Two-step random access method for unlicensed frequency band, terminal device, and computer-readable storage medium

Abstract

Embodiments of this disclosure disclose a 2-step random access method for an unlicensed band, a terminal device, and a computer-readable storage medium. The method is executed by a terminal device and includes: determining (S102), based on an LBT detection result, whether to send an msgA and whether to update a power ramping counter for the msgA, where the power ramping counter is used to determine transmission power for the msgA, and the msgA includes a PRACH and a PUSCH; and determining (S104), based on a sending status of the msgA, whether to update a transmission counter for the msgA.

Description

Two-step random access method and device for unlicensed frequency bands

[0001] Cross-reference to related applications

[0002] This application claims priority to Chinese patent application filed on August 8, 2019, with application number 201910731201.1 and entitled "Two-step random access method and apparatus for unlicensed frequency bands", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to the field of communications, and more particularly to a two-step random access method and device for unlicensed frequency bands. Background Technology

[0004] Unlicensed frequency bands are one of the effective methods to address the scarcity of spectrum resources in mobile communication networks. By extending New Radio (NR) technology from licensed frequency bands to unlicensed frequency bands, system capacity and performance can be improved. NR introduces a two-step random access (2-step RACH) process. However, how terminal devices initiate 2-step RACH in unlicensed frequency bands is a technical problem that urgently needs to be solved in related technologies.

[0005] Summary of the Invention

[0006] This disclosure provides a two-step random access method and device for unlicensed frequency bands, offering a solution for random access in unlicensed frequency bands in NR systems.

[0007] In a first aspect, a two-step random access method for unlicensed frequency bands is provided, the method being executed by a terminal device, the method comprising:

[0008] Based on the Listen Before Talk (LBT) detection results, it is determined whether to send msgA and whether to update the power adjustment counter of msgA; wherein, the power adjustment counter is used to determine the transmission power of msgA, and msgA includes the Physical Random Access Channel (PRACH) and the Physical Uplink Shared Channel (PUSCH);

[0009] Based on the transmission status of msgA, determine whether to update the transmission counter of msgA.

[0010] Secondly, a terminal device is provided, the terminal device comprising:

[0011] The sending module is used to determine whether to send msgA based on the LBT detection result;

[0012] The processing module is used to determine whether to update the power adjustment counter of msgA based on the LBT detection result; wherein the power adjustment counter is used to determine the transmission power of msgA, and msgA includes PRACH and PUSCH;

[0013] The processing module is further configured to determine whether to update the transmission counter of msgA based on the transmission status of msgA.

[0014] Thirdly, a terminal device is provided, the terminal device including a processor, a memory, and a computer program stored in the memory and executable on the processor, wherein when the computer program is executed by the processor, it implements the steps of the two-step random access method for unlicensed frequency bands as described in the first aspect.

[0015] Fourthly, a computer-readable storage medium is provided, on which a computer program is stored, which, when executed by a processor, implements the steps of the two-step random access method for unlicensed frequency bands as described in the first aspect.

[0016] In this embodiment of the disclosure, the terminal device determines whether to send msgA and whether to update the power adjustment counter of msgA based on the LBT detection results in the unlicensed frequency band, and determines whether to update the transmission counter of msgA based on the transmission status of msgA. This embodiment of the disclosure provides a solution for two-step random access in unlicensed frequency bands in NR systems, which facilitates improving the spectrum utilization of NR systems and improving communication efficiency. Attached Figure Description

[0017] The accompanying drawings, which are included to provide a further understanding of this disclosure and form part of this disclosure, illustrate exemplary embodiments of the present disclosure and are used to explain the disclosure, but do not constitute an undue limitation of the disclosure. In the drawings:

[0018] Figure 1 is a schematic flowchart of a two-step random access method for an unlicensed frequency band according to an embodiment of the present disclosure;

[0019] Figure 2 is a schematic diagram of the structure of a terminal device according to an embodiment of the present disclosure;

[0020] Figure 3 is a schematic diagram of the structure of a terminal device according to another embodiment of the present disclosure. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this disclosure clearer, the technical solutions of this disclosure will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this disclosure, and not all of them. Based on the embodiments of this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure. In the various embodiments of this specification, "and / or" means at least one of the preceding and following terms.

[0022] It should be understood that the technical solutions of the embodiments of this disclosure can be applied to various communication systems, such as: Long Term Evolution (LTE) systems, LTE Frequency Division Duplex (FDD) systems, LTE Time Division Duplex (TDD) systems, Universal Mobile Telecommunication System (UMTS) or Worldwide Interoperability for Microwave Access (WiMAX) communication systems, 5G systems, or New Radio (NR) systems, or subsequent evolution communication systems.

[0023] In the embodiments of this disclosure, the terminal device may include, but is not limited to, a mobile station (MS), a mobile terminal, a mobile phone, user equipment (UE), a handset, portable equipment, a vehicle, etc. The terminal device may communicate with one or more core networks via a radio access network (RAN). For example, the terminal device may be a mobile phone (or "cellular" phone), a computer with wireless communication capabilities, etc. The terminal device may also be a portable, pocket-sized, handheld, computer-embedded, or vehicle-mounted mobile device.

[0024] As shown in Figure 1, one embodiment of this disclosure provides a two-step random access method 100 for unlicensed frequency bands. This method can be executed by a terminal device and includes the following steps:

[0025] S102: Based on the LBT detection results, determine whether to send msgA and whether to update the power ramping counter of msgA.

[0026] Before transmitting msgA on the unlicensed NR band, the terminal device needs to perform LBT (Level-Based Transmission). Specifically, the terminal device can perform Clear Channel Assessment (CCA) / extended Clear Channel Assessment (eCCA) to listen for the channel in the aforementioned unlicensed band, i.e., perform Energy Detection (ED). When the energy is below a certain threshold, the channel is judged to be empty, i.e., LBT detection is successful, and msgA can be transmitted. When the energy is higher than or equal to the aforementioned threshold, the channel is judged to be busy, i.e., LBT detection fails, and msgA cannot be transmitted.

[0027] In this step, msgA includes PRACH and PUSCH. Before this step, LBT detection can be performed on PRACH and PUSCH separately. The execution of this step can be as follows (of course, it is not limited to the following example):

[0028] If the PRACH LBT detection is successful and other additional conditions are met, then the PRACH can be sent; otherwise, if the PRACH LBT detection fails and / or the above additional conditions are not met, then the PRACH will not be sent.

[0029] If the PUSCH LBT detection is successful and other additional conditions are met, then PUSCH can be sent; otherwise, if the PUSCH LBT detection fails and / or the above additional conditions are not met, then PUSCH will not be sent.

[0030] The question of whether to update the power adjustment counter of msgA mentioned in this step includes two cases: 1. Update the count value of the power adjustment counter, that is, increment the count value of the power adjustment counter by 1; 2. Keep the count value of the power adjustment counter unchanged, that is, pause the count value of the power adjustment counter.

[0031] Of course, adding 1 to the power adjustment counter is the simplest way to implement it. You can also add 2, 3, or other counting units to the power adjustment counter. The specific value to add can be agreed upon in advance in the protocol.

[0032] In this embodiment, PRACH and PUSCH can share a single power adjustment counter, or they can use different power adjustment counters respectively.

[0033] If PRACH and PUSCH share a power adjustment counter, this step is performed as follows:

[0034] If at least one of the PRACH and PUSCH LBT detections is successful, the shared power adjustment counter can be incremented by 1; if both PRACH and PUSCH LBT detections fail, the shared power adjustment counter can be paused.

[0035] For example, if PRACH and PUSCH use different power adjustment counters, this step is executed as follows:

[0036] If the PRACH LBT detection is successful, the PRACH power adjustment counter is incremented by 1; if the PRACH LBT detection fails, the PRACH power adjustment counter is paused. If the PUSCH LBT detection is successful, the PUSCH power adjustment counter is incremented by 1; if the PUSCH LBT detection fails, the PUSCH power adjustment counter is paused.

[0037] S104: Based on the transmission status of msgA, determine whether to update the transmission counter of msgA.

[0038] The transmission status of msgA mentioned in the embodiments of this specification includes whether PRACH and PUSCH are sent. It may also include some situations after msgA is sent, such as whether the msgB receive window times out or whether the contention resolution is successful.

[0039] Normally, the msgB receiving window is started only after msgA is sent. The success of contention resolution can only be determined after msgA (e.g., PUSCH) is sent. Therefore, the msgA sending situations mentioned in the embodiments of this specification include two situations: msgB receiving window timeout and contention resolution failure.

[0040] The question of whether to update the transmission counter of msgA mentioned in this step includes two cases: 1. Update the count value of the transmission counter, that is, increment the count value of the transmission counter by 1; 2. Keep the count value of the transmission counter unchanged, that is, pause the count value of the transmission counter.

[0041] As mentioned earlier, msgA includes PRACH and PUSCH. In this embodiment, PRACH and PUSCH can share a single transmission counter or use different transmission counters respectively.

[0042] For example, PRACH and PUSCH share a single transmission counter:

[0043] If at least one of PRACH and PUSCH is sent, the shared transmission counter can be incremented by 1; if neither PRACH nor PUSCH is sent, the shared transmission counter can be paused.

[0044] For example, PRACH and PUSCH use different transfer counters:

[0045] If a PRACH is sent, the PRACH transmission counter is incremented by 1; if no PRACH is sent, the PRACH transmission counter is paused. Similarly, if a PUSCH is sent, the PUSCH transmission counter is incremented by 1; if no PUSCH is sent, the PUSCH transmission counter is paused.

[0046] The two-step random access method for unlicensed frequency bands provided in this disclosure involves a terminal device determining, based on LBT detection results, whether to transmit msgA and whether to update the power adjustment counter of msgA, and further determining whether to update the transmission counter of msgA based on the transmission status of msgA. This disclosure provides a solution for two-step random access in unlicensed frequency bands in NR systems, facilitating improved spectrum utilization and communication efficiency.

[0047] The power adjustment counters mentioned in the various embodiments of this specification can be used to determine the transmit power of msgA. The following is a brief introduction to the process of determining the transmit power of PRACH, using different power adjustment counters for PRACH and PUSCH as examples.

[0048] The transmission power of the PRACH preamble can be calculated using the following formula:

[0049] preambleReceivedTargetPower+DELTA_PREAMBLE+(PREAMBLE_POWER_RAMPING_COUNTER–1)×PREAMBLE_POWER_RAMPING_STEP.

[0050] In the above calculation formula, preambleReceivedTargetPower is the target received power of the PRACH preamble; DELTA_PREAMBLE is the downlink path loss; PREAMBLE_POWER_RAMPING_COUNTER is the count value of the PRACH power adjustment counter, which is initially 1; PREAMBLE_POWER_RAMPING_STEP is the power adjustment level.

[0051] The above example, using different power adjustment counters for PRACH and PUSCH, illustrates how to calculate the transmit power of PRACH. Of course, the calculation process for PUSCH transmit power when using different power adjustment counters for PRACH and PUSCH, and for PRACH and PUSCH sharing a single power adjustment counter, is similar and will not be repeated here.

[0052] The above embodiments mention the transmission counter and power adjustment counter for msgA:

[0053] Optionally, msgA PRACH and msgA PUSCH share a single transmission counter and a single power adjustment counter; or

[0054] msgA PRACH and msgA PUSCH use different transmission counters but share a common power adjustment counter; or

[0055] msgA PRACH and msgA PUSCH share a single transmission counter but use different power adjustment counters; or

[0056] msgA PRACH and msgA PUSCH use different transmission counters and different power adjustment counters.

[0057] To illustrate in detail the two-step random access method for unlicensed frequency bands provided in this disclosure, the following will describe it in conjunction with several specific embodiments. The following embodiments all describe two-step RACH for unlicensed frequency bands.

[0058] Example 1

[0059] In Embodiment 1, msgA PRACH and msgA PUSCH share a common transmission counter and a common power adjustment counter. Embodiment 1 is described in two sub-embodiments.

[0060] First Sub-Implementation

[0061] If both msgA PRACH and msgA PUSCH LBT fail to detect, the physical layer sends an LBT failure indication to the higher layer to indicate that PRACH and PUSCH cannot be sent due to LBT failure.

[0062] Upon receiving the LBT failure instruction, the senior management immediately suspended the shared power adjustment counter.

[0063] In this embodiment, the terminal device does not send PRACH or PUSCH. The terminal device assumes that MsgB reception was unsuccessful and directly suspends the transmission counter.

[0064] It should be noted that the msgB mentioned in the various embodiments of this specification can specifically be a message sent by the network device to the terminal device in a 2-step RACH, and can include at least one of a random access response message and a contention resolution identifier.

[0065] Optionally, the terminal device may also determine whether to terminate the current random access process based on the number of times PRACH and / or PUSCH LBT detections fail;

[0066] If so, that is, if it is determined to terminate this random access process, then LBT failure recovery can be performed;

[0067] If not, i.e., the current random access procedure is not terminated, the next random access preparation continues. For example, the resource selection process for the next random access procedure is performed. The resources mentioned here include at least one of the following: random access type (RACH type), such as 2-step RACH or 4-step RACH; uplink carrier (UL carrier); Band Width Part (BWP); Synchronization Signal Block (SSB) (SS / PBCH block); Preamble group; Preamble; Random Access Channel Occasion (RO); MsgA PUSCH configuration, etc.

[0068] Second Sub-Implementation

[0069] If at least one of the PRACH and PUSCH LBT detections is successful, the physical layer sends an LBT indication to the higher layer, which includes at least one of the PRACH LBT success indication and the PUSCH LBT success indication.

[0070] After receiving the LBT instruction from the physical layer, the higher layer increments the power adjustment counter by 1 if additional conditions are met. These additional conditions may include, for example, that the power adjustment counter has not reached its maximum value.

[0071] Optionally, in this embodiment, if the higher layer receives the MsgA PRACH LBT success indication, it can prepare to send MsgA PRACH.

[0072] Optionally, in this embodiment, if the higher layer receives a MsgA PUSCH LBT success indication and also receives an uplink grant for MsgA PUSCH, it can prepare to send MsgA PUSCH.

[0073] In this embodiment, the terminal device may also initiate a msgB receive window after sending at least one of PRACH and PUSCH.

[0074] In this embodiment, if the msgB receive window times out and / or the contention resolution fails, the shared transmission counter is incremented by 1.

[0075] Example 2

[0076] In Embodiment 2, msgA PRACH and msgA PUSCH use different transmission counters but share a common power adjustment counter. Embodiment 2 is described in four sub-embodiments.

[0077] First Sub-Implementation

[0078] If the msgA PRACH LBT detection fails, then regardless of whether the msgA PUSCH LBT detection succeeds or fails, neither PRACH nor PUSCH will be sent.

[0079] Specifically, the physical layer sends an LBT indication to the higher layers. This LBT indication includes a PRACH LBT failure indication, and may also include a PUSCH LBT failure indication or a PUSCH LBT success indication.

[0080] Upon receiving the aforementioned LBT instruction, the senior management immediately suspended the power adjustment counter.

[0081] In this embodiment, the terminal device considers that MsgB has not been successfully received and directly suspends the transmission counter of PRACH; and also suspends the transmission counter of PUSCH.

[0082] Optionally, the terminal device may also determine whether to terminate the current random access process based on the number of PRACH and / or PUSCH LBT detection failures:

[0083] If so, that is, if it is determined to terminate this random access process, then LBT failure recovery can be performed;

[0084] If not, that is, the current random access process is not terminated, the next random access preparation continues, for example, the resource selection process of the next random access process is carried out.

[0085] The aforementioned method determines whether to terminate the current random access process based on the number of PRACH and / or PUSCH LBT detection failures. Specifically, for example, if the number of PRACH LBT detection failures reaches a preset threshold; or if the number of PUSCH LBT detection failures reaches a preset threshold; or if the maximum of the number of PRACH LBT detection failures and the number of PUSCH LBT detection failures reaches a preset threshold, then the current random access process can be terminated. Alternatively, if the number of PRACH LBT detection failures does not reach the preset threshold, but the number of PUSCH LBT detection failures reaches the preset threshold, then the current random access process can remain in place.

[0086] Second Sub-Implementation

[0087] The msgA PRACH LBT test was successful, while the msgA PUSCH LBT test failed.

[0088] In this embodiment, the physical layer sends an LBT indication to the higher layers. The LBT indication may include a PRACH LBT success indication and a PUSCH LBT failure indication.

[0089] Upon receiving the aforementioned LBT instruction, the higher management may increment the aforementioned common power adjustment counter by 1 if additional conditions are met.

[0090] Optionally, if the higher layer receives a PRACH LBT success indication, it can prepare to send msgA PRACH; if the higher layer receives a PUSCH LBT failure indication, it will not send msgA PUSCH.

[0091] Optionally, after sending PRACH, the terminal device can also start a msgB or msg2 receive window.

[0092] The msg2 receiving window mentioned in the various embodiments of this specification can be a time window used to receive random access response messages, specifically the RAR time window in the 4-step RACH.

[0093] For connected terminal devices, if the msgA PUSCH contains the Cell-Radio Network Temporary Identifier (C-RNTI) Link Control Layer Control Unit (MAC CE), then during the operation of the aforementioned msgB or msg2 receive window, the terminal device can only listen to the Physical Downlink Control Channel (PDCCH) scrambled with the Random Access-Radio Network Transmission Identifier (RA-RNTI) and not listen to the PDCCH scrambled with C-RNTI, or in other words, ignore the PDCCH scrambled with C-RNTI.

[0094] In one implementation, if the msgB or msg2 receive window times out and / or the contention resolution fails, the PRACH transmission counter is incremented by 1, and the PUSCH transmission counter is paused.

[0095] In another implementation, if the terminal device reverts to the 4-step random access procedure and sends the PUSCH, and the contention resolution fails, the transmission counter of PRACH is incremented by 1, and the transmission counter of PUSCH is also incremented by 1.

[0096] Optionally, in this embodiment, the physical layer sends indication information to the higher layer if at least one of the following conditions is met, the indication information being used to indicate a random access problem:

[0097] The PRACH transmission counter's count value reaches the first threshold;

[0098] The PUSCH transmission counter's count value reaches the second threshold;

[0099] The maximum of the count values ​​of the PRACH transmission counter and the PUSCH transmission counter reaches the third threshold.

[0100] Third Sub-Implementation

[0101] The msgA PRACH LBT test failed, while the msgA PUSCH LBT test succeeded.

[0102] In this embodiment, the physical layer sends an LBT indication to the higher layers, which includes a PRACH LBT failure indication and a PUSCH LBT success indication.

[0103] Upon receiving the aforementioned LBT instruction, the higher management may increment the shared power adjustment counter by 1 if additional conditions are met.

[0104] Optionally, once the higher layer receives a PUSCH LBT success indication and an uplink authorization for the MsgA PUSCH, it can prepare to send the MsgA PUSCH. If the higher layer receives a PRACH LBT failure indication, it will not send the MsgA PRACH.

[0105] Optionally, after the terminal device sends MsgA PUSCH, it can also start the msgB receive window.

[0106] If the above msgB receive window times out and / or the contention resolution fails, the PRACH transmission counter is paused and the PUSCH transmission counter is incremented by 1.

[0107] Optionally, in this embodiment, the physical layer sends indication information to the higher layer if at least one of the following conditions is met, the indication information being used to indicate a random access problem:

[0108] The PRACH transmission counter's count value reaches the first threshold;

[0109] The PUSCH transmission counter's count value reaches the second threshold;

[0110] The maximum of the count values ​​of the PRACH transmission counter and the PUSCH transmission counter reaches the third threshold.

[0111] Fourth Sub-Implementation Example

[0112] The msgA PRACH LBT test was successful, and the msgA PUSCH LBT test was also successful.

[0113] The physical layer sends an LBT indication to the higher layers, which includes a PRACH LBT success indication and a PUSCH LBT success indication.

[0114] After receiving the LBT instruction from the physical layer, the higher layer increments the power adjustment counter by 1 if additional conditions are met. These additional conditions may include, for example, that the power adjustment counter has not reached its maximum value.

[0115] Optionally, in this embodiment, once the higher layer receives the MsgA PRACH LBT success indication, it can prepare to send MsgA PRACH.

[0116] Optionally, in this embodiment, once the higher layer receives the MsgA PUSCH LBT success indication and the uplink authorization for MsgA PUSCH, it can prepare to send MsgA PUSCH.

[0117] In this embodiment, after sending PRACH and PUSCH, the terminal device can also start the msgB receiving window.

[0118] In this embodiment, if the msgB receive window times out and / or the contention resolution fails, the transmission counter of PRACH is incremented by 1, and the transmission counter of PUSCH is incremented by 1.

[0119] Optionally, in this embodiment, the physical layer sends indication information to the higher layer if at least one of the following conditions is met, the indication information being used to indicate a random access problem:

[0120] The PRACH transmission counter's count value reaches the first threshold;

[0121] The PUSCH transmission counter's count value reaches the second threshold;

[0122] The maximum of the count values ​​of the PRACH transmission counter and the PUSCH transmission counter reaches the third threshold.

[0123] Example 3

[0124] In Embodiment 3, msgA PRACH and msgA PUSCH share a common transmission counter, but use different power adjustment counters. This embodiment is divided into four sub-embodiments for description.

[0125] First Sub-Implementation

[0126] If the msgA PRACH LBT detection fails, then regardless of whether the msgA PUSCH LBT detection succeeds or fails, neither PRACH nor PUSCH will be sent.

[0127] Specifically, the physical layer sends an LBT indication to the higher layers. This LBT indication includes a PRACH LBT failure indication, and may also include a PUSCH LBT failure indication or a PUSCH LBT success indication.

[0128] Upon receiving a PRACH LBT failure indication, the upper layer directly suspends the PRACH power adjustment counter; upon receiving a PUSCH LBT failure indication or a PUSCH LBT success indication, the upper layer suspends the PUSCH power adjustment counter.

[0129] In this embodiment, the terminal device assumes that MsgB was not successfully received and directly suspends the shared transmission counter.

[0130] Optionally, the terminal device may also determine whether to terminate the current random access process based on the number of times PRACH and / or PUSCH LBT detections fail;

[0131] If so, that is, if it is determined to terminate this random access process, then LBT failure recovery can be performed;

[0132] If not, that is, the current random access process is not terminated, the next random access preparation continues, for example, the resource selection process of the next random access process is carried out.

[0133] Second Sub-Implementation

[0134] The msgA PRACH LBT test was successful, while the msgA PUSCH LBT test failed.

[0135] In this embodiment, the physical layer sends an LBT indication to the higher layers, which includes a PRACH LBT success indication and a PUSCH LBT failure indication.

[0136] Upon receiving the PRACH LBT success indication, the upper layer may increment the PRACH power adjustment counter by 1 if additional conditions are met; upon receiving the PUSCH LBT failure indication, the upper layer shall suspend the PUSCH power adjustment counter.

[0137] Optionally, if the higher layer receives a PRACH LBT success indication, it can prepare to send msgA PRACH; if the higher layer receives a PUSCH LBT failure indication, it will not send msgA PUSCH.

[0138] Optionally, after sending PRACH, the terminal device can also start a msgB or msg2 receive window.

[0139] If msgA PUSCH contains C-RNTI MAC CE, then during the operation of the above msgB or msg2 receive window, the terminal device can only listen to the RA-RNTI scrambled PDCCH and not listen to the C-RNTI scrambled PDCCH, or it can be said to ignore the C-RNTI scrambled PDCCH.

[0140] If the receive window for msgB or msg2 times out and / or the contention resolution fails, the shared transmission counter is incremented by 1. Of course, in this implementation, the terminal device can fall back to the 4-step random access procedure, having already sent the aforementioned PUSCH.

[0141] Third Sub-Implementation

[0142] The msgA PRACH LBT test failed, while the msgA PUSCH LBT test succeeded.

[0143] In this embodiment, the physical layer sends an LBT indication to the higher layers, which includes a PRACH LBT failure indication and a PUSCH LBT success indication.

[0144] After receiving a PRACH LBT failure indication, the upper layer can pause the PRACH power adjustment counter; after receiving a PUSCH LBT success indication, the upper layer can increment the PUSCH power adjustment counter by 1 if additional conditions are met.

[0145] Optionally, once the higher layer receives a PUSCH LBT success indication and an uplink authorization for the MsgA PUSCH, it can prepare to send the MsgA PUSCH. If the higher layer receives a PRACH LBT failure indication, it will not send the MsgA PRACH.

[0146] Optionally, after the terminal device sends MsgA PUSCH, it can also start the msgB receive window.

[0147] If the above msgB receive window times out and / or the contention resolution fails, the shared transmit counter is incremented by 1.

[0148] Fourth Sub-Implementation Example

[0149] The msgA PRACH LBT test was successful, and the msgA PUSCH LBT test was also successful.

[0150] The physical layer sends an LBT indication to the higher layers, which includes a PRACH LBT success indication and a PUSCH LBT success indication.

[0151] After receiving the LBT instruction from the physical layer, if additional conditions are met, the higher layer increments the power adjustment counter of PRACH by 1 and the power adjustment counter of PUSCH by 1.

[0152] Optionally, in this embodiment, once the higher layer receives the MsgA PRACH LBT success indication, it can prepare to send MsgA PRACH.

[0153] Optionally, in this embodiment, once the higher layer receives the MsgA PUSCH LBT success indication and the uplink authorization for MsgA PUSCH, it can prepare to send MsgA PUSCH.

[0154] In this embodiment, after sending PRACH and PUSCH, the terminal device can also start the msgB receiving window.

[0155] In this embodiment, if the msgB receive window times out and / or the contention resolution fails, the transmission counter of PRACH is incremented by 1, and the transmission counter of PUSCH is incremented by 1.

[0156] Example 4

[0157] In Example 4, msgA PRACH and msgA PUSCH use different transmission counters and different power adjustment counters. Example 4 is described in five sub-examples.

[0158] First Sub-Implementation

[0159] If the msgA PRACH LBT detection fails, then regardless of whether the msgA PUSCH LBT detection succeeds or fails, neither PRACH nor PUSCH will be sent.

[0160] Specifically, the physical layer sends an LBT indication to the higher layers. This LBT indication includes a PRACH LBT failure indication, and may also include a PUSCH LBT failure indication or a PUSCH LBT success indication.

[0161] Upon receiving the aforementioned PRACH LBT failure indication, the upper management immediately suspends the PRACH power adjustment counter; upon receiving the aforementioned PUSCH LBT failure indication or PUSCH LBT success indication, the upper management suspends the PUSCH power adjustment counter.

[0162] In this embodiment, the terminal device considers that MsgB has not been successfully received and directly suspends the transmission counter of PRACH; and also suspends the transmission counter of PUSCH.

[0163] Optionally, the terminal device may also determine whether to terminate the current random access process based on the number of times PRACH and / or PUSCH LBT detections fail;

[0164] If so, that is, if it is determined to terminate this random access process, then LBT failure recovery can be performed;

[0165] If not, that is, the current random access process is not terminated, the next random access preparation continues, for example, the resource selection process of the next random access process is carried out.

[0166] Second Sub-Implementation

[0167] The msgA PRACH LBT test was successful, while the msgA PUSCH LBT test failed.

[0168] In this embodiment, the physical layer sends an LBT indication to the higher layers, which includes a PRACH LBT success indication and a PUSCH LBT failure indication.

[0169] Upon receiving the PRACH LBT success indication, the upper layer may increment the PRACH power adjustment counter by 1 if additional conditions are met; upon receiving the PUSCH LBT failure indication, the upper layer shall suspend the PUSCH power adjustment counter.

[0170] Optionally, if the higher layer receives a PRACH LBT success indication, it can prepare to send msgA PRACH; if the higher layer receives a PUSCH LBT failure indication, it will not send msgA PUSCH.

[0171] Optionally, after sending PRACH, the terminal device can also start a msgB or msg2 receive window.

[0172] If msgA PUSCH contains C-RNTI MAC CE, then during the operation of the above msgB or msg2 receive window, the terminal device can only listen to the RA-RNTI scrambled PDCCH and not listen to the C-RNTI scrambled PDCCH, or it can be said to ignore the C-RNTI scrambled PDCCH.

[0173] In one implementation, if the msgB or msg2 receive window times out and / or the contention resolution fails, the PRACH transmission counter is incremented by 1, and the PUSCH transmission counter is paused.

[0174] In another implementation, if the terminal device reverts to the 4-step random access procedure and sends the PUSCH, and the contention resolution fails, the transmission counter of PRACH is incremented by 1, and the transmission counter of PUSCH is also incremented by 1.

[0175] Optionally, in this embodiment, the physical layer sends indication information to the higher layer if at least one of the following conditions is met, the indication information being used to indicate a random access problem:

[0176] The PRACH transmission counter's count value reaches the first threshold;

[0177] The PUSCH transmission counter's count value reaches the second threshold;

[0178] The maximum of the count values ​​of the PRACH transmission counter and the PUSCH transmission counter reaches the third threshold.

[0179] Third Sub-Implementation

[0180] The msgA PRACH LBT test was successful, while the msgA PUSCH LBT test failed.

[0181] In this embodiment, the physical layer sends an LBT indication to the higher layers, which includes a PRACH LBT success indication and a PUSCH LBT failure indication.

[0182] After receiving the above PRACH LBT success indication, the upper layer can increment the PRACH power adjustment counter by 1 if additional conditions are met; after receiving the above PUSCH LBT failure indication, the upper layer can also increment the PUSCH power adjustment counter by 1.

[0183] Optionally, if the higher layer receives a PRACH LBT success indication, it can prepare to send msgA PRACH; if the higher layer receives a PUSCH LBT failure indication, it will not send msgA PUSCH.

[0184] Optionally, after sending PRACH, the terminal device can also start a msgB or msg2 receive window.

[0185] If msgA PUSCH contains C-RNTI MAC CE, then during the operation of the above msgB or msg2 receive window, the terminal device can only listen to the RA-RNTI scrambled PDCCH and not listen to the C-RNTI scrambled PDCCH, or it can be said to ignore the C-RNTI scrambled PDCCH.

[0186] In one implementation, if the msgB or msg2 receive window times out and / or the contention resolution fails, the PRACH transmission counter is incremented by 1, and the PUSCH transmission counter is paused.

[0187] In another implementation, if the terminal device reverts to the 4-step random access procedure and sends the PUSCH, and the contention resolution fails, the transmission counter of PRACH is incremented by 1, and the transmission counter of PUSCH is also incremented by 1.

[0188] Optionally, in this embodiment, the physical layer sends indication information to the higher layer if at least one of the following conditions is met, the indication information being used to indicate a random access problem:

[0189] The PRACH transmission counter's count value reaches the first threshold;

[0190] The PUSCH transmission counter's count value reaches the second threshold;

[0191] The maximum of the count values ​​of the PRACH transmission counter and the PUSCH transmission counter reaches the third threshold.

[0192] Fourth Sub-Implementation Example

[0193] The msgA PRACH LBT test failed, while the msgA PUSCH LBT test succeeded.

[0194] In this embodiment, the physical layer sends an LBT indication to the higher layers, which includes a PRACH LBT failure indication and a PUSCH LBT success indication.

[0195] After receiving a PRACH LBT failure indication, the upper layer can suspend the PRACH power adjustment counter; after receiving a PUSCH LBT success indication and meeting additional conditions, the upper layer can increment the PUSCH power adjustment counter by 1.

[0196] Optionally, once the higher layer receives a PUSCH LBT success indication and an uplink authorization for the MsgA PUSCH, it can prepare to send the MsgA PUSCH. If the higher layer receives a PRACH LBT failure indication, it will not send the MsgA PRACH.

[0197] Optionally, after the terminal device sends MsgA PUSCH, it can also start the msgB receive window.

[0198] If the above msgB receive window times out and / or the contention resolution fails, the PRACH transmission counter is paused and the PUSCH transmission counter is incremented by 1.

[0199] Optionally, in this embodiment, the physical layer sends indication information to the higher layer if at least one of the following conditions is met, the indication information being used to indicate a random access problem:

[0200] The PRACH transmission counter's count value reaches the first threshold;

[0201] The PUSCH transmission counter's count value reaches the second threshold;

[0202] The maximum of the count values ​​of the PRACH transmission counter and the PUSCH transmission counter reaches the third threshold.

[0203] Fifth Sub-Example

[0204] The msgA PRACH LBT test was successful, and the msgA PUSCH LBT test was also successful.

[0205] The physical layer sends an LBT indication to the higher layers, which includes a PRACH LBT success indication and a PUSCH LBT success indication.

[0206] After receiving a successful PRACH LBT indication from the physical layer, the higher layer will increment the PRACH power adjustment counter by 1 if additional conditions are met. These additional conditions may include, for example, that the PRACH power adjustment counter has not reached its maximum value.

[0207] After receiving a successful PUSCH LBT indication from the physical layer, the higher layer will increment the PUSCH power adjustment counter by 1 if additional conditions are met. These additional conditions may include, for example, that the PUSCH power adjustment counter has not reached its maximum value.

[0208] Optionally, in this embodiment, once the higher layer receives the MsgA PRACH LBT success indication, it can prepare to send MsgA PRACH.

[0209] Optionally, in this embodiment, once the higher layer receives the MsgA PUSCH LBT success indication and the uplink authorization for MsgA PUSCH, it can prepare to send MsgA PUSCH.

[0210] In this embodiment, after sending PRACH and PUSCH, the terminal device can also start the msgB receiving window.

[0211] In this embodiment, if the msgB receive window times out and / or the contention resolution fails, the transmission counter of PRACH is incremented by 1, and the transmission counter of PUSCH is incremented by 1.

[0212] Optionally, in this embodiment, the physical layer sends indication information to the higher layer if at least one of the following conditions is met, the indication information being used to indicate a random access problem:

[0213] The PRACH transmission counter's count value reaches the first threshold;

[0214] The PUSCH transmission counter's count value reaches the second threshold;

[0215] The maximum of the count values ​​of the PRACH transmission counter and the PUSCH transmission counter reaches the third threshold.

[0216] The two-step random access method for unlicensed frequency bands according to embodiments of the present disclosure has been described in detail above with reference to FIG1 and various specific embodiments. The terminal device according to embodiments of the present disclosure will now be described in detail with reference to FIG2.

[0217] Figure 2 is a schematic diagram of the structure of a terminal device according to an embodiment of the present disclosure. As shown in Figure 2, the terminal device 200 includes:

[0218] The sending module 202 can be used to determine whether to send msgA based on the LBT detection result;

[0219] The processing module 204 can be used to determine whether to update the power adjustment counter of msgA based on the LBT detection result; wherein the power adjustment counter is used to determine the transmission power of msgA, and msgA includes PRACH and PUSCH;

[0220] The processing module 204 can also be used to determine whether to update the transmission counter of msgA based on the transmission status of msgA.

[0221] In this embodiment of the disclosure, the terminal device determines whether to send msgA and whether to update the power adjustment counter of msgA based on the LBT detection results in the unlicensed frequency band, and determines whether to update the transmission counter of msgA based on the transmission status of msgA. This embodiment of the disclosure provides a solution for two-step random access in unlicensed frequency bands in NR systems, which facilitates improving the spectrum utilization of NR systems and improving communication efficiency.

[0222] Alternatively, as an example,

[0223] The transmission counter of msgA includes a transmission counter shared by the PRACH and the PUSCH, and the power adjustment counter of msgA includes a power adjustment counter shared by the PRACH and the PUSCH; or,

[0224] The PRACH and PUSCH use different transmission counters, and the power adjustment counter of msgA includes a power adjustment counter shared by the PRACH and PUSCH; or,

[0225] The transmission counter of msgA includes a transmission counter shared by the PRACH and the PUSCH, but uses a different power adjustment counter; or,

[0226] The PRACH and PUSCH use different transmission counters and different power adjustment counters.

[0227] Optionally, as an embodiment, the transmission counter of msgA includes a transmission counter shared by the PRACH and the PUSCH, and the power adjustment counter of msgA includes a power adjustment counter shared by the PRACH and the PUSCH. The transmission module 202 can be used to not transmit the PRACH and not transmit the PUSCH if the PRACH LBT detection fails and the PUSCH LBT detection fails.

[0228] The processing module 204 can be used to pause the power adjustment counter and the transmission counter.

[0229] Optionally, as an embodiment, the transmission counter of msgA includes a transmission counter shared by the PRACH and the PUSCH, and the power adjustment counter of msgA includes a power adjustment counter shared by the PRACH and the PUSCH. The processing module 204 can also be used for:

[0230] If the PRACH LBT detection fails and the PUSCH LBT detection fails, then determine whether to terminate the current random access process based on the number of times the PRACH and / or PUSCH LBT detections fail.

[0231] If it is determined that the current random access process will be terminated, then LBT failure recovery will be performed.

[0232] Optionally, as an embodiment, the transmission counter of msgA includes a transmission counter shared by the PRACH and the PUSCH, and the power adjustment counter of msgA includes a power adjustment counter shared by the PRACH and the PUSCH. The processing module 204 can also be used for:

[0233] If at least one of the PRACH and PUSCH LBT detections is successful, the power adjustment counter is incremented by 1.

[0234] Optionally, as an embodiment, the sending module 202 can be used to send the PUSCH and start the msgB receiving window if the PUSCH LBT detection is successful;

[0235] The processing module 204 can be used to increment the transmission counter by 1 if the msgB receive window times out and / or the contention resolution fails.

[0236] Optionally, as an embodiment, the PRACH and the PUSCH use different transmission counters, and the power adjustment counter of the msgA includes a power adjustment counter shared by the PRACH and the PUSCH. The transmitting module 202 can be used to not transmit the PRACH and not transmit the PUSCH if the PRACH LBT detection fails.

[0237] The processing module 204 can be used to pause the power adjustment counter, pause the transmission counter of the PRACH, and pause the operation of incrementing the transmission counter of the PUSCH by 1.

[0238] Optionally, as an embodiment, the PRACH and PUSCH use different transmission counters, and the power adjustment counter of msgA includes a power adjustment counter shared by the PRACH and PUSCH. The processing module 204 can be used for:

[0239] If the PRACH LBT detection fails, determine whether to terminate the current random access process based on the number of times the PRACH and / or PUSCH LBT detections fail.

[0240] If it is determined that the current random access process will be terminated, then LBT failure recovery will be performed.

[0241] Optionally, as an embodiment, the PRACH and the PUSCH use different transmission counters, and the power adjustment counter of msgA includes a power adjustment counter shared by the PRACH and the PUSCH. The transmitting module 202 can be used to transmit the PRACH and not transmit the PUSCH if the PRACH LBT detection is successful and the PUSCH LBT detection fails.

[0242] And processing module 204, which can be used to increment the power adjustment counter by 1.

[0243] Optionally, as an embodiment, the terminal device 200 further includes a receiving module, which can be used for:

[0244] Launch the msgB or msg2 receiving window;

[0245] If the PUSCH contains the Cell Radio Network Temporary Identifier (C-RNTI) Link Control Layer Control Unit (MAC CE), then during the operation of the msgB or msg2 receive window, the Physical Downlink Control Channel (PDCCH) scrambled with the Random Access Radio Network Transmission Identifier (RA-RNTI) is monitored, but the PDCCH scrambled with the C-RNTI is not monitored.

[0246] Optionally, as an embodiment, the sending module 202 can be used to fall back to the 4-step random access procedure to send the PUSCH.

[0247] Optionally, as an embodiment, the processing module 204 can be used to increment the transmission counter of the PRACH by 1 and the transmission counter of the PUSCH by 1 if the msgB or msg2 receive window times out and / or the contention resolution fails.

[0248] Optionally, as one embodiment, the sending module 202 can be used to:

[0249] If at least one of the following conditions is met, an indication message is sent to a higher layer, the indication message being used to indicate a random access problem:

[0250] The PRACH transmission counter's count value reaches the first threshold;

[0251] The PUSCH transmission counter's count value reaches the second threshold;

[0252] The maximum of the count values ​​of the PRACH transmission counter and the PUSCH transmission counter reaches the third threshold.

[0253] Optionally, as an embodiment, the PRACH and the PUSCH use different transmission counters, and the power adjustment counter of msgA includes a power adjustment counter shared by the PRACH and the PUSCH. The transmitting module 202 can be used to transmit the PUSCH instead of the PRACH if the PRACH LBT detection fails and the PUSCH LBT detection succeeds.

[0254] And processing module 204, which can be used to increment the power adjustment counter by 1.

[0255] Optionally, as an embodiment, the terminal device 200 further includes a receiving module, which can be used for:

[0256] Start the msgB receiving window;

[0257] If the msgB receive window times out and / or the contention resolution fails, the PRACH transmission counter is paused and the PUSCH transmission counter is incremented by 1.

[0258] Optionally, as an embodiment, the sending module 202 may be configured to send indication information to a higher layer if at least one of the following conditions is met, the indication information being used to indicate a random access problem:

[0259] The PRACH transmission counter's count value reaches the first threshold;

[0260] The PUSCH transmission counter's count value reaches the second threshold;

[0261] The maximum of the count values ​​of the PRACH transmission counter and the PUSCH transmission counter reaches the third threshold.

[0262] Optionally, as an embodiment, the PRACH and the PUSCH use different transmission counters, and the power adjustment counter of msgA includes a power adjustment counter shared by the PRACH and the PUSCH. The transmitting module 202 can be used to: if the PRACH LBT detection is successful and the PUSCH LBT detection is successful, then transmit the PRACH and transmit the PUSCH.

[0263] And processing module 204, which can be used to increment the power adjustment counter by 1.

[0264] Optionally, as an embodiment, the terminal device 200 further includes a receiving module, which can be used for:

[0265] Start the msgB receiving window;

[0266] If the msgB receive window times out and / or the contention resolution fails, the transmission counter of the PRACH is incremented by 1, and the transmission counter of the PUSCH is incremented by 1.

[0267] Optionally, as an embodiment, the sending module 202 may be used to indicate a random access problem to a higher layer if at least one of the following conditions is met:

[0268] The PRACH transmission counter's count value reaches the first threshold;

[0269] The PUSCH transmission counter's count value reaches the second threshold;

[0270] The maximum of the count values ​​of the PRACH transmission counter and the PUSCH transmission counter reaches the third threshold.

[0271] Optionally, as an embodiment, the transmission counter of msgA includes a transmission counter shared by the PRACH and the PUSCH, but uses a different power adjustment counter. The transmission module 202 can be used to not transmit the PRACH and not transmit the PUSCH if the PRACH LBT detection fails.

[0272] The processing module 204 can be used to pause the power adjustment counter of the PRACH, pause the power adjustment counter of the PUSCH, and pause the transmission counter.

[0273] Optionally, as an embodiment, the transmission counter of msgA includes a transmission counter shared by the PRACH and the PUSCH, but uses a different power adjustment counter. The processing module 204 can be used for:

[0274] If the PRACH LBT detection fails, determine whether to terminate the current random access process based on the number of times the PRACH and / or PUSCH LBT detections fail.

[0275] If it is determined that the current random access process will be terminated, then LBT failure recovery will be performed.

[0276] Optionally, as an embodiment, the transmission counter of msgA includes a transmission counter shared by the PRACH and the PUSCH, but uses a different power adjustment counter. The transmitting module 202 can be used to transmit the PRACH and not transmit the PUSCH if the PRACH LBT detection is successful and the PUSCH LBT detection fails.

[0277] The processing module 204 can be used to increment the power adjustment counter of the PRACH by 1 and pause the power adjustment counter of the PUSCH.

[0278] Optionally, as an embodiment, the terminal device 200 further includes a receiving module, which can be used for:

[0279] Launch the msgB or msg2 receiving window;

[0280] If the PUSCH contains a C-RNTI MAC CE, then during the operation of the msgB or msg2 receive window, the RA-RNTI scrambled PDCCH is listened to, but the C-RNTI scrambled PDCCH is not listened to.

[0281] Optionally, as an embodiment, the processing module 204 can be used to increment the transmission counter by 1 if the msgB receive window times out and / or the contention resolution fails.

[0282] Optionally, as an embodiment, the transmission counter of msgA includes a transmission counter shared by the PRACH and the PUSCH, but uses a different power adjustment counter. The transmission module 202 can be used to send the PUSCH instead of the PRACH if the PRACH LBT detection fails and the PUSCH LBT detection succeeds.

[0283] The processing module 204 can be used to pause the power adjustment counter of the PRACH and increment the power adjustment counter of the PUSCH by 1.

[0284] Optionally, as an embodiment, the terminal device 200 further includes a receiving module, which can be used for:

[0285] Start the msgB receiving window;

[0286] If the msgB receive window times out and / or the contention resolution fails, the transmission counter is incremented by 1.

[0287] Optionally, as an embodiment, the transmission counter of msgA includes a transmission counter shared by the PRACH and the PUSCH, but uses a different power adjustment counter. The transmitting module 202 can be used to transmit the PRACH and the PUSCH if the PRACH LBT detection is successful and the PUSCH LBT detection is successful.

[0288] The processing module 204 can be used to increment the power adjustment counter of the PRACH by 1 and the power adjustment counter of the PUSCH by 1.

[0289] Optionally, as an embodiment, the terminal device 200 further includes a receiving module, which can be used for:

[0290] Start the msgB receiving window;

[0291] If the msgB receive window times out and / or the contention resolution fails, the transmission counter is incremented by 1.

[0292] Optionally, as an embodiment, the PRACH and the PUSCH use different transmission counters and different power adjustment counters. The transmitting module 202 can be used to not transmit the PRACH and the PUSCH if the PRACH LBT detection fails; and the processing module 204 can be used to pause the power adjustment counter of the PRACH, pause the power adjustment counter of the PUSCH, pause the transmission counter of the PRACH, and pause the operation of incrementing the transmission counter of the PUSCH by 1.

[0293] Optionally, as an embodiment, the PRACH and PUSCH use different transmission counters and different power adjustment counters. The processing module 204 can be used to:

[0294] If the PRACH LBT detection fails, determine whether to terminate the current random access process based on the number of times the PRACH and / or PUSCH LBT detections fail.

[0295] If it is determined that the current random access process will be terminated, then LBT failure recovery will be performed.

[0296] Optionally, as an embodiment, the PRACH and the PUSCH use different transmission counters and different power adjustment counters. The transmitting module 202 can be used to transmit the PRACH and not transmit the PUSCH if the PRACH LBT detection is successful and the PUSCH LBT detection fails.

[0297] The processing module 204 can be used to increment the power adjustment counter of the PRACH by 1 and pause the power adjustment counter of the PUSCH.

[0298] Optionally, as an embodiment, the terminal device 200 further includes a receiving module, which can be used for:

[0299] Launch the msgB or msg2 receiving window;

[0300] If the PUSCH contains a C-RNTI MAC CE, then during the operation of the msgB or msg2 receive window, the RA-RNTI scrambled PDCCH is listened to, but the C-RNTI scrambled PDCCH is not listened to.

[0301] Optionally, as an embodiment, the sending module 202 can be used to fall back to the 4-step random access procedure to send the PUSCH.

[0302] Optionally, as an embodiment, the processing module 204 can be used to increment the transmission counter of the PRACH by 1 and the transmission counter of the PUSCH by 1 if the msgB receive window times out and / or the contention resolution fails.

[0303] Optionally, as an embodiment, the sending module 202 may be configured to send indication information to a higher layer if at least one of the following conditions is met, the indication information being used to indicate a random access problem:

[0304] The PRACH transmission counter's count value reaches the first threshold;

[0305] The PUSCH transmission counter's count value reaches the second threshold;

[0306] The maximum of the count values ​​of the PRACH transmission counter and the PUSCH transmission counter reaches the third threshold.

[0307] Optionally, as an embodiment, the PRACH and the PUSCH use different transmission counters and different power adjustment counters. The transmitting module 202 can be configured to not transmit the PRACH and transmit the PUSCH if the PRACH LBT detection fails and the PUSCH LBT detection succeeds.

[0308] The processing module 204 can be used to pause the power adjustment counter of the PRACH and increment the power adjustment counter of the PUSCH by 1.

[0309] Optionally, as an embodiment, the terminal device 200 further includes a receiving module, which can be used to start the msgB receiving window;

[0310] The processing module 204 can be used to pause the transmission counter of the PRACH and increment the transmission counter of the PUSCH by 1 if the msgB receive window times out and / or the contention resolution fails.

[0311] Optionally, as an embodiment, the sending module 202 may be configured to send indication information to a higher layer if at least one of the following conditions is met, the indication information being used to indicate a random access problem:

[0312] The PRACH transmission counter's count value reaches the first threshold;

[0313] The PUSCH transmission counter's count value reaches the second threshold;

[0314] The maximum of the count values ​​of the PRACH transmission counter and the PUSCH transmission counter reaches the third threshold.

[0315] Optionally, as an embodiment, the PRACH and the PUSCH use different transmission counters and different power adjustment counters. The transmitting module 202 can be used to transmit the PRACH and the PUSCH if the PRACH LBT detection is successful and the PUSCH LBT detection is successful.

[0316] The processing module 204 can be used to increment the power adjustment counter of the PRACH by 1 and the power adjustment counter of the PUSCH by 1.

[0317] Optionally, as one embodiment, the processing module 204 can be used for:

[0318] Start the msgB receiving window;

[0319] If the msgB receive window times out and / or the contention resolution fails, the transmission counter of the PRACH is incremented by 1, and the transmission counter of the PUSCH is incremented by 1.

[0320] Optionally, as an embodiment, the sending module 202 may be used to indicate a random access problem to a higher layer if at least one of the following conditions is met:

[0321] The PRACH transmission counter's count value reaches the first threshold;

[0322] The PUSCH transmission counter's count value reaches the second threshold;

[0323] The maximum of the count values ​​of the PRACH transmission counter and the PUSCH transmission counter reaches the third threshold.

[0324] The terminal device 200 according to the embodiments of this disclosure can refer to the process of the method 100 corresponding to the embodiments of this disclosure. Furthermore, each unit / module in the terminal device 200 and the other operations and / or functions described above are for implementing the corresponding processes in the method 100 and can achieve the same or equivalent technical effects. For the sake of brevity, they will not be described in detail here.

[0325] Figure 3 is a block diagram of a terminal device according to another embodiment of this disclosure. The terminal device 300 shown in Figure 3 includes at least one processor 301, a memory 302, at least one network interface 304, and a user interface 303. The various components in the terminal device 300 are coupled together via a bus system 305. It is understood that the bus system 305 is used to implement communication between these components. In addition to a data bus, the bus system 305 also includes a power bus, a control bus, and a status signal bus. However, for clarity, all buses are labeled as bus system 305 in Figure 3.

[0326] The user interface 303 may include a display, keyboard, clicking device (e.g., mouse, trackball), touchpad, or touch screen.

[0327] It is understood that the memory 302 in this embodiment can be volatile memory or non-volatile memory, or may include both volatile and non-volatile memory. The non-volatile memory can be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory. The volatile memory can be random access memory (RAM), which serves as an external cache. By way of example, but not limitation, many forms of RAM are available, such as Static Random Access Memory (SRAM), Dynamic Random Access Memory (DRAM), Synchronous DRAM (SDRAM), Double Data Rate SDRAM (DDRSDRAM), Enhanced SDRAM (ESDRAM), Synchlink DRAM (SLDRAM), and Direct Rambus RAM (DRRAM). The memory 302 of the systems and methods described in this disclosure is intended to include, but is not limited to, these and any other suitable types of memory.

[0328] In some implementations, memory 302 stores elements such as executable modules or data structures, or subsets thereof, or extended sets thereof: operating system 3021 and application program 3022.

[0329] The operating system 3021 includes various system programs, such as the framework layer, core library layer, and driver layer, used to implement various basic business functions and handle hardware-based tasks. The application program 3022 includes various applications, such as a media player and a browser, used to implement various application functions. Programs implementing the methods of this disclosure embodiment can be included in the application program 3022.

[0330] In this embodiment of the disclosure, the terminal device 300 further includes a computer program stored on a memory 302 and executable on a processor 301, wherein the computer program, when executed by the processor 301, implements the steps of method 100.

[0331] The methods disclosed in the above embodiments of this disclosure can be applied to or implemented by processor 301. Processor 301 may be an integrated circuit chip with signal processing capabilities. In implementation, each step of the above method can be completed by the integrated logic circuit of the hardware in processor 301 or by instructions in software form. The processor 301 may be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. It can implement or execute the methods, steps, and logic block diagrams disclosed in the embodiments of this disclosure. The general-purpose processor may be a microprocessor or any conventional processor. The steps of the methods disclosed in the embodiments of this disclosure can be directly embodied in the execution of a hardware decoding processor, or executed by a combination of hardware and software modules in the decoding processor. The software modules may be located in random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, or other mature computer-readable storage media in the art. The computer-readable storage medium is located in memory 302. Processor 301 reads the information in memory 302 and, in conjunction with its hardware, completes the steps of the above method. Specifically, the computer-readable storage medium stores a computer program, which, when executed by processor 301, implements the steps of the above method 100 embodiment.

[0332] It is understood that the embodiments described in this disclosure can be implemented using hardware, software, firmware, middleware, microcode, or a combination thereof. For hardware implementation, the processing unit can be implemented in one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field-programmable gate arrays (FPGAs), general-purpose processors, controllers, microcontrollers, microprocessors, other electronic units for performing the functions described in this disclosure, or combinations thereof.

[0333] For software implementation, the techniques described in the embodiments of this disclosure can be implemented by modules (e.g., procedures, functions, etc.) that perform the functions described in the embodiments of this disclosure. The software code can be stored in memory and executed by a processor. The memory can be implemented in the processor or externally.

[0334] The terminal device 300 can implement the various processes implemented by the terminal device in the foregoing embodiments and can achieve the same or equivalent technical effects. To avoid repetition, it will not be described again here.

[0335] This disclosure also provides a computer-readable storage medium storing a computer program. When executed by a processor, the computer program implements the various processes of the embodiments of method 100 described above and achieves the same technical effects. To avoid repetition, it will not be described again here. The computer-readable storage medium may be a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk, etc.

[0336] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0337] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of this disclosure, in essence, or the part that contributes to the related technology, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) and includes several instructions to cause a terminal (which may be a mobile phone, computer, server, air conditioner, or network device, etc.) to execute the methods described in the various embodiments of this disclosure.

[0338] The embodiments of this disclosure have been described above with reference to the accompanying drawings. However, this disclosure is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this disclosure without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of this disclosure.

Claims

1. A two-step random access method for an unlicensed frequency band, the method being executed by a terminal device, the method comprising: Based on the LBT (Listen Before You Speak) detection results, determine whether to send msgA and whether to update the power adjustment counter of msgA; wherein, the power adjustment counter is used to determine the transmission power of msgA, and msgA includes the Physical Random Access Channel (PRACH) and the Physical Uplink Shared Channel (PUSCH); Based on the transmission status of msgA, determine whether to update the transmission counter of msgA.

2. The method as described in claim 1, wherein, The PRACH and PUSCH share a single transmission counter, but use different power adjustment counters; or The PRACH and PUSCH use different transmission counters and different power adjustment counters.

3. The method as described in claim 1, wherein, The transmission counter for msgA includes a transmission counter shared by the PRACH and the PUSCH, and the power adjustment counter for msgA includes a power adjustment counter shared by the PRACH and the PUSCH. The step of determining whether to send msgA and whether to update the power adjustment counter for msgA based on the LBT detection result, and determining whether to update the transmission counter for msgA based on the transmission status of msgA, includes: If the PRACH LBT detection fails, and the PUSCH LBT detection fails, then Do not send the PRACH, do not send the PUSCH; and Pause the power adjustment counter and pause the transmission counter.

4. The method of claim 1, wherein, The transmission counter of msgA includes a transmission counter shared by the PRACH and the PUSCH, and the power adjustment counter of msgA includes a power adjustment counter shared by the PRACH and the PUSCH. The method further includes: If the PRACH LBT detection fails, and the PUSCH LBT detection fails, then Based on the number of times the PRACH and / or PUSCH LBT detections fail, determine whether to terminate the current random access process; If it is determined that the current random access process will be terminated, then LBT failure recovery will be performed.

5. The method of claim 1, wherein, The transmission counter of msgA includes a transmission counter shared by the PRACH and the PUSCH, and the power adjustment counter of msgA includes a power adjustment counter shared by the PRACH and the PUSCH. Determining whether to update the power adjustment counter of msgA based on the LBT detection result includes: If at least one of the PRACH and PUSCH LBT detections is successful, then The power adjustment counter is incremented by 1.

6. The method of claim 5, wherein, The step of determining whether to send msgA based on the LBT detection result, and determining whether to update the transmission counter of msgA based on the sending status of msgA, includes: If the PUSCH LBT detection is successful, then send the PUSCH and start the msgB receiving window; If the msgB receive window times out and / or the contention resolution fails, the transmission counter is incremented by 1.

7. The method of claim 1, wherein, The transmission counter for msgA includes the transmission counter for PRACH and the transmission counter for PUSCH, with PRACH and PUSCH using different transmission counters. The power adjustment counter for msgA includes a power adjustment counter shared by PRACH and PUSCH. The step of determining whether to send msgA and whether to update the power adjustment counter for msgA based on the LBT detection result, and determining whether to update the transmission counter for msgA based on the transmission status of msgA, includes: If the PRACH LBT detection fails, then Do not send the PRACH, and do not send the PUSCH; and Pause the power adjustment counter, pause the PRACH transmission counter, and pause the increment operation of the PUSCH transmission counter.

8. The method of claim 1, wherein, The transmission counter of msgA includes the transmission counter of PRACH and the transmission counter of PUSCH, wherein PRACH and PUSCH use different transmission counters, and the power adjustment counter of msgA includes a power adjustment counter shared by PRACH and PUSCH. The method further includes: If the PRACH LBT detection fails, then Based on the number of times the PRACH and / or PUSCH LBT detections fail, determine whether to terminate the current random access process; If it is determined that the current random access process will be terminated, then LBT failure recovery will be performed.

9. The method of claim 1, wherein, The transmission counter for msgA includes the transmission counter for PRACH and the transmission counter for PUSCH, wherein PRACH and PUSCH use different transmission counters. The power adjustment counter for msgA includes a power adjustment counter shared by PRACH and PUSCH. Determining whether to send msgA and whether to update the power adjustment counter for msgA based on the LBT detection result includes: If the PRACH LBT detection succeeds and the PUSCH LBT detection fails, then Send the PRACH, but not the PUSCH; and The power adjustment counter is incremented by 1.

10. The method of claim 9, wherein, After sending the PRACH, the method further includes: Launch the msgB or msg2 receiving window; If the PUSCH contains the Cell Radio Network Temporary Identifier (C-RNTI) Link Control Layer Control Unit (MAC CE), then During the operation of the msgB or msg2 receive window, the Physical Downlink Control Channel (PDCCH) scrambled with the Random Access Radio Network Transmission Identifier (RA-RNTI) is monitored, but the PDCCH scrambled with the C-RNTI is not monitored.

11. The method of claim 10, wherein, After sending the PRACH, the method further includes: The process reverts to the 4-step random access procedure to send the PUSCH.

12. The method of claim 11, wherein, The step of determining whether to update the transmission counter of msgA based on the transmission status of msgA includes: If the receive window for msgB or msg2 times out and / or contention resolution fails, then The transmission counter of the PRACH is incremented by 1, and the transmission counter of the PUSCH is incremented by 1.

13. The method of claim 11, wherein, The method further includes: If at least one of the following conditions is met, an indication message is sent to a higher layer, the indication message being used to indicate a random access problem: The PRACH transmission counter's count value reaches the first threshold; The PUSCH transmission counter's count value reaches the second threshold; The maximum of the count values ​​of the PRACH transmission counter and the PUSCH transmission counter reaches the third threshold.

14. The method of claim 1, wherein, The transmission counter for msgA includes the transmission counter for PRACH and the transmission counter for PUSCH, wherein PRACH and PUSCH use different transmission counters. The power adjustment counter for msgA includes a power adjustment counter shared by PRACH and PUSCH. Determining whether to send msgA and whether to update the power adjustment counter for msgA based on the LBT detection result includes: If the PRACH LBT detection fails and the PUSCH LBT detection succeeds, then Instead of sending the PRACH, send the PUSCH; and The power adjustment counter is incremented by 1.

15. The method of claim 14, wherein, After sending the PUSCH, the method further includes: Start the msgB receiving window; The step of determining whether to update the transmission counter of msgA based on the transmission status of msgA includes: if the receive window of msgB times out and / or the contention resolution fails, then suspend the transmission counter of PRACH and increment the transmission counter of PUSCH by 1.

16. The method of claim 15, wherein, The method further includes: If at least one of the following conditions is met, an indication message is sent to a higher layer, the indication message being used to indicate a random access problem: The PRACH transmission counter's count value reaches the first threshold; The PUSCH transmission counter's count value reaches the second threshold; The maximum of the count values ​​of the PRACH transmission counter and the PUSCH transmission counter reaches the third threshold.

17. The method of claim 1, wherein, The transmission counter for msgA includes the transmission counter for PRACH and the transmission counter for PUSCH, wherein PRACH and PUSCH use different transmission counters. The power adjustment counter for msgA includes a power adjustment counter shared by PRACH and PUSCH. Determining whether to send msgA and whether to update the power adjustment counter for msgA based on the LBT detection result includes: If the PRACH LBT detection is successful, and the PUSCH LBT detection is successful, then Send the PRACH, send the PUSCH; and The power adjustment counter is incremented by 1.

18. The method of claim 17, wherein, After sending the PUSCH, the method further includes: Start the msgB receiving window; The step of determining whether to update the transmission counter of msgA based on the transmission status of msgA includes: if the receive window of msgB times out and / or the contention resolution fails, then increment the transmission counter of PRACH by 1 and increment the transmission counter of PUSCH by 1.

19. The method of claim 18, wherein, The method further includes: If at least one of the following conditions is met, then indicate the random access problem to the higher layers: The PRACH transmission counter's count value reaches the first threshold; The PUSCH transmission counter's count value reaches the second threshold; The maximum of the count values ​​of the PRACH transmission counter and the PUSCH transmission counter reaches the third threshold.

20. The method of claim 1, wherein, The transmission counter for msgA includes a transmission counter shared by the PRACH and the PUSCH. The power adjustment counter for msgA includes a power adjustment counter for the PRACH and a power adjustment counter for the PUSCH. The PRACH and the PUSCH use different power adjustment counters. The step of determining whether to send msgA and whether to update the power adjustment counter for msgA based on the LBT detection result, and determining whether to update the transmission counter for msgA based on the transmission status of msgA, includes: If the PRACH LBT detection fails, then Do not send the PRACH, and do not send the PUSCH; and Pause the power adjustment counter of the PRACH, pause the power adjustment counter of the PUSCH, and pause the transmission counter.

21. The method of claim 1, wherein, The transmission counter of msgA includes a transmission counter shared by the PRACH and the PUSCH, and the power adjustment counter of msgA includes a power adjustment counter for the PRACH and a power adjustment counter for the PUSCH. The PRACH and the PUSCH use different power adjustment counters. The method further includes: If the PRACH LBT detection fails, then Based on the number of times the PRACH and / or PUSCH LBT detections fail, determine whether to terminate the current random access process; If it is determined that the current random access process will be terminated, then LBT failure recovery will be performed.

22. The method of claim 1, wherein, The transmission counter for msgA includes a transmission counter shared by the PRACH and the PUSCH. The power adjustment counter for msgA includes a power adjustment counter for the PRACH and a power adjustment counter for the PUSCH. The PRACH and the PUSCH use different power adjustment counters. Determining whether to send msgA and whether to update the power adjustment counter for msgA based on the LBT detection result includes: If the PRACH LBT detection succeeds and the PUSCH LBT detection fails, then Send the PRACH, but not the PUSCH; and The power adjustment counter of the PRACH is incremented by 1, and the power adjustment counter of the PUSCH is paused.

23. The method of claim 22, wherein, After sending the PRACH, the method further includes: Launch the msgB or msg2 receiving window; If the PUSCH contains C-RNTI MAC CE, then During the operation of the msgB or msg2 receive window, the RA-RNTI scrambled PDCCH is monitored, but the C-RNTI scrambled PDCCH is not monitored.

24. The method of claim 23, wherein, The step of determining whether to update the transmission counter of msgA based on the transmission status of msgA includes: If the msgB receive window times out and / or the contention resolution fails, the transmission counter is incremented by 1.

25. The method of claim 1, wherein, The transmission counter for msgA includes a transmission counter shared by the PRACH and the PUSCH. The power adjustment counter for msgA includes a power adjustment counter for the PRACH and a power adjustment counter for the PUSCH. The PRACH and the PUSCH use different power adjustment counters. Determining whether to send msgA and whether to update the power adjustment counter for msgA based on the LBT detection result includes: If the PRACH LBT detection fails and the PUSCH LBT detection succeeds, then Instead of sending the PRACH, send the PUSCH; and Pause the power adjustment counter of the PRACH and increment the power adjustment counter of the PUSCH by 1.

26. The method of claim 25, wherein, After sending the PUSCH, the method further includes: Start the msgB receiving window; The step of determining whether to update the transmission counter of msgA based on the transmission status of msgA includes: if the receive window of msgB times out and / or the contention resolution fails, then incrementing the transmission counter by 1.

27. The method of claim 1, wherein, The transmission counter for msgA includes a transmission counter shared by the PRACH and the PUSCH. The power adjustment counter for msgA includes a power adjustment counter for the PRACH and a power adjustment counter for the PUSCH. The PRACH and the PUSCH use different power adjustment counters. Determining whether to send msgA and whether to update the power adjustment counter for msgA based on the LBT detection result includes: If the PRACH LBT detection is successful, and the PUSCH LBT detection is successful, then Send the PRACH, send the PUSCH; and The power adjustment counter of the PRACH is incremented by 1, and the power adjustment counter of the PUSCH is incremented by 1.

28. The method of claim 27, wherein, After sending the PUSCH, the method further includes: Start the msgB receiving window; The step of determining whether to update the transmission counter of msgA based on the transmission status of msgA includes: if the receive window of msgB times out and / or the contention resolution fails, then incrementing the transmission counter by 1.

29. The method of claim 1, wherein, The transmission counter for msgA includes the transmission counter for PRACH and the transmission counter for PUSCH, with PRACH and PUSCH using different transmission counters. The power adjustment counter for msgA includes the power adjustment counter for PRACH and the power adjustment counter for PUSCH, with PRACH and PUSCH using different power adjustment counters. The step of determining whether to send msgA and whether to update the power adjustment counter for msgA based on the LBT detection result, and determining whether to update the transmission counter for msgA based on the transmission status of msgA, includes: If the PRACH LBT detection fails, then Do not send the PRACH, and do not send the PUSCH; and Pause the power adjustment counter of the PRACH, pause the power adjustment counter of the PUSCH, pause the transmission counter of the PRACH, and pause the operation of incrementing the transmission counter of the PUSCH by 1.

30. The method of claim 1, wherein, The transmission counter of msgA includes the transmission counter of PRACH and the transmission counter of PUSCH, wherein the PRACH and the PUSCH use different transmission counters. The power adjustment counter of msgA includes the power adjustment counter of PRACH and the power adjustment counter of PUSCH, wherein the PRACH and the PUSCH use different power adjustment counters. The method further includes: If the PRACH LBT detection fails, then Based on the number of times the PRACH and / or PUSCH LBT detections fail, determine whether to terminate the current random access process; If it is determined that the current random access process will be terminated, then LBT failure recovery will be performed.

31. The method of claim 1, wherein, The transmission counter for msgA includes the transmission counter for PRACH and the transmission counter for PUSCH, wherein the PRACH and PUSCH use different transmission counters. The power adjustment counter for msgA includes the power adjustment counter for PRACH and the power adjustment counter for PUSCH, wherein the PRACH and PUSCH use different power adjustment counters. The step of determining whether to send msgA and whether to update the power adjustment counter for msgA based on the LBT detection result includes: If the PRACH LBT detection succeeds and the PUSCH LBT detection fails, then Send the PRACH, but not the PUSCH; and The power adjustment counter of the PRACH is incremented by 1, and the power adjustment counter of the PUSCH is paused.

32. The method of claim 31, wherein, After sending the PRACH, the method further includes: Launch the msgB or msg2 receiving window; If the PUSCH contains C-RNTI MAC CE, then During the operation of the msgB or msg2 receive window, the RA-RNTI scrambled PDCCH is monitored, but the C-RNTI scrambled PDCCH is not monitored.

33. The method of claim 32, wherein, After sending the PRACH, the method further includes: The process reverts to the 4-step random access procedure to send the PUSCH.

34. The method of claim 33, wherein, The step of determining whether to update the transmission counter of msgA based on the transmission status of msgA includes: If the msgB receive window times out and / or the contention resolution fails, the transmission counter of the PRACH is incremented by 1, and the transmission counter of the PUSCH is incremented by 1.

35. The method of claim 33, wherein, The method further includes: If at least one of the following conditions is met, an indication message is sent to a higher layer, the indication message being used to indicate a random access problem: The PRACH transmission counter's count value reaches the first threshold; The PUSCH transmission counter's count value reaches the second threshold; The maximum of the count values ​​of the PRACH transmission counter and the PUSCH transmission counter reaches the third threshold.

36. The method of claim 1, wherein, The transmission counter for msgA includes the transmission counter for PRACH and the transmission counter for PUSCH, wherein the PRACH and PUSCH use different transmission counters. The power adjustment counter for msgA includes the power adjustment counter for PRACH and the power adjustment counter for PUSCH, wherein the PRACH and PUSCH use different power adjustment counters. The step of determining whether to send msgA and whether to update the power adjustment counter for msgA based on the LBT detection result includes: If the PRACH LBT detection fails and the PUSCH LBT detection succeeds, then Instead of sending the PRACH, send the PUSCH; and Pause the power adjustment counter of the PRACH and increment the power adjustment counter of the PUSCH by 1.

37. The method of claim 36, wherein, After sending the PUSCH, the method further includes: Start the msgB receiving window; The step of determining whether to update the transmission counter of msgA based on the transmission status of msgA includes: if the receive window of msgB times out and / or the contention resolution fails, then suspend the transmission counter of PRACH and increment the transmission counter of PUSCH by 1.

38. The method of claim 37, wherein, The method further includes: If at least one of the following conditions is met, an indication message is sent to a higher layer, the indication message being used to indicate a random access problem: The PRACH transmission counter's count value reaches the first threshold; The PUSCH transmission counter's count value reaches the second threshold; The maximum of the count values ​​of the PRACH transmission counter and the PUSCH transmission counter reaches the third threshold.

39. The method of claim 1, wherein, The transmission counter for msgA includes the transmission counter for PRACH and the transmission counter for PUSCH, wherein the PRACH and PUSCH use different transmission counters. The power adjustment counter for msgA includes the power adjustment counter for PRACH and the power adjustment counter for PUSCH, wherein the PRACH and PUSCH use different power adjustment counters. The step of determining whether to send msgA and whether to update the power adjustment counter for msgA based on the LBT detection result includes: If the PRACH LBT detection is successful, and the PUSCH LBT detection is successful, then Send the PRACH, send the PUSCH; and The power adjustment counter of the PRACH is incremented by 1, and the power adjustment counter of the PUSCH is incremented by 1.

40. The method of claim 39, wherein, After sending the PUSCH, the method further includes: Start the msgB receiving window; The step of determining whether to update the transmission counter of msgA based on the transmission status of msgA includes: if the receive window of msgB times out and / or the contention resolution fails, then increment the transmission counter of PRACH by 1 and increment the transmission counter of PUSCH by 1.

41. The method of claim 40, wherein, The method further includes: If at least one of the following conditions is met, then indicate the random access problem to the higher layers: The PRACH transmission counter's count value reaches the first threshold; The PUSCH transmission counter's count value reaches the second threshold; The maximum of the count values ​​of the PRACH transmission counter and the PUSCH transmission counter reaches the third threshold.

42. A terminal device, comprising: The sending module is used to determine whether to send msgA based on the LBT detection result; The processing module is used to determine whether to update the power adjustment counter of msgA based on the LBT detection result; wherein the power adjustment counter is used to determine the transmission power of msgA, and msgA includes PRACH and PUSCH; The processing module is further configured to determine whether to update the transmission counter of msgA based on the transmission status of msgA.

43. A terminal device, comprising: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the computer program, when executed by the processor, implements the steps of the two-step random access method for an unlicensed frequency band as described in any one of claims 1 to 41.

44. A computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the two-step random access method for an unlicensed frequency band as described in any one of claims 1 to 41.