Access method, satellite, user equipment and communication device

Abstract

The invention relates to the technical field of wireless communication, in particular to an access method, a satellite, user equipment, a communication device, a computer readable storage medium and a computer program product. The access method comprises the following steps: receiving a connection request message from user equipment; in response to the connection request message, determining candidate satellites according to information of a second satellite and position information of the user equipment; a connection request response message is sent to the user equipment, and the connection request response message comprises the information of the candidate satellites; receiving a measurement report of the candidate satellite from the user equipment; determining a target satellite according to the measurement report of the candidate satellite; and sending the information of the target satellite to the user equipment, the information of the target satellite being used for indicating the user equipment to access the target satellite.

Description

Technical Field

[0001] The present disclosure relates to the field of wireless communication technology, and in particular to an access method, a satellite, a user equipment, a communication device, a computer-readable storage medium, and a computer program product. Background Art

[0002] With the development of communication technology, satellite networks are increasingly being used. Compared with ground networks, satellite networks have significant advantages in supporting emergency communications and ubiquitous connectivity. Satellite systems built using the advantages of satellites in different orbital planes have become an important means of achieving global communication coverage.

[0003] Satellite networks usually include high-orbit satellites and low-orbit satellites. High-orbit satellites have a large coverage area but higher latency, while low-orbit satellites have low latency but face problems such as frequent switching and severe Doppler frequency shift.

[0004] In related technologies, in order to fully combine the respective advantages and characteristics of high-orbit and low-orbit satellites, an architecture of separate deployment of centralized units (CU) and distributed units (DU) is adopted, with CU deployed on high-orbit satellites and DU deployed on low-orbit satellites.

[0005] In the above technology, the user equipment can only transmit data after successfully accessing the low-orbit satellite. However, the success rate of the user equipment directly accessing the low-orbit satellite with a faster moving speed is low, and the user's service experience is poor.

[0006] In addition, in order to select the corresponding low-orbit satellite, the user equipment needs to be configured with information of all low-orbit satellites, which results in high design complexity of the user equipment. Summary of the invention

[0007] In the related art, when a user device accesses a satellite system, there are problems such as a low success rate and high complexity of the user device.

[0008] In view of this, the present disclosure provides an access method that can effectively solve the above problems.

[0009] According to one aspect of the present disclosure, an access method is provided, which is performed by a first satellite and includes: receiving a connection request message from a user equipment; determining a candidate satellite in response to the connection request message according to information of a second satellite and position information of the user equipment; sending a connection request response message to the user equipment, wherein the connection request response message includes information of the candidate satellite; receiving a measurement report of the candidate satellite from the user equipment; determining a target satellite according to the measurement report of the candidate satellite; and sending information of the target satellite to the user equipment, wherein the information of the target satellite is used to instruct the user equipment to access the target satellite.

[0010] In some embodiments, the information of the second satellite includes ephemeris information of the second satellite, and in response to the connection request message, determining the candidate satellite based on the information of the second satellite and the location information of the user equipment includes: determining the location information of the user equipment based on the connection request message; determining the candidate satellite based on the ephemeris information of the second satellite and the location information of the user equipment.

[0011] In some embodiments, determining the location information of the user equipment according to the connection request message includes: determining the location information of the user equipment according to at least one of the strength, orientation, and signal propagation time of the connection request message.

[0012] In some embodiments, the information of the second satellite includes ephemeris information of the second satellite, and in response to the connection request message, determining the candidate satellite according to the information of the second satellite and the location information of the user equipment includes: determining the capability of the user equipment according to the connection request message; and determining the candidate satellite that is compatible with the capability of the user equipment according to the ephemeris information of the second satellite and the location information of the user equipment.

[0013] In some embodiments, the access method further includes: after sending the information of the target satellite to the user equipment, releasing the information of the user equipment and the information of the candidate satellite stored in the first satellite.

[0014] In some embodiments, the access method further includes: acquiring information of the second satellite, the information of the second satellite including at least one of an ID of the second satellite, ephemeris information, a beam ID, and a beam frequency.

[0015] In some embodiments, the access method also includes: for each second satellite within the coverage range of the first satellite, determining the interface connection status between the first satellite and the second satellite; when no interface connection is established between the first satellite and the second satellite, sending an interface connection establishment request message to the second satellite; and in response to receiving an interface connection establishment request response message from the second satellite, determining that the interface connection establishment is complete.

[0016] In some embodiments: the connection request message includes at least one of the ID and capability information of the user equipment; and / or the information of the candidate satellite includes at least one of the ID, beam ID, reference signal information, and usage frequency of the candidate satellite; and / or the measurement report of the candidate satellite includes at least one of the ID and reference signal strength of the candidate satellite; and / or the information of the target satellite includes at least one of the ID, beam ID, resource configuration information allocated to the user equipment for connecting to the target satellite, timing advance, and frequency deviation.

[0017] In some embodiments: the first satellite is a high-orbit satellite; the second satellite is a low-orbit satellite.

[0018] According to another aspect of the present disclosure, an access method is provided, which is performed by a user equipment, including: sending a connection request message to a first satellite; receiving a connection request response message from the first satellite, the connection request response message including information of a candidate satellite, the candidate satellite being determined based on information of a second satellite and position information of the user equipment; measuring the candidate satellite based on the connection request response message to generate a measurement report of the candidate satellite; sending the measurement report of the candidate satellite to the first satellite; receiving information of a target satellite from the first satellite; and accessing the target satellite based on the information of the target satellite.

[0019] In some embodiments, sending a connection request message to a first satellite includes: receiving a first broadcast message from the first satellite; and sending the connection request message to the first satellite according to the first broadcast message.

[0020] In some embodiments, the first broadcast message includes at least one of location information of the first satellite and resource configuration information allocated to the user equipment for connecting with the first satellite.

[0021] In some embodiments, based on the information of the target satellite, accessing the target satellite includes: receiving a second broadcast message from the target satellite; sending an access request message to the target satellite based on the second broadcast message; and determining that access is completed in response to receiving an access request response message from the target satellite.

[0022] In some embodiments: the second broadcast message includes at least one of the position information and reference signal information of the target satellite; and / or the access request message includes at least one of the ID, capability, and channel state information of the user equipment; and / or the access request response message includes resource configuration information allocated to the user equipment for connecting to the target satellite.

[0023] According to another aspect of the present disclosure, a satellite is provided, comprising: a first receiving module, configured to receive a connection request message from a user equipment; a first determining module, configured to determine a candidate satellite in response to the connection request message, according to information of a second satellite and location information of the user equipment; a first sending module, configured to send a connection request response message to the user equipment, the connection request response message including information of the candidate satellite; a second receiving module, configured to receive a measurement report of the candidate satellite from the user equipment; a second determining module, configured to determine a target satellite according to the measurement report of the candidate satellite; and a second sending module, configured to send information of the target satellite to the user equipment, the information of the target satellite being used to instruct the user equipment to access the target satellite.

[0024] According to another aspect of the present disclosure, a user equipment is provided, including: a first sending module, configured to send a connection request message to a first satellite; a first receiving module, configured to receive a connection request response message from the first satellite, the connection request response message including information of a candidate satellite, the candidate satellite being determined according to information of a second satellite and position information of the user equipment; a measurement module, configured to measure the candidate satellite according to the connection request response message to generate a measurement report of the candidate satellite; a second sending module, configured to send the measurement report of the candidate satellite to the first satellite; a second receiving module, configured to receive information of a target satellite from the first satellite; and an access module, configured to access the target satellite according to the information of the target satellite.

[0025] According to yet another aspect of the present disclosure, a communication device is provided, comprising: a memory; and a processor coupled to the memory, wherein the processor is configured to execute the access method as described in any one of the above items based on instructions stored in the memory.

[0026] According to another aspect of the present disclosure, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores computer instructions, and when the instructions are executed by a processor, the access method as described in any one of the above items is implemented.

[0027] According to another aspect of the present disclosure, a computer program product is provided, wherein the computer program product stores computer instructions, and when the instructions are executed by a processor, the access method as described in any one of the above items is implemented.

[0028] The access method proposed in the present disclosure reduces the complexity of the user equipment by selecting candidate satellites and target satellites by the first satellite without the need for the user equipment to make selections. Meanwhile, the first satellite sends the configuration related to accessing the target satellite to the user equipment, thereby improving the access success rate of the user equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The accompanying drawings, which constitute a part of the specification, illustrate embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0030] The present disclosure can be more clearly understood from the following detailed description with reference to the accompanying drawings.

[0031] in:

[0032] Figure 1 is a flow chart illustrating an access method according to some embodiments of the present disclosure;

[0033] Figure 2A is a flowchart illustrating determination of candidate satellites according to some embodiments of the present disclosure;

[0034] Figure 2B is a flowchart illustrating determination of candidate satellites according to other embodiments of the present disclosure;

[0035] Figure 3 is a flow chart showing an access method according to other embodiments of the present disclosure;

[0036] Figure 4 is a flow chart showing an access method according to some further embodiments of the present disclosure;

[0037] Figure 5 is a flow chart illustrating sending a connection request message according to some embodiments of the present disclosure;

[0038] Figure 6 is a flow chart illustrating accessing a target satellite according to some embodiments of the present disclosure;

[0039] Figure 7 is a schematic diagram illustrating a satellite communication system according to some embodiments of the present disclosure;

[0040] Figure 8 is a signaling flow chart illustrating an access method according to some embodiments of the present disclosure;

[0041] Fig. 9 is a block diagram illustrating a satellite according to some embodiments of the present disclosure;

[0042] Fig.10 is a block diagram illustrating a user equipment according to some embodiments of the present disclosure;

[0043] Fig.11 is a block diagram illustrating a communication device according to some embodiments of the present disclosure;

[0044] Fig.12 is a block diagram illustrating a computer system for implementing some embodiments of the present disclosure.

[0045] It should be understood that the size of each part shown in the accompanying drawings is not drawn according to the actual proportional relationship. In addition, the same or similar reference numerals represent the same or similar components. DETAILED DESCRIPTION

[0046] Various embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. The description of the embodiments is merely illustrative and is in no way intended to limit the present disclosure and its application or use. The present disclosure can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided to make the present disclosure thorough and complete and to fully express the scope of the present disclosure to those skilled in the art. It should be noted that unless otherwise specifically stated, the relative arrangement of the components and steps described in these embodiments should be interpreted as being merely illustrative and not as a limitation.

[0047] The words "first", "second" and similar words used in this disclosure do not indicate any order, quantity or importance, but are only used to distinguish different parts. The words "include" and similar words mean that the elements before the word include the elements listed after the word, and do not exclude the possibility of including other elements.

[0048] It should also be understood that any component, data or structure mentioned in the embodiments of the present disclosure can generally be understood as one or more, unless explicitly limited or otherwise indicated in the context.

[0049] User equipment, also known as terminal equipment (UE), terminal, etc. User equipment is a device with wireless transceiver function, which can communicate with one or more core networks (CN) through the access network equipment in the (radio) access network ((R)AN). It can be deployed on land, including indoors or outdoors, handheld, wearable or vehicle-mounted; it can also be deployed on the water surface, such as on a ship; it can also be deployed in the air, such as on an airplane, balloon or satellite. User equipment can be a mobile phone, a tablet computer, a computer with wireless transceiver function, a virtual reality (VR) terminal device, an augmented reality (AR) terminal device, a wireless terminal in industrial control, a wireless terminal in self-driving, a wireless terminal in remote medical, a wireless terminal in smart grid, a wireless terminal in transportation safety, a wireless terminal in smart city, a wireless terminal in smart home, etc.

[0050] All terms (including technical terms or scientific terms) used in the present disclosure have the same meanings as those understood by ordinary technicians in the field to which the present disclosure belongs, unless otherwise specifically defined. It should also be understood that terms defined in general dictionaries, such as general dictionaries, should be interpreted as having meanings consistent with their meanings in the context of the relevant technology, and should not be interpreted in an idealized or extremely formal sense, unless explicitly defined herein.

[0051] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered as part of the specification.

[0052] In traditional satellite access, user equipment directly accesses low-orbit satellites with relatively fast movement speeds, which results in low access success rate and high design complexity of user equipment.

[0053] In view of this, the present disclosure proposes an access method, which can improve the access success rate and reduce the complexity of user equipment.

[0054] First, combine Figure 1 An access method performed by a first satellite in the present disclosure is described. Figure 1 is a flow chart illustrating an access method according to some embodiments of the present disclosure.

[0055] like Figure 1 As shown, the access method includes: step S11, receiving a connection request message from a user device; step S12, determining a candidate satellite in response to the connection request message according to information of a second satellite and location information of the user device; step S13, sending a connection request response message to the user device, wherein the connection request response message includes information of the candidate satellite; step S14, receiving a measurement report of the candidate satellite from the user device; step S15, determining a target satellite according to the measurement report of the candidate satellite; and step S16, sending information of the target satellite to the user device, wherein the information of the target satellite is used to instruct the user device to access the target satellite.

[0056] The access method proposed in the present disclosure reduces the complexity of the user equipment by selecting candidate satellites and target satellites by the first satellite without the need for the user equipment to make selections. Meanwhile, the first satellite sends the configuration related to accessing the target satellite to the user equipment, thereby improving the access success rate of the user equipment.

[0057] In some embodiments, the first satellite is, for example, a high-orbit satellite, and the second satellite is, for example, a low-orbit satellite.

[0058] In the above access method, the high-orbit satellite can be used to select the candidate low-orbit satellite for measurement and the target low-orbit satellite for access for the user equipment, and provide corresponding configuration information. Since the high-orbit satellite is stationary relative to the ground, the connection between the user equipment and the high-orbit satellite is relatively stable. After the user equipment obtains the configuration information through the connection with the high-orbit satellite, it can access the low-orbit satellite, which can effectively improve the access success rate.

[0059] The above describes the overall solution of the access method proposed in the present disclosure. Next, the specific steps in the above access method will be described in detail.

[0060] In step S11, a connection request message is received from a user equipment.

[0061] When the user equipment needs to access the satellite network, the user equipment sends a connection request message to the first satellite, thereby attempting to establish a connection with the first satellite.

[0062] In some embodiments, the connection request message includes at least one of an ID and capability information of the user equipment.

[0063] By carrying the above information in the connection request message, the first satellite can accurately confirm the identity of the user equipment, thereby selecting a candidate satellite for the user equipment.

[0064] In step S12, in response to the connection request message, a candidate satellite is determined according to the information of the second satellite and the location information of the user equipment. The information of the second satellite includes, for example, ephemeris information of the second satellite.

[0065] Ephemeris information usually includes the satellite's orbit information, time information, etc., and can be used to determine the satellite's position, speed and other parameters.

[0066] After the first satellite receives the connection request message sent by the user equipment, the first satellite needs to determine a candidate satellite for the user equipment so as to select a target satellite for access from the group of candidate satellites.

[0067] In some embodiments, the specific steps of determining the candidate satellites are as follows: Figure 2A shown. Figure 2A is a flowchart illustrating determination of candidate satellites according to some embodiments of the present disclosure.

[0068] like Figure 2A As shown, step S12, in response to the connection request message, determining the candidate satellite according to the information of the second satellite and the location information of the user equipment may include steps S121 to S122.

[0069] In step S121, the location information of the user equipment is determined according to the connection request message.

[0070] Specifically, according to whether the user equipment has a positioning function, determining the location information of the user equipment is divided into two cases. The process of determining the location information in each case will be described below.

[0071] In the first case, the user equipment has a positioning function and can determine the position of the user equipment itself. In this case, the connection request message sent by the user equipment may additionally include the position information of the user equipment, and the first satellite obtains the position information of the user equipment through the connection request message.

[0072] In the second case, the user equipment does not have a positioning function. In this case, the first satellite needs to estimate the approximate position of the user equipment on the ground.

[0073] In some embodiments, the first satellite may determine the location information of the user equipment based on at least one of the strength, the orientation, and the signal propagation time of the connection request message.

[0074] For example, the first satellite can adopt a positioning method based on signal strength (RSSI) by measuring the received signal strength and combining the known user equipment transmitter power and propagation loss model to calculate the distance between the user equipment and the first satellite, thereby determining the location information of the user equipment.

[0075] Similarly, a positioning method based on angle of arrival (AOA) and / or a positioning method based on time of arrival (TOA) may also be used to determine the location information of the user equipment.

[0076] When performing the above positioning method, when the first satellite includes multiple antennas or antenna arrays, each antenna or antenna array can be used as a separate positioning point, and the location information of the user equipment is determined through collaborative calculation between different positioning points, thereby improving the accuracy of the location information.

[0077] The above positioning method can estimate the position of the user equipment without positioning function on the ground according to the connection request message, thereby determining the position information of the user equipment, so as to select candidate satellites for the user equipment.

[0078] In step S122, a candidate satellite is determined according to the ephemeris information of the second satellite and the position information of the user equipment.

[0079] According to the ephemeris information of the second satellite and the position information of the user equipment, the method of determining the candidate satellite may include: a distance-based selection method and a visible time-based selection method.

[0080] The distance-based selection method includes determining the position information of the second satellite according to the ephemeris information of the second satellite, and determining all second satellites whose distances to the user equipment are less than a specific distance threshold as candidate satellites according to the position information of the second satellite and the position information of the user equipment.

[0081] The above-mentioned selection method based on visible time includes determining the remaining time that the user equipment will remain within the coverage of the second satellite, that is, the remaining visible time, according to the ephemeris information of the second satellite and the location information of the user equipment, and determining all second satellites whose remaining visible time with the user equipment is greater than a specific time threshold as candidate satellites.

[0082] Through the above steps, the first satellite can screen out the second satellite that can provide communication services for the user equipment as a candidate satellite, which is used to determine the target satellite from the candidate satellites through subsequent steps.

[0083] By having the first satellite perform the selection of the candidate satellite, the information of the second satellite can be stored in the first satellite, and the user equipment does not need to be configured with the information of the second satellite, thereby reducing the complexity of the user equipment.

[0084] Based on the above Figure 2A The specific steps of determining candidate satellites in some embodiments are introduced. Figure 2B Specific steps for determining candidate satellites in other embodiments are introduced. Figure 2BFIG. 4 is a flowchart illustrating a method of determining candidate satellites according to other embodiments of the present disclosure.

[0085] like Figure 2B As shown, step S12, in response to the connection request message, determining the candidate satellite according to the information of the second satellite and the location information of the user equipment may also include steps S121' to S122'.

[0086] In step S121', the capability of the user equipment is determined according to the connection request message.

[0087] For example, as described above, the user equipment may include the capability information of the user equipment in the sent connection request message, so that the first satellite may directly determine the capabilities supported by the user equipment according to the connection request message.

[0088] The capabilities of the user equipment include, for example, the user equipment supporting beamforming technology, the user equipment supporting automatic satellite alignment capability, the user equipment supporting network traffic control, etc.

[0089] In step S122', a candidate satellite that is compatible with the capability of the user equipment is determined according to the ephemeris information of the second satellite and the location information of the user equipment.

[0090] By determining a candidate satellite that is compatible with the capabilities of the user equipment, the success rate of establishing a connection can be further improved. For example, when the user equipment supports beamforming technology, a second satellite that also supports beamforming technology can be selected as a candidate satellite, so that when the user equipment accesses the second satellite, it can directly use the beamforming technology for access.

[0091] It should be noted that Figure 2B The illustrated embodiments and Figure 2A There is no exclusive relationship between the illustrated embodiments, but rather it should be understood as an “and / or” relationship, where the first satellite can determine both the position of the user equipment and the candidate satellite that matches the capability of the user equipment.

[0092] In step S13, a connection request response message is sent to the user equipment, where the connection request response message includes information about the candidate satellite.

[0093] In some embodiments, the information of the candidate satellite includes at least one of an ID, a beam ID, reference signal information, and a used frequency of the candidate satellite.

[0094] After determining the candidate satellite, the first satellite sends the above information of the candidate satellite to the user equipment through a connection request response message, so that the user equipment can measure the reference signal of the candidate satellite.

[0095] In the above information, the use frequency refers to the frequency of the signal when the user equipment communicates with the candidate satellite. Generally, the use frequency includes at least a portion of the bandwidth in the L, S, C, X, Ku or Ka band. By configuring the use frequency for the user equipment in advance, mutual interference between the use frequencies of the user equipment and other devices can be avoided, thereby improving the success rate of user equipment access.

[0096] In step S14, a measurement report of the candidate satellite is received from the user equipment.

[0097] In some embodiments, the measurement report of the candidate satellite includes at least one of an ID of the candidate satellite and a reference signal strength.

[0098] After performing the measurement, the user equipment sends a measurement report of the candidate satellite to the first satellite, and includes the candidate satellite and the corresponding reference signal strength in the measurement report of the candidate satellite, so that the first satellite can use it as a reference when selecting the target satellite.

[0099] In step S15, a target satellite is determined based on the measurement report of the candidate satellite.

[0100] The first satellite may determine, according to the measurement report of the user equipment, a target satellite for the user equipment to access from among the candidate satellites.

[0101] For example, the first satellite may use the second satellite with the largest reference signal strength as the target satellite based on the measurement report of the user equipment. For another example, the first satellite may assign weights to the reference signal strength of the second satellite and the visible time relative to the user equipment, and determine the most suitable second satellite as the target satellite after weighted summation.

[0102] By selecting the target satellite through the first satellite, the information of the second satellite can be stored in the first satellite. The user equipment does not need to configure the information of the second satellite, which further reduces the complexity of the user equipment. The first satellite selects the target satellite based on the measurement report of the candidate satellite, and can determine the target satellite that is most suitable for the user equipment to access, thereby improving the access success rate.

[0103] In step S16, the information of the target satellite is sent to the user equipment, where the information of the target satellite is used to instruct the user equipment to access the target satellite.

[0104] In some embodiments, the information of the target satellite includes at least one of the ID of the target satellite, the beam ID, resource configuration information allocated to the user equipment for connecting to the target satellite, a timing advance, and a frequency offset.

[0105] In the above information, the timing advance refers to the time required to send the data packet in advance in order for the uplink packet of the user equipment to arrive at the satellite at the desired time. This time is determined by estimating the radio frequency transmission delay caused by the distance.

[0106] Frequency deviation refers to the difference between the received signal frequency and the transmitted signal frequency caused by the relative motion between the satellite and the user equipment. This difference is mainly caused by the Doppler effect, that is, when there is relative motion between the signal source and the observer, the signal frequency received by the observer is different from the frequency emitted by the source.

[0107] Resource configuration information includes, for example, the access time-frequency position, which refers to the time domain starting point and frequency domain starting point of the signal sent by the user equipment. Through the access time-frequency position, accurate signal synchronization can be achieved between the user equipment and the satellite, thereby improving the access success rate.

[0108] Before the user equipment accesses, the first satellite sends the access-related information to the user equipment in advance, so that the user equipment accesses according to the information, thereby improving the access success rate of the user equipment.

[0109] Based on the above Figure 1 Figure 2 introduces the access method proposed in some basic embodiments of the present disclosure. The access method selects candidate satellites and target satellites through a first satellite and accesses the target satellite, which can reduce the complexity of the user equipment and improve the success rate of user equipment access.

[0110] Next, we will base Figure 3 An access method in a further embodiment of the present disclosure is introduced. Figure 3 is a flowchart illustrating an access method according to some other embodiments of the present disclosure.

[0111] like Figure 3 As shown, the access method includes steps S10 to S17. Steps S11 to S16 have been combined with the above Figure 1 The above description has been made and will not be repeated here. The following focuses on describing steps S10 and S17.

[0112] In step S10, the information of the second satellite is obtained.

[0113] In some embodiments, the information of the second satellite includes at least one of an ID of the second satellite, ephemeris information, a beam ID, and a beam frequency.

[0114] In step S10, the first satellite receives pre-configured second satellite information, where the second satellite information includes information to be used in subsequent steps S11 to S16 for determining candidate satellites and target satellites and sending access-related configuration information to the user equipment.

[0115] The information of the second satellite mentioned above can be periodically sent by a ground data center, for example. By periodically updating the information of the second satellite stored in the first satellite, it is possible to avoid incorrect information used by the first satellite in subsequent processes, which may lead to access failure of user equipment and improve the access success rate.

[0116] In some embodiments, after acquiring the information of the second satellite, the first satellite may check the interface connection with the second satellite to ensure that the first satellite has established an interface connection with each second satellite within the coverage area. The specific steps may include: for each second satellite within the coverage area of ​​the first satellite, determining the interface connection status between the first satellite and the second satellite; when the first satellite has not established an interface connection with the second satellite, sending an interface connection establishment request message to the second satellite; and in response to receiving an interface connection establishment request response message from the second satellite, determining that the interface connection establishment is complete.

[0117] The interface connection establishment request message may include the ID of the first satellite. The interface connection establishment request response message may include at least one of the ID of the second satellite, ephemeris information, beam ID, beam frequency, and beam load status.

[0118] Through the above steps, it can be ensured that an interface connection is established between the first satellite and the second satellite, and the first satellite can communicate with the second satellite in real time to update information, further improving the success rate of the access process using the information of the second satellite.

[0119] In step S17, the information of the user equipment and the information of the candidate satellite stored in the first satellite is released.

[0120] After the first satellite sends the target satellite information to the user equipment, the target satellite selection has been completed, and the first satellite does not need to participate in the subsequent access process. In step S17, the first satellite can release the stored user equipment information and candidate satellite information to ensure that all related wireless resources are effectively recovered, thereby freeing up resources for other communication needs.

[0121] Based on the above Figures 1 to 3 The access method performed by the first satellite in some embodiments of the present disclosure is introduced. Figures 4 to 6 An access method performed by a user equipment in an embodiment of the present disclosure is introduced.

[0122] Figure 4 is a flow chart showing an access method according to some further embodiments of the present disclosure. Figure 4 As shown, the access method performed by the user equipment includes: step S41, sending a connection request message to the first satellite; S42, receiving a connection request response message from the first satellite, the connection request response message including information of a candidate satellite, the candidate satellite being determined according to information of the second satellite and position information of the user equipment; S43, measuring the candidate satellite according to the connection request response message to generate a measurement report of the candidate satellite; S44, sending the measurement report of the candidate satellite to the first satellite; S45, receiving information of a target satellite from the first satellite; S46, accessing the target satellite according to the information of the target satellite.

[0123] Step S41 and Figure 1 Step S42 corresponds to step S11 in Figure 1 Step S44 corresponds to step S13 in Figure 1 Step S45 corresponds to step S14 in Figure 1 Corresponding to step S16 in .

[0124] As shown above, the difference between the access method on the user equipment side and the access method on the first satellite side is that the access method on the user equipment side includes step S43 of measuring candidate satellites and step S46 of accessing target satellites, while the access method on the first satellite side includes step S12 of determining candidate satellites and step S15 of determining target satellites.

[0125] The access method executed by the user equipment reduces the complexity of the user equipment by receiving the candidate satellite and the target satellite selected by the first satellite, without the need for the user equipment to make a selection, and improves the access success rate of the user equipment by receiving the configuration related to the access target satellite.

[0126] Next, we will combine Figure 5 , Figure 6 The specific implementation methods of some steps of the access method on the user equipment side are introduced.

[0127] Figure 5 FIG. 4 is a flowchart showing sending a connection request message according to some embodiments of the present disclosure. Figure 5 As shown, step S41, sending a connection request message to the first satellite, may include steps S411 to S412.

[0128] In step S411, a first broadcast message from the first satellite is received.

[0129] When the user equipment needs to access, it can search for cells and receive first broadcast information of the first satellite. The first broadcast information is, for example, sent periodically by the first satellite to the ground, or sent to the ground when there are spare resources.

[0130] In some embodiments, the first broadcast message includes at least one of location information of the first satellite and resource configuration information allocated to the user equipment for connecting with the first satellite.

[0131] In step S412, the connection request message is sent to the first satellite according to the first broadcast message.

[0132] The user equipment may establish a connection with the first satellite according to information included in the first broadcast message, such as the location of the first satellite or the access time-frequency location in the resource configuration information for connecting with the first satellite, thereby sending a connection request message to the first satellite.

[0133] The above steps provide a specific embodiment of sending a connection request message. By receiving the first broadcast information of the first satellite and sending the connection request message according to the first broadcast message, the success rate of the user equipment sending the connection request message can be improved, thereby improving the success rate of the access method.

[0134] Figure 6 FIG. 1 is a flow chart showing access to a target satellite according to some embodiments of the present disclosure. Figure 6 As shown, step S46, accessing the target satellite according to the information of the target satellite may include steps S461 to S463.

[0135] In step S461, a second broadcast message from the target satellite is received.

[0136] After the user equipment receives the information of the target satellite, the target satellite access process begins. Similar to the process of connecting to the first satellite in some embodiments described above, the user equipment can receive the second broadcast message sent by the target satellite.

[0137] In some embodiments, the second broadcast message includes at least one of location information and reference signal information of the target satellite.

[0138] When necessary, for example, when the information needs to be updated, the second broadcast information may also again include information such as resource configuration information, timing advance, frequency offset, etc. allocated to the user equipment.

[0139] In step S462, an access request message is sent to the target satellite according to the second broadcast message.

[0140] The user equipment may access the target satellite based on the information of the target satellite in combination with the second broadcast information, including sending an access request message to the target satellite.

[0141] In some embodiments, the access request message includes at least one of the ID, capability, and channel state information of the user equipment.

[0142] In step S463, in response to receiving the access request response message from the target satellite, it is determined that the access is completed.

[0143] After receiving the access request information sent by the user equipment, the target satellite may send an access request response message as a reply. After receiving the access request response message, the user equipment confirms that the access is complete and starts data / signaling transmission with the target satellite.

[0144] In some embodiments, the access request response message includes resource configuration information allocated to the user equipment for connecting to the target satellite.

[0145] The above steps provide a specific embodiment of accessing a target satellite. By receiving the second broadcast information of the target satellite and sending an access request message according to the second broadcast message, the success rate of user equipment access can be improved.

[0146] Based on the above Figures 1 to 6 The access method in this disclosure is introduced. Figure 7 and Figure 8 A specific implementation scenario and access process of the present disclosure are introduced.

[0147] Figure 7 is a schematic diagram illustrating a satellite communication system according to some embodiments of the present disclosure.

[0148] like Figure 7 As shown, the satellite communication system 7 includes: a high-orbit satellite 71; a low-orbit satellite 72; and a user device 73.

[0149] The high-orbit satellite 71 may include a centralized unit 711 and a low-orbit satellite selection unit 712. The low-orbit satellite 72 may include a distributed unit 721.

[0150] The centralized unit 711 of the high-orbit satellite and the distributed unit 721 of the low-orbit satellite may communicate via an intersatellite link. The centralized unit 711 of the high-orbit satellite and the low-orbit satellite selection unit 712 may communicate via an internal interface. The user equipment 73 and the high-orbit satellite 71 and the low-orbit satellite 72 may communicate via an air interface.

[0151] Figure 7The multi-layer satellite network composed of high-orbit satellites and low-orbit satellites shown belongs to a specific application scenario of the access method proposed in the present disclosure. The access method proposed in the present disclosure is not limited to high-orbit and low-orbit satellite systems, but can also be applied to other satellite systems.

[0152] Next, we will combine Figure 8 The complete process of user equipment access in the above satellite system is introduced.

[0153] Figure 8 is a signaling flow chart showing an access method according to some embodiments of the present disclosure. Figure 8 As shown, the access method includes processes 801 to 816.

[0154] In process 801, a high-orbit satellite obtains information of a low-orbit satellite.

[0155] The high-orbit satellite can obtain information about all low-orbit satellites within the coverage area of ​​the high-orbit satellite, such as the ephemeris information and ID of the low-orbit satellite, and the ID and frequency of each beam on the low-orbit satellite.

[0156] In process 802, the high-orbit satellite determines the interface connection status with each low-orbit satellite within its coverage area.

[0157] The high-orbit satellite can obtain the ID of the low-orbit satellite within its coverage area based on the information of the pre-configured low-orbit satellite. For each low-orbit satellite within its coverage area, the high-orbit satellite queries whether an interface connection has been established with the low-orbit satellite. If the interface connection has been established, process 805 is directly executed; if the interface connection has not been established, process 803 is executed.

[0158] In process 803, the high-orbit satellite sends an interface connection establishment request message to the low-orbit satellite.

[0159] The interface connection establishment request message may include the ID of the high-orbit satellite, which is used to establish an interface connection with the low-orbit satellite, thereby communicating through an inter-satellite link.

[0160] In process 804, the low-orbit satellite sends an interface connection establishment request response message to the high-orbit satellite.

[0161] After receiving the interface connection establishment request message sent by the high-orbit satellite, the low-orbit satellite may send an interface connection establishment request response message as a reply. After receiving the interface connection establishment request response message, the high-orbit satellite determines that the interface connection establishment is completed.

[0162] The interface connection establishment request response message may include the ID of the second satellite, ephemeris information, beam ID, beam frequency, beam load status, etc.

[0163] In process 805 , the user equipment receives a first broadcast message from a high-orbit satellite.

[0164] When the user equipment needs to access, it can search for cells and receive the first broadcast information of the high-orbit satellite. The first broadcast information may include the location information of the high-orbit satellite, resource configuration information (such as access time and frequency location) allocated to the user equipment for connecting to the high-orbit satellite, and the like.

[0165] In process 806, the user equipment sends a connection request message to the high-orbit satellite.

[0166] The user equipment may send a connection request message according to the first broadcast message. For example, when the first broadcast message includes resource configuration information, the user equipment sends a connection request message to the high-orbit satellite according to the resource configuration allocated to it. The connection request message may include the ID and capability information of the user equipment.

[0167] In process 807 , the high-orbit satellite determines candidate satellites.

[0168] In response to the connection request message, the high-orbit satellite may determine a candidate satellite from the low-orbit satellites according to the information of the pre-configured low-orbit satellite and the location information of the user equipment.

[0169] When the user equipment does not have a positioning function, the high-orbit satellite can also determine the location information of the user equipment based on information such as the strength and direction of the connection request message sent by the user equipment.

[0170] As described above, the candidate satellite selection method may include a distance-based selection method or a visibility time-based selection method.

[0171] In process 808, the high-orbit satellite sends a connection request response message to the user equipment.

[0172] The high-orbit satellite sends information of the candidate satellite selected for the user equipment to the user equipment by sending a connection request response message.

[0173] The connection request response message may include the IDs, beam IDs, reference signal information, usage frequencies, resource configuration information for sending measurement reports, etc. of all candidate satellites selected by the high-orbit satellite for the user equipment.

[0174] In process 809, the user equipment performs measurement and generates a measurement report of the candidate satellite.

[0175] The user equipment measures the reference signal strength of each candidate satellite at the beam frequency corresponding to each candidate satellite according to the connection request response message, and generates a measurement report of the candidate satellite. The measurement report may include the ID of the candidate low-orbit satellite and the corresponding reference signal strength.

[0176] In process 810, the user equipment sends a measurement report of the candidate satellite to the high-orbit satellite.

[0177] In the case where the connection request response message includes resource configuration information for sending the measurement report, the user equipment may send the measurement report of the candidate satellite to the high-orbit satellite on the allocated resource configuration.

[0178] In process 811, the high-orbit satellite determines the target satellite.

[0179] The high-orbit satellite may determine the target satellite based on the measurement report of the candidate satellite sent by the user equipment. For example, the candidate satellite with the highest reference signal strength in the measurement report may be determined as the target satellite.

[0180] By having the high-orbit satellite perform the selection of the candidate satellite and the target satellite, the user equipment does not need to perform the selection, thereby reducing the complexity of the user equipment.

[0181] In process 812, the high-orbit satellite sends information of the target satellite to the user equipment.

[0182] The message includes at least the ID of the target satellite, the beam ID, resource configuration information allocated to the user equipment for connecting to the target satellite, the timing advance, the frequency offset, etc.

[0183] By sending the above information to the user equipment in advance through the high-orbit satellite so that the user equipment can access according to the above information, the success rate of the user equipment access can be improved.

[0184] In process 813, the high-orbit satellite releases the stored information of the user equipment and the information of the candidate satellites.

[0185] After the high-orbit satellite sends the target satellite information, the satellite selection step has been completed, and the subsequent access process no longer requires the high-orbit satellite to participate. Therefore, the high-orbit satellite can release the stored user equipment information and the information of the candidate satellite selected for the user equipment, thereby ensuring that all related wireless resources are effectively recovered and freeing up resources for other communication needs.

[0186] In process 814, the user equipment receives a second broadcast message from the target satellite.

[0187] After receiving the information of the target satellite, the user equipment may search and receive the second broadcast information of the target satellite. The second broadcast information may include the location information, reference signal information, etc. of the target satellite.

[0188] If necessary, the second broadcast information may also again include resource configuration information, timing advance, frequency offset, etc. allocated to the user equipment for connecting to the target satellite.

[0189] In process 815, the user equipment sends an access request message to the target satellite.

[0190] The user equipment may send an access request message to the target satellite at the allocated access time and frequency position according to the second broadcast message. The access request message may include the ID, capability, channel state information, etc. of the user equipment.

[0191] In process 816, the target satellite sends an access request response message to the user equipment.

[0192] After receiving the access request message sent by the user equipment, the target satellite may send an access request response message as a reply. After receiving the access request response message, the user equipment determines that the access is completed.

[0193] The access request response message may include resource configuration information allocated to the user equipment for connecting to the target satellite, etc.

[0194] Based on the above Figures 1 to 8 , an access method proposed in the present disclosure is introduced. In the access method proposed in the present disclosure, the first satellite selects candidate satellites and target satellites, and there is no need for user equipment to make selections, thereby reducing the complexity of the user equipment. At the same time, the first satellite sends the configuration related to accessing the target satellite to the user equipment, thereby improving the success rate of user equipment access.

[0195] Next, we will combine Figures 9 to 11 The present disclosure introduces a satellite, a user equipment, and a communication device, which can be used to execute the access method described above.

[0196] Fig. 9 is a block diagram illustrating a satellite according to some embodiments of the present disclosure. Fig. 9 As shown, the satellite 9 includes: a first receiving module 91, configured to receive a connection request message from a user equipment; a first determining module 92, configured to determine a candidate satellite in response to the connection request message according to information of the second satellite and position information of the user equipment; a first sending module 93, configured to send a connection request response message to the user equipment, wherein the connection request response message includes information of the candidate satellite; a second receiving module 94, configured to receive a measurement report of the candidate satellite from the user equipment; a second determining module 95, configured to determine a target satellite according to the measurement report of the candidate satellite; and a second sending module 96, configured to send information of the target satellite to the user equipment, wherein the information of the target satellite is used to instruct the user equipment to access the target satellite.

[0197] The first receiving module 91 of the satellite 9 can be used to perform Figure 1The first determination module 92 of the satellite 9 can be used to perform Figure 1 The first sending module 93 of the satellite 9 can be used to perform Figure 1 The second receiving module 94 of the satellite 9 can be used to perform Figure 1 The second determination module 95 of the satellite 9 can be used to perform Figure 1 The second sending module 96 of the satellite 9 can be used to perform Figure 1 Step S16 in .

[0198] Fig.10 is a block diagram illustrating a user device according to some embodiments of the present disclosure. Fig.10 As shown, the user equipment 10 includes: a first sending module 101, configured to send a connection request message to a first satellite; a first receiving module 102, configured to receive a connection request response message from the first satellite, the connection request response message including information of a candidate satellite, the candidate satellite being determined according to information of a second satellite and location information of the user equipment; a measuring module 103, configured to measure the candidate satellite according to the connection request response message to generate a measurement report of the candidate satellite; a second sending module 104, configured to send the measurement report of the candidate satellite to the first satellite; a second receiving module 105, configured to receive information of a target satellite from the first satellite; and an access module 106, configured to access the target satellite according to the information of the target satellite.

[0199] The first sending module 101 of the user equipment 10 can be used to perform Figure 4 The first receiving module 102 of the user equipment 10 can be used to perform Figure 4 The measurement module 103 of the user equipment 10 may be used to perform Figure 4 The second sending module 104 of the user equipment 10 can be used to perform Figure 4 The second receiving module 105 of the user equipment 10 can be used to perform Figure 4 The access module 106 of the user equipment 10 may be used to perform Figure 4 Step S46 in .

[0200] Fig.11 is a block diagram showing a communication device according to some embodiments of the present disclosure. Fig.11 As shown, the communication device 11 includes a memory 111; and a processor 112 coupled to the memory 111, and the processor 112 is used to execute the access method described in any of the above embodiments based on the instructions stored in the memory.

[0201] The satellite, user equipment and communication device mentioned above, by selecting candidate satellites and target satellites by the first satellite, without the need for the user equipment to make selections, reduces the complexity of the user equipment. At the same time, the first satellite sends the configuration related to accessing the target satellite to the user equipment, thereby improving the success rate of user equipment access.

[0202] Fig.12 is a block diagram illustrating a computer system for implementing some embodiments of the present disclosure.

[0203] like Fig.12 As shown, the computer system 12 may be in the form of a general-purpose computing device. The computer system 12 includes a memory 121, a processor 122, and a bus 120 that connects the various system components.

[0204] The memory 121 may be a computer-readable storage medium in various forms, such as a system memory, a non-volatile storage medium, etc. The system memory may store, for example, an operating system, an application, a boot loader (BootLoader), and other programs. The system memory may include a volatile storage medium, such as a random access memory (RAM) and / or a cache memory. The non-volatile storage medium may store, for example, instructions for executing the corresponding embodiment of the access method. The non-volatile storage medium includes, but is not limited to, a disk storage, an optical storage, a flash memory, and the like.

[0205] The processor 122 may be implemented by a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic devices, discrete gates or transistors, and other discrete hardware components. Accordingly, each module may be implemented by a central processing unit (CPU) running instructions in a memory that execute corresponding steps, or by a dedicated circuit that executes corresponding steps.

[0206] The bus 120 may use any of a variety of bus architectures, including, but not limited to, an Industry Standard Architecture (ISA) bus, a Micro Channel Architecture (MCA) bus, and a Peripheral Component Interconnect (PCI) bus.

[0207] The computer system 12 may also include an input / output interface 123, a network interface 124, a storage interface 125, etc. These interfaces 123, 124, 125, the memory 121, and the processor 122 may be connected via a bus 120. The input / output interface 123 may provide a connection interface for input / output devices such as a display, a mouse, and a keyboard. The network interface 124 may provide a connection interface for various networked devices. The storage interface 125 may provide a connection interface for external storage devices such as a floppy disk, a USB flash drive, and an SD card.

[0208] According to an embodiment of the present disclosure, the process described above with reference to the flowchart can be implemented as a computer software program. For example, some embodiments of the present disclosure include a computer program product, which, when executed on a computer, enables the computer to implement the access method described in any of the foregoing embodiments. The computer program product includes computer instructions carried on a computer-readable medium, the computer instructions containing program code for executing the method shown in the flowchart.

[0209] So far, various embodiments of the present disclosure have been described in detail. In order to avoid obscuring the concept of the present disclosure, some details known in the art are not described. Based on the above description, those skilled in the art can fully understand how to implement the technical solution disclosed here.

[0210] Although some specific embodiments of the present disclosure have been described in detail by way of examples, it should be understood by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present disclosure. It should be understood by those skilled in the art that the above embodiments may be modified or some technical features may be replaced by equivalents without departing from the scope and spirit of the present disclosure. The scope of the present disclosure is defined by the appended claims.

Claims

1. An access method, performed by a first satellite, comprising: receiving a connection request message from a user device; In response to the connection request message, determining a candidate satellite according to information of the second satellite and location information of the user equipment; Sending a connection request response message to the user equipment, wherein the connection request response message includes information about the candidate satellite; receiving, from the user equipment, a measurement report of the candidate satellite; Determining a target satellite according to the measurement report of the candidate satellite; The information of the target satellite is sent to the user equipment, where the information of the target satellite is used to instruct the user equipment to access the target satellite.

2. The access method according to claim 1, wherein: The information of the second satellite includes ephemeris information of the second satellite, and in response to the connection request message, determining the candidate satellite according to the information of the second satellite and the position information of the user equipment includes: Determining location information of the user equipment according to the connection request message; A candidate satellite is determined according to the ephemeris information of the second satellite and the position information of the user equipment.

3. The access method according to claim 2, wherein: Determining, according to the connection request message, the location information of the user equipment includes: The location information of the user equipment is determined according to at least one of the strength, the direction, and the signal propagation time of the connection request message.

4. The access method according to claim 1, wherein: The information of the second satellite includes ephemeris information of the second satellite, and in response to the connection request message, determining the candidate satellite according to the information of the second satellite and the position information of the user equipment includes: Determining a capability of the user equipment according to the connection request message; A candidate satellite that is compatible with the capability of the user equipment is determined according to the ephemeris information of the second satellite and the location information of the user equipment.

5. The access method according to claim 1, further comprising: After sending the information of the target satellite to the user equipment, the information of the user equipment and the information of the candidate satellite stored in the first satellite are released.

6. The access method according to claim 1, further comprising: The information of the second satellite is obtained, where the information of the second satellite includes at least one of an ID of the second satellite, ephemeris information, a beam ID, and a beam frequency.

7. The access method according to claim 6, further comprising: For each second satellite within the coverage of the first satellite, determining an interface connection state between the first satellite and the second satellite; When the first satellite has not established an interface connection with the second satellite, sending an interface connection establishment request message to the second satellite; In response to receiving the interface connection establishment request response message from the second satellite, it is determined that the interface connection establishment is completed.

8. The access method according to any one of claims 1 to 7, wherein: The connection request message includes at least one of the ID and capability information of the user equipment; and / or The information of the candidate satellite includes at least one of the ID, beam ID, reference signal information, and usage frequency of the candidate satellite; and / or The measurement report of the candidate satellite includes at least one of the ID and the reference signal strength of the candidate satellite; and / or The information of the target satellite includes at least one of the ID of the target satellite, the beam ID, resource configuration information allocated to the user equipment for connecting to the target satellite, a timing advance, and a frequency offset.

9. The access method according to any one of claims 1 to 7, wherein: The first satellite is a high-orbit satellite; The second satellite is a low-orbit satellite.

10. An access method, performed by a user equipment, comprising: Sending a connection request message to the first satellite; receiving a connection request response message from the first satellite, wherein the connection request response message includes information of a candidate satellite, wherein the candidate satellite is determined according to information of the second satellite and location information of the user equipment; Measuring the candidate satellite according to the connection request response message to generate a measurement report of the candidate satellite; sending a measurement report of the candidate satellite to the first satellite; receiving information of a target satellite from the first satellite; Access the target satellite according to the information of the target satellite.

11. The access method according to claim 10, wherein: Sending a connection request message to the first satellite includes: receiving a first broadcast message from the first satellite; The connection request message is sent to the first satellite according to the first broadcast message.

12. The access method according to claim 11, wherein: The first broadcast message includes at least one of location information of the first satellite and resource configuration information allocated to the user equipment for connecting with the first satellite.

13. The access method according to claim 10, wherein: Accessing the target satellite according to the information of the target satellite includes: receiving a second broadcast message from the target satellite; sending an access request message to the target satellite according to the second broadcast message; Access completion is determined in response to receiving an access request response message from the target satellite.

14. The access method according to claim 13, wherein: The second broadcast message includes at least one of the position information and reference signal information of the target satellite; and / or The access request message includes at least one of the ID, capability, and channel state information of the user equipment; and / or The access request response message includes resource configuration information allocated to the user equipment for connecting to the target satellite.

15. A satellite, comprising: A first receiving module is configured to receive a connection request message from a user device; A first determination module is configured to determine a candidate satellite in response to the connection request message according to information of the second satellite and location information of the user equipment; A first sending module is configured to send a connection request response message to the user equipment, wherein the connection request response message includes information of the candidate satellite; A second receiving module is configured to receive a measurement report of the candidate satellite from the user equipment; A second determination module is configured to determine a target satellite according to the measurement report of the candidate satellite; The second sending module is configured to send the information of the target satellite to the user equipment, where the information of the target satellite is used to instruct the user equipment to access the target satellite.

16. A user equipment, comprising: A first sending module is configured to send a connection request message to a first satellite; A first receiving module is configured to receive a connection request response message from the first satellite, wherein the connection request response message includes information of a candidate satellite, and the candidate satellite is determined according to information of the second satellite and location information of the user equipment; a measurement module, configured to measure the candidate satellite according to the connection request response message to generate a measurement report of the candidate satellite; A second sending module is configured to send a measurement report of the candidate satellite to the first satellite; A second receiving module is configured to receive information of a target satellite from the first satellite; The access module is configured to access the target satellite according to the information of the target satellite.

17. A communication device, comprising: Memory; and A processor coupled to the memory, the processor being configured to execute the access method according to any one of claims 1 to 14 based on instructions stored in the memory.

18. A computer-readable storage medium, wherein: The computer-readable storage medium stores computer instructions, and when the instructions are executed by a processor, the access method according to any one of claims 1 to 14 is implemented.

19. A computer program product, wherein: The computer program product stores computer instructions, and when the instructions are executed by a processor, the access method according to any one of claims 1 to 14 is implemented.

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