CN112235861B - Time synchronization method, time synchronization system and equipment suitable for self-organizing network - Google Patents
Time synchronization method, time synchronization system and equipment suitable for self-organizing network Download PDFInfo
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Abstract
The invention relates to a time synchronization method, a time synchronization system and a time synchronization device suitable for a self-organizing network, wherein the time synchronization method comprises the following steps: acquiring time information of a node and time information of interaction between the node and a neighbor node; clock deviation among all nodes is obtained according to the time information; carrying out weight adjustment and distribution on the clock deviation to obtain a weighted clock deviation; and correcting the local clock to finish time synchronization according to the weighted clock deviation. When the topology of the network is changed or the satellite time service is suddenly lost, all the nodes still keep the same synchronization mode without any switching, the clock synchronization effect does not fluctuate on a large scale, and the stability and the robustness of the clock synchronization of the self-organizing network are enhanced.
Description
Technical Field
The invention belongs to the technical field of communication, and particularly relates to a time synchronization method, a time synchronization system and time synchronization equipment suitable for a self-organizing network.
Background
With the development of ad hoc network technology, large-scale highly dynamic ad hoc networks are used in more and more scenes. If the unmanned aerial vehicle self-organizing network is used for completing military reconnaissance, the communication vehicle self-organizing network is used for realizing a mobile communication base station and the like.
When each node in the network needs precise cooperative work, the clock synchronization in the network becomes very important. Normally, the ad hoc network is equipped with a satellite time service function, but in some scenes, the satellite time service function fails or only some nodes have the satellite time service function. In such a scenario, the nodes in the network need to exchange time information through a time synchronization protocol.
The traditional time synchronization protocol mostly adopts master-slave time synchronization, namely, a slave node requests time information from a master node and adjusts a local clock according to calculated clock deviation. However, in a wireless ad hoc network formed by mobile nodes such as unmanned planes, vehicles, ships or mobile sensors, the nodes in the network keep moving at a high speed, communication links among the nodes are unstable, the reliability of the nodes is not high, the topology of the network is changed frequently, and the wireless ad hoc network has strong dynamic property. If the traditional master-slave time synchronization method is still adopted in the network, the problems of master node loss, frequent master-slave relationship change along with topology change and the like can be encountered, so that the reliability and robustness of the overall time synchronization of the network are influenced, and the problem that the time synchronization precision of the network is difficult to improve can be caused.
Disclosure of Invention
In order to solve the above problems in the prior art, the present invention provides a time synchronization method, a time synchronization system and a device suitable for an ad hoc network. The technical problem to be solved by the invention is realized by the following technical scheme:
the invention provides a time synchronization method suitable for a self-organizing network, which comprises the following steps:
acquiring time information of a node and time information of interaction between the node and a neighbor node;
clock deviation among all nodes is obtained according to the time information;
carrying out weight adjustment and distribution on the clock deviation to obtain a weighted clock deviation;
correcting a local clock to finish time synchronization according to the weighted clock deviation;
wherein the time information comprises timestamp information and a clock status parameter.
In one embodiment of the invention, the method further comprises:
and calculating to obtain the variance of the clock deviation according to the clock deviation, and determining neighbor node information interacted in the next time synchronization process according to the variance of the clock deviation, wherein the neighbor node information comprises the number and objects of neighbor nodes.
In an embodiment of the present invention, acquiring time information of a node and time information of interaction between the node and its neighboring nodes further includes:
setting the clock state parameters of the nodes according to the constructed self-organizing network, and if the nodes have the satellite time service function, setting the clock state parameters to s0Otherwise, set its clock state parameter to snull；
And realizing the interaction between the node and the neighbor nodes thereof.
In an embodiment of the present invention, the performing weight adjustment and distribution on the clock bias to obtain a weighted clock bias includes:
judging whether the node has a satellite time service function or not according to the clock state parameter of the node and the clock state parameter received by the node;
if so, keeping the clock state parameter of the node unchanged, and distributing all the weights to the node;
otherwise, updating the clock state parameter of the node to the received minimum clock state parameter plus 1, carrying out arithmetic mean calculation on the clock deviations receiving the same clock state parameter to obtain a mean clock deviation, distributing a maximum weight to the mean clock deviation corresponding to the minimum clock state parameter, and dividing the remaining weight equally by the mean clock deviations corresponding to the remaining clock state parameters;
and weighting and calculating according to the distributed weight values to obtain weighted clock deviation.
In an embodiment of the present invention, calculating a variance of a clock bias according to the clock bias, and determining neighbor node information interacting in a next time synchronization process according to the variance of the clock bias, includes:
calculating the variance of the clock deviation according to the clock deviation;
comparing the variance of the clock deviation with a preset threshold, if the variance of the clock deviation is larger than the threshold, determining that the number of the neighbor nodes which interact in the next time synchronization process is larger than the number of the neighbor nodes which interact in the last time synchronization process, and selecting the neighbor nodes in sequence from small to large according to the clock deviation;
and if the variance of the clock deviation is smaller than the threshold, determining that the number of the neighbor nodes interacted in the next time synchronization process is smaller than or equal to the number of the neighbor nodes interacted in the last time synchronization process, and selecting the neighbor nodes in sequence from small to large according to the clock deviation.
The invention also provides a time synchronization system, comprising:
the time tracking and synchronizing module is used for acquiring the time information of the node and the time information of the interaction between the node and the neighbor nodes;
the clock deviation information processing module is used for obtaining the clock deviation among the nodes according to the time information;
the self-adaptive weight value adjusting and distributing module is used for adjusting and distributing the weight value of the clock deviation to obtain a weighted clock deviation;
and the time tracking and synchronizing module is also used for correcting the local clock to finish time synchronization according to the weighted clock deviation.
In one embodiment of the present invention, the time synchronization system further includes:
the synchronous signaling frame transceiving control module is used for calculating the variance of the clock deviation according to the clock deviation, determining interactive neighbor node information in the next time synchronization process according to the variance of the clock deviation, and generating a first control signal or a second control signal, wherein the neighbor node information comprises the number and objects of neighbor nodes;
and the synchronous signaling frame receiving and sending module is used for realizing interaction between the node and the neighbor nodes thereof according to the first control signal or the second control signal.
In an embodiment of the present invention, the adaptive weight adjustment allocating module includes:
the node judging unit is used for judging whether the node has a satellite time service function or not according to the clock state parameter of the node and the clock state parameter received by the node;
a weight adjustment and distribution unit for performing weight adjustment and distribution according to the judgment result of the node judgment unit, wherein,
when the node has the satellite time service function, keeping the clock state parameter of the node unchanged, and distributing all the weights to the node;
when the node does not have the satellite time service function, updating the clock state parameter of the node into the received minimum clock state parameter plus 1, carrying out arithmetic average calculation on the clock deviations receiving the same clock state parameter to obtain an average clock deviation, distributing a maximum weight to the average clock deviation corresponding to the minimum clock state parameter, and dividing the average clock deviation corresponding to the residual clock state parameter into two equal residual weights;
and the weighted clock deviation calculating unit is used for obtaining the weighted clock deviation through weighted calculation according to the distributed weight values.
In an embodiment of the present invention, the synchronization signaling frame transceiving control module includes:
the variance calculation unit is used for calculating the variance of the clock deviation according to the clock deviation;
the comparison unit is used for comparing the variance of the clock deviation with a preset threshold value;
a control signal generating unit for generating the first control signal and the second control signal according to a comparison result of the comparing unit,
when the variance of the clock deviation is larger than the threshold value, determining that the number of the neighbor nodes which interact in the next time of time synchronization is larger than the number of the neighbor nodes which interact in the last time of time synchronization, sequentially selecting the neighbor nodes from small to large according to the clock deviation, and generating the first control signal;
and when the variance of the clock deviation is smaller than the threshold value, determining that the number of the neighbor nodes which interact in the next time synchronization process is smaller than or equal to the number of the neighbor nodes which interact in the last time synchronization process, sequentially selecting the neighbor nodes from small to large according to the clock deviation, and generating the second control signal.
The invention also provides a time-synchronized processing device comprising a memory and a processor, wherein,
a memory for storing a computer program;
a processor for implementing the method steps of any of the above embodiments when executing the program stored in the memory.
Compared with the prior art, the invention has the beneficial effects that:
1. the time synchronization method applicable to the self-organizing network determines clock deviation through exchanging time information among nodes, dynamically distributes weights to the clock deviation difference according to clock state parameters of neighbor nodes, and then corrects a local clock according to the weighted clock deviation, when the topology of the network is changed or satellite time service is suddenly lost, all the nodes still keep the same synchronization mode without any switching, the effect of clock synchronization can not generate large-scale fluctuation, and the stability and the robustness of the clock synchronization of the self-organizing network are enhanced;
2. according to the time synchronization method applicable to the self-organizing network, in the time synchronization process, the variance of the clock deviation is obtained according to the clock deviation calculation, the number of the neighbor nodes which interact in the next time synchronization process is determined according to the variance of the clock deviation, and communication resources can be saved.
The foregoing description is only an overview of the technical solutions of the present invention, and in order to make the technical means of the present invention more clearly understood, the present invention may be implemented in accordance with the content of the description, and in order to make the above and other objects, features, and advantages of the present invention more clearly understood, the following preferred embodiments are described in detail with reference to the accompanying drawings.
Drawings
Fig. 1 is a flowchart of a time synchronization method applied to an ad hoc network according to an embodiment of the present invention;
fig. 2 is a scenario in which a time synchronization method according to an embodiment of the present invention is applied;
fig. 3 is a flowchart of another time synchronization method applicable to an ad hoc network according to an embodiment of the present invention;
FIG. 4 is a schematic flow chart of clock skew dynamic weight adjustment and distribution according to an embodiment of the present invention;
fig. 5 is a schematic flowchart of determining information of a neighboring node performing interaction according to an embodiment of the present invention;
fig. 6 is a schematic structural diagram of a time synchronization system according to an embodiment of the present invention;
FIG. 7 is a schematic structural diagram of another time synchronization system provided in the embodiment of the present invention;
FIG. 8 is a schematic structural diagram of an adaptive weight adjustment distribution module according to an embodiment of the present invention;
fig. 9 is a schematic structural diagram of a synchronization signaling frame transceiving control module according to an embodiment of the present invention;
fig. 10 is a schematic structural diagram of a time synchronization processing apparatus according to an embodiment of the present invention.
Icon: 1-a time tracking and synchronization module; 2-a clock deviation information processing module; 3-self-adaptive weight adjustment distribution module; 4-synchronous signaling frame receiving and sending control module; 5-synchronous signaling frame receiving and sending module; 301-a node judgment unit; 302-weight adjustment allocation unit; 303-weighted clock deviation calculation unit; 401-variance calculation unit; 402-a comparison unit; 403-a control signal generation unit; 100-a memory; 200-a processor.
Detailed Description
To further illustrate the technical means and effects of the present invention adopted to achieve the predetermined objects, a time synchronization method, a time synchronization system and a device for an ad hoc network according to the present invention are described in detail below with reference to the accompanying drawings and the detailed description.
The foregoing and other technical matters, features and effects of the present invention will be apparent from the following detailed description of the embodiments, which is to be read in connection with the accompanying drawings. The technical means and effects of the present invention adopted to achieve the predetermined purpose can be more deeply and specifically understood through the description of the specific embodiments, however, the attached drawings are provided for reference and description only and are not used for limiting the technical scheme of the present invention.
Example one
Referring to fig. 1, fig. 1 is a flowchart of a time synchronization method for an ad hoc network according to an embodiment of the present invention. As shown in the figure, the time synchronization method applicable to the ad hoc network of the present embodiment includes:
s1: acquiring time information of a node and time information of interaction between the node and a neighbor node;
wherein the time information comprises timestamp information and clock status parameters. In this embodiment, the time information of the interaction of the neighbor nodes is obtained, and may be the time information of the interaction of all the neighbor nodes or the time information of the interaction of part of the neighbor nodes.
Further, before step S1, the method further includes:
and setting clock state parameters of the nodes according to the constructed self-organizing network, and realizing interaction between the nodes and the neighbor nodes.
Specifically, please refer to fig. 2 in combination, where fig. 2 is a scenario in which a time synchronization method according to an embodiment of the present invention is applied. As shown in the figure, if the node has the satellite time service function, the clock state parameter is set to s0Otherwise, set its clock state parameter to snullI.e. the clock state parameter of node0 in the figure is set to s0The clock state parameters of node1, node2, and node3 are all set to snull。
S2: clock deviation among all nodes is obtained according to the time information;
specifically, a neighbor table is obtained according to the constructed self-organizing network, a corresponding relation is established between clock state parameters in the time information and the neighbor table, and clock deviation among nodes is calculated by using an IEEE802.1AS protocol.
S3: carrying out weight adjustment and distribution on the clock deviation to obtain a weighted clock deviation;
specifically, referring to fig. 4, fig. 4 is a schematic flow chart illustrating the adjustment and distribution of the clock bias dynamic weights according to the embodiment of the present invention, and as shown in the drawing, step S3 includes:
judging whether the node has a satellite time service function or not according to the clock state parameter of the node and the clock state parameter received by the node;
if so, keeping the clock state parameter of the node unchanged, and distributing all the weights to the node;
otherwise, updating the clock state parameter of the node to the received minimum clock state parameter plus 1, carrying out arithmetic average calculation on the clock deviations receiving the same clock state parameter to obtain an average clock deviation, distributing a maximum weight to the average clock deviation corresponding to the minimum clock state parameter, and dividing the average clock deviation corresponding to the remaining clock state parameters into two halves;
and weighting and calculating according to the distributed weight values to obtain weighted clock deviation.
Specifically, step S3 is described by taking the scenario in fig. 2 as an example, where the clock state parameter of node0 is S0Then, it is determined that it has the satellite time service function and maintains the clock state parameter s0And if not, ignoring other time information received by node0, selecting to keep the local clock, and assigning all weights, namely 1, to node 0.
The clock state parameter of node1 is snullThen, it is determined that node1 does not have the satellite time service function, and the received clock status parameters include the clock status parameter s of node00Clock state parameter s of node2nullAnd the clock state parameter s of node3null. Wherein the received minimum clock state parameter is s0Then, it is determined that node1 is a neighbor of a node with a satellite time service function, and the clock state parameter of node1 is updated to s0+1, i.e. s1. The clock state parameter of the similar node2 is also updated to s1By analogy, the clock status parameter of node3 is updated to s1+1I.e. s2。
It should be noted that, as the hop distance between the node and the node having the satellite time service function is longer, the larger the clock state parameter value of the node is, the smaller the reliability thereof is.
Then, the received clock deviations of the same clock state parameter are arithmetically averaged to obtain an average clock deviation (offset)0,offset1,offset2,...,offsetn) And a clock state parameter(s)0,s1,s2...sn) And correspond to each other.
Then, setting weights for different average clock deviations, firstly selecting the minimum clock state parameter, distributing the maximum weight to the corresponding average clock deviation, then dividing the rest weights equally by the rest clock state parameters, and finally obtaining the weighted clock deviation according to the weighted calculation of the weight distributed by each clock state parameter. It should be noted that, in this embodiment, the larger the clock status parameter value is, the smaller the weight of the corresponding average clock skew is.
S4: and according to the weighted clock deviation, correcting the local clock to finish time synchronization.
It should be noted that, after all nodes in the ad hoc network perform rounds according to the method of the present embodiment, the nodes in the ad hoc network synchronize to the node having the satellite time service or the average value of the clocks of all nodes in the network.
According to the time synchronization method applicable to the self-organizing network, the clock deviation is determined through exchanging time information among the nodes, the weight is dynamically distributed to the clock deviation difference according to the clock state parameters of the neighbor nodes, then the local clock is corrected according to the weighted clock deviation, when the topology of the network changes or the satellite time service suddenly disappears, all the nodes still keep the same synchronization mode without any switching, the effect of clock synchronization cannot fluctuate in a large scale, and the stability and the robustness of the clock synchronization of the self-organizing network are enhanced.
Further, referring to fig. 3, fig. 3 is a flowchart of another time synchronization method suitable for an ad hoc network according to an embodiment of the present invention. As shown in the figure, compared with the above embodiments, the time synchronization method of the present embodiment further includes:
s3': and calculating to obtain the variance of the clock deviation according to the clock deviation, and determining the information of the neighbor nodes interacted in the next time synchronization process according to the variance of the clock deviation.
The neighbor node information includes the number of neighbor nodes and objects.
In this embodiment, in the next time synchronization process, the time information of interaction between a node and its neighboring nodes is obtained according to the determined number and objects of the neighboring nodes.
Specifically, please refer to fig. 5, where fig. 5 is a schematic flowchart illustrating a process of determining information of a neighboring node performing interaction according to an embodiment of the present invention. As shown, step S3' includes:
calculating the variance of the clock deviation according to the clock deviation;
comparing the variance of the clock deviation with a preset threshold, if the variance of the clock deviation is greater than the threshold, determining that the number of neighbor nodes interacted in the next time synchronization process is greater than the number of neighbor nodes interacted in the last time synchronization process, and selecting the neighbor nodes in sequence from small to large according to the clock deviation;
and if the variance of the clock deviation is smaller than the threshold value, determining that the number of the neighbor nodes which interact in the next time synchronization process is smaller than or equal to the number of the neighbor nodes which interact in the last time synchronization process, and selecting the neighbor nodes in turn from small to large according to the clock deviation.
In this embodiment, the threshold is set according to the accuracy of time synchronization and the number of nodes.
If the variance of the clock deviation is larger than the threshold value, the synchronization state of the self-organizing network is not ideal, and in the next time synchronization process, more neighbor nodes or all neighbor nodes can be selected to exchange time information so as to accelerate the time synchronization of the self-organizing network.
If the variance of the clock deviation is smaller than the threshold value, the synchronization state of the self-organizing network is close to convergence, and then in the next time synchronization process, the current number of neighbor nodes or fewer neighbor nodes can be selected to exchange time information, so that the communication overhead is saved.
Preferably, the neighbor nodes are selected in sequence from small to large according to the clock deviation, so that the convergence speed can be increased.
After all nodes in the ad hoc network perform rounds according to the method of the embodiment, the nodes in the ad hoc network synchronize to the nodes having satellite time service or the average value of clocks of all nodes in the network.
Other steps of this embodiment are the same as those of the previous embodiment, and are not described herein again.
In the time synchronization method applicable to the self-organizing network, in the time synchronization process, the variance of the clock deviation is obtained according to the clock deviation calculation, and the number of the neighbor nodes which interact in the next time synchronization process is determined according to the variance of the clock deviation, so that the communication resources can be saved.
Example two
Fig. 6 shows a schematic structural diagram of a time synchronization system according to an embodiment of the present invention, where fig. 6 is a schematic structural diagram of a time synchronization system according to an embodiment of the present invention. As shown in the figure, the time synchronization system of the present embodiment includes: the system comprises a time tracking and synchronizing module 1, a clock deviation information processing module 2 and a self-adaptive weight value adjusting and distributing module 3, wherein the time tracking and synchronizing module 1 is used for acquiring time information of a node and time information of interaction between the node and a neighbor node of the node; the clock deviation information processing module 2 is used for obtaining the clock deviation among the nodes according to the time information; the self-adaptive weight adjustment distribution module 3 is used for performing weight adjustment and distribution on the clock deviation to obtain a weighted clock deviation, and further, the time tracking and synchronization module 1 is also used for correcting the local clock according to the weighted clock deviation to complete time synchronization.
In the present embodiment, the time tracking and synchronizing module 1, as a virtual clock, forms a local clock together with a local reference clock source. The time tracking and synchronizing module 1 is a phase-locked loop circuit, and the phase-locked loop circuit adjusts the clock synchronization error and the frequency error according to the weighted clock deviation.
Referring to fig. 7, fig. 7 is a schematic structural diagram of another time synchronization system according to an embodiment of the present invention. As shown in the figure, in other embodiments, the time synchronization system further includes a synchronization signaling frame transceiving control module 4 and a synchronization signaling frame receiving and transmitting module 5. The synchronous signaling frame transceiving control module 4 is configured to calculate a variance of a clock bias according to the clock bias, determine interactive neighbor node information in a next time synchronization process according to the variance of the clock bias, and generate a first control signal or a second control signal, where the neighbor node information includes the number and objects of neighbor nodes. The synchronous signaling frame receiving and sending module 5 is configured to implement interaction between a node and a neighboring node thereof according to the first control signal or the second control signal.
Specifically, the synchronization signaling frame transceiving control module 4 determines the number of the interacted neighboring nodes, the objects and the specific interaction mode in the next time synchronization process according to the clock deviation and the current network topology connection relationship. The synchronous signaling frame receiving and sending module 5 is used for exchanging time information between the node and the neighboring node, including timestamp information and clock state parameters.
Further, please refer to fig. 8, where fig. 8 is a schematic structural diagram of an adaptive weight adjustment allocation module according to an embodiment of the present invention. As shown in the figure, the adaptive weight adjustment distribution module 3 includes a node judgment unit 301, a weight adjustment distribution unit 302, and a weighted clock bias calculation unit 303. In this embodiment, the node determining unit 301 is configured to determine whether a node has a satellite time service function according to a clock state parameter of the node and a clock state parameter received by the node; the weight value adjusting and distributing unit 302 is configured to perform weight value adjusting and distributing according to the determination result of the node determining unit 301, wherein when a node has a satellite time service function, a clock state parameter of the node is kept unchanged, and all weight values are distributed to the node; when the node does not have the satellite time service function, updating the clock state parameter of the node into the received minimum clock state parameter plus 1, carrying out arithmetic average calculation on the clock deviations receiving the same clock state parameter to obtain an average clock deviation, distributing a maximum weight to the average clock deviation corresponding to the minimum clock state parameter, and dividing the average clock deviation corresponding to the residual clock state parameter into two equal parts; and a weighted clock deviation calculating unit 303, configured to obtain a weighted clock deviation through weighted calculation according to the distributed weights.
Further, please refer to fig. 9, where fig. 9 is a schematic structural diagram of a synchronization signaling frame transceiving control module according to an embodiment of the present invention. As shown in the figure, the synchronous signaling frame transceiving control module 4 includes: a variance calculation unit 401, a comparison unit 402 and a control signal generation unit 403. In this embodiment, the variance calculating unit 401 is configured to calculate a variance of the clock offset according to the clock offset; the comparing unit 402 is configured to compare the variance of the clock offset with a preset threshold; the control signal generating unit 403 is configured to generate a first control signal and a second control signal according to the comparison result of the comparing unit 402, where when the variance of the clock deviation is greater than the threshold, it is determined that the number of neighboring nodes that interact in the next time synchronization process is greater than the number of neighboring nodes that interact in the last time synchronization process, and the neighboring nodes are sequentially selected from small to large according to the clock deviation, and generate the first control signal; and when the variance of the clock deviation is smaller than the threshold value, determining that the number of the neighbor nodes which interact in the next time of time synchronization process is smaller than or equal to the number of the neighbor nodes which interact in the last time of time synchronization process, sequentially selecting the neighbor nodes from small to large according to the clock deviation, and generating a second control signal.
EXAMPLE III
The embodiment provides a time synchronization processing device, comprising a memory 100 and a processor 200, wherein the memory 100 is used for storing a computer program; the processor 200 is configured to implement the method steps of the first embodiment when executing the program stored in the memory 100.
It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that an article or device that comprises a list of elements does not include only those elements but may include other elements not expressly listed. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of additional like elements in the article or device comprising the element. The terms "connected" or "coupled" and the like are not restricted to physical or mechanical connections, but may include electrical connections, whether direct or indirect.
The foregoing is a more detailed description of the invention in connection with specific preferred embodiments and it is not intended that the invention be limited to these specific details. For those skilled in the art to which the invention pertains, several simple deductions or substitutions can be made without departing from the spirit of the invention, and all shall be considered as belonging to the protection scope of the invention.
Claims (9)
1. A method for time synchronization in an ad hoc network, comprising:
acquiring time information of a node and time information of interaction between the node and a neighbor node;
clock deviation among all nodes is obtained according to the time information;
carrying out weight adjustment and distribution on the clock deviation to obtain a weighted clock deviation;
correcting a local clock to finish time synchronization according to the weighted clock deviation;
wherein the time information comprises timestamp information and clock state parameters;
and adjusting and distributing the weight of the clock deviation to obtain a weighted clock deviation, which comprises the following steps:
judging whether the node has a satellite time service function or not according to the clock state parameter of the node and the clock state parameter received by the node;
if so, keeping the clock state parameter of the node unchanged, and distributing all the weights to the node;
otherwise, updating the clock state parameter of the node to the received minimum clock state parameter plus 1, carrying out arithmetic mean calculation on the clock deviations receiving the same clock state parameter to obtain a mean clock deviation, distributing a maximum weight to the mean clock deviation corresponding to the minimum clock state parameter, and dividing the remaining weight equally by the mean clock deviations corresponding to the remaining clock state parameters;
and weighting and calculating according to the distributed weight values to obtain weighted clock deviation.
2. The method of claim 1, further comprising:
and calculating to obtain the variance of the clock deviation according to the clock deviation, and determining neighbor node information interacted in the next time synchronization process according to the variance of the clock deviation, wherein the neighbor node information comprises the number and objects of neighbor nodes.
3. The method of claim 1, wherein obtaining time information of a node and time information of interaction between the node and its neighboring nodes further comprises:
setting the clock state parameters of the nodes according to the constructed self-organizing network, and if the nodes have the satellite time service function, setting the clock state parameters to s0Otherwise, set its clock state parameter to snull；
And realizing the interaction between the node and the neighbor nodes thereof.
4. The method of claim 2, wherein calculating a variance of the clock bias according to the clock bias, and determining neighbor node information for interaction in a next time synchronization process according to the variance of the clock bias comprises:
calculating the variance of the clock deviation according to the clock deviation;
comparing the variance of the clock deviation with a preset threshold, if the variance of the clock deviation is larger than the threshold, determining that the number of the neighbor nodes which interact in the next time synchronization process is larger than the number of the neighbor nodes which interact in the last time synchronization process, and selecting the neighbor nodes in sequence from small to large according to the clock deviation;
and if the variance of the clock deviation is smaller than the threshold, determining that the number of the neighbor nodes interacted in the next time synchronization process is smaller than or equal to the number of the neighbor nodes interacted in the last time synchronization process, and selecting the neighbor nodes in sequence from small to large according to the clock deviation.
5. A time synchronization system, comprising:
the time tracking and synchronizing module is used for acquiring the time information of the node and the time information of the interaction between the node and the neighbor nodes;
the clock deviation information processing module is used for obtaining the clock deviation among the nodes according to the time information;
the self-adaptive weight value adjusting and distributing module is used for adjusting and distributing the weight value of the clock deviation to obtain a weighted clock deviation;
and the time tracking and synchronizing module is also used for correcting the local clock to complete time synchronization according to the weighted clock deviation.
6. The time synchronization system of claim 5, further comprising:
the synchronous signaling frame transceiving control module is used for calculating the variance of the clock deviation according to the clock deviation, determining interactive neighbor node information in the next time synchronization process according to the variance of the clock deviation, and generating a first control signal or a second control signal, wherein the neighbor node information comprises the number and objects of neighbor nodes;
and the synchronous signaling frame receiving and sending module is used for realizing interaction between the node and the neighbor nodes thereof according to the first control signal or the second control signal.
7. The system according to claim 5, wherein the adaptive weight adjustment distribution module comprises:
the node judging unit is used for judging whether the node has a satellite time service function or not according to the clock state parameter of the node and the clock state parameter received by the node;
a weight adjustment and distribution unit for performing weight adjustment and distribution according to the judgment result of the node judgment unit, wherein,
when the node has the satellite time service function, keeping the clock state parameter of the node unchanged, and distributing all the weights to the node;
when the node does not have the satellite time service function, updating the clock state parameter of the node into the received minimum clock state parameter plus 1, carrying out arithmetic average calculation on the clock deviations receiving the same clock state parameter to obtain an average clock deviation, distributing a maximum weight to the average clock deviation corresponding to the minimum clock state parameter, and dividing the average clock deviation corresponding to the residual clock state parameter into two equal residual weights;
and the weighted clock deviation calculating unit is used for obtaining the weighted clock deviation through weighted calculation according to the distributed weight values.
8. The time synchronization system according to claim 6, wherein the synchronization signaling frame transceiving control module comprises:
the variance calculation unit is used for calculating the variance of the clock deviation according to the clock deviation;
the comparison unit is used for comparing the variance of the clock deviation with a preset threshold value;
a control signal generating unit for generating the first control signal and the second control signal according to a comparison result of the comparing unit,
when the variance of the clock deviation is larger than the threshold value, determining that the number of the neighbor nodes which interact in the next time of time synchronization is larger than the number of the neighbor nodes which interact in the last time of time synchronization, sequentially selecting the neighbor nodes from small to large according to the clock deviation, and generating the first control signal;
and when the variance of the clock deviation is smaller than the threshold value, determining that the number of the neighbor nodes which interact in the next time synchronization process is smaller than or equal to the number of the neighbor nodes which interact in the last time synchronization process, sequentially selecting the neighbor nodes from small to large according to the clock deviation, and generating the second control signal.
9. A time-synchronized processing device, comprising a memory and a processor, wherein,
a memory for storing a computer program;
a processor for implementing the method steps of any one of claims 1 to 4 when executing a program stored in the memory.
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103813355A (en) * | 2014-02-21 | 2014-05-21 | 厦门大学 | Identification method for anomalous points of cooperative synchronization in distributed network |
| CN104185268A (en) * | 2014-09-13 | 2014-12-03 | 郑州航空工业管理学院 | Time slot synchronization algorithm suitable for self-organization networking |
| CN109041202A (en) * | 2018-08-02 | 2018-12-18 | 陕西集星合智防务科技有限公司 | A kind of distributed clock synchronized algorithm suitable for Ad hoc network |
| CN109982425A (en) * | 2019-01-28 | 2019-07-05 | 博频云彩（北京）科技有限公司 | Time quasi-synchronization method of centerless distributed network |
| CN111355551A (en) * | 2020-02-11 | 2020-06-30 | 西安电子科技大学 | Network clock synchronization method and device suitable for semi-stable link |
| CN111405654A (en) * | 2020-03-22 | 2020-07-10 | 西安电子科技大学 | Information transmission method between high dynamic wireless nodes |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US10069871B2 (en) * | 2016-02-01 | 2018-09-04 | Verizon Patent And Licensing Inc. | Measuring session initiation protocol (SIP) messaging latency |
| CN109792478B (en) * | 2016-09-01 | 2021-11-12 | 迪尤莱特公司 | Apparatus and method for adjusting focus based on focus target information |
| US20190223125A1 (en) * | 2018-01-12 | 2019-07-18 | Linear Technology Holding Llc | Measurement synchronization across networks |
-
2020
- 2020-09-03 CN CN202010918054.1A patent/CN112235861B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103813355A (en) * | 2014-02-21 | 2014-05-21 | 厦门大学 | Identification method for anomalous points of cooperative synchronization in distributed network |
| CN104185268A (en) * | 2014-09-13 | 2014-12-03 | 郑州航空工业管理学院 | Time slot synchronization algorithm suitable for self-organization networking |
| CN109041202A (en) * | 2018-08-02 | 2018-12-18 | 陕西集星合智防务科技有限公司 | A kind of distributed clock synchronized algorithm suitable for Ad hoc network |
| CN109982425A (en) * | 2019-01-28 | 2019-07-05 | 博频云彩（北京）科技有限公司 | Time quasi-synchronization method of centerless distributed network |
| CN111355551A (en) * | 2020-02-11 | 2020-06-30 | 西安电子科技大学 | Network clock synchronization method and device suitable for semi-stable link |
| CN111405654A (en) * | 2020-03-22 | 2020-07-10 | 西安电子科技大学 | Information transmission method between high dynamic wireless nodes |
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