Cross-slot interference detection method and apparatus, device, medium, and product

Abstract

Disclosed are a cross-slot interference detection method and apparatus, a device, a medium, and a product. A victim base station receives an interference reference signal sent by an interfering base station under the instruction of a core network device; and determines the interfering base station on the basis of a time-frequency code resource demodulated from the interference reference signal and a preset base station mapping relationship. By locating an interfering base station, accurate interference avoidance can be facilitated, thereby avoiding resource waste.

Description

Cross-time slot interference detection methods, devices, equipment, media and products

[0001] Cross-reference to related applications

[0002] This disclosure claims priority to Chinese Patent Application No. 202510476715.2, filed on April 16, 2025, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to the field of wireless technology, and in particular to a method, apparatus, device, medium, and product for detecting cross-time slot interference. Background Technology

[0004] The frame structure configuration defined by the 5G (5th Generation Mobile Communication Technology) standard is highly flexible, allowing for the configuration of different uplink and uplink ratios as needed based on service requirements. For example, the 4.9GHz (Giga-Hertz) band currently uses the DDDSUDSUU (7D3U) frame structure in existing networks for ordinary terminal users, with a downlink to uplink ratio of 7:3.

[0005] When different frame structures are configured for the same frequency band, cross-time slot interference occurs. Currently, existing networks avoid cross-time slot interference through physical isolation. With the introduction of integrated sensing and communication technology, cross-time slot interference between communication and sensing has emerged. Sensing base stations cannot avoid cross-time slot interference from communication base stations through physical isolation. Therefore, it is necessary to punch holes in all potentially interfering communication base stations' time slots, i.e., to silence them and not schedule them. Consequently, all potentially interfering base stations do not use this resource, resulting in serious resource waste. Summary of the Invention

[0006] The purpose of this disclosure is to provide a method, apparatus, device, medium, and product for detecting cross-time slot interference, which can facilitate accurate interference avoidance and avoid resource waste by locating base stations with interference.

[0007] To achieve the above objectives, this disclosure provides a cross-time slot interference detection method applied to an interfered base station, the method comprising:

[0008] Receive interference reference signals sent by the interfering base station under the instruction of the core network equipment;

[0009] The interfering base station is determined based on the time-frequency code resources demodulated in the interference reference signal and the preset base station mapping relationship.

[0010] This disclosure also provides a method for detecting cross-time slot interference, applied to an interfering base station, the method comprising:

[0011] Receive instructions from core network devices regarding the transmission of resources;

[0012] According to the transmission instruction, an interference reference signal is transmitted to the disturbed base station so that the disturbed base station can identify the interfering base station.

[0013] This disclosure also provides a method for detecting cross-time slot interference, applied to core network equipment, the method comprising:

[0014] Receive trigger commands sent by the disrupted base station;

[0015] Send a transmission instruction to a potential interfering base station within a preset area, so that the potential interfering base station sends an interference reference signal;

[0016] A reception instruction is sent to the disturbed base station so that the disturbed base station receives the interference reference signal and identifies the interfering base station.

[0017] This disclosure also provides a cross-time slot interference detection device, applied to an interfered base station, the device comprising:

[0018] The receiving module is configured to receive interference reference signals sent by the interfering base station under the instruction of the core network equipment;

[0019] The mapping module is configured to determine the interfering base station based on the demodulated time-frequency code resources in the interference reference signal and a preset base station mapping relationship.

[0020] This disclosure also provides a cross-time slot interference detection device, applied to an interfering base station, the device comprising:

[0021] The receiving module is configured to receive instructions from core network devices regarding the transmission of resources.

[0022] The transmitting module is configured to transmit an interference reference signal to the disturbed base station according to the transmitting instruction, so that the disturbed base station can identify the interfering base station.

[0023] This disclosure also provides a cross-time slot interference detection device, applied to core network equipment, the device comprising:

[0024] The triggering module is configured to receive triggering commands sent by the disturbed base station;

[0025] The first instruction module is configured to send a transmission instruction to a potential interfering base station within a preset area, so that the potential interfering base station sends an interfering reference signal.

[0026] The second instruction module is configured to send a reception instruction to the disturbed base station so that the disturbed base station receives the interference reference signal and identifies the interfering base station.

[0027] To achieve the above objectives, this disclosure also provides a communication device, including a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein the processor executes the computer program to implement the cross-time slot interference detection method as described in any of the above embodiments.

[0028] To achieve the above objectives, embodiments of this disclosure also provide a computer-readable storage medium, the computer-readable storage medium including a stored computer program, wherein, when the computer program is executed, it controls the device where the computer-readable storage medium is located to perform the cross-time slot interference detection method as described in any of the above embodiments.

[0029] To achieve the above objectives, this disclosure also provides a computer program product, including computer instructions, which, when executed by a processor, implement the cross-time slot interference detection method as described in any of the above embodiments.

[0030] Compared to related technologies, this disclosure discloses a cross-time slot interference detection method, apparatus, device, medium, and product. The disturbed base station receives an interference reference signal sent by the disturbing base station under the instruction of the core network equipment. Based on the demodulated time-frequency code resources in the interference reference signal and a preset base station mapping relationship, the disturbing base station is identified. By locating the interfering base station, accurate interference avoidance is facilitated, preventing resource waste. Attached Figure Description

[0031] Figure 1 is a schematic diagram illustrating the principle of cross-slot interference provided in the embodiments of this disclosure;

[0032] Figure 2 is a flowchart illustrating the cross-slot interference detection method provided in an embodiment of this disclosure;

[0033] Figure 3 is a schematic diagram of the principle of the time offset provided in the embodiment of this disclosure;

[0034] Figure 4 is another flowchart illustrating the cross-slot interference detection method provided in an embodiment of this disclosure.

[0035] Figure 5 is another flowchart illustrating the cross-slot interference detection method provided in this embodiment of the present disclosure;

[0036] Figure 6 is a schematic diagram of the principle of the cross-slot interference detection method provided in the embodiments of this disclosure;

[0037] Figure 7 is a schematic diagram of the time-domain cyclic shift structure provided in the embodiment of this disclosure;

[0038] Figure 8 is a schematic diagram showing the position of the symbol occupied by the interference reference signal provided in the embodiments of this disclosure;

[0039] Figure 9 is a schematic diagram of another position of the symbol occupied by the interference reference signal provided in an embodiment of this disclosure;

[0040] Figure 10 is a structural block diagram of the cross-time slot interference detection device provided in an embodiment of this disclosure;

[0041] Figure 11 is another structural block diagram of the cross-time slot interference detection device provided in an embodiment of this disclosure;

[0042] Figure 12 is another structural block diagram of the cross-time slot interference detection device provided in the embodiments of this disclosure;

[0043] Figure 13 is a structural block diagram of a communication device provided in an embodiment of this disclosure. Embodiments of the present invention

[0044] The technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. Based on the embodiments of this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0045] The frame structure configuration defined by the 5G standard is highly flexible, allowing for different uplink / downlink ratios to be configured as needed based on service requirements. Currently, the 4.9GHz band in existing networks for general terminal users is configured with a DDDSUDSUU (7D3U) frame structure, with a downlink / uplink ratio of 7:3, which can match service models where download traffic is higher than upload traffic for general terminals. However, for commercial users, there are scenarios where uplink traffic is the primary function, such as smart factories and smart hospitals, which require real-time uploading of high-definition video information. Currently, the 4.9GHz band is configured with a DSUUU (3U1D) frame structure to meet the high uplink traffic demands.

[0046] When different frame structures are configured for the same frequency band, there is a cross-slot interference problem. See Figure 1, which is a schematic diagram of the principle of cross-slot interference provided by the embodiment of this disclosure. In the figure, D and S of base station B will interfere with U of base station A at the corresponding time slot position.

[0047] To address the issue of cross-slot interference, the current network avoids cross-slot interference through physical isolation, allowing the deployment of the 3U1D frame structure only in closed areas (such as mines) and remote areas (where 4.9GHz 7D3U has not been built).

[0048] However, with the introduction of integrated sensing and communication technology, cross-time slot interference has emerged between communication and sensing. Sensing base stations cannot avoid cross-time slot interference from communication base stations through physical isolation. The current approach is to punch holes in the time slots of all nearby communication base stations that may interfere with sensing, i.e., to silence them, not schedule them, and not use the resources.

[0049] In the current scenario where communication base stations and sensing base stations coexist on the same frequency, in order to ensure sensing performance and avoid interference from overlapping time slots, it is necessary to stop scheduling all interference time slots of all communication base stations within a certain range (e.g., 20km) around the sensing base station, resulting in a significant waste of resources.

[0050] To address the aforementioned technical problems, this disclosure proposes a cross-slot interference detection method, applied to an interfered base station. Referring to Figure 2, which is a flowchart illustrating the cross-slot interference detection method provided in this disclosure, the method includes operations S1 to S2:

[0051] Operate S1 to receive the interference reference signal sent by the interfering base station under the instruction of the core network equipment;

[0052] Operation S2: Determine the interfering base station based on the demodulated time-frequency code resources in the interference reference signal and the preset base station mapping relationship.

[0053] In some embodiments, the relevant base station, namely the interfered sensing base station or other equipment with signal receiving function, is in a receiving state, waiting to receive the interference reference signal sent by the interfering base station under the instruction of the core network equipment.

[0054] As the control center of the entire communication network, the core network equipment sends instructions to the scrambling base station, requesting it to transmit an interference reference signal. After receiving the instructions from the core network equipment, the scrambling base station transmits the interference reference signal according to the prescribed parameters (such as time-frequency characteristics, transmission power, modulation method, etc.).

[0055] The disturbed base station captures and receives the interference reference signal through its own antenna and signal receiving module, and demodulates the interference reference signal to obtain time and frequency code resources.

[0056] After receiving the interfering reference signal, the disrupted base station demodulates it. Demodulation is the process of recovering the original signal from the received modulated signal, that is, extracting the time-frequency code resource information carried in the interfering reference signal. The disrupted base station analyzes and decodes the interfering reference signal to accurately obtain the time-frequency code resources. For example, the time-frequency code resource information describes the distribution of the interfering reference signal in the time and frequency dimensions, such as on which specific time slots (time domain information) and subcarriers (frequency domain information) the signal was transmitted.

[0057] The disrupted base stations have pre-stored base station mapping relationships. These mapping relationships are established during the system planning or configuration phase and include the correspondence between the disrupting base station and specific time-frequency code resources. These mapping relationships can be stored and managed through databases, tables, or other data structures. For example, a specific combination of time-frequency code resources corresponds to a specific base station identifier, such as a CLI-gNB-ID (Cross-Link Interference gNodeB Identifier).

[0058] The demodulated time-frequency code resources are compared with a preset base station mapping relationship. The disturbed base station searches for a record in the preset base station mapping relationship that matches the acquired time-frequency code resources. If a matching record is found, the disturbing base station that sent the interference reference signal can be identified based on the corresponding base station identifier information in the record. For example, when the demodulated time-frequency code resources are completely consistent with the time-frequency code resources of a certain record in the mapping relationship, the base station identifier corresponding to that record represents the disturbing base station.

[0059] The disturbed base station can accurately identify the identity of the disturbing base station based on the time-frequency code resources in the received interference reference signal, providing key information for subsequent interference processing and management. For example, it can take corresponding interference suppression measures or adjust communication parameters for the disturbing base station, avoiding punching all interference time slots of all potentially interfering base stations, ensuring the normal operation of the network and communication quality, and avoiding resource waste.

[0060] In another embodiment provided in this disclosure, the transmission of the cross-slot reference signal is mainly applied to two situations. The first is when a sensing base station is about to be deployed or when the sensing frame structure is adjusted. That is, it is foreseeable that the cross-slot interference problem will be encountered. The second is when a sensing base station that has been in use for a period of time has avoided cross-slot interference, but with the construction and deployment of co-frequency communication base stations, that is, the increase in interference sources, the interference level of the disturbed base station increases, and the sensing performance deteriorates. That is, it is considered that new cross-slot interference has appeared. Therefore, this disclosure needs to detect the triggering conditions before performing cross-slot interference detection.

[0061] The monitoring module, acting as the first network device of the disturbed base station, continuously monitors the surrounding network environment and the signals it receives in real time. It monitors multiple parameters and indicators. For example, it monitors the strength of the received signal; when the signal strength is below a preset threshold, it may indicate interference, which can be part of the first signal triggering condition. Alternatively, it monitors the bit error rate (BER); if the BER exceeds a specified range, it indicates the network may be in an abnormal state, necessitating the triggering of the CLI (Cross-Link Interference) mechanism. It can also monitor specific interference characteristic signals; the detection of these characteristic signals is also considered a fulfillment of the first signal triggering condition. The monitoring module continuously collects this relevant data and compares it with the preset first signal triggering condition. Once any one of the conditions is met, it is determined that the first signal triggering condition has been met, and then sends the first parameter to the core network device, triggering the core network device to instruct the disturbing base station to send an interference reference signal.

[0062] When the CLI mechanism is triggered, the control logic module inside the disturbed base station receives a corresponding trigger signal after the triggering conditions are determined to be met. Based on this trigger signal, the module initiates the CLI interference handling mechanism.

[0063] The first parameter, CLI-start, is determined and sent. The control logic module of the disturbed base station determines the value of the first parameter (CLI-start) according to the requirements of the CLI mechanism. If the current situation requires the initiation of the relevant first signal transmission and detection operations, the CLI-start parameter is set to 1; if it is not required, or if the current state is considered unsuitable for initiation, the parameter is set to 0. In some cases, if initiation is not performed by default and there are no special requirements, this parameter can be left unsent.

[0064] Once the value of the CLI-start parameter is determined, the disturbed base station sends the first parameter to the core network device through the communication link established with the relevant network device (such as core network device or other devices that communicate with it).

[0065] It should be noted that during the transmission process, the parameters are encapsulated according to a predetermined communication protocol to ensure that they are transmitted to the target device accurately. For example, a reliable transport layer protocol, such as TCP (Transmission Control Protocol), is used to guarantee reliable transmission of parameters, or appropriate checksums are added at the data link layer to detect whether errors occur during transmission.

[0066] The core network device or other related device that receives the first parameter (CLI-start) parses it after receiving it. Based on the received parameter value (0, 1, or no value received), it determines the subsequent operation.

[0067] If the received CLI-start parameter is 1, the core network device will schedule tasks related to the transmission and detection of interference reference signals according to its internal configuration and policies. This may include instructing the relevant transmitting devices to prepare to transmit interference reference signals and configuring the corresponding detection devices to monitor and analyze the first transmitted signal. If the received parameter is 0 or the device is not received, the core network device will maintain its current operating state and will not perform any additional operations related to the transmission and detection of interference reference signals.

[0068] Through the above trigger condition detection process, the CLI mechanism is triggered and the first parameter is sent when the first signal trigger condition is met. Compared with the conventional method of indiscriminately monitoring interference and interacting with signals on all base stations, this saves a significant amount of network bandwidth and base station processing power. For example, when no interference occurs, the interfering base station does not need to frequently send interference reference signals, and the core network equipment does not need to continuously perform complex interference analysis, allowing network resources to be concentrated on normal communication services and improving the overall network operating efficiency.

[0069] In another embodiment provided in this disclosure, the detection process for interference measurement triggering conditions specifically includes:

[0070] When a sensing base station, acting as a target for interference, is deployed, it performs interference detection. This involves real-time monitoring of the surrounding electromagnetic environment and analysis of various received signals. For example, it determines the presence and level of interference by measuring signal strength and spectral characteristics at different frequency bands. As the base station is gradually deployed, various potential interference sources within its coverage area may affect it. The interference detection module continuously monitors these changes, and once it detects that the interference level exceeds a pre-set initial threshold, it initiates subsequent operational procedures.

[0071] For example, when the sensing frame structure of a disturbed base station is adjusted, the change in frame structure affects the signal transmission and reception modes, potentially altering the base station's sensitivity to interference. In this case, the base station's interference detection module will reset the interference detection parameters and standards based on the new frame structure characteristics. During operation after the frame structure adjustment, the interference level is continuously monitored. If a significant increase in the interference level is detected, exceeding the interference threshold set for the new frame structure, the interference measurement trigger condition will be activated.

[0072] When a new interfering base station (which could be another communication base station, wireless device, etc.) enters the coverage area of ​​a disturbed base station, the disturbed base station will identify the new interference source by analyzing signal characteristics. For example, it may detect a new signal frequency band, a sudden increase in signal strength, or the appearance of a modulation scheme different from known signals. Once it is determined that a new interfering base station exists and the interference level increases as a result, exceeding the corresponding interference threshold, it will be determined that the interference measurement triggering condition has been met.

[0073] When the disturbed base station detects an increase in interference level exceeding a threshold in any of the above scenarios, it generates a first parameter and sends the first parameter to the core network device through a communication link established with the core network or network management system, triggering the core network device to instruct the disturbing base station to send an interference reference signal.

[0074] By monitoring interference levels in real time during key scenarios such as deployment, adjustment of sensing frame structure, and the addition of new interfering base stations, changes in interference can be detected promptly and corresponding measures can be taken. This avoids long-term impacts of interference on the communication and sensing functions of the sensing base station, ensuring the normal operation and quality of service of the network.

[0075] By sending a first parameter containing detailed interference information to the core network or network management system, the core network or network management system can accurately understand the specific situation of the interference, thereby triggering the CLI mechanism in a targeted manner and formulating appropriate interference handling, identifying the interfering base station, adjusting the interfering base station, avoiding interference, and improving the accuracy of interference handling.

[0076] In various scenarios (deployment, frame structure adjustment, addition of scrambling base stations), interference can be effectively detected and corresponding mechanisms triggered, enabling the sensing base station to better adapt to changes in the network environment. Whether it is environmental changes brought about by the deployment of new base stations, signal mode changes caused by frame structure adjustments, or new interference sources generated by newly added scrambling base stations, it can respond in a timely manner, enhancing the robustness and adaptability of the network.

[0077] In another embodiment provided in this disclosure, when the disturbed base station receives the interference signal sent by the disturbing base station, the specific operations include the following:

[0078] A stable and reliable communication connection is pre-established between the disrupted base station (such as a sensing base station) and the core network equipment. For example, this connection can be based on various communication technologies, such as wired fiber optic networks or wireless cellular networks, like 4G (4th Generation Mobile Communication Technology) and 5G. This ensures that data is delivered accurately and promptly during transmission.

[0079] The disrupted base station awaits a reception instruction from the core network equipment. Upon receiving this instruction, its internal signal processing and control modules parse it. The reception instruction typically contains crucial information related to the impending interference reference signal, such as the transmission time window, modulation scheme, and frequency range. By accurately parsing this information, the disrupted base station prepares for receiving the interference reference signal.

[0080] Based on the analysis results of the received indication, the disturbed base station will adjust its own detection parameters accordingly to accurately capture the time and frequency band of the interfering reference signal; and configure appropriate demodulation algorithms and parameters according to the modulation method of the signal so as to correctly demodulate the received signal.

[0081] The disrupted base station initiates a receiving operation according to the detection parameters specified in the receiving instruction. The disrupted base station monitors the signals received by its receiving antenna and searches for an interference reference signal that matches the characteristics described in the receiving instruction. Since the interference reference signal is transmitted by the disrupting base station under the instruction of the core network equipment, the disrupted base station has a high probability of receiving this signal within the specified time window.

[0082] After receiving the interference reference signal, the disturbed base station demodulates the signal and extracts the time and frequency code resources carried in the signal, so as to locate the disturbing base station in some embodiments.

[0083] The disturbed base station can accurately receive the interference reference signal sent by the disturbing base station according to the instructions of the core network equipment. This provides an important data foundation for subsequent analysis and location of the interference source and the implementation of corresponding interference suppression measures, which helps to ensure the normal operation of the communication network and improve communication quality.

[0084] In another embodiment provided in this disclosure, the process of determining the receiving instruction specifically includes the following operations:

[0085] Upon receiving the time-frequency code resource location information from the core network equipment, the communication receiving module of the disrupted base station remains in a continuous listening state, waiting for the core network equipment to send the time-frequency code resource location information. Once the core network equipment determines the time-frequency code resource location used by the disrupting base station to send the interference reference signal based on network interference management policies and other factors, it will send this information to the disrupted base station.

[0086] The time-frequency code resource location information describes in detail the specific location of the interference reference signal in the time and frequency dimensions, such as which time slots and subcarriers the signal is transmitted on.

[0087] The detection time-domain location information is received from the core network equipment. This information is also determined by the core network equipment based on network conditions and interference management requirements. It may include information such as the areas or ranges that the disturbed base station needs to focus on detecting when receiving interference reference signals. This detection time-domain location information helps the disturbed base station to receive and detect signals more effectively, improving detection efficiency and accuracy, and avoiding wasting resources on ineffective detection in unnecessary areas.

[0088] The time-frequency code resource location and the detection time-domain location are used as receiving instructions. The disrupted base station adjusts the frequency and time-related parameters of its receiving equipment based on the time-frequency code resource location information in the receiving instructions, ensuring accurate alignment with the transmission frequency and time slot of the interfering reference signal. Simultaneously, based on the detection time-domain location information, the key area and range for signal detection are set. After setting the parameters, the disrupted base station initiates the receiving operation within the time period instructed by the core network equipment to send the interfering reference signal. Within the specified time-frequency code resource location and detection time-domain location range, the interfering reference signal is searched for and captured. Once the interfering reference signal is received, the receiving module performs preliminary amplification, filtering, and other preprocessing operations, and then transmits the signal to the subsequent signal analysis and processing module for demodulation, decoding, and other processing as described in some embodiments, to obtain the time-frequency code resources carried in the interfering reference signal for interference localization of the interfering base station.

[0089] The disrupted base station can accurately receive reception instructions sent by the core network equipment and effectively receive interference reference signals sent by the disrupting base station based on this information. The disrupted base station clearly identifies the key areas or ranges to be detected when receiving interference reference signals. The disrupted base station can concentrate its resources and computing power on detection, without wasting time and resources in unnecessary areas, greatly improving the efficiency of detecting interference reference signals, obtaining interference-related information more quickly, and accelerating the response speed to interference situations.

[0090] In another embodiment provided in this disclosure, the process of receiving the time-frequency code resource location and the indicated detection time-domain location specifically includes the following operations:

[0091] Upon receiving the first indication signal sent by the core network equipment, for example, after receiving the first parameter, the core network or network management system assigns a number to the nearby co-frequency communication base station, i.e., the interfering base station, and sends the ID (Identity) of all potential interfering base stations in the preset area to the disturbed base station.

[0092] The first indication signal contains the IDs of all potential interfering base stations within a preset area. The affected base station accurately extracts the ID information from the received first indication signal. The affected base station internally stores a pre-established base station mapping relationship, which records the correspondence between different base station IDs and their corresponding time-frequency code resource locations. Based on the IDs of each potential interfering base station extracted from the first indication signal, the affected base station sequentially accesses the base station mapping relationship. Within the base station mapping relationship, the affected base station searches for the record corresponding to each potential interfering base station ID. For each matching record found, the corresponding time-frequency code resource location information is retrieved.

[0093] The core network or network management system sends a second indication signal CLI-Rx, indicating the interference reference signal reception resources, to the interfering base station. The affected base station processes the received second indication signal and accurately extracts the key information of the detection time offset from the signal. The detection time offset is usually a time-related parameter, which represents the amount of time adjustment made by the affected equipment for interference detection based on a certain reference time.

[0094] The disturbed base station directly uses the extracted detection time offset as a key parameter for the detection time domain location. When detecting interference signals subsequently, the disturbed base station uses this detection time offset to determine the specific detection time and range on the time axis. For example, the disturbed base station may start detecting interference signals earlier or later than the time indicated by the detection time offset, based on the reference time, and perform signal monitoring and analysis within the corresponding time interval.

[0095] By receiving a first indication signal from the core network equipment containing the IDs of all potential interfering base stations within a preset area, and determining the corresponding time-frequency code resource locations from the base station mapping relationship based on these IDs, the disturbed base station can accurately locate all potential interfering base stations and their signal transmission time-frequency code resource locations within the preset area, and detect the time offset to determine the detection time domain location. This allows the disturbed base station to detect interference reference signals at more precise time points and time periods. It enables more accurate capture of interference reference signals, avoids unnecessary invalid detections, thereby improving the accuracy of interference reference signal detection and enabling more accurate location of the interference source.

[0096] In another embodiment provided in this disclosure, the transmission and detection time-domain positions of the interference reference signal CLI-RS include both time and frequency domains. The frequency domain position can be obtained through the gNB set ID (gNodeB set Identity, 5G base station set identification code), and the time domain position can be obtained through the gNB set ID to determine the relative time domain position in the Yth DL-UL switching period (Downlink-Uplink switching period). See Figure 3, which is a schematic diagram illustrating the principle of the time offset provided in this embodiment. The starting reference time and absolute time for detecting the time domain position need to be determined using Figure 3.

[0097] The time offset is detected, including the starting reference time T0.

[0098] The window length T of the time domain period in which the interference reference signal is located is a large transmission period. Within this time period, potential interference sources in a sensing area can take turns transmitting the reference signal. The reference signal can be mapped to different base station IDs through time domain location.

[0099] The position index M of the time domain period of the interference reference signal relative to the starting reference time is the position index M of the long period in which the time domain of the first signal is located, starting from the starting reference time. M = 0, 1, 2, ..., which can be configured. That is, when the first indicator signal is 1, it is the next complete long period window. For example, if the time corresponding to the first indicator signal being 1 is the Ath long period window, then M = A+1.

[0100] The window length t of the uplink / downlink switching cycle in which the interference reference signal is located can be, for example, set to 0.5ms, 0.625ms, 1ms, 1.5ms, 2ms, 2.5ms, 3ms, etc.

[0101] The sequence number N of the uplink / downlink switching cycle in the time domain where the interference reference signal is located is the Nth small cycle window within the Mth long cycle window.

[0102] The received symbol positions occupied by the interference reference signal, i.e. the timing of the reception of the interference reference signal, i.e. the occupied symbol positions, are at least 4. For example, the received symbol positions are 4 bits. 0000 represents the 0th, 1st, 2nd, and 3rd symbols; 0001 represents the 1st, 2nd, 3rd, and 4th symbols, and so on. 1010 represents the 10th, 11th, 12th, and 13th symbols; 1011 represents the 0th to 6th symbols; 1100 represents the 7th to 13th symbols; and 1101 represents the 0th to 13th symbols.

[0103] In yet another embodiment provided in this disclosure, operation S2 in the above embodiment specifically includes the following operations:

[0104] Based on the time offset indicating the location of the time-frequency code resource, the disturbed base station flexibly configures the frequency domain and time domain parameters of its receiving antenna to accurately locate the time-frequency code resource block where the interference reference signal CLI-RS may occur.

[0105] The interfered base station signal continuously scans the set time-frequency code resources according to the receiving instruction. After receiving the interference reference signal, it demodulates the time-frequency code resources carried by it. For example, if the interference reference signal adopts the QPSK (Quadrature Phase Shift Keying) modulation method, the demodulation module extracts the bit stream representing the time-frequency code resources from the received complex signal according to the demodulation rules corresponding to QPSK.

[0106] Using the demodulated time-frequency code resources, the disturbed base station queries the mapping table of the matching relationship between the location of the time-frequency code resources and the corresponding potential interfering base station IDs stored locally, and determines the ID of the interfering base station that sent the interference reference signal, thereby realizing the detection of the interfering base station.

[0107] Meanwhile, the power detection module of the disturbed base station measures the power of the first received signal in real time, records it, and stores it in association with the corresponding disturbing base station ID. Utilizing a high-precision power sensor and real-time data processing capabilities ensures the accuracy of power measurement, providing a reliable basis for subsequent interference assessment.

[0108] Through signal detection, demodulation, and mapping table lookup processes, the disturbed base station can accurately resolve the ID of the interfering base station, precisely locating the interference source in complex communication network environments. By recording the received power of the interfering base station and using specific power values ​​as a measurement standard, a quantitative assessment of the interference level is achieved, rather than a vague qualitative one. This provides crucial data support for network administrators to formulate differentiated interference suppression strategies. For example, emergency power adjustments or frequency band avoidance measures can be taken against strong interference sources, while regular monitoring and optimization can be performed on weak interference sources, achieving precise control over interference avoidance.

[0109] In another embodiment provided in this disclosure, the base station mapping relationship includes the matching relationship between different time-frequency code resource locations and corresponding potential interfering base station IDs;

[0110] Each base station is uniquely identified by a CLI-gNB-ID. The transmitting end determines the transmission resources of the CLI-RS based on the configured CLI-gNB-ID, and conversely, the receiving end can uniquely deduce the transmitting end's CLI-gNB-ID information based on the resource location of the received CLI-RS. A resource for transmitting a CLI-RS is identified by its time-domain sequence number. Frequency domain number and sequence field number To determine this, different time-domain numbers represent different transmission opportunities, different frequency-domain numbers represent different frequency-domain resource locations, and different sequence-domain numbers represent different root sequences.

[0111] Understanding the time-frequency code resource usage of different potential interfering base stations helps core network equipment or network administrators allocate network resources rationally. For example, by identifying base stations with severe interference occupying certain frequency bands or time slots based on mapping relationships, the resource allocation of other base stations can be adjusted to avoid communication in these interfered areas, thereby optimizing the overall network resource utilization and improving network performance and capacity. Based on accurate base station mapping relationships, the network can take more targeted anti-interference measures. For instance, for known interference source base stations, interference suppression algorithms can be used to eliminate or reduce interference in specific time, frequency, or sequence domains based on the location of their used time-frequency code resources; or the operating parameters of the disturbed base stations can be adjusted to avoid the time-frequency code resources of the interference source, enhancing the network's anti-interference capability and ensuring communication reliability.

[0112] Another embodiment of this disclosure provides a cross-time slot interference detection method applied to an interfering base station. Referring to Figure 4, which is another flowchart of the cross-time slot interference detection method provided in this disclosure, the method includes the following operations:

[0113] Operate S401 to receive the instruction to send resources sent by the core network device;

[0114] In operation S402, an interference reference signal is sent to the disturbed base station according to the transmission instruction, so that the disturbed base station can determine the interfering base station.

[0115] In some embodiments, during interference detection, a stable communication connection is maintained between the interfering base station and the core network equipment. This connection typically relies on existing communication network architectures, such as 4G, 5G, or other wireless communication links or wired fiber optic links, to ensure the timeliness and accuracy of data transmission.

[0116] When the core network determines that a certain interfering base station needs to assist in locating the interference source based on network-wide interference monitoring, network optimization needs, or feedback information from the disturbed base station, it will send an instruction to the interfering base station to send resources. The interfering base station receives the instruction from the core network equipment.

[0117] It should be noted that the transmission instruction includes detailed information about the transmission resources of the interference reference signal, such as specific time-domain time slot arrangements, informing the interfering base station of the time period during which the signal will be transmitted. This time window may be accurate to the millisecond or even microsecond level so that the interfered base station can accurately receive the signal during the corresponding time period. The frequency-domain subcarrier allocation details specify which specific frequency resources the interfering base station should use to carry the interference reference signal to avoid frequency conflicts with other normal communication services. It also includes signal sequence-related parameters that may be involved, such as which root sequence is used to generate the interference reference signal to ensure the uniqueness and identifiability of the signal.

[0118] The interfering base station configures the corresponding parameters according to the transmission instructions and sends an interference reference signal to the interfered base station. This ensures that the interfered base station can successfully receive a clear and accurate interference reference signal.

[0119] Core network equipment can flexibly allocate interference reference signals sent by disruptive base stations based on the overall network interference situation, achieving refined management of interference. The disruptive base stations responding to the core network equipment's instructions by sending interference reference signals demonstrates the high degree of coordination among all nodes in the communication network. This enhances the network's overall anti-interference capability and adaptive adjustment ability, providing users with more reliable communication services.

[0120] In another embodiment provided in this disclosure, the receipt of the transmission instruction for transmission resources sent by the core network device includes:

[0121] When the core network determines, based on its monitoring and analysis of network interference and overall optimization needs, that it requires the assistance of the interfering base station for interference troubleshooting or testing, it will send specific time-frequency code resource location information. Upon receiving this information, the interfering base station accurately extracts the time-frequency code resource location description from the data packet. This description typically includes the time slot arrangement of the interfering reference signal in the time domain (accurate to a specific time segment, such as a millisecond-level time period) and the subcarrier distribution in the frequency domain (clearly defining the specific frequency resource range to be used to avoid conflicts with other normal communication services). This information is then stored in a local cache for subsequent configuration.

[0122] The harassing base station also receives transmission time-domain location information sent by the core network.

[0123] The time-frequency code resource location and the transmission time domain location are used as transmission indicators. The interference reference signal CLI-RS is transmitted according to the time offset relative to the time-frequency code resource location and the indicated transmission time domain location. The transmitter's time slot, frequency, and sequence parameters are configured based on the time-frequency code resource location to ensure that the interference reference signal is transmitted accurately and without error as required by the core network equipment.

[0124] The precise location of time-frequency code resources allows scrambling base stations to reasonably avoid transmitting time-frequency code resources used for normal communication services when sending interference reference signals, preventing unnecessary interference to other communications and achieving refined utilization of limited network resources. Simultaneously, transmitting time-domain location information guides scrambling base stations to send signals targeted to specific areas, avoiding indiscriminate signal propagation, reducing energy waste in non-target areas, and overall optimizing network resource allocation and improving network capacity.

[0125] In another embodiment provided in this disclosure, the process of determining the time-frequency code resource location and the transmission time domain location in the scheme specifically includes the following operations:

[0126] The core network equipment sends a third indication signal to the harassing base station, which contains the unique ID of the harassing base station, such as CLI-gNB-ID.

[0127] The harassing base station receives and parses the third indication signal, and extracts the base station ID from it.

[0128] It should be noted that the harassing base station internally stores a base station mapping table, which records the mapping relationship between different base station IDs and the corresponding time-frequency code resource locations (time domain number, frequency domain number, sequence domain number).

[0129] Based on the extracted base station ID, the interfering base station quickly searches the mapping table to determine the location of its own time-frequency code resource. For example:

[0130] It should be noted that the time-frequency code resource location includes: a time domain number (specifying which time slot within a certain period to transmit the signal), a frequency domain number (specifying which subcarriers or frequency bands to use), and a sequence domain number (selecting a specific root sequence to generate the signal).

[0131] The core network equipment sends a fourth indication signal to the interfering base station based on the network-wide time slot scheduling requirements, which includes the transmission time offset.

[0132] The harassing base station receives and parses the fourth indication signal, extracts the time offset, and determines the specific transmission time domain location.

[0133] The interfering base station, combining the determined time-frequency code resource location and transmission time domain location, configures transmission parameters, including: Time domain: opening a transmission window at the calculated transmission time domain location (T0 + Δt); Frequency domain: tuning to the subcarrier corresponding to the specified frequency domain sequence number; Sequence domain: generating an interference reference signal with a specific root sequence (such as the Zadoff-Chu sequence) based on the sequence domain sequence number. The interfering base station transmits the interference reference signal on time at the configured time-frequency code resource location, ensuring that the signal strictly follows the scheduling arrangements of the core network equipment. The interfered base station receives the signal according to the same mapping relationship and time-frequency code resource rules, completing the identification of the interference source.

[0134] This disclosed solution ensures that the time-frequency code resource location of each interfering base station is unique and fixed by binding the base station ID with a mapping relationship, avoiding signal interference caused by resource overlap between multiple base stations. Multiple base stations allocate non-conflicting time-frequency code resources through a mapping table, reducing the probability of co-channel interference. Core network equipment dynamically adjusts the transmission timing through time offset, achieving flexible scheduling of time slot resources across the entire network. In scenarios of network load fluctuations or sudden interference, the core network can quickly adjust the time offset, avoiding resource waste caused by static time slot allocation.

[0135] In another embodiment provided in this disclosure, the base station mapping relationship includes the matching relationship between different time-frequency code resource locations and corresponding potential interfering base station IDs;

[0136] Each base station is uniquely identified by a CLI-gNB-ID. The transmitting end determines the transmission resources of the CLI-RS based on the configured CLI-gNB-ID, and conversely, the receiving end can uniquely deduce the transmitting end's CLI-gNB-ID information based on the resource location of the received CLI-RS. A resource for transmitting a CLI-RS is identified by its time-domain sequence number. Frequency domain number and sequence field number To determine this, different time-domain numbers represent different transmission opportunities, different frequency-domain numbers represent different frequency-domain resource locations, and different sequence-domain numbers represent different root sequences.

[0137] Understanding the time-frequency code resource usage of different potential interfering base stations helps core network equipment or network administrators allocate network resources rationally. For example, by identifying base stations with severe interference occupying certain frequency bands or time slots based on mapping relationships, the resource allocation of other base stations can be adjusted to avoid communication in these interfered areas, thereby optimizing the overall network resource utilization and improving network performance and capacity. Based on accurate base station mapping relationships, the network can take more targeted anti-interference measures. For instance, for known interference source base stations, interference suppression algorithms can be used to eliminate or reduce interference in specific time, frequency, or sequence domains based on the location of their used time-frequency code resources; or the operating parameters of the disturbed base stations can be adjusted to avoid the time-frequency code resources of the interference source, enhancing the network's anti-interference capability and ensuring communication reliability.

[0138] In another embodiment provided in this disclosure, the transmission and detection time domain positions of CLI-RS include the time domain and the frequency domain. The frequency domain position can be obtained through the gNB set ID, and the time domain position can be obtained through the gNB set ID. The relative time domain position in the Yth DL-UL switching period is shown in Figure 3. The start reference time and absolute time of the detection time domain position need to be determined through Figure 3.

[0139] The time offset is detected, including the starting reference time T0.

[0140] The window length T of the time domain period in which the interference reference signal is located is a large transmission period. Within this time period, potential interference sources in a sensing area can take turns transmitting the reference signal. The reference signal can be mapped to different base station IDs through time domain location.

[0141] The position index M of the time domain period of the interference reference signal relative to the starting reference time is the position index M of the long period in which the time domain of the first signal is located, starting from the starting reference time. M = 0, 1, 2, ..., which can be configured. That is, when the first indicator signal is 1, it is the next complete long period window. For example, if the time corresponding to the first indicator signal being 1 is the Ath long period window, then M = A+1.

[0142] The window length t of the uplink / downlink switching cycle in which the interference reference signal is located can be, for example, set to 0.5ms, 0.625ms, 1ms, 1.5ms, 2ms, 2.5ms, 3ms, etc.

[0143] The sequence number N of the uplink / downlink switching cycle in the time domain where the interference reference signal is located is the Nth small cycle window within the Mth long cycle window.

[0144] The transmitted symbol positions occupied by the interference reference signal, i.e., the timing of the transmission of the interference reference signal, i.e., the occupied symbol positions, are at least 4. For example, the received symbol positions are 4 bits, where 0000 represents the 0th, 1st, 2nd, and 3rd symbols, 0001 represents the 1st, 2nd, 3rd, and 4th symbols, and so on. 1010 represents the 10th, 11th, 12th, and 13th symbols; 1011 represents the 0th to 6th symbols; 1100 represents the 7th to 13th symbols; and 1101 represents the 0th to 13th symbols.

[0145] In another embodiment provided in this disclosure, the interference reference signal is transmitted to the disturbed base station via an air interface.

[0146] The scrambling base station transmits an interfering reference signal over the air interface. Air interface transmission utilizes the propagation characteristics of electromagnetic waves in space to transmit signals. The transmitting end modulates the information to be transmitted (such as voice, data, images, etc.) onto a high-frequency carrier wave, and radiates the modulated signal into the surrounding space as electromagnetic waves through an antenna. The scrambling base station selects an appropriate modulation method and coding scheme based on the distance between itself and the scrambled base station, channel conditions, and communication protocol requirements. If the distance is short and the channel quality is good, a higher-order modulation method, such as 64QAM (Quadrature Amplitude Modulation) or even higher, may be used to increase the transmission rate. This is combined with an efficient coding scheme, such as LDPC (Low-Density Parity-Check) coding, to ensure the reliability of signal transmission. If the distance is long or the channel experiences fading or interference, the system will adjust to a more robust lower-order modulation method (such as QPSK) and a coding scheme with stronger error correction capabilities to ensure that the interfering reference signal reaches the scrambled base station accurately.

[0147] Compared to other complex or indirect methods of transmitting interference signals, using the air interface to directly transmit interference reference signals simplifies the transmission process and reduces errors and delays that may be introduced by intermediate links.

[0148] In another embodiment of this disclosure, a cross-slot interference detection method is provided, applied to core network equipment. Referring to Figure 5, which is a schematic flowchart of another cross-slot interference detection method provided in this embodiment, the method includes:

[0149] Operate S501 to receive the trigger command sent by the disturbed base station;

[0150] In operation S502, a transmission instruction is sent to a potential interfering base station within a preset area, so that the potential interfering base station transmits an interference reference signal;

[0151] In step S503, a reception instruction is sent to the disturbed base station so that the disturbed base station receives the interference reference signal and identifies the interfering base station.

[0152] In some embodiments, the core network equipment acts as the control center of the entire communication network, maintaining a stable and reliable two-way communication link with numerous disrupted base stations to ensure data interaction.

[0153] The disturbed base station tracks key indicators of its received signals in real time, including signal-to-noise ratio, bit error rate, and signal strength fluctuations. Once the interference level exceeds a preset threshold, the interference detection process is triggered. The disturbed base station sends a trigger command to the core network equipment (including the core network or network management system), and the core network equipment receives the command and triggers the CLI mechanism.

[0154] The core network equipment determines a pre-defined area within a certain radius, centered on the disturbed base station and estimated based on the interference propagation model. It then queries the stored base station database to identify all potential interfering base stations within this area that are using the same or similar frequency bands as the disturbed one and that exhibit frame structure interference.

[0155] For each potential interfering base station, the core network equipment sends an instruction. The instruction contains precise time-frequency code resource allocation information, clearly specifying the exact time domain location at which each potential interfering base station transmits the interference reference signal. The instruction is then sent to the corresponding potential interfering base station one by one.

[0156] The core network equipment also generates a reception instruction for the affected base station. The reception instruction includes the predicted location information of the time-frequency code resources of the interfering reference signal, and is derived from the corresponding transmission instruction sent to the potential interfering base station, informing the affected base station in which time domain intervals and frequency domain ranges to focus on receiving signals;

[0157] Upon receiving a transmission instruction from the core network equipment, a potential interfering base station immediately initiates the interference reference signal generation and configuration process. Based on the time-frequency code resource requirements in the instruction, it generates an interference reference signal conforming to a specific sequence and modulation scheme, and transmits the interference reference signal as electromagnetic waves over the air interface.

[0158] The disrupted base station adjusts its receiving antenna monitoring parameters in advance based on the reception instructions sent by the core network equipment to monitor the interference reference signal. Upon receiving the interference reference signal, it demodulates and decodes the signal, extracts the time-frequency code resource information contained within, and compares it with a pre-stored time-frequency code resource mapping table of potential interfering base stations. Based on the matching result, the identity of the disrupting base station is accurately determined. At the same time, auxiliary information such as the strength and arrival time of the interference reference signal sent by the disrupting base station is recorded, providing detailed data support for interference analysis and processing in subsequent embodiments.

[0159] By combining the sensitive interference monitoring and triggering of the disturbed base station with the powerful control and scheduling of the core network equipment, it is possible to respond quickly to interference events in complex communication network environments, accurately locate the area where potential interfering base stations are located, and prompt potential interfering base stations to send interference reference signals with clear characteristics, so that the disturbed base station can quickly and accurately identify the interfering base station.

[0160] In another embodiment provided in this disclosure, the process of sending a transmission instruction to a potential interfering base station specifically includes:

[0161] Referring to Figure 6, it is a schematic diagram of the principle of the cross-time slot interference detection method provided in the embodiments of this disclosure.

[0162] As the primary network device, the disturbed base station is located within the communication network and constantly monitors the status of its received signals. Once it detects interference conditions that meet the preset criteria (such as low signal-to-noise ratio or increased bit error rate), it immediately collects relevant interference information, encapsulates it into the first parameter CLI-start, and sends it to the core network or network management system.

[0163] As the core network / network management system of the third network device, it addresses the different needs of the disrupting and affected base stations. For the disrupting base station, which is the second network device, it sends a second signal CLI-gNB-ID containing only its own ID, allowing the disrupting base station to clearly identify itself as a unique identifier in this interference investigation process. For the affected base station, it sends a second signal CLI-gNB-ID covering the IDs of all disrupting base stations in the area, enabling the affected base station to know the full picture of potential interference sources and prepare for reception and analysis in advance.

[0164] Based on factors such as network time slot arrangements, spectrum planning, and the urgency of interference investigation, the core network / network management system meticulously calculates and generates a third signal CLI-Tx indicating the first signal transmission resources and a fourth signal CLI-Rx indicating the first signal reception resources. The third signal CLI-Tx specifies in detail the time-frequency code resources for the interfering base station to transmit the first signal CLI-RS, including specific time slot allocation (accurate to the microsecond level to ensure no conflict with other service time slots) and the selection of frequency domain subcarriers (avoiding critical communication frequency bands currently in use to reduce the impact on normal services). The fourth signal CLI-Rx specifies for the interfering base station when and in which frequency domains to focus on receiving the first signal CLI-RS, fully considering factors such as signal propagation delay and multipath effects, ensuring that the interfering base station can capture the signal at the appropriate "time" and "frequency band".

[0165] After receiving the second and third signals from the core network or network management system, the interfering base station quickly extracts its own ID and corresponding transmission resource information. Based on the relative time-frequency code resource position of the second signal, it determines the resource distinction between itself and other interfering base stations; then, combined with the time offset indication of the third signal, it ensures that the signal transmission process is initiated on time at the specified time domain position.

[0166] The disrupting base station generates a first signal CLI-RS and transmits it at a predetermined power by carefully adjusting the transmitter parameters, conveying crucial interference investigation information to the disrupted base station.

[0167] After receiving the second signal (containing the IDs of all interfering base stations) and the fourth signal CLI-Rx from the core network or network management system, the disturbed base station stores the ID information of all interfering base stations to prepare for subsequent identification of the interference source. On the other hand, based on the receiving resource indication in the fourth signal CLI-Rx, it quickly adjusts the pointing of its receiving antenna, frequency response range, and signal detection sensitivity and other detection parameters.

[0168] Based on the relative time-frequency code resource location of the second signal, the first signal CLI-RS is detected attentively within the corresponding time-frequency code resource "search interval". Once the signal is captured, the disturbed base station immediately initiates the demodulation and decoding process, extracts the time-frequency code resource information contained therein, and compares and matches it with the known information related to the disturbing base station ID. Based on the matching result, the identity of the disturbing base station is accurately determined, and key indicators such as the first signal received power of the disturbing base station are recorded for subsequent quantitative analysis of the interference level.

[0169] It should be noted that, in some embodiments, the third and first indication signals in this disclosure may be executed in the form of a second signal, and in some embodiments, the fourth and second indication signals in this disclosure may be executed in the form of a third signal.

[0170] Through unified scheduling by the core network or network management system, the harassing base station sends a first signal (CLI-RS) with distinct characteristics. The harassed base station, following a carefully designed reception process, can accurately capture and identify these signals from the complex electromagnetic environment, thereby accurately locating the harassing base station. Compared to traditional interference detection methods, this mechanism based on fine-grained time-frequency code resource allocation and ID matching greatly improves the accuracy of interference source location, effectively avoids misjudgments, and can identify the true harassing base station in a short time.

[0171] In another embodiment provided in this disclosure, the third indication signal or the first indication signal uses SSB (Synchronization Signal Block) or NCell-ID (NR Cell Identity) to record the ID of the potential interfering base station.

[0172] In some embodiments, after receiving the first parameters related to cross-time slot interference from the disturbed sensing base station, the core network or network management system will quickly and accurately determine the location and association between the communication base station (disrupting base station) and the sensing base station (disrupted base station) based on its stored network topology information and base station database. Since sensing services are localized, communication base stations within that area are identified as potential disrupting base stations.

[0173] The CLI-gNB-ID is named to uniquely identify potential interfering base stations. It is sent by a third network device (core network or network management) to the first network device (the affected base station) and the second network device (the interfering base station). Taking an interference range of 20km as an example, assuming the distance between communication stations is 200 meters, the number of communication base stations involved is π×20km×20km / (π×200m×200m)=10000. Considering that each base station has three sectors, the number of cells involved is 30000. To ensure that the cells can be uniquely identified, the CLI-gNB-ID is defined, which can be configured with 1 to 16 bits. Alternatively, the second signal uses SSB, applied when the number of base stations to be identified is in the tens or hundreds (SSB can uniquely identify 1008 cells). Or, the second signal uses NCell-ID (NR Cell Identity) from NCGI. NCell-ID is used to uniquely identify a specific cell in the network; it consists of 36 bits.

[0174] The core network or network management system assigns information numbers to these disruptive base stations for subsequent orderly scheduling. For each disruptive base station, the core network or network management system sends an indication signal containing only its own disruptive base station ID. This indication signal, or the first indication signal, utilizes existing SSBs or NCell-IDs (cell identifiers used to uniquely identify cells), leveraging the inherent synchronization and cell search capabilities of SSBs in 5G communication, or the precise cell identification function of NCell-IDs, enabling the disruptive base station to clearly identify itself. For affected sensing base stations, the core network or network management system sends a second signal covering all disruptive base station IDs in the area, informing the affected base station of the range of potential interference sources.

[0175] In another embodiment provided in this disclosure, the process for determining the ID of a potential interfering base station includes:

[0176] When the third indication signal or the first indication signal does not rely on existing SSB or NCell-ID, in order to achieve accurate interference identification and management, it is necessary to reconstruct the allocation principle of CLI-gNB-ID (i.e., the interfering base station identifier). In some embodiments, the scheme is as follows:

[0177] Within the specific area covered by the sensing service, a total of n sensing base stations were deployed. First, using precise geolocation technology and network planning algorithms, the geometric center of the sensing area was selected as a reference point. The selection of this reference point was optimized to ensure that its distance Di to the i-th (i=1,2,…,n) sensing base station was as close as possible, maximizing the balance of the spatial relationship between each sensing base station and the center point, and providing accurate reference coordinates for the subsequent identification of potential interference sources.

[0178] Using a selected center point as the origin, a predefined cross-timeslot interference distance Δ is established, for example, 20km. A circular area with a radius of Δ+Di is defined. All communication base stations operating in the same frequency band within this area are considered potential interference sources and included in the investigation. This screening method, based on both distance and frequency, can accurately focus on the group of base stations most likely to cause cross-timeslot interference, greatly narrowing the investigation scope and improving interference location efficiency.

[0179] Considering the unique characteristics of signal transmission directions in different sectors within the same site, especially the distinct interference patterns exhibited in back-to-back and head-on scenarios, potential interference sources were systematically numbered according to the chronological order of base station construction in the sensing area, organized by sector. Each sector corresponds to a unique numbering sequence, enabling the numbering to distinguish between different base stations.

[0180] In actual network expansion and iteration, if potential interference sources in the newly built area B overlap with potential interference sources in the previously built area A, to avoid redundancy and confusion in numbering, the existing numbers are directly reused for the overlapping base stations. Only newly added base stations or base stations in changed areas that have not yet been numbered are continued to be numbered according to established rules. This flexible yet rigorous numbering continuation mechanism ensures the consistency and accuracy of the entire CLI-gNB-ID system during dynamic network evolution.

[0181] Potential interference sources are numbered on a sector-by-sector basis, taking into full account the unique interference characteristics between different sectors within the same site. This allows for tailored interference suppression strategies to the specific circumstances of different sectors, such as adjusting transmit power, optimizing time slot allocation, and changing signal beam direction. This enables precise control of interference, avoiding the resource waste and poor results of a one-size-fits-all approach, and comprehensively improving the network's anti-interference performance.

[0182] In another embodiment provided in this disclosure, referring to Figure 7, it is a schematic diagram of the principle of the time-domain cyclic shift structure provided in the embodiment of this disclosure.

[0183] To ensure that the interfered base station (disturbed base station) can more easily complete signal reception within one symbol, CLI-RS occupies 2 symbols. The third indication signal or the first indication signal adopts a time-domain cyclic shift structure and reuses the FFT (Fast Fourier Transform) module on the Tx (Transmit) side or the IFFT (Inverse Fast Fourier Transform) module on the Rx (Receive) side.

[0184] A time-domain cyclic shift structure (as shown on the right side of Figure 7) is employed. The left side of the figure represents the conventional structure, which includes a cyclic prefix (CP) and two signal sequences (Seq). The right side represents the structure after time-domain cyclic shifting, which is more adaptable to specific communication requirements. This involves shifting a portion of the signal sequence (shifted Seq). This structure is capable of mitigating delays over extremely long paths, as signal transmission over long distances incurs delays. This structure can compensate for these delays to a certain extent, ensuring accurate signal reception.

[0185] The third indicator signal or the first indicator signal can reuse the Fast Fourier Transform (FFT) module on the transmitting side (Tx side) and the Inverse Fast Fourier Transform (IFFT) module on the receiving side (Rx side). This helps reduce hardware resource consumption, lower equipment costs, simplify signal processing, and improve the operating efficiency of the communication system.

[0186] In another embodiment provided in this disclosure, the transmission time offset includes a start reference time, the window length of the time domain period in which the interference reference signal is located, the position index number of the time domain period in which the interference reference signal is located relative to the start reference time, the window length of the uplink / downlink switching period in which the interference reference signal is located, the sequence number of the uplink / downlink switching period in which the interference reference signal is located in the time domain period, and the transmission symbol position occupied by the interference reference signal.

[0187] The detection time offset includes the start reference time, the window length of the time domain period in which the interference reference signal is located, the position index number of the time domain period in which the interference reference signal is located relative to the start reference time, the window length of the uplink / downlink switching period in which the interference reference signal is located, the sequence number of the uplink / downlink switching period in which the interference reference signal is located in the time domain period, and the received symbol position occupied by the interference reference signal.

[0188] The specific implementation schemes for the detection time offset and transmission time offset have been described in the previous embodiments, and will not be repeated in this embodiment.

[0189] In another embodiment provided in this disclosure, the calculation of the window length of the time domain period of the interference reference signal specifically includes the following operations:

[0190] The core network or network management system counts the number of co-frequency communication cells within the defined potential interference source range to obtain the total. For example, if a scan of an area within a specific radius centered on the center of the sensing region identifies 50 co-frequency communication cells, then total = 50.

[0191] Based on the network configuration and interference troubleshooting requirements, determine the window length t of the uplink / downlink handover cycle in which the interference reference signal is located. This value is usually determined during network planning or interference management strategy formulation; for example, t may be set to 5 milliseconds (ms).

[0192] Based on the transmission plan of the interference reference signal during the uplink / downlink switching cycle, its transmission time domain position p is determined. For example, if the interference reference signal is planned to be transmitted at the third specific time slot position during an uplink / downlink switching cycle, p corresponds to this position number.

[0193] Window length of the time-domain period of the interfering reference signal .

[0194] In another embodiment provided in this disclosure, referring to Figure 8, it is a schematic diagram of the position of the symbols occupied by the interference reference signal provided in this embodiment. From the time slot structure in Figure 8, a complete time slot is divided into multiple symbols. One time slot contains 14 symbols. Due to the characteristics of the sensing service, the first 7 symbols are occupied by sensing (marked as "sensing" in the first figure). Furthermore, because the current communication terminal does not support the anyPDCCH (any Physical Downlink Control Channel) function, the last 7 symbols originally planned for communication (marked as "F" in the first figure and "D" in the second figure) are idle. This provides available resources for the operation of the first signal (CLI - RS).

[0195] Since the last 7 symbols are idle, the related operation of the first signal CLI-RS, which can be used to interfere with the reference signal, occupies 2 symbols. Considering that there is a maximum delay of 2 symbols in signal transmission within the cross-slot interference range (e.g., at a distance of 20 km), and to minimize the impact on communication performance, it is stipulated that CLI-RS must be transmitted before the 10th symbol (inclusive) of the cross-slot. As can be seen from Figure 8a), there are 4 possible transmission positions that meet this condition: ① (symbols 7 and 8), ② (symbols 8 and 9), ③ (symbols 9 and 10), and ④ (symbols 10 and 11).

[0196] Because there is a maximum delay of 2 symbols in signal transmission, the detection position is set from symbol 7 to symbol 13 to ensure reception of the first signal. Figure 8b) shows four possible detection starting positions, each corresponding to a different reception window setting: ①: Detection starts from symbol 7; ②: Detection starts from symbol 8; ③: Detection starts from symbol 9; ④: Detection starts from symbol 9. When the disturbed base station performs signal detection, the maximum signal transmission delay (2 symbols) must be considered, so the detection position is set from symbol 7 to symbol 13. Thus, after the disturbing base station selects one of the above four positions to send the signal, the disturbed base station can receive the first signal, which may have a delay, within the set detection range, thereby completing the signal detection and reception.

[0197] When the communication terminal has low support for the anyPDCCH function: as mentioned above, the last 7 symbols of the cross time slot are idle and used for the first signal detection reception. The transmission position is in symbols 7-11, and the detection position is in symbols 7-13.

[0198] When the communication terminal improves its support for the anyPDCCH function, the last 7 symbols are scheduled by the communication network and cannot be used for operations related to the first signal. Therefore, the transmission and reception of the first signal are adjusted to the first 7 symbols. As shown in the transmission time slot diagram (see Figure 9), this is another schematic diagram of the symbol positions occupied by the interference reference signal provided in this embodiment. Referring to Figure 9a), there are 4 selectable transmission positions: ① (symbols 0 and 1), ② (symbols 1 and 2), ③ (symbols 2 and 3), and ④ (symbols 3 and 4). As shown in the detection time slot diagram, there are also 4 selectable detection positions: ① (symbols 0-2), ② (symbols 1-3), ③ (symbols 2-4), and ④ (symbols 3-5). The overall detection position is symbols 0-6.

[0199] Based on the waveform arrangement of the interfering base station, symbols 0-3 are currently LFM (Linear Frequency Modulation) waveforms, and symbols 4-6 are OFDM (Orthogonal Frequency Division Multiplexing) waveforms. Following the principle of maximizing multiplexing, the position with the highest proportion of OFDM waveform symbols (which are also OFDM waveforms) should be selected. Comparing the four possible positions (see Figure 9b), position ④ has the highest proportion of OFDM waveform symbols. Therefore, in some embodiments, the first signal is transmitted and detected at position ④. The interfering base station transmits the first signal in symbols 3 and 4, and the interfered base station detects the signal in symbols 3-5.

[0200] Depending on the varying levels of support for the anyPDCCH function by the communication terminals, the transmission and detection positions of the first signal can be flexibly adjusted to ensure effective transmission and reception of interference reference signals at different stages. This enhances the adaptability and compatibility of the solution and ensures the continuous and stable operation of the communication system as terminal capabilities evolve.

[0201] Another embodiment of this disclosure provides a cross-time slot interference detection device. Referring to Figure 10, which is a structural block diagram of the cross-time slot interference detection device provided in this embodiment, the device is applied to an interfered base station and includes:

[0202] The receiving module is configured to receive interference reference signals sent by the interfering base station under the instruction of the core network equipment;

[0203] The mapping module is configured to determine the interfering base station based on the demodulated time-frequency code resources in the interference reference signal and a preset base station mapping relationship.

[0204] The cross-slot interference detection device provided in this embodiment can perform all the operations and functions applied to the disturbed base station in the cross-slot interference detection method provided in any of the above embodiments. The specific functions of the device will not be described in detail here.

[0205] Another embodiment of this disclosure provides a cross-time slot interference detection device. Referring to Figure 11, which is another structural block diagram of the cross-time slot interference detection device provided in this disclosure, it is applied to the interfering base station. The device includes:

[0206] The receiving module is configured to receive instructions from core network devices regarding the transmission of resources.

[0207] The transmitting module is configured to transmit an interference reference signal to the disturbed base station according to the transmitting instruction, so that the disturbed base station can identify the interfering base station.

[0208] The cross-slot interference detection device provided in this embodiment can perform all the operations and functions applied to the interfering base station in the cross-slot interference detection method provided in any of the above embodiments. The specific functions of the device will not be described in detail here.

[0209] Another embodiment of this disclosure provides a cross-slot interference detection device. Referring to Figure 12, which is another structural block diagram of the cross-slot interference detection device provided in this disclosure, it is applied to core network equipment. The device includes:

[0210] The triggering module is configured to receive triggering commands sent by the disturbed base station;

[0211] The first instruction module is configured to send a transmission instruction to a potential interfering base station within a preset area, so that the potential interfering base station sends an interfering reference signal.

[0212] The second instruction module is configured to send a reception instruction to the disturbed base station so that the disturbed base station receives the interference reference signal and identifies the interfering base station.

[0213] The cross-slot interference detection device provided in this embodiment can perform all the operations and functions applied to the core network equipment in the cross-slot interference detection method provided in any of the above embodiments. The specific functions of the device will not be described in detail here.

[0214] Referring to Figure 13, which is a structural block diagram of a communication device 400 provided in an embodiment of this disclosure, the communication device 400 includes a processor 41, a memory 42, and a computer program stored in the memory 42 and executable on the processor 41. When the processor 41 executes the computer program, it implements the operations described in the various cross-time slot interference detection method embodiments above.

[0215] For example, the computer program may be divided into one or more modules / units, which are stored in the memory 42 and executed by the processor 41 to perform the present disclosure. The one or more modules / units may be a series of computer program instruction segments capable of performing a specific function, configured to describe the execution process of the computer program in the communication device 400.

[0216] The communication device 400 may include, but is not limited to, a processor 41 and a memory 42. Those skilled in the art will understand that the schematic diagram is merely an example of the communication device 400 and does not constitute a limitation on the communication device 400. It may include more or fewer components than illustrated, or combine certain components, or different components. For example, the communication device 400 may also include input / output devices, network access devices, buses, etc.

[0217] The processor 41 can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or any conventional processor. The processor 41 is the control center of the communication device 400, connecting all parts of the communication device 400 via various interfaces and lines.

[0218] The memory 42 can be configured to store the computer programs and / or modules. The processor 41 implements various functions of the communication device 400 by running or executing the computer programs and / or modules stored in the memory 42 and calling the data stored in the memory 42. The memory 42 may mainly include a program storage area and a data storage area. The program storage area may store the operating system, at least one application program required for a function (such as sound playback function, image playback function, etc.), etc.; the data storage area may store data created according to the use of the mobile phone (such as audio data, phonebook, etc.). In addition, the memory 42 may include high-speed random access memory, and may also include non-volatile memory, such as hard disk, memory, plug-in hard disk, smart media card (SMC), secure digital (SD) card, flash card, at least one disk storage device, flash memory device, or other volatile solid-state storage device.

[0219] If the modules / units integrated in the communication device 400 are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the methods of the above embodiments can also be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium or a computer program product. When executed by the processor 41, the computer program can implement the operations of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable medium can include: any entity or device capable of carrying the computer program code, recording media, USB flash drives, portable hard drives, magnetic disks, optical disks, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signals, telecommunication signals, and software distribution media, etc.

[0220] The above descriptions are some embodiments of this disclosure. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of this disclosure, and these improvements and modifications are also considered to be within the scope of protection of this disclosure.

Claims

1. A method of cross-slot interference detection, wherein, Applied to a disturbed base station, the method includes: Receive interference reference signals sent by the interfering base station under the instruction of the core network equipment; The interfering base station is determined based on the demodulated time-frequency code resources in the interference reference signal and the preset base station mapping relationship.

2. The cross-time slot interference detection method as described in claim 1, wherein, Before receiving the interference reference signal, the method further includes: When a preset interference measurement trigger condition is detected, a first parameter is sent to the core network device, triggering the core network device to instruct the interfering base station to send an interference reference signal.

3. The cross-time slot interference detection method as described in claim 2, wherein, The method further includes: When a change in frame structure is detected, or when a preset interference level indicator is detected to change beyond a preset threshold, it is determined that the interference measurement trigger condition is met.

4. The cross-time slot interference detection method as described in claim 1, wherein, The reception of the interference reference signal sent by the harassing base station under the instruction of the core network equipment includes: Receive the receiving instruction issued by the core network device; The interference reference signal transmitted by the harassing base station under the instruction of the core network equipment is received according to the receiving instruction.

5. The cross-time slot interference detection method as described in claim 4, wherein, The receiving instruction sent by the core network device includes: Receive the time-frequency code resource location sent by the core network device; Receive the detection time-domain location sent by the core network device; The time-frequency code resource location and the detection time domain location are used as the receiving indication.

6. The method for detecting cross-time slot interference as described in claim 5, wherein, Receiving the time-frequency code resource location sent by the core network device includes: Receive a first indication signal sent by the core network device, which includes the IDs of all potential interfering base stations within a preset area; The corresponding time-frequency code resource location is determined from the base station mapping relationship based on the IDs of different potential interfering base stations in the first indication signal; Receiving the detected time-domain location sent by the core network device includes: Receive a second indication signal, including the detection time offset, sent by the core network device; The detection time offset in the second indication signal is used as the detection time domain position.

7. The cross-time slot interference detection method as described in claim 6, wherein, The detection time offset includes the start reference time, the window length of the time domain period in which the interference reference signal is located, the position index number of the time domain period in which the interference reference signal is located relative to the start reference time, the window length of the uplink / downlink switching period in which the interference reference signal is located, the sequence number of the uplink / downlink switching period in which the interference reference signal is located in the time domain period, and the received symbol position occupied by the interference reference signal.

8. The cross-time slot interference detection method as described in claim 1, wherein, The step of determining the interfering base station based on the demodulated time-frequency code resources in the interference reference signal and the preset base station mapping relationship includes: Demodulate the time-frequency code resources from the interference reference signal; The corresponding base station ID is matched from the base station mapping relationship based on the time-frequency code resources to determine the interfering base station, and the received power of the interference reference signal is recorded.

9. The method for detecting cross-time slot interference as described in claim 1, wherein, The base station mapping relationship includes the matching relationship between different time-frequency code resource locations and the corresponding potential interfering base station IDs; The time-frequency code resource location includes a time-domain index representing different transmission times, a frequency-domain index representing different frequency-domain resource locations, and a sequence-domain index representing different root sequences.

10. A method for detecting cross-time slot interference, wherein, Applied to a harassing base station, the method includes: Receive instructions from core network devices regarding the transmission of resources; According to the transmission instruction, an interference reference signal is transmitted to the disturbed base station so that the disturbed base station can identify the interfering base station.

11. The method for detecting cross-time slot interference as described in claim 10, wherein, The instruction to send resources sent by the core network device includes: Receive the time-frequency code resource location sent by the core network device; Receive the transmission time domain location sent by the core network device; The time-frequency code resource location and the transmission time domain location are used as the transmission indication.

12. The cross-time slot interference detection method as described in claim 11, wherein, Receiving the time-frequency code resource location sent by the core network device includes: Receive a third indication signal, including the ID of the interfering base station, sent by the core network device; The location of the corresponding time-frequency code resource is determined from the base station mapping relationship based on the ID of the harassing base station; Receiving the transmission time domain location sent by the core network device includes: Receive a fourth indication signal, including a transmission time offset, sent by the core network device; The detection time offset is used as the detection time domain position.

13. The cross-time slot interference detection method as described in claim 12, wherein, The base station mapping relationship includes the matching relationship between different time-frequency code resource locations and corresponding potential interfering base stations; The time-frequency code resource location includes a time-domain index representing different transmission times, a frequency-domain index representing different frequency-domain resource locations, and a sequence-domain index representing different root sequences.

14. The cross-time slot interference detection method as described in claim 12, wherein, The detection time offset includes the start reference time, the window length of the time domain period in which the interference reference signal is located, the position index number of the time domain period in which the interference reference signal is located relative to the start reference time, the window length of the uplink / downlink switching period in which the interference reference signal is located, the sequence number of the uplink / downlink switching period in which the interference reference signal is located in the time domain period, and the transmission symbol position occupied by the interference reference signal.

15. The method for detecting cross-time slot interference as described in claim 10, wherein, The interference reference signal is transmitted to the disturbed base station via the air interface.

16. A method for detecting cross-time slot interference, wherein, Applied to core network equipment, the method includes: Receive trigger commands sent by the disrupted base station; Send a transmission instruction to a potential interfering base station within a preset area, so that the potential interfering base station sends an interference reference signal; A reception instruction is sent to the disturbed base station so that the disturbed base station receives the interference reference signal and identifies the interfering base station.

17. The cross-time slot interference detection method as described in claim 16, wherein, Sending transmission instructions to potential interfering base stations in a preset area, including: Send a third indication signal, including the ID of the potential interfering base station within the preset area, to the corresponding potential interfering base station; Send a fourth indication signal, including the transmission time offset, to the corresponding potential interfering base station; Sending a reception instruction to the disturbed base station includes: Send a first indication signal, including the IDs of all potential interfering base stations within a preset area, to the disturbed base station; A second indication signal, including the detected time offset, is sent to the disturbed base station.

18. The method for detecting cross-time slot interference as described in claim 17, wherein, The third indication signal or the first indication signal uses SSB or NCell-ID to record the ID of the potential interfering base station.

19. The method for detecting cross-time slot interference as described in claim 17, wherein, The process of determining the ID of the potential interfering base station in the third indication signal or the first indication signal includes: The distances between each disturbed base station to be analyzed are all located at the center origin of a preset interval; The interference area is determined based on the central origin and a preset interference radius; All base stations communicating on the same frequency within the interference area are considered potential interference base stations; Based on the order in which the base stations were built in the sensing area, potential interference sources were numbered by sector, and base stations that did not overlap with potential interference base stations in the areas where base stations were built after the sensing area was built were further numbered.

20. The method for detecting cross-time slot interference as described in claim 19, wherein, The third indication signal or the first indication signal adopts a time-domain cyclic shift structure and reuses the FFT module on the Tx side or the IFFT module on the Rx side.

21. The method for detecting cross-time slot interference as described in claim 17, wherein, The transmission time offset includes the start reference time, the window length of the time domain period in which the interference reference signal is located, the position index number of the time domain period in which the interference reference signal is located relative to the start reference time, the window length of the uplink / downlink switching period in which the interference reference signal is located, the sequence number of the uplink / downlink switching period in which the interference reference signal is located in the time domain period, and the transmission symbol position occupied by the interference reference signal. The detection time offset includes the start reference time, the window length of the time domain period in which the interference reference signal is located, the position index number of the time domain period in which the interference reference signal is located relative to the start reference time, the window length of the uplink / downlink switching period in which the interference reference signal is located, the sequence number of the uplink / downlink switching period in which the interference reference signal is located in the time domain period, and the received symbol position occupied by the interference reference signal.

22. The cross-time slot interference detection method as described in claim 21, wherein, The window length of the time domain period in which the interference reference signal is located ; in, The number of co-frequency communication cells involved in the potential interference source, where t is the window length of the uplink / downlink handover period in which the interference reference signal is located. The transmission time domain position of the interference reference signal within one uplink / downlink switching cycle.

23. The cross-time slot interference detection method as described in claim 21, wherein, When the communication terminal does not support the anyPDCCH function, the transmission symbol position occupied by the interference reference signal is any two consecutive symbols from the 7th to the 11th symbols; the detection symbol position occupied by the interference reference signal is any four consecutive symbols from the 7th to the 13th symbols. When the communication terminal supports the anyPDCCH function, the transmission symbol position occupied by the interference reference signal is any two consecutive symbols from symbol 0 to symbol 4; the detection symbol position occupied by the interference reference signal is any four consecutive symbols from symbol 0 to symbol 6.

24. A cross-time slot interference detection device, wherein, The device, applied to a disrupted base station, includes: The receiving module is configured to receive interference reference signals sent by the interfering base station under the instruction of the core network equipment; The mapping module is configured to determine the interfering base station based on the demodulated time-frequency code resources in the interference reference signal and a preset base station mapping relationship.

25. A cross-time slot interference detection device, wherein, The device, applied to a scrambling base station, includes: The receiving module is configured to receive instructions from core network devices regarding the transmission of resources. The transmitting module is configured to transmit an interference reference signal to the disturbed base station according to the transmitting instruction, so that the disturbed base station can identify the interfering base station.

26. A cross-time slot interference detection device, wherein, Applied to core network equipment, the device includes: The triggering module is configured to receive triggering commands sent by the disturbed base station; The first instruction module is configured to send a transmission instruction to a potential interfering base station within a preset area, so that the potential interfering base station sends an interfering reference signal. The second instruction module is configured to send a reception instruction to the disturbed base station so that the disturbed base station receives the interference reference signal and identifies the interfering base station.

27. A communication device, wherein, The method includes a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein the processor, when executing the computer program, implements the cross-time slot interference detection method as described in any one of claims 1 to 23.

28. A computer-readable storage medium, wherein, The computer-readable storage medium includes a stored computer program, wherein, when the computer program is executed, it controls the device on which the computer-readable storage medium is located to perform the cross-time slot interference detection method as described in any one of claims 1 to 23.

29. A computer program product, wherein, It includes computer instructions that, when executed by a processor, implement the cross-slot interference detection method as described in any one of claims 1 to 23.

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