Random access method, apparatus, device, and storage medium

Abstract

The application discloses a random access method and device, equipment and a storage medium, and relates to the field of mobile communication. The method comprises the following steps: determining a resource for sending a first message according to a time difference between a first time and a second time; wherein the first time is determined according to system information (SI) received by a terminal, the second time is determined according to an effective time of uplink synchronization assistance information received by the terminal, and the first message is used for initiating random access. The application can make terminals searching for the same base station at different times, avoid initiating random access at the same random access occasion, and thus avoid access conflicts of the terminals and reduce the access failure probability caused by the access conflicts.

Description

Technical Field

[0001] This application relates to the field of mobile communications, and in particular to a random access method, apparatus, device, and storage medium. Background Technology

[0002] The terminal initiates random access by sending Message 1 (Msg 1) or Message A (Msg A) to the base station. The terminal will send the above message to the base station during the random access occasion on the Random Access Channel (RACH).

[0003] Before a terminal initiates random access, uplink synchronization needs to be achieved. In a non-terrestrial network (NTN) system, the base station broadcasts a System Information Block (SIB) to configure uplink synchronization assistance information for the terminal. The SIB also specifies the epoch time of the uplink synchronization assistance information. The terminal then selects the first random access opportunity after the epoch time of the uplink synchronization assistance information to initiate random access.

[0004] For terminals that find the same base station at different times, there may be situations where the same effective time is configured. Consequently, terminals that find the same base station at different times may initiate random access at the same time (the same random access timing), resulting in access conflicts. Summary of the Invention

[0005] This application provides a random access method, apparatus, device, and storage medium. The technical solution is as follows:

[0006] According to one aspect of this application, a random access method is provided, the method being executed by a terminal, the method comprising:

[0007] Based on the time difference between the first and second moments, determine the resources for sending the first message;

[0008] The first time is determined based on the system information (SI) received by the terminal, the second time is determined based on the effective time of the uplink synchronization assistance information received by the terminal, and the first message is used to initiate random access.

[0009] According to another aspect of this application, a random access device is provided, the device comprising:

[0010] The determination module is used to determine the resources for sending the first message based on the time difference between the first moment and the second moment;

[0011] The first time is determined based on the SI received by the terminal, the second time is determined based on the effective time of the uplink synchronization assistance information received by the terminal, and the first message is used to initiate random access.

[0012] According to another aspect of this application, a terminal is provided, the terminal comprising: a processor; a transceiver connected to the processor; and a memory for storing executable instructions of the processor; wherein the processor is configured to load and execute the executable instructions to implement the random access method as described above.

[0013] According to another aspect of this application, a computer-readable storage medium is provided, wherein executable instructions are stored therein, which are loaded and executed by a processor to implement the random access method as described above.

[0014] According to another aspect of this application, a chip is provided, the chip including programmable logic circuitry and / or program instructions, which, when the chip is run on a computer device, are used to implement the random access method described above.

[0015] According to another aspect of this application, a computer program product or computer program is provided, the computer program product or computer program including computer instructions stored in a computer-readable storage medium, wherein a processor reads from the computer-readable storage medium and executes the computer instructions, causing a computer device to perform the random access method described above.

[0016] The technical solution provided in this application includes at least the following beneficial effects:

[0017] By enabling the terminal to determine the transmission resources for initiating random access based on the time difference between a first and a second time point, the terminal determines the transmission resources for the message based on the system information received by the terminal, and the second time point is determined based on the effective time of the uplink synchronization assistance information received by the terminal. This ensures that terminals that search for the same base station at different times avoid initiating random access at the same time, thereby avoiding access conflicts and reducing the probability of access failure due to access conflicts. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of an NTN scenario based on transparent payload provided in an exemplary embodiment of this application;

[0020] Figure 2 This is a schematic diagram of an NTN scenario based on regenerative load provided in an exemplary embodiment of this application;

[0021] Figure 3 This is a schematic diagram illustrating random access timing provided in an exemplary embodiment of this application;

[0022] Figure 4 This is a flowchart of a random access method provided in an exemplary embodiment of this application;

[0023] Figure 5 This is a flowchart of a random access method provided in an exemplary embodiment of this application;

[0024] Figure 6 This is a schematic diagram of a synchronization signal block and random access timing provided in an exemplary embodiment of this application;

[0025] Figure 7 This is a schematic diagram of a synchronization signal block and random access timing provided in an exemplary embodiment of this application;

[0026] Figure 8 This is a structural block diagram of a random access device provided in an exemplary embodiment of this application;

[0027] Figure 9 This is a schematic diagram of the structure of a communication device provided in an exemplary embodiment of this application. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0029] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0030] The terminology used in this disclosure is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. The singular forms “a,” “the,” and “the” as used in this disclosure and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any and all possible combinations of one or more of the associated listed items.

[0031] It should be understood that although the terms first, second, third, etc., may be used in this disclosure to describe various information, such information should not be limited to these terms. These terms are used only to distinguish information of the same type from one another. For example, without departing from the scope of this disclosure, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the word "if" as used herein may be interpreted as "when," "when," or "in response to determination."

[0032] An introduction to the NTN system:

[0033] Currently, the Third Generation Partnership Project (3GPP) is researching NTN technology. Compared to traditional terrestrial networks (TN), NTN systems utilize satellites and High Altitude Platform Stations (HAPS) for network deployment. Taking satellite communication as an example, theoretically only a few satellites are needed to achieve global coverage except for the polar regions. Compared to TN systems, NTN systems offer significant coverage advantages. Typical application scenarios for NTN systems include situations where base stations cannot be built or are damaged, such as continuous coverage in remote mountainous areas, deserts, oceans, and forests, or emergency communication during disasters or base station damage. Typical NTN system scenarios can be summarized as: all-terrain coverage, signaling offloading, emergency communication, the Internet of Things (IoT), and broadcast services.

[0034] NTN systems can include satellite systems. Based on satellite altitude, i.e., orbital altitude, satellite systems can be categorized into High Elliptical Orbit (HEO) satellites, Geostationary Earth Orbit (GEO) satellites, Medium Earth Orbit (MEO) satellites, and Low Earth Orbit (LEO) satellites. Furthermore, NTN systems may also include aerial network equipment such as High Altitude Platform Station (HAPS) communication systems; the network equipment involved in this application is not limited to the examples above.

[0035] LEO satellites: LEO satellites can be called non-geostationary satellites, and there are many types of non-geostationary satellites. Taking LEO satellites as an example, LEO satellites move relatively fast relative to the ground, approximately 7 km / s. Therefore, the coverage area provided by LEO satellites also moves with the LEO satellites. LEO satellite signals have short propagation distances, low link loss, and low requirements for the transmission power of user terminals.

[0036] GEO satellites: GEO satellites, also known as geostationary satellites, move at the same speed as the Earth's rotation system, thus remaining stationary relative to the ground. Consequently, the cell area of ​​a GEO satellite is also stationary. GEO satellite cells have a relatively large coverage area, typically with a cell diameter of 500 km.

[0037] In order to ensure the coverage of communication satellites and improve the system capacity of the entire satellite communication system, communication satellites use multi-beam coverage of the ground. A single communication satellite can form dozens or even hundreds of beams to cover the ground; a single satellite beam can cover a ground area with a diameter of tens to hundreds of kilometers.

[0038] Currently, 3GPP considers two types of satellites: transparent payload satellites and regenerative payload satellites. Figure 1 A schematic diagram of an NTN scenario based on transparent load transmission is shown. Figure 2 A schematic diagram of an NTN scenario based on regenerative load is shown.

[0039] The NTN network consists of the following network elements:

[0040] • One or more network devices 16: used to connect the satellite 14 and the data network 18 on the ground.

[0041] • Feeder Link: The link used for communication between network device 16 and satellite 14.

[0042] • Service Link: The link used for communication between user terminal 12 and satellite 14.

[0043] Satellite 14: Based on the functions it provides, it can be divided into two types: transparent payload and regenerative payload.

[0044] • Transparent payload: Provides only wireless frequency filtering, frequency conversion, and amplification functions. It only provides transparent signal forwarding and does not change the waveform signal it forwards.

[0045] • Regenerative payload: In addition to providing wireless frequency filtering, frequency conversion, and amplification functions, it can also provide demodulation / decoding, routing / conversion, and encoding / modulation functions. It has some or all of the functions of a base station.

[0046] • Inter-Satellite Links (ISL): Exist in NTN scenarios with regenerated payloads.

[0047] It should be noted that the terminal in the embodiments of this application can refer to UE (User Equipment), access terminal, user unit, user station, mobile station, mobile station, remote station, remote terminal, mobile device, wireless communication device, user agent, or user equipment. Optionally, the terminal can also be a cellular phone, cordless phone, SIP (Session Initiation Protocol) phone, WLL (Wireless Local Loop) station, PDA (Personal Digital Assistant), handheld device with wireless communication function, computing device or other processing device connected to a wireless modem, vehicle-mounted device, wearable device, terminal in 5GS (5th Generation System), or terminal in the future evolved PLMN (Public Land Mobile Network), etc., and the embodiments of this application are not limited in this respect.

[0048] The access network device in this application embodiment is a device deployed in an access network to provide wireless communication functions for terminals. Access network devices can include various forms of macro base stations, micro base stations, relay stations, access points, etc. In systems employing different wireless access technologies, the names of devices with access network device functions may differ; for example, in a 5G NR system, they are called gNodeB or gNB. As communication technologies evolve, the name "access network device" may change. For ease of description, in this application embodiment, the aforementioned devices providing wireless communication functions for terminals are collectively referred to as access network devices. Optionally, a communication relationship can be established between the terminal and core network devices through the access network device. For example, in a Long Term Evolution (LTE) system, the access network device can be one or more eNodeBs within an EUTRAN (Evolved Universal Terrestrial Radio Access Network) or EUTRAN; in a 5G NR system, the access network device can be one or more gNBs within an RAN or RAN.

[0049] The core network equipment primarily functions to provide user connectivity, manage users, and bear services, serving as the interface to external networks. For example, core network equipment in a 5G NR system may include AMF (Access and Mobility Management Function) entities, UPF (User Plane Function) entities, SMF (Session Management Function) entities, and Location Management Function (LMF) entities. Access network equipment and core network equipment can be collectively referred to as network equipment.

[0050] This section introduces the random access method for terminals:

[0051] Terminal random access can be divided into two types: 4-step random access and 2-step random access. A terminal initiates 4-step random access by sending Msg 1 to the base station. A terminal initiates 2-step random access by sending Msg A to the base station. In 4-step random access, after sending Msg 1, the terminal receives Msg 2 from the base station, then sends Msg 3 to the base station and receives Msg 4, thus completing the random access. In 2-step random access, after sending Msg A, the terminal receives Msg B from the base station, thus completing the random access. Msg A can be considered as a package of uplink Msg 1 and Msg 3, and Msg B can be considered as a package of downlink Msg 2 and Msg 4.

[0052] The terminal will select the RACH occasion to use from among multiple RACH occasions, and send Msg 1 or Msg A to the base station in the selected RACH occasion to initiate random access.

[0053] Before a terminal initiates random access, uplink synchronization must be ensured. In an NTN system, the base station broadcasts an SIB (System Instruction Block) to the terminal, thereby configuring uplink synchronization assistance information for the terminal to achieve uplink synchronization. This uplink synchronization assistance information includes at least one of satellite ephemeris and common timing advance (TA) parameter information. The SIB also specifies the epoch time of the uplink synchronization assistance information, meaning that the satellite ephemeris and common TA parameter information have a defined epoch time, which may be a future time.

[0054] When the uplink synchronization assistance information is configured with an epoch time, the terminal will select the first RACH occasion after the epoch time of the uplink synchronization assistance information to initiate random access. In the above case, for multiple terminals that search for the same cell at different times and receive cell broadcast messages (configured with the same epoch time), when they need to initiate random access, it may cause multiple terminals to initiate random access at the same time, resulting in access conflict.

[0055] For example, Figure 3 This is a schematic diagram illustrating random access timing provided in an exemplary embodiment of this application. For example... Figure 3As shown, the coordinate axis represents time. Terminals #1, #2, and #3 receive the SIB (NTN-SIB) broadcast by the cell at different times. This SIB is configured with the same uplink synchronization assistance information effective time. Since the uplink synchronization assistance information has not yet taken effect, terminals #1, #2, and #3 must wait for a random access opportunity (random access opportunity #2) after the effective time before they can initiate random access. In this case, terminals #1, #2, and #3 will simultaneously initiate random access during random access opportunity #2, resulting in an access conflict.

[0056] As illustrated by the examples above, terminals that find the same base station at different times may have the same uplink synchronization assistance information configured at the same effective time. Consequently, terminals that find the same base station at different times may initiate random access at the same time (the same random access opportunity), resulting in access conflicts.

[0057] The method provided in this application enables a terminal to determine the transmission resources for initiating random access based on the time difference between a first time and a second time. The first time is determined based on system information received by the terminal, and the second time is determined based on the effective time of uplink synchronization assistance information received by the terminal. This avoids terminals that find the same base station at different times from initiating random access at the same time, thereby preventing access conflicts and reducing the probability of access failure due to such conflicts.

[0058] Figure 4 A flowchart of a random access method according to an embodiment of this application is shown. This method can be applied to a terminal. The method includes:

[0059] Step 402: Determine the resource for sending the first message based on the time difference between the first and second moments.

[0060] The first message is used by the terminal to initiate random access; that is, the terminal initiates random access by sending the first message to the network device. The resources for sending the first message include at least one of the time-domain resources and frequency-domain resources used by the terminal when sending the first message.

[0061] Optionally, the first message includes at least one of the following:

[0062] Msg 1;

[0063] Msg A.

[0064] Msg 1 is used by the terminal to initiate a 4-step random access. Msg A is used by the terminal to initiate a 2-step random access.

[0065] The first time point is determined by the terminal based on the System Information (SI) received by the terminal, for example, the first time point is determined by the terminal based on the time when the SI is received. The second time point is determined by the terminal based on the effective time of the uplink synchronization assistance information received by the terminal. Optionally, the SI includes uplink synchronization assistance information. This time difference is positively correlated with the duration between the time when the terminal receives the SI and the effective time of the uplink synchronization assistance information.

[0066] Optionally, the first moment includes at least one of the following:

[0067] • The start or end time of the slot in which the terminal receives the SIB;

[0068] • The start or end time corresponding to the System Frame Number (SFN) and subframe number of the SIB received by the terminal;

[0069] • The start or end time of the system information time window (SI window) to which the SIB is located, as received by the terminal;

[0070] The SIB includes uplink synchronization assistance information.

[0071] Optionally, if the first moment includes multiple moments, i.e., there are multiple first moments, the terminal determines the time difference between each first moment and a second moment, thereby obtaining multiple time differences. The terminal then determines the average or weighted average of these multiple time differences as the time difference between the first moment and the second moment. Alternatively, the terminal determines the earliest first moment in the time domain and determines the time difference between that first moment and the second moment as the time difference between the first moment and the second moment. Alternatively, the terminal determines the latest first moment in the time domain and determines the time difference between that first moment and the second moment as the time difference between the first moment and the second moment. Alternatively, the terminal randomly selects a first moment from the multiple first moments and determines the time difference between the selected first moment and the second moment as the time difference between the first moment and the second moment. Alternatively, the terminal receives an instruction from a network device and determines the time difference between the first moment and the second moment indicated by the network device among the multiple first moments as the time difference between the first moment and the second moment.

[0072] Optionally, the second moment mentioned above is the moment when the uplink synchronization auxiliary information takes effect.

[0073] Network devices can explicitly indicate the effective time of uplink synchronization assistance information via SIB, or implicitly indicate the effective time of uplink synchronization assistance information.

[0074] Regarding the case where SIB explicitly indicates the effective time:

[0075] When the SIB explicitly indicates the effective time of the uplink synchronization assistance information, the SIB includes both the uplink synchronization assistance information and the effective time of the uplink synchronization assistance information. In this case, the effective time of the uplink synchronization assistance information determined by the terminal is the one indicated by the SIB.

[0076] Regarding the case where the SIB implicit indication takes effect:

[0077] When the SIB implicitly indicates the effective time of the uplink synchronization assistance information, the SIB includes the uplink synchronization assistance information but does not include its effective time. In this case, the terminal determines the effective time of the uplink synchronization assistance information based on the time the SIB is received. For example, the terminal determines the effective time of the uplink synchronization assistance information to be the end time of the system information time window in which the SIB is located.

[0078] Optionally, the above-mentioned SIB includes at least one of the following:

[0079] SIB19;

[0080] ·NTN-SIB.

[0081] The aforementioned uplink synchronization assistance information is used to achieve uplink synchronization of the terminal. Optionally, the aforementioned uplink synchronization assistance information includes at least one of the following:

[0082] • Satellite ephemeris information;

[0083] ·Common TA parameter information.

[0084] Optionally, the terminal determines the resource for sending the first message based on the time difference between the first and second moments. Specifically, the terminal determines the random access occasion (RACH occasion) for sending the Physical Random Access Channel (PRACH) based on this time difference. In the time domain, there are typically multiple random access occasions, and the terminal selects the appropriate occasion to initiate random access. Optionally, the larger the time difference, the earlier the random access occasion selected by the terminal is in the time domain. The smaller the time difference, the later the random access occasion selected by the terminal is in the time domain.

[0085] Optionally, the method provided in this application provides the following two ways to determine the timing of random access based on the time difference.

[0086] The first method for determining the timing of random access based on time difference:

[0087] The terminal determines the random access timing for sending PRACH based on the time difference between the first and second moments and n preset time differences:

[0088] • If the time difference is no greater than the m-th preset time difference and greater than the (m-1)-th preset time difference, the terminal determines to use the (nm)+1-th available random access opportunity;

[0089] • If the time difference is no greater than the first preset time difference, the terminal determines to use the nth available random access opportunity.

[0090] Available random access opportunities include those that occur after the effective time of the uplink synchronization assistance information in the time domain. The nth random access opportunity precedes the (n-1)th random access opportunity, and the (m-1)th preset time difference is less than the mth preset time difference. m is less than or equal to n, m and n are positive integers, and n is greater than or equal to 2.

[0091] The maximum time difference between the first and second moments is usually known. For example, the maximum difference between the first and second moments is 1024 system frames, or 10.24 seconds. Optionally, if the time difference is greater than the nth preset time difference, the terminal will use the first available random access opportunity.

[0092] Optionally, the division of the above n time differences is predefined, or the value of n is broadcast from the network device to the terminal. Optionally, when the value of n is broadcast from the network device to the terminal, the difference between the (m-1)th preset time difference and the mth preset time difference is predefined. In this case, the terminal only needs to know the value of n to calculate the random access opportunity it will use. Optionally, when the value of n is broadcast from the network device to the terminal, the maximum difference between the first time point and the second time point is predefined. In this case, the terminal only needs to know the value of n to calculate the difference between the (m-1)th and mth preset time differences, and thus calculate the random access opportunity it will use.

[0093] For example, the terminal determines the random access timing for sending PRACH based on the time difference between a first time point and a second time point, as well as two preset time differences. The first preset time difference is 5 seconds, and the second preset time difference is 10 seconds. If the time difference between the first time point and the second time point is no greater than 5 seconds, the terminal uses the second available random access timing. If the time difference between the first time point and the second time point is greater than 5 seconds but no greater than 10 seconds, the terminal uses the first available random access timing. If the time difference between the first time point and the second time point is greater than 10 seconds, the terminal also uses the first available random access timing.

[0094] The second method for determining the timing of random access based on time difference:

[0095] The terminal determines the random access timing for sending PRACH based on the validity period of the uplink synchronization assistance information, and the difference between the time difference between the first and second moments and the validity period:

[0096] • If the difference is no greater than y / x of the valid time and greater than (y-1) / x of the valid time, the terminal determines to use the (xy)+1th available random access opportunity;

[0097] • If the difference is no greater than 1 / x of the valid time, the terminal determines to use the xth available random access opportunity.

[0098] The validity period of the uplink synchronization assistance information refers to the duration during which the uplink synchronization assistance information is valid, starting from the effective time of the uplink synchronization assistance information. Optionally, the validity period of the uplink synchronization assistance information is also configured in the SIB. Available random access opportunities include random access opportunities that are in the time domain after the effective time of the uplink synchronization assistance information. The xth random access opportunity is before the (x-1)th random access opportunity. x is a preset value, which can be broadcast by the network device to the terminal. y is less than or equal to x, y and x are positive integers, and x is greater than or equal to 2.

[0099] The difference between the time difference between the first and second moments and the valid time is usually no greater than the valid time. Optionally, if the difference between the time difference between the first and second moments and the valid time is greater than the valid time, the terminal will use the first available random access opportunity.

[0100] For example, the value of x is 2, and the length of the valid time is P. If the difference between the time difference and the valid time is no greater than P and greater than P / 2, the terminal determines to use the first available random access opportunity. If the difference between the time difference and the valid time is no greater than P / 2, the terminal determines to use the second available random access opportunity.

[0101] Optionally, when the terminal has a selected beam (i.e., beamforming), the terminal will use beam-based random access timing, taking the beam's influence into account when selecting the random access timing. In this case, the terminal will select the random access timing for transmitting PRACH based on the time difference among the random access timings corresponding to the selected beam. That is, among the random access timings corresponding to the selected beam, the random access timing for transmitting PRACH is selected based on the above method. In this case, the terminal will only initiate random access for random access timings that include the selected beam.

[0102] In summary, the method provided in this embodiment determines the transmission resources for initiating random access by enabling the terminal to determine the transmission resources for the message based on the time difference between a first time and a second time. The first time is determined based on system information received by the terminal, and the second time is determined based on the effective time of the uplink synchronization assistance information received by the terminal. This prevents terminals that find the same base station at different times from initiating random access at the same time, thereby avoiding access conflicts and reducing the probability of access failure due to access conflicts.

[0103] Figure 5 A flowchart of a random access method according to an embodiment of this application is shown. This method can be applied to a terminal. The method includes:

[0104] Step 502: Determine the random access timing for sending PRACH based on the time difference between the first and second time points.

[0105] The first time point is determined by the terminal based on the SI received by the terminal, and the second time point is determined by the terminal based on the effective time of the uplink synchronization assistance information received by the terminal. Optionally, the SI includes uplink synchronization assistance information.

[0106] Optionally, the first moment includes at least one of the following:

[0107] • The start or end time of the time slot in which the terminal receives the SIB;

[0108] • The system frame number of the SIB and the start or end time corresponding to the subframe number received by the terminal;

[0109] • The start or end time of the system information time window where the SIB is located, received by the terminal;

[0110] The SIB includes uplink synchronization assistance information.

[0111] Optionally, if the first moment includes multiple moments, i.e., there are multiple first moments, the terminal determines the time difference between each first moment and a second moment, thereby obtaining multiple time differences. The terminal then determines the average or weighted average of these multiple time differences as the time difference between the first moment and the second moment. Alternatively, the terminal determines the earliest first moment in the time domain and determines the time difference between that first moment and the second moment as the time difference between the first moment and the second moment. Alternatively, the terminal determines the latest first moment in the time domain and determines the time difference between that first moment and the second moment as the time difference between the first moment and the second moment. Alternatively, the terminal randomly selects a first moment from the multiple first moments and determines the time difference between the selected first moment and the second moment as the time difference between the first moment and the second moment. Alternatively, the terminal receives an instruction from a network device and determines the time difference between the first moment and the second moment indicated by the network device among the multiple first moments as the time difference between the first moment and the second moment.

[0112] Optionally, the second moment mentioned above is the moment when the uplink synchronization auxiliary information takes effect.

[0113] Network devices can explicitly indicate the effective time of uplink synchronization assistance information via SIB, or implicitly indicate the effective time of uplink synchronization assistance information.

[0114] Regarding the case where SIB explicitly indicates the effective time:

[0115] When the SIB explicitly indicates the effective time of the uplink synchronization assistance information, the SIB includes both the uplink synchronization assistance information and the effective time of the uplink synchronization assistance information. In this case, the effective time of the uplink synchronization assistance information determined by the terminal is the one indicated by the SIB.

[0116] Regarding the case where the SIB implicit indication takes effect:

[0117] When the SIB implicitly indicates the effective time of the uplink synchronization assistance information, the SIB includes the uplink synchronization assistance information but does not include its effective time. In this case, the terminal determines the effective time of the uplink synchronization assistance information based on the time the SIB is received. For example, the terminal determines the effective time of the uplink synchronization assistance information to be the end time of the system information time window in which the SIB is located.

[0118] Optionally, the above-mentioned SIB includes at least one of the following:

[0119] SIB19;

[0120] ·NTN-SIB.

[0121] The aforementioned uplink synchronization assistance information is used to achieve uplink synchronization of the terminal. Optionally, the aforementioned uplink synchronization assistance information includes at least one of the following:

[0122] • Satellite ephemeris information;

[0123] ·Common TA parameter information.

[0124] In the time domain, there are typically multiple random access opportunities. A terminal can select the appropriate random access opportunity to initiate random access based on the aforementioned time difference. Optionally, the larger the time difference, the earlier the random access opportunity selected by the terminal is in the time domain. The smaller the time difference, the later the random access opportunity selected by the terminal is in the time domain.

[0125] Optionally, the method provided in this application provides the following two ways to determine the timing of random access based on the time difference.

[0126] The first method for determining the timing of random access based on time difference:

[0127] The terminal determines the random access timing for sending PRACH based on the time difference between the first and second moments and n preset time differences:

[0128] • If the time difference is no greater than the m-th preset time difference and greater than the (m-1)-th preset time difference, the terminal determines to use the (nm)+1-th available random access opportunity;

[0129] • If the time difference is no greater than the first preset time difference, the terminal determines to use the nth available random access opportunity.

[0130] Available random access opportunities include those that occur after the effective time of the uplink synchronization assistance information in the time domain. The nth random access opportunity precedes the (n-1)th random access opportunity, and the (m-1)th preset time difference is less than the mth preset time difference. m is less than or equal to n, m and n are positive integers, and n is greater than or equal to 2.

[0131] The maximum time difference between the first and second moments is usually known. For example, the maximum difference between the first and second moments is 1024 system frames, or 10.24 seconds. Optionally, if the time difference is greater than the nth preset time difference, the terminal will use the first available random access opportunity.

[0132] Optionally, the division of the above n time differences is predefined, or the value of n is broadcast from the network device to the terminal. Optionally, when the value of n is broadcast from the network device to the terminal, the difference between the (m-1)th preset time difference and the mth preset time difference is predefined. In this case, the terminal only needs to know the value of n to calculate the random access opportunity it will use.

[0133] The second method for determining the timing of random access based on time difference:

[0134] The terminal determines the random access timing for sending PRACH based on the validity period of the uplink synchronization assistance information, and the difference between the time difference between the first and second moments and the validity period:

[0135] • If the difference is no greater than y / x of the valid time and greater than (y-1) / x of the valid time, the terminal determines to use the (xy)+1th available random access opportunity;

[0136] • If the difference is no greater than 1 / x of the valid time, the terminal determines to use the xth available random access opportunity.

[0137] The validity period of the uplink synchronization assistance information refers to the duration during which the uplink synchronization assistance information is valid, starting from the effective time of the uplink synchronization assistance information. Optionally, the validity period of the uplink synchronization assistance information is also configured in the SIB. Available random access opportunities include random access opportunities that are in the time domain after the effective time of the uplink synchronization assistance information. The xth random access opportunity is before the (x-1)th random access opportunity. x is a preset value, which can be broadcast by the network device to the terminal. y is less than or equal to x, y and x are positive integers, and x is greater than or equal to 2.

[0138] The difference between the time difference between the first and second moments and the valid time is usually no greater than the valid time. Optionally, if the difference between the time difference between the first and second moments and the valid time is greater than the valid time, the terminal will use the first available random access opportunity.

[0139] Optionally, when the terminal has a selected beam (i.e., beamforming), the terminal will use beam-based random access timing, taking the beam's influence into account when selecting the random access timing. In this case, the terminal will select the random access timing for transmitting PRACH based on the time difference among the random access timings corresponding to the selected beam. That is, among the random access timings corresponding to the selected beam, the random access timing for transmitting PRACH is selected based on the above method. In this case, the terminal will only initiate random access for random access timings that include the selected beam.

[0140] In a specific example, the network device configures uplink synchronization assistance information to the terminal via SIB19 broadcast, with a broadcast period of 200ms. The terminal determines the effective time of the uplink synchronization assistance information as SFN#999subframe#1, and the corresponding effective time of the uplink synchronization assistance information is 30s. The physical random access channel configuration index (prach-ConfigurationIndex) = 2, and there is a random access opportunity every 4 SFNs, which can be represented as SFN = {1, 5, 9, 13…}.

[0141] In this embodiment, UE#1 receives SIB19 at SFN#1subframe#1, and UE#2 receives SIB19 at SFN#81subframe#1. In related technologies, both UE#1 and UE#2 should initiate random access at the first random access opportunity after the effective time, i.e., at SFN=1001. According to the method provided in this application, UE#1 receives SIB19 before UE#2 and should initiate random access earlier. UE#1 will initiate random access at SFN#1001, and UE#2 will initiate random access at SFN#1005. This avoids access conflicts between UE#1 and UE#2.

[0142] In a specific example, the parameters are configured as follows: Synchronization signal block - per random access channel - timing and code block - preamble each synchronization signal block (ssb-perRACH-OccasionAndCB-PreamblesPerSSB) is four: 13 & Message 1 - Frequency Division Multiplexing (msg1-FDM) is 1 & Synchronization signal block - Burst PositionsInBurstmediumBitmap is '11110000'.

[0143] For example, Figure 6 This is a schematic diagram illustrating a synchronization signal block and random access timing provided in an exemplary embodiment of this application. Figure 6As shown, based on the above parameter configuration, the cell transmits a total of 4 SSBs (ssb-PositionsInBurstmediumBitmap: '11110000'), 1 RACH occasion corresponds to 4 SSBs (ssb-perRACH-OccasionAndCB-PreamblesPerSSB four:13), and each SSB corresponds to 13 contention-based preambles (ssb-perRACH-OccasionAndCB-PreamblesPerSSB four:13). The base station can determine the SSB index by detecting the range of the preamble index. This mapping relationship is {SSB0: 0-12, SSB1: 16-28, SSB2: 32-44, SSB3: 48-60}.

[0144] Since each RO (Ranch Occasion) contains all beams at this point, the ROs selected by UE#1 and UE#2 are not affected by the beams. Therefore, the selection method can be the same as in the previous example. For example, UE#1 selects beam #1 corresponding to SSB#1, and UE#2 selects beam 2 corresponding to SSB#2.

[0145] In a specific example, the parameters are configured as follows: ssb-perRACH-OccasionAndCB-PreamblesPerSSB is 1:52 &msg1-FDM is 2 &ssb-PositionsInBurst mediumBitmap is '11110000'.

[0146] For example, Figure 7 This is a schematic diagram illustrating a synchronization signal block and random access timing provided in an exemplary embodiment of this application. Figure 7 As shown, by changing the configuration parameters in the previous example, in this example, one SSB corresponds to one RO, and each RO or SSB uses all 52 contention-based preambles. Thus, the base station cannot distinguish SSBs by preamble index; it can only distinguish them by ROs of different time-frequency resources. The four SSBs are mapped to four ROs of different time-frequency resources, from RO0 to RO3.

[0147] Specifically, UE#1 receives SIB19 in SFN#1subframe#1, and UE#1's selected beam #1 corresponds to SSB#1. UE#2 receives SIB19 in SFN#81subframe#1, and UE#2's selected beam #2 corresponds to SSB#2.

[0148] In the relevant technology, both UE#1 and UE#2 should initiate random access at the first random access opportunity after the effective time. That is, UE#1 initiates random access at the random access opportunity when SFN=1001 (corresponding to SSB#0 and SSB#1), and UE#2 initiates random access at the random access opportunity when SFN=1005 (corresponding to SSB#2 and SSB#3).

[0149] According to the method provided in the embodiments of this application, UE#1 receives SIB19 before UE#2 and should initiate random access earlier. UE#1 initiates random access at SFN#1001, while UE#2 initiates random access at SFN#1013 (the random access opportunity corresponding to the second available SSB#2). This avoids access conflicts between UE#1 and UE#2 when a selected beam is available.

[0150] In summary, the method provided in this embodiment determines the transmission resources for initiating random access by enabling the terminal to determine the transmission resources for the message based on the time difference between a first time and a second time. The first time is determined based on system information received by the terminal, and the second time is determined based on the effective time of the uplink synchronization assistance information received by the terminal. This prevents terminals that find the same base station at different times from initiating random access at the same time, thereby avoiding access conflicts and reducing the probability of access failure due to access conflicts.

[0151] It should be noted that the order of the method steps provided in the embodiments of this application can be appropriately adjusted, and the steps can also be added or removed as appropriate. Any method variations that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the protection scope of this application, and therefore will not be elaborated further.

[0152] Figure 8 A structural block diagram of a random access device provided in an exemplary embodiment of this application is shown. Figure 8 As shown, the device includes:

[0153] The determination module 801 is used to determine the resource for sending the first message based on the time difference between the first moment and the second moment;

[0154] The first time is determined based on the SI received by the terminal, the second time is determined based on the effective time of the uplink synchronization assistance information received by the terminal, and the first message is used to initiate random access.

[0155] In an alternative design, the first moment includes at least one of the following:

[0156] The start or end time of the time slot in which the terminal receives the SIB;

[0157] The terminal receives the system frame number where the SIB is located and the start or end time corresponding to the subframe number.

[0158] The start or end time of the system information time window in which the SIB is located, received by the terminal;

[0159] The SIB includes the uplink synchronization assistance information.

[0160] In an optional design, the effective time of the uplink synchronization assistance information is indicated by the SIB; or, the effective time of the uplink synchronization assistance information is determined based on the SIB received by the terminal.

[0161] In an optional design, the second moment is the moment when the uplink synchronization assistance information takes effect.

[0162] In an optional design, the determining module 801 is used for:

[0163] Based on the time difference, the random access timing for sending PRACH is determined.

[0164] In an optional design, the determining module 801 is used for:

[0165] Based on the time difference and n preset time differences, determine the random access timing for sending PRACH:

[0166] If the time difference is not greater than the m-th preset time difference and is greater than the (m-1)-th preset time difference, determine to use the (nm)+1-th available random access opportunity;

[0167] If the time difference is not greater than the first preset time difference, determine the nth available random access opportunity;

[0168] Wherein, the (m-1)th preset time difference is less than the mth preset time difference, m is less than or equal to n, and m and n are positive integers.

[0169] In an optional design, the determining module 801 is used for:

[0170] Based on the validity period of the uplink synchronization assistance information and the difference between the time difference and the validity period, the random access timing for sending PRACH is determined:

[0171] If the difference is not greater than y / x of the effective time and is greater than (y-1) / x of the effective time, the (xy)+1th available random access opportunity is determined to be used.

[0172] If the difference is not greater than 1 / x of the effective time, determine to use the xth available random access opportunity;

[0173] Where x is a preset value, y is less than or equal to x, and y and x are positive integers.

[0174] In an optional design, the determining module 801 is used for:

[0175] When the terminal has a selected beam, the random access timing for transmitting PRACH is selected based on the time difference during the random access timing corresponding to the selected beam.

[0176] In an optional design, the SIB includes at least one of the following:

[0177] SIB19;

[0178] NTN-SIB.

[0179] In an optional design, the uplink synchronization assistance information includes at least one of the following:

[0180] Satellite ephemeris information;

[0181] Public TA parameter information.

[0182] In an alternative design, the first message includes at least one of the following:

[0183] Msg 1;

[0184] Msg A.

[0185] It should be noted that the device provided in the above embodiments is only illustrated by the division of the above functional modules when implementing its functions. In actual applications, the above functions can be assigned to different functional modules according to actual needs, that is, the content structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0186] Regarding the apparatus in the above embodiments, the specific manner in which each module performs its operation has been described in detail in the embodiments related to the method, and will not be elaborated upon here.

[0187] Figure 9 The diagram shows a schematic of the structure of a communication device 90 provided in an exemplary embodiment of this application. The communication device 90 includes: a processor 901, a receiver 902, a transmitter 903, a memory 904, and a bus 905.

[0188] The processor 901 includes one or more processing cores. The processor 901 executes various functional applications and information processing by running software programs and modules.

[0189] The receiver 902 and the transmitter 903 can be implemented as a communication component, which can be a communication chip.

[0190] The memory 904 is connected to the processor 901 via the bus 905.

[0191] The memory 904 can be used to store at least one instruction, and the processor 901 can execute the at least one instruction to implement the various steps in the above method embodiments.

[0192] Furthermore, the memory 904 can be implemented by any type of volatile or non-volatile storage device or a combination thereof, including but not limited to: magnetic disks or optical disks, electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), static random access memory (SRAM), read-only memory (ROM), magnetic storage, flash memory, and programmable read-only memory (PROM).

[0193] When the communication device is implemented as a terminal, the processor and transceiver in the communication device involved in this application embodiment can be implemented together as a single communication chip, or the transceiver can be implemented as a separate communication chip. The transmitter in the transceiver performs the sending step performed by the terminal in any of the methods described above, the receiver in the transceiver performs the receiving step performed by the terminal in any of the methods described above, and the processor performs steps other than the sending and receiving steps, which will not be elaborated here.

[0194] In an exemplary embodiment, a computer-readable storage medium is also provided, which stores at least one instruction, at least one program, code set, or instruction set, wherein the at least one instruction, the at least one program, the code set, or the instruction set is loaded and executed by the processor to implement the random access method provided in the above-described method embodiments.

[0195] In an exemplary embodiment, a chip is also provided, the chip including programmable logic circuits and / or program instructions, which, when the chip is run on a communication device, is used to implement the random access method provided in the above-described method embodiments.

[0196] In an exemplary embodiment, a computer program product is also provided, which, when run on the processor of a computer device, causes the computer device to perform the above-described random access method.

[0197] Those skilled in the art will recognize that the functions described in the embodiments of this application in one or more of the above examples 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 code on a computer-readable medium. Computer-readable media include computer storage media and communication media, wherein communication media include any medium that facilitates the transfer of a computer program from one place to another. Storage media can be any available medium that can be accessed by a general-purpose or special-purpose computer.

[0198] The above description is merely an exemplary embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A random access method, characterized by, The method is executed by a terminal, and the method includes: Based on the time difference between the first and second moments and n preset time differences, determine the random access timing for transmitting the Physical Random Access Channel (PRACH): If the time difference is not greater than the m-th preset time difference and is greater than the (m-1)-th preset time difference, determine to use the (nm)+1-th available random access opportunity; If the time difference is not greater than the first preset time difference, determine the nth available random access opportunity; If the time difference is greater than the nth preset time difference, determine to use the first available random access opportunity; The first time point is determined based on the system information SI received by the terminal, the second time point is determined based on the effective time of the uplink synchronization assistance information received by the terminal, and the available random access opportunities include random access opportunities that are located after the effective time of the uplink synchronization assistance information in the time domain, with the nth random access opportunity occurring at the nth time point. After one random access opportunity, the (m-1)th preset time difference is less than the mth preset time difference, where m is less than or equal to n, m and n are positive integers, and n is greater than or equal to 2.

2. The method according to claim 1, characterized in that, The first moment includes at least one of the following: The start or end time of the time slot in which the terminal receives the system information block SIB; The terminal receives the system frame number where the SIB is located and the start or end time corresponding to the subframe number. The start or end time of the system information time window in which the SIB is located, received by the terminal; The SIB includes the uplink synchronization assistance information.

3. The method according to claim 2, characterized in that, The effective time of the uplink synchronization assistance information is indicated by the SIB; or, the effective time of the uplink synchronization assistance information is determined based on the SIB received by the terminal.

4. The method according to claim 1, characterized in that, The second moment is the moment when the uplink synchronization assistance information takes effect.

5. The method according to any one of claims 1 to 4, characterized in that, The method further includes: Based on the validity period of the uplink synchronization assistance information and the difference between the time difference and the validity period, the random access timing for sending PRACH is determined: If the difference is not greater than y / x of the effective time and is greater than (y-1) / x of the effective time, then the (xy)+1th available random access opportunity is determined to be used. If the difference is not greater than 1 / x of the effective time, determine to use the xth available random access opportunity; Where x is a preset value, y is less than or equal to x, and y and x are positive integers.

6. The method according to any one of claims 1 to 4, characterized in that, The determination of the random access timing for sending PRACH includes: When the terminal has a selected beam, the random access timing for transmitting PRACH is selected from the random access timings corresponding to the selected beam.

7. The method according to claim 2 or 3, characterized in that, The SIB includes at least one of the following: SIB19; Non-terrestrial network communication NTN-SIB.

8. The method according to any one of claims 1 to 4, characterized in that, The uplink synchronization assistance information includes at least one of the following: Satellite ephemeris information; Publicly scheduled advance TA parameter information.

9. A random access device, characterized in that, The device includes: The determination module is used to determine the random access timing for sending PRACH based on the time difference between the first and second moments and n preset time differences: If the time difference is not greater than the m-th preset time difference and is greater than the (m-1)-th preset time difference, determine to use the (nm)+1-th available random access opportunity; If the time difference is not greater than the first preset time difference, determine the nth available random access opportunity; If the time difference is greater than the nth preset time difference, determine to use the first available random access opportunity; The first time point is determined based on the SI received by the terminal, the second time point is determined based on the effective time of the uplink synchronization assistance information received by the terminal, and the available random access opportunities include random access opportunities that are in the time domain after the effective time of the uplink synchronization assistance information, with the nth random access opportunity occurring at the nth time point. After one random access opportunity, the (m-1)th preset time difference is less than the mth preset time difference, where m is less than or equal to n, m and n are positive integers, and n is greater than or equal to 2.

10. A terminal, characterized in that, The terminal includes: processor; A transceiver connected to the processor; Memory for storing the executable instructions of the processor; The processor is configured to load and execute the executable instructions to implement the random access method as described in any one of claims 1 to 8.

11. A computer-readable storage medium, characterized in that, The readable storage medium stores executable instructions, which are loaded and executed by a processor to implement the random access method as described in any one of claims 1 to 8.

12. A chip, characterized in that, The chip includes a programmable logic circuit or a program, and the chip is used to implement the random access method as described in any one of claims 1 to 8.

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