Wireless communication method and apparatus

Abstract

The present disclosure provides a method performed by a user equipment, comprising: sending a random access request message; receiving a random access response message; and when the random access response message comprises uplink resource allocation information of the user equipment, and when the random access is triggered by requesting to recover a radio link in which beamforming failure occurs, sending a message comprising indication information on the allocated uplink resource. The indication information indicates that the random access request message is sent due to requesting to recover a radio link in which beamforming failure occurs. Furthermore, the present disclosure also provides a corresponding user equipment.

Description

[0001] This application is a divisional application of Chinese invention patent application No. 201711414661.9, entitled "Wireless Communication Method and Apparatus", filed with the China National Intellectual Property Administration on December 22, 2017. Technical Field

[0002] This disclosure relates to the field of wireless communication technology, and more specifically to a method performed by a user equipment and a corresponding user equipment. Background Technology

[0003] With the rapid growth of mobile communications and tremendous technological advancements, the world is moving towards a fully interconnected network society, where anyone or anything can access information and share data anytime, anywhere. It is projected that by 2020, the number of connected devices will reach 50 billion, of which only about 10 billion will likely be mobile phones and tablets; the rest will be machines that communicate with each other, not just machines that interact with people. Therefore, designing systems to better support the Internet of Things is a topic requiring in-depth research.

[0004] To this end, at the 3GPP RAN#64 plenary meeting held in March 2016, a research project on new 5G radio access technology was proposed (see non-patent document: RP-160671 New SID Proposal: Study on New Radio Access Technology). The project description states that the operating frequency band of the new communication standard will be expandable to 100GHz, while at least meeting the needs of enhanced mobile broadband services, the communication needs of massive IoT UEs, and the service requirements of high reliability. The research work on this project was scheduled to conclude in 2018.

[0005] This research project plans to use beamforming for information transmission. Specifically, when using high-frequency communication, a thinner beam will be used to address the rapid fading of high-frequency channels. However, using a thinner beam for information transmission is susceptible to external changes, such as the rotation of the phone or obstruction from other objects.

[0006] In beamforming-based transmission scenarios, if the effective beam signal serving UE data / information transmission weakens or falls below a pre-configured threshold, data / information transmission is interrupted. The UE will then send a request to the network to reconfigure the effective working beam. To avoid prolonged service interruptions leading to connection rebuilding, accelerating this reconfiguration process is a problem that needs to be addressed. Summary of the Invention

[0007] This disclosure proposes a method executed by a user equipment and a corresponding user equipment to address at least some of the above problems.

[0008] According to one aspect of this disclosure, a method performed by a user equipment is proposed, comprising: sending a random access request message; receiving a random access response message; and, when the random access response message includes uplink resource allocation information of the user equipment, and when the random access is triggered by a request to restore a radio link experiencing beamforming failure, sending a message including indication information on the allocated uplink resources. The indication information indicates that the random access request message was sent due to a request to restore a radio link experiencing beamforming failure.

[0009] In one embodiment, the indication information includes the cell radio network temporary identifier "C-RNTI" and the media access control layer control element "MAC CE".

[0010] In one embodiment, the indication information includes a Media Access Control (MAC) control element “MAC CE” indicating that the random access request message was sent due to a request to restore a radio link where beamforming failure has occurred.

[0011] In one embodiment, the processing priority of the Media Access Control (MAC) control element "MAC CE" is higher than that of the MAC control element carrying BSR information and higher than that of the MAC control element carrying PHR information.

[0012] In one embodiment, upon receiving the random access response message, if the random access response carries backoff time information, the backoff time parameter of the user equipment's preamble is set to the product of the backoff time value in the random access response message and a specific coefficient.

[0013] In one embodiment, if no random access response message including the uplink resource allocation information of the user equipment is received within a specific time window, the backoff time of the preamble of the user equipment is set to the product of the backoff time parameter and a specific coefficient.

[0014] In one embodiment, the specific parameter is either pre-configured or randomly selected by the user equipment.

[0015] In one embodiment, the specific coefficient is equal to 0.

[0016] In one embodiment, the specific coefficient is greater than 0 and less than 1.

[0017] According to another aspect of this disclosure, a user equipment is provided, including a processor and a memory. Instructions are stored in the memory. When executed by the processor, the instructions cause the user equipment to perform the methods described above. Attached Figure Description

[0018] The above and other features of this disclosure will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, wherein:

[0019] Figure 1 This is a flowchart illustrating a method performed by a user equipment according to an embodiment of the present disclosure.

[0020] Figure 2 This is a block diagram illustrating a user equipment according to an embodiment of the present disclosure.

[0021] It should be noted that the accompanying drawings are not necessarily drawn to scale; the focus is on illustrating the principles of the technology disclosed herein. Furthermore, for clarity, similar reference numerals throughout the drawings refer to similar elements. Detailed Implementation

[0022] The present disclosure will now be described in detail with reference to the accompanying drawings and specific embodiments. It should be noted that the present disclosure should not be limited to the specific embodiments described below. Furthermore, for the sake of simplicity, detailed descriptions of well-known technologies not directly related to the present disclosure have been omitted to prevent confusion in understanding the present disclosure.

[0023] The following description uses NR mobile communication systems and their subsequent evolutions as example application environments, taking NR-supporting base stations and UE devices as examples, to specifically describe several implementation methods according to this disclosure. However, it should be noted that this disclosure is not limited to the following implementation methods, but is applicable to many other wireless communication systems, such as eLTE communication systems, and to other base stations and UE devices, such as eLTE-supporting base stations and UE devices. Furthermore, this disclosure is not limited to scenarios where wireless link interruptions are caused by beamforming / beamforming, but can also be used in scenarios where wireless link interruptions are caused by other reasons.

[0024] Before proceeding with the detailed description, the following explanations are provided for several terms used in this disclosure. Unless otherwise specified, all terms used in this disclosure shall have the meanings described below.

[0025] UE User Equipment

[0026] RLF Radio Link Failure

[0027] NR New Radio - Next-Generation Wireless Technology

[0028] LTE Long Term Evolution technology

[0029] Elte Enhanced Long Term Evolution (LTE)

[0030] Radio Resource Control (RC)

[0031] PDCP (Packet Data Convergence Protocol) is a layer-based protocol for packet data convergence.

[0032] RLC Radio Link Control (Radio Link Control Layer)

[0033] MAC Medium Access Control (layer)

[0034] PHY physical layer

[0035] MAC CE Medium Access Control Control Element

[0036] Media access control layer control elements

[0037] PUCCH Physical Uplink Control Channel

[0038] PDCCH (Physical Downlink Control Channel)

[0039] PDSCH (Physical Downlink Shared Channel)

[0040] DCI DownlinkControlInformation

[0041] TTI Transmission Time Interval

[0042] NDI New Data Indication

[0043] HARQ Hybrid Automatic Repeat Request

[0044] HARQ Process ID (HARQ Process Identifier)

[0045] BSR Buffer Status Report

[0046] PHR Power Headroom Report

[0047] SPS Semi-Persistent Scheduling

[0048] PDU Protocol Data Unit

[0049] When a UE detects a failure in the beamforming radio link during operation, it can request the network to reconfigure the radio link or the beam, or it can send a beam failure recover request. There are two request methods: one is contention-free (CF) random access (RA); the other is contention resoulution (CB) random access.

[0050] In CFRA operation, the UE is configured with a proprietary preamble before link failure. This preamble is uniquely associated with the UE's identity. That is, once the network receives the preamble, it can identify the UE, specifically its Cell Radio Network Temporary Identifier (C-RNTI). Furthermore, this preamble is assigned to the UE only for requesting beam recovery, link restoration, or link reconfiguration in the event of beam failure. When the network receives this preamble, it can scramble the PDCCH with the UE's C-RNTI and transmit the DCI on that PDCCH for downlink assignment or uplink scheduling. Once the UE correctly receives the DCI scrambled with its own C-RNTI, it considers the reconfiguration complete, or the beam failure recovery successful.

[0051] CFRA (Content-Free Access Restore) requires only two steps: the UE sends a preamble and then receives the DCI (Distributed Control Code) from the network, allowing the link to be quickly restored. However, this method has limitations. The UE can only send a pre-assigned preamble, unique to each UE, in a candidate beam direction if a valid candidate beam direction exists. In other words, the UE can only use this contention-free access method when a valid candidate link exists. A valid candidate link is defined as a link where the measured signal level or strength exceeds a specific threshold. These candidate links are also pre-configured for the UE by the network.

[0052] If no valid beam direction or candidate link exists, the UE can utilize Contention-Based Access (CBRA) for beam failure recovery. CBRA is a common access method. When a UE needs to initiate access, it randomly selects a preamble and sends it on the common PRACH resource. Because the preamble is randomly selected by the UE, other UEs with access needs may also select the same preamble and send it at the same time. Therefore, the network cannot uniquely identify the UE solely based on the received preamble, requiring further interaction to resolve contention conflicts. After receiving the preamble, the network sends a Random Access Response (RAR). This RAR carries a RAPID, allowing the UE to determine if the RAR was sent to it. The RAPID is the RandomAccess preamble ID; each preamble has its own corresponding RAPID. Therefore, after sending the preamble, the UE can determine whether the response is a response to the sent preamble based on the RAPID in the RAR.

[0053] In addition to the RAPID, the RAR also contains the uplink resource allocation (UL grant) corresponding to that RAPID. Once the UE confirms that the RAPID corresponds to the preamble it previously sent, the UE can send an uplink message on the UL grant corresponding to that RAPID. This message is usually called Message Three (MSG3). The content of MSG3 can vary depending on the reason the UE initiates access. For example, a UE in connected mode can initiate random access based on contention resolution when data arrives and triggers a scheduling request. In this case, the UE will carry its own C-RNTI in MSG3. After receiving such an MSG3, the network can schedule the UE in the subsequent Message Four (MSG4). As another example, a UE in connected mode can also initiate random access based on contention resolution when it receives a PDCCH order from the network. In this case, the UE will carry its own C-RNTI in MSG3, and after receiving such an MSG3, the network can send the UE a new timing advance in MSG4.

[0054] Similarly, for UEs that need to restore the link or send a beam failure recovery request, they can carry their own C-RNTI in MSG3, so that the network can schedule them in the following MSG4.

[0055] However, currently, the network cannot determine the reason why a UE initiates a contention-based random access procedure solely based on the C-RNTI carried by the MSG3. If the network could identify UEs initiating contention-based random access to restore the link, it could prioritize or prioritize scheduling these UEs, thereby avoiding prolonged link outages that could lead to the re-establishment of the UE's RRC connection and waste additional resources on re-establishing the RRC connection.

[0056] Figure 1 This is a flowchart illustrating a method performed by a user equipment according to an embodiment of the present disclosure.

[0057] In step S110, the user equipment (UE) sends a random access request message.

[0058] In step S120, the user equipment (UE) receives a random access response message.

[0059] In step S130, when the random access response message received in step S120 includes uplink resource allocation information for the user equipment (UE) and information indicating that the random access request was initiated by the UE due to a request to restore a radio link that has experienced beamforming failure, the UE sends a message including indication information on the allocated uplink resources. This indication information indicates that the random access request message was sent because of a request to restore a radio link that has experienced beamforming failure.

[0060] In one embodiment, the indication information may include the cell radio network temporary identifier “C-RNTI” and the media access control layer control element “MAC CE”.

[0061] Alternatively, the indication information may include a Media Access Control (MAC) CE indicating that the random access request message was sent due to a request to restore a radio link where beamforming failure has occurred. In this case, preferably, the MAC CE has a higher processing priority than the MAC CE carrying Buffer Status Report (BSR) information and the MAC CE carrying Power Headroom Report (PHR) information.

[0062] In one embodiment, upon receiving the random access response message, if the random access response carries backoff time information, the backoff time parameter of the user equipment's preamble can be set to the product of the backoff time value in the random access response message and a specific coefficient. Alternatively, if no random access response message including the user equipment's uplink resource allocation information is received within a specific time window, the backoff time of the user equipment's preamble can be set to the product of the backoff time parameter and a specific coefficient.

[0063] The specific parameter mentioned above can be pre-configured or randomly selected by the user device. For example, the specific coefficient can be greater than 0 and less than 1. Furthermore, the specific coefficient can be equal to 0.

[0064] The following examples illustrate in detail the message containing indication information sent by the user equipment (UE) in step S130.

[0065] Example 1: The indication information is implemented by C-RNTI MAC CE

[0066] The existing C-RNTI MAC CE contains 2 bytes to carry the C-RNTI (16 bits), which is identified by the corresponding LCID value in the LCID field of the MAC PDU subheader. For example, when LCID=111010 appears in the MAC PDU subheader, it indicates that the corresponding MAC CE is a C-RNTI MAC CE.

[0067] The novel C-RNTI MAC CE proposed in this disclosure may include two LCID values, each used for different scenarios:

[0068] - When the random access procedure is triggered or initiated by a condition or situation related to link reconfiguration or beam failure, the LCID that identifies the C-RNT MAC CE shall use LCID1 or the value of LCID1.

[0069] - If the random access procedure is not triggered for the reasons mentioned above, then the LCID that identifies the C-RNT MAC CE shall be LCID2 or the value of LCID2.

[0070] The phrase "the random access procedure is triggered or caused by a situation or condition related to link reconfiguration or beam failure" as described above and below can specifically refer to one or more of the following situations:

[0071] Scenario 1: The random access procedure is triggered or initiated by an instruction from the lower layer. Furthermore, the lower layer instruction could be a beam failure, a link failure, a link reconfiguration request, or a beam failure recovery request.

[0072] Scenario 2: The random access process is triggered or initiated by a beam failure recovery request or a link reconfiguration request;

[0073] Scenario 3: When C-RNTI MAC CE is used to indicate a beam failure recovery request or a link reconfiguration request.

[0074] The phrase "when the random access procedure is not triggered or caused by the aforementioned reasons" as described above and below can specifically refer to one or more of the following situations:

[0075] Scenario 1: The random access procedure is not triggered by an instruction from the lower layer. Furthermore, the lower layer instruction could be a beam failure, a link failure, a link reconfiguration request, or a beam failure recovery request.

[0076] Scenario 2: The random access procedure is not triggered by a beam failure recovery request or a link reconfiguration request;

[0077] Scenario 3: When C-RNTI MAC CE is not used to indicate a beam failure recovery request (beam failure recovery request) or a link reconfiguration request.

[0078] Scenario 4: When C-RNTI MAC CE is used for general random access procedures, such as random access procedures triggered by the RRC layer or random access procedures triggered by PDCCH commands.

[0079] For example, the C-RNTI MAC CE described above can be used in the following process.

[0080] When the UE successfully receives the Random Access Response (RAR) for the first time during the current random access procedure, the UE instructs the MAC entity, or the part of the MAC entity responsible for multiplexing and assembly functions, or instructs the Multiplexing and Assembly entity to include the C-RNTI MAC CE in the subsequent uplink transmission. Here, the subsequent uplink transmission may refer to the transmission of MSG3.

[0081] The UE then obtains the MAC PDU from the Multiplexing and Assembly Entity or the MAC Entity and stores it in the buffer of the MSG3. This MAC PDU is the content carried by the MSG3. Therefore, this MAC PDU contains the C-RNTI MAC CE.

[0082] When including C-RNTI MAC CE in the MAC PDU, if the current random access procedure is triggered by a situation or condition related to link reconfiguration or beam failure, then LCID1 is used to identify C-RNTI MAC CE. Specifically, C-RNTI MAC CE can be identified in the MAC PDU header. If it is not triggered by the situation described above, then LCID2 is used to identify C-RNTI MAC CE. Specifically, C-RNTI MAC CE can be identified in the MAC PDU header.

[0083] Example 2: Instructions are implemented by MAC CE

[0084] In this example, MAC CE is used as the indication information. This MAC CE can indicate one or more of the following:

[0085] Scenario 1: Random access is triggered by an instruction from the lower layer. Furthermore, the lower layer instruction could be a beam failure, a link failure, a link reconfiguration request, or a beam failure recovery request.

[0086] Scenario 2: Random access is triggered by a beam failure recovery request or a link reconfiguration request;

[0087] Scenario 3: C-RNTI MAC CE is used to indicate a beam failure recovery request or a link reconfiguration request;

[0088] Scenario 4: Indicates a beam failure recovery request or a link reconfiguration request.

[0089] The specific design of this MAC CE can be a MAC CE identified by a specific LCID value in the MAC PDU subheader. Its fixed length can be zero or non-zero. If it is non-zero, it can further carry some link or beam-related information. This can be called a MAC CE for failure recovery. This MAC CE for failure recovery can be used in the following processes:

[0090] When the UE successfully receives the RAR for the first time during the current random access procedure, the UE instructs the MAC entity, or the part of the MAC entity responsible for multiplexing and assembly, or the multiplexing and assembly entity, to include the C-RNTI MAC CE in the subsequent uplink transmission. In addition, if this random access procedure is triggered by a situation or condition related to link reconfiguration or beam failure, the MAC CE for failure recovery also needs to be included in the subsequent uplink transmission. Here, the subsequent uplink transmission may refer to the transmission of MSG3.

[0091] The UE then obtains the MAC PDU from the MAC entity, or from the part of the MAC entity responsible for multiplexing and assembly functions, or from the multiplexing and assembly entity, and stores it in the buffer of the MSG3. This MAC PDU is the content carried by the MSG3.

[0092] Therefore, if this random access procedure is triggered by a situation or condition related to link reconfiguration or beam failure, the MAC PDU obtained by the UE from the multiplexing and assembly entity will include the C-RNTI MAC CE and the MAC CE for failure recovery; in other words, MSG3 contains the C-RNTI MAC CE and the MAC CE for failure recovery. Otherwise, the MAC PDU obtained by the UE from the multiplexing and assembly entity will only contain the C-RNTI MAC CE and will not contain the MAC CE for failure recovery.

[0093] Example 3: The instruction message also indicates priority.

[0094] In this example, the MAC entity also sets the processing priority for the MAC CE used for failure recovery when reusing and assembling the MAC PDU. Specifically, this refers to the reuse and assembly processing priority.

[0095] A MAC PDU can contain one or more MAC CEs, as well as data from various logical channels. The size of a MAC PDU is fixed (determined by the UL grant received by the UE). Within a finite MAC PDU, if the UE needs to transmit multiple MAC CEs, a priority system needs to be established for these MAC CEs. This priority determines which MAC CE(s) are allocated space in the MAC PDU first, and then, if space remains, which MAC CE(s) are allocated next. In other words, the UE determines the order in which MAC CEs are allocated within the MAC PDU space based on a specific processing priority.

[0096] In the existing mechanism, when a UE simultaneously has a MAC CE for C-RNTI (a MAC CE carrying C-RNTI), a MAC CE for SPS confirmation (a MAC CE carrying semi-static scheduling confirmation), a MAC CE for BSR (a MAC CE carrying a buffer status report), and a MAC CE for PHR (a MAC CE carrying a power headroom report), the UE, when generating a MAC PDU, first considers placing the MAC CE for C-RNTI. If there is remaining space, it then places the MAC CE for SPS confirmation, followed by the MAC CE for BSR, and finally the MAC CE for PHR. Therefore, the processing priority order of these MAC CEs is: MAC CE for C-RNTI > MAC CE for SPS confirmation > MAC CE for BSR > MAC CE for PHR. Their processing order is as follows:

[0097] -MAC CE for C-RNTI;

[0098] -MAC CE for SPS confirmation;

[0099] -MAC CE for BSR;

[0100] -MAC CE for PHR;

[0101] Example 2 illustrates a new MAC CE that can be used to indicate information related to beam failure or link reconfiguration (see Example 2 for details), which can be referred to as the MAC CE for failure recovery. When this MAC CE is generated, to ensure that it and the MAC CE for C-RNTI are included in the same MAC PDU, the processing priority should be as follows:

[0102] MAC CE for failure recovery takes precedence over any of MAC CE for SPS confirmation, MAC CE for BSR, or MAC CE for PHR. One possible order is:

[0103] - MAC CE for failure recovery

[0104] -MAC CE for SPS confirmation

[0105] -MAC CE for BSR

[0106] -MAC CE for PHR.

[0107] Furthermore, the MAC CE for failure recovery and the MAC CE for C-RNTI can be considered to have the same priority, or the MAC CE for C-RNTI can have a higher priority than the MAC CE for failure recovery. If the UE's buffer contains data from non-uplink common control channels, the MAC CE for failure recovery can have a higher priority than such data. One possible ordering is:

[0108] -MAC CE for C-RNTI;

[0109] - MAC CE for failure recovery

[0110] -MAC CE for SPS confirmation;

[0111] -MAC CE for BSR;

[0112] -MAC CE for PHR;

[0113] -Data from the non-uplink common control channel

[0114] The focus of Examples 1-3 above is to enable the network side to identify UEs that trigger random access due to beam failure in MSG3. In existing contention-based random access processes, a backoff mechanism is used to avoid congestion during preamble transmission. This mechanism works by using a Backoff Indicator in the RAR, where the index indicated by the BIfield corresponds to a time value, typically in milliseconds.

[0115] After the UE receives the RAR,

[0116] If the RAR contains a BI field, the UE will set PREAMBLE_BACKOFF to the time value corresponding to the index indicated by the BI field;

[0117] If the RAR does not carry a BI field, then the UE sets the backoff time parameter PREAMBLE_BACKOFF to 0 milliseconds.

[0118] If the UE does not receive the C-RNTI-scrambled PDCCH within a specific time window, or does not receive the RAR carrying the RAPID corresponding to the preamble sent by the UE, the UE will randomly select a value between 0 and PREAMBLE_BACKOFF as the duration of the backoff time. Then, the UE will delay the transmission of the subsequent preamble for a period of time, which is the duration of the previously selected backoff time.

[0119] Considering the time-dependent nature of beam failure recovery, if the transmission delay is too long, the UE's transmission interruption will be too long, which may easily lead to wireless link connection failure. The following example 4-5 optimizes the transmission delay.

[0120] Example 4

[0121] In this example, after the UE receives the RAR containing the BI field,

[0122] - If the random access procedure is not triggered by a situation or condition related to link reconfiguration or beam failure, the UE will set the backoff time parameter PREAMBLE_BACKOFF to the time value corresponding to the index indicated by the BI field.

[0123] - If the random access procedure is triggered by a situation or condition related to link reconfiguration or beam failure, the UE sets the backoff time parameter PREAMBLE_BACKOFF to zero.

[0124] Another possible implementation is:

[0125] After the UE receives the RAR containing the BI field

[0126] - If the random access procedure is not triggered by a situation or condition related to link reconfiguration or beam failure, the UE sets the backoff time parameter PREAMBLE_BACKOFF to the time value corresponding to the index indicated by the BI field.

[0127] - If the random access procedure is triggered by a situation or condition related to link reconfiguration or beam failure, the UE sets PREAMBLE_BACKOFF to the time value corresponding to the index indicated by the BI field multiplied by a parameter (or coefficient).

[0128] This parameter (or coefficient) can be pre-configured by the network, such as being broadcast in system information, for calculating the UE's PREAMLE_BACKOFF in cases where the random access procedure is triggered by conditions related to link reconfiguration or beam failure, or it can be randomly selected by the UE. Preferably, this parameter is a number selected from 0 to 1, such that the final value of PREAMLE_BACKOFF does not exceed the time value corresponding to the index indicated by the BI field.

[0129] Example 5

[0130] In this example, if the UE does not receive the PDCCH scrambled by C-RNTI within a specific time window, or does not receive the RAR carrying the RAPID corresponding to the preamble sent by the UE, or if the contention resolution timer times out,

[0131] If the random access procedure is not triggered by a situation or condition related to link reconfiguration or beam failure, the UE randomly selects a value between 0 and the backoff time parameter PREAMBLE_BACKOFF as the backoff time duration, and delays the transmission of the subsequent preamble for a certain period of time. The delay duration is the previously selected backoff time duration.

[0132] If the random access procedure is triggered by a situation or condition related to link reconfiguration or beam failure, the UE does not need to delay sending the preamble. The UE can directly perform resource selection during the random access procedure.

[0133] Another possible implementation is:

[0134] When the UE does not receive a PDCCH scrambled by C-RNTI or a RAR carrying a RAPID corresponding to the preamble sent by the UE within a specific time window,

[0135] - If the random access procedure is not triggered by a situation or condition related to link reconfiguration or beam failure, then the UE randomly selects a value between 0 and the backoff time parameter PREAMBLE_BACKOFF as the backoff time duration, and delays the transmission of the subsequent preamble for a period of time, which is the duration of the previously selected backoff time.

[0136] - If the random access procedure is triggered by a situation or condition related to link reconfiguration or beam failure, then the UE randomly selects a value between 0 and the backoff time parameter PREAMBLE_BACKOFF, multiplies this value by a parameter (or coefficient) to obtain the backoff time duration, and delays the transmission of the subsequent preamble for a period of time, which is the duration of the previously selected backoff time.

[0137] This parameter (or coefficient) can be pre-configured by the network, such as being broadcast in system information, for calculating the UE's backoff time in cases where the random access procedure is triggered by conditions related to link reconfiguration or beam failure, or it can be randomly selected by the UE. Preferably, this parameter (or coefficient) is a number between 0 and 1 such that the final backoff time is less than or equal to the selected value.

[0138] Figure 2 This is a block diagram illustrating a user equipment 20 according to an embodiment of the present disclosure. Figure 2 As shown, the user equipment 20 includes a processor 210 and a memory 220. The processor 210 may include, for example, a microprocessor, a microcontroller, an embedded processor, etc. The memory 220 may include, for example, volatile memory (such as random access memory, RAM), a hard disk drive (HDD), non-volatile memory (such as flash memory), or other memory. Program instructions are stored on the memory 220. When executed by the processor 210, these instructions can perform the methods described in detail herein, executed by the user equipment (e.g., Figure 1 (The method shown).

[0139] A program running on a device according to this disclosure may be a program that enables a computer to perform the functions of embodiments of this disclosure by controlling a central processing unit (CPU). The program or the information processed by the program may be temporarily stored in volatile memory (such as random access memory RAM), hard disk drive (HDD), non-volatile memory (such as flash memory), or other memory systems.

[0140] Programs used to implement the functions of the embodiments of this disclosure can be recorded on a computer-readable recording medium. The corresponding functions can be implemented by causing a computer system to read and execute the programs recorded on the recording medium. The term "computer system" here can refer to a computer system embedded in the device, and may include an operating system or hardware (such as peripheral devices). "Computer-readable recording medium" can be a semiconductor recording medium, an optical recording medium, a magnetic recording medium, a short-time dynamic storage program recording medium, or any other computer-readable recording medium.

[0141] Various features or functional modules of the devices used in the above embodiments can be implemented or executed by circuits (e.g., monolithic or multi-chip integrated circuits). Circuits designed to perform the functions described in this specification may include general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic, discrete hardware components, or any combination of the above devices. A general-purpose processor may be a microprocessor, or any existing processor, controller, microcontroller, or state machine. The circuits described above may be digital circuits or analog circuits. In cases where advancements in semiconductor technology have led to new integrated circuit technologies that replace existing integrated circuits, one or more embodiments of this disclosure may also be implemented using these new integrated circuit technologies.

[0142] Furthermore, this disclosure is not limited to the embodiments described above. Although various examples of the embodiments have been described, this disclosure is not limited thereto. Fixed or non-mobile electronic devices installed indoors or outdoors can be used as UE devices or communication devices, such as AV devices, kitchen equipment, cleaning equipment, air conditioners, office equipment, vending machines, and other household appliances.

[0143] As described above, embodiments of this disclosure have been described in detail with reference to the accompanying drawings. However, the specific structure is not limited to the above embodiments, and this disclosure also includes any design modifications that do not depart from the spirit of this disclosure. Furthermore, various modifications can be made to this disclosure within the scope of the claims, and embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included within the technical scope of this disclosure. In addition, components with the same effects described in the above embodiments can be substituted for each other.

Claims

1. An apparatus as a user equipment (UE) or a component of the user equipment (UE), the apparatus comprising: The transmitting unit is configured and / or programmed to transmit a random access preamble; as well as The receiving unit is configured and / or programmed to receive random access responses. Wherein, if the random access response is successfully received for the first time during the current random access process, the device is configured as follows: The multiplexing and assembly entity indicates to the Media Access Control (MAC) layer control element CE that includes the Cell Radio Network Temporary Identifier (C-RNTI) in subsequent uplink transmissions. If the random access procedure is triggered for beam failure recovery: The instruction states that the multiplexing and assembly entity includes a MAC CE for failure recovery in the subsequent uplink transmission. From the multiplexing and assembly entity, obtain the MAC Packet Data Unit (PDU) including the MAC CE for C-RNTI and the MAC CE for failure recovery, and The MAC PDU is stored in the cache. The device is further configured such that the reuse and assembly processing of the MAC CE for failure recovery has a lower priority than the reuse and assembly processing of the MAC CE for C-RNTI, a higher priority than the reuse and assembly processing of the MAC CE for Buffer Status Report (BSR), and a higher priority than the reuse and assembly processing of the MAC CE for Power Headroom Report (PHR).

2. The apparatus according to claim 1, wherein, The MAC CE for failure recovery includes beam failure recovery information.

3. The apparatus according to any one of claims 1 and 2, wherein, During the random access process, the subsequent uplink transmission is the transmission of message 3 MSG3.

4. The apparatus according to claim 3, wherein, The MAC PDU is contained in the MSG3.

5. The apparatus according to any one of claims 1 to 4, wherein, The random access procedure is a contention-based random access (CBRA) procedure.

6. The apparatus according to any one of claims 1 to 5, wherein, The random access procedure is triggered when the UE is in connected state and identified by the C-RNTI, wherein the MAC CE for the C-RNTI contains the C-RNTI that identifies the UE.

7. A method performed by a user equipment (UE) or a component of the user equipment (UE), the method comprising: Send a random access preamble; Receive random access response; If the random access response is successfully received for the first time during the current random access process: The multiplexing and assembly entity is instructed to include the Media Access Control (MAC) CE element for the Cell Radio Network Temporary Identifier (C-RNTI) in subsequent uplink transmissions. If the random access procedure is triggered for beam failure recovery: The instruction indicates that the multiplexing and assembly entity includes a MAC CE for failure recovery in the subsequent uplink transmission; The MAC packet data unit (PDU) including the MAC CE for C-RNTI and the MAC CE for failure recovery is obtained from the multiplexing and assembly entity; as well as The MAC PDU is stored in the cache. Specifically, the reuse and assembly processing of MAC CE for failure recovery has a lower priority than the reuse and assembly processing of MAC CE for C-RNTI, a higher priority than the reuse and assembly processing of MAC CE for Buffer Status Report (BSR), and a higher priority than the reuse and assembly processing of MAC CE for Power Headroom Report (PHR).

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