CN102355319A - Time synchronization method and system for wireless sensor network - Google Patents
Time synchronization method and system for wireless sensor network Download PDFInfo
- Publication number
- CN102355319A CN102355319A CN2011102362643A CN201110236264A CN102355319A CN 102355319 A CN102355319 A CN 102355319A CN 2011102362643 A CN2011102362643 A CN 2011102362643A CN 201110236264 A CN201110236264 A CN 201110236264A CN 102355319 A CN102355319 A CN 102355319A
- Authority
- CN
- China
- Prior art keywords
- time
- synchronization packets
- child node
- clock
- synchronization
- 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.)
- Granted
Links
- 238000000034 method Methods 0.000 title claims abstract description 69
- 230000001360 synchronised effect Effects 0.000 claims abstract description 109
- 230000005540 biological transmission Effects 0.000 claims abstract description 59
- 230000008859 change Effects 0.000 claims description 21
- 238000012545 processing Methods 0.000 claims description 17
- 238000012417 linear regression Methods 0.000 claims description 16
- 238000001514 detection method Methods 0.000 claims description 6
- 238000012986 modification Methods 0.000 claims description 6
- 230000004048 modification Effects 0.000 claims description 6
- 238000004364 calculation method Methods 0.000 claims description 5
- 238000005265 energy consumption Methods 0.000 abstract description 12
- 230000008569 process Effects 0.000 description 23
- 239000002699 waste material Substances 0.000 description 6
- 238000006424 Flood reaction Methods 0.000 description 4
- 238000004891 communication Methods 0.000 description 3
- 230000007613 environmental effect Effects 0.000 description 3
- 206010012186 Delayed delivery Diseases 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 230000002452 interceptive effect Effects 0.000 description 2
- 238000002955 isolation Methods 0.000 description 2
- 238000012544 monitoring process Methods 0.000 description 2
- 230000001902 propagating effect Effects 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- 238000012546 transfer Methods 0.000 description 2
- 230000002950 deficient Effects 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 230000004927 fusion Effects 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
Images
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02D—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE
- Y02D30/00—Reducing energy consumption in communication networks
- Y02D30/70—Reducing energy consumption in communication networks in wireless communication networks
Landscapes
- Mobile Radio Communication Systems (AREA)
- Synchronisation In Digital Transmission Systems (AREA)
Abstract
The invention discloses a time synchronization method for a wireless sensor network. The method comprises the following steps of: generating a synchronous data packet, and marking a transmission timestamp in the synchronous data packet; transmitting the synchronous data packet to a child node; receiving the synchronous data packet, and marking a receiving timestamp in the synchronous data packet; and compensating for the clock drift of the child node according to the transmission timestamp and the receiving timestamp in the synchronous data packet. By the time synchronization method and the time synchronization system for the wireless sensor network, clock drift compensation between a parent node and the child node is realized only by transmitting the synchronous data packet to the child node to realize regional time synchronization in a region formed by the parent node and the child node, and compared with conventional all-network time synchronization, the regional time synchronization reduces network energy consumption and also can avoid the energy consumption caused by crosstalk interference as much as possible.
Description
[technical field]
The present invention relates to wireless sensor network technology, particularly relate to method for synchronizing time and system in a kind of wireless sensor network.
[background technology]
Time synchronized is the primary demand in the wireless sensor network; Employed big multi-protocols all need be carried out time synchronized with using in the wireless sensor network, and for example data fusion, range finding location, compressed sensing, low-power consumption MAC agreement, Routing Protocol, cooperation transmission and processing etc. all need realize the synchronous of time.Usually only pay attention to the raising of synchronization accuracy in traditional method for synchronizing time, and existing complicated environmental condition in the network environment is not furtherd investigate the influence that time synchronization process brings.Usually adopt the time synchronization protocol that floods (Flooding Time Synchronization Protocol is called for short FTSP) to realize the time synchronized in the wireless sensor network in traditional time synchronization process.
The time synchronization protocol that floods is a kind of method of the whole network time synchronized, and the node that in the agreement that floods, periodically elects a numbering minimum is as root node, and promptly other node in the network all carries out time synchronized with root node.The packet of each node broadcasts oneself election contest root node when the wireless sensor network time of implementation is synchronous, the minimum node of numbering is won and is become root node.After electing root node, root node is the broadcast synchronization packet in wireless sensor network, and other nodes receive synchrodata and comprise the synchronous of back realization and root node.The node in the root node communication range then is not merely able to through the mode and the root node of multi-hop synchronous.Each node when root node lost efficacy in the wireless sensor network begins to campaign for root node again.
The employed time synchronization protocol equal time method for synchronous that floods of wireless sensor network often need be set up one based on the tree-like of the whole network or level shape structure when carrying out time synchronized; And special in synchronously special root node or reference node being set in network, this will bring extra energy consumption.
Hence one can see that; In wireless sensor network, possesses very desirable experimental precision in the process of experiment to the method for synchronizing time that time synchronized proposed; But exist the defective of each node lot of consumption energy during the wireless sensor network in being applied to reality, especially the energy consumption of each node just becomes very big when combining with other application.
[summary of the invention]
Based on this, be necessary to provide a kind of method for synchronizing time that can reduce in the wireless sensor network that network energy consumes.
In addition, also be necessary to provide a kind of clock synchronization system that can reduce in the wireless sensor network that network energy consumes.
Method for synchronizing time in a kind of wireless sensor network comprises the steps:
Generate synchronization packets, and the mark transmitting time is stabbed in said synchronization packets;
Transmit said synchronization packets to child node;
Receive said synchronization packets, and the mark time of reception stabs in said synchronization packets;
Stab the drift of said child node compensating clock according to transmitting time stamp and time of reception in the said synchronization packets.
Preferably, said in said synchronization packets the step of the said timestamp of mark be:
Whether the detected transmission channel is in idle condition, if then obtain transmitting time from MAC layer;
Generating transmitting time according to the transmitting time that gets access to stabs;
The transmitting time stamp of said generation is marked in the said synchronization packets.
Preferably, said step from said synchronization packets to child node that transmit is:
Send the packet header in the said synchronization packets;
Treat that the transmission of said packet header finishes afterwards from the MAC layer acquisition time;
Transmitting time according to mark described in the synchronization packets of the said packet header of the said time modification that gets access to correspondence is stabbed;
Transmit the synchronization packets that the said transmitting time of having revised mark is stabbed.
Preferably, also comprise after the step of the said synchronization packets of said reception:
Whether judge synchronous sequence number in the said synchronization packets greater than the synchronous sequence number of storing in the said child node, if then get into the said step that the said time of reception of mark stabs in said synchronization packets.
Preferably, said step of stabbing the drift of said child node compensating clock according to transmitting time stamp and time of reception in the said synchronization packets is:
Obtain the byte alignment time through the byte length of synchronization packets and the merchant of emission rate;
According to time of reception in the said synchronization packets stab, transmitting time is stabbed and the byte alignment time obtains clock offset;
Said clock offset and child node time of living in are carried out least square line to fit and obtains linear regression straight line;
According to said linear regression straight line said child node is carried out the clock drift compensation.
Preferably, said according to also comprising after the step that time of reception in the said synchronization packets stabs, the transmitting time stamp obtains clock offset with the byte alignment time:
Said clock offset is stored in the historical data of said child node;
Said method also comprises:
When not receiving synchronization packets, from the historical data of child node, obtain the clock offset of storage, and according to the clock offset of said storage to the drift of said child node compensating clock.
Preferably, said step of stabbing the drift of said child node compensating clock according to transmitting time stamp and time of reception in the said synchronization packets also comprises before:
From the synchronization packets that receives, obtain the transmitting time of mark and stab and the time of reception stamp, and obtain the clock variable quantity through the difference that said time of reception stabs and transmitting time is stabbed;
Calculate the difference between said clock variable quantity and the change mean;
Whether judge said difference less than threshold value, if not, then remove the said synchronization packets that receives, if then get into and saidly stab and the step of time of reception stamp the drift of said child node compensating clock according to transmitting time in the said synchronization packets.
Preferably, also comprise:
Judge that the synchronization packets quantity that receives whether greater than the amount threshold of setting, if not, then gets into the step of the said synchronization packets of said reception, if, then
Whether the time of intercept of judging said child node reaches listening periods, if then said child node gets into sleep state;
Whether reach sleep cycle the length of one's sleep of judging said child node, if then wake said child node up, and get into the step of the said synchronization packets of said reception.
Preferably, also comprise:
According to length of one's sleep of said child node judging whether to reach lock in time, if, get into said through generating synchronization packets, and the step that the said transmitting time of mark is stabbed in said synchronization packets.
Preferably, also comprise after the step of the said synchronization packets of said reception:
Whether the father node of judging the said synchronization packets of transmission changes, if, then remove the clock offset of storing in the said child node, if not, then get into the step that receives said synchronization packets.
Clock synchronization system in a kind of wireless sensor network comprises:
The packet generation module is used to generate synchronization packets;
The mark processing module is used for stabbing in said synchronization packets mark transmitting time;
Transport module is used for transmitting said synchronization packets to child node;
Receiver module is used to receive said synchronization packets, and the mark time of reception stabs in said synchronization packets;
Compensating module is used for stabbing the drift of said child node compensating clock according to said synchronization packets transmitting time stamp and time of reception.
Preferably, said mark processing module comprises:
The Channel Detection unit is used for the detected transmission channel and whether is in idle condition, if then obtain transmitting time from MAC layer;
The timestamp indexing unit is used for generating transmitting time according to the transmitting time that gets access to and stabs, and the transmitting time stamp of said generation is marked in the said synchronization packets.
Preferably, said transport module comprises:
Transmitting element is used for sending packet header of said synchrodata;
Time acquisition unit is used to treat that the transmission of said packet header finishes afterwards from the MAC layer acquisition time;
Revise the unit, be used for transmitting time stamp according to mark described in the said time modification that the gets access to synchronization packets corresponding with said packet header;
Said transmitting element also is used to transmit the synchronization packets that the said transmitting time of having revised mark is stabbed.
Preferably, also comprise:
Synchronous sequence number judge module, whether the synchronous sequence number that is used for judging said synchronization packets is greater than the synchronous sequence number of storing in the said child node, if then notify said receiver module.
Preferably, said compensating module comprises:
Calibration computing is used for obtaining the byte alignment time through the byte length of synchronization packets and the merchant of emission rate;
The side-play amount computing unit is used for obtaining clock offset according to said synchronization packets time of reception stamp, transmitting time and byte alignment time;
Fit the unit, be used for that said clock offset and child node time of living in are carried out least square line and fit and obtain linear regression straight line;
The drift compensating unit is used for according to said linear regression straight line said child node being carried out the clock drift compensation.
Preferably, said side-play amount computing unit also is used for said clock offset is stored in the historical data of said child node;
Said drift compensating unit also is used for when not receiving synchrodata obtaining from the historical data of child node the clock offset of storage, and according to the clock offset of said storage to the drift of said child node compensating clock.
Preferably, also comprise:
Clock change calculations module is used for stabbing with time of reception from the transmitting time that the synchronization packets that receives is obtained mark and stabs, and stabs and the difference of transmitting time stamp obtains the clock variable quantity through said time of reception;
Difference calculating module is used to calculate the difference between said clock variable quantity and the change mean;
Whether the difference processing module is used to judge said difference less than threshold value, if not, then removes the said synchronization packets that receives, if then notify said compensating module.
Preferably, also comprise:
The received quantity judge module is used to judge that the synchronization packets quantity that receives whether greater than the amount threshold of setting, if not, then notifies said receiver module, if then notify the time of intercept judge module;
Said time of intercept judge module is used to judge whether the time of intercept of said child node reaches listening periods, if then said child node gets into sleep state;
The length of one's sleep, judge module was used to judge whether reach sleep cycle the length of one's sleep of said child node, if then wake said child node up, and notify said receiver module.
Preferably, also comprise:
The synchronous judgment module is used for judging whether to reach lock in time according to the length of one's sleep of said child node, if then notify said packet generation module.
Preferably, said receiver module is used to also judge whether the father node of the said synchronization packets of transmission changes, if, then remove the time offset of said child node storage, if not, then receive said synchronization packets.
Method for synchronizing time in the above-mentioned wireless sensor network and system; Only to child node transmitting synchronous packet; Realized the clock drift compensation between father node and the child node; In father node and the formed zone of child node, realize zonal time synchronized; Compare with traditional the whole network time synchronized and to have reduced the consumption of network energy, also can avoid as far as possible because the energy consumption that cross-talk is brought.
Method for synchronizing time in the above-mentioned wireless sensor network and system; After detecting transmission channel to be in idle condition, from MAC layer, obtain transmitting time and synchronization packets is sent; From application layer, do not obtain transmitting time; Help reducing source of error and directly from MAC layer, obtain transmitting time; And then the error in the reduction time synchronization process, the accuracy of raising time synchronized.
Method for synchronizing time in the above-mentioned wireless sensor network and system; Sending after the packet header in the synchronization packets acquisition time from MAC layer once more; And stab the various factors of making amendment to reduce in the network synchronous accuracy is impacted being marked on transmitting time that synchrodata wraps, improve the accuracy of time synchronized.
Method for synchronizing time in the above-mentioned wireless sensor network and system; After having received the synchronization packets of setting quantity if child node is intercepted shared time when reaching listening periods to transmission channel; Child node gets into sleep state; When reached sleep cycle the length of one's sleep, wake up and be in dormant child node; Having reduced idle time of intercept can be up to the energy expense that reduces communication significantly, and particularly most nodes are in the life span that sleep state can prolong whole network effectively in the not high occasion of environmental monitoring sample frequency.
[description of drawings]
Fig. 1 is the flow chart of the method for synchronizing time in the wireless sensor network among the embodiment;
Fig. 2 is the method flow diagram that the mark transmitting time is stabbed in synchronization packets among Fig. 1;
Fig. 3 is to the method flow diagram of child node transmitting synchronous packet among Fig. 1;
Fig. 4 obtains byte alignment time method flow chart among Fig. 1 through the byte length of synchronization packets and the merchant of emission rate;
Fig. 5 is the flow chart of the method for synchronizing time in the wireless sensor network among another embodiment;
Fig. 6 is the flow chart of the method for synchronizing time in the wireless sensor network among another embodiment;
Fig. 7 is the structural representation of the clock synchronization system in the wireless sensor network among the embodiment;
Fig. 8 is the structural representation of mark processing module among Fig. 7;
Fig. 9 is the structural representation of transport module among Fig. 7;
Figure 10 is the structural representation of the clock synchronization system in the wireless sensor network among another embodiment;
Figure 11 is the structural representation of compensating module among the embodiment;
Figure 12 is the structural representation of the clock synchronization system in the wireless sensor network among another embodiment;
Figure 13 is the structural representation of the clock synchronization system in the wireless sensor network among another embodiment.
[embodiment]
Fig. 1 shows the method for synchronizing time in the wireless sensor network among the embodiment, comprises the steps:
Step S110 generates synchronization packets, and the mark transmitting time is stabbed in synchronization packets.
In the present embodiment, be the minimizing energy consumption, and realize time synchronized rapidly that adopt sender-recipient's one-way synchronization mode, father node generates synchronization packets, and initiatively transmit the synchronization packets of generation to the child node of correspondence.
The residing time of mark current parent node in synchronization packets is so that the child node synchronization packets of announcement residing time of father node when sending.Also comprised corresponding synchronous sequence number in the synchronization packets, the node that has received a plurality of synchronization packets can pick out the synchronization packets of which synchronization packets for receiving recently through synchronous sequence number.
In a concrete embodiment, as shown in Figure 2, the above-mentioned step that the mark transmitting time is stabbed in synchronization packets is specially:
Step S201, whether the detected transmission channel is in idle condition, if, then get into step S203, if not, then be left intact.
In the present embodiment,, after having generated synchronization packets,, be in idle condition until this transmission channel at the first-class channel to be transmitted of MAC layer in order to reduce the error that transmission channel gets congestion and caused.
Step S203 obtains transmitting time from MAC layer.
In the present embodiment, compare, directly from MAC layer, obtain the residing time of father node when unimpeded and will improve the accuracy in the time synchronization process greatly detecting transmission channel as transmitting time with obtain the traditional scheme of father node time from application layer.
Step S205 generates transmitting time according to the transmitting time that gets access to and stabs.
Step S207 is marked on the transmitting time stamp that generates in the synchronization packets.
In the present embodiment; If normally from application layer, obtain the father node time as transmitting time according to traditional scheme; After getting access to the transmitting time that comes from application layer; Transmitting time successively need be transferred to MAC layer by application layer via transport layer, Internet etc.; And be marked in the synchronization packets; At this moment; If transmission channel is not in idle condition and the synchronization packets that has comprised transmitting time can not be transferred out; When treating that this synchronization packets is sent to child node by the transmission channel that is in idle condition; The resulting transmitting time of child node has been inaccurate transmitting time; Comprised the time that from application layer, successively is transferred to MAC layer and is spent in this transmitting time; This has caused transmitting time when obtaining, to exist error; And the time when not representing synchronization packets to send through this transmitting time after the delayed delivery of synchronization packets; There is great inaccuracy; Take place for fear of above-mentioned situation, directly acquisition time from MAC layer.
Step S130 is to child node transmitting synchronous packet.
In the present embodiment, father node generates synchronization packets, and in synchronization packets mark transmitting time stab the back and carry out the transmission of synchronization packets to the pairing child node of this father node.The whole network in the network topology was the tree node results, either a parent node, there is often a corresponding sub-node, and for most sites parent and child nodes are mutually transform the identity, that is, for a parent node purposes of the node to exist as child nodes, and with the parent node and the parent node of the other child node to form the isochronous packet transmission region; addition, the node is a parent node has child nodes corresponding , so the node will generate a synchronization packet and isochronous data packet is transmitted at most child node, also forms a parent node and child node of the propagating region, the propagation area is transmitted by a node outside the region interference, which can effectively reduce crosstalk interference isolation from other nodes through the propagation area in the propagation area of the child nodes for synchronous data packet transmission, to avoid this waste of energy caused by the transmission, especially in the node density causing a large waste of energy.
In a concrete embodiment, as shown in Figure 3, above-mentioned detailed process to child node transmitting synchronous packet is:
Step S131 sends the packet header in the synchronization packets.
In the present embodiment; Transmission delay has comprised the carrying out of emission lead code and initial symbol and the time of emission synchrodata in transmission course; The time of emission synchrodata is confirmed, depends on the distance between sender and the recipient, this difficult estimation; But because the aerial propagation velocity of synchronization packets is very fast; Propagation velocity can reach 3*108m/s, therefore can ignore, at this moment; For avoiding the generation of error, the packet header that at first will comprise lead code and initial symbol sends.
Step S133 treats that the packet header transmission finishes afterwards from the MAC layer acquisition time.
In the present embodiment,, the packet header transmission from MAC layer, obtains the present located time once more after finishing.
Step S135 stabs according to the transmitting time of mark in the corresponding synchronization packets in the time modification packet header that gets access to.
In the present embodiment, according to stabbing and make amendment being marked on transmitting time the synchronization packets from time that MAC layer gets access to once more, this mode can reduce that various possible factors impact synchronization accuracy in the network environment.
Step S137, the synchronization packets of the transmitting time stamp of mark has been revised in transmission.
In the present embodiment, in unimpeded transmission channel, transmitting time is stabbed the synchronization packets of having revised and transfer in the child node.
Step S150, the receiving isochronous data bag, and the mark time of reception stabs in synchronization packets.
In the present embodiment, child node after receiving the synchronization packets of sending by father node, the residing time of child node when mark receives synchronization packets in the synchronization packets that receives.
In another embodiment; Also comprise after the step of above-mentioned receiving isochronous data bag: judge that whether synchronous sequence number in the synchronization packets is greater than the synchronous sequence number of storing in the child node; If; Then get into the step that the mark time of reception stabs in synchronization packets; If not, then abandon the synchronization packets that receives.
In the present embodiment, when father node generates synchronization packets, a series of synchronization packets are carried out serial number, make each synchronization packets all comprise synchronous sequence number, this synchronous sequence number is unique for each synchronization packets.The synchronous sequence number of the synchronization packets that at first generates and sends is less, after synchronous sequence number in the synchronization packets sent bigger.
Synchronous sequence number in determining synchronization packets illustrates that greater than the synchronous sequence number of the synchronization packets that has received in the child node this synchronization packets that receives is effectively, need carry out the mark that time of reception stabs to it; Synchronous sequence number in determining synchronization packets illustrates that not greater than the synchronous sequence number of storing in the child node transmission of synchronization packets takes place can not carry out time synchronized to child node through this synchrodata unusually.
In another embodiment; In the network topology of wireless sensor network; The possibility of variations such as node is moved is very large, and moving the pairing father node of generation back child node will change, and also comprise after the step of above-mentioned reception with the step packet:
Whether the father node of judging the transmitting synchronous packet changes, if, then remove the clock offset of storing in the child node, if not, then return step S150.
In the present embodiment, in the process whether father node that carries out the transmitting synchronous packet has taken place to change, need not judge root node.Taken place to illustrate that the pairing father node of child node and the original father node that have received synchronization packets are not same nodes when changing when determining the transmitting synchronous packet; Need to remove the clock offset of storing in the child node, carry out the synchronous of time through the father node after changing again.
Step S170 stabs the drift of child node compensating clock according to transmitting time stamp and time of reception in the synchronization packets.
In the present embodiment, stab with the time of reception stamp by the transmitting time of institute's mark in the synchronization packets and can obtain time deviation, and then carry out the time synchronized in the child node according to this deviation.
In a concrete embodiment, as shown in Figure 4, above-mentioned detailed process of stabbing the drift of child node compensating clock according to transmitting time stamp and time of reception in the synchronization packets is:
Step S171 obtains the byte alignment time through the byte length of synchronization packets and the merchant of emission rate.
In the present embodiment; The accessed time has comprised the actual reception time and the byte alignment time of synchronization packets when receiving synchronization packets; Therefore need carry out the compensation of byte alignment time; The byte alignment time is confirmed; The emission rate that is chip is known; Be 19.2kbps, just can obtain the byte alignment time divided by the emission rate of chip with the byte length of synchronization packets.
Step S173, according to time of reception in the synchronization packets stab, transmitting time is stabbed and the byte alignment time obtains clock offset.
In the present embodiment; The difference of clock offset is actual reception when sending with synchronization packets between time time of living in; For calculating clock offset; Obtained the actual reception time by transmitting time stamp and the difference of byte alignment time; And then the difference of being stabbed with the actual reception time by time of reception obtained clock offset, and concrete procedures can be shown in following formula:
offset＝t
1-t
2-t
0
Wherein, offset is a clock offset, t
1For time of reception stabs, t
2Be byte alignment time, t
0For transmitting time is stabbed.
In another embodiment, above-mentioned according to time of reception in the synchronization packets stab, transmitting time is stabbed and the byte alignment time obtains also comprising after the step of clock offset clock offset is stored in the step in the historical data of child node.
In the present embodiment, in the process of carrying out time synchronized, the clock offset that calculates is stored in the historical data of child node, to make things convenient in follow-up time synchronization process user historical data.
Method for synchronizing time in the above-mentioned wireless sensor network also comprises the clock offset that when not receiving synchronization packets, from the historical data of child node, obtains storage, and according to the storage clock offset to the drift of child node compensating clock.
In the present embodiment; Because network environment is comparatively complicated; Situation that can't the receiving isochronous data bag happens occasionally; When receiving the synchronization packets that father node sends, will from stored history, not obtain the clock offset of storage, and realize the time synchronized of child node through the clock offset in the historical data.
In another embodiment, as shown in Figure 5, also comprise before according to the step that transmitting time in the synchronization packets is stabbed and time of reception stabs the drift of child node compensating clock:
Step S510 obtains the transmitting time of mark and stabs and the time of reception stamp, and obtains the clock variable quantity through the difference that time of reception stabs and transmitting time is stabbed from the synchronization packets that receives.
In the present embodiment; In the process of time synchronized; If clock offset is bigger; Then the description time synchronizing process possibility of makeing mistakes is very big; Can not carry out the time synchronized of child node through this clock offset; Therefore before child node is compensated clock drift, should stab according to transmitting time and carry out computing with the time of reception stamp and obtain rigidly connecting the pairing clock variable quantity of the synchronization packets of receiving, that is:
newoffset＝t
2-t
1
Wherein, newoffset rigidly connects the pairing clock variable quantity of the synchronization packets of receiving, t
2For time of reception stabs, t
1For transmitting time is stabbed.
Step S530, the difference between computing time variable quantity and the change mean.
In the present embodiment, change mean is calculated by the clock offset that is stored in the historical data.
Whether step S550 judges difference less than threshold value, if not, then gets into step S570, if then get into step S170.
In the present embodiment, difference is big more, and then the deviation between description time variable quantity and the change mean is big more, and time synchronization process exists wrong possibility also just big more, and difference is more little, and then the deviation between description time variable quantity and the change mean is more little.
When determining difference, utilize time of reception stamp and transmitting time stamp in this synchronization packets to carry out the compensation of clock drift less than threshold value; When determining difference not less than preset threshold, illustrate that the time of reception stamp of mark in this synchronization packets and transmitting time stamp are disabled, should remove the synchronization packets that this receives.
Step S570 removes the synchronization packets that receives.
Step S175 carries out least square line to clock offset and child node time of living in and fits and obtain linear regression straight line.
In the present embodiment, the method that fits through least square line calculates the slope and the deviation of a linear regression straight line, utilizes this linear regression straight line that the child node time of living in is carried out the clock drift compensation then.
Step S177 carries out the clock drift compensation according to linear regression straight line to child node.
In another embodiment, as shown in Figure 6, the method for synchronizing time in the above-mentioned wireless sensor network is further comprising the steps of:
Step S610 judges that the synchronization packets quantity that receives whether greater than the amount threshold of setting, if not, then gets into step S150, if then get into step S630.
In the present embodiment; In the process of child node receiving isochronous data bag; Be node energy consumption; In the synchronization packets quantity that receives during greater than the amount threshold set; Illustrate that the synchronization packets quantity that child node receives enough carried out time synchronized; Check then child node intercepts whether arrived the listening periods of setting to what transmission channel carried out; When the synchronization packets quantity that determines reception does not have greater than amount threshold; Child node should be proceeded the reception of synchronization packets, until the amount threshold that reaches setting.Amount threshold can be set according to the internal memory that sensor node had; The practical application that moves in the big or sensor node when the internal memory in the sensor node to the demand of internal memory hour; Amount threshold can be set at a bigger numerical value; Otherwise; Then set a less numerical value; In a preferred embodiment; Amount threshold is 5～8; This makes and neither can receive too much synchronization packets in the sensor node and take too much internal memory, can not make that also the precision of time synchronized is not high in the sensor node because the synchronization packets that receives is very few.
Step S630 judges whether the time of intercept of child node reaches listening periods, if, then get into step S650, if not, then get into step S640.
In the present embodiment, during greater than amount threshold, judge whether the time of intercept of child node has reached listening periods in the synchronization packets quantity that receives, if reached listening periods, then child node will get into sleep state.In a preferred embodiment, timer can be set in sensor node, timing is carried out in the activity in the sensor node, so that realize the control of sensor node.
Step S640 continues to intercept transmission channel.
Step S650, child node gets into sleep state.
Whether step S670 reaches sleep cycle the length of one's sleep of judging child node, if, then get into step S690, if not, then get into step S680.
In the present embodiment, the energy that node consumed when child node is in sleep state is very little, has greatly reduced network energy consumption, still, because child node also should be removed the reception that sleep state is proceeded synchronization packets.In a preferred embodiment, child node also can be provided with a timer, is used for carrying out timing its length of one's sleep, after reaching the time that timer sets, wakes child node immediately up length of one's sleep and gets into the state of intercepting.
Step S680 keeps sleep state.
Step S690 wakes child node up, and returns step S150.
In another embodiment, be in and also comprised following steps in the dormant child node:
According to length of one's sleep of child node judging whether to reach lock in time, if, then get into step S110, if not, then be left intact.
In the present embodiment; For most of nodes, both had unique father node; There is the child node of a plurality of nodes again as this node; Be that this node promptly is the child node of a certain father node; Be again the father node of other a plurality of nodes, therefore, this node both need receive the synchronization packets by the father node transmission; Synchronization packets according to father node is carried out time synchronized, need generate synchronization packets again to its child node transmission.
Owing to formed relatively independent propagation regions between each father node and the child node; Carry out time synchronized between the propagation regions without interfering with each other; A certain node receives the synchronization packets from father node in a propagation regions; After reaching the lock in time of setting, in another propagation regions, generate synchrodata again and send synchronization packets to its child node; Property performance period ground lock in time, reduce the waste of energy.
Fig. 7 shows the clock synchronization system in the wireless sensor network among the embodiment, comprises packet generation module 110, mark processing module 130, transport module 150, receiver module 170 and compensating module 190.
In the present embodiment, be the minimizing energy consumption, and realize time synchronized rapidly that adopt sender-recipient's one-way synchronization mode, the packet generation module 110 of father node generates synchronization packets.
In the present embodiment, mark processing module 130 is the residing time of mark current parent node in synchronization packets, so that the child node synchronization packets of announcement residing time of father node when sending.Also comprised corresponding synchronous sequence number in the synchronization packets, the node that has received a plurality of synchronization packets can pick out the synchronization packets of which synchronization packets for receiving recently through synchronous sequence number.
At one particularly among the embodiment, as shown in Figure 8, mark processing module 130 comprises Channel Detection unit 131 and timestamp indexing unit 133.
In the present embodiment, in order to reduce the error that transmission channel gets congestion and caused, Channel Detection unit 131 at the medium channel to be transmitted of MAC layer, is in idle condition until this transmission channel after having generated synchronization packets.
Directly from MAC layer, obtain the residing time of father node as transmitting time in Channel Detection unit 131 when unimpeded detecting transmission channel, compare with the traditional scheme that obtains the father node time from application layer and improved the accuracy the time synchronization process greatly.
In the present embodiment; If normally from application layer, obtain the father node time as transmitting time according to traditional scheme; After getting access to the transmitting time that comes from application layer; Transmitting time successively need be transferred to MAC layer by application layer via transport layer, Internet etc.; And be marked in the synchronization packets; At this moment; If transmission channel is not in idle condition and the synchronization packets that has comprised transmitting time can not be transferred out; When treating that this synchronization packets is sent to child node by the transmission channel that is in idle condition; The resulting transmitting time of child node has been inaccurate transmitting time; Comprised the time that from application layer, successively is transferred to MAC layer and is spent in this transmitting time; This has caused transmitting time when obtaining, to exist error; And the time when not representing synchronization packets to send through this transmitting time after the delayed delivery of synchronization packets; There is great inaccuracy; Take place for fear of above-mentioned situation, timestamp indexing unit 133 is acquisition time from MAC layer directly.
In the present embodiment; The packet generation module 110 of father node generates synchronization packets, and by mark processing module 130 in synchronization packets mark transmitting time stab back transport module 150 and initiatively carry out the transmission of synchronization packets to the pairing child node of this father node.The whole network in the network topology was the tree node results, either a parent node, there is often a corresponding sub-node, and for most sites parent and child nodes are mutually transform the identity, that is, for a parent node purposes of the node to exist as child nodes, and with the parent node and the parent node of the other child node to form the isochronous packet transmission region; addition, the node is a parent node has child nodes corresponding , so the node will generate a synchronization packet and isochronous data packet is transmitted at most child node, also forms a parent node and child node of the propagating region, the propagation area is transmitted by a node outside the region interference, which can effectively reduce crosstalk interference isolation from other nodes through the propagation area in the propagation area of the child nodes for synchronous data packet transmission, to avoid this waste of energy caused by the transmission, especially in the node density causing a large waste of energy.
In a concrete embodiment, as shown in Figure 9, transport module 150 comprises transmitting element 151, time acquisition unit 153 and revises unit 155.
Transmitting element 151 is used for sending packet header of synchrodata.
In the present embodiment; Transmission delay has comprised the carrying out of emission lead code and initial symbol and the time of emission synchrodata in transmission course; The time of emission synchrodata is confirmed; Depend on the distance between sender and the recipient; This difficult estimation; But because the aerial propagation velocity of synchronization packets is very fast; Propagation velocity can reach 3*108m/s; Therefore can ignore; At this moment; For avoiding the generation of error, the packet header that transmitting element 151 at first will comprise lead code and initial symbol sends.
In the present embodiment, time acquisition unit 153 is obtained from MAC layer the present located time once more after the packet header transmission finishes.
Revise unit 155, be used for stabbing according to the transmitting time of the time modification that the gets access to synchronization packets mark corresponding with packet header.
In the present embodiment, revise unit 155 according to stabbing and make amendment being marked on transmitting time the synchronization packets from time that MAC layer gets access to once more, this mode can reduce that various possible factors impact synchronization accuracy in the network environment.
Transmitting element 151 also is used to transmit the synchronization packets of the transmitting time stamp of having revised mark.
In the present embodiment, the synchronization packets that transmitting element 151 has been revised the transmitting time stamp in unimpeded transmission channel transfers in the child node.
In another embodiment; As shown in figure 10; Clock synchronization system in the above-mentioned wireless sensor network has also comprised synchronous sequence number judge module 210; Whether the synchronous sequence number that this synchronous sequence number judge module 210 is used for judging synchronization packets is greater than the synchronous sequence number of storing in the child node; If; Then notify receiver module 170, if not, then abandon the synchronization packets that receives.
In the present embodiment, when father node generates synchronization packets, a series of synchronization packets are carried out serial number, make each synchronization packets all comprise synchronous sequence number, this synchronous sequence number is unique for each synchronization packets.The synchronous sequence number of the synchronization packets that at first generates and sends is less, after synchronous sequence number in the synchronization packets sent bigger.
When synchronous sequence number judge module 210 determines the synchronous sequence number of the synchronization packets that synchronous sequence number in the synchronization packets received in greater than child node, illustrate that this synchronization packets that receives is effectively, need carry out the mark that time of reception stabs to it; When synchronous sequence number judge module 210 determines the synchronous sequence number that synchronous sequence number in the synchronization packets is stored in not greater than child node, the transmission that synchronization packets is described takes place unusual, can not carry out time synchronized to child node through this synchrodata.
In the present embodiment, the receiver module 170 of child node after receiving the synchronization packets of sending by father node, the residing time of child node when mark receives synchronization packets in the synchronization packets that receives.
In another embodiment; In the network topology of wireless sensor network; The possibility of variations such as node is moved is very large; Moving the pairing father node of generation back child node will change; Receiver module 170 is used to also judge whether the father node of transmitting synchronous packet changes, if then remove the time offset of child node storage; If not, receiving isochronous data bag then.
In the present embodiment, in the process whether father node that carries out the transmitting synchronous packet has taken place to change, need not judge root node.When determining the transmitting synchronous packet, receiver module 170 taken place to illustrate that the pairing father node of child node and the original father node that have received synchronization packets are not same nodes when changing; Need to remove the clock offset of storing in the child node, carry out the synchronous of time through the father node after changing again.
Compensating module 190 is used for stabbing the drift of child node compensating clock according to synchronization packets transmitting time stamp and time of reception.
In the present embodiment, compensating module 190 is stabbed by the transmitting time of institute's mark in the synchronization packets and the time of reception stamp can obtain time deviation, and then carries out the time synchronized in the child node according to this deviation.
In a concrete embodiment, as shown in figure 11, above-mentioned compensating module 190 comprises calibration computing 191, side-play amount computing unit 193, fits unit 195 and drift compensating unit 197.
In the present embodiment; The accessed time has comprised the actual reception time and the byte alignment time of synchronization packets when receiving synchronization packets; Therefore need carry out the compensation of byte alignment time; The byte alignment time is confirmed; The emission rate that is chip is known; Be 19.2kbps, the byte length of calibration computing 191 usefulness synchronization packets just can obtain the byte alignment time divided by the emission rate of chip.
Side-play amount computing unit 193 is used for obtaining clock offset according to synchronization packets time of reception stamp, transmitting time stamp and byte alignment time.
In the present embodiment; The difference of clock offset is actual reception when sending with synchronization packets between time time of living in; For calculating clock offset; Side-play amount computing unit 193 is stabbed by transmitting time and the difference of byte alignment time has obtained the actual reception time; And then the difference of being stabbed with the actual reception time by time of reception obtained clock offset, and concrete procedures can be shown in following formula:
offset＝t
1-t
2-t
0
Wherein, offset is a clock offset, t
1For time of reception stabs, t
2Be byte alignment time, t
0For transmitting time is stabbed.
In the present embodiment, fit slope and deviation that method that unit 195 fits through least square line calculates a linear regression straight line, utilize this linear regression straight line that the child node time of living in is carried out the clock drift compensation then.
Drift compensating unit 197 is used for according to linear regression straight line child node being carried out the clock drift compensation.
In another concrete embodiment, side-play amount computing unit 193 also is used for clock offset is stored in the historical data of child node.
In the present embodiment, side-play amount computing unit 193 is stored in the clock offset that calculates in the historical data of child node in the process of carrying out time synchronized, to make things convenient in follow-up time synchronization process user historical data.
Drift compensating unit 197 also is used for when not receiving synchrodata obtaining from the historical data of child node the clock offset of storage, and according to the clock offset of storage to the drift of child node compensating clock.
In the present embodiment; Because network environment is comparatively complicated; Situation that can't the receiving isochronous data bag happens occasionally; The clock offset that drift compensating unit 197 obtains storage from stored history when not receiving the synchronization packets that father node sends, and realize the time synchronized of child node through the clock offset in the historical data.
In another embodiment, as shown in figure 12, the clock synchronization system in the above-mentioned wireless sensor network also comprises clock change calculations module 310, difference calculating module 330 and difference processing module 350.
Clock change calculations module 310 is used for stabbing with time of reception from the transmitting time that the synchronization packets that receives is obtained mark and stabs, and stabs and the difference of transmitting time stamp obtains the clock variable quantity through time of reception.
In the present embodiment; In the process of time synchronized; If clock offset is bigger; Then the description time synchronizing process possibility of makeing mistakes is very big; Can not carry out the time synchronized of child node through this clock offset; Therefore before child node is compensated clock drift, clock change calculations module 310 should be stabbed according to transmitting time and carried out computing with the time of reception stamp and obtain rigidly connecting the pairing clock variable quantity of the synchronization packets of receiving, that is:
newoffset＝t
2-t
1
Wherein, newoffset rigidly connects the pairing clock variable quantity of the synchronization packets of receiving, t
2For time of reception stabs, t
1For transmitting time is stabbed.
In the present embodiment, change mean is calculated by the clock offset that is stored in the historical data.
Whether difference processing module 350 is used to judge difference less than threshold value, if not, then removes the synchronization packets that receives, if then notify compensating module 190.
In the present embodiment, difference is big more, and then the deviation between description time variable quantity and the change mean is big more, and time synchronization process exists wrong possibility also just big more, and difference is more little, and then the deviation between description time variable quantity and the change mean is more little.
When difference processing module 350 determines difference less than threshold value, utilize time of reception stamp and transmitting time stamp in this synchronization packets to carry out the compensation of clock drift; When difference processing module 350 determines difference not less than preset threshold, illustrate that the time of reception stamp of mark in this synchronization packets and transmitting time stamp are disabled, should remove the synchronization packets that this receives.
In another embodiment, as shown in figure 13, the clock synchronization system in the above-mentioned wireless sensor network also comprise received quantity judge module 410, time of intercept judge module 430 and the length of one's sleep judge module 450.
Received quantity judge module 410 is used to judge that the synchronization packets that receives whether greater than the amount threshold of setting, if not, then notifies receiver module 170, if then notify time of intercept judge module 430.
In the present embodiment; In the process of child node receiving isochronous data bag; Be node energy consumption; In the synchronization packets quantity that receives during greater than the amount threshold set; Illustrate that the synchronization packets quantity that child node receives enough carried out time synchronized; Check then child node intercepts whether arrived the listening periods of setting to what transmission channel carried out; The synchronization packets quantity that determines reception when received quantity judge module 410 is not during greater than amount threshold; Child node should be proceeded the reception of synchronization packets, until the amount threshold that reaches setting.Amount threshold can be set according to the internal memory that sensor node had; The practical application that moves in the big or sensor node when the internal memory in the sensor node to the demand of internal memory hour; Amount threshold can be set at a bigger numerical value; Otherwise; Then set a less numerical value; In a preferred embodiment; Amount threshold is 5～8; This makes and neither can receive too much synchronization packets in the sensor node and take too much internal memory, can not make that also the precision of time synchronized is not high in the sensor node because the synchronization packets that receives is very few.
Time of intercept judge module 430 is used to judge whether the time of intercept of child node reaches listening periods, if then child node gets into sleep state, if not, then is left intact, and proceeds to intercept.
In the present embodiment, during greater than amount threshold, time of intercept judge module 430 judges whether the time of intercept of child node has reached listening periods, if reached listening periods, then child node will get into sleep state in the synchronization packets quantity that receives.In a preferred embodiment, time of intercept judge module 430 can be a timer, and timing is carried out in the activity in the sensor node, so that realize the control of sensor node.
The length of one's sleep, judge module 450, whether reached sleep cycle the length of one's sleep that is used to judge child node, if, then wake child node up, and notice receiver module 170, if not, then keep sleep state.
In the present embodiment, the energy that node consumed when child node is in sleep state is very little, has greatly reduced network energy consumption, still, because child node also should be removed the reception that sleep state is proceeded synchronization packets.In a preferred embodiment, the length of one's sleep, judge module 450 also can be a timer, was used for carrying out timing its length of one's sleep, after reaching the time that timer sets, woke child node immediately up length of one's sleep and got into the state of intercepting.
In another embodiment; Clock synchronization system in the above-mentioned wireless sensor network has also comprised the synchronous judgment module; This synchronous judgment module is used for length of one's sleep according to child node judging whether to reach lock in time; If; Notification data bag generation module 110 then; If not, then be left intact.
In the present embodiment; For most of nodes, both had unique father node; There is the child node of a plurality of nodes again as this node; Be that this node promptly is the child node of a certain father node; Be again the father node of other a plurality of nodes, therefore, this node both need receive the synchronization packets by the father node transmission; Synchronization packets according to father node is carried out time synchronized, need generate synchronization packets again to its child node transmission.
Owing to formed relatively independent propagation regions between each father node and the child node; Carry out time synchronized between the propagation regions without interfering with each other; A certain node receives the synchronization packets from father node in a propagation regions; After reaching the lock in time of setting, in another propagation regions, generate synchrodata again and send synchronization packets to its child node; Property performance period ground lock in time, reduce the waste of energy.
Method for synchronizing time in the above-mentioned wireless sensor network and system; Only to child node transmitting synchronous packet; Realized the clock drift compensation between father node and the child node; In father node and the formed zone of child node, realize zonal time synchronized; Compare with traditional the whole network time synchronized and to have reduced the consumption of network energy, also can avoid as far as possible because the energy consumption that cross-talk is brought.
Method for synchronizing time in the above-mentioned wireless sensor network and system; After detecting transmission channel to be in idle condition, from MAC layer, obtain transmitting time and synchronization packets is sent; From application layer, do not obtain transmitting time; Help reducing source of error and directly from MAC layer, obtain transmitting time; And then the error in the reduction time synchronization process, the accuracy of raising time synchronized.
Method for synchronizing time in the above-mentioned wireless sensor network and system; Sending after the packet header in the synchronization packets acquisition time from MAC layer once more; And stab the various factors of making amendment to reduce in the network synchronous accuracy is impacted being marked on transmitting time that synchrodata wraps, improve the accuracy of time synchronized.
Method for synchronizing time in the above-mentioned wireless sensor network and system; After having received the synchronization packets of setting quantity if child node is intercepted shared time when reaching listening periods to transmission channel; Child node gets into sleep state; When reached sleep cycle the length of one's sleep, wake up and be in dormant child node; Having reduced idle time of intercept can be up to the energy expense that reduces communication significantly, and particularly most nodes are in the life span that sleep state can prolong whole network effectively in the not high occasion of environmental monitoring sample frequency.
The above embodiment has only expressed several execution mode of the present invention, and it describes comparatively concrete and detailed, but can not therefore be interpreted as the restriction to claim of the present invention.Should be pointed out that for the person of ordinary skill of the art under the prerequisite that does not break away from the present invention's design, can also make some distortion and improvement, these all belong to protection scope of the present invention.Therefore, the protection range of patent of the present invention should be as the criterion with accompanying claims.
Claims (20)
1. the method for synchronizing time in the wireless sensor network comprises the steps:
Generate synchronization packets, and the mark transmitting time is stabbed in said synchronization packets;
Transmit said synchronization packets to child node;
Receive said synchronization packets, and the mark time of reception stabs in said synchronization packets;
Stab the drift of said child node compensating clock according to transmitting time stamp and time of reception in the said synchronization packets.
2. the method for synchronizing time in the wireless sensor network according to claim 1 is characterized in that, said in said synchronization packets the step of the said timestamp of mark be:
Whether the detected transmission channel is in idle condition, if then obtain transmitting time from MAC layer;
Generating transmitting time according to the transmitting time that gets access to stabs;
The transmitting time stamp of said generation is marked in the said synchronization packets.
3. the method for synchronizing time in the wireless sensor network according to claim 1 is characterized in that, said step from said synchronization packets to child node that transmit is:
Send the packet header in the said synchronization packets;
Treat that the transmission of said packet header finishes afterwards from the MAC layer acquisition time;
Transmitting time according to mark described in the synchronization packets of the said packet header of the said time modification that gets access to correspondence is stabbed;
Transmit the synchronization packets that the said transmitting time of having revised mark is stabbed.
4. the method for synchronizing time in the wireless sensor network according to claim 1 is characterized in that, also comprises after the step of the said synchronization packets of said reception:
Whether judge synchronous sequence number in the said synchronization packets greater than the synchronous sequence number of storing in the said child node, if then get into the said step that the said time of reception of mark stabs in said synchronization packets.
5. the method for synchronizing time in the wireless sensor network according to claim 1 is characterized in that, said step of stabbing the drift of said child node compensating clock according to transmitting time stamp and time of reception in the said synchronization packets is:
Obtain the byte alignment time through the byte length of synchronization packets and the merchant of emission rate;
According to time of reception in the said synchronization packets stab, transmitting time is stabbed and the byte alignment time obtains clock offset;
Said clock offset and child node time of living in are carried out least square line to fit and obtains linear regression straight line;
According to said linear regression straight line said child node is carried out the clock drift compensation.
6. the method for synchronizing time in the wireless sensor network according to claim 5 is characterized in that, and is said according to also comprising after the step that time of reception in the said synchronization packets stabs, the transmitting time stamp obtains clock offset with the byte alignment time:
Said clock offset is stored in the historical data of said child node;
Said method also comprises:
When not receiving synchronization packets, from the historical data of child node, obtain the clock offset of storage, and according to the clock offset of said storage to the drift of said child node compensating clock.
7. the method for synchronizing time in the wireless sensor network according to claim 1 is characterized in that, said step of stabbing the drift of said child node compensating clock according to transmitting time stamp and time of reception in the said synchronization packets also comprises before:
From the synchronization packets that receives, obtain the transmitting time of mark and stab and the time of reception stamp, and obtain the clock variable quantity through the difference that said time of reception stabs and transmitting time is stabbed;
Calculate the difference between said clock variable quantity and the change mean;
Whether judge said difference less than threshold value, if not, then remove the said synchronization packets that receives, if then get into and saidly stab and the step of time of reception stamp the drift of said child node compensating clock according to transmitting time in the said synchronization packets.
8. the method for synchronizing time in the wireless sensor network according to claim 1 is characterized in that, also comprises:
Judge that the synchronization packets quantity that receives whether greater than the amount threshold of setting, if not, then gets into the step of the said synchronization packets of said reception, if, then
Whether the time of intercept of judging said child node reaches listening periods, if then said child node gets into sleep state;
Whether reach sleep cycle the length of one's sleep of judging said child node, if then wake said child node up, and get into the step of the said synchronization packets of said reception.
9. the method for synchronizing time in the wireless sensor network according to claim 8 is characterized in that, also comprises:
According to length of one's sleep of said child node judging whether to reach lock in time, if, get into said through generating synchronization packets, and the step that the said transmitting time of mark is stabbed in said synchronization packets.
10. the method for synchronizing time in the wireless sensor network according to claim 1 is characterized in that, also comprises after the step of the said synchronization packets of said reception:
Whether the father node of judging the said synchronization packets of transmission changes, if, then remove the clock offset of storing in the said child node, if not, then get into the step that receives said synchronization packets.
11. the clock synchronization system in the wireless sensor network is characterized in that, comprising:
The packet generation module is used to generate synchronization packets;
The mark processing module is used for stabbing in said synchronization packets mark transmitting time;
Transport module is used for transmitting said synchronization packets to child node;
Receiver module is used to receive said synchronization packets, and the mark time of reception stabs in said synchronization packets;
Compensating module is used for stabbing the drift of said child node compensating clock according to said synchronization packets transmitting time stamp and time of reception.
12. the clock synchronization system in the wireless sensor network according to claim 11 is characterized in that, said mark processing module comprises:
The Channel Detection unit is used for the detected transmission channel and whether is in idle condition, if then obtain transmitting time from MAC layer;
The timestamp indexing unit is used for generating transmitting time according to the transmitting time that gets access to and stabs, and the transmitting time stamp of said generation is marked in the said synchronization packets.
13. the clock synchronization system in the wireless sensor network according to claim 11 is characterized in that, said transport module comprises:
Transmitting element is used for sending packet header of said synchrodata;
Time acquisition unit is used to treat that the transmission of said packet header finishes afterwards from the MAC layer acquisition time;
Revise the unit, be used for transmitting time stamp according to mark described in the said time modification that the gets access to synchronization packets corresponding with said packet header;
Said transmitting element also is used to transmit the synchronization packets that the said transmitting time of having revised mark is stabbed.
14. the clock synchronization system in the wireless sensor network according to claim 11 is characterized in that, also comprises:
Synchronous sequence number judge module, whether the synchronous sequence number that is used for judging said synchronization packets is greater than the synchronous sequence number of storing in the said child node, if then notify said receiver module.
15. the clock synchronization system in the wireless sensor network according to claim 11 is characterized in that, said compensating module comprises:
Calibration computing is used for obtaining the byte alignment time through the byte length of synchronization packets and the merchant of emission rate;
The side-play amount computing unit is used for obtaining clock offset according to said synchronization packets time of reception stamp, transmitting time and byte alignment time;
Fit the unit, be used for that said clock offset and child node time of living in are carried out least square line and fit and obtain linear regression straight line;
The drift compensating unit is used for according to said linear regression straight line said child node being carried out the clock drift compensation.
16. the clock synchronization system in the wireless sensor network according to claim 15 is characterized in that, said side-play amount computing unit also is used for said clock offset is stored in the historical data of said child node;
Said drift compensating unit also is used for when not receiving synchrodata obtaining from the historical data of child node the clock offset of storage, and according to the clock offset of said storage to the drift of said child node compensating clock.
17. the clock synchronization system in the wireless sensor network according to claim 11 is characterized in that, also comprises:
Clock change calculations module is used for stabbing with time of reception from the transmitting time that the synchronization packets that receives is obtained mark and stabs, and stabs and the difference of transmitting time stamp obtains the clock variable quantity through said time of reception;
Difference calculating module is used to calculate the difference between said clock variable quantity and the change mean;
Whether the difference processing module is used to judge said difference less than threshold value, if not, then removes the said synchronization packets that receives, if then notify said compensating module.
18. the method for synchronizing time in the wireless sensor network according to claim 11 is characterized in that, also comprises:
The received quantity judge module is used to judge that the synchronization packets quantity that receives whether greater than the amount threshold of setting, if not, then notifies said receiver module, if then notify the time of intercept judge module;
Said time of intercept judge module is used to judge whether the time of intercept of said child node reaches listening periods, if then said child node gets into sleep state;
The length of one's sleep, judge module was used to judge whether reach sleep cycle the length of one's sleep of said child node, if then wake said child node up, and notify said receiver module.
19. the clock synchronization system in the wireless sensor network according to claim 18 is characterized in that, also comprises:
The synchronous judgment module is used for judging whether to reach lock in time according to the length of one's sleep of said child node, if then notify said packet generation module.
20. the clock synchronization system in the wireless sensor network according to claim 11; It is characterized in that; Said receiver module is used to also judge whether the father node of the said synchronization packets of transmission changes; If; Then remove the time offset of said child node storage; If not, then receive said synchronization packets.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201110236264.3A CN102355319B (en) | 2011-08-17 | 2011-08-17 | Time synchronization method and system for wireless sensor network |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201110236264.3A CN102355319B (en) | 2011-08-17 | 2011-08-17 | Time synchronization method and system for wireless sensor network |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN102355319A true CN102355319A (en) | 2012-02-15 |
| CN102355319B CN102355319B (en) | 2015-07-08 |
Family
ID=45578820
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201110236264.3A Active CN102355319B (en) | 2011-08-17 | 2011-08-17 | Time synchronization method and system for wireless sensor network |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN102355319B (en) |
Cited By (37)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102740430A (en) * | 2012-07-17 | 2012-10-17 | 宇龙计算机通信科技(深圳)有限公司 | Signaling time-synchronous communication device and method without data indicating list |
| CN103281772A (en) * | 2013-04-23 | 2013-09-04 | 中国科学院计算技术研究所 | Time synchronization method and system of wireless sensor network |
| 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 |
| CN103458498A (en) * | 2013-09-16 | 2013-12-18 | 山东省计算中心 | Intelligent wireless sensor network time synchronization method |
| CN103516504A (en) * | 2012-09-27 | 2014-01-15 | 深圳市友讯达科技发展有限公司 | Network node clock synchronization method, nodes and system |
| CN103813382A (en) * | 2012-11-14 | 2014-05-21 | 华为技术有限公司 | Clock synchronization method, device and system |
| CN103957589A (en) * | 2014-04-01 | 2014-07-30 | 安徽工程大学 | Multi-hop and low-cost distributed clock synchronization method |
| CN104053223A (en) * | 2013-03-13 | 2014-09-17 | 中国科学院大学 | Low-power wireless sensor network time synchronization method |
| CN104396305A (en) * | 2012-06-14 | 2015-03-04 | 诺基亚通信公司 | Fast recovering for network listening schemes in synchronization over air for small cells |
| WO2015078113A1 (en) * | 2013-11-26 | 2015-06-04 | 深圳市倍轻松科技股份有限公司 | Physiological signal real-time detection method and system |
| WO2015078112A1 (en) * | 2013-11-26 | 2015-06-04 | 深圳市倍轻松科技股份有限公司 | Physiological signal detection processing method and system |
| CN104981742A (en) * | 2013-06-12 | 2015-10-14 | 富士电机株式会社 | Distribution device, distribution system, and distribution method |
| CN105406933A (en) * | 2015-10-26 | 2016-03-16 | 飞亚达（集团）股份有限公司 | Time synchronization method and synchronization system |
| CN106169234A (en) * | 2016-08-29 | 2016-11-30 | 常州维格电子有限公司 | A kind of intelligent gas meter monitoring system and the means of communication thereof |
| CN106707873A (en) * | 2017-01-16 | 2017-05-24 | 上海兆芯集成电路有限公司 | Sensor hub, data synchronizing method and device between application processors |
| CN106788854A (en) * | 2017-02-08 | 2017-05-31 | 上海航天控制技术研究所 | A kind of spacecraft time base correction method of high reliability |
| CN106850116A (en) * | 2017-03-10 | 2017-06-13 | 国网上海市电力公司 | A kind of method for synchronizing time based on linear weighted function least square method |
| CN107548092A (en) * | 2017-08-04 | 2018-01-05 | 深圳市盛路物联通讯技术有限公司 | A kind of data processing method and system of distributed network delay |
| CN107995681A (en) * | 2017-11-16 | 2018-05-04 | 全球能源互联网研究院有限公司 | A kind of wireless sense network method for synchronizing time and device |
| CN108400828A (en) * | 2017-02-08 | 2018-08-14 | 宏达国际电子股份有限公司 | Communication system and synchronous method |
| CN108924922A (en) * | 2018-08-01 | 2018-11-30 | 合肥工业大学 | A kind of chain synchronous method synchronization time of WSN cluster type topology |
| CN109257133A (en) * | 2018-09-14 | 2019-01-22 | 武汉虹信通信技术有限责任公司 | A kind of the whole network clock synchronizing method and device applied to LTE rail transit network |
| CN109769223A (en) * | 2019-02-28 | 2019-05-17 | 上海电气集团股份有限公司 | A kind of acquisition method and data collection system of noise signal wireless synchronization |
| CN109981204A (en) * | 2019-02-21 | 2019-07-05 | 福建星云电子股份有限公司 | A kind of Multi-Machine Synchronous method of BMS analogue system |
| CN109995422A (en) * | 2018-01-02 | 2019-07-09 | 北京松果电子有限公司 | Uplink synchronisation method, device, storage medium and electronic equipment |
| CN110337679A (en) * | 2017-02-17 | 2019-10-15 | 日本电信电话株式会社 | Sensing system and timestamp bearing calibration |
| CN110366101A (en) * | 2019-07-26 | 2019-10-22 | 杭州微萤科技有限公司 | A kind of method that UWB centralization calculating realization positions on a large scale |
| CN110446156A (en) * | 2019-07-26 | 2019-11-12 | 杭州微萤科技有限公司 | A kind of method that the realization of UWB distributed computing positions on a large scale |
| DE102019200733A1 (en) | 2019-01-22 | 2020-07-23 | Carl Zeiss Industrielle Messtechnik Gmbh | Method and device for determining at least one spatial position and orientation of at least one tracked measuring device |
| CN111555833A (en) * | 2020-04-24 | 2020-08-18 | 光荣出行(深圳)科技有限公司 | Data transmission processing method based on wireless module |
| CN111954165A (en) * | 2020-08-12 | 2020-11-17 | 深圳蓝奥声科技有限公司 | Wireless synchronous data transmission method and device |
| US11026202B2 (en) | 2018-03-08 | 2021-06-01 | Connected Intelligence Systems Ltd. | Method and system for synchronizing a mesh network |
| CN113180698A (en) * | 2021-04-30 | 2021-07-30 | 西安臻泰智能科技有限公司 | Wireless automatic deviation compensation method for electroencephalogram device and electroencephalogram device |
| CN113260040A (en) * | 2021-05-31 | 2021-08-13 | 深圳市爱图仕影像器材有限公司 | Time code synchronization method and network system |
| CN113613326A (en) * | 2021-08-30 | 2021-11-05 | 麦芯(太仓)科技有限公司 | Ad hoc network node synchronization method, device and storage medium |
| CN113922912A (en) * | 2021-12-09 | 2022-01-11 | 深圳市爱图仕影像器材有限公司 | Clock synchronization method and device and electronic equipment |
| CN114035740A (en) * | 2021-11-13 | 2022-02-11 | 北京津发科技股份有限公司 | Clock crystal oscillator synchronization method, device and system |
Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1972182A (en) * | 2006-12-04 | 2007-05-30 | 中国科学院计算技术研究所 | A method for improving wireless sensor network time synchronization precision |
| CN101035129A (en) * | 2007-01-11 | 2007-09-12 | 上海交通大学 | Traffic-adapted radio sensor network channel access control method |
| CN101237640A (en) * | 2007-01-30 | 2008-08-06 | 世意法（北京）半导体研发有限责任公司 | Dormancy mode control for real time service in broadband wireless access communication system |
| CN101466142A (en) * | 2009-01-08 | 2009-06-24 | 上海交通大学 | Synchronization method for layered time comparative clock in wireless sensor network |
| CN101489290A (en) * | 2008-01-15 | 2009-07-22 | 瑞昱半导体股份有限公司 | Receiving apparatus, signal processing system and signal receiving method |
| CN101523829A (en) * | 2006-10-12 | 2009-09-02 | 皇家飞利浦电子股份有限公司 | Method and system for time synchronization in a sensor network |
| CN101646233A (en) * | 2009-09-17 | 2010-02-10 | 浙江大学 | Wireless sensor data highly efficient collecting method based on clustering |
| CN101697502A (en) * | 2009-09-22 | 2010-04-21 | 哈尔滨工业大学 | Method for precisely synchronizing wireless sensor network under coal mine |
| CN101778405A (en) * | 2010-01-05 | 2010-07-14 | 武汉理工大学 | Method and system for synchronous acquisition of wireless sensor network for structural health monitoring |
| CN102118849A (en) * | 2011-03-02 | 2011-07-06 | 重庆邮电大学 | Time synchronization method applicable to wireless sensor network |
-
2011
- 2011-08-17 CN CN201110236264.3A patent/CN102355319B/en active Active
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101523829A (en) * | 2006-10-12 | 2009-09-02 | 皇家飞利浦电子股份有限公司 | Method and system for time synchronization in a sensor network |
| CN1972182A (en) * | 2006-12-04 | 2007-05-30 | 中国科学院计算技术研究所 | A method for improving wireless sensor network time synchronization precision |
| CN101035129A (en) * | 2007-01-11 | 2007-09-12 | 上海交通大学 | Traffic-adapted radio sensor network channel access control method |
| CN101237640A (en) * | 2007-01-30 | 2008-08-06 | 世意法（北京）半导体研发有限责任公司 | Dormancy mode control for real time service in broadband wireless access communication system |
| CN101489290A (en) * | 2008-01-15 | 2009-07-22 | 瑞昱半导体股份有限公司 | Receiving apparatus, signal processing system and signal receiving method |
| CN101466142A (en) * | 2009-01-08 | 2009-06-24 | 上海交通大学 | Synchronization method for layered time comparative clock in wireless sensor network |
| CN101646233A (en) * | 2009-09-17 | 2010-02-10 | 浙江大学 | Wireless sensor data highly efficient collecting method based on clustering |
| CN101697502A (en) * | 2009-09-22 | 2010-04-21 | 哈尔滨工业大学 | Method for precisely synchronizing wireless sensor network under coal mine |
| CN101778405A (en) * | 2010-01-05 | 2010-07-14 | 武汉理工大学 | Method and system for synchronous acquisition of wireless sensor network for structural health monitoring |
| CN102118849A (en) * | 2011-03-02 | 2011-07-06 | 重庆邮电大学 | Time synchronization method applicable to wireless sensor network |
Non-Patent Citations (2)
| Title |
|---|
| 景博等: "《智能网络传感器与无线传感器网络》", 1 January 2011 * |
| 林志雄: "一种低开销的传感器网络时间同步算法", 《山东轻工业学院学报》 * |
Cited By (58)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| 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 |
| CN104396305A (en) * | 2012-06-14 | 2015-03-04 | 诺基亚通信公司 | Fast recovering for network listening schemes in synchronization over air for small cells |
| CN102740430A (en) * | 2012-07-17 | 2012-10-17 | 宇龙计算机通信科技(深圳)有限公司 | Signaling time-synchronous communication device and method without data indicating list |
| CN102740430B (en) * | 2012-07-17 | 2015-12-16 | 宇龙计算机通信科技(深圳)有限公司 | Countless according to instruction list signaling time synchronized communication means and method |
| CN103516504A (en) * | 2012-09-27 | 2014-01-15 | 深圳市友讯达科技发展有限公司 | Network node clock synchronization method, nodes and system |
| CN103813382B (en) * | 2012-11-14 | 2018-03-27 | 华为技术有限公司 | Clock synchronizing method, equipment and system |
| CN103813382A (en) * | 2012-11-14 | 2014-05-21 | 华为技术有限公司 | Clock synchronization method, device and system |
| CN104053223A (en) * | 2013-03-13 | 2014-09-17 | 中国科学院大学 | Low-power wireless sensor network time synchronization method |
| CN103281772B (en) * | 2013-04-23 | 2016-05-25 | 中国科学院计算技术研究所 | A kind of method for synchronizing time of wireless sensor network and system |
| CN103281772A (en) * | 2013-04-23 | 2013-09-04 | 中国科学院计算技术研究所 | Time synchronization method and system of wireless sensor network |
| CN104981742B (en) * | 2013-06-12 | 2017-09-19 | 富士电机株式会社 | Dispensing device, dissemination system and distribution method |
| CN104981742A (en) * | 2013-06-12 | 2015-10-14 | 富士电机株式会社 | Distribution device, distribution system, and distribution method |
| CN103458498B (en) * | 2013-09-16 | 2014-06-18 | 山东省计算中心 | Intelligent wireless sensor network time synchronization method |
| CN103458498A (en) * | 2013-09-16 | 2013-12-18 | 山东省计算中心 | Intelligent wireless sensor network time synchronization method |
| WO2015078112A1 (en) * | 2013-11-26 | 2015-06-04 | 深圳市倍轻松科技股份有限公司 | Physiological signal detection processing method and system |
| WO2015078113A1 (en) * | 2013-11-26 | 2015-06-04 | 深圳市倍轻松科技股份有限公司 | Physiological signal real-time detection method and system |
| CN103957589B (en) * | 2014-04-01 | 2017-03-29 | 安徽工程大学 | A kind of distributed clock synchronous method of multi-hop low overhead |
| CN103957589A (en) * | 2014-04-01 | 2014-07-30 | 安徽工程大学 | Multi-hop and low-cost distributed clock synchronization method |
| CN105406933A (en) * | 2015-10-26 | 2016-03-16 | 飞亚达（集团）股份有限公司 | Time synchronization method and synchronization system |
| CN106169234A (en) * | 2016-08-29 | 2016-11-30 | 常州维格电子有限公司 | A kind of intelligent gas meter monitoring system and the means of communication thereof |
| CN106707873A (en) * | 2017-01-16 | 2017-05-24 | 上海兆芯集成电路有限公司 | Sensor hub, data synchronizing method and device between application processors |
| CN106707873B (en) * | 2017-01-16 | 2019-02-26 | 上海兆芯集成电路有限公司 | Sense the method for data synchronization and its device between hub and application processor |
| CN106788854A (en) * | 2017-02-08 | 2017-05-31 | 上海航天控制技术研究所 | A kind of spacecraft time base correction method of high reliability |
| CN108400828A (en) * | 2017-02-08 | 2018-08-14 | 宏达国际电子股份有限公司 | Communication system and synchronous method |
| CN108400828B (en) * | 2017-02-08 | 2020-07-31 | 宏达国际电子股份有限公司 | Communication system and synchronization method |
| US10602471B2 (en) | 2017-02-08 | 2020-03-24 | Htc Corporation | Communication system and synchronization method |
| US10952175B2 (en) | 2017-02-08 | 2021-03-16 | Htc Corporation | Communication system and synchronization method |
| CN111756468A (en) * | 2017-02-08 | 2020-10-09 | 宏达国际电子股份有限公司 | Communication system and synchronization method |
| CN110337679B (en) * | 2017-02-17 | 2021-12-31 | 日本电信电话株式会社 | Sensing system and timestamp correction method |
| CN110337679A (en) * | 2017-02-17 | 2019-10-15 | 日本电信电话株式会社 | Sensing system and timestamp bearing calibration |
| CN106850116B (en) * | 2017-03-10 | 2018-04-13 | 国网上海市电力公司 | A kind of method for synchronizing time based on linear weighted function least square method |
| CN106850116A (en) * | 2017-03-10 | 2017-06-13 | 国网上海市电力公司 | A kind of method for synchronizing time based on linear weighted function least square method |
| CN107548092B (en) * | 2017-08-04 | 2021-01-26 | 深圳市盛路物联通讯技术有限公司 | Distributed network delay data processing method and system |
| CN107548092A (en) * | 2017-08-04 | 2018-01-05 | 深圳市盛路物联通讯技术有限公司 | A kind of data processing method and system of distributed network delay |
| CN107995681A (en) * | 2017-11-16 | 2018-05-04 | 全球能源互联网研究院有限公司 | A kind of wireless sense network method for synchronizing time and device |
| CN109995422A (en) * | 2018-01-02 | 2019-07-09 | 北京松果电子有限公司 | Uplink synchronisation method, device, storage medium and electronic equipment |
| US11026202B2 (en) | 2018-03-08 | 2021-06-01 | Connected Intelligence Systems Ltd. | Method and system for synchronizing a mesh network |
| CN108924922A (en) * | 2018-08-01 | 2018-11-30 | 合肥工业大学 | A kind of chain synchronous method synchronization time of WSN cluster type topology |
| CN108924922B (en) * | 2018-08-01 | 2021-03-05 | 合肥工业大学 | Chain synchronization time synchronization method of WSN (Wireless sensor network) cluster topology |
| CN109257133A (en) * | 2018-09-14 | 2019-01-22 | 武汉虹信通信技术有限责任公司 | A kind of the whole network clock synchronizing method and device applied to LTE rail transit network |
| CN109257133B (en) * | 2018-09-14 | 2021-02-19 | 武汉虹信科技发展有限责任公司 | Whole-network clock synchronization method and device applied to LTE (Long term evolution) rail transit network |
| US11841433B2 (en) | 2019-01-22 | 2023-12-12 | Carl Zeiss Industrielle Messtechnik Gmbh | Method and apparatus for determining at least one spatial position and orientation of at least one tracked measuring device |
| DE102019200733A1 (en) | 2019-01-22 | 2020-07-23 | Carl Zeiss Industrielle Messtechnik Gmbh | Method and device for determining at least one spatial position and orientation of at least one tracked measuring device |
| CN109981204A (en) * | 2019-02-21 | 2019-07-05 | 福建星云电子股份有限公司 | A kind of Multi-Machine Synchronous method of BMS analogue system |
| CN109769223B (en) * | 2019-02-28 | 2022-06-10 | 上海电气集团股份有限公司 | Noise signal wireless synchronization acquisition method and data acquisition system |
| CN109769223A (en) * | 2019-02-28 | 2019-05-17 | 上海电气集团股份有限公司 | A kind of acquisition method and data collection system of noise signal wireless synchronization |
| CN110446156A (en) * | 2019-07-26 | 2019-11-12 | 杭州微萤科技有限公司 | A kind of method that the realization of UWB distributed computing positions on a large scale |
| CN110366101A (en) * | 2019-07-26 | 2019-10-22 | 杭州微萤科技有限公司 | A kind of method that UWB centralization calculating realization positions on a large scale |
| CN111555833A (en) * | 2020-04-24 | 2020-08-18 | 光荣出行(深圳)科技有限公司 | Data transmission processing method based on wireless module |
| CN111954165A (en) * | 2020-08-12 | 2020-11-17 | 深圳蓝奥声科技有限公司 | Wireless synchronous data transmission method and device |
| CN111954165B (en) * | 2020-08-12 | 2022-07-15 | 深圳蓝奥声科技有限公司 | Wireless synchronous data transmission method and device |
| CN113180698A (en) * | 2021-04-30 | 2021-07-30 | 西安臻泰智能科技有限公司 | Wireless automatic deviation compensation method for electroencephalogram device and electroencephalogram device |
| CN113180698B (en) * | 2021-04-30 | 2024-03-01 | 西安臻泰智能科技有限公司 | Wireless automatic deviation compensation method of electroencephalogram device and electroencephalogram device |
| CN113260040A (en) * | 2021-05-31 | 2021-08-13 | 深圳市爱图仕影像器材有限公司 | Time code synchronization method and network system |
| US11722976B2 (en) | 2021-05-31 | 2023-08-08 | Aputure Imaging Industries Co., Ltd. | Time code synchronization method |
| CN113613326A (en) * | 2021-08-30 | 2021-11-05 | 麦芯(太仓)科技有限公司 | Ad hoc network node synchronization method, device and storage medium |
| CN114035740A (en) * | 2021-11-13 | 2022-02-11 | 北京津发科技股份有限公司 | Clock crystal oscillator synchronization method, device and system |
| CN113922912A (en) * | 2021-12-09 | 2022-01-11 | 深圳市爱图仕影像器材有限公司 | Clock synchronization method and device and electronic equipment |
Also Published As
| Publication number | Publication date |
|---|---|
| CN102355319B (en) | 2015-07-08 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102355319B (en) | Time synchronization method and system for wireless sensor network | |
| KR101508369B1 (en) | Method for transmitting information packets within an asynchronous wireless communication network and network node implementing it | |
| US9226252B2 (en) | Recursive time synchronization protocol method for wireless sensor networks | |
| Carrano et al. | Survey and taxonomy of duty cycling mechanisms in wireless sensor networks | |
| CN102740427B (en) | Method for awakening wireless sensor, wireless sensor and wireless sensor system | |
| CN101335587B (en) | Accurate time synchronization method for industrial wireless network | |
| CN101562489B (en) | Method for time synchronization in wireless sensor network | |
| KR100699510B1 (en) | Accurate time synchronization protocol for wireless sensor network | |
| CN101588628A (en) | Clock synchronizing method for wireless sensor network | |
| KR100819037B1 (en) | Method of time synchronization for wireless sensor network and sensor node | |
| CN103796338B (en) | Wireless sensor component and TDMA self-organized network implementation method | |
| PL1815650T3 (en) | Synchronization and data transmission method | |
| CN102752843B (en) | A kind of method for synchronizing time | |
| CN101827378A (en) | Blending MAC protocol design method suitable for wireless sensor network | |
| CN104202801B (en) | A kind of sleep/wake method of wireless kilowatt meter reading-out system | |
| CN104202803A (en) | Energy-saving MAC protocol communication method based on wireless sensor network | |
| Gheorghe et al. | Fault-tolerant flooding time synchronization protocol for wireless sensor networks | |
| WO2009008681A2 (en) | Time synchronization and routing method in wireless sensor network, and apparatus for enabling the method | |
| Chen et al. | Guard beacon: An energy-efficient beacon strategy for time synchronization in wireless sensor networks | |
| CN102638901A (en) | Wireless sensor network self-adapting MAC (medium access control) protocol suitable for industry monitoring | |
| Hu et al. | Vertical and horizontal synchronization services with outlier detection in underwater acoustic networks | |
| CN103259883A (en) | Self-organizing low-power-consumption wireless network IP address administration method | |
| Sheu et al. | Ratio-based time synchronization protocol in wireless sensor networks | |
| Nguyen et al. | Extensions of the ieee802. 15.4 protocol for ultra-low energy real-time communication | |
| Bae et al. | Time synchronization in wireless sensor networks |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| EE01 | Entry into force of recordation of patent licensing contract |
Application publication date: 20120215 Assignee: Shenzhen city wall Creative Technology Ltd. Assignor: SHENZHEN INSTITUTES OF ADVANCED TECHNOLOGY CHINESE ACADEMY OF SCIENCES Contract record no.: X2023980040491 Denomination of invention: Time synchronization methods and systems in wireless sensor networks Granted publication date: 20150708 License type: Common License Record date: 20230824 Application publication date: 20120215 Assignee: Shenzhen Mingji Agricultural Development Co.,Ltd. Assignor: SHENZHEN INSTITUTES OF ADVANCED TECHNOLOGY CHINESE ACADEMY OF SCIENCES Contract record no.: X2023980040490 Denomination of invention: Time synchronization methods and systems in wireless sensor networks Granted publication date: 20150708 License type: Common License Record date: 20230824 |
|
| EE01 | Entry into force of recordation of patent licensing contract | ||
| EE01 | Entry into force of recordation of patent licensing contract |
Application publication date: 20120215 Assignee: Zuowei (Dongguan) Technology Co.,Ltd. Assignor: SHENZHEN INSTITUTES OF ADVANCED TECHNOLOGY CHINESE ACADEMY OF SCIENCES Contract record no.: X2023980043067 Denomination of invention: Time synchronization methods and systems in wireless sensor networks Granted publication date: 20150708 License type: Common License Record date: 20231008 |
|
| EE01 | Entry into force of recordation of patent licensing contract | ||
| EE01 | Entry into force of recordation of patent licensing contract | ||
| EE01 | Entry into force of recordation of patent licensing contract |
Application publication date: 20120215 Assignee: Shenzhen Zhangchao Technology Co.,Ltd. Assignor: SHENZHEN INSTITUTES OF ADVANCED TECHNOLOGY CHINESE ACADEMY OF SCIENCES Contract record no.: X2023980043397 Denomination of invention: Time synchronization methods and systems in wireless sensor networks Granted publication date: 20150708 License type: Common License Record date: 20231013 |
|
| EE01 | Entry into force of recordation of patent licensing contract |
Application publication date: 20120215 Assignee: SHENZHEN LENZ INNOVATION TECHNOLOGY Co.,Ltd. Assignor: SHENZHEN INSTITUTES OF ADVANCED TECHNOLOGY CHINESE ACADEMY OF SCIENCES Contract record no.: X2023980043784 Denomination of invention: Time synchronization methods and systems in wireless sensor networks Granted publication date: 20150708 License type: Common License Record date: 20231019 |
|
| EE01 | Entry into force of recordation of patent licensing contract | ||
| EE01 | Entry into force of recordation of patent licensing contract |
Application publication date: 20120215 Assignee: SHENZHEN ZHONGZHI INVESTMENT CO.,LTD. Assignor: SHENZHEN INSTITUTES OF ADVANCED TECHNOLOGY CHINESE ACADEMY OF SCIENCES Contract record no.: X2023980044067 Denomination of invention: Time synchronization methods and systems in wireless sensor networks Granted publication date: 20150708 License type: Common License Record date: 20231024 Application publication date: 20120215 Assignee: Shenzhen Wufeng Lihong Trading Co.,Ltd. Assignor: SHENZHEN INSTITUTES OF ADVANCED TECHNOLOGY CHINESE ACADEMY OF SCIENCES Contract record no.: X2023980044081 Denomination of invention: Time synchronization methods and systems in wireless sensor networks Granted publication date: 20150708 License type: Common License Record date: 20231024 Application publication date: 20120215 Assignee: Shenzhen Ruofei Culture Communication Co.,Ltd. Assignor: SHENZHEN INSTITUTES OF ADVANCED TECHNOLOGY CHINESE ACADEMY OF SCIENCES Contract record no.: X2023980044080 Denomination of invention: Time synchronization methods and systems in wireless sensor networks Granted publication date: 20150708 License type: Common License Record date: 20231024 Application publication date: 20120215 Assignee: Shenzhen shengxin'an information consulting enterprise Assignor: SHENZHEN INSTITUTES OF ADVANCED TECHNOLOGY CHINESE ACADEMY OF SCIENCES Contract record no.: X2023980044079 Denomination of invention: Time synchronization methods and systems in wireless sensor networks Granted publication date: 20150708 License type: Common License Record date: 20231024 Application publication date: 20120215 Assignee: Shenzhen Zhijun Industrial Investment Co.,Ltd. Assignor: SHENZHEN INSTITUTES OF ADVANCED TECHNOLOGY CHINESE ACADEMY OF SCIENCES Contract record no.: X2023980044078 Denomination of invention: Time synchronization methods and systems in wireless sensor networks Granted publication date: 20150708 License type: Common License Record date: 20231024 Application publication date: 20120215 Assignee: Shenzhen Wenchuang Intellectual Property Service Co.,Ltd. Assignor: SHENZHEN INSTITUTES OF ADVANCED TECHNOLOGY CHINESE ACADEMY OF SCIENCES Contract record no.: X2023980044069 Denomination of invention: Time synchronization methods and systems in wireless sensor networks Granted publication date: 20150708 License type: Common License Record date: 20231024 Application publication date: 20120215 Assignee: Jiajingjie Environmental Technology Co.,Ltd. Assignor: SHENZHEN INSTITUTES OF ADVANCED TECHNOLOGY CHINESE ACADEMY OF SCIENCES Contract record no.: X2023980044068 Denomination of invention: Time synchronization methods and systems in wireless sensor networks Granted publication date: 20150708 License type: Common License Record date: 20231024 |
|
| EE01 | Entry into force of recordation of patent licensing contract | ||
| EE01 | Entry into force of recordation of patent licensing contract |
Application publication date: 20120215 Assignee: Shenzhen Mengchuang Culture Development Co.,Ltd. Assignor: SHENZHEN INSTITUTES OF ADVANCED TECHNOLOGY CHINESE ACADEMY OF SCIENCES Contract record no.: X2023980049247 Denomination of invention: Time synchronization methods and systems in wireless sensor networks Granted publication date: 20150708 License type: Common License Record date: 20231130 Application publication date: 20120215 Assignee: Shenzhen Jinshiwan Technology Co.,Ltd. Assignor: SHENZHEN INSTITUTES OF ADVANCED TECHNOLOGY CHINESE ACADEMY OF SCIENCES Contract record no.: X2023980049245 Denomination of invention: Time synchronization methods and systems in wireless sensor networks Granted publication date: 20150708 License type: Common License Record date: 20231130 Application publication date: 20120215 Assignee: Chuangke Zhinong (Shenzhen) Industrial Development Co.,Ltd. Assignor: SHENZHEN INSTITUTES OF ADVANCED TECHNOLOGY CHINESE ACADEMY OF SCIENCES Contract record no.: X2023980049240 Denomination of invention: Time synchronization methods and systems in wireless sensor networks Granted publication date: 20150708 License type: Common License Record date: 20231130 Application publication date: 20120215 Assignee: Chuangke Port (Shenzhen) Science and Technology Innovation Center Assignor: SHENZHEN INSTITUTES OF ADVANCED TECHNOLOGY CHINESE ACADEMY OF SCIENCES Contract record no.: X2023980049236 Denomination of invention: Time synchronization methods and systems in wireless sensor networks Granted publication date: 20150708 License type: Common License Record date: 20231130 |
|
| EE01 | Entry into force of recordation of patent licensing contract | ||
| EE01 | Entry into force of recordation of patent licensing contract |
Application publication date: 20120215 Assignee: Jingyun Grapefruit Technology (Shenzhen) Co.,Ltd. Assignor: SHENZHEN INSTITUTES OF ADVANCED TECHNOLOGY CHINESE ACADEMY OF SCIENCES Contract record no.: X2023980051450 Denomination of invention: Time synchronization methods and systems in wireless sensor networks Granted publication date: 20150708 License type: Common License Record date: 20231211 Application publication date: 20120215 Assignee: Shenzhen Dongfang Huilian Technology Co.,Ltd. Assignor: SHENZHEN INSTITUTES OF ADVANCED TECHNOLOGY CHINESE ACADEMY OF SCIENCES Contract record no.: X2023980051448 Denomination of invention: Time synchronization methods and systems in wireless sensor networks Granted publication date: 20150708 License type: Common License Record date: 20231211 Application publication date: 20120215 Assignee: Shenzhen Xunming Trading Co.,Ltd. Assignor: SHENZHEN INSTITUTES OF ADVANCED TECHNOLOGY CHINESE ACADEMY OF SCIENCES Contract record no.: X2023980051409 Denomination of invention: Time synchronization methods and systems in wireless sensor networks Granted publication date: 20150708 License type: Common License Record date: 20231211 Application publication date: 20120215 Assignee: Shenzhen Nanshan District Qiangfenfu Hotel Assignor: SHENZHEN INSTITUTES OF ADVANCED TECHNOLOGY CHINESE ACADEMY OF SCIENCES Contract record no.: X2023980051406 Denomination of invention: Time synchronization methods and systems in wireless sensor networks Granted publication date: 20150708 License type: Common License Record date: 20231211 Application publication date: 20120215 Assignee: Shenzhen Minghua Trading Co.,Ltd. Assignor: SHENZHEN INSTITUTES OF ADVANCED TECHNOLOGY CHINESE ACADEMY OF SCIENCES Contract record no.: X2023980051405 Denomination of invention: Time synchronization methods and systems in wireless sensor networks Granted publication date: 20150708 License type: Common License Record date: 20231211 Application publication date: 20120215 Assignee: Shenzhen Yingqi Consulting Co.,Ltd. Assignor: SHENZHEN INSTITUTES OF ADVANCED TECHNOLOGY CHINESE ACADEMY OF SCIENCES Contract record no.: X2023980051402 Denomination of invention: Time synchronization methods and systems in wireless sensor networks Granted publication date: 20150708 License type: Common License Record date: 20231211 Application publication date: 20120215 Assignee: Shenzhen Haocai Digital Technology Co.,Ltd. Assignor: SHENZHEN INSTITUTES OF ADVANCED TECHNOLOGY CHINESE ACADEMY OF SCIENCES Contract record no.: X2023980051250 Denomination of invention: Time synchronization methods and systems in wireless sensor networks Granted publication date: 20150708 License type: Common License Record date: 20231212 |
|
| EE01 | Entry into force of recordation of patent licensing contract | ||
| EE01 | Entry into force of recordation of patent licensing contract |
Application publication date: 20120215 Assignee: Jianyangkai Advertising Department, Nanshan District, Shenzhen Assignor: SHENZHEN INSTITUTES OF ADVANCED TECHNOLOGY CHINESE ACADEMY OF SCIENCES Contract record no.: X2023980051397 Denomination of invention: Time synchronization methods and systems in wireless sensor networks Granted publication date: 20150708 License type: Common License Record date: 20231212 Application publication date: 20120215 Assignee: Shenzhen Weilan Sports Culture Development Co.,Ltd. Assignor: SHENZHEN INSTITUTES OF ADVANCED TECHNOLOGY CHINESE ACADEMY OF SCIENCES Contract record no.: X2023980051394 Denomination of invention: Time synchronization methods and systems in wireless sensor networks Granted publication date: 20150708 License type: Common License Record date: 20231212 Application publication date: 20120215 Assignee: Shenzhen Weigao Investment Development Co.,Ltd. Assignor: SHENZHEN INSTITUTES OF ADVANCED TECHNOLOGY CHINESE ACADEMY OF SCIENCES Contract record no.: X2023980051257 Denomination of invention: Time synchronization methods and systems in wireless sensor networks Granted publication date: 20150708 License type: Common License Record date: 20231212 |
|
| EE01 | Entry into force of recordation of patent licensing contract |