WO2022135517A1

WO2022135517A1 - Method executed by user equipment and user equipment

Info

Publication number: WO2022135517A1
Application number: PCT/CN2021/140791
Authority: WO
Inventors: 张崇铭; 刘仁茂
Original assignee: 夏普株式会社; 张崇铭
Priority date: 2020-12-25
Filing date: 2021-12-23
Publication date: 2022-06-30
Also published as: CN114698148A

Abstract

Provided by the present invention are a method executed by a user equipment and the user equipment. The method executed by the user equipment comprises: the user equipment initiates an RRC connection recovery process; the user equipment executes access control and determines whether an access attempt is barred or allowed; when the user equipment determines that the access attempt is allowed, the user equipment determines whether there is an ongoing RRC connection recovery process for small data transmission; and when the user equipment determines that there is an ongoing RRC connection recovery process for small data transmission, the user equipment executes a fallback operation or generates a fallback instruction for the user equipment to execute the fallback operation.

Description

Method performed by user equipment and user equipment

technical field

The present invention relates to the technical field of wireless communication, and more particularly, the present invention relates to a method performed by a user equipment and a corresponding base station and user equipment.

Background technique

In order to shorten the transmission delay and save the signaling overhead, the UE entering the RRC inactive state (RRC INACTIVE STATE) can send a transmission block ( Transport Block). This transmission method may be referred to as PUR transmission. In the process of random access, a transport block carrying user data may also be sent in message 3 or message A. Both ways can be referred to as small data transfers.

When the UE is in the INACTIVE state, the upper layer of the UE, such as the non-access stratum, may request the UE to resume the RRC connection (request resumption of an RRC connection). If the UE supports and decides to use the small data transmission mode, the UE can send a MAC PDU in the PUR or random access process, and the MAC PDU carries the RRC connection recovery request message and user data. Such an RRC connection restoration procedure may be referred to as an RRC connection restoration procedure for small data transmission (or as a small data transmission-triggered RRC connection restoration procedure).

During the process of the UE performing the RRC connection restoration for small data transmission, the UE may trigger a new RRC connection restoration process again. Then, how to operate the newly triggered RRC connection recovery process is a problem that needs to be solved.

SUMMARY OF THE INVENTION

In order to solve the above problems in the prior art, the present invention provides a method performed by a user equipment and the user equipment, which are used to solve the problem that the UE triggers a new RRC again during the process of performing the RRC connection recovery for small data transmission. The question of how to proceed during the connection recovery process.

According to an aspect of the present invention, there is provided a method performed by a user equipment, comprising: the user equipment initiates an RRC connection recovery procedure; the user equipment performs access control, and determines whether an access attempt is prohibited or allowed; When the user equipment determines that the access attempt is allowed, the user equipment determines whether there is an ongoing RRC connection recovery procedure for small data transmission; and when the user equipment determines that there is an ongoing RRC connection recovery procedure for small data transmission During the RRC connection recovery process for data transmission, the user equipment performs a fallback operation or generates a fallback instruction for the user equipment to perform the fallback operation.

In the above method performed by the user equipment, preferably, when the user equipment performs the access control, the user equipment determines whether the access attempt is prohibited or allowed according to the access type and the access identifier.

In the above method performed by the user equipment, preferably, when the user equipment determines that the access attempt is prohibited, the user equipment ends or stops the RRC connection recovery process.

In the above method performed by the user equipment, preferably, the user equipment determines whether there is an ongoing RRC connection recovery process for small data transmission by judging whether the timer is running.

In the above method performed by the user equipment, preferably, the fallback operation performed by the user equipment is one or more of the following operations: delete keys that have been generated or acquired; rebuild for SRB and DRB RLC entity; suspend SRBs and DRBs except SRB0; configure the bottom layer, stop integrity protection and encryption protection; reset the MAC layer; stop the timer; restart the timer.

In the above method performed by the user equipment, preferably, when the user equipment determines that there is an ongoing RRC connection recovery process for small data transmission, the user equipment further performs the following operation: start the transmission of RRC Recovery request message.

In the above method performed by the user equipment, preferably, when the user equipment determines that there is no ongoing RRC connection recovery process for small data transmission, the user equipment performs one of the following operations or Multiple: adopt the value of the layer 1 parameter provided in the system information block or the value of the default layer 1 parameter of the UE, wherein the layer 1 parameter is the initial system bandwidth segment or the timing advance offset; adopt the default value of the UE The configuration of the SRB1; adopt the default MAC cell group configuration of the UE; start the transmission of the RRC recovery request message.

According to another aspect of the present invention, a user equipment is provided, comprising: a processor; and a memory storing instructions; wherein the instructions execute any of the above methods when executed by the processor.

According to the method performed by the user equipment and the user equipment according to the present invention, it is possible to solve the problem of how the UE operates when a new RRC connection restoration process is triggered again during the process of performing the RRC connection restoration for small data transmission.

Description of drawings

The above and other features of the present invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, wherein:

FIG. 1 is a flowchart showing a method executed by a user equipment according to the present invention.

FIG. 2 is a block diagram showing a schematic configuration of a user equipment according to the present invention.

Detailed ways

The present invention will be described in detail below with reference to the accompanying 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 not directly related to the present invention are omitted in order to avoid obscuring the understanding of the present invention.

Before the specific description, some terms mentioned in the present invention are explained as follows. Unless otherwise indicated, terms referred to in the present invention have the following meanings.

UE User Equipment User Equipment

NR New Radio new generation wireless technology

LTE Long Term Evolution long term evolution technology

eLTE Enhanced Long Term Evolution Enhanced Long Term Evolution Technology

RRC Radio Resource Control Radio Resource Control (layer)

MAC Medium Access Control Media Access Control (layer)

PDU Packet Data Unit packet data unit

PUSCH Physical Uplink Shared Channel Physical Uplink Shared Channel

PDCCH Physical Downlink Control Channel Physical Downlink Control Channel

DCCH Dedicated Control CHannel dedicated control channel

CCCH Common Control CHannel Common Control Channel

SDAP Service Data Adaptation Protocol Business Data Adaptation Layer Protocol

PDCP Packet Data Convergence Protocol Packet Data Convergence Protocol

RLC Radio Link Control, radio link layer control protocol

DRB Data Radio Bearer Data Radio Bearer

SRB Signalling Radio Bearer Signaling Radio Bearer

SRB0 Signalling Radio Bearer 00 Signaling Radio Bearer

SRB1 Signalling Radio Bearer Signalling Radio Bearer 11

SDT Small Data Transmission small data transmission

RNAU Radio Access Network-based Notification Area Update

RSRP Reference Signal Receiving Power, reference signal received power

Hereinafter, the NR mobile communication system and its subsequent evolved versions are used as an example application environment, and the base station and UE equipment supporting NR are used as examples to specifically describe various embodiments according to the present invention. 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 eLTE, communication systems, or NB-Iot systems, or LTE-M systems. And it can be applied to other base stations and UE devices, such as base stations and UE devices supporting eLTE/NB-Iot/LTE-M.

Hereinafter, with regard to small data transfer, the following description is given.

When the UE is in the INACTIVE state, the upper layer of the UE, such as a non-access stratum (Non-access stratum, NAS), can request the UE to resume the RRC connection (request resumption of an RRC connection). Such a request usually occurs when the upper layer has data arriving. In addition, the access stratum (Access stratum, AS) of the UE, such as the RRC layer, may also request the UE to restore the RRC connection (request resumption of an RRC connection). Such a request usually occurs when the RNAU is triggered, or when the UE receives a paging message from the network side in the INACTIVE state.

Based on the request, the UE will trigger the RRC connection recovery process. During this process, the UE will send an RRC connection recovery request message to the base station/network side.

A UE entering an RRC inactive state (RRC INACTIVE STATE) can send a transport block (Transport Block) of a predetermined size and carrying data on a preconfigured uplink resource (configured grant, CG). This transmission method can be called CG-based small data transmission. In the process of random access, a transport block carrying user data may also be sent in message 3 or message A. Both of these transmission methods can be referred to as Small data transmission (SDT). Since such a transmission is always performed in an inactive state, such a transmission manner can also be referred to as data transmission of the UE in an inactive state.

A data radio bearer (DRB) that can be transmitted in a small data transmission mode is called a data radio bearer (DRB for SDT) based on small data transmission. Such a DRB may also be referred to as a DRB configured with Small Data Transfer (SDT).

A data radio bearer that does not allow small data transmission is called a data radio bearer not based on small data transmission (DRB for Non-SDT). Such a DRB may also be referred to as a DRB that is not configured for small data transfer (SDT).

The UE may decide to use the small data transmission method based on the following reasons:

- The data arriving at the upper layer can be carried by a data radio bearer based on small data transmission (DRB for SDT), or can be transmitted via a data radio bearer based on small data transmission (DRB for SDT).

- The size of the arriving data does not exceed the established threshold.

- The currently measured RSRP value meets the requirements of RSRP using small data transmission.

During the RRC connection recovery process, if the UE adopts the transmission mode of small data, the UE needs to recover the DRB first, and generate a corresponding key to encrypt the data packet.

In order to solve the problems mentioned in the background art, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

Wherein, SRB0 and SRB1 appearing in the following embodiments all adopt the meanings known in the art, that is, SRB0 is used to transmit RRC messages using the CCCH logical channel, and SRB1 is used to transmit RRC messages using the DCCH logical channel and NAS layer messages .

In step S101, the user equipment initiates an RRC connection recovery process.

In step S102, the user equipment performs access control and determines whether the access attempt is barred or allowed.

In step S103, when the user equipment determines that the access attempt is allowed, the user equipment determines whether there is an ongoing RRC connection recovery process for small data transmission.

In step S104, when the user equipment determines that there is an ongoing RRC connection recovery process for small data transmission, the user equipment performs a fallback operation or generates a fallback instruction for the user equipment to perform a fallback operation.

Hereinafter, each step of the above method will be described in detail.

Initially, the UE initiates the RRC connection recovery procedure.

In the process of initiating RRC connection recovery, the UE performs access control (access control).

In the access control process, the UE can determine whether the access attempt (access attempt) is barred or allowed according to information such as the access category (Access Category) and the access identifier (Access Category). allowed).

When the UE determines that the access attempt is barred, the UE ends or stops the RRC connection recovery procedure.

Otherwise, that is, when the UE determines that the access attempt is allowed, the UE continues to perform operations related to RRC connection recovery, including:

The UE determines whether there is an ongoing RRC connection recovery process. Preferably, this RRC connection recovery process is an RRC connection recovery process for small data transmission (that is, triggered by small data transmission, or using a small data transmission method) RRC connection recovery process). Because the UE will start the timer T319 when initiating the RRC connection recovery process. Then, the operation of the UE judging whether there is an ongoing RRC connection recovery process can be equivalently expressed as the UE judging whether T319 is running.

In the RRC connection recovery process for small data transmission (ie, the RRC connection recovery process triggered by small data transmission, or the RRC connection recovery process using the small data transmission mode), the UE may start a timer different from T319 , assuming it is Timer-1, then preferably, the UE can determine whether Timer-1 is running.

If the UE has an ongoing RRC connection recovery procedure (ie, T319 or Timer-1 is running), the UE may at least perform one or more of the following operations:

-Delete the generated (gengerate) or obtained (derive) key (security key), which may specifically include the key generated by using the nextHopChainingCount contained in the received RRC release message, which may be used for RRC authentication, user plane (User plane) authentication and encryption keys.

- Rebuild RLC entities for SRBs and DRBs, preferably, here all SRBs and all DRBs

- Suspend SRBs and DRBs except SRB0

-Configure the bottom layer (mainly refers to the PDCP layer), stop integrity protection and encryption protection

-Reset MAC layer (reset MAC)

-Stop (Stop) timer T319, or restart (restart) T319

-stop timer Timer-1

All of the above operations can be referred to as fallbacks.

As a supplement, if the UE does not have an ongoing RRC connection recovery procedure (ie, neither T319 nor Timer-1 is running), the UE does not perform the above fallback operation.

Next, regarding other possible situations of the above specific steps, the following is divided into Embodiment 1 and Embodiment 2 for further detailed description.

Example 1

In the process of initiating RRC connection recovery, the UE performs access control;

Otherwise, that is, when the UE determines that the access attempt is allowed, the UE determines whether there is an ongoing RRC connection recovery procedure (ie, determines whether T319 or Timer-1 is running).

When the UE has an ongoing RRC connection recovery procedure (ie, T319 or Timer-1 is running),

Then the UE can perform the above-mentioned fallback operation. Alternatively, the UE generates a fallback indication. Preferably, based on the fallback indication, the UE performs the above-mentioned fallback operation. For example, the UE generates a fallback indication at the RRC layer, and when the UE generates the fallback indication in the RRC connection recovery procedure, the UE performs a fallback operation.

As a supplement, if the UE does not have an ongoing RRC connection recovery procedure (ie, neither T319 nor Timer-1 is running, the UE does not perform the above fallback operation.

In addition, when the UE determines that the access attempt is allowed, the operations related to the RRC connection recovery that the UE may perform further include one or more of the following operations:

The value of the layer 1 parameter (L1 parameter) provided in the system information block or the value of the default layer 1 parameter of the UE is adopted, wherein the layer 1 parameter here may be the initial system bandwidth part (initial Bandwidth part, BWP), It can also be a timing advance offset;

Use the UE default SRB1 configuration (apply default SRB1 configuration);

Use the default MAC cell group configuration of the UE (apply the default MAC Cell Group configuration);

Initiate transmission of the RRC Recovery Request message.

Embodiment 2

On the basis of Embodiment 1, when the UE determines that the access attempt is allowed,

If the UE has an ongoing RRC connection recovery procedure for small data transmission (that is, T319 or Timer-1 is running), then in addition to performing the fallback operation in Embodiment 1, the UE also performs the following operations:

- The UE initiates transmission of the RRC Recovery Request message.

If the UE does not have an ongoing RRC connection recovery procedure for small data transmission (ie, neither T319 nor Timer-1 is running), the UE performs one or more of the following operations:

- Use the value of the layer 1 parameter (L1 parameter) provided in the system information block or the value of the default layer 1 parameter of the UE, where the layer 1 parameter here can be the initial system bandwidth part (initial Bandwidth part, BWP) , or timing advance offset;

-Using the UE default SRB1 configuration (apply default SRB1 configuration);

-Using the default MAC cell group configuration of the UE (apply the default MAC Cell Group configuration);

- Initiate transmission of the RRC Recovery Request message.

FIG. 2 is a schematic structural block diagram of the user equipment involved in the present invention.

As shown in FIG. 2 , the user equipment 200 includes at least a processor 201 and a memory 202 . The processor 201 may include, for example, a microprocessor, a microcontroller, an embedded processor, or the like. The memory 202 may include, for example, volatile memory (eg, random access memory RAM), a hard disk drive (HDD), non-volatile memory (eg, flash memory), or other memory systems, or the like. Program instructions are stored on the memory 202 . When the instruction is executed by the processor 201, one or several steps of the method described in the above-mentioned FIG. 1 of the present disclosure and executed by the user equipment can be executed.

The method and related apparatus of the present disclosure have been described above in conjunction with the 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 under the condition that no contradiction occurs. The method of the present invention is not limited to the steps and sequences 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 and that can be used in a base station, an MME, or a UE, and so on. The various identifiers shown above are only exemplary and not restrictive, and the present disclosure is not limited to the specific information elements exemplified by these identifiers. Numerous changes and modifications may occur to those skilled in the art in light of the teachings of the illustrated embodiments.

It should be understood that the above-described embodiments of the present disclosure may be implemented by software, hardware, or a combination of both. For example, the various components inside the base station and the user equipment in the above embodiments may be implemented by various devices, including but not limited to: analog circuit devices, digital circuit devices, digital signal processing (DSP) circuits, programmable processing Controllers, Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs), Programmable Logic Devices (CPLDs), etc.

Furthermore, the program running on the device according to the present invention may be a program that causes the computer to implement the functions of the embodiments of the present invention by controlling a central processing unit (CPU). The program or information processed by the program may be temporarily stored in volatile memory (eg, random access memory RAM), a hard disk drive (HDD), non-volatile memory (eg, flash memory), or other memory systems.

A program for realizing the functions of the embodiments of the present invention can be recorded on a computer-readable recording medium. The corresponding functions can be realized by causing a computer system to read programs recorded on the recording medium and execute the programs. A "computer system" as used herein may be a computer system embedded in the device, and may include an operating system or hardware (such as peripherals). The "computer-readable recording medium" may be a semiconductor recording medium, an optical recording medium, a magnetic recording medium, a recording medium that dynamically stores a program for a short period of time, or any other recording medium readable by a computer.

The various features or functional blocks of the devices used in the above-described embodiments may be implemented or performed by electrical circuits (eg, 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. A general-purpose processor may be a microprocessor or any existing processor, controller, microcontroller, or state machine. The above circuit may be a digital circuit or an analog circuit. Where new integrated circuit technologies have emerged as a result of advances in semiconductor technology to replace existing integrated circuits, one or more embodiments of the present invention may also be implemented using these new integrated circuit technologies.

Furthermore, the present invention is not limited to the above-described embodiments. Although various examples of the described embodiments have been described, the 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 conditioners, 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 accompanying drawings. However, the specific structure is not limited to the above-mentioned embodiment, 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 technical means disclosed in different embodiments are also included in the technical scope of the present invention. In addition, the components described in the above-described embodiments having the same effect may be substituted for each other.

Claims

A method performed by a user equipment, comprising:

The user equipment initiates an RRC connection recovery process;

the user equipment performs access control and determines whether an access attempt is barred or allowed;

When the user equipment determines that the access attempt is allowed, the user equipment determines whether there is an ongoing RRC connection recovery procedure for small data transmission; and

When the user equipment determines that there is an ongoing RRC connection recovery procedure for small data transmission, the user equipment performs a fallback operation or generates a fallback instruction for the user equipment to perform the fallback operation.
The method performed by user equipment according to claim 1, wherein,

When performing access control, the user equipment determines whether the access attempt is prohibited or allowed according to the access type and the access identifier.
The method performed by user equipment according to claim 1, wherein,

When the user equipment determines that the access attempt is prohibited, the user equipment ends or stops the RRC connection recovery process.
The method performed by user equipment according to claim 1, wherein,

The user equipment judges whether there is an ongoing RRC connection recovery process for small data transmission by judging whether the timer is running.
The method performed by user equipment according to claim 1, wherein,

The fallback operation performed by the user equipment is one or more of the following operations:

Delete keys that have been generated or obtained;

Rebuild RLC entities for SRB and DRB;

Suspend SRBs and DRBs except SRB0;

Configure the bottom layer, stop integrity protection and encryption protection;

reset the MAC layer;

stop the timer;

Restart the timer.
The method performed by user equipment according to claim 1, wherein,

When the user equipment determines that there is an ongoing RRC connection recovery process for small data transmission, the user equipment further performs the following operations:

Initiate transmission of the RRC Recovery Request message.
The method performed by user equipment according to claim 1, wherein,

When the user equipment determines that there is no ongoing RRC connection recovery process for small data transmission, the user equipment performs one or more of the following operations:

Adopt the value of the layer 1 parameter provided in the system information block or the value of the default layer 1 parameter of the UE, wherein the layer 1 parameter is the initial system bandwidth segment or the timing advance offset;

Use the default SRB1 configuration of the UE;

Use the default MAC cell group configuration of the UE;

Initiate transmission of the RRC Recovery Request message.
A user equipment comprising:

processor; and

memory, storing instructions;

wherein the instructions, when executed by the processor, perform the method of any one of claims 1 to 7.