Method and system for radar detection of moving objects based on infrastructure of telecommunication network elements
By dividing telecommunications network base stations into groups with adaptive mode switching, the method addresses resource limitations, enabling efficient radar detection and telecommunications services by optimizing base station roles and resource allocation.
Patent Information
- Authority / Receiving Office
- RU · RU
- Patent Type
- Patents
- Current Assignee / Owner
- FEDERALNOE GOSUDARSTVENNOE UNITARNOE PREDPRIYATIE ZASHCHITAINFOTRANS MINISTERSTVA TRANSPORTA ROSSIJSKOJ FEDERATSII
- Filing Date
- 2026-01-29
- Publication Date
- 2026-06-30
AI Technical Summary
Existing telecommunications network-based radar systems face challenges in providing telecommunications services while maintaining the ability to detect moving objects, as they often require additional emitters and cannot be reconfigured in real-time to adapt to subscriber needs, leading to resource limitations.
A method where base stations in a telecommunications network are divided into groups, with one active and three passive stations, allowing dynamic switching between radar and telecommunications modes based on subscriber requests, using existing infrastructure and LTE protocol for signal processing.
Enhances the probability of providing telecommunications services while enabling radar detection by optimizing resource allocation and adaptively reallocating base station roles, ensuring continuous service availability and efficient resource utilization.
Smart Images
Figure 00000003_ABST
Abstract
Description
[0001] The invention relates to methods for detecting moving objects (for example, unmanned aerial vehicles or ground vehicles) using a technical system built on the basis of an existing infrastructure of telecommunication network elements that are used as radars to ensure the safety of airspace use. [G01S 13 / 00, G01S 13 / 87, G01S 13 / 02, G01S 13 / 46]
[0002] A METHOD FOR PERFORMING RADIO FREQUENCY (RF) SENSING USING A MOBILE DEVICE IN A WIRELESS COMMUNICATION NETWORK is known from the prior art [WO2022173525A1, published 08 / 18 / 2022]. The essence of the method lies in using a mobile device to determine the location of objects (e.g., walls, vehicles) by analyzing echo signals in a wireless network. To do this, the mobile device, knowing its position relative to the network object (base station), receives the configuration from the server, measures the arrival time of the direct (LOS) signal and the arrival time of its reflection from the object. Based on the difference between these times and the known position of the device, the coordinates of the reflecting object are calculated, the data about which is then transmitted.
[0003] Also known from the prior art is a DISTRIBUTED PASSIVE DETECTION SYSTEM BASED ON A CELLULAR MOBILE COMMUNICATION BASE STATION AND A NETWORK USING THIS STATION [CN101986169A, published 03 / 16 / 2011]. The essence of the invention lies in the creation of a distributed system for passive detection and tracking of targets (e.g., aircraft, ships) based on a cellular communications infrastructure. The system uses existing base stations into which detection units are integrated. These units passively receive and process third-party signals (e.g., from television and radio broadcasts) reflected from targets, extracting parameters (arrival time, Doppler shift, angle of arrival). The data received from several stations is transmitted via communication channels (for example, via the E1 interface) to a centralized main control center, where it is combined, the target’s position is calculated and refined, its recognition, the trajectory is displayed on a map, and the operation of the entire distributed sensor network is controlled.
[0004] The closest in technical essence is the LTE-BASED PASSIVE RADAR SYSTEM [WO2020146995A1, published July 23, 2020]. The essence of the invention lies in a passive radar system that uses LTE cellular signals as non-target radiation sources. The system receives a direct reference signal from an LTE base station and a reflected echo signal from a moving target, digitizes them, and then performs coherent processing taking into account crosstalk to generate digital target data, which enables the detection and tracking of objects without emitting their own signal and using existing communications infrastructure.
[0005] The main technical problem with the analog and prototype systems is the low probability of providing telecommunications services to subscribers while maintaining the ability to implement a radar mode for detecting moving objects based on the infrastructure of telecommunications network elements. This is due to the fact that the analog and prototype solutions do not provide the ability to implement a separate radar mode when needed. As a result, infrastructure resources are constantly spent on the operation of the radar system, thereby limiting the resources allocated for providing communications services. Furthermore, the analog and prototype solutions do not provide the ability to reconfigure the radar system in real time by reassigning the roles of base stations (emitting, passive, and service provider) depending on subscriber needs.Also, the analog and prototype solutions do not provide for the possibility of using elements of the communication network infrastructure as active (radiating) elements, which is why additional third-party emitters that are not part of the telecommunications network infrastructure are required for the operation of the radar system.
[0006] The objective of the invention is to eliminate the shortcomings of the prototype.
[0007] The technical result is to increase the probability of providing telecommunications services to subscribers while ensuring the possibility of implementing a radar mode for detecting moving objects based on the infrastructure of telecommunications network elements, which is achieved due to the fact that the method of radar detection of moving objects based on the infrastructure of telecommunications network elements is characterized by the fact that initially the set of base stations of the existing telecommunications network controlled by the server is divided into groups, each of which includes at least four base stations, among which there is at least one set of four base stations, in which there is a base station that can be active, such that at a distance of no more than the target detection range from it there are three base stations that can be passive,When a control signal is received from the server to switch the group to radar mode, one of the base stations, which may be active, becomes active and acts as a transmitter of a probing signal; three base stations, which may be passive and are located at a distance of no more than the detection range, become passive; when an object moves, based on the delay values of the reflected signals coming from the three passive base stations, the detection of a moving object is realized;
[0008] In radar mode, if a subscriber is in the coverage area of one passive base station and a request for the provision of telecommunications services is received, then within the group to which the specified passive base station belongs, a check is made to see if there is an unused base station that can be passive; if so, it becomes a passive base station, and the base station in the coverage area of which the subscriber is located switches to the mode of providing telecommunications services.
[0009] in radar mode, if a subscriber is in the coverage area of one active base station and a request for the provision of telecommunications services is received, within the group to which the specified active base station belongs, a check is made to see if there is an unused set of four base stations, including a base station that can be active and three base stations that can be passive and are at a distance of no more than the detection range, while in the coverage areas of which there are no subscribers with a request for the provision of telecommunications services, if such a set is found, then the base station that can be active becomes the active base station, those base stations that can be passive become passive base stations, and the base station in the coverage area of which the subscriber is located switches to the mode of providing telecommunications services,
[0010] If the subscriber is in the coverage area of one active base station, then resource blocks are periodically allocated from the protocol frame structure, which are used to transmit probing radio signals,
[0011] If a subscriber is within the coverage area of one passive base station, then resource blocks are periodically allocated from the protocol frame structure, which are used to receive reflected signals.
[0012] In particular, the existing telecommunications network operates on the basis of the LTE protocol.
[0013] In particular, the existing telecommunications network operates on the basis of the LTE-M protocol.
[0014] Specifically, the base stations and the server are connected by a fiber-optic communication line and support synchronization according to the IEEE1588 v2 protocol.
[0015] In particular, the formation of a group is implemented as follows: one potentially active base station is taken and the target detection range is calculated, then the number of base stations that are at the target detection range or closer to the potentially active one is determined, if three other base stations or more are at the specified distance, then a group is formed in which the potentially active station can be active, and the remaining base stations can be passive when implementing the radar mode.
[0016] In particular, the formation of a group is implemented as follows: one potentially active base station is taken and the target detection range is calculated, then the number of base stations that are at a distance of the target detection range or closer to the potentially active one is determined, if more than three other base stations are at the specified distance, then the potentially active base station can be active, the remaining base stations can be passive, and for each of the base stations that can be passive, a similar calculation is implemented, where they act as potentially active, if the condition is met that more than three other base stations are at a distance of the target detection range or closer to them, they can also be active when implementing the radar mode.
[0017] In particular, the formation of groups is implemented on the basis of solving an optimization problem using the method of global numerical optimization of a particle swarm for the entire existing telecommunication network.
[0018] Specifically, the base station that is active is randomly selected from the base stations that can be active.
[0019] In particular, when forming groups, a restriction has been introduced on the selection of an active base station in a group so that the station closest to the current one cannot simultaneously be the active base station in a neighboring group.
[0020] The claimed technical result is achieved due to the fact that the radar detection system of moving objects based on the infrastructure of elements of telecommunication networks is characterized by the fact that it includes a server that is connected to base stations, wherein all base stations are divided into groups, each of which includes at least four base stations, among which there is at least one set of four base stations, in which there is a base station that can be active, such that at a distance of no more than the target detection range from it there are three base stations that can be passive, the base stations in the groups are configured with the possibility of switching to a radar mode, in which one of the base stations, which can be active, becomes active and acts as an emitter of a probing signal, three base stations,which may be passive and are located at a distance of no more than the detection range from the active one, become passive,
[0021] In radar mode, if a subscriber is in the coverage area of one passive base station and a request for the provision of telecommunications services is received, then within the group to which the specified passive base station belongs, a check is made to see if there is an unused base station that can be passive; if so, it becomes a passive base station, and the base station in whose coverage area the subscriber is located switches to the mode of providing telecommunications services,
[0022] in the radar mode, if a subscriber is in the coverage area of one active base station and a request for the provision of telecommunications services is received, within the group to which the said active base station belongs, it is checked whether there is an unused set of four base stations, including a base station that can be active and three base stations that can be passive and are at a distance of no more than the detection range, while in the coverage areas of which there are no subscribers with a request for the provision of telecommunications services, if such a set is found, then the base station that can be active becomes the active base station, those base stations that can be passive become passive base stations, and the base station in the coverage area of which the subscriber is located switches to the mode of providing telecommunications services,
[0023] If the subscriber is in the coverage area of one active base station, then resource blocks are periodically allocated from the protocol frame structure, which are used to transmit probing radio signals,
[0024] If a subscriber is within the coverage area of one passive base station, then resource blocks are periodically allocated from the protocol frame structure, which are used to receive reflected signals.
[0025] Figures 1 and 2 show options for forming groups of base stations.
[0026] Fig. 3 shows a variant of calculating the coverage area of a group of base stations.
[0027] Figure 4 shows a portion of a frame with resource blocks of the LTE communication protocol.
[0028] The drawings indicate:
[0029] 1 – active base station;
[0030] 2 – passive base station.
[0031] Implementation of the invention
[0032] A radar detection system for moving objects based on the infrastructure of telecommunications network elements is characterized by its composition consisting of base stations divided into groups and geographically separated from one another. Each base station in the detection system can operate in one of two modes: radar mode or telecommunications service mode (hereinafter, telecommunications mode). When in radar mode, a base station can be an active base station 1 (which operates only for transmission), a passive base station 2 (which operates only for reception), or in telecommunications service mode. Each group consists of at least four base stations. During the implementation of the claimed method, one active base station 1 and at least three passive base stations 2 operate simultaneously in each group.All base stations are connected to a server with a computing unit capable of managing the base stations, including switching operating modes (radar and telecommunications), forming groups based on a predetermined structure, and managing the base stations within the group (i.e., determining at any given moment which are active, which are passive, and which are providing communications services). The distributed location system is based on an LTE network. The network of base station radio nodes and the server are connected by a fiber-optic communication line and support synchronization using the IEEE1588 v2 protocol. The base station and server structure is standard for providing telecommunications services. The computing unit integrated into the server for forming and managing groups of base stations in radar mode can be implemented using hardware, software, or a combination of hardware and software.
[0033] The method for radar detection of unmanned moving objects based on the infrastructure of telecommunication network elements is characterized by the fact that it is implemented on the existing communications infrastructure.
[0034] During the implementation of the claimed method, each base station of the detection system can operate in one of two modes: radar or telecommunications. Mode switching is accomplished through control from the server with the computing unit. If the base station is in telecommunications mode, it operates normally, providing wireless communication for subscribers within its coverage area. If the base station is in radar mode, it partially or completely loses its ability to provide telecommunications services. Concurrently, each base station in radar mode can be assigned to active emission mode (active base station 1), passive reception mode (passive base station 2), or it can be inactive and continue to provide telecommunications services.
[0035] To implement the claimed method, all base stations are divided into base station groups. Each group includes at least four base stations so that in radar mode there is at least one active base station 1 and at least three passive base stations 2.
[0036] In radar mode, target detection in the system is performed using radar analysis of time delays of probing signals reflected by targets within the network coverage area (observation zone). The source of the probing signals will be active base station 1. The radio channel model for the propagation of the signal emitted by the base station and reflected from the target will look like this: active base station 1 – target – receiving (passive 2) base station. Moreover, to solve the problem of triangulating target coordinates, at least three passive base stations 2 will be required to receive the signal reflected from the target.
[0037] At the preliminary stage, groups of base stations are formed on the existing telecommunications network.
[0038] In this embodiment, groups are formed as follows. LTE network base stations are located on the terrain. The coordinates of the base stations are predetermined, as are the radiotechnical parameters of their receivers and transmitters (radiated power, antenna gain, receive path gain, and receiver sensitivity). Next, one potentially active base station is selected and the maximum distance (Lmax) at which the reflected signal will exceed the sensitivity threshold (target detection range), meaning the target will be detected, is calculated. Next, the number of base stations located at or closer to the potentially active one (<=Lmax) is determined. If three or more other (linked) base stations are located within the specified distance, a group is formed, in which the potentially active station can be active (1), and all the remaining (linked) stations can be passive (2).If the specified condition is not met, the next base station is taken, which becomes a potentially active base station.
[0039] An implementation option is also possible when there are strictly more than three linked base stations within the Lmax distance. In this case, each linked station becomes potentially active in turn, and Lmax is calculated for each new potentially active base station (in this case, only those linked and active base stations that participated in the previous calculation iteration are included in the calculation). If at least three linked stations are detected for any of the calculated potentially active base stations, then within the group, this station also becomes active (1). The base station from which the calculation began is also considered active (1). Thus, for a group with an arbitrary number of base stations, those whose radar coverage (<=Lmax) includes at least three other base stations are selected. These base stations can be designated as active (1) in the group, and all others as passive (2).
[0040] Based on the above, it can be concluded that a sufficient condition for the implementation of the method is the presence of at least four base stations in the group, from which a set of four base stations can be formed, one of which can be active, the other three passive.
[0041] The limitation on the number of base stations in a group can be either natural, related to the limitations of the network architecture used (due to the exhaustion of combinations when a potentially active base station has at least three base stations), or specified (forced), for example, when the size of a group is limited by the maximum possible number of base stations included in it or by a certain territory from which base stations can be assigned to groups.
[0042] In the embodiment, after the formation of one group, the general coverage area of the group is determined, then one of the nearest base stations not included in the coverage area of the group is taken and a new group begins to be formed, while those base stations that are already included in one of the groups are not considered as candidates for inclusion in the new group.
[0043] After all the groups in a given area have been formed, the overall coverage area can be estimated. If it meets the system requirements, the specified group configuration is retained; if not, the option of reorganizing the groups is possible. In one embodiment, the problem of redistributing radio stations in groups to maximize the coverage area can be solved as an optimization problem using the global numerical optimization method of particle swarm [Kennedy, J.; Eberhart, R. (1995). Particle Swarm Optimization. Proceedings of IEEE International Conference on Neural Networks. Vol. IV. pp. 1942–1948.][Blok, I. N., “Construction of a Software-Algorithmic Model of the Particle Swarm Method” / / CyberLeninka Electronic Library], where the initial conditions are the previously obtained or arbitrary configuration, and the number of base stations in the group is a constraint.
[0044] After completing the preliminary stage, the system can operate in both telecommunications and radar modes. Switching between modes can be performed on demand (for example, by activating the corresponding "Unmanned Danger" mode) or, for example, time-based, based on control input from the server computer.
[0045] When entering the radar mode, in each group, one base station from those that can be active becomes active 1, three associated passive 2. The initial selection of a specific active base station 1 from possible ones can be random, as well as the selection of associated passive 2 (if the number of associated is more than three).
[0046] In the embodiment for areas with a small number of potential subscribers, control of the assignment of active 1 and passive 2 base stations in a group can be implemented taking into account the possibility of providing telecommunication services to subscribers.
[0047] If a subscriber is within the coverage area of one base station, which at a given moment is passive base station 2, and a request for the provision of telecommunications services is received, then the following is implemented: within the group to which the specified passive base station 2 belongs, a check is made to see if there are any unused base stations that could act as passive stations for the current configuration of the group; if such a station is found, then it becomes passive base station 2, and the base station in whose coverage area the subscriber is located switches to the mode of providing telecommunications services, while the active base station 1 does not change or is not reassigned.If there is no unused base station (due, for example, to the fact that there are only 4 base stations in the group, i.e. there are no unused base stations, or all unused base stations are busy providing telecommunications services), then the possibility of using telecommunications services is limited.
[0048] In the embodiment, if a subscriber is in the coverage area of one base station, which at a particular moment in time is an active base station 1, and a request for the provision of a telecommunications service is received, then the following is implemented: within the framework of the group to which the specified active base station 1 belongs, it is checked whether there are unused stations that can be active with three free associated passive base stations; if such a station is found, then it becomes the new active base station 1, the associated stations become passive base stations 2, and the base station in whose coverage area the subscriber is located switches to the mode of providing telecommunications services.
[0049] In this embodiment, when a subscriber is within the coverage area of several base stations, if at least one of them is not active (1) or passive (2), then telecommunications services are provided through it. If the subscriber is within the coverage area of only passive base stations, an attempt at redistribution is made similar to the above (i.e., a free base station that could be passive is searched for). If the subscriber is within the coverage area of passive (2) and active (1) base stations, then an attempt at redistribution is made first, searching for a free passive base station. If none is found, then an attempt at redistribution is made similar to the above (a station that could be active (1) is searched for with three free, connected passive (2) base stations.
[0050] To prevent a case where a subscriber is in the coverage area of two active 1 base stations, a restriction can be introduced on the selection of the active base station 1 in a group so that at the same time the active base station 1 in the neighboring group is not the station closest to the current one.
[0051] Within the claimed method, each group in the system can be considered an autonomous subsystem solving the radar task of target detection and tracking. In this case, for each group, a region of maximum target detection range can be determined based on the emitted signal power and the sensitivity of the base station receivers, given a fixed minimum target radar cross-section (RCS). Combining these regions across all base station groups yields the overall detection range of the entire system.
[0052] Option for calculating the group coverage area when groups are formed from strictly four base stations.
[0053] For a given minimum permissible value of the target's RCS, the following sequence of actions must be performed:
[0054] 1. Based on the array of specified coordinates for the placement of passive base stations 2, calculate the geographic center of the entire location system.
[0055] 2. From this center, emit a beam at an azimuth of 0 degrees at a certain distance, for example, 10 km (the range of 10 km is defined as the first approximation of the bisection method) and determine the geographic coordinates of the target location - this forms the search segment of the zone boundary.
[0056] 3. For two coordinates – the location point of the active base station 1 and the location point – determine the number of passive base stations 2 that can detect this signal.
[0057] 4. If the number of BSs capable of detecting the signal:
[0058] a. If less than 3, then return to point 2, doubling the distance.
[0059] b. If more than 3, then return to step 3, reducing the distance by 2 times and moving the starting point of the segment to its middle.
[0060] c. Perform this action until the segment length is greater than the required resolution of the system.
[0061] 5. Save the coordinates of the obtained zone boundary point.
[0062] 6. Proceed to step 2 by increasing the azimuth value by 0.5 degrees (the azimuth step value can be selected dynamically based on the required angular resolution when determining the detection zone.) Continue until the azimuth value is greater than or equal to 360 degrees.
[0063] Option for determining target coordinates.
[0064] The target, located at a certain point in space, will be the source of the reflection of the probing signal, which will be recorded by passive base stations 2. Knowing the time of emission of the probing signal, passive base stations 2 will be able to accurately determine the delay time on the propagation path from the active base station 1 to the target, and from the target to the passive base station 2. The accuracy of the time determination will be determined by the accuracy of the synchronization time of the base stations, as well as the period of the LTE network data transmission frames.
[0065] A grid-based numerical calculation algorithm has been implemented to determine the coordinates of the reflection source of the probing signal. Its essence is as follows.
[0066] The entire energy detection zone should be divided into a set of grid cells. The shape of the grid cells can generally be chosen to ensure uniform, continuous coverage of the entire observation area. The most effective grid construction options are tetrahedral and rectangular.
[0067] The tetrahedral mesh, composed of triangles, is most effective in ensuring uniform filling of the detection zone, taking into account its complex geometric shape.
[0068] The rectangular grid ensures maximum performance of the target coordinate calculation algorithm.
[0069] Each grid cell must have a central point defined by its geographic coordinates. This point will serve as the reference point for the distance calculation method.
[0070] The essence of the method is as follows. For each grid cell, a hypothesis is developed that the target is located within the grid cell. In this case, it can be assumed that the target, located within this cell, will generate a delay time for the reflected probing signal at each base station within the energy detection zone. Testing this hypothesis involves comparing the actual set of probing signal reception times currently received at each base station with the delay time the target would generate if located within this grid cell, taking into account its deviation from the center—the reference point of this cell.
[0071] Detection area definition option.
[0072] Since the detection of UAVs by the LTE network base station system is carried out using a radar method, it is necessary to determine the maximum range at which a target with a given RCS can be detected, taking into account the sensitivity limitations of the base station equipment.
[0073] The problem is formulated as follows. LTE network base stations are located on the terrain. The coordinates of the base stations are predetermined, as are the radiotechnical parameters of their receivers and transmitters (radiated power, antenna gain, receive path gain, and receiver sensitivity).
[0074] The process begins with the emission of a probing (or pilot) signal. The transmitter has a power of P0. The signal is emitted by an antenna with a gain of G0. The signal then propagates in free space to a target at a distance from the active base station 1 equal to R1. The signal is attenuated due to its dispersion over the area of the sphere. Thus, in the target's area, the signal's power will be 4πR1 lower than the emitted signal. 2 times. The signal is reflected by the target in accordance with its RCS. Thus, at the target's location, the power
[0075]
[0076] where P изл – the power of the probing signal emitted by the active base station 1;
[0077] σ – target RCS;
[0078] R1 – distance from the active base station 1 to the target in meters.
[0079] The reflected signal then propagates to the location of the "passive" base station, where it is received by its antenna. We will assume that the antennas of all base stations have identical characteristics. In this case, the signal at the antenna output of passive base station 2 can be determined as follows.
[0080]
[0081] where P отр – the power of the signal reflected by the target;
[0082] G0– antenna gain;
[0083] R2 – distance from the target to the “passive” BS.
[0084] After this, the signal received by the passive base station antenna undergoes processing and filtering in the receiving path. Generally, this process can be defined as signal amplification with a coefficient of G1. The amplified analog signal is fed to the digital receiver, where the signal delay time along the propagation path from the transmitting active base station 1 to the passive base station 2 is determined. The receiver has a sensitivity threshold. If the received and amplified analog signal's power is below the sensitivity threshold, the signal will not be received by the receiver, and therefore, the target will not be detected.
[0085] Thus, the target detection range (the distance at which the reflected signal exceeds the sensitivity threshold Lmax) can be estimated based on the signal power received by passive base station 2. Signal attenuation here is affected by the range from active base station 1 to the target (power is inversely proportional to the square of the range), the range from the target to passive base station 2 (power is inversely proportional to the square of the range), and the target's radar cross section. The antenna gain and receive path values for this problem will be constants determined at the system design stage (the beginning of the modeling process).
[0086] Lmax can also be determined by any other method known from the prior art, for example, by modeling, calculation or experiment.
[0087] Protocol usage option
[0088] The LTE network transmits data using time-frequency division multiplexing. A frame structure is used for data transmission on the downlink (from the base station to the subscriber) and the uplink (from the subscriber to the base station). The number of downlinks is significantly smaller than the number of uplinks. The resource block of the data exchange protocol is shown below.
[0089] In the event of a situation where there is a subscriber with a request for the provision of communication services, and all nearby base stations are active 1 or passive 2 without the possibility of reconfiguration, it is possible that communication services are provided by a functioning active 1 or passive 2 base station.
[0090] This is achieved by the LTE network transmitting data using time-frequency division multiplexing. A frame structure is used for data transmission in the downlink (from the base station to the subscriber) and uplink (from the subscriber to the BS). The number of downlinks is significantly smaller than the number of uplinks. Fig. 4 shows a subframe of the communication protocol (where subframe is a subframe with a minimum scheduling interval of 1 ms, consisting of two slots, Slot 0 and Slot 1, each 0.5 ms long, each slot consisting of 7 OFDM symbols, and 12 subcarriers (Subcarriers) are used simultaneously in the frame; one resource block is 12 subcarriers with 7 symbols each). To solve the radar problem during the operation of the LTE (pLTE or LTE-M) network, resource blocks can be allocated at a specified frequency for transmitting a probing signal and receiving reflected signals from objects in the observation zone.In the implementation variant, upon command from the server, every 10th or 5th frame with resource blocks is allocated for the radar mode, the rest are used for the telecommunication mode.
[0091] The claimed technical result—increasing the probability of providing telecommunications services to subscribers while enabling the implementation of a radar mode for detecting moving objects based on the infrastructure of telecommunications network elements—is achieved by allowing each base station to operate in two modes: normal service provision and radar mode, when this capability may be limited. Thus, in the absence of a UAV threat, the probability of providing telecommunications services remains maximal and is determined by the network infrastructure itself. However, in radar mode, this probability is also increased by the fact that groups can be formed, including with redundant members, thereby creating an intra-group reserve of free (or easily switchable) resources.This means that at any given time, a group, even one operating in radar mode, contains base stations that are either already in communication mode or can be switched to it without disrupting the detection task, as their radar function can be assumed by other, redundant group elements. The assignment of a specific base station to the role of active 1 or passive 2 at the moment of radar mode activation is not fixed. The system is constantly prepared to quickly change its configuration in response to an external event—a subscriber request for communication service. This directly increases the likelihood that a new subscriber will find a base station capable of serving them within the group's area. Furthermore, this implementation option maintains the ability to provide communication services even when there is no redundant resource for reconfiguration in the group, thanks to the ability to use protocol resource blocks.Thus, the probability of service provision ceases to be a random variable dependent on location and becomes a controllable parameter dependent on the degree of group redundancy and the efficiency of the redistribution algorithm. At the same time, the proposed approach minimizes the need for frequent and complex redistribution, reducing the computational load and increasing the overall stability of the system. It aims to find the least expensive way to serve a subscriber in terms of reconfiguration, thereby improving the speed and reliability of the procedure.
[0092] Examples of forming base station groups
[0093] Example 1: Group with one active base station 1 (minimum configuration).
[0094] Consider a terrain area with four base stations (BS) located on cellular operator towers. Preliminary calculations have established that the maximum target detection range, Lmax, for the "Lesnik" base station (an active candidate) is 5 km. There are exactly three other BSs within a 5 km radius of "Lesnik": "Tayezhnik," "Fontan," and "Bereza." Since the requirement of "at least three linked stations" is met, a group is formed. In this configuration, only "Alpha" can act as the first active emitting station, since the Lmax calculation for any of the other three stations ("Tayezhnik," "Fontan," and "Breza") shows that there are fewer than three other BSs from this set within a 5 km radius. Therefore, the group is defined with one mandatory active BS, "Lesnik," and three mandatory passive BSs, "Tayezhnik," "Fontan," and "Bereza."Any attempt to assign the active role to another station in this group will result in a violation of the minimum configuration requirements.
[0095] Example 2: Group with two potentially active base stations.
[0096] There are five base stations in another area: Yel, Dacha, Reka, Ozero, and Prosek. The Lmax calculation for Yel shows a value of 6 km. Four other stations are within this radius. An iterative process begins: each of the four "linked" stations is checked as an active candidate. It turns out that for Reka, Lmax is 5.5 km, and four other base stations from the original set, including Yel, are also within this radius. Thus, both Yel and Reka meet the criterion of "having at least three other base stations in the group within their reach." Stations Dacha, Ozero, and Prosek do not meet this criterion. A group of five BSs is formed, in which two stations (Yel and Reka) are active and can be assigned to this role depending on operational needs or the selection algorithm. The remaining three stations are passive for both possible configurations, creating the necessary reserve for adaptive control.
[0097] Reallocation example for a passive base station
[0098] In a group consisting of five base stations ("Yel", "Dacha", "Reka", "Ozero", and "Proseka"), "Yel" is currently assigned as active station 1 (A-BS), while "Dacha", "Reka", and "Ozero" are assigned as passive stations 2 (P-BS). Station "Proseka" is in service mode and is not configured for radar operation. A subscriber arrives within the coverage area of passive station 2 "Ozero" and initiates a data transmission session. The adaptive control module, upon receiving the request, analyzes the group and detects a free base station, "Proseka", which is within the coverage area of active station 1 "Yel" and can technically become passive. The system performs a reconfiguration: base station "Proseka" switches to passive radar mode and begins receiving reflected signals, while base station "Ozero" is immediately released and switches to telecommunications mode to service the subscriber.The radar circuit remains operational (A-BS "El" + P-BS "Dacha", "Reka", "Proseka"), and the subscriber receives the requested communication service.
[0099] Reallocation example for an active base station
[0100] In a group of five base stations ("Yel", "Dacha", "Reka", "Ozero", and "Proseka"), base station 1 "Dacha" is designated as active, while the other two are passive: "Yel", "Reka", and "Ozero". "Proseka" is free. A critical voice call from a subscriber originates within the coverage area of the active base station "Dacha". The active station reassignment algorithm checks whether another base station in the group can take its place. Analysis shows that the free base station "Proseka" can become the new active station, as there are three available passive stations in the group: "Yel", "Reka", and "Ozero". The system performs a sequential switchover: first, the Proseka base station is designated as the new active station 1 and begins emitting a probing signal, then, after synchronization is confirmed, the Dacha base station is removed from the active role and switches to communication mode to receive a call.Radar surveillance continues without interruption with the new configuration (A-BS "Proseka" + P-BS ("El", "Reka", "Ozero") and the critical telecommunications service has been successfully provided.
[0101] Example of achieving the stated technical result
[0102] A single network of 50 base stations with fixed technical parameters was used for the simulation. The following methods were used to implement radar based on these base stations:
[0103] The first method is in accordance with the stated solution, with 12 groups of stations from 4 to 6 in each (from 1 to 3 potentially active base stations in groups).
[0104] the second method - in accordance with the stated solution, except that there was no possibility of implementing operation in two modes, only the radar mode was provided;
[0105] The third method is in accordance with the stated solution, except that there was no possibility of redistributing the roles of base stations within a group (all groups were formed from a set of four base stations).
[0106] In the simulation, the probability of a subscriber requiring communications services, the number of subscribers, and their routes within the overlap zone were random variables with specified parameters characterizing the probability of a subscriber appearing in a sparsely populated industrial area. Based on the simulation results, the ratio of the number of times subscribers requested communications services and the service was provided to the total number of requests was calculated, thereby assessing the probability of providing telecommunications services to subscribers. In the simulation, the probability of UAV appearance was considered insignificant 50% of the time, and the corresponding probability was considered significant 50% of the time, and, if provided for by the option, switching to radar mode was implemented. The following results were obtained from the simulation:
[0107] The first method – the assessment of the probability of providing telecommunication services to subscribers was 0.89;
[0108] the second method – the assessment of the probability of providing telecommunication services to subscribers was 0.56;
[0109] The third method – the assessment of the probability of providing telecommunication services to subscribers was 0.64.
[0110] This confirms the possibility of achieving the stated technical result thanks to the essential features of the technical solution.
[0111] The simulation results made it possible to calculate the expected characteristics of a radar system implementing the stated method:
[0112] Radar system type – distributed;
[0113] carrier frequency of the probing signal is 360 MHz;
[0114] the distance between the elements of the distributed grid is no more than 5000 m;
[0115] antenna radiation pattern width in the azimuth plane is 90 degrees;
[0116] the antenna radiation pattern width in the elevation plane is 16 / 24 degrees;
[0117] peak power of transceivers in “Radar” mode – no more than 40 W;
[0118] maximum detection range – not less than 7 km;
[0119] The target's RCS (including aircraft-type UAVs) is 0.01 m 2 / 0.3 m 2 ;
[0120] Antenna suspension height – not less than 16 m;
[0121] The duration of the probing pulse in the “Radar” mode is not less than 1 ms;
[0122] Probing pulse repetition frequency – not less than 100 Hz;
[0123] False alarm rate, % – less than 1.
Claims
1. A method for radar detection of moving objects based on the infrastructure of elements of telecommunications networks, characterized in that initially the set of base stations of an existing telecommunications network controlled by a server is divided into groups, each of which includes at least four base stations, among which there is at least one set of four base stations, in which there is a base station that can be active, such that at a distance of no more than the target detection range from it there are three base stations that can be passive, upon receipt of a control action from the server to switch the group to radar mode, one of the base stations, which can be active, becomes active and acts as an emitter of a probing signal, three base stations, which can be passive and are at a distance of no more than the detection range, become passive,when an object moves, based on the delay values of reflected signals coming from three passive base stations, the detection of a moving object is implemented, in radar mode, if a subscriber is in the coverage area of one passive base station and a request for the provision of a telecommunications service is received, then within the group to which the said passive base station belongs, a check is made to see whether there is an unused base station that could be passive; if so, it becomes a passive base station, and the base station in whose coverage area the subscriber is located switches to the mode of providing telecommunications services, in radar mode, if a subscriber is within the coverage area of one active base station and a request for the provision of a telecommunications service is received, within the group to which the said active base station belongs, a check is made to see whether there is an unused set of four base stations, including a base station that can be active and three base stations that can be passive and are at a distance of no more than the detection range, while in the coverage areas of which there are no subscribers with a request for the provision of telecommunications services; if such a set is found, then the base station that can be active becomes the active base station, those base stations that can be passive become passive base stations, and the base station in the coverage area of which the subscriber is located switches to the mode of providing telecommunications services, If a subscriber is within the coverage area of one active base station, then resource blocks are periodically allocated from the protocol frame structure, which are used to transmit probing radio signals, If a subscriber is within the coverage area of one passive base station, then resource blocks are periodically allocated from the protocol frame structure, which are used to receive reflected signals.
2. The method according to paragraph 1, characterized in that the existing telecommunications network operates on the basis of the LTE protocol.
3. The method according to paragraph 1, characterized in that the existing telecommunications network operates on the basis of the LTE-M protocol.
4. The method according to paragraph 1, characterized in that the base stations and the server are connected by a fiber-optic communication line and support synchronization according to the IEEE1588 v2 protocol.
5. The method according to paragraph 1, characterized in that the formation of the group is realized in the following way: one potentially active base station is taken and the target detection range is calculated, then the number of base stations that are at the distance of the target detection range or closer to the potentially active one is determined, if three other base stations or more are located at the specified distance, then a group is formed in which the potentially active station can be active, and the remaining base stations can be passive when implementing the radar mode.
6. The method according to paragraph 1, characterized in that the formation of the group is implemented in the following way: one potentially active base station is taken and the target detection range is calculated, then the number of base stations that are at a distance of the target detection range or closer to the potentially active one is determined, if more than three other base stations are at the specified distance, then the potentially active base station can be active, the remaining base stations can be passive, and for each of the base stations that can be passive, a similar calculation is implemented, where they act as potentially active, if the condition is met that more than three other base stations are at a distance of the target detection range or closer to them, they can also be active when implementing the radar mode.
7. The method according to paragraph 1, characterized in that the formation of groups is implemented on the basis of solving an optimization problem using the method of global numerical optimization of a particle swarm for the entire existing telecommunications network.
8. The method according to claim 1, characterized in that the base station, which is active, is selected from base stations that may be active randomly.
9. The method according to paragraph 1, characterized in that when forming groups, a restriction is introduced on the selection of an active base station in the group in such a way that at the same time in the neighboring group the active base station is not the station closest to the current one.
10. A system for radar detection of moving objects based on the infrastructure of elements of telecommunication networks, characterized in that it includes a server that is connected to base stations, wherein all base stations are divided into groups, each of which includes at least four base stations, among which there is at least one set of four base stations, in which there is a base station that can be active, such that at a distance of no more than the target detection range from it there are three base stations that can be passive, the base stations in the groups are configured with the ability to switch to a radar mode, in which one of the base stations, which can be active, becomes active and acts as an emitter of a probing signal, three base stations, which can be passive and are at a distance of no more than the detection range from the active one, become passive, in radar mode, if a subscriber is in the coverage area of one passive base station and a request for the provision of a telecommunications service is received, then within the group to which the said passive base station belongs, a check is made to see whether there is an unused base station that could be passive; if so, it becomes a passive base station, and the base station in whose coverage area the subscriber is located switches to the mode of providing telecommunications services, in radar mode, if a subscriber is within the coverage area of one active base station and a request for the provision of a telecommunications service is received, within the group to which the said active base station belongs, a check is made to see whether there is an unused set of four base stations, including a base station that can be active and three base stations that can be passive and are at a distance of no more than the detection range, while in the coverage areas of which there are no subscribers with a request for the provision of telecommunications services; if such a set is found, then the base station that can be active becomes the active base station, those base stations that can be passive become passive base stations, and the base station in the coverage area of which the subscriber is located switches to the mode of providing telecommunications services, If a subscriber is within the coverage area of one active base station, then resource blocks are periodically allocated from the protocol frame structure, which are used to transmit probing radio signals, If a subscriber is within the coverage area of one passive base station, then resource blocks are periodically allocated from the protocol frame structure, which are used to receive reflected signals.