A random access method and related apparatus

Abstract

The application relates to the technical field of wireless communication, in particular to a random access method and related device. The method comprises the following steps: a first request message is sent. The first request message comprises a first random access preamble, and a first transmission resource used is located in a first uplink carrier in N1 second uplink carriers. The N1 second uplink carriers are all used for random access. A first response message is received. The first response message comprises a first preamble identifier of the first random access preamble and a first RAR. A first RNTI used for scrambling of the first response message is determined based on the first transmission resource and a first carrier identifier. The first carrier identifier is an identifier of the first uplink carrier in a plurality of second uplink carriers, and the plurality of second uplink carriers comprise the N1 second uplink carriers. Alternatively, the first response message further comprises the first carrier identifier. Alternatively, a second transmission resource of the first response message is associated with the first uplink carrier. The method can improve the random access efficiency of a terminal device.

Description

Technical Field

[0001] This application relates to the field of wireless communication technology, and in particular to a random access method and related apparatus. Background Technology

[0002] In current random access schemes, terminal devices complete random access on the downlink component carrier (DL CC) that detects the synchronization signal and PBCH block (SSB), as well as its corresponding uplink component carrier (UL CC). Typically, one downlink carrier corresponds to one uplink carrier. With the continuous expansion of wireless communication services, schemes have been proposed where one downlink carrier simultaneously corresponds to multiple different uplink carriers to reduce the power consumption and complexity of terminal devices.

[0003] When multiple terminal devices initiate random access on multiple uplink carriers corresponding to the same downlink carrier, the random access preamble and physical random access channel (PRACH) resources used to initiate random access are determined autonomously by each terminal device. Therefore, it's possible for these terminal devices to determine identical random access preamble and PRACH resources. In this scenario, when performing random access based on the existing random access scheme, the network device sends the same response message to all the terminal devices, indicating competition among them. Ultimately, only one terminal device can complete the random access. Therefore, when multiple terminal devices initiate random access on multiple uplink carriers corresponding to the same downlink carrier, and the related indices of the random access preamble and PRACH resources determined by these terminal devices are identical, the current random access scheme suffers from low efficiency and poor applicability. Summary of the Invention

[0004] To address the aforementioned problems, this application provides a random access method and related apparatus. This random access method offers high random access efficiency and broad applicability.

[0005] The following sections introduce this application from multiple perspectives. It is easy to understand that the implementation methods of these multiple aspects can be referenced from each other.

[0006] Firstly, this application provides a random access method. This method is applicable to a first terminal device or a device within the first terminal device (such as a module, circuit, processor, chip, or chip system within the first terminal device). Alternatively, this method is applicable to a logical node, logical module, or software capable of implementing all or part of the functions of the first terminal device.

[0007] The method includes: a first terminal device sending a first request message to a network device. The first request message may include a first random access preamble, and the first transmission resource used by the first request message is located on a first uplink carrier. Here, the first uplink carrier may include N1 second uplink carriers, and all N1 second uplink carriers can be used to request access to the network device. N1 is a positive integer greater than or equal to 2. The first terminal device receives a first response message from the network device. The first response message may include a first preamble identifier of the first random access preamble and a first random access response (RAR). The first response message may be scrambled based on a first radionetwork temporary identifier (RNTI). The first RNTI is determined based on the first transmission resource and a first carrier identifier of the first uplink carrier. Here, the first carrier identifier is the identifier of the first uplink carrier among a plurality of second uplink carriers, and these plurality of second uplink carriers include at least the aforementioned N1 second uplink carriers. Alternatively, the first response message may also include a first carrier identifier. Alternatively, a second transmission resource used to transmit the first response message is associated with the first uplink carrier.

[0008] In the above implementation, by scrambling the RNTI of the first response message, the content contained in the first response message, or the second transmission resources used to transmit the first response message, an association can be established between the first response message and the first uplink carrier used to transmit the first request message. This not only enables the network device to distinguish between terminal devices initiating random access on different second uplink carriers and to feed back the first response message associated with the first uplink carrier to the first terminal device, but also enables the first terminal device to identify and correctly receive the first response message corresponding to its own first request message, thereby completing random access. In scenarios where multiple terminal devices initiate random access on N1 second uplink carriers, using the random access method provided in this application allows the network device to feed back a response message associated with each second uplink carrier and containing a RAR to one or more terminal devices corresponding to each second uplink carrier, and to allocate a temporary cell radio network temporary identifier (TC-RNTI) associated with each second uplink carrier to one or more terminal devices corresponding to each second uplink carrier. Correspondingly, each terminal device associated with a second uplink carrier can identify and correctly receive the response message associated with each second uplink carrier. In this way, there is no competition between terminal devices initiating random access on different second uplink carriers, so one terminal device on each second uplink carrier will have a chance to successfully access the network. Therefore, the random access method provided in this application has high random access efficiency and strong applicability. Furthermore, when multiple terminal devices initiate random access on multiple uplink carriers corresponding to the same downlink carrier, and the random access preamble and the relevant index of the physical random access channel resources determined by these multiple terminal devices are consistent, the random access method provided in this application can overcome the problem of low random access efficiency in existing random access schemes.

[0009] In conjunction with the first aspect, in one possible implementation, the first TC-RNTI indicated by the first RAR is associated with the first request message. Alternatively, the TC-RNTI assigned by the network device to terminal devices initiating random access on different uplink carriers is associated with the uplink carriers used by these terminal devices, and the TC-RNTIs assigned to terminal devices initiating random access on different uplink carriers are different.

[0010] In conjunction with the first aspect, in one possible implementation, the first RNTI is determined based on the first carrier identifier of the first transmission resource and the first uplink carrier. This may include: the first RNTI being determined based on the index of the first orthogonal frequency division multiplexing (OFDM) symbol of the first transmission resource, the index of the first time slot of the first transmission resource, the frequency domain index of the first transmission resource, the first carrier identifier of the first uplink carrier, and the second carrier identifier of the first uplink carrier. Here, the second carrier identifier is used to indicate whether the first uplink carrier is a normal uplink component carrier (NUL) or a supplementary uplink component carrier (SUL).

[0011] In the above implementation, the first carrier identifier of the first uplink carrier is introduced during the calculation of the first RNTI used to scramble the first response message, so as to indicate that the first response message is a response message to the first request message used to initiate random access on the first uplink carrier. The method is simple and easy to implement, and can reduce random access latency.

[0012] In conjunction with the first aspect, in one possible implementation, when the first RNTI is a random access radio network temporary identifier (RA-RNTI) used for 4-step random access, the first RNTI satisfies the following formula (1):

[0013] RNTI1=1+s_id+14×t_id+14×80×f_id+14×80×8×c_id2+14×80×8×2×c_id1×2 (1)

[0014] Wherein, RNTI1 is the first RNTI, s_id is the index of the first OFDM symbol of the first transmission resource, t_id is the index of the first time slot of the first transmission resource, f_id is the frequency domain index of the first transmission resource, c_id1 is the first carrier identifier, and c_id2 is the second carrier identifier.

[0015] In conjunction with the first aspect, in one possible implementation, when the first RNTI is the RNTI of message B used in 2-step random access (i.e., MSGB-RNTI), the first RNTI satisfies the following formula (2):

[0016] RNTI1=1+s_id+14×t_id+14×80×f_id+14×80×8×c_id2+

[0017] 14×80×8×2×c_id1+14×80×8×2×(c_id1+1)(2)

[0018] For a detailed explanation of each parameter, please refer to formula (1).

[0019] The above implementation provides a calculation method for RA-RNTI under 4-step random access and MSGB-RNTI under 2-step random access. This calculation method is compatible with existing protocols. When no more than one NUL and no more than one SUL are used, it allows older terminal devices to work on network devices that support the random access method provided in this application, further improving the applicability of the random access method provided in this application.

[0020] In conjunction with the first aspect, in one possible implementation, when the first RNTI is a RA-RNTI used for 4-step random access and the first uplink carrier is an uplink carrier of an associated SUL, the first RNTI satisfies the above formula (1). However, when the first RNTI is a RA-RNTI used for 4-step random access and the first uplink carrier is an uplink carrier of an unassociated SUL, the first RNTI satisfies the following formula (3):

[0021] RNTI1=14×80×8×2×N3+1+s_id+14×t_id+14×80×f_id+

[0022] 14×80×8×c_id2+14×80×8×2×c_id1(3)

[0023] Wherein, N3 is the number of SULs in the N1 second uplink carriers, and the details of the other parameters can be found in formula (1).

[0024] In conjunction with the first aspect, in one possible implementation, when the first RNTI is the MSGB-RNTI used for 2-step random access and the first uplink carrier is an uplink carrier of an associated SUL, the first RNTI satisfies the above formula (2). However, when the first RNTI is the MSGB-RNTI used for 2-step random access and the first uplink carrier is an uplink carrier of an unassociated SUL, the first RNTI satisfies the following formula (4):

[0025] RNTI1=14×80×8×2×N3+1+s_id+14×t_id+14×80×f_id+14×80×8×c_id2+14×80×8×c_id1+14×80×8×(c_id1+1)(4)

[0026] Wherein, N3 is the number of SULs in the N1 second uplink carriers, and the details of the other parameters can be found in formula (1).

[0027] The above implementation provides another method for calculating RA-RNTI under 4-step random access and MSGB-RNTI under 2-step random access. This calculation method is compatible with existing protocols. When no more than one NUL and no more than one SUL are used, it allows older terminal devices to operate on network devices that support the random access method provided in this application, further improving the applicability of the random access method provided in this application. In addition, this calculation method also ensures that if a certain NUL does not have an associated SUL configured, the RNTI value corresponding to that SUL will not be reserved for that NUL's SUL. In other words, this calculation method does not need to consider the SUL corresponding to that NUL when calculating the RNTI value. This method can also reduce the risk of the RNTI value exceeding the specified range.

[0028] In conjunction with the first aspect, in one possible implementation, where the first RNTI is the RA-RNTI used for 4-step random access, the first RNTI satisfies the following formula (5):

[0029] RNTI1=1+s_id+14×t_id+14×80×f_id+14×80×8×c_id2+14×80×8×2×c_id1 (5)

[0030] For a detailed explanation of each parameter, please refer to formula (1).

[0031] In conjunction with the first aspect, in one possible implementation, when the first RNTI is the MSGB-RNTI used for 2-step random access, the first RNTI satisfies the following formula (6):

[0032] RNTI1=1+s_id+14×t_id+14×80×f_id+14×80×8×c_id2+14×80×8×2×c_id1+14×80×8×2×N2 (6)

[0033] Where N2 is the number of NULs in the N1 second uplink carriers, and the details of the other parameters can be found in formula (1). Optionally, “14×80×8×2×N2” in the formula can be replaced with “14×80×8×N1”.

[0034] The above implementation presents another method for calculating RA-RNTI under 4-step random access and MSGB-RNTI under 2-step random access. This calculation method is partially compatible with existing protocols and can improve the applicability of the random access method provided in this application to a certain extent.

[0035] In conjunction with the first aspect, in one possible implementation, when the first RNTI is a RA-RNTI used for 4-step random access and the first uplink carrier is an uplink carrier of an associated SUL, the first RNTI satisfies the above formula (5). However, when the first RNTI is a RA-RNTI used for 4-step random access and the first uplink carrier is an uplink carrier of an unassociated SUL, the first RNTI satisfies the following formula (7):

[0036] RNTI1=14×80×8×N3+1+s_id+14×t_id+14×80×f_id+14×80×8×c_id2+14×80×8×c_id1(7)

[0037] For a detailed explanation of each parameter, please refer to formula (1).

[0038] In conjunction with the first aspect, in one possible implementation, where the first RNTI is the MSGB-RNTI used for 2-step random access and the first uplink carrier is the uplink carrier of the associated SUL, the first RNTI satisfies the following formula (8):

[0039] RNTI1=1+s_id+14×t_id+14×80×f_id+14×80×8×c_id2+14×80×8×2×c_id1+14×80×8×N1 (8)

[0040] For a detailed explanation of each parameter, please refer to formula (1).

[0041] In conjunction with the first aspect, in one possible implementation, when the first RNTI is the MSGB-RNTI used for 2-step random access and the first uplink carrier is an uplink carrier of an unassociated SUL, the first RNTI satisfies the following formula (9):

[0042] RNTI1=14×80×8×N3+1+s_id+14×t_id+14×80×f_id+14×80×8×c_id2+14×80×8×c_id1+14×80×8×N1 (9)

[0043] Wherein, N3 is the number of SULs in the N1 second uplink carriers, and the details of the other parameters can be found in formula (1). Optionally, “14×80×8×N1” in the formula can be replaced with “14×80×8×2×N2”, where N2 is the number of NULs in the N1 second uplink carriers.

[0044] The above implementation provides another method for calculating RA-RNTI under 4-step random access and MSGB-RNTI under 2-step random access. This calculation method is partially compatible with existing protocols and can improve the applicability of the random access method provided in this application to a certain extent. In addition, this calculation method also ensures that if a NUL does not have an associated SUL configured, the RNTI value corresponding to the SUL of that NUL will not be reserved. In other words, this calculation method does not need to consider the SUL corresponding to the NUL when calculating the RNTI value. Through this method, the risk of the RNTI value exceeding the specified range can also be reduced.

[0045] In conjunction with the first aspect, in one possible implementation, when the first response message is scrambled based on the first RNTI, the first NUL and the first uplink carrier associated with the first uplink carrier both correspond to the first carrier identifier, or the first SUL and the first uplink carrier associated with the first uplink carrier both correspond to the first carrier identifier.

[0046] In conjunction with the first aspect, in one possible implementation, where the first RNTI is determined based on the index of the first OFDM symbol, the index of the first time slot, the frequency domain index of the first transmission resource, the first carrier identifier, and the second carrier identifier, the first carrier identifier can be an NUL index or a SUL index.

[0047] In conjunction with the first aspect, in one possible implementation, the first RNTI is determined based on the first carrier identifier of the first transmission resource and the first uplink carrier, including: the first RNTI is determined based on the index of the first OFDM symbol of the first transmission resource, the index of the first time slot of the first transmission resource, the frequency domain index of the first transmission resource, and the first carrier identifier of the first uplink carrier.

[0048] In the above implementation, the first carrier identifier of the first uplink carrier is introduced during the RNTI determination process to establish the association between the random access response message and the uplink carrier used by the requesting network device, without needing to distinguish between NUL and SUL using other indexes. This method is simpler, reduces the complexity of RNTI calculation, and thus further improves random access efficiency.

[0049] In conjunction with the first aspect, in one possible implementation, when the first RNTI is a RA-RNTI used for 4-step random access, the first RNTI satisfies the following formula (10):

[0050] RNTI1=1+s_id+14×t_id+14×80×f_id+14×80×8×c_id1(10)

[0051] For a detailed explanation of each parameter, please refer to formula (1).

[0052] In conjunction with the first aspect, in one possible implementation, when the first RNTI is the MSGB-RNTI used for 2-step random access, the first RNTI satisfies the following formula (11):

[0053] RNTI1=1+s_id+14×t_id+14×80×f_id+14×80×8×c_id1+14×80×8×N1(11)

[0054] For a detailed explanation of each parameter, please refer to formula (1).

[0055] The above implementation provides another method for calculating RA-RNTI under 4-step random access and MSGB-RNTI under 2-step random access. This calculation method is compatible with existing protocols. When no more than one NUL and no more than one SUL are used, it allows older terminal devices to work on network devices that support the random access method provided in this application, further improving the applicability of the random access method provided in this application.

[0056] In conjunction with the first aspect, in one possible implementation, when the first RNTI is a RA-RNTI used for 4-step random access, the first RNTI satisfies the following formula (12):

[0057] RNTI1=1+s_id+14×t_id+14×80×f_id+14×80×8×2×c_id1(12)

[0058] For a detailed explanation of each parameter, please refer to formula (1).

[0059] In conjunction with the first aspect, in one possible implementation, when the first RNTI is the MSGB-RNTI used for 2-step random access, the first RNTI satisfies the following formula (13):

[0060] RNTI1=1+s_id+14×t_id+14×80×f_id+14×80×8×c_id1+14×80×8×(c_id1+1)(13)

[0061] For a detailed explanation of each parameter, please refer to formula (1).

[0062] The above implementation presents another method for calculating RA-RNTI under 4-step random access and MSGB-RNTI under 2-step random access. This calculation method is partially compatible with existing protocols and can improve the applicability of the random access method provided in this application to a certain extent.

[0063] In conjunction with the first aspect, in one possible implementation, when the first RNTI is determined based on the index of the first OFDM symbol of the first transmission resource, the index of the first time slot of the first transmission resource, the frequency domain index of the first transmission resource, and the first carrier identifier of the first uplink carrier, the first carrier identifier is the uplink carrier index of the first uplink carrier among N1 second uplink carriers.

[0064] In conjunction with the first aspect, in one possible implementation, the aforementioned N1 second uplink carriers belong to a first uplink carrier set (also referred to as a first uplink carrier group). Multiple uplink carriers in the first uplink carrier set belong to the same frequency band, and / or, the aforementioned N1 second uplink carriers belong to the same timing advance group (TAG).

[0065] In conjunction with the first aspect, in one possible implementation, where the first response message further includes a first carrier identifier, the first carrier identifier can be used to indicate that the first response message is a response message to a first request message transmitted on the first uplink carrier. Alternatively, the first carrier identifier can be used to indicate that the first response message is used in response to a random access request message transmitted on the first uplink carrier.

[0066] In the above implementation, the response messages corresponding to request messages sent on different uplink carriers are distinguished by carrier identifiers, which enables the terminal device to quickly identify and receive its own response message, thereby reducing the latency caused by the terminal device receiving the response message.

[0067] In conjunction with the first aspect, in one possible implementation, if the first response message also includes a first carrier identifier, the first carrier identifier is the identifier of the first uplink carrier among a plurality of second uplink carriers, and the plurality of second uplink carriers includes at least the aforementioned N1 second uplink carriers.

[0068] In conjunction with the first aspect, in one possible implementation, the first carrier identifier may be included in the first RAR.

[0069] In conjunction with the first aspect, in one possible implementation, the first carrier identifier may be included in the uplink grant information in the first RAR, or the first carrier identifier may be included in the timing advance command (TAC) in the first RAR.

[0070] In the above implementation, using existing fields in the first RAR to carry the first carrier identifier can ensure the compatibility of the random access method provided in this application with existing random access methods, thereby making the random access method provided in this application more applicable.

[0071] In conjunction with the first aspect, in one possible implementation, the first RAR is supplemented with a first field, in which the aforementioned first carrier identifier is included.

[0072] In the above implementation, the first field added to the first RAR carries the first carrier identifier, which can reduce the parsing complexity of the improved first RAR, thereby improving the efficiency of the random access method provided in this application.

[0073] In conjunction with the first aspect, in one possible implementation, the first RAR can be a first medium access control random access response (MAC-RAR), a first success RAR, or a first fallback RAR.

[0074] In conjunction with the first aspect, in one possible implementation, if the first response message also includes a first carrier identifier, and if the first uplink carrier is a NUL, then the first carrier identifier can be the NUL index of the first uplink carrier among the N1 second uplink carriers. If the first uplink carrier is a SUL, then the first carrier identifier can be the SUL index of the first uplink carrier among the N1 second uplink carriers. Furthermore, the carrier identifiers of the associated NUL and SUL among the N1 second uplink carriers can be the same or different.

[0075] In conjunction with the first aspect, in one possible implementation, where the first response message also includes a first carrier identifier, the first carrier identifier is the uplink carrier index of the first uplink carrier among N1 second uplink carriers.

[0076] In conjunction with the first aspect, in one possible implementation, the second transmission resource includes: a first time-domain resource containing the first physical downlink control channel (PDCCH) corresponding to the first response message, a first frequency-domain resource containing the first PDCCH corresponding to the first response message, or a first time-frequency resource containing the first PDCCH corresponding to the first response message. This can be understood as the first time-domain resource containing the first PDCCH corresponding to the first response message, the first frequency-domain resource containing the first PDCCH corresponding to the first response message, or the first time-frequency resource containing the first PDCCH corresponding to the first response message being associated with the first uplink carrier, or associated with the first request message transmitted on the first uplink carrier.

[0077] In the above implementation, the time-domain resource, frequency-domain resource, or time-frequency resource where the PDCCH corresponding to the random access response message is located is associated with the uplink carrier. This allows the terminal device to perform blind PDCCH detection on the corresponding time-domain resource, frequency-domain resource, or time-frequency resource based on the uplink carrier from which it sent its request message, thereby quickly identifying and receiving its own response message. This implementation method can also reduce the latency caused by the terminal device receiving the response message.

[0078] In conjunction with the first aspect, in one possible implementation, the method may further include: a first terminal device receiving first configuration information. The first configuration information can be used to determine the association of the aforementioned N1 second uplink carriers with N4 third transmission resources. It can be understood that a third transmission resource is associated with one or more second uplink carriers, or in other words, a third transmission resource is associated with a request message transmitted on one or more second uplink carriers. The aforementioned second transmission resource is one of these N4 third transmission resources. Each third transmission resource is used for blind detection of the PDCCH of the response message corresponding to a random access initiated on a second uplink carrier. The function of each of these N4 third transmission resources is similar; the following example uses the third transmission resource j1 corresponding to any second uplink carrier i among the N1 second uplink carriers in the N4 third transmission resources. Third transmission resource j1 is a resource used to monitor the second PDCCH corresponding to the target response message. This target response message is used to respond to a target request message, which is used to transmit a random access preamble on the second uplink carrier i. Here, N4 is a positive integer less than or equal to N1.

[0079] In conjunction with the first aspect, in one possible implementation, the third transmission resource j1 includes: the time-domain resource where the second PDCCH is located, the frequency-domain resource where the second PDCCH is located, or the time-frequency resource where the second PDCCH is located. This can be understood as the time-domain resource where the second PDCCH is located, the frequency-domain resource where the second PDCCH is located, or the time-frequency resource where the second PDCCH is located is associated with the second uplink carrier i; or, the time-domain resource where the second PDCCH is located, the frequency-domain resource where the second PDCCH is located, or the time-frequency resource where the second PDCCH is located is associated with a request message containing a random access preamble transmitted on the second uplink carrier i.

[0080] In conjunction with the first aspect, in one possible implementation, each of the aforementioned N4 third transmission resources is determined based on its corresponding control resource set (i.e., CORESET) and search space set. When the third transmission resource j1 includes the time-domain resource where the second PDCCH resides, the search space sets corresponding to these N4 third transmission resources are different. In this case, different search space sets are associated with different second uplink carriers, or different search space sets are associated with request messages containing random access preambles transmitted on different second uplink carriers. When the third transmission resource j1 includes the frequency-domain resource where the second PDCCH resides, the control resource sets corresponding to these N4 third transmission resources are different. In this case, different control resource sets are associated with different second uplink carriers, or different control resource sets are associated with request messages containing random access preambles transmitted on different second uplink carriers.

[0081] When the third transmission resource j1 includes the time-frequency resource where the second PDCCH is located, the search space set and / or control resource set corresponding to these N4 third transmission resources are different.

[0082] For example, among the N4 third transport resources, there are third transport resource 1 and third transport resource 2. Third transport resource 1 is determined based on control resource set 1 and search space set 1, and third transport resource 2 is determined based on control resource set 2 and search space set 2. Control resource set 1 and control resource set 2 are different, while search space set 1 and search space set 2 are the same. In this case, it can be understood that control resource set 1 is associated with the second uplink carrier 1 associated with third transport resource 1, and control resource set 2 is associated with the second uplink carrier 2 associated with third transport resource 2. Alternatively, it can be understood that control resource set 1 is associated with the request message containing a random access preamble transmitted on the second uplink carrier 1 associated with third transport resource 1, and control resource set 2 is associated with the request message containing a random access preamble transmitted on the second uplink carrier 2 associated with third transport resource 2.

[0083] Alternatively, control resource set 1 and control resource set 2 are the same, but search space set 1 and search space set 2 are different. In this case, search space set 1 can be understood as being associated with the second uplink carrier 1 associated with the third transmission resource 1, and search space set 2 is associated with the second uplink carrier 2 associated with the third transmission resource 2. Alternatively, search space set 1 can be understood as being associated with a request message containing a random access preamble transmitted on the second uplink carrier 1 associated with the third transmission resource 1, and search space set 2 is associated with a request message containing a random access preamble transmitted on the second uplink carrier 2 associated with the third transmission resource 2.

[0084] In the above implementation, each third transmission resource is distinguished by the control resource set and / or search space set corresponding to each third transmission resource, thereby corresponding to different uplink carriers for sending request messages, or target request messages on uplink carriers used to send request messages. This method is simple and easy to implement, and can reduce the complexity of the random access method provided in this application.

[0085] In conjunction with the first aspect, in one possible implementation, when the third transmission resource j1 includes the time-domain resource where the second PDCCH is located, the search space sets corresponding to these N4 third transmission resources are different subsets of the same search space set. When the third transmission resource j1 includes the frequency-domain resource where the second PDCCH is located, the control resource sets corresponding to these N4 third transmission resources are different subsets of the same control resource set. When the third transmission resource j1 includes the time-frequency resource where the second PDCCH is located, the search space sets corresponding to these N4 third transmission resources are different subsets of the same search space set, and / or, the control resource sets corresponding to these N4 third transmission resources are different subsets of the same control resource set.

[0086] In the above implementation, the above N4 different third transmission resources are determined by partitioning the same control resource set and / or the same search space set into subsets, thereby corresponding to different uplink carriers for sending request messages, or target request messages on uplink carriers used to send request messages, which can ensure the resource utilization efficiency of the control resource set and / or search space set.

[0087] In conjunction with the first aspect, in one possible implementation, the aforementioned N1 second uplink carriers are associated with a first downlink carrier, and the first downlink carrier can be used to transmit a first response message.

[0088] In conjunction with the first aspect, in one possible implementation, receiving the first response message may specifically include: receiving the aforementioned first response message when the first terminal device supports random access on N1 second uplink carriers, or when the first terminal device requests random access on N1 second uplink carriers, or interpreting the information in the first response message. Here, the first terminal device supporting random access on N1 second uplink carriers, or the first terminal device requesting random access on N1 second uplink carriers, can both be understood as the first terminal device needing to determine one of the N1 second uplink carriers to initiate random access to the network device.

[0089] In conjunction with the first aspect, in one possible implementation, when the first terminal device supports random access on N1 second uplink carriers, or when the first terminal device requests random access on N1 second uplink carriers, the method may further include: the first terminal device determining a first transmission resource from a target transmission resource set, and / or, the first terminal device determining a first random access preamble from a target random access preamble set. Wherein, the target transmission resource set is used for the transmission of the random access preamble of the target terminal device, the target random access preamble set is used for the random access of the target terminal device, and the target terminal device is a terminal device that supports random access on N1 second uplink carriers.

[0090] In the above implementation, the first terminal device can report its support for initiating random access on N1 second uplink carriers or request to initiate random access on N1 second uplink carriers by using the random access preamble or transmission resources used to initiate random access. This enables the network device to feed back the first response message in the manner provided in this application, thereby ensuring the reliable implementation of the random access method provided in this application.

[0091] In conjunction with the first aspect, in one possible implementation, the method may further include: a first terminal device receiving second configuration information and / or third configuration information from a network device. The second configuration information is used to indicate or determine that N1 second uplink carriers are associated with a first downlink carrier. The third configuration information is used to indicate or determine N1 fourth transmission resources associated with the N1 second uplink carriers. Here, the fourth transmission resource corresponding to any one of the N1 second uplink carriers i is used for the transmission of the random access preamble used in random access initiated from the second uplink carrier i.

[0092] In conjunction with the first aspect, the aforementioned first request message can be message 1 (i.e., msg1) in a 4-step random access process, and the aforementioned first response message can be message 2 (i.e., msg2) in a 4-step random access process. Alternatively, the aforementioned first request message can be message A (i.e., msgA) in a 2-step random access process, and the aforementioned first response message can be message B (i.e., msgB) in a 2-step random access process.

[0093] Secondly, this application provides a random access method. This method is applicable to network devices or devices within network devices (such as modules, circuits, processors, chips, or chip systems within the network device). Alternatively, it is applicable to logical nodes, logical modules, or software capable of implementing all or part of the functions of a network device.

[0094] The method includes: a network device receiving a first request message from a first terminal device. The first request message may include a first random access preamble, and the first transmission resource used by the first request message is located on a first uplink carrier. Here, the first uplink carrier may include N1 second uplink carriers, and all N1 second uplink carriers can be used to request access to the network device, where N1 is a positive integer greater than or equal to 2. The network device sends a first response message. The first response message may include a first preamble identifier of the first random access preamble and a first RAR. The first response message may be scrambled based on a first RNTI. The first RNTI may be determined based on the first transmission resource and a first carrier identifier of the first uplink carrier. Here, the first carrier identifier is the identifier of the first uplink carrier among a plurality of second uplink carriers, and these plurality of second uplink carriers include at least the aforementioned N1 second uplink carriers. Alternatively, the first response message may also include a first carrier identifier. Or, the second transmission resource used to transmit the first response message is associated with the first uplink carrier.

[0095] In the above implementation, by scrambling the RNTI of the first response message, the content contained in the first response message, or the second transmission resources used to transmit the first response message, an association can be established between the first response message and the first uplink carrier used to transmit the first request message. This implementation method ensures that there is no competition between terminal devices initiating random access on different second uplink carriers, so that one terminal device on each second uplink carrier will have a chance to successfully access the network. Therefore, the random access method provided in this application has high random access efficiency and strong applicability. Furthermore, when multiple terminal devices initiate random access on multiple uplink carriers corresponding to the same downlink carrier, and the random access preamble and the relevant index of the physical random access channel resources determined by these multiple terminal devices are consistent, the random access method provided in this application can overcome the problem of low random access efficiency in existing random access schemes.

[0096] In conjunction with the second aspect, in one possible implementation, the first TC-RNTI indicated by the first RAR is associated with the first request message. Alternatively, the TC-RNTI assigned by the network device to terminal devices initiating random access on different uplink carriers is associated with the uplink carriers used by these terminal devices, and the TC-RNTIs assigned to terminal devices initiating random access on different uplink carriers are different.

[0097] In conjunction with the second aspect, in one possible implementation, the first RNTI is determined based on the first transmission resource and the first carrier identifier of the first uplink carrier. This may include: the first RNTI being determined based on the index of the first OFDM symbol of the first transmission resource, the index of the first time slot of the first transmission resource, the frequency domain index of the first transmission resource, the first carrier identifier of the first uplink carrier, and the second carrier identifier of the first uplink carrier. Here, the second carrier identifier is used to indicate whether the first uplink carrier is NUL or SUL.

[0098] In conjunction with the second aspect, in one possible implementation, when the first RNTI is a random access radio network temporary identifier (RA-RNTI) used for 4-step random access, the first RNTI satisfies the following formula (1):

[0099] RNTI1=1+s_id+14×t_id+14×80×f_id+14×80×8×c_id2+14×80×8×2×c_id1×2 (1)

[0100] For a detailed explanation of each parameter, please refer to the preceding text.

[0101] In conjunction with the second aspect, in one possible implementation, when the first RNTI is the RNTI of message B used in 2-step random access (i.e., MSGB-RNTI), the first RNTI satisfies the following formula (2):

[0102] RNTI1=1+s_id+14×t_id+14×80×f_id+14×80×8×c_id2+14×80×8×2×c_id1+14×80×8×2×(c_id1+1) (2)

[0103] For a detailed explanation of each parameter, please refer to the preceding text.

[0104] In conjunction with the second aspect, in one possible implementation, when the first RNTI is a RA-RNTI used for 4-step random access and the first uplink carrier is an uplink carrier of an associated SUL, the first RNTI satisfies the above formula (1). However, when the first RNTI is a RA-RNTI used for 4-step random access and the first uplink carrier is an uplink carrier of an unassociated SUL, the first RNTI satisfies the following formula (3):

[0105] RNTI1=14×80×8×2×N3+1+s_id+14×t_id+14×80×f_id+14×80×8×c_id2+14×80×8×2×c_id1 (3)

[0106] For a detailed explanation of each parameter, please refer to the preceding text.

[0107] In conjunction with the second aspect, in one possible implementation, when the first RNTI is the MSGB-RNTI used for 2-step random access and the first uplink carrier is an uplink carrier of an associated SUL, the first RNTI satisfies the above formula (2). However, when the first RNTI is the MSGB-RNTI used for 2-step random access and the first uplink carrier is an uplink carrier of an unassociated SUL, the first RNTI satisfies the following formula (4):

[0108] RNTI1=14×80×8×2×N3+1+s_id+14×t_id+14×80×f_id+14×80×8×c_id2+14×80×8×c_id1+14×80×8×(c_id1+1) (4)

[0109] For a detailed explanation of each parameter, please refer to the preceding text.

[0110] In conjunction with the second aspect, in one possible implementation, when the first RNTI is the RA-RNTI used for 4-step random access, the first RNTI satisfies the following formula (5):

[0111] RNTI1=1+s_id+14×t_id+14×80×f_id+14×80×8×c_id2+14×80×8×2×c_id1 (5)

[0112] For a detailed explanation of each parameter, please refer to the preceding text.

[0113] In conjunction with the second aspect, in one possible implementation, when the first RNTI is the MSGB-RNTI used for 2-step random access, the first RNTI satisfies the following formula (6):

[0114] RNTI1=1+s_id+14×t_id+14×80×f_id+14×80×8×c_id2+14×80×8×2×c_id1+14×80×8×2×N2 (6)

[0115] For details on each parameter, please refer to the preceding text. Optionally, “14×80×8×2×N2” in formula (6) can be replaced with “14×80×8×N1”.

[0116] In conjunction with the second aspect, in one possible implementation, when the first RNTI is a RA-RNTI used for 4-step random access and the first uplink carrier is an uplink carrier of an associated SUL, the first RNTI satisfies the above formula (5). However, when the first RNTI is a RA-RNTI used for 4-step random access and the first uplink carrier is an uplink carrier of an unassociated SUL, the first RNTI satisfies the following formula (7):

[0117] RNTI1=14×80×8×N3+1+s_id+14×t_id+14×80×f_id+14×80×8×c_id2+14×80×8×c_id1 (7)

[0118] For a detailed explanation of each parameter, please refer to the preceding text.

[0119] In conjunction with the second aspect, in one possible implementation, where the first RNTI is the MSGB-RNTI used for 2-step random access and the first uplink carrier is the uplink carrier of the associated SUL, the first RNTI satisfies the following formula (8):

[0120] RNTI1=1+s_id+14×t_id+14×80×f_id+14×80×8×c_id2+14×80×8×2×c_id1+14×80×8×N1 (8)

[0121] For a detailed explanation of each parameter, please refer to the preceding text.

[0122] In conjunction with the second aspect, in one possible implementation, when the first RNTI is the MSGB-RNTI used for 2-step random access and the first uplink carrier is an uplink carrier of an unassociated SUL, the first RNTI satisfies the following formula (9):

[0123] RNTI1=14×80×8×N3+1+s_id+14×t_id+14×80×f_id+14×80×8×c_id2+14×80×8×c_id1+14×80×8×N1 (9)

[0124] For a detailed explanation of each parameter, please refer to the preceding text. Optionally, “14×80×8×N1” in the formula can be replaced with “14×80×8×2×N2”, where N2 is the number of NULs in the N1 second uplink carriers.

[0125] In conjunction with the second aspect, in one possible implementation, when the first response message is scrambled based on the first RNTI, both the first NUL associated with the first uplink carrier and the first uplink carrier correspond to the first carrier identifier, or both the first SUL associated with the first uplink carrier and the first uplink carrier correspond to the first carrier identifier. Alternatively, when the first uplink carrier is an NUL, both the first uplink carrier and its associated SUL correspond to the first carrier identifier. When the first uplink carrier is an SUL, both the first uplink carrier and its associated NUL correspond to the first carrier identifier. Furthermore, when the first response message is scrambled based on the first RNTI, if both the first NUL associated with the first uplink carrier and the first uplink carrier correspond to the first carrier identifier, or both the first SUL associated with the first uplink carrier and the first uplink carrier correspond to the first carrier identifier, then the first RNTI satisfies any one of the above formulas (1) to (9).

[0126] In conjunction with the second aspect, in one possible implementation, when the first RNTI is determined based on the index of the first OFDM symbol, the index of the first time slot, the frequency domain index of the first transmission resource, the first carrier identifier, and the second carrier identifier, the first uplink carrier identifier can be either an NUL index or a SUL index. The first carrier identifier being either an NUL index or a SUL index can be understood as follows: when the first uplink carrier is NUL, the first carrier identifier is the NUL index of the first uplink carrier among the N1 second uplink carriers; when the first uplink carrier is SUL, the first carrier identifier is the SUL index of the first uplink carrier among the N1 second uplink carriers.

[0127] For example, the first carrier identifier can be used to indicate which NUL or SUL the first uplink carrier is among the plurality of second uplink carriers. Alternatively, the first carrier identifier can also be used to indicate which NUL or SUL the first uplink carrier is among the N1 second uplink carriers.

[0128] In conjunction with the second aspect, in one possible implementation, the first RNTI is determined based on the first carrier identifier of the first transmission resource and the first uplink carrier, including: the first RNTI is determined based on the index of the first OFDM symbol of the first transmission resource, the index of the first time slot of the first transmission resource, the frequency domain index of the first transmission resource, and the first carrier identifier of the first uplink carrier.

[0129] In conjunction with the second aspect, in one possible implementation, when the first RNTI is a RA-RNTI used for 4-step random access, the first RNTI satisfies the following formula (10):

[0130] RNTI1=1+s_id+14×t_id+14×80×f_id+14×80×8×c_id1 (10)

[0131] For a detailed explanation of each parameter, please refer to the preceding text.

[0132] In conjunction with the second aspect, in one possible implementation, when the first RNTI is the MSGB-RNTI used for 2-step random access, the first RNTI satisfies the following formula (11):

[0133] RNTI1=1+s_id+14×t_id+14×80×f_id+14×80×8×c-id1+14×80×8×N1 (11)

[0134] For a detailed explanation of each parameter, please refer to the preceding text.

[0135] In conjunction with the second aspect, in one possible implementation, when the first RNTI is a RA-RNTI used for 4-step random access, the first RNTI satisfies the following formula (12):

[0136] RNTI1=1+s_id+14×t_id+14×80×f_id+14×80×8×2×c_id1 (12)

[0137] For a detailed explanation of each parameter, please refer to the preceding text.

[0138] In conjunction with the second aspect, in one possible implementation, when the first RNTI is the MSGB-RNTI used for 2-step random access, the first RNTI satisfies the following formula (13):

[0139] C-RNTI1=1+s_id+14×t_id+14×80×f_id+14×80×8×c_id1+14×80×8×(c_id1+1) (13)

[0140] For a detailed explanation of each parameter, please refer to the preceding text.

[0141] In conjunction with the second aspect, in one possible implementation, when the first RNTI is determined based on the index of the first OFDM symbol of the first transmission resource, the index of the first time slot of the first transmission resource, the frequency domain index of the first transmission resource, and the first carrier identifier of the first uplink carrier, the first carrier identifier is the uplink carrier index of the first uplink carrier among N1 second uplink carriers.

[0142] In conjunction with the second aspect, in one possible implementation, the aforementioned N1 second uplink carriers belong to a first uplink carrier set (also referred to as a first uplink carrier group). Multiple uplink carriers in the first uplink carrier set belong to the same frequency band, and / or, the aforementioned N1 second uplink carriers belong to the same timing advance group.

[0143] Furthermore, the first carrier identifier is the index of the first uplink carrier within the first uplink carrier set. It can be understood that this first uplink carrier set can consist of multiple second uplink carriers including N1 second uplink carriers, or it can consist only of the aforementioned N1 second uplink carriers.

[0144] In conjunction with the second aspect, one possible implementation involves configuring multiple uplink carrier sets, and these multiple uplink carrier sets can reuse the same carrier identifier. That is, two different uplink carriers in two different uplink carrier sets can be associated with the same RNTI. This is because the random access procedures implemented based on different uplink carrier sets are independent of each other. Therefore, there is no competition between terminal devices initiating random access on uplink carriers in different uplink carrier sets. Thus, even if different uplink carriers belonging to different uplink carrier sets correspond to the same carrier identifier or are associated with the same RNTI, it will not affect their respective random access processes.

[0145] In conjunction with the first aspect, in one possible implementation, where the first response message further includes a first carrier identifier, the first carrier identifier can be used to indicate that the first response message is a response message to a first request message transmitted on the first uplink carrier. Alternatively, the first carrier identifier can be used to indicate that the first response message is used in response to a random access request message transmitted on the first uplink carrier.

[0146] In conjunction with the second aspect, in one possible implementation, if the first response message also includes a first carrier identifier, the first carrier identifier is the identifier of the first uplink carrier among a plurality of second uplink carriers, and the plurality of second uplink carriers includes at least the aforementioned N1 second uplink carriers.

[0147] In conjunction with the second aspect, in one possible implementation, the first carrier identifier is included in the first RAR.

[0148] In conjunction with the second aspect, in one possible implementation, the first carrier identifier is included in the uplink grant information in the first RAR, or the first carrier identifier is included in the TAC in the first RAR.

[0149] In conjunction with the second aspect, in one possible implementation, the first includes the transmit power control command field, frequency domain resource allocation field, or modulation and coding scheme field in the uplink authorization information.

[0150] In conjunction with the second aspect, in one possible implementation, the first RAR is given a new first field in which the aforementioned first carrier identifier is included.

[0151] In the above implementation, the first field added to the first RAR carries the first carrier identifier, which can reduce the parsing complexity of the improved first RAR, thereby improving the efficiency of the random access method provided in this application.

[0152] In the second aspect of the set, in one possible implementation, the first RAR can be a first MAC-RAR, a first successful RAR, or a first rollback RAR.

[0153] In conjunction with the second aspect, in one possible implementation, if the first response message also includes a first carrier identifier, and if the first uplink carrier is a NUL, then the first carrier identifier can be the NUL index of the first uplink carrier among the N1 second uplink carriers. If the first uplink carrier is a SUL, then the first carrier identifier can be the SUL index of the first uplink carrier among the N1 second uplink carriers. Furthermore, the carrier identifiers associated with the NUL and SUL among the N1 second uplink carriers can be the same or different.

[0154] In conjunction with the second aspect, in one possible implementation, if the first response message also includes a first carrier identifier, the first carrier identifier is the uplink carrier index of the first uplink carrier among N1 second uplink carriers.

[0155] In conjunction with the second aspect, in one possible implementation, the second transmission resource includes: a first time-domain resource where the first PDCCH corresponding to the first response message resides, a first frequency-domain resource where the first PDCCH corresponding to the first response message resides, or a first time-frequency resource where the first PDCCH corresponding to the first response message resides. This can be understood as the first time-domain resource where the first PDCCH corresponding to the first response message resides, the first frequency-domain resource where the first PDCCH corresponding to the first response message resides, or the first time-frequency resource where the first PDCCH corresponding to the first response message resides, being associated with the first uplink carrier, or being associated with the first request message transmitted on the first uplink carrier.

[0156] In conjunction with the second aspect, in one possible implementation, the method may further include: the network device sending first configuration information to the first terminal device. The first configuration information can be used to determine the association of the aforementioned N1 second uplink carriers with N4 third transmission resources. It can be understood that a third transmission resource is associated with one or more second uplink carriers, or in other words, a third transmission resource is associated with a request message sent on one or more second uplink carriers. The aforementioned second transmission resource is one of these N4 third transmission resources. Each third transmission resource is used for blind detection of the PDCCH of the response message corresponding to a random access initiated on a second uplink carrier. The function of each of these N4 third transmission resources is similar; the following example uses the third transmission resource j1 corresponding to any second uplink carrier i among the N1 second uplink carriers in the N4 third transmission resources. Third transmission resource j1 is a resource used to monitor the second PDCCH corresponding to the target response message. This target response message is used to respond to a target request message, which is used to send a random access preamble on the second uplink carrier i. Here, N4 is a positive integer less than or equal to N1.

[0157] In conjunction with the second aspect, in one possible implementation, the third transmission resource j1 includes: the time-domain resource where the second PDCCH is located, the frequency-domain resource where the second PDCCH is located, or the time-frequency resource where the second PDCCH is located. This can be understood as the time-domain resource where the second PDCCH is located, the frequency-domain resource where the second PDCCH is located, or the time-frequency resource where the second PDCCH is located is associated with the second uplink carrier i; or, the time-domain resource where the second PDCCH is located, the frequency-domain resource where the second PDCCH is located, or the time-frequency resource where the second PDCCH is located is associated with the target request message transmitted on the second uplink carrier i.

[0158] In conjunction with the second aspect, in one possible implementation, each of the aforementioned N4 third transmission resources is determined based on the control resource set and search space set corresponding to each third transmission resource.

[0159] When the third transmission resource j1 includes the time-domain resource where the second PDCCH is located, the search space sets corresponding to these N4 third transmission resources are different. In this case, different search space sets are associated with different second uplink carriers, or different search space sets are associated with request messages containing random access preambles transmitted on different second uplink carriers. When the third transmission resource j1 includes the frequency-domain resource where the second PDCCH is located, the control resource sets corresponding to these N4 third transmission resources are different. In this case, different control resource sets are associated with different second uplink carriers, or different control resource sets are associated with request messages containing random access preambles transmitted on different second uplink carriers.

[0160] When the third transmission resource j1 includes the time-frequency resource where the second PDCCH is located, the search space set corresponding to these N4 third transmission resources and / or the control resource set are different.

[0161] For example, among the N4 third transport resources, there are third transport resource 1 and third transport resource 2. Third transport resource 1 is determined based on control resource set 1 and search space set 1, and third transport resource 2 is determined based on control resource set 2 and search space set 2. Control resource set 1 and control resource set 2 are different, while search space set 1 and search space set 2 are the same. In this case, it can be understood that control resource set 1 is associated with the second uplink carrier 1 associated with third transport resource 1, and control resource set 2 is associated with the second uplink carrier 2 associated with third transport resource 2. Alternatively, it can be understood that control resource set 1 is associated with the request message containing a random access preamble transmitted on the second uplink carrier 1 associated with third transport resource 1, and control resource set 2 is associated with the request message containing a random access preamble transmitted on the second uplink carrier 2 associated with third transport resource 2.

[0162] Alternatively, control resource set 1 and control resource set 2 are the same, but search space set 1 and search space set 2 are different. In this case, search space set 1 can be understood as being associated with the second uplink carrier 1 associated with the third transmission resource 1, and search space set 2 is associated with the second uplink carrier 2 associated with the third transmission resource 2. Alternatively, search space set 1 can be understood as being associated with a request message containing a random access preamble transmitted on the second uplink carrier 1 associated with the third transmission resource 1, and search space set 2 is associated with a request message containing a random access preamble transmitted on the second uplink carrier 2 associated with the third transmission resource 2.

[0163] In conjunction with the second aspect, in one possible implementation, when the third transmission resource j1 includes the time-domain resource where the second PDCCH resides, the search space sets corresponding to these N4 third transmission resources are different subsets of the same search space set. When the third transmission resource j1 includes the frequency-domain resource where the second PDCCH resides, the control resource sets corresponding to these N4 third transmission resources are different subsets of the same control resource set. When the third transmission resource j1 includes the time-frequency resource where the second PDCCH resides, the search space sets corresponding to these N4 third transmission resources are different subsets of the same search space set, and the control resource sets corresponding to these N4 third transmission resources are also different subsets of the same control resource set.

[0164] In conjunction with the second aspect, in one possible implementation, the aforementioned N1 second uplink carriers are associated with a first downlink carrier, and the first downlink carrier can be used to transmit a first response message.

[0165] In conjunction with the second aspect, in one possible implementation, sending a first response message may specifically include: the network device sending the aforementioned first response message when it determines that the first terminal device supports random access on N1 second uplink carriers, or when it determines that the first terminal device requests random access on N1 second uplink carriers.

[0166] In conjunction with the second aspect, in one possible implementation, the method may further include: if the network device determines that the first transmission resource is included in the target transmission resource set, and / or determines that the first random access preamble is included in the target random access preamble set, then it can be determined that the first terminal device supports random access on N1 second uplink carriers, or that the first terminal device requests random access on N1 second uplink carriers. Wherein, the target transmission resource set is used for the transmission of the random access preamble of the target terminal device, the target random access preamble set is used for the random access of the target terminal device, and the target terminal device is a terminal device that supports random access on N1 second uplink carriers.

[0167] In conjunction with the second aspect, in one possible implementation, the method may further include: the network device sending second configuration information and / or third configuration information. The second configuration information is used to indicate or determine that N1 second uplink carriers are associated with a first downlink carrier. The third configuration information is used to indicate or determine N1 fourth transmission resources associated with the N1 second uplink carriers. Here, the fourth transmission resource corresponding to any one of the N1 second uplink carriers i is used for the transmission of the random access preamble used in random access initiated from the second uplink carrier i.

[0168] In conjunction with the second aspect, the aforementioned first request message can be message 1 (i.e., msg1) in a 4-step random access process, and the aforementioned first response message can be message 2 (i.e., msg2) in a 4-step random access process. Alternatively, the aforementioned first request message can be message A (i.e., msgA) in a 2-step random access process, and the aforementioned first response message can be message B (i.e., msgB) in a 2-step random access process.

[0169] Thirdly, this application provides a random access method. This method is applicable to a first terminal device or a device within the first terminal device (such as a module, circuit, processor, chip, or chip system within the first terminal device). Alternatively, it is applicable to logical nodes, logical modules, or software capable of implementing all or part of the functions of the first terminal device.

[0170] The method includes: a first terminal device sending a second request message to a network device. Here, the second request message may include a first contention resolution identifier used by the first terminal device to initiate random access on a first uplink carrier. The first terminal device receives a second response message from the network device. The second response message includes the first contention resolution identifier and the first C-RNTI of the first terminal device. Alternatively, the second response message may be scrambled based on a second TC-RNTI, and the second response message may include the first contention resolution identifier. The first carrier identifier corresponding to the first uplink carrier and the second TC-RNTI can be used to determine the first C-RNTI of the first terminal device. Here, the first carrier identifier is the identifier of the first uplink carrier among a plurality of second uplink carriers, and the plurality of second uplink carriers includes at least N1 second uplink carriers. All N1 second uplink carriers are used to request access to the network device, where N1 is a positive integer greater than or equal to 2.

[0171] In the above implementation, the network device sends a second response message to the first terminal device that successfully competes for random access via the first uplink carrier. Accordingly, the first terminal device can determine its success through the second response message. Furthermore, the first terminal device can directly extract the first C-RNTI assigned to it by the network device from the second response message, or determine its corresponding first C-RNTI by scrambling the second TC-RNTI of the second response message and the first carrier identifier of the first uplink carrier used to initiate random access. Therefore, when one or more terminal devices initiate random access on a certain uplink carrier, the above random access method ensures that at least one of these terminal devices will have a chance to successfully access the network. Further, when different terminal devices initiate random access to the network device on different uplink carriers, the above random access method eliminates competition between terminal devices initiating random access on different uplink carriers, ensuring that at least one terminal device on an uplink carrier initiating random access has a chance to successfully access the network. Therefore, the random access method provided in this application has high random access efficiency and strong applicability. When multiple terminal devices initiate random access on multiple uplink carriers corresponding to the same downlink carrier, and the random access preamble and the relevant index of the physical random access channel resources determined by these multiple terminal devices are consistent, the random access method provided in this application can overcome the problem of low random access efficiency in existing random access methods.

[0172] In conjunction with the third aspect, in one possible implementation, where the first carrier identifier corresponding to the first uplink carrier and the second TC-RNTI are used to determine the first C-RNTI of the first terminal device, the first C-RNTI satisfies the following formula (14):

[0173] C-RNTI1=TC-RNTI2+c_id1 (14)

[0174] Wherein, C-RNTI1 is the first C-RNTI, TC-RNTI2 is the second TC-RNTI, and c_id1 is the first carrier identifier.

[0175] In the above implementation, the sum of the first carrier identifier and the second TC-RNTI is determined as the first C-RNTI. The method is simple and easy to implement, and can further improve the random access efficiency of the random access method.

[0176] In conjunction with the third aspect, in one possible implementation, if the first uplink carrier is a NUL, then the first carrier identifier can be the NUL index of the first uplink carrier among the N1 second uplink carriers. If the first uplink carrier is a SUL, then the first carrier identifier can be the SUL index of the first uplink carrier among the N1 second uplink carriers. Furthermore, in the current implementation, the carrier identifiers of the associated NUL and SUL carriers among the N1 second uplink carriers may be the same or different.

[0177] In conjunction with the third aspect, in one possible implementation, the first carrier is identified as the uplink carrier index of the first uplink carrier among N1 second uplink carriers.

[0178] In conjunction with the third aspect, in one possible implementation, if the second response message includes a first C-RNTI, the first C-RNTI may be included in the media access control protocol data unit (MAC-PDU) of the second response message. For example, a second field may be added to the MAC-PDU, and the first C-RNTI may be carried in this second field.

[0179] In conjunction with the third aspect, in one possible implementation, the second response message may further include N1-1 third contention resolution identifiers in addition to the first contention resolution identifier. These N1-1 third contention resolution identifiers are the contention resolution identifiers for N1-1 third terminal devices that initiate random access on N1-1 second uplink carriers (excluding the first uplink carrier). In this case, the second response message may also include N1-1 second C-RNTIs corresponding to these N1-1 third terminal devices. Alternatively, the second TC-RNTI scrambled in the second response message and the N1-1 carrier identifiers corresponding to these N1-1 second uplink carriers are used to determine the N1-1 second C-RNTIs corresponding to these N1-1 third terminal devices. That is, the second response message can also be used by these N1-1 third terminal devices to determine that the contention was successful and to obtain their respective second C-RNTIs.

[0180] Fourthly, this application provides a random access method. This method is applicable to network devices or devices within network devices (such as modules, circuits, processors, chips, or chip systems within the network device). Alternatively, it is applicable to logical nodes, logical modules, or software capable of implementing all or part of the functions of a network device.

[0181] The method includes: a network device receiving a second request message, wherein the second request message may include a first contention resolution identifier used by a first terminal device to initiate random access on a first uplink carrier. The network device sends a second response message. The second response message includes the first contention resolution identifier and a first cell radio network temporary identifier (C-RNTI) of the first terminal device. Alternatively, the second response message is scrambled based on a second TC-RNTI, and includes the first contention resolution identifier of the first terminal device. The first carrier identifier corresponding to the first uplink carrier and the second TC-RNTI are used to determine the first C-RNTI of the first terminal device. The first carrier identifier is the identifier of the first uplink carrier among a plurality of second uplink carriers, which at least include the identifiers from the aforementioned N1 second uplink carriers. All N1 second uplink carriers are used to request access to the network device. N1 is a positive integer greater than or equal to 2.

[0182] In the above implementation, the network device sends a second response message to the first terminal device that successfully competes for random access via the first uplink carrier. Accordingly, the first terminal device can determine its success through the second response message. Furthermore, the first terminal device can directly extract the first C-RNTI assigned to it by the network device from the second response message, or determine its corresponding first C-RNTI by scrambling the second TC-RNTI of the second response message and the first carrier identifier of the first uplink carrier used to initiate random access. Therefore, when one or more terminal devices initiate random access on a certain uplink carrier, the above random access method ensures that at least one of these terminal devices will have a chance to successfully access the network. Further, when different terminal devices initiate random access to the network device on different uplink carriers, the above random access method eliminates competition between terminal devices initiating random access on different uplink carriers, ensuring that at least one terminal device on an uplink carrier initiating random access has a chance to successfully access the network. Therefore, the random access method provided in this application has high random access efficiency and strong applicability. When multiple terminal devices initiate random access on multiple uplink carriers corresponding to the same downlink carrier, and the random access preamble and the relevant index of the physical random access channel resources determined by these multiple terminal devices are consistent, the random access method provided in this application can overcome the problem of low random access efficiency in existing random access methods.

[0183] In conjunction with the fourth aspect, in one possible implementation, where the first carrier identifier corresponding to the first uplink carrier and the second TC-RNTI are used to determine the first C-RNTI of the first terminal device, the first C-RNTI satisfies the following formula (14):

[0184] C-RNTI1=TC-RNTI2+c_id1 (14)

[0185] Wherein, C-RNTI1 is the first C-RNTI, TC-RNTI2 is the second TC-RNTI, and c_id1 is the first carrier identifier.

[0186] In conjunction with the fourth aspect, in one possible implementation, if the first uplink carrier is a NUL, then the first carrier identifier can be the NUL index of the first uplink carrier among the N1 second uplink carriers. If the first uplink carrier is a SUL, then the first carrier identifier can be the SUL index of the first uplink carrier among the N1 second uplink carriers. Furthermore, in the current implementation, the carrier identifiers of the associated NUL and SUL carriers among the N1 second uplink carriers may be the same or different.

[0187] In conjunction with the fourth aspect, in one possible implementation, the first carrier is identified as the uplink carrier index of the first uplink carrier among N1 second uplink carriers.

[0188] In conjunction with the fourth aspect, in one possible implementation, if the second response message includes a first C-RNTI, the first C-RNTI may be included in the MAC-PDU of the second response message. For example, a second field may be added to the MAC-PDU, and the first C-RNTI may be carried in the second field.

[0189] In conjunction with the fourth aspect, in one possible implementation, the second response message may further include N1-1 third contention resolution identifiers in addition to the first contention resolution identifier. These N1-1 third contention resolution identifiers are the contention resolution identifiers for N1-1 third terminal devices that initiate random access on N1-1 second uplink carriers (excluding the first uplink carrier). In this case, the second response message may also include N1-1 second C-RNTIs corresponding to these N1-1 third terminal devices. Alternatively, the second TC-RNTI scrambled in the second response message and the N1-1 carrier identifiers corresponding to these N1-1 second uplink carriers are used to determine the N1-1 second C-RNTIs corresponding to these N1-1 third terminal devices. That is, the second response message can also be used by these N1-1 third terminal devices to determine that the contention was successful and to obtain their respective second C-RNTIs.

[0190] Fifthly, this application provides a random access method. This method is applicable to terminal equipment or devices within terminal equipment (such as modules, circuits, processors, chips, or chip systems within the terminal equipment). Alternatively, it is applicable to logical nodes, logical modules, or software capable of implementing all or part of the functions of the terminal equipment.

[0191] The method includes: a first terminal device sending a third request message, wherein the third request message includes a first random access preamble of the first terminal device and / or a first contention resolution identifier of the first terminal device. The first terminal device receives a fourth PDCCH on a first downlink carrier, the fourth PDCCH including first scheduling information of the fourth PDSCH corresponding to a third response message. The third response message is used to respond to the third request message. The first scheduling information includes a fifth carrier identifier corresponding to a second downlink carrier. The second downlink carrier is different from the first downlink carrier. This fifth carrier identifier is used to indicate that the fourth PDSCH is transmitted on the second downlink carrier.

[0192] In the above implementation, network devices and terminal devices can adapt to scenarios where control transmission and data transmission are decoupled by supporting cross-carrier scheduling of response message PDSCH using PDCCH. This increases scheduling flexibility and allows response message transmissions under different channel conditions to be scheduled on appropriate spectrum, thereby improving resource utilization efficiency and communication performance.

[0193] In conjunction with the fifth aspect, in one possible implementation, the third request message includes the first random access preamble of the first terminal device, the third request message is message 1 (i.e., msg1) in the four-step random access process, and the third response message is message 2 (i.e., msg2) in the four-step random access process. Alternatively, the third request message includes the first contention resolution identifier of the first terminal device, the third request message is message 3 (i.e., msg3) in the four-step random access process, and the third response message is message 4 (i.e., msg4) in the four-step random access process. Still another possibility is that the third request message includes the first random access preamble and the first contention resolution identifier of the first terminal device, the third request message is message A (i.e., msgA) in the two-step random access process, and the third response message is message B (i.e., msgB) in the two-step random access process.

[0194] In conjunction with the fifth aspect, in one possible implementation, the first scheduling information is included in the downlink control information (DCI) transmitted in the fourth PDCCH. For example, the format of this DCI could be DCI1_0.

[0195] In conjunction with the fifth aspect, in one possible implementation, the fifth carrier identifier is an identifier of the second downlink carrier among a plurality of downlink carriers. For example, the fifth carrier identifier can be a downlink carrier index of the second downlink carrier among a plurality of downlink carriers, indicating which downlink carrier it is among the plurality of downlink carriers.

[0196] In conjunction with the fifth aspect, in one possible implementation, the method further includes: the first terminal device receiving a fourth PDSCH on the second downlink carrier.

[0197] Sixthly, this application provides a random access method. This method is applicable to network devices or devices within network devices (such as modules, circuits, processors, chips, or chip systems within the network device). Alternatively, it is applicable to logical nodes, logical modules, or software capable of implementing all or part of the functions of a network device.

[0198] The method includes: receiving a third request message, wherein the third request message includes a first random access preamble of a first terminal device and / or a first contention resolution identifier of the first terminal device; transmitting a fourth PDCCH on a first downlink carrier, the fourth PDCCH including first scheduling information of a fourth PDSCH corresponding to a third response message. The third response message is used to respond to the third request message. The first scheduling information includes a fifth carrier identifier corresponding to a second downlink carrier. The second downlink carrier is different from the first downlink carrier. The fifth carrier identifier is used to indicate that the fourth PDSCH is transmitted on the second downlink carrier.

[0199] In conjunction with the sixth aspect, in one possible implementation, the third request message includes a first random access preamble of the first terminal device, the third request message is message 1 (i.e., msg1) in the four-step random access process, and the third response message is message 2 (i.e., msg2) in the four-step random access process. Alternatively, the third request message includes a first contention resolution identifier of the first terminal device, the third request message is message 3 (i.e., msg3) in the four-step random access process, and the third response message is message 4 (i.e., msg4) in the four-step random access process. Still another possibility is that the third request message includes the first random access preamble and the first contention resolution identifier of the first terminal device, the third request message is message A (i.e., msgA) in the two-step random access process, and the third response message is message B (i.e., msgB) in the two-step random access process.

[0200] In conjunction with the sixth aspect, in one possible implementation, the first scheduling information is included in the downlink control information (DCI) transmitted in the fourth PDCCH. For example, the format of this DCI could be DCI1_0.

[0201] In conjunction with the sixth aspect, in one possible implementation, the fifth carrier identifier is an identifier of the second downlink carrier among multiple downlink carriers. For example, the fifth carrier identifier can be a downlink carrier index of the second downlink carrier among multiple downlink carriers, indicating which downlink carrier it is among the multiple downlink carriers.

[0202] In conjunction with the sixth aspect, in one possible implementation, the method further includes: transmitting a fourth PDSCH on a second downlink carrier.

[0203] Seventhly, embodiments of this application provide a communication device comprising modules, units, or means for implementing the random access method described in any of the preceding aspects or any possible implementations of the random access method described in any of the preceding aspects. These modules, units, or means can be implemented in hardware, software, or by hardware executing corresponding software. The hardware or software includes one or more modules or units corresponding to the aforementioned functions.

[0204] It should be understood that the communication device may be a first terminal device involved in the first aspect or any possible implementation of the first aspect, or a network device involved in the second aspect or any possible implementation of the second aspect.

[0205] Alternatively, the communication device may be a first terminal device involved in the third aspect or any possible implementation of the third aspect, or a network device involved in the fourth aspect or any possible implementation of the fourth aspect.

[0206] Alternatively, the communication device may be a first terminal device as described in the fifth aspect or any possible implementation thereof, or a network device as described in the sixth aspect or any possible implementation thereof.

[0207] Eighthly, this application provides a communication device. The communication device may include at least one processor. This at least one processor is configured to execute the random access method provided by the first aspect or any possible implementation thereof, or to execute the random access method provided by the second aspect or any possible implementation thereof, or to execute the random access method provided by the third aspect or any possible implementation thereof, or to execute the random access method provided by the fourth aspect or any possible implementation thereof, or to execute the random access method provided by the fifth aspect or any possible implementation thereof, or to execute the random access method provided by the sixth aspect or any possible implementation thereof.

[0208] Optionally, the communication device also includes a memory for storing necessary program instructions and data. Furthermore, the memory may be coupled to the processor, or it may be independent of the processor.

[0209] Optionally, the communication device may further include a transceiver for transmitting and / or receiving information related to the random access method provided by the first aspect or any possible implementation thereof, or for transmitting and / or receiving information related to the random access method provided by the second aspect or any possible implementation thereof, or for transmitting and / or receiving information related to the random access method provided by the third aspect or any possible implementation thereof, or for transmitting and / or receiving information related to the random access method provided by the fourth aspect or any possible implementation thereof, or for transmitting and / or receiving information related to the random access method provided by the fifth aspect or any possible implementation thereof, or for transmitting and / or receiving information related to the random access method provided by the sixth aspect or any possible implementation thereof.

[0210] Optionally, the communication device may also include a bus system through which at least one processor, memory, and transceiver can be coupled.

[0211] Ninthly, this application provides a computer program product including instructions that, when executed on a computer, cause the computer to perform the random access method described in any of the preceding aspects or any possible implementation thereof.

[0212] Tenthly, this application provides a computer-readable storage medium storing a computer program that, when executed, implements the random access method provided by the first aspect or any possible implementation thereof, or the random access method provided by the second aspect or any possible implementation thereof, or the random access method provided by the third aspect or any possible implementation thereof, or the random access method provided by the fourth aspect or any possible implementation thereof, or the random access method provided by the fifth aspect or any possible implementation thereof, or the random access method provided by the sixth aspect or any possible implementation thereof.

[0213] Eleventhly, this application provides a chip system comprising at least a processor. The processor executes computer execution instructions to cause a device equipped with the chip system to perform the random access method provided by the first aspect or any possible implementation thereof, or to perform the random access method provided by the second aspect or any possible implementation thereof, or to perform the random access method provided by the third aspect or any possible implementation thereof, or to perform the random access method provided by the fourth aspect or any possible implementation thereof, or to perform the random access method provided by the fifth aspect or any possible implementation thereof, or to perform the random access method provided by the sixth aspect or any possible implementation thereof.

[0214] In conjunction with aspect nine, in one possible implementation, the chip system may further include interface circuitry. This interface circuitry is used to receive computer execution instructions and transmit them to the processor.

[0215] In a twelfth aspect, this application provides a communication device, which may include a processor and an interface circuit. The interface circuit is configured to receive signals from other communication devices outside the communication device and transmit them to the processor, or to send signals from the processor to other communication devices outside the communication device. The processor is configured to implement, through logic circuits or by executing computer programs or instructions, the random access method provided by the first aspect or any possible implementation thereof, or the random access method provided by the second aspect or any possible implementation thereof, or the random access method provided by the third aspect or any possible implementation thereof, or the random access method provided by the fourth aspect or any possible implementation thereof, or the random access method provided by the fifth aspect or any possible implementation thereof, or the random access method provided by the sixth aspect or any possible implementation thereof.

[0216] It should be understood that the communication device can be a first terminal device involved in the random access method provided by any of the possible implementations of the first, third, or fifth aspects above, or an apparatus containing the first terminal device, or an apparatus contained in the first terminal device, such as a chip system. Alternatively, the communication device can be a network device involved in the random access method provided by any of the possible implementations of the second, fourth, or sixth aspects above, or an apparatus containing the network device, or an apparatus contained in the network device, such as a chip system.

[0217] In a thirteenth aspect, this application provides a communication system. This communication system may include the first terminal device and network device described above.

[0218] The first terminal device is used to implement the random access method provided by any possible implementation of any one of the first, third, or fifth aspects, and the network device is used to implement the random access method provided by any one of the second, fourth, or sixth aspects. Attached Figure Description

[0219] Figure 1 This is a schematic diagram of the structure of a communication system provided in this application;

[0220] Figure 2 This is a flowchart illustrating a random access method provided in this application;

[0221] Figure 3 This is a schematic diagram illustrating the allocation of a search space set and a control resource set provided in this application;

[0222] Figure 4 This is another schematic diagram of the allocation of the search space set and control resource set provided in this application;

[0223] Figure 5 This is another schematic diagram of the allocation of the search space set and control resource set provided in this application;

[0224] Figure 6 This is another schematic diagram of the allocation of the search space set and control resource set provided in this application;

[0225] Figure 7 This is another schematic diagram of the allocation of the search space set and control resource set provided in this application;

[0226] Figure 8 This is another flowchart illustrating a random access method provided in this application;

[0227] Figure 9 This is another flowchart illustrating a random access method provided in this application;

[0228] Figure 10 This is another flowchart illustrating a random access method provided in this application;

[0229] Figure 11 This is another flowchart illustrating a random access method provided in this application;

[0230] Figure 12 This is a flowchart illustrating another random access method provided in this application;

[0231] Figure 13 This is a schematic diagram of the structure of a communication device provided in this application;

[0232] Figure 14 This is a schematic diagram of the structure of another communication device provided in this application;

[0233] Figure 15 This is a schematic diagram of another communication device provided in this application. Detailed Implementation

[0234] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings.

[0235] The technical solutions provided in this application can be applied to various communication systems, such as: Long Term Evolution (LTE) systems, LTE Frequency Division Duplex (FDD) systems, LTE Time Division Duplex (TDD) systems, 5th Generation (5G) systems, or New Radio (NR) systems. In addition, they can also be applied to subsequent evolution systems.

[0236] Please see Figure 1 , Figure 1 This is a schematic diagram of the structure of a communication system provided in this application. Figure 1 As shown, the communication system 10 includes a radio access network (RAN) 100 and a core network (CN) 200. RAN 100 includes at least one RAN node (e.g., ...). Figure 1 110a and 110b in the above) and at least one terminal (such as Figure 1 (120a-120j in the original text). RAN 100 may also include other RAN nodes, such as wireless relay equipment and / or wireless backhaul equipment. Figure 1 (Not shown in the image). The terminal connects to the RAN node wirelessly. The RAN node connects to the core network 200 wirelessly or via a wired connection. The core network equipment in the core network 200 and the RAN node in the RAN 100 can be different physical devices, or they can be the same physical device integrating core network logical functions and radio access network logical functions.

[0237] RAN100 can be a cellular system related to the 3rd Generation Partnership Project (3GPP), such as 4G, 5G mobile communication systems, or future-oriented evolution systems. RAN100 can also be an open access network (O-RAN or ORAN), a cloud radio access network (CRAN), or a wireless fidelity (WiFi) system. RAN100 can also be a communication system that integrates two or more of the above systems.

[0238] RAN nodes, sometimes also called access network devices, network devices, RAN entities, or access nodes, constitute part of the communication system and are used to help terminals achieve wireless access. Multiple RAN nodes in communication system 10 can be of the same type or different types. In some scenarios, the roles of RAN nodes and terminals are relative, for example... Figure 1 Network element 120i can be a helicopter or a drone, and it can be configured as a mobile base station. For terminals 120j that access RAN 100 through network element 120i, network element 120i is a base station; however, for base station 110a, network element 120i is a terminal. RAN nodes and terminals are sometimes referred to as communication devices, for example... Figure 1 Network elements 110a and 110b can be understood as communication devices with base station functions, while network elements 120a-120j can be understood as communication devices with terminal functions.

[0239] In one possible scenario, a RAN node can be a base station, an evolved NodeB (eNodeB), an access point (AP), a transmission reception point (TRP), a next-generation NodeB (gNB), a base station in a future mobile communication system, or an access node in a WiFi system, etc. Figure 1 110a), micro base stations or indoor stations (such as Figure 1The RAN node can be a relay node or donor node (as described in section 110b), or a wireless controller in a CRAN scenario. Optionally, the RAN node can also be a server, wearable device, vehicle, or in-vehicle equipment. For example, the access network equipment in vehicle-to-everything (V2X) technology can be a roadside unit (RSU). All or part of the functions of the RAN node in this application can also be implemented through software functions running on hardware, or through virtualization functions instantiated on a platform (e.g., a cloud platform). The RAN node can also be equipped with communication modules, circuits, or chips that perform corresponding communication functions. The RAN node can also be configured with program instructions for performing corresponding communication functions and corresponding program instructions. The RAN node in this application can also be a logical node, logical module, or software capable of implementing all or part of the RAN node functions.

[0240] In another possible scenario, multiple RAN nodes collaborate to assist the terminal in achieving wireless access, with different RAN nodes each implementing a portion of the base station's functions. For example, RAN nodes can be central units (CUs), distributed units (DUs), CU-control plane (CPs), CU-user plane (UPs), or radio units (RUs), etc. CUs and DUs can be set up separately or included in the same network element, such as a baseband unit (BBU). RUs can be included in radio frequency equipment or radio frequency units, such as remote radio units (RRUs), active antenna units (AAUs), or remote radio heads (RRHs).

[0241] In different systems, CU (or CU-CP and CU-UP), DU, or RU may have different names, but those skilled in the art will understand their meaning. For example, in an ORAN system, CU can also be called O-CU (open CU), DU can also be called O-DU, CU-CP can also be called O-CU-CP, CU-UP can also be called O-CU-UP, and RU can also be called O-RU. For ease of description, this application uses CU, CU-CP, CU-UP, DU, and RU as examples. Any of the units among CU (or CU-CP, CU-UP), DU, and RU in this application can be implemented through software modules, hardware modules, or a combination of software and hardware modules.

[0242] A terminal can be a device or module that accesses the aforementioned communication system and has corresponding communication functions. A terminal can also be called a terminal device, user equipment (UE), mobile station, mobile terminal, etc. Terminals can be widely used in various scenarios, such as device-to-device (D2D), vehicle-to-everything (V2X) communication, machine-type communication (MTC), Internet of Things (IoT), virtual reality, augmented reality, industrial control, autonomous driving, telemedicine, smart grids, smart furniture, smart offices, smart wearables, smart transportation, smart cities, etc. Terminals can be mobile phones, tablets, computers with wireless transceiver capabilities, wearable devices, vehicles, drones, helicopters, airplanes, ships, robots, robotic arms, smart home devices, transportation vehicles with wireless communication capabilities, communication modules, etc. The embodiments of this application do not limit the device form of the terminal. A terminal typically contains a communication module, circuit, or chip that performs the corresponding communication function. The terminal can also be configured with program instructions for performing the corresponding communication function.

[0243] Combination Figure 1 The communication system 10 shown in this application embodiment can be specifically implemented by the RAN node and the terminal in the communication system 10 in collaboration. For ease of distinction, in this application embodiment, the RAN node will be uniformly referred to as a network device, and the terminal will be uniformly referred to as a first terminal device.

[0244] To facilitate the explanation and understanding of the random access method provided in this application, several concepts involved in this application will be explained below.

[0245] 1. Carrier aggregation, uplink carrier, and downlink carrier

[0246] Carrier aggregation technology combines multiple component carriers (CCs) to form a wider bandwidth. These component carriers can be carriers within the same frequency band (i.e., intra-band aggregation) or carriers from different frequency bands (i.e., inter-band aggregation). For example, two 20MHz carriers can be bundled into a 40MHz bandwidth, thereby improving data transmission rate and spectral efficiency. It should be understood that in the embodiments of this application, component carriers can also be simply referred to as carriers.

[0247] In practice, carrier aggregation can be divided into uplink carrier aggregation and downlink carrier aggregation. Network devices are configured with uplink and downlink carriers in pairs. That is, for every uplink carrier configured, a corresponding downlink carrier is configured, and the corresponding uplink and downlink carriers form a cell. Additionally, a Single Uplink Utility (SUL) can be configured for a specific uplink carrier to enhance uplink coverage and transmission rate. An uplink carrier configured with an SUL can also be called a Non-Uplink Utility (NUL). Furthermore, each uplink or downlink carrier should simultaneously support the transmission or reception of both data and control signals.

[0248] Furthermore, to support a smaller number of downlink carriers, a decoupling scheme for uplink and downlink capabilities of the terminal device is proposed. For example, uplink and downlink carriers can be configured in a non-paired manner. With uplink and downlink capability decoupling, the number of uplink carriers supported by the terminal device is inconsistent, and the uplink carrier data is greater than the downlink carrier data. Since each uplink carrier corresponds to one downlink carrier, a scenario arises where multiple uplink carriers simultaneously correspond to one downlink carrier. The random access method provided in this application is applicable to this scenario.

[0249] It should be noted that the carrier involved in this application may also be a cell, a bandwidth part (BWP), or a band.

[0250] 2. Contention-based random access (CBRA)

[0251] Contention-based random access, simply put, means that the random access preamble used by the terminal device is not specifically assigned by the network device, but determined by the terminal device itself. Therefore, after receiving the random access preamble, the network device cannot distinguish which preamble was sent by the terminal device. Consequently, the terminal device also needs to send its unique contention resolution identifier to the network device. Then, after receiving the contention resolution identifier from the terminal device, the network device determines whether the terminal device can access the network. If the network device determines that the terminal device can access the network, it will return the contention resolution identifier for that terminal device. Accordingly, upon receiving the contention resolution identifier from the network device, the terminal device can confirm that its random access was successful. If the network device determines that the terminal device cannot access the network, it will not return the contention resolution identifier for that terminal device. Accordingly, if the terminal device does not detect the contention resolution identifier from the network device, it can confirm that its random access has failed. In a contention-based random access scenario, when multiple terminal devices simultaneously initiate random access to the network device, the network device will select one terminal device from among these and determine that it can access the network. In other words, there is a competition relationship between these multiple terminal devices.

[0252] In practical applications, contention-based random access can be used for initial radio resource control (RRC) connection establishment, RRC connection reconstruction, and recovery from the RRC active state (i.e., RRC inactive state) or the RRC idle state (i.e., RRC idle state) to the RRC connected state (i.e., RRC connected state).

[0253] 3. Competition-based 4-step random access

[0254] Existing technologies provide two schemes for the random access process: one is called 4-step random access, and the other is an enhanced or optimized version of 4-step random access, called 2-step random access.

[0255] The so-called contention-based four-step random access can include the following steps:

[0256] S11, the terminal device sends a random access request message to the network device.

[0257] Specifically, the terminal device (referred to as terminal device A for clarity) can randomly determine a random access preamble (let's assume it's preamble A) from the preamble pool. Terminal device A can also determine the physical random access channel resource (PRACH resource) and then send a random access request message to the network device via the PRACH channel on that resource. This random access request message includes the random access preamble determined by terminal device A. Correspondingly, the network device receives the random access request message via the PRACH channel.

[0258] In general, in a 4-step random access process, the random access request message can be referred to as message 1 (i.e., msg1).

[0259] S12, the network device sends a random access response message to terminal device A.

[0260] Specifically, after receiving a random access request message from terminal device A, the network device can send a random access response message corresponding to the random access request message back to terminal device A.

[0261] For example, a network device can send scheduling information for the Physical Downlink Shared Channel (PDSCH) to terminal device A via the PDCCH. Here, the PDSCH scheduling information is carried within the downlink control information (DCI) carried by the PDCCH, typically in the format DCIformat1_0. This PDSCH is scrambled by RA-RNTI. Then, the network device can send the PDSCH to terminal device A based on the aforementioned scheduling information. This PDSCH carries a random access request message. This random access request message includes the random access preamble identifier corresponding to random access preamble A and MAC-RAR, and the MAC-RAR can be used to indicate terminal device A's TAC, uplink grant information, TC-RNTI, etc. Correspondingly, terminal device A descrambles the blindly detected PDSCH using the calculated RA-RNTI to obtain the PDSCH scheduling information carried on DCI1_0, and can monitor the PDSCH based on this scheduling information. Once terminal device A detects the PDSCH, it can descramble the PDSCH using RA-RNTI to obtain the random access preamble identifier and MAC-RAR carried in the random access request message. Terminal device A can also determine the TAC, uplink grant information, TC-RNTI, and other information indicated by the MAC-RAR.

[0262] In general, the random access response message in a 4-step random access procedure can be referred to as message 2 (i.e., msg2).

[0263] It should also be noted that the above RA-RNTI is determined by terminal device A and network device based on the physical random access channel resources used by terminal device A. For example, the RA-RNTI can satisfy the following formula (15):

[0264] RA-RNTI=1+s_id+14×t_id+14×80×f_id+14×80×8×c_id2 (15)

[0265] Wherein, s_id is the index of the first OFDM symbol of the physical random access channel resource. It can be a positive integer greater than or equal to 0 and less than 14. t_id is the index of the first time slot of the physical random access channel resource. It can be a positive integer greater than or equal to 0 and less than 80. f_id is the frequency domain index of the physical random access channel resource. It can be a positive integer greater than or equal to 0 and less than 8. c_id2 is the carrier identifier of the uplink carrier used for physical random access channel transmission. This carrier identifier is used to indicate whether the uplink carrier used for physical random access channel transmission is NUL or SUL. Typically, a c_id2 value of 0 indicates that the uplink carrier is NUL, and a value of 1 indicates that the uplink carrier is SUL.

[0266] S13, Terminal device A sends a scheduled transmission request message to the network device.

[0267] Specifically, after determining the TAC, uplink grant information, TC-RNTI, and other information indicated by the MAC-RAR, terminal device A can determine the scheduled transmission request message. This scheduled transmission request message may contain information such as the contention resolution identifier of terminal device A. Then, terminal device A can determine the time-frequency resources of the physical uplink shared channel (PUSCH) based on the uplink grant information. Terminal device A can then send the PUSCH carrying the scheduled transmission message to the network device through these time-frequency resources. Here, the PUSCH is scrambled based on the aforementioned TC-RNTI. Correspondingly, after detecting the PUSCH on the corresponding time-frequency resources, the network device can descramble it using the TC-RNTI to obtain the contention resolution identifier and other information of terminal device A.

[0268] In general, the scheduling transmission request message in the 4-step random access can also be referred to as message 3 (i.e., msg3), RRC establishment request message, etc.

[0269] S14, the network device sends a contention resolution response message to the terminal device.

[0270] Specifically, a network device may simultaneously receive scheduling transmission request messages from multiple terminal devices. The network device will identify the same terminal device from among these and determine that it can access the network. Let's assume terminal device A is the terminal device selected by the network device. In this case, the network device can determine the contention resolution response message, which includes information such as the contention resolution identifier of terminal device A. Then, the network device can send new scheduling information for the Physical Downlink Shared Channel (PDSCH) to terminal device A again via the PDCCH. Here, the new scheduling information for the PDSCH is also carried in the DCI carried by the PDCCH. Furthermore, this PDCCH is scrambled by TC-RNTI. Then, the network device can send the PDSCH to terminal device A based on the new scheduling information. This PDSCH carries the aforementioned contention resolution response message. Correspondingly, terminal device A descrambles the blindly detected PDCCH using the calculated TC-RNTI to obtain the new scheduling information for the PDSCH, and can monitor the PDSCH based on this new scheduling information. When terminal device A detects the PDSCH, it can descramble the PDSCH using the TC-RNTI to obtain a contention resolution response message. Then, terminal device A retrieves its own contention resolution identifier from this message and confirms that it has completed random access (or that its random access was successful). The terminal device can then convert the TC-RNTI into its own unique C-RNTI.

[0271] In general, the contention to resolve the response message in a 4-step random access process can also be referred to as message 4 (i.e., msg4).

[0272] 4. Competition-based two-step random access

[0273] The so-called contention-based two-step random access can be understood as an enhanced version of four-step random access. Specifically, it may include the following steps:

[0274] S21, the terminal device sends a random access request message to the network device.

[0275] Specifically, the terminal device (referred to as terminal device A for clarity) can randomly select a random access preamble from the random access preamble pool (let's assume it's preamble A). Terminal device A can also determine the physical random access channel resource (PRACH resource). Simultaneously, the terminal device can determine its contention resolution identifier and other information. Here, the random access request message may include the random access preamble A and the contention resolution identifier of terminal device A. It can also be understood that the random access request message includes messages 1 and 3 from the four-step random access process. Then, the terminal device can send the random access preamble A to the network device through the selected PRACH resource, and send a PUSCH to the network device according to the PUSCH transmission opportunity corresponding to that PRACH resource. This PUSCH carries the contention resolution identifier and other information of terminal device A. Correspondingly, the network device can receive the random access request message from the terminal device and obtain the random access preamble A and contention resolution identifier of terminal device A.

[0276] In general, during a two-step random access process, the aforementioned random access request message can also be referred to as message A (i.e., msgA).

[0277] S22, the network device sends a contention resolution response message to the terminal device.

[0278] Specifically, a network device may simultaneously receive scheduling transmission request messages from multiple terminal devices. When these terminal devices compete for access, the network device determines which terminal device has successfully won the competition. Here, we assume terminal device A is the terminal device selected by the network device. In this case, the network device can determine a contention resolution response message. This contention resolution response message includes either a successful random access response (i.e., successRAR) or a fallback access response (i.e., fallbackRAR) for the terminal device. The success RAR may include the contention resolution identifier of terminal device A and the C-RNTI assigned to the terminal device. The fallback RAR carries the TC-RNTI assigned to the terminal device but does not carry the contention resolution identifier of terminal device A. For example, the network device sends out a success RAR if both PRACH and PUSCH are correctly received. The network device sends out a fallback RAR if PRACH is correctly received but PUSCH is not correctly received.

[0279] Furthermore, upon receiving a contention resolution response message, if the terminal device determines that the contention resolution message includes a success RAR, it can determine that it has completed random access based on the contention resolution identifier included in the success RAR and determine the C-RNTI assigned to it. If the terminal device determines that the contention resolution message includes a fallback RAR, it can fall back to the 4-step random access procedure and execute the relevant procedures for the 4-step random access.

[0280] It should be noted that after obtaining the contention resolution identifier, the network device can send new scheduling information for the PDSCH to terminal device A via the PDCCH. This PDCCH is scrambled using MSGB-RNTI. Then, the network device can send the PDSCH to terminal device A based on the aforementioned scheduling information. This PDSCH carries the contention resolution response message. Correspondingly, terminal device A descrambles the blindly detected PDCCH using the calculated MSGB-RNTI to obtain the PDSCH scheduling information and can monitor the PDSCH based on this information. Once terminal device A detects the PDSCH, it can descramble it using MSGB-RNTI to obtain the contention resolution response message.

[0281] It should also be noted that the MSGB-RNTI can be determined by terminal device A and network device based on the physical random access channel resources used by terminal device A. For example, the MSGB-RNTI can satisfy the following formula (16):

[0282] MSGB-RNTI=1+s_id+14×t_id+14×80×f_id+14×80×8×c_id2+14×80×8×2(16)

[0283] The descriptions of s_id, t_id, f_id and c_id2 can be found in the description of formula (15) above, and will not be repeated here.

[0284] In existing technologies, when multiple terminal devices initiate random access to a network device on multiple uplink carriers corresponding to the same downlink carrier, the random access preamble and physical random access channel (PRACH) resources used to initiate random access are determined autonomously by each terminal device. Therefore, it's possible for these terminal devices to determine identical random access preambles and PRACH resources. In this scenario, based on existing random access schemes, the network device sends the same response message to all terminal devices, indicating a competition among them. Ultimately, only one terminal device will successfully access the network. For example, consider a 4-step random access scenario with 5 uplink carriers, each with 4 terminal devices initiating random access. If the random access preamble and PRACH resource indices determined by these 20 terminal devices are identical, the network device will receive the same random access preamble sent by these 20 terminal devices on the same PRACH resource across the 5 uplink carriers. Then, the network device can determine msg2. Since the network devices send the random access response msg2 based on PRACH resources and the random access preamble, and indicate the TC-RNTI in msg2, the TC-RNTIs of these 20 terminal devices are identical. Furthermore, because the existing RA-RNTI is determined based on PRACH resources, the RA-RNTI used to scramble the msg2 for these 20 terminal devices is also identical. In other words, these 20 terminal devices will receive the same msg2. Therefore, there is a competition among these 20 terminal devices, and ultimately only one can complete random access. Thus, when multiple terminal devices initiate random access on multiple uplink carriers corresponding to the same downlink carrier, and the random access preamble and physical random access channel resource indices determined by these multiple terminal devices are identical, the existing random access scheme suffers from low access efficiency.

[0285] Therefore, the technical problem to be solved by this application is: how to improve the random access efficiency of the random access method.

[0286] Please see Figure 2 , Figure 2 This is a flowchart illustrating a random access method provided in this application. This method is applicable to... Figure 1 The communication system shown can be implemented by the first terminal device and network devices working together.

[0287] It should be noted that the random access method provided in this application is applicable to the case where a terminal device determines one uplink carrier from N1 second uplink carriers and initiates random access to the network device on that uplink carrier. Here, N1 is a positive integer greater than or equal to 2. Optionally, the N1 second uplink carriers include at least two NUL or at least two SUL uplink carriers. For example, suppose there are N5 terminal devices simultaneously initiating random access to the network device on each of the N1 second uplink carriers, where N5 is a positive integer greater than or equal to N1. Here, one or more terminal devices can initiate random access on each second uplink carrier. All N5 terminal devices can use the random access method provided in this embodiment to initiate random access to the network device. The implementation process of random access for these N5 terminal devices is similar, the only difference being that some terminal devices successfully access the network device while others fail. Therefore, for ease of understanding and to avoid redundancy, the following will use the process of the first terminal device and the network device among the N5 terminal devices executing the random access method provided in this application as an example. Here, the first terminal device is one of the N5 terminal devices that successfully connected randomly. Furthermore, this application also provides scenarios 1 and 2 to which this random access method is applicable. In scenario 1, the first terminal device and the network device use a 4-step random access method. In scenario 2, the first terminal device and the network device use a 2-step random access method. For descriptions of the 4-step and 2-step random access methods, please refer to the preceding text; they will not be repeated here.

[0288] like Figure 2 As shown, the random access method provided in this application may include the following steps:

[0289] S210, the first terminal device sends a first request message to the network device. The first request message includes a first random access preamble and uses a first transmission resource located on a first uplink carrier. Accordingly, the network device receives the first request message.

[0290] In some feasible implementations, the first terminal device may send a first request message to the network device during the random access process. This first request message may include a first random access preamble determined by the first terminal device. Furthermore, the first transmission resource used by the first request message is located on a first uplink carrier. Alternatively, the first terminal device initiates random access to the network device through the first request message transmitted on the first uplink carrier. Here, the first transmission resource located on the first uplink carrier can be described as the frequency domain resource of the first transmission resource being contained within the first uplink carrier, or it can be described as the frequency domain resource of the first transmission resource being contained within a certain bandwidth part (BWP) of the first uplink carrier. The first uplink carrier may be included in N1 second uplink carriers, where N1 is a positive integer greater than or equal to 2. All N1 second uplink carriers can be used to request access to the network device, or in other words, terminal devices initiate random access to the network device on all N1 second uplink carriers. Correspondingly, the network device can receive the first request message from the first terminal device.

[0291] In this embodiment, the first request message can be understood as a random access request message sent on the first uplink carrier, and the first response message can be understood as a random access response message corresponding to the random access request message. Typically, the first request message can be sent via a physical random access channel. In this case, the first transmission resource can be understood as a physical random access channel resource (i.e., PRACH resource) determined by the first terminal device.

[0292] The implementation process of step S210 will be further explained below in conjunction with scenarios 1 and 2 described above.

[0293] Scene 1:

[0294] In one possible approach, the first request message can be msg1 in the 4-step random access, and the first transport resource can be the PRACH resource used by msg1 (for ease of distinction, it will be referred to as the first PRACH resource in the following description).

[0295] In scenario 1, the first terminal device can determine the first random access preamble from a preset or configured random access preamble code pool. The first terminal device can also determine a first uplink carrier from N1 second uplink carriers and determine the first PRACH resource associated with the first uplink carrier. Then, the first terminal device can determine msg1 containing the first random access preamble. Further, the first terminal device can send msg1 to the network device via PRACH on the first PRACH resource. Correspondingly, the network device can receive msg1 from the first terminal device via PRACH on the first PRACH resource.

[0296] Scene 2:

[0297] In one possible approach, the first request message can be msgA in a two-step random access, and the first transport resource can be the first PRACH resource used to transport the first random access preamble in msgA.

[0298] In scenario 2, the first terminal device can determine the first random access preamble from a preset or configured random access preamble code pool. The first terminal device can also determine the first uplink carrier from N1 second uplink carriers and determine the first PRACH resource located on the first uplink carrier. Then, the first terminal device can determine msgA, which includes the first random access preamble and the contention resolution identifier of the first terminal device (hereinafter referred to as the first contention resolution identifier for ease of distinction). Further, the first terminal device can send the first random access preamble in msgA to the network device via PRACH on the first PRACH resource. The first terminal device can also determine a PUSCH transmission opportunity from multiple PUSCH groups corresponding to the first PRACH resource (hereinafter referred to as the first PUSCH transmission opportunity for ease of distinction). Here, each PUSCH group includes several PUSCH transmission opportunities of the same resource size. Then, the first terminal device can also send the first contention resolution identifier and other information contained in msgA to the network device via PUSCH on the first PUSCH transmission opportunity. At this point, the first terminal device has completed the transmission of msgA. Correspondingly, the network device can receive the first random access preamble contained in msgA via PRACH on the first PRACH resource. The network device can also receive information such as the first contention resolution identifier contained in msgA via PUSCH on the first PUSCH transmission opportunity. At this point, the network device has completed the reception of msgA.

[0299] S220, the network device determines a first response message, which may include a first preamble identifier of a first random access preamble and a first RAR. The first response message may be scrambled based on a first RNTI. The first RNTI is determined based on a first transmission resource and a first carrier identifier of a first uplink carrier. The first carrier identifier is the identifier of the first uplink carrier among a plurality of second uplink carriers, and the plurality of second uplink carriers includes at least the aforementioned N1 second uplink carriers. Alternatively, the first response message may also include a first carrier identifier. Alternatively, the second transmission resource used to transmit the first response message is associated with the first uplink carrier.

[0300] In some feasible implementations, after receiving a first request message, the network device can determine a first response message corresponding to the first request message. The first response message may include a first preamble identifier and a first RAR (Random Access Preamble). In one implementation, the first response message may be scrambled based on a first RNTI (Real-Time Interchange Detection), and the first RNTI is determined based on a first transmission resource and a first carrier identifier of a first uplink carrier. Here, the first carrier identifier is the identifier of the first uplink carrier among a plurality of second uplink carriers, and these plurality of second uplink carriers include at least the aforementioned N1 second uplink carriers. In another implementation, the first response message may also directly include the first carrier identifier. In yet another implementation, the second transmission resource used to transmit the first response message is associated with the first uplink carrier.

[0301] It should be understood that the first carrier identifier can be a carrier identifier specifically used by the first uplink carrier during the random access procedure. That is, the carrier identifier of the first uplink carrier used for scheduling and transmission after access can be different from the first carrier identifier.

[0302] It should be understood that, in the embodiments of this application, scrambling a message based on RNTI can mean that the cyclic redundancy check (CRC) of that message is scrambled based on RNTI. For example, scrambling a first response message based on the first RNTI means that the CRC of the first response message is scrambled based on the first RNTI. Correspondingly, descrambling a message based on RNTI can mean that the CRC of that message is descrambled based on RNTI. For example, descrambling a first response message based on the first RNTI means that the CRC of the first response message is descrambled based on the first RNTI.

[0303] Optionally, in scenario 1, the first response message can be msg2 in the 4-step random access process. The first RAR can be the first MAC-RAR, meaning the first response message can include the first preamble identifier corresponding to the first random access preamble and the first MAC-RAR. This first MAC-RAR can be used to indicate the first TAC of the first terminal device, the uplink grant information of the first terminal device (i.e., UL grant information, mainly used for resource allocation of msg3 subsequently sent by the first terminal device), and the first TC-RNTI of the first terminal device (which can be used for scrambling of msg3 subsequently sent by the first terminal device), etc.

[0304] Furthermore, in scenario 1, the first RNTI can be the RA-RNTI used in the 4-step random access.

[0305] Optionally, in scenario 2, the first response message can be the msgB from the two-step random access process. The first RAR can be either the first successful RAR or the first fallback RAR; that is, the first response message can also include the first successful RAR and the first preamble identifier corresponding to the first random access preamble. The first successful RAR or the first fallback RAR can carry the first contention resolution identifier of the first terminal device.

[0306] Furthermore, in scenario 2, the first RNTI can be the MSGB-RNTI used in the 2-step random access.

[0307] The following will further explain step S220 in conjunction with implementation methods 1, 2, and 3 of the first response message, as well as scenarios 1 and 2 described above. Here, in implementation method 1, the first response message is scrambled based on a first RNTI, and the first RNTI is determined based on a first transmission resource and a first carrier identifier. In implementation method 2, the first response message directly includes the first carrier identifier. In implementation method 3, the second transmission resource used to transmit the first response message is associated with a first uplink carrier.

[0308] Method 1 for implementing the first response message:

[0309] This implementation can be understood as indicating that the first response message is a response message corresponding to the first request message by changing the calculation method of the first RNTI corresponding to the first response message. Alternatively, it can be described as using the first RNTI corresponding to the first response message to identify the first uplink carrier where the first request message corresponding to the first response message resides.

[0310] In practice, the network device can determine the first carrier identifier corresponding to the first uplink carrier where the first transmission resource is located based on the first request message, and calculate the first RNTI based on the first transmission resource and the first carrier identifier. Further, the network device can determine a first preamble identifier including a first random access preamble and a first RAR, and scramble the first response message using the first RNTI.

[0311] The process of calculating the first RNTI by the network device will be explained below, combining the scenarios 1 and 2 described above.

[0312] In a first possible implementation, the first RNTI can be determined based on the index of the first orthogonal frequency division multiplexing (OFDM) symbol of the first transmission resource, the index of the first time slot of the first transmission resource, the frequency domain index of the first transmission resource, the first carrier identifier of the first uplink carrier, and the second carrier identifier of the first uplink carrier. Here, the second carrier identifier is used to indicate whether the first uplink carrier is a normal uplink carrier (NUL) or a standard uplink carrier (SUL). For example, a value of 0 for the second carrier identifier can indicate that the first uplink carrier is NUL, and a value of 1 for the second carrier identifier can indicate that the first uplink carrier is SUL. It should be understood that the description of the value of the second carrier identifier here is merely exemplary, and in actual implementation, the second carrier identifier can also adopt other possible values, which are not limited in this application.

[0313] In other words, if a transmission resource similar to the first transmission resource (let's assume it's the x-th transmission resource) exists, and the index of the first OFDM symbol, the index of the first time slot, the frequency domain index, and the second carrier identifier corresponding to the second uplink carrier of the x-th transmission resource are all the same as the first transmission resource, but the carrier identifier of the second uplink carrier of the x-th transmission resource is different from the first carrier identifier of the first uplink carrier among the N1 second uplink carriers, then the RNTI of the x-th transmission resource pair (which can also be described as the RNTI of the response message corresponding to the x-th request message transmitted by the x-th transmission resource) is different from the first RNTI.

[0314] In the above implementation, the first carrier identifier of the first uplink carrier is introduced during the calculation of the first RNTI used to scramble the first response message, so as to indicate that the first response message is a response message to the first request message used to initiate random access on the first uplink carrier. The method is simple and easy to implement, and can reduce random access latency.

[0315] The different calculation methods for the first RNTI will be explained in detail below.

[0316] The specific calculation method for the first RNTI:

[0317] In scenario 1 above, the first RNTI is the RA-RNTI used in 4-step random access. In this case, the first RNTI satisfies the following formula (1):

[0318] RNTI1=1+s_id+14×t_id+14×80×f_id+14×80×8×c_id2+14×80×8×2×c_id1×2(1)

[0319] Wherein, RNTI1 is the first RNTI, s_id is the index of the first OFDM symbol of the first transmission resource, t_id is the index of the first time slot of the first transmission resource, f_id is the frequency domain index of the first transmission resource, c_id1 is the first carrier identifier, and c_id2 is the second carrier identifier.

[0320] Furthermore, in scenario 2 above, the first RNTI is the MSGB-RNTI used for two-step random access. In this case, the first RNTI satisfies the following formula (2):

[0321] RNTI1=1+s_id+14×t_id+14×80×f_id+14×80×8×c_id2+14×80×8×2×c_id1+14×80×8×2×(c_id1+1) (2)

[0322] The descriptions of each parameter can be found in Formula (1) above, and will not be repeated here.

[0323] For example, please refer to Table 1-1, which is an example of the value range of a first RNTI provided in this application. The table shows the possible values ​​of the first RNTI calculated based on formula (1) and formula (2). For ease of illustration, we take N1 second uplink carriers, including NUL1, SUL1 associated with NUL1, NUL2, SUL2 associated with NUL2, and NUL3, as an example, and assume that the values ​​of the first carrier identifiers of NUL1, SUL1, NUL2, SUL2, and NUL3 are 0, 0, 1, 1, and 2, respectively. As shown in Table 1-1, for the above 5 second uplink carriers, the values ​​of the RNTI calculated using the above formula (1) and formula (2) are continuous and non-overlapping. For example, the RA-RNTI value calculated for NUL1 in scenario 1 ranges from 1 to 8960, while the RA-RNTI value calculated for its associated SUL1 in scenario 1 ranges exactly from 8961 to 17920. Next, the MSGB-RNTI value calculated for NUL1 in scenario 2 ranges from 17921 to 26880, while the RA-RNTI value calculated for its associated SUL1 in scenario 2 ranges exactly from 26881 to 35840. The value ranges for other second uplink carriers can be found in Table 1-1, and will not be elaborated upon here. These calculation results precisely cover the RNTI values ​​in existing technologies, thus demonstrating good compatibility. Furthermore, as shown in Table 1-1, the SUL associated with NUL3 is not actually configured, but the value range of RA-RNTI corresponding to its associated SUL has been reserved, which is 80641-89600. This can avoid the situation where the SUL associated with NUL3 is actually configured but no RA-RNTI is available.

[0324] Table 1-1 Example of the value range of a first RNTI

[0325]

[0326] The above implementation provides a calculation method for RA-RNTI under 4-step random access and MSGB-RNTI under 2-step random access. This calculation method is compatible with existing protocols. When no more than one NUL and no more than one SUL are used, it allows older terminal devices to work on network devices that support the random access method provided in this application, further improving the applicability of the random access method provided in this application.

[0327] Method 2 for calculating the first RNTI:

[0328] In scenario 1 above, the first RNTI can be the RA-RNTI used for 4-step random access. When the first uplink carrier is an uplink carrier associated with a SUL, the first RNTI satisfies the above formula (1). In the embodiments of this application, the uplink carrier associated with a SUL specifically refers to the first uplink carrier being an NUL associated with a SUL, or the first uplink carrier being a SUL, and so on, and will not be repeated hereafter.

[0329] When the first uplink carrier is an uplink carrier of an unassociated SUL, the first RNTI can satisfy the following formula (3):

[0330] RNTI1=14×80×8×2×N3+1+s_id+14×t_id+14×80×f_id+14×80×8×c_id2+14×80×8×2×c_id1 (3)

[0331] Where N3 is the number of SULs in the N1 second uplink carriers, or in other words, N3 is the number of NULs with associated SULs in the N1 second uplink carriers. The descriptions of the other parameters can be found in the previous formula (1), and will not be repeated here. It should be understood that since formula (3) is used for uplink carriers without associated SULs, there is no need to distinguish between NULs and SULs, so the term "14×80×8×c_id2" in formula (3) can also be omitted.

[0332] It should be understood that, in the embodiments of this application, an uplink carrier without an associated SUL refers to an uplink carrier that is an NUL and has no associated SUL. The same applies below, and will not be repeated hereafter.

[0333] Furthermore, the first RNTI can also be the MSGB-RNTI used for two-step random access. When the first uplink carrier is an uplink carrier associated with a SUL, the first RNTI satisfies the above formula (2). Or, when the first uplink carrier is an NUL associated with a SUL, or an SUL associated with a NUL, the first RNTI satisfies the above formula (2).

[0334] When the first uplink carrier is an uplink carrier of an unassociated SUL, the first RNTI satisfies the following formula (4):

[0335] RNTI1=14×80×8×2×N3+1+s_id+14×t_id+14×80×f_id+14×80×8×c_id2+14×80×8×c_id1+14×80×8×(c_id1+1) (4)

[0336] Wherein, N3 is the number of SULs in the N1 second uplink carriers, and the descriptions of the other parameters can be found in the previous formula (1), which will not be repeated here. It should be understood that since formula (4) is used for uplink carriers without associated SULs, there is no need to distinguish between NULs and SULs, so the term "14×80×8×c_id2" in formula (3) can also be omitted.

[0337] For example, please refer to Table 1-2, which is another example of the range of values ​​for the first RNTI provided in this application. The table shows the possible values ​​of the first RNTI calculated based on formulas (1) to (4). For ease of illustration, we still take N1 second uplink carriers, including NUL1, SUL1 associated with NUL1, NUL2, SUL2 associated with NUL2, and NUL3 as examples. As shown in Table 1-2, for the above 5 second uplink carriers, the values ​​of the first RNTI calculated using formulas (1) to (4) are also continuous and non-overlapping. Such calculation results can just cover the values ​​of RNT I in the prior art, so the compatibility is good. In addition, as shown in Table 1-2, SUL associated with NUL3 is not actually configured, so the range of values ​​for RA-RNTI corresponding to its associated SUL is no longer reserved, which can reduce the risk of RNTI values ​​exceeding the range.

[0338] Table 1-2 provides another example of the value range for the first RNTI.

[0339]

[0340] The above implementation provides another method for calculating RA-RNTI under 4-step random access and MSGB-RNTI under 2-step random access. This calculation method is compatible with existing protocols. When no more than one NUL and no more than one SUL are used, it allows older terminal devices to operate on network devices that support the random access method provided in this application, further improving the applicability of the random access method provided in this application. In addition, this calculation method also ensures that if a certain NUL does not have an associated SUL configured, the RNTI value corresponding to that SUL will not be reserved for that NUL's SUL. In other words, this calculation method does not need to consider the SUL corresponding to that NUL when calculating the RNTI value. This method can also reduce the risk of the RNTI value exceeding the specified range.

[0341] Method 3 for calculating the first RNTI:

[0342] In scenario 1, the first RNTI can be the RA-RNTI used for 4-step random access. In this case, the first RNTI satisfies the following formula (5):

[0343] RNTI1=1+s_id+14×t_id+14×80×f_id+14×80×8×c_id2+14×80×8×2×c_id1 (5)

[0344] The descriptions of each parameter can be found in Formula (1) above, and will not be repeated here.

[0345] Furthermore, in scenario 2, the first RNTI can be the MSGB-RNTI in a two-step random access process. In this case, the first RNTI satisfies the following formula (6):

[0346] RNTI1=1+s_id+14×t_id+14×80×f_id+14×80×8×c_id2+14×80×8×2×c_id1+14×80×8×2×N2 (6)

[0347] Where N2 is the number of NULs in the N1 second uplink carriers, and the descriptions of the other parameters can be found in the previous formula (1), which will not be repeated here. Optionally, “14×80×8×2×N2” in formula (6) can be replaced with 14×80×8×N1.

[0348] For example, please refer to Table 1-3, which is another example of the range of values ​​for the first RNTI provided in this application. The table shows the possible values ​​of the first RNTI calculated based on formulas (5) and (6). For ease of illustration, we take N1 second uplink carriers, including NUL1, SUL1 associated with NUL1, NUL2, SUL2 associated with NUL2, and NUL3, as an example. As shown in Table 1-3, for the above 5 second uplink carriers, the values ​​of the first RNTI calculated using formulas (5) to (6) are also continuous and non-overlapping. Such calculation results can just cover the values ​​of RNTI in the prior art, so the compatibility is good. Furthermore, as shown in Table 1-3, SUL associated with NUL3 is not actually configured, but the range of values ​​for the RA-RNTI corresponding to its associated SUL is still reserved.

[0349] Table 1-3 provides another example of the value range for the first RNTI.

[0350]

[0351] The above implementation presents another method for calculating RA-RNTI under 4-step random access and MSGB-RNTI under 2-step random access. This calculation method is partially compatible with existing protocols and can improve the applicability of the random access method provided in this application to a certain extent.

[0352] Method 4 for calculating the first RNTI:

[0353] In scenario 1 above, the first RNTI can be the RA-RNTI used for 4-step random access. When the first uplink carrier is an uplink carrier of an associated SUL, the first RNTI satisfies the above formula (5). When the first uplink carrier is an uplink carrier of an unassociated SUL, the first RNTI satisfies the following formula (7):

[0354] RNTI1=14×80×8×N3+1+s_id+14×t_id+14×80×f_id+14×80×8×c_id2+14×80×8×c_id1 (7)

[0355] Wherein, N3 is the number of SULs in the N1 second uplink carriers, and the descriptions of the other parameters can be found in the previous formula (1), which will not be repeated here. It should be understood that since formula (7) is used for uplink carriers without associated SULs, there is no need to distinguish between NULs and SULs, so the term "14×80×8×c_id2" in formula (7) can also be omitted.

[0356] Furthermore, in scenario 2 above, the first RNTI can be the MSGB-RNTI used for two-step random access. When the first uplink carrier is an associated SUL uplink carrier, the first RNTI satisfies the following formula (8):

[0357] RNTI1=1+s_id+14×t_id+14×80×f_id+14×80×8×c_id2+14×80×8×2×c_id1+14×80×8×N1 (8)

[0358] The descriptions of each parameter can be found in Formula (1) above, and will not be repeated here.

[0359] Furthermore, when the first RNTI is the MSGB-RNTI used for 2-step random access and the first uplink carrier is an uplink carrier of an unassociated SUL, the first RNTI satisfies the following formula (9):

[0360] RNTI1=14×80×8×N3+1+s_id+14×t_id+14×80×f_id+14×80×8×c_id2+14×80×8×c_id1+14×80×8×N1 (9)

[0361] Wherein, N3 is the number of SULs in the N1 second uplink carriers, and the descriptions of the other parameters can be found in the previous formula (1), which will not be repeated here. It should be understood that since formula (9) is used for uplink carriers without associated SULs, there is no need to distinguish between NULs and SULs, so the term "14×80×8×c_id2" in formula (9) can also be omitted. Optionally, "14×80×8×N1" in formula (9) can also be replaced with "14×80×8×2×N2", where N2 is the number of NULs in the N1 second uplink carriers.

[0362] For example, please refer to Table 1-4, which is another example of the range of values ​​for the first RNTI provided in this application. The table shows the possible values ​​of the first RNTI calculated based on formula (5) and formulas (7) to (9). For ease of illustration, we take N1 second uplink carriers, including NUL1, SUL1 associated with NUL1, NUL2, SUL2 associated with NUL2, and NUL3, as an example. As shown in Table 1-4, for the above 5 second uplink carriers, the values ​​of the first RNTI calculated using formulas (5) and formulas (7) to (9) are also continuous and non-overlapping. Furthermore, as shown in Table 1-4, since SUL associated with NUL3 is not actually configured, the range of values ​​for the RA-RNTI corresponding to its associated SUL will not be reserved.

[0363] Table 1-4 provides another example of the value range for the first RNTI.

[0364]

[0365] The above implementation provides another method for calculating RA-RNTI under 4-step random access and MSGB-RNTI under 2-step random access. This calculation method is partially compatible with existing protocols and can improve the applicability of the random access method provided in this application to a certain extent. In addition, this calculation method also ensures that if a NUL does not have an associated SUL configured, the RNTI value corresponding to the SUL of that NUL will not be reserved. In other words, this calculation method does not need to consider the SUL corresponding to the NUL when calculating the RNTI value. Through this method, the risk of the RNTI value exceeding the specified range can also be reduced.

[0366] Optionally, when the first response message is scrambled based on the first RNTI, both the first NUL and the first uplink carrier associated with the first uplink carrier correspond to the first carrier identifier, or both the first SUL and the first uplink carrier associated with the first uplink carrier correspond to the first carrier identifier. This can also be understood as follows: when the first uplink carrier is either the first NUL or the first SUL, if the first NUL and the first SUL are associated, or if the first NUL and the first SUL belong to the same cell, then both the first NUL and the first SUL correspond to the first carrier identifier. Alternatively, it can be said that the first uplink carrier and the first NUL associated with it both correspond to the first carrier identifier, or both the first SUL associated with the first uplink carrier and the first uplink carrier correspond to the first carrier identifier. Furthermore, it can be said that when the first uplink carrier is a NUL, both the first uplink carrier and its associated SUL correspond to the first carrier identifier, or the first carrier identifier corresponding to the first uplink carrier and its associated SUL are the same. When the first uplink carrier is SUL, both the first uplink carrier and its associated NUL correspond to the first carrier identifier, or in other words, the first carrier identifiers corresponding to the first uplink carrier and its associated NUL are the same. It can be understood that when the first response message is scrambled based on the first RNTI, the network device does not need to distinguish whether the first uplink carrier is NUL or SUL by the first carrier identifier c_id1 when calculating the first RNTI using any of the above formulas (1) to (9), because the value of the second carrier identifier c_id2 can already distinguish whether the first uplink carrier is NUL or SUL.

[0367] Optionally, when the first RNTI is calculated based on any one of formulas (1) to (9) above, the first carrier identifier can be an NUL index or a SUL index. Here, the first carrier identifier can be an NUL index or a SUL index, which can be understood as follows: when the first uplink carrier is NUL, the first carrier identifier is the NUL index of the first uplink carrier among the N1 second uplink carriers; when the first uplink carrier is SUL, the first carrier identifier is the SUL index of the first uplink carrier among the N1 second uplink carriers. Optionally, the NUL index can be understood as a number in the NUL dimension, used to indicate which NUL it is. The SUL index can be understood as a number in the SUL dimension, used to indicate which SUL it is. Of course, the first carrier identifier can also be the SUL index or the NUL index of the first uplink carrier among multiple second uplink carriers including the aforementioned N1 second uplink carriers.

[0368] For example, assume that the N1 second uplink carriers include five second uplink carriers: NUL1, SUL1 associated with NUL1, NUL2, SUL2 associated with NUL2, and NUL3. The NUL index of NUL1 is 0, the NUL index of NUL2 is 2, the SUL index of SUL1 is 0, and the SUL index of SUL2 is 1. When the first uplink carrier is NUL1, the first carrier identifier is 0; when the first uplink carrier is NUL2, the first carrier identifier is 1, and so on.

[0369] It should be understood that the description of the implementation of the first carrier identifier here is exemplary. In actual implementation, the first carrier identifier may also adopt other possible implementation methods, and this application does not impose specific restrictions on them.

[0370] In a second possible implementation, the first RNTI can be determined based on the index of the first OFDM symbol of the first transmission resource, the index of the first time slot of the first transmission resource, the frequency domain index of the first transmission resource, and the first carrier identifier of the first uplink carrier. That is, the network device can calculate the aforementioned first RNTI based on the index of the first OFDM symbol of the first transmission resource, the index of the first time slot of the first transmission resource, the frequency domain index of the first transmission resource, and the first carrier identifier of the first uplink carrier, and use it for scrambling the first response message.

[0371] In the above implementation, the first carrier identifier of the first uplink carrier is introduced during the RNTI determination process to establish the association between the random access response message and the uplink carrier used by the requesting network device, without needing to distinguish between NUL and SUL using other indexes. This method is simpler, reduces the complexity of RNTI calculation, and thus further improves random access efficiency.

[0372] The following will further explain the different specific calculation methods of the first RNTI.

[0373] Method 5 for calculating the first RNTI:

[0374] In scenario 1 above, the first RNTI can be the RA-RNTI used for 4-step random access. In this case, the first RNTI satisfies the following formula (10):

[0375] RNTI1=1+s_id+14×t_id+14×80×f_id+14×80×8×c_id1(10)

[0376] The descriptions of each parameter can be found in Formula (1) above, and will not be repeated here.

[0377] In scenario 2 above, the first RNTI is the MSGB-RNTI used for two-step random access. In this case, the first RNTI satisfies the following formula (11):

[0378] RNTI1=1+s_id+14×t_id+14×80×f_id+14×80×8×c-id1+14×80×8×N1(11)

[0379] The descriptions of each parameter can be found in Formula (1) above, and will not be repeated here.

[0380] For example, please refer to Table 1-5, which is another example of the range of values ​​for the first RNTI provided in this application. The table shows the possible values ​​of the first RNTI calculated based on formula (10) and formula (11). For ease of illustration, we take N1 second uplink carriers, including NUL1, SUL1 associated with NUL1, and NUL2, as an example. As shown in Table 1-5, for the above three second uplink carriers, the values ​​of the first RNTI calculated using formula (10) and formula (11) are also continuous and non-overlapping. Furthermore, as shown in Table 1-5, since SUL associated with NUL2 is not actually configured, the range of values ​​for RA-RNTI corresponding to its associated SUL will not be reserved, and this is the value of MSGB-RNTI of NUL2.

[0381] Table 1-5 provides another example of the value range for the first RNTI.

[0382]

[0383] The above implementation provides another method for calculating RA-RNTI under 4-step random access and MSGB-RNTI under 2-step random access. This calculation method is compatible with existing protocols. When no more than one NUL and no more than one SUL are used, it allows older terminal devices to work on network devices that support the random access method provided in this application, further improving the applicability of the random access method provided in this application.

[0384] Method 6 for calculating the first RNTI:

[0385] In scenario 1 above, the first RNTI can be the RA-RNTI used for 4-step random access. In this case, the first RNTI satisfies the following formula (12):

[0386] RNTI1=1+s_id+14×t_id+14×80×f_id+14×80×8×2×c_id1 (12)

[0387] The descriptions of each parameter can be found in Formula (1) above, and will not be repeated here.

[0388] In scenario 2 above, the first RNTI is the MSGB-RNTI used for two-step random access. In this case, the first RNTI satisfies the following formula (13):

[0389] C-RNTI1=1+s_id+14×t_id+14×80×f_id+14×80×8×c_id1+14×80×8×(c_id1+1) (13)

[0390] The descriptions of each parameter can be found in Formula (1) above, and will not be repeated here.

[0391] For example, please refer to Table 1-6, which is another example of the first RNTI value provided in this application. The table shows the possible values ​​of the first RNTI calculated based on formula (12) and formula (13). For ease of illustration, we take N1 second uplink carriers, including NUL1, SUL1 associated with NUL1, and NUL2, as an example. As shown in Table 1-6, for the above three second uplink carriers, the values ​​of the first RNTI calculated using formula (12) and formula (13) are also continuous and non-overlapping. Furthermore, as shown in Table 1-6, since SUL associated with NUL2 is not actually configured, the range of RA-RNTI corresponding to its associated SUL will not be reserved, and the value of MSGB-RNTI of NUL2 will follow.

[0392] Table 1-6 provides another example of the value range for the first RNTI.

[0393]

[0394] The above implementation presents another method for calculating RA-RNTI under 4-step random access and MSGB-RNTI under 2-step random access. This calculation method is partially compatible with existing protocols and can improve the applicability of the random access method provided in this application to a certain extent.

[0395] Optionally, when the first RNTI is determined based on the index of the first OFDM symbol of the first transmission resource, the index of the first time slot of the first transmission resource, the frequency domain index of the first transmission resource, and the first carrier identifier of the first uplink carrier, the identifier used to mark a certain NUL among the N1 second uplink carriers is not the same as the identifier used to mark the SUL associated with this NUL. That is, when the first uplink carrier is an NUL, the value of the first carrier identifier corresponding to the first uplink carrier is different from that when the first uplink carrier is an SUL associated with the NUL.

[0396] This can also be understood as follows: the first NUL associated with the first uplink carrier corresponds to the third carrier identifier, and the third carrier identifier is different from the first carrier identifier. Or, the first SUL associated with the first uplink carrier corresponds to the fourth carrier identifier, and the fourth carrier identifier is different from the first carrier identifier. Or, in other words, when the first uplink carrier is the first NUL, and the first NUL and the first SUL are associated, or when the first NUL and the first SUL belong to the same cell, the first NUL corresponds to the first carrier identifier, and the first SUL corresponds to the fourth carrier identifier. When the first uplink carrier is the first SUL, and the first NUL and the first SUL are associated, or when the first NUL and the first SUL belong to the same cell, the first NUL corresponds to the third carrier identifier, and the first SUL corresponds to the first carrier identifier. It can be understood that when the first response message is scrambled based on the first RNTI, when the network device calculates the first RNTI using any one of the above formulas (10) to (13), it needs to consider whether the first uplink carrier is NUL or SUL, and needs to distinguish between NUL and SUL using different indices. It should be understood that, in conjunction with the above examples, when the first uplink carrier is the first NUL and the first SUL corresponds to the fourth carrier identifier, the fourth carrier identifier can be considered as the first carrier identifier and substituted into the formula when calculating the RNTI of the first SUL using any one of formulas (10) to (13). Similarly, when the first uplink carrier is the first SUL and the first NUL corresponds to the third carrier identifier, the third carrier identifier can be considered as the first carrier identifier and substituted into the formula when calculating the RNTI of the first SNL using any one of formulas (10) to (13). In other words, the third carrier identifier and the fourth carrier identifier have the same uses in any one of formulas (10) to (13) as the first carrier identifier (i.e., they can both be used as the parameter c_id1).

[0397] Optionally, when the first RNTI is determined based on the index of the first OFDM symbol of the first transmission resource, the index of the first time slot of the first transmission resource, the frequency domain index of the first transmission resource, and the first carrier identifier of the first uplink carrier, the first carrier identifier is the uplink carrier index of the first uplink carrier among the N1 second uplink carriers. Alternatively, when the first RNTI is calculated based on any one of the above formulas (10) to (13), the first carrier identifier can be the uplink carrier index. Optionally, the uplink carrier index can be understood as a number in the uplink carrier dimension, used to indicate which uplink carrier it is. That is, the first carrier identifier can be used to indicate which uplink carrier the first uplink carrier is among the multiple second uplink carriers containing N1 second uplink carriers. Alternatively, the first carrier identifier can also be used to indicate which uplink carrier the first uplink carrier is among the N1 second uplink carriers.

[0398] For example, assume that the N1 second uplink carriers include five second uplink carriers: NUL1, SUL1 associated with NUL1, NUL2, SUL2 associated with NUL2, and NUL3. The uplink carrier index of NUL1 is 0, the uplink carrier index of NUL2 is 1, the uplink carrier index of SUL1 is 2, the uplink carrier index of SUL1 is 3, and the uplink carrier index of SUL2 is 4. When the first uplink carrier is NUL1, the first carrier identifier is 0; when the first uplink carrier is SUL1, the first carrier identifier is 1, and so on.

[0399] It should be noted that when calculating the first RNTI based on any one of the above formulas (1) to (13), if the communication system specifies the allowable range of the first RNTI, the calculated value of the first RNTI may exceed the allowable range. In view of this, this application also provides several solutions.

[0400] One possible approach is that when the network device determines that the calculated value of the first RNTI exceeds the allowed range, it can map this value to an unused RNTI value. For example, if a SUL associated with an uplink carrier is not configured, the RA-RNTI value of that associated SUL may be unused. When the RNTI value corresponding to another uplink carrier exceeds the allowed range, it can be replaced by a value from the unused RA-RNTI range. This avoids the problem of the first RNTI value being unusable due to it exceeding the allowed range.

[0401] The second possible method is that after the network device calculates the value of the first RNTI using the above formulas, it can further calculate the modulus of this first RNTI and use the calculated modulus to scramble the first response message. Using the modulus method can also avoid the problem of the first RNTI value being unusable due to it exceeding the allowed range.

[0402] It should be understood that the descriptions of the various formulas involved in this application (such as one or more of formulas (1) to (14) above) are merely exemplary. In actual implementation, these formulas may have one or more variations, such as merging some terms in the formula, or splitting one term in the formula into more terms. It should be noted that the possible variations of these formulas should also fall within the protection scope of this application.

[0403] It should also be noted that in the first implementation of the first response message, the first TC-RNTI indicated by the first RAR is associated with the first request message. In other words, the first TC-RNTI is the TC-RNTI configured by the network device for a terminal device that sends a first request message with a first random access preamble on the first uplink carrier. It is understood that in the method provided in this application, if two terminal devices both send random access request messages to the network device with the same or different random access preambles on a certain uplink carrier, the network device will configure the same TC-RNTI for these two terminal devices. If two terminal devices send random access request messages to the network device with the same or different random access preambles on different uplink carriers, the network device will configure different TC-RNTIs for these two terminal devices. For example, suppose that the N6 terminal devices also include a third terminal device. If the third terminal device also initiates random access to the network device on the first uplink carrier, the network device will also configure the aforementioned first TC-RNTI for the third terminal device. If the third terminal device initiates random access to the network device on a second uplink carrier other than the first uplink carrier, the TC-RNTI configured by the network device for the third terminal device is different from the first TC-RNTI mentioned above.

[0404] Method 2 for implementing the first response message:

[0405] This implementation can be understood as indicating that the first response message is a response message to the first request message by adding a first carrier identifier to the first response message. Alternatively, it can be described as identifying the first uplink carrier on which the first request message corresponding to the first response message resides by adding a first carrier identifier to the first response message.

[0406] In practice, the network device can determine the first transmission resource based on the first request message. Then, the network device can obtain the first carrier identifier corresponding to the first uplink carrier and determine a first response message including the first preamble identifier of the first random access preamble, the first RAR, and the first carrier identifier. The first carrier identifier can be used to indicate that the first response message is a response message to the first request message sent on the first uplink carrier. Alternatively, the first carrier identifier can be used to indicate that the first response message is a random access response message corresponding to a random access request message sent on the first uplink carrier. Or, the first carrier identifier can be used to indicate that the first response message is used to respond to a random access request message sent on the first uplink carrier.

[0407] In the above implementation, the response messages corresponding to request messages sent on different uplink carriers are distinguished by carrier identifiers, which enables the terminal device to quickly identify and receive its own response message, thereby reducing the latency caused by the terminal device receiving the response message.

[0408] It should be noted that, in this implementation, the first response message can be scrambled using a second RNTI. This second RNTI can be a RA-RNTI or MSGB-RNTI calculated based on an existing random access scheme, or it can be a RA-RNTI or MSGB-RNTI calculated based on the method provided in the first implementation of the first response message described above. This application does not impose any specific restrictions on this.

[0409] In some feasible implementations, the first carrier identifier may be included in the first RAR.

[0410] Optionally, the first carrier identifier may be included in the uplink grant information in the first RAR, or the first carrier identifier may be included in the timing advance command in the first RAR.

[0411] For example, the first carrier identifier may be included in the transmit power control command field, frequency domain resource allocation field, or modulation and coding scheme field in the uplink grant information.

[0412] Here, using existing fields in the first RAR to carry the first carrier identifier can ensure the compatibility of the random access method provided in this application with existing random access methods, thereby making the random access method provided in this application more applicable.

[0413] Optionally, the first RAR may have a new first field, in which the aforementioned first carrier identifier is included.

[0414] Here, the addition of a first field in the first RAR to carry the first carrier identifier can reduce the parsing complexity of the improved first RAR, thereby improving the efficiency of the random access method provided in this application.

[0415] The following section will explain the specific implementation of the first carrier identifier in the first RAR, based on scenarios 1 and 2 described above.

[0416] In scenario 1, the first RAR can be the first MAC-RAR. Optionally, the first carrier identifier can be included in the uplink grant information in the first MAC-RAR, or the first carrier identifier can be included in the timing advance command in the first MAC-RAR.

[0417] Optionally, the first MAC-RAR can also have a new first field, in which the aforementioned first carrier identifier is included.

[0418] In scenario 2, the aforementioned first RAR can be either a first successful RAR or a first fallback RAR. In this case, the first carrier identifier can be included in the first successful RAR. For example, the first carrier identifier can be included in the timing advance command in the first successful RAR. Alternatively, the first carrier identifier can be included in the first fallback RAR. For example, it can be included in the uplink grant information in the first fallback RAR, or in the timing advance command in the first fallback RAR.

[0419] It should be understood that this is only an example, and in actual implementation, the first carrier identifier may also be included in other locations in the first successful RAR. This application does not impose any specific restrictions.

[0420] It should be understood that the above is only an example. In actual implementation, the first carrier identifier may also be included in other positions or fields within the first response message. This application does not impose specific restrictions.

[0421] Optionally, if the first carrier identifier is included in the first response, the carrier identifiers of the NUL and SUL associated with the N1 second uplink carriers can be the same. This can also be understood as follows: when the first uplink carrier is a first NUL or a first SUL, if the first NUL and the first SUL are associated, or if the first NUL and the first SUL belong to the same cell, then both the first NUL and the first SUL correspond to the first carrier identifier. Alternatively, it can be said that the first uplink carrier and its associated first NUL both correspond to the first carrier identifier, or that the first SUL associated with the first uplink carrier and the first uplink carrier both correspond to the first carrier identifier. Furthermore, it can be said that when the first uplink carrier is a NUL, the first uplink carrier and its associated SUL both correspond to the first carrier identifier, or that the first carrier identifiers corresponding to the first uplink carrier and its associated SUL are the same. When the first uplink carrier is a SUL, the first uplink carrier and its associated NUL both correspond to the first carrier identifier, or that the first carrier identifiers corresponding to the first uplink carrier and its associated NUL are the same.

[0422] For example, the first carrier identifier can be either a NUL index or a SUL index. Alternatively, if the first uplink carrier is NUL, then the first carrier identifier can be the NUL index of the first uplink carrier among the N1 second uplink carriers. If the first uplink carrier is SUL, then the first carrier identifier can be the SUL index of the first uplink carrier among the N1 second uplink carriers.

[0423] Alternatively, if the first response message also includes a first carrier identifier, the identifier used to mark a certain NUL among the N1 second uplink carriers is not the same as the identifier used to mark the SUL associated with that NUL. That is, when the first uplink carrier is an NUL, the value of the first carrier identifier corresponding to the first uplink carrier is different from when the first uplink carrier is an SUL associated with that NUL.

[0424] For example, the first carrier identifier can also be the uplink carrier index of the first uplink carrier among N1 second uplink carriers. The descriptions of the NUL index, SUL index, and uplink carrier index can be found above and will not be repeated here.

[0425] In simple terms, if the first response also includes a first carrier identifier, the first uplink carrier can be distinguished as NUL or SUL by the first carrier identifier, or it can be distinguished as NUL or SUL without the first carrier identifier. This application does not impose any restrictions on this.

[0426] It should also be noted that, similar to the first implementation of the first response message, in the second implementation of the first response message, the first TC-RNTI indicated by the first RAR is associated with the first request message. In other words, the first TC-RNTI is the TC-RNTI configured by the network device for the terminal device that sends the first request message on the first uplink carrier with the first random access preamble.

[0427] Method 3 for implementing the first response message:

[0428] This implementation can be understood as using the second transmission resources used by the first response message to indicate that the first response message is a response message corresponding to the first request message. Alternatively, it can be understood as using the second transmission resources used by the first response message to identify the first uplink carrier where the first request message corresponding to the first response message resides.

[0429] In practice, after receiving the first request message, the network device can determine the corresponding first response message. The second transmission resource used to transmit this first response message is associated with the first uplink carrier.

[0430] In some possible implementations, the second transmission resource may include: the first time-domain resource where the first PDCCH corresponding to the first response message is located, the first frequency-domain resource where the first PDCCH corresponding to the first response message is located, or the first time-frequency resource where the first PDCCH corresponding to the first response message is located. Alternatively, the second transmission resource is the first time-domain resource, the first frequency-domain resource, or the first time-frequency resource for the first terminal device to perform blind detection (i.e., PDCCH monitoring) of the first PDCCH. Or, the second transmission resource is the first time-domain resource, the first frequency-domain resource, or the first time-frequency resource for the first terminal device to monitor the first PDCCH corresponding to the first response message.

[0431] It should be understood that the first PDCC can be used to schedule the first PDSCH, and the first PDSCH can be used to send a first response message to a first request message sent on the first uplink carrier. Therefore, it can also be understood that the first time-domain resource where the first PDCCH corresponding to the first response message resides is associated with the first uplink carrier. Alternatively, the first frequency-domain resource where the first PDCCH corresponding to the first response message resides is associated with the first uplink carrier. Or, the first time-frequency resource where the first PDCCH corresponding to the first response message resides is associated with the first uplink carrier. Or, the first time-domain resource where the first PDCCH corresponding to the first response message resides is associated with the first request message sent on the first uplink carrier. Or, the first frequency-domain resource where the first PDCCH corresponding to the first response message resides is associated with the first request message sent on the first uplink carrier. Or, the first time-frequency resource where the first PDCCH corresponding to the first response message resides is associated with the first request message sent on the first uplink carrier.

[0432] It should be understood that the preceding explanation uses the first uplink carrier as an example. In actual implementation, each of the aforementioned N1 second uplink carriers has associated transmission resources for the PDCCH corresponding to the blind detection response message, and these resources are all different. For example, for the aforementioned first uplink carrier and any second uplink carrier i other than the first uplink carrier, when the first uplink carrier is associated with the first time domain resource where the first PDCCH corresponding to the first response message is located, the second uplink carrier i can be associated with the second time domain resource where the third PDCCH is located. Here, the second time domain resource where the third PDCCH is located is used for PDCCH monitoring of the response message corresponding to the random access initiated on the second uplink carrier i. In the embodiments of this application, the expressions "monitoring" and "blind detection" are equivalent. Similarly, when the first uplink carrier is associated with the first frequency domain resource where the first PDCCH corresponding to the first response message is located, the second uplink carrier i can be associated with the second frequency domain resource where the third PDCCH is located. Here, the second frequency domain resources where the third PDCCH resides are used for PDCCH monitoring of the response message corresponding to random access initiated on the second uplink carrier i. When the first uplink carrier is associated with the first time-frequency resource where the first PDCCH corresponding to the first response message resides, the second uplink carrier i can be associated with the second time-frequency resource where the third PDCCH resides. Here, the second time-frequency resource where the third PDCCH resides is used for PDCCH monitoring of the response message corresponding to random access initiated on the second uplink carrier i.

[0433] In the above implementation, the time-domain resource, frequency-domain resource, or time-frequency resource where the PDCCH corresponding to the random access response message is located is associated with the uplink carrier. This allows the terminal device to perform blind PDCCH detection on the corresponding time-domain resource, frequency-domain resource, or time-frequency resource based on the uplink carrier from which it sent its request message, thereby quickly identifying and receiving its own response message. This implementation method can also reduce the latency caused by the terminal device receiving the response message.

[0434] In some feasible implementations, when using implementation method three with the first response message, the network device sends first configuration information to the terminal device. This first configuration information can be used to determine or indicate the association of the aforementioned N1 second uplink carriers with N4 third transmission resources. It should be understood that the aforementioned second transmission resources are one of these N4 third transmission resources. Each of these N4 third transmission resources is used for blind detection of the PDCCH of the response message corresponding to a random access initiated on a second uplink carrier.

[0435] Since the functions of each of the N4 third transmission resources are similar, the following example uses any one of the N1 second uplink carriers, i, and its corresponding third transmission resource j1 among the N4 third transmission resources. In actual implementation, third transmission resource j1 is used to monitor the second PDCCH corresponding to the target response message. This target response message is used to respond to the target request message, which is used to send a random access preamble on the second uplink carrier i. Here, N4 is a positive integer less than or equal to N1. Taking the N5 terminal devices mentioned above as an example, when these N5 terminal devices simultaneously initiate random access to the network device through the N1 second uplink carriers, each terminal device can use the third transmission resource associated with its uplink carrier to blindly detect the PDCCH used to transmit the response message corresponding to its sent random access preamble, so as to further complete the reception of the response message corresponding to its sent random access preamble.

[0436] Accordingly, the terminal device can receive the aforementioned first configuration information and determine the association of the N1 second uplink carriers with the N4 third transmission resources based on the first configuration information. It should be noted that, since the RNTI used in the scrambling first response message is inherently different when the first uplink carrier is NUL or SUL, the associated third transmission resources for the N1 second uplink carriers can be the same or different; this application does not impose specific restrictions on this.

[0437] In one possible implementation, the third transmission resource j1 may include: the time-domain resource where the second PDCCH is located, the frequency-domain resource where the second PDCCH is located, or the time-frequency resource where the second PDCCH is located. Alternatively, the time-domain resource, the frequency-domain resource, or the time-frequency resource where the second PDCCH is located may be associated with the second uplink carrier i. It can also be understood that the time-domain resource, the frequency-domain resource, or the time-frequency resource where the second PDCCH is located are associated with the target request message transmitted on the second uplink carrier i.

[0438] It should be understood that when the third transmission resource j1 is the time-domain resource where the second PDCCH resides, it indicates that for one or more terminal devices initiating random access to the network device on any one of the N1 second uplink carriers i, the time-domain resources for blindly detecting the second PDCCH of these one or more terminal devices are the same and associated with the second uplink carrier i, or associated with the target request message sent on the second uplink carrier i. In this case, the time-domain resources included in the different third transmission resources among the N4 third transmission resources are different.

[0439] When the third transmission resource j1 is the frequency domain resource where the second PDCCH resides, it indicates that for one or more terminal devices initiating random access to the network device on any one of the N1 second uplink carriers i, the frequency domain resources for blind detection of the second PDCCH by these one or more terminal devices are the same and associated with the second uplink carrier i, or associated with the target request message sent on the second uplink carrier i. In this case, the frequency domain resources included in the different third transmission resources among the N4 third transmission resources are different.

[0440] When the third transmission resource j1 is the time-frequency resource where the second PDCCH resides, it indicates that for one or more terminal devices initiating random access to the network device on any one of the N1 second uplink carriers i, the time-frequency resources for blindly detecting the second PDCCH of these one or more terminal devices are the same and associated with the second uplink carrier i, or associated with the target request message sent on the second uplink carrier i. In this case, the time-frequency resources included in the different third transmission resources among the N4 third transmission resources are different.

[0441] In one possible implementation, each of the N4 third transmission resources can be determined based on the control resource set and search space set corresponding to each third transmission resource. When the third transmission resource j1 includes the time-domain resource where the second PDCCH resides, the search space sets corresponding to these N4 third transmission resources are different.

[0442] When the third transmission resource j1 includes the frequency domain resources where the second PDCCH is located, the control resource sets corresponding to these N4 third transmission resources are different.

[0443] When the third transmission resource j1 includes the time-frequency resource where the second PDCCH is located, the search space sets corresponding to these N4 third transmission resources are different and / or the corresponding control resource sets are different. Alternatively, when the third transmission resource j1 includes the time-frequency resource where the second PDCCH is located, the search space sets corresponding to the aforementioned N4 third transmission resources are different, and the corresponding control resource sets are different. Or, the search space sets corresponding to the N4 third transmission resources are different, and the corresponding control resource sets are the same. Or, the search space sets corresponding to the N4 third transmission resources are the same, and the corresponding control resource sets are different. In this case, it can be understood that when the third transmission resource j1 includes the time-frequency resource where the second PDCCH is located, the time-frequency resources determined by the search space sets and control resource sets corresponding to each of the third transmission resources are different. It can also be understood that at least one of the search space sets and control resource sets corresponding to each of the N4 third transmission resources is different, or that the search space sets and / or control resource sets corresponding to each of the N4 third transmission resources are different.

[0444] In the above implementation, each third transmission resource is distinguished by the control resource set and / or search space set corresponding to each third transmission resource, thereby corresponding to different uplink carriers for sending request messages, or target request messages on uplink carriers used to send request messages. This method is simple and easy to implement, and can reduce the complexity of the random access method provided in this application.

[0445] In one possible implementation, where the third transmission resource associated with each of the aforementioned N1 second uplink carriers is the time-domain resource where the second PDCCH resides, the network device can configure N4 different search space sets for these N1 second uplink carriers to determine the N4 third transmission resources associated with them. Optionally, the network device can configure the same control resource set for these N1 second uplink carriers. This can also be understood as the network device configuring a search space set associated with each second uplink carrier and uniformly configuring a single control resource set for all N1 second uplink carriers. Then, the search space set associated with each second uplink carrier and this unified control resource set can be used to determine the third transmission resource associated with each second uplink carrier.

[0446] For example, assume that the N1 second uplink carriers include uplink carrier 1, uplink carrier 2, uplink carrier 3, and uplink carrier 4. Also assume that the associated NUL and SUL have different third transport resources, i.e., there are also four third transport resources: third transport resource 1, third transport resource 2, third transport resource 3, and third transport resource 4. See [link to relevant documentation]. Figure 3 , Figure 3 This is a schematic diagram illustrating the allocation of a search space set and a control resource set, as provided in this application. For example... Figure 3 As shown, in practical implementation, network devices can configure associated search space sets 1, 2, 3, and 4 for uplink carriers 1, 2, 3, and 4 respectively, and configure control resource set 1 for these four uplink carriers. Specifically, search space set 1 and control resource set 1 are used to determine the third transmission resource 1; search space set 2 and control resource set 1 are used to determine the third transmission resource 2; search space set 3 and control resource set 1 are used to determine the third transmission resource 3; and search space set 4 and control resource set 1 are used to determine the third transmission resource 4. This allows the third transmission resources 1, 2, 3, and 4 to be associated with uplink carriers 1, 2, 3, and 4 respectively. If we assume that the associated NUL and SUL are associated with the same third transport resource, then uplink carrier 1 (NUL), uplink carrier 2 (SUL), uplink carrier 3 and uplink carrier 4 are associated with three third transport resources, where uplink carrier 1 and uplink carrier 2 correspond to the same third transport resource.

[0447] In one possible implementation, where the third transmission resource associated with each of the N1 second uplink carriers is a frequency domain resource where the second PDCCH resides, the network device can configure N4 different control space sets for these N1 second uplink carriers to determine the N4 third transmission resources associated with them. It should be understood that the network device can configure the same search space set for these N1 second uplink carriers. Alternatively, the network device can configure a control resource set associated with each second uplink carrier and a unified search space set for all N1 second uplink carriers. Then, the control resource set associated with each second uplink carrier and this unified search space set can be used to determine the third transmission resource associated with each second uplink carrier.

[0448] For example, assume that the N1 second uplink carriers include uplink carrier 1, uplink carrier 2, uplink carrier 3, and uplink carrier 4. Also assume that the associated NUL and SUL have different third transport resources, i.e., there are also four third transport resources: third transport resource 1, third transport resource 2, third transport resource 3, and third transport resource 4. See [link to relevant documentation]. Figure 4 , Figure 4 This is another schematic diagram illustrating the allocation of the search space set and control resource set provided in this application. For example... Figure 4As shown, in practical implementation, network devices can configure associated control resource sets 1, 2, 3, and 4 for uplink carriers 1, 2, 3, and 4 respectively, and configure search space set 1 for these four uplink carriers. Search space set 1 and control resource set 1 are used to determine the third transmission resource 1; search space set 1 and control resource set 2 are used to determine the third transmission resource 2; search space set 1 and control resource set 3 are used to determine the third transmission resource 3; and search space set 1 and control resource set 4 are used to determine the third transmission resource 4. This allows the third transmission resources 1, 2, 3, and 4 to be associated with uplink carriers 1, 2, 3, and 4 respectively. If we assume that the associated NUL and SUL are associated with the same third transmission resource, uplink carrier 1 (NUL), uplink carrier 2 (SUL), uplink carrier 3, and uplink carrier 4 are associated with three third transmission resources, where uplink carrier 1 and uplink carrier 2 correspond to the same third transmission resource.

[0449] In one possible implementation, where the third transmission resource associated with each of the aforementioned N1 second uplink carriers is the time-frequency resource where the second PDCCH resides, the network device can configure N7 different control resource sets and N8 different search space sets for these N1 second uplink carriers. These 7 different control resource sets and N8 different search space sets are combined to determine N4 third transmission resources associated with these N1 second uplink carriers. It should be understood that the product of N7 and N8 is N4. Alternatively, it can be understood that the network device can configure one control resource set and one search space set associated with each second uplink carrier. Some second uplink carriers may have the same control resource set, and some may have the same search space set. Then, the control resource set and search space set associated with each second uplink carrier can be used to determine the third transmission resource associated with each second uplink carrier.

[0450] For example, assume that the N1 second uplink carriers include uplink carrier 1, uplink carrier 2, uplink carrier 3, and uplink carrier 4. Also assume that the associated NUL and SUL have different third transport resources, i.e., there are also four third transport resources: third transport resource 1, third transport resource 2, third transport resource 3, and third transport resource 4. See [link to relevant documentation]. Figure 5 , Figure 5 This is another schematic diagram illustrating the allocation of the search space set and control resource set provided in this application. For example... Figure 5As shown, in practical implementation, network devices can configure control resource set 1, control resource set 2, search space set 1, and search space set 2 for uplink carrier 1, uplink carrier 2, uplink carrier 3, and uplink carrier 4. Uplink carrier 1 is associated with control resource set 1 and search space set 1, which can be used to determine the third transmission resource 1 associated with uplink carrier 1. Uplink carrier 2 is associated with control resource set 1 and search space set 2, which can be used to determine the third transmission resource 2 associated with uplink carrier 2. Uplink carrier 3 is associated with control resource set 2 and search space set 1, which can be used to determine the third transmission resource 3 associated with uplink carrier 3. Uplink carrier 4 is associated with control resource set 2 and search space set 2, which can be used to determine the third transmission resource 4 associated with uplink carrier 1. This allows third transmission resources 1, 2, 3, and 4 to be associated with uplink carriers 1, 2, 3, and 4, respectively. If we assume that the associated NUL and SUL are associated with the same third transmission resource, then uplink carrier 1 (NUL), uplink carrier 2 (SUL), uplink carrier 3, and uplink carrier 4 are associated with three third transmission resources, where uplink carrier 1 and uplink carrier 2 correspond to the same third transmission resource.

[0451] It should be understood that, in the embodiments of this application, the search space set and / or control resource set configured for each second uplink carrier and associated therewith can be used to determine the third transmission resource associated with each second uplink carrier.

[0452] It should be noted that when configuring associated search space sets and control resource sets for each second uplink carrier simultaneously, the association with the second uplink carrier can be distinguished first from the time domain dimension, and then from the frequency domain dimension. For example... Figure 5 As shown, the association with different second uplink carriers is first distinguished in the time domain dimension of the search space set. For example, uplink carrier 1 is associated with search space set 1, and uplink carrier 2 is associated with search space set 2. However, both uplink carrier 1 and uplink carrier 2 are associated with control resource set 1. Then, the association with the second uplink carrier is distinguished in the frequency domain dimension. For example, uplink carrier 3 is associated with control resource set 2. It is associated with the same search space as uplink carrier 1, but with a different control resource set.

[0453] Of course, one can first distinguish the correlation with the second uplink carrier from the frequency domain dimension, and then distinguish the correlation with the second uplink carrier from the time domain dimension. Please see [link / reference]. Figure 6 , Figure 6 This is another schematic diagram illustrating the allocation of the search space set and control resource set provided in this application. For example... Figure 6As shown, the association with different second uplink carriers is first distinguished in the time domain dimension of the control resource set. For example, uplink carrier 1 is associated with control resource set 1, and uplink carrier 2 is associated with control resource set 2. However, both uplink carrier 1 and uplink carrier 2 are associated with search space set 1. Then, the association with the second uplink carrier is distinguished again in the time domain dimension. For example, uplink carrier 3 is associated with search space set 2, which is associated with the same control resource set as uplink carrier 1, but with a different search space set.

[0454] In one possible implementation, when the third transmission resource j1 includes the time-domain resource where the second PDCCH is located, the search space sets corresponding to these N4 third transmission resources are different subsets of the same search space set. When the third transmission resource j1 includes the frequency-domain resource where the second PDCCH is located, the control resource sets corresponding to these N4 third transmission resources are different subsets of the same control resource set. When the third transmission resource j1 includes the time-frequency resource where the second PDCCH is located, the search space sets corresponding to these N4 third transmission resources are different subsets of the same search space set, and / or, the control resource sets corresponding to these N4 third transmission resources are different subsets of the same control resource set. That is, when the third transmission resource j1 includes the time-domain resource where the second PDCCH is located, the N4 search space sets corresponding to these N4 third transmission resources can be obtained by partitioning a large search space. When the third transmission resource j1 includes the frequency-domain resource where the second PDCCH is located, the N4 control resource sets corresponding to these N4 third transmission resources can be obtained by partitioning a large control resource set. When the third transmission resource j1 includes the time-frequency resource where the second PDCCH is located, the N7 different control resource sets corresponding to these N4 third transmission resources can be obtained by partitioning a large control resource set, and / or, the N8 search space sets corresponding to these N4 third transmission resources can be obtained by partitioning a large search space set.

[0455] In the above implementation, the above N4 different third transmission resources are determined by partitioning the same control resource set and / or the same search space set into subsets, thereby corresponding to different uplink carriers for sending request messages, or target request messages on uplink carriers used to send request messages, which can ensure the resource utilization efficiency of the control resource set and / or search space set.

[0456] The above combination Figures 3 to 6All the described schemes are illustrated using the example of independent search space sets. In another possible implementation, since the search space set is a periodic resource, it can be used as a different search space set in different periods. That is, a search space set is divided into multiple search space subsets according to different periods, and each search space subset is associated with a different uplink carrier. For example, for a certain search space set, it can be associated with different uplink carriers in odd-numbered periods and even-numbered periods. Or, its odd-numbered periods are a first search space subset, and its even-numbered periods are a second search space set, with the first and second search space subsets corresponding to different uplink carriers.

[0457] Please see Figure 7 , Figure 7 This is another schematic diagram illustrating the allocation of the search space set and control resource set provided in this application. For example... Figure 7 As shown, the network device configures odd-numbered periods of control resource set 1 and search space set 1 for uplink carrier 1. The odd-numbered periods of search space set 1 serve as a subset of the search space, used to determine the third transmission resource 1 associated with uplink carrier 1 in conjunction with control resource set 1. Alternatively, it can be understood that uplink carrier 1 is associated with control resource set 1 and the odd-numbered periods of search space set 1. The network device configures even-numbered periods of control resource set 1 and search space set 1 for uplink carrier 2. The even-numbered periods of search space set 1 serve as another subset of the search space, used to determine the third transmission resource 2 associated with uplink carrier 2 in conjunction with control resource set 1. Alternatively, it can be understood that uplink carrier 2 is associated with control resource set 1 and the even-numbered periods of search space set 1. Similarly, the network device configures odd-numbered periods of control resource set 2 and search space set 1 for uplink carrier 3. The odd-numbered periods of search space set 1 serve as a subset of the search space, used to determine the third transmission resource 3 associated with uplink carrier 3 in conjunction with control resource set 2. This can also be understood as uplink carrier 3 being associated with the odd-numbered periods of control resource set 2 and search space set 1. The network device configures uplink carrier 4 with the even-numbered periods of control resource set 2 and search space set 1. The even-numbered periods of search space set 1 serve as another subset of the search space, used to determine the third transmission resource 4 associated with uplink carrier 4 in conjunction with control resource set 2. Alternatively, this can be understood as uplink carrier 4 being associated with the even-numbered periods of control resource set 2 and search space set 1.

[0458] It should also be noted that the search space set and / or control resource set associated with each of the N1 second uplink carriers mentioned above can be configured by the network device for the terminal device, or it can be predefined by the protocol. This application does not impose any specific restrictions on this.

[0459] Optionally, when the third transmission resource j1 includes the time-domain resource where the second PDCCH is located, the association between different uplink carriers and the corresponding time-domain resource where the second PDCCH is located is determined according to the network configuration. For example, the time-domain resource is a search space set. Optionally, when the third transmission resource j1 includes the frequency-domain resource where the second PDCCH is located, the association between different uplink carriers and the corresponding frequency-domain resource where the second PDCCH is located is determined according to the network configuration. For example, the frequency-domain resource is a control resource set. Optionally, when the third transmission resource j1 includes the time-frequency resource where the second PDCCH is located, the association between different uplink carriers and the corresponding time-frequency resource where the second PDCCH is located is determined according to the network configuration. For example, the time-frequency resource is a set of time-frequency resources for second PDCCH monitoring determined based on the search space set and the control resource set.

[0460] For example, based on different time-frequency resources, the configuration can be as follows: Uplink carrier 1 corresponds to control resource set 1 and search space set 1. Uplink carrier 2 corresponds to control resource set 2 and search space set 1. Uplink carrier 3 corresponds to control resource set 1 and search space set 2. Uplink carrier 4 corresponds to control resource set 2 and search space set 2. For example, based on different frequency domain resources, the configuration can be as follows: Uplink carrier 1 corresponds to control resource set 1 and search space set 1. Uplink carrier 2 corresponds to control resource set 2 and search space set 1. Uplink carrier 3 corresponds to control resource set 3 and search space set 1. Uplink carrier 4 corresponds to control resource set 4 and search space set 1. For example, based on different time domain resources, the configuration can be as follows: Uplink carrier 1 corresponds to control resource set 1 and search space set 1. Uplink carrier 2 corresponds to control resource set 1 and search space set 2. Uplink carrier 3 corresponds to control resource set 1 and search space set 3. Uplink carrier 4 corresponds to control resource set 1 and search space set 4.

[0461] In some feasible implementations, the N1 second uplink carriers provided in this application may belong to a first uplink carrier set (also referred to as a first uplink carrier group). Optionally, multiple uplink carriers in the first uplink carrier set belong to the same frequency band, and / or, the aforementioned N1 second uplink carriers belong to the same timing advance group.

[0462] Furthermore, the first carrier identifier is the index of the first uplink carrier within the first uplink carrier set. It can be understood that this first uplink carrier set can consist of multiple second uplink carriers, including N1 second uplink carriers as described above, or it can consist solely of the aforementioned N1 second uplink carriers.

[0463] Furthermore, the network device can be configured with multiple uplink carrier sets. Optionally, different uplink carrier sets are associated with different downlink carriers. Optionally, random access initiated on any uplink carrier in an uplink carrier set will have its corresponding access response received on the associated downlink carrier. It is understood that these multiple uplink carrier sets can reuse the same carrier identifier. That is, two different uplink carriers in two different uplink carrier sets can be associated with the same RNTI. This is because the random access processes implemented based on different uplink carrier sets are independent of each other. Therefore, there is no competition between terminal devices initiating random access on uplink carriers in different uplink carrier sets. Even if different uplink carriers belonging to different uplink carrier sets correspond to the same carrier identifier or are associated with the same RNTI, it will not affect their random access processes. For example, if the network device is configured with a second uplink carrier set in addition to the first uplink carrier set mentioned above, then different uplink carriers in the first and second uplink carrier sets can correspond to the same carrier identifier.

[0464] S230, the network device sends a first response message to the first terminal device. Correspondingly, the first terminal device receives the first response message.

[0465] In some feasible implementations, the aforementioned N1 second uplink carriers are associated with the first downlink carrier. Optionally, the network device can send a first response message via the first downlink carrier. Correspondingly, the first terminal device can receive the first response message via the first downlink carrier.

[0466] In one possible implementation, when the first response message adopts the implementation method one described above, the first terminal device can calculate the first RNTI in the same way as the network device. Then, if the first terminal device detects the first response message based on the first RNTI, it can determine that the first response message is the response message corresponding to the first request message it sent. Then, the first terminal device can obtain the first preamble identifier and the first RAR of the first random access preamble based on the first response message.

[0467] In another possible implementation, when the first response message adopts the second implementation method described above, the first terminal device can calculate the second RNTI in the same way as the network device. Then, the first terminal device can detect the first response message based on the second RNTI. Further, if the first terminal device determines that the first response message also includes the first carrier identifier corresponding to the first uplink carrier, it can determine that the first response message is the response message corresponding to the first request message it sent. Then, the first terminal device can obtain the first preamble identifier and the first RAR of the first random access preamble based on the first response message.

[0468] In another possible implementation, when the first response message adopts the implementation method three described above, the first terminal device can calculate the second RNTI in the same way as the network device. Then, the first terminal device blindly detects the first PDCCH on the second transmission resource associated with the first uplink carrier. If the first terminal device detects the first PDCCH, it can receive the PDSCH carrying the first response message based on the scheduling information in the first PDCCH. Then, the first terminal device can descramble the first response message through the second RNTI and obtain the first preamble identifier and the first RAR of the first random access preamble based on the first response message.

[0469] For a detailed description of the implementation of the first RAR, please refer to the previous description of the contents of the first RAR based on scenario 1 and scenario 2, which will not be repeated here.

[0470] In the above implementation, by scrambling the RNTI of the first response message, the content contained in the first response message, or the second transmission resources used to transmit the first response message, an association can be established between the first response message and the first uplink carrier used to transmit the first request message. This not only enables the network device to distinguish between terminal devices initiating random access on different second uplink carriers and to feed back the first response message associated with the first uplink carrier to the first terminal device, but also enables the first terminal device to identify and correctly receive the first response message corresponding to its own first request message, thereby completing random access. In scenarios where multiple terminal devices initiate random access on N1 second uplink carriers, using the random access method provided in this application allows the network device to feed back a response message associated with each second uplink carrier and containing a RAR to one or more terminal devices corresponding to each second uplink carrier, and to allocate a temporary cell radio network temporary identifier (TC-RNTI) associated with each second uplink carrier to one or more terminal devices corresponding to each second uplink carrier. Correspondingly, each terminal device associated with a second uplink carrier can identify and correctly receive the response message associated with each second uplink carrier. In this way, there is no competition between terminal devices initiating random access on different second uplink carriers, so one terminal device on each second uplink carrier will have a chance to successfully access the network. Therefore, the random access method provided in this application has high random access efficiency and strong applicability. Furthermore, when multiple terminal devices initiate random access on multiple uplink carriers corresponding to the same downlink carrier, and the random access preamble and the relevant index of the physical random access channel resource determined by these multiple terminal devices are consistent, the random access method provided in this application can...

[0471] In some feasible implementations, such as Figure 2As shown, the method may further include the following steps:

[0472] S240, the first terminal device completes random access based on the first response message.

[0473] In one possible implementation, in scenario 1, the first terminal device can obtain the first TC-RNTI indicated by the first response message. Then, the first terminal device can send msg3 containing its first contention resolution identifier to the network device, and this msg3 is scrambled using the first TC-RNTI. Then, the first terminal device and the network device can transmit msg4 until the first terminal device determines that it has completed random access and obtained its corresponding first C-RNTI. Optionally, the value of the first C-RNTI obtained by the first terminal device can be the same as the first TC-RNTI.

[0474] In scenario 2, if the first terminal device determines that the first RAR contains its corresponding first contention resolution identifier, it can determine that random access has been completed. Then, the first terminal device can determine its corresponding first C-RNTI based on the first RAR.

[0475] Optionally, if the first RAR is a first successful RAR, the first successful RAR may directly include the aforementioned first C-RNTI. If the first RAR is a first fallback RAR, it can fall back to 4-step random access. In this case, the first fallback RAR will indicate the TC-RNTI used in 4-step random access (here still referred to as the first TC-RNTI). Then, the first terminal device can send msg3 scrambled based on the first TC-RNTI and receive the corresponding msg4. If the first terminal device determines that it has successfully contested based on the received msg4, it can determine the first C-RNTI based on the first TC-RNTI. Optionally, the first terminal device can determine the first C-RNTI based on the first TC-RNTI using the method provided in this application for determining the C-RNTI based on TC-RNTI, or it can use other possible methods, which are not limited here.

[0476] For some feasible implementation methods, please refer to Figure 8 , Figure 8 This is another flowchart illustrating a random access method provided in this application. For example... Figure 8 As shown, the method may further include the following steps:

[0477] S250, the network device determines that the first terminal device supports random access on N1 second uplink carriers, or determines that the first terminal device requests random access on N1 second uplink carriers.

[0478] In some feasible implementations, the network device may execute step S220 above when it determines that the first terminal device supports random access on N1 second uplink carriers, or when it determines that the first terminal device requests random access on N1 second uplink carriers. Alternatively, it can be understood that the network device and the first terminal device will only use the random access method provided in this application to perform random access when it is determined that the first terminal device supports random access on N1 second uplink carriers, or when it is determined that the first terminal device requests random access on N1 second uplink carriers, specifically employing steps S220 and S230 above.

[0479] In one feasible implementation, the network device may determine, based on the first transmission resource or the first random access preamble, that the first terminal device supports random access on N1 second uplink carriers or that the first terminal device requests random access on N1 second uplink carriers.

[0480] For example, a target transmission resource set is configured, which includes multiple transmission resources. This target transmission resource set is specifically used for the transmission of the random access preamble of a target terminal device, which is a terminal device that supports random access on N1 second uplink carriers. When a first terminal device determines that it supports initiating or requests random access on N1 second uplink carriers, it can determine the aforementioned first transmission resource from the target transmission resources. Correspondingly, when the network device determines that the first transmission resource is included in the target transmission resource set, it can determine that the first terminal device supports random access on N1 second uplink carriers, or that the first terminal device requests random access on N1 second uplink carriers.

[0481] For example, a target random access preamble set is configured. This target random access preamble set includes multiple random access preambles. This target random access preamble set is used for random access by a target terminal device, which is a terminal device that supports random access on N1 second uplink carriers. When a first terminal device determines that it supports initiating random access on N1 second uplink carriers or requests to initiate random access on N1 second uplink carriers, it can determine the aforementioned first random access preamble from the target random access preamble set. Correspondingly, when the network device determines that the first random access preamble is included in the target random access preamble set, it can determine that the first terminal device supports random access on N1 second uplink carriers, or that the first terminal device requests random access on N1 second uplink carriers.

[0482] In short, it involves configuring a specific set of transmission resources and a set of random access preambles. When a first terminal device supports the ability to initiate random access on N1 second uplink carriers, or requests to initiate random access on N1 second uplink carriers, it can use the transmission resources in this specific set of transmission resources and / or the random access preambles in this specific set of random access preambles to report its capabilities or requirements to the network device. Accordingly, the network device determines whether the first terminal device supports random access on N1 second uplink carriers, or requests random access on N1 second uplink carriers, based on the first transmission resources or the first random access preamble used by the first terminal device.

[0483] In the above implementation, the first terminal device can report its support for initiating random access on N1 second uplink carriers or request to initiate random access on N1 second uplink carriers by using the random access preamble or transmission resources used to initiate random access. This enables the network device to feed back the first response message in the manner provided in this application, thereby ensuring the reliable implementation of the random access method provided in this application.

[0484] For some feasible implementation methods, please refer to Figure 9 , Figure 9 This is another flowchart illustrating a random access method provided in this application. For example... Figure 9 As shown, the method may also include the following steps:

[0485] S260, the network device sends second configuration information and / or third configuration information to the first terminal device. Correspondingly, the first terminal device receives the second configuration information and / or third configuration information.

[0486] In some feasible uplink methods, the network device may send second configuration information to the first terminal device. This second configuration information can be used to indicate or determine the association of N1 second uplink carriers with the first downlink carrier. Optionally, the N1 second uplink carriers may be the uplink carrier set mentioned above. Correspondingly, the first terminal device may receive the second configuration information and determine the association of the N1 second uplink carriers with the first downlink carrier based on the second configuration information.

[0487] In some feasible implementations, the network device may also send third configuration information to the first terminal device. This third configuration information is used to indicate or determine the set of PRACH resources associated with each of the N1 second uplink carriers for sending request messages, and / or, the set of random access preambles.

[0488] Optionally, the PRACH resource sets associated with each of the N1 second uplink carriers mentioned above may be the same or different.

[0489] Optionally, the random access preamble set associated with each of the N1 second uplink carriers can be the same or different.

[0490] Optionally, the PRACH resource set used for sending request messages on each second uplink carrier may include one or more PRACH resources. When the PRACH resource set corresponding to a certain second uplink carrier includes multiple PRACH resources, if a terminal device initiates random access on that second uplink carrier, the PRACH resource for sending the request message can be determined from the multiple PRACH resources.

[0491] Optionally, the set of random access preambles used to send request messages on each second uplink carrier may include one or more random access preambles. When the set of random access preambles corresponding to a certain second uplink carrier includes multiple random access preambles, if a terminal device initiates random access on that second uplink carrier, the random access preamble used to send the request message can be determined from the multiple random access preambles.

[0492] In some feasible implementations, the second and / or third configuration information can be transmitted via RRC messages, for example, in the case of a non-initial CBRA. Alternatively, the second and / or third configuration information can be transmitted via system information block (SIB) messages, for example, in the case of an initial CBRA.

[0493] It should be further noted that in scenario 2 described above, if the first RAR included in the first response message is the first fallback RAR, then the first terminal device will switch to 4-non-random access. Specifically, after receiving the first response message, the first terminal device will send msg3 containing its first contention resolution identifier to the network device. Further, after receiving msg3, the network device will send msg4 containing its first contention resolution identifier to the first terminal device. Furthermore, upon receiving msg4 containing its first contention resolution identifier, the first terminal device can determine that it has completed random access and has converted the C-RNTI based on the TC-RNTI allocated by the network device.

[0494] It should also be noted that, when using the first response message one described above, or when using the first response message implementation method two described above, or when using the first response message implementation method three described above, one NUL involved in this application can be associated with one SUL, or can be associated with multiple SULs simultaneously. Furthermore, when the first uplink carrier is an NUL, if the N1 second uplink carriers also include multiple SULs associated with the first uplink carrier, then the identifiers of these multiple SULs in the N1 second uplink carriers are different. For example, assuming the first carrier identifier of the first uplink carrier is 0, then the identifiers of these multiple SULs in the N1 second uplink carriers can be 1, 2, 3, etc., respectively.

[0495] Furthermore, when calculating the first RNTI using any of the formulas (1) to (9) mentioned above, for N1 second uplink carriers, when a certain second uplink carrier is NUL and is associated with multiple SULs, the identifiers (for the first uplink carrier, this identifier is the second carrier identifier c_id2 mentioned above) corresponding to this second uplink carrier and its associated multiple SULs are not the same. Taking the first uplink carrier as an example, when the first uplink carrier is NUL, the value of its corresponding second carrier identifier c_id2 can be 0. When the first uplink carrier is NUL and associated with SUL1, SUL2 to SULx, the values ​​of the second carrier identifier c_id2 are 1, 2 to x, respectively. Here, x is a positive integer. Optionally, when a NUL is associated with multiple SULs (e.g., x), the product term of the parameters related to the number of uplink carriers (such as N1, N2, or N3) in the above formula can be changed from "×2" to "×(1+x)".

[0496] It should be understood that the preceding text primarily uses the interaction between a first terminal device that initiates random access on the first uplink carrier and successfully accesses the network device as an example to illustrate the various steps of the random access method provided in this application. In actual implementation, N5 terminal devices, including the first terminal device, can initiate random access to the network device on N1 second uplink carriers respectively. Since the interaction process between each terminal device and the network device is similar to the interaction process between the first terminal device and the network device described above, the preceding text does not describe in detail the operations performed by other terminal devices besides the first terminal device. However, it should be understood that, using the random access method provided in this application, even if the relevant indexes and random access preambles of the random access channel resources determined by the aforementioned N5 terminal devices are completely identical, there will be no competition between terminal devices initiating random access on different uplink carriers. Therefore, using the random access method provided in this application, each uplink carrier in which a terminal device initiates random access will have an opportunity to complete random access, effectively solving the problem of low access efficiency in existing random access methods.

[0497] Please see Figure 10 , Figure 10 This is another flowchart illustrating a random access method provided in this application. This method is also applicable to... Figure 1 The communication system shown can be implemented by the first terminal device and network devices working together.

[0498] It should be noted that this random access method is also applicable to situations where a terminal device determines one uplink carrier among N1 second uplink carriers and initiates random access to the network device on that uplink carrier. For example, suppose there are N5 terminal devices initiating random access to the network device on each of the N1 second uplink carriers, where N5 is a positive integer greater than or equal to N1. Here, one or more terminal devices can initiate random access on a single second uplink carrier. All N5 terminal devices can use the random access method provided in this embodiment to initiate random access to the network device. The implementation process of random access for these N5 terminal devices is similar, the only difference being that some terminal devices successfully access the network while others fail. Therefore, for ease of understanding and to avoid redundancy, the following will use the process of the first terminal device among the N5 terminal devices and the network device executing the random access method provided in this application as an example. Here, the first terminal device is the terminal device among the N5 terminal devices that initiates random access on the first uplink carrier among the N1 second uplink carriers, and this first terminal device will successfully access the network. In addition, the random access method provided in this application is also applicable to scenarios 1 and 2 described in Embodiment 1.

[0499] like Figure 10As shown, the random access method includes the following steps:

[0500] S910, the first terminal device sends a second request message to the network device, the second request message including a first contention resolution identifier used by the first terminal device to initiate random access on the first uplink carrier. Correspondingly, the network device receives the second request message.

[0501] In some feasible implementations, during the random access process, the first terminal device may send a second request message to the network device. This second request message may include a first contention resolution identifier used by the first terminal device to initiate random access on the first uplink carrier. Correspondingly, the network device may receive the first request message from the first terminal device and obtain the first contention resolution identifier. Optionally, the second request message includes the first contention resolution identifier used by the first terminal device to initiate random access on the first uplink carrier; it can also be understood that the second request message is used by the first terminal device to initiate random access on the first uplink carrier, and the second request information includes the first contention resolution identifier.

[0502] Optionally, in scenario 1, the aforementioned second request message can be msg3 in the 4-step random access process. This second request message can be scrambled based on the second TC-RNTI indicated by the network device in the sent msg2.

[0503] Optionally, in scenario 2, the aforementioned second request downlink can be a msgA with two steps of random access. In this case, the second request message may also include information such as the first random access preamble of the first terminal device.

[0504] S920, the network device determines a second response message, which includes a first contention resolution identifier and a first C-RNTI of the first terminal device. Alternatively, the second response message is scrambled based on a second TC-RNTI, and includes the first contention resolution identifier. The first carrier identifier corresponding to the first uplink carrier and the second TC-RNTI are used to determine the first C-RNTI of the first terminal device.

[0505] In some feasible implementations, after receiving the second request message, the network device can determine the second response message corresponding to the second request message. This second response message may include a first contention resolution identifier and a first C-RNTI of the first terminal device. Alternatively, the second response message may be scrambled based on a second TC-RNTI, and may include the first contention resolution identifier. Here, the first carrier identifier corresponding to the first uplink carrier and the second TC-RNTI can be used to determine the first C-RNTI of the first terminal device. The first carrier identifier is the identifier of the first uplink carrier among a plurality of second uplink carriers, and the plurality of second uplink carriers includes at least N1 second uplink carriers. All N1 second uplink carriers are used to request access to the network device, where N1 is a positive integer greater than or equal to 2.

[0506] Method 1 for implementing the second response message:

[0507] In one possible implementation, under scenario 1 or scenario 2 described above, after receiving the second request message, if the network device determines that the first terminal device has successfully contested the contention, it can determine the first C-RNTI of the first terminal device. Then, the network device can determine a second response message containing the first contention resolution identifier and the first C-RNTI.

[0508] Method 2 for implementing the second response message:

[0509] In another possible implementation, under scenario 1, after the network device obtains N5 first contention resolution identifiers and determines that the first terminal device among these N5 second terminal devices has successfully competed, it can use the second TC-RNTI indicated by its previously sent msg2 to scramble and send a second response message containing the first contention resolution identifier.

[0510] Optionally, in scenario 1, the second response message can be msg4 from the 4-step random access.

[0511] Optionally, in scenario 2, the second response message can be msgB from the two-step random access procedure. In this case, the second response message may include a second successful RAR or a second fallback RAR. The second fallback RAR may include or indicate information such as a first contention resolution identifier and a second TC-RNTI. The second successful RAR may include or indicate a first contention resolution identifier and a first TC-RNTI.

[0512] S930, the network device sends a second response message to the first terminal device.

[0513] In some feasible implementations, the aforementioned N1 second uplink carriers are associated with the first downlink carrier. Optionally, the network device can send a second response message via the first downlink carrier.

[0514] S940, the first terminal device receives the second response message and completes random access based on the second response message.

[0515] In some feasible implementations, the first terminal device can receive the second response message via the first downlink carrier and complete random access based on the second response message.

[0516] In one possible implementation, when the second response message adopts the first implementation method described above, after receiving the second response message, the first terminal device can determine that it has completed random access based on the first contention resolution identifier contained in the second response message, and obtain the first C-RNTI assigned to it by the network device from the second response message.

[0517] In another possible implementation, when the second response message adopts the second implementation method described above, after receiving the second response message, the first terminal device can determine that it has completed random access based on the first contention resolution identifier contained in the second response message. Then, the first terminal device can obtain the second TC-RNTI used for scrambling the second response message, and determine its corresponding first C-RNTI based on the second TC-RNTI and the first carrier identifier of the first uplink carrier.

[0518] For example, the first C-RNTI described above can satisfy the following formula (14):

[0519] C-RNTI1=TC-RNTI2+c_id1 (14)

[0520] Wherein, C-RNTI1 is the first C-RNTI, TC-RNTI2 is the second TC-RNTI, and c_id1 is the first carrier identifier. That is to say, the first terminal device can calculate the first C-RNTI based on the second TC-RNTI and the first carrier identifier using formula (14).

[0521] It should be understood that the above formula (14) is only exemplary. In actual implementation, the first terminal may also use other methods to calculate the first C-RNTI based on the second TC-RNTI and the first carrier identifier. This application does not impose any specific restrictions on this.

[0522] It should be understood that while the first terminal device initiates random access to the network device via the first carrier, other terminal devices may also initiate random access to the network device via the first uplink carrier, and these other terminal devices may also execute the random access method provided in this application. When these other terminal devices compete with the first terminal device (e.g., using the same random access channel resource and random access preamble), this application uses the scenario where the network device determines that the first terminal device has successfully competed and these other terminal devices have failed to compete as an example for illustration.

[0523] In the above implementation, the network device sends a second response message to the first terminal device that successfully competes for random access via the first uplink carrier. Accordingly, the first terminal device can determine its success through the second response message. Furthermore, the first terminal device can directly extract the first C-RNTI assigned to it by the network device from the second response message, or determine its corresponding first C-RNTI by scrambling the second TC-RNTI of the second response message and the first carrier identifier of the first uplink carrier used to initiate random access. Therefore, when one or more terminal devices initiate random access on a certain uplink carrier, the above random access method ensures that at least one of these terminal devices will have a chance to successfully access the network. Further, when different terminal devices initiate random access to the network device on different uplink carriers, the above random access method eliminates competition between terminal devices initiating random access on different uplink carriers, ensuring that at least one terminal device on an uplink carrier initiating random access has a chance to successfully access the network. Therefore, the random access method provided in this application has high random access efficiency and strong applicability. When multiple terminal devices initiate random access on multiple uplink carriers corresponding to the same downlink carrier, and the random access preamble and the relevant index of the physical random access channel resources determined by these multiple terminal devices are consistent, the random access method provided in this application can overcome the problem of low random access efficiency in existing random access methods.

[0524] For some feasible implementation methods, please refer to Figure 11 , Figure 11 This is another flowchart illustrating a random access method provided in this application.

[0525] like Figure 11 As shown, the method may further include the following steps:

[0526] S950, the network device determines that the first terminal device supports random access on N1 second uplink carriers, or determines that the first terminal device requests random access on N1 second uplink carriers.

[0527] In some feasible implementations, the network device may execute step S920 above when it determines that the first terminal device supports random access on N1 second uplink carriers, or when it determines that the first terminal device requests random access on N1 second uplink carriers. Alternatively, it can be understood that the network device will only use the random access method provided in this application to interact with the first terminal device and execute steps S920 and S930 above when it determines that the first terminal device supports random access on N1 second uplink carriers, or when it determines that the first terminal device requests random access on N1 second uplink carriers.

[0528] In one feasible implementation, the network device can determine, based on the aforementioned first transmission resources and / or the first random access preamble, whether the first terminal device supports random access on N1 second uplink carriers or whether the first terminal device requests random access on N1 second uplink carriers. For a detailed implementation process, please refer to the corresponding process described in step S250 above; it will not be repeated here.

[0529] In some feasible implementations, the association between the N1 second uplink carriers and the first downlink carrier can be configured by the network device or predefined by the protocol.

[0530] In some feasible implementations, both the first NUL and the first uplink carrier associated with the first uplink carrier can correspond to the first carrier identifier. Alternatively, both the first SUL and the first uplink carrier associated with the first uplink carrier can correspond to the first carrier identifier. Specifically, when the first uplink carrier is either the first NUL or the first SUL, if the first NUL and the first SUL are associated, or if the first NUL and the first SUL belong to the same cell, then both the first NUL and the first SUL correspond to the first carrier identifier. Alternatively, it can be said that the first uplink carrier and the first NUL associated with it both correspond to the first carrier identifier, or that the first SUL associated with the first uplink carrier and the first uplink carrier both correspond to the first carrier identifier. Furthermore, it can be said that when the first uplink carrier is an NUL, both the first uplink carrier and its associated SUL correspond to the first carrier identifier, or that the first carrier identifier corresponding to the first uplink carrier and its associated SUL is the same. When the first uplink carrier is an SUL, both the first uplink carrier and its associated NUL correspond to the first carrier identifier, or that the first carrier identifier corresponding to the first uplink carrier and its associated NUL is the same. It is understood that when the first response message is scrambled based on the first RNTI, the network device does not need to consider whether the first uplink carrier is NUL or SUL when calculating the first RNTI using any one of the above formulas (1) to (9), because the value of c_id2 can already distinguish between NUL and SUL.

[0531] Optionally, if the first uplink carrier is NUL, then the first carrier identifier can be the NUL index of the first uplink carrier among the N1 second uplink carriers. If the first uplink carrier is SUL, then the first carrier identifier can be the SUL index of the first uplink carrier among the N1 second uplink carriers.

[0532] In some feasible implementations, the first NUL associated with the first uplink carrier corresponds to the third carrier identifier, and the third carrier identifier is different from the first carrier identifier. Alternatively, the first SUL associated with the first uplink carrier corresponds to the fourth carrier identifier, and the fourth carrier identifier is different from the first carrier identifier. This can also be understood as follows: when the first uplink carrier is the first NUL, and the first NUL and the first SUL are associated, or when the first NUL and the first SUL belong to the same cell, the first NUL corresponds to the first carrier identifier, and the first SUL corresponds to the fourth carrier identifier. Or, when the first uplink carrier is the first SUL, and the first NUL and the first SUL are associated, or when the first NUL and the first SUL belong to the same cell, the first NUL corresponds to the fourth carrier identifier, and the first SUL corresponds to the first carrier identifier.

[0533] Optionally, the first carrier identifier can be the uplink carrier index of the first uplink carrier among N1 second uplink carriers.

[0534] The descriptions of the NUL index, SUL index, and uplink carrier index can be found in the previous text, and will not be repeated here.

[0535] In some feasible implementations, where the second response message includes a first C-RNTI, the first C-RNTI may be included in the MAC-PDU of the second response message. For example, a second field may be added to the MAC-PDU, and the first C-RNTI may be carried in this second field.

[0536] In some feasible implementations, the second response message may further include N1-1 third contention resolution identifiers in addition to the first contention resolution identifier. These N1-1 third contention resolution identifiers are the contention resolution identifiers of N1-1 third terminal devices that initiate random access on N1-1 second uplink carriers (excluding the first uplink carrier). It should be understood that these N1-1 third terminal devices are also applicable to the random access method provided in this application. In this case, the second response message may further include N1-1 second C-RNTIs corresponding to these N1-1 third terminal devices. Alternatively, the second TC-RNTI scrambled in the second response message and the N1-1 carrier identifiers corresponding to these N1-1 second uplink carriers are used to determine the N1-1 second C-RNTIs corresponding to these N1-1 third terminal devices. That is, the second response message can also be used by these N1-1 third terminal devices to determine that the contention was successful and to obtain their respective second C-RNTIs. The interaction process between the N1-1 third terminal devices and the network device can be referred to in the same way as the interaction process between the first terminal device and the network device, and will not be repeated here.

[0537] It should be understood that the preceding text used the interaction between a first terminal device that initiates random access on the first uplink carrier and successfully accesses the network device as an example to illustrate the various steps of the random access method provided in this application. In actual implementation, N5 terminal devices, including the first terminal device, can initiate random access to the network device on N1 second uplink carriers respectively. Since the interaction process between each terminal device and the network device is similar to the interaction process between the first terminal device and the network device described above, the preceding text did not describe in detail the operations performed by other terminal devices besides the first terminal device. However, it should be understood that, using the random access method provided in this application, even if the relevant indexes and random access preambles of the random access channel resources determined by the above N5 terminal devices are completely consistent, there will be no competition between terminal devices initiating random access on different uplink carriers. Therefore, using the random access method provided in this application, each uplink carrier in which a terminal device initiates random access will have an opportunity to complete random access, which can effectively solve the problem of low access efficiency in existing random access methods.

[0538] It should also be noted that, Figures 2 to 9 or Figures 10 to 11 In the random access method shown, all N1 second uplink carriers correspond to the same first downlink carrier. This scenario is merely exemplary and is not a limitation. Figures 2 to 9 or Figures 10 to 11The random access method shown can only be applied to this scenario. In some possible scenarios, multiple downlink carriers and multiple uplink carriers can be configured, and the number of downlink carrier data is no less than the number of uplink carriers. However, during the random access process, transmission will only occur on one of these multiple downlink carriers and its associated multiple uplink carriers. In this case, Figures 2 to 9 or Figures 10 to 11 The random access method shown also applies.

[0539] This application also provides another random access method. In this random access method, in addition to supporting the decoupling of data transmission and control transmission, the terminal device and the network device should also support cross-carrier scheduling. Cross-carrier scheduling means that for msg2, msg4, or msgB, the corresponding PDCCH and the PDSCH scheduled by that PDCCH are not transmitted on the same downlink carrier.

[0540] Please see Figure 12 , Figure 12 This is a flowchart illustrating another random access method provided in this application. This method is also applicable to... Figure 1 The communication system shown can be implemented collaboratively by a first terminal device and network devices. For example... Figure 12 As shown, the method may include the following steps:

[0541] S121, the first terminal device sends a third request message to the network device. The third request message includes the first terminal device's first random access preamble and / or the first contention resolution identifier. Accordingly, the network device receives the third request message.

[0542] In some feasible implementations, during the random access process, the first terminal device may send a third request message to the network device. This third request message may include the first terminal device's first random access preamble and / or its first contention resolution identifier. Accordingly, the network device receives the third request message.

[0543] Optionally, the third request message includes the first random access preamble of the first terminal device, and the third request message is message 1 (i.e., msg1) in the 4-step random access process. Alternatively, the third request message includes the first contention resolution identifier of the first terminal device, and the third request message is message 3 (i.e., msg3) in the 4-step random access process. Still another option is that the third request message includes both the first random access preamble and the first contention resolution identifier of the first terminal device, and the third request message is message A (i.e., msgA) in the 2-step random access process.

[0544] S122, the network device sends a fourth PDCCH to the first terminal device on the first downlink carrier. The fourth PDCCH includes first scheduling information of the fourth PDSCH corresponding to the third response message. The third response message is used to respond to the third request message. The first scheduling information includes a fifth carrier identifier corresponding to the second downlink carrier. The second downlink carrier is different from the first downlink carrier. The fifth carrier identifier is used to indicate that the fourth PDSCH is transmitted on the second downlink carrier. Accordingly, the first terminal device receives the fourth PDCCH on the first downlink carrier.

[0545] In some feasible implementations, the network device may receive a third request message and determine first scheduling information. The first scheduling information is used to schedule a fourth PDSCH corresponding to a third response message. The third response message is used to respond to the third request message. The fourth PDSCH is used to carry the third response message. The first scheduling information may include a fifth carrier identifier corresponding to a second downlink carrier. The second downlink carrier is different from the first downlink carrier. The fifth carrier identifier is used to indicate that the fourth PDSCH is transmitted based on the second downlink carrier. Then, the network device may transmit the fourth PDCCH on the first downlink carrier. Correspondingly, the first terminal device receives the fourth PDCCH on the first downlink carrier and obtains the first scheduling information.

[0546] Optionally, if the third request message includes the first random access preamble of the first terminal device, the third response message can be message 2 (i.e., msg2) in the four-step random access process. If the third request message includes the first contention resolution identifier of the first terminal device, the third response message can be message 4 (i.e., msg4) in the four-step random access process. If the third request message includes both the first random access preamble and the first contention resolution identifier of the first terminal device, the third response message can be message B (i.e., msgB) in the two-step random access process.

[0547] Optionally, the fifth carrier identifier can be an identifier for the second downlink carrier among multiple downlink carriers. It should be understood that these multiple downlink carriers may also include the aforementioned first downlink carrier.

[0548] For example, the fifth carrier identifier can be a downlink carrier index of the second downlink carrier among a plurality of downlink carriers, which is used to indicate which downlink carrier the second downlink carrier is among a plurality of downlink carriers.

[0549] Optionally, the aforementioned first scheduling information may be included in the downlink control information (DCI) on the fourth PDCCH. For example, the format of this DCI may be DCI1_0.

[0550] Furthermore, when the third response message is msg2, the DCI carrying the first scheduling information is scrambled by RA-RNTI. When the third response message is msg4, the DCI carrying the first scheduling information is scrambled by TC-RNTI. When the third response message is msgB, the DCI carrying the first scheduling information is scrambled by MSGB-RNTI.

[0551] Optionally, the first scheduling information may also include information such as the time and frequency resources of the fourth PDSCH.

[0552] In short, for msg2, its corresponding fourth PDCCH can be transmitted on the first downlink carrier, while the fourth PDSCH of msg2 scheduled by this fourth PDCCH can be transmitted on a second downlink carrier different from the first downlink carrier. To achieve this, the fourth PDCCH sent by the network device can carry the carrier identifier of the second downlink carrier, so as to indicate that the fourth PDSCH scheduled by the fourth PDCCH is transmitted on the second downlink carrier. Accordingly, after blindly detecting the fourth PDCCH, the terminal device can determine that the fourth PDSCH is transmitted on the second downlink carrier based on the fourth PDCCH, and further receive the fourth PDSCH on the second downlink carrier. Optionally, the carrier identifier of the second downlink carrier can be carried in the DCI carried by the fourth PDCCH. It should be understood that the specific implementation process of cross-carrier scheduling of the PDSCH of msg4 or msgB is similar to that of msg2, and will not be described in detail here.

[0553] In the above implementation, network devices and terminal devices can adapt to scenarios where control transmission and data transmission are decoupled by supporting cross-carrier scheduling of response message PDSCH using PDCCH. This increases scheduling flexibility and allows response message transmissions under different channel conditions to be scheduled on appropriate spectrum, thereby improving resource utilization efficiency and communication performance.

[0554] In some feasible implementation methods, such as Figure 12 As shown, the method may further include the following steps:

[0555] S123, the network device transmits a fourth PDSCH on the second downlink carrier, the fourth PDSCH carrying a third response message. Correspondingly, the first terminal device receives the fourth PDSCH on the second downlink carrier.

[0556] Optionally, after sending the fourth PDCCH, the network device may send a fourth PDSCH to the first terminal device on the second downlink carrier based on the first scheduling information. This fourth PDSCH carries the third response message. Accordingly, the first terminal device may receive the fourth PDSCH on the second downlink carrier and thus obtain the third response message.

[0557] It should also be noted that in the embodiments of this application, "association" can be replaced with "correspondence". For example, object 1 and correspondence 2 are associated, which is equivalent to object 1 and object 2 being correspondent. Similarly, "association relationship" can be replaced with "correspondence relationship". For example, object 1 and correspondence 2 have an association relationship, which is equivalent to object 1 and object 2 having a correspondence relationship.

[0558] It should also be noted that the description of the execution order of each method step in this application is exemplary and not limiting. In some possible implementations, the execution order of certain steps may change. It should be understood that various methods derived from changes in the execution order of the method steps also fall within the protection scope of this application.

[0559] It should also be noted that both NUL and SUL in this application refer to uplink carriers. The NUL in this application can also be called UL, for example, when there is no associated SUL. Or, an NUL with an associated SUL is called an NUL, while an NUL without an associated SUL is called a UL. In this application, the number of NULs can be determined based on network device configuration or according to a predefined value. Alternatively, in this application, the number of SULs or the number of NULs with associated SULs can be determined based on network device configuration or according to a predefined value. For example, the predefined number of SULs or the number of NULs with associated SULs can be 1 or 2. In this application, a set or collection is used to indicate that it includes one or more corresponding objects, and does not limit the existence of a specific set of these one or more objects. For example, the uplink carrier set mentioned above refers to the association between one or more uplink carriers, not that such a set necessarily exists.

[0560] The above, combined with Figures 2 to 12 The random access method provided in the embodiments of this application is described in detail below. Figures 13 to 15 The communication device provided in the embodiments of this application is described in detail. It should be understood that the description of the embodiments of this communication device corresponds to the description of the embodiments of the sensing method; therefore, any parts not described in detail can be referred to the foregoing method embodiments.

[0561] Please see Figure 13 , Figure 13 This is a schematic diagram of the structure of a communication device provided in this application. Figure 13 As shown, the communication device 130 may include a transceiver unit 131 and a processing unit 132. Here, the transceiver unit 131 may also be referred to as a transceiver module, and the processing unit 132 may also be referred to as a processing module.

[0562] In some feasible implementations, the communication device 130 can correspond to Figures 2 to 9 The method described refers to a first terminal device, or a component (such as a circuit, processor, chip, or chip system) configured in the first terminal device. The communication device 130 may include implementations of... Figures 2 to 9 The method executed by the first terminal device involved includes corresponding modules, units, or means, which can be implemented in hardware, software, or by hardware executing corresponding software. The software or hardware includes one or more modules or units corresponding to the aforementioned functions.

[0563] In a specific implementation, processing unit 132 is used to trigger transceiver unit 131 to send a first request message. The first request message includes a first random access preamble, and the first transmission resource used by the first request message is located on a first uplink carrier. The first uplink carrier is included in N1 second uplink carriers, all of which are used to request access to the network device, where N1 is a positive integer greater than or equal to 2. Transceiver unit 131 is also used to receive a first response message, which includes a first preamble identifier of the first random access preamble and a first random access response (RAR). The first response message is scrambled based on a first radio network temporary identifier (RNTI). The first RNTI is determined based on the first transmission resource and a first carrier identifier of the first uplink carrier. The first carrier identifier is the identifier of the first uplink carrier among multiple second uplink carriers, and the multiple second uplink carriers include at least N1 second uplink carriers. Alternatively, the first response message also includes a first carrier identifier. Alternatively, the second transmission resource used to transmit the first response message is associated with the first uplink carrier.

[0564] For example, the first RNTI is determined based on the first transmission resource and the first carrier identifier of the first uplink carrier, including: the first RNTI is determined based on the index of the first orthogonal frequency division multiplexing (OFDM) symbol of the first transmission resource, the index of the first time slot of the first transmission resource, the frequency domain index of the first transmission resource, the first carrier identifier of the first uplink carrier, and the second carrier identifier of the first uplink carrier, wherein the second carrier identifier is used to indicate that the first uplink carrier is a regular uplink carrier NUL or a supplementary uplink carrier SUL.

[0565] For example, in the case where the first RNTI is the RA-RNTI used for 4-step random access, the first RNTI satisfies:

[0566] RNTI1=1+s_id+14×t_id+14×80×f_id+14×80×8×c_id2+14×80×8×2×c_id1×2

[0567] Wherein, RNTI1 is the first RNTI, s_id is the index of the first OFDM symbol, t_id is the index of the first time slot, f_id is the frequency domain index of the first transmission resource, c_id1 is the first carrier identifier, and c_id2 is the second carrier identifier.

[0568] For example, in the case where the first RNTI is the MSGB-RNTI used for 2-step random access, the first RNTI satisfies:

[0569] RNTI1=1+s_id+14×t_id+14×80×f_id+14×80×8×c_id2+14×80×8×2×c_id1+

[0570] 14×80×8×2×(c_id1+1)

[0571] Wherein, RNTI1 is the first RNTI, s_id is the index of the first OFDM symbol, t_id is the index of the first time slot, f_id is the frequency domain index of the first transmission resource, c_id1 is the value of the first carrier identifier, and c_id2 is the value of the second carrier identifier.

[0572] For example, the first response message is scrambled based on the first RNTI. The first NUL and the first uplink carrier associated with the first uplink carrier both correspond to the first carrier identifier. Alternatively, the first SUL and the first uplink carrier associated with the first uplink carrier both correspond to the first carrier identifier.

[0573] For example, if the first response message also includes a first carrier identifier, the first carrier identifier is used to indicate that the first response message is a response message to a first request message sent on a first uplink carrier.

[0574] For example, the first carrier identifier is the identifier of the first uplink carrier among a plurality of second uplink carriers, the plurality of second uplink carriers including at least N1 second uplink carriers.

[0575] For example, the first carrier identifier is included in the uplink grant information in the first RAR, or the first carrier identifier is included in the timing advance instruction in the first RAR.

[0576] For example, the second transmission resource includes: the first time domain resource where the first PDCCH corresponding to the first response message is located, the first frequency domain resource where the first PDCCH corresponding to the first response message is located, or the first time-frequency resource where the first PDCCH corresponding to the first response message is located.

[0577] For example, the transceiver unit 131 is further configured to: receive first configuration information, wherein the first configuration information is used to determine that N1 second uplink carriers are associated with N4 third transmission resources, the second transmission resource is one of the N4 third transmission resources, any one of the N1 second uplink carriers i is associated with the third transmission resource j1 of the N4 third transmission resources, the third transmission resource j1 is a resource used to monitor the second PDCCH corresponding to the target response message, the target response message is used to respond to the target request message, the target request message is used to send a random access preamble on the second uplink carrier i, and N4 is a positive integer less than or equal to N1.

[0578] For example, the third transmission resource j1 includes: the time domain resource where the second PDCCH is located, the frequency domain resource where the second PDCCH is located, or the time-frequency resource where the second PDCCH is located.

[0579] For example, each of the N4 third transmission resources is determined based on the control resource set and search space set corresponding to each third transmission resource. When third transmission resource j1 includes the time-domain resource where the second PDCCH resides, the search space sets corresponding to the N4 third transmission resources are different. When third transmission resource j1 includes the frequency-domain resource where the second PDCCH resides, the control resource sets corresponding to the N4 third transmission resources are different. When third transmission resource j1 includes the time-frequency resource where the second PDCCH resides, the search space sets corresponding to the N4 third transmission resources are different, and / or, the corresponding control resource sets are different.

[0580] For example, when the third transmission resource j1 includes the time-domain resource where the second PDCCH is located, the search space sets corresponding to the N4 third transmission resources are different subsets of the same search space set. When the third transmission resource j1 includes the frequency-domain resource where the second PDCCH is located, the control resource sets corresponding to the N4 third transmission resources are different subsets of the same control resource set. When the third transmission resource j1 includes the time-frequency resource where the second PDCCH is located, the search space sets corresponding to the N4 third transmission resources are different subsets of the same search space set, and the control resource sets corresponding to the N4 third transmission resources are also different subsets of the same control resource set.

[0581] In some feasible implementations, the communication device 130 can correspond to Figures 2 to 9 The network device involved in the method shown, or a component (such as a circuit, processor, chip, or chip system) configured in the network device. The communication device 130 may include implementations of... Figures 2 to 9The network device involved executes a method, and the corresponding module, unit, or means can be implemented in hardware, software, or by hardware executing corresponding software. The software or hardware includes one or more modules or units corresponding to the aforementioned functions.

[0582] Specifically, transceiver unit 131 is used to receive a first request message, wherein the first request message includes a first random access preamble, the first transmission resource used by the first request message is located on a first uplink carrier, the first uplink carrier is included in N1 second uplink carriers, all N1 second uplink carriers are used to request access to the network device, and N1 is a positive integer greater than or equal to 2. Processing unit 132 is used to trigger transceiver unit 131 to send a first response message, wherein the first response message includes a first preamble identifier of the first random access preamble and a first random access response (RAR). The first response message is scrambled based on a first RNTI, the first RNTI is determined based on the first transmission resource and the first carrier identifier of the first uplink carrier, the first carrier identifier is the identifier of the first uplink carrier among multiple second uplink carriers, and the multiple second uplink carriers include at least N1 second uplink carriers. Alternatively, the first response message also includes a first carrier identifier. Alternatively, the second transmission resource used to transmit the first response message is associated with the first uplink carrier.

[0583] For example, the first RNTI is determined based on the first carrier identifier of the first transmission resource and the first uplink carrier, including: the first RNTI is determined based on the index of the first orthogonal frequency division multiplexing (OFDM) symbol of the first transmission resource, the index of the first time slot of the first transmission resource, the frequency domain index of the first transmission resource, the first carrier identifier used to indicate the first uplink carrier among N1 second uplink carriers, and the second carrier identifier corresponding to the first uplink carrier, wherein the second carrier identifier is used to indicate that the first uplink carrier is NUL or SUL.

[0584] For example, in the case where the first RNTI is the RA-RNTI used for 4-step random access, the first RNTI satisfies:

[0585] RNTI1=1+s_id+14×t_id+14×80×f_id+14×80×8×c_id2+14×80×8×2×c_id1×2

[0586] Wherein, RNTI1 is the first RNTI, s_id is the index of the first OFDM symbol, t_id is the index of the first time slot, f_id is the frequency domain index of the first transmission resource, c_id1 is the value of the first carrier identifier, and c_id2 is the value of the second carrier identifier.

[0587] For example, in the case where the first RNTI is the MSGB-RNTI used for 2-step random access, the first RNTI satisfies:

[0588] RNTI1=1+s_id+14×t_id+14×80×f_id+14×80×8×c_id2+14×80×8×2×c_id1+14×80×8×2×(c_id1+1)

[0589] Wherein, RNTI1 is the first RNTI, s_id is the index of the first OFDM symbol, t_id is the index of the first time slot, f_id is the frequency domain index of the first transmission resource, c_id1 is the value of the first carrier identifier, and c_id2 is the value of the second carrier identifier.

[0590] For example, if the first response message also includes a first carrier identifier, the first carrier identifier is used to indicate that the first response message is a response message to a first request message sent on a first uplink carrier.

[0591] For example, the second transmission resource includes: the first time domain resource where the first PDCCH corresponding to the first response message is located, the first frequency domain resource where the first PDCCH corresponding to the first response message is located, or the first time-frequency resource where the first PDCCH corresponding to the first response message is located.

[0592] For example, the transceiver unit is further configured to: receive first configuration information, wherein the first configuration information is used to determine that N1 second uplink carriers are associated with N4 third transmission resources, the second transmission resource is one of the N4 third transmission resources, any one of the N1 second uplink carriers i is associated with the third transmission resource j1 of the N4 third transmission resources, the third transmission resource j1 is a resource used to monitor the second PDCCH corresponding to the target response message, the target response message is used to respond to the target request message, the target request message is used to send a random access preamble on the second uplink carrier i, and N4 is a positive integer less than or equal to N1.

[0593] In some feasible implementations, the communication device 130 can correspond to Figures 10 to 11 The method described refers to a first terminal device, or a component (such as a circuit, processor, chip, or chip system) configured in the first terminal device. The communication device 130 may include implementations of... Figures 10 to 11 The method executed by the first terminal device involved includes corresponding modules, units, or means, which can be implemented in hardware, software, or by hardware executing corresponding software. The software or hardware includes one or more modules or units corresponding to the aforementioned functions.

[0594] Specifically, processing unit 132 is used to trigger transceiver unit 131 to send a second request message, wherein the second request message includes a first contention resolution identifier used by the first terminal device to initiate random access on the first uplink carrier, and transceiver unit 131 is used to receive a second response message. The second response message includes the first contention resolution identifier of the first terminal device and the first C-RNTI of the first terminal device. Alternatively, the second response message is scrambled based on a second RNTI, and includes the first contention resolution identifier of the first terminal device. The first carrier identifier corresponding to the first uplink carrier and the second RNTI are used to determine the first C-RNTI of the first terminal device. The first carrier identifier is the identifier of the first uplink carrier among multiple second uplink carriers, and the multiple second uplink carriers include at least N1 identifiers among the second uplink carriers. All N1 second uplink carriers are used to request access to the network device, and N1 is a positive integer greater than or equal to 2.

[0595] For example, the first carrier identifier corresponding to the first uplink carrier and the second TC-RNTI are used to determine the first C-RNTI of the first terminal device, and the first C-RNTI satisfies:

[0596] C-RNTI1=TC-RNTI2+c_id1

[0597] Wherein, C-RNTI1 is the first C-RNTI, TC-RNTI2 is the second TC-RNTI, and c_id1 is the first carrier identifier.

[0598] In some feasible implementations, the communication device 130 can correspond to Figures 10 to 11 The network device involved in the method shown, or a component (such as a circuit, processor, chip, or chip system) configured in the network device. The communication device 130 may include implementations of... Figures 10 to 11 The network device involved executes a method, and the corresponding module, unit, or means can be implemented in hardware, software, or by hardware executing corresponding software. The software or hardware includes one or more modules or units corresponding to the aforementioned functions.

[0599] Specifically, the transceiver unit 131 is configured to: receive a second request message, wherein the second request message includes a first contention resolution identifier used by the first terminal device to initiate random access on the first uplink carrier; and the processing unit 132 is configured to trigger the transceiver unit 131 to send a second response message. The second response message includes the first contention resolution identifier of the first terminal device and the first C-RNTI of the first terminal device. Alternatively, the second response message is scrambled based on a second RNTI, and includes the first contention resolution identifier of the first terminal device. The first carrier identifier corresponding to the first uplink carrier and the second RNTI are used to determine the first C-RNTI of the first terminal device. The first carrier identifier is the identifier of the first uplink carrier among multiple second uplink carriers, and the multiple second uplink carriers include at least N1 identifiers among the second uplink carriers. All N1 second uplink carriers are used to request access to the network device, and N1 is a positive integer greater than or equal to 2.

[0600] For example, the first carrier identifier corresponding to the first uplink carrier and the second TC-RNTI are used to determine the first C-RNTI of the first terminal device, and the first C-RNTI satisfies:

[0601] C-RNTI1=TC-RNTI2+c_id1

[0602] Wherein, C-RNTI1 is the first C-RNTI, TC-RNTI2 is the second TC-RNTI, and c_id1 is the first carrier identifier.

[0603] In some feasible implementations, the communication device 130 can correspond to Figure 12 The method described refers to a first terminal device, or a component (such as a circuit, processor, chip, or chip system) configured in the first terminal device. The communication device 130 may include implementations of... Figure 12 The method executed by the first terminal device involved includes corresponding modules, units, or means, which can be implemented in hardware, software, or by hardware executing corresponding software. The software or hardware includes one or more modules or units corresponding to the aforementioned functions.

[0604] In a specific implementation, processing unit 132 is used to trigger transceiver unit 131 to receive a third request message, wherein the third request message includes a first random access preamble of the first terminal device and / or a first contention resolution identifier of the first terminal device. Processing unit 132 is also used to trigger transceiver unit 131 to receive a fourth PDCCH on a first downlink carrier, wherein the fourth PDCCH includes first scheduling information of the fourth PDSCH corresponding to the third response message. The third response message is used to respond to the third request message. The first scheduling information includes a fifth carrier identifier corresponding to a second downlink carrier. The second downlink carrier is different from the first downlink carrier. This fifth carrier identifier is used to indicate that the fourth PDSCH is transmitted on the second downlink carrier.

[0605] For example, the third request message includes the first random access preamble of the first terminal device, the third request message is message 1 (i.e., msg1) in the 4-step random access, and the third response message is message 2 (i.e., msg2) in the 4-step random access. Alternatively, the third request message includes the first contention resolution identifier of the first terminal device, the third request message is message 3 (i.e., msg3) in the 4-step random access, and the third response message is message 4 (i.e., msg4) in the 4-step random access. Or, the third request message includes the first random access preamble and the first contention resolution identifier of the first terminal device, the third request message is message A (i.e., msgA) in the 2-step random access, and the third response message is message B (i.e., msgB) in the 2-step random access.

[0606] For example, the first scheduling information is included in the DCI of the fourth PDCCH transmission.

[0607] For example, the fifth carrier identifier is the identifier of the second downlink carrier among multiple downlink carriers.

[0608] For example, transceiver unit 131 is also configured to receive a fourth PDSCH on a second downlink carrier.

[0609] In some feasible implementations, the communication device 130 can correspond to Figure 12 The network device involved in the method shown, or a component (such as a circuit, processor, chip, or chip system) configured in the network device. The communication device 130 may include implementations of... Figure 12 The network device involved executes a method, and the corresponding module, unit, or means can be implemented in hardware, software, or by hardware executing corresponding software. The software or hardware includes one or more modules or units corresponding to the aforementioned functions.

[0610] In a specific implementation, transceiver unit 131 is used to receive a third request message, wherein the third request message includes a first random access preamble of the first terminal device and / or a first contention resolution identifier of the first terminal device. Processing unit 132 is used to trigger transceiver unit 131 to transmit a fourth PDCCH on a first downlink carrier. The fourth PDCCH includes first scheduling information of the fourth PDSCH corresponding to the third response message. The third response message is used to respond to the third request message. The first scheduling information includes a fifth carrier identifier corresponding to a second downlink carrier. The second downlink carrier is different from the first downlink carrier. This fifth carrier identifier is used to indicate that the fourth PDSCH is transmitted on the second downlink carrier.

[0611] For example, the third request message includes the first random access preamble of the first terminal device, the third request message is message 1 (i.e., msg1) in the 4-step random access, and the third response message is message 2 (i.e., msg2) in the 4-step random access. Alternatively, the third request message includes the first contention resolution identifier of the first terminal device, the third request message is message 3 (i.e., msg3) in the 4-step random access, and the third response message is message 4 (i.e., msg4) in the 4-step random access. Or, the third request message includes the first random access preamble and the first contention resolution identifier of the first terminal device, the third request message is message A (i.e., msgA) in the 2-step random access, and the third response message is message B (i.e., msgB) in the 2-step random access.

[0612] For example, the first scheduling information is included in the DCI of the fourth PDCCH transmission.

[0613] For example, the fifth carrier identifier is the identifier of the second downlink carrier among multiple downlink carriers.

[0614] For example, transceiver unit 131 is also configured to transmit a fourth PDSCH via a second downlink carrier.

[0615] Please see Figure 14 , Figure 14 This is a schematic diagram of another communication device provided in this application. The communication device 140 can be used... Figures 2 to 9 The operations performed by the first terminal device or network device in the random access parties involved. Alternatively, the communication device 140 can be used for... Figures 10 to 11 The operations performed by the first terminal device or network device in the random access parties involved. Alternatively, the communication device 140 can be used for... Figure 12 The operations performed by the first terminal device or network device in the random access parties involved. The communication device 140 may include: a processor 141.

[0616] Optionally, the communication device may also include a memory 142.

[0617] Memory 142 is used to store related instructions and data. Memory 142 stores the following elements: executable modules or data structures, or subsets thereof, or extended sets thereof:

[0618] Operation instructions: This includes various operation instructions used to perform various operations.

[0619] Operating system: includes various system programs used to implement various basic business functions and handle hardware-based tasks.

[0620] Figure 14 Only one memory is shown in the image; of course, multiple memory can be configured as needed.

[0621] Optionally, the communication device 140 may further include a transceiver 144. The transceiver 144 may be a communication module or a transceiver circuit. In the embodiments of this application, the transceiver 144 is used to perform the above-described... Figures 2 to 9 or Figures 10-11 The message or information sending and receiving operations in the random access methods involved.

[0622] Processor 141 may be a controller, a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. Processor 141 may also be a combination that implements computing functions, such as a combination of one or more microprocessors, a combination of a DSP and a microprocessor, etc.

[0623] Optionally, the communication device may also include a bus system 143. In specific applications, the various components of the communication device 140 are coupled together through the bus system 143, which, in addition to a data bus, may also include a power bus, a control bus, and a status signal bus, etc. However, for the sake of clarity, in... Figure 14 All buses are labeled as Bus System 143. For ease of representation, Figure 14 The image shown is only schematic.

[0624] In specific implementation, the communication device 140 can perform... Figures 2 to 9 or Figures 10 to 11 or Figure 12 The steps performed by the first terminal device or network device in the random access method involved. Specifically, when the communication device 140 is used to implement... Figures 2 to 9 or Figures 10 to 11 In the random access method involved, when each step is executed by the first terminal device or network device, the processor 141 can implement the function of the processing unit 132, and the transceiver 144 is used to implement the function of the transceiver unit 131.

[0625] Please see Figure 15 , Figure 15 This is a schematic diagram of another communication device provided in this application. The communication device 150 may include a processor 151 and an interface circuit 152. The interface circuit 152 can be used to receive signals from other communication devices besides the communication device 150 and transmit them to the processor, or to send signals from the processor to other communication devices besides the communication device 150. The processor 151 can be used to implement the sensing method described in the preceding embodiments through logic circuits or by executing computer programs or instructions.

[0626] In some possible designs, the communication device 150 can be Figures 2 to 9 or Figures 10 to 11 or Figure 12 The apparatus, such as a chip system, included in the first terminal device or network device in the random access method involved.

[0627] It should be noted that in practical applications, the processor in the embodiments of this application can be an integrated circuit chip with signal processing capabilities. During implementation, each step of the above method embodiments can be completed by the integrated logic circuits in the processor's hardware or by instructions in software form. The processor can be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. It can implement or execute the methods, steps, and logic block diagrams disclosed in the embodiments of this application. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the methods disclosed in the embodiments of this application can be directly embodied in the execution of a hardware decoding processor, or by a combination of hardware and software modules in the decoding processor. The software modules can be located in random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, or other mature storage media in the art. This storage medium is located in memory, and the processor reads the information in the memory and, in conjunction with its hardware, completes the steps of the above method.

[0628] It is understood that the memory in the embodiments of this application can be volatile memory or non-volatile memory, or may include both volatile and non-volatile memory. The non-volatile memory can be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory. The volatile memory can be random access memory (RAM), which is used as an external cache. By way of example, but not limitation, many forms of RAM are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous linked dynamic random access memory (SLDRAM), and direct rambus RAM (DR RAM). It should be noted that the memories described in the embodiments of this application are intended to include, but are not limited to, these and any other suitable types of memory.

[0629] This application also provides a computer-readable medium having a computer program stored thereon, which, when executed by a computer, implements... Figures 2 to 9 or Figures 10 to 11 or Figure 12 The steps of the random access method involved, performed by the first terminal device or network device.

[0630] This application also provides a computer program product that, when executed by a computer, implements... Figures 2 to 9 or Figures 10 to 11 or Figure 12 The various steps performed by the first terminal device or network device in the random access method involved.

[0631] This application also provides a chip, which includes at least a processor. The processor is used to perform... Figures 2 to 9 or Figures 10 to 11 or Figure 12 The various steps performed by the first terminal device or network device in the random access method involved.

[0632] Optionally, the chip may also include interface circuitry. This interface circuitry is used to receive computer execution instructions and transmit them to the processor.

[0633] This application also provides a chip system including a processor for supporting the implementation of a device on which the chip system is mounted. Figures 2 to 9 or Figures 10 to 11 or Figure 12 The random access method involves various steps performed by the first terminal device or network device, such as generating or processing the data and / or information involved in the above method. In one possible design, the chip system further includes a memory for storing program instructions and data necessary for the data transmission device. The chip system may be composed of chips or may include chips and other discrete components.

[0634] This application also provides a communication system. This communication system includes at least the first terminal device and the network device described above. The first terminal device and the network device work together to implement the random access method described in the preceding embodiments.

[0635] In the above method embodiments, implementation can be achieved entirely or partially through software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented entirely or partially in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., digital video disc (DVD), or a semiconductor medium (e.g., solid-state disk (SSD)).

[0636] In the various embodiments of this application, unless otherwise specified or in case of logical conflict, the terminology and / or descriptions between different embodiments are consistent and can be referenced by each other. Technical features in different embodiments can be combined to form new embodiments based on their inherent logical relationships.

[0637] It is understood that the various numerical designations used in the embodiments of this application are merely for descriptive convenience and are not intended to limit the scope of the embodiments of this application. The order of the process numbers described above does not imply the order of execution; the execution order of each process should be determined by its function and internal logic.

[0638] The above description is merely a preferred embodiment of the technical solution of this application and is not intended to limit the scope of protection of this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A random access method, characterized in that, The method is applicable to a first terminal device or a device within a first terminal device, and the method includes: Send a first request message, wherein the first request message includes a first random access preamble, the first transmission resource used by the first request message is located on a first uplink carrier, the first uplink carrier is included in N1 second uplink carriers, all of the N1 second uplink carriers are used to request access to the network device, and N1 is a positive integer greater than or equal to 2; Receive a first response message, wherein the first response message includes a first preamble identifier of the first random access preamble and a first random access response (RAR); The first response message is scrambled based on the first radio network temporary identifier (RNTI). The first RNTI is determined based on the first transmission resource and the first carrier identifier of the first uplink carrier. The first carrier identifier is the identifier of the first uplink carrier among a plurality of second uplink carriers. The plurality of second uplink carriers includes at least the N1 second uplink carriers. Alternatively, the first response message may also include a first carrier identifier; Alternatively, the second transmission resource used to transmit the first response message may be associated with the first uplink carrier.

2. The method according to claim 1, characterized in that, The first RNTI is determined based on the first transmission resource and the first carrier identifier of the first uplink carrier, including: The first RNTI is determined based on the index of the first orthogonal frequency division multiplexing (OFDM) symbol of the first transmission resource, the index of the first time slot of the first transmission resource, the frequency domain index of the first transmission resource, the first carrier identifier of the first uplink carrier, and the second carrier identifier of the first uplink carrier. The second carrier identifier is used to indicate that the first uplink carrier is a regular uplink carrier (NUL) or a supplementary uplink carrier (SUL).

3. The method according to claim 2, characterized in that, When the first RNTI is the RA-RNTI used for 4-step random access, the first RNTI satisfies: RNTI 1=1+s_id+14×t_id+14×80×f_id+14×80×8×c_id2+14×80×8×2×c_id1×2 Wherein, RNTI 1 is the first RNTI, s_id is the index of the first OFDM symbol, t_id is the index of the first time slot, f_id is the frequency domain index of the first transmission resource, c_id1 is the first carrier identifier, and c_id2 is the second carrier identifier.

4. The method according to claim 2 or 3, characterized in that, When the first RNTI is the MSGB-RNTI used for 2-step random access, the first RNTI satisfies: RNTI 1=1+s_id+14×t_id+14×80×f_id+14×80×8×c_id2+14×80×8×2×c_id1+14×80×8×2×(c_id1+1) Wherein, RNTI 1 is the first RNTI, s_id is the index of the first OFDM symbol, t_id is the index of the first time slot, f_id is the frequency domain index of the first transmission resource, c_id1 is the value of the first carrier identifier, and c_id2 is the value of the second carrier identifier.

5. The method according to any one of claims 2-4, characterized in that, The first response message is based on a first RNTI scramble; The first NUL associated with the first uplink carrier and the first uplink carrier both correspond to the first carrier identifier; Alternatively, both the first SUL associated with the first uplink carrier and the first uplink carrier correspond to the first carrier identifier.

6. The method according to claim 1, characterized in that, If the first response message further includes a first carrier identifier, the first carrier identifier is used to indicate that the first response message is a response message to the first request message sent on the first uplink carrier.

7. The method according to claim 6, characterized in that, The first carrier identifier is the identifier of the first uplink carrier among a plurality of second uplink carriers, and the plurality of second uplink carriers includes at least the N1 second uplink carriers.

8. The method according to claim 6 or 7, characterized in that, The first carrier identifier is included in the uplink grant information in the first RAR, or the first carrier identifier is included in the timing advance instruction in the first RAR.

9. The method according to claim 1, wherein the second transmission resource comprises: The first time domain resource where the first PDCCH corresponding to the first response message is located, the first frequency domain resource where the first PDCCH corresponding to the first response message is located, or the first time-frequency resource where the first PDCCH corresponding to the first response message is located.

10. The method according to claim 9, characterized in that, The method further includes: Receive first configuration information, wherein the first configuration information is used to determine that the N1 second uplink carriers are associated with N4 third transmission resources, the second transmission resource is one of the N4 third transmission resources, any one of the N1 second uplink carriers i is associated with the third transmission resource j1 of the N4 third transmission resources, the third transmission resource j1 is a resource used to monitor the second PDCCH corresponding to the target response message, the target response message is used to respond to the target request message, the target request message is used to send a random access preamble on the second uplink carrier i, and N4 is a positive integer less than or equal to N1.

11. The method according to claim 10, characterized in that, The third transmission resource j1 includes: the time domain resource where the second PDCCH is located, the frequency domain resource where the second PDCCH is located, or the time-frequency resource where the second PDCCH is located.

12. The method according to claim 11, characterized in that, Each of the N4 third transmission resources is determined based on the control resource set and search space set corresponding to each third transmission resource; When the third transmission resource j1 includes the time-domain resource where the second PDCCH is located, the search space sets corresponding to the N4 third transmission resources are different; When the third transmission resource j1 includes the frequency domain resources where the second PDCCH is located, the control resource sets corresponding to the N4 third transmission resources are different; When the third transmission resource j1 includes the time-frequency resource where the second PDCCH is located, the search space sets corresponding to the N4 third transmission resources are different, and / or the control resource sets corresponding to them are different.

13. The method according to claim 12, characterized in that, When the third transmission resource j1 includes the time domain resource where the second PDCCH is located, the search space set corresponding to the N4 third transmission resources is a different subset of the same search space set; When the third transmission resource j1 includes the frequency domain resources where the second PDCCH is located, the control resource sets corresponding to the N4 third transmission resources are different subsets of the same control resource set; When the third transmission resource j1 includes the time-frequency resource where the second PDCCH is located, the search space set corresponding to the N4 third transmission resources is a different subset of the same search space set, and the control resource set corresponding to the N4 third transmission resources is a different subset of the same control resource set.

14. A random access method, characterized in that, The method is applicable to a first terminal device or a device within a first terminal device, and the method includes: Send a second request message, wherein the second request message includes a first contention resolution identifier used by the first terminal device to initiate random access on the first uplink carrier; Receive the second response message; The second response message includes the first contention resolution identifier and the first cell radio network temporary identifier (C-RNTI) of the first terminal device; Alternatively, the second response message is scrambled based on the second TC-RNTI. The second response message includes the first contention resolution identifier, the first carrier identifier corresponding to the first uplink carrier, and the second RNTI used to determine the first C-RNTI of the first terminal device. The first carrier identifier is the identifier of the first uplink carrier among a plurality of second uplink carriers. The plurality of second uplink carriers includes at least N1 second uplink carriers. All N1 second uplink carriers are used to request access to the network device, and N1 is a positive integer greater than or equal to 2.

15. The method according to claim 14, characterized in that, The first carrier identifier corresponding to the first uplink carrier and the second TC-RNTI are used to determine the first C-RNTI of the first terminal device, wherein the first C-RNTI satisfies: C-RNTI 1 = TC-RNTI 2 + c_id1 Wherein, C-RNTI 1 is the first C-RNTI, TC-RNTI 2 is the second TC-RNTI, and c_id1 is the first carrier identifier.

16. A random access method, characterized in that, The method is applicable to network devices or devices within network devices, and the method includes: Receive a first request message, wherein the first request message includes a first random access preamble, the first transmission resource used by the first request message is located on a first uplink carrier, the first uplink carrier is included in N1 second uplink carriers, all of the N1 second uplink carriers are used to request access to the network device, and N1 is a positive integer greater than or equal to 2; Send a first response message, wherein the first response message includes a first preamble identifier of the first random access preamble and a first random access response (RAR); The first response message is scrambled based on a first RNTI, which is determined based on the first transmission resource and a first carrier identifier of the first uplink carrier. The first carrier identifier is the identifier of the first uplink carrier among a plurality of second uplink carriers, and the plurality of second uplink carriers includes at least the N1 second uplink carriers. Alternatively, the first response message may also include a first carrier identifier; Alternatively, the second transmission resource used to transmit the first response message may be associated with the first uplink carrier.

17. The method according to claim 16, characterized in that, The first RNTI is determined based on the first transmission resource and the first carrier identifier of the first uplink carrier, including: The first RNTI is determined based on the index of the first orthogonal frequency division multiplexing (OFDM) symbol of the first transmission resource, the index of the first time slot of the first transmission resource, the frequency domain index of the first transmission resource, the first carrier identifier used to indicate the first uplink carrier among N1 second uplink carriers, and the second carrier identifier corresponding to the first uplink carrier. The second carrier identifier is used to indicate that the first uplink carrier is NUL or SUL.

18. The method according to claim 17, characterized in that, When the first RNTI is the RA-RNTI used for 4-step random access, the first RNTI satisfies: RNTI 1=1+s_id+14×t_id+14×80×f_id+14×80×8×c_id2+14×80×8×2×c_id1×2 Wherein, RNTI 1 is the first RNTI, s_id is the index of the first OFDM symbol, t_id is the index of the first time slot, f_id is the frequency domain index of the first transmission resource, c_id1 is the value of the first carrier identifier, and c_id2 is the value of the second carrier identifier.

19. The method according to claim 17 or 18, characterized in that, When the first RNTI is the MSGB-RNTI used for 2-step random access, the first RNTI satisfies: RNTI 1=1+s_id+14×t_id+14×80×f_id+14×80×8×c_id2+14×80×8×2×c_id1+14×80×8×2×(c_id1+1) Wherein, RNTI 1 is the first RNTI, s_id is the index of the first OFDM symbol, t_id is the index of the first time slot, f_id is the frequency domain index of the first transmission resource, c_id1 is the value of the first carrier identifier, and c_id2 is the value of the second carrier identifier.

20. The method according to claim 16, characterized in that, If the first response message further includes a first carrier identifier, the first carrier identifier is used to indicate that the first response message is a response message to the first request message sent on the first uplink carrier.

21. The method of claim 16, wherein the second transmission resource comprises: The first time domain resource where the first PDCCH corresponding to the first response message is located, the first frequency domain resource where the first PDCCH corresponding to the first response message is located, or the first time-frequency resource where the first PDCCH corresponding to the first response message is located.

22. The method according to claim 21, characterized in that, The method further includes: Receive first configuration information, wherein the first configuration information is used to determine that the N1 second uplink carriers are associated with N4 third transmission resources, the second transmission resource is one of the N4 third transmission resources, any one of the N1 second uplink carriers i is associated with the third transmission resource j1 of the N4 third transmission resources, the third transmission resource j1 is a resource used to monitor the second PDCCH corresponding to the target response message, the target response message is used to respond to the target request message, the target request message is used to send a random access preamble on the second uplink carrier i, and N4 is a positive integer less than or equal to N1.

23. A random access method, characterized in that, The method is applicable to network devices or devices within network devices, and the method includes: Receive a second request message, wherein the second request message includes a first contention resolution identifier used by the first terminal device to initiate random access on the first uplink carrier; Send a second response message; The second response message includes the first contention resolution identifier of the first terminal device and the first C-RNTI of the first terminal device; Alternatively, the second response message is scrambled based on the second RNTI. The second response message includes the first contention resolution identifier of the first terminal device, the first carrier identifier corresponding to the first uplink carrier, and the second RNTI used to determine the first C-RNTI of the first terminal device. The first carrier identifier is the identifier of the first uplink carrier among a plurality of second uplink carriers. The plurality of second uplink carriers include at least the identifiers among the N1 second uplink carriers. All N1 second uplink carriers are used to request access to the network device, and N1 is a positive integer greater than or equal to 2.

24. The method according to claim 23, characterized in that, The first carrier identifier corresponding to the first uplink carrier and the second TC-RNTI are used to determine the first C-RNTI of the first terminal device, wherein the first C-RNTI satisfies: C-RNTI 1 = TC-RNTI 2 + c_id1 Wherein, C-RNTI 1 is the first C-RNTI, TC-RNTI 2 is the second TC-RNTI, and c_id1 is the first carrier identifier.

25. A communication device, characterized in that, The communication device includes a unit for implementing the random access method as described in any one of claims 1-13, 14-15, 16-22, or 23-24.

26. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed, implements the random access method as described in any one of claims 1-13, 14-15, 16-22, or 23-24.

27. A chip system, characterized in that, Including the processor; The processor is configured to execute computer execution instructions to cause a device equipped with the chip system to perform the random access method as described in any one of claims 1-13, 14-15, 16-22, or 23-24.

28. The chip system according to claim 27, characterized in that, The chip system also includes an interface circuit, which is used to receive computer execution instructions and transmit them to the processor.

29. A computer program product, said computer program product being executed by a computer using the random access method as described in any one of claims 1-13, 14-15, 16-22, or 23-24.

30. A communication device, characterized in that, include: At least one processor and memory; The memory is used to store computer programs; The processor is configured to execute a computer program stored in the memory, causing the communication device to perform the random access method as described in any one of claims 1-13, 14-15, 16-22, or 23-24.

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