KR102428935B1 - Method and apparatus of performing synchronization - Google Patents

Abstract

A method and apparatus for performing synchronization according to an embodiment obtains information on a synchronization environment of terminals distributed on a network, and based on the information on the synchronization environment, a clock phase of a target terminal according to a synchronization signal received from each of the terminals Synchronization is performed by adjusting the variable values of the phase response function for correcting , and controlling the clock phase of the target terminal based on the variable values of the phase response function.

Description

SYNCHRONIZATION METHOD AND APPARATUS OF PERFORMING SYNCHRONIZATION

According to one embodiment, a method and apparatus for performing pulse-coupling synchronization robust to a synchronization interference signal to increase synchronization reliability in a distributed synchronization system are disclosed.

Distributed synchronization algorithm is a method of synchronizing in a distributed form by exchanging synchronization-related information between terminals. It can be used when there is no centripetal point. As an example of a distributed synchronization algorithm, a Pulse-Coupled Synchronization (PCS) method in which each terminal synchronizes by exchanging light emission signals having a certain period with each other, inspired by a biological field such as a firefly for example.

In general, the data packet-based synchronization method is difficult to apply in a network with a large number of terminals because data required for synchronization increases as the number of terminals increases, and unnecessary power and calculation amount increase accordingly.

In contrast, the pulse-coupling synchronization (PCS) method does not depend on the number of terminals because only an impulse, which is a light emitting signal, is used for synchronization. However, in the pulse-coupling synchronization (PCS) method, synchronization can be performed only when all terminals comply with the method, and synchronization cannot be guaranteed if a specific terminal does not follow the method or there is a synchronization interference attack .

The above-mentioned background art is possessed or acquired by the inventor in the process of deriving the disclosure of the present application, and it cannot be said that it is necessarily known technology disclosed to the general public prior to the present application.

According to an embodiment, synchronization reliability may be improved in a distributed synchronization system by a pulse-coupling synchronization method that is robust to a synchronization interference signal.

According to an embodiment, appropriate distributed synchronization according to the synchronization attack environment can be obtained by appropriately adjusting the variable values of the phase response function according to information on the synchronization environment of terminals distributed on the network.

According to one embodiment, the synchronization system under a synchronization attack having an arbitrary period by controlling the clock phase of the target terminal based on the phase response function having variable values adjusted according to information on the synchronization environment of the terminals distributed on the network. While making it robust, it can improve the time it takes to synchronize.

According to an embodiment, a method for performing synchronization includes: obtaining information on a synchronization environment of terminals distributed on a network; adjusting variable values of a phase response function (PRF) that corrects a clock phase of a target terminal according to a synchronization signal received from each of the terminals based on the information on the synchronization environment ; and performing synchronization by controlling the clock phase of the target terminal based on the variable values of the phase response function.

The information on the synchronization environment includes the number of synchronization terminals synchronized with each other among the terminals, the number of attacker terminals attacking the target terminal, a synchronization period in which the synchronization terminals transmit the synchronization signal, and the attacker It may include at least one of an attack period in which the terminal transmits an attack signal.

Adjusting the variable values of the phase response function may include adjusting the variable values of the phase response function based on at least one of a type of an attack signal for the terminals and information on the synchronization environment. have.

The variable values of the phase response function include a first variable and a second variable corresponding to the clock phase of the target terminal, a phase threshold corresponding to the target terminal, and a coupling strength between the target terminal and a terminal synchronized with each other. ) may include at least one of.

The step of adjusting the variable values of the phase response function includes adjusting the variable values of the phase response function by determining the range of coupling strength between synchronous terminals synchronized with each other according to the attack period of the attacker terminal attacking the target terminal. may include steps.

The step of adjusting the variable values of the phase response function includes a first corresponding to the clock phase of the target terminal according to a combination of a range of coupling strength between synchronous terminals synchronized with each other and an attack period of an attacker terminal attacking the target terminal. detecting a range of ratios between the first variable and the second variable; and adjusting variable values of the phase response function based on a range of a ratio between the first variable and the second variable.

The step of adjusting the variable values of the phase response function based on the range of the ratio between the first variable and the second variable may include that the ratio between the first variable and the second variable is greater than the lower limit threshold ratio, but close to 1. It may include adjusting the variable values of the phase response function to correspond to the excluded range.

The adjusting of the variable values of the phase response function may include calculating an effect of a ratio between a first variable and a second variable corresponding to the clock phase of the target terminal on synchronization performance; and adjusting variable values of the phase response function in consideration of the influence.

Calculating the effect on the synchronization performance using a performance function including a first term corresponding to a synchronization probability corresponding to the target terminal and a second term corresponding to a synchronization rate corresponding to the target terminal calculating the effect of the ratio between the first variable and the second variable on the synchronization performance, wherein each of the first and second terms includes a first variable corresponding to a clock phase of the target terminal and It may be a function of a second variable, a phase threshold corresponding to the target terminal, and a coupling strength between the target terminal and a terminal synchronized with each other.

The second term corresponding to the synchronization speed may be expressed by the following [Equation].

[Equation]

는 상기 위상 응답 함수의 상기 제1 변수를 나타내고,

는 상기 위상 응답 함수의 상기 제2 변수를 나타내며, 0 ≤

,

≤ 1 인 실수임.) (Here, D represents a phase threshold corresponding to the target terminal.

represents the first variable of the phase response function,

denotes the second variable of the phase response function, 0 ≤

,

Real numbers with ≤ 1.)

Constraints of variable values of the phase response function may be set based on information about the synchronization environment.

The performing of the synchronization may include calculating a result of controlling the clock phase of the current time of the target terminal based on the variable values of the phase response function; and performing the synchronization by compensating for the phase of the current time by the result of controlling the clock phase of the current time and the coupling strength of the target terminal.

Calculating the result of controlling the phase of the current time of the target terminal is a pulse by compensating for the clock phase of the current time of the target terminal according to the variable values of the phase response function expressed as in the following [Equation] - It may include the step of performing coupling synchronization.

[Equation]

는 상기 위상 응답 함수의 제1 변수를 나타내고,

는 상기 위상 응답 함수의 제2 변수를 나타냄,

는 대상 단말의 클럭 위상을 나타내고, D는 상기 대상 단말에 대응하는 위상 임계치를 나타냄.)(here,

represents the first variable of the phase response function,

represents the second variable of the phase response function,

denotes a clock phase of the target terminal, and D denotes a phase threshold corresponding to the target terminal.)

According to an embodiment, a computer program stored in a computer-readable recording medium may be combined with hardware to execute a method for performing synchronization.

According to an embodiment, an apparatus for performing synchronization includes: a communication interface for obtaining information about a synchronization environment of terminals distributed on a network; and adjusting variable values of a phase response function for correcting a clock phase of a target terminal according to a synchronization signal received from each of the terminals based on the information on the synchronization environment, and based on the variable values of the phase response function and a processor for performing synchronization by controlling the clock phase of the target terminal.

The information on the synchronization environment includes the number of synchronization terminals synchronized with each other among the terminals, the number of attacker terminals attacking the target terminal, a synchronization period in which the synchronization terminals transmit the synchronization signal, and an attack signal by the attacker terminal may include at least one of an attack cycle for transmitting

The processor may adjust variable values of the phase response function based on at least one of a type of an attack signal for the terminals and information on the synchronization environment.

The variable values of the phase response function are at least one of a first variable and a second variable corresponding to the clock phase of the target terminal, a phase threshold corresponding to the target terminal, and a coupling strength between the target terminal and a terminal synchronized with each other. may include.

The processor may adjust variable values of the phase response function by determining a range of coupling strength between synchronous terminals synchronized with each other according to an attack period of an attacker terminal attacking the target terminal.

The processor determines the ratio between the first variable and the second variable corresponding to the clock phase of the target terminal according to a combination of a range of coupling strength between synchronization terminals synchronized with each other and an attack period of an attacker terminal attacking the target terminal. A range may be detected, and variable values of the phase response function may be adjusted based on a range of a ratio between the first variable and the second variable.

The processor calculates a result of controlling the clock phase of the current time of the target terminal based on the variable values of the phase response function, and determines the result of controlling the clock phase of the current time and the coupling strength of the target terminal. The synchronization may be performed by compensating for the phase of the current time by the

According to one side, synchronization reliability in a distributed synchronization system can be improved by a pulse-coupling synchronization method that is robust to a synchronization interference signal.

According to one side, it is possible to obtain appropriate distributed synchronization according to the synchronization attack environment by appropriately adjusting the variable values of the phase response function according to information on the synchronization environment of terminals distributed on the network.

According to one side, under a synchronization attack having an arbitrary period by controlling the clock phase of the target terminal based on the phase response function having variable values of the phase response function adjusted according to information on the synchronization environment of the terminals distributed on the network. While making the synchronization system robust, the time required for synchronization can be improved.

1 is a diagram illustrating a synchronization environment of a distributed synchronization system according to an embodiment;
2 is a graph illustrating a result of a simulation of a situation in which an attacker terminal performs a synchronous attack with a special period according to an embodiment;
3 is a flowchart illustrating a method for performing synchronization according to an embodiment;
4 is a graph illustrating a result of analyzing a synchronization probability of a phase response function according to a change in coupling strength and variable values through a simulation experiment in a distributed synchronization system under a synchronization environment according to an embodiment;
5 is a graph illustrating a result of analyzing a synchronization time of a phase response function according to a change in coupling strength and variable values through a simulation experiment in a distributed synchronization system under a synchronization environment according to an embodiment;
6 is a diagram illustrating a result of analyzing a synchronization probability of a phase response function according to an attack period and a change in variable values through a simulation experiment in a distributed synchronization system under a synchronization environment according to another embodiment;
7 is a diagram illustrating a result of analyzing a synchronization time of a phase response function according to a change in coupling strength and variable values through a simulation experiment in a distributed synchronization system under a synchronization environment according to another embodiment;
8 is a block diagram of an apparatus for performing synchronization according to an embodiment;

Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. However, since various changes may be made to the embodiments, the scope of the patent application is not limited or limited by these embodiments. It should be understood that all modifications, equivalents and substitutes for the embodiments are included in the scope of the rights.

Terms used in the examples are used for the purpose of description only, and should not be construed as limiting. The singular expression includes the plural expression unless the context clearly dictates otherwise. In the present specification, terms such as “comprise” or “have” are intended to designate that a feature, number, step, operation, component, part, or combination thereof described in the specification exists, but one or more other features It is to be understood that it does not preclude the possibility of the presence or addition of numbers, steps, operations, components, parts, or combinations thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which the embodiment belongs. Terms such as those defined in a commonly used dictionary should be interpreted as having a meaning consistent with the meaning in the context of the related art, and should not be interpreted in an ideal or excessively formal meaning unless explicitly defined in the present application. does not

In addition, in the description with reference to the accompanying drawings, the same components are assigned the same reference numerals regardless of the reference numerals, and the overlapping description thereof will be omitted. In the description of the embodiment, if it is determined that a detailed description of a related known technology may unnecessarily obscure the gist of the embodiment, the detailed description thereof will be omitted.

In addition, in describing the components of the embodiment, terms such as first, second, A, B, (a), (b), etc. may be used. These terms are only for distinguishing the elements from other elements, and the essence, order, or order of the elements are not limited by the terms. When it is described that a component is “connected”, “coupled” or “connected” to another component, the component may be directly connected or connected to the other component, but between each component another component It will be understood that may also be "connected", "coupled" or "connected".

Components included in one embodiment and components having a common function will be described using the same names in other embodiments. Unless otherwise stated, descriptions described in one embodiment may be applied to other embodiments as well, and detailed descriptions within the overlapping range will be omitted.

1 is a diagram illustrating a synchronization environment of a distributed synchronization system according to an embodiment. 1 , two synchronization terminals (target terminal 110, terminal 120) and synchronization terminals (target terminal 110, terminal 120) synchronized with each other in a distributed synchronization system according to an embodiment ), a synchronization environment is shown with one attacker terminal 130 interfering with or attacking synchronization between the two. The distributed synchronization system according to an embodiment may be, for example, a Pulse-Coupled Synchronization (PCS) system.

In this specification, 'synchronized terminal(s)' may correspond to terminals synchronized with each other. For example, in FIG. 1 , the terminal 120 may transmit a synchronization signal to the target terminal 110 so that the target terminal 110 is synchronized with itself (the terminal 120 ). The terminal 120 may be, for example, a distributed terminal belonging to the same network as the target terminal 110 . In this way, the target terminal 110 and the terminal 120 synchronized with each other may be referred to as synchronization terminals 110 and 120 . The synchronization terminals 110 and 120 may be, for example, two or more. In FIG. 1 , a terminal 120 desiring to synchronize the target terminal 110 among the synchronization terminals 110 and 120 may transmit a synchronization signal for distributed synchronization at regular synchronization intervals. The terminal 120 may transmit, for example, a synchronization signal for distributed synchronization to neighboring terminals at regular synchronization periods in a broadcast manner. The synchronization signal may be, for example, an impulse signal or a firing signal. In this case, the 'target terminal' 110 may correspond to a terminal that wants to perform synchronization with another terminal by adjusting its clock phase in accordance with the synchronization signal transmitted by the terminal 120 .

In addition, the 'attacker terminal' 130 may correspond to a terminal that interferes with or attacks synchronization between the synchronization terminals 110 and 120 by transmitting an attack signal. The attacker terminal 130 may be, for example, one, or may be plural. The attacker terminal 130 may transmit an attack signal to the synchronous terminals 110 and 120 at a specific attack cycle. 1 , the attacker terminal 130 may interfere with or attack synchronization between the synchronization terminals 110 and 120 by transmitting an attack signal to the synchronization terminals 110 and 120 .

The basic concept of Pulse-Coupled Synchronization (PCS) according to an embodiment is to emit a firing signal at each cycle by using a clock of a specific cycle built in each terminal, and the emitted firing signal This is to allow peripheral terminals to synchronize by modifying their clock cycles. In this case, the clock phase of the terminal 120 transmitting the synchronization signal may gradually increase from 0 to 1 in one period and then decrease. The terminal 120 may transmit, for example, a synchronization signal to neighboring terminals at the moment when the clock phase becomes 1. In this case, the clock phase from 0 to 1 may correspond to, for example, a value obtained by normalizing 2π.

The peripheral terminals receiving the synchronization signal may correct their clock phase to match the phase of the synchronization signal. For example, peripheral terminals may correct their clock phase close to 0 when their clock phase is less than 0.5, and may correct their clock phase close to 1 when their clock phase is greater than 0.5.

The above-described pulse-coupling synchronization process may be defined as in Equation 1 below.

는

번째 단말에서 동기 신호를 받은 시간(sec)을 나타내며,

는

초 순간에서의

번째 단말의 클럭 위상을 나타낸다.

는

초 직후를 의미한다. 또한,

는

번째 단말과

번째 단말 사이 커플링 강도(coupling strength)를 나타낸다. 커플링 강도는 예를 들어, 채널 환경 및 커플링되는 단말들 간의 거리에 따라 정해질 수 있는 변수이다. 이때, 커플링되는 단말들은 예를 들어, 서로 동기화되는 동기 단말들일 수도 있고, 또는 대상 단말과 대상 단말을 공격하는 공격자 단말일 수도 있다.

는 위상 응답 함수(Phase Response Function; PRF)로서, 단말들이 받은 동기 신호에 따라 자신의 클럭 위상을 수정하는 방법을 표현하는 함수이다. here,

Is

Indicates the time (sec) at which the synchronization signal is received from the second terminal,

Is

in seconds

Indicates the clock phase of the second terminal.

Is

It means immediately after seconds. In addition,

Is

the second terminal

Indicates the coupling strength between the second terminals. Coupling strength is, for example, a variable that may be determined according to a channel environment and a distance between coupled terminals. In this case, the coupled terminals may be, for example, synchronous terminals that are synchronized with each other, or may be a target terminal and an attacker terminal that attacks the target terminal.

is a phase response function (PRF), and is a function expressing a method of correcting their clock phase according to the synchronization signal received by the terminals.

는 예를 들어, 주변 단말(j)의 동기 신호에 의해 수정된 대상 단말(예를 들어, i번째 단말, 이하, 단말(i))의 클럭 위상에 해당할 수 있다. 대상 단말(i)은

초 순간의 자신의 클럭 위상

을, 자신과 커플링되는 주변 단말(j)과의 커플링 강도

및 위상 응답 함수

에 의해 보상함으로써 자신의 클럭 위상

이 주변 단말(j)의 동기 신호에 동기화되도록 할 수 있다. 다시 말해,

는 t초 순간의 자신의 클럭 위상

에 대한 보상분에 해당할 수 있다. 이와 같이 펄스-커플링 동기화 시에는 어떠한 위상 응답 함수를 사용하는가에 따라 대상 단말(110)의 동기화 여부(예를 들어, 위상 응답 함수에 따라 동기화가 될 확률; 동기화 확률)과 동기화에 소요되는 시간(예를 들어, 위상 응답 함수에 따라 동기화에 요구되는 시간; 동기화 시간)이 결정될 수 있다. 실시예에 따라, 동기화 시간은 위상 응답 함수에 따른 동기화 속도로 표현될 수 있다.Also, in Equation 1

For example, may correspond to the clock phase of the target terminal (eg, the i-th terminal, hereinafter, terminal (i)) modified by the synchronization signal of the peripheral terminal (j). The target terminal (i) is

own clock phase in seconds

, the strength of the coupling with the peripheral terminal (j) coupled to itself

and phase response function

their clock phase by compensating by

It can be synchronized with the synchronization signal of the peripheral terminal (j). In other words,

is its own clock phase at the t second instant

may be eligible for compensation. As such, in the pulse-coupling synchronization, whether the target terminal 110 is synchronized according to which phase response function is used (eg, synchronization probability according to the phase response function; synchronization probability) and the time required for synchronization (eg, time required for synchronization according to the phase response function; synchronization time) may be determined. According to an embodiment, the synchronization time may be expressed as a synchronization rate according to a phase response function.

)의 동기화 속도가 가장 빠를 수 있다. For example, assume a network in which there is no attacker terminal interfering with the synchronization of the terminal. In a network without an attacker terminal, if the frequencies (periods) of the clocks embedded in each terminal are all the same, for example, the phase response function (

) may have the fastest synchronization speed.

는 대상 단말의 클럭 위상에 해당할 수 있다. here,

may correspond to the clock phase of the target terminal.

However, if there is an attacker terminal 130 that periodically sends a false synchronization signal to prevent synchronization of the synchronization terminals 110 and 120 in the network, the synchronization time becomes longer or the synchronization terminals 110 and 120 fail to synchronize. problems may arise. Here, the 'synchronization time' means the time it takes until the difference between the clock phases of the two terminals synchronized with each other becomes 0 when synchronization is achieved.

Such a problem may occur especially in a situation in which the attacker terminal performs a synchronous attack with a special period as shown in FIG. 2 below.

)를 사용하여 동기화를 수행하고, 공격자 단말이 특수한 주기를 가지는 공격 신호를 전송하여 동기화를 방해함으로써 동기 단말들의 클럭 위상들의 차이가 무한히 진동하는 상황이 도시된다. 2 is a graph illustrating a result of a simulation of a situation in which an attacker terminal performs a synchronous attack with a special period according to an embodiment. Referring to FIG. 2, for example, each terminal has a phase response function (

) to perform synchronization, and the attacker terminal transmits an attack signal having a special period to prevent synchronization, so that the difference in clock phases of the synchronization terminals vibrates infinitely.

)를 사용하여 동기화를 수행하는 경우, 공격자 단말이 도 2에서와 같이 특수한 주기(예를 들어, 동기 신호의 송신 주기)를 가진 공격 신호를 전송한다고 하자. 이 경우, 단말들은 동기화되지 못하고, 동기 단말들의 클럭 위상들의 차이가 무한히 진동하는 형태가 되어 동기화에 실패할 수 있다. For example, each terminal has a phase response function (

), it is assumed that the attacker terminal transmits an attack signal having a special period (eg, a synchronization signal transmission period) as shown in FIG. 2 . In this case, the terminals may not be synchronized, and the difference between clock phases of the synchronization terminals may be in the form of infinite oscillation, and synchronization may fail.

)를 일 예로 들 수 있다.An attack that prevents synchronization by intentionally transmitting an erroneous signal to other terminals may be referred to as a 'Byzantine attack'. As a phase response function against such a Byzantine attack, for example, the phase response function (

) can be given as an example.

Here, D may correspond to a phase threshold for determining how much to compensate for the clock phase of the target terminal when the synchronization signal is received.

)는 위상 임계치(D)보다 작은 클럭 위상에 대해서는 위상 제어(phase control)를 수행하기 않기 때문에 예를 들어, 동기 신호의 송신 주기와 같은 특정 주기를 가진 동기화 방해 공격에 강인할 수 있다. 하지만, 위상 응답 함수(

)는 위상 임계치(D)보다 작은 클럭 위상에 대해서는 위상 제어를 수행하기 않기 때문에 위상을 보상하는 정도가 줄어들게 되고, 이에 따라 동기화 시간이 오래 소요될 수 있다. According to Equation 3, the phase response function (

) does not perform phase control with respect to a clock phase smaller than the phase threshold D, so it can be robust against a synchronization interference attack having a specific period such as a transmission period of a synchronization signal. However, the phase response function (

), since phase control is not performed for a clock phase smaller than the phase threshold D, the degree of phase compensation is reduced, and accordingly, a long synchronization time may be required.

)를 이용하여 위상 응답 함수(

)을 사용하는 경우에 특정 주기를 가지는 공격 신호에 의해 동기 단말들의 클럭 위상들의 차이가 무한히 진동하여 동기화에 실패하는 문제 및 위상 응답 함수(

)를 사용하는 경우에 동기화 시간이 길어지는 문제를 해결할 수 있다. Therefore, in one embodiment, a new form of the phase response function (

) using the phase response function (

), the problem that synchronization fails because the difference between the clock phases of the synchronous terminals is infinitely oscillated by an attack signal having a specific period and the phase response function (

) can solve the problem that the synchronization time becomes long.

)는 예를 들어, 아래의 수학식 4와 같이 정의될 수 있다. A phase response function according to an embodiment (

) may be defined as, for example, Equation 4 below.

은 대상 단말의 클럭 위상(

)에 대응하는 제1 변수이고,

는 대상 단말의 클럭 위상(

)에 대응하는 제2 변수일 수 있다. 또한, D는 대상 단말에 대응하는 위상 임계치로서, 예를 들어, 0보다 크고, 1보다 작은 실수에 해당할 수 있다. here,

is the clock phase of the target terminal (

) is the first variable corresponding to,

is the clock phase of the target terminal (

) may be a second variable corresponding to . In addition, D is a phase threshold corresponding to the target terminal, and may correspond to, for example, a real number greater than 0 and less than 1.

In Equation 4, the phase threshold D may correspond to a phase value that determines whether to apply the first variable or the second variable to the clock phase when the target terminal receives the synchronization signal.

)의 변수들의 값을 적절하게 조절함으로써 특정 주기를 가지는 비잔틴 공격에 따른 동기화 조건을 회피할 수 있다. 일 실시예에 따른 위상 응답 함수(

)를 이용하여 동기화를 수행하는 과정은 아래의 도 3을 참조하여 구체적으로 설명한다. In one embodiment, the phase response function (

), it is possible to avoid the synchronization condition according to the Byzantine attack having a specific period by appropriately adjusting the values of the variables. A phase response function according to an embodiment (

), the process of performing synchronization will be described in detail with reference to FIG. 3 below.

3 is a flowchart illustrating a method for performing synchronization according to an embodiment. Referring to FIG. 3 , the apparatus for performing synchronization according to an embodiment obtains information on synchronization environments of terminals distributed on a network ( 310 ). The network according to an embodiment may correspond to, for example, an Internet of Things (IoT) network including a plurality of devices, or a network in which synchronization set-up between distributed devices is not performed, It is not necessarily limited thereto. Here, the terminals may include, for example, various devices such as a smart TV including an IoT function, a smart refrigerator, an AI speaker, a sensor terminal, etc., in addition to a mobile phone, a tablet, a netbook, and a personal computer (PC), and must be limited thereto. it doesn't happen

Information on the synchronization environment includes, for example, the number of terminals synchronized with each other ('synchronization terminals') among terminals distributed on the network, the number of attacker terminals attacking the target terminal, It may include at least one of a synchronization period and an attack period in which the attacker terminal transmits an attack signal.

)에 대응하는 제1 변수(

) 및 제2 변수(

),대상 단말에 대응하는 위상 임계치(

), 및 대상 단말(i)과 서로 동기화되는 단말(j) 간의 커플링 강도(

) 중 적어도 하나를 포함할 수 있다. 커플링 강도는 예를 들어, 대상 단말의 현재 시점의 채널 환경과 대상 단말과 커플링되는 단말 간의 거리에 의해 결정될 수 있다. The synchronization performing apparatus includes: a phase response function for correcting a clock phase of a target terminal according to a synchronization signal received from each of the terminals based on the information on the synchronization environment obtained in step 310; PRF) variable values are adjusted ( 320 ). Here, the variable values of the phase response function are the clock phase (

) corresponding to the first variable (

) and the second variable (

), the phase threshold corresponding to the target terminal (

), and the coupling strength between the target terminal (i) and the terminal (j) synchronized with each other (

) may include at least one of. The coupling strength may be determined, for example, by the channel environment of the current view of the target UE and the distance between the target UE and the coupled UE.

The synchronization performing apparatus may adjust variable values of the phase response function based on at least one of a type (or type) of an attack signal for terminals (eg, synchronization terminals) and information on a synchronization environment.

In step 320, the synchronization performing apparatus, for example, according to the combination of the range of the coupling strength between the synchronization terminals are synchronized with each other and the attack period of the attacker terminal attacking the target terminal, the second corresponding to the clock phase of the target terminal A range of ratios between the first variable and the second variable may be detected. The synchronization performing apparatus may adjust variable values of the phase response function based on a range of a ratio between the first variable and the second variable.

Alternatively, the synchronization performing apparatus may calculate the effect of a ratio between the first variable and the second variable corresponding to the clock phase of the target terminal on synchronization performance. The synchronization performing apparatus may calculate the effect on synchronization performance by using, for example, a performance function for synchronization probability and synchronization speed (or synchronization time). The performance function may include, for example, a first term corresponding to a synchronization probability corresponding to the target terminal and a second term corresponding to a synchronization rate corresponding to the target terminal. The synchronization performing apparatus may adjust variable values of the phase response function in consideration of an effect of a ratio between the first variable and the second variable on synchronization performance.

A method in which the synchronization performing apparatus adjusts variable values of the phase response function based on information on the synchronization environment will be described in detail with reference to FIGS. 4 to 7 below.

According to an embodiment, the apparatus for performing synchronization may adjust variable values of the phase response function optimized through a library or computer simulation according to an environment.

The synchronization performing apparatus performs synchronization by controlling the clock phase of the target terminal based on the variable values of the phase response function ( 330 ). Here, the synchronization may correspond to, for example, Pulse-Coupled Synchronization (PCS). The synchronization performing apparatus determines the compensation value by considering the influence of the surrounding synchronization signal on the current clock phase along with the coupling strength by the phase response function having the variable values adjusted in step 320, and sets the determined compensation value to the current clock phase. Synchronization can be performed by reflecting the phase. The synchronization performing apparatus may perform synchronization by, for example, Equation 1 described above.

In operation 330 , the synchronization performing apparatus may calculate a result of controlling the clock phase of the current time of the target terminal based on, for example, variable values of the phase response function. The synchronization performing apparatus may perform pulse-coupling synchronization by, for example, compensating for the clock phase of the current time of the target terminal according to variable values of the phase response function defined as in Equation 4 above.

In step 330 , the synchronization performing apparatus may perform synchronization by compensating for the phase of the current time based on the result of controlling the clock phase of the current time and the coupling strength of the target terminal. In this case, the target terminal may perform synchronization to synchronize with another terminal by adjusting its clock phase through a synchronization signal received from another terminal (synchronization terminal) that is synchronized with each other.

4 is a graph illustrating a result of analyzing a synchronization probability of a phase response function according to a change in coupling strength and variable values through a simulation experiment in a distributed synchronization system under a synchronization environment according to an embodiment. Referring to FIG. 4 , a result of analyzing a synchronization probability in a synchronization environment in which there are two synchronization terminals and one attacker terminal according to an embodiment is shown.

) = 1인 경우에 커플링 강도와 제2 변수(

) 값의 변화에 따른 위상 응답 함수의 동기화 확률을 나타낸다. The graph of FIG. 4 shows the first variable (

) = 1, the coupling strength and the second variable (

) represents the synchronization probability of the phase response function according to the change of the value.

For example, it is assumed that the period of the Byzantine attack is 0.6, and the coupling strength between the attacker terminal and the target terminal is equal to the coupling strength between the synchronous terminals. In this case, the synchronization probability in each graph of FIG. 4 may be defined as the probability that the target terminal is synchronized within 30 cycles when the initial clock phase of the target terminal is viewed randomly.

)의 제1 변수(

) = 1이고, 제2 변수(

) 값이 0.25, 0.5, 및 0.75로 각각 변화되는 경우의 동기화 확률을 나타낸다.The graph of FIG. 4 is, for example, a phase response function (

) of the first variable (

) = 1, and the second variable (

) represents the synchronization probability when the values are changed to 0.25, 0.5, and 0.75, respectively.

)와 달리, 일 실시예에서는 위상 응답 함수(

)의 제1 변수(

) = 1이고, 제2 변수(

) = 0.25 인 경우에 커플링 강도가 0.5보다 크면 동기화 확률이 항상 1이 됨을 파악할 수 있다. 또한, 위상 응답 함수(

)의 제1 변수(

) = 1이고, 제2 변수(

) = 0.5인 경우에는 커플링 강도가 0.55보다 낮은 경우를 제외하고는 동기화 확률이 1이 됨을 파악할 수 있다. 이와 달리, 위상 응답 함수(

)의 제1 변수(

) = 1이고, 제2 변수(

) = 0.75인 경우에는 커플링 강도와 무관하게 동기화 확률이 1이 되지 않음을 파악할 수 있다. According to the graph of FIG. 4, the above-described phase response function (

), in one embodiment the phase response function (

) of the first variable (

) = 1, and the second variable (

) = 0.25, it can be seen that the synchronization probability is always 1 if the coupling strength is greater than 0.5. Also, the phase response function (

) of the first variable (

) = 1, and the second variable (

) = 0.5, it can be seen that the synchronization probability becomes 1, except when the coupling strength is lower than 0.55. In contrast, the phase response function (

) of the first variable (

) = 1, and the second variable (

) = 0.75, it can be seen that the synchronization probability does not become 1 regardless of the coupling strength.

In other words, when the first variable is fixed, the synchronization performing apparatus determines the second variable to have a value in the range of 0.25 to 0.5 so that synchronization is perfectly performed. In this case, the coupling strength may have a constraint that must be greater than 0.5 or a range of values greater than or equal to 0.55.

)를 사용하는 경우, 커플링 강도가 0.5보다 크면, 동기화 확률이 항상 1이 됨을 알 수 있다. 일 실시예에 따른 위상 응답 함수(

)에서 예를 들어, 제1 변수(

) = 0으로 설정하고, 제2 변수(

) = 1로 설정하는 경우, 위상 응답 함수(

)는 위상 응답 함수(

)와 같아질 수 있다. 따라서, 동기화 수행 장치는 예를 들어, 제1 변수(

) = 0 으로, 제2 변수(

) = 1로 설정함으로써 커플링 강도가 0.5보다 큰 대상 단말의 동기화 확률을 최대화할 수 있다. Alternatively, in the graph of FIG. 4, the phase response function (

), if the coupling strength is greater than 0.5, it can be seen that the synchronization probability is always 1. A phase response function according to an embodiment (

) in, for example, the first variable (

) = 0, and the second variable (

) = 1, the phase response function (

) is the phase response function (

) can be equal to Therefore, the synchronization performing device, for example, the first variable (

) = 0 , so that the second variable (

) = 1, it is possible to maximize the synchronization probability of the target terminal having a coupling strength greater than 0.5.

Synchronization performing apparatus according to an embodiment, for example, based on the information on the synchronization environment such as the attack period of the phase response function, the synchronization period, the first variable, the second variable, the phase response function, such as the strength of the coupling By setting constraints on variable values, that is, the range of variable values of the phase response function, synchronization can be performed perfectly.

5 is a graph illustrating a result of analyzing a synchronization time of a phase response function according to a change in coupling strength and variable values through a simulation experiment in a distributed synchronization system under a synchronization environment according to an embodiment. Referring to FIG. 5 , a result of analyzing a synchronization time of a target terminal in a synchronization environment with two synchronization terminals and one attacker terminal according to an embodiment is shown.

For example, it is assumed that the coupling strength between the attacker terminal and the target terminal is equal to the coupling strength between the synchronization terminals. In this case, each graph of FIG. 5 represents the synchronization time of the target terminal according to the change of the coupling strength and the value of the second variable.

)를 사용하여 동기화를 수행한 경우에 위상 응답 함수(

)을 사용한 경우보다는 동기화 시간이 길지만, 위상 응답 함수(

)를 사용한 경우보다는 동기화 시간이 짧음을 확인할 수 있다. In the graph of FIG. 5, the phase response function (

) using the phase response function (

) is longer than when using the phase response function (

), it can be seen that the synchronization time is shorter than in the case of using

)에서 예를 들어, 제1 변수(

) = 0로 설정하고, 제2 변수(

) = 0.5로 설정하는 경우, 위상 응답 함수(

)는 위상 응답 함수(

)와 같아질 수 있다. 따라서, 동기화 수행 장치는 예를 들어, 제1 변수(

) = 0로 설정하고, 제2 변수(

) = 0.5로 설정함으로써 대상 단말의 동기화 시간을 최소화할 수 있다. A phase response function according to an embodiment (

) in, for example, the first variable (

) = 0, and the second variable (

) = 0.5, the phase response function (

) is the phase response function (

) can be equal to Therefore, the synchronization performing device, for example, the first variable (

) = 0, and the second variable (

) = 0.5, the synchronization time of the target terminal can be minimized.

According to one embodiment, according to the variable values of the phase response function, the degree of robustness to the attack signal that interferes with synchronization, that is, a trade-off between the synchronization probability and the synchronization time required for synchronization It can be confirmed that there is In an embodiment, appropriate distributed synchronization according to a synchronization attack environment may be obtained by adjusting variable values of the phase response function.

6 is a diagram illustrating a result of analyzing a synchronization probability of a phase response function according to a change in coupling strength and variable values through a simulation experiment in a distributed synchronization system under a synchronization environment according to another embodiment. Referring to FIG. 6 , graphs 610 , 620 , 630 , and 640 analyzing the synchronization probability of a phase response function in a synchronization environment in which there are three synchronization terminals and one attacker terminal according to an embodiment are shown. For example, assume that the synchronization period is 1000 and the attack period is 400 in the synchronization environment of FIG. 6 . In an embodiment, the 'attack period' may be a period for a synchronization interference attack, and the 'synchronization period' may correspond to a period for synchronizing. Also, in this context, the synchronization period of 1000 and the attack period of 400 may indicate a relative concept that the attack period is 4 ms when the synchronization period of devices to be synchronized is 10 ms. In this case, when the synchronization period is 1000, one period is divided into 1000 times for performing the algorithm, and the synchronization period is expressed as 1000 to view the divided times as 1 for convenience. In an embodiment, the absolute time units of the synchronization period and the attack period may vary according to hardware conditions of the synchronization performing apparatus. For example, if there is hardware with a period of 10 ms, 1/100 ms is the unit, and if the period is 1 second, ms may be the unit.

)의 값 및 제2 변수(

)의 값을 변화시킴에 따라 위상 응답 함수(PRF)의 동기화 확률이 변화되는 것을 볼 수 있다. 도 6에서 각 그래프에서 노란색과 같이 색상이 연한 부분일수록 동기화 확률이 높음을 나타내고, 남색과 같이 색상이 진한 부분일수록 동기화 확률이 낮음을 나타낼 수 있다. In this case, in FIG. 6, the coupling strength (l), the first variable of the phase response function (

) and the second variable (

It can be seen that the synchronization probability of the phase response function (PRF) is changed as the value of ) is changed. In each graph in FIG. 6 , a lighter color such as yellow may indicate a higher synchronization probability, and a darker color such as indigo blue may indicate a lower synchronization probability.

) 및 제2 변수(

)를 '1'로 설정함으로써 동기화 확률 '1'을 달성할 수 있음을 볼 수 있다. For example, when the coupling strength l is greater than 0.5 as in the graph 630 and graph 640 of FIG. 6 , the first variable of the phase response function (

) and the second variable (

) to '1', it can be seen that the synchronization probability '1' can be achieved.

) 및 제2 변수(

)가 서로 비슷한 값을 가지는 환경에서 동기화 확률이 열화되는 것을 볼 수 있다. In addition, as in the graph 610 and the graph 620 of FIG. 6 , when the coupling strength l becomes smaller than 0.1, the first variable of the phase response function (

) and the second variable (

), it can be seen that the synchronization probability deteriorates in the environment where the values are similar to each other.

)의 값이 0.4이고, 제2 변수(

)의 값이 1인 경우에 가장 높은 동기화 확률 값(예를 들어, 0.7 또는 0.8)을 가짐을 볼 수 있다. In addition, in the section where the coupling strength l is 0.1 or less as in the graph 610 and the graph 620 through numerical analysis, for example, the first variable (

) has a value of 0.4, and the second variable (

) is 1, it can be seen that it has the highest synchronization probability value (eg, 0.7 or 0.8).

7 is a graph illustrating a result of analyzing the synchronization time of a phase response function according to an attack period and a change in variable values through a simulation experiment in a distributed synchronization system under a synchronization environment according to another embodiment. Referring to FIG. 7 , graphs 710 , 720 , 730 , and 740 analyzing the synchronization time of the phase response function (PRF) in a synchronization environment in which there are three synchronization terminals and one attacker terminal are shown.

For example, assume that the synchronization period is 1000 in the synchronization environment of FIG. 7 .

)의 값 및 제2 변수(

)의 값을 변화시킴에 따라 위상 응답 함수(PRF)의 동기화 확률이 변화되는 것을 볼 수 있다. 도 7의 각 그래프에서 색상이 연한 부분일수록 동기화 확률이 높음을 나타내고, 색상이 진한 부분일수록 동기화 확률이 낮음을 나타낼 수 있다. In this case, in FIG. 7, the attack period, the first variable of the phase response function (

) and the second variable (

It can be seen that the synchronization probability of the phase response function (PRF) is changed as the value of ) is changed. In each graph of FIG. 7 , a lighter color may indicate a higher synchronization probability, and a darker color may indicate a lower synchronization probability.

) 및 제2 변수(

)가 '1'이 되는 경우에 가장 높은 동기화 확률을 달성하는 것을 볼 수 있다. 또한, 그래프(710) 및 그래프(720)와 같이, 공격 주기가 200 또는 400으로 짧아질수록 위상 응답 함수의 제1 변수(

)와 제2 변수(

)가 서로 비슷한 값을 가지는 경우, 다시 말해, 제1 변수와 제2 변수 간의 비율이 1에 가까워지는 경우에 동기화 확률이 열화되는 것을 볼 수 있다. 이때, 제1 변수 및 제2 변수 간의 비율은 하한 임계 비율(예를 들어, 0.05)보다는 클 수 있다. For example, when the attack period is sufficiently long, such as 700 or more, as in the graph 730 and graph 740 of FIG. 7 , the first variable (

) and the second variable (

) becomes '1', it can be seen that the highest synchronization probability is achieved. In addition, as in the graph 710 and the graph 720, the shorter the attack period is to 200 or 400, the shorter the first variable (

) and the second variable (

) have similar values, that is, when the ratio between the first variable and the second variable approaches 1, it can be seen that the synchronization probability deteriorates. In this case, the ratio between the first variable and the second variable may be greater than the lower limit threshold ratio (eg, 0.05).

) = 0.5이고, 제2 변수(

) = 1인 경우에 가장 높은 동기화 확률 값(예를 들어, 0.7 또는 0.8)을 가짐을 볼 수 있다. In addition, when the attack period has a low value (for example, a value lower than 400) as in the graph 710 and the graph 720 through numerical analysis, for example, the first variable (

) = 0.5, and the second variable (

) = 1, it can be seen that it has the highest synchronization probability value (eg, 0.7 or 0.8).

In an embodiment, variable values of the phase response function may be adjusted by determining the range of the coupling strength between synchronous terminals synchronized with each other according to the attack period of the attacker terminal attacking the target terminal based on the above-mentioned matters.

The apparatus for performing synchronization according to an embodiment includes, for example, a first corresponding to a clock phase of a target terminal according to a combination of a range of coupling strength between synchronization terminals synchronized with each other and an attack period of an attacker terminal attacking the target terminal A range of ratios between the variable and the second variable may be detected. The synchronization performing apparatus may adjust variable values of the phase response function based on a range of a ratio between the first variable and the second variable. For example, the synchronization performing apparatus may adjust the variable values of the phase response function so that the ratio between the first variable and the second variable is greater than the lower limit threshold ratio, but falls within a range excluding approaching to 1.

Alternatively, the apparatus for performing synchronization according to an embodiment calculates the effect of the ratio between the first variable and the second variable corresponding to the clock phase of the target terminal on the synchronization performance, and calculates the variable values of the phase response function in consideration of the calculated effect. can be adjusted

The synchronization performing apparatus may calculate, for example, an effect of a ratio between the first variable and the second variable on synchronization performance by using a performance function. In this case, the performance function may include, for example, a first term corresponding to a synchronization probability corresponding to the target terminal and a second term corresponding to a synchronization rate corresponding to the target terminal. Each of the first term and the second term may be a function of a first variable and a second variable corresponding to the clock phase of the target terminal, a phase threshold corresponding to the target terminal, and a coupling strength between the target terminal and the terminal synchronized with each other. .

The synchronization speed is, for example, the probability of each section (for example, the section of the clock phase to which the first variable is applied and the section of the clock phase to which the second variable is applied) according to the phase threshold (D) and the corresponding section It may be determined based on the variable value.

에 의해 구할 수 있다. In this case, the second term corresponding to the synchronization rate is, for example,

can be obtained by

는 위상 응답 함수의 제1 변수를,

는 위상 응답 함수의 상기 제2 변수를 나타내며, 각 변수는 0 ≤

,

≤ 1인 실수일 수 있다. Here, D represents the phase threshold corresponding to the target terminal,

is the first variable of the phase response function,

denotes the second variable of the phase response function, each variable being 0 ≤

,

It can be a real number with ≤ 1.

8 is a block diagram of an apparatus for performing synchronization according to an embodiment. Referring to FIG. 8 , the apparatus 800 for performing synchronization includes a communication interface 810 , a processor 830 , and a memory 850 . The communication interface 810 , the processor 830 , and the memory 850 may communicate with each other via the communication bus 805 .

The communication interface 810 acquires information on the synchronization environment of terminals distributed on the network. Information on the synchronization environment includes the number of terminals synchronized with the target terminal among the terminals, the number of attacker terminals attacking the target terminal, a synchronization period in which at least one synchronization terminal transmits a synchronization signal, and an attack signal by the attacker terminal. It may include at least one of the transmission attack period.

)에 대응하는 제1 변수(

) 및 제2 변수(

),대상 단말에 대응하는 위상 임계치(

), 및 대상 단말(i)과 서로 동기화되는 적어도 하나의 동기 단말(j) 간의 커플링 강도(

) 중 적어도 하나를 포함할 수 있다. The processor 830 adjusts variable values of a phase response function that corrects a clock phase of a target terminal according to a synchronization signal received from each of the terminals, based on information on the synchronization environment. The variable values of the phase response function are, for example, the clock phase (

) corresponding to the first variable (

) and the second variable (

), the phase threshold corresponding to the target terminal (

), and the coupling strength between the target terminal (i) and at least one synchronization terminal (j) synchronized with each other (

) may include at least one of.

The processor 830 performs synchronization by controlling the clock phase of the target terminal based on variable values of the phase response function.

The processor 830 may adjust variable values of the phase response function based on at least one of a type of an attack signal for the terminals and information on a synchronization environment.

The processor 830 may adjust variable values of the phase response function by determining a range of coupling strength between the target terminal and at least one synchronization terminal synchronized with each other according to the attack period of the attacker terminal attacking the target terminal.

The processor 830 configures the first variable and the second variable corresponding to the clock phase of the target terminal according to a combination of a range of coupling strength between the target terminal and at least one synchronization terminal synchronized with each other and an attack period of an attacker terminal attacking the target terminal. The range of the ratio between the two variables may be detected, and variable values of the phase response function may be adjusted based on the range of the ratio between the first variable and the second variable.

The processor 830 may calculate a result of controlling the clock phase of the current time of the target terminal based on the variable values of the phase response function. The processor 830 may perform synchronization by compensating for the phase of the current time by the result of controlling the clock phase of the current time and the coupling strength of the target terminal.

The memory 850 may store information about the information on the synchronization environment acquired by the communication interface 810 . Also, the memory 850 may store variable values of the phase response function adjusted by the processor 830 . The memory 850 may store the final clock phase of the target terminal according to a result of synchronization performed by the processor 830 .

Also, the processor 830 may perform the at least one method described above with reference to FIGS. 1 to 7 or an algorithm corresponding to the at least one method. The processor 830 may be a hardware-implemented data processing device having a circuit having a physical structure for executing desired operations. For example, desired operations may include code or instructions included in a program. For example, a hardware-implemented prediction device may include a microprocessor, a central processing unit, a processor core, a multi-core processor, a multiprocessor, It may include an application-specific integrated circuit (ASIC) or a field programmable gate array (FPGA).

The processor 830 may execute a program and control the synchronization performing apparatus 800 . The program code executed by the processor 830 may be stored in the memory 850 .

The memory 850 may store various pieces of information generated in the process of the above-described processor 830 . In addition, the memory 850 may store various data and programs. The memory 850 may include a volatile memory or a non-volatile memory. The memory 850 may include a mass storage medium such as a hard disk to store various data.

The method according to the embodiment may be implemented in the form of program instructions that can be executed through various computer means and recorded in a computer-readable medium. The computer-readable medium may include program instructions, data files, data structures, etc. alone or in combination. The program instructions recorded on the medium may be specially designed and configured for the embodiment, or may be known 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, and magnetic such as floppy disks. - includes magneto-optical media, and hardware devices specially configured to store and execute program instructions, such as ROM, RAM, flash memory, and the like. Examples of program instructions include not only machine language codes such as those generated by a compiler, but also high-level language codes that can be executed by a computer using an interpreter or the like. The hardware devices described above may be configured to operate as one or more software modules to perform the operations of the embodiments, and vice versa.

Software may comprise a computer program, code, instructions, or a combination of one or more of these, which configures a processing device to operate as desired or is independently or collectively processed You can command the device. The software and/or data may be any kind of machine, component, physical device, virtual equipment, computer storage medium or device, to be interpreted by or to provide instructions or data to the processing device. , or may be permanently or temporarily embody in a transmitted signal wave. The software may be distributed over networked computer systems and stored or executed in a distributed manner. Software and data may be stored in one or more computer-readable recording media.

As described above, although the embodiments have been described with reference to the limited drawings, those skilled in the art may apply various technical modifications and variations based on the above. For example, the described techniques are performed in an order different from the described method, and/or the described components of the system, structure, apparatus, circuit, etc. are combined or combined in a different form than the described method, or other components Or substituted or substituted by equivalents may achieve an appropriate result.

Therefore, other implementations, other embodiments, and equivalents to the claims are also within the scope of the following claims.

110: target terminal
115: Synchronization signal
120: synchronous terminal
130: attacker terminal
135: attack signal (Attack signal)

Claims (20)

obtaining information on a synchronization environment of terminals distributed on a network;
adjusting variable values of a phase response function (PRF) that corrects a clock phase of a target terminal according to a synchronization signal received from each of the terminals based on the information on the synchronization environment ; and
performing synchronization by controlling the clock phase of the target terminal based on variable values of the phase response function
including,
The step of adjusting the variable values of the phase response function is
The range of the ratio between the first variable and the second variable corresponding to the clock phase of the target terminal is detected according to a combination of a range of coupling strength between synchronization terminals synchronized with each other and an attack period of an attacker terminal attacking the target terminal to do; and
adjusting variable values of the phase response function based on a range of a ratio between the first variable and the second variable;
containing,
How to do synchronization. According to claim 1,
Information about the synchronous environment is
The number of synchronization terminals synchronized with each other among the terminals, the number of attacker terminals attacking the target terminal, a synchronization period in which the synchronization terminals transmit the synchronization signal, and the attacker terminal transmitting an attack signal comprising at least one of an attack period;
How to do synchronization. According to claim 1,
The step of adjusting the variable values of the phase response function is
adjusting variable values of the phase response function based on at least one of a type of an attack signal for the terminals and information on the synchronization environment
containing,
How to do synchronization. According to claim 1,
The variable values of the phase response function are
Including at least one of a first variable and a second variable corresponding to the clock phase of the target terminal, a phase threshold corresponding to the target terminal, and a coupling strength between the target terminal and a terminal synchronized with each other,
How to do synchronization. According to claim 1,
The step of adjusting the variable values of the phase response function is
Adjusting variable values of the phase response function by determining a range of coupling strength between synchronous terminals synchronized with each other according to an attack period of an attacker terminal attacking the target terminal
containing,
How to do synchronization. delete According to claim 1,
Adjusting the variable values of the phase response function based on the range of the ratio between the first variable and the second variable comprises:
adjusting variable values of the phase response function so that the ratio between the first variable and the second variable is greater than a lower limit threshold ratio, but falls within a range excluding getting close to 1.
containing,
How to do synchronization. According to claim 1,
The step of adjusting the variable values of the phase response function is
calculating an effect of a ratio between a first variable and a second variable corresponding to the clock phase of the target terminal on synchronization performance; and
adjusting variable values of the phase response function in consideration of the influence
containing,
How to do synchronization. 9. The method of claim 8,
The step of calculating the effect on the synchronization performance is
A ratio between the first variable and the second variable using a performance function including a first term corresponding to a synchronization probability corresponding to the target terminal and a second term corresponding to a synchronization rate corresponding to the target terminal Calculating the effect of this on the synchronization performance
including,
Each of the first term and the second term is
A function of a first variable and a second variable corresponding to the clock phase of the target terminal, a phase threshold corresponding to the target terminal, and a coupling strength between the target terminal and a terminal synchronized with each other,
How to do synchronization. 10. The method of claim 9,
The second term corresponding to the synchronization rate is
Expressed in the [Equation] below,
How to do synchronization.
[Equation]

(Here, D represents a phase threshold corresponding to the target terminal.

represents the first variable of the phase response function,

denotes the second variable of the phase response function, 0 ≤

,

Real numbers with ≤ 1.) According to claim 1,
Constraints of the variable values of the phase response function are
Set based on the information about the synchronization environment,
How to do synchronization. According to claim 1,
The step of performing the synchronization is
calculating a result of controlling the clock phase of the current time of the target terminal based on the variable values of the phase response function; and
performing the synchronization by compensating for the phase of the current time by a result of controlling the clock phase of the current time and a coupling strength of the target terminal
containing,
How to do synchronization. 13. The method of claim 12,
Calculating the result of controlling the clock phase of the current time of the target terminal comprises:
Performing pulse-coupling synchronization by compensating for the clock phase of the current time of the target terminal according to the variable values of the phase response function expressed as shown in the following [Equation]
containing,
How to do synchronization.
[Equation]

(here,

represents the first variable of the phase response function,

represents the second variable of the phase response function,

represents the clock phase of the target terminal, and D represents the phase threshold corresponding to the target terminal) A computer program stored in a computer-readable recording medium in combination with hardware to execute the method of any one of claims 1 to 5 and 7 to 13. a communication interface for obtaining information on a synchronization environment of terminals distributed on a network; and
Based on the information on the synchronization environment, the variable values of the phase response function for correcting the clock phase of the target terminal are adjusted according to the synchronization signal received from each of the terminals, and based on the variable values of the phase response function, the A processor that performs synchronization by controlling the clock phase of the target terminal
including,
the processor
The range of the ratio between the first variable and the second variable corresponding to the clock phase of the target terminal is detected according to a combination of a range of coupling strength between synchronization terminals synchronized with each other and an attack period of an attacker terminal attacking the target terminal do,
adjusting variable values of the phase response function based on a range of a ratio between the first variable and the second variable;
Synchronization device. 16. The method of claim 15,
Information about the synchronous environment is
At least among the number of synchronization terminals synchronized with each other among the terminals, the number of attacker terminals attacking the target terminal, a synchronization period in which the synchronization terminals transmit the synchronization signal, and an attack period in which the attacker terminal transmits an attack signal including one,
Synchronization device. 16. The method of claim 15,
the processor
Adjusting variable values of the phase response function based on at least one of a type of an attack signal for the terminals and information on the synchronization environment,
Synchronization device. 16. The method of claim 15,
The variable values of the phase response function are
Including at least one of a first variable and a second variable corresponding to the clock phase of the target terminal, a phase threshold corresponding to the target terminal, and a coupling strength between the target terminal and a terminal synchronized with each other,
Synchronization device. 16. The method of claim 15,
the processor
Adjusting the variable values of the phase response function by determining the range of coupling strength between synchronous terminals synchronized with each other according to the attack period of the attacker terminal attacking the target terminal,
Synchronization device. 16. The method of claim 15,
the processor
Based on the variable values of the phase response function, a result of controlling the clock phase of the current time of the target terminal is calculated, and the current time by the result of controlling the clock phase of the current time and the coupling strength of the target terminal performing the synchronization by compensating for the phase of the viewpoint,
Synchronization device.

Images