CN115334683A

CN115334683A - Method, apparatus, and storage medium for random access

Info

Publication number: CN115334683A
Application number: CN202110512019.4A
Authority: CN
Inventors: 宣一荻; 余健; 郭志恒
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2021-05-11
Filing date: 2021-05-11
Publication date: 2022-11-11
Also published as: WO2022237739A1

Abstract

Methods, terminal devices, network devices and media for random access are provided. The method comprises the step that the terminal equipment repeatedly sends the uplink message to the network equipment based on the first repetition times. The uplink message is scheduled by a random access response message. The method further includes the terminal device starting a contention resolution timer for receiving downlink control information associated with the contention resolution message before the number of times of the repeated transmission of the uplink message reaches the first number of times of repetition or the repeated transmission is completed. The start time of the contention resolution timer is associated with at least one of: the processing delay of the network device, the first repetition number, and the time required for the repeated sending of the first repetition number of the uplink message, where the processing delay of the network device includes a delay of the network device for processing the uplink message. The method can reduce the random access delay of the terminal equipment.

Description

Method, apparatus and storage medium for random access

Technical Field

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

Background

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

In coverage limited scenarios, the coverage needs to be increased by repeated transmission of Msg3. After successfully receiving the Msg3 that is repeatedly transmitted, the network device transmits Downlink Control Information (DCI) associated with the contention resolution message to the terminal device through a Physical Downlink Control Channel (PDCCH). Hereinafter, the contention resolution message is also referred to as message 4 or Msg4. Accordingly, the terminal device may start a contention resolution timer and detect the PDCCH after the contention resolution timer is started until the contention resolution timer expires. When the Msg3 is transmitted repeatedly, if the contention resolution timer is started too early, the terminal device detects the PDCCH within a time range in which the Msg4 cannot be received, and energy of the terminal device is wasted; if the contention resolution timer is started too late, a large access delay is caused when the network device correctly receives the Msg3 before the terminal device completes the repeated transmission. Therefore, how to start the contention resolution timer at an appropriate time when the Msg3 repeatedly transmits is a problem to be solved.

Disclosure of Invention

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

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

In some embodiments, additionally, the terminal device may cancel subsequent duplicate transmissions of the uplink message if the terminal device successfully receives DCI associated with the contention resolution message before the number of duplicate transmissions of the uplink message reaches the first number of duplicates or the duplicate transmissions are complete. In this way, the waste of energy for the terminal device to send the uplink message can be avoided.

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

In some embodiments, alternatively, if the time required for the first repetition number of repeated transmission of the uplink message exceeds the processing delay, the start time of the contention resolution timer may be T1+1 time unit after the second repetition number of repeated transmission of the uplink message. 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 a second repetition number associated with the first repetition number based on the first repetition number, and further determine a first time unit after repeated transmission of the second repetition number of the uplink message as the start time of the contention resolution timer, wherein the second repetition number is smaller than the first repetition number.

In some embodiments, the terminal device may determine a second repetition number associated with the first repetition number based on the first repetition number, and further determine a first time unit after the repeated transmission of the second repetition number of the uplink message as the start time of the contention resolution timer, wherein the second repetition number is less than or equal to the first repetition number. In a case where the first number of repetitions is less than or equal to a threshold, the second number of repetitions is equal to the first number of repetitions; in a case where the first repetition number is greater than the threshold value, the second repetition number is smaller than the first repetition number.

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 DCI associated with the contention resolution message within a timing range of the contention resolution timer except for a predetermined time period prior to each subsequent repeated transmission of the uplink message. The predetermined period is determined based on the sum of the upstream transmission preparation time and the downstream reception processing time of the terminal device. The subsequent repeat transmission is after the first repeat transmission of the upstream message.

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

In a second aspect of the disclosure, a method implemented at a network device for random access is provided. The method includes the network device receiving a repeatedly transmitted uplink message from the terminal device based on a first repetition number. The uplink message is scheduled by a random access response message. The method further comprises the following steps: before the number of times of the repeated transmission of the uplink message reaches the first number of times of repetition or the repeated transmission is completed, if the network device successfully receives the uplink message, the network device transmits DCI associated with the contention resolution message to the terminal device after the contention resolution timer is started. 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 a time required for the repeated transmission of the first repetition number of the uplink message. The processing delay of the network device includes a delay of the network device processing the upstream message. By using the method, the random access delay of the terminal equipment can be reduced.

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

In some embodiments, the processing latency of the network device may be predefined. Alternatively, the network device may transmit 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 DCI associated with the contention resolution message within a timing range of the contention resolution timer except for a predetermined time period prior to each subsequent repeated transmission of the uplink message. The predetermined period is determined based on the sum of the upstream transmission preparation time and the downstream reception processing time of the terminal device. The subsequent repeat transmission is after the first repeat transmission of the upstream message.

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

In a third aspect of the 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 to, with the processor, cause the terminal device to perform a method according to the first aspect of the disclosure.

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

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

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

In a seventh aspect of the 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 a method according to the first aspect of the present disclosure.

In an eighth aspect of the 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 a method according to the second aspect of the present disclosure.

Drawings

Features, advantages, and other aspects of various implementations of the 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 illustrated herein by way of example, and not by way of limitation, in the figures of the accompanying drawings:

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

figure 2 illustrates a signaling interaction diagram for a random access procedure in accordance with some embodiments of the present disclosure;

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

figure 4 illustrates a signaling interaction diagram for a random access procedure in accordance with some embodiments of the present disclosure;

fig. 5A illustrates a schematic diagram of the start Time of a contention resolution timer in a Time Division Duplex (TDD) scenario, in accordance with some embodiments of the present disclosure;

fig. 5B illustrates a schematic diagram of the start time of a contention resolution timer in a Frequency Division Duplex (FDD) scenario, in accordance with some embodiments of the present disclosure;

fig. 6A illustrates a schematic diagram of start times of contention resolution timers in a TDD scenario according to further embodiments of the present disclosure;

fig. 6B illustrates a schematic diagram of the start time of a contention resolution timer in an FDD scenario according to further embodiments of the present disclosure;

fig. 7A illustrates a schematic diagram of start times of contention resolution timers in a TDD scenario according to yet further embodiments of the present disclosure;

figure 7B illustrates a schematic diagram of the start time of a contention resolution timer in an FDD scenario in accordance with further embodiments of the present disclosure;

figure 7C illustrates a schematic diagram of the start time of a contention resolution timer in an FDD scenario, in accordance with yet further embodiments of the present disclosure;

fig. 8 illustrates a flow diagram of a method for random access in accordance with some embodiments of the present disclosure;

fig. 9 shows a flow diagram of a method for random access in accordance with further embodiments of the present disclosure; and

fig. 10 illustrates a block diagram of an example electronic device, in accordance with some embodiments of the present disclosure.

The same or similar reference numbers in the various drawings identify the same or similar elements.

Detailed Description

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

In describing embodiments of the present disclosure, the terms "include" and its derivatives should be interpreted as being inclusive, i.e., "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 understood as "at least one embodiment". The terms "first," "second," and the like may refer to different or the same object. Other explicit and implicit definitions are also possible below. A statement 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 of A, at least one of B and at least one of C, where three elements A, B and C are exemplified above, the meaning of a statement can be obtained according to the foregoing rules when there are more elements in the statement.

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 may be used interchangeably.

Embodiments of the present disclosure may be implemented in accordance with any suitable communication protocol, including, but not limited to, fourth generation (4G) and fifth generation (5G) cellular communication protocols, wireless local area network communication protocols such as Institute of Electrical and Electronics Engineers (IEEE) 802.11, and/or any other protocol now known or later developed. The technical solution of the embodiments of the present disclosure is applied to comply with 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), universal Mobile Telecommunications System (UMTS), narrowband internet of things (NB-IoT) communication system, future fifth generation (5G) system, or new radio access technology (NR), among others.

For purposes of illustration, embodiments of the present disclosure are described below in the context of a third generation partnership project (3 GPP) communication system of 5G. However, it should be understood that the embodiments of the present disclosure are not limited to being applied to a 5G communication system, but may be applied to any other communication system in which there is a similar problem as long as there is a downlink communication link and an uplink communication link 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, communication system 100 includes network device 110 and terminal devices 120-1, 120-2, 120-3, 120-4. Hereinafter, for purposes of discussion, terminal devices 120-1, 120-2, 120-3, 120-4 are collectively referred to as terminal devices 120 or individually as terminal devices 120. Network device 110 is capable of communicating with terminal device 120. The network device 110 transmitting control information and/or data to the terminal device 120 is called Downlink (DL) communication, and the terminal device 120 transmitting control information and/or data to the network device 110 is called Uplink (UL) communication.

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

Terminal device 120 refers to any device capable of communicating with network device 110. As an example, the terminal device 120 may include sensors that primarily include cell phones, cars, tablets, and smart speakers, train detectors, gas stations, and so forth. The main functions of the terminal device 120 include, but are not limited to: collect data, receive control information and/or downlink data from the network device 110, send electromagnetic waves, and send control information and/or uplink data to the network device 110.

It will be appreciated that the number of network devices 110 and terminal devices 120 shown in fig. 1 is merely an example and is not intended to suggest any limitation. Communication system 100 may include any suitable number of network devices 110 and terminal devices 120, as may be practical.

Terminal device 120 may access the network for communication by performing a random access procedure. The random access includes contention-based random access and non-contention-based random access. Non-contention based access is typically used in cases where the terminal device 120 has been able to successfully receive Radio Resource Control (RRC) signaling. A signaling interaction diagram of the random access procedure will be described below by taking a contention-based random access procedure as an example.

Fig. 2 illustrates a signaling interaction diagram for a random access procedure 200, in accordance with some embodiments of the present disclosure. For purposes of discussion, the 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 procedure 200 may also be performed between a network device and a terminal device in any other communication scenario.

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 (PRACH). In some embodiments, the terminal device 120 may determine the time-frequency resource and the preamble for transmitting the preamble according to the system message received from the network device 110 and a selected Synchronization Signal Block (SSB) index.

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

After receiving 240Msg2, terminal device 120 sends 250Msg3 on the time-frequency resource indicated in Msg2.Msg 3 is carried by the Physical Uplink Shared Channel (PUSCH).

When multiple terminal devices 120 simultaneously request to access the network, the network device 110 needs to determine which terminal device is selected for access in the 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 from the DCI, the random access is considered successful. If the terminal device 120 does not successfully receive the DCI transmitted to itself, or the Msg4 received according to the DCI is not transmitted to itself by the network device, the random access is considered to be failed. Since the terminal device 120 cannot determine which time slot the network device 110 will send the DCI associated with the 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 a contention resolution timer) is defined in the existing standard, and if the terminal device 120 does not receive DCI transmitted to itself before the contention resolution timer expires, the random access is considered to be failed. Subsequently, the terminal device 120 may restart the random access procedure.

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

To ensure that the terminal device 120 can successfully access the network, the successful transmission of each message during the random access procedure is first ensured. Since success of random access by the terminal device 120 is mainly limited to Msg3 carrying much information, the existing standard conference has determined to improve coverage performance by repeated transmission of Msg3.

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

Fig. 3 shows a diagram of the start time of a contention resolution timer in an LTE system. In fig. 3, each square represents a slot, each slot comprising 14 symbols, a subcarrier spacing of 15kHz, and a switching period of 5ms for uplink and downlink, comprising 5 slots. The frame structure is configured as 3:1:1, i.e., the number of downlink slots (denoted as "D"): number of flexible slots (denoted "S"): the ratio between the number of uplink slots (denoted as "U") =3:1:1.

the terminal device repeatedly sends Msg3 to the network device four times with indices #1 to #4, denoted 311 to 314 in fig. 3. The network device determines whether Msg3 was received correctly after receiving all four repeated transmissions of Msg3. If the network device correctly receives Msg3, e.g., the network device correctly receives the second iteration 312 of Msg3, then the network device sends Msg4 to the terminal device. The sending of Msg4 occurs after the last repeated sending 314 of Msg3 is completed. Accordingly, the terminal device starts a contention resolution timer to receive DCI associated with Msg4 after all the repeated transmissions of Msg3 are completed, i.e., at slot 315.

In the example of fig. 3, msg4 is sent after all the repeated sends of Msg3 are completed. However, the network device may have successfully received Msg3 before the last repeat transmission of Msg3. This limits the terminal device to receive DCI associated with Msg4 only after the last repeated transmission of Msg3 is complete. Accordingly, this also limits the network device to only being able to send DCI associated with Msg4 after the last repeated send of Msg3. This causes a large access delay and causes unnecessary waste of energy for the Msg3 repeat transmission. Particularly, when the network device randomly accesses and schedules the number of repetitions of Msg3, the network device is judged only by the energy of the preamble because no Channel State Information (CSI) or other Information exists, so that the number of repetitions scheduled by the network device is inaccurate, and the network device has a high probability of scheduling repetitions of more times, so as to ensure the performance of coverage-limited terminal devices.

At least in response to the above problems, and potentially other related problems, embodiments of the present disclosure propose a scheme for random access. According to this scheme, the terminal device starts a contention resolution timer for receiving DCI associated with Msg4 before the number of times of the repeated transmission of Msg3 reaches the first number of times of repetition or the repeated transmission is completed. Accordingly, before the number of times of the repeated transmission of the Msg3 reaches the first number of times of repetition or the repeated transmission is completed, if the network device successfully receives the Msg3, the network device transmits DCI associated with the Msg4 to the terminal device after the contention resolution timer is started. The scheme can reduce the random access delay of the terminal equipment. Embodiments of the present disclosure will be described in detail below with reference to fig. 4 to 7.

Fig. 4 shows a signaling interaction diagram of an example process 400 for random access in accordance with an embodiment of the disclosure. For purposes of discussion, the 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 scenario.

As shown in fig. 4, terminal device 120 repeatedly sends 410 an upstream message (also referred to as Msg 3) to network device 110 based on a first number of repetitions. Accordingly, the network device 110 receives 420 the repeatedly transmitted Msg3 from the terminal device 120 based on the first repetition number. The Msg3 is scheduled by a random access response message (also called Msg 2). In some embodiments, to acquire time-frequency resources for Msg3, terminal device 120 may perform

acts

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

Before the number of repeated transmissions of Msg3 reaches the first number of repetitions or the repeated transmissions are complete, terminal device 120 starts 430 a contention resolution timer for receiving DCI associated with a contention resolution message (also referred to as Msg 4). The start time of the contention resolution timer is associated with at least one of: a processing delay of the network device 110 (denoted by T1), a first number of repetitions, and a time required for the repeated transmission of the first number of repetitions of Msg3 (denoted 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 latency of network device 110 includes the latency of network device 110 processing Msg3. Furthermore, the processing delay of network device 110 may also include a delay for network device 110 to prepare a PDCCH for carrying DCI associated with Msg4. In other words, the processing latency of the network device 110 may include the time from when the network device 110 receives Msg3 to when the network device 110 sends a PDCCH for carrying DCI associated with Msg4. The time required for the first repetition of the retransmission of Msg3 is the number of time cells from the first symbol after the end of the first retransmission of Msg3 to the first symbol after the end of the last retransmission of Msg3. It is to be understood that the last repeat transmission of Msg3 herein refers to the last repeat transmission among the repeat transmissions of the first number of repetitions. For example, when the first repetition number is 4, the last repetition transmission of Msg3 is the 4 th repetition transmission. Examples of time cells may include, but are not limited to: subframes, slots, and OFDM symbols. Embodiments regarding determining the start time of the contention resolution timer will be described in detail below with reference to fig. 5A to 7C.

If network device 110 successfully receives Msg3 before the number of repeated transmissions of Msg3 reaches the first number of repetitions or the repeated transmissions are complete, network device 110 transmits 440 DCI associated with Msg4 to terminal device 120 after the contention resolution timer is started. It should be appreciated that network device 110 may not send DCI associated with Msg4 immediately after successfully receiving one repeat transmission of Msg3, but rather wait until the contention resolution timer starts before sending DCI associated with Msg4.

Accordingly, end device 120 receives 450Msg4 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 a terminal identity included in Msg4. Examples of such terminal identities include, but are not limited to: cell-Radio Network Temporary identity (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. Further, the terminal device 120 may start the random access procedure again.

According to the embodiment of the disclosure, before the number of times of the repeated transmission of the Msg3 reaches the first number of times of the repeated transmission or the repeated transmission is completed, the terminal device starts a contention resolution timer for receiving DCI associated with the Msg4, so that the random access delay of the terminal device can be reduced.

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

In some embodiments, the processing latency of network device 110 is predefined. Alternatively, the processing delay of network device 110 may be indicated by network device 110 in system information (e.g., SIB 1).

In some embodiments, end device 120 may be a coverage limited end device, such as an end device that supports Msg3 repeat transmissions. In such an embodiment, the contention resolution timer may have a timing length of N subframes (N slots when the subcarrier spacing is 15 kHz), where N is greater than the time interval between two adjacent repeated transmissions of Msg3. In some embodiments, N may be indicated by network device 110 in a first predefined parameter in system information (e.g., SIB 1). As an example, N may be equal to 8.

In some embodiments, the terminal device 120 may not be a coverage limited terminal device, such as a terminal device that does not support Msg3 repeated transmissions. In such an embodiment, the timing length of the contention resolution timer may be M subframes (M slots when the subcarrier spacing is 15kHz, M being a natural number). In some embodiments, M may be indicated by network device 110 in a second predefined parameter (e.g., rach-ConfigCommon) in system information (e.g., SIB 1). The second predefined parameter is different from the first predefined parameter.

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

To indicate the appropriate timing length to terminal device 120, network device 110 needs to determine whether terminal device 120 is a coverage-limited terminal device. To this end, network device 110 may employ either of the following two schemes.

The first scheme is as follows: the network device 110 may reserve dedicated PRACH resources for the terminal device whose coverage is limited, for example, a new type of PRACH resources may be added. For example, the terminal device 120 may select to use the reserved PRACH resource when the Reference Signal Received Power (RSRP) is smaller than a predefined threshold, wherein the predefined threshold for RSRP may be signaled in SIB 1. If the network device 110 receives the preamble transmitted 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.

Scheme II: the network device 110 may identify a coverage limited terminal device through repeated transmission of PRACH. The coverage-limited terminal equipment can improve the access probability through repeated transmission of the PRACH. The network device 110 identifies whether there is coverage-limited terminal device access by detecting the number of repeated transmission of the PRACH. If so, the network device 110 may utilize a redundancy field of a Modulation and Coding Scheme (MCS) to indicate the number of repeated transmissions of the Msg3 when transmitting the RAR UL grant.

It should be understood that the above two schemes are only examples, and the network device 110 may determine whether the terminal device 120 is a coverage-limited terminal device in other manners.

Hereinafter, some embodiments of determining the start time of the contention resolution timer will be described in detail with reference to fig. 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+1 time unit after the first repeated transmission of the Msg3 as the start time of the contention resolution timer. As an example, in the case that the time unit is an OFDM symbol, the start time of the contention resolution timer may be specifically T1+1 th OFDM symbol; when the time unit is a time slot, the start time of the contention resolution timer may be specifically a first OFDM symbol of a T1+1 th time slot; in the case that the time unit is a subframe, the start time of the contention resolution timer may be specifically the first OFDM symbol of the T1+1 th subframe. This embodiment will be described in detail below with reference to fig. 5A and 5B.

Fig. 5A illustrates a schematic diagram of start times of contention resolution timers in a Time Division Duplex (TDD) scenario, according to some embodiments of the present disclosure. In fig. 5A, each square represents a time slot, each time slot includes 14 symbols, the subcarrier spacing is 15kHz, the uplink and downlink switching period is 10ms, and the uplink and downlink switching period includes 10 time slots. The frame structure is configured as 8:1:1, the number of downlink slots (denoted as "D"): number of flexible slots (denoted "S"): the ratio between the number of uplink slots (denoted as "U") =8:1:1. the processing delay T1 of the network device 110 is 6 slots. The timing length of the contention resolution timer is 8 slots at a subcarrier spacing of 15kHz.

Terminal device 120 repeatedly sends Msg3 four times to network device 110, with indices #1 through #4, shown in fig. 5A as 511 through 514. The terminal device 120 starts a contention resolution timer at the T1+1 time unit after the first repeated transmission of Msg3. That is, the terminal device 120 starts the contention resolution timer at the 7 th time unit (i.e., the 6 th symbol, 14+1 st symbol) 521 after the Msg3#1 (indicated as 511) is transmitted.

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

time cells

522, 523, and 524 after the subsequent repeated

transmissions

512, 513, and 514 of the Msg3, respectively. Fig. 5B illustrates a schematic diagram of the start time of a contention resolution timer in a Frequency Division Duplex (FDD) scenario, according to some embodiments of the present disclosure. In fig. 5B, each square represents a slot, each slot comprising 14 symbols, with subcarrier spacing of 15kHz. The processing delay T1 of the network device 110 includes 6 slots.

Terminal device 120 repeatedly sends Msg3 four times to network device 110, with indices #1 through #4, denoted 531 through 534 in fig. 5B. The terminal device 120 starts a contention resolution timer at the T1+1 time unit after the first repeated transmission of Msg3. That is, terminal device 120 starts the contention resolution timer at 7 th time unit (i.e., 6 th symbol 14+ 1) 541 after Msg3#1 (denoted as 531) transmission.

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

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 first number of repetitions of the repeated transmission of Msg3 and the processing delay T1 of the network device 110. Specifically, terminal device 120 may compare T2 with T1. If T2 is greater than T1, the terminal device 120 determines the T1+1 time unit of the Msg3 after the first repeated transmission 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+1 th time cell 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 fig. 6A and 6B.

Fig. 6A illustrates a schematic diagram of start times of contention resolution timers in a TDD scenario according to further embodiments of the present disclosure. The example of fig. 6A is similar to the example of fig. 5A, with the difference that fig. 6A further illustrates the magnitude relationship between the time T2 required for the first number of repetitions of the repeated transmission of Msg3 and the processing latency 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, the terminal device 120 determines the T1+1 time unit of Msg3 after the first repeated transmission as the start time of the contention resolution timer. That is, the terminal device 120 starts the contention resolution timer at the 7 th time unit (i.e., the 6 th symbol, 14+1 st symbol) 521 after the Msg3#1 (indicated as 511) is transmitted.

Fig. 6B illustrates a diagram of start times of contention resolution timers in an FDD scenario, according to further embodiments of the disclosure. The example of fig. 6B is similar to the example of fig. 5B, except that fig. 6B further illustrates a magnitude relationship between the time T2 required for the first number of repetitions of the repeated transmission of Msg3 and the processing delay T1 of the network device 110. In the example of fig. 6B, T1 includes 6 slots and T2 includes 3 slots. Since T2 is smaller than 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. That is, the terminal device 120 starts the contention resolution timer at the 1 st time unit 611 after the Msg3#4 (denoted as 534) transmission.

In some embodiments, the terminal device 120 may determine the start time of the contention resolution timer based on the first number of repetitions of Msg3. For example, the terminal device 120 may determine a second repetition number (denoted by i) associated with the first repetition number based on the first repetition number, and further determine a first time unit after the repeated transmission of the second repetition number of the 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 a second repetition number (denoted by i) associated with the first repetition number based on the first repetition number, and further determine a first time unit after the repeated transmission of the second repetition number of the Msg3 as the start time of the contention resolution timer, wherein the second repetition number is less than or equal to the first repetition number; the second number of repetitions is equal to the first number of repetitions in a case where the first number of repetitions is less than or equal to a threshold, and the second number of repetitions is less than the first number of repetitions in a case where the first number of repetitions is greater than the threshold. As an example, the following tables 1 and 2 show an association between the first repetition number of the Msg3 and the start time of the contention resolution timer (i.e., an association between the first repetition number and the second repetition number). The terminal device 120 may determine the start time of the contention resolution timer based on table 1 or table 2.

TABLE 1

First number of repetitions of Msg3	Start time of contention resolution timer
		2	After the 1 st retransmission of Msg3 is completed
4	After the 2 nd repeated Msg3 transmission is finished
		8	After the 4 th repeated Msg3 transmission is finished
16	After the 8 th retransmission of Msg3 is finished

TABLE 2

First number of repetitions of Msg3	Start time of contention resolution timer
		2	After the 2 nd repeated Msg3 transmission is finished
4	After the 4 th repeated Msg3 transmission is finished
		8	After the 4 th repeated Msg3 transmission is finished
16	After the 8 th repeated Msg3 transmission is finished

Table 1 shows an example in which the second number of repetitions is smaller than the first number of repetitions. As shown in table 1, when the first repetition number of the Msg3 is 2, the second repetition number is 1, which means that the network device 110 has a high probability of successfully decoding after receiving the Msg3 for the first time. Therefore, the terminal device 120 starts the contention resolution timer in the first time unit after the end of the 1 st retransmission of the Msg3. When the first repetition number of Msg3 is 4, the second repetition number is 2, so that the terminal device 120 starts the contention resolution timer in the first time unit after the 2 nd repeated transmission of Msg3 is finished. When the first repetition number of Msg3 is 8, the second repetition number is 4, so that the terminal device 120 starts the contention resolution timer in the first time unit after the 4 th repeated transmission of Msg3 is finished. When the first repetition number of the Msg3 is 16, the second repetition number is 8, so that the terminal device 120 starts the contention resolution timer in the first time unit after the 8 th repetition transmission of the Msg3 is finished.

Table 2 shows an example in which the second repetition number is less than or equal to the first repetition number, 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 in the first time unit after the end of the 2 nd repeated transmission of the Msg3. When the first repetition number of Msg3 is 4, the second repetition number is 4, so that the terminal device 120 starts the contention resolution timer in the first time unit after the 4 th repeated transmission of Msg3 is finished. When the first repetition number of Msg3 is 8, the second repetition number is 4, so that the terminal device 120 starts the contention resolution timer in the first time unit after the 4 th repeated transmission of Msg3 is finished. When the first repetition number of the Msg3 is 16, the second repetition number is 8, so that the terminal device 120 starts the contention resolution timer in the first time unit after the 8 th repetition transmission of the Msg3 is finished.

It should be understood that tables 1 and 2 only show one example of the correlation 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, and that other correlations between the two are possible.

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

Fig. 7A illustrates a schematic diagram of a start time of a contention resolution timer in a TDD scenario, in accordance with further embodiments of the present disclosure. The example of fig. 7A is similar to the example of fig. 6A, with the difference that, in the example of fig. 7A, the terminal device 120 determines the start time of the contention resolution timer based on not only the magnitude relationship of T2 and T1 but also the first number of repetitions of Msg3. Specifically, the terminal device 120 compares T2 with T1. Since T2 is greater than T1, the terminal device 120 determines the T1+1 time unit after the i-th (second number of repetitions) repeated transmission of Msg3 as the start time of the contention resolution timer. The second number of repetitions i can be determined, for example, according to table 1 or table 2. In this example, since the first repetition number is equal to 4, the second repetition number i may be determined to be equal to 2 according to table 1. Thus, terminal device 120 starts the contention resolution timer at 7 th time unit (i.e., 6 × 14+1 symbol) 711 after Msg3#2 (denoted as 512) transmission.

Fig. 7B illustrates a diagram of a start time of a contention resolution timer in an FDD scenario, in accordance with further embodiments of the present disclosure. The example of fig. 7B is similar to the example of fig. 6B, with the difference that, in the example of fig. 7B, the terminal device 120 determines the start time of the contention resolution timer based on not only the magnitude relationship of T2 and T1 but also the first number of repetitions of Msg3. In the example of fig. 7B, T1 includes 6 slots and T2 includes 3 slots. Since T2 is smaller than T1, the terminal device 120 determines the T1+1 time unit of Msg3 after the first repeated transmission as the start time of the contention resolution timer. That is, the terminal device 120 starts the contention resolution timer at the 7 th time unit (i.e., the 6 th symbol, 14+1 st symbol) 721 after the Msg3#1 (denoted as 531) is transmitted.

Figure 7C illustrates a schematic diagram of the start time of a contention resolution timer in an FDD scenario, according to still further embodiments of the present disclosure. The example of fig. 7C is similar to the example of fig. 7B, except that, in the example of 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, terminal device 120 starts the contention resolution timer at the first time cell 731 after Msg3#4 (denoted 534) transmission.

It should be understood that in fig. 5A, 6A and 7A, with a subcarrier spacing of 15kHz, a switching period of 10ms for the uplink and downlink, and a frame structure configured to be 8:1:1 are described as examples, but the scope of the present disclosure is not limited thereto.

In some embodiments, terminal device 120 may cancel a subsequent repeat transmission of Msg3 if terminal device 120 successfully receives DCI associated with Msg4 before the number of repeat transmissions of Msg3 reaches the first number of repeats or the repeat transmission is complete. By eliminating subsequent repeated transmissions of Msg3, wasted energy for terminal device 120 to transmit Msg3 can be avoided.

In some embodiments, optionally, to enable terminal device 120 to cancel subsequent repeated transmissions of Msg3, network device 110 is within the timing range of the contention resolution timer except for a predetermined period of time prior to each subsequent repeated transmission of Msg3And sending DCI associated with Msg4. In other words, network device 110 does not send DCI associated with Msg4 for a predetermined period of time before each subsequent repeat of Msg3. The predetermined time period is based on the uplink transmission preparation time (by T) of the terminal device 120 _proc Denoted by d) and downlink reception processing time (denoted by d) ₁ Representation) is determined. Upstream transmission preparation time T _proc The downlink reception processing time d can be calculated as described in section 6.4 of TS 38.213 ₁ May be reported by terminal device 120 to network device 110. As an example, the predetermined time period may include W symbols before the first time domain symbol corresponding to Msg3 of any subsequent repeated transmission. The timing range of the contention resolution timer may be determined by the timing length (e.g., M subframes) and the start time of the contention resolution timer, e.g., M subframes after the contention resolution timer is started.

In some embodiments, the terminal device 120 may send a message 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 number of repetitions. Alternatively, the terminal device 120 may send capability information to the network device 110 indicating whether the terminal device 120 has the capability to start the contention resolution timer before the repeated sending of Msg3 reaches the first number of repetitions. Alternatively, the terminal device 120 may send a message to the network device 110 to indicate whether the terminal device 120 can cancel the subsequent repeated sending before the repeated sending of Msg3 reaches the first number of repetitions. Alternatively, the terminal device 120 may send capability information to the network device 110, the capability information indicating whether the terminal device 120 has the capability to cancel the subsequent repeated sending before the repeated sending of the Msg3 reaches the first number of repetitions. For this purpose, the terminal device 120 may employ either of the following two schemes.

The first scheme is as follows: the network device 110 reserves a dedicated PRACH resource for the terminal device 120 that can report the information, that is, a new type of PRACH resource may be added. For example, the network device 110 may reserve dedicated

PRACH resources

1 and 2 for the terminal device 120. If terminal device 120 sends Msg1 using PRACH resource 1, network device 110 knows that terminal device 120 will start a contention resolution timer before the repeated sending of Msg3 reaches the first number of repetitions. If terminal device 120 sends Msg1 using PRACH resource 2, network device 110 knows that terminal device 120 will not start the contention resolution timer before the repeated sending of Msg3 reaches the first number of repetitions.

Scheme II: network device 110 may determine, via a Demodulation Reference Signal (DMRS) port used by Msg3 or Msg1, whether terminal device 120 starts a contention resolution timer before the first number of repetitions is reached for the repeated transmission of Msg3. Currently, terminal device 120 uses a default DMRS port to transmit Msg3. If network device 110 detects that the port used by Msg3 is different from the default DMRS port, then it is assumed that terminal device 120 will start the contention resolution timer before the first number of repetitions of the repeated transmission of Msg3.

It should be understood that the above two schemes are only examples, and the terminal device 120 may indicate whether it starts the contention resolution timer in advance by other means.

Fig. 8 shows a flowchart of an example method 800 for random access in accordance with some embodiments of the present disclosure. In some embodiments, the example method 800 may be implemented by the terminal device 120 in the example communication system 100, for example, by a processor or processing unit of the terminal device 120 in cooperation with other components (e.g., 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, the example method 800 will be described with reference to fig. 1.

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

At block 820, the terminal device 120 starts a contention resolution timer for receiving 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 transmissions are complete. The start time of the contention resolution timer is associated with at least one of: a processing delay of the network device 110, a first number of repetitions, and a time required for repeated transmission of the first number of repetitions of the upstream message. The processing delay includes the delay of network device 110 in processing the upstream message.

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

In some embodiments, additionally, the terminal device 120 may cancel subsequent repeated transmissions of the uplink message if the terminal device 120 successfully receives 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 transmissions are completed. In this way, waste of energy for terminal device 120 to send uplink messages can be avoided.

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

In some embodiments, the start time of the contention resolution timer may alternatively be the T1+1 th time unit if the time required for the first number of repetitions of the uplink message to be repeatedly transmitted exceeds the processing delay.

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

In some embodiments, the processing latency of 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.

In some embodiments, additionally, terminal device 120 may receive DCI associated with a contention resolution message within a timing range of the contention resolution timer except for a predetermined time period prior to each subsequent repeated transmission of the uplink message. The predetermined period of time is determined based on the sum of the upstream transmission preparation time and the downstream reception processing time of the terminal device 120. The subsequent repeat transmission is after the first repeat transmission of the upstream message.

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

Fig. 9 shows a flowchart of an example method 900 for random access according to further 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, by a processor or processing unit of the network device 110 in cooperation with other components (e.g., 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, the example method 900 will be described with reference to fig. 1.

At block 910, network device 110 receives a repeatedly transmitted upstream message from terminal device 120 based on the first number of repetitions. The uplink message is scheduled by a random access response message.

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

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

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

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

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

In some embodiments, the network device 110 may transmit DCI associated with the contention resolution message within a timing range of the contention resolution timer except for a predetermined time period prior to each subsequent repeated transmission of the uplink message. The predetermined period of time is determined based on the sum of the upstream transmission preparation time and the downstream reception processing time of the terminal device 120. The subsequent repeat transmission is after the first repeat transmission of the upstream message.

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

Fig. 10 shows a block diagram of an example electronic device 1000, in accordance with embodiments of the present disclosure. Example electronic device 1000 may be used to implement communication devices such as network device 110 and terminal device 120 in fig. 1. Accordingly, the example electronic device 1000 may also be referred to herein as the example communication device 1000. As shown in fig. 10, an example communication device 1000 may include a processor 1010 and a memory 1020 coupled to the processor 1010. Stored in memory 1020 are computer program instructions 1025. Additionally, the example communications device 1000 may also include a communications module 1030 coupled to the processor 1010. The communications module 1030 may be for bi-directional communications and may have at least one cable, fiber optic cable, wireless interface, etc. for facilitating communications. The communication interface may represent any interface for communicating with other devices.

The processor 1010 may be of any type suitable to the local technical environment, and may include one or more of the following as non-limiting examples: general purpose computers, special purpose computers, microprocessors, digital Signal Processors (DSPs) and processors based on a multi-core Processor architecture. The example communication device 1000 may have multiple processors, such as an application specific integrated circuit chip that is slaved in time with a clock synchronized to the main processor. The 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, a hard Disk, a Compact Disk (CD), a Digital Versatile Disk (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 cannot be persisted during a power loss. Computer program instructions 1025 may include computer-executable instructions that are executable by associated processor 1010. In some embodiments, computer program instructions 1025 may be stored in the ROM of memory 1020. Processor 1010 may perform various suitable actions and processes by loading memory 1020 into the RAM of memory 1020. Embodiments of the present disclosure may be implemented by computer program instructions 1025 to cause example communication device 1000 to perform any of the methods or processes of the present disclosure as discussed above with reference to fig. 4, 8, and 9. Of course, 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 in a computer-readable medium. Such computer-readable media may be included in the example communication device 1000 (e.g., memory 1020) or in other storage accessible to the example communication device 1000. Example communication device 1000 may read computer program instructions 1025 from the computer-readable medium into RAM of memory 1020 for execution. The computer-readable medium may include various tangible, non-volatile storage devices, such as ROM, EPROM, flash memory, a hard disk, a CD, a DVD, and so forth.

In general, the various example embodiments of this 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 of the disclosure (e.g., a method, apparatus, or device) may be partially or fully implemented on a computer-readable medium. While aspects of embodiments of the disclosure have been illustrated and described as block diagrams, flow charts, or using some other pictorial representation, it is well understood that the blocks, apparatus, systems, techniques or methods described herein may be implemented in, as non-limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller 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 program modules, included in a device executing on a physical or virtual processor of the target to perform the example methods or example processes 400, 800, and 900 described above with respect to fig. 4, 8, and 9. Generally, program modules may include routines, programs, libraries, objects, classes, components, data structures, etc. that perform particular tasks or implement particular abstract data types. In various embodiments, the functionality of the program modules may be combined or split between program modules as described. Computer-executable instructions for program modules may be executed within local or distributed devices. In a distributed facility, program modules may be located in both local and remote memory storage media.

Program code for implementing the methods of the present disclosure may be written in one or more programming languages. These computer program code may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus, such that the program code, when executed by the computer or other programmable data processing apparatus, causes the functions/acts specified in the flowchart and/or block diagram to be performed. 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 an apparatus, device or processor to perform the various processes and operations described above. Examples of a carrier include a signal, computer readable medium, 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 a machine-readable storage medium include an electrical connection having one or more wires, a portable computer diskette, a hard disk, a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination thereof.

Further, 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 may be beneficial. Likewise, while the above discussion contains certain specific implementation details, this should not be construed as limiting the scope of any invention or claims, but rather as a description of specific embodiments that may be directed to a particular invention. 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

1. A method for random access, comprising:

the terminal equipment repeatedly sends uplink messages to the network equipment based on the first repetition times, wherein the uplink messages are scheduled by the random access response messages; and

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

wherein a start time of the contention resolution timer is associated with at least one of:

a processing delay of the network device, the processing delay comprising a delay of the network device to process the upstream message,

the first number of repetitions, and

a time required for the repeated transmission of the first number of repetitions of the uplink message.

2. The method of claim 1, further comprising:

and before the repeated sending times of the uplink message reach the first repeated times or the repeated sending is completed, if the terminal equipment successfully receives the downlink control information, the terminal equipment cancels the subsequent repeated sending of the uplink message.

3. The method of claim 1, wherein the start time of the contention resolution timer is:

and the T1+1 time unit after the uplink message is repeatedly sent for the first time, wherein T1 represents the processing time delay.

4. The method of claim 3, wherein:

if the time required for the repeated transmission of the first repetition number of the uplink message exceeds the processing delay, the starting time of the contention resolution timer is the T1+1 time unit.

5. The method of claim 1, wherein:

if the time required for the first repetition number of repeated transmissions of the uplink message exceeds the processing delay, the start time of the contention resolution timer is T1+1 th time unit after the second repetition number of repeated transmissions of the uplink message, where the second repetition number is associated with and smaller than the first repetition number, and T1 represents the processing delay.

6. The method of any of claims 2 to 5, wherein the processing latency is predefined.

7. The method of any of claims 2 to 5, further comprising:

the terminal device receives system information indicating the processing delay from the network device.

8. The method of claim 1, further comprising:

after the contention resolution timer is started, if the repeated transmission of the uplink message does not reach the first repetition number, the terminal device restarts the contention resolution timer after each subsequent repeated transmission of the uplink message.

9. The method of claim 1, further comprising:

the terminal device receives the downlink control information within a 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 period of time being determined based on a sum of an uplink transmission preparation time and a downlink reception processing time of the terminal device, the subsequent repeated transmission being after a first repeated transmission of the uplink message.

10. The method of claim 1, further comprising:

and the terminal equipment sends information to the network equipment, wherein the information indicates whether the terminal equipment starts the contention resolution timer before the repeated sending of the uplink message reaches the first repeated times.

11. A method for random access, comprising:

the network equipment receives an uplink message which is repeatedly sent from the terminal equipment based on the first repetition number, wherein the uplink message is scheduled by the random access response message; and

before the number of times of the repeated transmission of the uplink message reaches the first number of times of repetition or the repeated transmission is completed, if the network device successfully receives the uplink message, the network device transmits downlink control information associated with a contention resolution message to the terminal device after a contention resolution timer is started,

the first number of repetitions, and

12. The method of claim 11, wherein the start time of the contention resolution timer is:

13. The method of claim 12, wherein:

14. The method of claim 11, wherein:

if the time required for the first repetition number of repeated transmissions of the uplink message exceeds the processing delay, the start time of the contention resolution timer is the T1+1 time unit after the second repetition number of repeated transmissions of the uplink message, where 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.

15. The method of any of claims 11-14, wherein the processing latency is predefined.

16. The method of any of claims 11 to 14, further comprising:

and the network equipment sends system information indicating the processing delay to the terminal equipment.

17. 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 repetition number, the contention resolution timer is restarted after each subsequent repeated transmission of the uplink message.

18. The method of claim 11, wherein the network device sending the downlink control information to the terminal device comprises:

the network device transmits the downlink control information within a 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 period of time being determined based on a sum of an uplink transmission preparation time and a downlink reception processing time of the terminal device, the subsequent repeated transmission being located after a first repeated transmission of the uplink message.

19. The method of claim 11, further comprising:

and the network equipment receives information from the terminal equipment, wherein the information indicates whether the terminal equipment starts the contention resolution timer before the repeated sending times of the uplink message reach the first repeated times.

20. A terminal device, comprising:

a processor; and

a memory storing computer program instructions, the memory and the computer program instructions configured to, with the processor, cause the terminal device to perform the method of any of claims 1-10.

21. A network device, comprising:

a processor; and

a memory storing computer program instructions, the memory and the computer program instructions configured to, with the processor, cause the network device to perform the method of any of claims 11-19.

22. A computer readable medium storing machine executable instructions which, when executed by a terminal device, cause the terminal device to perform the method of any one of claims 1-10.

23. A computer readable medium storing machine executable instructions that when executed by a network device cause the network device to perform the method of any one of claims 11-19.

24. A computer program product comprising machine executable instructions which, when executed by a terminal device, cause the terminal device to perform the method of any one of claims 1 to 10.

25. A computer program product comprising machine executable instructions which, when executed by a terminal device, cause the terminal device to perform the method of any one of claims 11-19.