A base station timing method and system based on EMM information message

Abstract

The present invention relates to the field of communication technology, and in particular to a base station timing method and system based on EMM information messages. The method comprises the following steps: regularly detecting the synchronization state of a base station, detecting the synchronization source state if the base station is out of sync, and if the synchronization source fails, starting a backup timing process to determine whether a UE has accessed the base station; if no UE has accessed, ending the timing process; if a UE has accessed, intercepting and parsing NAS layer signaling of the UE to obtain an EMM Information message sent by a core network, and extracting timestamp information from the EMM Information message; comparing the timestamp with the base station system time to determine whether the base station system time needs to be calibrated. When the base station synchronization source fails, the present invention can utilize UE access to obtain the timestamp information in the EMM Information message sent by the core network, thereby providing a new backup timing path for the base station, greatly improving the ability of the base station to maintain time synchronization in a complex environment, and enhancing the reliability of the communication network.

Description

Technical Field

[0001] The present invention relates to the field of communication technology, and in particular to a base station timing method and system based on EMM (EPS Mobility Management) information messages. Background Art

[0002] In wireless communication systems, base station time synchronization is crucial. If base station time is out of sync, it will affect user equipment (UE) access, handover, and network maintenance.

[0003] Existing technologies typically rely on synchronization sources such as GPS, NTP (Network Time Protocol), or IEEE 1588. However, if the synchronization source fails (e.g., due to signal obstruction or network interruption), the base station time may become out of sync, resulting in degraded communication quality. Existing solutions often rely on redundant synchronization sources or complex hardware, which is costly and complex to deploy. Therefore, a low-cost backup timing solution is urgently needed. Summary of the Invention

[0004] The present invention aims to provide a low-cost and easy-to-implement pico base station timing solution when other synchronization sources of the base station fail, thereby ensuring the stability and accuracy of the base station system time and guaranteeing the normal operation of wireless communications.

[0005] In order to achieve the purpose of the present invention, the following technical solutions are adopted:

[0006] A first aspect of the present invention provides a base station timing method based on EMM information messages, comprising the following steps:

[0007] Regularly check the synchronization status of the base station. If the base station loses synchronization, check the synchronization source status. If the synchronization source fails, start the backup timing process to determine whether there is a UE accessing the base station.

[0008] If no UE is connected, the timing process is terminated. If a UE is connected, the NAS layer signaling of the UE is intercepted and parsed, the EMM Information message sent by the core network is obtained, and the timestamp information is extracted from the EMM Information message;

[0009] The timestamp is compared with the base station system time to determine whether the base station system time needs to be calibrated.

[0010] A further improvement is that the specific method of comparing the timestamp with the base station system time to determine whether the base station system time needs to be calibrated includes: calculating the deviation value between the timestamp and the base station system time, and if the absolute value of the deviation value exceeds a preset threshold, calibrating the base station system time and marking it as a synchronized state.

[0011] A further improvement is that the synchronization source is any one of the following: a GPS synchronization source, an IEEE 1588 synchronization source.

[0012] A further improvement is that the method for checking whether the GPS synchronization source has failed includes: reading the status register of the GPS receiver to obtain the number of satellites, signal strength, and positioning accuracy information to determine whether the GPS synchronization source is working properly; the method for checking whether the IEEE 1588 synchronization source has failed includes: monitoring the sending and receiving of time synchronization messages in the IEEE 1588 network to check whether there is packet loss or excessive delay.

[0013] A further improvement is that the specific method of extracting the timestamp information from the EMM Information message includes: decoding the "Time Stamp" field in the EMM Information message according to the 3GPP TS 24.301 protocol to obtain the precise time information in the UTC format.

[0014] A further improvement is that a timer is provided inside the base station for automatically performing synchronization status checks at preset time intervals.

[0015] A further improvement is that the specific method of intercepting the NAS layer signaling of the UE includes:

[0016] The UE identification information is sent to the signaling parsing module, and the signaling parsing module intercepts the NAS layer signaling data from the communication link between the base station and the UE according to the UE identification.

[0017] A second aspect of the present invention provides a base station timing system based on EMM information messages, comprising:

[0018] The synchronization detection module is used to regularly detect the synchronization status of the base station and detect the synchronization source status if the base station is out of sync;

[0019] The backup timing startup module is used to start the backup timing process when the synchronization source failure is detected;

[0020] The timestamp extraction module is used to determine whether a UE has accessed the base station; if no UE has accessed, the timing process is terminated; if a UE has accessed, the NAS layer signaling of the UE is intercepted and parsed, the EMM Information message sent by the core network is obtained, and the timestamp information is extracted from the EMM Information message;

[0021] The comparison and calibration module is used to compare the timestamp with the base station system time to determine whether the base station system time needs to be calibrated.

[0022] The third aspect of the present invention proposes an electronic device, comprising a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein when the processor executes the computer program, it implements a base station timing method based on EMM information message as described in any one of the first aspects.

[0023] The fourth aspect of the present invention proposes a computer-readable storage medium, which includes a stored computer program, wherein when the computer program is running, the device where the computer-readable storage medium is located is controlled to execute a base station timing method based on EMM information messages as described in any one of the first aspects.

[0024] The beneficial effects of the present invention are:

[0025] When the base station synchronization source fails, the present invention can utilize UE access to obtain the timestamp information in the EMMInformation message sent by the core network, providing a new backup timing path for the base station, greatly improving the base station's ability to maintain time synchronization in complex environments, and enhancing the reliability of the communication network.

[0026] The present invention is applicable to base station systems, as well as base station plus repeater extended coverage systems, and is particularly applicable to distributed wireless systems, including optical fiber remote distributed systems, cable remote frequency shift repeater systems, frequency shift systems, sea area communications, low-altitude communications, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a flow chart of a base station timing method based on EMM information messages of the present invention;

[0028] Figure 2 A schematic diagram of an electronic device. DETAILED DESCRIPTION

[0029] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0030] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0031] Please refer to the attached Figure 1 A first aspect of an embodiment of the present invention provides a base station timing method based on an EMM information message, comprising the following steps:

[0032] Step S1: Regularly check the synchronization status of the base station. If the base station is out of synchronization, check the synchronization source status. If the synchronization source fails, start the backup timing process to determine whether there is a UE accessing the base station.

[0033] Specifically, a timer is provided inside the base station for automatically performing synchronization status checks at preset time intervals.

[0034] It is understandable that this step involves periodic checks on the synchronization status of the base station. If the base station is found to be out of sync (i.e., no longer synchronized with other network components), it is necessary to further check the status of the synchronization source. If the synchronization source also fails, the system will start the backup timing process and at the same time check whether there is user equipment (UE) access. For the detection of the synchronization source, it can be determined whether it has failed by checking the working status of the synchronization source equipment, signal transmission conditions, etc. Regular detection can timely detect synchronization problems and avoid service interruptions caused by time asynchrony. Starting the backup timing process can provide an additional safety net when the primary synchronization source is unavailable, ensuring that the base station can maintain service to at least a certain extent. Checking the UE access status helps determine whether it is necessary to continue with the subsequent steps.

[0035] Step S2: If no UE accesses, the timing process is terminated. If a UE accesses, the NAS (Non-Access Stratum) layer signaling of the UE is intercepted and parsed, the EMM Information message sent by the core network is obtained, and the timestamp information is extracted from the EMM Information message.

[0036] It should be understood that EMM Information messages typically contain information related to user authentication and security settings. The present invention utilizes the timestamp embedded in them for synchronization purposes, which increases data utilization efficiency. Simply put, based on the role of EMM Information messages in the control plane interaction between the user equipment (UE) and the mobility management entity (MME), the timestamp information carried in these messages is used to subsequently recover the base station clock. Because EMM Information signaling relies on UE access, if there is no UE access, this signaling cannot be obtained. The timing process ends and step 1 is repeated, waiting for UE access. UE access can be determined by the communication connection status between the base station and the UE, such as whether the base station has received a specific access signal or request message sent by the UE. In practice, a dedicated signaling parsing module can be used to parse NAS signaling and accurately extract the timestamp information according to the EMM Information signaling format specifications. It should also be noted that the pico base station cell must be activated and have UE access, which is a prerequisite for obtaining EMM Information signaling.

[0037] Step S3: Compare the timestamp with the base station system time to determine whether the base station system time needs to be calibrated.

[0038] Specifically, the method for comparing the timestamp with the base station system time to determine whether the base station system time needs to be calibrated includes calculating a deviation between the timestamp and the base station system time, and if an absolute value of the deviation exceeds a preset threshold, calibrating the base station system time and marking the base station as in sync. If the deviation does not exceed the preset threshold, calibrating the base station system time is not required.

[0039] It should be understood that by setting a reasonable preset threshold, it can be ensured that the calibration operation is only triggered when a sufficiently large time difference is detected, avoiding unnecessary frequent calibration. For example, if the time represented by the timestamp is 10:00:00.123 (hours: minutes: seconds. milliseconds) and the base station system time is 10:00:00.150, the difference between the two is 0.027 seconds. The judgment standard for excessive deviation can be set based on the actual application scenario and the communication system's requirements for time accuracy. For example, when the time deviation exceeds a certain threshold (such as 50 milliseconds), it is determined to be excessive, and the calibration operation is initiated to adjust the base station system time to be consistent with the timestamp information.

[0040] When the base station's original synchronization source fails, this solution directly utilizes the timestamp information in the EMMInformation message sent by the core network without the need for additional hardware. This timestamp originates from the core network and is synchronized with the network clock, enabling low-cost, highly reliable base station timing and ensuring system time synchronization. Compared to traditional solutions that rely on external synchronization sources (such as GPS), this solution can still obtain reliable time information even when the GPS signal is interfered with by external factors such as weather and geographical conditions, or when the synchronization source equipment fails.

[0041] The present invention does not require additional configuration of complex and expensive synchronization equipment, and can achieve time synchronization using existing communication signaling, which reduces costs. The implementation process is relatively simple and does not require large-scale modification of base station hardware. It only requires adding corresponding signaling parsing and time processing function modules at the software level.

[0042] In this embodiment, the synchronization source is any one of the following: a GPS synchronization source, an IEEE 1588 synchronization source (Precision Time Protocol, PTP).

[0043] Specifically, the method for checking whether the GPS synchronization source is invalid includes: obtaining the number of satellites, signal strength, and positioning accuracy information by reading the status register of the GPS receiver to determine whether the GPS synchronization source is working normally; the method for checking whether the IEEE 1588 synchronization source is invalid includes: monitoring the sending and receiving of time synchronization messages in the IEEE 1588 network to check whether there is packet loss or excessive delay.

[0044] As you can understand, GPS provides global coverage and high time accuracy. Directly reading data from the GPS receiver's status register provides real-time information on the current synchronization status. A multi-dimensional assessment, combining multiple indicators such as the number of satellites, signal strength, and positioning accuracy, allows for a more accurate assessment of the GPS synchronization source's functioning. The IEEE 1588 protocol enables high-precision time synchronization within a local area network (LAN), making it suitable for a variety of network environments. Monitoring the transmission of time synchronization messages not only assesses the status of the synchronization source but also indirectly reflects the overall health of the network. If problems such as packet loss or excessive latency are detected, prompt action can be taken to repair the problem or switch to a backup synchronization source, minimizing service impact.

[0045] In a preferred embodiment of this embodiment, in step S2, the specific method for extracting timestamp information from the EMM Information message includes decoding the "TimeStamp" field in the EMM Information message according to 3GPP TS 24.301 to obtain precise time information in UTC (Coordinated Universal Time) format. Directly parsing specific fields rather than the entire message reduces unnecessary computation and resource consumption, thereby improving processing efficiency.

[0046] In one feasible solution of this implementation, in step S2, the specific method of intercepting the NAS layer signaling of the UE includes:

[0047] The UE identification information is sent to the signaling parsing module, and the signaling parsing module intercepts the NAS layer signaling data from the communication link between the base station and the UE according to the UE identification.

[0048] As you can understand, after receiving the UE identifier, the signaling parsing module uses this information to locate and intercept NAS layer signaling data in the communication link between the base station and the UE. Because the NAS layer sits above the control plane and primarily handles functions like mobility management and session management, it contains information crucial for time synchronization, such as EMM Information messages. By accurately intercepting and parsing NAS layer signaling, the base station can more effectively utilize time information from the core network to calibrate its own time, thereby ensuring quality of service and user experience.

[0049] In one feasible solution of this embodiment, the signaling parsing module uses a neural network model based on deep learning to perform signaling parsing. The neural network model consists of an input layer, multiple hidden layers, and an output layer. Specifically:

[0050] The input layer receives preprocessed NAS layer signaling data. The preprocessing process includes data cleaning, normalization, and other operations to improve data quality and consistency, facilitating better learning for the neural network. It can be understood that the data cleaning phase is to remove noise, duplicate data, and malformed data from the signaling data; the normalization phase is to normalize the values ​​of each field in the signaling data to a specific range, for example, mapping the data values ​​to the interval [0, 1].

[0051] The hidden layer adopts a multi-layer convolutional neural network (CNN) structure, which extracts features by sliding the convolution kernel on the signaling data to effectively capture local features and patterns in the signaling data. Nonlinear transformations are performed between each hidden layer through activation functions (such as the ReLU function) to increase the expressive power of the model.

[0052] The output layer uses a softmax function to map the features extracted by the hidden layer into the probability distribution of each signaling type, thereby accurately identifying the EMM Information message.

[0053] During the model training phase, a large amount of labeled NAS-layer signaling data from various scenarios is collected. This data contains various signaling types and their corresponding correct identifiers (e.g., whether it is an EMM Information message). This data is divided into training, validation, and test sets. The training set is used to train model parameters, the validation set is used to adjust model hyperparameters to prevent overfitting, and the test set is used to evaluate the model's final performance. During training, stochastic gradient descent (SGD) is used to update the model's weights and biases. By continuously adjusting these parameters, the model's loss function on the training set is gradually reduced. After multiple rounds of training, the model's accuracy on the validation set has reached a stable and high level. When new signaling data is input, the trained model can quickly output a signaling type determination. Upon identifying a specific EMM Information message header (e.g., 0x123456), the message content is extracted.

[0054] It's understandable that after training with a large amount of labeled signaling data, the model can quickly and accurately filter EMM Information messages from complex signaling flows. This solves the problem of accurately parsing EMM Information messages from UE NAS layer signaling, significantly improving the accuracy of signaling parsing and enhancing the ability to obtain EMM Information messages in complex signaling environments.

[0055] A second aspect of an embodiment of the present invention proposes a base station timing system based on EMM information messages, which corresponds to a base station timing method based on EMM information messages provided in the above-mentioned embodiment of the present invention. Since a base station timing system based on EMM information messages provided in an embodiment of the present invention corresponds to a base station timing method based on EMM information messages provided in the above-mentioned embodiment of the present invention, the implementation method of the aforementioned base station timing method based on EMMinformation messages is also applicable to a base station timing system based on EMMinformation messages provided in this embodiment.

[0056] Specifically, the system includes the following modules:

[0057] The synchronization detection module is used to regularly detect the synchronization status of the base station and detect the synchronization source status if the base station is out of sync;

[0058] The backup timing startup module is used to start the backup timing process when the synchronization source failure is detected;

[0059] The timestamp extraction module is used to determine whether a UE has accessed the base station; if no UE has accessed, the timing process is terminated; if a UE has accessed, the NAS layer signaling of the UE is intercepted and parsed, the EMM Information message sent by the core network is obtained, and the timestamp information is extracted from the EMM Information message;

[0060] The comparison and calibration module is used to compare the timestamp with the base station system time to determine whether the base station system time needs to be calibrated.

[0061] See also Figure 2 , an embodiment of the present invention also provides an electronic device and a computer-readable storage medium.

[0062] like Figure 2 FIG2 is a schematic diagram of an electronic device provided in accordance with an embodiment of the present invention. The electronic device in accordance with this embodiment includes a processor 11, a memory 12, and a computer program stored in the memory and executable by the processor 11. When the processor 11 executes the computer program, the steps in the aforementioned embodiment of a base station timing method based on EMM information are implemented. Alternatively, when the processor 11 executes the computer program, the functions of the modules / units in the aforementioned apparatus embodiments are implemented.

[0063] Exemplarily, the computer program may be divided into one or more modules / units, which are stored in the memory and executed by the processor 11 to implement the present invention. The one or more modules / units may be a series of computer program instruction segments capable of implementing specific functions, and the instruction segments are used to describe the execution process of the computer program in the electronic device.

[0064] The electronic device may include, but is not limited to, a processor and a memory. Those skilled in the art will appreciate that the schematic diagram is merely an example of an electronic device and does not limit the electronic device. The electronic device may include more or fewer components than shown, or a combination of certain components, or different components. For example, the electronic device may also include input and output devices, network access devices, buses, etc.

[0065] The processor 11 may be a central processing unit (CPU), other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA), other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor, etc. The processor is the control center of the electronic device and connects various parts of the entire electronic device using various interfaces and lines.

[0066] The memory 12 can be used to store the computer programs and / or modules. The processor implements various functions of the electronic device by running or executing the computer programs and / or modules stored in the memory and calling the data stored in the memory. The memory can mainly include a program storage area and a data storage area, wherein the program storage area can store an operating system 121, an application 122 required for at least one function (such as a sound playback function, an image playback function, etc.); the data storage area can store data created based on the use of the mobile phone (such as audio data, a phone book, etc.). In addition, the memory can include a high-speed random access memory and can also include a non-volatile memory, such as a hard disk, a memory, a plug-in hard disk, a smart memory card (Smart Media Card, SMC), a secure digital (Secure Digital, SD) card, a flash card (Flash Card), at least one disk storage device, a flash memory device, or other volatile solid-state storage device.

[0067] Wherein, if the module / unit integrated in the electronic device is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present invention implements all or part of the process in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium, and when the computer program is executed by the processor, it can implement the steps of the above-mentioned various method embodiments. Wherein, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form, etc. The computer-readable medium may include: any entity or device that can carry the computer program code, recording medium, USB flash drive, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electric carrier signal, telecommunication signal and software distribution medium, etc.

[0068] It should be noted that the device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed across multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the present embodiment. In addition, in the drawings of the device embodiments provided by the present invention, the connection relationship between the modules indicates that there is a communication connection between them, which may be specifically implemented as one or more communication buses or signal lines. A person of ordinary skill in the art can understand and implement the present invention without inventive effort.

[0069] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

Claims

1. A base station timing method based on EMM information message, characterized in that: The following steps are involved: Regularly check the synchronization status of the base station. A timer is set inside the base station to automatically perform synchronization status checks at preset time intervals. If the base station loses synchronization, the synchronization source status is checked. If the synchronization source fails, the backup timing process is started to determine whether there is a UE accessing the base station. If no UE is accessed, the timing process is terminated. If a UE is accessed, the NAS layer signaling of the UE is intercepted and parsed, the EMM Information message sent by the core network is obtained, and the timestamp information is extracted from the EMM Information message. The specific method of intercepting the NAS layer signaling of the UE includes: sending the UE identification information to the signaling parsing module, and the signaling parsing module intercepting the NAS layer signaling data from the communication link between the base station and the UE according to the UE identification; The timestamp is compared with the base station system time to determine whether the base station system time needs to be calibrated. The specific method includes: calculating the deviation value between the timestamp and the base station system time. If the absolute value of the deviation value exceeds a preset threshold, the base station system time is calibrated and marked as a synchronization state.

2. A base station timing method based on EMM information message according to claim 1, characterized in that, The synchronization source is any one of the following: GPS synchronization source, IEEE 1588 synchronization source.

3. A base station timing method based on EMM information message according to claim 2, characterized in that, Methods for checking whether the GPS synchronization source is invalid include: reading the GPS receiver's status register to obtain information about the number of satellites, signal strength, and positioning accuracy to determine whether the GPS synchronization source is working properly; methods for checking whether the IEEE 1588 synchronization source is invalid include: monitoring the sending and receiving of time synchronization messages in the IEEE 1588 network to check for packet loss or excessive delay.

4. A base station timing method based on EMM information message according to claim 1, characterized in that: The specific method for extracting the timestamp information from the EMM Information message includes: decoding the "Time Stamp" field in the EMM Information message according to the 3GPP TS 24.301 protocol to obtain the precise time information in the UTC format.

5. A base station timing system based on EMM information messages, used to execute a base station timing method based on EMM information messages according to any one of claims 1 to 4, characterized in that: include: The synchronization detection module is used to regularly detect the synchronization status of the base station and detect the synchronization source status if the base station is out of sync; The backup timing startup module is used to start the backup timing process when the synchronization source failure is detected; A timestamp extraction module is used to determine whether a UE has accessed the base station; If no UE is connected, the timing process is terminated. If a UE is connected, the NAS layer signaling of the UE is intercepted and parsed, the EMM Information message sent by the core network is obtained, and the timestamp information is extracted from the EMM Information message; The comparison and calibration module is used to compare the timestamp with the base station system time to determine whether the base station system time needs to be calibrated.

6. An electronic device, characterized in that: The method comprises a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein when the processor executes the computer program, the method implements a base station timing method based on an EMM information message as described in any one of claims 1 to 4.

7. A computer-readable storage medium, characterized in that The computer-readable storage medium includes a stored computer program, wherein when the computer program is running, the device where the computer-readable storage medium is located is controlled to execute the base station timing method based on EMM information message according to any one of claims 1 to 4.

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