WO2020025023A1 - Random access method, terminal device and network device - Google Patents

Abstract

A random access method, a terminal device and a network device, which can reduce a resource conflict on an unlicensed frequency band in the process of random access. The method comprises: a terminal device determining fallback information for sending a first message in the process of random access, wherein the fallback information is used for indicating, when a physical random access channel (PRACH) resource arrives, a time range required to be awaited for the terminal device to delay channel listening, and/or indicating, when channel listening is successful, a time range required to be awaited for the delay of sending the first message; and the terminal device sending the first message based on the fallback information.

Description

Random access method, terminal equipment and network equipment

This application claims priority from a Chinese patent application filed with the Chinese Patent Office on August 1, 2018, with application number 201810864568.6, with the invention name "random access method, terminal device, and network device", the entire contents of which are incorporated by reference in this.

Technical field

Embodiments of the present application relate to the field of communications, and in particular, to a method for random access, a terminal device, and a network device.

Background technique

New Radio (NR) systems support data transmission on unlicensed frequency bands. When communication equipment communicates on unlicensed spectrum, it needs to be based on the principle of Listen Before Talk (LBT) . That is, a communication device needs to perform channel detection (or channel monitoring) before sending a signal on a channel with an unlicensed spectrum. Only when the channel is idle, the communication device can send data; if the channel is busy (that is, the channel is Occupied), the communication device cannot send data.

For random access on unlicensed spectrum, several messages in the random access process need to meet the above-mentioned channel listening requirements. In other words, before transmitting each random access message, the terminal device or network device needs to perform channel listening to determine whether the channel is idle. If the channel is idle, the corresponding random access message can be transmitted.

However, if the current channel is preempted by another system, such as a Wireless Fidelity (WIFI) system, random access processes initiated by different terminal devices need to be delayed until the channel becomes idle again. This will cause multiple terminal devices to preempt the first available Physical Random Access Channel (PRACH) resources for random access when the channel enters idle, resulting in a significantly increased probability of resource conflicts.

Summary of the invention

Embodiments of the present application provide a random access method, terminal device, and network device, which can reduce resource conflicts in a random access process on an unlicensed spectrum.

According to a first aspect, a method for random access is provided, including: determining, by a terminal device, fallback information for sending a first message in a random access process, wherein the fallback information is used to indicate the terminal The time range during which the device delays waiting for channel listening when the PRACH resource of the physical random access channel arrives, and / or the time range during which the first message is required to be delayed when the interception is successful; the terminal device Based on the back-off information, the first message is sent.

In a second aspect, a method for random access is provided, including: network equipment determining fallback information for a terminal device to send a first message in a random access process, wherein the fallback information is used to indicate The range of time that the terminal device needs to wait for the channel to delay when the PRACH resource of the physical random access channel arrives, and / or the range of time that it needs to wait to delay sending the first message when the interception is successful; The network device sends instruction information to the terminal device, where the instruction information is used to indicate the fallback information.

According to a third aspect, a terminal device is provided, and the terminal device can execute the foregoing first aspect or the method in any optional implementation manner of the first aspect. Specifically, the terminal device may include a functional module for executing the foregoing first aspect or the method in any possible implementation manner of the first aspect.

According to a fourth aspect, a network device is provided, and the network device can execute the foregoing second aspect or the method in any optional implementation manner of the second aspect. Specifically, the network device may include a functional module for performing the foregoing second aspect or the method in any possible implementation manner of the second aspect.

In a fifth aspect, a terminal device is provided, including a processor and a memory. The memory is configured to store a computer program, and the processor is configured to call and run the computer program stored in the memory, and execute the foregoing first aspect or a method in any possible implementation manner of the first aspect.

According to a sixth aspect, a network device is provided, including a processor and a memory. The memory is used to store a computer program, and the processor is used to call and run the computer program stored in the memory to execute the second aspect or the method in any possible implementation manner of the second aspect.

In a seventh aspect, a chip is provided for implementing the foregoing first aspect or the method in any possible implementation manner of the first aspect. Specifically, the chip includes a processor for invoking and running a computer program from the memory, so that the device installed with the chip executes the method in the first aspect or any possible implementation manner of the first aspect.

According to an eighth aspect, a chip is provided for implementing the foregoing second aspect or the method in any possible implementation manner of the second aspect. Specifically, the chip includes a processor for invoking and running a computer program from the memory, so that the device installed with the chip executes the method in the second aspect or any possible implementation manner of the second aspect.

In a ninth aspect, a computer-readable storage medium is provided for storing a computer program that causes a computer to execute the foregoing first aspect or the method in any possible implementation manner of the first aspect.

According to a tenth aspect, a computer-readable storage medium is provided for storing a computer program that causes a computer to execute the foregoing second aspect or the method in any possible implementation manner of the second aspect.

According to an eleventh aspect, a computer program product is provided, including computer program instructions that cause a computer to execute the foregoing first aspect or a method in any possible implementation manner of the first aspect.

According to a twelfth aspect, a computer program product is provided, including computer program instructions that cause a computer to perform the foregoing second aspect or a method in any possible implementation manner of the second aspect.

According to a thirteenth aspect, a computer program is provided that, when run on a computer, causes the computer to execute the above-mentioned first aspect or the method in any possible implementation manner of the first aspect.

In a fourteenth aspect, a computer program is provided that, when run on a computer, causes the computer to execute the second aspect or the method in any possible implementation manner of the second aspect.

Through the above technical solution, before initiating random access, the terminal device obtains fallback information for sending a first message (for example, Msg1) in the random access access process, and the fallback information is used to instruct the terminal device When the PRACH resource arrives, the time range required to wait for channel monitoring is delayed, and / or the time range required to delay sending the first message when channel monitoring is successful. The terminal device may perform channel listening and / or message sending based on the back-off information. Since the fallback information may be different for different terminal devices, different terminal devices may send the first message at different time positions, thereby reducing the probability of resource conflicts.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of a possible wireless communication system applied in an embodiment of the present application.

FIG. 2 is a schematic flowchart interaction diagram of contention-based random access.

FIG. 3 is a schematic flowchart interaction diagram of non-contention random access.

FIG. 4 is a schematic flowchart of a random access method according to an embodiment of the present application.

FIG. 5 is a schematic diagram of sending a first message based on a fallback window according to an embodiment of the present application.

6 (a) and 6 (b) are schematic diagrams of sending a first message based on a backoff duration according to an embodiment of the present application.

FIG. 7 is a schematic flowchart of a random access method according to an embodiment of the present application.

FIG. 8 is a schematic block diagram of a terminal device according to an embodiment of the present application.

FIG. 9 is a schematic block diagram of a network device according to an embodiment of the present application.

FIG. 10 is a schematic structural diagram of a communication device according to an embodiment of the present application.

FIG. 11 is a schematic structural diagram of a chip according to an embodiment of the present application.

FIG. 12 is a schematic block diagram of a communication system according to an embodiment of the present application.

detailed description

The technical solutions in the embodiments of the present application will be described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, but not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

The technical solutions of the embodiments of the present application can be applied to various communication systems, for example, a Global System for Mobile (GSM) system, a Code Division Multiple Access (CDMA) system, and a Wideband Code Division Multiple Access (Wideband Code Division Multiple Access) system, General Packet Radio Service (GPRS), Long Term Evolution (LTE) system, LTE Frequency Division Duplex (FDD) system, LTE Time Division Duplex (TDD) system, Advanced Long-Term Evolution (LTE-A) system, New Radio (NR) system, NR system evolution system, LTE on unlicensed spectrum (LTE-based access to unlicensed spectrum (LTE-U) system, NR-based access to unlicensed spectrum (NR-U) system, Universal Mobile Telecommunication System (UMTS), global Interconnected Microwave Access (WiMAX) Communication System Systems, wireless local area networks (WLAN), wireless local area networks (WLAN), wireless fidelity (WiFi), next-generation communication systems, or other communication systems.

Generally speaking, traditional communication systems support a limited number of connections and are easy to implement. However, with the development of communication technology, mobile communication systems will not only support traditional communications, but also support device-to-device (Device to Device, D2D) communication, machine-to-machine (M2M) communication, machine-type communication (MTC), and vehicle-to-vehicle (V2V) communication, etc. The embodiments of this application can also be applied to these communications system.

Optionally, the communication system in the embodiment of the present application may be applied to a Carrier Aggregation (CA) scenario, a dual connectivity (DC) scenario, or a standalone (SA) deployment. Network scene.

Exemplarily, the communication system 100 applied in the embodiment of the present application is shown in FIG. 1. The wireless communication system 100 may include a network device 110. The network device 110 may be a device that communicates with a terminal device. The network device 110 may provide communication coverage for a specific geographic area, and may communicate with terminal devices located within the coverage area. Optionally, the network device 100 may be a base station (Base Transceiver Station, BTS) in a GSM system or a CDMA system, or a base station (NodeB, NB) in a WCDMA system, or an evolved base station in an LTE system. (Evolutional NodeB, eNB or eNodeB), or a network-side device in an NR system, or a wireless controller in a Cloud Radio Access Network (CRAN), or the network device may be a relay station, an access point Point of entry, vehicle-mounted equipment, wearable equipment, network-side equipment in the next generation network, or network equipment in a public land mobile network (PLMN) that will evolve in the future.

The wireless communication system 100 further includes at least one terminal device 120 located within a coverage area of the network device 110. The terminal device 120 may be mobile or fixed. Optionally, the terminal device 120 may refer to an access terminal, user equipment (UE), user unit, user station, mobile station, mobile station, remote station, remote terminal, mobile device, user terminal, terminal, wireless communication Device, user agent, or user device. The access terminal can be a cellular phone, a cordless phone, a Session Initiation Protocol (SIP) phone, a Wireless Local Loop (WLL) station, a Personal Digital Processing (PDA), and wireless communication. Functional handheld devices, computing devices, or other processing devices connected to a wireless modem, in-vehicle devices, wearable devices, terminal devices in future 5G networks, or terminal devices in future evolved PLMNs. Among them, optionally, terminal devices 120 may also perform terminal direct device (D2D) communication.

Specifically, the network device 110 may provide services for a cell, and the terminal device 120 communicates with the network device 110 through a transmission resource (for example, a frequency domain resource or a spectrum resource) used by the cell, and the cell may be the network device 110 ( For example, a cell corresponding to a base station) may belong to a macro base station or a small cell (small cell). Here, the small cell may include: an urban cell, a micro cell, and a pico cell ( Pico cells, femto cells, etc. These small cells have the characteristics of small coverage and low transmission power, and are suitable for providing high-speed data transmission services.

FIG. 1 exemplarily shows one network device and two terminal devices. Optionally, the wireless communication system 100 may include multiple network devices and the coverage range of each network device may include other numbers of terminal devices. The application example does not limit this.

Optionally, the wireless communication system 100 may further include other network entities such as a network controller, a mobility management entity, and the like in this embodiment of the present application is not limited thereto.

It should be understood that the device having a communication function in the network / system in the embodiments of the present application may be referred to as a communication device. Taking the communication system 100 shown in FIG. 1 as an example, the communication device may include a network device 110 and a terminal device 120 having a communication function, and the network device 110 and the terminal device 120 may be specific devices described above, and are not described herein again. The communication device may further include other devices in the communication system 100, such as other network entities such as a network controller, a mobile management entity, and the like, which is not limited in the embodiment of the present application.

After the cell search process, the terminal device has achieved downlink synchronization with the cell, so the terminal device can receive downlink data. However, the terminal equipment can only perform uplink transmission if it obtains uplink synchronization with the cell. The terminal device can establish a connection with the cell and obtain uplink synchronization through a random access procedure (Random Access Procedure, RAR). In other words, through random access, the terminal device can obtain uplink synchronization, and obtain a unique identifier assigned by the network device, that is, a cell wireless network temporary identity (C-RNTI). Therefore, random access can be applied not only in the initial access, but also in the case where the user's uplink synchronization is lost. In order to facilitate understanding, the random access process will be briefly introduced below with reference to FIG. 2 and FIG. 3.

The random access process can usually be triggered by one of the following types of trigger events:

(1) Initial access.

(2) Handover.

(3) RRC connection re-establishment.

(4) In the RRC connection state, when the downlink data arrives, the uplink is in an "unsynchronized" state.

At this time, after the downlink data arrives, the terminal device needs to reply with an Acknowledgement (ACK) or a negative Acknowledgement (NACK).

(5) In the RRC connection state, when the uplink data arrives, the uplink is in an "unsynchronized" state.

(6) In the RRC connection state, no physical uplink control channel (PUCCH) resource is available for scheduling request (SR) transmission.

At this time, the terminal device that is already in the uplink synchronization state is allowed to use a Random Access Channel (RACH) to replace the role of the SR.

(7) The terminal device transitions from the RRC inactive state (RRC_INACTIVE) to the active state (RRC_ACTIVE).

(8) The terminal device requests other system information (OSI).

(9) Beam failure recovery of terminal equipment.

The process of random access mainly has two forms, one is contention-based random access process (contention based RACH), which includes 4 steps; the other is non-contention random access process (contention free RACH), where Includes 2 steps.

FIG. 2 is a flow interaction diagram of a contention-based random access process. As shown in FIG. 2, the random access process may include the following four steps:

Step 1. Message (Msg) 1.

The terminal device sends Msg1 to the base station to tell the network device that the terminal device initiates a random access request. The Msg1 carries a Random Access Preamble (RAP), or a random access preamble sequence or preamble. Sequence, preamble, etc. At the same time, Msg1 can also be used for network equipment to estimate the transmission delay between it and the terminal equipment and use it to calibrate the uplink time.

Step 2. Msg 2.

After receiving the Msg1 sent by the terminal device, the network device sends the Msg2, that is, a Random Access Response (RAR) message to the terminal device. The Msg2 may carry, for example, a Time Advance (TA), an uplink authorization instruction such as configuration of uplink resources, and a temporary cell-radio network temporary identity (TC-RNTI).

The terminal device monitors a physical downlink control channel (PDCCH) within a random access response time window (RAR window) to receive RAR messages returned by the network device. The RAR message can be descrambled using the corresponding RA-RNTI.

If the terminal device does not receive the RAR message returned by the network device within the RAR time window, the random access process is considered to have failed.

If the terminal device successfully receives an RAR message, and the preamble index (preamble index) carried in the RAR message is the same as the index of the preamble sent by the terminal device through Msg1, it is considered that the RAR is successfully received, and the terminal The device can stop monitoring within the RAR time window.

Among them, Msg2 may include RAR messages for multiple terminal devices, and each terminal device RAR message may include a random access preamble identifier (RAPD) (RAPID) used by the terminal device, used to transmit Msg3 Resource information, TA adjustment information, TC-RNTI, etc.

Step 3. Msg.

After receiving the RAR message, the terminal device determines whether the RAR is its own RAR message. For example, the terminal device can use the preamble identifier to check. After determining that it is its own RAR message, the terminal device generates Msg3 at the RRC layer. And send Msg3 to the network device. It needs to carry identification information of the terminal device and the like.

Specifically, for different random access triggering events, Msg3 in step 3 of the 4-step random access process may include different contents for scheduled transmission (Scheduled Transmission).

For example, for the initial access scenario, Msg 3 may include an RRC Connection Request (RRC Connection Request) generated by the RRC layer, which carries at least the non-access stratum (NAS) identification information of the terminal device, and may also carry For example, the Serving-Temporary Mobile Subscriber Identity (S-TMSI) or random number of the terminal device; For the connection reconstruction scenario, Msg3 may include an RRC Connection Re-establishment Request generated by the RRC layer ) And does not carry any NAS messages, it may also carry, for example, Cell Radio Network Temporary Identifier (C-RNTI) and Protocol Control Information (Protocol Control Information) (PCI), etc. For the switching scenario, Msg3 may include The RRC Handover Complete message generated by the RRC layer and the C-RNTI of the terminal device can also carry, for example, a Buffer Status Report (BSR); for other triggering events such as the scenario where uplink / downlink data arrives, Msg 3 At least the C-RNTI of the terminal equipment is required.

Step 4. Msg 4.

The network device sends Msg4 to the terminal device, and the terminal device correctly receives Msg4 to complete the contention resolution. For example, during the RRC connection establishment process, Msg 4 may carry an RRC connection establishment message.

Since the terminal device in step 3 will carry its own unique identifier in Msg3, such as C-RNTI or identification information from the core network (such as S-TMSI or a random number), the network device will The unique identifier of the terminal device is carried in Msg 4 to specify the terminal device that wins the competition. The other terminal devices that did not win the competition will re-initiate random access.

FIG. 3 is a flow interaction diagram of a non-contention random access process. As shown in FIG. 3, the random access process may include the first two steps in FIG. 2 (ie, step 1 and step 2 in FIG. 2). among them:

Step 0: The network device sends a random access preamble assignment (RA) preamble assignment message to the terminal device.

Step 1, Msg1.

The terminal device sends Msg1 to the base station to inform the network device that the terminal device has initiated a random access request, and the Msg1 carries a random access preamble.

Step 2. Msg 2.

After receiving the Msg1 sent by the terminal device, the network device sends the Msg2, or RAR message, to the terminal device. The Msg2 may carry information such as TA information, uplink authorization instructions such as uplink resource configuration, and TC-RNTI.

If the terminal device does not receive the RAR message returned by the network device within the RAR time window, it considers that the random access process has failed. If the terminal device successfully receives an RAR message, and the preamble index carried in the RAR message is the same as the index of the preamble sent by the terminal device through Msg1, it is considered that the RAR is successfully received, and the terminal device can stop the RAR at this time. Listening to the message.

For Msg1 and Msg2 in the non-competitive random access process, please refer to the foregoing description of Msg1 and Msg2 in the contention-based random access process.

When a terminal device needs to initiate random access on a licensed spectrum, since multiple terminal devices may be configured with a common PRACH resource, different terminal devices may compete for resources on the same PRACH resource. When a resource conflict occurs, for example, multiple terminal devices choose the same PRACH occasion. In this way, the network device can carry a backoff indicator (BI) in the RAR message of Msg2. A terminal device that has experienced a resource conflict can generate a random number based on the backoff indication, so that when the next PRACH resource arrives, it will delay according to the random number, thereby delaying the corresponding time to send Msg1, thereby mitigating the resource conflict to a certain extent The probability.

In CA scenarios, DC scenarios, and SA network deployment scenarios, terminal devices need to initiate random access on unlicensed spectrum. At this time, several kinds of messages in the random access process need to meet the above-mentioned channel listening requirements, that is, to meet the LBT requirements. In other words, before transmitting each random access message, the terminal device or network device needs to perform channel listening to determine whether the channel is idle. If the channel is idle, the corresponding random access message can be transmitted.

However, if the current channel is preempted by another system, such as a Wireless Fidelity (WIFI) system, random access processes initiated by different terminal devices need to be delayed until the channel becomes idle again. This will cause multiple terminal devices to preempt the first available PRACH resource for random access when the channel enters idle, thereby causing a significant increase in the probability of resource conflicts.

Therefore, the embodiment of the present application proposes that, before initiating random access, the terminal device obtains fallback information for sending the first message (for example, Msg1) in the random access access process, and the fallback information is used to indicate The terminal device delays the waiting time range required for channel listening when the PRACH resource arrives, and / or delays the waiting time range required for sending the first message when the channel monitoring is successful. The terminal device may perform channel listening and / or message sending based on the back-off information. Since the fallback information may be different for different terminal devices, different terminal devices may send the first message at different time positions, thereby reducing the probability of resource conflicts.

FIG. 4 is a schematic flowchart of a random access method 400 according to an embodiment of the present application. The method described in FIG. 4 may be executed by a terminal device, and the terminal device may be, for example, the terminal device 120 shown in FIG. 1. As shown in FIG. 4, the random access method 400 may include some or all of the following steps. among them:

In 410, the terminal device determines backoff information for sending the first message in the random access process.

Wherein, the back-off information is used to instruct the terminal device to delay a time range required for channel monitoring when a PRACH resource arrives, and / or, to delay sending the first message when channel monitoring is successful. The time range to wait.

That is, the fallback information can be used to indicate:

The range of time to wait for PRACH resources to delay waiting for channel listening; or,

The time range required to wait for PRACH resources to arrive and delay sending the first message when the interception is successful; or

At the same time, it indicates the time range required to delay waiting for channel monitoring when the PRACH resource arrives, and the time range required to delay sending the first message when channel monitoring succeeds.

It should be understood that the fallback information may indicate that the terminal device does not perform a delay operation, for example, the fallback information indicates that the terminal device does not need to perform a delay operation by indicating that the time range is 0 or by other means. At this time, the terminal device can directly perform channel listening when PRACH resources arrive without delay, and / or, directly perform channel listening when PRACH resources arrive and send the first message immediately after the interception is successful. No delay is required.

It should also be understood that, if the interception is successful, that is, the LBT is successful, it means that the interception channel is idle or the channel is not occupied; if the interception failure is that of the LBT, it means that the interception channel is busy or the channel is occupied. Optionally, the terminal device may determine whether the interception is successful by measuring information such as signal quality and signal power of the received signal.

In 420, the terminal device sends the first message based on the fallback information.

Specifically, the terminal device may determine the fallback information to be used based on a predetermined rule or a configuration of the network device. The fallback information may indicate that the terminal device does not perform a delay operation; or the fallback information may instruct the terminal device to perform a delay operation, and further indicates a time range in which a delay is required. The time range may be used to determine a specific time that the terminal device needs to wait before performing channel monitoring and / or sending the first time. For example, the terminal device may generate a backoff random number (hereinafter also referred to as a backoff value) within the time range. When the PRACH resource arrives, wait for the time corresponding to the random number and then perform channel listening, or, when the PRACH resource arrives, perform channel monitoring and when the interception is successful, wait for the time corresponding to the random number and then send the first one. Message.

In a possible implementation manner, the fallback information includes information of a fallback window, and the fallback window includes at least one PRACH resource that can be used to send the first message.

Wherein, in 420, the terminal device sends the first message based on the fallback information, including: the terminal device selects a PRACH resource among the at least one PRACH resource in the fallback window; the terminal device selects the PRACH Channel monitoring is performed on the resource, and when the interception is successful, the first message is sent on the PRACH resource.

The fallback information may include, for example, the length and / or location information of the fallback window. The terminal device may select a PRACH resource among at least one PRACH resource in the fallback window, and perform channel detection in the selected PRACH resource. Listen, when the listening result is that the channel is idle, send the first message on the PRACH resource.

The fallback window may include, for example, a plurality of consecutive PRACH resources after the last PRACH resource that failed to listen. For example, as shown in FIG. 5, if the terminal device fails to perform channel monitoring on PRACH resource 1, the fallback window may include PRACH resource 2, PRACH resource 3, and PRACH resource 4. The terminal device may randomly select one or more PRACH resources among the multiple PRACH resources included in the fallback window for channel monitoring.

Taking FIG. 5 as an example, after the terminal device fails to perform channel monitoring on the PRACH resource 1, it can perform channel monitoring again on the subsequent PRACH resource. The fallback information includes information of a fallback window, and the fallback window includes three PRACH resources, that is, PRACH resources 2, PRACH resources 3, and PRACH resources 4. The terminal device may randomly select one PRACH resource among the three PRACH resources to perform channel monitoring, for example, select PRACH resource 3 to perform channel monitoring.

If the terminal device fails to perform channel monitoring on the PRACH resource 3, it cannot send the first message on the PRACH resource 3. If the terminal device successfully performs channel monitoring on the PRACH resource 3, it can send the first message on the PRACH resource 3.

It should be understood that the starting position of the fallback window may be the starting position of PRACH resource 2, or the ending position of PRACH resource 1, or may be, for example, the ending position of PRACH resource 1 and PRACH resource 2 shown in FIG. 5 A certain time-domain position between the starting positions of the is not limited in the embodiment of the present application.

In another possible implementation manner, the rollback information includes a rollback duration.

Among them, in 420, the terminal device sends the first message based on the back-off information, including: after the terminal device fails to listen to the channel on the PRACH resource, it performs channel listening on the next PRACH resource and succeeds in listening Time, delay sending the first message according to the fallback duration; or, when the next PRACH resource arrives, the terminal device performs channel listening based on the fallback duration delay, and sends the first message when the interception is successful Message.

In other words, after a terminal device fails channel monitoring on a PRACH resource, it can perform channel monitoring on the next PRACH resource. At this time, the terminal device may perform channel monitoring on subsequent PRACH resources according to the back-off information sent by the network device or by itself. The rollback information includes a rollback duration. The terminal device performs channel interception in the next PRACH resource and, after interception is successful, sends the first message according to the fallback duration (for example, generates a random number within the time range indicated by the fallback duration, and waits The first message is sent after the duration corresponding to the random number); or, the terminal device may also perform channel listening based on the fallback duration when the next PRACH resource arrives (for example, at the time indicated by the fallback duration) Generate a random number within the range, wait for the length of time corresponding to the random number, and then perform channel listening), and send the first message after successful interception.

Taking FIG. 6 (a) and FIG. 6 (b) as examples, after the terminal device fails to perform channel monitoring on the PRACH resource 1, it can perform channel monitoring again on the subsequent PRACH resource. The rollback information includes a rollback duration. Assume that the rollback duration is 30ms. At this time, the terminal device can generate a random number as the fallback value within 0ms-30ms, for example, select 20ms as the fallback value. As shown in FIG. 6 (a), the terminal device directly performs channel interception when the PRACH resource 2 arrives. If the interception succeeds, it waits for 20ms and then sends the first message when the interception succeeds. Alternatively, as shown in FIG. 6 (b), after the PRACH resource 2 arrives, the terminal device may perform channel listening after a delay of 20 ms. If the interception is successful, the first message is sent on the PRACH resource 2.

In the embodiment of the present application, optionally, before determining the fallback information, the terminal device may receive instruction information sent by the network device, where the instruction information is used to indicate the fallback information. That is, the network device may configure the fallback information for the terminal device, and notify the terminal device through the instruction information. The indication information is carried in, for example, system information, or the indication information may be a specific sequence.

Alternatively, optionally, the terminal device may also determine the fallback information based on a predetermined rule. The predetermined rule may include, for example, the number of consecutive failures of channel listening before the random access process, the trigger event of the random access, and the type of service such as Quality of Service (QoS) Class Identifier (QCI) , Channel access priority, and so on.

The following uses the predetermined rule as the number of consecutive failures and the trigger event of the random access as examples to describe in detail a process in which the terminal device determines the fallback information.

Way 1

The terminal device may determine the back-off information according to the number of consecutive failures of channel listening before the random access process.

For example, if the number of failed channel listening or LBT failures before the first message is sent before, it means that the busier the channel, the higher the probability of collision, and accordingly, for example, the fallback information in the fallback information The smaller the window length and / or the fallback time can be set to ensure that the terminal device can access the system as soon as possible. Conversely, if the number of failed channel listening or LBT failures when sending the first message before is smaller, it means that the more free the channel is, the lower the probability of collision will be. Accordingly, the length of the fallback window and / or The larger the rollback duration can be set.

Wherein, optionally, the number of consecutive failures includes the number of consecutive failures of the terminal device performing channel monitoring on the PRACH resource, and / or the number of consecutive failures of performing channel monitoring on the data channel.

That is, the number of consecutive failures may only include the number of times that channel monitoring has failed for random access, or may also include the number of times that channel monitoring has previously failed for data transmission.

Taking Table 1 as an example, it is assumed that the fallback information includes the length of the fallback window. Wherein, when the length of the backoff window is 0, it means that the terminal device does not need to perform a delay operation, that is, it does not need to perform channel monitoring and / or delay sending the first message, but can perform the channel when the PRACH resource arrives Listen for and send this first message when the listening is successful. When the length of the fallback window is another non-zero value, it means that the terminal device needs to perform a delay operation and the length of the fallback window used when performing the delay operation is the value.

For example, if the number of consecutive failures of channel monitoring by the terminal device before the random access is 3, the terminal device may randomly select a PRACH resource within a time window of 30 ms in length after the arrival of the new PRACH resource Perform channel listening again, and send the first message on the PRACH resource when the listening is successful.

Table I

number of failures	Fallback window length
0-2 times	0ms
3-4 times	30ms
4-5 times	60ms
5-6 times	90ms
6 times or more	120ms

It should be understood that it is also possible to configure only one duration of the fallback window, that is, the length of the fallback window is a default value. When the next PRACH resource arrives, the terminal device either does not perform a delay operation or selects a PRACH resource for random access in a default length fallback window. Optionally, the terminal device may determine whether to perform the delay operation according to the number of consecutive failures.

For example, taking FIG. 5 as an example, after the terminal device fails to listen to the channel on PRACH resource 1, if the number of consecutive failures of previous channel listening is less than or equal to the threshold, the terminal device can directly perform channel monitoring on PRACH resource 2 and The first message is sent when the interception is successful; if the number of consecutive failures of previous channel interception is greater than the threshold, the terminal device will randomly select a PRACH resource for channel interception in the fallback window of default length.

Of course, the number of interception failures may not be considered. As long as the terminal device failed to intercept the channel on the PRACH resource last time, when a new PRACH resource arrives, it is necessary to select a PRACH resource in the fallback window of the default length. Perform channel listening.

Taking Table 2 as an example, it is assumed that the rollback information includes the rollback duration. When the rollback duration is 0, it means that the terminal device does not need to perform a delay operation. That is, the terminal device does not need to perform channel listening and / or delay sending the first message in a delayed manner, but can perform channel listening when the PRACH resource arrives and send the first message when the listening is successful. When the rollback duration is a non-zero value, it means that the terminal device needs to perform a delay operation and the rollback duration used when performing the delay operation can be generated based on the non-zero value.

For example, if the number of consecutive failures of channel monitoring before the random access by the terminal device is 5 times, the terminal device can select a random number between 0ms-20ms, such as 15ms, then the terminal device can Wait 15ms after the PRACH resource arrives and then perform channel listening, so that the first message is sent when the interception is successful; or, the terminal device can directly perform channel interception after the new PRACH resource arrives, and wait when the interception is successful The first message is sent again in 15ms.

Table II

number of failures	Fallback duration
0-1 times	0ms
2-3 times	0ms-10ms
4-5 times	0ms-20ms
6-7 times	0ms-30ms
7 times or more	0ms-40ms

It should be understood that only one rollback duration may be configured, that is, the rollback duration is a default value. When the next PRACH resource arrives, the terminal device either does not perform a delay operation or generates a fallback value based on the default value, thereby delaying the fallback value on the PRACH resource and then performing channel monitoring, or directly on the PRACH resource. Perform channel listening and delay the backoff value before sending the first message when the listening is successful. Optionally, the terminal device may determine whether to perform the delay operation according to the number of consecutive failures.

For example, taking Figure 6 (a) and Figure 6 (b) as an example, after the terminal device fails to listen to the channel on PRACH resource 1, if the number of consecutive failures of previous channel listening is less than or equal to the threshold, the terminal device can directly If channel interception is performed on PRACH resource 2 and the first message is sent when the interception succeeds, if the number of consecutive failed channel interceptions previously exceeds the threshold, the terminal device will generate a reply based on the default fallback duration. Backoff value, thereby delaying the backoff value on the PRACH resource 2 and then performing channel listening, or directly performing channel listening on the PRACH resource 2 and delaying the backoff value when the interception is successful and then sending the first one Message.

Of course, the number of interception failures may not be considered, but as long as the terminal device failed to intercept the channel on the PRACH resource last time, when a new PRACH resource arrives, it needs to generate a response based on the default fallback duration. Backoff value, thereby delaying the backoff value on the PRACH resource 2 and then performing channel listening, or directly performing channel listening on the PRACH resource 2 and delaying the backoff value before sending the first one when the interception is successful Message.

It should be understood that, in addition to the manner in which the rollback information is determined according to the number of interception failures shown in Tables 1 and 2 above, after the terminal device counts the number of previous consecutive failures in the interception, it can also determine the rollback by other means information. For example, the terminal device may calculate the fallback duration and / or the length of the fallback window based on a specific formula based on the number of listening failures. This embodiment of the present application does not limit this in any way.

Way 2

The terminal device may determine the fallback information according to a trigger event that triggers the random access process.

The triggering event of the random access process may include, for example, any one of the following: initial access; handover; radio resource control RRC connection reestablishment; in the RRC connection state, when downlink data arrives, the uplink is in an "asynchronous" state; RRC In the connected state, when the uplink data arrives, the uplink is in the "unsynchronized" state; in the RRC connected state, there is no available physical uplink control channel PUCCH resource for scheduling the transmission of the requested SR; the transition from the RRC inactive state to the active state; Request other system information OSI; beam failure recovery.

When the trigger event of the random access process has a higher priority, for example, when the trigger event is a handover or beam failure recovery, the terminal device may not perform a delay operation, or the terminal device performs a delay operation but uses a length of a fallback window or a rollback window. Back length is small.

Taking Table 3 as an example, it is assumed that the fallback information carries the length of the fallback window. Wherein, when the length of the backoff window is 0, it means that the terminal device does not need to perform a delay operation, that is, it does not need to perform channel monitoring and / or delay sending the first message, but can perform the channel when the PRACH resource arrives Listen for and send this first message when the listening is successful. When the length of the fallback window is another non-zero value, it means that the terminal device needs to perform a delay operation and the length of the fallback window used when performing the delay operation is the value.

For example, when the trigger event of the pre-random access process to be initiated is RRC connection reestablishment, the terminal device may randomly select a PRACH resource for channel listening within a time window of 30ms in length after the arrival of the new PRACH resource, and When the interception is successful, the first message is sent on the selected PRACH resource.

Table three

It should be understood that it is also possible to configure only one duration of the fallback window, that is, the length of the fallback window is a default value. When the next PRACH resource arrives, the terminal device either does not perform a delay operation or selects a PRACH resource for random access in a default length fallback window. Optionally, the terminal device may determine whether to perform a delay operation according to a trigger event of random access to be initiated.

For example, taking FIG. 5 as an example, after the terminal device fails to monitor the channel on PRACH resource 1, if the priority of the trigger event of the random access to be initiated is greater than or equal to the threshold, the terminal device can directly perform channel detection on PRACH resource 2. Listen and send the first message when the interception is successful; if the priority of the trigger event of the random access to be initiated is less than the threshold, the terminal device will randomly select a PRACH resource for the channel in the fallback window of default length Listen.

Of course, it is not necessary to consider the trigger event of random access. As long as the terminal device failed to listen on the PRACH resource last time, when a new PRACH resource arrives, it is necessary to select a PRACH in the fallback window of the default length. Resources perform channel listening.

Taking Table 4 as an example, it is assumed that the rollback information includes the rollback duration. When the rollback duration is 0, it means that the terminal device does not need to perform a delay operation. That is, the terminal device does not need to delay for channel listening and / or does not need to delay sending the first message, but can perform channel listening when PRACH resources arrive and send the first message when the interception is successful. . When the rollback duration is a non-zero value, it means that the terminal device needs to perform a delay operation and the rollback duration used when performing the delay operation can be generated based on the non-zero value.

For example, when the triggering event in the current random access process is the initial access, the terminal device can select a duration such as 30ms within 0ms-40ms, then the terminal device can wait for 30ms after the new PRACH resource arrives before performing channel monitoring. Therefore, the first message is sent when the interception is successful; or, the terminal device can directly perform channel interception after the new PRACH resource arrives, and wait for 30ms before the first successful message is sent.

Table four

It should be understood that only one rollback duration may be configured, that is, the rollback duration is a default value. When the next PRACH resource arrives, the terminal device either does not perform a delay operation or generates a fallback value based on the default value, thereby delaying the fallback value on the PRACH resource and then performing channel monitoring, or directly on the PRACH resource. Perform channel listening and delay the backoff value before sending the first message when the listening is successful. Optionally, the terminal device may determine whether to perform a delay operation according to a trigger event of random access to be initiated.

For example, taking FIG. 6 (a) and FIG. 6 (b) as an example, after the terminal device fails to listen to the channel on PRACH resource 1, if the priority of the trigger event of the random access to be initiated is greater than or equal to the threshold, the terminal device may Channel monitoring is performed directly on PRACH resource 2 and the first message is sent when the interception is successful; if the trigger event priority of the random access to be initiated is less than the threshold, the terminal device will use the default fallback duration To generate a fallback value, thereby delaying the fallback value on the PRACH resource 2 and then performing channel listening, or directly performing channel listening on the PRACH resource 2 and delaying the fallback value before sending when the interception is successful The first message.

Of course, it is not necessary to consider the trigger event of random access. As long as the terminal device failed to listen on the PRACH resource last time, when a new PRACH resource arrives, it needs to generate a fallback based on the default fallback duration. Value, thereby delaying the backoff value on the PRACH resource 2 and then performing channel listening, or performing channel listening directly on the PRACH resource 2 and delaying the backoff value before sending the first message when the interception is successful .

Because the number of consecutive failures of previous channel monitoring by different terminal equipment may be different, and / or the terminal equipment may trigger different random events to trigger the random access process, the fallback information obtained may also be different. The time and location of sending the first message are also different, which greatly reduces the probability of sending resource conflicts during the random access process.

It should be understood that the rollback window and rollback duration in the embodiments of the present application may be used in combination. For example, if the terminal device fails to listen to the channel on the PRACH resource selected in the fallback window, it can perform channel monitoring and / or send the first message on the next PRACH resource based on the fallback time; or, if the terminal device After failing to perform channel monitoring based on the rollback duration delay, you can select PRACH resources for channel monitoring in the rollback window.

It should also be understood that the method described in the embodiments of the present application may be used to send the first message in the random access process, but the present application is not limited thereto. Several other messages in the random access process need to meet the above channel listening requirements, that is, LBT requirements. Therefore, the above method can also be used to target other messages in the random access process, such as the second message (such as Msg2) , The third message (such as Msg 3), the fourth message (such as Msg 4), etc. for channel monitoring and / or message sending.

That is, the first message in each of the above methods may be replaced with other messages in the random access process, and the terminal device that sends the other messages may use the methods described above to determine the fallback information for transmitting the other messages. Message.

It should also be understood that the method in the embodiment of the present application may be applied to a 4-step random access process, and may also be applied to a 2-step random access process. In addition, the method in the embodiment of the present application can be applied to a contention-based random access process (contention based RACH) and a non-contention-based random access process (contention free RACH).

FIG. 7 is a schematic flowchart of a random access method 700 according to an embodiment of the present application. The method described in FIG. 7 may be executed by a network device, which may be, for example, the network device 110 shown in FIG. 1. As shown in FIG. 7, the random access method 700 may include some or all of the following steps. among them:

In 710, the network device determines backoff information for the terminal device to send the first message in the random access process.

Wherein, the back-off information is used to instruct the terminal device to delay the time range required for channel listening when the PRACH resource of the physical random access channel arrives, and / or delay sending the first The range of time to wait for a message.

In 720, the network device sends instruction information to the terminal device, where the instruction information is used to indicate the fallback information.

Therefore, before the terminal device initiates random access, the network device configures the terminal device with fallback information for sending the first message (for example, Msg1), which is used to instruct the terminal device to delay when the PRACH resource arrives. The range of time to wait for channel listening, and / or the range of time to wait to delay sending the first message when channel listening is successful. The terminal device may perform channel listening and / or message sending based on the back-off information. Because the back-off information may be different for different terminal devices, different terminal devices can send the first message at different time positions, thereby reducing the probability of resource conflicts.

Optionally, the determining, by the network device, the fallback information used for the terminal device to send the first message in the random access process includes: the network device determines the fallback information according to a predetermined rule.

Optionally, the determining, by the network device, the fallback information according to a predetermined rule includes: determining, by the network device, the fallback according to a number of consecutive failures in channel monitoring performed by the terminal device before the random access process. information.

Optionally, the number of consecutive failures includes the number of consecutive failures of the terminal device performing channel listening on the PRACH resource, and / or the number of consecutive failures of performing channel listening on the data channel.

Optionally, the instruction information is carried in system information, or the instruction information is a specific sequence.

It should be understood that, for a detailed process of determining the fallback information by the network device, reference may be made to the detailed description of the process of determining the fallback information by the terminal device in FIG. 4. For brevity, details are not described herein again.

It should be noted that, under the premise of no conflict, the embodiments described in this application and / or the technical features in each embodiment can be arbitrarily combined with each other, and the technical solution obtained after the combination should also fall into the protection scope of this application .

In various embodiments of the present application, the size of the serial numbers of the above processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not deal with the implementation process of the embodiments of the present application. Constitute any limitation.

The communication method according to the embodiment of the present application is described in detail above. The device according to the embodiment of the present application will be described below with reference to FIGS. 8 to 11. The technical features described in the method embodiment are applicable to the following device embodiments.

FIG. 8 is a schematic block diagram of a terminal device 800 according to an embodiment of the present application. As shown in FIG. 8, the terminal device 800 includes a processing unit 810 and a transceiver unit 720, where:

The processing unit 810 is configured to determine fallback information for sending a first message in a random access process, where the fallback information is used to instruct the terminal device to delay when a PRACH resource of a physical random access channel arrives. The time range required to wait for channel monitoring, and / or the time range required to delay sending the first message when channel monitoring is successful.

The transceiver unit 820 is configured to send the first message based on the fallback information.

Therefore, before initiating random access, the terminal device determines the fallback information for sending the first message (such as Msg1) in the random access access process, and the fallback information is used to instruct the terminal device when the PRACH resource arrives. The range of time required to delay waiting for channel listening, and / or the range of time required to delay sending the first message when channel listening is successful. The terminal device may perform channel listening and / or message sending based on the back-off information. Because the fallback information may be different for different terminal devices, different terminal devices may send the first message at different time positions, thereby reducing the probability of resource conflicts.

Optionally, the processing unit 810 is specifically configured to determine the fallback information according to a predetermined rule.

Optionally, the processing unit 810 is specifically configured to determine the fallback information according to the number of consecutive failures of channel monitoring before the random access process.

Optionally, the number of consecutive failures includes the number of consecutive failures of the terminal device performing channel listening on the PRACH resource, and / or the number of consecutive failures of performing channel listening on the data channel.

Optionally, the processing unit 810 is specifically configured to determine the fallback information according to a trigger event that triggers the random access process.

Optionally, the event that triggers the random access includes any one of the following events: initial access; initial access; handover; radio resource control RRC connection reestablishment; in the RRC connection state, when downlink data arrives, the uplink is in "Unsynchronized" state; in the RRC connected state, when the uplink data arrives, the uplink is in the "unsynchronized" state; in the RRC connected state, no physical uplink control channel PUCCH resource is available for scheduling the transmission of the requested SR; the RRC is inactive State to active state; request other system information OSI; beam failure recovery.

Optionally, the transceiver unit 820 is further configured to receive instruction information sent by a network device, where the instruction information is used to indicate the fallback information; and the processing unit 810 is specifically configured to: according to the instruction information To determine the fallback information.

Optionally, the instruction information is carried in system information, or the instruction information is a specific sequence.

Optionally, the fallback information includes information of a fallback window, and the fallback window includes at least one physical random access channel PRACH resource that can be used to send the first message, wherein the processing unit 810 And is further configured to: select one PRACH resource among the at least one PRACH resource in the fallback window; wherein the transceiver unit 820 is specifically configured to perform channel monitoring on the selected PRACH resource, and When the interception is successful, the first message is sent on the PRACH resource.

Optionally, the rollback information includes a rollback duration, wherein the transceiver unit 820 is specifically configured to: after the channel interception fails on the PRACH resource, perform channel interception on the next PRACH resource and succeed in interception Send the first message according to the backoff duration; or, when the next PRACH resource arrives, perform channel listening based on the backoff duration delay, and send the The first message.

It should be understood that the terminal device 800 may perform corresponding operations performed by the terminal device in the foregoing method 400. For brevity, details are not described herein again.

FIG. 9 is a schematic block diagram of a network device 900 according to an embodiment of the present application. As shown in FIG. 9, the network device 900 includes a processing unit 910 and a transceiver unit 920, where:

The processing unit 910 is configured to determine fallback information for a terminal device to send a first message in a random access process, where the fallback information is used to indicate that the terminal device arrives on a physical random access channel PRACH resource A time range required to wait for the channel to be time-delayed, and / or a time range required to delay the sending of the first message when the channel is successfully monitored;

The transceiver unit 920 sends the terminal device instruction information, where the instruction information is used to indicate the fallback information.

Therefore, before the terminal device initiates random access, the network device configures the terminal device with fallback information for sending the first message (for example, Msg1), which is used to instruct the terminal device to delay when the PRACH resource arrives. The range of time to wait for channel listening, and / or the range of time to wait to delay sending the first message when channel listening is successful. The terminal device may perform channel listening and / or message sending based on the back-off information. Because the fallback information may be different for different terminal devices, different terminal devices may send the first message at different time positions, thereby reducing the probability of resource conflicts.

Optionally, the processing unit 910 is specifically configured to determine the fallback information according to a predetermined rule.

Optionally, the processing unit 910 is specifically configured to determine the fallback information according to the number of consecutive failures in which the terminal device performs channel monitoring on the PRACH resource before the random access process.

Optionally, the number of consecutive failures includes the number of consecutive failures of the terminal device performing channel listening on the PRACH resource, and / or the number of consecutive failures of performing channel listening on the data channel.

Optionally, the instruction information is carried in system information, or the instruction information is a specific sequence.

It should be understood that the communication device 900 may perform corresponding operations performed by the network device in the foregoing method 700. For brevity, details are not described herein again.

FIG. 10 is a schematic structural diagram of a communication device 1000 according to an embodiment of the present application. The communication device 1000 shown in FIG. 10 includes a processor 1010, and the processor 1010 can call and run a computer program from a memory to implement the method in the embodiment of the present application.

Optionally, as shown in FIG. 10, the communication device 1000 may further include a memory 1020. The processor 1010 may call and run a computer program from the memory 1020 to implement the method in the embodiment of the present application.

The memory 1020 may be a separate device independent of the processor 1010, or may be integrated in the processor 1010.

Optionally, as shown in FIG. 10, the communication device 1000 may further include a transceiver 1030, and the processor 1010 may control the transceiver 1030 to communicate with other devices, and specifically, may send information or data to other devices, or receive other Information or data sent by the device.

The transceiver 1030 may include a transmitter and a receiver. The transceiver 1030 may further include an antenna, and the number of antennas may be one or more.

Optionally, the communication device 1000 may specifically be a terminal device in the embodiment of the present application, and the communication device 1000 may implement a corresponding process implemented by the terminal device in each method in the embodiments of the present application. For brevity, details are not described herein again. .

Optionally, the communication device 1000 may specifically be a network device according to an embodiment of the present application, and the communication device 1000 may implement a corresponding process implemented by a network device in each method in the embodiments of the present application. .

FIG. 11 is a schematic structural diagram of a chip according to an embodiment of the present application. The chip 1100 shown in FIG. 11 includes a processor 1110, and the processor 1110 can call and run a computer program from a memory to implement the method in the embodiment of the present application.

Optionally, as shown in FIG. 11, the chip 1100 may further include a memory 1120. The processor 1110 may call and run a computer program from the memory 1120 to implement the method in the embodiment of the present application.

The memory 1120 may be a separate device independent of the processor 1110, or may be integrated in the processor 1110.

Optionally, the chip 1100 may further include an input interface 1130. The processor 1110 may control the input interface 1130 to communicate with other devices or chips. Specifically, the processor 1110 may obtain information or data sent by other devices or chips.

Optionally, the chip 1100 may further include an output interface 1140. The processor 1110 may control the output interface 1140 to communicate with other devices or chips. Specifically, the processor 1110 may output information or data to the other devices or chips.

Optionally, the chip may be applied to the terminal device in the embodiment of the present application, and the chip may implement the corresponding process implemented by the terminal device in each method of the embodiment of the present application. For brevity, details are not described herein again.

Optionally, the chip may be applied to the network device in the embodiment of the present application, and the chip may implement the corresponding process implemented by the network device in each method of the embodiment of the present application. For brevity, details are not described herein again.

It should be understood that the chip mentioned in the embodiments of the present application may also be referred to as a system-level chip, a system chip, a chip system, or a system-on-chip.

It should be understood that the processor in the embodiment of the present application may be an integrated circuit chip and has a signal processing capability. In the implementation process, each step of the foregoing method embodiment may be completed by using an integrated logic circuit of hardware in a processor or an instruction in a form of software. The above processor may be a general-purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), an off-the-shelf programmable gate array (Field, Programmable Gate Array, FPGA), or other Programming logic devices, discrete gate or transistor logic devices, discrete hardware components. Various methods, steps, and logical block diagrams disclosed in the embodiments of the present application can be implemented or executed. A general-purpose processor may be a microprocessor or the processor may be any conventional processor or the like. The steps of the method disclosed in combination with the embodiments of the present application may be directly implemented by a hardware decoding processor, or may be performed by using a combination of hardware and software modules in the decoding processor. The software module may be located in a mature storage medium such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory, or an electrically erasable programmable memory, a register, and the like. The storage medium is located in a memory, and the processor reads the information in the memory and completes the steps of the foregoing method in combination with its hardware.

It can be understood that the memory in the embodiment of the present application may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memory. Among them, the non-volatile memory may be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), and an electronic memory. Erase programmable read-only memory (EPROM, EEPROM) or flash memory. The volatile memory may be Random Access Memory (RAM), which is used as an external cache. By way of example, but not limitation, many forms of RAM are available, such as Static Random Access Memory (SRAM), Dynamic Random Access Memory (DRAM), Synchronous Dynamic Random Access Memory (Synchronous DRAM, SDRAM), double data rate synchronous dynamic random access memory (Double SDRAM, DDR SDRAM), enhanced synchronous dynamic random access memory (Enhanced SDRAM, ESDRAM), synchronous connection dynamic random access memory (Synchlink DRAM, SLDRAM ) And direct memory bus random access memory (Direct Rambus RAM, DR RAM). It should be noted that the memory of the systems and methods described herein is intended to include, but is not limited to, these and any other suitable types of memory.

It should be understood that the foregoing memory is exemplary but not restrictive. For example, the memory in the embodiment of the present application may also be a static random access memory (static RAM, SRAM), a dynamic random access memory (dynamic RAM, DRAM), Synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (Double SDRAM, DDR SDRAM), enhanced synchronous dynamic random access memory (enhanced SDRAM, ESDRAM), synchronous connection Dynamic random access memory (synch link DRAM, SLDRAM) and direct memory bus random access memory (Direct RAMbus RAM, DR RAM) and so on. That is, the memories in the embodiments of the present application are intended to include, but not limited to, these and any other suitable types of memories.

FIG. 12 is a schematic block diagram of a communication system 1200 according to an embodiment of the present application. As shown in FIG. 12, the communication system 1200 includes a terminal device 1210 and a network device 1220. among them:

The terminal device 1210 is configured to determine fallback information for sending a first message in a random access process.

The network device 1220 is configured to determine fallback information used for the terminal device to send a first message in a random access process.

Wherein, the back-off information is used to instruct the terminal device to delay the time range required for channel listening when the PRACH resource of the physical random access channel arrives, and / or delay sending the first The range of time to wait for a message.

Specifically, the terminal device 1210 may be used to implement the corresponding functions implemented by the terminal device in the above method 400, and the composition of the terminal device 1210 may be as shown in the terminal device 800 in FIG. To repeat.

Specifically, the network device 1220 may be used to implement the corresponding functions implemented by the network device in the foregoing method 700, and the composition of the network device 1220 may be as shown in the network device 900 in FIG. To repeat.

An embodiment of the present application further provides a computer-readable storage medium for storing a computer program.

Optionally, the computer-readable storage medium can be applied to the network device in the embodiment of the present application, and the computer program causes the computer to execute the corresponding process implemented by the network device in each method in the embodiment of the present application. No longer.

Optionally, the computer-readable storage medium can be applied to the terminal device in the embodiments of the present application, and the computer program causes the computer to execute the corresponding processes implemented by the terminal device in each method of the embodiments of the present application. For simplicity, here No longer.

An embodiment of the present application further provides a computer program product, including computer program instructions.

Optionally, the computer program product can be applied to the terminal device in the embodiment of the present application, and the computer program instruction causes the computer to execute a corresponding process implemented by the terminal device in each method in the embodiment of the present application. More details.

Optionally, the computer program product can be applied to the network device in the embodiment of the present application, and the computer program instruction causes the computer to execute a corresponding process implemented by the network device in each method in the embodiment of the present application. More details.

The embodiment of the present application also provides a computer program.

Optionally, the computer program may be applied to the terminal device in the embodiment of the present application. When the computer program is run on a computer, the computer is caused to execute a corresponding process implemented by the terminal device in each method in the embodiment of the present application. , Will not repeat them here.

Optionally, the computer program may be applied to a network device in the embodiment of the present application. When the computer program is run on a computer, the computer is caused to execute a corresponding process implemented by the network device in each method in the embodiment of the present application. , Will not repeat them here.

It should be understood that the terms "system" and "network" are often used interchangeably herein. The term "and / or" in this document is only a kind of association relationship describing related objects, which means that there can be three kinds of relationships, for example, A and / or B can mean: A exists alone, A and B exist simultaneously, and exists alone B these three cases. In addition, the character "/" in this article generally indicates that the related objects are an "or" relationship.

It should also be understood that in the embodiment of the present invention, “B corresponding to (corresponding to) A” means that B is associated with A, and B can be determined according to A. However, it should also be understood that determining B based on A does not mean determining B based on A alone, but also determining B based on A and / or other information.

Those of ordinary skill in the art may realize that the units and algorithm steps of each example described in connection with the embodiments disclosed herein can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed by hardware or software depends on the specific application and design constraints of the technical solution. Professional technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices, and units described above can refer to the corresponding processes in the foregoing method embodiments, and are not repeated here.

In the several embodiments provided in this application, it should be understood that the disclosed systems, devices, and methods may be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the unit is only a logical function division. In actual implementation, there may be another division manner. For example, multiple units or components may be combined or may be combined. Integration into another system, or some features can be ignored or not implemented. In addition, the displayed or discussed mutual coupling or direct coupling or communication connection may be indirect coupling or communication connection through some interfaces, devices or units, which may be electrical, mechanical or other forms.

The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, may be located in one place, or may be distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the objective of the solution of this embodiment.

In addition, the functional units in the embodiments of the present application may be integrated into one processing unit, or each of the units may exist separately physically, or two or more units may be integrated into one unit.

If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application is essentially a part that contributes to the existing technology or a part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a storage medium, including Several instructions are used to cause a computer device (which may be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in the embodiments of the present application. The aforementioned storage media include: U disks, mobile hard disks, read-only memory (ROM), random access memory (RAM), magnetic disks or compact discs, and other media that can store program codes .

The above is only a specific implementation of this application, but the scope of protection of this application is not limited to this. Any person skilled in the art can easily think of changes or replacements within the technical scope disclosed in this application. It should be covered by the protection scope of this application. Therefore, the protection scope of this application shall be subject to the protection scope of the claims.

Claims (37)

1. A method for random access, characterized in that the method includes:

   The terminal device determines fallback information for sending a first message in a random access process, where the fallback information is used to instruct the terminal device to delay performing channel listening when a physical random access channel PRACH resource arrives A time range required to wait, and / or a time range required to delay sending the first message when channel listening is successful;

   The terminal device sends the first message based on the fallback information.
2. The method according to claim 1, wherein the determining, by the terminal device, the fallback information for sending the first message in the random access process comprises:

   The terminal device determines the fallback information according to a predetermined rule.
3. The method according to claim 2, wherein the determining, by the terminal device, the fallback information according to a predetermined rule comprises:

   The terminal device determines the fallback information according to the number of consecutive failures of channel listening before the random access process.
4. The method according to claim 3, wherein the number of consecutive failures comprises the number of consecutive failures of the terminal device performing channel listening on a PRACH resource, and / or, the number of consecutive failures of performing channel listening on a data channel number of failures.
5. The method according to claim 2, wherein the determining, by the terminal device, the fallback information according to a predetermined rule comprises:

   The terminal device determines the fallback information according to a trigger event that triggers the random access process.
6. The method according to claim 5, wherein the event that triggers the random access comprises any one of the following events:

   Initial access

   Switch

   Radio resource control RRC connection re-establishment;

   In the RRC connection state, when the downlink data arrives, the uplink is in an "asynchronous" state;

   In the RRC connection state, when the uplink data arrives, the uplink is in an "unsynchronized" state;

   In the RRC connection state, no physical uplink control channel PUCCH resource is available for scheduling the transmission of the requested SR;

   Transition from RRC inactive state to active state;

   Request other system information OSI;

   Beam failure recovery.
7. The method according to claim 1, further comprising:

   Receiving, by the terminal device, instruction information sent by a network device, where the instruction information is used to indicate the fallback information;

   Wherein, the determining, by the terminal device, the fallback information for sending the first message in the random access process includes:

   The terminal device determines the fallback information according to the instruction information.
8. The method according to claim 7, wherein the indication information is carried in system information, or the indication information is a specific sequence.
9. The method according to any one of claims 1 to 8, wherein the fallback information includes information of a fallback window, and the fallback window includes at least one information that can be used to send the first message. Physical random access channel PRACH resources,

   Wherein, the terminal device sending the first message based on the fallback information includes:

   Selecting, by the terminal device, a PRACH resource among the at least one PRACH resource in the fallback window;

   The terminal device performs channel interception on the selected PRACH resource, and when the interception succeeds, sends the first message on the PRACH resource.
10. The method according to any one of claims 1 to 8, wherein the fallback information includes a fallback duration,

    Wherein, the terminal device sending the first message based on the fallback information includes:

    After the terminal device fails to listen to the channel on the PRACH resource, perform channel monitoring on the next PRACH resource, and when the interception is successful, delay sending the first message according to the fallback duration; or,

    When the next PRACH resource arrives, the terminal device performs channel listening according to the backoff duration delay, and sends the first message when the listening is successful.
11. A method for random access, characterized in that the method includes:

    The network device determines the fallback information used for the terminal device to send the first message in the random access process, wherein the fallback information is used to instruct the terminal device to delay the channel when the physical random access channel PRACH resource arrives. A time range to wait for listening, and / or a time range to delay waiting to send the first message when channel interception is successful;

    The network device sends instruction information to a terminal device, where the instruction information is used to indicate the fallback information.
12. The method according to claim 11, wherein the determining, by the network device, the fallback information used for the terminal device to send the first message in the random access process comprises:

    The network device determines the fallback information according to a predetermined rule.
13. The method according to claim 12, wherein the determining, by the network device, the fallback information according to a predetermined rule comprises:

    The network device determines the back-off information according to the number of consecutive failures of channel monitoring by the terminal device before the random access process.
14. The method according to claim 13, wherein the number of consecutive failures includes the number of consecutive failures of the terminal device performing channel listening on a PRACH resource, and / or, the number of consecutive failures of performing channel monitoring on a data channel number of failures.
15. The method according to any one of claims 11 to 14, wherein the instruction information is carried in system information, or the instruction information is a specific sequence.
16. A terminal device, wherein the terminal device includes:

    A processing unit, configured to determine fallback information used to send a first message in a random access process, wherein the fallback information is used to instruct the terminal device to delay when a PRACH resource of a physical random access channel arrives A time range required to wait for channel listening, and / or a time range required to delay sending the first message when channel monitoring is successful;

    The transceiver unit is configured to send the first message based on the fallback information.
17. The terminal device according to claim 16, wherein the processing unit is specifically configured to:

    The fallback information is determined according to a predetermined rule.
18. The terminal device according to claim 17, wherein the processing unit is specifically configured to:

    The back-off information is determined according to the number of consecutive failures of channel monitoring before the random access process.
19. The terminal device according to claim 18, wherein the number of consecutive failures comprises the number of consecutive failures of the terminal device performing channel monitoring on a PRACH resource, and / or Number of consecutive failures.
20. The terminal device according to claim 17, wherein the processing unit is specifically configured to:

    Determining the fallback information according to a trigger event that triggers the random access process.
21. The terminal device according to claim 20, wherein the event that triggers the random access comprises any one of the following events:

    Initial access

    Switch

    Radio resource control RRC connection re-establishment;

    In the RRC connection state, when the downlink data arrives, the uplink is in an "asynchronous" state;

    In the RRC connection state, when the uplink data arrives, the uplink is in an "unsynchronized" state;

    In the RRC connection state, no physical uplink control channel PUCCH resource is available for scheduling the transmission of the requested SR;

    Transition from RRC inactive state to active state;

    Request other system information OSI;

    Beam failure recovery.
22. The terminal device according to claim 16, wherein the transceiver unit is further configured to:

    Receiving instruction information sent by a network device, where the instruction information is used to indicate the fallback information;

    The processing unit is specifically configured to:

    Determining the fallback information according to the instruction information.
23. The terminal device according to claim 22, wherein the instruction information is carried in system information, or the instruction information is a specific sequence.
24. The terminal device according to any one of claims 16 to 23, wherein the fallback information includes information of a fallback window, and the fallback window includes at least one available for sending the first message Physical random access channel PRACH resources,

    The processing unit is further configured to:

    Selecting a PRACH resource from the at least one PRACH resource in the fallback window;

    The transceiver unit is specifically configured to:

    Channel monitoring is performed on the selected PRACH resource, and when the interception is successful, the first message is sent on the PRACH resource.
25. The terminal device according to any one of claims 16 to 23, wherein the fallback information includes a fallback duration,

    The transceiver unit is specifically configured to:

    After the channel monitoring fails on the PRACH resource, channel monitoring is performed on the next PRACH resource, and when the monitoring is successful, the first message is sent according to the backoff duration; or

    When the next PRACH resource arrives, channel listening is performed according to the backoff duration delay, and the first message is sent when the listening is successful.
26. A network device, characterized in that the network device includes:

    A processing unit, configured to determine fallback information for a terminal device to send a first message in a random access process, wherein the fallback information is used to instruct the terminal device when a PRACH resource of a physical random access channel arrives Delay the time range required to wait for channel listening, and / or the time range required to delay sending the first message when channel monitoring is successful;

    The transceiver unit is configured to send instruction information to the terminal device, where the instruction information is used to indicate the fallback information.
27. The network device according to claim 26, wherein the processing unit is specifically configured to:

    The fallback information is determined according to a predetermined rule.
28. The network device according to claim 27, wherein the processing unit is specifically configured to:

    The fallback information is determined according to the number of consecutive failures of channel monitoring by the terminal device before the random access process.
29. The network device according to claim 28, wherein the number of consecutive failures includes the number of consecutive failures of the terminal device performing channel listening on a PRACH resource, and / or, Number of consecutive failures.
30. The network device according to any one of claims 26 to 29, wherein the instruction information is carried in system information, or the instruction information is a specific sequence.
31. A terminal device, characterized in that the terminal device includes a processor and a memory, the memory is used to store a computer program, and the processor is used to call and run a computer program stored in the memory to execute claim 1 The method according to any one of 10 to 10.
32. A network device, characterized in that the network device includes a processor and a memory, the memory is used to store a computer program, and the processor is used to call and run the computer program stored in the memory to execute claim 11 The method according to any one of to 15.
33. A chip, characterized in that the chip includes a processor, and the processor is configured to call and run a computer program from a memory, so that a device installed with the chip executes any one of claims 1 to 10. Method, or performing the method according to any one of claims 11 to 15.
34. A computer-readable storage medium, characterized in that it is used for storing a computer program, which causes a computer to execute the method according to any one of claims 1 to 10, or to execute the method according to any one of claims 11 to 15. The method of one item.
35. A computer program product, comprising computer program instructions, the computer program instructions causing a computer to perform the method according to any one of claims 1 to 10, or to perform the method according to any one of claims 11 to 15. The method described.
36. A computer program, wherein the computer program causes a computer to execute the method according to any one of claims 1 to 10, or to execute the method according to any one of claims 11 to 15.
37. A communication system, comprising a terminal device according to any one of claims 16 to 25 and a network device according to any one of claims 26 to 30.

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