CN100428691C - Time synchronous device and synchronous method of digital household network - Google Patents
Time synchronous device and synchronous method of digital household network Download PDFInfo
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- CN100428691C CN100428691C CNB2005101208258A CN200510120825A CN100428691C CN 100428691 C CN100428691 C CN 100428691C CN B2005101208258 A CNB2005101208258 A CN B2005101208258A CN 200510120825 A CN200510120825 A CN 200510120825A CN 100428691 C CN100428691 C CN 100428691C
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Abstract
The present invention provides a time synchronizing device and a time synchronizing method for a digital household network. The synchronizing device comprises at least two sets of time servers and time stamp printing equipment arranged in the time servers and digital household electric appliances. The synchronizing method is that the digital household electric appliances simultaneously send synchronous request to the two time servers every time, and the differences of the time of the household electrical appliances and the time of the two time servers are respectively obtained. If the differences of two results are not great, synchronization is thought to be successful, and if the differences of two results are greater than a tolerance range, network situation is thought to be poor. The synchronous request is sent again. The present invention uses the time synchronizing method, so the present invention can eliminate the inaccurate error of clocks in the household electric appliances and automatically finds the situation of failure. In a poor network environment, time synchronization can still maintain higher precision.
Description
Technical field
The invention belongs to the Time synchronization technique field of radio communication, particularly relate to a kind of Time synchronization technique that is applied to digital home network.
Technical background
Digital home is along with the development of 3C integration technology, more and more receive the concern of industry, it will form an industry in the future gradually, will have high performance computer, Digital Television, digital refrigerator, digital air-conditioning, digital camera, mobile communication terminal, digital home security protection equipment etc. in the digital home.To comprise various a large amount of digital household appliances.
Along with reaching its maturity of digital home appliance, the ratio of digital household appliances in market increases gradually, and we can predict the development looks of digital home in the future.In the future not only the quantity of digital household appliances can increase, and kind also will become more and more abundanter.In a digital home, may comprise the many household electrical appliances of Digital Television, digital microwave stove, digital air-conditioning, digital thermal hydrophone or the like, digital household appliances will affect our life at each face of each side.
Comprise a large amount of digital household appliances in the digital home, have many household electrical appliances need know the Current Standard time, to guarantee correct work.Need in the afternoon open automatically at 5 as air-conditioning, water heater needs at night open toward the bathtub water fillings automatically etc. at 9, and these realization all needs in our household electrical appliances correct time is arranged.If household electrical appliances need collaborative work like clockwork, this just needs the clock of our household electrical appliances must be synchronously, and synchronous with the standard time.At this moment need us to set up an accurate clock synchronization system.
But numerous digital household appliances is obeyed the unified scheduling of home owner if want collaborative work, and we must make the clock of digital household appliances and standard time synchronously.Household electrical appliances just can engrave when we imagine and do the thing that we want after receiving indication like this.But the network quality of wireless network differs very big compared with cable network, and in order to guarantee the precision of digital household appliances time synchronized, the method for traditional cable network is no longer suitable.
Though the Time synchronization technique of many maturations has been arranged now, and the mature technique majority is to be applied in the cable network.For the network of this complexity of wireless family local area network (LAN), network topology is not fixed, the position of the equipment in the network, and UNICOM's situation of LA Management Room changes through regular meeting; The transmission quality of network usually can not guarantee that also because the decay of transmission signals, time-delay is common problem, also might be directed at network packet and repeatedly retransmit.Existing classical NTP (NTP (Network Time Protocol)) generally needs the precognition network topology structure, could realize the time synchronized of anticipation precision, and this wireless home network for us is unpractical.Though now have some Time synchronization technique to solve the difficult point of wireless network time synchronized, but they only improve the sending and receiving end program structure on the application layer in procotol and improve precision, but for the physical state of complexity, this is not enough, our technology has solved this problem, further improves the precision of time synchronized.
In numerous digital household appliances,, must produce harmful effect simultaneously to the operation of these household electrical appliances if logic fault has appearred in the clock of certain household electrical appliances.We need a kind ofly can find the household electrical appliances clock failure automatically, and locate the method for damaging clock rapidly.
Summary of the invention
The objective of the invention is to overcome the deficiencies in the prior art, a kind of time synchronism apparatus of digital home network is provided.
Another object of the present invention is to according to time synchronism apparatus, a kind of method for synchronizing time of digital home network is provided.
In order to realize goal of the invention one, the technical scheme of employing is:
A kind of time synchronism apparatus of digital home network, comprise time server, timestamp printing device, described time server one end is connected with digital family network appliance, the other end connects the recognized standard time device, the present invention adopts the identical time server of at least two covers, and described timestamp printing device is arranged at respectively in interconnective digital family network appliance and the time server.Described timestamp printing device is provided with the trigger equipment of open printing timestamp, and described trigger equipment just sends triggering signal when data arrive data link layer.
The present invention has added two time servers in digital home network, increased timing tracking accuracy and each spent time synchronously of minimizing of digital household appliances in the family.Used two time servers simultaneously, also increased the robustness of digital home's clock system, when one of them time server is out of order, also had the another one time server to provide the standard time for digital home.
Described two time servers can be connected with the standard time, and the time of server self and standard time synchronous, this standard time can be the server that standard time is provided on the Internet, it also can be the standard time service etc. of GPS, make the time unanimity of two time servers, here consistent is interpreted as two time difference in allowed limits.
Digital household appliances carries out time synchronized with a time server in the following way:
Digital household appliances is to time server transmitting time synchronous data requests bag, and is engraved in to wrap when request package sends and prints digital household appliances time stamp T 1; After time server receives the request package of digital household appliances, print at once and go up time server time stamp T 2; Time server is handled request package and is finished, and sends to answer bag, and answers the time stamp T 3 of wrapping the time-write interval server in request; Digital household appliances receives answers bag, digital household appliances time stamp T 4 in the printing.According to T1, T2, T3, T4, can obtain the time difference of server and household electrical appliances.Adjust the time of household electrical appliances according to the time difference.
Timestamp printing device of the present invention is the ability time-write interval when data arrive data link layer.This all is that the application layer that occurs in the procotol is different with the printing of general timestamp opportunity, transfer to data link layer the opportunity that the present invention stabs the time-write interval, propose a kind of new Time Synchronization Network agreement, make the timestamp in the time synchronized packet more accurate.
In order to realize goal of the invention two, the technical scheme of employing is:
A kind of method for synchronizing time of digital home network comprises the steps:
(1) digital household appliances is to time server A transmitting time synchronization packets, and the current time of digital household appliances is stabbed TA1 is printed in the time synchronized packet;
(2) time server A receives the time synchronized packet that digital household appliances sends over, and the time stamp T A2 of time of reception synchronization packets is printed in this packet;
(3) time server A handles the time synchronized packet that digital household appliances sends, and returns this time synchronized packet and give digital household appliances, and the time stamp T A3 that simultaneously transmission is returned this packet is printed in the packet;
(4) digital household appliances receives the time synchronized packet that time server A returns, and the time stamp T A4 that will receive the return data bag is printed in the packet;
(5) digital household appliances calculates the time difference Da of digital household appliances time and time server A according to time stamp T A1, TA2, TA3, TA4;
(6) carrying out step (1) in (5), digital household appliances also carries out time synchronized by time synchronized packet and time server B, and on the time synchronized packet, print free TB1, TB2, TB3, the TB4 of stabbing, calculate time difference Db with digital household appliances and time server B;
(7) in allowed limits, the time synchronized success is adjusted the time of household electrical appliances and is also returned as if the difference between Da and the Db; If the difference between Da and the Db exceeds allowed band, then request time is synchronous once more, and repeating step (1) is to (7).
To be that digital household appliances is each send synchronization request to two time servers to method for synchronizing time of the present invention simultaneously, obtains the difference of the time on household electrical appliances time and two time servers respectively.If two result differences are little, then think synchronous success; If two result differences greater than tolerance, think that then network condition is not good, send synchronization request once more.
In the technique scheme, described time server A, time server B were connected with the standard time, and with time and standard time synchronous.This standard time can be the server that standard time is provided on the Internet, also can be the standard time service etc. of GPS, makes the time unanimity of two time servers, and here consistent is interpreted as two time difference in allowed limits.
Method for synchronizing time of the present invention also includes server A or the step (8) damaged of time server B detection time, and is specific as follows:
After the step (7) of method for synchronizing time of the present invention calculates Da, Db, if the difference continuous several times between Da and the Db all exceeds allowed band, then judge and have at least a time server to damage, time server A and time server B add up the current time of all digital household appliances respectively, and with standard time comparison, by the check comparison result consistent time server of determining damage whether.
Two results that the synchronization request that digital household appliances sends to two time servers at every turn obtains, if two results' difference continuous several times, thinks then that one of them time server is out of order greater than predetermined value, digital household appliances is reported fault to time server.Time server is made comparison to the time of the time of oneself and standard time and digital household appliances, and which platform time server fault location occurs on.Remaining server normal time works on, and the method for synchronization of whole network makes existing single time server method into.
Method for synchronizing time of the present invention also includes the step (9) that detects the digital appliances fault, and is specific as follows:
Digital household appliances with time server A or B deadline synchronously after, time difference Da or Db are turned back to time server A or B, if time difference Da that continuous several times is returned or Db all greater than predetermined value, judge that then the clock of this digital household appliances breaks down.
When time synchronized packet of the present invention arrives the data link layer of digital household appliances or time server, start triggering signal by trigger equipment and print upward timestamp.
Because each lock in time, all to print repeatedly timestamp wrapping, the present invention is different from the general way at the application layer time-write interval of procotol stamp, by improving procotol, make the printing of timestamp transfer to data link layer opportunity, only when packet really sends or moment of just having arrived of packet print timestamp, increased the precision of timestamp.
The step of concrete transmission/time of reception sync packet is as follows:
Transmitting time synchronization packets step:
(a) the transmitting terminal application layer is sent the request of transmitting time synchronization packets to network, does not comprise timestamp information in the packet at this moment to be sent;
(b) through the conventional network protocols stack, packet arrives the data link layer of transmitting terminal, and data link layer obtains current time information from system clock, toward the packet time-write interval stab and the transmission packet in network;
(c) send and successfully directly change step (d) over to, require to retransmit if send failure, then data link layer is taken out current time information from system clock again, and the timestamp in the print data bag sends once more again.Step (c) constantly circulates until sending successfully.
(d) transmission finishes.
Time of reception synchronization packets step:
(A) receiving terminal receives the time synchronized packet in the network;
(B) packet arrives data link layer, and take out current time information from system clock this moment, toward packet time-write interval stamp;
(C) packet arrives application layer through the legacy protocol stack, and application layer can be stabbed readout time.
Beneficial effect of the present invention is:
(1) adopts two time servers in logic
In order to deal with the network condition of wireless home network complexity, the present invention has added two time servers in digital home network.Having used the benefit of two time servers in logic is to have increased timing tracking accuracy and each spent time synchronously of minimizing of digital household appliances in the family.Used two time servers simultaneously, also increased the robustness of digital home's clock system, when one of them time server is out of order, also had the another one time server to provide the standard time for digital home.
(2) fault of discovery time server automatically
The present invention has used two time servers, and when one of them time server was out of order, digital household appliances determined the time server of problem in time server that we can be by an other operational excellence and the home network.
(3) can find the failure condition of the clock unit of equipment in the digital home network automatically
When the digital household appliances clock in family's network breaks down, the present invention can be in time to the user report failure condition and the information of giving the household electrical appliances that are out of order.Remove the user from and search the trouble of fault.
(4) timestamp of time synchronized packet transmission is more accurate
The present invention transfers to data link layer to the opportunity that the time-write interval stabs, and proposes a kind of new Time Synchronization Network agreement, makes the timestamp in the time synchronized packet more accurate.
Description of drawings
Fig. 1 is the time synchronized logic diagram of digital household appliances and time server;
Fig. 2 is the building-block of logic of time synchronism apparatus of the present invention;
Fig. 3 is a timestamp print protocol stack architecture schematic diagram of the present invention;
Fig. 4 is one embodiment of the present of invention structure chart.
Embodiment
The present invention is described further below in conjunction with accompanying drawing.
Time synchronism apparatus of the present invention as shown in Figure 2, comprise time server A, time server B, described time server A, time server B are connected with digital household appliances with standard time clock respectively, timestamp printing equipment of the present invention is arranged at respectively in time server A, B and the digital household appliances, because it mainly is a logical concept, realize the timestamp printing by software design, so mark among the figure.
The embodiments of the invention structural representation as shown in Figure 4, digital household appliances such as digital air-conditioning, Digital Television, digital thermal hydrophone, digital lamp are arranged in the digital home, these digital household appliances are connected with time server B with time server A by home gateway, time server A and time server B also are connected the standard time clock of Internet by home gateway, or the standard time clock of GPS.The clock accuracy of supposing digital lamp is not very high, and the digital thermal hydrophone is the running of keeping clock by powered battery, but its battery exhausts, and the clock of water heater is not walked.
Be associated in network on the digital household appliances of each and time correlation all regularly to time server A and time server B transmitting time synchronization request bag.Though the clock of digital lamp is inaccurate, have benefited from digital lamp at set intervals all synchronously once, the clocking error of digital lamp maintains in the acceptable scope all the time, and the error of clock can not accumulated.The clock of digital thermal hydrophone is not walked fully, the change of each time all is because the result after the time synchronized, because after the time synchronized, water heater need return to server to the clocking error of clock of oneself and server, the water heater clocking error result who receives when the server continuous several times is greater than a predetermined value, so server is judged the clock of water heater and is damaged, to system or user report failure condition.
In the present a certain moment, perhaps the network condition of digital home is bad, and time-delay end to end is very big, and packet the situation of failure often occurs sending owing to the network quality problem, needs the retransmission data bag.At this moment, because whether the transmission of having used two time servers, the present invention can judge current network exerts an adverse impact to our synchronization packets, digital household appliances can be refused the excessive time synchronized packet of error.Owing to often send the packet failure, timestamp is printed all and is being sent or the printing time of reception, after sending failure, send new packet once more, again the time-write interval stabs, avoided stabbing situation about when retransmitting, can not change, and timestamp is also more accurate has reflected the real transmission and the time of reception in the application layer time-write interval.
In the foregoing description, the time synchronized logic of digital household appliances and time server as shown in Figure 1; Digital household appliances is to time server transmitting time synchronous data requests bag, and is engraved in to wrap when request package sends and prints digital household appliances time stamp T 1; After time server receives the request package of digital household appliances, print at once and go up time server time stamp T 2; Time server is handled request package and is finished, and sends to answer bag, and answers the time stamp T 3 of wrapping the time-write interval server in request; Digital household appliances receives answers bag, digital household appliances time stamp T 4 in the printing.According to T1, T2, T3, T4, can obtain the time difference of server and household electrical appliances.Adjust the time of household electrical appliances according to the time difference.
In the foregoing description, timestamp print protocol stack architecture schematic diagram as shown in Figure 3, it all is that the application layer that occurs in the procotol is different opportunity that the timestamp of present embodiment is printed with the printing of general timestamp, transferring to data link layer the opportunity of time-write interval stamp, propose a kind of new Time Synchronization Network agreement, make the timestamp in the time synchronized packet more accurate.
Above-mentioned owing to used method for synchronizing time, can not only eliminate the error of inaccurate clock in the household electrical appliances, can also find the situation of fault automatically, and in abominable network environment, time synchronized still can keep higher precision.
Claims (5)
1, a kind of method for synchronizing time that adopts the digital home network of time synchronism apparatus is characterized in that:
Described synchronizer comprises time server, timestamp printing device, described time server one end is connected with digital family network appliance, the other end connects the recognized standard time device, synchronizer adopts the identical time server of at least two covers, and described timestamp printing device is arranged at respectively in interconnective digital family network appliance and the time server, described timestamp printing device is provided with the trigger equipment of open printing timestamp, and described trigger equipment just sends triggering signal when data arrive data link layer;
Described method for synchronous comprises the steps:
(1) digital household appliances is to time server A transmitting time synchronization packets, and the current time of digital household appliances is stabbed TA1 is printed in the time synchronized packet;
(2) time server A receives the time synchronized packet that digital household appliances sends over, and the time stamp T A2 of time of reception synchronization packets is printed in this packet;
(3) time server A handles the time synchronized packet that digital household appliances sends, and returns this time synchronized packet and give digital household appliances, and the time stamp T A3 that simultaneously transmission is returned this packet is printed in the packet;
(4) digital household appliances receives the time synchronized packet that time server A returns, and the time stamp T A4 that will receive the return data bag is printed in the packet;
(5) digital household appliances calculates the time difference Da of digital household appliances time and time server A according to time stamp T A1, TA2, TA3, TA4;
(6) carrying out step (1) in (5), digital household appliances also carries out time synchronized by time synchronized packet and time server B, and on the time synchronized packet, print free TB1, TB2, TB3, the TB4 of stabbing, calculate time difference Db with digital household appliances and time server B;
(7) in allowed limits, the time synchronized success is adjusted the time of household electrical appliances and is also returned as if the difference between Da and the Db; If the difference between Da and the Db exceeds allowed band, then request time is synchronous once more, and repeating step (1) is to (7).
2, the method for synchronizing time of the digital home network of employing time synchronism apparatus according to claim 1 is characterized in that described time server A, time server B were connected with the standard time, and with time and standard time synchronous.
3, the method for synchronizing time of the digital home network of employing time synchronism apparatus according to claim 1 and 2 is characterized in that described method for synchronous also includes server A or the step (8) damaged of time server B detection time, and is specific as follows:
After described step (7) calculates Da, Db, if the difference continuous several times between Da and the Db all exceeds allowed band, then judge and have at least a time server to damage, time server A and time server B add up the current time of all digital household appliances respectively, and with standard time comparison, by the check comparison result consistent time server of determining damage whether.
4, the method for synchronizing time of the digital home network of employing time synchronism apparatus according to claim 3 is characterized in that described method for synchronous also includes the step (9) that detects the digital appliances fault, and is specific as follows:
Digital household appliances with time server A or B deadline synchronously after, time difference Da or Db are turned back to time server A or B, if time difference Da that continuous several times is returned or Db all greater than predetermined value, judge that then the clock of this digital household appliances breaks down.
5, the method for synchronizing time of the digital home network of employing time synchronism apparatus according to claim 4, when it is characterized in that described time synchronized packet arrives the data link layer of digital household appliances or time server, start triggering signal by trigger equipment and print upward timestamp.
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| CNB2005101208258A CN100428691C (en) | 2005-12-22 | 2005-12-22 | Time synchronous device and synchronous method of digital household network |
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| CNB2005101208258A CN100428691C (en) | 2005-12-22 | 2005-12-22 | Time synchronous device and synchronous method of digital household network |
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| CN100428691C true CN100428691C (en) | 2008-10-22 |
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Families Citing this family (13)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN1913422B (en) * | 2006-07-03 | 2011-03-30 | 华为技术有限公司 | Time server and method for increasing output precision of time server |
| CN101364978B (en) * | 2007-08-10 | 2011-06-22 | 鸿富锦精密工业（深圳）有限公司 | Instant time clock precise verification system and method |
| CN101315543B (en) * | 2008-06-28 | 2010-06-16 | 黄更 | Network digital alarm clock, long-range control method and signal synchronous transmission method |
| JP4735706B2 (en) * | 2008-11-10 | 2011-07-27 | ソニー株式会社 | Date and time information providing system and date and time information providing method |
| CN102421012B (en) * | 2011-11-16 | 2014-01-22 | 王白 | Method and system for acquiring screenshot picture of television program |
| CN102546009B (en) | 2012-01-17 | 2014-12-24 | 华为技术有限公司 | Optical fiber symmetry detecting method and device |
| CN103051316B (en) * | 2012-12-12 | 2015-03-18 | 中北大学 | Synchronous triggering system in distributed type measurement |
| CN104678922B (en) * | 2013-12-02 | 2017-09-29 | 广东美的制冷设备有限公司 | Time control method and system based on Internet of Things |
| CN106452648B (en) * | 2014-06-26 | 2019-08-02 | 青岛海信移动通信技术股份有限公司 | A kind of method for synchronizing time and communication terminal |
| CN106027191B (en) * | 2016-05-23 | 2018-09-21 | 北京小米移动软件有限公司 | Update method, device and the terminal device of time |
| 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 |
| CN108234052A (en) * | 2016-12-15 | 2018-06-29 | 佛山市顺德区美的电热电器制造有限公司 | The method, apparatus and system that a kind of clock synchronizes |
| CN110620629A (en) * | 2018-06-19 | 2019-12-27 | 佛山市顺德区美的电热电器制造有限公司 | Clock synchronization method, equipment and computer storage medium |
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