Method, device and storage medium for random access

Abstract

A method, terminal device, network device, and medium for random access are provided. The method includes the terminal device repeatedly transmitting an uplink message to the network device based on a first repetition count. This uplink message is scheduled by a random access response message. The method further includes, before the number of repetitions of the uplink message reaches the first repetition count or before the repetitions are completed, the terminal device starts a contention-resolving timer to receive downlink control information associated with a contention-resolving message. The start time of the contention-resolving timer is associated with at least one of the following: the processing latency of the network device, the first repetition count, and the time required for the repetition of the first repetition count of the uplink message, where the processing latency of the network device includes the latency of the network device processing the uplink message. This method can reduce the random access latency of the terminal device.

Description

Technical Field

[0001] This disclosure relates to the field of communications, and more specifically to methods, apparatus and storage media for random access. Background Technology

[0002] Terminal devices can access the network for communication by executing a random access procedure. To ensure successful network access, the successful transmission of each message during the random access procedure must first be guaranteed. During the random access procedure, after successfully receiving the random access response from the network device, the terminal device needs to send an uplink message to the network device. In the following text, this uplink message will also be referred to as message 3 or Msg3.

[0003] In coverage-constrained scenarios, repeated transmissions of Msg3 are necessary to increase coverage. After successfully receiving the retransmitted Msg3, the network device sends Downlink Control Information (DCI) associated with the contention resolution message to the terminal device via the Physical Downlink Control Channel (PDCCH). This contention resolution message will also be referred to as message 4 or Msg4 below. Correspondingly, the terminal device starts a contention resolution timer and checks the PDCCH from the start of the timer until its timeout. If the contention resolution timer starts too early during Msg3 retransmission, the terminal device may check the PDCCH within a timeframe where it is unlikely to receive Msg4, resulting in wasted energy. If the timer starts too late, significant access latency may occur if the network device correctly receives Msg3 before the terminal device completes its retransmission. Therefore, determining the appropriate time to start the contention resolution timer during Msg3 retransmission is a crucial issue. Summary of the Invention

[0004] The exemplary embodiments disclosed herein provide a scheme for random access.

[0005] In a first aspect of this disclosure, a method for random access implemented at a terminal device is provided. The method includes the terminal device repeatedly transmitting an uplink message to a network device based on a first repetition count. The uplink message is scheduled by a random access response message. The method further includes, before the number of repetitions of the uplink message reaches the first repetition count or before the repetitions are completed, the terminal device starts a contention resolution timer for receiving downlink control information associated with a contention resolution message. The start time of the contention resolution timer is associated with at least one of the following: the processing latency of the network device, the first repetition count, and the time required for the repetition of the first repetition count of the uplink message. The processing latency of the network device includes the latency of the network device processing the uplink message. This method can reduce the random access latency of the terminal device.

[0006] In some embodiments, additionally, if the terminal device successfully receives the DCI associated with the contention resolution message before the number of retransmissions of the uplink message reaches the first retransmission count or before the retransmission is completed, the terminal device may cancel subsequent retransmissions of the uplink message. This avoids wasting energy on uplink message transmission by the terminal device.

[0007] In some embodiments, the start time of the contention resolution timer can be the T1+1th time unit after the first repeated transmission of the uplink message, where T1 represents the processing delay of the network device.

[0008] In some embodiments, alternatively, if the time required for the repeated transmission of the first repetition of the uplink message exceeds the processing latency of the network device, the start time of the contention resolution timer can be the T1+1th time unit, where T1 represents the processing latency of the network device.

[0009] In some embodiments, alternatively, if the time required for retransmission of the first repetition of the uplink message exceeds the processing latency, the start time of the contention resolution timer can be the (T1+1)th time unit after the second repetition of the uplink message. The second repetition is associated with and less than the first repetition. T1 represents the processing latency of the network device.

[0010] 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 then determine the first time unit after the repetition 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 the first repetition number.

[0011] 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 then determine the first time unit after the repetition of the second repetition 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. If the first repetition number is less than or equal to a threshold, the second repetition number is equal to the first repetition number; if the first repetition number is greater than the threshold, the second repetition number is less than the first repetition number.

[0012] In some embodiments, the processing latency of the network device can be predefined. Alternatively, the terminal device can receive system information indicating the processing latency from the network device.

[0013] In some embodiments, additionally, after starting the contention resolution timer, if the retransmission of the uplink message does not reach the first retransmission count, the terminal device may restart the contention resolution timer after each subsequent retransmission of the uplink message.

[0014] In some embodiments, additionally, the terminal device may receive the DCI associated with the contention-resolved message outside the timing range of the contention-resolved timer, except for a predetermined period of time preceding each subsequent retransmission of the uplink message. This predetermined period of time is determined based on the sum of the terminal device's uplink transmission preparation time and downlink reception processing time. Subsequent retransmissions occur after the first retransmission of the uplink message.

[0015] In some embodiments, the terminal device may additionally send information to the network device indicating whether the terminal device should start a contention resolution timer before the repeated transmission of uplink messages reaches a first repetition count.

[0016] In a second aspect of this disclosure, a method for random access implemented at a network device is provided. The method includes the network device receiving repeatedly transmitted uplink messages from a terminal device based on a first repetition count. The uplink messages are scheduled by a random access response message. The method further includes: if the network device successfully receives the uplink message before the number of repetitions of the uplink message reaches the first repetition count or before repetitions are completed, the network device sends a DCI associated with the contention resolution message to the terminal device after a contention resolution timer is started. The start time of the contention resolution timer is associated with at least one of the following: the processing latency of the network device, the first repetition count, and the time required for repetitions of the first repetition count of the uplink message. The processing latency of the network device includes the latency of the network device processing the uplink message. Using this method, the random access latency of the terminal device can be reduced.

[0017] In some embodiments, the start time of the contention resolution timer can be the T1+1th time unit after the first repeated transmission of the uplink message, where T1 represents the processing delay of the network device.

[0018] In some embodiments, alternatively, if the time required for the repeated transmission of the first repetition of the uplink message exceeds the processing latency of the network device, the start time of the contention resolution timer can be the T1+1th time unit, where T1 represents the processing latency of the network device.

[0019] In some embodiments, alternatively, if the time required for the retransmission of the first repetition of the uplink message exceeds the processing latency of the network device, the start time of the contention resolution timer can be the (T1+1)th time unit after the retransmission of the second repetition of the uplink message. The second repetition is associated with and less than the first repetition, and T1 represents the processing latency of the network device.

[0020] In some embodiments, the processing latency of the network device can be predefined. Alternatively, the network device can send system information indicating the processing latency to the terminal device.

[0021] In some embodiments, additionally, if the retransmission of an uplink message does not reach the first retransmission number after the contention resolution timer is started, the contention resolution timer is restarted after each subsequent retransmission of the uplink message.

[0022] In some embodiments, the network device may transmit the DCI associated with the contention-resolved message outside the time frame of the contention-resolved timer, except for a predetermined period of time preceding each subsequent retransmission of the uplink message. This predetermined period of time is determined based on the sum of the terminal device's uplink transmission preparation time and downlink reception processing time. Subsequent retransmissions occur after the first retransmission of the uplink message.

[0023] In some embodiments, the network device may additionally receive information from the terminal device indicating whether the terminal device should start a contention resolution timer before the number of times the uplink message is retransmitted reaches a first repetition count.

[0024] In a third aspect of this disclosure, a terminal device is provided. The terminal device includes a processor and a memory. Computer program instructions are stored thereon. The memory and the computer program instructions are configured, together with the processor, to cause the terminal device to perform the method according to a first aspect of this disclosure.

[0025] In a fourth aspect of this disclosure, a network device is provided. The network device includes a processor and a memory. Computer program instructions are stored thereon. The memory and the computer program instructions are configured, together with the processor, to cause the network device to perform the method according to a second aspect of this disclosure.

[0026] In a fifth aspect of this disclosure, a computer-readable medium is provided. The computer-readable medium stores machine-executable instructions. When executed by a terminal device, the machine-executable instructions cause the terminal device to perform the method according to a first aspect of this disclosure.

[0027] In a sixth aspect of this disclosure, a computer-readable medium is provided. The computer-readable medium stores machine-executable instructions. When executed by a network device, the machine-executable instructions cause the network device to perform the method according to a second aspect of this disclosure.

[0028] In a seventh aspect of this disclosure, a computer program product is provided. The computer program product includes machine-executable instructions. When executed by a terminal device, the machine-executable instructions cause the terminal device to perform the method according to a first aspect of this disclosure.

[0029] In an eighth aspect of this disclosure, a computer program product is provided. The computer program product includes machine-executable instructions. When executed by a terminal device, the machine-executable instructions cause the terminal device to perform the method according to a second aspect of this disclosure. Attached Figure Description

[0030] The features, advantages, and other aspects of various implementations of this disclosure will become more apparent from the accompanying drawings and the following detailed description. Several implementations of this disclosure are illustrated herein by way of example, not limitation, in the accompanying drawings:

[0031] Figure 1 A schematic block diagram of a communication system in which embodiments of the present disclosure may be implemented is shown;

[0032] Figure 2 A signaling interaction diagram for a random access procedure according to some embodiments of the present disclosure is shown;

[0033] Figure 3 A schematic diagram showing the start time of the contention resolution timer in an LTE system is provided.

[0034] Figure 4 A signaling interaction diagram for a random access procedure according to some embodiments of the present disclosure is shown;

[0035] Figure 5A A schematic diagram illustrating contention resolution of timer start-up time in a time division duplex (TDD) scenario according to some embodiments of the present disclosure is shown.

[0036] Figure 5B A schematic diagram illustrating the start time of a contention resolution timer in a frequency division duplex (FDD) scenario according to some embodiments of the present disclosure is shown.

[0037] Figure 6A A schematic diagram of the start time of the contention resolution timer in a TDD scenario according to some other embodiments of the present disclosure is shown;

[0038] Figure 6B A schematic diagram illustrating the start time of a contention resolution timer in an FDD scenario according to other embodiments of the present disclosure is shown;

[0039] Figure 7A A schematic diagram of the start time of the contention resolution timer in a TDD scenario according to some further embodiments of the present disclosure is shown;

[0040] Figure 7B A schematic diagram illustrating the start time of a contention resolution timer in an FDD scenario according to further embodiments of the present disclosure is shown;

[0041] Figure 7C A schematic diagram illustrating the start time of a contention resolution timer in an FDD scenario according to some embodiments of the present disclosure is shown.

[0042] Figure 8 A flowchart of a method for random access according to some embodiments of the present disclosure is shown;

[0043] Figure 9 A flowchart of a method for random access according to other embodiments of this disclosure is shown; and

[0044] Figure 10 A block diagram of an example electronic device according to some embodiments of the present disclosure is shown.

[0045] In the various figures, the same or similar reference numerals represent the same or similar elements. Detailed Implementation

[0046] Embodiments of this disclosure will now be described in more detail with reference to the accompanying drawings. While some embodiments of this disclosure are shown in the drawings, it should be understood that this disclosure can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of this disclosure. It should be understood that the accompanying drawings and embodiments of this disclosure are for illustrative purposes only and are not intended to limit the scope of protection of this disclosure.

[0047] In the description of embodiments of this disclosure, the term "comprising" and similar terms should be understood as open-ended inclusion, i.e., "including but not limited to". The term "based on" should be understood as "at least partially based on". The term "an embodiment" or "the embodiment" should be understood as "at least one embodiment". The terms "first", "second", etc., may refer to different or the same objects. Other explicit and implicit definitions may also be included below. Expressions such as "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 examples use three elements, A, B, and C, for illustration. When there are more elements in the expression, the meaning of the expression can be obtained according to the foregoing rules.

[0048] In the description of embodiments of this disclosure, the terms "symbol" and "Orthogonal Frequency Division Multiplexing (OFDM) symbol" have the same meaning and are therefore used interchangeably.

[0049] The embodiments of this disclosure can be implemented according to any suitable communication protocol, including but not limited to cellular communication protocols such as fourth-generation (4G) and fifth-generation (5G), wireless local area network communication protocols such as IEEE 802.11, and / or any other protocols currently known or to be developed in the future. The technical solutions of the embodiments of this disclosure are applicable to any suitable communication system, such as: General Packet Radio Service (GPRS), Long Term Evolution (LTE) systems, Frequency Division Duplex (FDD) systems, Time Division Duplex (TDD) systems, Universal Mobile Telecommunications System (UMTS), Narrowband Internet of Things (NB-IoT) communication systems, future fifth-generation (5G) systems, or New Radio Access Technologies (NR), etc.

[0050] For illustrative purposes, embodiments of this disclosure are described below in the context of 5G 3rd Generation Partnership Project (3GPP) communication systems. However, it should be understood that embodiments of this disclosure are not limited to 5G communication systems, but can be applied to any other communication system with similar problems, provided that the communication system has downlink and uplink communication links.

[0051] Figure 1A schematic block diagram of a communication system 100 in which embodiments of the present disclosure may be implemented is shown. As shown, the communication system 100 includes a network device 110 and terminal devices 120-1, 120-2, 120-3, and 120-4. Hereinafter, for the purposes of discussion, terminal devices 120-1, 120-2, 120-3, and 120-4 are collectively referred to as terminal device 120 or simply as terminal device 120. The network device 110 is capable of communicating with the terminal devices 120. The sending of control information and / or data from the network device 110 to the terminal devices 120 is referred to as downlink (DL) communication, and the sending of control information and / or data from the terminal devices 120 to the network device 110 is referred to as uplink (UL) communication.

[0052] Network device 110 refers to any device capable of communicating with terminal device 120. As an example, network device 110 may include NodeB, evolved NodeB, base station in a 5G mobile communication system, Next generation NodeB (gNB), base station in a future mobile communication system, or access node in a Wi-Fi system, etc.

[0053] Terminal device 120 refers to any device capable of communicating with network device 110. As an example, terminal device 120 may include, primarily, mobile phones, vehicles, tablets, as well as sensors such as smart speakers, train detectors, and gas station sensors. The main functions of terminal device 120 include, but are not limited to: collecting data, receiving control information and / or downlink data from network device 110, transmitting electromagnetic waves, and sending control information and / or uplink data to network device 110.

[0054] Understandable. Figure 1 The number of network devices 110 and terminal devices 120 shown is merely an example and is not intended to impose any limitation. The communication system 100 may include any appropriate number of network devices 110 and terminal devices 120 as needed.

[0055] Terminal device 120 can access the network for communication by executing a random access procedure. Random access includes contention-based random access and contention-free random access. Contention-free access is typically used when terminal device 120 is already able to successfully receive Radio Resource Control (RRC) signaling. The signaling interaction diagram of the random access procedure will be described below using a contention-based random access procedure as an example.

[0056] Figure 2 A signaling interaction diagram for a random access procedure 200 according to some embodiments of the present disclosure is shown. For purposes of discussion, reference will be made to... Figure 1 The various elements shown herein describe the random access procedure 200. However, it should be understood that the random access procedure 200 can also be performed between network devices and terminal devices in any other communication scenario.

[0057] like Figure 2 As shown, terminal device 120 sends a preamble 210 to network device 110. Hereinafter, the message carrying this 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, terminal device 120 may determine the time-frequency resources and the preamble for sending the preamble based on system messages received from network device 110 and the selected Synchronization Signal Block (SSB) index.

[0058] After receiving the 220 preamble, network device 110 allocates time-frequency resources for the Random Access Response (RAR) message and scheduling information for Msg3 to terminal device 120. Hereinafter, the RAR message is also referred to as message 2 or Msg2. Msg2 includes the scheduling information for Msg3, namely the RAR UL grant information. The RAR UL grant information indicates the time-frequency resources used for Msg3. Then, network device 110 sends 230 Msg2 to terminal device 120.

[0059] After receiving 240Msg2, terminal device 120 transmits 250Msg3 on the time-frequency resources indicated in Msg2. Msg3 is carried by the Physical Uplink Shared Channel (PUSCH).

[0060] When multiple terminal devices 120 simultaneously request network access, network device 110 needs to determine which terminal device to select for random access and send Msg4 to the selected terminal device. Msg4 is mainly used for contention resolution. If terminal device 120 successfully receives the DCI sent to it and successfully receives Msg4 based on the DCI, the random access is considered successful. If terminal device 120 fails to receive the DCI sent to it, or if the Msg4 received based on the DCI is not sent by the network device, the random access is considered to have failed. Since terminal device 120 cannot determine in which time slot the network device 110 will send the DCI associated with Msg4, terminal device 120 uses a blind detection method to monitor the PDCCH of each downlink time slot. Therefore, the existing standard defines a timer for random access contention resolution (hereinafter also referred to as the contention resolution timer). If terminal device 120 does not receive the DCI sent to it before the contention resolution timer expires, the random access is considered to have failed. Subsequently, terminal device 120 can restart the random access process.

[0061] Because downlink transmission power is greater than uplink transmission power, cell coverage is typically limited by uplink transmission. In 4G and 5G wireless communication systems, energy is typically accumulated through repeated PUSCH transmissions to increase the probability of successful signal reception and improve coverage.

[0062] To ensure that terminal device 120 can successfully access the network, the successful transmission of each message during the random access process must first be guaranteed. Since the success of random access for terminal device 120 is mainly limited by Msg3, which carries a lot of information, existing standards discussion meetings have determined to improve coverage performance by repeatedly sending Msg3.

[0063] The LTE system supports repeated transmissions of Msg3. In an LTE system, after receiving all repeated Msg3 transmissions, the network device determines whether Msg3 was received correctly. If the network device received Msg3 correctly, it sends Msg4 to the terminal device. The transmission of Msg4 occurs after the last repeated transmission of Msg3. Accordingly, the terminal device starts a contention-resolution timer after all repeated transmissions of Msg3 have been completed to receive the DCI associated with Msg4. In other words, the terminal device starts a contention-resolution timer after the number of repeated transmissions of Msg3 has reached a predetermined number to receive the DCI associated with Msg4.

[0064] Figure 3 This diagram illustrates the start time of the contention resolution timer in an LTE system. Figure 3In this frame, each block represents a time slot, each time slot includes 14 symbols, the subcarrier spacing is 15kHz, the uplink and downlink switching period is 5ms, and it includes 5 time slots. The frame structure is configured as 3:1:1, that is, the ratio between the number of downlink time slots (represented by "D") : the number of flexible time slots (represented by "S") : the number of uplink time slots (represented by "U") is 3:1:1.

[0065] The terminal device repeatedly sends Msg3 to the network device four times, with indices #1 to #4. Figure 3 The timeslots are 311 to 314. After receiving all four repetitions of Msg3, the network device determines whether Msg3 has been received correctly. If the network device has received Msg3 correctly, for example, if it has received the second repetition of Msg3 (312), then the network device sends Msg4 to the terminal device. The transmission of Msg4 occurs after the last repetition of Msg3 (314) has been completed. Accordingly, after all repetitions of Msg3 have been completed, i.e., in timeslot 315, the terminal device starts a contention-resolved timer to receive the DCI associated with Msg4.

[0066] exist Figure 3 In the example, Msg4 is only transmitted after all repetitions of Msg3 have been completed. However, the network device may successfully receive Msg3 before the last repetition. This restricts the terminal device to receiving the DCI associated with Msg4 only after the last repetition of Msg3 has been completed. Correspondingly, this also restricts the network device to transmitting the DCI associated with Msg4 only after the last repetition of Msg3. This results in significant access latency and unnecessary energy waste from repetitive Msg3 transmissions. In particular, when randomly scheduling the number of Msg3 repetitions, the network device, lacking Channel State Information (CSI) and relying solely on the energy of the preamble, inaccurately schedules the number of repetitions. The network device is highly likely to schedule more repetitions to ensure the performance of coverage-limited terminal devices.

[0067] At least to address the aforementioned problems and other potential related issues, embodiments of this disclosure propose a scheme for random access. According to this scheme, before the number of retransmissions of Msg3 reaches a first retransmission count or before the retransmission is completed, the terminal device starts a contention resolution timer to receive the DCI associated with Msg4. Correspondingly, if the network device successfully receives Msg3 before the number of retransmissions of Msg3 reaches the first retransmission count or before the retransmission is completed, the network device sends the DCI associated with Msg4 to the terminal device after the contention resolution timer is started. This scheme can reduce the random access latency of the terminal device. The following will refer to... Figure 4 The embodiments of this disclosure will be described in detail with reference to Figure 7.

[0068] Figure 4 A signaling interaction diagram of an example procedure 400 for random access according to an embodiment of the present disclosure is shown. For purposes of discussion, reference will be made to... Figure 1 The various elements shown are used to describe example process 400. However, it should be understood that example process 400 can also be executed between network devices and terminal devices in any other communication scenario.

[0069] like Figure 4 As shown, terminal device 120 repeatedly sends an uplink message 410 (also referred to as Msg3) to network device 110 based on a first repetition count. Correspondingly, network device 110 receives the 420 repeatedly sent Msg3 from terminal device 120 based on the first repetition count. This Msg3 is scheduled by a random access response message (also referred to as Msg2). In some embodiments, to obtain time-frequency resources for Msg3, terminal device 120 may perform the above-referenced... Figure 2 Actions 210 and 240 are described. In some embodiments, the first repetition count of Msg3 may be indicated by network device 110 in Msg2. In other embodiments, the first repetition count may be indicated by network device 110 in other indication information, such as in System Information Block 1 (SIB1) or DCI. In still other embodiments, the first repetition count may be predefined.

[0070] Before the number of retransmissions of Msg3 reaches the first retransmission count or before the retransmission is completed, terminal device 120 starts a contention resolution timer 430 to receive the DCI associated with the contention resolution message (also referred to as Msg4). The start time of the contention resolution timer is associated with at least one of the following: the processing delay of network device 110 (represented by T1), the first retransmission count, and the time required for the retransmission of the first retransmission count of Msg3 (represented by T2). In other words, terminal device 120 determines the start time of the contention resolution timer based on at least one of the above. The processing delay of network device 110 includes the delay of network device 110 processing Msg3. In addition, the processing delay of network device 110 may also include the delay of network device 110 preparing the PDCCH, which is used to carry the DCI associated with Msg4. In other words, the processing delay of network device 110 may include the time from network device 110 receiving Msg3 to network device 110 sending the PDCCH, which is used to carry the DCI associated with Msg4. The time required for the first retransmission of Msg3 is the number of time units between the first symbol after the first retransmission of Msg3 and the first symbol after the last retransmission of Msg3. It can be understood that the last retransmission of Msg3 here refers to the last retransmission within the first retransmission count. For example, in the case of a first retransmission count of 4, the last retransmission of Msg3 refers to the 4th retransmission. Examples of time units may include, but are not limited to, subframes, time slots, and OFDM symbols. An embodiment for determining the start time of the contention resolution timer will be referred to below. Figures 5A to 7C Let me describe it in detail.

[0071] If network device 110 successfully receives Msg3 before the first retransmission of Msg3 is reached or the retransmission is completed, then network device 110 sends DCI associated with Msg4 to terminal device 120 after the contention resolution timer is started. It should be understood that network device 110 may not immediately send DCI associated with Msg4 after successfully receiving one retransmission of Msg3, but will wait until the contention resolution timer starts before sending DCI associated with Msg4.

[0072] Accordingly, terminal device 120 receives 450Msg4 from network device 110. After successfully receiving the DCI associated with Msg4, terminal device 120 can receive Msg4 based on the DCI associated with Msg4.

[0073] Optionally, upon receiving Msg4, terminal device 120 can determine the terminal identifier included in Msg4. Examples of this terminal identifier include, but are not limited to, a Cell-Radio Network Temporary Identifier (C-RNTI). If this terminal identifier is the same as the terminal identifier of terminal device 120, terminal device 120 determines that random access is successful; if this terminal identifier is different from the terminal identifier of terminal device 120, terminal device 120 determines that random access has failed. Then, terminal device 120 can restart the random access process.

[0074] According to embodiments of this disclosure, before the number of repeated transmissions of Msg3 reaches the first number of repetitions or before the repeated transmissions are completed, the terminal device starts a contention resolution timer to receive the DCI associated with Msg4, which can reduce the random access latency of the terminal device.

[0075] 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. This latency may include one or more time units. Examples of time units may include, but are not limited to, subframes, time slots, and OFDM symbols.

[0076] In some embodiments, the processing latency of network device 110 is predefined. Alternatively, the processing latency of network device 110 may be indicated by network device 110 in system information (e.g., SIB1).

[0077] In some embodiments, terminal device 120 may be a coverage-limited terminal device, such as a terminal device that supports repeated transmission of Msg3. In such embodiments, the timing length of the contention resolution timer may be N subframes (N time 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., SIB1). As an example, N may be equal to 8.

[0078] In some embodiments, terminal device 120 may not be a coverage-limited terminal device, such as a terminal device that does not support repeated transmission of Msg3. In such embodiments, the timing length of the contention resolution timer can be M subframes (M time slots when the subcarrier spacing is 15kHz, where M is 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., SIB1). The second predefined parameter differs from the first predefined parameter described above.

[0079] It should be understood that the timing lengths N and M of the race-resolved timer can be any suitable value, and the scope of this disclosure is not limited in this respect.

[0080] In order to instruct the terminal device 120 on an appropriate timing length, the network device 110 needs to determine whether the terminal device 120 is a coverage-limited terminal device. For this purpose, the network device 110 can employ either of the following two methods.

[0081] Option 1: Network device 110 can reserve dedicated PRACH resources for terminal devices with limited coverage, for example, by adding a new type of PRACH resource. For instance, when the Reference Signal Received Power (RSRP) is less than a predefined threshold, terminal device 120 can choose to use the reserved PRACH resource, where the predefined threshold for RSRP can be notified in SIB1. If network device 110 receives the preamble sent by terminal device 120 on the reserved PRACH resource, then network device 110 can determine that terminal device 120 is a terminal device with limited coverage.

[0082] Option 2: Network device 110 can identify coverage-limited terminal devices by repeatedly transmitting PRACH. Coverage-limited terminal devices can increase their access probability by repeatedly transmitting PRACH. Network device 110 identifies whether a coverage-limited terminal device has accessed the network by detecting the number of times PRACH is repeatedly transmitted. If so, network device 110 can use the redundancy field of the Modulation and Coding Scheme (MCS) to indicate the number of times Msg3 is repeatedly transmitted when transmitting the RAR UL grant.

[0083] It should be understood that the above two schemes are merely examples, and network device 110 can also determine whether terminal device 120 is a terminal device with limited coverage through other means.

[0084] In the following text, reference will be made to Figures 5A to 7C This section describes in detail some embodiments for determining the start time of the race-resolver timer.

[0085] In some embodiments, terminal device 120 can determine the start time of the contention resolution timer based on the processing delay T1 of network device 110. Specifically, terminal device 120 can determine the (T1+1)th 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 can be the (T1+1)th OFDM symbol; when the time unit is a time slot, the start time of the contention resolution timer can be the first OFDM symbol of the (T1+1)th time slot; when the time unit is a subframe, the start time of the contention resolution timer can be the first OFDM symbol of the (T1+1)th subframe. The following will refer to... Figure 5A and 5B This embodiment will now be described in detail.

[0086] Figure 5A A schematic diagram illustrating the contention resolution timer start-up time in a time-division duplex (TDD) scenario according to some embodiments of the present disclosure is shown. Figure 5A In this frame, each square represents a time slot, each time slot includes 14 symbols, the subcarrier spacing is 15kHz, the uplink / downlink transition period is 10ms, and the uplink / downlink transition period contains 10 time slots. The frame structure is configured as 8:1:1, meaning the ratio of downlink time slots (denoted as "D") to flexible time slots (denoted as "S") to uplink time slots (denoted as "U") is 8:1:1. The processing delay T1 of network device 110 is 6 time slots. The contention resolution timer has a timing length of 8 time slots when the subcarrier spacing is 15kHz.

[0087] Terminal device 120 repeatedly sends Msg3 four times to network device 110, with indices #1 to #4. Figure 5A The symbols are 511 to 514. Terminal device 120 starts the contention resolution timer in the (T1+1)th time unit after the first repeated transmission of Msg3. That is, terminal device 120 starts the contention resolution timer in the 7th time unit (i.e., the 6*14+1th symbol) 521 after Msg3#1 (represented as 511) is transmitted.

[0088] In some embodiments, after starting the contention resolution timer, if the repeated transmission of Msg3 does not reach the first repetition count, the terminal device 120 restarts (i.e., re-starts) the contention resolution timer after each subsequent repeated transmission of Msg3. For example, in Figure 5A In the example, after the contention resolution timer is started, since Msg3 is not retransmitted four times, the terminal device 120 restarts the contention resolution timer again in time units 522, 523 and 524 after the subsequent retransmissions of Msg3 512, 513 and 514. Figure 5B A schematic diagram illustrating the start time of a contention resolution timer in a frequency division duplex (FDD) scenario according to some embodiments of the present disclosure is shown. Figure 5B In this diagram, each square represents a time slot, each time slot includes 14 symbols, and the subcarrier spacing is 15 kHz. The processing delay T1 of network device 110 includes 6 time slots.

[0089] Terminal device 120 repeatedly sends Msg3 four times to network device 110, with indices #1 to #4. Figure 5B The symbols are 531 to 534. Terminal device 120 starts the contention resolution timer at the (T1+1)th time unit after the first repeated transmission of Msg3. That is, terminal device 120 starts the contention resolution timer at the 7th time unit (i.e., the 6*14+1th symbol) 541 after the transmission of Msg3#1 (represented as 531).

[0090] In some embodiments, after the contention resolution timer is started, if the repeated transmission of Msg3 does not reach the first repetition count, the terminal device 120 restarts (i.e. re-starts) the contention resolution timer at the T1+1th time unit after each subsequent repeated transmission of Msg3.

[0091] In some embodiments, terminal device 120 can determine the start time of the contention resolution timer based on the time T2 required for the first retransmission of Msg3 and the processing delay T1 of network device 110. Specifically, terminal device 120 can compare T2 with T1. If T2 is greater than T1, terminal device 120 determines the (T1+1)th time unit after the first retransmission of Msg3 as the start time of the contention resolution timer. If T2 is less than or equal to T1, terminal device 120 determines the first time unit after the last retransmission of Msg3 as the start time of the contention resolution timer. Alternatively, if T2 is less than or equal to T1, terminal device 120 determines the (T1+1)th time unit after the last retransmission of Msg3 as the start time of the contention resolution timer. The following will refer to... Figure 6A and 6B This embodiment will now be described in detail.

[0092] Figure 6A A schematic diagram of the start time of the contention resolution timer in a TDD scenario according to other embodiments of the present disclosure is shown. Figure 6A Examples and Figure 5A Similar to the example, the difference between the two is that... Figure 6A The relationship between the time T2 required for the first retransmission of Msg3 and the processing delay T1 of network device 110 is further illustrated. Figure 6AIn the example, T1 includes 6 time slots, and T2 includes 30 time slots, each containing 14 symbols. Since T2 is greater than T1, the terminal device 120 determines the (T1+1)th 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 7th time unit (i.e., the 6th * 14+1th symbol) 521 after the transmission of Msg3#1 (represented as 511).

[0093] Figure 6B A schematic diagram of the start time of the contention resolution timer in an FDD scenario according to some other embodiments of the present disclosure is shown. Figure 6B Examples and Figure 5B Similar to the example, the difference between the two is that... Figure 6B The relationship between the time T2 required for the first retransmission of Msg3 and the processing delay T1 of network device 110 is further illustrated. Figure 6B In the example, T1 includes 6 time slots, and T2 includes 3 time slots. Since T2 is less than T1, the terminal device 120 determines the start time of the contention resolution timer as the first time unit after the last repeated transmission of Msg3. That is, the terminal device 120 starts the contention resolution timer in the first time unit 611 after Msg3#4 (represented as 534) is transmitted.

[0094] In some embodiments, the terminal device 120 may determine the start time of the contention resolution timer based on the first repetition count of Msg3. For example, the terminal device 120 may determine a second repetition count (denoted by i) associated with the first repetition count based on the first repetition count, and then determine the first time unit after the repetition of the second repetition count of Msg3 as the start time of the contention resolution timer, wherein the second repetition count is less than the first repetition count. Alternatively, the terminal device 120 may determine a second repetition count (denoted by i) associated with the first repetition count based on the first repetition count, and then determine the first time unit after the repetition of the second repetition count of Msg3 as the start time of the contention resolution timer, wherein the second repetition count is less than or equal to the first repetition count; if the first repetition count is less than or equal to a threshold, the second repetition count is equal to the first repetition count, and if the first repetition count is greater than the threshold, the second repetition count is less than the first repetition count. As an example, Tables 1 and 2 below show the correlation between the first repetition count of Msg3 and the start time of the contention resolution timer (i.e., the correlation between the first repetition count and the second repetition count). The terminal device 120 may determine the start time of the contention resolution timer based on Table 1 or Table 2.

[0095] Table 1

[0096] The first repetition of Msg3 Race-resolved timer startup time 2 After the first repeated transmission of Msg3, 4 After the second retransmission of Msg3, 8 After the fourth retransmission of Msg3 16 After the 8th retransmission of Msg3

[0097] Table 2

[0098] The first repetition of Msg3 Race-resolved timer startup time 2 After the second retransmission of Msg3, 4 After the fourth retransmission of Msg3 8 After the fourth retransmission of Msg3 16 After the 8th retransmission of Msg3

[0099] Table 1 shows examples where the second repetition count is less than the first repetition count. As shown in Table 1, when the first repetition count of Msg3 is 2 and the second repetition count is 1, it means that the network device 110 has a high probability of successfully decoding Msg3 after receiving it for the first time. Therefore, the terminal device 120 starts the contention resolution timer in the first time unit after the first repetition of Msg3 ends. When the first repetition count of Msg3 is 4 and the second repetition count is 2, the terminal device 120 starts the contention resolution timer in the first time unit after the second repetition of Msg3 ends. When the first repetition count of Msg3 is 8 and the second repetition count is 4, the terminal device 120 starts the contention resolution timer in the first time unit after the fourth repetition of Msg3 ends. When the first repetition count of Msg3 is 16 and the second repetition count is 8, the terminal device 120 starts the contention resolution timer in the first time unit after the eighth repetition of Msg3 ends.

[0100] Table 2 shows examples where the second repetition count is less than or equal to the first repetition count, and the threshold in the examples in Table 2 can be 4. As shown in Table 2, when the first repetition count of Msg3 is 2, the second repetition count is 2. Therefore, terminal device 120 starts a contention resolution timer in the first time unit after the second repetition of Msg3 ends. When the first repetition count of Msg3 is 4, the second repetition count is 4, so terminal device 120 starts a contention resolution timer in the first time unit after the fourth repetition of Msg3 ends. When the first repetition count of Msg3 is 8, the second repetition count is 4, so terminal device 120 starts a contention resolution timer in the first time unit after the fourth repetition of Msg3 ends. When the first repetition count of Msg3 is 16, the second repetition count is 8, so terminal device 120 starts a contention resolution timer in the first time unit after the eighth repetition of Msg3 ends.

[0101] It should be understood that Tables 1 and 2 only show one example of the correlation between the first repetition of Msg3 and the start time of the race-resolve timer, and the scope of this disclosure is not limited in this respect, and other correlations between the two are also possible.

[0102] In some embodiments, the terminal device 120 can determine the start time of the contention resolution timer based on the first repetition number of Msg3 and 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. Specifically, the terminal device 120 can compare the time T2 required for the repeated transmission of the first repetition 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+1)th time unit after the repeated transmission of the second repetition number of Msg3 as the start time of the contention resolution timer. The second repetition number is associated with the first repetition number. The second repetition number is less than the first repetition number, or the second repetition number is less than or equal to the first repetition number. If the first repetition number is less than or equal to a threshold, the second repetition number is equal to the first repetition number; if the first repetition number is greater than the threshold, the second repetition number is less than the first repetition number. If T2 is less than or equal to T1, then the terminal device 120 determines the start time of the contention resolution timer as the first time unit after the last repeated transmission of Msg3, or determines the start time of the contention resolution timer as the T1+1th time unit after the first repeated transmission of Msg3. The following will refer to... Figure 7A , 7B The embodiment will be described in detail below with reference to 7C.

[0103] Figure 7A A schematic diagram of the start time of a contention resolution timer in a TDD scenario according to some further embodiments of the present disclosure is shown. Figure 7A Examples and Figure 6A Similar to the example, the difference between the two is that, in Figure 7A In the example, terminal device 120 determines the start time of the contention resolution timer based not only on the relationship between T2 and T1 but also on the first repetition number of Msg3. Specifically, terminal device 120 compares T2 with T1. Since T2 is greater than T1, terminal device 120 determines the (T1+1)th time unit after the i-th (second repetition) retransmission of Msg3 as the start time of the contention resolution timer. The second repetition number i can be determined, for example, from Table 1 or Table 2. In this example, since the first repetition number is equal to 4, the second repetition number i can be determined to be equal to 2 according to Table 1. Thus, terminal device 120 starts the contention resolution timer at the 7th time unit (i.e., the 6*14+1th symbol) 711 after Msg3#2 (represented as 512) is transmitted.

[0104] Figure 7B A schematic diagram of the start time of the contention resolution timer in an FDD scenario according to some further embodiments of the present disclosure is shown. Figure 7B Examples and Figure 6BSimilar to the example, the difference between the two is that, in Figure 7B In the example, terminal device 120 determines the start time of the contention resolution timer not only based on the magnitude relationship between T2 and T1, but also based on the first repetition count of Msg3. Figure 7B In the example, T1 includes 6 time slots, and T2 includes 3 time slots. Since T2 is less than T1, the terminal device 120 determines the (T1+1)th 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 7th time unit (i.e., the 6*14+1th symbol) 721 after the transmission of Msg3#1 (represented as 531).

[0105] Figure 7C A schematic diagram of the start time of the contention resolution timer in an FDD scenario according to some embodiments of the present disclosure is shown. Figure 7C Examples and Figure 7B Similar to the example, the difference between the two is that, in Figure 7C In the example, terminal device 120 determines the start time of the contention resolution timer as the first time unit after the last repeated transmission of Msg3. That is, terminal device 120 starts the contention resolution timer in the first time unit 731 after Msg3#4 (represented as 534) is transmitted.

[0106] It should be understood that, Figure 5A , 6A In 7A, an example is described with a subcarrier spacing of 15 kHz, an uplink and downlink switching period of 10 ms, and a frame structure configured as 8:1:1, but the scope of this disclosure is not limited thereto.

[0107] In some embodiments, if the terminal device 120 successfully receives the DCI associated with Msg4 before the number of retransmissions of Msg3 reaches the first retransmission count or before the retransmission is completed, the terminal device 120 may cancel subsequent retransmissions of Msg3. By canceling subsequent retransmissions of Msg3, the energy wasted by the terminal device 120 in transmitting Msg3 can be avoided.

[0108] Optionally, in order to enable terminal device 120 to cancel subsequent retransmissions of Msg3, network device 110 transmits the DCI associated with Msg4 outside of a predetermined time period before each subsequent retransmission of Msg3 within the timing range of the contention resolution timer. In other words, network device 110 does not transmit the DCI associated with Msg4 within the predetermined time period before each subsequent retransmission of Msg3. This predetermined time period is based on the uplink transmission preparation time of terminal device 120 (determined by T). procThe sum of the uplink transmission preparation time (represented by d1) and the downlink reception processing time (represented by d1) is determined. proc The downlink receive processing time d1 can be calculated as described in Section 6.4 of TS 38.213 and can be reported by terminal device 120 to network device 110. As an example, this predetermined time period may include W symbols preceding the first time-domain symbol corresponding to any subsequently retransmitted Msg3. The timing range of the contention resolution timer can be determined by the timing length of the contention resolution timer (e.g., M subframes) and its start time, such as M subframes after the contention resolution timer starts.

[0109] In some embodiments, terminal device 120 may send information to network device 110 to instruct whether terminal device 120 should start a contention resolution timer before the repeated transmission of Msg3 reaches a first repetition count. Alternatively, terminal device 120 may send capability information to network device 110, indicating whether terminal device 120 has the capability to start a contention resolution timer before the repeated transmission of Msg3 reaches a first repetition count. Alternatively, terminal device 120 may send information to network device 110 to instruct whether terminal device 120 can cancel subsequent repeated transmissions before the repeated transmission of Msg3 reaches a first repetition count. Alternatively, terminal device 120 may send capability information to network device 110, indicating whether terminal device 120 has the capability to cancel subsequent repeated transmissions before the repeated transmission of Msg3 reaches a first repetition count. For this purpose, terminal device 120 may employ either of the following two schemes.

[0110] Option 1: Network device 110 reserves dedicated PRACH resources for terminal device 120 capable of reporting this information; that is, a new type of PRACH resource can be added. For example, network device 110 can reserve dedicated PRACH resource 1 and PRACH resource 2 for terminal device 120. If terminal device 120 uses PRACH resource 1 to send Msg1, network device 110 knows that terminal device 120 will start a contention resolution timer before the repeated transmission of Msg3 reaches the first repetition count. If terminal device 120 uses PRACH resource 2 to send Msg1, network device 110 knows that terminal device 120 will not start a contention resolution timer before the repeated transmission of Msg3 reaches the first repetition count.

[0111] Option 2: Network device 110 can determine whether terminal device 120 starts a contention-resolving timer before the first repetition count of Msg3 is reached by using the demodulation reference signal (DMRS) port used by Msg3 or Msg1. Currently, terminal device 120 uses the default DMRS port to transmit Msg3. If network device 110 detects that the port used by Msg3 is different from the default DMRS port, it assumes that terminal device 120 will start the contention-resolving timer before the first repetition count of Msg3 is reached.

[0112] It should be understood that the above two schemes are merely examples, and the terminal device 120 can also use other methods to indicate whether to start the contention resolution timer in advance.

[0113] Figure 8 A flowchart of an example method 800 for random access according to some embodiments of the present disclosure is shown. In some embodiments, the example method 800 may be implemented by a terminal device 120 in the example communication system 100, for example by a processor or processing unit of the terminal device 120 in conjunction 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 explanation, reference will be made to... Figure 1 Let's describe example method 800.

[0114] At box 810, terminal device 120 repeatedly sends uplink messages to network device 110 based on a first repetition count. These uplink messages are scheduled by a random access response message.

[0115] At box 820, before the number of retransmissions of the uplink message reaches the first retransmission count or before the retransmission is completed, terminal device 120 starts a contention resolution timer for receiving the DCI associated with the contention resolution message. The start time of the contention resolution timer is associated with at least one of the following: the processing delay of network device 110, the first retransmission count, and the time required for the retransmission of the first retransmission count of the uplink message. The processing delay includes the delay of network device 110 in processing the uplink message.

[0116] Method 800 can reduce the random access latency of terminal devices.

[0117] In some embodiments, additionally, if the terminal device 120 successfully receives the DCI associated with the contention resolution message before the number of retransmissions of the uplink message reaches the first retransmission count or before the retransmission is completed, the terminal device 120 may cancel subsequent retransmissions of the uplink message. In this way, energy wasted by the terminal device 120 in transmitting uplink messages can be avoided.

[0118] In some embodiments, the start time of the contention resolution timer can be the T1+1th time unit after the first repeated transmission of the uplink message, where T1 represents the processing delay of the network device 110.

[0119] In some embodiments, alternatively, if the time required for repeated transmission of the first repetition of the uplink message exceeds the processing delay, the start time of the contention resolution timer can be the T1+1th time unit.

[0120] In some embodiments, alternatively, if the time required for retransmission of the first repetition of the uplink message exceeds the processing delay, the start time of the contention resolution timer can be the (T1+1)th time unit after the second repetition of the uplink message. The second repetition is associated with and less than the first repetition. T1 represents the processing delay of network device 110.

[0121] In some embodiments, the processing latency of network device 110 can be predefined. Alternatively, terminal device 120 can receive system information indicating the processing latency from network device 110.

[0122] In some embodiments, additionally, after starting the contention resolution timer, if the retransmission of the uplink message does not reach the first retransmission count, the terminal device 120 may restart the contention resolution timer after each subsequent retransmission of the uplink message.

[0123] In some embodiments, additionally, terminal device 120 may receive the DCI associated with the contention-resolved message outside the timing range of the contention-resolved timer, except for a predetermined period of time preceding each subsequent retransmission of the uplink message. This predetermined period of time is determined based on the sum of the uplink transmission preparation time and the downlink reception processing time of terminal device 120. Subsequent retransmissions occur after the first retransmission of the uplink message.

[0124] In some embodiments, terminal device 120 may additionally send information to network device 110 indicating whether terminal device 120 should start a contention resolution timer before the repeated transmission of uplink messages reaches a first repetition count.

[0125] Figure 9A flowchart of an example method 900 for random access according to other embodiments of the present disclosure is shown. In some embodiments, the example method 900 may be implemented by a network device 110 in the example communication system 100, for example by a processor or processing unit of the network device 110 in conjunction 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 explanation, reference will be made to... Figure 1 Let's describe example method 900.

[0126] At box 910, network device 110 receives repeatedly transmitted uplink messages from terminal device 120 based on a first repetition count. These uplink messages are scheduled by a random access response message.

[0127] At box 920, if network device 110 successfully receives an uplink message before the number of retransmissions of the uplink message reaches the first retransmission count or before the retransmission is completed, network device 110 sends a DCI associated with the contention-resolved message to terminal device 120 after the contention-resolved timer is started. The start time of the contention-resolved timer is associated with at least one of the following: the processing delay of network device 110, the first retransmission count, and the time required for the retransmission of the first retransmission count of the uplink message. The processing delay includes the delay of network device 110 in processing the uplink message.

[0128] Method 900 can reduce the random access latency of terminal devices.

[0129] In some embodiments, the start time of the contention resolution timer can be the T1+1th time unit after the first repeated transmission of the uplink message, where T1 represents the processing delay of the network device 110.

[0130] In some embodiments, alternatively, if the time required for repeated transmission of the first repetition of the uplink message exceeds the processing delay, the start time of the contention resolution timer can be the T1+1th time unit.

[0131] In some embodiments, alternatively, if the time required for retransmission of the first repetition of the uplink message exceeds the processing delay, the start time of the contention resolution timer can be the (T1+1)th time unit after the retransmission of the second repetition of the uplink message. The second repetition is associated with and less than the first repetition, and T1 represents the processing delay.

[0132] In some embodiments, the processing latency of network device 110 can be predefined. Alternatively, network device 110 can send system information indicating the processing latency to terminal device 120.

[0133] In some embodiments, additionally, if the retransmission of an uplink message does not reach the first retransmission number after the contention resolution timer is started, the contention resolution timer is restarted after each subsequent retransmission of the uplink message.

[0134] In some embodiments, network device 110 may transmit the DCI associated with the contention-resolved message outside of a predetermined time period preceding each subsequent retransmission of the uplink message within the timing range of the contention-resolved timer. This predetermined time period is determined based on the sum of the uplink transmission preparation time and the downlink reception processing time of terminal device 120. Subsequent retransmissions occur after the first retransmission of the uplink message.

[0135] In some embodiments, network device 110 may additionally receive information from terminal device 120 indicating whether terminal device 120 should start a contention resolution timer before the number of times an uplink message is repeatedly transmitted reaches a first repetition count.

[0136] Figure 10 A block diagram of an example electronic device 1000 according to an embodiment of the present disclosure is shown. The example electronic device 1000 can be used to implement a communication device, such as... Figure 1 The example electronic device 1000 includes network device 110 and terminal device 120, etc. Therefore, in this document, the example electronic device 1000 can also be referred to as the example communication device 1000. Figure 10 As shown, the example communication device 1000 may include a processor 1010 and a memory 1020 coupled to the processor 1010. The memory 1020 stores computer program instructions 1025. Furthermore, the example communication device 1000 may also include a communication module 1030 coupled to the processor 1010. The communication module 1030 can be used for bidirectional communication and may have at least one cable, optical fiber, wireless interface, etc., to facilitate communication. The communication interface can represent any interface used for communicating with other devices.

[0137] Processor 1010 can be of any type suitable for the local technical environment, and as a non-limiting example, can include one or more of the following: general-purpose computer, special-purpose computer, microprocessor, digital signal processor (DSP), and processor based on a multi-core processor architecture. Example communication device 1000 can have multiple processors, such as application-specific integrated circuit (ASIC) chips that follow a clock synchronized with the main processor in time. Memory 1020 can include one or more non-volatile memories and one or more volatile memories. Examples of non-volatile memories include, but are not limited to, read-only memory (ROM), electrically erasable programmable read-only memory (EPROM), flash memory, hard disk, compressed disk (CD), digital versatile distribution (DVD), and other magnetic and / or optical storage devices. Examples of volatile memories include, but are not limited to, random access memory (RAM) or other volatile memories that do not persist during power loss. Computer program instructions 1025 may include computer-executable instructions that are executable by the associated processor 1010. In some embodiments, computer program instructions 1025 may be stored in the ROM of memory 1020. Processor 1010 may perform various appropriate actions and processes by loading memory 1020 into RAM of memory 1020. Embodiments of this disclosure may be implemented by computer program instructions 1025 to cause example communication device 1000 to perform as described above. Figure 4 , Figure 8 and Figure 9 Any method or process described in this disclosure. Of course, embodiments of this disclosure can also be implemented by hardware or a combination of software and hardware.

[0138] In some embodiments, computer program instructions 1025 may be tangibly contained in a computer-readable medium. Such a computer-readable medium may be included in the example communication device 1000 (e.g., 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 into 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, etc.

[0139] Generally, the various exemplary embodiments of this disclosure can be implemented in hardware or dedicated circuitry, software, logic, or any combination thereof. Some aspects can be implemented in hardware, while others can be implemented in firmware or software that can be executed by a controller, microprocessor, or other computing device. For example, in some embodiments, the various examples of this disclosure (e.g., methods, apparatus, or devices) can be implemented in whole or in part on a computer-readable medium. When aspects of embodiments of this disclosure are illustrated or described as block diagrams, flowcharts, or using some other graphical representation, it will be understood that the blocks, apparatuses, systems, techniques, or methods described herein can be implemented as non-limiting examples in hardware, software, firmware, dedicated circuitry or logic, general-purpose hardware or controllers or other computing devices, or some combination thereof.

[0140] This 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, for performing the above-described... Figure 4 , Figure 8 and Figure 9 Example methods or procedures 400, 800, and 900 are described. Generally, a program module may include routines, programs, libraries, objects, classes, components, data structures, etc., which perform a specific task or implement a specific abstract data structure. In various embodiments, the functionality of a program module may be combined or divided among the described program modules. The computer-executable instructions for a program module may execute on a local or distributed device. In a distributed device, the program module may reside on both local and remote storage media.

[0141] Program code used to implement the methods of this disclosure may be written in one or more programming languages. This computer program code may be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing apparatus, such that, when executed by the computer or other programmable data processing apparatus, the program code causes the functions / operations specified in the flowcharts and / or block diagrams to be performed. The program code may be executed entirely on a computer, partially on a computer, as a stand-alone software package, partially on a computer and partially on a remote computer, or entirely on a remote computer or server. In the context of this disclosure, the 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 so on.

[0142] Computer-readable media can be computer-readable signal media or computer-readable storage media. Computer-readable media can be, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatuses, or devices, or any suitable combination thereof. More detailed examples of machine-readable storage media include electrical connections with one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable compact disc read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0143] Furthermore, although the operations are depicted in a specific order, this should not be construed as requiring such operations to be performed in the specific order shown or in a sequential order, or to execute all illustrated operations to obtain the desired result. In some cases, multitasking or parallel processing may be beneficial. Similarly, although the foregoing discussion contains certain specific implementation details, this should not be construed as limiting the scope of any invention or claim, but rather as a description of specific embodiments that may be implemented with respect to a particular invention. Certain features described in this specification in the context of separate embodiments may also be implemented integratedly in a single embodiment. Conversely, various features described in the context of a single embodiment may also be implemented separately in multiple embodiments or in any suitable sub-combination.

[0144] Although the subject matter has been described in language specific to structural features and / or methodological actions, it should be understood that the subject matter defined in the appended claims is not limited to the specific features or actions described above. Rather, the specific features and actions described above are disclosed as exemplary forms of implementing the claims.

Claims

1. A method for random access, comprising: repeating, by a terminal device, sending of an uplink message to a network device based on a first repetition number, the uplink message being scheduled by a random access response message; and starting, by the terminal device, a contention resolution timer for receiving downlink control information associated with a contention resolution message before a number of repetitions of the sending of the uplink message reaches the first repetition number, or before the sending of the uplink message is completed, wherein a time at which the terminal device starts the contention resolution timer is associated with at least one of: a processing delay of the network device, the processing delay comprising a time delay for the network device to process the uplink message, the first repetition number, and a time required for the first repetition number of repetitions of the uplink message. 2.The method of claim 1, further comprising: cancelling, by the terminal device, subsequent repetitions of the uplink message if the terminal device successfully receives the downlink control information before the number of the repetitions of the uplink message reaches the first repetition number or the repetitions are completed. 3.The method of claim 1, wherein the time at which the terminal device starts the contention resolution timer is: a T 1 + 1 th time unit after a first repetition of the uplink message, T 1 representing the processing delay. 4.The method of claim 3, wherein: if the time required for the first repetition number of repetitions of the uplink message exceeds the processing delay, the time at which the terminal device starts the contention resolution timer is the T 1 + 1 th time unit. 5.The method of claim 1, wherein: if the time required for the first repetition number of repetitions of the uplink message exceeds the processing delay, the time at which the terminal device starts the contention resolution timer is a T 1 + 1 th time unit after a second repetition of the uplink message, the second repetition being associated with the first repetition number and being less than the first repetition number, T 1 representing the processing delay. 6.The method of any one of claims 2 to 5, wherein the processing delay is predefined. 7.The method of any one of claims 2 to 5, further comprising: receiving, by the terminal device, system information from the network device indicating the processing delay. 8.The method of claim 1, further comprising: if the repetitions of the uplink message do not reach the first repetition number after starting the contention resolution timer, restarting, by the terminal device, the contention resolution timer after each subsequent repetition 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 time period before each subsequent repeated transmission of the uplink message, the predetermined time period 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: The terminal device sends information to the network device, the information indicating whether the terminal device starts the contention resolution timer before the repeated transmissions of the uplink message reach the first repetition number.

11. A method for random access, comprising: A network device receives repeated transmissions of an uplink message from a terminal device based on a first repetition number, the uplink message being scheduled by a random access response message; and If the network device successfully receives the uplink message before the number of repeated transmissions of the uplink message reaches the first repetition number, or before the repeated transmissions of the uplink message are completed, the network device sends downlink control information associated with a contention resolution message to the terminal device after a contention resolution timer is started, wherein the contention resolution timer is started at a time associated with at least one of: a processing delay of the network device, the processing delay including a time for the network device to process the uplink message, the first repetition number, and a time required for the first repetition number of repeated transmissions of the uplink message.

12. The method of claim 11, wherein the contention resolution timer is started at a time that is: a Tl+1th time unit after a first repeated transmission of the uplink message, Tl representing the processing delay.

13. The method of claim 12, wherein: if the time required for the first repetition number of repeated transmissions of the uplink message exceeds the processing delay, the contention resolution timer is started at the Tl+1th time unit.

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 contention resolution timer is started at a Tl+1th time unit after a second repetition number of repeated transmissions of the uplink message, the second repetition number being associated with the first repetition number and being less than the first repetition number, Tl representing the processing delay.

15. The method of any one of claims 11 to 14, wherein the processing delay is predefined.

16. The method of any one of claims 11 to 14, further comprising: The network device sends system information to the terminal device indicating the processing delay.

17. The method of claim 11, further comprising: If the repeated sending of the uplink message does not reach the first repetition number after the contention resolution timer is started, the contention resolution timer is restarted after each subsequent repeated sending of the uplink message.

18. The method of claim 11, wherein the sending, by the network device, of the downlink control information to the terminal device comprises: the sending, by the network device, of the downlink control information within a timing range of the contention resolution timer except for a predetermined time period before each subsequent repeated sending of the uplink message, the predetermined time period 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 sending being after a first repeated sending of the uplink message.

19. The method of claim 11, further comprising: the receiving, by the network device, of information from the terminal 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.

20. A terminal device, comprising: a processor; and a memory storing computer program instructions, the memory and the computer program instructions being configured to, with the processor, cause the terminal device to perform the method of any one 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 being configured to, with the processor, cause the network device to perform the method of any one of claims 11-19.

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

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

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