WO2020151650A1

WO2020151650A1 - Reset method for radio link control layer and user equipment

Info

Publication number: WO2020151650A1
Application number: PCT/CN2020/073178
Authority: WO
Inventors: 张崇铭; 刘仁茂; 坪井秀和
Original assignee: 夏普株式会社; 鸿颖创新有限公司
Priority date: 2019-01-22
Filing date: 2020-01-20
Publication date: 2020-07-30
Also published as: CN111465115A

Abstract

The invention of the present application provides a reset method for a radio link control (RLC) layer, and a user equipment. The reset method for the radio link control layer comprises: a user equipment requests to obtain system information, and upon receiving an indication of a random access problem or an indication that the system information request fails, the user equipment releases an RLC entity.

Description

Resetting method of radio link control layer and user equipment

Technical field

The present invention relates to the field of wireless communication technology, and more specifically, the present invention relates to a method for resetting a radio link control layer and a user equipment.

Background technique

With the rapid growth of mobile communications and the tremendous advancement of technology, the world will move towards a completely interconnected network society, that is, anyone or anything can obtain information and share data at any time and anywhere. It is estimated that by 2020, the number of connected devices will reach 50 billion, of which only about 10 billion may be mobile phones and tablets. The others are not machines that talk to people, but machines that talk to each other. Therefore, how to design a system to better support the Internet of Everything is a subject that requires in-depth research.

For this reason, at the Third Generation Partnership Project (3GPP) RAN#64 plenary meeting held in March 2016, a research topic of new 5G wireless access technology was proposed (see Non-Patent Document: RP-160671 New SID Proposal: Study on New Radio Access Technology). In the description of the work item, the working frequency band of the new communication standard in the future can be expanded to 100GHz, and at the same time it will at least meet the needs of enhanced mobile broadband services, the communication needs of massive IoT terminals, and the business needs of high reliability requirements. The project research work will be completed in 2018.

In a 5G system or called an NR access system (New Radio Access) system, UE (User Equipment, user equipment/terminal equipment) can obtain required system information by request. The request process may be that the UE sends an RRCSystemInfoRequest message, which is an RRC (Radio Resource Control, radio resource control) layer message, which is sent to the lower layer for transmission after being generated at the RRC layer. When the message is sent to the RLC (Radio Link Control) layer, it will be buffered in the transmission buffer area of the RLC layer in the form of RLC PDU (Protocol Data Unit). When the MAC (Medium Access Control) layer indicates to the RLC that there is an available uplink grant (UL grant), the RLC PDU in the buffer area is sent to the MAC layer, and at the same time the buffer area is emptied, which contains the After the RLC PDU of the RRC message is sent to the MAC layer, the buffer area becomes empty.

When the UE obtains system information by request, it will trigger a random access procedure (RA) for SI (System Information) request at the MAC layer. This random access procedure is used in the system. Information request. FIG. 4 schematically shows the steps of the MAC layer performing the random access process in the process of obtaining system information through request. Below, FIG. 4 is used to describe the steps of the MAC layer performing the random access procedure. The random access procedure performed by the MAC layer includes the following steps.

S41: Send a preamble to the base station.

S42: Receive a random access response (Random Access Response, RAR) sent by the base station. If the MAC header (hearder) corresponding to this random access response contains the index (index) of the preamble sequence sent in step S41, the UE may use the uplink grant (UL grant) carried in this RAR to send uplink data.

S43: Once a valid UL grant is obtained, the MAC layer of the UE will indicate to the RLC layer as mentioned above. The RLC layer sends the RLC PDU in the buffer to the MAC layer. At the MAC layer, the PDU will be MAC The form of PDU is stored in MSG3 buffer (buffer area).

S44: The UE sends the MAC PDU in the MSG3 buffer to the base station. This step may be called MSG3 sending.

S45: If the UE receives a contention resolution identity (Contention Resolution Identity) MAC CE (Control Element), and the content sent in the MAC CE and MSG3 match, that is, the contention conflict is resolved, the UE will indicate to the upper layer to receive the system Information request confirmation information (an acknowledgement for SI request).

In the above process, if the UE does not obtain a valid uplink grant (UL grant) in step S42, then the data in the RLC buffer will not be emptied. If the UE needs to establish an RRC connection at this time, the UE will generate an RRC connection establishment request message RRCSetupReqest message, and send it to the lower layer. Similarly, this message will be buffered in the RLC transmission buffer in the form of RLC PDU. In this way, there are two RLC PDUs in the transmission buffer area of the RLC, one RLC PDU carries the RRCSystemInfoRequest message, and the other RLC PDU carries the RRCSetupReqest message. At the same time, the MAC layer is undergoing a random access process, which is triggered by the establishment of an RRC connection. When in this random access process, the UE receives a valid uplink grant (UL grant) and will indicate to the RLC. In order, the RLC PDU carrying the RRCSystemInfoRequest message will be sent to the MAC first. Therefore, the UE originally wanted to send an RRC connection establishment message, but because the RLC buffer had a system information request message that could not be sent before, an error message was sent. How to avoid this kind of error is a problem that needs to be solved.

Summary of the invention

In order to solve at least a part of the above-mentioned problems, the present invention provides a method and user equipment for resetting the radio link control layer that can solve the above-mentioned problems in the process of acquiring system information.

According to the present invention, a method for resetting the radio link control layer is proposed, including: a user equipment requests to obtain system information, and when receiving an indication of a random access problem or an indication of a failure of the system information request, the user equipment releases the wireless link Road control RLC entity.

Preferably, in the above method, the user equipment requesting to obtain system information specifically includes: setting the content of the RRCSystemInfoRequest message, which is a radio resource control system information request message, and submitting the message to the lower layer for transmission.

Preferably, in the above method, if the user equipment receives an indication of a random access problem or an indication of a failure of the system information request while waiting for the lower layer to indicate the system information request confirmation information, the user equipment releases the RLC entity that carries the signaling SRB0 Or reset the media access control MAC layer.

Preferably, in the above method, when the user equipment decides to stop a random access process, the user equipment indicates a random access problem or a system information request failure to the upper layer.

Preferably, in the above method, when the random access response receiving window ra-ResponseWindow times out, and the user equipment has not yet received the random access response carrying the random access preamble sequence identifier that matches the sequence number of the sent preamble sequence During RAR, judge the value of the variable PREAMBLE_TRANSMISSION_COUNTER. When its value is equal to the maximum allowable transmission times of the preamble sequence plus 1, if the random access process is a random access process for requesting system information, or by requesting system information The triggered random access process, or the random access process related to the system information request, indicates to the upper layer that the system information request failed. If the random access process is not a random access process related to the system information request, then Indicate random access problems to the upper layer.

Preferably, in the above method, the specific operation of the user equipment to release the RLC entity is: the RLC layer is requested by the upper layer to release the RLC entity, and the user equipment discards all radio link control service data units RLC SDU and radio link control protocol data Unit RLC PDU, and release RLC entity.

Preferably, in the above method, the specific operation of the user equipment to release the RLC entity is: the user equipment establishes the RLC entity or rebuilds the RLC entity.

Preferably, in the above method, establishing the RLC entity or rebuilding the RLC entity includes discarding all RLC SDUs and RLC PDUs, and setting or resetting the state variable of the RLC to an initial value.

Preferably, in the above method, the stopped random access process is a random access process used to request system information, or a random access process triggered by a system information request, or is related to a system information request Random access process.

The present invention provides a user equipment, comprising: a processor; and a memory storing instructions, wherein the instructions execute the method according to any one of claims 1 to 9 when run by the processor.

Invention effect

According to the method for resetting the radio link control layer of the present invention, errors can be avoided in the process of obtaining system information in a request manner, and system information can be obtained correctly.

Description of the drawings

The above and other features of the present disclosure will become more apparent through the following detailed description in conjunction with the accompanying drawings, among which:

FIG. 1 schematically shows a flowchart of a method for resetting a radio link control layer in Embodiment 1 of the present disclosure.

FIG. 2 schematically shows a flowchart of a method for resetting a radio link control layer in Embodiment 2 of the present disclosure.

Fig. 3 schematically shows a block diagram of the user equipment involved in the present disclosure.

FIG. 4 schematically shows the steps of the MAC layer performing the random access process in the process of obtaining system information through request.

detailed description

The present invention will be described in detail below in conjunction with the drawings and specific embodiments. It should be noted that the present invention should not be limited to the specific embodiments described below. In addition, for the sake of brevity, detailed descriptions of well-known technologies that are not directly related to the present invention are omitted to prevent confusion in the understanding of the present invention.

In the following, taking the NR (New Radio) mobile communication system and its subsequent evolved versions as an example application environment, multiple embodiments according to the present invention are described in detail. However, it should be pointed out that the present invention is not limited to the following embodiments, but can be applied to more other wireless communication systems, such as LTE communication systems, and can be applied to other base stations and terminal devices, such as those supporting eMTC, MMTC, etc. Base station and terminal equipment.

Before detailed description, the following descriptions of several terms mentioned in the present invention will be made. Unless otherwise indicated, the terms involved in the present invention have the following meanings.

UE User Equipment User Equipment/Terminal Equipment

MAC Medium Access Control Media Access Control

RRC Radio Resource Control Radio Resource Control

Preamble preamble sequence

SIB System Information Block System Information Block

SI System Information System Information

SRB Signaling Radio Bearer signaling radio bearer

RLC Radio Link Control Radio Link Control

TM Transparent Mode Transparent transmission mode

PDU Protocol Data Unit Protocol data unit

SDU Service Data Unit Service data unit

UE User Equipment User Equipment

CCCH Common Control Channel Common Control Channel

MCG Master Cell Group Primary cell group

CE Control Element

There are two ways for the UE to obtain system information: the first is to broadcast the system information through the base station, and the UE receives the broadcasted system information to obtain the content of the system information; the second is to obtain the system information in an on-demand manner The so-called on-demand method means that the UE sends a system information request message to the base station/network, which can be a specific preamble sequence, a preamble sequence corresponding to a specific system information type, or an RRC message; the network side/base station receives the request After the message, at a specific time, the system information is sent by broadcasting, and the UE receives the broadcasted system information at the corresponding time to obtain the content of the system information. Therefore, the system information obtained by the on-demand method can also be called on-demand system information.

The UE obtains the on-demand system information by request. The request process may be that the UE sends an RRCSystemInfoRequest message, which is an RRC layer message, which is transmitted through the CCCH channel. In the LTE or NR system, SRB0 is the signaling bearer for RRC messages transmitted on the CCCH channel. Therefore, the RRCSystemInfoRequest message is carried on SRB0 for transmission. The RLC entity of SRB0 adopts the TM transmission mode. When the RRCSystemInfoRequest message is generated at the RRC layer, it is sent to the lower layer for transmission. When the message is sent to the RLC layer, it will be buffered in the transmission buffer of the RLC entity corresponding to SRB0 in the form of RLC PDU. When the MAC layer indicates to the RLC that there is an available uplink grant (UL grant), the RLC PDU in the buffer area is sent to the MAC layer, and at the same time the buffer area is cleared, that is, the RLC PDU containing the RRC message is sent to the MAC layer After the layer, the buffer area becomes empty (empty).

In the process of obtaining system information through request, the UE triggers a random access procedure for SI request at the MAC layer, and this random access procedure is used for system information request. The random access procedure performed by the MAC layer will be described with reference to FIG. 4. The random access process performed by the MAC layer includes the following steps

S41: Send a preamble to the base station.

S43: Once a valid UL grant is obtained, the MAC layer of the UE will indicate to the RLC layer as mentioned above, and the RLC layer will send the RLC PDU in the buffer to the MAC layer. At the MAC layer, this PDU will exist in the form of MAC PDU MSG3 buffer.

S45: If the UE receives the Contention Resolution Identity MAC CE, and the content sent in the MAC CE matches the content sent in MSG3, that is, the contention conflict is resolved, the UE will indicate to the upper layer that the system information request confirmation message (anacknowledgement for SI request).

In step S42, if the UE does not receive the RAR, the UE will continue to perform step S41. If the number of times the preamble sequence is sent exceeds or equals the maximum allowable number of times, the MAC can determine that a random access problem has occurred (random access problem) , MAC can indicate the problem to the upper layer.

Considering the reason why the UE did not obtain a valid UL grant in step S42, if the RLC buffer can be cleared when this reason/condition occurs, the problem can be solved.

Hereinafter, several embodiments of the present invention will be described in detail.

Example 1

When the UE is in the process of requesting system information, preferably, the system information request adopts the method of sending RRCSystemInfoRequest message, or based on the method of sending RRCSystemInfoRequest message, if the random access problem indication (random access problem indication) indicated from the MAC layer is received access problem indication), the UE releases the RLC entity, preferably, the UE releases the RLC entity of SRB0. And optionally, the UE resets the MAC layer. FIG. 1 schematically shows a flowchart of a method for resetting a radio link control layer in Embodiment 1 of the present disclosure. The method for resetting the radio link control layer in Embodiment 1 of the present disclosure will be described in detail with reference to FIG. 1.

As shown in Figure 1, an implementation of Embodiment 1 can be

Step S11: The UE requests to obtain system information, which may be the UE starting to transmit the RRCSystemInfoRequest message, which may specifically include: setting the content of the RRCSystemInfoRequest message, and submitting the message to the lower layer for transmission.

Step S12: When receiving the random access problem indication, the UE releases the RLC entity of SRB0. Preferably, if the UE receives a random access problem indication while waiting for the lower layer to indicate the system information request acknowledgement (anacknowledgement for SI request), the UE releases the RLC entity of SRB0. And optionally, the UE resets the MAC layer.

"Random access problem indication" in the above process:

-It may be based on the prior art and indicated by the MAC layer, specifically including: in a random access process, the UE judges the value of the variable PREAMBLE_TRANSMISSION_COUNTER, when its value is equal to the maximum allowable transmission times of the preamble sequence plus 1, The MAC layer will indicate the random access problem to the upper layer.

-It can also be that when the UE decides to stop a random access procedure, the UE indicates the random access problem to the upper layer. Preferably, the stopped random access process is a random access process for requesting system information, or a random access process triggered by requesting system information, or a random access process related to system information requests. The prior art allows the UE to automatically stop an ongoing random access process and re-trigger a new random access process according to the priority of the triggered random access process event. For example, when the UE is in a random access process triggered by a system information request, if the upper layer of the UE triggers a new random access process due to the request to establish an RRC connection, then from the priority considerations, the RRC connection establishment takes precedence If the level is higher than the system information request, the UE can stop the ongoing random access process, which leads to the "UE cannot obtain a valid UL grant" as described in the background. Then the UE can indicate the random access problem to the upper layer while deciding to stop the ongoing random access process.

In the above process, the MAC layer may indicate the "random access problem", preferably, the MAC layer of MCG.

The specific operation of "UE release RLC entity" in the above process can be: RLC layer is requested by the upper layer to release RLC entity, UE discards all RLC SDU and RLC PDU, and releases RLC entity

An alternative operation of "UE releasing RLC entity" in the above process is that the UE establishes or re-establishes the RLC entity, preferably, the UE establishes or re-establishes the RLC entity for SRB0 . Establishing an RLC entity or re-establishing an RLC entity may include discarding all RLC SDUs and RLC PDUs, and setting or resetting the state variables of the RLC to initial values.

Example 2:

The difference from Embodiment 1 is that in Embodiment 1, the UE releases the RLC entity after receiving the random access problem indication. In this embodiment, the UE can release the RLC entity based on the received system information request failure indication.

FIG. 2 schematically shows a flowchart of a method for resetting a radio link control layer in Embodiment 2 of the present disclosure. The method executed by the user equipment in Embodiment 1 of the present disclosure will be described in detail with reference to FIG. 2.

As shown in Figure 2, an implementation of Embodiment 2 can be

Step S21: The UE requests to obtain system information, which may be the UE starting to transmit the RRCSystemInfoRequest message, which may specifically include: setting the content of the RRCSystemInfoRequest message, and submitting the message to the lower layer for transmission.

Step S22: When receiving the indication that the system information request failed, the UE releases the RLC entity of SRB0. Preferably, if the UE receives an indication that the system information request has failed while waiting for the lower layer to indicate an acknowledgement for SI request, the UE releases the RLC entity of SRB0. And optionally, the UE resets the MAC layer.

The "system information request failure indication" here can occur in one or more of the following situations:

-In a random access process, the UE judges the value of the variable PREAMBLE_TRANSMISSION_COUNTER. When its value is equal to the maximum allowable transmission times of the preamble sequence plus 1, if this random access process is used for system information request, or If triggered by a system information request, or related to a system information request, the UE indicates to the upper layer that the system information request has failed. Preferably, the UE determines the value of the variable PREAMBLE_TRANSMISSION_COUNTER in the process of receiving the RAR.

-It can also be when the random access response receiving window (ra-ResponseWindow) times out and the UE has not received the RAR that carries the random access preamble identifier (Random Access Preamble identifiers) that matches the sequence number of the sent preamble sequence When the value of the variable PREAMBLE_TRANSMISSION_COUNTER is judged; when its value is equal to the maximum allowable number of transmissions of the preamble sequence plus 1, if this random access process is a random access process for requesting system information, or by requesting system information And the random access process triggered, or the random access process related to the system information request, indicates the failure of the system information request to the upper layer; if the random access process is not related to the system information request, the upper layer indicates the random access process Into the problem.

-When the UE decides to stop a random access procedure, the UE indicates to the upper layer that the system information request has failed. Preferably, this stopped random access process is a random access process used to request system information, or a random access process triggered by a system information request, or a random access process related to a system information request.

Based on the aforementioned "system information request failure indication", the UE may perform other operations in Embodiment 1.

In particular, this "system information request failure indication" may also adopt other names, such as an access failure indication or a RACH failure indication.

In the above process, the MAC layer may indicate "system information request failed", preferably, the MAC layer of MCG.

Example 3

In Embodiments 1 and 2, the UE releases the RLC entity based on the instruction, so as to achieve the purpose of clearing the RLC buffer. In this embodiment, another method is provided. Considering that the messages sent by the UE through the SRB0 or CCCH logical channel are:

RRC setup request message, RRCSetupRequest Message

RRC resume request message, RRCResumeRequest Message

RRC reestablishment request message, RRC ReestablishmentRequest Message

RRC system information request message, RRCSystemInfoResqest Message

In order to avoid that when the UE sends the above information through SRB0, the RLC buffer of the RLC entity of SRB0 stores the RLC PDU that has not been sent before. Therefore, in the process of triggering the transmission of any of the above information, or when sending any of the above information Before or at the same time, the UE rebuilds or releases the RLC entity, preferably, the RLC entity of SRB0. Specific implementations may include:

(1) When the upper layer of the UE requests to establish an RRC connection, the UE initiates the RRC connection establishment process. In the initial execution behavior, at least one of the following behaviors is included:

-Rebuild RLC for all established RBs

-Release the RLC entity of SRB0

-Establish or re-establish RLC entities for SRB0

Preferably, the above-mentioned behaviors occur before the transmission of the RRCSetupRequest message.

(2) When the upper layer of the UE requests to establish an RRC connection, the UE initiates the RRC connection establishment process. In the behavior of initialization execution, the UE adopts a pre-configured (specified) or a default (default) CCCH configuration. In the process of adopting this configuration, at least one of the following behaviors is included:

-Release the RLC entity of SRB0

-Establish or re-establish RLC entities for SRB0

(3) When the upper layer of the UE requests to resume the suspended (suspended) RRC connection, the UE initiates the RRC connection recovery process. In the initial execution of the behavior, including at least one of the following behaviors:

-Rebuild RLC for all established RBs

-Release the RLC entity of SRB0

-Establish or re-establish RLC entities for SRB0

Preferably, the above actions occur before the transmission of the RRCResumeRequest message

(4) When the upper layer of the UE requests to resume the suspended (suspended) RRC connection, the UE initiates the RRC connection recovery process. In the behavior of initialization execution, the UE adopts a pre-configured (specified) or a default (default) CCCH configuration. In the process of adopting this configuration, at least one of the following behaviors is included:

-Release the RLC entity of SRB0

-Establish or re-establish RLC entities for SRB0

(5) When the UE requests on-demand system information, it starts to transmit RRCSystemInfoRequet message, and before starting to transmit RRCSystemInfoRequest message, or during the process of initializing the transmission of the message, perform one of the following actions:

-Release the RLC entity of SRB0

-Establish or re-establish RLC entities for SRB0

(6) When the UE requests on-demand system information, the UE adopts the pre-configured (specified) or the default (default) CCCH configuration. The configuration process includes at least one of the following actions:

-Release the RLC entity of SRB0

-Establish or re-establish an RLC entity for SRB0.

Therefore, according to the foregoing embodiments, the present disclosure provides a method for resetting the radio link control layer that can solve the problems generated in the process of acquiring system information.

Variations

Hereinafter, FIG. 3 is used to illustrate a user equipment that can execute the method executed by the user equipment described in detail above in this disclosure as a modified example.

Fig. 3 is a block diagram schematically showing a user equipment involved in the present disclosure.

As shown in FIG. 3, the user equipment UE80 includes a processor 801 and a memory 802. The processor 801 may include, for example, a microprocessor, a microcontroller, an embedded processor, and the like. The memory 802 may include, for example, a volatile memory (such as a random access memory RAM), a hard disk drive (HDD), a non-volatile memory (such as a flash memory), or other memories. The memory 802 stores program instructions. When the instruction is executed by the processor 801, it can execute the above-mentioned method executed by the user equipment described in detail in the present invention.

The method and related equipment of the present disclosure have been described above in conjunction with preferred embodiments. Those skilled in the art can understand that the methods shown above are only exemplary, and the various embodiments described above can be combined with each other without any contradiction. The method of the present invention is not limited to the steps and sequence shown above. The user equipment shown above may include more modules, for example, may also include modules that can be developed or developed in the future that can be used for base stations, MMEs, or UEs, and so on. The various identifiers shown above are only exemplary rather than restrictive, and the present disclosure is not limited to specific information elements as examples of these identifiers. Those skilled in the art can make many changes and modifications based on the teaching of the illustrated embodiment.

In this application, "base station" may refer to a mobile communication data and control switching center with larger transmission power and wider coverage area, including functions such as resource allocation and scheduling, data reception and transmission. "User equipment" may refer to a user's mobile terminal, for example, including mobile phones, notebooks, and other terminal devices that can communicate with base stations or micro base stations wirelessly.

The program running on the device according to the present invention may be a program that enables the computer to implement the functions of the embodiments of the present invention by controlling a central processing unit (CPU). The program or the information processed by the program can 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.

A program for realizing the functions of each embodiment of the present invention can be recorded on a computer-readable recording medium. Corresponding functions can be realized by causing the computer system to read the programs recorded on the recording medium and execute these programs. The so-called "computer system" herein may be a computer system embedded in the device, and may include an operating system or hardware (such as peripheral devices). The "computer-readable recording medium" may be a semiconductor recording medium, an optical recording medium, a magnetic recording medium, a recording medium storing a program dynamically for a short time, or any other recording medium readable by a computer.

It should be understood that the above-mentioned embodiments of the present disclosure can be implemented by software, hardware or a combination of both software and hardware. For example, the various components inside the base station and the user equipment in the foregoing embodiment may be implemented by various devices. Various features or functional modules of the devices used in the above-mentioned embodiments may be implemented or executed by circuits (for example, single-chip or multi-chip integrated circuits). Circuits designed to perform the functions described in this specification can include general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field programmable gate arrays (FPGA), or other programmable logic devices, discrete Gate or transistor logic, discrete hardware components, or any combination of the above devices. The general-purpose processor may be a microprocessor, or any existing processor, controller, microcontroller, or state machine. The above-mentioned circuit can be a digital circuit or an analog circuit. In the case of new integrated circuit technologies that replace existing integrated circuits due to advances in semiconductor technology, one or more embodiments of the present invention can also be implemented using these new integrated circuit technologies.

In addition, the present invention is not limited to the above-mentioned embodiment. Although various examples of the embodiment have been described, the present invention is not limited thereto. Fixed or non-mobile electronic equipment installed indoors or outdoors can be used as terminal equipment or communication equipment, such as AV equipment, kitchen equipment, cleaning equipment, air conditioning, office equipment, vending machines, and other household appliances.

As above, the embodiments of the present invention have been described in detail with reference to the drawings. However, the specific structure is not limited to the above embodiments, and the present invention also includes any design changes that do not deviate from the gist of the present invention. In addition, various modifications can be made to the present invention within the scope of the claims, and embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention. In addition, the components having the same effects described in the above embodiments may be substituted for each other.

Claims

A method for resetting the radio link control layer includes:

The user equipment requests system information,

When receiving an indication of a random access problem or an indication of a system information request failure, the user equipment releases the radio link control RLC entity.
The method of claim 1, wherein:

The user equipment request to obtain system information specifically includes:

Set the radio resource control system information request message, namely the content of the RRCSystemInfoRequest message, and submit the message to the lower layer for transmission.
The method of claim 2, wherein:

If the user equipment receives an indication of a random access problem or an indication of a failure of the system information request while waiting for the lower layer to indicate the system information request confirmation information, the user equipment releases the RLC entity of the signaling radio bearer SRB0 or resets the media access control MAC layer.
The method of claim 1, wherein:

When the user equipment decides to stop a random access process, the user equipment indicates to the upper layer the random access problem or the system information request failure.
The method of claim 1, wherein:

When the random access response receiving window ra-ResponseWindow times out, and the user equipment has not received the random access response RAR that carries the random access preamble sequence identifier and the sequence number of the sent preamble sequence, it is determined that the variable PREAMBLE_TRANSMISSION_COUNTER is set. Value, when its value is equal to the maximum allowable transmission times of the preamble sequence plus 1, if the random access process is a random access process used to request system information, or a random access process triggered by requesting system information, Or it is a random access process related to the system information request, then it indicates to the upper layer that the system information request has failed,

If the random access process is not a random access process related to the system information request, then indicate the random access problem to the upper layer.
The method according to any one of claims 1 to 5, wherein:

The specific operation of the user equipment to release the RLC entity is: the RLC layer is requested by the upper layer to release the RLC entity, the user equipment discards all radio link control service data units RLC SDU and radio link control protocol data unit RLC PDU, and releases the RLC entity .
The method according to any one of claims 1 to 5, wherein:

The specific operation of the user equipment to release the RLC entity is: the user equipment establishes the RLC entity or rebuilds the RLC entity.
The method according to claim 7, wherein:

Establishing an RLC entity or rebuilding an RLC entity includes discarding all RLC SDUs and RLC PDUs, and setting or resetting RLC state variables to initial values.
The method of claim 4, wherein:

The stopped random access process is a random access process used to request system information, or a random access process triggered by a system information request, or a random access process related to a system information request.
A user equipment including:

Processor; and

Memory, storing instructions;

Wherein, the instruction executes the method according to any one of claims 1 to 9 when run by the processor.