CN111869306A

CN111869306A - Random access method, terminal equipment and network equipment

Info

Publication number: CN111869306A
Application number: CN201980016875.1A
Authority: CN
Inventors: 石聪
Original assignee: Guangdong Oppo Mobile Telecommunications Corp Ltd
Current assignee: Guangdong Oppo Mobile Telecommunications Corp Ltd
Priority date: 2018-08-01
Filing date: 2019-08-01
Publication date: 2020-10-30
Anticipated expiration: 2039-08-01
Also published as: TW202008810A; CN111869306B; WO2020025023A1

Abstract

A random access method, a terminal device and a network device can reduce resource conflict in the random access process on an unlicensed spectrum. The method comprises the following steps: the method comprises the steps that terminal equipment determines backspacing information used for sending a first message in a random access process, wherein the backspacing information is used for indicating that the terminal equipment delays a time range required by channel interception when Physical Random Access Channel (PRACH) resources arrive, and/or delaying the time range required by sending the first message when channel interception succeeds; and the terminal equipment sends the first message based on the rollback information.

Description

Random access method, terminal equipment and network equipment

The present application claims priority from chinese patent application entitled "method of random access, terminal device, and network device" filed on 1/8/2018 at chinese patent office, application number 201810864568.6, the entire contents of which are incorporated herein by reference.

Technical Field

The embodiment of the application relates to the field of communication, in particular to a random access method, terminal equipment and network equipment.

Background

In a New Radio (NR) system, data transmission over an unlicensed frequency spectrum (unlicensed frequency bands) is supported, and when a communication device communicates over the unlicensed frequency spectrum, a Listen Before Talk (LBT) principle is required. That is, before the communication device sends a signal on the channel of the unlicensed spectrum, it needs to perform channel detection (or called channel sensing) first, and only when the channel is idle, the communication device can send data; if the channel is busy (i.e., the channel is occupied), the communication device cannot transmit data.

For random access on unlicensed spectrum, several messages in the random access process need to meet the above-mentioned channel sensing requirement. That is, before transmitting each random access message, the terminal device or the network device needs to perform channel sensing to determine whether the channel is idle, and the corresponding random access message can be transmitted if the channel is idle.

However, if the current channel is preempted by other systems, such as a Wireless Fidelity (WIFI) system, the random access procedure initiated by different terminal devices needs to be delayed until the channel is idle again. This may cause that multiple terminal devices all preempt a first available Physical Random Access Channel (PRACH) resource for Random Access when the Channel enters idle, thereby causing a probability of resource collision to increase significantly.

Disclosure of Invention

The embodiment of the application provides a random access method, terminal equipment and network equipment, which can reduce resource conflict in a random access process on an unlicensed spectrum.

In a first aspect, a method for random access is provided, including: the method comprises the steps that terminal equipment determines backspacing information used for sending a first message in a random access process, wherein the backspacing information is used for indicating that the terminal equipment delays a time range required by channel interception when Physical Random Access Channel (PRACH) resources arrive and/or delays the time range required by sending the first message when the interception is successful; and the terminal equipment sends the first message based on the rollback information.

In a second aspect, a method for random access is provided, including: the network equipment determines back-off information used for a terminal equipment to send a first message in a random access process, wherein the back-off information is used for indicating a time range required by delaying channel interception when a Physical Random Access Channel (PRACH) resource of the terminal equipment arrives and/or delaying the time range required by sending the first message when the interception is successful; and the network equipment sends indication information to the terminal equipment, wherein the indication information is used for indicating the rollback information.

In a third aspect, a terminal device is provided, where the terminal device may perform the method in the first aspect or any optional implementation manner of the first aspect. In particular, the terminal device may comprise functional modules for performing the method of the first aspect or any possible implementation manner of the first aspect.

In a fourth aspect, there is provided a network device that may perform the method of the second aspect or any alternative implementation manner of the second aspect. In particular, the network device may comprise functional modules for performing the method of the second aspect or any possible implementation of the second aspect.

In a fifth aspect, a terminal device is provided that includes a processor and a memory. The memory is used for storing a computer program, and the processor is used for calling and running the computer program stored in the memory to execute the method of the first aspect or any possible implementation manner of the first aspect.

In a sixth aspect, a network device is provided that includes a processor and a memory. The memory is used for storing a computer program, and the processor is used for calling and running the computer program stored in the memory to execute the method of the second aspect or any possible implementation manner of the second aspect.

In a seventh aspect, a chip is provided for implementing the first aspect or the method in any possible implementation manner of the first aspect. In particular, the chip comprises a processor for calling and running a computer program from a memory, such that a device in which the chip is installed performs the method as described above in the first aspect or any possible implementation manner of the first aspect.

In an eighth aspect, a chip is provided for implementing the method of the second aspect or any possible implementation manner of the second aspect. In particular, the chip comprises a processor for calling and running a computer program from a memory, such that a device in which the chip is installed performs the method as described above in the second aspect or any possible implementation of the second aspect.

A ninth aspect provides a computer readable storage medium storing a computer program for causing a computer to perform the method of the first aspect or any possible implementation manner of the first aspect.

A tenth aspect provides a computer-readable storage medium for storing a computer program for causing a computer to perform the method of the second aspect or any possible implementation manner of the second aspect.

In an eleventh aspect, there is provided a computer program product comprising computer program instructions to cause a computer to perform the method of the first aspect or any possible implementation manner of the first aspect.

In a twelfth aspect, there is provided a computer program product comprising computer program instructions to cause a computer to perform the method of the second aspect or any possible implementation manner of the second aspect.

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

In a fourteenth aspect, there is provided a computer program which, when run on a computer, causes the computer to perform the method of the second aspect or any possible implementation of the second aspect.

Through the technical scheme, before initiating random access, the terminal device obtains the back-off information used for sending the first message (e.g. Msg1) in the random access process, wherein the back-off information is used for indicating the time range of waiting for delaying channel sensing when the PRACH resource arrives and/or the time range of waiting for delaying sending the first message when channel sensing is successful. The terminal device may perform channel sensing and/or messaging based on the fallback information. Since the fallback information may be different for different terminal devices, different terminal devices may send the first message at different time locations, thereby reducing the probability of resource collision.

Drawings

Fig. 1 is a schematic diagram of a possible wireless communication system to which an embodiment of the present application is applied.

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

Fig. 3 is a schematic flow interaction diagram of non-contention random access.

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

Fig. 5 is a diagram illustrating sending a first message based on a backoff window according to an embodiment of the present application.

Fig. 6(a) and 6(b) are diagrams illustrating that a first message is sent based on a backoff duration according to an embodiment of the present application.

Fig. 7 is a schematic flow chart of a method of random access 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 of an embodiment of the present application.

Fig. 10 is a schematic configuration diagram of a communication apparatus according to an embodiment of the present application.

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

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

Detailed Description

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, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

The technical scheme of the embodiment of the application can be applied to various communication systems, for example: a Global System for Mobile communications (GSM) System, a Code Division Multiple Access (CDMA) System, a Wideband Code Division Multiple Access (WCDMA) System, a General Packet Radio Service (GPRS), a Long Term Evolution (Long Term Evolution, LTE) System, a LTE Frequency Division Duplex (FDD) System, a LTE Time Division Duplex (TDD) System, a Long Term Evolution (Advanced) Evolution (LTE-A) System, a New Radio (New Radio, NR) System, an Evolution System of an NR System, a non-licensed spectrum (LTE-based) System, a non-licensed spectrum (LTE-based General communication) System, a non-licensed spectrum (NR) System, a non-licensed spectrum (Mobile-NR) System, UMTS), Worldwide Interoperability for Microwave Access (WiMAX) communication system, Wireless Local Area Network (WLAN), Wireless Fidelity (WiFi), next generation communication system, or other communication system.

Generally, conventional Communication systems support a limited number of connections and are easy to implement, however, with the development of Communication technology, mobile Communication systems will support not only conventional Communication, but also, for example, Device-to-Device (D2D) Communication, Machine-to-Machine (M2M) Communication, Machine Type Communication (MTC), and Vehicle-to-Vehicle (V2V) Communication, and the embodiments of the present application can also be applied to these Communication systems.

Optionally, the communication system in the embodiment of the present application may be applied to a Carrier Aggregation (CA) scenario, may also be applied to a Dual Connectivity (DC) scenario, and may also be applied to an independent (SA) networking scenario.

Illustratively, a 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. Network device 110 may be a device that communicates with a terminal device. Network device 110 may provide communication coverage for a particular geographic area and may communicate with terminal devices located within that coverage area. Optionally, the Network device 100 may be a Base Transceiver Station (BTS) in a GSM system or a CDMA system, a Base Station (NodeB, NB) in a WCDMA system, an evolved Node B (eNB or eNodeB) in an LTE system, a Network side device in an NR system, or a wireless controller in a Cloud Radio Access Network (CRAN), or a Network device in a relay Station, an Access point, a vehicle-mounted device, a wearable device, a Network side device in a next generation Network, or a Network device in a Public Land Mobile Network (PLMN) for future evolution, or the like.

The wireless communication system 100 also includes at least one terminal device 120 located within the coverage area of the network device 110. The terminal device 120 may be mobile or stationary. Alternatively, terminal Equipment 120 may refer to an access terminal, User Equipment (UE), subscriber unit, subscriber station, mobile station, remote terminal, mobile device, User terminal, wireless communication device, User agent, or User Equipment. An access terminal may be a cellular telephone, a cordless telephone, a Session Initiation Protocol (SIP) phone, a Wireless Local Loop (WLL) station, a Personal Digital Assistant (PDA), a handheld device having Wireless communication capabilities, a computing device or other processing device connected to a Wireless modem, a vehicle mounted device, a wearable device, a terminal device in a future 5G network or a terminal device in a future evolved PLMN, etc. Optionally, a Device to Device (D2D) communication may be performed between the terminal devices 120.

Specifically, the network device 110 may provide a service for a cell, and the terminal device 120 communicates with the network device 110 through a transmission resource (e.g., a frequency domain resource or a spectrum resource) used by the cell, where the cell may be a cell corresponding to the network device 110 (e.g., a base station), and the cell may belong to a macro base station or a base station corresponding to a Small cell (Small cell), where the Small cell may include: urban cells (Metro cells), Micro cells (Micro cells), Pico cells (Pico cells), Femto cells (Femto cells), and the like, and the small cells have the characteristics of small coverage area and low transmission power, and are suitable for providing high-rate data transmission services.

Fig. 1 exemplarily shows one network device and two terminal devices, and optionally, the wireless communication system 100 may include a plurality of network devices and may include other numbers of terminal devices within the coverage of each network device, which 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, a mobility management entity, and the like, which is not limited in this embodiment.

It should be understood that a device having a communication function in a 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 the specific devices described above and are not described herein again; the communication device may also include other devices in the communication system 100, such as other network entities, for example, a network controller, a mobility management entity, and the like, which is not limited in this embodiment.

After the cell search procedure, the terminal device has acquired downlink synchronization with the cell, and therefore the terminal device can receive downlink data. However, the terminal device can perform uplink transmission only if it acquires uplink synchronization with the cell. The terminal device may establish a connection with a cell and acquire uplink synchronization through a Random Access Procedure (RAR). That is, through random access, the terminal device may obtain uplink synchronization, and obtain a Cell Radio Network Temporary Identity (C-RNTI), which is a unique identifier allocated to the terminal device by the Network device. Therefore, the random access can be applied not only in the initial access, but also in the case of the uplink synchronization loss of the user. For ease of understanding, the random access procedure will be briefly described below in conjunction with fig. 2 and 3.

The random access procedure may be triggered by one of several types of triggering events:

(1) initial access (initial access).

(2) Handover (handover).

(3) RRC Connection reestablishment (RRC Connection Re-establishment).

(4) In the RRC connected state, when downlink data arrives, the uplink is in an "out-of-sync" state.

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

(5) In the RRC connected state, when uplink data arrives, the uplink is in an "out-of-sync" state.

(6) In the RRC connected state, there is no Physical Uplink Control Channel (PUCCH) resource available for Scheduling Request (SR) transmission.

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

(7) The terminal device transitions from an RRC INACTIVE state (RRC _ INACTIVE) to an ACTIVE state (RRC _ ACTIVE).

(8) The terminal device requests Other System Information (OSI).

(9) And (4) recovering the beam failure of the terminal equipment.

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

Fig. 2 is a flow interaction diagram of a contention-based random access procedure. As shown in fig. 2, the random access procedure 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 has initiated a Random Access request, where the Msg1 carries a Random Access Preamble (RAP), or is called a Random Access Preamble sequence, a Preamble, and the like. Meanwhile, the Msg1 can also be used for the network device to estimate the transmission delay between the network device and the terminal device and calibrate the uplink time according to the estimation delay.

Step 2, Msg 2.

After receiving the Msg1 sent by the terminal device, the network device sends Msg 2, that is, a Random Access Response (RAR) message to the terminal device. The Msg 2 may carry, for example, a Time Advance (TA), an uplink grant instruction, such as configuration of an uplink resource, a Temporary Cell-Radio Network Temporary Identity (TC-RNTI), and the like.

The terminal device monitors a Physical Downlink Control Channel (PDCCH) in a random access response time window (RAR window) for receiving an RAR message replied by the network device. The RAR message may be descrambled using a corresponding RA-RNTI.

And if the terminal equipment does not receive the RAR message replied by the network equipment in the RAR time window, the random access process is considered to fail.

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

The Msg 2 may include RAR messages for a plurality of terminal devices, and the RAR message of each terminal device may include a random access preamble identifier (RAP identity, RAPID), information of resources used for transmitting Msg 3, TA adjustment information, TC-RNTI, and the like.

Step 3, Msg 3.

After receiving the RAR message, the terminal device determines whether the RAR is an RAR message belonging to the terminal device, for example, the terminal device may perform a check by using a preamble identifier, and after determining that the RAR message belongs to the terminal device, the terminal device generates Msg 3 in an RRC layer and sends Msg 3 to the network device. Wherein identification information of the terminal device, etc. needs to be carried.

Specifically, the Msg 3 in step 3 of the 4-step random access procedure may include different contents for different random access trigger events 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 an RRC layer, where at least Non-Access Stratum (NAS) identification information of the terminal device is carried, and may also carry, for example, a service-Temporary Mobile Subscriber Identity (S-TMSI) or a random number of the terminal device; for the Connection reestablishment scenario, the Msg 3 may include an RRC Connection reestablishment Request (RRC Connection Re-establishment Request) generated by the RRC layer, does not carry any NAS message, and may also carry, for example, a Cell Radio Network Temporary Identifier (C-RNTI) and Protocol Control Information (PCI), etc.; for a Handover scenario, Msg 3 may include an RRC Handover complete message (RRC Handover Confirm) generated by an RRC layer and a C-RNTI of the terminal device, and may also carry, for example, a Buffer Status Report (BSR); for other triggering events such as the scene of uplink/downlink data arrival, Msg 3 at least needs to include the C-RNTI of the terminal device.

Step 4, Msg 4.

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

Since the terminal device in step 3 will carry its unique identity in Msg 3, such as C-RNTI or identification information from the core network (e.g. S-TMSI or a random number), the network device will carry the unique identity of the terminal device in Msg 4 in the contention resolution mechanism to designate the terminal device that wins the contention. While other terminal devices that have not won contention resolution will re-initiate random access.

Fig. 3 is a flow interaction diagram of a non-contention random access procedure. As shown in fig. 3, the random access procedure may include the first two steps in fig. 2 (i.e., step 1 and step 2 in fig. 2). Wherein:

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 Msg1 to the base station to inform the network device that the terminal device initiates a random access request, wherein the Msg1 carries a random access preamble.

Step 2, Msg 2.

After receiving the Msg1 sent by the terminal device, the network device sends Msg 2, namely an RAR message, to the terminal device. The Msg 2 may carry TA information, an uplink grant instruction such as configuration of uplink resources, and TC-RNTI and other information, for example.

And if the terminal equipment does not receive the RAR message replied by the network equipment in the RAR time window, the random access process is considered to fail. If the terminal device successfully receives an RAR message and the preamble index carried in the RAR message is the same as the preamble index sent by the terminal device through Msg1, the terminal device determines that the RAR message is successfully received, and at this time, the terminal device can stop monitoring the RAR message.

For Msg1 and Msg 2 in the non-contention random access process, reference may be specifically made to the foregoing description of Msg1 and Msg 2 in the contention-based random access process, and for brevity, details are not described here again.

When a terminal device needs to initiate random access on a licensed band (licensed band), different terminal devices may compete for resources on the same PRACH resource because a plurality of terminal devices may be configured with a common PRACH resource. When resource collision occurs, for example, multiple terminal devices select the same PRACH opportunity (PRACH opportunity). In this way, the network device may carry a Backoff Indicator (BI) in the RAR message of the Msg 2. The terminal device having the resource conflict may generate a random number based on the backoff indicator, so as to delay the next PRACH resource arrival according to the random number, thereby delaying the corresponding time for transmitting the Msg1, thereby alleviating the probability of the resource conflict to a certain extent.

In a CA scenario, a DC scenario, and an SA networking scenario, a terminal device needs to initiate random access on an unlicensed spectrum. At this time, several messages in the random access procedure need to satisfy the above channel sensing requirement, i.e. the LBT requirement. That is, before transmitting each random access message, the terminal device or the network device needs to perform channel sensing to determine whether the channel is idle, and the corresponding random access message can be transmitted if the channel is idle.

However, if the current channel is preempted by other systems, such as a Wireless Fidelity (WIFI) system, the random access procedure initiated by different terminal devices needs to be delayed until the channel is idle again. Therefore, a plurality of terminal devices all preempt the first available PRACH resource for random access when the channel enters idle, and the probability of resource collision is obviously increased.

Therefore, the embodiment of the present application proposes that, before initiating random access, a terminal device obtains backoff information for sending a first message (e.g., Msg1) in a random access process, where the backoff information is used to indicate a time range for the terminal device to delay waiting for performing channel sensing when PRACH resources arrive and/or a time range for delaying waiting for sending the first message when channel sensing succeeds. The terminal device may perform channel sensing and/or messaging based on the fallback information. Since the fallback information may be different for different terminal devices, different terminal devices may send the first message at different time locations, thereby reducing the probability of resource collision.

Fig. 4 is a schematic flow chart diagram of a method 400 of random access in an embodiment of the present application. The method described in fig. 4 may be performed by a terminal device, which may be, for example, terminal device 120 shown in fig. 1. As shown in fig. 4, the method 400 of random access may include some or all of the following steps. Wherein:

in 410, the terminal device determines backoff (backoff) information for transmitting a first message in a random access procedure.

The backoff information is used to instruct the terminal device to delay a waiting time range for channel sensing when the PRACH resource arrives, and/or delay the waiting time range for sending the first message when the channel sensing is successful.

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

delaying the waiting time range required for channel monitoring when the PRACH resource arrives; alternatively, the first and second electrodes may be,

when the PRACH resource arrives, carrying out channel monitoring and delaying the time range required for sending the first message when the monitoring is successful; alternatively, the first and second electrodes may be,

and simultaneously indicating the time range of waiting for delaying channel sensing when the PRACH resource arrives and the time range of waiting for delaying the sending of the first message when the channel sensing is successful.

It should be understood that the fallback information may indicate that the terminal device does not perform the delaying operation, e.g., the fallback information indicates that the terminal device does not need to perform the delaying operation by indicating that the time range is 0 or by other means. In this case, the terminal device may directly perform channel sensing without delay sensing when the PRACH resource arrives, and/or directly perform channel sensing when the PRACH resource arrives and immediately transmit the first message without delay after sensing is successful.

It should also be understood that the sensing success, i.e., LBT success, indicates that the channel is sensed to be free or not occupied; the sensing failure, i.e. LBT failure, means that the channel is sensed to be busy or occupied. Alternatively, the terminal device may determine whether the listening was successful by measuring information such as signal quality, signal power, etc. 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 by itself based on a predetermined rule or a configuration of the network device. The fallback information may instruct the terminal device not to perform the delaying operation; alternatively, the fallback information may indicate that the terminal device performs a delaying operation and further indicate 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 channel sensing and/or transmitting 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. And waiting for the time length corresponding to the random number when the PRACH resource arrives, and then carrying out channel sensing, or carrying out channel sensing when the PRACH resource arrives, and waiting for the time length corresponding to the random number when the sensing is successful, and then sending the first message.

In one possible implementation manner, the backoff information includes information of a backoff window, where the backoff window includes at least one PRACH resource available for transmitting the first message.

Wherein, in 420, the terminal device sends the first message based on the fallback information, including: the terminal equipment selects PRACH resources from the at least one PRACH resource in the backoff window; and the terminal equipment carries out channel interception on the selected PRACH resource and sends the first message on the PRACH resource when the interception is successful.

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

The backoff window may include, for example, a consecutive number of PRACH resources after the PRACH resource that failed to listen last. For example, as shown in fig. 5, if the terminal device fails to perform channel sensing on PRACH resource 1, the backoff 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 sensing among the plurality of PRACH resources included in the backoff window.

Taking fig. 5 as an example, after the channel sensing on the PRACH resource 1 is failed, the terminal device may perform channel sensing again on the subsequent PRACH resource. The backoff information includes information of a backoff window, and the backoff window includes three PRACH resources, that is, PRACH resource 2, PRACH resource 3, and PRACH resource 4. The terminal device may randomly select one PRACH resource from the three PRACH resources to perform channel sensing, for example, select PRACH resource 3 to perform channel sensing.

If the terminal equipment fails to perform channel sensing on the PRACH resource 3, the first message cannot be sent on the PRACH resource 3. If the terminal device successfully performs channel sensing on the PRACH resource 3, the first message may be sent on the PRACH resource 3.

It should be understood that the starting position of the backoff window may be a starting position of PRACH resource 2, may also be an ending position of PRACH resource 1, or may be a time domain position between the ending position of PRACH resource 1 and the starting position of PRACH resource 2, for example, as shown in fig. 5, which is not limited in this embodiment of the present invention.

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

Wherein, in 420, the terminal device sends the first message based on the fallback information, including: after the channel interception on the PRACH resource fails, the terminal equipment carries out channel interception on the next PRACH resource, and when the interception succeeds, the terminal equipment delays to send the first message according to the rollback duration; or, the terminal device delays to perform channel sensing according to the backoff duration when the next PRACH resource arrives, and sends the first message when sensing is successful.

That is, after the channel sensing fails on a certain PRACH resource, the terminal device may perform channel sensing on the next PRACH resource. At this time, the terminal device may determine the backoff information according to the backoff information sent by the network device or itself, and perform channel sensing again on the subsequent PRACH resource. Wherein, the rollback information comprises rollback duration. The terminal device performs channel sensing in the next PRACH resource and sends the first message according to the backoff duration after the sensing is successful (for example, a random number is generated within a time range indicated by the backoff duration, and the first message is sent after waiting for a duration corresponding to the random number); or, the terminal device may also perform channel sensing according to the backoff duration when the next PRACH resource arrives (for example, generate a random number within the time range indicated by the backoff duration, and perform channel sensing after waiting for the duration corresponding to the random number), and send the first message after sensing is successful.

Taking fig. 6(a) and fig. 6(b) as an example, after the terminal device fails to perform channel sensing on the PRACH resource 1, the terminal device may perform channel sensing again on the subsequent PRACH resource. Wherein, the rollback information comprises rollback duration. It is assumed that the backoff duration is 30 ms. At this time, the terminal device may generate a random number as a backoff value within 0ms to 30ms, for example, 20ms is selected as the backoff value. As shown in fig. 6(a), the terminal device directly performs channel sensing when the PRACH resource 2 arrives, and if sensing is successful, waits for 20ms to send the first message again when sensing is successful. Alternatively, as shown in fig. 6(b), the terminal device may delay the PRACH resource 2 to perform channel sensing again by 20ms, and if the sensing is successful, send the first message on the PRACH resource 2.

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

Or, 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 sensing before the random access procedure, a trigger event of the random access, a traffic type such as Quality of Service (QoS) Class Identifier (QCI), a channel access priority, and the like.

The following describes the process of determining the backoff information by the terminal device in detail, taking the predetermined rule as the number of consecutive failures and the trigger event of the random access as an example.

Mode 1

The terminal device may determine the backoff information according to the number of consecutive failures of channel sensing performed before the random access procedure.

For example, if the number of failures of channel sensing, i.e. LBT, before the first message is sent is more, this means that the channel is busy, the probability of collision is higher, and accordingly, the length of the backoff window and/or the backoff duration in the backoff information may be set to be smaller, so as to ensure that the terminal device can access the system as soon as possible. Conversely, if the number of failures of channel sensing, i.e. LBT, is less when the first message is sent before, this means that the more idle the channel is, the lower the probability of collision is, and accordingly, the length of the backoff window and/or the backoff duration may be set to be larger.

Optionally, the number of consecutive failures includes a number of consecutive failures for the terminal device to perform channel sensing on the PRACH resource, and/or a number of consecutive failures for the terminal device to perform channel sensing on the data channel.

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

Taking table one as an example, assume that the backoff information includes the length of the backoff window. When the length of the backoff window is 0, it indicates that the terminal device does not need to perform a delay operation, that is, does not need to delay channel sensing and/or delay sending of the first message, but may perform channel sensing when the PRACH resource arrives and send the first message when sensing is successful. When the length of the backoff window is other non-0 values, it indicates that the terminal device needs to perform a delay operation and the length of the backoff window used when performing the delay operation is the value.

For example, if the number of consecutive failures of the terminal device to perform channel sensing is 3 before the random access, the terminal device may randomly select a PRACH resource within a time window with a length of 30ms after the new PRACH resource arrives to perform channel sensing again, and send the first message on the PRACH resource when sensing is successful.

Watch 1

Number of failures	Length of the back-off window
0 to 2 times	0ms
3-4 times	30ms
4-5 times	60ms
5-6 times	90ms
More than 6 times	120ms

It should be understood that only one type of length of the backoff window may be configured, i.e., the length of the backoff window is a default value. When the next PRACH resource comes, the terminal device either does not perform the delay operation or selects one PRACH resource for random access in a backoff window with a default length. Alternatively, 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 channel sensing on the PRACH resource 1 is failed, if the number of consecutive failures of the previous channel sensing is less than or equal to the threshold, the terminal device may directly perform channel sensing on the PRACH resource 2 and send the first message when the sensing is successful; if the continuous failure times of the channel sensing before is greater than the threshold, the terminal device randomly selects one PRACH resource in the backoff window with the default length for channel sensing.

Of course, the number of times of the failed listening may not be considered, and as long as the terminal device fails to perform channel listening on the PRACH resource last time, when a new PRACH resource arrives, it is necessary to select one PRACH resource in the backoff window of the default length for performing channel listening.

Taking table two as an example, it is assumed that the backoff duration is included in the backoff information. When the backoff duration is 0, it indicates that the terminal device does not need to perform the delay operation. That is, the terminal device does not need to delay channel sensing and/or delay sending the first message, but can sense the channel when the PRACH resource arrives and send the first message when sensing is successful. When the backoff duration is other non-0 values, the indication indicates that the terminal device needs to perform the delay operation, and the backoff duration used when the delay operation is performed may be generated based on the non-0 values.

For example, if the number of consecutive failures of the terminal device to perform channel sensing is 5 before the random access, and the terminal device may select a random number between 0ms and 20ms, for example, 15ms, then the terminal device may wait for 15ms to perform channel sensing after the new PRACH resource arrives, and then send the first message when sensing is successful; alternatively, the terminal device may directly perform channel sensing after the new PRACH resource arrives, and wait for 15ms to send the first message when sensing is successful.

Watch two

Number of failures	Length of rollback
0 to 1 time	0ms
2-3 times	0ms-10ms
4-5 times	0ms-20ms
6-7 times	0ms-30ms
More than 7 times	0ms-40ms

It should be understood that only one backoff duration may be configured, i.e., the backoff duration is a default value. When the next PRACH resource comes, the terminal device either does not execute the delay operation, or generates a backoff value based on the default value, so as to delay the backoff value on the PRACH resource and then perform channel sensing, or directly perform channel sensing on the PRACH resource and delay the backoff value when sensing is successful and then send the first message. Alternatively, the terminal device may determine whether to perform the delay operation according to the number of consecutive failures.

For example, taking fig. 6(a) and fig. 6(b) as an example, after the channel sensing on the PRACH resource 1 by the terminal device fails, if the number of consecutive failures of the previous channel sensing is less than or equal to the threshold, the terminal device may directly perform channel sensing on the PRACH resource 2 and send the first message when the sensing is successful; if the number of consecutive failures of channel sensing is greater than the threshold, the terminal device generates a backoff value based on the default backoff duration, so as to delay the backoff value on the PRACH resource 2 and then perform channel sensing, or directly perform channel sensing on the PRACH resource 2 and delay the backoff value when sensing is successful and then send the first message.

Of course, the number of times of the sensing failure may not be considered, but the terminal device needs to generate a backoff value based on the default backoff duration when a new PRACH resource arrives as long as the channel sensing fails on the PRACH resource last time, so as to delay the backoff value on the PRACH resource 2 and then perform channel sensing, or directly perform channel sensing on the PRACH resource 2 and delay the backoff value when sensing succeeds and then send the first message.

It should be understood that, in addition to the manner of determining the fallback information according to the number of listening failures shown in the above table i and table ii, after the terminal device counts the number of consecutive listening failures before, the fallback information may also be determined by other manners. For example, the terminal device may calculate the backoff duration and/or the length of the backoff window according to a certain formula based on the number of listening failures. The embodiment of the present application is not limited to this.

Mode 2

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

The trigger event of the random access procedure may include, for example, any one of the following: initial access; switching; reestablishing Radio Resource Control (RRC) connection; in the RRC connection state, when downlink data arrives, the uplink is in an 'asynchronous' state; in the RRC connection state, when uplink data arrives, the uplink is in an 'asynchronous' state; in an RRC connected state, no available physical uplink control channel PUCCH resource is used for transmitting a scheduling request SR; transition from RRC inactive state to active state; request other system information OSI; and recovering the beam failure.

When the priority of the trigger event of the random access procedure is higher, for example, 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 uses a smaller backoff window or backoff length.

Taking table three as an example, it is assumed that the length of the backoff window is carried in the backoff information. When the length of the backoff window is 0, it indicates that the terminal device does not need to perform a delay operation, that is, does not need to delay channel sensing and/or delay sending of the first message, but may perform channel sensing when the PRACH resource arrives and send the first message when sensing is successful. When the length of the backoff window is other non-0 values, it indicates that the terminal device needs to perform a delay operation and the length of the backoff window used when performing the delay operation is the value.

For example, when the trigger event of the pre-random access procedure to be initiated is RRC connection reestablishment, the terminal device may randomly select one PRACH resource for channel sensing within a time window with a length of 30ms after the new PRACH resource arrives, and send the first message on the selected PRACH resource when sensing is successful.

Watch III

It should be understood that only one type of length of the backoff window may be configured, i.e., the length of the backoff window is a default value. When the next PRACH resource comes, the terminal device either does not perform the delay operation or selects one PRACH resource for random access in a backoff window with a default length. Alternatively, the terminal device may determine whether to perform the delaying operation according to a trigger event of the random access to be initiated.

For example, taking fig. 5 as an example, after the channel interception on the PRACH resource 1 by the terminal device fails, 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 directly perform channel interception on the PRACH resource 2 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 smaller than the threshold, the terminal equipment randomly selects one PRACH resource in the backoff window with the default length to perform channel sensing.

Of course, the triggering event of random access may also not be considered, and as long as the terminal device fails to perform channel sensing on the PRACH resource last time, when a new PRACH resource arrives, it is necessary to select one PRACH resource in the backoff window of the default length for channel sensing.

Taking table four as an example, it is assumed that the backoff period is included in the backoff information. When the backoff duration is 0, it indicates that the terminal device does not need to perform the delay operation. That is, the terminal device does not need to delay channel sensing and/or send the first message, but can sense the channel when the PRACH resource arrives and send the first message when sensing is successful. When the backoff duration is other non-0 values, the indication indicates that the terminal device needs to perform the delay operation, and the backoff duration used when the delay operation is performed may be generated based on the non-0 values.

For example, when the triggering event in the current random access process is initial access, the terminal device may select a duration, for example, 30ms, within 0ms to 40ms, and then the terminal device may wait for 30ms to perform channel sensing after the new PRACH resource arrives, so as to send the first message when sensing is successful; alternatively, the terminal device may directly perform channel sensing after the new PRACH resource arrives, and wait for 30ms to send the first message when sensing is successful.

Watch four

It should be understood that only one backoff duration may be configured, i.e., the backoff duration is a default value. When the next PRACH resource comes, the terminal device either does not execute the delay operation, or generates a backoff value based on the default value, so as to delay the backoff value on the PRACH resource and then perform channel sensing, or directly perform channel sensing on the PRACH resource and delay the backoff value when sensing is successful and then send the first message. Alternatively, the terminal device may determine whether to perform the delaying operation according to a trigger event of the random access to be initiated.

For example, taking fig. 6(a) and fig. 6(b) as an example, after the channel sensing on the PRACH resource 1 by the terminal device fails, 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 directly perform channel sensing on the PRACH resource 2 and send the first message when the sensing is successful; if the priority of the trigger event of the random access to be initiated is less than the threshold, the terminal device generates a backoff value based on the default backoff duration, so as to delay the backoff value on the PRACH resource 2 and then perform channel sensing, or directly perform channel sensing on the PRACH resource 2 and delay the backoff value when sensing is successful and then send the first message.

Of course, the trigger event of random access may also be disregarded, and as long as the terminal device fails to perform channel sensing on the PRACH resource last time, when a new PRACH resource arrives, a backoff value needs to be generated based on the default backoff duration, so that the backoff value is delayed on the PRACH resource 2 before performing channel sensing, or the backoff value is delayed when sensing is successful after directly performing channel sensing on the PRACH resource 2 and then sending the first message.

Because the continuous failure times of different terminal devices in channel sensing before the channel sensing may be different, and/or the trigger event of the terminal device triggering the random access process may be different, the obtained backoff information may also be different, so that the time positions of channel sensing and sending the first message are also different, thereby greatly reducing the probability of sending resource collision in the random access process.

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 to perform channel sensing on the PRACH resource selected in the backoff window, the terminal device may perform channel sensing and/or send the first message on the next PRACH resource based on the backoff duration; or, if the terminal device does not succeed after delaying the channel sensing based on the backoff duration, the PRACH resource may be selected for the channel sensing in the backoff window.

It should also be understood that the method described in the embodiment of the present application may be used to send the first message in the random access procedure, but the present application is not limited thereto. Several other messages in the random access procedure need to satisfy the above channel sensing requirement, i.e. the LBT requirement, so the method can also be used to perform channel sensing and/or message sending for other messages in the random access procedure, for example, a second message (e.g. Msg 2), a third message (e.g. Msg 3), a fourth message (e.g. Msg 4), etc.

That is, the first message in the above methods may be replaced by another message in the random access procedure, and the terminal device sending the other message may determine the backoff information by using the above methods for transmitting the other message.

It should also be understood that the method of the embodiment of the present application may be applied to a 4-step random access procedure, and may also be applied to a 2-step random access procedure. Also, 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).

Fig. 7 is a schematic flow chart diagram of a method 700 of random access in an embodiment of the present application. The method described in fig. 7 may be performed by a network device, which may be, for example, network device 110 shown in fig. 1. As shown in fig. 7, the method 700 of random access may include some or all of the following steps. Wherein:

in 710, the network device determines backoff (backoff) information for the terminal device to send a first message in a random access procedure.

The backoff information is used to instruct the terminal device to delay a time range required to wait for channel sensing when a Physical Random Access Channel (PRACH) resource arrives, and/or delay the time range required to wait for sending the first message when the channel sensing is successful.

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

Therefore, before the terminal device initiates random access, the network device configures fallback information for sending a first message (e.g., Msg1) for the terminal device, where the fallback information is used to instruct the terminal device to delay a time range to wait for performing channel sensing when PRACH resources arrive and/or delay a time range to wait for sending the first message when channel sensing succeeds. The terminal device may perform channel sensing and/or messaging based on the fallback information. Since the fallback information may be different for different terminal devices, different terminal devices may send the first message at different time locations, thereby reducing the probability of resource collision.

Optionally, the determining, by the network device, fallback information for a terminal device to send a first message in a 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: and the network equipment determines the rollback information according to the continuous failure times of the terminal equipment for channel interception before the random access process.

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

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

It should be noted that, without conflict, the embodiments and/or technical features in the embodiments described in the present application may be arbitrarily combined with each other, and the technical solutions obtained after the combination also fall within the protection scope of the present application.

In the embodiments of the present application, the sequence numbers of the above-mentioned processes do not mean the execution sequence, and the execution sequence of each process should be determined by its function and inherent logic, and should not constitute any limitation to the implementation process of the embodiments of the present application.

Having described the communication method according to the embodiment of the present application in detail above, an apparatus according to the embodiment of the present application will be described below with reference to fig. 8 to 11, and the technical features described in the method embodiment are applicable to the following apparatus embodiments.

Fig. 8 is a schematic block diagram of a terminal device 800 according to an embodiment of the application. As shown in fig. 8, the terminal device 800 includes a processing unit 810 and a transceiving unit 720, wherein:

the processing unit 810 is configured to: determining backoff information for sending a first message in a random access process, wherein the backoff information is used for indicating a time range required by the terminal equipment to delay channel sensing when Physical Random Access Channel (PRACH) resources arrive, and/or delaying the time range required by sending the first message when channel sensing succeeds.

The transceiving unit 820 is configured to: and sending the first message based on the rollback information.

Therefore, before initiating random access, the terminal device determines backoff information for sending a first message (e.g., Msg1) in a random access procedure, where the backoff information is used to indicate a time range for the terminal device to wait for delaying channel sensing when PRACH resources arrive and/or a time range for waiting for delaying sending the first message when channel sensing succeeds. The terminal device may perform channel sensing and/or messaging based on the fallback information. Since the fallback information may be different for different terminal devices, different terminal devices may send the first message at different time locations, thereby reducing the probability of resource collision.

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

Optionally, the processing unit 810 is specifically configured to: and determining the rollback information according to the continuous failure times of channel interception before the random access process.

Optionally, the processing unit 810 is specifically configured to: and determining the rollback information according to a trigger event for triggering the random access process.

Optionally, the event triggering the random access includes any one of the following events: initial access; initial access; switching; reestablishing Radio Resource Control (RRC) connection; in the RRC connection state, when downlink data arrives, the uplink is in an 'asynchronous' state; in the RRC connection state, when uplink data arrives, the uplink is in an 'asynchronous' state; in an RRC connected state, no available physical uplink control channel PUCCH resource is used for transmitting a scheduling request SR; transition from RRC inactive state to active state; request other system information OSI; and recovering the beam failure.

Optionally, the transceiver 820 is further configured to: receiving indication information sent by a network device, wherein the indication information is used for indicating the rollback information; wherein the processing unit 810 is specifically configured to: and determining the rollback information according to the indication information.

Optionally, the backoff information includes information of a backoff window, where the backoff window includes at least one physical random access channel PRACH resource that can be used for sending the first message, and the processing unit 810 is further configured to: selecting one PRACH resource from the at least one PRACH resource in the backoff window; wherein the transceiver 820 is specifically configured to: and carrying out channel interception on the selected PRACH resource, and sending the first message on the PRACH resource when the interception is successful.

Optionally, the fallback information includes a fallback duration, where the transceiver 820 is specifically configured to: after the channel interception on the PRACH resource fails, carrying out channel interception on the next PRACH resource, and when the interception succeeds, delaying to send the first message according to the rollback duration; or, when the next PRACH resource arrives, delaying to perform channel sensing according to the backoff duration, and sending the first message when sensing is successful.

It should be understood that the terminal device 800 may perform corresponding operations performed by the terminal device in the method 400, and therefore, for brevity, detailed description is omitted here.

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 transceiving unit 920, wherein:

the processing unit 910 is configured to: determining backoff information used for a terminal device to send a first message in a random access process, wherein the backoff information is used for indicating that the terminal device delays a time range required by waiting for channel sensing when Physical Random Access Channel (PRACH) resources arrive, and/or delaying the time range required by sending the first message when the channel sensing is successful;

the transceiving unit 920 sends indication information, where the indication information is used to indicate the fallback information.

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

Optionally, the processing unit 910 is specifically configured to: and determining the rollback information according to the continuous failure times of the terminal equipment for carrying out channel monitoring on the PRACH resources before the random access process.

It should be understood that the communication device 900 can perform the corresponding operations performed by the network device in the method 700, and therefore, for brevity, the description is not repeated herein.

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 may call and execute 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. From the memory 1020, the processor 1010 may call and execute a computer program to implement the method in the embodiment of the present application.

The memory 1020 may be a separate device from the processor 1010 or may be integrated into 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 transmit information or data to the other devices or receive information or data transmitted by the other devices.

The transceiver 1030 may include a transmitter and a receiver, among others. 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 embodiment of the present application, and for brevity, details are not described here again.

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

Fig. 11 is a schematic structural diagram of a chip of 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. From the memory 1120, the processor 1110 can call and run a computer program to implement the method in the embodiment of the present application.

The memory 1120 may be a separate device from the processor 1110, or may be integrated into the processor 1110.

Optionally, the chip 1100 may also include an input interface 1130. The processor 1110 may control the input interface 1130 to communicate with other devices or chips, and in particular, 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, and in particular, 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 in the embodiment of the present application, and for brevity, details are not described here 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 in the embodiment of the present application, and for brevity, details are not described here again.

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

It should be understood that the processor of the embodiments of the present application may be an integrated circuit chip having signal processing capabilities. In implementation, the steps of the above method embodiments may be performed by integrated logic circuits of hardware in a processor or instructions in the form of software. The 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 (FPGA) or other Programmable logic device, discrete Gate or transistor logic device, or discrete hardware components. The various methods, steps, and logic blocks disclosed in the embodiments of the present application may be implemented or performed. 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 connection with the embodiments of the present application may be directly implemented by a hardware decoding processor, or implemented by a combination of hardware and software modules in the decoding processor. The software module may be located in ram, flash memory, rom, prom, or eprom, registers, etc. storage media as is well known in the art. The storage medium is located in a memory, and a processor reads information in the memory and completes the steps of the method in combination with hardware of the processor.

It will be appreciated that the memory in the embodiments of the subject application can be either volatile memory or nonvolatile memory, or can include both volatile and nonvolatile memory. The non-volatile Memory may be a Read-Only Memory (ROM), a Programmable ROM (PROM), an Erasable PROM (EPROM), an Electrically Erasable PROM (EEPROM), or a flash Memory. Volatile Memory can be Random Access Memory (RAM), which acts as 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 (DRAM), Synchronous Dynamic random access memory (Synchronous DRAM, SDRAM), Double Data Rate Synchronous Dynamic random access memory (DDR SDRAM), Enhanced Synchronous SDRAM (ESDRAM), Synchronous link SDRAM (SLDRAM), and Direct Rambus RAM (DR RAM). It should be noted that the memory of the systems and methods described herein is intended to comprise, without being limited to, these and any other suitable types of memory.

It should be understood that the above memories are exemplary but not limiting illustrations, for example, the memories in the embodiments of the present application may also be Static Random Access Memory (SRAM), dynamic random access memory (dynamic RAM, DRAM), Synchronous Dynamic Random Access Memory (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (enhanced SDRAM, ESDRAM), Synchronous Link DRAM (SLDRAM), Direct Rambus RAM (DR RAM), and the like. That is, the memory in the embodiments of the present application is intended to comprise, without being limited to, these and any other suitable types of memory.

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. Wherein:

the terminal device 1210 is configured to: and determining the fallback information for sending the first message in the random access process.

The network device 1220 is configured to: and determining the fallback information for the terminal equipment to send the first message in the random access process.

Specifically, the terminal device 1210 may be configured to implement corresponding functions implemented by the terminal device in the method 400, and the composition of the terminal device 1210 may be as shown in the terminal device 800 in fig. 8, which is not described herein again for brevity.

Specifically, the network device 1220 may be configured to implement corresponding functions implemented by the network device in the method 700, and the composition of the network device 1220 may be as shown in the network device 900 in fig. 9, which is not described herein again for brevity.

The embodiment of the application also provides a computer readable storage medium for storing the computer program.

Optionally, the computer-readable storage medium may be applied to the network device in the embodiment of the present application, and the computer program enables the computer to execute the corresponding process implemented by the network device in each method in the embodiment of the present application, which is not described herein again for brevity.

Optionally, the computer-readable storage medium may be applied to the terminal device in the embodiment of the present application, and the computer program enables the computer to execute the corresponding process implemented by the terminal device in each method in the embodiment of the present application, which is not described herein again for brevity.

Embodiments of the present application also provide a computer program product comprising computer program instructions.

Optionally, the computer program product may be applied to the terminal device in the embodiment of the present application, and the computer program instructions enable the computer to execute the corresponding processes implemented by the terminal device in the methods in the embodiment of the present application, which are not described herein again for brevity.

Optionally, the computer program product may be applied to the network device in the embodiment of the present application, and the computer program instructions enable the computer to execute corresponding processes implemented by the network device in the methods in the embodiment of the present application, which are not described herein again for brevity.

The embodiment of the application also provides a computer program.

Optionally, the computer program may be applied to the terminal device in the embodiment of the present application, and when the computer program runs on a computer, the computer is enabled to execute the corresponding process implemented by the terminal device in each method in the embodiment of the present application, and for brevity, details are not described here again.

Optionally, the computer program may be applied to the network device in the embodiment of the present application, and when the computer program runs on a computer, the computer is enabled to execute the corresponding process implemented by the network device in each method in the embodiment of the present application, and for brevity, details are not described here again.

It should be understood that the terms "system" and "network" are often used interchangeably herein. The term "and/or" herein is merely an association describing an associated object, meaning that three relationships may exist, e.g., a and/or B, may mean: a exists alone, A and B exist simultaneously, and B exists alone. In addition, the character "/" herein generally indicates that the former and latter related objects are in an "or" relationship.

It should also be understood that in the present embodiment, "B corresponding to" means that B is associated with a, from which B can be determined. It should also be understood that determining B from a does not mean determining B from a alone, but may be determined from a and/or other information.

Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

It is clear to those skilled in the art that, for convenience and brevity of description, the specific working processes of the above-described systems, apparatuses and units may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.

In the several embodiments provided in the present application, it should be understood that the disclosed system, apparatus and method may be implemented in other ways. For example, the above-described apparatus embodiments are merely illustrative, and for example, the division of the unit is only one logical functional division, and other divisions may be realized in practice, for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown 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 an electrical, mechanical or other form.

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.

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

The functions, if implemented in the form of software functional units and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present application or portions thereof that substantially contribute to the prior art may be embodied in the form of a software product stored in a storage medium and including instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method according to the embodiments of the present application. And the aforementioned storage medium includes: various media capable of storing program codes, such as a usb disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk, or an optical disk.

The above description is only for the specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present application, and shall be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

A method of random access, the method comprising:

the method comprises the steps that terminal equipment determines backspacing information used for sending a first message in a random access process, wherein the backspacing information is used for indicating that the terminal equipment delays a time range required by channel interception when Physical Random Access Channel (PRACH) resources arrive, and/or delaying the time range required by sending the first message when channel interception succeeds;

and the terminal equipment sends the first message based on the rollback information.
The method of claim 1, wherein the determining, by the terminal device, the fallback information for sending the first message in the random access procedure comprises:

and the terminal equipment determines the rollback information according to a preset rule.
The method of claim 2, wherein the terminal device determines the fallback information according to a predetermined rule, and comprises:

and the terminal equipment determines the rollback information according to the continuous failure times of channel interception before the random access process.
The method of claim 3, wherein the consecutive number of failures comprises a consecutive number of failures for channel sensing on a PRACH resource by the terminal device, and/or a consecutive number of failures for channel sensing on a data channel.
The method of claim 2, wherein the terminal device determines the fallback information according to a predetermined rule, and comprises:

and the terminal equipment determines the rollback information according to a trigger event for triggering the random access process.
The method according to claim 5, wherein the event triggering the random access comprises any one of the following events:

initial access;

switching;

reestablishing Radio Resource Control (RRC) connection;

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

in the RRC connection state, when uplink data arrives, the uplink is in an 'asynchronous' state;

in an RRC connected state, no available physical uplink control channel PUCCH resource is used for transmitting a scheduling request SR;

transition from RRC inactive state to active state;

request other system information OSI;

and recovering the beam failure.
The method of claim 1, further comprising:

the terminal equipment receives indication information sent by network equipment, wherein the indication information is used for indicating the rollback information;

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

and the terminal equipment determines the rollback information according to the indication information.
The method of claim 7, wherein the indication information is carried in system information, or wherein the indication information is a specific sequence.
The method according to any of claims 1 to 8, wherein the back-off information comprises information of a back-off window comprising at least one physical random access channel, PRACH, resource available for sending the first message,

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

the terminal equipment selects PRACH resources from the at least one PRACH resource in the backoff window;

and the terminal equipment carries out channel interception on the selected PRACH resource and sends the first message on the PRACH resource when the interception is successful.
The method according to any of claims 1 to 8, wherein the fallback information comprises a fallback duration,

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

the terminal equipment carries out channel interception on the next PRACH resource after the channel interception on the PRACH resource fails, and delays to send the first message according to the rollback duration when the channel interception is successful; alternatively, the first and second electrodes may be,

and the terminal equipment delays to carry out channel interception according to the backoff duration when the next PRACH resource arrives, and sends the first message when interception is successful.
A method of random access, the method comprising:

the network equipment determines back-off information used for a terminal equipment to send a first message in a random access process, wherein the back-off information is used for indicating a time range required by delaying channel interception when a Physical Random Access Channel (PRACH) resource of the terminal equipment arrives, and/or delaying the time range required by sending the first message when channel interception is successful;

and the network equipment sends indication information to the terminal equipment, wherein the indication information is used for indicating the rollback information.
The method of claim 11, wherein the network device determining the fallback information for the terminal device to send the first message in the random access procedure comprises:

the network device determines the fallback information according to a predetermined rule.
The method of claim 12, wherein the network device determines the fallback information according to a predetermined rule, comprising:

and the network equipment determines the rollback information according to the continuous failure times of the terminal equipment for channel interception before the random access process.
The method according to claim 13, wherein the number of consecutive failures comprises a number of consecutive failures for channel sensing on the PRACH resource by the terminal device and/or a number of consecutive failures for channel sensing on the data channel.
The method according to any one of claims 11 to 14, wherein the indication information is carried in system information, or wherein the indication information is a specific sequence.
A terminal device, characterized in that the terminal device comprises:

the processing unit is used for determining backoff information used for sending a first message in a random access process, wherein the backoff information is used for indicating that the terminal equipment delays a time range required by waiting for channel sensing when Physical Random Access Channel (PRACH) resources arrive and/or delaying the time range required by sending the first message when the channel sensing is successful;

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

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

and determining the rollback information according to the continuous failure times of channel interception before the random access process.
The terminal device of claim 18, wherein the consecutive number of failures comprises a consecutive number of failures for channel sensing on a PRACH resource by the terminal device and/or a consecutive number of failures for channel sensing on a data channel.
The terminal device of claim 17, wherein the processing unit is specifically configured to:

and determining the rollback information according to a trigger event for triggering the random access process.
The terminal device according to claim 20, wherein the event triggering the random access comprises any one of the following events:

initial access;

switching;

reestablishing Radio Resource Control (RRC) connection;

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

in the RRC connection state, when uplink data arrives, the uplink is in an 'asynchronous' state;

in an RRC connected state, no available physical uplink control channel PUCCH resource is used for transmitting a scheduling request SR;

transition from RRC inactive state to active state;

request other system information OSI;

and recovering the beam failure.
The terminal device according to claim 16, wherein the transceiver unit is further configured to:

receiving indication information sent by a network device, wherein the indication information is used for indicating the rollback information;

wherein the processing unit is specifically configured to:

and determining the rollback information according to the indication information.
The terminal device according to claim 22, wherein the indication information is carried in system information, or wherein the indication information is a specific sequence.
The terminal device according to any of claims 16 to 23, wherein the back-off information comprises information of a back-off window comprising at least one physical random access channel, PRACH, resource available for sending the first message,

wherein the processing unit is further to:

selecting one PRACH resource from the at least one PRACH resource in the backoff window;

wherein the transceiver unit is specifically configured to:

and carrying out channel interception on the selected PRACH resource, and sending the first message on the PRACH resource when the interception is successful.
The terminal device according to any of claims 16 to 23, wherein the fallback information comprises a fallback duration,

wherein the transceiver unit is specifically configured to:

after the channel interception on the PRACH resource fails, carrying out channel interception on the next PRACH resource, and when the interception succeeds, delaying to send the first message according to the rollback duration; alternatively, the first and second electrodes may be,

and when the next PRACH resource arrives, delaying to carry out channel monitoring according to the backoff duration, and sending the first message when the monitoring is successful.
A network device, characterized in that the network device comprises:

the processing unit is used for determining backoff information used for a terminal device to send a first message in a random access process, wherein the backoff information is used for indicating the terminal device to delay a time range required by channel sensing when Physical Random Access Channel (PRACH) resources arrive and/or delaying the time range required by sending the first message when channel sensing is successful;

and the transceiver unit is used for sending indication information to the terminal equipment, wherein the indication information is used for indicating the rollback information.
The network device of claim 26, wherein the processing unit is specifically configured to:

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

and determining the rollback information according to the continuous failure times of the terminal equipment for channel interception before the random access process.
The network device of claim 28, wherein the consecutive number of failures comprises a consecutive number of failures for channel sensing on a PRACH resource by the terminal device and/or a consecutive number of failures for channel sensing on a data channel.
The network device according to any of claims 26 to 29, wherein the indication information is carried in system information or the indication information is a specific sequence.
A terminal device, characterized in that the terminal device comprises a processor and a memory for storing a computer program, the processor being adapted to invoke and execute the computer program stored in the memory to perform the method of any of claims 1 to 10.
A network device comprising a processor and a memory, the memory storing a computer program, the processor being configured to invoke and execute the computer program stored in the memory to perform the method of any of claims 11 to 15.
A chip, characterized in that it comprises a processor for calling up and running a computer program from a memory, causing a device in which the chip is installed to perform the method of any of claims 1 to 10, or to perform the method of any of claims 11 to 15.
A computer-readable storage medium for storing a computer program which causes a computer to perform the method of any one of claims 1 to 10 or to perform the method of any one of claims 11 to 15.
A computer program product comprising computer program instructions to cause a computer to perform the method of any of claims 1 to 10 or to perform the method of any of claims 11 to 15.
A computer program, characterized in that the computer program causes a computer to perform the method of any of claims 1 to 10, or to perform the method of any of claims 11 to 15.
A communication system comprising a terminal device according to any of claims 16 to 25 and a network device according to any of claims 26 to 30.