WO2020252633A1

WO2020252633A1 - Backoff method, device and system for random access preamble

Info

Publication number: WO2020252633A1
Application number: PCT/CN2019/091577
Authority: WO
Inventors: 路杨
Original assignee: 富士通株式会社; 路杨
Priority date: 2019-06-17
Filing date: 2019-06-17
Publication date: 2020-12-24

Abstract

Provided in an embodiment of the present application are a backoff method, device and system for a random access preamble. The method comprises: when initiating a two-step random access procedure, a terminal device transmitting a first message to a network device, the first message comprising a two-step random access preamble and data; the terminal device receiving backoff indicator information transmitted by the network device; if the two-step random access procedure was not successfully completed, the terminal device performing a backoff procedure according to the backoff indicator information before transmitting a two-step or four-step random access preamble next time.

Description

Method, device and system for random access preamble back-off

Technical field

The embodiments of the present application relate to the field of communications.

Background technique

In the fifth-generation new wireless key technical indicators (5G NR KPI) defined by the International Telecommunication Union (ITU), the connection density of the massive machine type communication (mMTC) scenario needs to reach 1 million terminal devices/square kilometer, which is ultra-high and reliable. The delay of the ultra-low delay service in URLLC needs to be less than 1ms. Among them, the mMTC scenario requires a low-cost, low-signaling overhead, low-latency, and low-power communication system, because a large number of uplink small data packet bursts generated by massive machine-type communication terminal equipment need to pass random The access is sent to the network, and if it is based on the traditional 4-step random access (4-step RA) method and orthogonal multiple access technology, the air interface signaling overhead and transmission delay are relatively large; similarly, the business of the uRLLC scenario is mainly It is a periodic or event-triggered small data packet, and random access is used to send uplink data with a high probability. The existing 4-step random access method cannot meet the requirements of low signaling overhead and low delay. In addition, for vehicle-to-vehicle communication (V2V) and enhanced mobile broadband (eMBB) application scenarios, there may also be small data packet services, and the transmission under the 4-step random access mode is also inefficient. In addition, in the unlicensed spectrum, because the channel access is based on the wireless fidelity (WiFi) carrier monitoring technology's listen before talk (LBT) mechanism, when the network device or terminal device detects that the channel is idle, that is, when the LBT is successful Before sending the signal, using the existing 4-step random access method will greatly affect the access success rate and access delay.

2-step random access (2-step RA) method and non-orthogonal multiple access technology are general solutions for reducing random access signaling overhead and delay, which can eliminate the uplink scheduling process during random access , Especially for small data packets and unlicensed frequency band services, there are obvious efficiency improvements. It can meet the needs of low cost, low power consumption, and massive small data packets in the application scenarios of massive large connection mMTC in the future, and meet the low latency and low power of frequent small data packets and random burst services in eMBB, uRLLC, V2V and other application scenarios Consumption requirements are generally applicable to random access to unlicensed spectrum and licensed spectrum.

It should be noted that the above introduction to the technical background is only for the convenience of a clear and complete description of the technical solution of the present application, and to facilitate the understanding of those skilled in the art. It should not be considered that the above technical solutions are well-known to those skilled in the art just because these solutions are described in the background art part of this application.

Summary of the invention

The inventor found that after the terminal device sends the 2-step CBRA preamble, it may receive the MsgB or fall-back random access response sent by the network device. At the same time, the network device can send a backoff indication (BI) to the terminal device when sending the random access response according to the load on the 2-step random access resource to instruct the terminal device to send the 2-step random access next time Backoff before preamble or 4-step random access preamble. However, the related art only provides a back-off method for the preamble of the traditional 4-step random access process, and does not disclose the back-off mechanism of the preamble of the 2-step random access process.

In order to solve at least one of the above-mentioned problems or solve other similar problems, embodiments of the present application provide a random access preamble backoff method, device, and system. In the 2-step CBRA process, the network device randomly The load situation on the access resource and/or 4-step random access resource, send backoff instruction information to the terminal device, and the terminal device will send the 2-step random access preamble or 4-step random access next time according to the backoff instruction information Back off before the preamble.

According to the first aspect of the embodiments of the present application, there is provided a random access preamble backoff method, wherein the method includes:

The terminal device sends a first message to the network device when initiating two-step random access, where the first message includes a two-step random access preamble and data;

Receiving, by the terminal device, backoff instruction information sent by the network device;

In the case where the two-step random access is not successfully completed, the terminal device performs back-off according to the back-off instruction information before sending the next two-step or four-step random access preamble.

According to a second aspect of the embodiments of the present application, there is provided a random access preamble back-off method, wherein the method includes:

The network device receives a first message (MsgA) sent when the terminal device initiates two-step random access, where the first message includes a two-step random access preamble and data;

The network device sends backoff instruction information to the terminal device, where the backoff instruction information is used to instruct the terminal device that has not successfully completed the two-step random access to backoff before the next two-step or four-step random access preamble is sent.

According to a third aspect of the embodiments of the present application, there is provided an apparatus for random access preamble back-off, which is configured in a terminal device, wherein the apparatus includes:

A sending unit, which sends a first message to the network device when the terminal device initiates two-step random access, where the first message includes a two-step random access preamble and data;

A receiving unit, which receives backoff instruction information sent by the network device;

When the terminal device fails to successfully complete the two-step random access, the sending unit performs backoff before sending the two-step or four-step random access preamble next time according to the backoff instruction information.

According to a fourth aspect of the embodiments of the present application, there is provided an apparatus for random access preamble back-off, which is configured in a network device, wherein the apparatus includes:

A receiving unit, which receives a first message (MsgA) sent by the terminal device when initiating a two-step random access, the first message including a two-step random access preamble and data;

A sending unit that sends backoff instruction information to the terminal device, where the backoff instruction information is used to indicate that the terminal device that has not successfully completed the two-step random access performs backoff before sending the two-step or four-step random access preamble next time.

According to a fifth aspect of the embodiments of the present application, there is provided a terminal device, wherein the terminal device includes the device described in the foregoing third aspect.

According to a sixth aspect of the embodiments of the present application, there is provided a network device, wherein the network device includes the apparatus described in the foregoing fourth aspect.

According to a seventh aspect of the embodiments of the present application, a communication system is provided, the communication system including the terminal device described in the fifth aspect and the network device described in the sixth aspect.

According to other aspects of the embodiments of the present application, there is provided a computer-readable program, wherein when the program is executed in a terminal device, the program causes the computer to execute the method described in the first aspect in the terminal device .

According to other aspects of the embodiments of the present application, there is provided a storage medium storing a computer-readable program, wherein the computer-readable program enables a computer to execute the method described in the foregoing first aspect in a terminal device.

According to other aspects of the embodiments of the present application, a computer-readable program is provided, wherein when the program is executed in a network device, the program causes the computer to execute the method described in the foregoing second aspect in the network device .

According to other aspects of the embodiments of the present application, there is provided a storage medium storing a computer-readable program, wherein the computer-readable program enables a computer to execute the method described in the foregoing second aspect in a network device.

One of the beneficial effects of the embodiments of this application is that in the 2-step CBRA process, the network device sends a backoff instruction to the terminal device according to the load on the 2-step random access resource and/or the 4-step random access resource According to the backoff instruction information, the terminal device performs backoff before sending the 2-step random access preamble or 4-step random access preamble next time, thereby providing a backoff mechanism for the preamble of the 2-step random access process .

With reference to the following description and drawings, specific implementations of the application are disclosed in detail, and the manner in which the principles of the application can be adopted is indicated. It should be understood that the scope of the implementation of the present application is not limited thereby. Within the scope of the spirit and terms of the appended claims, the implementation of the present application includes many changes, modifications and equivalents.

Features described and/or shown for one embodiment can be used in one or more other embodiments in the same or similar manner, combined with features in other embodiments, or substituted for features in other embodiments .

It should be emphasized that the term "comprising/comprising" when used herein refers to the existence of features, components, steps or components, but does not exclude the existence or addition of one or more other features, components, steps or components.

Description of the drawings

The elements and features described in one drawing or one embodiment of the embodiment of the present application may be combined with the elements and features shown in one or more other drawings or embodiments. In addition, in the drawings, similar reference numerals indicate corresponding parts in several drawings, and may be used to indicate corresponding parts used in more than one embodiment.

The included drawings are used to provide a further understanding of the embodiments of the present application, which constitute a part of the specification, are used to illustrate the embodiments of the present application, and together with the text description, explain the principle of the present application. Obviously, the drawings in the following description are only some embodiments of the application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative work. In the attached picture:

Fig. 1 is a schematic diagram of a communication system according to an embodiment of the present application;

Figure 2 is a schematic diagram of a 4-step random access method;

Figure 3 is a schematic diagram of a 2-step random access method;

Figure 4 is a schematic diagram of a fallback from 2-step random access to 4-step random access;

FIG. 5 is a schematic diagram of a random access preamble back-off method according to an embodiment of the first aspect of the present application;

Fig. 6 is a schematic diagram of a scenario of random access preamble backoff;

Figure 7 is a schematic diagram of another scenario of random access preamble backoff;

FIG. 8 is a schematic diagram of another scenario of random access preamble backoff;

FIG. 9 is a schematic diagram of another scenario of random access preamble backoff;

FIG. 10 is a schematic diagram of a random access preamble back-off method according to an embodiment of the second aspect of the present application;

FIG. 11 is a schematic diagram of an apparatus for random access preamble back-off in an embodiment of the third aspect of the present application;

FIG. 12 is a schematic diagram of a random access preamble back-off apparatus according to an embodiment of the fourth aspect of the present application;

FIG. 13 is a schematic diagram of a terminal device according to an embodiment of the fifth aspect of the present application;

Fig. 14 is a schematic diagram of a network device according to an embodiment of the sixth aspect of the present application.

Detailed ways

With reference to the drawings, the foregoing and other features of this application will become apparent through the following description. In the specification and drawings, specific implementations of the application are specifically disclosed, which indicate some implementations in which the principles of the application can be adopted. It should be understood that the application is not limited to the described implementations, on the contrary, the The application includes all modifications, variations and equivalents falling within the scope of the appended claims.

In the embodiments of this application, the terms "first", "second", etc. are used to distinguish different elements from the terms, but they do not indicate the spatial arrangement or temporal order of these elements. These elements should not be used by these terms. Limited. The term "and/or" includes any and all combinations of one or more of the associated listed terms. The terms "comprising", "including", "having" and the like refer to the existence of the stated features, elements, elements or components, but do not exclude the presence or addition of one or more other features, elements, elements or components.

In the embodiments of the present application, the singular forms "a", "the", etc. include plural forms, which should be broadly understood as "a" or "a type" rather than being limited to the meaning of "a"; in addition, the term "so" "Said" should be understood to include both singular and plural forms, unless the context clearly indicates otherwise. In addition, the term "based on" should be understood as "based at least in part on..." and the term "based on" should be understood as "based at least in part on..." unless the context clearly dictates otherwise.

In the embodiments of this application, the term "communication network" or "wireless communication network" may refer to a network that meets any of the following communication standards, such as Long Term Evolution (LTE), and Enhanced Long Term Evolution (LTE-A, LTE-A). Advanced), Wideband Code Division Multiple Access (WCDMA, Wideband Code Division Multiple Access), High-Speed Packet Access (HSPA, High-Speed Packet Access), etc.

Moreover, the communication between devices in the communication system can be carried out according to any stage of communication protocol, for example, it can include but not limited to the following communication protocols: 1G (generation), 2G, 2.5G, 2.75G, 3G, 4G, 4.5G and future 5G, New Radio (NR, New Radio), etc., and/or other currently known or future communication protocols.

In the embodiments of the present application, the term "network device" refers to, for example, a device in a communication system that connects a terminal device to a communication network and provides services for the terminal device. Network equipment may include but is not limited to the following equipment: base station (BS, Base Station), access point (AP, Access Point), transmission and reception point (TRP, Transmission Reception Point), broadcast transmitter, mobile management entity (MME, Mobile Management Entity), gateway, server, radio network controller (RNC, Radio Network Controller), base station controller (BSC, Base Station Controller), etc.

Among them, the base station may include but is not limited to: Node B (NodeB or NB), evolved Node B (eNodeB or eNB), 5G base station (gNB), etc., and may also include remote radio head (RRH, Remote Radio Head) , Remote Radio Unit (RRU, Remote Radio Unit), relay (relay) or low-power node (such as femto, pico, etc.). And the term "base station" can include some or all of their functions, and each base station can provide communication coverage for a specific geographic area. The term "cell" may refer to a base station and/or its coverage area, depending on the context in which the term is used.

In the embodiments of the present application, the term "User Equipment" (UE, User Equipment) refers to, for example, a device that accesses a communication network through a network device and receives network services, and may also be referred to as "Terminal Equipment" (TE, Terminal Equipment). The terminal equipment can be fixed or mobile, and can also be called a mobile station (MS, Mobile Station), terminal, user, subscriber station (SS, Subscriber Station), access terminal (AT, Access Terminal), station, etc. Wait.

Among them, terminal devices may include but are not limited to the following devices: cellular phones (Cellular Phone), personal digital assistants (PDAs, Personal Digital Assistant), wireless modems, wireless communication devices, handheld devices, machine-type communication devices, laptop computers, Cordless phones, smart phones, smart watches, digital cameras, etc.

For another example, in scenarios such as the Internet of Things (IoT), a terminal device may also be a machine or device that performs monitoring or measurement. For example, it may include, but is not limited to: Machine Type Communication (MTC) terminals, Vehicle-mounted communication terminals, device to device (D2D, Device to Device) terminals, machine to machine (M2M, Machine to Machine) terminals, etc.

The following describes the scenarios of the embodiments of the present application through examples, but the embodiments of the present application are not limited thereto.

FIG. 1 is a schematic diagram of a communication system according to an embodiment of the present application, which schematically illustrates a case where a terminal device and a network device are taken as an example. As shown in FIG. 1, the communication system 100 may include: a network device 101 and a terminal device 102. For the sake of simplicity, Figure 1 only uses one terminal device as an example for illustration. The network device 101 is, for example, the network device gNB in the NR system.

In the embodiment of the present application, existing services or services that can be implemented in the future can be performed between the network device 101 and the terminal device 102. For example, these services include but are not limited to: enhanced mobile broadband (eMBB, enhanced Mobile Broadband), large-scale machine type communication (mMTC, massive Machine Type Communication), and high-reliability and low-latency communication (URLLC, Ultra-Reliable and Low- Latency Communication), etc.

Wherein, the terminal device 102 may send data to the network device 101, for example, using an unauthorized transmission mode. The network device 101 can receive data sent by one or more terminal devices 102, and feedback information (for example, acknowledgement ACK/non-acknowledgement NACK) information to the terminal device 102, and the terminal device 102 can confirm the end of the transmission process according to the feedback information, or can further Perform new data transmission, or data retransmission can be performed.

Figure 2 is a schematic diagram of a 4-step contention-based random access (4-step CBRA) method. As shown in Figure 2, in 4-step CBRA, the first step is that the terminal device selects the preamble for random access (preamble), send the preamble (Msg1) in the contention-based random access opportunity (RO, Random access Occasion) pre-configured by the system; in the second step, the network device will send a random access response (RAR) after receiving the preamble. , Random Access Response) (Msg2), the terminal device authorized to send the preamble has a dedicated uplink resource (such as physical uplink shared channel resource, referred to as PUSCH resource) and allocates a temporary cell radio network temporary identifier (called temporary C-RNTI or TC) -RNTI), indicating the uplink advance of the PUSCH; the third step, the terminal device sends a message (msg3) carrying signaling or data on the PUSCH resource; the fourth step, if the msg3 is successfully received, the network device sends the target This msg3 contention resolution signaling (msg4).

Figure 3 is a schematic diagram of a 2-step contention-based random access method (2-step CBRA). As shown in Figure 3, in 2-step CBRA, in the first step, the terminal device sends MsgA, and MsgA includes a random access method. Incoming preamble (referred to as MsgA preamble) and data part (MsgA signaling or service data, payload, referred to as MsgA data), the terminal device can send MsgA preamble in the competing RO and send MsgA in the competing PUSCH resource Signaling or service data; in the second step, the network device sends MsgB after receiving the MsgA, and sends a random access response and contention resolution message to the terminal device through the MsgB. Therefore, in the two-step contention-based random access method, the terminal equipment can transmit without uplink scheduling during the random access process, upload signaling or service data in one step, and reduce random access signaling and delay.

On the other hand, the network equipment can demodulate the MsgA data through the demodulation reference signal (DMRS, Demodulation Reference Signal) sent on the PUSCH resource of the MsgA data, where the DMRS sequence is the same as the sequence index used by the MsgA preamble sent by the terminal device ( index) related, the network device can obtain the DMRS corresponding to the preamble sequence index (preamble index) according to the preamble demodulated in the RO resource. In addition, if multiple terminal devices select different preamble sequence indexes (preamble index) in 2-step CBRA and transmit MsgA data on the same PUSCH resource, the network device can demodulate the DMRS corresponding to the preamble sequence index (preamble index) Output MsgA data.

However, because the demodulation performance of the preamble is higher than the demodulation of different PUSCH data based on DMRS on the same PUSCH resource, it may happen that the network device can successfully demodulate the MsgA preamble, but the demodulation of the MsgA data fails. If 2-step CBRA fails and falls back to 4-step CBRA, the network device will send a fall-back random access response (Msg2) to the terminal device to make the terminal device resend the data part of MsgA.

Figure 4 is a schematic diagram of the fallback from 2-step CBRA to 4-step CBRA. As shown in Figure 4, after receiving the MsgA sent by the terminal device, the network device feeds back Msg2 to the terminal device. Therefore, the random access process starts from 2-step CBRA is rolled back to 4-step CBRA, and the follow-up process is the same as 4-step CBRA.

Various embodiments of the present application will be described below in conjunction with the drawings. These implementation manners are only exemplary, and are not limitations to the application.

Embodiments of the first aspect

The embodiment of the first aspect of the present application provides a random access preamble backoff method, which is applied to terminal equipment. FIG. 5 is a schematic diagram of the random access preamble backoff method of this embodiment. Please refer to FIG. 5, the method includes:

Operation 501: the terminal device sends a first message (MsgA) to the network device when initiating two-step random access, where the first message includes the two-step random access preamble and data;

Operation 502: the terminal device receives backoff instruction information sent by the network device;

Operation 503: The terminal device performs backoff according to the backoff instruction information before sending a two-step or four-step random access preamble next time when the two-step random access is not successfully completed.

In operation 501, in one or more embodiments, the terminal device will initiate a two-step random access in at least one of the following situations:

The initial access of the terminal equipment in the radio resource control (RRC) idle state;

Re-establish the RRC connection of the terminal device;

Switching of terminal equipment;

The terminal device has uplink or downlink data to send in the RRC connection state, but the uplink is in an asynchronous state;

Access of terminal equipment in the RRC inactive state; and

The terminal device initiates a system information request or beam failure recovery (Beam Failure Recovery).

In the 2-step random access process, the network equipment accesses resources according to 2-step random access (PRACH occasion and PUSCH occasion, PRACH occasion is used to send 2-step random access preamble, and PUSCH occasion is used to send data) and/ Or the load condition on the 4-step random access resource (PRACH occasion, used to send the 4-step random access preamble), and send backoff indication information to the terminal device. The terminal device receives the backoff instruction information sent by the network device, and performs backoff according to the backoff instruction information before sending the 2-step random access preamble or the 4-step random access preamble next time. This provides a preamble back-off mechanism for the 2-step random access process.

In an embodiment of operation 503, if the terminal device receives the first random access response (that is, the fall-back random access response), it means that the terminal device has not successfully completed the two-step random access initiated in operation 501. The terminal device falls back to the four-step random access process. If the terminal device does not successfully complete the four-step random access process, for example, the terminal device does not receive the four-step random access contention resolution information, the terminal device will send four Before the random access preamble, backoff is performed according to the backoff instruction information; wherein, the first random access response includes the uplink resource grant for the terminal device to send the second message (msg3), and the cell wireless network temporary identifier (TC- RNTI) and time advance command; if the terminal device does not receive the first random access response, for example, the terminal device does not receive the second random access response (that is, MsgB) and the first random access response, or the terminal device If the second random access response is received but the contention resolution information contained in the second random access response does not match the information in the above-mentioned first message, it indicates that the terminal device has not successfully completed the two-step random access initiated in operation 501. Then the terminal device continues the two-step random access process, and performs backoff according to the foregoing backoff instruction information before sending the next two-step random access preamble.

In another embodiment of operation 503, if the terminal device receives the first random access response (that is, the fall-back random access response), it means that the terminal device has not successfully completed the two-step random access initiated in operation 501. If the terminal device does not successfully complete the four-step random access process, for example, the terminal device does not receive the four-step random access contention resolution information, it will perform the same as the previous one. The example is different, the terminal device does not back-off before sending the four-step random access preamble next time; wherein, the first random access response includes the uplink resource authorization for the terminal device to send the second message (msg3), the temporary wireless network of the cell Identification (TC-RNTI) and time advance command; if the terminal device does not receive the first random access response, for example, the terminal device does not receive the first random access response and the second random access response (ie MsgB), Or, if the terminal device receives the second random access response but the contention resolution information contained in the second random access response does not match the information in the first message, it indicates that the terminal device has not successfully completed the two steps initiated in operation 501 For random access, the terminal device continues the two-step random access process, and performs backoff according to the foregoing backoff instruction information before sending the next two-step random access preamble.

According to the embodiment of the first aspect of the present application, the terminal device falls back to the four-step random access process when it fails to successfully complete the two-step random access process, or continues the two-step random access process, if it falls back to the four-step random access process In the random access process, if the four-step random access process is not successfully completed, back-off or no back-off is performed before the next four-step random access preamble is sent; if the two-step random access process is continued, the following Back off before sending two-step random access preamble at a time. This provides a preamble back-off mechanism for the 2-step random access process.

In the embodiment of the first aspect of the present application, if the terminal device falls back to the four-step random access process, the terminal device also sends a second message (msg3) to the network device. In one or more embodiments, the terminal device The first message data buffer of the two-step random access that is not completed successfully sends the second message, for example:

In one or more embodiments, the terminal device directly copies the media access control protocol data unit (MAC PDU) data packet in the data buffer of the first message to the data buffer of the second message, and then copies the above The MAC PDU data packet is sent as the hybrid automatic repeat request (HARQ) new transmission data of the second message.

In one or more embodiments, the terminal device directly sends the MAC PDU data packet in the data buffer of the first message as the HARQ newly transmitted data of the second message.

In one or more embodiments, the terminal device assembles a new MAC PDU data packet according to the uplink resource authorization in the first random access response. If the MAC PDU data packet in the data buffer of the first message contains a media access control service data unit (MAC SDU) or a C-RNTI MAC control unit (MAC CE), then the MAC SDU or the C-RNTI MAC The CE is assembled into a new MAC PDU data packet. Put the new MAC PDU data packet into the data buffer of the second message; send the new MAC PDU data packet as HARQ new transmission data of the second message.

The above several embodiments are just examples, and the terminal device may also send the above second message (msg3) in other ways.

In the embodiment of the first aspect of the present application, the terminal device performs backoff according to the backoff instruction information before sending the two-step or four-step random access preamble next time. In one or more embodiments, the terminal device performs backoff based on the backoff instruction information. Set the preamble backoff value, and when it is determined that the above two-step random access process is unsuccessful, choose one from 0 to the preamble backoff value as the backoff time for sending the above two or four-step random access preamble, and then The aforementioned two-step or four-step random access preamble is not sent within the back-off time, thereby completing the back-off action. This application is not limited to this, and the terminal device can also back off according to other principles according to the back off instruction information.

In one or more embodiments, the foregoing preamble backoff value includes the backoff value before the terminal device sends the four-step random access preamble and/or the backoff value before the terminal device sends the two-step random access preamble. For example, in one or more embodiments, the terminal device sets the backoff values for the two-step random access preamble and the four-step random access preamble respectively, and when the two-step random access preamble is sent the next time, the two-step random access preamble is used. The backoff value of the random access preamble is used for backoff. When the four-step random access preamble is sent next time, the backoff value for the four-step random access preamble is used for backoff. For another example, in one or more embodiments, the terminal device only sets a backoff value, and the backoff value is used for backoff regardless of whether the next two-step random access preamble or the four-step random access preamble is sent next.

In one or more embodiments of operation 502, the terminal device monitors the physical downlink control channel (PDCCH) scrambled by the random access RNTI, and if the PDCCH scrambled by the random access RNTI is detected, and scheduled by the PDCCH The random access response MAC PDU contains the back-off instruction information field, and the terminal device obtains the back-off instruction information from the back-off instruction information field. Wherein, the random access RNTI may be related to the random access opportunity time-frequency resource location of the random access preamble of the first message sent by the terminal device and the uplink carrier, or may also be related to the type of machine access response. This application is not limited to this, and the random access RNTI can also be related to other conditions.

In one or more embodiments, the foregoing back-off indication information field includes a two-step random access back-off indication information field and/or a four-step random access back-off indication information field, where the two-step random access back-off indication information field includes The back-off instruction information is used to indicate the back-off for two-step random access, that is, the terminal device accordingly performs the back-off instruction information in the two-step random access back-off instruction information field before sending the two-step random access preamble next time Backoff; the backoff instruction information contained in the four-step random access backoff indication information field is used to indicate the backoff for the four-step random access, that is, the terminal device according to this before sending the four-step random access preamble next time The four-step random access backoff instruction information in the backoff instruction information field performs backoff.

In one or more embodiments, in addition to the foregoing backoff indication information field, the foregoing random access response MAC PDU also includes a random access response (first random access response or second random access response) for the terminal device, That is, the backoff indication information of the terminal device and the random access response (first random access response or second random access response) of the terminal device are multiplexed in the same RAR MAC PDU, then in operation 503, the terminal device Before the next two-step or four-step random access preamble is sent, back-off is performed according to the back-off indication information in the RAR MAC PDU.

In one or more embodiments, in addition to the foregoing backoff indication information field, the foregoing random access response MAC PDU also includes random access responses (first random access response or second random access response) for other terminal devices. That is, the backoff indication information of the terminal device and the random access response (first random access response or second random access response) of the terminal device are multiplexed in different RAR MAC PDUs, then in operation 503, the terminal Before sending the two-step or four-step random access preamble next time, the device performs back-off according to the back-off indication information in the RAR MAC PDU.

In the embodiments of the first aspect of the present application, since the content and format of the first random access response and the second random access response are different, in one or more embodiments, different random access responses are carried by different random access responses. MAC PDU.

In one or more embodiments, the aforementioned random access response MAC PDU includes two RAR MAC PDUs, which are called the first RAR MAC PDU and the second RAR MAC PDU. The first RAR MAC PDU contains the first random access response for the aforementioned terminal device or the first random access response for other terminal devices, that is, the first RAR MAC PDU only carries the first random access response; the second RAR The MAC PDU contains the second random access response for the aforementioned terminal device or the second random access response for other terminal devices, that is, the second RAR MAC PDU only carries the second random access response. The foregoing backoff instruction information field is included in the first RAR MAC PDU, or included in the second RAR MAC PDU, or both the first RAR MAC PDU and the second RAR MAC PDU include the back off instruction information field. According to the backoff indication information contained in the first RAR MAC PDU or the second RAR MAC PDU, the terminal device performs backoff before sending the two-step or four-step random access preamble next time.

For example, the terminal device performs backoff according to the backoff indication information in the first RAR MAC PDU before sending the two-step or four-step random access preamble next time. That is, regardless of whether the terminal device sends a two-step random access preamble or a four-step random access preamble next time, it will use the backoff indication information in the first random access response MAC PDU to back off, regardless of the second RAR MAC Whether the PDU contains backoff indication information.

For another example, the terminal device performs backoff according to the backoff indication information in the second RAR MAC PDU before sending the two-step or four-step random access preamble next time. That is, regardless of whether the terminal device sends the two-step random access preamble or the four-step random access preamble next time, the backoff indication information in the second random access response MAC PDU is used for backoff, regardless of the first RAR MAC Whether the PDU contains backoff indication information.

For another example, if the terminal device sends a two-step random access preamble next time, the terminal device will back off before sending the two-step random access preamble according to the backoff indication information in the first RAR MAC PDU. If the terminal device next time After sending the four-step random access preamble, the terminal device performs backoff according to the back-off indication information in the second RAR MAC PDU before sending the four-step random access preamble next time.

For another example, if the terminal device sends the four-step random access preamble next time, the terminal device will back off according to the backoff indication information in the first RAR MAC PDU before sending the four-step random access preamble next time. If the two-step random access preamble is sent, the terminal device will back off according to the back-off indication information in the second RAR MAC PDU before sending the two-step random access preamble next time.

In the embodiment of this application, in order to make the first random access response and the second random access response use different RAR MAC PDU bearers, the PDCCH used to schedule the first RAR MAC PDU and the second RAR MAC PDU uses different random Access RNTI scrambling; or, the PDCCH used to schedule the first RAR MAC PDU and the second RAR MAC PDU use different search spaces or CORESET; or, the PDCCH used to schedule the first RAR MAC PDU and the second RAR MAC PDU Use different DCI formats or DCI domains.

For example, the PDCCH used to schedule the first RAR MAC PDU is scrambled by the first random access RNTI, the PDCCH used to schedule the second RAR MAC PDU is scrambled by the second random access RNTI, and the first random access RNTI is scrambled with the first random access RNTI. 2. The random access RNTI is different.

For another example, the PDCCH used for scheduling the first RAR MAC PDU uses the first search space, and the PDCCH used for scheduling the second RAR MAC PDU uses the second search space, and the first search space is different from the second search space.

For another example, the PDCCH used to schedule the first RAR MAC PDU uses the first DCI format (DCI format), and the PDCCH used to schedule the second RAR MAC PDU uses the second DCI format, and the first DCI format is different from the second DCI format.

For another example, the DCI content of the PDCCH used to schedule the first RAR MAC PDU is different from the DCI content of the PDCCH used to schedule the second RAR MAC PDU.

The foregoing description has been given by taking the foregoing random access response MAC PDU containing two RAR MAC PDUs as an example. This application is not limited to this. The foregoing random access response MAC PDU may also include more than two RAR MAC PDUs, for example, including three The RAR MAC PDU is respectively called the first RAR MAC PDU, the second RAR MAC PDU, and the third RAR MAC PDU. The implementation manners are similar to the foregoing, and the description is omitted here.

Fig. 6 is a schematic diagram of an application scenario of the random access preamble backoff method according to an embodiment of the present application. In the application scenario of Fig. 6, the terminal device sends a two-step random access preamble or a four-step random access next time The preamble will be backed off before, and the first random access response and the second random access response are multiplexed in the same RAR MAC PDU.

As shown in Figure 6, UE a and UE b send the msgA preamble on the same 2-step random access PRACH RO. The gNB successfully demodulates the msgA PUSCH data of UE b, but fails to correctly decode the msgA PUSCH data of UE a, and only demodulates the msgA preamble sent by UE a. The gNB sends the first random access response and the second random access response to UE a and UE b respectively, and multiplexes them in one RAR PDU. The gNB sets the backoff indication information field according to the average load on the 2-step random access resource and the 4-step random access resource. UE a and UE b set PREAMBLE_BACKOFF according to the back-off instruction information. UEa did not receive the second random access response and received the first random access response, and went back to the 4-step random access process and sent msg3, but UEa failed to successfully complete the 4-step random access according to msg4 sent by gNB The access contention is resolved, UEa generates a uniformly distributed random number between 0 and PREAMBLE_BACKOFF as the backoff time for the next 4-step random access preamble, and sends the 4-step random access preamble after the backoff time . The UE b receives the second random access response, but fails to successfully resolve the contention according to the second random access response, and continues with 2-step random access. The UE b generates a uniformly distributed random number between 0 and PREAMBLE_BACKOFF , As the backoff time for sending the 2-step random access preamble next time, send the 2-step random access preamble after the backoff time.

FIG. 7 is a schematic diagram of another application scenario of the random access preamble backoff method according to an embodiment of the present application. In the application scenario of FIG. 7, the terminal device performs backoff before sending the two-step random access preamble next time, and back After returning to the four-step random access procedure, no backoff is performed before sending the four-step random access preamble, and the first random access response and the second random access response are multiplexed in the same RAR MAC PDU.

As shown in Figure 7, UE a and UE b send the msgA preamble on the same 2-step random access PRACH RO. The gNB successfully demodulates the msgA PUSCH data of UE b, but fails to correctly decode the msgA PUSCH data of UE a, and only demodulates the msgA preamble sent by UE a. The gNB sends the first random access response and the second random access response to UE a and UE b respectively, and multiplexes them in one RAR PDU. The gNB sets the backoff indication information field according to the load of the 2-step random access resources. UE a and UE b set PREAMBLE_BACKOFF according to the back-off instruction information. The UE a did not receive the second random access response and received the first random access response, and went back to the 4-step random access process and sent msg3, but the UE a failed to successfully complete the 4-step according to the msg4 sent by the gNB The contention for random access is resolved, and the UE a directly sends the 4-step random access preamble without backoff. The UE b receives the second random access response, but fails to successfully resolve the contention according to the second random access response, and continues with 2-step random access. The UE b generates a uniformly distributed random number between 0 and PREAMBLE_BACKOFF , As the backoff time for sending the 2-step random access preamble next time, send the 2-step random access preamble after the backoff time.

FIG. 8 is a schematic diagram of another application scenario of the random access preamble backoff method according to an embodiment of the present application. In the application scenario of FIG. 8, the terminal device sends a two-step random access preamble or a four-step random access next time. Backoff will be performed before entering the preamble, and the first random access response and the second random access response are multiplexed in different RAR MAC PDUs.

As shown in Figure 8, UE a and UE b send the msgA preamble on the same 2-step random access PRACH RO. The gNB successfully demodulates the msgA PUSCH data of UE b, but fails to correctly decode the msgA PUSCH data of UE a, and only demodulates the msgA preamble sent by UE a. The gNB sends the first random access response and the second random access response to UE a and UE b respectively, and multiplexes them in different RAR MAC PDUs (first RAR MAC PDU and second RAR MAC PDU). The gNB sets the second backoff indication information field in the second RAR MAC PDU and the first backoff indication information field in the first RAR MAC PDU according to the load conditions on the 2-step random access resources and the 4-step random access resources respectively. , Respectively used to indicate the backoff of 2-step random access preamble and 4-step random access preamble. UE a and UE b set PREAMBLE_BACKOFF_4step according to the first backoff instruction information, and set PREAMBLE_BACKOFF_2step according to the second backoff instruction information. The UE a did not receive the second random access response and received the first random access response, and went back to the 4-step random access process and sent msg3, but the UE a failed to successfully complete the 4-step according to the msg4 sent by the gNB The contention of random access is resolved. The UE a generates a uniformly distributed random number between 0 and PREAMBLE_BACKOFF_4step as the backoff time for the next 4-step random access preamble, and sends 4-step random access after the backoff time Preamble. The UE b receives the second random access response, but fails to successfully complete the contention resolution according to the second random access response, and continues with 2-step random access. The UE b generates a uniformly distributed random number between 0 and PREAMBLE_BACKOFF_2step , As the backoff time for sending the 2-step random access preamble next time, send the 2-step random access preamble after the backoff time.

FIG. 9 is a schematic diagram of another application scenario of the random access preamble backoff method according to an embodiment of the present application. In the application scenario of FIG. 9, the terminal device performs backoff before sending the two-step random access preamble next time, and sends four No backoff is performed before the random access preamble, and the first random access response and the second random access response are multiplexed in different RAR MAC PDUs.

As shown in Figure 9, UE a and UE b send the msgA preamble on the same 2-step random access PRACH RO. The gNB successfully demodulates the msgA PUSCH data of UE b, but fails to correctly decode the msgA PUSCH data of UE a, and only demodulates the msgA preamble sent by UE a. The gNB sends the first random access response and the second random access response to UE a and UE b respectively, and multiplexes them in different RAR MAC PDUs (first RAR MAC PDU and second RAR MAC PDU). The gNB sets the first backoff indication information field in the first RAR PDU according to the load condition on the 2-step random access resource to indicate the backoff of the 2-step random access preamble. UE a and UE b set PREAMBLE_BACKOFF according to the first backoff instruction information. The UE a did not receive the second random access response and received the first random access response, and went back to the 4-step random access process and sent msg3, but the UE a failed to successfully complete the 4-step according to the msg4 sent by the gNB The contention for random access is resolved, and the UE a directly sends the 4-step random access preamble without backoff. The UE b receives the second random access response, but fails to successfully resolve the contention according to the second random access response, and continues with 2-step random access. The UE b generates a uniformly distributed random number between 0 and PREAMBLE_BACKOFF , As the backoff time for sending the 2-step random access preamble next time, send the 2-step random access preamble after the backoff time.

The embodiment of the present application provides a back-off method for sending a random access preamble, and the method provides a preamble back-off mechanism for a 2-step random access process. In the 2-step RA process, the network device sends backoff instruction information to the terminal device according to the load on the 2-step random access resource and/or 4-step random access resource, and the terminal device sends the backoff instruction information next time according to the backoff instruction information Backoff before the 2-step random access preamble or 4-step random access preamble.

Embodiments of the second aspect

The embodiment of the second aspect of the present application provides a random access preamble backoff method, which is applied to a network device, and is a network-side processing corresponding to the method of the embodiment of the first aspect. The same content of the embodiment will not be repeated.

FIG. 10 is a schematic diagram of a random access preamble backoff method according to an embodiment of the second aspect of the present application. As shown in FIG. 10, the method includes:

Operation 1001: a network device receives a first message (MsgA) sent by a terminal device when initiating two-step random access, where the first message includes a two-step random access preamble and data;

Operation 1002: The network device sends backoff instruction information to the terminal device, where the backoff instruction information is used to indicate that the terminal device that has not successfully completed the two-step random access before sending the two-step or four-step random access preamble next time Back off.

In the embodiment of the second aspect of the present application, the terminal device sends a first message (MsgA) to the network device when initiating two-step random access, and the first message includes a two-step random access preamble and data. The network device receives the first message sent by the terminal device, and sends backoff instruction information to the terminal device. The network device also sends a random access response to the terminal device according to the demodulation situation of the first message. For example, if the network device successfully demodulates the data of the first message, the network device sends a second random access response to the terminal device; where the second random access response contains random access contention resolution information; if the network device successfully resolves The two-step random access preamble of the first message is adjusted, but the data of the first message cannot be successfully demodulated, the network device sends a first random access response to the terminal device; wherein, the first random access response includes The terminal device sends the second message (msg3) uplink resource grant, cell radio network temporary identification (TC-RNTI) and time advance command. The contents of the first random access response and the second random access response have been described in the embodiment of the first aspect, and will not be repeated here.

In operation 1002, in one or more embodiments, the aforementioned backoff indication information is used to instruct the terminal device that receives the first random access response to fall back to the four-step random access process, and if the four-step random access is not successfully completed In the case of the entry process, the backoff is performed according to the foregoing backoff instruction information, or no backoff is performed before the next four-step random access preamble is sent. In addition, the backoff instruction information is also used to instruct the terminal device that has not completed the two-step random access to continue the two-step random access process, and back off according to the backoff instruction information before sending the two-step random access preamble next time. Here, the terminal device that has not completed the two-step random access is, for example, the terminal device that has not received the second random access response and the first random access response, or the terminal device that has received the second random access response but the second random access response Incoming a terminal device whose contention resolution information contained in the response does not match the information in the first message. The processing of the terminal device has been described in the embodiment of the first aspect, and will not be repeated here.

In operation 1002, in one or more embodiments, the network device sends the PDCCH scrambled by the random access RNTI and the random access response MAC PDU scheduled by the PDCCH to the terminal device, and the random access response MAC PDU includes backoff Indication information field, the backoff instruction information field contains the foregoing backoff instruction information.

In one or more embodiments, the above-mentioned back-off indication information field includes a two-step random access back-off indication information field and/or a four-step random access back-off indication information field, that is, the network equipment respectively instructs two-step random access Backoff instruction information for preamble backoff and backoff instruction information for four-step random access preamble backoff. The backoff instruction information field has already been described in the embodiment of the first aspect, and will not be repeated here.

In one or more embodiments, the random access response MAC PDU includes the first random access response or the second random access response for the terminal device, and/or the first random access response for other terminal devices. Incoming response or second random access response. For example, the network device multiplexes the random access responses of different terminal devices that send the msgA preamble on the same random access opportunity into the same RAR MAC PDU, as shown in Figure 6-7.

In one or more embodiments, the foregoing random access response MAC PDU includes a first RAR MAC PDU and a second RAR MAC PDU, and different random access responses are carried in different RAR MAC PDUs; the first RAR MAC PDU is carried Contains the first random access response for the aforementioned terminal device or the first random access response for other terminal devices; the second RAR MAC PDU contains the second random access response for the aforementioned terminal device or the first random access response for other terminal devices. 2. Random access response. For example, the network device multiplexes the first random access responses of different terminal devices that send the msgA preamble on the same random access opportunity into a first RAR MAC PDU, and sends msgA on the same random access opportunity The second random access responses of different terminals of the preamble are multiplexed into a second RAR MAC PDU, as shown in Figure 8-9.

In one or more embodiments, in order to make the first random access response and the second random access response use different RAR MAC PDU bearers, the PDCCH used to schedule the first RAR MAC PDU and the second RAR MAC PDU are different Random access RNTI scrambling; or, the PDCCH used to schedule the first RAR MAC PDU and the second RAR MAC PDU uses different search spaces or CORESET; or, it is used to schedule the first RAR MAC PDU and the second RAR MAC PDU The PDCCH uses different DCI formats or DCI domains.

In the embodiment of the second aspect of the present application, the backoff indication information field is included in the first RAR MAC PDU, or included in the second RAR MAC PDU, or included in both the first RAR MAC PDU and the second RAR MAC PDU Backoff instruction information field. According to the backoff indication information contained in the first RAR MAC PDU or the second RAR MAC PDU, the terminal device performs backoff before sending the two-step or four-step random access preamble next time. The content that the terminal device performs backoff according to the backoff indication information in the first RAR MAC PDU or the second RAR MAC PDU before sending the next two-step or four-step random access preamble has been explained in the embodiment of the first aspect , I won’t repeat it here.

In the embodiment of the second aspect of the present application, the network device also sets the backoff indication information according to the load on the two-step random access resource and/or the four-step random access resource, and the terminal device sets the preamble according to the backoff instruction information Backoff value (PREAMBLE_BACKOFF), and when it is determined that the two-step random access process is unsuccessful, a number is randomly selected from 0 to the preamble backoff value as the next time the two-step random access or four-step random access preamble is sent During the backoff time, the two-step or four-step random access preamble is not sent during the backoff time. The processing of the terminal device has been described in the embodiment of the first aspect, and will not be repeated here.

Embodiments of the third aspect

The embodiment of the third aspect of the present application provides a random access preamble backoff device, which is configured in a terminal device. Since the principle of the device to solve the problem is similar to the method of the embodiment of the first aspect, the specific implementation can refer to the method of the embodiment of the first aspect, and the same contents will not be repeated.

FIG. 11 is a schematic diagram of an apparatus 1100 for random access preamble backoff according to an embodiment of the third aspect of the present application. As shown in FIG. 11, the apparatus 1100 includes a sending unit 1101 and a receiving unit 1102. The sending unit 1101 is used to send a first message to the network device when the terminal device initiates two-step random access, the first message includes the two-step random access preamble and data; the receiving unit 1102 is used to receive backoff indication information sent by the network device ; The sending unit 1101 in the case of the terminal device not successfully completing the two-step random access, back off according to the above back-off instruction information before sending the next two-step or four-step random access preamble.

In one embodiment, the sending unit 1101 performs backoff before sending the two-step or four-step random access preamble next time according to the back-off instruction information when the terminal device does not successfully complete the two-step random access, including:

If the terminal device receives the first random access response, the terminal device falls back to the four-step random access process. If the terminal device does not successfully complete the four-step random access process, the sending unit 1101 sends the four-step random access next time Before the preamble, backoff is performed according to the foregoing backoff indication information; where the first random access response includes the uplink resource grant for the terminal to send the second message (msg3), the cell radio network temporary identifier (TC-RNTI), and the time advance command ；

If the terminal device does not receive the second random access response and the first random access response, or the terminal device receives the second random access response but the contention resolution information contained in the second random access response is the same as that in the first message If the information does not match, the terminal device continues the two-step random access process, and the sending unit 1101 performs backoff according to the foregoing backoff instruction information before sending the next two-step random access preamble.

In another embodiment, the sending unit 1101 performs backoff before sending the two-step or four-step random access preamble next time according to the back-off instruction information when the terminal device does not successfully complete the two-step random access, including:

If the terminal device receives the first random access response, the terminal device falls back to the four-step random access process. If the terminal device does not successfully complete the four-step random access process, the sending unit 1101 sends the four-step random access next time Before the preamble, no backoff is performed; where the first random access response includes the uplink resource authorization for the terminal device to send the second message (msg3), the cell radio network temporary identifier (TC-RNTI), and the time advance command;

If the terminal device does not receive the first random access response and the second random access response, or the terminal device receives the second random access response but the contention resolution information contained in the second random access response is the same as that in the first message If the information does not match, the terminal device continues the two-step random access process, and the sending unit 1101 performs backoff according to the foregoing backoff instruction information before sending the next two-step random access preamble.

In the embodiment of the third aspect of the present application, after the terminal device falls back to the four-step random access procedure, the sending unit 1101 also sends a second message (msg3) to the network device, wherein the sending unit 1101 fails to complete according to the above The first message data buffer of the two-step random access of the second message is sent;

For example, the sending unit 1101 directly copies the MAC PDU data packet in the data buffer of the first message to the data buffer of the second message, and then sends the MAC PDU data packet as HARQ new transmission data of the second message; for another example, The sending unit 1101 directly sends the MAC PDU data packet in the data buffer of the first message as the HARQ new transmission data of the second message; for another example, the sending unit 1101 sends the first message according to the uplink resource authorization in the first random access response. The MAC SDU and/or C-RNTI MAC control unit included in the MAC PDU data packet in the data buffer of one message is assembled into a new MAC PDU data packet; the new MAC PDU data packet is put into the data buffer of the second message; Send the new MAC PDU data packet as the HARQ new transmission data of the second message.

In the embodiments of the third aspect of the present application, in one or more embodiments, the sending unit 1101 performs backoff before sending the two-step or four-step random access preamble next time according to the backoff instruction information, including:

The sending unit 1101 sets the preamble backoff value according to the foregoing backoff indication information; when determining that the foregoing two-step random access process is unsuccessful, randomly selects a number from 0 to the preamble backoff value as the preamble before sending the random access preamble. Backoff time: The random access preamble is not sent during the backoff time.

In one or more embodiments, the foregoing preamble backoff value includes the backoff value before the sending unit 1101 sends the four-step random access preamble and/or the backoff value before the sending unit 1101 sends the two-step random access preamble.

In the embodiments of the third aspect of the present application, in one or more embodiments, the receiving unit 1102 receives the backoff instruction information sent by the network device, including:

The receiving unit 1102 monitors the PDCCH scrambled by the random access RNTI; if the PDCCH scrambled by the random access RNTI is detected, and the random access response MAC PDU scheduled by the PDCCH contains the backoff indication information field, then backoff The instruction information domain obtains the foregoing backoff instruction information.

In one or more embodiments, the backoff instruction information field includes a two-step random access backoff instruction information field and/or a four-step random access backoff instruction information field.

In one or more embodiments, the random access response MAC PDU includes the first random access response or the second random access response for the above-mentioned terminal device, or includes the first random access response or the first random access response for other terminal devices. Second random access response.

In one or more embodiments, the random access response MAC PDU includes a first RAR MAC PDU and a second RAR MAC PDU; the first RAR MAC PDU includes the first random access response for the above-mentioned terminal device or for other terminals The first random access response of the device; the second RAR MAC PDU contains the second random access response for the above-mentioned terminal device or the second random access response for other terminal devices.

In one or more embodiments, the PDCCH used for scheduling the first RAR MAC PDU is scrambled by the first random access RNTI, and the PDCCH used for scheduling the second RAR MAC PDU is scrambled by the second random access RNTI. The first random access RNTI is different from the second random access RNTI.

In one or more embodiments, the PDCCH used to schedule the first RAR MAC PDU uses the first search space, and the PDCCH used to schedule the second RAR MAC PDU uses the second search space, the first search space and the second search space different.

In one or more embodiments, the PDCCH used to schedule the first RAR MAC PDU uses the first DCI format, and the PDCCH used to schedule the second RAR MAC PDU uses the second DCI format, the first DCI format and the second DCI format different.

In one or more embodiments, the DCI content of the PDCCH used to schedule the first RAR MAC PDU is different from the DCI content of the PDCCH used to schedule the second RAR MAC PDU.

In one or more embodiments, the sending unit 1101 performs back-off according to the back-off indication information in the first RAR MAC PDU before sending the two-step or four-step random access preamble next time.

In one or more embodiments, the sending unit 1101 performs back-off according to the back-off indication information in the second RAR MAC PDU before sending the two-step or four-step random access preamble next time.

In one or more embodiments, if the sending unit 1101 sends the two-step random access preamble next time, the sending unit 1101 will send the two-step random access preamble next time according to the backoff indication information in the first RAR MAC PDU Backoff was performed before. If the sending unit 1101 sends the four-step random access preamble next time, the sending unit 1101 performs backoff before sending the four-step random access preamble next time according to the backoff indication information in the second RAR MAC PDU.

In one or more embodiments, if the sending unit 1102 sends the four-step random access preamble next time, the sending unit 1101 sends the four-step random access preamble next time according to the backoff indication information in the first RAR MAC PDU Backoff is performed before. If the sending unit 1101 sends the two-step random access preamble next time, the sending unit 1101 performs backoff before sending the two-step random access preamble next time according to the backoff indication information in the second RAR MAC PDU.

The embodiment of the present application provides a back-off method for sending a random access preamble, and the method provides a preamble back-off mechanism for a 2-step random access process.

Embodiment of the fourth aspect

The embodiment of the fourth aspect of the present application provides a random access preamble backoff device, which is configured in a network device. Since the problem-solving principle of the device is similar to the method of the embodiment of the second aspect, the specific implementation can refer to the method of the embodiment of the second aspect, and the same contents will not be repeated.

FIG. 12 is a schematic diagram of an apparatus 1200 for random access preamble backoff in this embodiment. As shown in FIG. 12, the apparatus 1200 includes: a receiving unit 1201 and a sending unit 1202. The receiving unit 1201 is configured to receive a first message (MsgA) sent by the terminal device when initiating a two-step random access, the first message includes a two-step random access preamble and data; the sending unit 1202 is used to send a backoff to the terminal device Indication information, the back-off instruction information is used to indicate that the terminal device that has not successfully completed the two-step random access will back-off before sending the two-step or four-step random access preamble next time.

In the embodiment of the fourth aspect of the present application, the sending unit 1202 further sends a random access response to the terminal device according to the demodulation situation of the first message; wherein, if the network device successfully demodulates the data of the first message, it sends The unit 1202 sends a second random access response to the terminal device; where the second random access response contains random access contention resolution information; if the network device successfully demodulates the two-step random access preamble of the first message, but If the data of the first message cannot be successfully demodulated, the sending unit 1202 sends a first random access response to the terminal device; where the first random access response includes an uplink resource grant for the terminal device to send the second message (msg3) , Cell radio network temporary identification (TC-RNTI) and time advance command.

In one or more embodiments, the back-off indication information is used to instruct the terminal device that has received the first random access response to fall back to the four-step random access process, and in the case that the four-step random access process is not successfully completed , Before sending the four-step random access preamble next time, back-off is performed according to the back-off instruction information, or no back-off is performed.

In one or more embodiments, the back-off indication information is used to indicate the terminal device that has not received the second random access response and the first random access response, or it is used to indicate that the second random access response is received but the first random access response is received. 2. The terminal device whose contention resolution information contained in the random access response does not match the information in the first message continues the two-step random access process, and performs the above backoff instruction information before sending the two-step random access preamble next time Retreat.

In one or more embodiments, the sending unit 1202 sends back-off indication information to the terminal device, including:

The sending unit 1202 sends the PDCCH scrambled by the random access RNTI and the random access response MAC PDU scheduled by the PDCCH to the terminal device. The random access response MAC PDU contains the backoff indication information field, and the backoff indication information field includes the above backoff Instructions.

In one or more embodiments, the PDCCH used to schedule the first RAR MAC PDU uses the first DCI format (DCI format), and the PDCCH used to schedule the second RAR MAC PDU uses the second DCI format. The first DCI format is the same as The second DCI format is different.

In one or more embodiments, the first RAR MAC PDU includes the backoff indication information field; or, the second RAR MAC PDU includes the backoff indication information field; or, the first RAR MAC PDU and the second RAR MAC PDU include backoff Indicates the information field.

In the embodiment of the fourth aspect of the present application, as shown in FIG. 12, the device 1200 further includes:

The processing unit 1203, which sets the back-off indication information according to the load on the two-step random access resource and/or the four-step random access resource, the terminal device sets the preamble back-off value according to the back-off indication information, and determines the two-step When the random access process is unsuccessful, a number is randomly selected from 0 to the preamble backoff value as the backoff time before sending the random access preamble, and the random access preamble is not sent during the backoff time.

Embodiment of the fifth aspect

The embodiment of the fifth aspect of the present application provides a terminal device, and the terminal device includes the apparatus of the embodiment of the third aspect.

FIG. 13 is a schematic diagram of a terminal device according to an embodiment of the fifth aspect of the present application. As shown in FIG. 13, the terminal device 1300 may include a central processing unit 1301 and a memory 1302; the memory 1302 is coupled to the central processing unit 1301. It is worth noting that this figure is exemplary; other types of structures can also be used to supplement or replace this structure to implement telecommunication functions or other functions.

In one embodiment, the functions of the apparatus of the embodiment of the third aspect are integrated into the central processing unit 1301, and the central processing unit 1301 implements the functions of the apparatus of the embodiment of the third aspect. The functions of the device are incorporated here, so I won’t repeat them here.

In another embodiment, the device of the embodiment of the third aspect is configured separately from the central processing unit 1301. For example, the device of the embodiment of the third aspect is configured as a chip connected to the central processing unit 1301, through the central processing unit 1301. The control of 1301 realizes the function of the device of the embodiment of the third aspect.

As shown in FIG. 13, in one or more embodiments, the terminal device 1300 further includes: a communication module 1303, an input unit 1304, an audio processing unit 1305, a display 1306, and a power supply 1307. It is worth noting that the terminal device 1300 does not necessarily include all the components shown in FIG. 13; in addition, in other embodiments, the terminal device 1300 also includes components not shown in FIG. 27, and related technologies may be referred to.

As shown in FIG. 13, the central processing unit 1301 is sometimes also called a controller or an operating control. In one or more embodiments, it includes a microprocessor or other processor devices and/or logic devices. The central processing unit 1301 receives Input and control the operations of various components of the terminal device 1300.

Among them, the memory 1302 is, for example, one or more of a cache, a flash memory, a hard drive, a removable medium, a volatile memory, a non-volatile memory, or other suitable devices. A variety of information can be stored, in addition to storing and executing programs related to the information. And the central processing unit 1301 executes the program stored in the memory 1302 to implement information storage or processing. The functions of other components are similar to the existing ones, so I won't repeat them here. Each component of the terminal device 1300 may be implemented by dedicated hardware, firmware, software, or a combination thereof, without departing from the scope of the present application.

The terminal device of this embodiment provides a backoff method for sending random access preambles, and the method provides a preamble backoff mechanism for a 2-step random access process.

Embodiments of the sixth aspect

The embodiment of the sixth aspect of the present application provides a network device, and the network device includes the device of the embodiment of the fourth aspect.

Fig. 14 is a schematic diagram of a network device according to an embodiment of the sixth aspect of the present application. As shown in FIG. 14, the network device 1400 includes: a central processing unit (CPU) 1401 and a memory 1402; the memory 1402 is coupled to the central processing unit 1401. The memory 1402 stores various data; in addition, it also stores information processing programs, which are executed under the control of the central processing unit 1401 to receive various information sent by the terminal device and send various information to the terminal device.

In one embodiment, the functions of the apparatus of the embodiment of the fourth aspect are integrated into the central processing unit 1401, and the central processing unit 1401 implements the functions of the apparatus of the embodiment of the fourth aspect. The functions of the device are incorporated here, so I won’t repeat them here.

In another embodiment, the device of the embodiment of the fourth aspect is configured separately from the central processing unit 1401. For example, the device of the embodiment of the fourth aspect is configured as a chip connected to the central processing unit 1401, through the central processing unit 1401. The control to realize the function of the device of the embodiment of the fourth aspect.

In addition, as shown in FIG. 14, in one or more embodiments, the network device 1400 further includes: a transceiver 1403, an antenna 1404, etc.; wherein the functions of the above-mentioned components are similar to those of the prior art, and will not be repeated here. It is worth noting that the network device 1400 does not necessarily include all the components shown in FIG. 14; in addition, in other embodiments, the network device 1400 also includes components not shown in FIG. 14, which can refer to the prior art .

The network device of this embodiment provides a backoff method for sending random access preambles, and the method provides a preamble backoff mechanism for a 2-step random access process.

Embodiments of the seventh aspect

The embodiment of the seventh aspect of the present application provides a communication system including a network device and a terminal device. The network device is, for example, the network device 1400 of the embodiment of the sixth aspect, and the terminal device is, for example, the embodiment of the fifth aspect.的terminal equipment 1300.

In this embodiment, the terminal device is, for example, a UE served by gNB, which includes the conventional composition and functions of the terminal device in addition to the functions of the device in the embodiment of the third aspect, as described in the embodiment of the fifth aspect , I won’t repeat it here.

In this embodiment, the network device may be, for example, the gNB in the NR, which includes the conventional composition and functions of the network device in addition to the functions of the device in the embodiment of the fourth aspect, as described in the embodiment of the sixth aspect. I will not repeat them here.

Through the communication system of this embodiment, a backoff method for sending random access preambles is provided, and the method provides a preamble backoff mechanism for a 2-step random access process.

The embodiments of the present application also provide a computer-readable program, wherein when the program is executed in the terminal device, the program causes the computer to execute the method of the embodiment of the first aspect in the terminal device.

An embodiment of the present application also provides a storage medium storing a computer-readable program, wherein the computer-readable program enables a computer to execute the method of the embodiment of the first aspect in a terminal device.

An embodiment of the present application also provides a computer-readable program, wherein when the program is executed in a network device, the program causes a computer to execute the method of the embodiment of the second aspect in the network device.

An embodiment of the present application also provides a storage medium storing a computer-readable program, where the computer-readable program enables a computer to execute the method of the embodiment of the second aspect in a network device.

The above devices and methods of this application can be implemented by hardware, or by hardware combined with software. This application relates to such a computer-readable program, when the program is executed by a logic component, the logic component can realize the above-mentioned device or constituent component, or the logic component can realize the above-mentioned various methods Or operation. Logic components such as field programmable logic components, microprocessors, processors used in computers, etc. This application also relates to storage media for storing the above programs, such as hard disks, magnetic disks, optical disks, DVDs, flash memory, etc.

The method/device described in combination with the embodiments of the present application may be directly embodied as hardware, a software module executed by a processor, or a combination of the two. For example, one or more of the functional block diagrams shown in FIGS. 11 and 12 and/or one or more combinations of the functional block diagrams may correspond to each software module of the computer program flow or each hardware module. These software modules can respectively correspond to the operations shown in Figures 5 and 10. These hardware modules can be implemented by solidifying these software modules using a field programmable gate array (FPGA), for example.

The software module can be located in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, removable disk, CD-ROM or any other form of storage medium known in the art. A storage medium may be coupled to the processor, so that the processor can read information from the storage medium and write information to the storage medium; or the storage medium may be a component of the processor. The processor and the storage medium may be located in the ASIC. The software module can be stored in the memory of the mobile terminal, or can be stored in a memory card that can be inserted into the mobile terminal. For example, if the device (such as a mobile terminal) uses a larger-capacity MEGA-SIM card or a large-capacity flash memory device, the software module can be stored in the MEGA-SIM card or a large-capacity flash memory device.

For one or more of the functional blocks and/or one or more combinations of the functional blocks described in the accompanying drawings 11 and 12, it can be implemented as a general-purpose processor or digital signal processing for performing the functions described in this application. DSP, Application Specific Integrated Circuit (ASIC), Field Programmable Gate Array (FPGA) or other programmable logic device, discrete gate or transistor logic device, discrete hardware component, or any suitable combination thereof. One or more of the functional blocks and/or one or more combinations of the functional blocks described in FIGS. 11 and 12 can also be implemented as a combination of computing devices, for example, a combination of DSP and microprocessor, multiple One microprocessor, one or more microprocessors in communication with the DSP, or any other such configuration.

The application is described above in conjunction with specific implementations, but it should be clear to those skilled in the art that these descriptions are all exemplary and do not limit the scope of protection of the application. Those skilled in the art can make various variations and modifications to the application according to the spirit and principle of the application, and these variations and modifications are also within the scope of the application.

Claims

A device for random access preamble backoff is configured in terminal equipment, wherein the device includes:

A sending unit, when the terminal device initiates two-step random access, it sends a first message to the network device, where the first message includes a two-step random access preamble and data;

A receiving unit, which receives backoff instruction information sent by the network device;

When the terminal device fails to successfully complete the two-step random access, the sending unit performs backoff before sending the two-step or four-step random access preamble next time according to the backoff instruction information.
The apparatus according to claim 1, wherein the sending unit sends a two-step or four-step random access preamble in the next time according to the backoff instruction information when the terminal device has not successfully completed the two-step random access Back off before the code, including:

If the terminal device receives the first random access response, the terminal device falls back to the four-step random access process, and if the terminal device does not successfully complete the four-step random access process, the sending unit Before the next four-step random access preamble is sent, backoff is performed according to the backoff indication information; wherein, the first random access response includes the uplink resource grant for the terminal to send the second message (msg3), cell Temporary wireless network identification (TC-RNTI) and time advance command;

If the terminal device does not receive the second random access response and the first random access response, or the terminal device receives the second random access response but the contention resolution contained in the second random access response If the information does not match the information in the first message, the terminal device continues the two-step random access process, and the sending unit performs backoff according to the backoff instruction information before sending the two-step random access preamble next time .
The apparatus according to claim 1, wherein the sending unit sends a two-step or four-step random access preamble in the next time according to the backoff instruction information when the terminal device has not successfully completed the two-step random access Back off before the code, including:

If the terminal device receives the first random access response, the terminal device falls back to the four-step random access process, and if the terminal device does not successfully complete the four-step random access process, the sending unit Before the next four-step random access preamble is sent, no backoff will be performed; wherein, the first random access response includes the uplink resource grant for the terminal to send the second message (msg3), and the cell wireless network temporary identifier ( TC-RNTI) and time advance order;

If the terminal device does not receive the first random access response and the second random access response, or the terminal device receives the second random access response but the contention resolution contained in the second random access response If the information does not match the information in the first message, the terminal device continues the two-step random access process, and the sending unit performs backoff according to the backoff instruction information before sending the two-step random access preamble next time .
The apparatus according to claim 2, wherein, after the terminal device reverts to a four-step random access procedure, the sending unit sends a second message (msg3) to the network device,

Wherein, the sending unit directly copies the MAC PDU data packet in the data buffer of the first message to the data buffer of the second message, and then uses the MAC PDU data packet as the HARQ of the second message. Send new data;

Alternatively, the sending unit directly sends the MAC PDU data packet in the data buffer of the first message as HARQ new transmission data of the second message;

Alternatively, the sending unit assembles the MAC SDU or C-RNTI MAC control unit contained in the MAC PDU data packet in the data buffer of the first message according to the uplink resource grant in the first random access response into New MAC PDU data packet; Put the new MAC PDU data packet into the data buffer of the second message; Send the new MAC PDU data packet as HARQ new transmission data of the second message.
The apparatus according to claim 3, wherein, after the terminal device falls back to the four-step random access procedure, the sending unit sends a second message (msg3) to the network device,

Wherein, the sending unit directly copies the MAC PDU data packet in the data buffer of the first message to the data buffer of the second message, and then uses the MAC PDU data packet as the HARQ of the second message. Send new data;

Alternatively, the sending unit directly sends the MAC PDU data packet in the data buffer of the first message as HARQ new transmission data of the second message;

Alternatively, the sending unit assembles the MAC SDU or C-RNTI MAC control unit contained in the MAC PDU data packet in the data buffer of the first message according to the uplink resource grant in the first random access response into New MAC PDU data packet; Put the new MAC PDU data packet into the data buffer of the second message; Send the new MAC PDU data packet as HARQ new transmission data of the second message.
The apparatus according to claim 1, wherein the receiving unit receiving backoff instruction information sent by the network device comprises:

The receiving unit monitors the PDCCH scrambled by the random access RNTI; if the PDCCH scrambled by the random access RNTI is detected, and the random access response MAC PDU scheduled by the PDCCH contains the backoff indication information field, then The back-off instruction information field obtains the back-off instruction information.
The apparatus according to claim 6, wherein the backoff instruction information field comprises a two-step random access backoff instruction information field and/or a four-step random access backoff instruction information field.
The apparatus according to claim 6, wherein the random access response MAC PDU includes a first random access response or a second random access response for the terminal device, or includes a first random access response for other terminal devices Random access response or second random access response.
The apparatus according to claim 6, wherein the random access response MAC PDU includes a first RAR MAC PDU and a second RAR MAC PDU;

The first RAR MAC PDU includes a first random access response for the terminal device or a first random access response for other terminal devices;

The second RAR MAC PDU includes a second random access response for the terminal device or a second random access response for other terminal devices.
The device according to claim 9, wherein:

The PDCCH used for scheduling the first RAR MAC PDU is scrambled by the first random access RNTI, the PDCCH used for scheduling the second RAR MAC PDU is scrambled by the second random access RNTI, and the first random access RNTI The incoming RNTI is different from the second random access RNTI; or,

The PDCCH used for scheduling the first RAR MAC PDU uses a first search space, and the PDCCH used for scheduling the second RAR MAC PDU uses a second search space, and the first search space is different from the second search space; or ,

The PDCCH used to schedule the first RAR MAC PDU uses the first DCI format (DCI format), and the PDCCH used to schedule the second RAR MAC PDU uses the second DCI format. The first DCI format is the same as the first DCI format. 2. The DCI format is different; or,

The DCI content of the PDCCH used for scheduling the first RAR MAC PDU is different from the DCI content of the PDCCH used for scheduling the second RAR MAC PDU.
The device according to claim 9, wherein:

The sending unit performs back-off according to the back-off indication information in the first RAR MAC PDU before sending the two-step or four-step random access preamble next time; or,

The sending unit performs backoff according to the backoff indication information in the second RAR MAC PDU before sending the two-step or four-step random access preamble next time; or,

If the sending unit sends the two-step random access preamble next time, the sending unit performs back-off according to the back-off indication information in the first RAR MAC PDU before sending the two-step random access preamble next time, If the sending unit sends the four-step random access preamble next time, the sending unit performs backoff before sending the four-step random access preamble next time according to the backoff indication information in the second RAR MAC PDU; or,

If the sending unit sends the four-step random access preamble next time, the sending unit performs backoff according to the backoff indication information in the first RAR MAC PDU before sending the four-step random access preamble next time, If the sending unit sends the two-step random access preamble next time, the sending unit performs backoff before sending the two-step random access preamble next time according to the backoff indication information in the second RAR MAC PDU.
A device for random access preamble back-off is configured in network equipment, wherein the device includes:

A receiving unit, which receives a first message (MsgA) sent by the terminal device when initiating a two-step random access, the first message including a two-step random access preamble and data;

A sending unit that sends backoff instruction information to the terminal device, where the backoff instruction information is used to indicate that the terminal device that has not successfully completed the two-step random access performs backoff before sending the two-step or four-step random access preamble next time.
The device according to claim 12, wherein:

The sending unit also sends a random access response to the terminal device according to the demodulation situation of the first message; wherein,

If the network device successfully demodulates the data of the first message, the sending unit sends a second random access response to the terminal device; wherein, the second random access response includes random access contention resolution information;

If the network device successfully demodulates the two-step random access preamble of the first message, but cannot successfully demodulate the data of the first message, the sending unit sends the first random access preamble to the terminal device. Incoming response; wherein, the first random access response includes an uplink resource grant for the terminal to send a second message (msg3), a cell radio network temporary identification (TC-RNTI), and a timing advance command.
The device according to claim 13, wherein:

The back-off indication information is used to instruct the terminal device that receives the first random access response to fall back to the four-step random access process, and in the case that the four-step random access process is not successfully completed, send four-step random access next time Backoff according to the backoff instruction information before random access to the preamble, or no backoff;

The back-off indication information is used to indicate the terminal equipment that has not received the second random access response and the first random access response, or is used to indicate that the second random access response is received but the The terminal device whose contention resolution information contained in the second random access response does not match the information in the first message continues the two-step random access procedure, and performs the backoff according to the backoff before sending the two-step random access preamble next time Instruct the information to back off.
The apparatus according to claim 12, wherein the sending unit sending backoff instruction information to the terminal device comprises:

The sending unit sends the PDCCH scrambled by the random access RNTI and the random access response MAC PDU scheduled by the PDCCH to the terminal device, where the random access response MAC PDU includes a backoff indication information field, and the backoff The indication information field contains the backoff indication information.
The apparatus according to claim 15, wherein the back-off instruction information field comprises a two-step random access back-off instruction information field and/or a four-step random access back-off instruction information field.
The apparatus according to claim 15, wherein the random access response MAC PDU includes a first random access response or a second random access response for the terminal device, or includes a first random access response for other terminal devices. Random access response or second random access response.
The apparatus according to claim 15, wherein the random access response RAR MAC PDU includes a first RAR MAC PDU and a second RAR MAC PDU;

The first RAR MAC PDU includes a first random access response for the terminal device or a first random access response for other terminal devices;

The second RAR MAC PDU includes a second random access response for the terminal device or a second random access response for other terminal devices.
The device according to claim 18, wherein

The PDCCH used for scheduling the first RAR MAC PDU is scrambled by the first random access RNTI, the PDCCH used for scheduling the second RAR MAC PDU is scrambled by the second random access RNTI, and the first random access RNTI The incoming RNTI is different from the second random access RNTI; or,

The PDCCH used for scheduling the first RAR MAC PDU uses a first search space, and the PDCCH used for scheduling the second RAR MAC PDU uses a second search space, and the first search space is different from the second search space; or ,

The PDCCH used to schedule the first RAR MAC PDU uses the first DCI format (DCI format), the PDCCH used to schedule the second RAR MAC PDU uses the second DCI format, and the first DCI format is the same as the first DCI format. 2. The DCI format is different; or,

The DCI content of the PDCCH used for scheduling the first RAR MAC PDU is different from the DCI content of the PDCCH used for scheduling the second RAR MAC PDU.
The device according to claim 18, wherein:

The first RAR MAC PDU includes the backoff instruction information field; or,

The second RAR MAC PDU includes the backoff indication information field; or,

The first RAR MAC PDU and the second RAR MAC PDU include the backoff indication information field.