Multiple uplink carrier access method, device, equipment and readable storage medium

Abstract

The embodiment of the present application provides a method, apparatus, device and readable storage medium for accessing multiple uplink carriers, the method comprising: obtaining one or more first uplink carriers selected by the terminal and / or a second uplink carrier indicated by the network side; performing four-step random access according to the one or more first uplink carriers and the second uplink carriers, or performing two-step random access according to the multiple first uplink carriers; wherein the first uplink carrier is used to send MSG1 in the four-step random access, the second uplink carrier is used to send MSG3 in the four-step random access, or the multiple first uplink carriers are used to send MSGA in the two-step random access. In the embodiment of the present application, by initiating random access on multiple uplink carriers, the success probability of random access is enhanced, the system robustness is enhanced, and the uplink resources of the cell are fully utilized.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of communication technology, and in particular to a method, apparatus, device and readable storage medium for accessing multiple uplink carriers. Background Art

[0002] The fifth generation of mobile communication technology (5th generation, 5G) introduced supplementary uplink technology, which includes 1 downlink carrier and 2 uplink carriers in a cell. The 2 uplink carriers include 1 ordinary uplink carrier and 1 supplementary uplink carrier. The ordinary uplink carrier is the uplink carrier corresponding to 1 downlink carrier. If it is a frequency division duplex (Frequency Division Duplexing, FDD) carrier, the ordinary uplink carrier is the uplink carrier corresponding to the downlink carrier in FDD. If it is a time division duplex (Time Division Duplexing, TDD) carrier, the ordinary uplink carrier is the same as the downlink carrier. The supplementary uplink carrier is a separate uplink carrier.

[0003] When the terminal initiates random access in the idle state, it will select an uplink carrier in the currently resident cell to initiate random access. The selection of the uplink carrier is based on the downlink signal strength (for example, the reference signal receiving power (RSRP)), that is, it is selected based on the coverage; after the uplink carrier is selected, the random access process will be completed on the selected uplink carrier.

[0004] Since the uplink carrier is selected based on the RSRP of the downlink signal, that is, only the coverage is considered without considering the interference, it is very likely that the terminal selects an uplink carrier based on the coverage, but the carrier has interference, resulting in terminal access failure. According to the existing cell selection criteria, it is more intuitive to add the Reference Signal Receiving Quality (RSRQ) threshold as a reference, but since RSRQ is the quality measured in the downlink, it cannot reflect the interference of the supplementary uplink carrier, and cannot solve this problem.

[0005] At the same time, since the random access process in the current communication system must be completed on the same carrier, if there is interference, the terminal may have successfully sent message 1 (MSG1), but failed to send message 3 (MSG3), resulting in the failure of the entire random access process. This will have a significant negative impact on some ultra-reliable and low-latency communication (URLLC) type users. Summary of the invention

[0006] An object of the embodiments of the present application is to provide a method, apparatus, device and readable storage medium for accessing multiple uplink carriers to solve the problem of random access process failure.

[0007] In a first aspect, an embodiment of the present application provides a method for accessing multiple uplink carriers, which is executed by a terminal and includes:

[0008] Acquire one or more first uplink carriers selected by the terminal and / or a second uplink carrier indicated by the network side;

[0009] Performing four-step random access according to the one or more first uplink carriers and the second uplink carrier, or performing two-step random access according to the multiple first uplink carriers;

[0010] The first uplink carrier is used to send MSG1 in four-step random access, the second uplink carrier is used to send MSG3 in four-step random access, or the multiple first uplink carriers are used to send MSGA in two-step random access.

[0011] Optionally, acquiring one or more first uplink carriers selected by the terminal includes:

[0012] Selecting one or more first uplink carriers according to a reference signal received power RSRP and a first RSRP threshold measured by the terminal;

[0013] The first RSRP threshold is used by the terminal to select a first uplink carrier.

[0014] Optionally, selecting one or more first uplink carriers according to the RSRP measured by the terminal and a first RSRP threshold includes:

[0015] If the RSRP measured by the terminal is lower than or equal to the first RSRP threshold, selecting a first uplink carrier corresponding to the first RSRP threshold;

[0016] or,

[0017] If the RSRP measured by the terminal is higher than the first RSRP threshold, one or more first uplink carriers corresponding to the first RSRP threshold are selected.

[0018] Optionally, if the RSRP measured by the terminal is lower than or equal to the first RSRP threshold, the selected first uplink carrier is SUL, or the coverage is greater than a preset value, or the frequency is lower than a preset value of the uplink carrier;

[0019] or,

[0020] If the RSRP measured by the terminal is higher than the first RSRP threshold, the selected first uplink carrier is NUL, or the coverage is smaller than a preset value, or the frequency is higher than a preset value.

[0021] Optionally, the method further comprises:

[0022] Determine, according to the RSRP of the one or more first uplink carriers and the second RSRP threshold, to initiate a 2-step random access 2-step RA or a 4-step random access 4-step RA on each first uplink carrier;

[0023] The second RSRP threshold is used to select 2-step RA and 4-step RA, and the second RSRP threshold corresponds to one or more first uplink carriers.

[0024] Optionally, if the RSRP measured by the terminal is lower than or equal to the first RSRP threshold, and a first uplink carrier is selected, determining to initiate a 2-step random access 2-step RA or a 4-step random access 4-step RA on each first uplink carrier according to the RSRP of the one or more first uplink carriers and the second RSRP threshold, includes:

[0025] If the RSRP measured by the terminal is higher than a second RSRP threshold corresponding to the first uplink carrier, initiating a 2-step RA on the first uplink carrier;

[0026] If the RSRP measured by the terminal is lower than or equal to a second RSRP threshold corresponding to the first uplink carrier, a 4-step RA is initiated on the first uplink carrier.

[0027] Optionally, if the RSRP measured by the terminal is higher than the first RSRP threshold, and multiple first uplink carriers are selected, determining to initiate a 2-step RA or a 4-step RA on each first uplink carrier according to the RSRP of the one or more first uplink carriers and the second RSRP threshold includes:

[0028] If the RSRP of at least one first uplink carrier among the multiple first uplink carriers is higher than the second RSRP threshold, a 2-step RA is initiated on the at least one first uplink carrier; otherwise, a 4-step RA is initiated on the multiple first uplink carriers.

[0029] Optionally, initiating a 2-step RA on the at least one first uplink carrier includes:

[0030] According to the transmission priority indicated by the network side or determined autonomously by the terminal, the preamble in the MSGA is sent on a first uplink carrier, and the PUSCH in the MSGA is sent on other first uplink carriers.

[0031] Optionally, a bandwidth of the first uplink carrier for sending the preamble is smaller than a bandwidth of the first uplink carrier for sending the PUSCH;

[0032] or,

[0033] The frequency of the first uplink carrier for transmitting the preamble is higher than the frequency of the first uplink carrier for transmitting the PUSCH.

[0034] Optionally, the method further comprises:

[0035] If 4-step RA fails on the first uplink carrier selected by the terminal, 4-step RA is initiated on other uplink carriers corresponding to the first RSRP threshold according to the RSRP measured by the terminal and the first RSRP threshold.

[0036] Optionally, four steps of random access are performed, including:

[0037] If the terminal has dual connectivity or uplink carrier aggregation capability, MSG1 is sent simultaneously on multiple first uplink carriers;

[0038] or,

[0039] If the terminal does not have dual connectivity or uplink carrier aggregation capability, MSG1 is sent on multiple first uplink carriers in a time division multiplexing manner.

[0040] Optionally, the multiple first uplink carriers correspond to a group of preamble code resources configured by the network side for the terminal, and the group of preamble code resources includes multiple preamble codes.

[0041] Optionally, acquiring a second uplink carrier indicated by the network side includes:

[0042] A MSG2 is received in response to the MSG1, where the MSG2 indicates a second uplink carrier selected by the network side for sending the MSG3.

[0043] Optionally, the first bit in the scheduling information in the MSG2 indicates the second uplink carrier, or the second bit in the MAC payload in the MSG2 indicates the second uplink carrier.

[0044] Optionally, the uplink carrier indicated for sending MSG3 is an uplink frequency band number or an uplink frequency position or an uplink carrier number of the uplink carrier indicated for sending MSG3.

[0045] Optionally, the scheduling information of MSG2 further indicates the time-frequency resources of the uplink carrier for sending MSG3, and / or the temporary C-RNTI of the first uplink carrier.

[0046] In a second aspect, an embodiment of the present application provides a method for accessing multiple uplink carriers, which is performed by a network side device and includes:

[0047] Processing a four-step random access performed by a terminal on one or more first uplink carriers and a second uplink carrier, or processing a two-step random access performed by a terminal on multiple first uplink carriers;

[0048] The first uplink carrier is used to send MSG1 in four-step random access, the second uplink carrier is used to send MSG3 in four-step random access, or the multiple first uplink carriers are used to send MSGA in two-step random access.

[0049] Optionally, a four-step random access process is performed, including:

[0050] MSG2 is sent to the terminal, where the MSG2 indicates a second uplink carrier, where the second uplink carrier is used to send MSG3 in the four-step random access, where the second uplink carrier is different from the first uplink carrier, and where the first uplink carrier is used to send MSG1 in the four-step random access.

[0051] Optionally, the method further comprises:

[0052] Receiving MSG1 via one or more first uplink carriers;

[0053] Determine uplink channel information according to the MSG1;

[0054] A second uplink carrier is selected according to the uplink channel information.

[0055] Optionally, the first bit in the scheduling information in the MSG2 indicates the second uplink carrier, or the second bit in the MAC payload in the MSG2 indicates the second uplink carrier.

[0056] Optionally, the MSG2 indicates the uplink frequency band number or the uplink frequency position or the uplink carrier number of the uplink carrier sending the MSG3.

[0057] Optionally, the scheduling information of MSG2 further indicates the time-frequency resources of the uplink carrier for sending MSG3, and / or the temporary C-RNTI of the first uplink carrier.

[0058] Optionally, before the step of processing the terminal performing two-step random access on multiple first uplink carriers, the method further includes:

[0059] The transmission priority of the preamble and the PUSCH in the MSGA on the plurality of first uplink carriers is indicated to the terminal.

[0060] In a third aspect, an embodiment of the present application provides an access device for multiple uplink carriers, including:

[0061] A first acquisition module, used to acquire one or more first uplink carriers selected by the terminal and / or a second uplink carrier indicated by the network side;

[0062] A first processing module, configured to perform four-step random access according to the one or more first uplink carriers and the second uplink carrier, or perform two-step random access according to the multiple first uplink carriers;

[0063] The first uplink carrier is used to send MSG1 in four-step random access, the second uplink carrier is used to send MSG3 in four-step random access, or the multiple first uplink carriers are used to send MSGA in two-step random access.

[0064] In a fourth aspect, an embodiment of the present application provides an access device for multiple uplink carriers, including:

[0065] A third processing module is used to process four-step random access performed by the terminal on one or more first uplink carriers and second uplink carriers, or to process two-step random access performed by the terminal on multiple first uplink carriers;

[0066] The first uplink carrier is used to send MSG1 in four-step random access, the second uplink carrier is used to send MSG3 in four-step random access, or the multiple first uplink carriers are used to send MSGA in two-step random access.

[0067] In a fifth aspect, an embodiment of the present application provides an access device for multiple uplink carriers, including:

[0068] A third processing module is used to process four-step random access performed by the terminal on one or more first uplink carriers and second uplink carriers, or to process two-step random access performed by the terminal on multiple first uplink carriers;

[0069] The first uplink carrier is used to send MSG1 in four-step random access, the second uplink carrier is used to send MSG3 in four-step random access, or the multiple first uplink carriers are used to send MSGA in two-step random access.

[0070] In a sixth aspect, an embodiment of the present application provides a network side device, comprising: a processor, a memory, and a program stored in the memory and executable on the processor, wherein the program, when executed by the processor, implements the steps of the method described in the first aspect.

[0071] In the seventh aspect, an embodiment of the present application provides a network side device, comprising: a processor, a memory, and a program stored in the memory and executable on the processor, wherein the program, when executed by the processor, implements the steps of the method described in the second aspect.

[0072] In an eighth aspect, an embodiment of the present application provides a readable storage medium having a program stored thereon, and when the program is executed by a processor, the steps of the method described in the first aspect or the second aspect are implemented.

[0073] In the embodiment of the present application, by initiating random access on multiple uplink carriers, the success probability of random access is enhanced, the system robustness is enhanced, and the uplink resources of the cell are fully utilized. BRIEF DESCRIPTION OF THE DRAWINGS

[0074] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Also, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0075] Figure 1 is a block diagram of a wireless communication system to which the embodiments of the present application can be applied;

[0076] Figure 2 This is one of the flow charts of the method for accessing multiple uplink carriers according to an embodiment of the present application;

[0077] Figure 3 This is one of the flowcharts of the access method of multiple uplink carriers in the embodiment of the present application.

[0078] Figure 4 It is one of the schematic diagrams of RSRP threshold configuration in the embodiment of the present application;

[0079] Figure 5 is a schematic diagram of MSG2 in an embodiment of the present application;

[0080] Figure 6 This is the second schematic diagram of RSRP threshold configuration in an embodiment of the present application;

[0081] Figure 7 This is one of the schematic diagrams of the access device for multiple uplink carriers according to an embodiment of the present application;

[0082] Figure 8This is the second schematic diagram of the access device for multiple uplink carriers according to an embodiment of the present application;

[0083] Fig. 9 is a schematic diagram of a terminal according to an embodiment of the present application;

[0084] Fig.10 It is a schematic diagram of the network side device of an embodiment of the present application. DETAILED DESCRIPTION

[0085] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0086] The term "comprise" and any variation thereof in the specification and claims of the present application are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units need not be limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices. In addition, the use of "and / or" in the specification and claims to indicate at least one of the connected objects, such as A and / or B, means that A alone, B alone, and A and B exist in three cases.

[0087] In the embodiments of the present application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific way.

[0088] It is worth noting that the technology described in the embodiments of the present application is not limited to the Long Term Evolution (LTE) / LTE-Advanced (LTE-A) system, but can also be used in other wireless communication systems, such as Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), Single-carrier Frequency Division Multiple Access (SC-FDMA) and other systems. The terms "system" and "network" in the embodiments of the present application are often used interchangeably, and the described technology can be used for the above-mentioned systems and radio technologies as well as other systems and radio technologies. However, the following description describes a new radio (NR) system for example purposes, and NR terms are used in most of the following descriptions, although these technologies can also be applied to applications other than NR system applications, such as the 6th Generation (6G) communication system.

[0089] Figure 1A block diagram of a wireless communication system applicable to an embodiment of the present application is shown. The wireless communication system includes a terminal 11 and a network side device 12. Among them, the terminal 11 can also be called a terminal device or a user terminal (User Equipment, UE), and the terminal 11 can be a mobile phone, a tablet computer (Tablet Personal Computer), a laptop computer (Laptop Computer) or a notebook computer, a personal digital assistant (Personal Digital Assistant, PDA), a handheld computer, a netbook, an ultra-mobile personal computer (ultra-mobile personal computer, UMPC), a mobile Internet device (Mobile Internet Device, MID), a wearable device (Wearable Device) or a vehicle-mounted device (VUE), a pedestrian terminal (PUE) and other terminal side devices, and the wearable device includes: a bracelet, a headset, glasses, etc. It should be noted that the specific type of the terminal 11 is not limited in the embodiment of the present application. The network side device 12 can be a base station or a core network, wherein the base station can be referred to as a node B, an evolved node B, an access point, a base transceiver station (Base Transceiver Station, BTS), a radio base station, a radio transceiver, a basic service set (Basic Service Set, BSS), an extended service set (Extended Service Set, ESS), a B node, an evolved B node (eNB), a home B node, a home evolved B node, a WLAN access point, a WiFi node, a transmitting and receiving point (Transmitting Receiving Point, TRP) or some other suitable term in the field. As long as the same technical effect is achieved, the base station is not limited to the specified technical vocabulary. It should be noted that in the embodiment of the present application, only the base station in the NR system is taken as an example, but the specific type of the base station is not limited.

[0090] See also Figure 2 , an embodiment of the present application provides a method for accessing multiple uplink carriers, which is executed by a terminal, and the specific steps include: step 201 and step 202.

[0091] Step 201: Acquire one or more first uplink carriers selected by the terminal and / or a second uplink carrier indicated by the network side;

[0092] Performing four-step random access according to the one or more first uplink carriers and the second uplink carrier, or performing two-step random access according to the multiple first uplink carriers;

[0093] The first uplink carrier is used to send message 1 (MSG1) in four-step random access, the second uplink carrier is used to send message 3 (MSG3) in four-step random access, or the multiple first uplink carriers are used to send message A (MSGA) in two-step random access.

[0094] In the embodiment of the present application, obtaining one or more first uplink carriers selected by the terminal includes:

[0095] One or more first uplink carriers are selected according to a reference signal received power (RSRP) measured by the terminal and a first RSRP threshold; wherein the first RSRP threshold is used by the terminal to select the first uplink carrier.

[0096] In the embodiment of the present application, selecting one or more first uplink carriers according to the RSRP measured by the terminal and the first RSRP threshold includes:

[0097] If the RSRP measured by the terminal is lower than or equal to the first RSRP threshold, selecting a first uplink carrier corresponding to the first RSRP threshold;

[0098] or,

[0099] If the RSRP measured by the terminal is higher than the first RSRP threshold, one or more first uplink carriers corresponding to the first RSRP threshold are selected.

[0100] In an embodiment of the present application, if the RSRP measured by the terminal is lower than or equal to the first RSRP threshold, the selected first uplink carrier is SUL, or the coverage range is greater than a preset value, or the frequency is lower than the preset value of the uplink carrier; or, if the RSRP measured by the terminal is higher than the first RSRP threshold, the selected first uplink carrier is NUL, or the coverage range is less than a preset value, or the frequency is higher than the preset value of the uplink carrier.

[0101] In an embodiment of the present application, the method further includes:

[0102] Determining, according to the RSRP of the one or more first uplink carriers and the second RSRP threshold, to initiate a 2-step random access (2-step RA) or a 4-step random access (4-step RA) on each first uplink carrier;

[0103] The second RSRP threshold is used to select 2-step RA and 4-step RA, and the second RSRP threshold corresponds to one or more first uplink carriers.

[0104] In an embodiment of the present application, if the RSRP measured by the terminal is lower than or equal to the first RSRP threshold, and a first uplink carrier is selected, the determining, according to the RSRP of the one or more first uplink carriers and the second RSRP threshold, to initiate a 2-step random access 2-step RA or a four-step random access 4-step RA on each first uplink carrier includes:

[0105] If the RSRP measured by the terminal is higher than a second RSRP threshold corresponding to the first uplink carrier, initiating a 2-step RA on the first uplink carrier;

[0106] If the RSRP measured by the terminal is lower than or equal to a second RSRP threshold corresponding to the first uplink carrier, a 4-step RA is initiated on the first uplink carrier.

[0107] In an embodiment of the present application, if the RSRP measured by the terminal is higher than the first RSRP threshold, and multiple first uplink carriers are selected, the determining, according to the RSRP of the one or more first uplink carriers and the second RSRP threshold, to initiate a 2-step RA or a 4-step RA on each first uplink carrier includes:

[0108] If the RSRP of at least one first uplink carrier among the multiple first uplink carriers is higher than the second RSRP threshold, a 2-step RA is initiated on the at least one first uplink carrier; otherwise, a 4-step RA is initiated on the multiple first uplink carriers.

[0109] In the embodiment of the present application, initiating a 2-step RA on the at least one first uplink carrier includes:

[0110] According to the transmission priority indicated by the network side or determined autonomously by the terminal, a preamble in the MSGA is sent on a first uplink carrier, and a physical uplink shared channel (Physical Uplink Shared Channel, PUSCH) in the MSGA is sent on other first uplink carriers.

[0111] In an embodiment of the present application, the method further includes:

[0112] If 4-step RA fails on the first uplink carrier selected by the terminal, 4-step RA is initiated on other uplink carriers corresponding to the first RSRP threshold according to the RSRP measured by the terminal and the first RSRP threshold.

[0113] In the embodiment of the present application, the four-step random access in step 201 includes: if the terminal has dual connection or uplink carrier aggregation capability, MSG1 is sent on multiple first uplink carriers simultaneously; or, if the terminal does not have dual connection or uplink carrier aggregation capability, MSG1 is sent on multiple first uplink carriers by time division multiplexing.

[0114] In this embodiment of the present application, the plurality of first uplink carriers correspond to a group of preamble code resources configured by the network side for the terminal, and the group of preamble code resources includes a plurality of preamble codes.

[0115] In the embodiment of the present application, obtaining the second uplink carrier indicated by the network side includes:

[0116] A MSG2 is received in response to the MSG1, where the MSG2 indicates a second uplink carrier selected by the network side for sending a message 3 (MSG3).

[0117] In an embodiment of the present application, it is characterized in that the first bit in the scheduling information in the MSG2 indicates the second uplink carrier, or the second bit in the MAC payload in the MSG2 indicates the second uplink carrier.

[0118] In the embodiment of the present application, the uplink carrier indicated for sending MSG3 is the uplink frequency band number or the uplink frequency position or the uplink carrier number of the uplink carrier indicated for sending MSG3.

[0119] In the embodiment of the present application, the scheduling information of MSG2 further indicates the time-frequency resources of the uplink carrier for sending MSG3, and / or the temporary C-RNTI of the first uplink carrier.

[0120] In the embodiment of the present application, by initiating random access on multiple uplink carriers, the success probability of random access is enhanced, the system robustness is enhanced, and the uplink resources of the cell are fully utilized.

[0121] See also Figure 3 , the embodiment of the present application provides an access method, which is performed by a network side device, and the specific steps include:

[0122] Step 301: Processing a four-step random access performed by a terminal on one or more first uplink carriers and a second uplink carrier, or processing a two-step random access performed by a terminal on multiple first uplink carriers;

[0123] The first uplink carrier is used to send MSG1 in four-step random access, the second uplink carrier is used to send MSG3 in four-step random access, or the multiple first uplink carriers are used to send MSGA in two-step random access.

[0124] In the embodiment of the present application, the four-step random access processing is performed, including:

[0125] MSG2 is sent to the terminal, where the MSG2 indicates a second uplink carrier, where the second uplink carrier is used to send MSG3 in the four-step random access, where the second uplink carrier is different from the first uplink carrier, and where the first uplink carrier is used to send MSG1 in the four-step random access.

[0126] In the embodiment of the present application, the method further includes: receiving MSG1 through one or more first uplink carriers; determining uplink channel information according to the MSG1; and selecting a second uplink carrier according to the uplink channel information.

[0127] In the embodiment of the present application, the first bit in the scheduling information in the MSG2 indicates the second uplink carrier, or the second bit in the MAC payload in the MSG2 indicates the second uplink carrier.

[0128] In the embodiment of the present application, the uplink carrier indicated for sending MSG3 is the uplink frequency band number or the uplink frequency position or the uplink carrier number of the uplink carrier indicated for sending MSG3.

[0129] In the embodiment of the present application, the scheduling information of MSG2 further indicates the time-frequency resources of the uplink carrier for sending MSG3, and / or the temporary C-RNTI of the first uplink carrier.

[0130] In the embodiment of the present application, before the step of processing the terminal performing two-step random access on multiple first uplink carriers, the method further includes:

[0131] The transmission priority of the preamble and the PUSCH in the MSGA on the plurality of first uplink carriers is indicated to the terminal.

[0132] In the embodiment of the present application, by initiating random access on multiple uplink carriers, the success probability of random access is enhanced, the system robustness is enhanced, and the uplink resources of the cell are fully utilized.

[0133] The following is an introduction to Plan 1, Plan 2, Plan 3 and Plan 4.

[0134] Solution 1: (Four-step RACH).

[0135] Step 1: The terminal receives a first RSRP threshold sent by the network, where the first RSRP threshold corresponds to one or more uplink (UL) carriers in the cell (for example, one RSRP threshold corresponds to one UL carrier, or one RSRP threshold corresponds to multiple UL carriers), and the terminal selects an uplink carrier for random access according to the RSRP threshold. Specifically:

[0136] a) If the RSRP measured by the terminal is lower than or equal to the first RSRP threshold, the terminal selects a supplementary uplink (SUL) or a UL with a larger coverage or a lower frequency to send MSG1;

[0137] b) If the RSRP measured by the terminal is higher than the first RSRP threshold, the terminal selects a normal uplink (normal UL, NUL) or a UL with a smaller coverage or a higher frequency to send MSG1.

[0138] Step 2: The terminal receives a UL carrier number or index sent by the network, for example, NUL is uplink carrier 1 and SUL is uplink carrier 2.

[0139] Step 3: The network receives the random access MSG1 sent by the terminal, and obtains uplink channel information by detecting the preamble, for example, uplink channel quality or RSRQ reported by the terminal.

[0140] Step 4: The network makes a judgment based on the uplink channel information. If it is judged that the uplink channel quality or RSRQ is lower than or equal to a certain threshold, it means that the uplink quality is poor and the probability of failure to send MSG3 is also high. If the RSRP measured by the terminal is higher than the first RSRP threshold at this time, that is, multiple UL carriers are covered, then in order to ensure random access performance, the network instructs the terminal in MSG2 (equivalent to random access response) to send MSG3 on other UL carriers (UL carriers not sent by MSG1, but at the same time RSRP is higher than the first RSRP threshold);

[0141] a) Add a bit in the scheduling information of MSG2 (e.g., UL Grant) to indicate the uplink carrier on which MSG3 is sent, or indicate the uplink carrier on which MSG3 is sent in a reserved bit of the media access control (MAC) payload of MSG2, wherein the bit indicates the uplink frequency band number or the uplink frequency position or the uplink carrier number or index.

[0142] b) The scheduling information (e.g., UL Grant) of MSG2 carries information about random access resources (e.g., time-frequency resources) of the uplink carrier for sending MSG3; further, the UL Grant of RAR also includes: a temporary cell radio network temporary identifier (Cell Radio Network Temporary Identifier, C-RNTI) of the uplink carrier for sending MSG3, see Figure 5 .

[0143] i. To complete this step, the network needs to negotiate random access resources of at least two uplink carriers, and the temporary C-RNTI allocated to the terminal by the uplink carrier that sends MSG1.

[0144] Table 1 shows the relationship between the random access response authorization field and the number of bits.

[0145] Table 1:

[0146] Random access response authorization field (RAR grant field) Number of bits Frequency hopping flag 1 Msg3 PUSCH frequency resource allocation 14 Msg3 PUSCH time resource allocation 4 Modulation and Coding Scheme (MCS) 4 TPC command for Msg3 PUSCH 3 Channel State Information Request (CSI request) 1

[0147] Step 5: The terminal transmits MSG3 on the UL carrier indicated by MSG2 according to the scheduling information in MSG2, and continues to complete the random access process.

[0148] Step 6: The network side receives MSG3 and sends MSG4.

[0149] Example 1-1: (Four-step RACH).

[0150] See also Figure 4 The cell has 1 downlink (DL) and 2 uplinks (UL) (including normal uplink (NUL) and supplementary uplink (SUL)), where NUL and DL are time division duplex (TDD) frequency bands, SUL is the uplink supplementary frequency band, the carrier number of NUL is uplink carrier 1, and the carrier number of SUL is uplink carrier 2.

[0151] The network side sends a first RSRP threshold, which corresponds to the SUL carrier. If the RSRP measured by the terminal is lower than or equal to the first RSRP threshold, the terminal selects the SUL carrier to initiate random access. If the RSRP measured by the terminal is higher than the first RSRP threshold, the terminal selects the NUL carrier to initiate random access.

[0152] The terminal receives the first RSRP threshold. At this time, the RSRP measured by the terminal is higher than the first RSRP threshold, and the terminal initiates random access on the NUL carrier (uplink carrier 1) and sends MSG1.

[0153] The network side receives MSG1 sent by the terminal and finds that the uplink quality between the terminal and the network side is poor. Therefore, it informs the terminal in MSG2 to send MSG3 on the SUL carrier (uplink carrier 2), and at the same time informs the terminal of the time-frequency position of MSG3 and the temporary RNTI.

[0154] The terminal sends MSG3 on the SUL carrier (uplink carrier 2) according to the scheduling information in MSG2. The network side receives MSG3 and sends MSG4.

[0155] Example 1-2: (Four-step RACH)

[0156] See also Figure 6 The cell has 1 DL and 3 UL (including NUL, SUL1 and SUL2). NUL and DL are one frequency band, and SUL1 and SUL2 are uplink supplementary frequency bands.

[0157] The network side sends the first RSRP threshold (including RSRP threshold 1 and RSRP threshold 2), RSRP threshold 1 corresponds to SUL1, if the RSRP measured by the terminal is lower than or equal to RSRP threshold 1, the terminal selects the SUL1 carrier to initiate random access; if the RSRP measured by the terminal is higher than RSRP threshold 1 and lower than or equal to RSRP threshold 2, the terminal selects the SUL2 carrier to initiate random access; if the RSRP measured by the terminal is higher than RSRP threshold 2, the terminal selects the NUL carrier to initiate random access.

[0158] If the RSRP measured at the terminal side is higher than RSRP threshold 1 and lower than or equal to RSRP threshold 2, the terminal selects SUL2 for random access, that is, sends MSG1.

[0159] The network side receives MSG1 sent by the terminal and finds that the uplink quality between the terminal and the network side is poor. Therefore, it informs the terminal in MSG2 to send MSG3 on the SUL2 carrier, and at the same time informs the terminal of the time-frequency position of MSG3, the frequency of the SUL2 carrier, and the temporary RNTI.

[0160] The terminal sends MSG3 on the SUL2 carrier according to the scheduling information of MSG2. The network receives MSG3 and sends MSG4.

[0161] Example 1-3: (Four-step RACH)

[0162] See also Figure 6 The cell has 1 DL and 3 UL (including: NUL, SUL1 and SUL2). NUL and DL are one frequency band, and SUL1 and SUL2 are uplink supplementary frequency bands.

[0163] The network side sends the first RSRP threshold (including RSRP threshold 1 and RSRP threshold 2), RSRP threshold 1 corresponds to SUL1, if the RSRP measured by the terminal is lower than or equal to RSRP threshold 1, the terminal selects the SUL1 carrier to initiate random access; if the RSRP measured by the terminal is higher than RSRP threshold 1 and lower than or equal to RSRP threshold 2, the terminal selects the SUL2 carrier to initiate random access; if the RSRP measured by the terminal is higher than RSRP threshold 2, the terminal selects the NUL carrier to initiate random access.

[0164] If the RSRP measured by the terminal is higher than RSRP threshold 2, the terminal selects NUL for random access, that is, sends MSG1.

[0165] The network side receives MSG1 sent by the terminal and finds that the uplink quality between the terminal and the network side is poor. The network side determines the uplink carrier on which the terminal sends MSG3 based on the load and / or interference conditions of the SUL1 and SUL2 carriers. For example, if the load on the SUL2 carrier is large, the network side informs the terminal in MSG2 to send MSG3 on the SUL1 carrier, and at the same time informs the terminal of the time-frequency position of sending MSG3, the frequency of the SUL1 carrier, and the temporary RNTI.

[0166] The terminal sends MSG3 on the SUL1 carrier according to the scheduling information of MSG2. The network receives MSG3 and sends MSG4.

[0167] Solution 2: (Four-step RACH).

[0168] Step 1: The terminal receives a first RSRP threshold sent by the network side, where the first RSRP threshold corresponds to one or more UL carriers in the cell (one RSRP may correspond to one UL carrier, or one RSRP may correspond to multiple UL carriers), and the terminal selects an uplink carrier for random access according to the first RSRP threshold. Specifically:

[0169] a) If the RSRP measured by the terminal is lower than or equal to the first RSRP threshold, the terminal selects the SUL or a UL with a larger coverage or a lower frequency for random access.

[0170] b) If the RSRP measured by the terminal is higher than the first RSRP threshold, the terminal selects the NUL or a UL with a smaller coverage or a higher frequency for random access.

[0171] Step 2: If the terminal fails to perform random access on the selected uplink carrier, if the cell has other uplink carriers, the terminal performs a random access process on other uplink carriers that meet the first RSRP threshold.

[0172] For example, according to current standards, after a random access failure occurs in the first selected UL of the terminal, a radio link failure occurs.

[0173] Example 2-1: (Four-step RACH).

[0174] See also Figure 4 , the cell has 1 DL and 2 UL (NUL and SUL), where NUL and DL are TDD frequency bands, and SUL is the uplink supplementary frequency band.

[0175] The network sends a first RSRP threshold, which corresponds to the SUL carrier. If the RSRP measured by the terminal is lower than or equal to the first RSRP threshold, the terminal selects the SUL carrier to initiate random access. If the RSRP measured by the terminal is higher than the first RSRP threshold, the terminal selects the NUL carrier to initiate random access.

[0176] If the terminal fails in random access on the NUL carrier, it re-initiates random access on the SUL carrier.

[0177] Solution 3: (Four-step RACH)

[0178] Step 1: The terminal receives a first RSRP threshold sent by the network side, where the first RSRP threshold corresponds to one or more UL carriers in the cell (one RSRP may correspond to one UL carrier, or one RSRP may correspond to multiple UL carriers), and the terminal selects an uplink carrier for random access according to the first RSRP threshold. Specifically:

[0179] a) If the RSRP measured by the terminal is lower than or equal to the first RSRP threshold, the terminal selects the SUL or an uplink carrier with a larger coverage or a lower frequency for random access.

[0180] b) If the RSRP measured by the terminal is higher than the first RSRP threshold, the terminal chooses to perform random access on multiple UL carriers simultaneously.

[0181] Step 2: The terminal receives an uplink carrier number or index sent by the network, for example, NUL is uplink carrier 1, and SUL is uplink carrier 2.

[0182] Step 3: If the RSRP measured by the terminal is higher than the first RSRP threshold, the terminal selects to perform random access on multiple uplink carriers simultaneously, specifically including the terminal sending MSG1 on multiple uplink carriers:

[0183] i. A terminal with dual connectivity or uplink carrier aggregation capability can send uplinks on multiple uplink carriers simultaneously and perform random access.

[0184] ii. A terminal that does not have dual connectivity or uplink carrier aggregation capabilities can perform random access on multiple uplink carriers in time division.

[0185] Step 4: The network side allocates a group of preamble code resources specifically for sending MSG1 on multiple uplink carriers. This group of preamble code resources contains a mapping relationship, that is, indicating which preamble codes belong to a random access process. If the terminal wants to send MSG1 on multiple uplink carriers, the allocated preamble code resources are selected.

[0186] Step 5: The network side receives MSG1 sent by the terminal. If a preamble code belonging to a UE is detected on multiple uplink carriers, the network side selects an uplink carrier with better uplink channel quality and / or lighter load according to the uplink channel quality and / or load, for the terminal to send MSG3; if the preamble code of the UE is detected on only one uplink carrier, the uplink carrier is selected for the terminal to send MSG3.

[0187] Step 6: When sending MSG2, the network side adds a bit in the UL Grant of MSG2 to indicate the uplink carrier for sending MSG3, or indicates the uplink carrier for sending MSG3 in the reserved bit of the MAC payload of MSG2. The newly added bit or reserved bit can indicate the uplink frequency band number or the uplink frequency position or the uplink carrier number.

[0188] a) The time-frequency resources of the uplink carrier and / or the temporary C-RNTI of the uplink carrier are carried in the UL Grant of MSG2.

[0189] b) To complete this step, the network needs to negotiate the random access resources of at least two uplink carriers, and the temporary C-RNTI allocated to the terminal by the uplink carrier sending MSG1, see Figure 5 and Table 1.

[0190] Step 7: The terminal transmits MSG3 according to the scheduling information in MSG2.

[0191] Step 8: The network side receives MSG3 and sends MSG4.

[0192] Example 3-1: (Four-step RACH).

[0193] See also Figure 4 The cell has 1 DL and 2 UL (NUL and SUL), where NUL and DL are TDD frequency bands, and SUL is an uplink supplementary frequency band. Here, the NUL carrier is numbered as uplink carrier 1, and the SUL carrier is numbered as uplink carrier 2.

[0194] The network side sends a first RSRP threshold, which corresponds to the SUL carrier. If the RSRP measured by the terminal is lower than or equal to the first RSRP threshold, the SUL carrier is selected to initiate random access. If the RSRP measured by the terminal is higher than the first RSRP threshold, SUL and NUL are selected to initiate random access at the same time.

[0195] The network side allocates special preamble codes for initiating random access in multiple ULs, and maps the preamble codes therein, for example, preamble 1 code and preamble 2 code are grouped together. When the network side receives these two preamble codes, it knows that they are from the same UE.

[0196] The terminal receives the first RSRP threshold. At this time, the RSRP measured by the terminal is higher than the first SRP threshold. The terminal initiates random access on NUL carrier 1 and SUL carrier 2, and sends two MSG1s. The preamble code used to send MSG1 is a preamble code resource specially allocated by the network, for example, including preamble1 code and preamble2 code.

[0197] The network side receives MSG1 sent by the terminal and successfully detects MSG1 sent by the terminal on both NUL and SUL. At this time, the network finds that the uplink channel quality of the SUL carrier is better, so it informs the terminal in MSG2 to send MSG3 on the SUL carrier (uplink carrier 2), and at the same time informs the terminal of the time-frequency position of MSG3 and the temporary RNTI.

[0198] The terminal sends MSG3 on the SUL carrier (uplink carrier 2) according to the scheduling information of MSG2. The network side receives MSG3 and sends MSG4.

[0199] Example 3-2: (Four-step RACH)

[0200] See also Figure 6 The cell has 1 DL and 3 UL (NUL, SUL1 and SUL2). NUL and DL are in the same frequency band, and SUL1 and SUL2 are uplink supplementary frequency bands.

[0201] The network sends the first RSRP (RSRP threshold 1 and RSRP threshold 2), RSRP threshold 1 corresponds to SUL1. If the RSRP measured by the terminal is lower than or equal to RSRP threshold 1, the terminal selects the SUL1 carrier to initiate random access; if the RSRP measured by the terminal is higher than RSRP threshold 1 and lower than or equal to RSRP threshold 2, the terminal selects SUL2 and SUL1 carriers to initiate random access; if the RSRP is higher than RSRP threshold 2, the terminal selects 2 uplink carriers from NUL, SUL1 and SUL2 carriers to initiate random access.

[0202] The network side allocates special preamble code resources for initiating random access in multiple ULs, and maps the preamble codes therein, for example, preamble 1 code and preamble 2 code are grouped together. When the network side receives these two preamble codes, it knows that they are from the same UE.

[0203] The terminal receives the first RSRP threshold. At this time, the RSRP measured by the terminal is higher than RSRP threshold 1 and lower than RSRP threshold 2. Then the terminal initiates random access at SUL1 and SUL2, and sends two MSG1s. The preamble code used to send MSG1 is the preamble code resource specially allocated by the network, such as preamble1 code and preamble2 code.

[0204] The network side receives MSG1 sent by the terminal and successfully detects MSG1 sent by the terminal on both SUL1 and SUL2. At this time, the network finds that the uplink channel quality of SUL1 is better, so it informs the terminal in MSG2 to send MSG3 on SUL1, and at the same time informs the terminal of the time-frequency position of MSG3 and the temporary RNTI.

[0205] The terminal sends MSG3 in SUL1 according to the scheduling information measured by the terminal. The network side receives MSG3 and sends MSG4.

[0206] Example 3-3: (Four-step RACH)

[0207] See also Figure 6 The cell has 1 DL and 3 UL (NUL, SUL1 and SUL2). NUL and DL are in the same frequency band, and SUL1 and SUL2 are uplink supplementary frequency bands.

[0208] The network side sends the first RSRP threshold (RSRP threshold 1 and RSRP threshold 2), RSRP threshold 1 corresponds to SUL1. If the RSRP measured by the terminal is lower than or equal to RSRP threshold 1, the SUL1 carrier is selected to initiate random access; if the RSRP measured by the terminal is higher than RSRP threshold 1 and lower than or equal to RSRP threshold 2, SUL2 and SUL1 carriers are selected to initiate random access; if the RSRP measured by the terminal is higher than RSRP threshold 2, 2 UL carriers are selected from NUL, SUL1 and SUL2 to initiate random access.

[0209] The network side allocates special preamble code resources for initiating random access in multiple ULs, and maps the preamble codes in the preamble code resources, for example, preamble 1 and preamble 2 are grouped together. When the network receives these two preamble codes, it knows that they are from the same UE.

[0210] The terminal receives the first RSRP threshold. At this time, the RSRP measured by the terminal is higher than RSRP threshold 2. The terminal initiates random access on NUL and SUL2 and sends two MSG1s. The preamble code used to send MSG1 is the preamble code resource specially allocated by the network, such as preamble1 and preamble2.

[0211] The network receives MSG1 sent by the terminal and successfully detects MSG1 sent by the terminal on both NUL and SUL2. At this time, the network finds that the uplink channel quality of SUL2 is better, so it informs the terminal in MSG2 to send MSG3 on SUL2, and informs the terminal of the time-frequency position of MSG3 and the temporary RNTI.

[0212] Optionally, if the uplink channel quality of NUL and SUL2 is very poor, the network side informs the terminal in MSG2 to send MSG3 on SUL1, and informs the terminal of the time-frequency position of MSG3 and the temporary RNTI.

[0213] The terminal sends MSG3 on the uplink carrier indicated in MSG2 according to the scheduling information of MSG2. The network receives MSG3 and sends MSG4.

[0214] Example 3-4: (Four-step RACH)

[0215] See also Figure 6 The cell has 1 DL and 3 UL (including NUL, SUL1 and SUL2). NUL and DL are one frequency band, and SUL1 and SUL2 are uplink supplementary frequency bands.

[0216] The network side sends the first RSRP (including: RSRP threshold 1 and RSRP threshold 2), RSRP threshold 1 corresponds to SUL1, if the RSRP measured by the terminal is lower than or equal to RSRP threshold 1, the SUL1 carrier is selected to initiate random access; if the RSRP measured by the terminal is higher than RSRP threshold 1 and lower than or equal to RSRP threshold 2, SUL2 and SUL1 carriers are selected to initiate random access; if the RSRP measured by the terminal is higher than RSRP threshold 2, 2 uplink carriers are selected from NUL, SUL1 and SUL2 to initiate random access.

[0217] The network side allocates special preamble code resources for initiating random access in multiple ULs, and maps the preamble codes therein, for example, preamble 1 and preamble 2 are grouped together. When the network side receives these two preamble codes, it knows that they are from the same UE.

[0218] The terminal receives the first RSRP threshold. At this time, the RSRP measured by the terminal is higher than RSRP threshold 2. The terminal initiates random access on NUL and SUL2 and sends two MSG1s. The preamble code used to send MSG1 is the preamble code resource specially allocated by the network side, such as preamble1 and preamble2.

[0219] The network side receives MSG1 sent by the terminal and successfully detects MSG1 sent by the terminal on both NUL and SUL2. At this time, the network finds that the uplink channel quality of SUL2 is better, so it informs the terminal in MSG2 to send MSG3 on SUL2, and at the same time informs the terminal of the time-frequency position of MSG3 and the temporary RNTI.

[0220] Optionally, if the uplink channel quality of NUL and SUL2 is very poor, the network side informs the terminal in MSG2 to send MSG3 on SUL1, and informs the terminal of the time-frequency position of MSG3 and the temporary RNTI. The terminal sends MSG3 on the uplink carrier indicated in MSG2 according to the scheduling information of MSG2. The network side receives MSG3 and sends MSG4.

[0221] Solution 4: (Two-step RACH)

[0222] Step 1: The terminal receives a first RSRP threshold sent by the network, where the first RSRP threshold corresponds to one or more UL carriers in the cell (for example, one first RSRP threshold corresponds to one uplink carrier, or one first RSRP threshold corresponds to multiple uplink carriers), and the terminal selects an uplink carrier for random access according to the RSRP threshold.

[0223] Step 2: The terminal receives the carrier number or index of the uplink carrier sent by the network, for example, NUL is uplink carrier 1, and SUL is uplink carrier 2.

[0224] Step 3: If the RSRP measured by the terminal is lower than or equal to the first RSRP threshold, the terminal selects the SUL or an uplink carrier with a larger coverage or a lower frequency for random access.

[0225] a) The terminal receives a second RSRP threshold for selecting 2-step random access (2-step RA) and 4-step random access (4-stepRA) sent by the network. There is a second RSRP threshold for each uplink carrier of the cell. For example, NUL and SUL each correspond to one second RSRP threshold.

[0226] b) If the RSRP measured by the terminal is higher than the second RSRP threshold, the terminal initiates 2-step RA on the uplink carrier; if the RSRP measured by the terminal is lower than or equal to the second RSRP threshold, the terminal initiates 4-step RA on the uplink carrier.

[0227] Step 4: If the RSRP measured by the terminal is higher than the first RSRP threshold, the terminal can initiate random access on multiple uplink carriers.

[0228] a) The terminal receives second RSRP thresholds for selecting 2-step RA and 4-step RA for multiple uplink carriers sent by the network (each uplink carrier corresponds to a second RSRP threshold).

[0229] b) If there is only one uplink carrier whose RSRP is higher than the second RSRP threshold, a 2-step RA is initiated on this uplink carrier; otherwise, a 4-step RA is initiated (for example, it is possible to fall back to scheme 1, scheme 2, or scheme 3).

[0230] c) If there are more than two uplink carriers with a rate higher than the second RSRP threshold, one uplink carrier is selected to send the preamble code and the other uplink carrier is selected to send the PUSCH.

[0231] As in step 4 c), the terminal needs to determine the uplink carrier for sending the preamble code and the PUSCH, as follows:

[0232] a) Select an uplink carrier with smaller bandwidth to send the preamble code, and select an uplink carrier with larger bandwidth to send the PUSCH;

[0233] b) Select an uplink carrier with a higher frequency to send the preamble code, and select an uplink carrier with a lower frequency to send the PUSCH;

[0234] c) The network instructs each uplink carrier among multiple uplink carriers whether to send preamble or PUSCH first.

[0235] Step 5: If the terminal initiates random access on multiple uplink carriers, the terminal needs to indicate the uplink carrier on which the PUSCH is sent, including the uplink frequency band number or the uplink frequency position or the uplink carrier number, while sending the preamble code.

[0236] Step 6: The network receives the MSGA sent by the terminal, including the preamble code and PUSCH, and sends the MSGB.

[0237] Step 8: The terminal receives the MSGB sent by the network.

[0238] Example 4-1: (Two-step RACH)

[0239] See also Figure 4 The cell has 1 DL and 2 UL (NUL and SUL), where NUL and DL are TDD frequency bands, SUL is an uplink supplementary frequency band, the NUL carrier is numbered as uplink carrier 1, and the SUL carrier is numbered as uplink carrier 2.

[0240] The network sends a first RSRP threshold, which corresponds to the SUL carrier. If the RSRP measured by the terminal is lower than or equal to the first RSRP threshold, the SUL carrier is selected to initiate random access. If the RSRP measured by the terminal is higher than the first RSRP threshold, both SUL and NUL can be selected to initiate random access.

[0241] The network sends a second RSRP threshold. The SUL carrier corresponds to RSRP_SUL threshold 2, and the NUL carrier corresponds to RSRP_NUL threshold 2. When the RSRP measured by the terminal is higher than the second RSRP threshold, it means that 2-step RACH can be performed, otherwise 4-step RACH is performed.

[0242] At this time, the RSRP measured by the terminal 1 is higher than the first RSRP threshold, higher than the RSRP_NUL threshold 2, and higher than the RSRP_SUL threshold 2, then the terminal 1 can perform 2-step RACH on multiple uplink carriers.

[0243] The network side indicates that NUL is the uplink carrier that preferentially sends PUSCH, and SUL is the uplink carrier that preferentially sends preamble code.

[0244] Terminal 1 sends a preamble code on the SUL, sends a PUSCH on the NUL, and informs the network in the PUSCH that it sends the preamble code on the SUL.

[0245] Optionally, if the network does not indicate the uplink carrier priority, the terminal 1 selects an uplink carrier with a smaller bandwidth or a higher frequency to send a preamble code, and selects an uplink carrier with a larger bandwidth or a lower frequency to send a PUSCH.

[0246] At this time, the RSRP measured by the terminal 2 is higher than the first RSRP threshold, higher than the RSRP_NUL threshold 2, and lower than or equal to the RSRP_SUL threshold 2, then the terminal 2 performs 2-step RACH on the NUL.

[0247] At this time, the RSRP of terminal 3 is lower than or equal to the first RSRP threshold and higher than RSRP_SUL threshold 2, so terminal 3 performs 2-step RACH on SUL.

[0248] At this time, the RSRP measured by terminal 4 is higher than the first RSRP threshold, lower than or equal to RSRP_NUL threshold 2, and lower than or equal to RSRP_SUL threshold 2, then terminal 4 refers to scheme 1, scheme 2, and scheme 3 to perform 4-step RACH.

[0249] The network receives the MSGA sent by the terminal, including the preamble code and PUSCH.

[0250] See also Figure 7 The present application provides a multi-uplink carrier access device, the device 700 comprising:

[0251] A first acquisition module 701 is used to acquire one or more first uplink carriers selected by the terminal and / or a second uplink carrier indicated by the network side;

[0252] A first processing module 702, configured to perform four-step random access according to the one or more first uplink carriers and the second uplink carrier, or perform two-step random access according to the multiple first uplink carriers;

[0253] The first uplink carrier is used to send MSG1 in four-step random access, the second uplink carrier is used to send MSG3 in four-step random access, or the multiple first uplink carriers are used to send MSGA in two-step random access.

[0254] In the embodiment of the present application, the first acquisition module 701 is further used to: select one or more first uplink carriers according to the RSRP measured by the terminal and a first RSRP threshold; wherein the first RSRP threshold is used by the terminal to select the first uplink carrier.

[0255] In the embodiment of the present application, selecting one or more first uplink carriers according to the RSRP measured by the terminal and the first RSRP threshold includes:

[0256] If the RSRP measured by the terminal is lower than or equal to the first RSRP threshold, selecting a first uplink carrier corresponding to the first RSRP threshold;

[0257] or,

[0258] If the RSRP measured by the terminal is higher than the first RSRP threshold, one or more first uplink carriers corresponding to the first RSRP threshold are selected.

[0259] In the embodiment of the present application, if the RSRP measured by the terminal is lower than or equal to the first RSRP threshold, the selected first uplink carrier is SUL, or the coverage is greater than a preset value, or the frequency is lower than the uplink carrier of the preset value;

[0260] or,

[0261] If the RSRP measured by the terminal is higher than the first RSRP threshold, the selected first uplink carrier is NUL, or the coverage is smaller than a preset value, or the frequency is higher than a preset value.

[0262] In the embodiment of the present application, the apparatus 700 further includes:

[0263] A determination module, configured to determine, based on the RSRP of the one or more first uplink carriers and the second RSRP threshold, whether to initiate a 2-step random access (2-step RA) or a 4-step random access (4-step RA) on each first uplink carrier;

[0264] The second RSRP threshold is used to select 2-step RA and 4-step RA, and the second RSRP threshold corresponds to one or more first uplink carriers.

[0265] In an embodiment of the present application, if the RSRP measured by the terminal is lower than or equal to the first RSRP threshold, and a first uplink carrier is selected, the determining, according to the RSRP of the one or more first uplink carriers and the second RSRP threshold, to initiate a 2-step random access 2-step RA or a four-step random access 4-step RA on each first uplink carrier includes:

[0266] If the RSRP measured by the terminal is higher than a second RSRP threshold corresponding to the first uplink carrier, initiating a 2-step RA on the first uplink carrier;

[0267] If the RSRP measured by the terminal is lower than or equal to a second RSRP threshold corresponding to the first uplink carrier, a 4-step RA is initiated on the first uplink carrier.

[0268] In an embodiment of the present application, if the RSRP measured by the terminal is higher than the first RSRP threshold, and multiple first uplink carriers are selected, the determining, according to the RSRP of the one or more first uplink carriers and the second RSRP threshold, to initiate a 2-step RA or a 4-step RA on each first uplink carrier includes:

[0269] If the RSRP of at least one first uplink carrier among the multiple first uplink carriers is higher than the second RSRP threshold, a 2-step RA is initiated on the at least one first uplink carrier; otherwise, a 4-step RA is initiated on the multiple first uplink carriers.

[0270] In the embodiment of the present application, initiating a 2-step RA on the at least one first uplink carrier includes:

[0271] According to the transmission priority indicated by the network side or determined autonomously by the terminal, the preamble in the MSGA is sent on a first uplink carrier, and the PUSCH in the MSGA is sent on other first uplink carriers.

[0272] In the embodiment of the present application, the bandwidth of the first uplink carrier for sending the preamble is smaller than the bandwidth of the first uplink carrier for sending the PUSCH;

[0273] or,

[0274] The frequency of the first uplink carrier for transmitting the preamble is higher than the frequency of the first uplink carrier for transmitting the PUSCH.

[0275] In the embodiment of the present application, the apparatus 700 further includes:

[0276] The second processing module is configured to initiate a 4-step RA on other uplink carriers corresponding to the first RSRP threshold according to the RSRP measured by the terminal and the first RSRP threshold if the 4-step RA fails on the first uplink carrier selected by the terminal.

[0277] In the embodiment of the present application, four steps of random access are performed, including:

[0278] If the terminal has dual connectivity or uplink carrier aggregation capability, MSG1 is sent simultaneously on multiple first uplink carriers;

[0279] or,

[0280] If the terminal does not have dual connectivity or uplink carrier aggregation capability, MSG1 is sent on multiple first uplink carriers in a time division multiplexing manner.

[0281] In this embodiment of the present application, the plurality of first uplink carriers correspond to a group of preamble code resources configured by the network side for the terminal, and the group of preamble code resources includes a plurality of preamble codes.

[0282] In the embodiment of the present application, obtaining the second uplink carrier indicated by the network side includes:

[0283] A MSG2 is received in response to the MSG1, where the MSG2 indicates a second uplink carrier selected by the network side for sending the MSG3.

[0284] In the embodiment of the present application, the first bit in the scheduling information in the MSG2 indicates the second uplink carrier, or the second bit in the MAC payload in the MSG2 indicates the second uplink carrier.

[0285] In the embodiment of the present application, the uplink carrier indicated for sending MSG3 is the uplink frequency band number or the uplink frequency position or the uplink carrier number of the uplink carrier indicated for sending MSG3.

[0286] In the embodiment of the present application, the scheduling information of MSG2 further indicates the time-frequency resources of the uplink carrier for sending MSG3, and / or the temporary C-RNTI of the first uplink carrier.

[0287] The access device provided in the embodiment of the present application can achieve Figure 2 The various processes implemented by the method embodiment shown achieve the same technical effect and will not be described again here to avoid repetition.

[0288] See also Figure 8 , an embodiment of the present application provides an access device for multiple uplink carriers, the device 800 comprising:

[0289] The third processing module 801 is used to process a four-step random access performed by a terminal on one or more first uplink carriers and a second uplink carrier, or to process a two-step random access performed by a terminal on multiple first uplink carriers;

[0290] The first uplink carrier is used to send MSG1 in four-step random access, the second uplink carrier is used to send MSG3 in four-step random access, or the multiple first uplink carriers are used to send MSGA in two-step random access.

[0291] In an embodiment of the present application, the third processing module 801 is further used to: send MSG2 to the terminal, wherein MSG2 indicates a second uplink carrier, wherein the second uplink carrier is used to send MSG3 in the four-step random access, and the second uplink carrier is different from the first uplink carrier, wherein the first uplink carrier is used to send MSG1 in the four-step random access.

[0292] In the embodiment of the present application, the third processing module 801 is further used to: receive MSG1 through one or more first uplink carriers; determine uplink channel information according to the MSG1; and select a second uplink carrier according to the uplink channel information.

[0293] In the embodiment of the present application, the first bit in the scheduling information in the MSG2 indicates the second uplink carrier, or the second bit in the MAC payload in the MSG2 indicates the second uplink carrier.

[0294] In the embodiment of the present application, the MSG2 indicates the uplink frequency band number or the uplink frequency position or the uplink carrier number of the uplink carrier sending the MSG3.

[0295] In the embodiment of the present application, the scheduling information of MSG2 further indicates the time-frequency resources of the uplink carrier for sending MSG3, and / or the temporary C-RNTI of the first uplink carrier.

[0296] In the embodiment of the present application, the third processing module 801 is further used to: indicate to the terminal the transmission priority of the preamble and PUSCH in the MSGA on the multiple first uplink carriers.

[0297] The terminal provided in the embodiment of the present application can achieve Figure 2 The various processes implemented by the method embodiment shown achieve the same technical effect and will not be described again here to avoid repetition.

[0298] Fig. 9 A schematic diagram of the hardware structure of a terminal for implementing an embodiment of the present application.

[0299] The terminal 900 includes but is not limited to: a radio frequency unit 901, a network module 902, an audio output unit 903, an input unit 904, a sensor 905, a display unit 906, a user input unit 907, an interface unit 908, a memory 909, and a processor 910.

[0300] Those skilled in the art will appreciate that the terminal 900 may also include a power source (such as a battery) for supplying power to various components, and the power source may be logically connected to the processor 910 through a power management system, thereby implementing functions such as managing charging, discharging, and power consumption management through the power management system. Fig. 9 The terminal structure shown in the figure does not constitute a limitation on the terminal. The terminal may include more or fewer components than shown in the figure, or combine certain components, or arrange the components differently, which will not be described in detail here.

[0301] It should be understood that in the embodiment of the present application, the input unit 904 may include a graphics processor (Graphics Processing Unit, GPU) 9041 and a microphone 9042, and the graphics processor 6041 processes the image data of the static picture or video obtained by the image capture device (such as a camera) in the video capture mode or the image capture mode. The display unit 906 may include a display panel 9061, and the display panel 9061 may be configured in the form of a liquid crystal display, an organic light emitting diode, etc. The user input unit 907 includes a touch panel 9071 and other input devices 9072. The touch panel 9071 is also called a touch screen. The touch panel 9071 may include two parts: a touch detection device and a touch controller. Other input devices 9072 may include, but are not limited to, a physical keyboard, function keys (such as volume control keys, switch keys, etc.), a trackball, a mouse, and a joystick, which will not be repeated here.

[0302] In the embodiment of the present application, the radio frequency unit 901 receives downlink data from the network side device and sends it to the processor 910 for processing; in addition, the uplink data is sent to the network side device. Generally, the radio frequency unit 901 includes but is not limited to an antenna, at least one amplifier, a transceiver, a coupler, a low noise amplifier, a duplexer, etc.

[0303] The memory 909 can be used to store software programs or instructions and various data. The memory 609 can mainly include a storage program or instruction area and a storage data area, wherein the storage program or instruction area can store an operating system, an application program or instruction required for at least one function (such as a sound playback function, an image playback function, etc.), etc. In addition, the memory 909 can include a high-speed random access memory, and can also include a non-volatile memory, wherein the non-volatile memory can be a read-only memory (Read-Only Memory, ROM), a programmable read-only memory (Programmable ROM, PROM), an erasable programmable read-only memory (Erasable PROM, EPROM), an electrically erasable programmable read-only memory (Electrically EPROM, EEPROM) or a flash memory. For example, at least one disk storage device, a flash memory device, or other non-volatile solid-state storage devices.

[0304] The processor 910 may include one or more processing units; optionally, the processor 910 may integrate an application processor and a modem processor, wherein the application processor mainly processes an operating system, a user interface, and application programs or instructions, etc., and the modem processor mainly processes wireless communications, such as a baseband processor. It is understandable that the modem processor may not be integrated into the processor 910.

[0305] The terminal provided in the embodiment of the present application can achieve Figure 2 The various processes implemented by the method embodiment shown achieve the same technical effect and will not be described again here to avoid repetition.

[0306] The present application embodiment also provides a network side device. Fig.10 As shown, the network side device 1000 includes: an antenna 1001, a radio frequency device 1002, and a baseband device 1003. The antenna 1001 is connected to the radio frequency device 1002. In the uplink direction, the radio frequency device 1002 receives information through the antenna 1001 and sends the received information to the baseband device 1003 for processing. In the downlink direction, the baseband device 1003 processes the information to be sent and sends it to the radio frequency device 1002. The radio frequency device 1002 processes the received information and sends it out through the antenna 1001.

[0307] The frequency band processing device may be located in the baseband device 1003 . The method performed by the network-side device in the above embodiment may be implemented in the baseband device 1003 . The baseband device 1003 includes a processor 1004 and a memory 1005 .

[0308] The baseband device 1003 may include, for example, at least one baseband board on which a plurality of chips are arranged. Fig.10 As shown, one of the chips is, for example, a processor 1004, which is connected to a memory 1005 to call a program in the memory 1005 to execute the network device operations shown in the above method embodiment.

[0309] The baseband device 1003 may further include a network interface 1006 for exchanging information with the radio frequency device 1002 . The interface may be, for example, a common public radio interface (CPRI).

[0310] Specifically, the network side device of the embodiment of the present invention further includes: instructions or programs stored in the memory 1005 and executable on the processor 1004, and the processor 1004 calls the instructions or programs in the memory 1005 to execute Figure 8 The methods executed by the modules shown achieve the same technical effects, and therefore will not be described here in detail to avoid repetition.

[0311] The network side device provided in the embodiment of the present application can achieve Figure 2 Or each process implemented by the method embodiment shown in 3, and achieves the same technical effect, to avoid repetition, it will not be repeated here.

[0312] The embodiment of the present application also provides a readable storage medium on which a program or instruction is stored. When the program or instruction is executed by a processor, the above Figure 2 or Figure 3 The various processes of the method embodiment shown can achieve the same technical effect, and will not be described again here to avoid repetition.

[0313] The processor is the processor in the terminal described in the above embodiment. The readable storage medium includes a computer readable storage medium, such as a computer read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0314] The steps of the method or algorithm described in conjunction with the contents disclosed in this application can be implemented in hardware or by executing software instructions in a processor. The software instructions can be composed of corresponding software modules, and the software modules can be stored in RAM, flash memory, ROM, EPROM, EEPROM, registers, hard disks, mobile hard disks, read-only optical disks, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor so that the processor can read information from the storage medium and write information to the storage medium. Of course, the storage medium can also be a component of the processor. The processor and the storage medium can be carried in an ASIC. In addition, the ASIC can be carried in a core network interface device. Of course, the processor and the storage medium can also exist in the core network interface device as discrete components.

[0315] Those skilled in the art should be aware that in one or more of the above examples, the functions described in this application can be implemented using hardware, software, firmware, or any combination thereof. When implemented using software, these functions can be stored in a computer-readable medium or transmitted as one or more instructions or codes on a computer-readable medium. Computer-readable media include computer storage media and communication media, wherein communication media include any media that facilitates the transmission of a computer program from one place to another. The storage medium can be any available medium that a general or special-purpose computer can access.

[0316] The specific implementation methods described above further illustrate the purpose, technical solutions and beneficial effects of the present application in detail. It should be understood that the above description is only the specific implementation methods of the present application and is not intended to limit the scope of protection of the present application. Any modifications, equivalent substitutions, improvements, etc. made on the basis of the technical solutions of the present application should be included in the scope of protection of the present application.

[0317] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the embodiments of the present application may adopt the form of complete hardware embodiments, complete software embodiments, or embodiments in combination with software and hardware. Moreover, the embodiments of the present application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0318] The embodiments of the present application are described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0319] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0320] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0321] Obviously, those skilled in the art can make various changes and modifications to the embodiments of the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the embodiments of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. A method for accessing multiple uplink carriers, executed by a terminal, characterized in that: include: Acquire multiple first uplink carriers selected by the terminal and a second uplink carrier indicated by the network side; performing four-step random access according to the multiple first uplink carriers and the second uplink carrier, or Acquire multiple first uplink carriers selected by the terminal; Performing two-step random access according to the multiple first uplink carriers; The multiple first uplink carriers are used to send message 1MSG1 in four-step random access, the second uplink carrier is used to send message 3MSG3 in four-step random access, or the multiple first uplink carriers are used to send message AMSGA in two-step random access; Wherein, obtaining multiple first uplink carriers selected by the terminal includes: Selecting a plurality of first uplink carriers according to a reference signal received power RSRP measured by the terminal and a first RSRP threshold, wherein the first RSRP threshold is used by the terminal to select a first uplink carrier; The step of selecting a plurality of first uplink carriers according to the RSRP measured by the terminal and the first RSRP threshold includes: If the RSRP measured by the terminal is higher than the first RSRP threshold, multiple first uplink carriers corresponding to the first RSRP threshold are selected.

2. The access method according to claim 1, characterized in that: If the RSRP measured by the terminal is higher than the first RSRP threshold, the selected multiple first uplink carriers are NUL, or the coverage is smaller than a preset value, or the frequency is higher than a preset value.

3. The access method according to claim 2, characterized in that: The method further comprises: Determine, according to the RSRP of the multiple first uplink carriers and the second RSRP threshold, to initiate a 2-step random access 2-step RA or a 4-step random access 4-step RA on each first uplink carrier; The second RSRP threshold is used to select 2-step RA and 4-step RA, and the second RSRP threshold corresponds to multiple first uplink carriers.

4. The access method according to claim 2, characterized in that: If the RSRP measured by the terminal is higher than the first RSRP threshold, and multiple first uplink carriers are selected, determining to initiate a 2-step RA or a 4-step RA on each first uplink carrier according to the RSRP of the multiple first uplink carriers and the second RSRP threshold includes: If the RSRP of at least one first uplink carrier among the multiple first uplink carriers is higher than the second RSRP threshold, a 2-step RA is initiated on the multiple first uplink carriers; otherwise, a 4-step RA is initiated on the multiple first uplink carriers.

5. The access method according to claim 2, characterized in that: Initiating a 2-step RA on the multiple first uplink carriers, comprising: According to the transmission priority indicated by the network side or determined autonomously by the terminal, the preamble in the MSGA is sent on a first uplink carrier, and the PUSCH in the MSGA is sent on other first uplink carriers.

6. The access method according to claim 5, characterized in that: The bandwidth of the first uplink carrier for sending the preamble is smaller than the bandwidth of the first uplink carrier for sending the PUSCH; or, The frequency of the first uplink carrier for transmitting the preamble is higher than the frequency of the first uplink carrier for transmitting the PUSCH.

7. The access method according to claim 1, characterized in that: The method further comprises: If the 4-step RA fails on the first uplink carrier selected by the terminal, a 4-step RA is initiated on other uplink carriers corresponding to the first RSRP threshold according to the RSRP measured by the terminal and the first RSRP threshold.

8. The access method according to claim 1, characterized in that: Four steps of random access are performed, including: If the terminal has dual connectivity or uplink carrier aggregation capability, MSG1 is sent simultaneously on the multiple first uplink carriers; or, If the terminal does not have dual connectivity or uplink carrier aggregation capability, MSG1 is sent on the multiple first uplink carriers in a time division multiplexing manner.

9. The access method according to claim 8, characterized in that: The multiple first uplink carriers correspond to a group of preamble code resources configured by the network side for the terminal, and the group of preamble code resources includes multiple preamble codes.

10. The access method according to claim 1, characterized in that: Acquiring a second uplink carrier indicated by the network side, including: A MSG2 is received in response to the MSG1, where the MSG2 indicates a second uplink carrier selected by the network side for sending the MSG3.

11. The access method according to claim 10, characterized in that: The first bit in the scheduling information in the MSG2 indicates the second uplink carrier, or the second bit in the media access control MAC payload in the MSG2 indicates the second uplink carrier.

12. The access method according to claim 10, characterized in that: The uplink carrier indicated for sending MSG3 is an uplink frequency band number or an uplink frequency position or an uplink carrier number of the uplink carrier indicated for sending MSG3.

13. The access method according to claim 10, characterized in that: The scheduling information of MSG2 further indicates the time-frequency resources of the uplink carrier for sending MSG3, and / or the temporary C-RNTI of the first uplink carrier.

14. A method for accessing multiple uplink carriers, executed by a network side device, characterized in that: include: Sending a first RSRP threshold to the terminal, where the first RSRP threshold corresponds to one or more UL carriers in the cell, and the first RSRP is used by the terminal to select multiple first uplink carriers for random access; Send MSG2 to the terminal, where MSG2 indicates a second uplink carrier, where the second uplink carrier is different from the first uplink carrier Processing a four-step random access performed by a terminal on the multiple first uplink carriers and the second uplink carriers, or processing a two-step random access performed by a terminal on the multiple first uplink carriers; The multiple first uplink carriers are used to send MSG1 in four-step random access, the second uplink carrier is used to send MSG3 in four-step random access, or the multiple first uplink carriers are used to send MSGA in two-step random access; The multiple first uplink carriers are determined in the following manner: if the RSRP measured by the terminal is higher than the first RSRP threshold, the terminal selects the multiple first uplink carriers corresponding to the first RSRP threshold.

15. The access method according to claim 14, characterized in that: The method further comprises: Receiving MSG1 via a plurality of first uplink carriers; Determine uplink channel information according to the MSG1; A second uplink carrier is selected according to the uplink channel information.

16. The access method according to claim 14, characterized in that: The first bit in the scheduling information in the MSG2 indicates the second uplink carrier, or the second bit in the MAC payload in the MSG2 indicates the second uplink carrier.

17. The access method according to claim 14, characterized in that: The MSG2 indicates the uplink frequency band number or uplink frequency position or uplink carrier number of the uplink carrier sending the MSG3.

18. The access method according to claim 14, characterized in that: The scheduling information of MSG2 further indicates the time-frequency resources of the uplink carrier for sending MSG3, and / or the temporary C-RNTI of the first uplink carrier.

19. The access method according to claim 14, characterized in that: Before the step of performing two-step random access processing on the terminal on multiple first uplink carriers, the method further includes: The transmission priority of the preamble and the PUSCH in the MSGA on the plurality of first uplink carriers is indicated to the terminal.

20. A device for accessing multiple uplink carriers, characterized in that: include: A first acquisition module, used to acquire multiple first uplink carriers selected by the terminal and a second uplink carrier indicated by the network side; A first processing module, configured to perform four-step random access according to the multiple first uplink carriers and the second uplink carrier, or perform two-step random access according to the multiple first uplink carriers; The multiple first uplink carriers are used to send MSG1 in four-step random access, the second uplink carrier is used to send MSG3 in four-step random access, or the multiple first uplink carriers are used to send MSGA in two-step random access; The first acquisition module is further configured to select a plurality of first uplink carriers corresponding to the first RSRP threshold if the RSRP measured by the terminal is higher than a first RSRP threshold.

21. A device for accessing multiple uplink carriers, characterized in that: include: A third processing module is configured to send a first RSRP threshold to the terminal, where the first RSRP threshold corresponds to one or more UL carriers in the cell, and the first RSRP is used by the terminal to select multiple first uplink carriers for random access; send MSG2 to the terminal, where the MSG2 indicates a second uplink carrier, and the second uplink carrier is different from the first uplink carrier; process the four-step random access performed by the terminal on the multiple first uplink carriers and the second uplink carrier, or process the two-step random access performed by the terminal on the multiple first uplink carriers; The multiple first uplink carriers are used to send MSG1 in four-step random access, the second uplink carrier is used to send MSG3 in four-step random access, or the multiple first uplink carriers are used to send MSGA in two-step random access; The multiple first uplink carriers are determined in the following manner: if the RSRP measured by the terminal is higher than the first RSRP threshold, the terminal selects the multiple first uplink carriers corresponding to the first RSRP threshold.

22. A terminal, characterized in that: include: A processor, a memory, and a program stored in the memory and executable on the processor, wherein the program implements the steps of the method according to any one of claims 1 to 13 when executed by the processor.

23. A network side device, characterized in that: include: A processor, a memory, and a program stored in the memory and executable on the processor, wherein when the program is executed by the processor, the steps of the method according to any one of claims 14 to 19 are implemented.

24. A readable storage medium, characterized in that: The readable storage medium stores a program, and when the program is executed by a processor, the steps of the method according to any one of claims 1 to 19 are implemented.

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