Satellite-ground switching method and device in NB-IoT NTN and communication equipment

Abstract

The invention discloses a satellite-ground switching method and device in an NB-IoT NTN (Narrow Band Internet of Things), and communication equipment. The method comprises: receiving measurement control information issued by a network side, the measurement control information being used for indicating a user terminal to measure network quality of an NB-IoT NTN cell and a TN cell, the NB-IoT NTN cell and the TN cell being adjacent to each other; the measurement result is sent to the network side, under the condition that the measurement result meets the network switching condition, the network switching mode is obtained, the network switching process of the switching mode is completed, network switching is carried out, and the switching mode at least comprises one of switching based on redirection, switching based on position updating, switching based on an X2 interface and switching based on an S1 interface.

Description

Technical Field

[0001] The present application relates to the field of communication technology, and in particular to a satellite-to-ground switching method, device and communication equipment in NB-IoT NTN. Background Art

[0002] The existing technology can only switch between NB-IoT NTN (Narrowband Internet of Things Non-Terrestrial Network) and traditional TN (Terrestrial Network) networks by cell reselection, which will cause communication interruption. This is fatal for IoT devices that require continuous and stable connections, such as smart sensors for remote monitoring. If communication is interrupted, data may be lost and key information cannot be obtained immediately. Summary of the invention

[0003] The embodiments of the present application provide a satellite-to-ground switching method, apparatus, and communication equipment in an NB-IoT NTN, so as to at least solve the technical problem in the related art that the communication stability is poor due to the use of cell reselection for network switching.

[0004] According to one aspect of an embodiment of the present application, a satellite-to-ground switching method in NB-IoT NTN is provided, including: receiving measurement control information sent by a network side, the measurement control information being used to instruct a user terminal to measure the network quality of a NB-IoT NTN cell and a TN cell, wherein the NB-IoT NTN cell and the TN cell are adjacent cells to each other; sending a measurement result to the network side, and when the measurement result meets a network switching condition, obtaining a network switching mode, completing a network switching process of the switching mode, so as to perform a network switching, wherein the switching mode includes at least one of the following: switching based on redirection, switching based on location update, switching based on an X2 interface, and switching based on an S1 interface.

[0005] Optionally, the measurement result is sent to the network side, including: when the reference signal reception power of the serving cell is lower than a first signal power threshold, sending a first event result to the network side; when the reference signal reception power of the adjacent cell is higher than a second signal power threshold, sending a second event result to the network side, wherein the adjacent cell is a cell adjacent to the serving cell, and the serving cell is a cell currently accessed by the user terminal, wherein, when the user terminal sends the first event result and the second event result to the network side at the same time, it is determined that the measurement result meets the network switching condition, and the network switching process is triggered.

[0006] Optionally, the network switching process of the switching mode is completed to perform network switching, including: when the switching mode is the redirection-based switching, receiving a wireless resource control RRC release message sent by the network side, the RRC release message is used to instruct the user terminal to redirect; extracting the cell configuration information of the target cell from the RRC release message through the first chip, and sending the cell configuration information to the second chip; synchronizing with the target cell according to the cell configuration information through the second chip, and after completing the synchronization, initiating competitive random access in the target cell to access the target cell, the cell configuration information includes at least: a cell frequency and a physical cell identifier, the target cell is the adjacent cell, wherein the first chip and the second chip are applicable to different communication networks, and the first chip and the second chip are both deployed inside the user terminal.

[0007] Optionally, the method also includes: when the switching mode is the switching of the location update, when the reference signal receiving power of the service cell is less than a third signal power threshold and / or the data channel block error rate of the service cell is greater than a preset block error rate threshold, determining that the measurement result meets the network switching condition, and triggering the network switching process.

[0008] Optionally, the network switching process of the switching mode is completed to perform network switching, including: receiving a switching command sent by the network side through the first chip, and sending the switching command to the second chip; competing for random access in the target cell through the second chip to access the target cell; sending a location update request to the network side of the target cell, the location update request containing a globally unique temporary identifier GUTI, and the GUTI is used to complete the location update, wherein the first chip and the second chip are applicable to different communication networks, and the first chip and the second chip are both deployed inside the user terminal.

[0009] Optionally, completing the network switching process of the switching mode to perform network switching includes: when the switching mode is a switching based on the X2 interface, receiving a switching indication message sent by the base station of the serving cell, wherein the switching indication message is sent by the base station of the serving cell after sending a switching request message to the base station of the target cell through the X2 interface and receiving a switching request response message sent by the base station of the target cell through the X2 interface, and the base station of the serving cell is also used to send the service cache data in the switching process to the base station of the target cell through the X2 interface; when receiving the switching indication message, releasing the current connection and accessing the base station of the target cell, wherein after the user terminal accesses the base station of the target cell, the base station of the target cell sends a path switching message to the core network element, and the path switching message is used to change the bearer of the user terminal from the base station of the serving cell to the base station of the target cell.

[0010] Optionally, completing the network switching process of the switching mode to perform network switching includes:

[0011] In the case where the switching mode is a switching based on the S1 interface, receiving a switching indication message sent by the base station of the serving cell, wherein the switching indication message is sent by the base station of the serving cell after receiving a switching command sent by a source core network element through the S1 interface, the switching command is sent by the source core network element after receiving a path switching response message sent by a target core network element, the path switching response message is sent by the target core network element after receiving a switching request response sent by the base station of the target cell, the switching request response is sent by the base station of the target cell in response to the switching request sent by the target core network element, and the switching request is sent by the target core network element in response to the path switching request message sent by the source core network element, wherein the path switching request message is used to request to change the bearer of the user terminal from the base station of the serving cell to the base station of the target cell;

[0012] When the handover indication message is received, a contention random access is initiated in the target cell to access the target cell.

[0013] According to another aspect of an embodiment of the present application, a satellite-to-ground switching device in an NB-IoT NTN is also provided, including: a receiving module, used to receive measurement control information sent by a network side, the measurement control information being used to instruct a user terminal to measure the network quality of a NB-IoT NTN cell and a TN cell, wherein the NB-IoT NTN cell and the TN cell are adjacent cells to each other; a switching module, used to send a measurement result to the network side, and when the measurement result meets the network switching condition, obtain a network switching mode, complete the network switching process of the switching mode, and perform a network switching, wherein the switching mode includes at least one of the following: switching based on redirection, switching based on location update, switching based on an X2 interface, and switching based on an S1 interface.

[0014] According to another aspect of an embodiment of the present application, a communication device is also provided, including: a memory and a processor, wherein the memory is used to store program instructions; and the processor is connected to the memory and is used to execute the satellite-to-ground switching method in the above-mentioned NB-IoT NTN.

[0015] According to another aspect of an embodiment of the present application, a non-volatile storage medium is also provided, which includes a stored computer program, wherein the device where the non-volatile storage medium is located executes the above-mentioned satellite-to-ground switching method in NB-IoT NTN by running the computer program.

[0016] According to another aspect of the embodiments of the present application, a computer program product is also provided, including computer instructions, which, when executed by a processor, implement the satellite-to-ground switching method in the above-mentioned NB-IoT NTN.

[0017] In an embodiment of the present application, by receiving measurement control information sent by the network side, the measurement control information is used to instruct the user terminal to measure the network quality of the NB-IoT NTN cell and the TN cell, wherein the NB-IoT NTN cell and the TN cell are adjacent cells to each other; sending the measurement result to the network side, and when the measurement result meets the network switching condition, obtaining the network switching mode, completing the network switching process of the switching mode, so as to perform network switching, and the switching mode includes at least one of the following: switching based on redirection, switching based on location update, switching based on X2 interface, and switching based on S1 interface, thereby achieving the purpose of determining different switching processes according to different switching modes to complete the network switching, thereby achieving the technical effect of improving communication stability, and then solving the technical problem of poor communication stability due to the use of cell reselection for network switching in the related technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0019] Figure 1 It is a hardware structure block diagram of a computer terminal for implementing a satellite-to-ground switching method in NB-IoT NTN according to an embodiment of the present application;

[0020] Figure 2 is a flow chart of a satellite-to-ground switching method in NB-IoT NTN according to an embodiment of the present application;

[0021] Figure 3 It is a flow chart of a redirection method according to the related art;

[0022] Figure 4 It is a flow chart of a location updating method according to the related art;

[0023] Figure 5 It is a flow chart of a switching method based on an X2 interface or an S1 interface in the related art;

[0024] Figure 6 This is a schematic diagram of NB-IoT NTN network coverage according to an embodiment of the present application;

[0025] Figure 7 is a flow chart of a network switching based on a redirection method according to an embodiment of the present application;

[0026] Figure 8 is another network switching flow chart based on redirection according to an embodiment of the present application;

[0027] Fig. 9 is a flow chart of a network switching based on a location update method according to an embodiment of the present application;

[0028] Fig.10 is another flow chart of network switching based on location update mode according to an embodiment of the present application;

[0029] Fig.11 is a flow chart of a network switching based on an X2 interface mode according to an embodiment of the present application;

[0030] Fig.12 is another network switching flow chart based on the X2 interface mode according to an embodiment of the present application;

[0031] Fig.13 is a flow chart of network switching based on the S1 interface mode according to an embodiment of the present application;

[0032] Fig.14 is another network switching flow chart based on the S1 interface mode according to an embodiment of the present application;

[0033] Fig.15 It is a structural diagram of a satellite-to-ground switching device in an NB-IoT NTN according to an embodiment of the present application. DETAILED DESCRIPTION

[0034] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present application.

[0035] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0036] The information collected in the embodiments of the present application is information and data authorized by the user or fully authorized by all parties, and the collection, storage, use, processing, transmission, provision, disclosure and application of the relevant data comply with the relevant laws, regulations and standards of the relevant regions, take necessary confidentiality measures, do not violate public order and good morals, and provide corresponding operation entrances for users to choose to authorize or reject automated decision-making results; if the user chooses to reject, the expert decision-making process will be entered.

[0037] In order to solve the problems existing in the related art, the embodiment of the present application provides a satellite-to-ground switching method in NB-IoT NTN, which can be operated on Figure 1 In the computer terminal shown, the computer terminal is explained below.

[0038] The satellite-to-ground switching method embodiment in NB-IoT NTN provided in the embodiment of the present application can be executed in a mobile terminal, a computer terminal or a similar computing device. Figure 1The hardware structure block diagram of a computer terminal for implementing the satellite-to-ground switching method in NB-IoT NTN is shown. Figure 1 As shown, the computer terminal 10 may include one or more (102a, 102b, ..., 102n are used to illustrate) processors (the processor may include but is not limited to a processing device such as a microprocessor MCU or a programmable logic device FPGA), a memory 104 for storing data, and a transmission module 106 for communication functions connected via a wired and / or wireless network. In addition, it may also include: a display, a keyboard, a cursor control device, an input / output interface (I / O interface), a universal serial bus (USB) port (which may be included as one of the ports of the I / O interface), a network interface, and a BUS bus. Those skilled in the art can understand that Figure 1 The structure shown is only for illustration and does not limit the structure of the above electronic device. Figure 1 More or fewer components as shown, or with Figure 1 Different configurations are shown.

[0039] It should be noted that the one or more processors and / or other data processing circuits described above may generally be referred to herein as "data processing circuits". The data processing circuits may be embodied in whole or in part as software, hardware, firmware, or any other combination thereof. In addition, the data processing circuit may be a single independent processing module, or may be incorporated in whole or in part into any of the other components in the computer terminal 10. As described in the embodiments of the present application, the data processing circuit acts as a processor control (e.g., selection of a variable resistor terminal path connected to an interface).

[0040] The memory 104 can be used to store software programs and modules of application software, such as the program instructions / data storage device corresponding to the satellite-to-ground switching method in the NB-IoT NTN in the embodiment of the present application. The processor executes various functional applications and data processing by running the software programs and modules stored in the memory 104, that is, realizing the satellite-to-ground switching method in the NB-IoT NTN mentioned above. The memory 104 may include a high-speed random access memory, and may also include a non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some instances, the memory 104 may further include a memory remotely arranged relative to the processor, and these remote memories may be connected to the computer terminal 10 via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0041] The transmission module 106 is used to receive or send data via a network. The specific example of the above network may include a wireless network provided by a communication provider of the computer terminal 10. In one example, the transmission module 106 includes a network adapter (Network Interface Controller, NIC), which can be connected to other network devices through a base station so as to communicate with the Internet. In one example, the transmission module 106 can be a radio frequency (RF) module, which is used to communicate with the Internet wirelessly.

[0042] The display may be, for example, a touch screen liquid crystal display (LCD) that enables a user to interact with a user interface of the computer terminal 10 .

[0043] It should be noted that, in some optional embodiments, the above Figure 1 The computer terminal shown may include hardware elements (including circuits), software elements (including computer code stored on a computer-readable medium), or a combination of hardware elements and software elements. It should be noted that Figure 1 This is merely one example of a particular embodiment and is intended to illustrate the types of components that may be present in the computer terminal described above.

[0044] In the above operating environment, an embodiment of the present application provides an embodiment of a satellite-to-ground switching method in an NB-IoT NTN. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in an order different from that shown here.

[0045] Figure 2 : is a flow chart of a satellite-to-ground switching method in NB-IoT NTN according to an embodiment of the present application, such as Figure 2 As shown, the method comprises the following steps:

[0046] Step S202, receiving measurement control information sent by the network side, where the measurement control information is used to instruct the user terminal to measure the network quality of the NB-IoT NTN cell and the TN cell, wherein the NB-IoT NTN cell and the TN cell are adjacent cells to each other;

[0047] Step S204, sending the measurement result to the network side, and when the measurement result meets the network switching condition, obtaining the network switching method, completing the network switching process of the switching method to perform network switching, and the switching method includes at least one of the following: switching based on redirection, switching based on location update, switching based on X2 interface, and switching based on S1 interface.

[0048] Through the above steps S202 to S204, by receiving the measurement control information sent by the network side, the measurement control information is used to instruct the user terminal to measure the network quality of the NB-IoT NTN cell and the TN cell, wherein the NB-IoT NTN cell and the TN cell are adjacent cells to each other; sending the measurement result to the network side, and when the measurement result meets the network switching condition, obtaining the network switching method, completing the network switching process of the switching method, so as to perform network switching, and the switching method includes at least one of the following: switching based on redirection, switching based on location update, switching based on X2 interface, and switching based on S1 interface, thereby achieving the purpose of determining different switching processes according to different switching methods to complete network switching, thereby achieving the technical effect of improving communication stability, and further solving the technical problem of poor communication stability caused by using cell reselection for network switching in related technologies. The following is a detailed description.

[0049] It should be noted that cell reselection refers to the process in which a mobile terminal switches from the current serving cell to another more suitable cell in an idle state according to certain rules and measurement results. The purpose is to ensure that the mobile terminal is always connected to a cell with better signal quality and better service to improve communication quality and user experience. However, existing NB-IoT terminals only support inter-system switching for cell reselection, for example: switching from NB-IoT NTN to TN, and during the cell reselection process, the mobile terminal needs to switch from the old cell to the new cell, during which communication interruption and data loss may occur.

[0050] like Figure 3 As shown, in the related art, the method of switching from the source system to the target system based on the redirection method is as follows: the terminal first performs measurement and reports it to the source system. After receiving the measurement event, the source system determines that redirection is required and sends an RRC Connection Release message to the terminal, which carries a Release with Redirect message unit, including the frequency information of the target system.

[0051] The terminal searches for cells on the specified frequency and receives broadcast messages from the target system to obtain access parameters. Finally, the terminal performs random access based on the access parameters. However, the NB-IoT terminal in the related technology does not support measurement reporting, so the redirection process cannot be completed.

[0052] like Figure 4 As shown, the process of completing the location update in the related technology is as follows: ① The terminal sends a location update request TAU ​​Request, which is a NAS signaling. The TAU Request message is carried by the RRC Connection Setup Complete message, and the RRC Connection Setup Complete message is the last message in the RRC connection establishment process; after the base station receives the RRC Connection Setup Complete message, it extracts the TAU Request message from it, does not process it, and forwards it to the MME; ② After the MME receives the TAU request from the terminal, it determines whether to authenticate the terminal based on the terminal's security information. If the terminal's security information has expired, the MME must authenticate the terminal, otherwise, no authentication is required; ③ In the NAS encryption process, the Security Mode Command message sent by the MME specifies the encryption algorithm of the NAS signaling for the terminal. After receiving it, the terminal performs NAS encryption and integrity protection according to the algorithm, and replies to the Security Mode Complete message. ④ After confirming that the user is a legitimate user, the MME updates the user's context based on the location information reported by the user. And by carrying TAU Accept in the DL NASTransfer message, the TAU request of the same user is accepted; ⑤ If the MME does not allocate a new GUTI for the terminal, the terminal does not need to reply to the TAU Complete message, otherwise the terminal will reply to the TAU Complete message after receiving the TAU Accept message, and the base station will forward the TAU Complete message of the terminal to the MME, but the NB-IoT terminal in the related technology does not support the location update process.

[0053] like Figure 5 As shown, in the related art, the switching process based on the X2 interface and the S1 interface is similar, and is divided into two steps: the measurement process and the switching process. However, the NB-IoT terminal in the related art does not support switching, so the switching process cannot be completed.

[0054] In some embodiments of the present application, the measurement result is sent to the network side, including: when the reference signal reception power of the serving cell is lower than the first signal power threshold, sending a first event result to the network side; when the reference signal reception power of the adjacent cell is higher than the second signal power threshold, sending a second event result to the network side, wherein the adjacent cell is a cell adjacent to the serving cell, and the serving cell is a cell currently accessed by the user terminal, wherein, when the user terminal simultaneously sends the first event (measurement event NTN-TN-E1) result and the second event (measurement event NTN-TN-E2) result to the network side, it is determined that the measurement result meets the network switching condition, and the network switching process is triggered.

[0055] In the case where the switching mode is the redirection-based switching, a radio resource control RRC release message sent by the network side is received, and the RRC release message is used to instruct the user terminal to redirect; the cell configuration information of the target cell is extracted from the RRC release message by the first chip, and the cell configuration information is sent to the second chip; the second chip is synchronized with the target cell according to the cell configuration information, and after the synchronization is completed, a competitive random access is initiated in the target cell to access the target cell, and the cell configuration information includes at least: a cell frequency and a physical cell identifier, and the target cell is the adjacent cell, wherein the first chip and the second chip are applicable to different communication networks, and the first chip and the second chip are both deployed inside the user terminal. For example: the first chip is an LTE chip, the second chip is an IoT NTN chip, or the first chip is an IoT NTN chip, and the second chip is an LTE chip.

[0056] like Figure 6 As shown, the user terminal uses two chips (one supporting the NB-IoT NTN protocol and the other supporting the TN protocol) or a multi-mode chip (one chip supports both the NB-IoT NTN protocol and the TN protocol). The network decides the network switching between TN and NB-IoT NTN based on the signal quality measured and reported by the terminal or the signal quality measured by the base station. The NB-IoT NTN cell and the TN cell are neighboring cells to each other, and the NB-IoT NTN base station and the TN base station are under the same MME.

[0057] like Figure 7As shown, in the case of switching from the TN network to the NB-IoT NTN network based on redirection switching, the switching steps are as follows: Step a. UE (LTE chip) accesses the LTE network and establishes a service connection; Step b. The LTE network sends a measurement control message to the UE (LTE chip), which includes: Measurement object: serving cell and adjacent cell; Measurement events NTN-TN-E1 and NTN-TN-E2: NB-IoT NTN network and TN network belong to heterogeneous frequency and heterogeneous system measurements, NTN-TN-E1 event is used to start heterogeneous frequency measurement, NTN-TN-E1 event includes threshold-RSRP1 (first signal power threshold), the signal of the serving cell is weaker than threshold-RSRP1, triggering the sending of the measurement report; NTN-TN-E2 event includes threshold-RSRP2 (second signal power threshold), the heterogeneous system neighboring cell signal is stronger than threshold-RSRP2, triggering the sending of the measurement report;

[0058] It can be understood that the serving cell is a source cell where the user terminal is located, and the neighboring cell is a target cell to which the user terminal switches.

[0059] Step c. The RSRP of the serving cell measured by the UE (LTE chip) is weaker than threshold-RSRP1, triggering the NTN-TN-E1 event to be reported to the LTE network; the RSRP of the neighboring NB-IoT NTN cell measured by the UE (LTE chip) is stronger than threshold-RSRP2, triggering the NTN-TN-E2 event to be reported to the LTE network;

[0060] Step d. The LTE network makes a redirection decision based on the NTN-TN-E1 and NTN-TN-E2 measurement results reported by the UE (LTE chip). If both NTN-TN-E1 and NTN-TN-E2 measurement reports are received, it means that the signal of the serving cell is weaker than the first signal power threshold, and the signal of the neighboring NB-IoT NTN cell is stronger than the second signal power threshold, then the redirection process to the NB-IoT NTN network is triggered;

[0061] Step e. After the redirection process is triggered, the LTE network sends an RRC release message to the UE (LTE chip) to indicate the redirection command, and carries relevant information about the redirected NB-IoT NTN cell, such as frequency information, PCI, etc.;

[0062] Step f. After receiving the redirection command from the LTE network, the UE (LTE chip) sends the relevant information of the target NB-IoT NTN cell carried in the command to the NB-IoT NTN chip through an internal message; after receiving the frequency information of the NB-IoT NTN cell, the NB-IoT NTN chip searches for the cell of the NB-IoT NTN network and tries to synchronize with the target cell;

[0063] Step g. After the UE (IoT NTN chip) searches for the NB-IoT NTN cell at the specified frequency and completes synchronization, it initiates contention random access in the NB-IoT NTN cell and establishes a new connection;

[0064] Step h. MME restores the service based on UE (NB-IoT NTN chip) redirected access.

[0065] like Figure 8 As shown, in the case of switching from the NB-IoT NTN network to the TN network based on redirection switching, the switching steps are as follows:

[0066] Step a. UE (NB-IoT NTN chip) accesses the NB-IoT NTN network and establishes a service connection;

[0067] Step b. The NB-IoT NTN network sends a measurement control message to the UE (NB-IoT NTN chip), which includes: measurement objects: serving cell and neighboring cell; measurement events NTN-TN-E1 and NTN-TN-E2: the NB-IoT NTN network and the TN network belong to heterogeneous frequency and heterogeneous system measurements. The NTN-TN-E1 event is used to start heterogeneous frequency measurements. The NTN-TN-E1 event includes threshold-RSRP1. The signal of the serving cell is weaker than threshold-RSRP1, which triggers the sending of the measurement report; the NTN-TN-E2 event includes threshold-RSRP2. The signal of the heterogeneous system neighboring cell is stronger than threshold-RSRP2, which triggers the sending of the measurement report;

[0068] Step c. The RSRP of the serving cell measured by the UE (NB-IoT NTN chip) is weaker than threshold-RSRP1, triggering the NTN-TN-E1 event to be reported to the NB-IoT NTN network; the RSRP of the neighboring TN cell measured by the UE (NB-IoT NTN chip) is stronger than threshold-RSRP2, triggering the NTN-TN-E2 event to be reported to the NB-IoT NTN network;

[0069] Step d. The NB-IoT NTN network makes a redirection decision based on the NTN-TN-E1 and NTN-TN-E2 measurement results reported by the UE (NB-IoT NTN chip). If both NTN-TN-E1 and NTN-TN-E2 measurement reports are received, it means that the signal of the serving cell is weaker than the absolute threshold 1, and the signal of the neighboring TN cell is stronger than the absolute threshold 2, then the redirection process to the TN network is triggered;

[0070] Step e. After the redirection process is triggered, the NB-IoT NTN network sends an RRC release message to the UE (NB-IoT NTN chip) to indicate the redirection command, and carries relevant information about the redirected LTE cell, such as frequency information, PCI, etc.;

[0071] Step f. After receiving the redirection command from the NB-IoT NTN network, the UE (NB-IoT NTN chip) sends the relevant information of the target LTE cell carried in the command to the LTE chip through an internal message; after receiving the frequency information of the LTE cell, the LTE chip searches for the cell of the LTE network and tries to synchronize with the target cell;

[0072] Step g. After the UE (LTE chip) searches for an LTE cell at a specified frequency and completes synchronization, it initiates contention random access in the LTE cell and establishes a new connection;

[0073] Step h. MME performs service recovery based on UE (LTE chip) redirected access.

[0074] In the case where the switching mode is the switching of the location update, when the reference signal receiving power of the serving cell is less than the third signal power threshold and / or the data channel block error rate of the serving cell is greater than the preset block error rate threshold, it is determined that the measurement result meets the network switching condition, and the network switching process is triggered.

[0075] A switching command sent by a network side is received through a first chip, and the switching command is sent to a second chip; random access is competed in a target cell through the second chip to access the target cell; a location update request is sent to the network side of the target cell, wherein the location update request includes a globally unique temporary identifier GUTI, and the GUTI is used to complete the location update, wherein the first chip and the second chip are applicable to different communication networks, and the first chip and the second chip are both deployed inside the user terminal.

[0076] like Fig. 9 As shown, in the case of switching from a TN network to a NB-IoT NTN network based on a location update switching method, the switching steps are as follows;

[0077] Step a. UE (LTE chip) accesses the LTE network and performs data transmission;

[0078] Step b. The LTE network makes a decision based on RSRP (DMRS received power) and BLER (block error rate): Condition 1: RSRP is weaker than threshold-RSRP (third signal power threshold); Condition 2: BLER is greater than threshold-BLER (preset block error rate threshold);

[0079] It should be noted that it can be based on condition one or condition two, or it can refer to both condition one and condition two.

[0080] Step c. If the demodulation reference signal RSRP of the serving cell measured by the LTE network is weaker than the threshold-RSRP, and / or the target BLER of the data channel is greater than the threshold-BLER, the switching process to the NB-IoT NTN network is triggered; after the switching process is triggered, the LTE network sends a switching command message to the UE (LTE chip);

[0081] Step d. After receiving the handover command from the LTE network, the UE (LTE chip) sends the NAS security information, integrity protection information, and the handover command to the NB-IoT NTN chip through an internal message. The UE starts the NB-IoT NTN chip and triggers the access process to the NB-IoT NTN network.

[0082] Step e. UE (NB-IoT NTN chip) initiates random access competition in the NB-IoT NTN cell and establishes a new connection;

[0083] Step f. The NB-IoT NTN network and the TN network are different systems, and location update is required; the TAU request will carry the GUTI (Globally Unique Temporary Identifier), and the MME can identify the switching user through the GUTI;

[0084] Step g. MME performs service recovery according to GUTI and continues data transmission.

[0085] like Fig.10 As shown, in the case of switching from the NB-IoT NTN network to the TN network based on location update switching, the switching steps are as follows;

[0086] Step a. UE (NB-IoT NTN chip) accesses the NB-IoT NTN network and performs data transmission;

[0087] Step b. The NB-IoT NTN network makes a decision based on RSRP (DMRS received power) and BLER (block error rate): Condition 1: RSRP is weaker than threshold-RSRP; Condition 2: BLER is greater than threshold-BLER;

[0088] It should be noted that it can be based on condition one or condition two, or it can refer to both condition one and condition two.

[0089] Step c. If the demodulation reference signal RSRP of the serving cell measured by the NB-IoT NTN network is weaker than the threshold-RSRP and the target BLER of the data channel is greater than the threshold-BLER, the switching process to the LTE network is triggered; after the switching process is triggered, the NB-IoT NTN network sends a switching command message to the UE (NB-IoT NTN chip);

[0090] Step d. After receiving the handover command from the NB-IoT NTN network, the UE (NB-IoT NTN chip) sends the NAS security information, integrity protection information, and the handover command to the LTE chip through an internal message. The UE starts the LTE chip and triggers the access process to the LTE network.

[0091] Step e. The UE (LTE chip) initiates a random access competition in the LTE cell to establish a new connection;

[0092] Step f. The NB-IoT NTN network and the TN network are different systems, and location update is required; the TAU request will carry the GUTI (Globally Unique Temporary Identifier), and the MME can identify the switching user through the GUTI;

[0093] Step g. MME performs service recovery according to GUTI and continues data transmission.

[0094] In the case where the switching mode is a switching based on the X2 interface, a switching indication message sent by the base station of the serving cell is received, wherein the switching indication message is sent after the base station of the serving cell sends a switching request message to the base station of the target cell through the X2 interface and receives a switching request response message sent by the base station of the target cell through the X2 interface, and the base station of the serving cell is also used to send the service cache data in the switching process to the base station of the target cell through the X2 interface; in the case of receiving the switching indication message, the current connection is released and the base station of the target cell is accessed, wherein after the user terminal accesses the base station of the target cell, the base station of the target cell sends a path switching message to the core network element, and the path switching message is used to change the bearer of the user terminal from the base station of the serving cell to the base station of the target cell.

[0095] like Fig.11 As shown in the figure, when the switching mode is based on the X2 interface, the specific steps for switching from the TN (LTE) network to the NB-IoT NTN network are as follows:

[0096] Step a. The UE initiates access to the LTE network and establishes service transmission;

[0097] Step b. The LTE network sends a measurement control message to the UE, which includes: measurement objects: serving cell and neighboring cell; measurement events NTN-TN-E1 and NTN-TN-E2: NB-IoT NTN network and TN network belong to heterogeneous frequency and heterogeneous system measurements. The NTN-TN-E1 event is used to start heterogeneous frequency measurement. The NTN-TN-E1 event includes threshold-RSRP1. The signal of the serving cell is weaker than threshold-RSRP1, which triggers the sending of the measurement report; the NTN-TN-E2 event includes threshold-RSRP2. The signal of the heterogeneous system neighboring cell is stronger than threshold-RSRP2, which triggers the sending of the measurement report;

[0098] Step c. The RSRP of the serving cell measured by the UE is weaker than threshold-RSRP1, triggering the NTN-TN-E1 event to be reported to the LTE network; the RSRP of the neighboring NB-IoT NTN cell measured by the UE is stronger than threshold-RSRP2, triggering the NTN-TN-E2 event to be reported to the LTE network;

[0099] Step d. The LTE network makes a handover decision based on the NTN-TN-E1 and NTN-TN-E2 measurement results reported by the UE. If both NTN-TN-E1 and NTN-TN-E2 measurement reports are received, indicating that the signal of the serving cell is weaker than the first signal power threshold, and the signal of the neighboring NB-IoT NTN cell is stronger than the second signal power threshold, the handover process to the NB-IoT NTN network is triggered;

[0100] Step e. The LTE base station sends a handover request message to the NB-IoT NTN base station, carrying the target cell identifier, UE context, and forwarding data related information to prepare for handover;

[0101] Step f. The NB-IoT NTN base station determines that the terminal can be accepted according to the handover request information, allocates air interface resources for the UE access, and sends the above information to the LTE base station through the handover request response;

[0102] Step g. After receiving the handover request response, the LTE base station confirms that the NB-IoT NTN base station is ready to take over the UE and sends a handover indication message to the UE. At the same time, the LTE base station forwards the service cache data during the handover to the NB-IoT NTN base station via the X2 bearer;

[0103] Step h. After receiving the handover indication message, the UE releases the current connection and accesses the NB-IoT NTN base station through a competitive random access process;

[0104] Step i. After the NB-IoT NTN base station confirms the UE access, it sends a path switching request message to the MME to change the terminal's bearer from the source base station to the target base station;

[0105] Step j. The NB-IoT NTN base station sends a resource release message to the LTE base station, notifying the LTE base station to release the context related to the terminal;

[0106] Step k.UE continues to send and receive data through the NB-IoT NTN base station.

[0107] like Fig.12 As shown in the figure, when the switching mode is based on the X2 interface, the specific steps for switching from the NB-IoT NTN network to the TN network are as follows:

[0108] Step a. UE initiates access to the NB-IoT NTN network and establishes service transmission;

[0109] Step b. The NB-IoT NTN network sends a measurement control message to the UE, which includes: measurement objects: serving cell and neighboring cell; measurement events NTN-TN-E1 and NTN-TN-E2: Since the NB-IoT NTN network and the TN network are heterogeneous frequency and heterogeneous system measurements, the NTN-TN-E1 event is used to start heterogeneous frequency measurement. The NTN-TN-E1 event includes threshold-RSRP1. If the signal of the serving cell is weaker than threshold-RSRP1, the sending of the measurement report is triggered; the NTN-TN-E2 event includes threshold-RSRP2. If the signal of the heterogeneous system neighboring cell is stronger than threshold-RSRP2, the sending of the measurement report is triggered;

[0110] Step c. The RSRP of the serving cell measured by the UE is weaker than threshold-RSRP1, triggering the NTN-TN-E1 event to be reported to the NB-IoT NTN network; the RSRP of the neighboring LTE cell measured by the UE is stronger than threshold-RSRP2, triggering the NTN-TN-E2 event to be reported to the NB-IoT NTN network;

[0111] Step d. The NB-IoT NTN network makes a handover decision based on the NTN-TN-E1 and NTN-TN-E2 measurement results reported by the UE. If both NTN-TN-E1 and NTN-TN-E2 measurement reports are received, indicating that the signal of the serving cell is weaker than threshold-RSRP1 and the signal of the neighboring LTE cell is stronger than threshold-RSRP2, the handover process to the LTE network is triggered;

[0112] Step e. The NB-IoT NTN base station sends a handover request message to the LTE base station, carrying the target cell identifier, UE context, and forwarding data related information to prepare for handover;

[0113] Step f. The LTE base station determines that the terminal can be accepted according to the handover request information, allocates air interface resources for the UE access, and sends the above information to the NB-IoT NTN base station through the handover request response;

[0114] Step g. After receiving the handover request response, the NB-IoT NTN base station confirms that the LTE base station is ready to take over the UE and sends a handover indication message to the UE. At the same time, the NB-IoT NTN base station forwards the service cache data during the handover to the LTE base station via the X2 bearer;

[0115] Step h. After receiving the handover indication message, the UE releases the current connection and accesses the LTE base station through a competitive random access process;

[0116] Step i. After the LTE base station confirms the UE access, it sends a path switching request message to the MME to change the terminal's bearer from the source base station to the target base station;

[0117] Step j. The LTE base station sends a resource release message to the NB-IoT NTN base station, notifying the NB-IoT NTN base station to release the terminal-related context; the UE continues to send and receive data through the LTE base station.

[0118] In the case where the switching mode is a switching based on the S1 interface, receiving a switching indication message sent by the base station of the serving cell, wherein the switching indication message is sent by the base station of the serving cell after receiving a switching command sent by a source core network element through the S1 interface, the switching command is sent by the source core network element after receiving a path switching response message sent by a target core network element, the path switching response message is sent by the target core network element after receiving a switching request response sent by the base station of the target cell, the switching request response is sent by the base station of the target cell in response to the switching request sent by the target core network element, and the switching request is sent by the target core network element in response to the path switching request message sent by the source core network element, wherein the path switching request message is used to request to change the bearer of the user terminal from the base station of the serving cell to the base station of the target cell;

[0119] When the handover indication message is received, a contention random access is initiated in the target cell to access the target cell.

[0120] Fig.13 and Fig.14 The figure shows the process of switching from TN (LTE) network to NB-IoT NTN network and from NB-IoT NTN network to TN (LTE) network respectively in the case of switching based on S1 interface. The switching process based on S1 interface is basically the same as the switching process based on X2 interface. The main difference is that the switching based on S1 interface is that MME forwards the switching request signaling and path switching request signaling to the target base station. MME is used as the switching intermediary to realize the signaling interaction between the source base station and the target base station to complete the switching, which will not be repeated here.

[0121] It needs to be explained that Fig.13 and Fig.14 The source MME corresponds to the MME of the service cell, and the target MME corresponds to the MME of the target cell. In actual application scenarios, the source MME and the target MME may be the same MME. In order to better illustrate the process of switching between the source base station and the target base station based on the MME as a switching intermediary in the embodiment of the present application, the source MME and the target MME are used to distinguish.

[0122] A satellite-to-ground switching method in NB-IoT NTN proposed in an embodiment of the present application receives newly added measurement configurations: threshold-RSRP1, threshold-RSRP2, NTN-TN-E1 and NTN-TN-E2, and triggers NTN-TN-E1 to report to the base station based on the RSRP of the service cell being weaker than threshold-RSRP1; measures that the RSRP of the neighboring NB-IoT NTN cell is stronger than threshold-RSRP2, triggering NTN-TN-E2 to report to the base station; (Difference from the prior art: the NB-IoT terminal supports measurement reporting); the LTE chip and the NB-IoT NTN chip share frequency information, PCI, NAS security information, integrity protection information and other configuration information through configuration messages; (Difference from the prior art: the NB-IoT terminal supports redirection and location update functions), realizing switching based on the X2 / S1 interface. (Difference from the prior art: the NB-IoT terminal supports X2 / S1 switching).

[0123] After the base station receives the newly added measurement events NTN-TN-E1 and NTN-TN-E2 reported by the UE, it indicates that the signal of the serving cell is weaker than threshold-RSRP1, and the signal of the neighboring cell is stronger than threshold-RSRP2, which triggers the switching process between the NB-IoT NTN and TN networks; at the same time, the base station can also make judgments based on the existing technical parameters RSRP (DMRS received power) and BLER (block error rate). The base station measures that the demodulation reference signal RSRP of the serving cell is weaker than the threshold-RSRP, and / or the target BLER of the data channel is greater than the threshold-BLER, which triggers the switching process between the NB-IoT NTN and TN networks; 3. Based on 1, the newly added measurement events of the NB-IoT terminal realize the switching based on the X2 / S1 interface; if the base station allows the switching between the NTN and TN networks, the base station triggers the random access process of the terminal to the target network through RRC release messages, switching commands, etc.; supports multiple switching modes: based on redirection, location update, X2 interface, and S1 interface.

[0124] Fig.15 A satellite-to-ground switching device in an NB-IoT NTN according to an embodiment of the present application includes:

[0125] The receiving module 150 is used to receive measurement control information sent by the network side, where the measurement control information is used to instruct the user terminal to measure the network quality of the NB-IoT NTN cell and the TN cell, wherein the NB-IoT NTN cell and the TN cell are adjacent cells to each other;

[0126] The switching module 152 is used to send the measurement result to the network side, and when the measurement result meets the network switching condition, obtain the network switching mode, complete the network switching process of the switching mode, and perform network switching. The switching mode includes at least one of the following: switching based on redirection, switching based on location update, switching based on X2 interface, and switching based on S1 interface.

[0127] Through the satellite-to-ground switching device in the above-mentioned NB-IoT NTN, through the above-mentioned steps S202 to S204, by receiving the measurement control information sent by the network side, the measurement control information is used to instruct the user terminal to measure the network quality of the NB-IoT NTN cell and the TN cell, wherein the NB-IoT NTN cell and the TN cell are adjacent cells to each other; sending the measurement result to the network side, and when the measurement result meets the network switching condition, obtaining the network switching mode, completing the network switching process of the switching mode, so as to perform network switching, and the switching mode includes at least one of the following: switching based on redirection, switching based on location update, switching based on X2 interface, and switching based on S1 interface, thereby achieving the purpose of determining different switching processes according to different switching modes to complete network switching, thereby achieving the technical effect of improving communication stability, and then solving the technical problem of poor communication stability caused by using cell reselection for network switching in the related technology.

[0128] It should be noted that Fig.15 The satellite-to-ground switching device in the NB-IoT NTN shown is used to perform Figure 2 The satellite-to-ground switching method in the NB-IoT NTN shown in the figure, therefore, the relevant explanations in the above-mentioned satellite-to-ground switching method in the NB-IoT NTN are also applicable to the satellite-to-ground switching device in the NB-IoT NTN, and are not repeated here.

[0129] An embodiment of the present application also provides a communication device, including: a memory and a processor, wherein the memory is used to store program instructions; the processor is connected to the memory and is used to execute the satellite-to-ground switching method in the above-mentioned NB-IoT NTN.

[0130] An embodiment of the present application also provides a non-volatile storage medium, which includes a stored computer program, wherein the device where the non-volatile storage medium is located executes the above-mentioned satellite-to-ground switching method in NB-IoT NTN by running the computer program.

[0131] An embodiment of the present application also provides a computer program product, including computer instructions, which, when executed by a processor, implement the steps of the satellite-to-ground switching method in the NB-IoT NTN in the present application.

[0132] The serial numbers of the above-mentioned embodiments of the present application are for description only and do not represent the advantages or disadvantages of the embodiments.

[0133] In the above embodiments of the present application, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, please refer to the relevant description of other embodiments.

[0134] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. Among them, the device embodiments described above are only schematic. For example, the division of the units can be a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of units or modules, which can be electrical or other forms.

[0135] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple units. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0136] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0137] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, in essence, or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions to enable a communication device (which can be a personal computer, a server or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), mobile hard disk, disk or optical disk and other media that can store program codes.

[0138] The above is only a preferred implementation of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A satellite-to-ground switching method in NB-IoT NTN, characterized in that: include: Receive measurement control information sent by the network side, where the measurement control information is used to instruct the user terminal to measure the network quality of the NB-IoT NTN cell and the TN cell, where the NB-IoT NTN cell and the TN cell are adjacent cells to each other; Send the measurement result to the network side, and when the measurement result meets the network switching condition, obtain the network switching mode, complete the network switching process of the switching mode to perform network switching, and the switching mode includes at least one of the following: switching based on redirection, switching based on location update, switching based on X2 interface, and switching based on S1 interface.

2. The method according to claim 1, characterized in that Sending the measurement result to the network side includes: When the reference signal received power of the serving cell is lower than the first signal power threshold, sending a first event result to the network side; In a case where the reference signal received power of a neighboring cell is higher than a second signal power threshold, a second event result is sent to the network side, wherein the neighboring cell is a cell adjacent to the service cell, and the service cell is a cell currently accessed by the user terminal, wherein, in a case where the user terminal simultaneously sends the first event result and the second event result to the network side, it is determined that the measurement result meets the network switching condition, and the network switching process is triggered.

3. The method according to claim 2, characterized in that The network switching process of the switching mode is completed to perform network switching, including: When the switching mode is the redirection-based switching, receiving a radio resource control RRC release message sent by a network side, where the RRC release message is used to instruct the user terminal to redirect; Extracting cell configuration information of the target cell from the RRC release message through the first chip, and sending the cell configuration information to the second chip; The second chip is synchronized with the target cell according to the cell configuration information, and after the synchronization is completed, competitive random access is initiated in the target cell to access the target cell, wherein the cell configuration information at least includes: a cell frequency and a physical cell identifier, and the target cell is the adjacent cell, wherein the first chip and the second chip are applicable to different communication networks, and the first chip and the second chip are both deployed inside the user terminal.

4. The method according to claim 1, characterized in that: The method further comprises: In the case where the switching mode is the switching of the location update, when the reference signal receiving power of the serving cell is less than the third signal power threshold and / or the data channel block error rate of the serving cell is greater than the preset block error rate threshold, it is determined that the measurement result meets the network switching condition, and the network switching process is triggered.

5. The method according to claim 4, characterized in that The network switching process of the switching mode is completed to perform network switching, including: Receiving a switching command sent by the network side through the first chip, and sending the switching command to the second chip; Compete for random access in the target cell through the second chip to access the target cell; A location update request is sent to the network side of the target cell, wherein the location update request includes a globally unique temporary identifier GUTI, and the GUTI is used to complete the location update, wherein the first chip and the second chip are applicable to different communication networks, and the first chip and the second chip are both deployed inside the user terminal.

6. The method according to claim 2, characterized in that The network switching process of the switching mode is completed to perform network switching, including: In a case where the handover mode is a handover based on an X2 interface, receiving a handover indication message sent by the base station of the serving cell, wherein the handover indication message is sent after the base station of the serving cell sends a handover request message to the base station of the target cell through the X2 interface and receives a handover request response message sent by the base station of the target cell through the X2 interface, and the base station of the serving cell is further used to send service cache data in the handover process to the base station of the target cell through the X2 interface; When the switching indication message is received, the current connection is released and the base station of the target cell is accessed, wherein after the user terminal accesses the base station of the target cell, the base station of the target cell sends a path switching message to the core network element, and the path switching message is used to change the bearer of the user terminal from the base station of the serving cell to the base station of the target cell.

7. The method according to claim 2, characterized in that The network switching process of the switching mode is completed to perform network switching, including: In the case where the switching mode is a switching based on the S1 interface, receiving a switching indication message sent by the base station of the serving cell, wherein the switching indication message is sent by the base station of the serving cell after receiving a switching command sent by a source core network element through the S1 interface, the switching command is sent by the source core network element after receiving a path switching response message sent by a target core network element, the path switching response message is sent by the target core network element after receiving a switching request response sent by the base station of the target cell, the switching request response is sent by the base station of the target cell in response to the switching request sent by the target core network element, and the switching request is sent by the target core network element in response to the path switching request message sent by the source core network element, wherein the path switching request message is used to request to change the bearer of the user terminal from the base station of the serving cell to the base station of the target cell; When the handover indication message is received, a contention random access is initiated in the target cell to access the target cell.

8. A satellite-to-ground switching device in NB-IoT NTN, characterized in that: include: A receiving module, configured to receive measurement control information sent by a network side, wherein the measurement control information is used to instruct a user terminal to measure the network quality of an NB-IoT NTN cell and a TN cell, wherein the NB-IoT NTN cell and the TN cell are adjacent cells to each other; A switching module is used to send the measurement result to the network side, and when the measurement result meets the network switching condition, obtain the network switching mode, complete the network switching process of the switching mode, so as to perform network switching, and the switching mode includes at least one of the following: switching based on redirection, switching based on location update, switching based on X2 interface, and switching based on S1 interface.

9. A communication device, characterized in that: include: A memory and a processor, wherein the memory is used to store program instructions; The processor is connected to the memory and is used to execute the satellite-to-ground switching method in the NB-IoT NTN according to any one of claims 1 to 7.

10. A computer program product comprising computer instructions, characterized in that: When the computer instructions are executed by the processor, the satellite-to-ground switching method in the NB-IoT NTN described in any one of claims 1 to 7 is implemented.

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