signal (CSI-RS) is When dedicated two-step random access preambles corresponding to group A and group B are set for the synchronization signal block (SSB) or the channel state information reference signal (CSI-RS), it includes selecting the dedicated two-step random access preamble of group A or group B based on the path loss and / or the transport block size (TB size) of the first message (MsgA) of the two-step non-competitive random access procedure. The modulation and coding scheme (MCS) of the physical uplink shared channel (PUSCH) corresponding to the dedicated two-step random access preambles of group A and group B is different.

[0267] (Appendix 14) The method according to Appendix 13, The step of selecting the dedicated two-step random access preamble of group A or group B based on the path loss and / or the transport block size (TB size) of MsgA is When the path loss is less than the loss threshold and / or the transport block size (TB Size) of the first message (MsgA) is greater than the transport block size threshold, set the two-step random access preamble to be transmitted as the dedicated two-step random access preamble of group B; Otherwise, it includes setting the two-step random access preamble to be transmitted as the dedicated two-step random access preamble of group A.

[0268] (Appendix 15) The method according to any one of Appendices 1-14, After the step of sending an initial message for random access on the random access resource, the method further: A method that, if a random access procedure is incomplete, includes re-selecting a random access resource.

[0269] (Note 16) The method described in Appendix 15, If the terminal device has selected a two-step random access resource, or if the random access type is two-step random access, A method to repeat the two-step random access resource selection when a random access procedure fails to complete successfully.

[0270] (Note 17) The method described in Appendix 16, If the random access procedure does not complete successfully, and the count for sending the random access preamble is greater than the threshold N, A method for setting the random access type to 4-step random access and performing 4-step random access resource selection.

[0271] (Note 18) The method described in Appendix 15, If the terminal has selected a 4-step random access resource, or if the random access type is 4-step random access, A method for repeating the 4-step random access resource selection process when random access fails to complete successfully.

[0272] (Note 19) The method described in Appendix 16 or 18, The step of selecting random access resources again is, A method comprising: if there are two non-conflicting random access resources that satisfy the selection criteria within the backoff time, or if it is determined that there are non-conflicting random access resources that satisfy the selection criteria, then perform a random access resource selection again before the end of the backoff time; otherwise, perform a random access resource selection again after the end of the backoff time.

[0273] (Note 20) The method described in Appendix 15, If a two-step non-conflicting random access resource is selected, then the random access being incomplete means that A method for sending a first message (MsgA) of a two-step non-conflicting random access, including not receiving a second message (MsgB) before the end of the two-step random access response receiving window (ra-ResponseWindow2-step).

[0274] (Note 21) A random access method applied to network devices, This includes transmitting configuration information for random access of one or more bandwidth parts to a terminal device. The aforementioned configuration information includes a two-step random access resource, The method wherein the two-step random access resource includes a synchronous signal block (SSB) for two-step random access, a two-step random access preamble, a two-step random access preamble access opportunity, and a two-step random access physical uplink shared channel (PUSCH) resource.

[0275] (Note 22) The method described in Appendix 21, further, This includes transmitting a first threshold to the terminal device. The first threshold is a method used by the terminal device to determine the random access type.

[0276] (Note 23) The method described in Appendix 22, The method wherein the first threshold includes a first threshold for an additional uplink link (SUL) or a first threshold for a normal uplink link.

[0277] (Note 24) The method described in Appendix 21, further, This includes setting up a dedicated two-step random access resource for the terminal device, A method wherein the dedicated two-step random access resource includes at least one synchronization signal block (SSB) or channel status information reference signal (CSI-RS) and a dedicated two-step random access preamble corresponding to the synchronization signal block (SSB) or channel status information reference signal (CSI-RS).

[0278] (Note 25) The method described in Appendix 24, further, This includes transmitting a second threshold value to the terminal device, The method wherein the second threshold is used by the terminal device to select a synchronization signal block (SSB) or a channel status information reference signal (CSI-RS).

[0279] (Note 26) The method described in Appendix 24, The synchronization signal block (SSB) or channel status information reference signal (CSI-RS) is configured with a dedicated two-step random access preamble corresponding to group A and group B. The modulation and coding schemes (MCS) of the physical uplink shared channels (PUSCH) corresponding to the dedicated two-step random access preambles of Group A and Group B are different.

[0280] (Note 27) A random access method applied to terminal devices, Receive a two-step non-conflicting random access resource configuration sent by the network device for the first message (MsgA); and This includes sending a first message (MsgA) of a two-step non-conflicting random access procedure to the network device. The first message includes a two-step non-conflicting random access preamble and a physical uplink sharing channel, in this method.

[0281] (Note 28) The method described in Appendix 27, A method in which the terminal device receives the two-step non-conflicting random access resource configuration by physical downlink control channel (PDCCH) or radio resource control (RRC) signaling.

[0282] (Note 29) The method described in Appendix 27, The aforementioned two-step non-conflicting random access resources include dedicated two-step random access resources, A method wherein the dedicated two-step random access resource includes at least one synchronization signal block (SSB) or channel status information reference signal (CSI-RS) and a dedicated two-step random access preamble corresponding to the synchronization signal block (SSB) or channel status information reference signal (CSI-RS).

[0283] (Note 30) The method described in Appendix 27, Sending the first message (MsgA) of a two-step non-conflicting random access procedure to the aforementioned network device is: Select a dedicated two-step random access preamble and one synchronization signal block (SSB) or channel status information reference signal (CSI-RS) to transmit the physical uplink shared channel (PUSCH); Set the two-step random access preamble to be transmitted as a dedicated two-step random access preamble corresponding to the synchronization signal block (SSB) or channel status information reference signal (CSI-RS); Determine the preamble access opportunity for a two-step random access corresponding to the next available synchronization signal block (SSB) or channel status information reference signal (CSI-RS); The uplink grant is determined based on the random access preamble of the two steps and the physical uplink shared channel (PUSCH) corresponding to the preamble access opportunity; and A method comprising sending the first message (MsgA) based on the uplink grant.

[0284] (Note 31) The method described in Appendix 27, further, A method comprising determining that the reception of a random access response was successful and that the random access was successfully completed upon receiving the second message (MsgB) transmitted by a network device.

[0285] (Note 32) The method described in Appendix 31, Receiving the second message (MsgB) sent by the network device means that A method comprising successfully demodulating a medium access control layer protocol data unit (MAC PDU) scheduled by a physical downlink control channel (PDCCH) addressed to a cell radio network temporary identifier (C-RNTI), wherein the medium access control layer protocol data unit includes a timing advance instruction medium access layer control element (TAC MAC CE).

[0286] (Note 33) The method described in Appendix 32, further, Uplink grant information is received in a physical downlink control channel (PDCCH) addressed to a Cell Radio Network Temporary Identifier (C-RNTI), and the uplink grant information is used to schedule retransmissions in the Hybrid Automatic Retransmission Request (HARQ) process of the uplink shared channel; and A method comprising performing HARQ retransmission of the uplink shared channel based on the uplink grant information.

[0287] (Note 34) The method described in Appendix 32, further, This includes successfully demodulating a Medium Access Control Layer Protocol Data Unit (MAC PDU) scheduled by a physical downlink control channel addressed to a Second Message Radio Network Temporary Identifier (MsgB-RNTI), and confirming that RAPID in one subprotocol data unit (subPDU) of the Medium Access Control Layer Protocol Data Unit (MAC PDU) matches a two-step non-conflicting random access preamble transmitted by the terminal device, A method wherein the subprotocol data unit (subPDU) includes at least uplink grant information.

[0288] (Note 35) The method described in Appendix 34, further, A method comprising retransmitting the physical uplink shared channel based on the uplink grant information in the subprotocol data unit (subPDU).

[0289] (Note 36) The method described in Appendix 31, Receiving the second message (MsgB) sent by the network device means that This includes successfully demodulating a Medium Access Control Layer Protocol Data Unit (MAC PDU) scheduled by a physical downlink control channel addressed to a Second Message Radio Network Temporary Identifier (MsgB-RNTI), and ensuring that a Random Access Preamble Indicator (RAPID) in one subprotocol data unit (subPDU) of the Medium Access Control Layer Protocol Data Unit (MAC PDU) matches a two-step non-conflicting random access preamble transmitted by the terminal device, A method wherein the subprotocol data unit (subPDU) includes at least a timing advance instruction (TAC).

[0290] (Note 37) The method described in Appendix 36, The aforementioned subPDU further includes uplink grant information, The method further includes retransmitting the uplink shared channel of the first message (MsgA) based on the uplink grant information.

[0291] (Note 38) The method described in Appendix 36, further, Uplink grant information is received in the physical downlink control channel (PDCCH) addressed to the Cell Radio Network Temporary Identifier (C-RNTI), and the uplink grant information is used to schedule retransmissions in the Hybrid Automatic Retransmission Request (HARQ) process of the uplink shared channel; and A method comprising retransmitting the physical uplink shared channel (PUSCH) based on the uplink grant information.

[0292] (Note 39) The methods described in appendices 33, 35, and 38, further, A method comprising not retransmitting a physical uplink shared channel (PUSCH) based on the uplink grant information if a second message (msgB) is not received when uplink grant information for scheduling the retransmission of a physical uplink shared channel (PUSCH) is received.

[0293] (Note 40) The method described in Appendix 31, Having received the second message (MsgB) transmitted by the network device and the response to the Hybrid Automatic Retransmission Request (HARQ) transmitted for the physical uplink shared channel, it is confirmed that random access has been completed. A method in which the response to the aforementioned Hybrid Automatic Retransmission Request (HARQ) is used to indicate that the network device has successfully demodulated the physical uplink shared channel.

[0294] (Note 41) The method described in Appendix 40, The response to the aforementioned Hybrid Automatic Retransmission Request (HARQ) is the exact response to the Hybrid Automatic Retransmission Request carried by the physical downlink control channel; or The response to the aforementioned Hybrid Automatic Retransmission Request (HARQ) is new data for the Hybrid Automatic Retransmission Request process, which is scheduled by the physical downlink control channel, in this method.

[0295] (Note 42) A random access method applied to network devices, Send a two-step non-conflicting random access resource configuration to the terminal device; and This includes receiving the first message (MsgA) of a two-step non-conflicting random access procedure from the terminal device, The first message includes a two-step non-conflicting random access preamble and a physical uplink sharing channel, in this method.

[0296] (Note 43) The method described in Appendix 42, A method for transmitting a two-step non-conflicting random access resource configuration to a terminal device via physical downlink control channel (PDCCH) or radio resource control (RRC) signaling.

[0297] (Note 44) The method described in Appendix 42, The method wherein the two-step non-conflicting random access resource includes a dedicated two-step random access resource, the dedicated two-step random access resource includes at least one synchronization signal block (SSB) or channel state information reference signal (CSI-RS) and a dedicated two-step random access preamble corresponding to the synchronization signal block (SSB) or channel state information reference signal (CSI-RS).

[0298] (Note 45) The method described in Appendix 42, further, The aforementioned two-step non-competitive random access preamble has been successfully demodulated; and A method comprising sending a second message (MsgB) to the terminal device.

[0299] (Note 46) The method described in Appendix 45, The step of sending a second message (MsgB) to the terminal device is: The terminal device is to transmit a physical downlink control channel (PDCCH) addressed to a cell radio network temporary identifier (C-RNTI), and also to transmit a media access control layer protocol data unit (MAC PDU) scheduled by the PDCCH. The MACPDU includes a Timing Advance Instruction Medium Access Layer Control Element (TAC MAC CE) in the method.

[0300] (Note 47) The method described in Appendix 46, further, If the two-step non-conflicting random access preamble is successfully demodulated, but the uplink shared channel is not successfully demodulated, A physical downlink control channel (PDCCH) addressed to a Cell Radio Network Temporary Identifier (C-RNTI) is transmitted to the terminal device, the PDCCH includes uplink grant information, and the uplink grant information is used to schedule the retransmission of the HARQ process on the uplink shared channel; and A method comprising receiving a retransmission of the HARQ process of the uplink shared channel of the terminal device transmission based on the uplink grant information.

[0301] (Note 48) The method described in Appendix 47, Before transmitting the physical downlink control channel (PDCCH) addressed to the Cell Radio Network Temporary Identifier (C-RNTI) to the terminal device, the second message (MsgB) is transmitted. The method wherein the PDCCH includes uplink scheduling information for scheduling retransmission of HARQ processes on the uplink shared channel.

[0302] (Note 49) The method described in Appendix 46, The step of sending a second message (MsgB) to the terminal device further includes: If the two-step non-conflicting random access preamble is successfully demodulated, but the uplink shared channel is not successfully demodulated, This includes transmitting a physical downlink control channel (PDCCH) addressed to a second message radio network temporary identifier (msgB-RNTI) to the terminal device, and also transmitting a MAC PDU scheduled by the PDCCH. A method wherein the RAPID in one subprotocol data unit (subPDU) contained in the MAC PDU matches the two-step non-conflicting random access preamble, and the subPDU contains at least uplink grant information.

[0303] (Note 50) The method described in Appendix 49, The uplink grant information contained in the subPDU is used by the terminal device to retransmit the uplink shared channel. The above method further, A method comprising receiving the uplink shared channel of the terminal device retransmission based on uplink grant information in the subPDU.

[0304] (Note 51) The method described in Appendix 45, The step of sending a second message (MsgB) to the terminal device is: This includes transmitting a physical downlink control channel (PDCCH) addressed to a second message radio network temporary identifier (msgB-RNTI) to the terminal device, and also transmitting a MAC PDU scheduled by the PDCCH. A method wherein the RAPID in one subprotocol data unit (subPDU) contained within the MAC PDU matches the two-step non-conflicting random access preamble, and the subPDU contains at least a timing advance instruction (TAC).

[0305] (Note 52) The method described in Appendix 51, The subPDU further includes uplink grant information, which the terminal device uses to retransmit the uplink shared channel. The above method further, A method comprising receiving the uplink shared channel of the terminal device retransmission based on the uplink grant information.

[0306] (Note 53) The method described in Appendix 51, further, A physical downlink control channel (PDCCH) addressed to a Cell Radio Network Temporary Identifier (C-RNTI) is transmitted to the terminal device, the PDCCH includes uplink grant information, and the uplink grant information is used to schedule the retransmission of the HARQ process on the uplink shared channel; and A method comprising receiving a retransmission of the HARQ process of the uplink shared channel of the terminal device transmission based on the uplink grant information.

[0307] (Note 54) The method described in Appendix 53, Before transmitting the physical downlink control channel (PDCCH) addressed to the Cell Radio Network Temporary Identifier (C-RNTI) to the terminal device, the second message (MsgB) is transmitted. The method wherein the PDCCH includes uplink scheduling information for scheduling retransmission of HARQ processes on the uplink shared channel.

[0308] (Note 55) The method described in Appendix 45, further, If the aforementioned uplink shared channel is successfully demodulated, This includes transmitting a response to a Hybrid Automatic Retransmission Request (HARQ) sent for the uplink sharing channel to the terminal device, A method in which the response to the aforementioned Hybrid Automatic Retransmission Request (HARQ) is used to indicate that the network device has successfully demodulated the uplink shared channel.

[0309] (Note 56) The method described in Appendix 55, The response to the aforementioned Hybrid Automatic Retransmission Request (HARQ) is the exact response to the Hybrid Automatic Retransmission Request carried by the physical downlink control channel; or The response to the aforementioned Hybrid Automatic Retransmission Request (HARQ) is new data for the Hybrid Automatic Retransmission Request process, which is scheduled by the physical downlink control channel, in this method.

[0310] (Note 57) The method described in Appendix 42, further, A method comprising sending a second message (MsgB) to the terminal device when the two-step non-conflicting random access preamble has been successfully demodulated and the uplink shared channel has been successfully demodulated.

[0311] (Note 27a) The method described in Appendix 27, further, Start the response window for the second message (MsgB); and A method comprising monitoring a PDCCH addressed to C-RNTI and a PDCCH addressed to MsgB-RNTI while the response window for the MsgB is running.

Claims

1. A transmitting unit that can transmit a first signal relating to a two-step non-conflicting random access procedure in accordance with the configuration of a two-step non-conflicting random access resource, which includes a reference signal and a two-step non-conflicting random access preamble corresponding to the reference signal. A receiving unit capable of receiving a second signal which is a response to the first signal, including the two-step non-competitive random access preamble and a physical uplink sharing channel, A control unit capable of monitoring the first physical downlink control channel (PDCCH) corresponding to the message radio network temporary identifier (MsgB-RNTI) of the second signal, and demodulating the first media access control layer protocol data unit (MAC PDU) scheduled by the first physical downlink control channel (PDCCH), Includes, At least one random access preamble indicator (RAPID) in a subprotocol data unit (subPDU) of the first media access control layer protocol data unit (MAC PDU) corresponds to the two-step non-conflicting random access preamble, and the subprotocol data unit (subPDU) includes uplink grant information and TAC (timing advance command). The transmitting unit, based on the uplink grant information, retransmits the physical uplink shared channel included in the first signal. The control unit monitors the second physical downlink control channel (PDCCH) corresponding to the cell radio network temporary identifier (C-RNTI) of the second signal, and when it successfully demodulates the second media access control layer protocol data unit (MAC PDU) which includes a timing progress command media access layer control element (TAC MAC CE) scheduled by the second physical downlink control channel (PDCCH), it determines that the two-step non-conflicting random access procedure has been completed. A terminal characterized by the following features.

2. The receiving unit can receive information including the setting of non-conflicting random access resources in the two steps. The terminal according to feature 1.

3. The aforementioned reference signal includes a synchronization signal block (SSB) or a channel status information reference signal (CSI-RS). The terminal according to feature 1 or 2.

4. A receiving unit capable of receiving a first signal relating to a two-step non-conflicting random access procedure, which is set according to the configuration of a two-step non-conflicting random access resource that includes a reference signal and a two-step non-conflicting random access preamble corresponding to the reference signal, The transmitting unit, Includes, The transmitting unit can transmit to the terminal a second signal which is a response to the first signal, including the two-step non-conflicting random access preamble and a physical uplink sharing channel. When the terminal receives the second signal, it determines that the two-step non-conflicting random access procedure has been completed. The transmitting unit can transmit a first physical downlink control channel (PDCCH) addressed to the message radio network temporary identifier (MsgB-RNTI) of the second signal, and a first media access control layer protocol data unit (MAC PDU) scheduled by the first physical downlink control channel (PDCCH). At least one random access preamble indicator (RAPID) in a subprotocol data unit (subPDU) of the first media access control layer protocol data unit (MAC PDU) matches the two-step non-conflicting random access preamble, and the subprotocol data unit (subPDU) includes at least uplink grant information and TAC (timing advance command), The transmitting unit can transmit a second physical downlink control channel (PDCCH) that is addressed to the cell radio network temporary identifier (C-RNTI) of the second signal. The second physical downlink control channel (PDCCH) schedules a second media access control layer protocol data unit (MAC PDU) which includes a timing progress instruction media access layer control element (TAC MAC CE). A base station characterized by the following features.

5. The transmitting unit can transmit information including the setting of non-conflicting random access resources in the two steps. The base station according to feature 4.

6. The aforementioned reference signal includes a synchronization signal block (SSB) or a channel status information reference signal (CSI-RS). The base station according to claim 4 or 5.

7. A communication system including base stations and terminals, The terminal transmits a first signal relating to a two-step non-conflicting random access procedure to the base station, in accordance with the configuration of a two-step non-conflicting random access resource that includes a reference signal and a two-step non-conflicting random access preamble corresponding to the reference signal. The terminal receives a second signal which is a response to the first signal, which includes the two-step non-competitive random access preamble and a physical uplink sharing channel. The terminal monitors the first physical downlink control channel (PDCCH) corresponding to the Message Radio Network Temporary Identifier (MsgB-RNTI) of the second signal, and performs the process of demodulating the first media access control layer protocol data unit (MAC PDU) scheduled by the first physical downlink control channel (PDCCH). At least one random access preamble indicator (RAPID) in a subprotocol data unit (subPDU) of the first media access control layer protocol data unit (MAC PDU) corresponds to the two-step non-conflicting random access preamble, and the subprotocol data unit (subPDU) includes uplink grant information and TAC (timing advance command). The terminal, based on the uplink grant information, retransmits the physical uplink shared channel included in the first signal. The terminal monitors the second physical downlink control channel (PDCCH) corresponding to the cell radio network temporary identifier (C-RNTI) of the second signal, and determines that the two-step non-conflicting random access procedure is complete when it successfully demodulates the second media access control layer protocol data unit (MAC PDU) which includes a timing progress command media access layer control element (TAC MAC CE) scheduled by the second physical downlink control channel (PDCCH). A communication system characterized by the following features.

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