CN104105195A - Large-scale wireless sensor network time synchronizer based on clock frequency dynamic detection - Google Patents
Large-scale wireless sensor network time synchronizer based on clock frequency dynamic detection Download PDFInfo
- Publication number
- CN104105195A CN104105195A CN201410296752.7A CN201410296752A CN104105195A CN 104105195 A CN104105195 A CN 104105195A CN 201410296752 A CN201410296752 A CN 201410296752A CN 104105195 A CN104105195 A CN 104105195A
- Authority
- CN
- China
- Prior art keywords
- node
- clock frequency
- message
- root node
- synchronous
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Landscapes
- Mobile Radio Communication Systems (AREA)
Abstract
The invention brings forward a large-scale wireless sensor network time synchronizer based on clock frequency dynamic detection. A rapid tracking strategy is performed on the abruptly changed clock frequency nodes via statistic analysis of clock frequency data so that the nodes are ensured to monitor the clock frequency state in real time. A multi-hop path selection mechanism is adopted, and a synchronization path with great quality is simply and rapidly selected so that a synchronization error multi-hop accumulation phenomenon is effectively inhibited and synchronization precision is enhanced. Strategies of root node reselection and level information periodic updating are respectively adopted by aiming at the situation of failure of root nodes and common nodes in a large-scale wireless sensor network.
Description
Technical field
The invention belongs to the time synchronized field between wireless sensor network node.
Background technology
Wireless sensor network (Wireless Sensor Networks, WSNs) is made up of a large amount of nodes, along with the continuous increase of network size, and the clock frequency phenomenon of easily undergoing mutation, and accumulated error is serious on synchronization accuracy impact.According to the sending and receiving mode of sync message, WSNs time synchronized model is mainly divided three classes: based on sender-recipient bi-directional synchronization model, based on sender's one-way synchronization model with based on recipient-recipient synchronistic model.Existing WSNs Time Synchronization Mechanism, not to the contingent sudden change situation of clock frequency, provides corresponding settlement mechanism.Once clock frequency is undergone mutation, historical data does not empty in time, and this will cause synchronous error sharply to increase, and synchronous error is with the lasting accumulation on path that is diffused in of synchronizing information, finally causes occurring the phenomenon of synchronization accuracy degradation.
In typical protocol, RBS (Reference Broadcast Synchronization) utilizes a gateway node associated time scale information between two broadcast domains, thereby it is synchronous to realize multi-hop the whole network, but agreement does not detect the quality of gateway node, do not consider transmission delay and the error accumulation problem after association, brought yet.TPSN (Timing-sync Protocol for Sensor Networks) and Tiny-Sync/Mini-Sync all use bi-directional switching technology, wherein the multi-hop synchronization policy based on spanning tree is not taked corresponding measure to node failure, there is synchronisation of nodes failure in network time, especially, when this situation appears near the position of reference node, will synchronously cause fatal impact to the whole network.FTSP (Flooding Time Synchronization Protocol) adopts the strategy that distributes unique ID number to the whole network node, determines markers priority according to ID size, finally makes the whole network converge to the time standard of minimum ID node.This mechanism is only admitted node ID number and is not considered the stability of nodal clock, in the time that unsettled node has obtained less ID, will synchronously make a big impact to the whole network.LTS (Lightweight Time Synchronization) has carried out quantitative analysis to the multi-hop error accumulation of layer-stepping synchronous protocol, although the spanning tree using rule has been considered the selection of synchronous path, but logic is too complicated, and shortage specific aim is selected in the path of individual node.CCS (Consensus Clock Synchronization) has proposed the thought of an internal virtual clock, all nodes are converged on an internal virtual clock standard, though there is not like this multi-hop stationary problem, but this dummy clock and standard time clock exist certain deviation, particularly in the time that transforming, the markers of carrying out the standard time will go wrong.
Summary of the invention
For effectively solving the problem that in large scale network, clock frequency is easily undergone mutation, suppress synchronous error multi-hop and accumulate serious phenomenon, and provide respectively corresponding resolution policy to root node inefficacy and ordinary node inefficacy, the invention provides a kind of massive wireless sensor synchrotimer based on clock frequency detection of dynamic.This synchronizer is by application detection of dynamic mechanism, make the real-time monitoring clock frequency status of node, select suitable clock frequency method of estimation according to the result detecting, and choose relatively preferably synchronous path, suppress the multi-hop accumulation of synchronous error, within the scope of macroreticular, obtain high synchronization accuracy and strong robustness.
The present invention is achieved by the following technical solutions:
The synchronizer foundation of this technical scheme and the specific implementation process of safeguarding are as follows:
(1) root node election
First, at network establishment stage, can distribute unique No. ID for each node, then open root node election mechanism by arbitrary node in network, the root node election message that broadcast transmission comprises self root node number.Node initial condition, the root node number of storage is empty, when receiving root node election message, take out the root node number wherein comprising, with comparing for No. ID of self, get smaller between the two as root node, then in root node election message, be written into new root node information, continue broadcast root node election message, guarantee that each node can receive root node election message.Final network is root node by No. ID minimum node election, as the time standard of network.
(2) network layer generates
Root node is made as 0 by the synchronous level of oneself, and broadcasts a level and find message, wherein comprises the level number of oneself.Then, when all hop neighbor nodes of reference node are received after this message, extract hierarchical information wherein, the level of oneself number is made as to this value and adds 1, after rewriting message again and be oneself level number, its broadcast is gone out, subsequent node continues to utilize this message to determine the synchronous level of oneself.This action is performed until the fringe node of network, so sets up the synchronous level of the whole network.
(3) synchronous operation
Network layer generate complete after, periodically send sync message by root node, in message, comprise synchronized timestamp, level number and round number, its middle-level number and round number are that lower level node judges the whether effective important mark of this message.If the sync message receiving meets the demands, lower level node carries out clock frequency detection of dynamic according to time stamp data, determine the clock frequency state of self, select suitable clock frequency method of estimation, obtain the clock frequency deviation estimated value of node oneself, make self to synchronize with upper layer node, then continue a downward node layer and send synchronization message.This action is continued until the fringe node of network, completes the time synchronized of the whole network node.
(4) multi-hop synchronous path is selected
The mechanism of the transmission of sync message based on inundation therefore all can forward sync message after node completes synchronously, guarantees that the node of lower floor can deadline synchronizing process.The node of lower floor adopts the sync message information that meets the demands and arrive the earliest.In order to suppress in large scale network, the problem that the synchronous accumulated error of multi-hop is serious is elected preferably path on path.Massive wireless sensor synchronizer is according to nodal clock state, controls the transmission rate of sync message, and the transmission sync message that the good node of synchronizing quality can be relatively early guarantees that lower level node can select preferably synchronous path.
The core of massive wireless sensor synchronizer of the present invention comprises clock frequency detection of dynamic and multihop path selection mechanism, and details is as follows:
The variation of clock frequency is divided into three kinds of patterns by we, is respectively steady pattern, observing pattern and Catastrophe Model.In synchronizing process, when node receives synchrodata at every turn, first utilize gradient method estimating clock frequency, be instantaneous estimation value.According to the clock frequency characteristic of sensor node, clock has stable characteristic in the starting stage, and synchronous initial stage node is to Data Collection and storage.Then calculate according to the data of record the assembly average that clock frequency is estimated, and according to calculating maximum estimated difference, i.e. the maximum of estimated value and estimated mean value absolute difference.By maximum estimated difference, we set first detection reference gate and are limited to noise measuring thresholding.In order to improve the accuracy of detection, generally maximum estimated difference is carried out to expansion by a small margin as noise measuring threshold value.On the basis of noise gate, add frequency change minimum detection value, as frequency change detection threshold.Due in large scale network, be subject to the impact of accumulated error, therefore in the time that changing thresholding, setpoint frequency considers node level difference, accumulated error difference, need to adjust according to the level under node.
When receiving after new sync message information, first clock frequency is detected.Then process according to following three kinds of situations.Detailed process is as follows
if instantaneous estimation value is less than noise measuring thresholding with the difference of estimating assembly average, think that clock frequency is in steady pattern.Utilize this synchrodata information and adopt least square method to estimate clock frequency, upgrading and estimate average statistical, noise check thresholding and frequency change detection threshold.
if difference has exceeded noise gate, but be less than frequency change detection threshold, think that clock frequency is in observing pattern.May there is variation in nodal clock frequency now, also may, because this synchronization noise is larger, cause evaluated error sharply to increase, need to abandon this synchronizing information and utilize and estimate Estimation of Mean clock frequency, but do not need clear history data point information, do not need to upgrade detection threshold value equivalence yet.
if difference has exceeded frequency change detection threshold, think that clock frequency undergos mutation, need to empty all historical datas of storage, and estimation average statistical, noise measuring threshold value and frequency change detected value be set to 0, restart Data Collection.
Synchronizer of the present invention has proposed effective resolution policy to node failure situation:
(1) root node inefficacy countermeasure
Root node is as the time standard of network, self-evident for the importance of time synchronization protocol.In the time that root node lost efficacy, level number be 1 node can be more early with respect to the node of other levels discovery and definite root node situation about losing efficacy.In order to save the consumption of energy, shorten time of re-electing, it is in 1 node that the scope that root node is re-elected is fixed on level number, selects wherein No. ID minimum node as new root node.
(2) ordinary node inefficacy countermeasure
So-called ordinary node is exactly all nodes except root node in network.Because the transmission of sync message adopts the mechanism of inundation, generally, as long as just have the node that can communicate by letter and can not lose efficacy.But in order to reduce the impact of redundant information, node needed hierarchical information to detect before synchronous.This just will cause node to have the node that can communicate by letter, but still cannot complete synchronous situation.So in order to solve this situation, ordinary node, when in the time that do not receive effective sync message information 2 synchronizing cycles, upgrade the hierarchical information of self automatically, the number of dropping to a lower level can continue synchronously it.
Beneficial effect of the present invention is:
1. clock frequency detection of dynamic
Clock frequency detection of dynamic is as the core of synchronizer of the present invention, real-time monitor node frequency state, in the time that clock frequency is undergone mutation, can follow the tracks of fast, and allow node according to the transmission rate of clock quality control sync message, guarantee that lower level node can select preferably synchronous path, thereby at utmost reduce the multi-hop accumulation of synchronous error.Provide respectively corresponding strategy for root node inefficacy and ordinary node inefficacy, made node obtain the ability of tackling node failure, ensured the reliability of synchronizing process.
2. synchronization accuracy
Fig. 4 is the synchronous error comparison of the present invention TSP-CF-LSN based on clock frequency variation model (the Time Synchronization Protocol Based on Clock Frequency Dynamic Detection for Large Scale Wireless Sensor Networks) synchronizer, the FTSP based on the constant model of clock frequency and the FTSP based on clock frequency variation model that propose.FTSP protocol synchronization error based on the constant model of clock is less, and the error within the scope of single-hop is 2.2054 μ s, and average synchronous error is 3.2483 μ s.FTSP agreement is in the time being applied to clock frequency variation model, and synchronous error is by increase sharply, and the error within the scope of single-hop has increased to 35.862 μ s, and mean error is increased to 45.062 μ s.
TSP-CF-LSN synchronizer, owing to adopting dynamic testing method, can effectively detect clock frequency and change.Adopt multihop path to select mechanism simultaneously, played inhibitory action for accumulated error.The single-hop synchronous error of application TSP-CF-LSN synchronizer is 2.6062 μ s, and average synchronous error is 5.9538 μ s, well below the same FTSP based on clock frequency variation model.So in the time synchronization process based on clock frequency variation model, carry out clock frequency detection very important.
3. multihop path is selected
Fig. 5 is that the multi-hop synchronous path that proposes of the present invention is selected mechanism and do not added multi-hop and synchronize that to select machine-processed synchronizer, interstitial content be 100.Network is grid type structure, and the synchronous duration is 3000s.In the time that synchronous jumping figure is less than 5 jumping, the synchronous error of two kinds of methods is very nearly the same, but since the 6th jumping, has added multihop path and selected the synchronization accuracy of machine-processed synchronizer to select machine-processed synchronizer apparently higher than not adding synchronous path, along with the increase of jumping figure, it is obvious that result is more tending towards.Multi-hop synchronous path selects mechanism to have good inhibition to accumulated error.
Brief description of the drawings
Fig. 1 is massive wireless sensor synchrotimer flow chart of the present invention;
Fig. 2 is that the root node of massive wireless sensor synchrotimer of the present invention lost efficacy and ordinary node inefficacy reply schematic diagram;
Fig. 3 is that massive wireless sensor synchrotimer synchronous path of the present invention is selected schematic diagram;
Fig. 4 is massive wireless sensor synchrotimer of the present invention and the other times synchronous error comparison diagram with footwork;
Fig. 5 is the inhibition figure of massive wireless sensor synchrotimer of the present invention to the accumulation of macroreticular time synchronization error multi-hop.
Embodiment
Below in conjunction with drawings and the specific embodiments, the present invention is further detailed explanation.
The present invention is a kind of massive wireless sensor synchrotimer based on clock frequency detection of dynamic.By real-time monitored clock frequency state, in the time that nodal frequency is undergone mutation phenomenon, follow the tracks of fast.By nodal clock information, select relatively preferably synchronous path simultaneously, suppress the multi-hop accumulation of synchronous error.And lost efficacy and ordinary node inefficacy for root node, corresponding resolution policy is provided respectively, within the scope of large scale network, obtain high synchronization accuracy and strong robustness.
In conjunction with Fig. 1, massive wireless sensor synchrotimer flow process of the present invention is passed through following steps successively:
(1) root node election
First, at network establishment stage, can distribute unique No. ID for each node, then open root node election mechanism by arbitrary node in network, the root node election message that broadcast transmission comprises self root node number.Node initial condition, the root node number of storage is empty, when receiving root node election message, take out the root node number wherein comprising, with comparing for No. ID of self, get smaller between the two as root node, then in root node election message, be written into new root node information, continue broadcast root node election message, guarantee that each node can receive root node election message.Final network is root node by No. ID minimum node election, as the time standard of network.
(2) network layer generates
Root node is made as 0 by the synchronous level of oneself, and broadcasts a level and find message, wherein comprises the level number of oneself.Then, when all hop neighbor nodes of reference node are received after this message, extract hierarchical information wherein, the level of oneself number is made as to this value and adds 1, after rewriting message again and be oneself level number, its broadcast is gone out, subsequent node continues to utilize this message to determine the synchronous level of oneself.This action is performed until the fringe node of network, so sets up the synchronous level of the whole network.
(3) synchronous operation
Network layer generate complete after, periodically send sync message by root node, in message, comprise synchronized timestamp, level number and round number, its middle-level number and round number are that lower level node judges the whether effective important mark of this message.If the sync message receiving meets the demands, lower level node carries out clock frequency detection of dynamic according to time stamp data, determine the clock frequency state of self, select suitable clock frequency method of estimation, obtain the clock frequency deviation estimated value of node oneself, make self to synchronize with upper layer node, then continue a downward node layer and send synchronization message.This action is continued until the fringe node of network, completes the time synchronized of the whole network node.
(4) multi-hop synchronous path is selected
The mechanism of the transmission of sync message based on inundation therefore all can forward sync message after node completes synchronously, guarantees that the node of lower floor can deadline synchronizing process.The node of lower floor adopts the sync message information that meets the demands and arrive the earliest.In order to suppress in large scale network, the problem that the synchronous accumulated error of multi-hop is serious is elected preferably path on path.Massive wireless sensor synchronizer is according to nodal clock state, controls the transmission rate of sync message, and the transmission sync message that the good node of synchronizing quality can be relatively early guarantees that lower level node can select preferably synchronous path.
In requisition for what illustrate be finally; above embodiment is only unrestricted in order to technical scheme of the present invention to be described; although the present invention is had been described in detail with reference to preferred embodiment; but protection scope of the present invention is not limited to this; any be familiar with those skilled in the art the present invention disclose technical scope in; the amendment that can expect easily or be equal to replacement, and do not depart from the spirit and scope of technical solution of the present invention, within all should being encompassed in protection scope of the present invention.
Claims (4)
1. the massive wireless sensor synchrotimer based on clock frequency detection of dynamic, is characterized in that: proposed a kind of clock frequency detection of dynamic mechanism, in the time that nodal clock frequency is undergone mutation, this mechanism is followed the tracks of nodal clock frequency state fast; Node is selected relatively preferably synchronous path adaptively according to clock information simultaneously, can suppress massive wireless sensor multi-hop error accumulation phenomenon.
2. the massive wireless sensor synchrotimer based on clock frequency detection of dynamic according to claim 1, it is characterized in that: for the situation that root node lost efficacy and ordinary node lost efficacy, adopt respectively root node to re-elect the strategy that upgrades node hierarchical information with timing, avoid synchronizing network all to paralyse because of indivedual node failures, strengthened the robustness of time synchronized.
3. the massive wireless sensor synchrotimer based on clock frequency detection of dynamic according to claim 1 and 2, it is characterized in that: every hop node is foundation according to the parametric variable recording in frequency dynamic testing mechanism, select relatively excellent synchronous path, effectively suppress synchronous error multi-hop Accumulation Phenomenon, obtain high synchronization accuracy.
4. according to the massive wireless sensor synchrotimer described in claim 1,2 or 3, it is characterized in that: specifically pass through following steps:
(1) root node election
First, at network establishment stage, for each node distributes unique No. ID, then open root node election mechanism by arbitrary node in network, the root node election message that broadcast transmission comprises self root node number; Node initial condition, the root node number of storage is empty, when receiving root node election message, take out the root node number wherein comprising, with comparing for No. ID of self, get smaller between the two as root node, then in root node election message, be written into new root node information, continue broadcast root node election message, guarantee that each node can receive root node election message; Final network is root node by No. ID minimum node election, as the time standard of network;
(2) network layer generates
Root node is made as 0 by the synchronous level of oneself, and broadcasts a level and find message, wherein comprises the level number of oneself; Then, when all hop neighbor nodes of reference node are received after this message, extract hierarchical information wherein, the level of oneself number is made as to this value and adds 1, after rewriting message again and be oneself level number, its broadcast is gone out, subsequent node continues to utilize this message to determine the synchronous level of oneself; This action is performed until the fringe node of network, so sets up the synchronous level of the whole network;
(3) synchronous operation
Network layer generate complete after, periodically send sync message by root node, in message, comprise synchronized timestamp, level number and round number, its middle-level number and round number are that lower level node judges the whether effective important mark of this message; If the sync message receiving meets the demands, lower level node carries out clock frequency detection of dynamic according to time stamp data, determine the clock frequency state of self, select suitable clock frequency method of estimation, obtain the clock frequency deviation estimated value of node oneself, make self to synchronize with upper layer node, then continue a downward node layer and send synchronization message; This action is continued until the fringe node of network, completes the time synchronized of the whole network node;
(4) multi-hop synchronous path is selected
The mechanism of the transmission of sync message based on inundation, therefore all can forward sync message whenever node completes after synchronous, guarantees that the node of lower floor can deadline synchronizing process; The node of lower floor adopts the sync message information that meets the demands and arrive the earliest; In order to be suppressed in large scale network, the problem that the synchronous accumulated error of multi-hop is serious is elected preferably path on path; Massive wireless sensor synchronizer is according to nodal clock state, controls the transmission rate of sync message, and the transmission sync message that the good node of synchronizing quality can be relatively early guarantees that lower level node can select preferably synchronous path.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410296752.7A CN104105195A (en) | 2014-06-27 | 2014-06-27 | Large-scale wireless sensor network time synchronizer based on clock frequency dynamic detection |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410296752.7A CN104105195A (en) | 2014-06-27 | 2014-06-27 | Large-scale wireless sensor network time synchronizer based on clock frequency dynamic detection |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN104105195A true CN104105195A (en) | 2014-10-15 |
Family
ID=51672899
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201410296752.7A Pending CN104105195A (en) | 2014-06-27 | 2014-06-27 | Large-scale wireless sensor network time synchronizer based on clock frequency dynamic detection |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN104105195A (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105025568A (en) * | 2015-06-16 | 2015-11-04 | 山东大学（威海） | Large-scaled wireless sensor network synchronizer based on frequency offset bidding and dynamic topology |
| CN105142211A (en) * | 2015-09-02 | 2015-12-09 | 上海大学 | Neighborhood averaging clock synchronization algorithm of wireless sensor network |
| CN108900273A (en) * | 2018-08-09 | 2018-11-27 | 山东省计算中心（国家超级计算济南中心） | A kind of consistent method for synchronizing time of wireless sensor network multi-hop |
| WO2019100963A1 (en) * | 2017-11-27 | 2019-05-31 | 华为技术有限公司 | Communication processing method and device |
| CN112654978A (en) * | 2018-09-25 | 2021-04-13 | 万迪斯科股份有限公司 | Method, equipment and system for checking data consistency in distributed heterogeneous storage system in real time |
| CN114584246A (en) * | 2022-03-01 | 2022-06-03 | 四川九洲电器集团有限责任公司 | Wireless ad hoc network time synchronization method, system and medium based on FPGA |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20100124240A1 (en) * | 2008-11-19 | 2010-05-20 | Institute For Information Industry | Method and system for network synchronization |
| US20100238890A1 (en) * | 2009-03-19 | 2010-09-23 | Bae Systems Information And Electronic Systems Integration, Inc. | Time synchronization for distributed mobile ad hoc networks |
| CN103298099A (en) * | 2012-03-04 | 2013-09-11 | 山东大学威海分校 | Time synchronizing method based on bimodal clock frequency estimation |
| CN103873224A (en) * | 2014-03-11 | 2014-06-18 | 中国电子科技集团公司第二十八研究所 | Construction method for high-precision time synchronization system based on IP (internet protocol) network |
-
2014
- 2014-06-27 CN CN201410296752.7A patent/CN104105195A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20100124240A1 (en) * | 2008-11-19 | 2010-05-20 | Institute For Information Industry | Method and system for network synchronization |
| US20100238890A1 (en) * | 2009-03-19 | 2010-09-23 | Bae Systems Information And Electronic Systems Integration, Inc. | Time synchronization for distributed mobile ad hoc networks |
| CN103298099A (en) * | 2012-03-04 | 2013-09-11 | 山东大学威海分校 | Time synchronizing method based on bimodal clock frequency estimation |
| CN103873224A (en) * | 2014-03-11 | 2014-06-18 | 中国电子科技集团公司第二十八研究所 | Construction method for high-precision time synchronization system based on IP (internet protocol) network |
Non-Patent Citations (2)
| Title |
|---|
| 姜颖等: "低开销的无线传感器网络时间同步算法研究", 《计算机科学》 * |
| 董恩清等: "基于动态路径列表的无线传感器网络时间同步协议", 《光学 精密工程》 * |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105025568A (en) * | 2015-06-16 | 2015-11-04 | 山东大学（威海） | Large-scaled wireless sensor network synchronizer based on frequency offset bidding and dynamic topology |
| CN105142211A (en) * | 2015-09-02 | 2015-12-09 | 上海大学 | Neighborhood averaging clock synchronization algorithm of wireless sensor network |
| WO2019100963A1 (en) * | 2017-11-27 | 2019-05-31 | 华为技术有限公司 | Communication processing method and device |
| US11191050B2 (en) | 2017-11-27 | 2021-11-30 | Huawei Technologies Co., Ltd. | Communication processing method and apparatus |
| CN108900273A (en) * | 2018-08-09 | 2018-11-27 | 山东省计算中心（国家超级计算济南中心） | A kind of consistent method for synchronizing time of wireless sensor network multi-hop |
| CN112654978A (en) * | 2018-09-25 | 2021-04-13 | 万迪斯科股份有限公司 | Method, equipment and system for checking data consistency in distributed heterogeneous storage system in real time |
| CN112654978B (en) * | 2018-09-25 | 2024-03-08 | 西拉塔股份有限公司 | Method, equipment and system for checking data consistency in real time in distributed heterogeneous storage system |
| CN114584246A (en) * | 2022-03-01 | 2022-06-03 | 四川九洲电器集团有限责任公司 | Wireless ad hoc network time synchronization method, system and medium based on FPGA |
| CN114584246B (en) * | 2022-03-01 | 2023-08-15 | 四川九洲电器集团有限责任公司 | FPGA-based wireless ad hoc network time synchronization method, system and medium |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN104105195A (en) | Large-scale wireless sensor network time synchronizer based on clock frequency dynamic detection | |
| Su et al. | Time-diffusion synchronization protocol for wireless sensor networks | |
| CN101909345B (en) | Multi-hop dynamic ad hoc network method of wide field sensor network | |
| CN101466142B (en) | Synchronization method for layered time comparative clock in wireless sensor network | |
| Xu et al. | Comparison study to hierarchical routing protocols in wireless sensor networks | |
| CN102123473A (en) | Dynamic clustering mechanism-based target tracking method for wireless sensor network | |
| CN110278048B (en) | Hierarchical Ad Hoc network time synchronization method based on clustering algorithm | |
| Singh et al. | Energy‐efficient QoS‐aware intelligent hybrid clustered routing protocol for wireless sensor networks | |
| CN103178917B (en) | A kind of clock synchronizing method of collaboration communication, system and information taken node | |
| Qiu et al. | SRTS: A self-recoverable time synchronization for sensor networks of healthcare IoT | |
| CN103546868B (en) | A kind of method for synchronizing time of wireless sensor network, network system and node | |
| CN103596235A (en) | Wireless sensor network route ant colony algorithm optimization method | |
| CN102196554A (en) | Method for realizing average clock synchronization of wireless sensor network through cluster averaging | |
| CN104104495A (en) | Wireless sensor network intelligent routing synchronizer based on dynamic route list | |
| CN106912100A (en) | Appliance network method for synchronizing time based on TPSN and TSync | |
| CN107071848A (en) | A kind of target tracking algorism based on cluster structured reduction energy consumption | |
| CN103763765B (en) | A kind of motor synchronizing method of wireless sensor network | |
| CN105025568A (en) | Large-scaled wireless sensor network synchronizer based on frequency offset bidding and dynamic topology | |
| Wang et al. | Random time source protocol in wireless sensor networks and synchronization in industrial environments | |
| CN111555835B (en) | Time synchronization method, system and medium for medical Internet of things | |
| CN102724741B (en) | Micro-cycle-based sleep method adapted to routing nodes in wireless sensor network | |
| Boukerche et al. | An energy aware coverage-preserving scheme for wireless sensor networks | |
| CN103298099A (en) | Time synchronizing method based on bimodal clock frequency estimation | |
| CN104185210A (en) | Dormancy scheduling based congestion control method of data source | |
| Zhang et al. | Time synchronization in wireless sensor networks under maximum value based time synchronization protocol with switching topology |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20141015 |
|
| WD01 | Invention patent application deemed withdrawn after publication |