TW202008810A - Random access method, terminal device and network equipment capable of reducing resource conflict on unlicensed frequency band during random access process - Google Patents

Abstract

An embodiment of the present invention discloses a random access method, equipment and computer storage media. In which, the method includes: receiving a random access response (RAR) message based on a first identification message, wherein the RAR message carries a second identification message; and detecting a physical downlink control channel (PDCCH) within a predetermined time window according to the second identification message or a third identification message having a correlated relationship with the second identification message; wherein the PDCCH is scrambled through the second identification message or the third identification message.

Description

Random access method, terminal equipment and network equipment

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

The new radio interface (New Radio, NR) system supports data transmission on unlicensed frequency bands (unlicensed frequency bands). When communication equipment communicates on unlicensed frequency bands, it needs to be based on Listen Before Talk (LBT). in principle. That is, before a communication device sends a signal on a channel in an unlicensed spectrum, it needs to perform channel detection (or channel listening). 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 the unlicensed spectrum, several messages in the random access process need to meet the above channel listening requirements. That is to say, before transmitting each random access message, the terminal device or the network device needs to perform channel listening to determine whether the channel is idle, and the corresponding random access message can be transmitted only if the channel is idle.

However, if the current channel is preempted by other systems such as Wireless Fidelity (WIFI) system, the random access process initiated by different terminal devices needs to be delayed until the channel is idle again. This will cause multiple terminal devices to seize the first available physical random access channel (PRACH) resource for random access when the channel enters idle, resulting in a significantly increased probability of resource conflicts.

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

In a first aspect, a random access method is provided, including: a terminal device determining a back-off message for sending a first message in a random access process, wherein the back-off message is used to instruct the terminal device The time range required to delay channel listening when the PRACH resource of the entity random access channel arrives, and/or the time range required to delay sending the first message when the listening is successful; the terminal device is based on The back-off message sends the first message.

In a second aspect, a method for random access is provided, including: a network device determining a back-off message for a terminal device to send a first message in a random access process, wherein the back-off message is used to indicate The terminal device delays the time range required for channel listening when the PRACH resource of the entity random access channel arrives, and/or the time range required for delaying the sending of the first message when the listening is successful; The network device sends an instruction message to the terminal device, where the instruction message is used to instruct the fallback message.

In a third aspect, a terminal device is provided, which can execute the method in the first aspect or any optional implementation manner of the first aspect. Specifically, the terminal device may include a functional module for performing the method in the first aspect or any possible implementation manner of the first aspect.

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

According to a fifth aspect, a terminal 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 perform the method in the first aspect or 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 perform the method in the second aspect or any possible implementation manner of the second aspect.

In a seventh aspect, a wafer is provided for implementing the method in the first aspect or any possible implementation manner of the first aspect. Specifically, the chip includes a processor for calling 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 wafer is provided for implementing the method in the second aspect or any possible implementation manner of the second aspect. Specifically, the chip includes a processor for calling 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, which causes the computer to execute the method in the first aspect or 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, which causes the computer to execute the method in the second aspect or any possible implementation manner of the second aspect.

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

In a twelfth aspect, a computer program product is provided, which includes computer program instructions that cause the computer to execute the method in the second aspect or any possible implementation manner of the second aspect.

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

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

Through the above technical solution, before initiating random access, the terminal device obtains a fallback message for sending the first message (for example, Msg 1) in the random access process, and the fallback message is used to instruct the terminal device The time range required to delay the channel listening when the PRACH resource arrives, and/or the time range required to delay the first message when the channel listening is successful. The terminal device may perform channel interception and/or message transmission based on the back-off message. Since the back-off message 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.

The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are a part of the embodiments of the present application, but not all 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 work 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, such as: Global System of Mobile Communication (GSM) system, Code Division Multiple Access (CDMA) system, and Broadband Code Division Multiple Access (Wideband Code Division Multiple Access, WCDMA) 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 Interface (NR) system, NR system evolution system, unlicensed spectrum LTE-based access to unlicensed spectrum (LTE-U) system, NR-based access to unlicensed spectrum (NR-U) system on the unlicensed spectrum, Universal Mobile Telecommunication System (UMTS) ), Worldwide Interoperability for Microwave Access (WiMAX) communication system, Wireless Local Area Networks (WLAN), Wireless Fidelity (WiFi), next-generation communication systems or other communication systems, etc.

Generally speaking, traditional communication systems support a limited number of connections and are easy to implement. However, with the development of communication technologies, mobile communication systems will not only support traditional communication, but also support, for example, 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 the present application can also be applied to these communications system.

Optionally, the communication system in the embodiments of the present application may be applied to a carrier aggregation (CA) scenario, a dual connectivity (Dual Connectivity, DC) scenario, or a standalone (SA) configuration. Web 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 network equipment 110. The network device 110 may be a device that communicates with a terminal device. The network device 110 can provide communication coverage for a specific geographic area, and can communicate with terminal devices located within the coverage area. Optionally, the network device 100 may be a base transceiver station (Base Transceiver Station, BTS) in a GSM system or a CDMA system, or a node (NodeB, NB) in a WCDMA system, or an LTE system. Evolutionary Node (Evolutional Node B, eNB or eNodeB), or a network-side device in the NR system, or a wireless controller in the Cloud Radio Access Network (CRAN), or the network device It can be a relay station, an access point, an in-vehicle device, a wearable device, a network-side device in a next-generation network, or a network device in a public land mobile network (PLMN) that is evolving in the future.

The wireless communication system 100 further includes at least one terminal device 120 located within the coverage 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 (User Equipment, UE), user unit, user station, mobile station, mobile station, remote station, remote terminal, mobile device, user Terminal, terminal, wireless communication equipment, user agent or user device. The access terminal may be a mobile phone, a wireless phone, a Session Initiation Protocol (SIP) phone, a Wireless Local Loop (WLL) station, a personal digital assistant (PDA), a wireless Communication-enabled handheld devices, computing devices, or other processing devices connected to wireless modems, in-vehicle devices, wearable devices, terminal devices in future 5G networks, or terminal devices in future evolved PLMNs, etc. Among them, optionally, terminal direct connection (Device to Device, D2D) communication may also be performed between the terminal devices 120.

Specifically, the network device 110 may provide services for a cell, and the terminal device 120 communicates with the network device 110 through transmission resources (for example, frequency domain resources, or spectrum resources) used by the cell, and the cell may It is a cell corresponding to the network device 110 (such as a base transceiver station). The cell may belong to a macro base station or a base transceiver station corresponding to a small cell (Small cell). The small cell here may include: an urban cell (Metro cell), Micro cells, 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 each network device may include other numbers of terminals within the coverage area. The device is not limited in this embodiment of the present application.

Optionally, the wireless communication system 100 may further include other network entities such as a network controller, an action management entity, etc. This embodiment of the present application does not limit this.

It should be understood that the devices with communication functions in the network/system in the embodiments of the present application may be referred to as communication devices. 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 with a communication function. The network device 110 and the terminal device 120 may be the specific devices described above. It will be described again; the communication device may also include other devices in the communication system 100, such as network controllers, action management entities and other network entities, which are not limited in the embodiments 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 device can perform uplink transmission only if it has achieved 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). That is to say, through random access, the terminal device can obtain uplink synchronization, and obtain the unique identifier (Cell Radio Network Temporary Identity, C-RNTI) assigned by the network device. Therefore, random access can be applied not only in initial access, but also in the case where the user's uplink synchronization is lost. For ease of understanding, the random access process will be briefly described below with reference to FIGS. 2 and 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 the "out of sync" state. At this time, after the downlink data arrives, the terminal device needs to reply (Acknowledgement, ACK) or negative acknowledgement (Negative Acknowledgement, NACK).

(5) In the RRC connection state, when the upstream data arrives, the upstream is in the "out of sync" state.

(6) In the RRC connected state, no physical uplink control channel (Physical Uplink Control Channel, PUCCH) resources are 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 (Random Access Channel, RACH) to replace the role of SR.

(7) The terminal equipment transitions from the RRC non-active state (RRC_INACTIVE) to the active state (RRC_ACTIVE).

(8) The terminal device requests other system information (Other System Information, OSI).

(9) Beam failure recovery of terminal equipment (beam failure recovery).

There are two main forms of random access, one is contention based random access (contention based RACH), which includes 4 steps; the other is non-contention based random access (contention free RACH), which includes 2 Steps.

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, Msg 1.

The terminal device sends Msg 1 to the base transceiver station to tell the network device that the terminal device initiated a random access request. The Msg 1 carries a random access preamble (Random Access Preamble, RAP), or random access preamble Sequence, preamble, preamble, etc. At the same time, Msg 1 can also be used for network equipment to estimate the transmission delay between it and the terminal equipment and to calibrate the uplink time.

Step 2. Msg 2.

After receiving the Msg 1 sent by the terminal device, the network device sends Msg 2, a random access response (Random Access Response, RAR) message, to the terminal device. The Msg 2 may carry, for example, Time Advance (TA), uplink authorization commands such as configuration of uplink resources, and Temporary Cell-Radio Network Temporary Identity (TC-RNTI).

The terminal device monitors the physical downlink control channel (PDCCH) in the random access response time window (RAR window) to receive the RAR message 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, it is considered that the random access process fails this time.

If the terminal device successfully receives a 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 Msg 1, it is considered that the RAR has been successfully received, and the terminal The device can stop monitoring in the RAR time window.

Among them, Msg 2 may include RAR messages for multiple terminal devices, and the RAR message of each terminal device may include a random access preamble identifier (RAP Identify, RAPID) used by the terminal device to transmit Msg 3 Resource information, TA adjustment information, TC-RNTI, etc.

Step 3, Msg 3.

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 Msg 3 at the RRC layer. And send Msg 3 to the network equipment. Which needs to carry the identification information of the terminal equipment, etc.

Specifically, for different random access trigger events, Msg 3 in step 3 of the 4-step random access process may include different content to perform 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 at least carries 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 equipment; for connection re-establishment scenarios, Msg 3 may include the RRC Connection Re-establishment request (RRC Connection Re-establishment) generated by the RRC layer Request) and does not carry any NAS messages, and can also carry, for example, Cell Radio Network Temporary Identifier (C-RNTI) and Protocol Control Information (PCI), etc.; for handover scenarios, Msg 3 It may include the RRC Handover Confirm message (RRC Handover Confirm) generated by the RRC layer and the C-RNTI of the terminal equipment, and may also carry, for example, a Buffer Status Report (BSR); for other trigger events such as the arrival of uplink/downlink data , Msg 3 needs to include at least the C-RNTI of the terminal equipment.

Step 4, Msg 4.

The network device sends Msg 4 to the terminal device, and the terminal device correctly receives Msg 4 to complete the contention resolution (Contention Resolution). For example, in the process of establishing an RRC connection, Msg 4 may carry an RRC connection establishment message.

Since the terminal device in step 3 will carry its own unique identifier in Msg 3, such as C-RNTI or the identification message from the core network (such as S-TMSI or a random number), the network device is in the competition resolution mechanism, The unique identifier of the terminal device will be carried in Msg 4 to designate the terminal device that has won the competition. However, other terminal devices that do not win the competition will re-initiate random access.

FIG. 3 is a flow interaction diagram of a non-contentious random access process. As shown in FIG. 3, the random access process may include the first two steps in FIG. 2 (that is, 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, Msg 1.

The terminal device sends Msg 1 to the base transceiver station to inform the network device that the terminal device initiated a random access request, and the Msg 1 carries a random access preamble.

Step 2. Msg 2.

After receiving the Msg 1 sent by the terminal device, the network device sends the Msg 2 or RAR message to the terminal device. The Msg 2 may carry TA messages, uplink authorization commands such as uplink resource configuration, and TC-RNTI, for example.

If the terminal device does not receive the RAR message returned by the network device within the RAR time window, it is considered that the random access process fails this time. If the terminal device successfully receives a RAR message, and the index of the preamble carried in the RAR message is the same as the index of the preamble sent by the terminal device through Msg 1, it is considered that the RAR has been successfully received, and the terminal device can stop the RAR The news is monitored.

For details of Msg 1 and Msg 2 in the non-contention random access process, reference may be made to the foregoing description of Msg 1 and Msg 2 in the contention-based random access process. For brevity, they are not repeated here.

When a terminal device needs to initiate random access on a licensed band (licensed band), 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 resource conflicts occur, for example, multiple terminal devices select the same PRACH occasion (PRACH occasion). In this way, the network device can carry a Backoff Indicator (BI) in the Msg 2 RAR message. A terminal device that has a resource conflict can generate a random number based on the backoff indication, so that when the next PRACH resource arrives, it is delayed according to the random number, thereby delaying the corresponding time to send Msg 1 and thus alleviating 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 messages in the random access process need to meet the above channel interception requirements, that is, the LBT requirements. That is to say, before transmitting each random access message, the terminal device or the network device needs to perform channel listening to determine whether the channel is idle, and the corresponding random access message can be transmitted only if the channel is idle.

However, if the current channel is preempted by other systems such as Wireless Fidelity (WIFI) system, the random access process initiated by different terminal devices needs to be delayed until the channel is idle again. This will cause multiple terminal devices to seize the first available PRACH resource for random access when the channel enters idle, thus resulting in a significantly increased probability of resource conflicts.

Therefore, the embodiment of the present application proposes that before initiating random access, the terminal device obtains a back-off message for sending the first message (for example, Msg 1) in the process of random access, and the back-off message is used to indicate The terminal device delays the waiting time range for channel listening when the PRACH resource arrives, and/or delays the waiting time range for sending the first message when the channel listening is successful. The terminal device may perform channel interception and/or message transmission based on the back-off message. Since the back-off message 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 a backoff message for sending the first message in the random access process.

Wherein, the back-off message is used to indicate the time range that the terminal device needs to wait for the channel listening delay when the PRACH resource arrives, and/or the delay in sending the first message when the channel listening succeeds The range of time to wait.

In other words, the fallback message can be used to indicate:

The time range required to delay channel listening when the PRACH resource arrives; or,

The time range to wait for the channel to wait when the PRACH resource arrives and delay the sending of the first message when the listening is successful; or,

At the same time, it indicates the time range required to delay the channel listening when the PRACH resource arrives, and the time range required to delay the sending of the first message when the channel listening is successful.

It should be understood that the back-off message may indicate that the terminal device does not perform the delay operation. For example, the back-off message indicates that the time range is 0 or other means to indicate that the terminal device does not need to perform the delay operation. At this time, the terminal device can directly perform channel listening without delay listening when the PRACH resource arrives, and/or, directly perform channel listening when the PRACH resource arrives and send the first message immediately after the successful listening without Delayed sending.

It should also be understood that the successful interception, that is, LBT success, indicates that the channel is detected to be idle or the channel is not occupied; the failed interception, that is, LBT fails, indicates that the channel is detected to be busy or the channel is occupied. Optionally, the terminal device may determine whether the interception is successful by measuring the signal quality, signal power, and other information of the received signal.

In 420, the terminal device sends the first message based on the back-off message.

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

In a possible implementation manner, the back-off message includes a back-off window message, and the back-off 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 back-off message, including: the terminal device selects the PRACH resource among the at least one PRACH resource in the back-off window; the terminal device selects the PRACH resource Channel listening is performed on the resource, and when the listening is successful, the first message is sent on the PRACH resource.

The back-off message may include, for example, the length and/or location information of the back-off window. The terminal device may select one PRACH resource from at least one PRACH resource in the back-off 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 back-off window may include, for example, a plurality of consecutive PRACH resources after the PRACH resource that failed to listen last time. For example, as shown in FIG. 5, if the terminal device fails to perform channel listening 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 for channel listening among the multiple PRACH resources included in the back-off window.

Taking FIG. 5 as an example, after the channel monitoring fails on the PRACH resource 1, the terminal device may perform channel monitoring on the subsequent PRACH resource again. The back-off message includes a back-off window message, and the back-off window includes three PRACH resources, namely, PRACH resource 2, PRACH resource 3, and PRACH resource 4. The terminal device may randomly select one PRACH resource among the three PRACH resources for channel interception, for example, select PRACH resource 3 for channel interception.

If the terminal device fails to perform channel listening on PRACH resource 3, it cannot send the first message on PRACH resource 3. If the terminal device succeeds in channel listening on the PRACH resource 3, it may send the first message on the PRACH resource 3.

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

In another possible implementation, the back-off message includes the back-off duration.

Among them, in 420, the terminal device sends the first message based on the back-off message, including: after the terminal device fails to listen to the channel on the PRACH resource, the channel device listens to the channel on the next PRACH resource, and the interception succeeds Time, the first message is delayed according to the backoff 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 a message.

In other words, after the channel monitoring fails on a certain PRACH resource, the terminal device can perform channel monitoring on the next PRACH resource. At this time, the terminal device may perform channel listening on subsequent PRACH resources according to the back-off message sent by the network device or determined by itself. Among them, the rollback message includes the rollback duration. The terminal device performs channel listening in the next PRACH resource and after successful listening, sends the first message according to the back-off duration (for example, generates a random number within the time range indicated by the back-off duration, And wait for the duration corresponding to the random number before sending the first message); or, the terminal device may also perform channel listening according to the backoff duration when the next PRACH resource arrives (for example, during the backoff) Generate a random number within the time range indicated by the duration, and wait for the duration corresponding to the random number before performing channel listening), and send the first message after successful listening.

Taking FIG. 6a and FIG. 6b as examples, after the terminal device fails to perform channel listening on PRACH resource 1, it may perform channel listening again on subsequent PRACH resources. Among them, the rollback message includes the rollback duration. Assume that the back-off duration is 30 ms. At this time, the terminal device can generate a random number as the fallback value within 0 ms-30 ms, for example, select 20 ms as the fallback value. As shown in FIG. 6a, the terminal device directly listens to the channel when the PRACH resource 2 arrives. If the interception is successful, it waits 20 ms before sending the first message. Alternatively, as shown in FIG. 6b, the terminal device may delay channel 20 ms after PRACH resource 2 arrives, and if the interception is successful, send the first message in PRACH resource 2.

In the embodiment of the present application, optionally, before determining the back-off message, the terminal device may receive an instruction message sent by the network device, where the instruction message is used to indicate the back-off message. In other words, the network device may configure the back-off message for the terminal device, and notify the terminal device through the instruction message. The instruction message is carried in a system message, for example, or the instruction message may be a specific sequence.

Or, optionally, the terminal device may also determine the fallback message 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 service type such as Quality of Service (QoS) class identifier (QoS Class Identifier, QCI) , Priority of channel access, etc.

The following uses the predetermined rule as the number of consecutive failures and the trigger event of the random access as an example to describe in detail the process in which the terminal device determines the back-off message.

Way 1

The terminal device may determine the back-off message according to the number of consecutive failures of channel listening before the random access process. For example, if the number of LBT failures before channel listening before sending the first message is higher, it means that the channel is busier and the probability of collision is higher. Correspondingly, for example, the fallback message in the fallback message The smaller the window length and/or back-off duration can be set, to ensure that the terminal device can access the system as soon as possible. Conversely, if the number of LBT failures during channel listening before sending the first message is less, it means that the channel is idler and the probability of collision is lower. Correspondingly, the length and/or length of the fallback window The larger the back-off duration can be set.

Wherein, optionally, the number of consecutive failures includes the number of consecutive failures in which the terminal device performs channel listening on the PRACH resource, and/or the number of consecutive failures in which the channel listening is performed on the data channel.

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

Taking Table 1 as an example, assume that the rollback message includes the length of the rollback window. Among them, when the length of the back-off window is 0, it means that the terminal device does not need to perform a delay operation, that is, it does not need to delay channel monitoring and/or delay sending the first message, but can perform channel detection when the PRACH resource arrives. Listen and send the first message when the listening is successful. When the length of the back-off window is other non-zero value, it means that the terminal device needs to perform a delay operation and the length of the back-off window used when performing the delay operation is the value.

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

Table I

It should be understood that only one duration of the back-off window may be configured, that is, the length of the back-off window is a preset 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 back-off window of a preset length. 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 consecutive failures of channel listening is less than or equal to the threshold, the terminal device may directly perform channel listening on PRACH resource 2 and The first message is sent when the interception is successful; if the number of consecutive failed channel interceptions before is greater than the threshold, the terminal device will randomly select a PRACH resource for channel interception in the fallback window of the default length.

Of course, it is not necessary to consider the number of interception failures. As long as the terminal device fails channel listening on the PRACH resource last time, when a new PRACH resource arrives, it is necessary to select a PRACH in the fallback window of a preset length Channel listening for resources.

Taking Table 2 as an example, assume that the rollback message includes the rollback duration. Wherein, when the back-off 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 channel listening and/or delay sending the first message, but can perform channel listening when the PRACH resource arrives and send the first message when the listening is successful. When the back-off duration is other non-zero value, it means that the terminal device needs to perform a delay operation and the back-off duration used when performing the delay operation can be generated based on the non-zero value.

For example, if the terminal device has 5 consecutive failures in channel listening before this random access, the terminal device can select a random number between 0 ms-20 ms, such as 15 ms, then the terminal device can After the new PRACH resource arrives, wait for 15 ms before channel monitoring, so that the first message is sent when the listening is successful; or, the terminal device can directly perform channel listening after the new PRACH resource arrives, and detect When the listening is successful, wait 15 ms before sending the first message.

Table II

It should be understood that only one type of back-off duration may be configured, that is, the back-off duration is a preset value. When the next PRACH resource arrives, the terminal device either does not perform the delay operation, or generates a backoff value based on the preset value, so as to delay the backoff value on the PRACH resource before channel listening, or on the PRACH resource Directly listen to the channel and delay the fallback 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 FIG. 6a and FIG. 6b as an example, after the terminal device fails to listen to the channel on PRACH resource 1, if the number of consecutive consecutive failures of channel listening is less than or equal to the threshold, the terminal device can directly perform the channel on PRACH resource 2. Listen and send the first message when the listening is successful; if the number of consecutive failures of channel listening before is greater than the threshold, the terminal device will generate a fallback value based on the default fallback duration, so that Delay the backoff value on the PRACH resource 2 to perform channel interception, or directly perform channel interception on the PRACH resource 2 and delay the backoff value when the interception is successful before sending the first message.

Of course, the number of failures to listen may not be considered. Instead, as long as the terminal device fails channel listening on the PRACH resource last time, when a new PRACH resource arrives, it needs to be generated based on the preset backoff duration. A backoff value, so that the backoff value is delayed on the PRACH resource 2 before channel listening, or the channel listening is directly performed on the PRACH resource 2 and the backoff value is delayed when the listening is successful before sending the first a message.

It should be understood that, in addition to the manner of determining the back-off message according to the number of interception failures shown in Tables 1 and 2, the terminal device may also use other methods to determine the back-off after counting the number of consecutive listening failures before message. For example, the terminal device may calculate the back-off duration and/or the back-off window length based on a certain formula based on the number of listening failures. The embodiments of the present application do not limit this.

Way 2

The terminal device may determine the back-off message according to the 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 the downlink data arrives, the uplink is in the "out of synchronization" state; the RRC connection In the state, when the uplink data arrives, the uplink is in the "out of sync" state; in the RRC connected state, there is no physical uplink control channel PUCCH resource available for scheduling the transmission of the request SR; the transition from the RRC non-starting state to the start state; the request Other system information OSI; beam failure recovery.

When the priority of the trigger events of the random access process is higher, for example, when the trigger event is handover or beam failure recovery, the terminal device may not perform the delay operation, or the terminal device performs the delay operation but the length or back-off window used is The retreat length is small.

Taking Table 3 as an example, assume that the back-off message carries the length of the back-off window. Among them, when the length of the back-off window is 0, it means that the terminal device does not need to perform a delay operation, that is, it does not need to delay channel monitoring and/or delay sending the first message, but can perform channel detection when the PRACH resource arrives. Listen and send the first message when the listening is successful. When the length of the back-off window is other non-zero value, it means that the terminal device needs to perform a delay operation and the length of the back-off 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 re-establishment, the terminal device may randomly select a PRACH resource for channel listening within a time window of 30 ms 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 3

It should be understood that only one duration of the back-off window may be configured, that is, the length of the back-off window is a preset 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 back-off window of a preset length. Optionally, the terminal device may determine whether to perform the delay operation according to the trigger event of the random access to be initiated.

For example, taking FIG. 5 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 can directly perform channel detection on PRACH resource 2. Listen and send the first message when the listening is successful; if the priority of the triggering 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 the default length Listen.

Of course, the trigger event of random access may not be considered. As long as the terminal device fails to listen to the channel on the PRACH resource last time, when a new PRACH resource arrives, it is necessary to select one of the fallback windows of a preset length Channel listening is performed on PRACH resources.

Taking Table 4 as an example, assume that the rollback message includes the rollback duration. Wherein, when the back-off 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 channel listening and/or does not need to delay sending the first message, but can perform channel listening when the PRACH resource arrives and send the first message when the listening is successful. When the back-off duration is other non-zero value, it means that the terminal device needs to perform a delay operation and the back-off 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 initial access, the terminal device can select a time period, such as 30 ms, within 0 ms-40 ms, then the terminal device can wait 30 ms after the arrival of the new PRACH resource. Channel listening, so that the first message is sent when the listening is successful; or, the terminal device can directly perform channel listening after the new PRACH resource arrives, and wait for 30 ms before sending the first message when the listening is successful Messages.

Table 4

It should be understood that only one back-off duration may be configured, that is, the back-off duration is a preset value. When the next PRACH resource arrives, the terminal device either does not perform the delay operation, or generates a backoff value based on the preset value, so that the backoff value is delayed on the PRACH resource before channel listening, or on the PRACH resource Directly listen to the channel and delay the fallback 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 trigger event of the random access to be initiated.

For example, taking FIG. 6a and FIG. 6b as an example, after the terminal device fails to listen to the channel on PRACH resource 1, if the priority order of the trigger events of the random access to be initiated is greater than or equal to the threshold, the terminal device may directly on PRACH resource 2. Perform channel listening and send the first message when the listening 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 generate a fallback based on the default fallback duration Value, so that the backoff value is delayed on the PRACH resource 2 before channel listening, or the channel listening is directly performed on the PRACH resource 2 and the backoff value is delayed when the listening is successful before sending the first message .

Of course, the trigger event of the random access may not be considered. As long as the terminal device fails to listen to the channel on the PRACH resource last time, when a new PRACH resource arrives, it needs to generate a new one based on the preset backoff duration. The backoff value, so that the backoff value is delayed on the PRACH resource 2 before channel listening, or the channel listening is directly performed on the PRACH resource 2 and the backoff value is delayed when the listening is successful before sending the first Messages.

Because different terminal devices may have different consecutive failures in channel listening before, and/or the terminal device may trigger the random access process differently, the back-off message may also be different, so that channel listening and The time position of sending the first message is also different, which greatly reduces the probability of sending resource collision during random access.

It should be understood that the rollback window and the rollback duration in the embodiments of the present application may be used in combination. For example, if the terminal device fails channel listening on the PRACH resource selected in the back-off window, it can perform channel listening and/or send the first message on the next PRACH resource based on the back-off duration; or, if the terminal After the device does not succeed in channel listening based on the delay of the backoff duration, it can select PRACH resources for channel listening in the backoff 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 to this. Several other messages in the random access process need to meet the above channel listening requirements, that is, meet the LBT requirements, so the above method can also be used for other messages in the random access process such as the second message (such as Msg 2) , The third message (such as Msg 3), the fourth message (such as Msg 4), etc. for channel listening and/or message sending.

That is to say, the first message in the above methods can be replaced with other messages in the random access process, and the terminal device that sends the other messages can use the methods described above to determine the fallback message for transmission of the other messages news.

It should also be understood that the method of 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 of the embodiment of the present application may be applied to a contention based random access procedure (contention based RACH) and a non-contention based random access procedure (contention free RACH).

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 performed by a network device, and the network device 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 a backoff message for the terminal device to send the first message in the random access process.

Wherein, the back-off message is used to instruct the terminal device to delay the time range required to wait for channel listening when the PRACH resource of the entity 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 an instruction message to the terminal device, where the instruction message is used to instruct the back-off message.

Therefore, before the terminal device initiates random access, the network device configures the terminal device with a back-off message for sending the first message (for example, Msg 1). The back-off message is used to instruct the terminal device to delay when the PRACH resource arrives The time range required to wait for channel listening, and/or the time range required to delay sending the first message when channel listening is successful. The terminal device may perform channel interception and/or message transmission based on the back-off message. Since the back-off message 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 network device determining the back-off message for the terminal device to send the first message in the random access process includes: the network device determining the back-off message according to a predetermined rule.

Optionally, the network device determining the back-off message according to a predetermined rule includes: the network device determining the number of consecutive failures of the channel monitoring by the terminal device before the random access process. Back message.

Optionally, the number of consecutive failures includes the number of consecutive failures in which the terminal device performs channel listening on the PRACH resource, and/or the number of consecutive failures in which channel monitoring is performed on the data channel.

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

It should be understood that, for the detailed process of the network device determining the back-off message, reference may be made to the specific description of the process of determining the back-off message by the terminal device in FIG.

It should be noted that, without 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 within the scope of protection of this application .

In various embodiments of the present application, the size of the sequence numbers of the above processes does not mean the order of execution, and the execution order of each process should be determined by its function and inherent logic, and should not constitute the implementation process of the embodiments of the present application. Any limitation.

The communication method according to an embodiment of the present application has been described in detail above, and 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.

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

The transceiver unit 820 is configured to send the first message based on the back-off message.

Therefore, before initiating random access, the terminal device determines a fallback message for sending the first message (for example, Msg 1) in the random access process. The fallback message is used to indicate that the terminal device arrives at the PRACH resource. The time range required to wait for channel listening with time delay, and/or the time range required to delay sending the first message when channel listening is successful. The terminal device may perform channel interception and/or message transmission based on the back-off message. Since the back-off message 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 message according to a predetermined rule.

Optionally, the processing unit 810 is specifically configured to determine the back-off message according to the number of consecutive failures of channel listening before the random access process.

Optionally, the number of consecutive failures includes the number of consecutive failures in which the terminal device performs channel listening on the PRACH resource, and/or the number of consecutive failures in which channel monitoring is performed on the data channel.

Optionally, the processing unit 810 is specifically configured to determine the back-off message 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 the downlink data arrives, the uplink is at " Out of sync state; in RRC connected state, when upstream data arrives, the upstream is in "out of sync" state; in RRC connected state, there is no available physical uplink control channel PUCCH resource for scheduling request SR transmission; from RRC inactive state Transition to the start state; request other system information OSI; beam failure recovery.

Optionally, the transceiver unit 820 is further configured to: receive an instruction message sent by a network device, and the instruction message is used to instruct the fallback message; wherein, the processing unit 810 is specifically configured to: according to the instruction Message to confirm the fallback message.

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

Optionally, the back-off message includes a back-off window message including at least one entity random access channel PRACH resource that can be used to send the first message, wherein the processing unit 810 Also used to: select one PRACH resource among the at least one PRACH resource in the back-off window; wherein, the transceiver unit 820 is specifically configured to: perform channel listening on the selected PRACH resource, and When the interception is successful, the first message is sent on the PRACH resource.

Optionally, the back-off message includes a back-off duration, wherein the transceiver unit 820 is specifically configured to: after channel listening fails on the PRACH resource, perform channel listening on the next PRACH resource and listen on When successful, send the first message according to the backoff duration delay; or, when the next PRACH resource arrives, perform channel listening according to the backoff duration delay, and when the listening is successful Send the first message.

It should be understood that the terminal device 800 may perform the corresponding operations performed by the terminal device in the above method 400, and for the sake of brevity, no further details are provided here.

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 a fallback message for the terminal device to send the first message in the random access process, wherein the fallback message is used to indicate that the terminal device arrives at the physical random access channel PRACH resource The time range required to wait for channel listening with time delay, and/or the time range required to delay sending the first message when channel listening is successful;

The transceiver unit 920 sends an instruction message to the terminal device, and the instruction message is used to instruct the back-off message.

Therefore, before the terminal device initiates random access, the network device configures the terminal device with a back-off message for sending the first message (for example, Msg 1). The back-off message is used to instruct the terminal device to delay when the PRACH resource arrives The time range required to wait for channel listening, and/or the time range required to delay sending the first message when channel listening is successful. The terminal device may perform channel interception and/or message transmission based on the back-off message. Since the back-off message 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 message according to a predetermined rule.

Optionally, the processing unit 910 is specifically configured to determine the back-off message according to the number of consecutive failures of the terminal device to perform channel listening on the PRACH resource before the random access process.

Optionally, the number of consecutive failures includes the number of consecutive failures in which the terminal device performs channel listening on the PRACH resource, and/or the number of consecutive failures in which channel monitoring is performed on the data channel.

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

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

10 is a schematic structural diagram of a communication device 1000 provided by 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 the 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 can call and run a computer program from the memory 1020 to implement the method in the embodiments 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, specifically, may send messages or data to other devices, or receive other Messages or data sent by the device.

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

Optionally, the communication device 1000 may specifically be the terminal device of the embodiment of the present application, and the communication device 1000 may implement the corresponding process implemented by the terminal device in each method of the embodiment of the present application. .

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 the corresponding process implemented by the network device in each method of the embodiment of the present application. Repeat again.

11 is a schematic structural diagram of a wafer of an embodiment of the present application. The chip 1100 shown in FIG. 11 includes a processor 1110. The processor 1110 can call and run a computer program from the 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 can 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 wafer 1100 may further include an input interface 1130. The processor 1110 can control the input interface 1130 to communicate with other devices or chips. Specifically, it can obtain messages or data sent by other devices or chips.

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

Optionally, the wafer can be applied to the terminal equipment in the embodiments of the present application, and the wafer can implement the corresponding processes implemented by the terminal equipment in each method of the embodiments of the present application.

Optionally, the chip can be applied to the network device in the embodiment of the present application, and the chip can implement the corresponding process implemented by the network device in each method of the embodiment of the present application. For the sake of brevity, no further description is provided here.

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

It should be understood that the processor in the embodiment of the present application may be an integrated circuit chip with signal processing capabilities. In the implementation process, the steps of the foregoing method embodiments may be completed by instructions in the form of hardware integrated logic circuits or software in the processor. The aforementioned processor may be a general-purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a ready-made programmable gate array (Field Programmable Gate Array, FPGA), or Other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components. The methods, steps, and logical block diagrams disclosed in the embodiments of the present application may be implemented or executed. The 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 conjunction with the embodiments of the present application may be directly implemented and executed by a hardware decoding processor, or may be executed and completed by a combination of hardware and software modules in the decoding processor. The software module may be located in a random storage memory, a flash memory, a read-only memory, a programmable read-only memory or an electrically readable and writable programmable memory, a register, and other mature storage media in the art. The storage medium is located in the memory. The processor reads the information in the memory and combines the hardware to complete the steps of the above method.

It can be understood that the memory in the embodiments of the present application may be volatile memory or non-volatile memory, or may include both volatile and non-volatile memory. Among them, the non-volatile memory may be read-only memory (Read-Only Memory, ROM), programmable read-only memory (Programmable ROM, PROM), erasable programmable read-only memory (Erasable PROM) , EPROM), electrically erasable and programmable read-only memory (Electrically EPROM, EEPROM) or flash memory. The volatile memory may be a random access memory (Random Access Memory, RAM), which is used as an external cache memory. By way of example but not limitation, many forms of RAM are available, such as static random access memory (Static RAM, SRAM), dynamic random access memory (Dynamic RAM, 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 limiting, for example, the memory in the embodiments of the present application may also be static random access memory (static RAM, SRAM), dynamic random access memory (dynamic RAM) , DRAM), synchronous dynamic random access memory (synchronous DRAM, SDRAM), double data rate synchronous dynamic random access memory (double data rate SDRAM, DDR SDRAM), enhanced synchronous dynamic random access memory (enhanced SDRAM, ESDRAM), synchronous link dynamic random access memory (synch link DRAM, SLDRAM) and direct memory bus random access memory (Direct Rambus RAM, DR RAM), etc. That is to say, the memories in the embodiments of the present application are intended to include but are 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 used to: determine a back-off message for sending the first message in the random access process.

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

Wherein, the back-off message is used to instruct the terminal device to delay the time range required to wait for channel listening when the PRACH resource of the entity 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. Repeat.

Specifically, the network device 1220 may be used to implement the corresponding functions implemented by the network device in the above method 700, and the composition of the network device 1220 may be as shown in the network device 900 in FIG. 9, for simplicity, I will not repeat them here.

The embodiments of the present application also provide a computer-readable storage medium for storing computer programs.

Optionally, the computer-readable storage medium can be applied to the network device in the embodiments of the present application, and the computer program enables the computer to execute the corresponding process implemented by the network device in each method of the embodiments of the present application. For simplicity, I will not repeat them here.

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

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

Optionally, the computer program product can be applied to the terminal device in the embodiments of the present application, and the computer program instructions cause the computer to execute the corresponding process implemented by the terminal device in each method of the embodiment of the present application. Repeat again.

Optionally, the computer program product can be applied to the network device in the embodiments of the present application, and the computer program instructions enable the computer to execute the corresponding process implemented by the network device in each method of the embodiment of the present application. This will not be repeated here.

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

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

Optionally, the computer program can be applied to the network device in the embodiments of the present application. When the computer program runs on the computer, the computer is allowed to execute the corresponding process implemented by the network device in each method of the embodiment of the present application. For brevity, I 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 article is just an association relationship describing related objects, indicating that there can be three relationships, for example, A and/or B, which can mean: A exists alone, A and B exist simultaneously, and B exists alone. three situations. In addition, the character “/” in this article generally indicates that the related objects are a “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, and B may also be determined based on A and/or other messages.

Persons of ordinary skill in the art may realize that the units and algorithm steps of the examples described in conjunction 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 in hardware or software depends on the specific application of the technical solution and design constraints. Professional technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

Those skilled in the art can clearly understand that for the convenience and conciseness of the description, the specific working process of the system, device and unit described above can refer to the corresponding process in the foregoing method embodiments, which will not be repeated here.

In the several embodiments provided in this application, it should be understood that the disclosed system, device, and method 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 division of logical functions. In actual implementation, there may be other divisions, for example, multiple units or elements may be combined or integrated To 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 an indirect coupling or communication connection through some interfaces, devices or units, and may be in electrical, mechanical or other forms.

The unit described as a separate component may or may not be physically separated, and the component displayed as a unit may or may not be a physical unit, that is, it 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 purpose of the solution of this embodiment.

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

If the function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application essentially or part of the contribution to the existing technology or part of the technical solution can be reflected in the form of a software product, the computer software product is stored in a storage medium, including several The instruction is used to enable 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 methods described in the embodiments of the present application. The aforementioned storage media include: flash drives, mobile hard drives, read-only memory (Read-Only Memory, ROM), random access memory (Random Access Memory, RAM), disks or optical discs, etc. can store program code Medium.

The above is only the 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 scope of protection of this application. Therefore, the scope of protection of this application shall be subject to the content of the scope of patent application.

100‧‧‧Communication system 110‧‧‧Network equipment 120‧‧‧terminal equipment 410, 420‧‧‧ steps 710, 720‧‧‧ steps 800‧‧‧terminal equipment 810‧‧‧Processing unit 820‧‧‧Transceiver unit 900‧‧‧Network equipment 910‧‧‧ processing unit 920‧‧‧ transceiver unit 1000‧‧‧Communication equipment 1010‧‧‧ processor 1020‧‧‧Memory 1030‧‧‧Transceiver

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

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

FIG. 3 is a schematic process interaction diagram of non-contentious random access

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

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

6a and 6b are schematic diagrams of sending the first message based on the back-off duration according to an embodiment of the present application.

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

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

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

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

11 is a schematic structural diagram of a wafer of an embodiment of the present application.

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

410, 420‧‧‧ steps

Claims (20)

A random access method, wherein the method includes: The terminal device determines a back-off message for sending the first message in the random access process, where the back-off message is used to instruct the terminal device to delay channel listening when the PRACH resource of the physical random access channel arrives The time range required to wait, or the time range required to delay sending the first message when the channel listens successfully; The terminal device sends the first message based on the back-off message. The method according to item 1 of the patent application scope, wherein the terminal device determines the fallback message for sending the first message in the random access process, including: The terminal device determines the back-off message according to a predetermined rule. The method according to item 2 of the patent application scope, wherein the terminal device determines the fallback message according to a predetermined rule, including: The terminal device determines the back-off message according to the number of consecutive failures of channel listening before the random access process. The method according to item 3 of the patent application scope, wherein the number of consecutive failures includes the number of consecutive failures in which the terminal device performs channel listening on the PRACH resource, or the consecutive failures in performing channel listening on the data channel frequency. The method according to item 2 of the patent application scope, wherein the terminal device determines the fallback message according to a predetermined rule, including: The terminal device determines the back-off message according to a trigger event that triggers the random access process. The method according to item 5 of the patent application scope, wherein the event that triggers the random access includes any one of the following events: Initial access Switch Radio resource control RRC connection reestablishment; In the RRC connection state, when the downstream data arrives, the upstream is in the "out of sync" state; In the RRC connection state, when the upstream data arrives, the upstream is in the "out of sync" state; In the RRC connection state, no physical uplink control channel PUCCH resources are available for scheduling request SR transmission; Transition from RRC non-starting state to starting state; Request other system information OSI; Beam failure recovery. The method according to item 1 of the patent application scope, wherein the method further comprises: The terminal device receives an instruction message sent by a network device, where the instruction message is used to instruct the fallback message; Wherein, the terminal device determining the fallback message used to send the first message in the random access process includes: The terminal device determines the rollback message according to the instruction message. The method according to item 7 of the patent application scope, wherein the instruction message is carried in a system message, or the instruction message is a specific sequence. The method according to any one of items 1 to 8 of the patent application scope, wherein the back-off message includes a back-off window message including at least one available for sending the first message Of entities randomly access the channel PRACH resources, Wherein, the terminal device sends the first message based on the back-off message, including: The terminal device selects a PRACH resource among the at least one PRACH resource in the back-off window; The terminal device performs channel interception on the selected PRACH resource, and when the interception is successful, sends the first message on the PRACH resource. The method according to any one of items 1 to 8 of the patent application scope, wherein the back-off message includes a back-off duration, Wherein, the terminal device sends the first message based on the back-off message, including: After the channel monitoring fails on the PRACH resource, the terminal device performs channel monitoring on the next PRACH resource, and when the listening is successful, delays sending the first message according to the backoff duration; or, When the next PRACH resource arrives, the terminal device performs channel interception according to the backoff duration delay, and sends the first message when the interception is successful. A terminal device, wherein the terminal device includes: The processing unit is used to determine a back-off message for sending the first message in the random access process, wherein the back-off message is used to instruct the terminal device to delay when the physical random access channel PRACH resource arrives The time range required for channel listening, or the time range required for delaying the sending of the first message when channel listening is successful; The transceiver unit is used for sending the first message based on the back-off message. The terminal device according to item 11 of the patent application scope, wherein the processing unit is specifically configured to: Determine the back-off message according to a predetermined rule. The terminal device according to item 12 of the patent application scope, wherein the processing unit is specifically used for: The back-off message is determined according to the number of consecutive failures of channel listening before the random access process. The terminal device according to item 13 of the patent application range, wherein the number of consecutive failures includes the number of consecutive failures in which the terminal device performs channel listening on the PRACH resource, or, the continuous channel listening on the data channel number of failures. The terminal device according to item 12 of the patent application scope, wherein the processing unit is specifically used for: The back-off message is determined according to the trigger event that triggers the random access process. The terminal device according to item 15 of the patent application scope, wherein the event that triggers the random access includes any one of the following events: Initial access Switch Radio resource control RRC connection reestablishment; In the RRC connection state, when the downlink data arrives, the uplink is in the "out of sync" state; In the RRC connection state, when the upstream data arrives, the upstream is in the "out of sync" state; In the RRC connection state, no physical uplink control channel PUCCH resources are available for scheduling request SR transmission; Transition from RRC non-starting state to starting state; Request other system information OSI; Beam failure recovery. The terminal device according to item 11 of the patent application scope, wherein the transceiver unit is further used to: Receiving an instruction message sent by a network device, where the instruction message is used to instruct the fallback message; Wherein, the processing unit is specifically used for: According to the instruction message, the rollback message is determined. The terminal device according to item 17 of the patent application scope, wherein the instruction message is carried in a system message, or the instruction message is a specific sequence. The terminal device according to any one of items 11 to 18 of the patent application range, wherein the back-off message includes a message of a back-off window, and the back-off window includes at least one available for sending the first article The entity of the message randomly accesses the channel PRACH resources, Among them, the processing unit is also used for: Among the at least one PRACH resource in the back-off window, select one PRACH resource; Wherein, the transceiver unit is specifically used for: Perform channel interception on the selected PRACH resource, and upon successful interception, send the first message on the PRACH resource. The terminal device according to any one of items 11 to 18 of the patent application scope, wherein the back-off message includes a back-off duration, Wherein, the transceiver unit is specifically used for: After channel interception fails on the PRACH resource, channel interception is performed on the next PRACH resource, and when the interception succeeds, the first message is delayed according to the backoff duration; or, When the next PRACH resource arrives, channel interception is performed according to the backoff duration delay, and the first message is sent when the interception is successful.

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