A method and system for mobile station traffic transmission based on NTN satellite and 5G-A base station

Abstract

This invention relates to the field of wireless communication technology, and particularly to a method and system for mobile station traffic transmission based on the collaboration of NTN satellite and 5G-A base station. When the mobile station detects that its downlink quality is compared with a first preset threshold and its own power margin is zero, it triggers a satellite control plane connection when uplink is restricted. When the mobile station's uplink is restricted but the base station's downlink is available, the NTN satellite transmits control plane signaling and uplink data, while the terrestrial 5G-A base station transmits downlink user plane data, achieving optimal division of labor and saving satellite resources. By determining whether the downlink quality of the cooperating base station is lower than a second preset threshold, the invention further distinguishes between "uplink-only restricted" and "both uplink and downlink restricted" scenarios. When downlink is also restricted, the satellite takes over user plane data to ensure uninterrupted communication.

Description

Technical Field

[0001] This invention relates to the field of wireless communication technology, and in particular to a method and system for mobile station traffic transmission based on the combination of NTN satellite and 5G-A base station. Background Technology

[0002] As 5G networks evolve towards 5G-Advanced, non-terrestrial network (NTN) technology has become an important component of the 3GPP standard, aiming to extend the coverage of terrestrial networks through satellite communication. NTN technology enables terminals such as smartphones to establish direct connections with satellites, providing basic communication services to remote areas, oceans, aviation, and other regions that are difficult to cover by traditional terrestrial networks.

[0003] Currently, NTN technology faces several key challenges: First, satellite communication suffers from problems such as large transmission delays, severe Doppler frequency offset, and unstable links, resulting in low data transmission rates and high costs. Second, in scenarios where uplink is limited but downlink is available between mobile stations and terrestrial base stations (such as at the cell edge or where uplink interference exists), existing solutions cannot fully utilize the downlink capacity resources of terrestrial base stations. Third, transmitting downlink username data via satellite causes unnecessary consumption of satellite resources, increasing user communication costs.

[0004] Existing technologies have attempted to address some of the issues. For example, Huawei Technologies Co., Ltd.'s patent application CN111629400A discloses a satellite cooperative communication method that triggers other satellite beams to share the load by monitoring satellite link traffic, but it does not address the separation of control plane and user plane transmission in uplink-constrained scenarios. Related patents from ZTE and China Mobile also primarily focus on satellite access stability or terminal parameter adjustments, failing to solve the fundamental problem of how to collaboratively utilize satellite control links and ground base station data links. MediaTek, in its 6G NTN technology white paper, proposed a complementary approach between satellites and ground base stations, but did not specifically address resource optimization methods for uplink-constrained scenarios.

[0005] Therefore, there is an urgent need for an innovative technical solution that can intelligently separate the control plane and user plane in scenarios where uplink is restricted on mobile devices, and jointly schedule NTN satellites and multiple 5G-A base station resources to achieve seamless connection of communication services and efficient utilization of resources. Summary of the Invention

[0006] Therefore, there is a need to provide a method and system for mobile station traffic transmission based on the combination of NTN satellite and 5G-A base station to solve the technical problems involved in the above background technology.

[0007] To achieve the above objectives, in a first aspect, this application provides a method for mobile station traffic transmission based on the combination of NTN satellite and 5G-A base station, comprising the following steps:

[0008] S1. When the mobile station is connected to the 5G-A base station, it detects the downlink quality and its own power margin with the 5G-A base station, and determines whether the downlink quality is lower than the first preset threshold and its own power margin is zero. If so, the mobile station initiates a control plane connection to the NTN satellite.

[0009] S2. After the mobile station establishes a control plane connection with the NTN satellite, the mobile station sends its location information and measurement reports of surrounding 5G-A base stations to the NTN satellite.

[0010] S3 and NTN satellites receive the location information of the mobile station and the measurement reports of the surrounding 5G-A base stations, and forward them to the ground gateway station;

[0011] S4. Based on the received location information and measurement report, the ground gateway station selects at least one 5G-A base station from its surrounding 5G-A base stations to form a cooperative set. It determines whether the downlink quality of the 5G-A base stations in the cooperative set is lower than the second preset threshold. If so, the NTN satellite is responsible for transmitting the user plane data of the mobile station and accessing the core network.

[0012] S5. The mobile station continues to monitor its surrounding 5G-A base stations until the ground gateway station determines that there are 5G-A base stations in the cooperative group with downlink quality not lower than the second preset threshold. Then, the 5G-A base stations in the cooperative group with downlink quality not lower than the second preset threshold are responsible for segmenting and transmitting the mobile station's downlink data.

[0013] Unlike existing technologies, the technical solution of this application defines a mobile station traffic transmission method based on the joint operation of NTN satellite and 5G-A base station. This method involves the mobile station actively detecting uplink quality and comparing it with a first preset threshold. When the mobile station's uplink is restricted but the base station's downlink is available, the NTN satellite transmits control plane signaling (ensuring connection stability) and uplink data, while the terrestrial 5G-A base station transmits user plane downlink data (ensuring transmission efficiency), achieving optimal division of labor between the two. By determining whether the downlink quality of the cooperative base stations is lower than a second preset threshold, the system further distinguishes between "uplink-only restriction" and "both uplink and downlink restriction" scenarios. When downlink is also restricted, the satellite takes over user plane data, ensuring uninterrupted communication and demonstrating the system's robustness. When there are base stations with acceptable downlink quality in the cooperative set, a segmented transmission method is adopted, dividing data packets into blocks and sending them concurrently from multiple base stations, significantly improving downlink peak rate and spectral efficiency.

[0014] In one embodiment of the present invention, in step S4, if the downlink quality of all 5G-A base stations in the cooperative set is lower than the second preset threshold, it is determined whether the 5G-A base stations in the cooperative set meet the replication transmission requirements. If yes, the 5G-A base stations in the cooperative set that meet the replication transmission requirements are responsible for replicating and transmitting the downlink data of the mobile station; if no, the NTN satellite is responsible for transmitting the user plane data of the mobile station.

[0015] As described above, when the downlink quality of all base stations in the cooperative set is below the second preset threshold but still meets the requirements for duplicate transmission, the method of synchronously replicating the same data packets by multiple base stations is adopted. This utilizes spatial diversity gain to improve the reception success rate, making it particularly suitable for services with extremely high reliability requirements, such as VoNR and emergency control signaling. Based on different downlink quality levels, it automatically switches between "split transmission" (high throughput mode), "duplicate transmission" (high reliability mode), and "pure satellite transmission" (backup mode), achieving fine-grained matching of service quality and channel conditions.

[0016] As one embodiment of the present invention, the uplink quality in step S1 is evaluated based on at least one of the following parameters: the reference signal received power of the 5G-A base station, the signal-to-interference-plus-noise ratio, the uplink transmission bit error rate, or the uplink retransmission rate.

[0017] As described above, the evaluation parameters for uplink quality are further defined. By comprehensively considering multiple dimensions such as RSRP, SINR, bit error rate, and retransmission rate, the system avoids false or missed triggers based on a single threshold, ensuring that satellite-ground cooperative transmission is only initiated when truly needed, thus reducing unnecessary satellite resource consumption.

[0018] As one embodiment of the present invention, the measurement report in step S2 includes: the physical cell identifier of the detectable 5G-A base station, the reference signal received power measurement value of each 5G-A base station, the signal-to-interference-plus-noise ratio measurement value of each 5G-A base station, and the signal arrival time difference of each 5G-A base station.

[0019] As described above, the specific content of the surrounding base station measurement information reported by the mobile station is limited. By reporting multi-dimensional information such as PCI, RSRP, SINR, and signal arrival time difference, sufficient channel state data is provided to the satellite-ground cooperative controller, enabling it to select the combination with the best signal quality and synchronization conditions from multiple candidate base stations, thereby improving the gain of cooperative transmission.

[0020] In one embodiment of the present invention, step S4 involves selecting at least one 5G-A base station to form a cooperative set, including the following steps:

[0021] 5G-A base stations whose estimated path loss with the mobile station is less than the loss threshold are selected to obtain the first set of data;

[0022] Exclude 5G-A base stations in the first set of data whose current load exceeds a preset load ratio to obtain the second set of data;

[0023] Select N 5G-A base stations with the best signal quality from the second set of data, where N is an integer from 1 to 4.

[0024] As described above, the three-step mechanism of path loss screening (ensuring signal coverage), load exclusion (avoiding overloaded base stations from affecting performance), and signal quality sorting (selecting the optimal node) ensures that the selected cooperative set possesses the three characteristics of "signal reachability," "resource availability," and "optimal performance." N takes the integer value from 1 to 4, allowing for flexible expansion from single-base station cooperation (i.e., ordinary downlink transmission) to multi-base station aggregation, adapting to scenarios with different deployment densities and capacity requirements.

[0025] Secondly, this application provides a mobile station traffic transmission system based on the combination of NTN satellite and 5G-A base station, including:

[0026] The mobile station, when connected to a 5G-A base station, detects its downlink quality and its own power margin with the 5G-A base station, and determines whether the downlink quality is lower than a first preset threshold and its own power margin is zero. If so, the mobile station initiates a control plane connection via the NTN satellite. After the mobile station establishes a control plane connection with the NTN satellite, it sends its location information and measurement reports of surrounding 5G-A base stations to the NTN satellite, and continues to monitor its surrounding 5G-A base stations.

[0027] NTN satellites are used to forward location information and measurement reports of nearby 5G-A base stations received from mobile stations to ground gateway stations;

[0028] The ground gateway station is used to select at least one 5G-A base station from its surrounding 5G-A base stations to form a cooperative set based on the received location information and measurement reports. It determines whether the downlink quality of all 5G-A base stations in the cooperative set is lower than a second preset threshold. If so, the NTN satellite is responsible for transmitting the user plane data of the mobile station and accessing the core network. When it is determined that there is a 5G-A base station in the cooperative set with a downlink quality not lower than the second preset threshold, the 5G-A base station in the cooperative set with a downlink quality not lower than the second preset threshold is responsible for segmenting and transmitting the downlink data of the mobile station.

[0029] A 5G-A base station cluster, comprising multiple 5G-A base stations, is used to form a cooperative set under the scheduling of a ground gateway station. When there is a 5G-A base station in the cooperative set with a downlink quality not lower than the second preset threshold, the 5G-A base station in the cooperative set with a downlink quality not lower than the second preset threshold is responsible for segmenting and transmitting the downlink data of the mobile station.

[0030] Unlike existing technologies, the system in this application consists of a mobile station, an NTN satellite, a ground gateway station, and a 5G-A base station cluster, forming a complete closed loop. The mobile station is responsible for sensing and reporting, the satellite is responsible for control plane relay, the gateway station is responsible for decision-making and scheduling, and the base stations are responsible for data execution. Each component performs its specific function, resulting in efficient collaboration. The ground gateway station, acting as a satellite-ground collaborative controller, centrally manages core logic such as base station selection, cooperative set formation, downlink quality determination, and transmission mode switching, reducing the complexity of distributed decision-making and ensuring policy consistency.

[0031] In one embodiment of the present invention, the ground gateway station is further configured to determine whether the 5G-A base stations in the cooperative set meet the replication transmission requirements if the downlink quality of all 5G-A base stations in the cooperative set is lower than a second preset threshold. If yes, the 5G-A base stations in the cooperative set that meet the replication transmission requirements are responsible for replicating and transmitting the downlink data of the mobile station; otherwise, the NTN satellite is responsible for transmitting the user plane data of the mobile station.

[0032] As described above, end-to-end support for the replication transmission mode is achieved at the system level. When the downlink quality of the cooperative set base stations does not meet the second threshold but is still operational, it automatically degrades to the replication transmission mode, trading bandwidth for reliability, avoiding a direct switch to the high-cost, high-latency satellite link, and achieving a balance between cost and performance.

[0033] As one embodiment of the present invention, the uplink quality in step S1 is evaluated based on at least one of the following parameters: the reference signal received power of the 5G-A base station, the signal-to-interference-plus-noise ratio, the uplink transmission bit error rate, or the uplink retransmission rate.

[0034] As can be seen from the above description, the quality assessment parameters are clearly defined in the system architecture, ensuring the consistency of technical features from the method to the system implementation, and enhancing the integrity and implementability of the patent.

[0035] As one embodiment of the present invention, the measurement report in step S2 includes: the physical cell identifier of the detectable 5G-A base station, the reference signal received power measurement value of each 5G-A base station, the signal-to-interference-plus-noise ratio measurement value of each 5G-A base station, and the signal arrival time difference of each 5G-A base station.

[0036] As can be seen from the above description, the measurement report content is clearly defined in the system architecture, ensuring the consistency of technical features from method to system implementation, and enhancing the integrity and implementability of the patent.

[0037] In one embodiment of the present invention, the ground gateway station is further configured to filter 5G-A base stations whose path loss estimate with respect to the mobile station is less than a loss threshold to obtain a first set of data; exclude 5G-A base stations in the first set of data whose current load exceeds a preset load ratio to obtain a second set of data; and select N 5G-A base stations with the best signal quality from the second set of data, where N is an integer from 1 to 4.

[0038] As described above, by centrally performing path loss calculation, load filtering, and signal quality sorting at ground gateway stations, mobile stations only need to report raw measurement values ​​without performing complex calculations. This reduces the power consumption and computing power requirements of mobile stations, which is beneficial for miniaturization and battery life optimization of terminal devices.

[0039] Thirdly, this application provides a communication device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the steps of the mobile station traffic transmission method based on the combination of NTN satellite and 5G-A base station.

[0040] Unlike existing technologies, the technical solution of this application embeds the aforementioned method into a communication device in the form of a computer program. This provides an alternative implementation method besides dedicated terminals, enabling existing general-purpose communication devices (such as base stations, core network equipment, and terminals with software-defined capabilities) to acquire the satellite-ground cooperative transmission capability defined in this invention through software upgrades, thereby reducing deployment costs and lowering the barriers to promotion.

[0041] Fourthly, this application provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the steps of the mobile station traffic transmission method based on the combination of NTN satellite and 5G-A base station.

[0042] Unlike existing technologies, the technical solution of this application protects the aforementioned method in the form of a computer-readable storage medium. This covers the software implementation of the method, preventing others from implementing the invention through software distribution, pre-installation, or other means without producing physical equipment, thus further strengthening the scope of patent protection and its commercial value.

[0043] The above description of the invention is merely an overview of the technical solution of this application. In order to enable those skilled in the art to better understand the technical solution of this application and to implement it based on the description and drawings, and to make the above-mentioned objectives and other objectives, features and advantages of this application easier to understand, the following description is provided in conjunction with the specific embodiments and drawings of this application. Attached Figure Description

[0044] The accompanying drawings are only used to illustrate the principles, implementation methods, applications, features, and effects of specific embodiments of this application and other related content, and should not be considered as limitations on this application.

[0045] In the accompanying drawings of the instruction manual:

[0046] Figure 1 This is a flowchart illustrating the steps of the mobile station traffic transmission method based on the combination of NTN satellite and 5G-A base station in this application.

[0047] Figure 2 This is a schematic diagram of the architecture of the mobile station traffic transmission system based on the combination of NTN satellite and 5G-A base station in this application;

[0048] Figure 3 A schematic diagram of the control plane protocol stack for the NG-RAN architecture of transparent forwarding in satellite communication in this application;

[0049] Figure 4 This is a flowchart illustrating the data offloading and aggregation process for the multi-base station cooperative downlink in this application.

[0050] Figure 5 This is the state transition diagram of the dynamic resource scheduling algorithm in this application;

[0051] The reference numerals used in the above figures are explained as follows:

[0052] 1. Mobile station; 2. NTN satellite; 3. 5G-A base station cluster; 4. Ground gateway station. Detailed Implementation

[0053] To illustrate the possible application scenarios, technical principles, implementable specific solutions, and achievable objectives and effects of this application in detail, the following description, in conjunction with the listed specific embodiments and accompanying drawings, provides a detailed explanation. The embodiments described herein are merely illustrative of the technical solutions of this application and are therefore intended to limit the scope of protection of this application.

[0054] In this document, the term "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The term "embodiment" appearing in various places throughout the specification does not necessarily refer to the same embodiment, nor does it specifically limit its independence or connection with other embodiments. In principle, in this application, as long as there are no technical contradictions or conflicts, the technical features mentioned in each embodiment can be combined in any way to form corresponding implementable technical solutions.

[0055] Unless otherwise defined, the technical terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the use of related terms herein is merely for the purpose of describing particular embodiments and is not intended to limit this application.

[0056] In the description of this application, the term "and / or" is used to describe the logical relationship between objects, indicating that three relationships can exist. For example, A and / or B means: A exists, B exists, and A and B exist simultaneously. Additionally, the character " / " in this document generally indicates that the preceding and following objects have an "or" logical relationship.

[0057] In this application, terms such as “first” and “second” are used only to distinguish one entity or operation from another, and do not necessarily require or imply any actual quantity, hierarchy or order relationship between these entities or operations.

[0058] Without further limitations, the use of terms such as “comprising,” “including,” “having,” or other similar open-ended expressions in this application is intended to cover non-exclusive inclusion, which does not exclude the presence of additional elements in a process, method, or product that includes the stated elements, such that a process, method, or product that includes a list of elements may include not only those defined elements but also other elements not expressly listed, or elements inherent to such a process, method, or product.

[0059] As understood in the Examination Guidelines, in this application, expressions such as "greater than," "less than," and "exceeding" are understood to exclude the stated number; expressions such as "above," "below," and "within" are understood to include the stated number. Furthermore, in the description of the embodiments in this application, "multiple" means two or more (including two), and similar expressions related to "multiple" are also understood in this way, such as "multiple groups" and "multiple times," unless otherwise explicitly specified.

[0060] In the description of the embodiments of this application, the space-related expressions used, such as "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "vertical," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," indicate the orientation or positional relationship based on the orientation or positional relationship shown in the specific embodiments or drawings. They are only for the purpose of describing the specific embodiments of this application or for the reader's understanding, and do not indicate or imply that the device or component referred to must have a specific position, a specific orientation, or be constructed or operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0061] Unless otherwise expressly specified or limited, the terms "installation," "connection," "linking," "fixing," and "setting," as used in the description of the embodiments of this application, should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral arrangement; it can be a direct connection or an indirect connection through an intermediate medium; it can be a relationship of two components combined together, an interaction relationship between two components, or a connection within two structures. Those skilled in the art to which this application pertains can understand the specific meaning of the above terms in the embodiments of this application according to the specific circumstances.

[0062] Example 1

[0063] See Figure 1 The present invention provides a method for mobile station traffic transmission based on the combination of NTN satellite and 5G-A base station, comprising the following steps:

[0064] S1. When the mobile station is connected to the 5G-A base station, it detects the downlink quality and its own power headroom (PHR) with the 5G-A base station, and determines whether the downlink quality is lower than a first preset threshold and its own power headroom is zero. If so, the mobile station initiates a control plane connection to the NTN satellite. The uplink quality is evaluated based on at least one of the following parameters: the reference signal received power of the 5G-A base station, the signal-to-interference-plus-noise ratio, the uplink transmission bit error rate, or the uplink retransmission rate.

[0065] In this embodiment, the first preset threshold is when the reference signal received power RSRP < -110dBm and the signal-to-interference-plus-noise ratio SINR < -3dB, and this condition persists for a time T1 of 5 seconds. Alternatively, the reference signal received power RSRP < -113dBm, and this condition persists for a time T1 of 5 seconds.

[0066] S2. After the mobile station establishes a control plane connection with the NTN satellite, the mobile station sends its location information and measurement reports of surrounding 5G-A base stations to the NTN satellite.

[0067] In this embodiment, the measurement report includes: the physical cell identifier of the detectable 5G-A base station, the reference signal received power measurement value of each 5G-A base station, the signal-to-interference-plus-noise ratio measurement value of each 5G-A base station, and the signal arrival time difference of each 5G-A base station.

[0068] S3 and NTN satellites receive the location information of the mobile station and the measurement reports of the surrounding 5G-A base stations, and forward them to the ground gateway station;

[0069] S4. Based on the received location information and measurement report, the ground gateway station selects at least one 5G-A base station from its surrounding 5G-A base stations to form a cooperative set. It then determines whether the downlink quality of all 5G-A base stations in the cooperative set is lower than a second preset threshold. If so, the NTN satellite is responsible for transmitting the mobile station's user plane data and connecting it to the core network. In this embodiment, the second preset threshold is defined as follows: when the reference signal received power (RSRP) is less than -115 dBm and the signal-to-interference-plus-noise ratio (SINR) is less than -3 dB, and this condition persists for a duration of T2 for 5 seconds; or when the reference signal received power (RSRP) is less than -118 dBm, and this condition persists for a duration of T2 for 5 seconds.

[0070] Furthermore, selecting at least one 5G-A base station to form a cooperative set includes the following steps: filtering 5G-A base stations whose path loss estimate with the mobile station is less than a loss threshold to obtain a first set of data; excluding 5G-A base stations in the first set of data whose current load exceeds a preset load ratio to obtain a second set of data; and selecting N 5G-A base stations with the best signal quality from the second set of data, where N is an integer from 1 to 4.

[0071] Furthermore, in step S4, if the downlink quality of all 5G-A base stations in the cooperative set is lower than the second preset threshold, it is determined whether the 5G-A base stations in the cooperative set meet the replication transmission requirements. If so, the 5G-A base stations in the cooperative set that meet the replication transmission requirements are responsible for replicating and transmitting the downlink data of the mobile station; if not, the NTN satellite is responsible for transmitting the user plane data of the mobile station.

[0072] S5. The mobile station continues to monitor its surrounding 5G-A base stations until the ground gateway station determines that there are 5G-A base stations in the cooperative group with downlink quality not lower than the second preset threshold. Then, the 5G-A base stations in the cooperative group with downlink quality not lower than the second preset threshold are responsible for segmenting and transmitting the mobile station's downlink data.

[0073] In this embodiment, the above-described mobile station traffic transmission method based on the combination of NTN satellite and 5G-A base station is applied to the following systems, such as... Figure 2 As shown, the system comprises four main components:

[0074] Mobile Station 1 (UE): A dual-mode mobile terminal capable of simultaneously connecting to both NTN satellites and terrestrial 5G-A base stations. It integrates a satellite communication antenna and a cellular network antenna, supporting the measurement and reporting of wireless parameters from surrounding base stations. Specifically, the mobile station includes a satellite communication module, a cellular communication module, and a joint processor. In this scheme, when connected to a 5G-A base station, it detects the downlink quality and its own power headroom (PHR) with the 5G-A base station, and determines whether the downlink quality is below a first preset threshold and its own power headroom is zero. If so, the mobile station initiates a control plane connection via the NTN satellite. After establishing a control plane connection with the NTN satellite, the mobile station sends its location information and measurement reports from surrounding 5G-A base stations to the NTN satellite and continues to monitor surrounding 5G-A base stations.

[0075] NTN Satellite 2, a low-Earth orbit satellite (500-2000km altitude) employing transparent relay mode, includes a phased array antenna and a frequency converter transponder, responsible for relaying control signaling for mobile stations. The satellite system connects to the ground gateway station and accesses the 5G core network control plane functions. In this scheme, it is used to forward the location information received from the mobile station and measurement reports from surrounding 5G-A base stations to the ground gateway station.

[0076] Ground gateway station 4 includes a satellite-ground coordination controller, responsible for collaborative decisions such as mobile station location tracking, satellite access control, base station selection, and resource allocation. This entity interacts with 5G core network functions such as AMF and SMF to obtain network status information. In this scheme, it is used to select at least one 5G-A base station from its surrounding 5G-A base stations to form a cooperative set based on the received location information and measurement reports. It determines whether the downlink quality of all 5G-A base stations in the cooperative set is lower than a second preset threshold. If so, the NTN satellite is responsible for transmitting the mobile station's user plane data and accessing the core network. When it is determined that there is a 5G-A base station in the cooperative set with a downlink quality not lower than the second preset threshold, the 5G-A base station in the cooperative set with a downlink quality not lower than the second preset threshold is responsible for segmenting and transmitting the mobile station's downlink data.

[0077] The 5G-A base station cluster 3 comprises multiple 5G-A base stations, i.e., multiple gNodeB base stations deployed around the mobile station, interconnected via the Xn interface, supporting Cooperative Multipoint Transport (CoMP) technology to jointly provide downlink data services. The base station cluster is centrally scheduled by a central unit (CU) for resource pooling management. In this scheme, it is used to form a cooperative set under the scheduling of the ground gateway station. When there is a 5G-A base station in the cooperative set with downlink quality not lower than a second preset threshold, that 5G-A base station is responsible for segmenting and transmitting the mobile station's downlink data.

[0078] Example 2

[0079] See Figure 5 Based on the above embodiment 1, the specific implementation steps of the mobile station traffic transmission method based on NTN satellite and 5G-A base station of the present invention include:

[0080] Step 1: Uplink Restriction Detection and Satellite Access

[0081] The mobile station periodically measures the RSRP and SINR values ​​of the serving base station. If the downlink quality remains below a preset threshold (e.g., RSRP < -110dBm and SINR < 0dB, or RSRP < -113dBm) for a duration of T1 (e.g., 5 seconds) and the mobile station has zero power margin, it is determined to be in an uplink-limited state. The mobile station activates its satellite communication module and initiates a control plane connection request via the NTN satellite to complete the network registration and authentication process. At this time, the mobile station maintains downlink synchronization with the ground base station. The preset threshold can be issued by the network side or pre-configured by the terminal.

[0082] Step 2: Location Reporting and Base Station Selection

[0083] The mobile station reports its precise location information (GPS coordinates) and measurement reports from nearby detectable base stations (including PCI, RSRP, SINR, and other parameters of at least the three strongest base stations) to the ground-based satellite-ground cooperative controller via a satellite link. The satellite-ground cooperative controller selects the set of base stations to participate in the cooperation based on the following criteria:

[0084] 1. Path loss estimate between base station and mobile station;

[0085] 2. Current load status of each base station;

[0086] 3. Transmission delay difference between base stations (must be less than the threshold to ensure synchronization). This mainly relies on the deep integration of 5G-A's dual / multi-connectivity technology (NR-DC) and carrier aggregation, as well as the multi-radio link parallel processing capability of the mobile phone baseband chip.

[0087] 4. Typically, 1-4 base stations are selected to form a cooperative set, including the cell where the mobile station is currently camped as the main base station.

[0088] It should be noted that the weights of RSRP, load, and latency vary depending on the specific service and should be configured according to the actual service requirements. In this scheme, the candidate base station list is traversed, excluding the currently serving base station. The distance and path loss between the candidate base station and the mobile station are calculated, and base stations with path loss less than a threshold (e.g., 150dB) and current load less than a preset proportion (e.g., 70%) are selected. The base stations are sorted in descending order of RSRP, and the top N base stations (N is 1-4) are selected as the cooperative set.

[0089] Step 3: Establish control plane and user plane

[0090] The control plane establishes PDU sessions via satellite links, allowing the satellite ground station to access the 5G core network control plane functions (AMF / SMF). The user plane establishes data radio bearers (DRBs) through multiple selected base stations, each allocated dedicated time and frequency resources for transmitting data to mobile stations. The satellite-ground coordination controller generates differentiated scheduling policies for each base station, including: power allocation ratio, modulation and coding scheme (MCS) level, and time slot allocation mode.

[0091] In this embodiment, as Figure 3 As shown, the processing differences between satellite links and base station links at different protocol layers are compared, as detailed below:

[0092] UE-side signaling initiation: The UE generates NAS signaling, which is encapsulated sequentially through RRC, PDCP, RLC, MAC, and PHY layers, and then transmitted to the satellite via the NR-Uu air interface.

[0093] Transparent satellite forwarding: The satellite only performs radio frequency / physical layer transparent transmission, does not process the protocol stack, and forwards the signal to the NTN gateway.

[0094] NTN Gateway Transparent Transmission: The gateway also transparently forwards the signal to the ground gNB.

[0095] gNB protocol processing and forwarding: gNB decapsulates the signaling layer by layer from PHY upwards to restore RRC / NAS signaling; then, through the NG-C interface, it encapsulates the signaling through NGAP, SCTP, IP, and L2 / L1 layers and forwards the NAS signaling to the 5GC's AMF.

[0096] AMF signaling processing: AMF decapsulates the signaling layer by layer from L1 upwards, and finally parses the NAS signaling to complete the signaling interaction on the core network side.

[0097] The downlink process is executed in reverse: NAS signaling initiated by AMF travels along the reverse path (AMF→gNB→NTN gateway→satellite→UE), is encapsulated / decapsulated by the corresponding protocol stack, and is finally delivered to the UE.

[0098] Step 4: Collaborative Data Transfer

[0099] Multiple base stations transmit data synchronously according to a scheduling strategy, and mobile stations use joint reception technology to combine signals from different base stations. To reduce interference, adjacent base stations use different demodulation reference signal (DMRS) ports and scrambling sequences. Data offloading can be performed in the following two modes:

[0100] Copy transmission: The same data packets are sent simultaneously from multiple base stations, improving reliability;

[0101] Segmented transmission: Data packets are segmented and sent from different base stations to increase throughput.

[0102] In this embodiment, as Figure 4 As shown, the data offloading and aggregation steps of the multi-base station cooperative downlink are as follows: Step 1: The mobile station establishes an RRC connection with the master base station; Step 2: The master base station negotiates carrier aggregation resources with the cooperating base stations through the Xn interface; Step 3: The master base station offloads data to the master base station and cooperating base stations according to the mobile station's needs; Step 4: The master base station and cooperating base stations transmit data to the mobile station through different carriers; Step 5: The mobile station receives and aggregates the data streams from each base station.

[0103] Step 5: Dynamic Adjustment and Switching

[0104] The satellite-ground coordination controller continuously monitors the following parameters and dynamically adjusts the transmission strategy accordingly:

[0105] Satellite link quality (latency, bit error rate);

[0106] Base station-mobile station channel status;

[0107] Changes in service QoS requirements.

[0108] When the primary base station changes or the members of the cooperative set change, the handover process is coordinated through the satellite control plane to ensure user plane continuity. If downlink is also restricted, the user plane also switches to satellite communication, while simultaneously detecting downlink quality. Once the downlink quality meets the usage conditions, the user plane switches back to the base station.

[0109] Dynamically adjust the proportion of satellite and base station resources according to service type:

[0110] For session-based services (such as VoNR): satellite resources are allocated fixed bandwidth for SIP signaling; base station resources ensure low-latency and high-reliability transmission, using a replication transmission mode.

[0111] For interactive services (such as web browsing): satellite resources are used only for TCP control messages; base station resources adopt a segmented transmission mode to improve throughput.

[0112] Background services (such as file downloads): satellite resources are used to the minimum (only keep-alive signaling is used); base station resources aggregate all available bandwidth and adopt frequency division multiplexing mode.

[0113] Example 3

[0114] Taking an emergency communication scenario in a mountainous area as an example, the specific application of this invention is illustrated below:

[0115] Scenario Description: Rescue team members carrying a dual-mode terminal supporting this invention enter a mountainous area. Uplink to the ground base station in this area is restricted (due to mountain obstruction), but downlink signals are still receivable. The terminal detects that the downlink RSRP has dropped to -115dBm and its own power margin is zero, triggering a satellite connection.

[0116] Control plane establishment: The terminal establishes a control plane connection via NTN satellite and reports its location (22.302587°N, 102.506474°E) and measurement information from surrounding base stations. The satellite-ground cooperative controller selects three visible base stations (PCI101 / 203 / 307) to form a cooperative set.

[0117] User plane transmission:

[0118] Video transmission: Base stations 101 and 203 use a copy transmission mode to send real-time video streams to ensure reliability;

[0119] File download: Three base stations jointly provide 20MHz bandwidth, with peak rates reaching 80-200Mbps;

[0120] Location update: Precise location information is sent via satellite every 30 seconds.

[0121] Dynamic adjustment: When the team members move to the other side of the hillside, the PCI307 signal weakens, the satellite-ground coordination controller removes it from the cooperation set, and adds a new PCI412 base station. The handover process is seamless for the service.

[0122] This embodiment shows that, compared with a pure satellite communication solution, the present invention can provide more than 10 times the data rate, while reducing satellite traffic consumption by 90%; compared with the traditional terrestrial solution, the communication coverage is significantly expanded.

[0123] The core innovation of this invention lies in: creatively distinguishing the transmission needs of the control plane and the user plane in uplink-limited scenarios, utilizing the wide coverage characteristics of satellites to ensure reliable transmission of control signaling, and at the same time making full use of the downlink resources of the terrestrial network through multi-base station cooperation to achieve optimal resource allocation and maximize user experience.

[0124] Example 4

[0125] This application provides a communication device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, it implements the steps of the mobile station traffic transmission method based on the combination of NTN satellite and 5G-A base station.

[0126] Unlike existing technologies, the technical solution of this application embeds the aforementioned method into a communication device in the form of a computer program. This provides an alternative implementation method besides dedicated terminals, enabling existing general-purpose communication devices (such as base stations, core network equipment, and terminals with software-defined capabilities) to acquire the satellite-ground cooperative transmission capability defined in this invention through software upgrades, thereby reducing deployment costs and lowering the barriers to promotion.

[0127] Example 5

[0128] This application provides a computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the steps of the mobile station traffic transmission method based on the combination of NTN satellite and 5G-A base station.

[0129] Unlike existing technologies, the technical solution of this application protects the aforementioned method in the form of a computer-readable storage medium. This covers the software implementation of the method, preventing others from implementing the invention through software distribution, pre-installation, or other means without producing physical equipment, thus further strengthening the scope of patent protection and its commercial value.

[0130] Finally, it should be noted that although the above embodiments have been described in the text and drawings of this application, this should not limit the scope of patent protection of this application. Any technical solutions that are based on the essential concept of this application and utilize the content described in the text and drawings of this application, resulting in equivalent structural or procedural substitutions or modifications, as well as the direct or indirect application of the technical solutions of the above embodiments to other related technical fields, are all included within the scope of patent protection of this application.

Claims

1. A method for mobile station traffic transmission based on the combination of NTN satellite and 5G-A base station, characterized in that, Includes the following steps: S1. When the mobile station is connected to the 5G-A base station, it detects the downlink quality and its own power margin with the 5G-A base station, and determines whether the downlink quality is lower than the first preset threshold and its own power margin is zero. If so, the mobile station initiates a control plane connection to the NTN satellite. S2. After the mobile station establishes a control plane connection with the NTN satellite, the mobile station sends its location information and measurement reports of surrounding 5G-A base stations to the NTN satellite. S3 and NTN satellites receive the location information of the mobile station and the measurement reports of the surrounding 5G-A base stations, and forward them to the ground gateway station; S4. Based on the received location information and measurement report, the ground gateway station selects at least one 5G-A base station from its surrounding 5G-A base stations to form a cooperative set. It determines whether the downlink quality of the 5G-A base stations in the cooperative set is lower than the second preset threshold. If so, the NTN satellite is responsible for transmitting the user plane data of the mobile station and accessing the core network. S5. The mobile station continues to monitor its surrounding 5G-A base stations until the ground gateway station determines that there are 5G-A base stations in the cooperative group with downlink quality not lower than the second preset threshold. Then, the 5G-A base stations in the cooperative group with downlink quality not lower than the second preset threshold are responsible for segmenting and transmitting the mobile station's downlink data.

2. The mobile station traffic transmission method based on the combination of NTN satellite and 5G-A base station as described in claim 1, characterized in that, In step S4, if the downlink quality of all 5G-A base stations in the cooperative set is lower than the second preset threshold, it is determined whether the 5G-A base stations in the cooperative set meet the replication transmission requirements. If yes, the 5G-A base stations in the cooperative set that meet the replication transmission requirements are responsible for replicating and transmitting the downlink data of the mobile station; if no, the NTN satellite is responsible for transmitting the user plane data of the mobile station.

3. The mobile station traffic transmission method based on the combination of NTN satellite and 5G-A base station according to claim 1, characterized in that, The uplink quality in step S1 is evaluated based on at least one of the following parameters: the reference signal received power of the 5G-A base station, the signal-to-interference-plus-noise ratio, the uplink transmission bit error rate, or the uplink retransmission rate.

4. The mobile station traffic transmission method based on the combination of NTN satellite and 5G-A base station according to claim 1, characterized in that, The measurement report in step S2 includes: the physical cell identifier of the detectable 5G-A base station, the reference signal received power measurement value of each 5G-A base station, the signal-to-interference-plus-noise ratio measurement value of each 5G-A base station, and the signal arrival time difference of each 5G-A base station.

5. The mobile station traffic transmission method based on the combination of NTN satellite and 5G-A base station according to claim 1, characterized in that, In step S4, at least one 5G-A base station is selected to form a cooperative set, including the following steps: 5G-A base stations whose estimated path loss with the mobile station is less than the loss threshold are selected to obtain the first set of data. Exclude 5G-A base stations in the first set of data whose current load exceeds a preset load ratio to obtain the second set of data; Select N 5G-A base stations with the best signal quality from the second set of data, where N is an integer from 1 to 4.

6. A mobile station traffic transmission system based on the combination of NTN satellite and 5G-A base station, characterized in that, include: The mobile station, when connected to a 5G-A base station, detects its downlink quality and its own power margin with the 5G-A base station, and determines whether the downlink quality is lower than a first preset threshold and its own power margin is zero. If so, the mobile station initiates a control plane connection via the NTN satellite. After the mobile station establishes a control plane connection with the NTN satellite, it sends its location information and measurement reports of surrounding 5G-A base stations to the NTN satellite, and continues to monitor its surrounding 5G-A base stations. NTN satellites are used to forward location information and measurement reports of nearby 5G-A base stations received from mobile stations to ground gateway stations; The ground gateway station is used to select at least one 5G-A base station from its surrounding 5G-A base stations to form a cooperative set based on the received location information and measurement report. It determines whether the downlink quality of the 5G-A base stations in the cooperative set is lower than the second preset threshold. If so, the NTN satellite is responsible for transmitting the user plane data of the mobile station and accessing the core network. When it is determined that there is a 5G-A base station in the cooperative set with a downlink quality not lower than the second preset threshold, the 5G-A base station in the cooperative set with a downlink quality not lower than the second preset threshold shall be responsible for segmenting and transmitting the downlink data of the mobile station. A 5G-A base station cluster, comprising multiple 5G-A base stations, is used to form a cooperative set under the scheduling of a ground gateway station. When there is a 5G-A base station in the cooperative set with a downlink quality not lower than the second preset threshold, the 5G-A base station in the cooperative set with a downlink quality not lower than the second preset threshold is responsible for segmenting and transmitting the downlink data of the mobile station.

7. The mobile station traffic transmission system based on the combination of NTN satellite and 5G-A base station as described in claim 6, characterized in that, The ground gateway station is also used to determine whether the 5G-A base stations in the cooperative set meet the replication transmission requirements if the downlink quality of all 5G-A base stations in the cooperative set is lower than the second preset threshold. If yes, the 5G-A base stations in the cooperative set that meet the replication transmission requirements are responsible for replicating and transmitting the downlink data of the mobile station; if no, the NTN satellite is responsible for transmitting the user plane data of the mobile station.

8. The mobile station traffic transmission system based on the combination of NTN satellite and 5G-A base station as described in claim 6, characterized in that, The uplink quality in step S1 is evaluated based on at least one of the following parameters: the reference signal received power of the 5G-A base station, the signal-to-interference-plus-noise ratio, the uplink transmission bit error rate, or the uplink retransmission rate.

9. The mobile station traffic transmission system based on the combination of NTN satellite and 5G-A base station as described in claim 6, characterized in that, The measurement report in step S2 includes: the physical cell identifier of the detectable 5G-A base station, the reference signal received power measurement value of each 5G-A base station, the signal-to-interference-plus-noise ratio measurement value of each 5G-A base station, and the signal arrival time difference of each 5G-A base station.

10. The mobile station traffic transmission system based on the combination of NTN satellite and 5G-A base station as described in claim 6, characterized in that, The ground gateway station is also used to filter 5G-A base stations whose path loss estimate with respect to the mobile station is less than the loss threshold to obtain a first set of data; exclude 5G-A base stations in the first set of data whose current load exceeds a preset load ratio to obtain a second set of data; and select N 5G-A base stations with the best signal quality from the second set of data, where N is an integer from 1 to 4.

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