WO2022237739A1

WO2022237739A1 - Method for random access, device, and storage medium

Info

Publication number: WO2022237739A1
Application number: PCT/CN2022/091795
Authority: WO
Inventors: 宣一荻; 余健; 郭志恒
Original assignee: 华为技术有限公司
Priority date: 2021-05-11
Filing date: 2022-05-09
Publication date: 2022-11-17
Also published as: CN115334683A

Abstract

Provided are a method for random access, a terminal device, a network device, and a medium. The method comprises a terminal device repeatedly transmits an uplink message to a network device on the basis of a first repetition number. The uplink message is scheduled by a random access response message. The method further comprises, before the number of repeated transmissions of the uplink message reaches the first repetition number or the repetition transmission is completed, the terminal device starts a contention resolution timer to receive downlink control information associated with a contention resolution message. The start time of the contention resolution timer is associated with at least one of: a processing delay of the network device, the first repetition number, and the time required for the first repetition number of repeated transmissions of the uplink message, and the processing delay of the network device comprises a delay of the network device processing the uplink message. By using the method, the random access delay of the terminal device can be reduced.

Description

Method, device and storage medium for random access

technical field

The present disclosure relates to the field of communication, and more particularly, to a method, device and storage medium for random access.

Background technique

A terminal device can access the network for communication by performing a random access procedure. In order to ensure that the terminal device can successfully access the network, it is first necessary to ensure the successful transmission of each message in the random access process. In the random access process, after successfully receiving the random access response from the network device, the terminal device needs to send an uplink message to the network device. Hereinafter, this uplink message is also referred to as message 3 or Msg3.

In the case of limited coverage, the repeated transmission of Msg3 is required to increase the coverage. After successfully receiving the repeatedly sent Msg3, the network device will send downlink control information (Downlink Control Information, DCI) associated with the contention resolution message to the terminal device through the Physical Downlink Control Channel (PDCCH). Hereinafter, this contention resolution message is also referred to as message 4 or Msg4. Correspondingly, the terminal device starts the contention resolution timer, and detects the PDCCH after the contention resolution timer is started and before the contention resolution timer expires. When Msg3 is repeatedly transmitted, if the contention resolution timer is started too early, the terminal device will detect the PDCCH within the time range when it is impossible to receive Msg4, resulting in a waste of energy for the terminal device; if the contention resolution timer is started too late, then In the case that the network device correctly receives the Msg3 before the repeated transmission of the terminal device is completed, a large access delay is caused. Therefore, how to start the contention resolution timer at an appropriate time when the Msg3 is repeatedly transmitted is an urgent problem to be solved.

Contents of the invention

Example embodiments of the present disclosure provide a scheme for random access.

In a first aspect of the present disclosure, a method for random access implemented at a terminal device is provided. The method includes that the terminal device repeatedly sends the uplink message to the network device based on the first repetition times. The uplink message is scheduled by the random access response message. The method further includes that the terminal device starts a contention resolution timer for receiving downlink control information associated with the contention resolution message before the number of repeated transmissions of the uplink message reaches the first number of repetitions or before the repeated transmission is completed. The start time of the contention resolution timer is associated with at least one of the following: a processing delay of the network device, a first number of repetitions, and a time required for repeated transmission of the first number of repetitions of the uplink message. The processing delay of the network device includes the delay of the network device processing the uplink message. The method can reduce the random access delay of the terminal equipment.

In some embodiments, additionally, if the terminal device successfully receives the DCI associated with the contention resolution message before the number of repeated transmissions of the uplink message reaches the first number of repetitions or the repeated transmission is completed, the terminal device may cancel the uplink message Subsequent re-sends. In this way, energy waste for the terminal device to send uplink messages can be avoided.

In some embodiments, the start time of the contention resolution timer may be the T1+1th time unit after the first repeated sending of the uplink message, where T1 represents the processing delay of the network device.

In some embodiments, alternatively, if the time required for the repeated transmission of the first number of repetitions of the uplink message exceeds the processing delay of the network device, the start time of the contention resolution timer may be the T1+1th time unit , T1 represents the processing delay of the network device.

In some embodiments, alternatively, if the time required for the repeated transmission of the first repeated number of times of the uplink message exceeds the processing delay, the start time of the contention resolution timer may be the repeated transmission of the second repeated number of times of the uplink message The next T1+1 time unit. The second number of repetitions is associated with and less than the first number of repetitions. T1 represents the processing delay of the network device.

In some embodiments, the terminal device may determine the second number of repetitions associated with the first number of repetitions based on the first number of repetitions, and then determine the first time unit after the repeated transmission of the second number of repetitions of the uplink message as the contention Resolve the start time of the timer, where the second number of repetitions is less than the first number of repetitions.

In some embodiments, the terminal device may determine the second number of repetitions associated with the first number of repetitions based on the first number of repetitions, and then determine the first time unit after the repeated transmission of the second number of repetitions of the uplink message as the contention Resolve the start time of the timer where the second repetition count is less than or equal to the first repetition count. When the first number of repetitions is less than or equal to the threshold, the second number of repetitions is equal to the first number of repetitions; when the first number of repetitions is greater than the threshold, the second number of repetitions is smaller than the first number of repetitions.

In some embodiments, the processing latency of the network device may be predefined. Alternatively, the terminal device may receive system information indicating the processing delay from the network device.

In some embodiments, additionally, after starting the contention resolution timer, if the repeated transmission of the uplink message does not reach the first number of repetitions, the terminal device may restart the contention resolution timer after each subsequent repeated transmission of the uplink message .

In some embodiments, additionally, the terminal device may receive the DCI associated with the contention resolution message within the timing range of the contention resolution timer except for a predetermined time period before each subsequent repeated transmission of the uplink message. The predetermined time period is determined based on the sum of uplink transmission preparation time and downlink reception processing time of the terminal device. Subsequent retransmissions are located after the first retransmission of the uplink message.

In some embodiments, additionally, the terminal device may send information to the network device, the information indicating whether the terminal device starts the contention resolution timer before the repeated sending of the uplink message reaches the first repetition number.

In a second aspect of the present disclosure, a method for random access implemented at a network device is provided. The method includes that the network device receives repeatedly sent uplink messages from the terminal device based on the first repetition times. The uplink message is scheduled by the random access response message. The method also includes: if the network device successfully receives the uplink message before the number of repeated sending of the uplink message reaches the first number of repetitions or before the repeated sending is completed, the network device sends a contention and contention message to the terminal device after the contention resolution timer is started. Resolves the DCI associated with the message. The start time of the contention resolution timer is associated with at least one of the following: a processing delay of the network device, a first number of repetitions, and a time required for repeated transmission of the first number of repetitions of the uplink message. The processing delay of the network device includes the delay of the network device processing the uplink message. With this method, the random access delay of the terminal equipment can be reduced.

In some embodiments, alternatively, if the time required for repeated transmission of the first repeated number of uplink messages exceeds the processing delay of the network device, the start time of the contention resolution timer may be the second repeated number of uplink messages The T1+1th time unit after the repeated sending of . The second repetition number is associated with the first repetition number and is smaller than the first repetition number, and T1 represents a processing delay of the network device.

In some embodiments, the processing latency of the network device may be predefined. Alternatively, the network device may send system information indicating the processing delay to the terminal device.

In some embodiments, additionally, after the contention resolution timer is started, if the repeated transmission of the uplink message does not reach the first number of repetitions, the contention resolution timer is restarted after each subsequent repeated transmission of the uplink message.

In some embodiments, the network device may transmit the DCI associated with the contention resolution message within the timing range of the contention resolution timer except for a predetermined period of time before each subsequent repeated transmission of the uplink message. The predetermined time period is determined based on the sum of uplink transmission preparation time and downlink reception processing time of the terminal device. Subsequent retransmissions are located after the first retransmission of the uplink message.

In some embodiments, additionally, the network device may receive information from the terminal device, the information indicating whether the terminal device starts the contention resolution timer before the number of repeated transmissions of the uplink message reaches the first number of repetitions.

In a third aspect of the present disclosure, a terminal device is provided. The terminal device includes a processor and a memory. Computer program instructions are stored. The memory and the computer program instructions are configured, together with the processor, to cause the terminal device to perform the method according to the first aspect of the present disclosure.

In a fourth aspect of the present disclosure, a network device is provided. The network device includes a processor and a memory. Computer program instructions are stored. The memory and computer program instructions are configured, together with the processor, to cause the network device to perform the method according to the second aspect of the present disclosure.

In a fifth aspect of the present disclosure, a computer readable medium is provided. The computer-readable medium stores machine-executable instructions. The machine-executable instructions, when executed by the terminal device, cause the terminal device to perform the method according to the first aspect of the present disclosure.

In a sixth aspect of the present disclosure, a computer readable medium is provided. The computer-readable medium stores machine-executable instructions. The machine-executable instructions, when executed by the network device, cause the network device to perform the method according to the second aspect of the present disclosure.

In a seventh aspect of the present disclosure, a computer program product is provided. The computer program product includes machine-executable instructions. The machine-executable instructions, when executed by the terminal device, cause the terminal device to perform the method according to the first aspect of the present disclosure.

In an eighth aspect of the present disclosure, a computer program product is provided. The computer program product includes machine-executable instructions. The machine-executable instructions, when executed by the terminal device, cause the terminal device to perform the method according to the second aspect of the present disclosure.

Description of drawings

The features, advantages and other aspects of various implementations of the present disclosure will become more apparent with reference to the following detailed description when taken in conjunction with the accompanying drawings. Several implementations of the present disclosure are shown here by way of illustration and not limitation, in the accompanying drawings:

Figure 1 shows a schematic block diagram of a communication system in which embodiments of the present disclosure may be implemented;

FIG. 2 shows a signaling interaction diagram for a random access procedure according to some embodiments of the present disclosure;

3 shows a schematic diagram of the start time of the contention resolution timer in the LTE system;

FIG. 4 shows a signaling interaction diagram for a random access procedure according to some embodiments of the present disclosure;

FIG. 5A shows a schematic diagram of the start time of the contention resolution timer in a Time Division Duplex (Time Division Duplex, TDD) scenario according to some embodiments of the present disclosure;

5B shows a schematic diagram of the start time of the contention resolution timer in a frequency division duplex (Frequency Division Duplex, FDD) scenario according to some embodiments of the present disclosure;

FIG. 6A shows a schematic diagram of start time of a contention resolution timer in a TDD scenario according to other embodiments of the present disclosure;

FIG. 6B shows a schematic diagram of the start time of the contention resolution timer in the FDD scenario according to other embodiments of the present disclosure;

FIG. 7A shows a schematic diagram of the start time of a contention resolution timer in a TDD scenario according to still other embodiments of the present disclosure;

Fig. 7B shows a schematic diagram of the start time of the contention resolution timer in the FDD scenario according to some other embodiments of the present disclosure;

FIG. 7C shows a schematic diagram of the start time of the contention resolution timer in the FDD scenario according to some further embodiments of the present disclosure;

FIG. 8 shows a flowchart of a method for random access according to some embodiments of the present disclosure;

FIG. 9 shows a flowchart of a method for random access according to other embodiments of the present disclosure; and

FIG. 10 shows a block diagram of an example electronic device according to some embodiments of the present disclosure.

In the various drawings, the same or similar reference numerals denote the same or similar elements.

Detailed ways

Embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although certain embodiments of the present disclosure are shown in the drawings, it should be understood that the disclosure may be embodied in various forms and should not be construed as limited to the embodiments set forth herein; A more thorough and complete understanding of the present disclosure. It should be understood that the drawings and embodiments of the present disclosure are for exemplary purposes only, and are not intended to limit the protection scope of the present disclosure.

In the description of the embodiments of the present disclosure, the term "comprising" and its similar expressions should be interpreted as an open inclusion, that is, "including but not limited to". The term "based on" should be understood as "based at least in part on". The term "one embodiment" or "the embodiment" should be read as "at least one embodiment". The terms "first", "second", etc. may refer to different or the same object. Other definitions, both express and implied, may also be included below. Expressions similar to "at least one of A, B and C" or "at least one of A, B or C" should be understood as any of the following: at least one A; at least one B; at least one C; At least one A and at least one B; at least one A and at least one C; at least one B and at least one C; at least one A, at least one B and at least one C, the above is an example of three elements of A, B and C To illustrate, when there are more elements in the expression, the meaning of the expression can be obtained according to the aforementioned rules.

In the description of the embodiments of the present disclosure, the terms "symbol" and "Orthogonal Frequency Division Multiplexing (OFDM) symbol" have the same meaning and thus can be used interchangeably.

Embodiments of the present disclosure may be implemented according to any suitable communication protocol, including, but not limited to, fourth generation (4G) and fifth generation (5G) cellular communication protocols, such as Institute of Electrical and Electronics Engineers (IEEE) 802.11, etc. wireless local area network communication protocol, and/or any other protocol currently known or developed in the future. The technical solutions of the embodiments of the present disclosure are applied to any appropriate communication system, for example: General Packet Radio Service (GPRS), Long Term Evolution (LTE) system, Frequency Division Duplex (FDD) system, Time Division Duplex (TDD), general Mobile Communication System (UMTS), Narrow Band Internet of Things (NB-IoT) Communication System, Future Fifth Generation (5G) System or New Radio Access Technology (NR), etc.

For illustration purposes, embodiments of the present disclosure are described below in the context of a 5G 3rd Generation Partnership Project (3GPP) communication system. However, it should be understood that the embodiments of the present disclosure are not limited to be applied to the 5G communication system, but can be applied to any other communication systems with similar problems, as long as there are downlinks and uplinks in the communication system .

Fig. 1 shows a schematic block diagram of a communication system 100 in which embodiments of the present disclosure may be implemented. As shown in the figure, the communication system 100 includes a network device 110 and terminal devices 120-1, 120-2, 120-3, and 120-4. Hereinafter, for purposes of discussion, terminal devices 120-1, 120-2, 120-3, 120-4 are referred to collectively as terminal device 120 or individually as terminal device 120. The network device 110 is capable of communicating with the terminal device 120 . The sending of control information and/or data by the network device 110 to the terminal device 120 is referred to as downlink (Downlink, DL) communication, and the sending of control information and/or data by the terminal device 120 to the network device 110 is referred to as uplink (Uplink, UL) communication.

The network device 110 refers to any device capable of communicating with the terminal device 120 . As an example, the network device 110 may include a NodeB (NodeB), an evolved NodeB (eNodeB), a base station in a 5G mobile communication system, a next generation mobile communication NodeB (Next generation NodeB, gNB), and a base station in a future mobile communication system A base station or an access node in a Wi-Fi system, etc.

Terminal device 120 refers to any device capable of communicating with network device 110 . As an example, the terminal device 120 may mainly include sensors such as mobile phones, cars, tablet computers, smart speakers, train detectors, and gas stations. The main functions of the terminal device 120 include but are not limited to: collecting data, receiving control information and/or downlink data from the network device 110 , sending electromagnetic waves, and sending control information and/or uplink data to the network device 110 .

It can be understood that the number of network devices 110 and terminal devices 120 shown in FIG. 1 is only an example, and is not intended to pose any limitation. According to actual needs, the communication system 100 may include any appropriate number of network devices 110 and terminal devices 120 .

The terminal device 120 may access the network for communication by performing a random access procedure. Random access includes contention-based random access and non-contention-based random access. The non-contention-based access is generally used in a situation where the terminal device 120 has been able to successfully receive radio resource control (Radio Resource Control, RRC) signaling. In the following, the contention-based random access procedure will be taken as an example to describe the signaling interaction diagram of the random access procedure.

Fig. 2 shows a signaling interaction diagram for a random access procedure 200 according to some embodiments of the present disclosure. For purposes of discussion, random access procedure 200 will be described with reference to various elements shown in FIG. 1 . However, it should be understood that the random access process 200 may also be performed between a network device and a terminal device in any other communication scenarios.

As shown in FIG. 2 , the terminal device 120 sends 210 a preamble (Preamble) to the network device 110 . Hereinafter, the message carrying the preamble is also referred to as message 1 or Msg1. In some embodiments, the preamble may be carried by a physical random access channel (Physical Random Access Channel, PRACH). In some embodiments, the terminal device 120 may determine the time-frequency resource and the preamble for sending the preamble according to the system message received from the network device 110 and the selected synchronization signal block (Synchronization Signal Block, SSB) index.

After receiving the 220 preamble, the network device 110 allocates time-frequency resources for a Random Access Response (Random Access Response, RAR) message, scheduling information of Msg3, etc. for the terminal device 120. Hereinafter, the RAR message is also referred to as message 2 or Msg2. Msg2 includes the scheduling information of Msg3, that is, RAR UL grant (authorization) information. The RAR UL grant information indicates the time-frequency resource used for Msg3. Furthermore, the network device 110 sends 230 Msg2 to the terminal device 120 .

After receiving 240Msg2, terminal device 120 sends 250Msg3 on the time-frequency resource indicated in Msg2. Msg3 is carried by a Physical Uplink Shared Channel (PUSCH).

When multiple terminal devices 120 request to access the network at the same time, the network device 110 needs to determine which terminal device to select for this random access, and send 270Msg4 to the selected terminal device. Msg4 is mainly used for contention resolution. If the terminal device 120 successfully receives 280 the DCI sent to itself and successfully receives Msg4 according to the DCI, it is considered that the random access is successful. If the terminal device 120 fails to receive the DCI sent to itself, or if the Msg4 received according to the DCI is not sent to itself by the network device, it is considered that the random access fails. Since the terminal device 120 cannot determine in which time slot the network device 110 will send the DCI associated with Msg4, the terminal device 120 monitors the PDCCH of each downlink time slot in a blind detection manner. Therefore, a timer for random access contention resolution (hereinafter also referred to as contention resolution timer) is defined in the existing standard. If the terminal device 120 does not receive the DCI, it is considered that the random access has failed. Subsequently, the terminal device 120 may restart the random access procedure.

Since the transmission power of downlink communication is greater than that of uplink communication, the coverage capability of a cell is usually limited by uplink communication. In 4G and 5G wireless communication systems, energy accumulation is usually performed through PUSCH repeated transmission to increase the probability of successful signal reception and improve coverage.

In order to ensure that the terminal device 120 can successfully access the network, it is first necessary to ensure the successful transmission of each message during the random access process. Since the success of the random access of the terminal device 120 is mainly limited by the Msg3 carrying more information, the existing standard discussion meeting has determined that the coverage performance can be improved by repeatedly sending the Msg3.

The LTE system supports repeated sending of Msg3. In the LTE system, after receiving all the repeatedly sent Msg3s, the network equipment determines whether the Msg3s are received correctly. If the network device receives Msg3 correctly, the network device sends Msg4 to the terminal device. The sending of Msg4 occurs after the last repeat sending of Msg3 is completed. Correspondingly, the terminal device starts the contention resolution timer after all repeated transmissions of Msg3 are completed, so as to receive the DCI associated with Msg4. In other words, the terminal device starts the contention resolution timer after the number of repeated transmissions of Msg3 reaches the predetermined number, so as to receive the DCI associated with Msg4.

Fig. 3 shows a schematic diagram of the start time of the contention resolution timer in the LTE system. In FIG. 3 , each block represents a time slot, and each time slot includes 14 symbols, the subcarrier interval is 15 kHz, and the uplink and downlink switching period is 5 ms, including 5 time slots. The frame structure is configured as 3:1:1, that is, the number of downlink time slots (indicated as "D"): the number of flexible time slots (indicated as "S"): the number of uplink time slots (indicated as "U") The ratio between = 3:1:1.

The terminal device repeatedly sends Msg3 to the network device four times, the indexes are #1 to #4, which are represented as 311 to 314 in FIG. 3 . After receiving all four repeated transmissions of Msg3, the network device determines whether Msg3 is received correctly. If the network device correctly receives Msg3, for example, the network device correctly receives the second repetition of Msg3 312, the network device sends Msg4 to the terminal device. The sending of Msg4 occurs after the last repeated sending 314 of Msg3 is completed. Correspondingly, after all repeated transmissions of Msg3 are completed, that is, at time slot 315, the terminal device starts a contention resolution timer to receive the DCI associated with Msg4.

In the example of FIG. 3, Msg4 will not be sent until all retransmissions of Msg3 are completed. However, the network device may have successfully received Msg3 before the last retransmission of Msg3. This restricts the terminal device to receive the DCI associated with Msg4 only after the last retransmission of Msg3 is completed. Correspondingly, this also limits the network device to only sending the DCI associated with Msg4 after the last repeated sending of Msg3. This causes a relatively large access delay, and causes energy waste of unnecessary repeated sending of Msg3. In particular, when the network device randomly accesses and schedules the number of repetitions of Msg3, since there is no channel state information (Channel State Information, CSI) and other information, only the energy of the preamble is used to judge, resulting in an inaccurate number of repetitions scheduled by the network device. A network device tends to schedule more repetitions with a high probability to ensure the performance of coverage-limited terminal devices.

To at least address the above problems and potentially other related problems, embodiments of the present disclosure propose a scheme for random access. According to this solution, before the number of repeated transmissions of Msg3 reaches the first number of repeated transmissions or before the repeated transmissions are completed, the terminal device starts a contention resolution timer for receiving the DCI associated with Msg4. Correspondingly, before the number of repeated transmissions of Msg3 reaches the first number of repetitions or the repeated transmission is completed, if the network device successfully receives Msg3, the network device sends the DCI associated with Msg4 to the terminal device after the contention resolution timer is started. . This solution can reduce the random access delay of the terminal equipment. Embodiments of the present disclosure will be described in detail below with reference to FIGS. 4 to 7 .

FIG. 4 shows a signaling interaction diagram of an example procedure 400 for random access according to an embodiment of the present disclosure. For purposes of discussion, example process 400 will be described with reference to various elements shown in FIG. 1 . However, it should be understood that the example process 400 may also be performed between a network device and a terminal device in any other communication scenarios.

As shown in FIG. 4 , the terminal device 120 repeatedly sends 410 an uplink message (also referred to as Msg3 ) to the network device 110 based on the first number of repetitions. Correspondingly, the network device 110 receives 420 the repeatedly sent Msg3 from the terminal device 120 based on the first number of repetitions. The Msg3 is scheduled by a random access response message (also referred to as Msg2). In some embodiments, in order to obtain time-frequency resources for Msg3, terminal device 120 may perform

actions

210 and 240 described above with reference to FIG. 2 . In some embodiments, the first number of repetitions of Msg3 may be indicated by the network device 110 in Msg2. In some other embodiments, the first number of repetitions may be indicated by the network device 110 in other indication information, for example, indicated in a System Information Block 1 (System Information Block1, SIB1) or DCI. In yet other embodiments, the first number of repetitions may be predefined.

The terminal device 120 starts 430 a contention resolution timer for receiving the DCI associated with the contention resolution message (also referred to as Msg4 ) before the number of repeated transmissions of Msg3 reaches the first number of repetitions or the repeated transmission is completed. The start time of the contention resolution timer is associated with at least one of the following: the processing delay of the network device 110 (represented by T1), the first number of repetitions, and the time required for repeated transmission of the first number of repetitions of Msg3 ( represented by T2). In other words, the terminal device 120 determines the start time of the contention resolution timer based on at least one of the above. The processing delay of the network device 110 includes the delay of the network device 110 processing Msg3. In addition, the processing delay of the network device 110 may also include the delay of the network device 110 preparing the PDCCH, where the PDCCH is used to bear the DCI associated with Msg4. In other words, the processing delay of the network device 110 may include the time from when the network device 110 receives the Msg3 to when the network device 110 sends the PDCCH, where the PDCCH is used to carry the DCI associated with the Msg4. The time required for the repeated transmission of the first repeated number of Msg3 is the number of time units between the first symbol after the first repeated transmission of Msg3 and the first symbol after the last repeated transmission of Msg3. It can be understood that the last repeated sending of Msg3 here refers to the last repeated sending of the first repeated sending. For example, when the first repetition count is 4, the last repeated transmission of Msg3 refers to the fourth repeated transmission. Examples of time units may include, but are not limited to: subframes, slots, and OFDM symbols. Embodiments of determining the start time of the contention resolution timer will be described in detail below with reference to FIGS. 5A to 7C .

Before the number of repeated transmissions of Msg3 reaches the first repeated number of times or the repeated transmission is completed, if the network device 110 successfully receives Msg3, the network device 110 sends 440 a message associated with Msg4 to the terminal device 120 after the contention resolution timer is started. DCI. It should be understood that the network device 110 may not immediately send the DCI associated with Msg4 after successfully receiving a repeated transmission of Msg3, but wait until the contention resolution timer starts before sending the DCI associated with Msg4.

Correspondingly, terminal device 120 receives 450 Msg4 from network device 110 . After successfully receiving the DCI associated with Msg4, the terminal device 120 may receive Msg4 according to the DCI associated with Msg4.

Optionally, after receiving Msg4, terminal device 120 may determine the terminal identifier included in Msg4. Examples of the terminal identifier include but are not limited to: Cell-Radio Network Temporary Identifier (C-RNTI). If the terminal identifier is the same as the terminal identifier of the terminal device 120, the terminal device 120 determines that the random access is successful; if the terminal identifier is different from the terminal identifier of the terminal device 120, the terminal device 120 determines that the random access fails. Furthermore, the terminal device 120 may start the random access procedure again.

According to an embodiment of the present disclosure, before the number of repeated transmissions of Msg3 reaches the first number of repetitions or the repeated transmission is completed, the terminal device starts the contention resolution timer for receiving the DCI associated with Msg4, which can reduce the randomness of the terminal device. Access delay.

In some embodiments, the processing latency of the network device 110 may include layer 2 and/or layer 3 processing latency of the network device 110 . The delay may include one or more time units. Examples of time units may include, but are not limited to: subframes, slots, and OFDM symbols.

In some embodiments, the processing latency of the network device 110 is predefined. Alternatively, the processing delay of the network device 110 may be indicated by the network device 110 in system information (such as SIB1).

In some embodiments, the terminal device 120 may be a terminal device with limited coverage, for example, a terminal device that supports repeated sending of Msg3. In such an embodiment, the timing length of the contention resolution timer may be N subframes (N time slots when the subcarrier interval is 15 kHz), and N is greater than the time interval between two adjacent repeated transmissions of Msg3. In some embodiments, N may be indicated by the network device 110 in a first predefined parameter in the system information (eg SIB1). As an example, N may be equal to 8.

In some embodiments, the terminal device 120 may not be a terminal device with limited coverage, for example, a terminal device that does not support repeated sending of Msg3. In such an embodiment, the timing length of the contention resolution timer may be M subframes (M time slots when the subcarrier interval is 15 kHz, and M is a natural number). In some embodiments, M may be indicated by the network device 110 in a second predefined parameter (eg Rach-ConfigCommon) in the system information (eg SIB1). The second predefined parameter is different from the first predefined parameter described above.

It should be understood that the timing lengths N and M of the contention resolution timer may be any appropriate values, and the scope of the present disclosure is not limited in this respect.

In order to indicate an appropriate timing length to the terminal device 120, the network device 110 needs to determine whether the terminal device 120 is a coverage-limited terminal device. To this end, the network device 110 may adopt any one of the following two solutions.

Solution 1: the network device 110 may reserve a dedicated PRACH resource for a terminal device with limited coverage, for example, a new type of PRACH resource may be added. For example, when the Reference Signal Received Power (RSRP) is less than a predefined threshold, the terminal device 120 may choose to use the reserved PRACH resource, where the predefined threshold of RSRP may be notified in SIB1. If the network device 110 receives the preamble sent by the terminal device 120 on the reserved PRACH resource, the network device 110 may determine that the terminal device 120 is a coverage-limited terminal device.

Solution 2: The network device 110 may identify the terminal device with limited coverage through repeated transmission of the PRACH. The coverage-limited terminal equipment can increase the access probability by repeatedly sending the PRACH. The network device 110 identifies whether there is access of a terminal device with limited coverage by detecting the number of repeated transmissions of the PRACH. If yes, the network device 110 may use the redundant field of the Modulation and Coding Scheme (MCS) to indicate the number of repeated transmissions of Msg3 when transmitting the RAR UL grant.

It should be understood that the above two solutions are merely examples, and the network device 110 may also determine whether the terminal device 120 is a terminal device with limited coverage in other ways.

Hereinafter, some embodiments of determining the start time of the contention resolution timer will be described in detail with reference to FIGS. 5A to 7C .

In some embodiments, the terminal device 120 may determine the start time of the contention resolution timer based on the processing delay T1 of the network device 110 . Specifically, the terminal device 120 may determine the T1+1th time unit after the first repeated transmission of Msg3 as the start time of the contention resolution timer. As an example, when the time unit is an OFDM symbol, the start time of the contention resolution timer may specifically be the T1+1th OFDM symbol; when the time unit is a time slot, the start time of the contention resolution timer may specifically be It is the first OFDM symbol of the T1+1th time slot; when the time unit is a subframe, the start time of the contention resolution timer may specifically be the first OFDM symbol of the T1+1th subframe. This embodiment will be described in detail below with reference to FIGS. 5A and 5B .

FIG. 5A shows a schematic diagram of start times of a contention resolution timer in a time division duplex (TDD) scenario according to some embodiments of the present disclosure. In FIG. 5A , each block represents a time slot, each time slot includes 14 symbols, the subcarrier interval is 15kHz, the uplink and downlink conversion period is 10ms, and the uplink and downlink conversion period contains 10 time slots. The frame structure is configured as 8:1:1, that is, the number of downlink time slots (indicated as "D"): the number of flexible time slots (indicated as "S"): the number of uplink time slots (indicated as "U") The ratio between = 8:1:1. The processing delay T1 of the network device 110 is 6 time slots. The timing length of the contention resolution timer is 8 time slots when the subcarrier interval is 15 kHz.

The terminal device 120 repeatedly sends the Msg3 to the network device 110 four times, indexed as #1 to #4, denoted as 511 to 514 in FIG. 5A . The terminal device 120 starts the contention resolution timer at the T1+1th time unit after the first repeated transmission of Msg3. That is, the terminal device 120 starts the contention resolution timer at the seventh time unit (ie, the 6*14+1 symbol) 521 after sending Msg3#1 (denoted as 511 ).

In some embodiments, after starting the contention resolution timer, if the repeated transmission of Msg3 does not reach the first number of repetitions, the terminal device 120 restarts (that is, restarts) the contention resolution timer after each subsequent repeated transmission of Msg3 . For example, in the example of FIG. 5A , after the contention resolution timer is started, since the repeated transmission of Msg3 has not reached four times, the terminal device 120, after the subsequent repeated

transmissions

512, 513 and 514 of Msg3, the

time units

522, 523 and 524 restart the contention resolution timer respectively. FIG. 5B shows a schematic diagram of start times of a contention resolution timer in a frequency division duplex (FDD) scenario according to some embodiments of the present disclosure. In FIG. 5B , each block represents a time slot, each time slot includes 14 symbols, and the subcarrier spacing is 15 kHz. The processing delay T1 of the network device 110 includes 6 time slots.

The terminal device 120 repeatedly sends the Msg3 to the network device 110 four times, indexed as #1 to #4, denoted as 531 to 534 in FIG. 5B . The terminal device 120 starts the contention resolution timer at the T1+1th time unit after the first repeated transmission of Msg3. That is, the terminal device 120 starts the contention resolution timer at the seventh time unit (ie, the 6*14+1 symbol) 541 after the sending of Msg3#1 (denoted as 531 ).

In some embodiments, after starting the contention resolution timer, if the repeated transmission of Msg3 does not reach the first repeated number of times, the terminal device 120 restarts at the T1+1th time unit after each subsequent repeated transmission of Msg3 ( ie restart) contention resolution timer.

In some embodiments, the terminal device 120 may determine the start time of the contention resolution timer based on the time T2 required for the repeated transmission of the first repeated number of Msg3 and the processing delay T1 of the network device 110 . Specifically, the terminal device 120 may compare T2 with T1. If T2 is greater than T1, the terminal device 120 determines the T1+1th time unit after the first repeated transmission of Msg3 as the start time of the contention resolution timer. If T2 is less than or equal to T1, the terminal device 120 determines the first time unit after the last repeated transmission of Msg3 as the start time of the contention resolution timer. Alternatively, if T2 is less than or equal to T1, the terminal device 120 determines the T1+1th time unit after the last repeated transmission of Msg3 as the start time of the contention resolution timer. This embodiment will be described in detail below with reference to FIGS. 6A and 6B .

Fig. 6A shows a schematic diagram of start time of a contention resolution timer in a TDD scenario according to other embodiments of the present disclosure. The example in FIG. 6A is similar to the example in FIG. 5A , the difference between the two is that FIG. 6A further shows the relationship between the time T2 required for the repeated transmission of the first repetition number of Msg3 and the processing delay T1 of the network device 110 . In the example of FIG. 6A , T1 includes 6 slots and T2 includes 30 slots, each slot including 14 symbols. Since T2 is greater than T1, terminal device 120 determines the T1+1th time unit after the first repeated transmission of Msg3 as the start time of the contention resolution timer. That is, the terminal device 120 starts the contention resolution timer at the seventh time unit (ie, the 6*14+1 symbol) 521 after sending Msg3#1 (denoted as 511 ).

Fig. 6B shows a schematic diagram of start time of a contention resolution timer in an FDD scenario according to other embodiments of the present disclosure. The example in FIG. 6B is similar to the example in FIG. 5B , the difference between the two is that FIG. 6B further shows the size relationship between the time T2 required for the repeated transmission of the first repetition number of Msg3 and the processing delay T1 of the network device 110 . In the example of FIG. 6B, T1 includes 6 time slots and T2 includes 3 time slots. Since T2 is smaller than T1, terminal device 120 determines the first time unit after the last repeated transmission of Msg3 as the start time of the contention resolution timer. That is, the terminal device 120 starts the contention resolution timer at the first time unit 611 after sending Msg3#4 (shown as 534 ).

In some embodiments, the terminal device 120 may determine the start time of the contention resolution timer based on the first repetition number of Msg3. For example, the terminal device 120 may determine the second number of repetitions (indicated by i) associated with the first number of repetitions based on the first number of repetitions, and then determine the first time unit after the repeated transmission of the second number of repetitions of Msg3 as The start time of the contention resolution timer, wherein the second repetition number is smaller than the first repetition number. Alternatively, the terminal device 120 may determine the second number of repetitions (indicated by i) associated with the first number of repetitions based on the first number of repetitions, and then determine the first time unit after the repeated transmission of the second number of repetitions of Msg3 as The start time of the contention resolution timer, wherein the second number of repetitions is less than or equal to the first number of repetitions; in the case of the first number of repetitions less than or equal to the threshold, the second number of repetitions is equal to the first number of repetitions, and in the case of the first number of repetitions If it is greater than the threshold, the second number of repetitions is smaller than the first number of repetitions. As an example, Table 1 and Table 2 below show the association between the first repetition number of Msg3 and the start time of the contention resolution timer (ie, the association between the first repetition number and the second repetition number). The terminal device 120 may determine the starting time of the contention resolution timer based on Table 1 or Table 2.

Table 1

Msg3的第一重复次数First repetition of Msg3	竞争解决定时器的启动时间The start time of the contention resolution timer
22	Msg3的第1次重复发送结束后After the 1st repeated sending of Msg3 ends
44	Msg3的第2次重复发送结束后After the 2nd repeated sending of Msg3 ends
88	Msg3的第4次重复发送结束后After the 4th repeated sending of Msg3 ends
1616	Msg3的第8次重复发送结束后After the 8th repeated sending of Msg3 ends

Table 2

Msg3的第一重复次数First repetition of Msg3	竞争解决定时器的启动时间The start time of the contention resolution timer
22	Msg3的第2次重复发送结束后After the 2nd repeated sending of Msg3 ends
44	Msg3的第4次重复发送结束后After the 4th repeated sending of Msg3 ends
88	Msg3的第4次重复发送结束后After the 4th repeated sending of Msg3 ends
1616	Msg3的第8次重复发送结束后After the 8th repeated sending of Msg3 ends

Table 1 shows an example where the second number of repetitions is smaller than the first number of repetitions. As shown in Table 1, when the first repetition number of Msg3 is 2, the second repetition number is 1, which means that the network device 110 has a higher probability of successful decoding after receiving Msg3 for the first time. Therefore, the terminal device 120 starts the contention resolution timer at the first time unit after the first repeated sending of Msg3 ends. When the first repetition number of Msg3 is 4, the second repetition number is 2, so the terminal device 120 starts the contention resolution timer at the first time unit after the second repetition of Msg3 is sent. When the first number of repetitions of Msg3 is 8, the second number of repetitions is 4, so the terminal device 120 starts the contention resolution timer at the first time unit after the fourth repetition of Msg3 is sent. When the first repetition number of Msg3 is 16, the second repetition number is 8, so the terminal device 120 starts the contention resolution timer at the first time unit after the 8th repetition sending of Msg3 ends.

Table 2 shows an example where the second number of repetitions is less than or equal to the first number of repetitions, and the threshold may be 4 in the example of Table 2. As shown in Table 2, when the first repetition number of Msg3 is 2, the second repetition number is 2. Therefore, the terminal device 120 starts the contention resolution timer at the first time unit after the second repeated sending of Msg3 ends. When the first repetition number of Msg3 is 4, the second repetition number is 4, so the terminal device 120 starts the contention resolution timer at the first time unit after the fourth repetition of Msg3 is sent. When the first repetition number of Msg3 is 8, the second repetition number is 4, so the terminal device 120 starts the contention resolution timer at the first time unit after the 4th repetition of Msg3 ends. When the first repetition number of Msg3 is 16, the second repetition number is 8, so the terminal device 120 starts the contention resolution timer at the first time unit after the 8th repetition sending of Msg3 ends.

It should be understood that Table 1 and Table 2 only show an example of the association relationship between the first number of repetitions of Msg3 and the start time of the contention resolution timer, and the scope of the present disclosure is not limited in this respect. It is also possible that other associations exist.

In some embodiments, the terminal device 120 may determine the contention resolution timing based on the first number of repetitions of Msg3 and the relationship between the time T2 required for repeated transmission of the first number of repetitions of Msg3 and the processing delay T1 of the network device 110 start-up time of the device. Specifically, the terminal device 120 may compare the time T2 required for repeated sending of the first repeated number of Msg3 with the processing delay T1 of the network device 110 . If T2 is greater than T1, the terminal device 120 determines the T1+1th time unit after the repeated transmission of the second repetition number of Msg3 as the start time of the contention resolution timer. The second number of repetitions is associated with the first number of repetitions. The second number of repetitions is less than the first number of repetitions, or the second number of repetitions is less than or equal to the first number of repetitions. When the first number of repetitions is less than or equal to the threshold, the second number of repetitions is equal to the first number of repetitions; when the first number of repetitions is greater than the threshold, the second number of repetitions is smaller than the first number of repetitions. If T2 is less than or equal to T1, the terminal device 120 determines the first time unit after the last repeated transmission of Msg3 as the start time of the contention resolution timer, or the T1+1th time unit after the first repeated transmission of Msg3 Determines the start time for the contention resolution timer. This embodiment will be described in detail below with reference to FIGS. 7A, 7B and 7C.

Fig. 7A shows a schematic diagram of the start time of the contention resolution timer in the TDD scenario according to some other embodiments of the present disclosure. The example in FIG. 7A is similar to the example in FIG. 6A. The difference between the two is that in the example in FIG. 7A, the terminal device 120 determines the contention resolution timer based on not only the size relationship between T2 and T1 but also the first repetition number of Msg3. Start Time. Specifically, the terminal device 120 compares T2 with T1. Since T2 is greater than T1, the terminal device 120 determines the T1+1th time unit after the i-th (second number of repetitions) of repeated transmission of Msg3 as the start time of the contention resolution timer. The second number of repetitions i can be determined according to Table 1 or Table 2, for example. In this example, since the first number of repetitions is equal to 4, it can be determined from Table 1 that the second number of repetitions i is equal to 2. Thus, the terminal device 120 starts the contention resolution timer at the seventh time unit (ie, the 6*14+1 symbol) 711 after the transmission of Msg3#2 (denoted as 512 ).

Fig. 7B shows a schematic diagram of the starting time of the contention resolution timer in the FDD scenario according to some other embodiments of the present disclosure. The example in FIG. 7B is similar to the example in FIG. 6B . The difference between the two is that in the example in FIG. 7B , the terminal device 120 determines the contention resolution timer based on not only the size relationship between T2 and T1 but also the first repetition number of Msg3 Start Time. In the example of FIG. 7B, T1 includes 6 time slots and T2 includes 3 time slots. Since T2 is smaller than T1, terminal device 120 determines the T1+1th time unit after the first repeated transmission of Msg3 as the start time of the contention resolution timer. That is, the terminal device 120 starts the contention resolution timer at the seventh time unit (ie, the 6*14+1 symbol) 721 after the transmission of Msg3#1 (denoted as 531 ).

Fig. 7C shows a schematic diagram of the start time of the contention resolution timer in the FDD scenario according to some further embodiments of the present disclosure. The example in FIG. 7C is similar to the example in FIG. 7B , the difference is that in the example in FIG. 7C , the terminal device 120 determines the first time unit after the last repeated transmission of Msg3 as the start time of the contention resolution timer. That is, the terminal device 120 starts the contention resolution timer at the first time unit 731 after sending Msg3#4 (denoted as 534 ).

It should be understood that in FIGS. 5A, 6A and 7A, the subcarrier spacing is 15 kHz, the uplink and downlink conversion period is 10 ms, and the frame structure is configured as 8:1:1 as an example for description, but the scope of the present disclosure does not It is not limited to this.

In some embodiments, if the terminal device 120 successfully receives the DCI associated with Msg4 before the number of repeated transmissions of Msg3 reaches the first repeated number or before the repeated transmission is completed, the terminal device 120 may cancel subsequent repeated transmissions of Msg3. By canceling the subsequent repeated sending of Msg3, the energy waste of the terminal device 120 sending Msg3 can be avoided.

In some embodiments, optionally, in order to enable the terminal device 120 to cancel the subsequent repeated transmission of Msg3, the network device 110, within the timing range of the contention resolution timer, except for the predetermined time period before each subsequent repeated transmission of Msg3 The DCI associated with Msg4 is sent out. In other words, network device 110 will not send the DCI associated with Msg4 within a predetermined period of time before each subsequent retransmission of Msg3. The predetermined time period is determined based on the sum of the uplink transmission preparation time (denoted by T _proc ) and the downlink reception processing time (denoted by d ₁ ) of the terminal device 120 . The uplink transmission preparation time T _proc can be calculated according to the method described in Section 6.4 of TS 38.213, and the downlink reception processing time d ₁ can be reported by the terminal device 120 to the network device 110 . As an example, the predetermined time period may include W symbols before the first time-domain symbol corresponding to any subsequent repeated transmission of Msg3. The timing range of the contention resolution timer may be determined by the timing length (for example, M subframes) and start time of the contention resolution timer, for example, M subframes after the contention resolution timer is started.

In some embodiments, the terminal device 120 may send information to the network device 110 to indicate whether the terminal device 120 starts the contention resolution timer before the repeated sending of Msg3 reaches the first repeated times. Alternatively, the terminal device 120 may send capability information to the network device 110, where the capability information indicates whether the terminal device 120 has the capability to start the contention resolution timer before the repeated sending of Msg3 reaches the first repeated times. Alternatively, the terminal device 120 may send information to the network device 110 to indicate whether the terminal device 120 can cancel the subsequent repeated sending of Msg3 before the repeated sending of Msg3 reaches the first repeated times. Alternatively, the terminal device 120 may send capability information to the network device 110, where the capability information indicates whether the terminal device 120 has the capability of canceling the subsequent repeated transmission before the repeated transmission of Msg3 reaches the first repeated times. To this end, the terminal device 120 may adopt any one of the following two solutions.

Solution 1: The network device 110 reserves a dedicated PRACH resource for the terminal device 120 capable of reporting the information, that is, a new type of PRACH resource can be added. For example, the network device 110 may reserve dedicated PRACH resource 1 and PRACH resource 2 for the terminal device 120 . If the terminal device 120 uses the PRACH resource 1 to send Msg1, the network device 110 knows that the terminal device 120 will start the contention resolution timer before the repeated sending of Msg3 reaches the first number of repetitions. If the terminal device 120 uses the PRACH resource 2 to send Msg1, the network device 110 knows that the terminal device 120 will not start the contention resolution timer before the repeated transmission of Msg3 reaches the first number of repetitions.

Solution 2: The network device 110 can determine whether the terminal device 120 starts the contention resolution timer before the repeated transmission of Msg3 reaches the first repetition times through the demodulation reference signal (Demodulation Reference Signal, DMRS) port used by Msg3 or Msg1. Currently, the terminal device 120 uses the default DMRS port to transmit Msg3. If the network device 110 detects that the port used by Msg3 is different from the default DMRS port, it is considered that the terminal device 120 will start the contention resolution timer before the repeated sending of Msg3 reaches the first repeated times.

It should be understood that the above two solutions are merely examples, and the terminal device 120 may also indicate whether to start the contention resolution timer in advance in other ways.

FIG. 8 shows a flowchart of an example method 800 for random access according to some embodiments of the present disclosure. In some embodiments, the example method 800 can be implemented by the terminal device 120 in the example communication system 100, for example, it can be implemented by a processor or a processing unit of the terminal device 120 in cooperation with other components (eg, a transceiver). In other embodiments, the example method 800 may also be implemented by other communication devices independent of the example communication system 100 . For ease of illustration, an example method 800 will be described with reference to FIG. 1 .

At block 810, the terminal device 120 repeatedly sends the uplink message to the network device 110 based on the first number of repetitions. The uplink message is scheduled by the random access response message.

At block 820, before the number of repeated transmissions of the uplink message reaches the first number of repetitions or the repeated transmission is completed, the terminal device 120 starts a contention resolution timer for receiving the DCI associated with the contention resolution message. The starting time of the contention resolution timer is associated with at least one of the following: the processing delay of the network device 110 , the first number of repetitions, and the time required for repeated transmission of the first number of repetitions of the uplink message. The processing delay includes the delay for the network device 110 to process the uplink message.

By using the method 800, the random access delay of the terminal device can be reduced.

In some embodiments, additionally, if the terminal device 120 successfully receives the DCI associated with the contention resolution message before the number of repeated transmissions of the uplink message reaches the first repeated number of times or the repeated transmission is completed, the terminal device 120 may cancel the Subsequent repeated sending of uplink messages. In this way, energy waste for the terminal device 120 to send uplink messages can be avoided.

In some embodiments, the start time of the contention resolution timer may be the T1+1th time unit after the first repeated sending of the uplink message, where T1 represents the processing delay of the network device 110 .

In some embodiments, alternatively, if the time required for the repeated transmission of the first repeated times of the uplink message exceeds the processing delay, the start time of the contention resolution timer may be the T1+1th time unit.

In some embodiments, alternatively, if the time required for the repeated transmission of the first repeated number of times of the uplink message exceeds the processing delay, the start time of the contention resolution timer may be the repeated transmission of the second repeated number of times of the uplink message The next T1+1 time unit. The second number of repetitions is associated with and less than the first number of repetitions. T1 represents the processing delay of the network device 110 .

In some embodiments, the processing latency of the network device 110 may be predefined. Alternatively, the terminal device 120 may receive system information indicating the processing delay from the network device 110 .

In some embodiments, additionally, after starting the contention resolution timer, if the repeated transmission of the uplink message does not reach the first number of repetitions, the terminal device 120 may restart the contention resolution timer after each subsequent repeated transmission of the uplink message device.

In some embodiments, additionally, the terminal device 120 may receive the DCI associated with the contention resolution message within the timing range of the contention resolution timer except for a predetermined time period before each subsequent repeated transmission of the uplink message. The predetermined period of time is determined based on the sum of the uplink transmission preparation time and downlink reception processing time of the terminal device 120 . Subsequent retransmissions are located after the first retransmission of the uplink message.

In some embodiments, additionally, the terminal device 120 may send information to the network device 110, the information indicating whether the terminal device 120 starts the contention resolution timer before the repeated sending of the uplink message reaches the first repeated times.

FIG. 9 shows a flowchart of an example method 900 for random access according to other embodiments of the present disclosure. In some embodiments, the example method 900 may be implemented by the network device 110 in the example communication system 100, for example, may be implemented by a processor or a processing unit of the network device 110 in cooperation with other components (eg, a transceiver). In other embodiments, the example method 900 may also be implemented by other communication devices independent of the example communication system 100 . For ease of illustration, an example method 900 will be described with reference to FIG. 1 .

At block 910, the network device 110 receives the repeatedly sent uplink message from the terminal device 120 based on the first repetition number. The uplink message is scheduled by the random access response message.

At block 920, if the network device 110 successfully receives the uplink message before the number of repeated transmissions of the uplink message reaches the first number of repetitions or the completion of the repeated transmission, the network device 110 sends a message to the terminal device 120 after the contention resolution timer is started. Send the DCI associated with the contention resolution message. The starting time of the contention resolution timer is associated with at least one of the following: the processing delay of the network device 110 , the first number of repetitions, and the time required for repeated transmission of the first number of repetitions of the uplink message. The processing delay includes the delay for the network device 110 to process the uplink message.

By using the method 900, the random access delay of the terminal device can be reduced.

In some embodiments, alternatively, if the time required for the repeated transmission of the first repeated number of times of the uplink message exceeds the processing delay, the start time of the contention resolution timer may be the repeated transmission of the second repeated number of times of the uplink message The next T1+1 time unit. The second repetition number is associated with and smaller than the first repetition number, and T1 represents a processing delay.

In some embodiments, the processing latency of the network device 110 may be predefined. Alternatively, the network device 110 may send system information indicating the processing delay to the terminal device 120 .

In some embodiments, the network device 110 may transmit the DCI associated with the contention resolution message within the timing range of the contention resolution timer except for a predetermined time period before each subsequent repeated transmission of the uplink message. The predetermined period of time is determined based on the sum of the uplink transmission preparation time and downlink reception processing time of the terminal device 120 . Subsequent retransmissions are located after the first retransmission of the uplink message.

In some embodiments, additionally, the network device 110 may receive information from the terminal device 120, the information indicating whether the terminal device 120 starts the contention resolution timer before the number of times of repeated transmission of the uplink message reaches the first number of repetitions.

FIG. 10 shows a block diagram of an example electronic device 1000 according to an embodiment of the present disclosure. The example electronic device 1000 may be used to implement a communication device, such as the network device 110 and the terminal device 120 in FIG. 1 . Therefore, the example electronic device 1000 may also be referred to as the example communication device 1000 herein. As shown in FIG. 10 , an example communications device 1000 may include a processor 1010 and a memory 1020 coupled to the processor 1010 . Memory 1020 has computer program instructions 1025 stored therein. Additionally, the example communications device 1000 may further include a communications module 1030 coupled to the processor 1010 . The communication module 1030 can be used for two-way communication, and can have at least one wire, fiber optic cable, wireless interface, etc. for facilitating communication. A communication interface may represent any interface for communicating with other devices.

The processor 1010 may be of any type suitable for the local technical environment, and may include, as non-limiting examples, one or more of the following: a general purpose computer, a special purpose computer, a microprocessor, a digital signal processor (Digital Signal Processor, DSP) and Processors based on multi-core processor architectures. The example communications device 1000 may have multiple processors, such as application specific integrated circuit chips that are slaved in time to a clock that is synchronized with a master processor. Memory 1020 may include one or more non-volatile memories and one or more volatile memories. Examples of non-volatile memory include, but are not limited to, Read-Only Memory (ROM), Electrically Erasable Programmable Read-Only Memory (EPROM), flash memory, hard disk, compact disk ( Compressed Disk (CD), Digital Versatile Distribution (DVD), and other magnetic and/or optical storage devices. Examples of volatile memory include, but are not limited to, Random Access Memory (RAM) or other volatile memory that does not persist during a power loss. Computer program instructions 1025 may include computer-executable instructions that are executable by an associated processor 1010 . In some embodiments, computer program instructions 1025 may be stored in ROM of memory 1020 . The processor 1010 can perform various appropriate actions and processes by loading the memory 1020 into the RAM of the memory 1020 . Embodiments of the present disclosure may be implemented by computer program instructions 1025 to cause the example communication device 1000 to perform any of the methods or processes of the present disclosure as discussed above with reference to FIGS. 4 , 8 and 9 . Of course, the embodiments of the present disclosure may also be implemented by hardware or a combination of software and hardware.

In some embodiments, computer program instructions 1025 may be tangibly embodied on a computer readable medium. Such computer-readable media may be included in the example communication device 1000 (eg, memory 1020 ) or in other storage devices accessible to the example communication device 1000 . The example communication device 1000 may read the computer program instructions 1025 from the computer readable medium to the RAM of the memory 1020 for execution. The computer readable medium may include various tangible non-volatile storage devices such as ROM, EPROM, flash memory, hard disk, CD, DVD, and the like.

In general, the various example embodiments of the present disclosure may be implemented in hardware or special purpose circuits, software, logic, or any combination thereof. Certain aspects may be implemented in hardware, while other aspects may be implemented in firmware or software, which may be executed by a controller, microprocessor or other computing device. For example, in some embodiments, various examples (eg, methods, apparatuses, or devices) of the present disclosure may be partially or fully implemented on a computer-readable medium. When aspects of the embodiments of the present disclosure are illustrated or described as block diagrams, flowcharts, or using some other graphical representation, it is to be understood that the blocks, devices, systems, techniques, or methods described herein may serve as non-limiting Examples are implemented in hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controllers or other computing devices, or some combination thereof.

The present disclosure also provides at least one computer program product stored on a non-transitory computer-readable storage medium. The computer program product includes computer-executable instructions, such as included in a program module executed in a device on a physical or virtual processor of a target, to perform the example described above with respect to FIGS. 4 , 8 and 9 Methods or example processes 400 , 800 and 900 . Generally, program modules may include routines, programs, libraries, objects, classes, components, data structures, etc. that perform particular tasks or implement particular abstract data structures. In various embodiments, the functionality of the program modules may be combined or divided between the described program modules. Computer-executable instructions for program modules may be executed within local or distributed devices. In a distributed device, program modules may be located in both local and remote storage media.

Program codes for implementing the methods of the present disclosure may be written in one or more programming languages. These computer program codes can be provided to processors of general-purpose computers, special-purpose computers, or other programmable data processing devices, so that when the program codes are executed by the computer or other programmable data processing devices, The functions/operations specified in are implemented. The program code may execute entirely on the computer, partly on the computer, as a stand-alone software package, partly on the computer and partly on a remote computer or entirely on the remote computer or server. In the context of the present disclosure, computer program code or related data may be carried by any suitable carrier to enable a device, apparatus or processor to perform the various processes and operations described above. Examples of carriers include signals, computer readable media, and the like.

The computer readable medium may be a computer readable signal medium or a computer readable storage medium. A computer readable medium may include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination thereof. More detailed examples of machine-readable storage media include electrical connections with one or more wires, portable computer diskettes, hard disks, random storage access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disc read only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof.

In addition, while operations are depicted in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown, or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In some cases, multitasking or parallel processing can be beneficial. Likewise, while the above discussion contains certain specific implementation details, these should not be construed as limitations on the scope of any invention or claims, but rather as a description of particular embodiments that may be directed to particular inventions. Certain features that are described in this specification in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable subcombination.

Although the subject matter has been described in language specific to structural features and/or methodological acts, it is to be understood that the subject matter defined in the appended claims is not limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

Claims

A method for random access comprising:

The terminal device repeatedly sends the uplink message to the network device based on the first number of repetitions, the uplink message is scheduled by the random access response message; and

Before the number of repeated transmissions of the uplink message reaches the first number of repetitions or the repeated transmission is completed, the terminal device starts a contention resolution timer for receiving downlink control information associated with the contention resolution message,

Wherein the start time of the contention resolution timer is associated with at least one of the following:

the processing delay of the network device, where the processing delay includes the delay of the network device processing the uplink message,

the first number of repetitions, and

The time required for repeated sending of the first number of repetitions of the uplink message.
The method of claim 1, further comprising:

Before the number of repeated transmissions of the uplink message reaches the first number of repetitions or before the repeated transmission is completed, if the terminal device successfully receives the downlink control information, the terminal device cancels the uplink Subsequent repeated sending of the message.
The method according to claim 1, wherein said start time of said contention resolution timer is:

T1+1th time unit after the first repeated sending of the uplink message, where T1 represents the processing delay.
The method of claim 3, wherein:

If the time required for repeated sending of the first number of repetitions of the uplink message exceeds the processing delay, the start time of the contention resolution timer is the T1+1th time unit.
The method of claim 1, wherein:

If the time required for repeated transmission of the first number of repetitions of the uplink message exceeds the processing delay, the start time of the contention resolution timer is the repetition of the second number of repetitions of the uplink message In the T1+1th time unit after sending, the second repetition number is associated with the first repetition number and is smaller than the first repetition number, and T1 represents the processing delay.
A method according to any one of claims 2 to 5, wherein said processing delay is predefined.
The method according to any one of claims 2 to 5, further comprising:

The terminal device receives system information indicating the processing delay from the network device.
The method of claim 1, further comprising:

After starting the contention resolution timer, if the repeated transmission of the uplink message does not reach the first number of repetitions, the terminal device restarts the Contention resolution timer.
The method of claim 1, further comprising:

The terminal device receives the downlink control information within the timing range of the contention resolution timer except for a predetermined time period before each subsequent repeated transmission of the uplink message, the predetermined time period being based on the terminal The sum of uplink sending preparation time and downlink receiving processing time of the device is determined, and the subsequent repeated sending is located after the first repeated sending of the uplink message.
The method of claim 1, further comprising:

The terminal device sends information to the network device, where the information indicates whether the terminal device starts the contention resolution timer before repeated sending of the uplink message reaches the first number of repetitions.
A method for random access comprising:

The network device receives a repeatedly sent uplink message from the terminal device based on the first number of repetitions, the uplink message is scheduled by the random access response message; and

Before the number of repeated transmissions of the uplink message reaches the first number of repetitions or the repeated transmission is completed, if the network device successfully receives the uplink message, the network device sends a notification after the contention resolution timer is started The terminal device sends downlink control information associated with the contention resolution message,

Wherein the start time of the contention resolution timer is associated with at least one of the following:

the processing delay of the network device, where the processing delay includes the delay of the network device processing the uplink message,

the first number of repetitions, and

The time required for repeated sending of the first number of repetitions of the uplink message.
The method according to claim 11, wherein said start time of said contention resolution timer is:

T1+1th time unit after the first repeated sending of the uplink message, where T1 represents the processing delay.
The method of claim 12, wherein:

If the time required for repeated sending of the first number of repetitions of the uplink message exceeds the processing delay, the start time of the contention resolution timer is the T1+1th time unit.
The method of claim 11, wherein:

If the time required for repeated transmission of the first number of repetitions of the uplink message exceeds the processing delay, the start time of the contention resolution timer is the repetition of the second number of repetitions of the uplink message In the T1+1th time unit after sending, the second repetition number is associated with the first repetition number and is smaller than the first repetition number, and T1 represents the processing delay.
A method according to any one of claims 11 to 14, wherein the processing delay is predefined.
The method according to any one of claims 11 to 14, further comprising:

The network device sends system information indicating the processing delay to the terminal device.
The method of claim 11, further comprising:

After the contention resolution timer is started, if the repeated transmission of the uplink message does not reach the first number of repetitions, the contention resolution timer is terminated after each subsequent repeated transmission of the uplink message Restart.
The method according to claim 11, wherein the network device sending the downlink control information to the terminal device comprises:

The network device sends the downlink control information within the timing range of the contention resolution timer except for a predetermined time period before each subsequent repeated transmission of the uplink message, the predetermined time period is based on the terminal The sum of uplink sending preparation time and downlink receiving processing time of the device is determined, and the subsequent repeated sending is located after the first repeated sending of the uplink message.
The method of claim 11, further comprising:

The network device receives information from the terminal device, the information indicating whether the terminal device starts the contention resolution timer before the number of repeated transmissions of the uplink message reaches the first number of repetitions.
A terminal device comprising:

processor; and

A memory stores computer program instructions, and the memory and the computer program instructions are configured to, together with the processor, cause the terminal device to execute the method according to any one of claims 1-10.
A network device comprising:

processor; and

A memory stores computer program instructions, and the memory and the computer program instructions are configured to, together with the processor, cause the network device to execute the method according to any one of claims 11-19.
A computer-readable medium storing machine-executable instructions, the machine-executable instructions, when executed by a terminal device, cause the terminal device to execute the method according to any one of claims 1-10.
A computer-readable medium storing machine-executable instructions that, when executed by a network device, cause the network device to perform the method according to any one of claims 11-19.
A computer program product comprising machine-executable instructions which, when executed by a terminal device, cause the terminal device to perform the method according to any one of claims 1-10.
A computer program product comprising machine-executable instructions which, when executed by a terminal device, cause the terminal device to perform the method according to any one of claims 11-19.