KR102801755B1 - Method and Apparatus for Tracking Physical Location of Cellular Device in Practical Environment - Google Patents

Abstract

A method and device for tracking the physical location of a mobile communication terminal in a real environment are presented. A method for tracking the physical location of a mobile communication terminal in a real environment, performed by a computer device according to one embodiment, includes the steps of: generating a plurality of packets that cannot be recognized by a terminal, which is a target of location tracking, to form a specific traffic pattern; and performing fingerprinting based on the specific traffic pattern to track an RNTI (Radio Network Temporary Identifier) of the terminal, and the physical location can be tracked using the RNTI of the terminal.

Description

Method and Apparatus for Tracking Physical Location of Cellular Device in Practical Environment

The embodiments below relate to a method and device for tracking a physical location, and more specifically, to a method and device for tracking a physical location of a mobile communication terminal in a real environment.

Existing physical location tracking systems for mobile communication terminals do not sufficiently consider the actual environment. In order to track the physical location of a terminal in a mobile communication network in a real environment, radio ID information called Radio Network Temporary Identifier (RNTI) is required. In other words, when location tracking is performed based on the uplink signal of a terminal in a mobile communication network, radio ID information called RNTI is required.

However, since RNTI is temporary ID information that changes periodically, continuous tracking of this ID is inevitable in order to continuously monitor the terminal's signal and track its location.

Korean Patent Publication No. 10-2019-0080276 relates to a method for measuring the position of a terminal in such a wireless communication system, and describes a technology for a method for accurately measuring the position of a terminal in a wireless communication system.

Korean Patent Publication No. 10-2019-0080276

The embodiments describe a method and device for tracking the physical location of a mobile communication terminal in a real environment, and more specifically, provide a technique for causing the terminal to increase its uplink signal power by deceiving the terminal into thinking that a base station has commanded an increase in uplink power.

The embodiments provide a method and device for tracking the physical location of a mobile terminal in a real environment, which can overcome the limitations of wireless signal-based location tracking that occur in real environments when tracking the location of a mobile terminal by deceiving the terminal into increasing the uplink signal power as if the base station had commanded an increase in uplink power.

A method for tracking a physical location of a mobile communication terminal in a real environment, performed by a computer device according to one embodiment, comprises the steps of: generating a plurality of packets that cannot be recognized by a terminal, which is a target of location tracking, to form a specific traffic pattern; and performing fingerprinting based on the specific traffic pattern to track an RNTI (Radio Network Temporary Identifier) of the terminal, and the physical location can be tracked using the RNTI of the terminal.

The method may further include a step of decoding a downlink control information (DCI) message broadcast by a base station using an RNTI of the terminal to obtain scheduling information regarding an uplink signal transmitted by the terminal; and a step of monitoring the uplink signal of the terminal and specifying a physical location based on the obtained scheduling information.

The method may further include manipulating a downlink control information (DCI) message in a wireless channel based on the RNTI of the terminal and the configuration of the base station.

By manipulating a downlink control information (DCI) message in a wireless channel, the terminal can decode the manipulated downlink control information (DCI) message, thereby forcibly changing the strength of an uplink signal without the will of the base station or the terminal.

The step of manipulating the above downlink control information (DCI) message may include the step of generating the manipulated downlink control information (DCI) message by setting a TPC command value so that the terminal varies the uplink signal strength; and the step of overlaying the manipulated signal with a signal timing suitable for a downlink channel broadcast by the base station.

The method may further include a step of distinguishing between a cellular repeater and the terminal by maximizing the signal power of the terminal.

The step of distinguishing between the cellular repeater and the terminal comprises: distinguishing between the cellular repeater and the terminal by monitoring a fluctuation range of signal strength when the signal power of the terminal is intentionally increased; and distinguishing between the cellular repeater and the terminal enables tracking of the physical location of the terminal.

In another embodiment, a device for tracking a physical location of a mobile terminal in a real environment includes a traffic pattern forming unit for forming a specific traffic pattern by generating a plurality of packets that cannot be recognized by a terminal, which is a location tracking target; and an RNTI tracking unit for tracking an RNTI (Radio Network Temporary Identifier) of the terminal by performing fingerprinting based on the specific traffic pattern, and the physical location can be tracked using the RNTI of the terminal.

The method may further include a scheduling information acquisition unit that obtains scheduling information about an uplink signal transmitted by the terminal by decoding a downlink control information (DCI) message broadcast by a base station using the RNTI of the terminal; and a physical location estimation unit that monitors the uplink signal of the terminal and specifies the physical location based on the obtained scheduling information.

The device may further include a DCI message manipulation unit that manipulates a downlink control information (DCI) message in a wireless channel based on the RNTI of the terminal and the configuration of the base station.

According to embodiments, a method and device for tracking the physical location of a mobile terminal in a real environment can be provided, which can overcome the limitations of wireless signal-based location tracking that occur in a real environment when tracking the location of a mobile terminal by deceiving the terminal into increasing the uplink signal power as if the base station had commanded an increase in uplink power.

FIG. 1 is a drawing for explaining a physical location tracking device of a mobile communication terminal in a real environment according to one embodiment.
FIG. 2 is a flowchart illustrating a method for tracking the physical location of a mobile communication terminal in an actual environment according to one embodiment.
FIG. 3 is a block diagram showing a physical location tracking device of a mobile communication terminal in a real environment according to one embodiment.
FIG. 4 is a flowchart illustrating a method for tracking the physical location of a mobile communication terminal in a real environment according to another embodiment.
FIG. 5 is a block diagram showing a physical location tracking device of a mobile communication terminal in a real environment according to another embodiment.
FIG. 6 is a drawing for explaining the configuration of a physical location tracking device of a mobile communication terminal in an actual environment according to one embodiment.
FIG. 7 is a drawing for explaining the configuration of a location tracking terminal according to one embodiment.

Hereinafter, embodiments will be described with reference to the attached drawings. However, the described embodiments may be modified in various other forms, and the scope of the present invention is not limited by the embodiments described below. In addition, various embodiments are provided to more completely explain the present invention to a person having average knowledge in the relevant technical field. The shapes and sizes of elements in the drawings may be exaggerated for a clearer description.

In this specification, a base station means a terminal node of a network that directly communicates with a terminal. Certain operations described as being performed by a base station in this document may, in some cases, be performed by an upper node of the base station. That is, it is obvious that various operations performed for communication with a terminal in a network composed of a plurality of network nodes including a base station may be performed by the base station or other network nodes other than the base station. 'Base station (BS)' may be replaced by terms such as fixed station, NodeB, evolved-NodeB (eNB), base transceiver system (BTS), access point (AP), and transmitter. In addition, 'Terminal' may be fixed or mobile, and may be replaced with terms such as UE (User Equipment), MS (Mobile Station), UT (user terminal), MSS (Mobile Subscriber Station), SS (Subscriber Station), AMS (Advanced Mobile Station), WT (Wireless terminal), MTC (Machine-Type Communication) device, M2M (Machine-to-Machine) device, D2D (Device-to-Device) device, and receiver.

Hereinafter, downlink means communication from a base station to a terminal, and uplink means communication from a terminal to a base station. In the downlink, the transmitter may be part of the base station, and the receiver may be part of the terminal. In the uplink, the transmitter may be part of the terminal, and the receiver may be part of the base station.

Specific terms used in the following description are provided to aid in understanding the present invention, and the use of such specific terms may be changed to other forms without departing from the technical spirit of the present invention.

The following technologies can be used in various wireless access systems, such as CDMA (code division multiple access), FDMA (frequency division multiple access), TDMA (time division multiple access), OFDMA (orthogonal frequency division multiple access), SC-FDMA (single carrier frequency division multiple access), and NOMA (non-orthogonal multiple access). CDMA can be implemented with radio technologies such as UTRA (universal terrestrial radio access) or CDMA2000. TDMA can be implemented with radio technologies such as GSM (global system for mobile communications)/GPRS (general packet radio service)/EDGE (enhanced data rates for GSM evolution). OFDMA can be implemented with radio technologies such as IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802-20, EUTRA (evolved UTRA). UTRA is a part of UMTS (universal mobile telecommunications system). 3GPP(3rd generation partnership project) LTE(long term evolution) is a part of E-UMTS(evolved UMTS) that uses E-UTRA, and adopts OFDMA in the downlink and SC-FDMA in the uplink. LTE-A(advanced) is an evolution of 3GPP LTE.

The following embodiments relate to a method and device for tracking the physical location of a mobile communication terminal in a real environment. When the uplink signal power of the terminal is weak, the base station commands an increase in the uplink power. The present embodiments are intended to deceive the terminal into thinking that the base station has commanded an increase in the uplink power, thereby causing the terminal to increase the uplink signal power.

FIG. 1 is a drawing for explaining a physical location tracking device of a mobile communication terminal in a real environment according to one embodiment.

Referring to FIG. 1, in a mobile communication system, a terminal (110) and a base station (120) exchange signals with each other. When the uplink signal power of the terminal (110) is weak, the base station (120) commands an increase in the uplink power. According to one embodiment, a physical location tracking device of a mobile communication terminal in an actual environment can deceive the terminal (110) into thinking that the base station (120) commands an increase in the uplink power, thereby causing the terminal (110) to increase the uplink signal power.

According to one embodiment, a location tracking terminal (130) is placed around a terminal (110) whose location is to be tracked, receives a signal transmitted by the terminal (110), and a location tracking server can track the location of the terminal (110). At this time, the location of the terminal (110) can be tracked based on the delay of the signal transmitted by the terminal (110) reaching each location tracking terminal (130), the size of the received signal, etc.

In addition, the position tracking terminal (130) can track the position of the terminal (110) using the angle or direction at which the signal is received. For example, the position tracking terminal (130) can include at least one uplink signal receiving unit, and the position tracking terminal (130) can track the position of the terminal (110) by combining the angle or direction at which the uplink signal is received, the reception time, and the reception power information from the antenna connected to each uplink signal receiving unit. As another example, the position tracking terminal (130) can include one or more uplink signal receiving units, and the position tracking terminal (130) transmits the angle or direction information at which the uplink signal is received from the antenna connected to each uplink signal receiving unit to the position tracking server, and the position tracking server can track the position of the terminal (110) by combining the reception angle or reception direction information, the reception time, and the reception power information of the received signal. Here, a large number of position tracking terminals (130) can be placed around the terminal (110) for accurate position tracking. In addition, by combining the measurement results of the location tracking terminal (130) as well as the size and time delay information of the signal received from the base station (120) and the information received from the location tracking terminal (130), a more accurate location can be tracked.

In order to track the physical location of such a mobile communication terminal, a link may need to be formed between the base station (120) and the terminal (110) so that the terminal (110) may transmit an uplink. In addition, even in the case of a terminal (110) that already has a link formed with the base station (120), the terminal (110) may be set to transmit a signal that the mobile communication network and the location tracking terminal (130) have agreed upon in advance for more accurate measurement.

The request for link formation between the terminal (110) and the base station (120) may be made directly by the location tracking terminal (130) to the mobile communication system. However, the searcher may transmit the request to the location tracking server, and the location tracking server may transmit the request to the mobile communication network, and receive information about the link from the mobile communication network and inform the location tracking terminal (130). In this process, one of the location tracking terminals (130) located near the terminal (110) may become a master and transmit requests for link formation, such as setting and cancellation. In addition, all location tracking terminals (130) may be made to have the same authority to request link formation, such as setting and cancellation.

The location tracking terminal (130) can receive an uplink signal transmitted by a terminal (110) in a mobile communication system and estimate the location of the terminal (110) based on the size of the signal and time delay information. In order to obtain the time at which the terminal (110) transmits a signal in the mobile communication system, the location tracking terminal (130) can include a downlink signal receiving unit, which is a signal transmitted by a base station (120).

The location tracking terminal (130) can capture a downlink signal transmitted by a mobile communication system and estimate the time at which an uplink signal is transmitted based on this. That is, it can obtain a reference time at which a reverse link signal is transmitted, and capture and receive a reverse signal transmitted by the terminal (110) around the reference time. Here, the downlink signal received by the location tracking terminal (130) can be set to receive a frequency band for transmitting control information or wireless resource allocation information, specifically, resource allocation information, to the terminal (110). In addition, the downlink signal receiving unit of the location tracking terminal (130) can receive a signal of a base station (120) that is establishing a call with the terminal (110). At this time, the downlink signal receiving unit equipped in the location tracking terminal (130) can receive information such as BCCH (Broadcasting Control Channel) or BCH, which is system information transmitted by the base station (120), and obtain overall parameters of the system.

When tracking a location based on a terminal's uplink signal in a mobile communication network, radio ID information called a Radio Network Temporary Identifier (RNTI) is required. However, since RNTI is temporary ID information that changes periodically, continuous tracking of this ID is inevitable in order to continuously monitor the terminal's signal and track its location.

Accordingly, the embodiments can implement a technology for creating a specific traffic pattern by generating a large number of packets that cannot be recognized by a location tracking target (terminal), such as silent SMS, spam SMS, and silent voice call, and then performing fingerprinting based on the pattern to track the target's RNTI.

In addition, when a third party (attacker) performs location tracking in a mobile communication network, there are bound to be many difficulties in setting up the same equipment as the base station. Accordingly, the attacker faces the difficulty of not being able to properly detect/monitor the uplink signal of the target terminal when tracking the location. For example, when a terminal is located close to a base station, the terminal transmits an uplink signal at low power, so it may be impossible for the attacker to detect the signal of the terminal.

To address this, the embodiments can provide an attack that can increase the signal power of a terminal to the maximum (e.g., 23 dBm) using only the terminal's RNTI information without separate authority by exploiting a vulnerability in the mobile communication standard. Based on this attack, the possibility and performance of location tracking can be improved.

In addition, mobile carriers can improve service quality by additionally installing a device called a cellular repeater to overcome poor radio channel conditions in the wireless network. This is usually used in places where base station signals do not reach well or inside buildings. In general, cellular repeaters use bidirectional radio antennas to amplify both the downlink signal sent by the base station and the uplink signal sent by the terminal.

Although this cellular repeater is quite helpful to users by contributing to improving the quality of LTE/5G services, it can be disadvantageous to attackers who are conducting location tracking. For example, if a terminal is located in an area where a cellular repeater is installed or inside a building, it will transmit a low-power uplink signal due to the influence of the cellular repeater, and the signal will be amplified by the cellular repeater and transmitted to the base station through the wireless antenna installed in the repeater. In this case, since the uplink signal of the terminal is detected by the wireless antenna of the cellular repeater, the attacker is likely to recognize the cellular repeater, not the targeted terminal, as a location tracking target.

To overcome this, the embodiments propose a method of distinguishing between a cellular repeater and a terminal by maximizing the signal power of the terminal using the method used previously. That is, the embodiments can distinguish between a cellular repeater and a terminal by maximizing the signal power of the terminal using only the RNTI information of the terminal.

The reason this method is possible is because the repeater always amplifies the signal with the same strength of power, so it is possible to distinguish it by monitoring the variation in signal strength when the signal power of the terminal is intentionally increased.

Below, a method and device for tracking the physical location of a mobile terminal in a real environment are described in more detail.

FIG. 2 is a flowchart illustrating a method for tracking the physical location of a mobile communication terminal in an actual environment according to one embodiment.

Referring to FIG. 2, a method for tracking a physical location of a mobile communication terminal in a real environment performed by a computer device according to one embodiment includes a step (S110) of generating a plurality of packets that cannot be recognized by a terminal, which is a target of location tracking, to form a specific traffic pattern, and a step (S120) of tracking an RNTI (Radio Network Temporary Identifier) of the terminal by performing fingerprinting based on the specific traffic pattern, and the physical location can be tracked using the RNTI of the terminal.

In addition, the method may further include a step (S130) of decoding a downlink control information (DCI) message broadcast by a base station using the RNTI of the terminal to obtain scheduling information regarding an uplink signal transmitted by the terminal, and a step (S140) of monitoring the uplink signal of the terminal and specifying its physical location based on the obtained scheduling information.

A method for tracking a physical location of a mobile communication terminal in a real environment according to one embodiment can be described in more detail by taking as an example a device for tracking a physical location of a mobile communication terminal in a real environment according to one embodiment.

FIG. 3 is a block diagram showing a physical location tracking device of a mobile communication terminal in a real environment according to one embodiment.

Referring to FIG. 3, a physical location tracking device (300) of a mobile communication terminal in an actual environment according to one embodiment may include a traffic pattern forming unit (310), an RNTI tracking unit (320), a scheduling information obtaining unit (330), and a physical location estimation unit (340).

In step (S110), the traffic pattern forming unit (310) can form a specific traffic pattern by generating a plurality of packets that cannot be recognized by the terminal that is the target of location tracking. The traffic pattern forming unit (310) can form a specific traffic pattern by generating a plurality of packets that do not interfere with the service of the terminal that is the target of location tracking, such as silent SMS, spam SMS, and silent voice call.

In step (S120), the RNTI tracking unit (320) can track the RNTI of the terminal by performing fingerprinting based on a specific traffic pattern.

In step (S130), the scheduling information acquisition unit (330) can obtain scheduling information about an uplink signal transmitted by the terminal by decoding a downlink control information (DCI) message broadcast by the base station using the RNTI of the terminal.

Accordingly, in step (S140), the physical location estimation unit (340) can monitor the uplink signal of the terminal and specify the physical location based on the acquired scheduling information.

The embodiments exploit vulnerabilities in mobile communication standards to increase the signal power of a terminal to a maximum (e.g., 23 dBm) using only the terminal's RNTI information without separate authorization.

Typically, a base station uses a Transmit Power Control (TPC) command in a DCI message to control the uplink signal strength of a terminal. By using the physical location tracking process of a mobile communication terminal in a real environment according to an embodiment described in FIGS. 2 and 3, the RNTI of the terminal can be obtained, and the DCI message in the wireless channel can be manipulated based on the RNTI and the configuration of the base station.

FIG. 4 is a flowchart illustrating a method for tracking the physical location of a mobile communication terminal in a real environment according to another embodiment.

Referring to FIG. 4, a method for tracking a physical location of a mobile communication terminal in a real environment performed by a computer device according to another embodiment includes a step (S210) of generating a plurality of packets that cannot be recognized by a terminal, which is a target of location tracking, to form a specific traffic pattern, and a step (S220) of tracking an RNTI of the terminal by performing fingerprinting based on the specific traffic pattern, and the physical location can be tracked using the RNTI of the terminal.

In addition, the method may further include a step (S230) of manipulating a downlink control information (DCI) message in a wireless channel based on the RNTI of the terminal and the configuration of the base station.

Additionally, the method may further include a step of distinguishing between a cellular repeater and a terminal by maximizing the signal power of the terminal according to an embodiment.

A method for tracking a physical location of a mobile terminal in a real environment according to another embodiment can be described in more detail with reference to an example of a device for tracking a physical location of a mobile terminal in a real environment according to another embodiment.

FIG. 5 is a block diagram showing a physical location tracking device of a mobile communication terminal in a real environment according to another embodiment.

Referring to FIG. 5, a physical location tracking device (500) of a mobile communication terminal in a real environment according to another embodiment may include a traffic pattern forming unit (510), an RNTI tracking unit (520), and a DCI message manipulation unit (530). In addition, according to an embodiment, the physical location tracking device (500) of a mobile communication terminal in a real environment according to another embodiment may further include a terminal determination unit.

In step (S210), the traffic pattern forming unit (510) can form a specific traffic pattern by generating a plurality of packets that cannot be recognized by the terminal that is the target of location tracking. The traffic pattern forming unit (510) can form a specific traffic pattern by generating a plurality of packets that do not interfere with the service of the terminal that is the target of location tracking, such as silent SMS, spam SMS, and silent voice call.

In step (S220), the RNTI tracking unit (520) can track the RNTI of the terminal by performing fingerprinting based on a specific traffic pattern.

In step (S230), the DCI message manipulation unit (530) can manipulate a downlink control information (DCI) message in a wireless channel based on the RNTI of the terminal and the configuration of the base station. Here, the configuration of the base station can be obtained through downlink channel monitoring. By manipulating the downlink control information (DCI) message in the wireless channel, the terminal decodes the manipulated downlink control information (DCI) message, thereby forcibly changing the strength of the uplink signal without the will of the base station or the terminal.

More specifically, the DCI message manipulation unit (530) can generate a manipulated downlink control information (DCI) message by setting a TPC command value so that the terminal changes the uplink signal strength, and then overwrite the manipulated signal with a signal timing (in subframe units: 1 millisecond) suitable for the downlink channel broadcast by the base station. At this time, the manipulated signal must be received with a stronger strength than a normal signal from the receiving terminal's perspective.

The terminal decodes the manipulated message and forcibly changes the uplink signal strength without the will of the base station or the terminal. As a result, the possibility and performance of location tracking can be improved by overcoming the shadow area.

Meanwhile, through the technology of forging DCI messages, it is possible to perform various manipulations, such as not only simply increasing the signal strength of a terminal, but also forcibly manipulating the scheduling of a terminal or reducing the signal strength of a terminal to a state where communication is impossible. This is because the targeted DCI message has various authority regarding mobile communication network control.

Furthermore, the embodiments can provide a method for distinguishing between a cellular repeater and a terminal by maximizing the signal power of the terminal by utilizing the method used above. This method is possible because the repeater always amplifies the signal with the same intensity of power, so that it is possible to distinguish between the terminal and the repeater by monitoring the variation in signal intensity when the signal power of the terminal is intentionally increased.

In another embodiment, a physical location tracking device (500) of a mobile communication terminal in a real environment may further include a terminal determination unit.

The terminal identification unit can distinguish between a cellular repeater and a terminal by maximizing the signal power of the terminal. The terminal identification unit monitors the fluctuation range of the signal strength when the signal power of the terminal is intentionally increased to distinguish between a cellular repeater and the terminal, and can track the physical location of the terminal by distinguishing the cellular repeater. Accordingly, the possibility and performance of location tracking can be improved by overcoming cellular repeaters installed in various places.

Thereafter, the scheduling information acquisition unit can obtain scheduling information about an uplink signal transmitted by the terminal by decoding a downlink control information (DCI) message broadcast by the base station using the RNTI of the terminal.

Accordingly, the physical location estimation unit can monitor the uplink signal of the terminal and identify the physical location based on the acquired scheduling information.

The system can be applied and utilized to all existing or future location tracking systems. When tracking the location of a mobile communication terminal in an actual environment, actual location tracking is possible according to the embodiments.

FIG. 6 is a drawing for explaining the configuration of a physical location tracking device of a mobile communication terminal in an actual environment according to one embodiment.

Referring to FIG. 6, it can be assumed that in a mobile communication system according to one embodiment, a base station (120) and a terminal (110) wirelessly exchange signals with each other. In one embodiment, the wireless signal may be a mobile communication system. Below, the mobile communication system may be described as an LTE mobile communication system. However, it is not limited to the corresponding communication system.

In a real environment, a physical location tracking device of a mobile communication terminal may include a location tracking terminal (130) that attempts to track the location of the terminal (110) and a location tracking server (140). Here, there may be one or more location tracking terminals (130). The location tracking terminal (130) may receive uplink and downlink signals transmitted between the terminal (110) and the base station (120) through an uplink signal receiving unit and a downlink signal receiving unit. Here, the uplink signal receiving unit and the downlink signal receiving unit of the location tracking terminal (130) are not the signal receiving units included in the base station (120) and the terminal, which are entities that transmit the uplink signal or the downlink signal, and may be characterized by receiving uplink signals and downlink signals of other communication equipment. The other communication equipment may be a terminal. When the location tracking terminal (130) receives an uplink signal, it may measure the reception time and radio wave intensity of the uplink signal of the terminal (110). In addition, it may also measure the direction and angle at which the signal is received. The location tracking terminal (130) measures the signal transmitted by the terminal (110) and transmits it to the location tracking server (140), and based on this, the location tracking server (140) can calculate the location of the terminal (110) and transmit it to the location tracking terminal (130). The location tracking terminal (130) that receives this location information can inform the user of the location of the terminal (110) through an output device such as a display unit.

First, the location tracking terminal (130) can receive identification information of the terminal (110) from the base station (120) through the communication unit. Here, the communication unit is a configuration that can transmit and receive signals with other communication equipment such as the base station (120) or the location tracking server (140), and may be a separate configuration from the uplink signal receiving unit or the downlink signal receiving unit. In another embodiment, the receiving side of the communication unit may be a configuration identical to the downlink signal receiving unit, and may be a configuration that receives a signal from the base station (120) or the location tracking server (140). For example, the frequency band used by the downlink signal transmitted to the terminal and the downlink frequency band used by the communication unit of the location tracking terminal (130) may use the same band, and may be received using a single downlink receiving unit.

In one embodiment, the location tracking terminal (130) can receive an RNTI corresponding to a temporary ID assigned to the terminal by a base station (120) as identification information of the terminal (110). The RNTI is used as a temporary ID of the terminal within a base station, and since it is not known which RNTI will be assigned to a terminal, anonymity can be maintained. In this embodiment, the RNTI is described based on a method of identifying a terminal, but it is to be noted that the present embodiments can be used with the same function if it is an ID temporarily assigned to a terminal within a base station or cell.

In one embodiment, when a missing person (or a person in distress) is reported, the base station (120) of the mobile communication network assigns one RNTI to the missing person and informs the location tracking terminals (130) of this RNTI information. The location estimation terminal (130) that has received the RNTI information can detect the uplink signal of the terminal (110) that transmits the uplink signal using the corresponding RNTI and estimate the location of this terminal (110). Although the base station can directly transmit the RNTI information to the location tracking terminal (130), the target terminal information server can be used so that the base station transmits the RNTI information to a communication server, and the communication server transmits the RNTI information to the location tracking terminal (130). In another embodiment, after the RNTI to be used for positioning is agreed upon in advance between the base station of the mobile communication network and the location tracking terminal (130), the base station assigns a predetermined RNTI to the terminal, and the location tracking terminal (130) can detect and measure a signal of the terminal using the RNTI. In addition, multiple RNTIs can be promised between the mobile communication network and the location tracking terminal (130), and in this case, information about which RNTI has been allocated to the terminal can be notified with a number of bits less than the number of bits of the RNTI. For example, if the RNTI consists of 16 bits and 8 RNTIs are promised to be allocated to the terminal, information about which RNTI is used can be notified to the location tracking terminal (130) with 3 bits.

In one embodiment, when or after the location tracking terminal (130) receives RNTI information of the terminal (110) whose location is to be tracked, the base station (120) can provide approximate location information of the terminal (110). Based on this information, the location tracking terminal (130) can be placed around the terminals (110) and location tracking can be attempted. The location tracking terminal (130) can attempt to detect an uplink signal transmitted based on the RNTI assigned to the terminal (110) whose location is to be tracked. The location tracking terminal (130) can receive downlink resource allocation information based on the RNTI to obtain resource allocation information of the terminal, and can detect and measure the uplink signal of the terminal based on this.

The position tracking terminal (130) can obtain the time synchronization of the uplink in order to receive the signal of the terminal (110) transmitting to the uplink. In order to obtain the time synchronization for the uplink transmission time, the position tracking terminals (130) can be equipped with a downlink signal receiving unit. That is, the downlink signal is received to obtain the time information of the system and, based on this, the time synchronization that the terminal (110) transmits to the reverse channel is obtained. In this process, if necessary, the downlink signal receiving unit equipped in the position tracking terminal (130) can receive information such as BCH and dynamic BCH, which are system information transmitted by the base station (120), and obtain the overall parameters of the system.

In this embodiment, a method can be proposed for a location tracking terminal (130) to obtain information on when a terminal (110) transmits a signal via uplink.

In one embodiment, the position tracking terminal (130) can receive control information through one or more downlink signal receiving units, and obtain resource allocation information of the uplink signal of the terminal based on the received control information and the terminal identification information. Specifically, the position tracking terminal (130) can receive a PDCCH (Physical Downlink Control Channel), which is control information transmitted in the downlink, using the downlink signal receiving unit to obtain information on whether an uplink signal is transmitted and information on the transmitted resources. The operation is different from that of the conventional LTE receiving unit in that the LTE downlink signal receiving unit receives control information transmitted to other users. In other words, it receives control information transmitted to other terminals (target terminals) rather than receiving control information transmitted to itself. Based on the target user control information received in this way, the position tracking terminal (130) can obtain information on uplink resources allocated to the terminal (110). In addition, in order to obtain additional information on uplink resource allocation during this process, the location tracking terminal (130) may additionally receive information on the PDSCH (Physical Downlink Shared channel) allocated and transmitted in addition to the control channel of the forward channel transmitted to the terminal (110).

When the base station (120) transmits information about these uplink transmission resources to the terminal, the format in which the base station (120) transmits the signal may be partially limited in order to reduce the reception complexity of the PDCCH and PDSCH of the terminal. In this case, the position tracking terminal (130) may receive transmission format information about the downlink signal from the base station, receive the downlink signal through one or more downlink signal receiving units using the transmission format information about the downlink signal, and process the received downlink signal to obtain control information.

For example, in the case of PDCCH, CCE aggregation levels 1, 2, 4, and 8 are all possible. However, in one embodiment, in order to reduce the complexity of control of the position tracking terminal (130), the base station may transmit the PDCCH to the terminal only at CCE aggregation level 8. Another example is to use CCE aggregation level 4 or 8 of the PDCCH. By limiting the CCE aggregation level in this way, when one position tracking terminal (130) performs position measurement of multiple terminals, the complexity for blind decoding of the PDCCH can be significantly reduced. In addition, in the present invention, when the base station allocates uplink resources of the terminal so that the position tracking terminal (130) can measure through the PDSCH, the complexity of the position tracking terminal (130) can be reduced by limiting the transmission mode. For example, when a base station allocates uplink resources to a terminal through PDSCH for measurement of a position tracking terminal (130), the transmission mode can be limited to a diversity transmission mode. By doing so, the position tracking terminal (130) can use only a transmission mode of a predetermined format without having to implement all possible transmission modes for the downlink, so the complexity can be greatly reduced.

Through the process, the location tracking terminal (130) can obtain information about the time and resources at which the terminal (110) transmits a signal via uplink. Based on this, the location tracking terminal (130) can receive the uplink signal transmitted by the terminal (110).

When the location tracking terminal (130) captures the signal of the terminal, it can measure the reception time and reception power of the uplink signal of the terminal, and transmit the measured information to the location tracking server (140). At this time, information about the signal of the terminal transmitted by each location tracking terminal (130) may include RNTI information of the terminal (or terminal ID information), reception time of the uplink signal, reception power information, etc. Here, the information on the reception time of the uplink signal may mean information on the relative reception time based on an absolute time created based on GPS, etc., shared among all location tracking terminals (130), and based on this. In other words, it may mean information on a common time shared among all location tracking terminals (130), and a relative reception time based on this time. In addition to the measurement information, the location tracking terminal (130) may transmit time information measured at the signal of the terminal (110), thereby enabling real-time location tracking. From the information on the above-mentioned reception time, information on the time at which the uplink signal is transmitted from the terminal to the location tracking terminal (130) may be calculated. In particular, multiple location tracking terminals (130) obtain information on the time of reception, or one location tracking terminal (130) obtains information on the time of reception at multiple locations, and based on this, information on the time delay of radio waves can be obtained, and based on this, the distance between the terminal and the location tracking terminal (130) can be calculated.

In a real environment, a physical location tracking device of a mobile communication terminal may be equipped with a location tracking server (140). The location tracking server (140) may receive the reception time and reception power information of the uplink signal of the terminal (110) from the location tracking terminal (130), calculate the location of the terminal (110) based on the reception time and reception power information of the uplink signal of the terminal (110), and transmit the calculated location information of the terminal (110) to the location tracking terminal (130). In addition, the location tracking terminal (130) may transmit information on the time at which the signal of the terminal was received to the location estimation server to inform it of when the measurement was performed. Based on this, the location tracking server may combine the measurement results of the location tracking terminal (130) performed at different times to track the location of the terminal.

In one embodiment, the location tracking server (140) can receive ID information of the terminal (110) and measurement information on the reception time and reception power of the uplink signal from one or more location tracking terminals (130). The ID information of the terminal can be RNTI, but a number defined in advance between the location tracking server and the location tracking terminal (130) can be assigned to one terminal and used. In addition, the location tracking server (140) can calculate the location of the terminal (110) based on information such as triangulation and radio attenuation based on the measurement information transmitted by the location tracking terminals (130) and transmit this information to the location tracking terminals (130). The location measurement method used at this time can apply various technologies that have been used in many previous studies, and the present embodiments can propose a system for a location tracking terminal (130) and its operating environment that enables such location measurement.

In one embodiment, the location tracking server (140) additionally receives, from the base station (120), the reception time and reception power information of the uplink signal of the terminal (110) received by the base station (120), and calculates the location of the terminal (110) by combining the reception time and reception power information of the uplink signal of the terminal (110) from the location tracking terminal (130), and the reception time and reception power information of the uplink signal of the terminal (110) from the base station (120). As a result, the accuracy of the location information of the terminal (110) can be improved by using not only the measurement information transmitted by each location tracking terminal (130), but also the information measured by the base station (120). That is, the base station (120) communicating with the terminal (110) can also measure the delay and reception power on the channel of the signal transmitted by the terminal (110) and transmit the measured information to the location tracking server (140). The location tracking server (140) receives measurement information on the uplink signal of the terminal (110) not only from the location tracking terminal (130) but also from the base station (120), and performs location tracking by combining the measurement information on the uplink signal of the terminal (110) from the base station (120) and the measurement information on the uplink signal of the terminal (110) from the location tracking terminal (130), thereby performing more accurate location tracking. In the process, the location tracking terminal (130) and the base station, which transmit the measurement result to the location tracking server, can also transmit their own location information to the location tracking server. The location tracking server can calculate the location of the terminal (110) based on the location information and the measurement results.

In this embodiment, the location tracking server (140) can transmit information of the terminal (110) including the calculated location information of the terminal (110) to the location tracking terminal (130). The location tracking terminal (130) that has received the location information of the terminal (110) outputs it to an output device including a display to inform the user. In one embodiment, the location tracking terminal (130) can display the location of the terminal (110) on a map as a method of informing the user of the location of the terminal (110).

The accuracy of location measurement may vary depending on where the location tracking terminal (130) is located. In order to measure the location more accurately, it is more effective to change the arrangement of the location tracking terminal (130) in a direction that reduces the measurement error. Therefore, the location tracking terminal (130) according to one embodiment transmits its own location information to the location tracking server (140), and the location tracking server (140) receives location information of one or more location tracking terminals (130) from one or more location tracking terminals (130), calculates the movement direction of one or more location tracking terminals (130) so that the arrangement between one or more location tracking terminals (130) and the terminals can reduce the location tracking error of the terminals, and transmits movement direction information of each of the one or more location tracking terminals (130) to each of the one or more location tracking terminals (130).

That is, the location tracking server (140) not only measures the location of the terminal (110) based on the measurement data transmitted by the location tracking terminal (130), but also transmits information on the direction of movement of each location tracking terminal (130) to the location tracking terminal (130). For example, not only the location of the terminal (110) may be displayed on the map, but also the location of the location tracking terminal (130) may be displayed, and information on the direction or destination in which the location tracking terminal (130) must move may be displayed using an arrow to reduce measurement error. In addition, the location tracking terminal (130) may display not only its own location but also the location information of other location tracking terminals (130) on the map to identify the locations among users of each location tracking terminal (130). In this case, the location of the terminal (110), the location of the location tracking terminal (130) being used, and the location of other location tracking terminals (130) may be displayed using different colors or shapes.

FIG. 7 is a drawing for explaining the configuration of a location tracking terminal according to one embodiment.

Referring to FIG. 7, a position tracking terminal according to an embodiment may include one or more downlink signal receiving units (710) and one or more uplink signal receiving units (720) for receiving mobile communication signals. In addition, the position tracking terminal may include a control unit (730) for controlling the received signals. According to an embodiment, the position tracking terminal may include a communication unit (740) capable of communicating with a base station, a position tracking server, or another position tracking terminal, a GPS receiving unit (770) for performing synchronization with absolute time, an input unit (750) for receiving input from a user, and a display unit (760) for displaying information processed by the control unit (730).

Here, the downlink signal receiving unit (710) and the uplink signal receiving unit (720) may be an LTE downlink signal receiving unit and an LTE uplink signal receiving unit. In this embodiment, the downlink signal receiving unit may operate by setting the frequency band in which the terminal transmits the uplink signal to the frequency band in which the control information is transmitted.

The downlink signal receiving unit (710) can capture the initial LTE downlink signal to obtain system time synchronization and perform the role of obtaining a base station ID and system information, etc. In addition, it can measure the signal transmitted from the base station to measure the strength of the downlink signal and display it on the display unit. In addition, it can display the ID of the base station or whether it is within the service range of the desired base station. Through this, it is possible to check whether the user is within the service range of the desired base station. BCCH, etc. can be received through the downlink signal receiving unit (710) and system information can be obtained.

In addition, the downlink signal receiving unit (710) can receive control information transmitted from the base station to the terminal. The LTE uplink signal receiving unit can receive information on uplink transmission resources allocated to the terminal. In another implementation example, resource allocation information of the terminal can be received from a communication server through the communication unit (740), and a location tracking server can be used as the communication server. In another implementation example, the resource allocation information and information can be used to set up transmission of the terminal's signal at a predefined resource and time between the mobile communication network and the location tracking terminal. Thereafter, the control unit (730) can detect the transmission signal of the terminal based on the information on the uplink transmission resources allocated to the terminal and calculate the arrival time and signal power of the signal.

In addition, the position tracking terminal can secure an absolute time reference and calculate the difference in time at which each position tracking terminal receives the terminal's uplink signal. In the embodiment of Fig. 7, the position tracking terminals can secure temporal synchronization based on the GPS signal received from the GPS receiving unit (770) to perform this role. In this process, other technologies such as SBAS and Galileo used for positioning or time information, as well as GPS, can be used or used in combination with GPS.

In an embodiment, a separate communication unit (740) may be used when communication with a location tracking server or direct communication with another location tracking terminal is required. The communication unit (740) may use a band different from the band in which the terminal's signal is measured. This is to prevent the communication device from interfering with the uplink signal transmitted by the terminal.

The location tracking terminal may be equipped with an output device such as a display to display the location of the terminal to the user. In addition, it may be equipped with an input unit (750) for user input, and the user may input additional information, such as manually inputting information on the current location of the location tracking terminal, through the input unit (750), thereby increasing the accuracy of location measurement.

As described above, according to the embodiments, the limitations of wireless signal-based location tracking that occur in real environments can be overcome when tracking the location of a mobile communication terminal by deceiving the terminal into increasing the uplink signal power as if the base station had commanded an increase in uplink power.

The devices described above may be implemented as hardware components, software components, and/or a combination of hardware components and software components. For example, the devices and components described in the embodiments may be implemented using one or more general-purpose computers or special-purpose computers, such as, for example, a processor, a controller, an arithmetic logic unit (ALU), a digital signal processor, a microcomputer, a field programmable array (FPA), a programmable logic unit (PLU), a microprocessor, or any other device capable of executing instructions and responding to them. The processing device may execute an operating system (OS) and one or more software applications running on the operating system. In addition, the processing device may access, store, manipulate, process, and generate data in response to the execution of the software. For ease of understanding, the processing device is sometimes described as being used alone, but those skilled in the art will appreciate that the processing device may include multiple processing elements and/or multiple types of processing elements. For example, the processing device may include multiple processors, or one processor and one controller. Additionally, other processing configurations, such as parallel processors, are also possible.

The software may include a computer program, code, instructions, or a combination of one or more of these, which may configure a processing device to perform a desired operation or may independently or collectively command the processing device. The software and/or data may be embodied in any type of machine, component, physical device, virtual equipment, computer storage medium, or device for interpretation by the processing device or for providing instructions or data to the processing device. The software may be distributed over network-connected computer systems and stored or executed in a distributed manner. The software and data may be stored on one or more computer-readable recording media.

The method according to the embodiment may be implemented in the form of program commands that can be executed through various computer means and recorded on a computer-readable medium. The computer-readable medium may include program commands, data files, data structures, etc., alone or in combination. The program commands recorded on the medium may be those specially designed and configured for the embodiment or may be those known to and available to those skilled in the art of computer software. Examples of the computer-readable recording medium include magnetic media such as hard disks, floppy disks, and magnetic tapes, optical media such as CD-ROMs and DVDs, magneto-optical media such as floptical disks, and hardware devices specially configured to store and execute program commands such as ROMs, RAMs, and flash memories. Examples of the program commands include not only machine language codes generated by a compiler, but also high-level language codes that can be executed by a computer using an interpreter, etc.

Although the embodiments have been described above by way of limited examples and drawings, those skilled in the art can make various modifications and variations from the above description. For example, appropriate results can be achieved even if the described techniques are performed in a different order than the described method, and/or components of the described system, structure, device, circuit, etc. are combined or combined in a different form than the described method, or are replaced or substituted by other components or equivalents.

Therefore, other implementations, other embodiments, and equivalents to the claims are also included in the scope of the claims described below.

Claims (10)

In a method for tracking the physical location of a mobile communication terminal in a real environment performed by a computer device,
A step of forming a specific traffic pattern by generating multiple packets that cannot be recognized by the terminal that is the target of location tracking; and
A step of tracking the RNTI (Radio Network Temporary Identifier) of the terminal by performing fingerprinting based on the above specific traffic pattern.
Including,
Further comprising a step of manipulating a downlink control information (DCI) message in a wireless channel based on the RNTI of the terminal and the configuration of the base station,
The steps for manipulating the above downlink control information (DCI) message are:
A step for generating the manipulated downlink control information (DCI) message by setting a TPC command value so that the terminal changes the uplink signal strength; and
By including a step of overlaying the manipulated signal with a signal timing suitable for the downlink channel broadcast by the above base station,
The above terminal decodes the manipulated downlink control information (DCI) message, thereby forcibly changing the strength of the uplink signal without the will of the base station or the terminal.
A method for tracking the physical location of a mobile terminal, which tracks the physical location using the RNTI of the terminal. In the first paragraph,
A step of decoding a downlink control information (DCI) message broadcast by a base station using the RNTI of the terminal to obtain scheduling information regarding an uplink signal transmitted by the terminal; and
A step of monitoring the uplink signal of the terminal and identifying its physical location based on the acquired scheduling information.
A method for tracking the physical location of a mobile terminal, further comprising: delete delete delete In the first paragraph,
The steps for manipulating the above downlink control information (DCI) message are:
A step of distinguishing between a cellular repeater and the terminal by maximizing the signal power of the terminal.
A method for tracking the physical location of a mobile terminal, further comprising: In Article 6,
The step of distinguishing between the above cellular repeater and the above terminal is:
When the signal power of the terminal is intentionally increased, the fluctuation range of the signal strength is monitored to distinguish between the cellular repeater and the terminal, and the physical location of the terminal is tracked by distinguishing the cellular repeater.
A method for tracking the physical location of a mobile terminal, characterized by: In a physical location tracking device for a mobile communication terminal in a real environment,
A traffic pattern forming unit that forms a specific traffic pattern by generating multiple packets that cannot be recognized by the terminal that is the target of location tracking; and
RNTI tracking unit that tracks the RNTI (Radio Network Temporary Identifier) of the terminal by performing fingerprinting based on the above specific traffic pattern.
Including,
It further includes a DCI message manipulation unit that manipulates a downlink control information (DCI) message in a wireless channel based on the RNTI of the terminal and the configuration of the base station.
The above DCI message manipulation unit
By generating the manipulated downlink control information (DCI) message by setting the TPC command value so that the above terminal changes the uplink signal strength, and overlaying the manipulated signal with a signal timing suitable for the downlink channel broadcast by the above base station,
The above terminal decodes the manipulated downlink control information (DCI) message, thereby forcibly changing the strength of the uplink signal without the will of the base station or the terminal.
A physical location tracking device for a mobile communication terminal that tracks the physical location using the RNTI of the terminal. In Article 8,
A scheduling information acquisition unit that decodes a downlink control information (DCI) message broadcast by a base station using the RNTI of the terminal to acquire scheduling information about an uplink signal transmitted by the terminal; and
A physical location estimation unit that monitors the uplink signal of the terminal and identifies the physical location based on the acquired scheduling information.
A physical location tracking device for a mobile terminal, further comprising: delete

Images