Mobility management system and mobility management method for base station

Abstract

The present disclosure provides a mobility management system and a mobility management method of a base station. In the mobility management system and the mobility management method of the base station: position data of a target terminal connected in a cell of the base station is acquired, and a motion trajectory of the terminal and a speed of the terminal are generated based on the acquired position data; a specific trajectory model satisfying a first preset condition in matching degree is selected from at least one trajectory model corresponding to the speed of the terminal based on a matching degree of the motion trajectory of the terminal relative to the at least one trajectory model; an initial matching degree of the motion trajectory of the terminal relative to the specific trajectory model is obtained; future position data of the terminal is predicted; the initial matching degree is updated; and it is determined whether the terminal will be connected to another base station.

Description

Technical Field

[0001] This disclosure generally relates to mobile communications, and more specifically, to a mobility management system and mobility management method for a base station. Background Technology

[0002] Current serving base stations lack predictive capabilities for terminal mobility management. Current terminal mobility management relies on cell measurement control of the terminal. To this end, the terminal continuously measures physical quantities in its own cell and neighboring cells and reports these measurements to the base station. The base station then determines, based on the specific circumstances, whether the terminal should remain in its current cell or initiate a handover to a neighboring base station (“cell”) (hereinafter referred to as “terminal handover” or “cell handover”), thereby achieving mobility management.

[0003] With increasingly faster transportation speeds, high-speed rail, for example, at 350 km / h, is already widespread worldwide. Currently, the fifth-generation new radio frequency range 2 (5G NR FR2) band has reached 36 GHz to 71 GHz, and the Asia-Pacific Hertz band, such as 140 GHz to 300 GHz and 0.1 THz to 10 THz, will be put into use in the future. The loss function Lbs for radio wave propagation in free space, as a function of frequency F and distance D, can be calculated as follows: Lbs = 32.45 + 20lgF (MHz) + 20lgD (km). Therefore, the higher the frequency and speed, the higher the signal loss, and the worse the timeliness of cell measurements performed by the terminal. Consequently, the accuracy of current channel measurements decreases, leading to increasingly inaccurate judgments made by base stations based on past measurements regarding the present time.

[0004] Frequent cell measurements by both the terminal and the base station lead to increased power consumption. Generally, once a terminal connects to a cell, the base station configures the terminal with measurement control messages. Since the base station doesn't know the terminal's exact location, it also doesn't know when the terminal will move to the cell edge. Therefore, in current mobile communication systems, the terminal continuously performs measurements before handover. When the terminal moves to the cell edge and sends a measurement report to the base station, the base station performs mobility management to enable the terminal to hand over to a nearby cell. These measurements are performed at a frequency measured in milliseconds and continue until the handover is complete. When the terminal is on a high-speed train, handovers become very frequent, inevitably leading to continuous measurements and significantly increasing power consumption. This is the primary reason why mobile phones consume so much power when used on high-speed trains. With the increasing prevalence and usage of mobile phones, this increased power consumption is inconsistent with current and future development concepts of low-carbon and environmentally friendly output, environmental protection, and green technology.

[0005] In addition, the current switching process has the problem of brief service interruptions, which has a significant impact on latency-sensitive services (such as real-time games) and results in a poor user experience on the terminal. Summary of the Invention

[0006] According to one aspect of this disclosure, a mobility management system for a base station includes: a data acquisition circuit configured to acquire location data of a connected target terminal in a cell of the base station, and generate a motion trajectory of the target terminal and determine the speed of the target terminal based on the acquired location data; a trajectory model selection circuit configured to select a specific trajectory model whose matching degree satisfies a first preset condition from the at least one trajectory model based on the matching degree of the target terminal's motion trajectory relative to at least one trajectory model corresponding to the speed of the target terminal, and obtain an initial matching degree of the target terminal's motion trajectory relative to the specific trajectory model; and a mobility management circuit configured to predict future location data of the target terminal based on the specific trajectory model, update the initial matching degree based on the predicted future location data, and determine whether the target terminal will be connected to another base station based on the updated matching degree and the specific trajectory model. The at least one trajectory model can define a trajectory for a terminal switching from the base station to a different base station while traveling at a determined speed, with the endpoint being the location at the time of the switchover.

[0007] Each of the following options can be implemented individually or in combination with at least one of the other options.

[0008] Optionally, the trajectory model selection circuit can be configured to determine the matching degree of the motion trajectory of the target terminal relative to the at least one preset trajectory model by determining the degree of overlap between the motion trajectory of the target terminal and each of the at least one trajectory model.

[0009] The mobility management system may further include: a trajectory storage circuit configured to store a predefined motion trajectory of the target terminal in the cell as one of the motion trajectories corresponding to the speed of the target terminal and the other base station when the target terminal switches to the other base station, wherein the predefined motion trajectory may be a set of location data that has passed through a predetermined time period from the switching time.

[0010] The trajectory storage circuit can also be configured to generate and store trajectory models by: extracting at least one motion trajectory from one or more motion trajectories stored for a specific base station, wherein the speeds corresponding to the extracted motion trajectories do not exceed a preset speed error and the motion directions of the extracted motion trajectories do not exceed a preset direction error; synthesizing the extracted motion trajectories into a single trajectory; and storing the synthesized trajectory as a trajectory model for the specific base station, and storing the speed statistics corresponding to the speeds of the extracted motion trajectories as speeds corresponding to the trajectory model for the specific base station.

[0011] The trajectory storage circuit can also be configured to regenerate and store the trajectory model when predetermined update conditions are met, wherein the predetermined update conditions may include at least one of the following: the number of motion trajectories stored for a specific base station reaches a predetermined number, a predetermined time period has elapsed, and a new base station appears in the neighboring cell of the base station.

[0012] The mobility management circuit can be configured to determine that the target terminal will be connected to the other base station when the updated matching degree meets a second preset condition.

[0013] The second preset condition may include at least one preset threshold condition that increases progressively, wherein: when the current matching degree of the target terminal's motion trajectory relative to the specific trajectory model meets the current level's preset threshold condition, the data acquisition circuit may acquire the target terminal's next location data at time intervals corresponding to the current level's preset threshold condition, and the mobility management circuit may update the current matching degree based on the comparison between the predicted next location data and the acquired next location data, and may determine whether the updated matching degree meets the next level's preset threshold condition; when the matching degree of the target terminal's motion trajectory relative to the specific trajectory model meets all preset threshold conditions, the mobility management circuit may determine that the target terminal will be connected to the other base station.

[0014] The mobility management circuit can be configured to update the current matching degree in the following ways: if the distance between the predicted next location data and the acquired next location data does not exceed a preset distance error, then the current matching degree is increased by a first preset value; if the distance between the predicted next location data and the acquired next location data exceeds a preset distance error, then a second preset value is subtracted from the current matching degree.

[0015] The mobility management circuit can be configured to perform mobility management on the target terminal according to a traditional protocol when the current matching degree of the target terminal's motion trajectory relative to the specific trajectory model does not meet the preset threshold condition of the current level.

[0016] When it is determined that the target terminal will be connected to the other base station, the target terminal can be connected to the other base station through dual connectivity or Cooperative Multipoint (CoMP) configuration.

[0017] After the specific trajectory model is selected, the data acquisition circuit can be configured to acquire the location data of the target terminal in the cell at time intervals longer than before the specific trajectory model was selected.

[0018] According to another aspect of this disclosure, a mobility management method for a base station is provided. The mobility management method may include: acquiring location data of a connected target terminal within a cell of the base station, and generating a motion trajectory of the target terminal and determining the speed of the target terminal based on the acquired location data; selecting a specific trajectory model from the at least one trajectory model whose matching degree satisfies a first preset condition based on the matching degree of the target terminal's motion trajectory relative to at least one trajectory model corresponding to the speed of the target terminal, and obtaining an initial matching degree of the target terminal's motion trajectory relative to the specific trajectory model; predicting future location data of the target terminal based on the specific trajectory model, updating the initial matching degree based on the predicted future location data, and determining whether the target terminal will be connected to another base station corresponding to the specific trajectory model based on the updated matching degree. The at least one trajectory model may define a trajectory for a terminal switching from the base station to a different base station while traveling at a determined speed, with the endpoint being the location at the time of the switchover.

[0019] The matching degree of the motion trajectory of the target terminal relative to the at least one trajectory model can be determined by determining the degree of overlap between the motion trajectory of the target terminal and each of the at least one trajectory model.

[0020] The mobility management method may further include: when the target terminal switches to the other base station, storing the predefined motion trajectory of the target terminal in the cell as one of the motion trajectories corresponding to the speed of the target terminal and the other base station, wherein the predefined motion trajectory is a set of location data that has passed through a predetermined time period before the handover time.

[0021] The mobility management method may further include generating and storing a trajectory model by: extracting at least one motion trajectory from one or more motion trajectories stored for a specific base station, wherein the speeds corresponding to the extracted motion trajectories do not exceed a preset speed error and the motion directions of the extracted motion trajectories do not exceed a preset direction error; synthesizing the extracted motion trajectories into a single trajectory; and storing the synthesized trajectory as a trajectory model for the specific base station, and storing the speed statistics corresponding to the speeds of the extracted motion trajectories as speeds corresponding to the trajectory model for the specific base station.

[0022] The mobility management method may further include: regenerating and storing the trajectory model when predetermined update conditions are met, wherein the predetermined update conditions include at least one of the following: the number of motion trajectories stored for a specific base station reaches a predetermined number, a predetermined time period has elapsed, and a new base station appears in the neighboring cell of the base station.

[0023] When the updated matching degree meets the second preset condition, it can be determined that the target terminal will be connected to the other base station.

[0024] The second preset condition may include at least one preset threshold condition that increases progressively, wherein: when the current matching degree of the target terminal's motion trajectory relative to the specific trajectory model meets the preset threshold condition of the current level, the future location data of the target terminal is acquired at time intervals corresponding to the preset threshold condition of the current level, and the current matching degree is updated based on the comparison between the predicted future location data and the acquired future location data, and it is determined whether the updated matching degree meets the preset threshold condition of the next level; when the matching degree of the target terminal's motion trajectory relative to the specific trajectory model meets all preset threshold conditions, it is determined that the target terminal will be connected to the other base station.

[0025] The step of updating the current matching degree may include: if the distance between the predicted future location data and the acquired future location data does not exceed a preset distance error, then the current matching degree is increased by a first preset value; if the distance between the predicted future location data and the acquired future location data exceeds a preset distance error, then a second preset value is subtracted from the current matching degree.

[0026] When the current matching degree of the target terminal's motion trajectory relative to the specific trajectory model does not meet the preset threshold condition of the current level, the target terminal can be managed for mobility according to the traditional protocol.

[0027] When it is determined that the target terminal will be connected to the other base station, the target terminal can be connected to the other base station through dual connectivity or Cooperative Multipoint (CoMP) configuration.

[0028] After the specific trajectory model is selected, the location data of the target terminal in the cell can be obtained at a longer time interval than before the specific trajectory model was selected.

[0029] The mobility management methods outlined above can be similarly expanded by operating according to the options described above for application to mobility management systems.

[0030] According to another aspect of this disclosure, a computer-readable storage medium is provided, wherein computer program instructions are stored on the computer-readable storage medium, which, when executed by a processor, cause a base station to implement the mobility management method described above.

[0031] According to various embodiments of this disclosure, by employing trajectory models for terminal mobility management, not only can the power consumption of base stations and terminals be reduced, but the user experience of the terminals can also be improved. Attached Figure Description

[0032] The above and other aspects, features and advantages of this disclosure will be more clearly understood from the following description of exemplary embodiments in conjunction with the accompanying drawings, wherein:

[0033] Figure 1 This is a diagram illustrating cell handover based on downlink reference signal measurements, as shown in the comparative example.

[0034] Figure 2 This is a schematic block diagram illustrating a communication system of a base station according to an exemplary embodiment of the present disclosure;

[0035] Figure 3 This is a diagram illustrating the process of generating / updating and applying a trajectory model according to an exemplary embodiment of the present disclosure;

[0036] Figure 4 These are example schematic diagrams illustrating application scenarios of a communication system according to exemplary embodiments of the present disclosure; and

[0037] Figure 5 This is a flowchart illustrating a communication method of a base station according to an exemplary embodiment of the present disclosure. Detailed Implementation

[0038] Figure 1 This is a diagram illustrating cell handover based on downlink reference signal measurements, as shown in the comparative example.

[0039] like Figure 1 As shown, traditional mobility management can be simply divided into the following three processes: measurement configuration process, terminal measurement execution and reporting process, and handover process.

[0040] During measurement configuration, the source cell base station can send downlink reference signal measurement control to the terminal. During terminal measurement execution and reporting, the terminal can perform downlink reference signal strength measurement at a specific frequency. When the measurement meets the measurement reporting threshold, the terminal can send a measurement report to the base station. During handover, the source cell base station can send terminal service and configuration data to the target cell base station and can send a cell handover command to the terminal. Subsequently, the terminal can disconnect from the source cell and establish a connection with the target cell to complete the cell handover.

[0041] However, for terminals at the cell edge, especially those moving rapidly, the attenuation of antenna beam energy in the air interface (the free-space path between the terminal and the base station) becomes more pronounced as radio spectrum frequencies increase to the FR2 band, Asia Pacific Hertz, and even terahertz band. Furthermore, channel parameters change more rapidly and drastically, exposing more shortcomings in current wireless mobile communication mobility management processes defined by protocols such as 3GPP. Using traditional technologies, the energy consumption of both the terminal and the base station is also difficult to control.

[0042] Embodiments of this invention provide a "multi-base station" prediction mechanism for terminal mobility management at the cell edge (a prediction mechanism implemented by each of multiple base stations in the network). Future networks (e.g., 6G networks) will natively possess artificial intelligence (AI) and machine learning (ML). Each base station can be trained based on a large amount of previously processed terminal information data to analyze terminal behavior and generate a final behavioral model. For example, each base station can have a truly self-optimizing network parameter function. Each base station can generate its own unique behavioral model to predict the mobility management of terminals that conform to the behavioral model, thereby reducing the measurement frequency between base stations and terminals, and thus reducing energy consumption. Furthermore, terminals preparing for handover at the cell edge can be pre-configured into states such as dual connectivity (DC) or CoMP (Cooperative Multipoint Transmission / Reception), allowing terminal services to handover without interruption, thereby improving the user experience. The following will combine... Figures 2 to 5 A mobility management system and mobility management method for a base station according to exemplary embodiments of the present disclosure are described in detail.

[0043] Figure 2 This is a schematic block diagram illustrating a mobility management system 200 for a base station according to an exemplary embodiment of the present disclosure.

[0044] The mobility management system 200 according to an exemplary embodiment can be installed in various base stations to realize mobility management of terminals. The mobility management system 200 may include a data acquisition circuit 210, a trajectory model selection circuit 220, and a mobility management circuit 230.

[0045] The data acquisition circuit 210 can acquire the location data of the connected target terminal within the cell of the base station, and generate the target terminal's motion trajectory and determine its speed based on the acquired location data. The base station may have the capability to "locate" the terminal (determine its position) and can acquire the target terminal's location data. For example, after the target terminal enters the cell, when the target terminal moves within the cell, or after obtaining permission from the terminal user, the base station can acquire the target terminal's location data at a default time interval or a "first time interval" (e.g., every 10 ms) (the first time interval may be dynamically determined). For example, the data acquisition circuit 210 can estimate the angle of arrival α based on the uplink direction of arrival of the target terminal (e.g., based on the uplink sounding reference signal (SRS) or a reference signal used for base station demodulation), and then estimate the distance d between the terminal and the base station based on the terminal's uplink arrival delay, thereby acquiring the target terminal's location data. Furthermore, the data acquisition circuit 210 can determine the target terminal's speed based on the time interval for acquiring the location data and the acquired location data. The resulting motion trajectory of the target terminal can be a set of location data or a continuous trajectory fitted based on the location data.

[0046] The trajectory model selection circuit 220 can select a specific trajectory model whose matching degree satisfies a first preset condition from the at least one trajectory model based on the matching degree of the target terminal's motion trajectory relative to at least one trajectory model corresponding to the target terminal's speed, and obtain the initial matching degree of the target terminal's motion trajectory relative to the specific trajectory model. Here, the at least one trajectory model can define the trajectory of a terminal moving at a determined speed while switching from this base station to another base station, with the end point being the position at the time of the switch. The trajectory model selection circuit 220 can start selecting a trajectory model for the target terminal when the target terminal moves to a predetermined edge area of ​​the cell, when the target terminal exceeds a predetermined speed, or when the network signal of the target terminal is poor. Optionally, when the target terminal is connected to a base station of the cell ("connected to the cell"), the trajectory model selection circuit 220 can continuously select a trajectory model for the target terminal in the cell.

[0047] For example, the trajectory model selection circuit 220 can determine the matching degree of the target terminal's motion trajectory relative to the at least one trajectory model by determining the degree of overlap between the target terminal's motion trajectory and the trajectory of each of the at least one trajectory model. For example, the trajectory model selection circuit 220 can determine the matching degree as the ratio of the overlap between the target terminal's motion trajectory and the length of each trajectory model to the length of the corresponding trajectory model. For example, the trajectory model selection circuit 220 can select at least one trajectory model from multiple trajectory models whose matching degree satisfies a first preset condition (e.g., 30%), and select a trajectory model from the selected at least one trajectory model whose speed is the same as the target terminal's speed as the specific trajectory model. As another example, the trajectory model selection circuit 220 can select at least one trajectory model from multiple trajectory models whose speed is the same as the target terminal's speed, and select a trajectory model from the selected at least one trajectory model whose matching degree satisfies the first preset condition.

[0048] Mobility management circuit 230 can predict the future location data (e.g., next location data) of the target terminal based on the specific trajectory model, update the initial matching degree based on the predicted future location data, and determine whether the target terminal will be connected to another base station corresponding to the specific trajectory model based on the updated matching degree. When the updated matching degree meets a second preset condition, mobility management circuit 230 can determine that the target terminal will be connected to the other base station (assuming that the other base station can handle the connection with the target terminal). When the updated matching degree does not meet the second preset condition, mobility management circuit 230 can perform mobility management on the target terminal according to a conventional protocol (e.g., 3GPP protocol).

[0049] In an exemplary embodiment of this disclosure, multiple specific trajectory models may be selected based on the first preset condition. In this case, the mobility management circuit 230 can perform the above operations on the multiple specific trajectory models at the same time. When the updated matching degree does not meet the first preset condition, the application of the corresponding specific trajectory model can be terminated.

[0050] Here, the aforementioned second preset condition may include at least one preset threshold condition that increases progressively. For example, the at least one preset threshold condition may be 30% (first level), 60% (second level), and 90% (third level). In another example, this is simply a threshold. When the current matching degree of the target terminal's motion trajectory relative to the specific trajectory model meets the preset threshold condition of the current level, the data acquisition circuit 210 may acquire the target terminal's next location data at time intervals corresponding to the preset threshold condition of the current level, and the mobility management circuit 230 may update the current matching degree based on a comparison between the predicted next location data and the acquired next location data, and determine whether the updated matching degree meets the preset threshold condition of the next level. For example, when the current matching degree of the target terminal's motion trajectory relative to the specific trajectory model meets the first-level preset threshold condition, the data acquisition circuit 210 can acquire the target terminal's next location data at time intervals corresponding to the first-level preset threshold condition (e.g., a second time interval of 100ms). The mobility management circuit 230 can update the current matching degree based on a comparison between the next location data predicted by the specific trajectory model and the acquired next location data, and determine whether the updated matching degree meets the second-level preset threshold condition. When the matching degree meets the second-level preset threshold condition, the data acquisition circuit 210 can acquire the target terminal's next location data at time intervals corresponding to the second-level preset threshold condition (e.g., a third time interval of 200ms). When the matching degree meets the third-level preset threshold condition (>90%), the data acquisition circuit 210 can acquire the target terminal's next location data at even longer time intervals, or, in special circumstances, stop acquiring the target terminal's next location data (e.g., equivalent to the time interval corresponding to the third-level preset threshold condition being set to an infinitely long condition). Here, the time interval corresponding to the preset threshold condition can be increased as the level of the preset threshold condition increases, thereby reducing the increase in power consumption caused by frequent measurements by the terminal and the base station.

[0051] Mobility management circuit 230 can update the current matching degree in the following ways: If the distance between the predicted next location data and the acquired next location data does not exceed a preset distance error, mobility management circuit 230 can increase the current matching degree by a first preset value. If the distance between the predicted next location data and the acquired next location data exceeds the preset distance error, mobility management circuit 230 can subtract a second preset value from the current matching degree. Here, the preset distance error may be related to positioning accuracy, etc. The first preset value may be the same as or different from the second preset value. The first preset value and the second preset value may be related to the corresponding time interval for acquiring location data, etc.

[0052] When the matching degree of the target terminal's motion trajectory relative to the specific trajectory model meets all preset threshold conditions, the mobility management circuit 230 can determine that the target terminal will be connected to another base station corresponding to the specific trajectory model (assuming that the other base station can handle additional connections). When it is determined that the target terminal will be connected to the other base station, the target terminal can be connected to the other base station through dual connectivity (DC) or cooperative multipoint (CoMP) configuration. When the current matching degree of the target terminal's motion trajectory relative to the specific trajectory model does not meet the preset threshold conditions of the current level, the mobility management circuit 230 can perform mobility management on the target terminal according to conventional protocols (e.g., 3GPP protocols).

[0053] Furthermore, the mobility management system 200 may also include a trajectory storage circuit (not shown) to store predefined motion trajectories of the terminal and generate and store trajectory models. When the target terminal "switches" to the other base station (meaning the target terminal's connection switches to the other base station), the trajectory storage circuit can store the target terminal's predefined motion trajectory in the cell as a motion trajectory corresponding to the target terminal's speed and the other base station. The predefined motion trajectory may be a set of location data preceding the handover time period.

[0054] According to embodiments of this disclosure, a base station can allocate a fixed-size storage space to each terminal (e.g., terminal 1, terminal 2, etc.) accessing the cell to record the terminal's location data. To prevent terminals that remain in the cell for extended periods without switching from occupying too much storage space, a cyclic overwrite storage method can be used. Therefore, when the terminal's location data reaches the end of its allocated storage space, new location data for the terminal can be overwritten starting from the beginning of the storage space. When a terminal switches from the cell to a neighboring cell, the set of location data preceding the location data at the time of switching over a predetermined time period constitutes the terminal's final movement trajectory from the cell to the neighboring cell. For example, when terminal 1 moves from one base station to another, the base station can continuously store terminal 1's location data in the allocated storage space. When terminal 1 switches from one base station to the other, for example, the location information recorded at the last moment of switching is [α...]. ho ,d ho ], and 0 <= ho <= max (maximum size of storage space), the predefined motion trajectory of terminal 1 stored (backtracked and sorted) by this base station is: terminal 1 {[α max-ho ,d max-ho ],…,[α ho-1 ,d ho-1 ],[α ho ,d ho Here, the motion trajectory of terminal 1 can be labeled as "motion trajectory 1".

[0055] It should be noted that the above methods of storing terminal location data are only examples. Terminal location data can also be stored in other ways according to various factors such as base station capabilities and service needs.

[0056] According to embodiments of this disclosure, a base station can group the motion trajectories of all terminals switching to another base station into a single group, and the storage space for this group of motion trajectories can be labeled "Base Station Path 2". Similarly, if there are other base stations nearby (e.g., base station 3, base station 4, etc.), the storage space for the motion trajectories of terminals switching from this base station to other base stations can be labeled "Base Station Path X" (e.g., base station path 3, base station path 4, etc.). The base station can group the data of these terminals according to their paths and store them locally for the trajectory storage circuit to statistically analyze and extract feature values, and generate a trajectory model. Here, the feature values ​​can be the direction of the terminal's motion trajectory and the terminal's speed, etc., to classify the motion trajectories based on the terminal's direction and speed.

[0057] On the other hand, considering that the base station may not be able to record the movement trajectories of all terminals switching to the Xth base station indefinitely, the base station can allocate a fixed amount of storage space for each "base station path X". For example, the base station can record a maximum of UEmax terminals for each "base station path X". The storage space for each "base station path X" can also adopt a circular recording method. For example, when the storage space is full, the records can be overwritten from the beginning. For example, the movement trajectory of the (UEmax+1)th terminal can overwrite the movement trajectory of the first terminal.

[0058] Note that the above method of storing the movement trajectory of a terminal switching to base station X is only an example. The movement trajectory of a terminal switching to base station X can also be stored in other ways according to various factors such as the base station's capabilities and service needs.

[0059] Based on the aforementioned stored terminal motion trajectory, the trajectory storage circuit can generate and store a trajectory model in the following manner: Extract at least one motion trajectory from one or more motion trajectories stored for a specific base station, wherein the speeds corresponding to the extracted motion trajectories do not exceed a preset speed error, and the motion directions of the extracted motion trajectories do not exceed a preset direction error; synthesize the extracted motion trajectories into a single trajectory; and store the synthesized trajectory as a trajectory model for the specific base station, and store the speed statistics corresponding to the extracted motion trajectories as speeds corresponding to the trajectory model for the specific base station. For example, the process of generating and storing the trajectory model can be initiated after the storage space of "Base Station Path 2" of the base station is filled from empty. Furthermore, the preset speed error and the preset direction error can be set according to factors such as the positioning accuracy of the base station for the terminal.

[0060] Furthermore, considering the issue of data aging, the trajectory model storage circuit can also regenerate and store the trajectory model under predetermined update conditions; in other words, the stored trajectory model is updated. The predetermined update conditions include at least one of the following: the number of motion trajectories stored for a specific base station reaches a predetermined number, a predetermined time period has elapsed, and a new base station appears in a neighboring cell of the base station.

[0061] For example, the trajectory model generation / update and storage process should be triggered after the storage space of "Base Station Path 2" at the base station is full again or after a predetermined time (e.g., 3 days or 7 days) to ensure the real-time performance of the feature values ​​of the extracted terminal's motion trajectory. This prevents changes in high-speed rail or highway routes from affecting the application of the trajectory model. Furthermore, after activation, the base station can obtain the location coordinates (e.g., GPS coordinates) of all neighboring base stations through an interface between base stations (e.g., the interface between LTE base stations is called the X2 interface). The base station can generate a regional map based on its own location coordinates. For example, the base station's neighboring base stations (e.g., the second base station, the third base station, etc.) may exist in the base station's regional map. However, after a period of time, for example, some of the base stations in the neighboring base station's area (e.g., the third base station) may be demolished. In this case, the base station can, for example, delete the data of "Base Station Path 3" and its corresponding trajectory model. Alternatively, a new base station (e.g., the fourth base station) may be built in the neighboring area of ​​the base station. In this case, the base station can initiate the process of generating and storing the trajectory model for the new fourth base station.

[0062] The following will combine Figure 3 Describe an example process for generating / updating and applying trajectory models.

[0063] Figure 3 This is a diagram illustrating the process of generating / updating and applying a trajectory model according to an exemplary embodiment of the present disclosure.

[0064] like Figure 3As shown, during the trajectory model generation / update process, under predetermined update conditions, in trajectory data acquisition operation S301, the base station equipped with the mobility management system 200 can acquire a large number of predefined time motion trajectories (hereinafter referred to as predefined motion trajectories) of connected terminals within its cell. These predefined motion trajectories are sets of location data from the terminal handover time forward through a predetermined time period. In trajectory data processing operation S302, the base station can process the acquired predefined motion trajectories. For example, they can be classified according to base station paths. Furthermore, the base station can allocate a fixed-size storage space for each "base station path X," and also allocate a fixed-size sub-storage space for each terminal under "base station path X." Both the storage space and sub-storage spaces can store data using a cyclic overlay method. In trajectory feature value extraction operation S303, the base station can extract feature values ​​from these motion trajectories, where the feature values ​​may include the direction of motion of the motion trajectory and the speed of the terminal corresponding to the motion trajectory. For example, during feature value extraction, the base station can extract feature values ​​from the data of "base station path X" using mathematical or statistical methods. For example, the extracted feature values ​​may be statistical averages. The base station can extract at least one motion trajectory from one or more motion trajectories stored for a specific base station based on the direction and speed of motion.

[0065] As an example, in order to improve the efficiency of generating / updating trajectory models, the base station can pre-remove the motion trajectories of terminals that are moving at low speed or not moving from multiple motion trajectories before extracting motion trajectories.

[0066] In trajectory model generation / update operation S304, the base station can synthesize the at least one motion trajectory into a single trajectory as a trajectory model based on statistical methods. For example, the base station can draw on methods from machine learning to address and avoid problems such as generalization, underfitting, overfitting, and bias. Ultimately, the base station can obtain a trajectory model from a large number of stored motion trajectories.

[0067] After the trajectory model is generated / updated, the base station can store multiple trajectory models, such as "base trajectory model 1", "base station path 2_2_feature value_300" (representing trajectory model 2 with a speed of 300km / h from the base station to the second base station), "base station path 3_1_feature value_100" (representing trajectory model 1 with a speed of 100km / h from the base station to the third base station), etc.

[0068] Based on the trajectory model generated / updated above, during the application of the trajectory model, firstly, in operation S305, the base station can perform a trajectory model applicability judgment. To this end, the base station can select a specific trajectory model whose matching degree meets a first preset condition from the at least one trajectory model based on the matching degree of the target terminal's motion trajectory relative to at least one trajectory model corresponding to the target terminal's speed. Here, the expression "corresponds to the target terminal's speed" can mean: (1) equal to or close to the target terminal's average speed over a recent period; (2) equal to or approximately close to the target terminal's highest speed over a recent period; or (3) equal to or approximately close to the speed of the target terminal at each moment or a specific number of moments in a recent period, etc.

[0069] Then, in operation S306, the base station can perform applicability tracking on the selected specific trajectory model. Here, the base station can update the matching degree based on the specific trajectory model. Next, in operation S307, the base station can perform mobility management prediction based on the updated matching degree. When the updated matching degree meets a second preset condition, it is predicted that the target terminal will be connected to the base station corresponding to the specific trajectory model. Finally, in operation S308, the target terminal can be connected to the corresponding base station through dual connectivity or CoMP configuration, etc., to complete terminal mobility management.

[0070] Furthermore, the trajectory model generation / update process described above can be performed simultaneously with the trajectory model application process. For example, the trajectory model generation / update process can be initiated as long as the preset update conditions are met.

[0071] Figure 4 This is an example schematic diagram illustrating an application scenario of a mobility management system 200 according to an exemplary embodiment of the present disclosure.

[0072] like Figure 4 As shown, a first base station and a second base station are illustrated, both of which are equipped with the aforementioned mobility management system 200. Firstly, the first and second base stations have stored their respective trajectory models through the trajectory model generation / update process described above. For example, the first base station stores a trajectory model for a high-speed rail route, and the second base station stores a trajectory model for a highway route. For instance, for a high-speed rail route, there can be two different models (the example terminal corresponds to speeds of 120 km / h and 300 km / h respectively), both on the same high-speed rail route, which can be denoted as "Base Station Path 2_Feature Value_120" and "Base Station Path 2_Feature Value_300" respectively.

[0073] The first base station can first acquire the location data of each terminal in the first cell in real time according to a first time interval (e.g., 10ms), and generate the motion trajectory of each terminal and determine the speed of each terminal based on the acquired location data. The first base station can select a specific trajectory model from the at least one trajectory model whose matching degree meets a first preset condition based on the matching degree of the motion trajectory of terminal x relative to at least one trajectory model corresponding to the speed of terminal x, for example, the specific trajectory model is the above-mentioned "base station path 2_feature value_300" trajectory model, and obtain the initial matching degree of the motion trajectory of terminal x relative to the specific trajectory model.

[0074] After selecting the specific trajectory model, the first base station predicts that terminal x may be switched to the second base station corresponding to the specific trajectory model. For example, the first base station believes that terminal x may enter... Figure 4 The first base station prediction area is shown (e.g., the area where the first base station predicts the terminal's next location data based on the specific trajectory model). For example, the terminal x can be added to a prediction queue that applies the "base station path 2_feature value_300" trajectory model. The prediction queue is a set of terminals for which the first base station will acquire the terminal's future (e.g., next) location data at time intervals different from the default time interval and will predict the terminal's future location data based on the specific trajectory model. In this case, the first base station can acquire the next location data of terminal x at a second time interval (e.g., 100ms) longer than the first time interval, and can predict the next location data of terminal x based on the "base station path 2_feature value_300" trajectory model, and update the matching degree based on the comparison between the predicted next location data and the acquired next location data. Therefore, the first base station no longer controls terminal x in the prediction queue to send traditional periodic or event-based reporting measurements, but only controls terminal x to send single measurement reports for updating the matching degree at necessary time points. After the specific trajectory model is selected, the first base station can acquire the location data of terminal x at a longer time interval than before the specific trajectory model was selected, in order to detect whether the location of terminal x is under the specific trajectory model or deviates from the specific trajectory model, which greatly reduces the measurement process between the terminal and the base station.

[0075] The matching degree (represented by "x_MatchRate") of terminal x relative to the specific trajectory model mentioned above in the predicted area of ​​the first base station may gradually increase over time. When x_MatchRate meets a second preset condition, for example, when x_MatchRate exceeds a second preset value (e.g., 90%), the first base station considers that terminal x has moved to an area ready to be switched to the second base station (e.g., as...). Figure 4As shown, this is a high-speed rail handover area. In this case, as an example, the first base station can send the control plane and service plane information of terminal x to the second base station in advance. Therefore, when terminal x moves to a location such as... Figure 4 When the high-speed rail handover area is shown, the first base station may no longer send a handover command. Instead, it may send dual connectivity or CoMP configuration information to ensure that the terminal's service plane is not interrupted during the handover. In this case, depending on the terminal's capabilities, the terminal may receive or send service data from both the first and second base stations simultaneously for a short period of time.

[0076] When the x_MatchRate of terminal x in the prediction area of ​​the first base station decreases, if the terminal x_MatchRate is lower than a first preset value (e.g., 30%), the base station can remove terminal x from the prediction queue of the application of the specific trajectory model (i.e., terminate the application of the specific trajectory model to terminal x) and manage its mobility in accordance with conventional protocols.

[0077] Furthermore, the transmission frequency of the terminal's location data measurement (e.g., the aforementioned second time interval of 100ms) can depend on the rate of change of the terminal's location data (i.e., the terminal's moving speed). The higher the terminal's moving speed, the more frequently the data is transmitted. For example, when the terminal's moving speed is fast, the second time interval can be appropriately reduced (e.g., set to 60ms).

[0078] In addition, such as Figure 4 As shown, the second base station equipped with the mobility management system 200 can also perform feature value extraction based on, for example, data from "base station path 1" in the same manner as the first base station to obtain a trajectory model for the road travel route, thereby performing mobility management on terminals connected to the second base station based on the trajectory model for the road travel route. Redundant discussions will be omitted for simplicity.

[0079] Figure 5 This is a flowchart illustrating a communication method of a base station according to an exemplary embodiment of the present disclosure.

[0080] In operation S510, the data acquisition circuit 210 can acquire the location data of the connected target terminal in the cell of the base station, and generate the motion trajectory of the target terminal and determine the speed of the target terminal based on the acquired location data.

[0081] In operation S520, the trajectory model selection circuit 220 can select a specific trajectory model whose matching degree satisfies a first preset condition from the at least one trajectory model based on the matching degree of the target terminal's motion trajectory relative to at least one trajectory model corresponding to the target terminal's speed, and obtain the initial matching degree of the target terminal's motion trajectory relative to the specific trajectory model. Here, the at least one trajectory model is the trajectory of a terminal moving at a determined speed while switching from one base station to another, with the endpoint being the position at the time of the switchover.

[0082] In operation S530, the mobility management circuit 230 can predict the future (e.g., next) location data of the target terminal based on the specific trajectory model, update the initial matching degree based on the predicted future location data, and determine whether the target terminal will be connected to another base station corresponding to the specific trajectory model based on the updated matching degree.

[0083] Here, the aforementioned circuit units (e.g., circuits such as 210, 220, and 230) can be integrated into a smaller number of circuit units, or divided into a larger number of circuit units, to achieve the same function. Furthermore, any of the aforementioned circuits (e.g., 210, 220, and 230) can be implemented as a general-purpose processing circuit running software, or as a dedicated hardware component, or a combination of software and hardware components.

[0084] According to exemplary embodiments of the present disclosure, a computer-readable storage medium is provided, wherein a computer program is stored thereon, which, when executed, implements a mobility management method for a base station according to exemplary embodiments of the present disclosure. Examples of computer-readable storage media include: read-only memory (ROM), random access programmable read-only memory (PROM), electrically erasable programmable read-only memory (EEPROM), random access memory (RAM), dynamic random access memory (DRAM), static random access memory (SRAM), flash memory, non-volatile memory, CD-ROM, CD-R, CD+R, CD-RW, CD+RW, DVD-ROM, DVD-R, DVD+R, DVD-RW, DVD+RW, DVD-RAM, BD-ROM, BD-R, BD-R LTH, BD-RE, Blu-ray or optical disc storage, hard disk drive (HDD), solid-state drive (SSD), card storage (such as multimedia cards, secure digital (SD) cards, or ultra-fast digital (XD) cards), magnetic tape, floppy disk, magneto-optical data storage device, optical data storage device, hard disk, solid-state drive, and any other device configured to store a computer program and any associated data, data files, and data structures in a non-transitory manner and to provide the computer program and any associated data, data files, and data structures to a processor or computer so that the processor or computer can execute the computer program. The computer program in the aforementioned computer-readable storage medium can run in an environment deployed in computer devices such as terminals, clients, hosts, agent devices, servers, etc. Furthermore, in one example, the computer program and any associated data, data files, and data structures are distributed across a networked computer system, such that the computer program and any associated data, data files, and data structures are stored, accessed, and executed in a distributed manner through one or more processors or computers.

[0085] According to an exemplary embodiment of the present invention, the base station can minimize the need for terminal measurement reporting by using trajectory models and update the matching degree through a one-time measurement reporting mechanism, thus saving signaling overhead. For example, since the trajectories of all terminals on a high-speed train can conform to a specific trajectory model of the base station, applying the specific trajectory model for mobility management will significantly reduce energy consumption in traditional measurements between terminals and base stations caused by measurement handover. As a result, the systems and devices conceived according to the present invention conform to the concepts of low-carbon emissions and environmentally friendly green technologies.

[0086] Furthermore, by employing handover technologies that are not based on 3GPP protocols, such as dual connectivity or CoMP configuration, there is no interruption of terminal services during cell handover. This improves the user experience of terminal services (especially for latency-sensitive services).

[0087] Because base stations possess native AI and ML capabilities, they can train themselves by analyzing large amounts of locally stored data to extract trajectory models of their own geographical locations, eliminating the need for manual planning and extensive network optimization testing. In other words, base stations possess true self-optimization capabilities. The low-Earth orbit satellite Starlink system can still use this method to apply the patented method to aircraft on their flight paths.

[0088] It should be understood that the inventive concept is not limited to the embodiments described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from the scope of the inventive concept as defined by the appended claims.

Claims

1. A mobility management system for a base station, comprising: The data acquisition circuit is configured to acquire the location data of the connected target terminal in the cell of the base station, and generate the motion trajectory of the target terminal and determine the speed of the target terminal based on the acquired location data; The trajectory model selection circuit is configured to select a specific trajectory model whose matching degree satisfies a first preset condition from the at least one trajectory model based on the matching degree of the motion trajectory of the target terminal relative to at least one trajectory model corresponding to the speed of the target terminal, and obtain the initial matching degree of the motion trajectory of the target terminal relative to the specific trajectory model. A mobility management circuit is configured to predict the future location data of the target terminal based on the specific trajectory model, update the initial matching degree based on the predicted future location data, and determine whether the target terminal will be connected to another base station based on the updated matching degree and the specific trajectory model. Each of the at least one trajectory model is defined for the trajectory of a terminal that switches from the base station to a different base station while traveling at a determined speed, with the endpoint being the position at the switching time. The mobility management circuit updates the initial matching degree based on a comparison between the predicted future location data and the acquired future location data.

2. The mobility management system of claim 1, wherein the trajectory model selection circuit is configured to determine the degree of matching between the motion trajectory of the target terminal and the at least one trajectory model in the following manner: The matching degree of the target terminal's motion trajectory relative to the at least one trajectory model is determined by determining the degree of overlap between the target terminal's motion trajectory and each of the at least one trajectory model.

3. The mobility management system as described in claim 1, further comprising: The trajectory storage circuit is configured to store, when the target terminal switches to the other base station, a predefined motion trajectory of the target terminal in the cell as one of the motion trajectories corresponding to the speed of the target terminal and the other base station. The predefined motion trajectory is a set of position data that is taken from the switching moment forward through a predetermined time period.

4. The mobility management system as described in claim 3, wherein, The trajectory storage circuit is also configured to generate and store trajectory models in the following ways: At least one motion trajectory is extracted from one or more motion trajectories stored for a specific base station, wherein the speeds corresponding to the extracted motion trajectories do not exceed a preset speed error and the motion directions of the extracted motion trajectories do not exceed a preset direction error. The extracted motion trajectories are combined into a single trajectory; and The synthesized trajectory is stored as a trajectory model for the specific base station, and the speed statistics corresponding to the extracted motion trajectory are stored as the speed corresponding to the trajectory model for the specific base station.

5. The mobility management system as described in claim 4, wherein, The trajectory storage circuit is also configured to regenerate and store the trajectory model when predetermined update conditions are met. The predetermined update conditions include at least one of the following: the number of motion trajectories stored for a specific base station reaches a predetermined number, a predetermined time period has elapsed, and a new base station appears in the neighboring cell of the base station.

6. The mobility management system as described in claim 1, wherein, The mobility management circuit is configured as follows: When the updated matching degree meets the second preset condition, it is determined that the target terminal will be connected to the other base station.

7. The mobility management system as described in claim 6, wherein, The second preset condition includes at least one preset threshold condition that increases progressively, wherein: When the current matching degree of the target terminal's motion trajectory relative to the specific trajectory model meets the preset threshold condition of the current level, the data acquisition circuit acquires the future location data of the target terminal at time intervals corresponding to the preset threshold condition of the current level. The mobility management circuit updates the current matching degree based on a comparison between the predicted future location data and the acquired future location data, and determines whether the updated matching degree meets the preset threshold condition of the next level. When the matching degree of the target terminal's motion trajectory with respect to the specific trajectory model meets all preset threshold conditions, the mobility management circuit determines that the target terminal will be connected to the other base station.

8. The mobility management system as described in claim 7, wherein, The mobility management circuitry is configured to update the current match score in the following ways: If the distance between the predicted future location data and the acquired future location data does not exceed a preset distance error, then the current matching degree is increased by a first preset value; If the distance between the predicted future location data and the acquired future location data exceeds a preset distance error, then a second preset value is subtracted from the current matching degree.

9. The mobility management system as described in claim 7, wherein, The mobility management circuit is configured to perform mobility management on the target terminal according to a traditional protocol when the current matching degree of the target terminal's motion trajectory relative to the specific trajectory model does not meet the preset threshold condition of the current level.

10. The mobility management system as claimed in claim 1, wherein, When it is determined that the target terminal will be connected to the other base station, the target terminal is connected to the other base station through a dual-connection or Cooperative Multipoint (CoMP) configuration.

11. The mobility management system as claimed in claim 1, wherein, After the specific trajectory model is selected, the data acquisition circuit is configured to acquire the location data of the target terminal in the cell at time intervals longer than before the specific trajectory model was selected.

12. A mobility management method for a base station, comprising: The location data of the connected target terminal in the cell of the base station is obtained, and the motion trajectory of the target terminal and the speed of the target terminal are generated based on the obtained location data. Based on the matching degree of the motion trajectory of the target terminal with respect to at least one trajectory model corresponding to the speed of the target terminal, a specific trajectory model whose matching degree satisfies a first preset condition is selected from the at least one trajectory model, and the initial matching degree of the motion trajectory of the target terminal with respect to the specific trajectory model is obtained. Based on the specific trajectory model, the future location data of the target terminal is predicted. The initial matching score is updated based on the predicted future location data. Based on the updated matching score, it is determined, according to the specific trajectory model, whether the target terminal will be connected to another base station. Each of the at least one trajectory model is defined for a terminal that is switching from the base station to a different base station while traveling at a determined speed, with the endpoint being the position at the switching time. The step of updating the initial matching degree includes: The initial matching degree is updated based on the comparison between the predicted future location data and the acquired future location data.

13. The mobility management method as described in claim 12, wherein, The degree of matching between the motion trajectory of the target terminal and the at least one trajectory model is determined in the following way: The matching degree of the target terminal's motion trajectory relative to the at least one trajectory model is determined by determining the degree of overlap between the target terminal's motion trajectory and each of the at least one trajectory model.

14. The mobility management method as described in claim 12, further comprising: When the target terminal switches to the other base station, the predefined motion trajectory of the target terminal in the cell is stored as one of the motion trajectories corresponding to the speed of the target terminal and the other base station. The predefined motion trajectory is a set of position data that is taken from the switching moment forward through a predetermined time period.

15. The mobility management method of claim 14, further comprising generating and storing the trajectory model in the following manner: Extract at least one motion trajectory from one or more motion trajectories stored for a specific base station, wherein, The velocities corresponding to the extracted motion trajectories do not exceed a preset velocity error, and the motion directions of the extracted motion trajectories do not exceed a preset direction error. The extracted motion trajectories are combined into a single trajectory; and The synthesized trajectory is stored as a trajectory model for the specific base station, and the speed statistics corresponding to the extracted motion trajectory are stored as the speed corresponding to the trajectory model for the specific base station.

16. The mobility management method as described in claim 15, further comprising: Under the condition that the predetermined update conditions are met, the trajectory model is regenerated and stored. The predetermined update conditions include at least one of the following: the number of motion trajectories stored for a specific base station reaches a predetermined number, a predetermined time period has elapsed, and a new base station appears in the neighboring cell of the base station.

17. The mobility management method as described in claim 12, wherein, When the updated matching degree meets the second preset condition, it is determined that the target terminal will be connected to the other base station.

18. The mobility management method as described in claim 17, wherein, The second preset condition includes at least one preset threshold condition that increases progressively, wherein: When the current matching degree of the target terminal's motion trajectory relative to the specific trajectory model meets the preset threshold condition of the current level, the future location data of the target terminal is acquired at time intervals corresponding to the preset threshold condition of the current level. The current matching degree is then updated based on a comparison between the predicted future location data and the acquired future location data, and it is determined whether the updated matching degree meets the preset threshold condition of the next level. When the matching degree of the target terminal's motion trajectory with respect to the specific trajectory model meets all preset threshold conditions, it is determined that the target terminal will be connected to the other base station.

19. The mobility management method as described in claim 18, wherein, The steps to update the current matching score include: If the distance between the predicted future location data and the acquired future location data does not exceed a preset distance error, then the current matching degree is increased by a first preset value; If the distance between the predicted future location data and the acquired future location data exceeds a preset distance error, then a second preset value is subtracted from the current matching degree.

20. The mobility management method as described in claim 18, wherein, When the current matching degree of the target terminal's motion trajectory with respect to the specific trajectory model does not meet the preset threshold condition of the current level, the target terminal's mobility is managed according to the traditional protocol.

21. The mobility management method as described in claim 12, wherein, When it is determined that the target terminal will be connected to the other base station, the target terminal is connected to the other base station through a dual-connection or Cooperative Multipoint (CoMP) configuration.

22. The mobility management method as described in claim 12, wherein, After the specific trajectory model is selected, the location data of the target terminal in the cell is acquired at a longer time interval than before the specific trajectory model was selected.

23. A computer-readable storage medium storing computer program instructions, wherein, When the computer program instructions are executed by a processor, the base station implements a mobility management method, the method comprising: The location data of the connected target terminal in the cell of the base station is obtained, and the motion trajectory of the target terminal and the speed of the target terminal are generated based on the obtained location data. Based on the matching degree of the motion trajectory of the target terminal with respect to at least one trajectory model corresponding to the speed of the target terminal, a specific trajectory model whose matching degree satisfies a first preset condition is selected from the at least one trajectory model, and the initial matching degree of the motion trajectory of the target terminal with respect to the specific trajectory model is obtained. Based on the specific trajectory model, the future location data of the target terminal is predicted. The initial matching score is updated based on the predicted future location data. Based on the updated matching score, it is determined, according to the specific trajectory model, whether the target terminal will be connected to another base station. Each of the at least one trajectory model is defined for a terminal that is switching from the base station to a different base station while traveling at a determined speed, with the endpoint being the position at the switching time. The step of updating the initial matching degree includes: The initial matching degree is updated based on the comparison between the predicted future location data and the acquired future location data.

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