CN101022416B - Method for regulating clock frequency, client and system - Google Patents
Method for regulating clock frequency, client and system Download PDFInfo
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Abstract
A method for regulating frequency of clock includes filtering virtual clock (VC) pulse to obtain network time delay wave form, filtering jitter of wave form when network is on transmission, judging whether phase difference accumulation value of VC to local recovery clock is over preset threshold or not at preset time interval (PTI) and judging whether there is network time delay jitter over preset message arrival frequency and amplitude range or not at PTI if it is, regulating frequency of two said clocks to be identical if it is or otherwise decreasing said value of two said clocks. The client end for realizing said method is also disclosed.
Description
Technical field
The present invention relates to the communication service field, relate in particular to a kind of method, client and system that adjusts clock frequency.
Background technology
PWE3 (the virtual end-to-end pseudo-line of Pseudo-Wire Emulation Edge-to-Edge) is a kind of a kind of technology mechanism that can go up the professional key property of simulation telecommunication path at PSN (Packet Switch Network packet switching network), artificial service comprises Ethernet service, frame relay service, ATM (AsynchronousTransfer Mode asynchronous transfer mode) business, TDM (Time Division Multiplex time division multiplexing) business etc., especially the PWE3 of TDM realizes comparatively complicated, reason is that server end can send message to client, but message can could arrive client by PSN, in the PSN network transmission process, data-bag lost might take place, postpone, phenomenons such as delay variation can cause client asynchronous with the local recovery clock frequency by the dummy clock frequency that message recovers.
Because of server generally is that message is set to the fixed length timed sending, therefore the message that sends can be regarded the clock pulse of one section rule as, if every frame is played a bag, just can regard the clock pulse of a rule as.Under ideal state, the message that client receives also is a cycle stability, can become a dummy clock according to the frequency retrieval of the message that receives so, and the frequency of this dummy clock is called the dummy clock frequency.
For synchronous at the message that keeps client and server end, client itself has a local recovery clock, this local recovery clock frequency is consistent with the frequency that server end sends message, can contrast the local recovery clock frequency and whether the dummy clock frequency is synchronous by phase demodulation, asynchronously will adjust the local recovery clock frequency.But because PSN is a time delay nondeterministic network, the civilian frequency of the frequency that server sends message in the short time period and client receiving might not equate, the dummy clock frequency also can be because the PSN time delay be uncertain and the clock source frequency of server end deviation to some extent.
Prior art according to different PSN networks, is estimated the amplitude of some PSN message time delays and the scope of frequency in order to address this problem.Set in advance the message that filter parameter can filter in the setting range in client and arrive frequency, dummy clock frequency just, the clock frequency after the filtration can be removed certain PSN web influence.Can add up the accumulated value that differs so at short notice owing to different dummy clocks that cause of frequency and local recovery clock, surpass certain limit value if differ accumulated value, just adjust the local clock frequency, do not surpass certain limit value, then do not adjust the local clock frequency if differ accumulated value.
For example, setting range is that frequency is 1Hz～10E-2Hz, and amplitude of variation is the following scope of 0.2us, and the dummy clock frequency jitter in this scope can be filtered.Frequency range that presets by filtration and the frequency jitter in the amplitude of variation can make the client terminal local recovered clock not be subjected to the influence of PSN network delay as far as possible so, and tracking server end clock source is more accurate.
But the method for this presetting range still is defective, and giving an example below illustrates:
Because a great sports meeting is held in some cities of whole network node the inside, causes network traffics big especially in the afternoon, just can subtract to evening.The amplitude of network delay has been used one hour by the value A value of rising to B, and the time delay increment is B-A=2us, and just being equivalent to a frequency this moment is the network delay shake of 2us for the 10-3Hz amplitude; But the shake of such network delay is not considered when presetting certain clock frequency and amplitude range.Therefore client is that can not to discern such shake be the influence that is caused by network itself, just adjust the adjustment of local recovery clock frequency above when presetting low frequency wonder 1Hz～10E-2Hz and 0.2us amplitude, thereby causing dummy clock frequency fluctuation as shown in Figure 1.
Method of the prior art in sum is exactly to consider the situation of change of PSN network in advance, set in advance frequency and the amplitude range that message arrives in client, when the situation that variation appears presetting in PSN is, just can filter it arrives frequency to message influence in client; But when surpassing frequency that its message that presets arrives and amplitude range, the variation that PSN occurs will append on the frequency of client reception message, will influence the frequency that client receives message, just can cause differing of dummy clock and local recovery clock, thereby cause the mistuning of local recovery clock frequency whole.
Summary of the invention
The technical problem that the embodiment of the invention will solve provides a kind of method, client and system that adjusts clock frequency.
For solving the problems of the technologies described above, the purpose of the embodiment of the invention is achieved through the following technical solutions:
Arrive the dummy clock pulse that frequency and amplitude range are filtered the message recovery that receives by the message that presets; According to the client reception server periodically send travel to and fro between client and server network time delay value half form network transfer delay waveform;
Arrive frequency and amplitude range, the shake of screen propagation delay time waveform by the message that presets; Judgement preset time at interval in, dummy clock and local recovery clock whether differ accumulated value above the limit value that presets, then be left intact if not; If then judge in this preset time interval, whether to exist and surpass the network transfer delay waveform shake that the described message that presets arrives frequency and amplitude range, it is consistent with the dummy clock frequency then to adjust the local recovery clock frequency if not, if then the accumulated value that differs of dummy clock and local recovery clock is reduced;
Perhaps
Arrive the dummy clock pulse that frequency and amplitude range are filtered the message recovery that receives by the message that presets; Obtain the network transfer delay waveform;
Judgement preset time at interval in, dummy clock and local recovery clock whether differ accumulated value above the limit value that presets, then be left intact if not; If then arrive frequency and amplitude range, the shake of screen propagation delay time waveform by the message that presets; Whether judgement exists in this preset time interval surpasses the network transfer delay waveform shake that the described message that presets arrives frequency and amplitude range, it is consistent with the dummy clock frequency then to adjust the local recovery clock frequency if not, if then the accumulated value that differs of dummy clock and local recovery clock is reduced.
Preferably, described method by the pulse of message recovery dummy clock is: the time interval of receiving two messages is set to high level, and the duration that message arrives is set to low level; The time interval of maybe receiving two messages is set to low level, and the duration that message arrives is set to high level.
The embodiment of the invention also provides a kind of client of adjusting clock frequency, and this client comprises: receiving element, Waveform fetch unit, filter element, limit value judging unit, shake judging unit, adjustment unit;
Receiving element is used to receive message;
Waveform fetch unit, be used to obtain the network transfer delay waveform, be used to also to obtain that server periodically sends travels to and fro between half of client and server network time delay value, form network transfer delay waveform by half of these described network delay values of periodically obtaining;
Filter element is used for arriving by the message that presets the scope of frequency and amplitude, filters the dummy clock pulse of the message recovery that receives; The shake of screen propagation delay time waveform;
The limit value judging unit is used for judging at preset time at interval, dummy clock and local recovery clock whether differ accumulated value above the limit value that presets;
The shake judging unit, be used for dummy clock and local recovery clock differ accumulated value when surpassing the limit value preset, judge whether to exist at interval to surpass the described message that presets and arrive frequency and shakes with the network transfer delay waveform of amplitude range at this preset time;
Adjustment unit is used for when there is not the network transfer delay waveform shake that surpasses described message arrival frequency that presets and amplitude range in the shake judging unit, and it is consistent with the dummy clock frequency to adjust the local recovery clock frequency; Obtain existing when surpassing the described message that presets and arriving the network transfer delay waveform shake of frequency and amplitude range at the shake judging unit, recovered clock and local clock differed the accumulated value reduction.
The embodiment of the invention also provides a kind of system that adjusts clock frequency, and this system comprises: server and client;
Server is used for sending message to client, and periodically travels to and fro between half of client and server network time delay value to what client sent statistics;
Client, be used to receive message, the scope that arrives frequency and amplitude by the message that presets is filtered in the dummy clock arteries and veins of the message recovery that receives, and reception is travelled to and fro between half of client and server network time delay value and formed the network transfer delay waveform by described value; Arrive the scope of frequency and amplitude, the shake of screen propagation delay time waveform by the message that presets; Judgement preset time at interval in, dummy clock and local recovery clock whether differ accumulated value above the limit value that presets, then be left intact if not; If then judge in this preset time interval, whether to exist and surpass the network transfer delay waveform shake that the described message that presets arrives frequency and amplitude range, it is consistent with the recovered clock frequency then to adjust the local clock frequency if not, if then the accumulated value that differs of recovered clock and local clock is reduced;
Perhaps
Server is used for sending message to client, and periodically obtains half that travel to and fro between client and server network time delay value; Send to client behind half formation network transfer delay waveform with described network delay value;
Client is used to receive message, receives the network transfer delay waveform; Arrive the scope of frequency and amplitude by the message that presets, filter the dummy clock pulse of the message recovery that receives, the shake of screen propagation delay time waveform; Judgement preset time at interval in, dummy clock and local recovery clock whether differ accumulated value above the limit value that presets, then be left intact if not; If then judge in this preset time interval, whether to exist and surpass the network transfer delay waveform shake that the described message that presets arrives frequency and amplitude range, it is consistent with the recovered clock frequency then to adjust the local clock frequency if not, if then the accumulated value that differs of recovered clock and local clock is reduced.
Above technical scheme as can be seen, server is according to its local clock source timed sending message, client goes out the client recovered clock according to the frequency retrieval that message arrives; Add Handshake Protocol at server end and client simultaneously, under Handshake Protocol, obtain the network delay waveform of PSN by the feedback of client, differ accumulated value when surpassing the limit value preset at recovered clock and local clock, consider the influence of the network delay waveform of PSN, avoid unidirectional message to arrive frequency information and be subjected to the PSN time delay influence to cause mistuning to put in order local recovery clock, thereby can under PSN environment complicated and changeable, obtain the local recovery clock of better quality.
Description of drawings
Fig. 1 adjusts dummy clock frequency oscillogram after the local recovery clock frequency for prior art;
Clock pulse figure when Fig. 2 sends message for the cycle;
Fig. 3 is for recovering the contrast timing chart of waveform and ideal situation;
Fig. 4 is that pulse missing influences figure to identified result for packet loss;
Fig. 5 is the Gaussian distribution model of network delay a short time the inside;
Fig. 6 is an embodiment of the invention flow chart;
Fig. 7 is for obtaining a kind of method of network delay waveform in the embodiment of the invention;
Fig. 8 is for obtaining the another kind of method of network delay waveform in the embodiment of the invention;
The network delay waveform of Fig. 9 for obtaining in the embodiment of the invention;
Figure 10 is the network delay waveform that filters in the embodiment of the invention after shaking;
Figure 11 differs the network delay waveform behind the accumulated value for the present invention turns down.
Embodiment
The problem that the embodiment of the invention mainly solves be client can not judge the recovered clock frequency shake owing to the PSN network causes, still since local recovery clock do not cause synchronously with server end clock source.In order to address this problem, adopted the method for obtaining the network delay waveform.After having obtained the network delay waveform, can judge whether to have surpassed the limit value that presets by the network delay waveform at the certain network delay increment of network delay in the time period, surpass the limit value that presets and then thought the influence that network delay causes, thereby avoided mistuning to put in order the local recovery clock frequency to a certain extent.
To know the embodiment of the invention in order introducing, at first to introduce the thinking that obtains the embodiment of the invention:
Because server generally is to be set to the fixed length timed sending according to its local clock source message, therefore the message that sends can be regarded the clock pulse of one section rule as, if every frame is played a bag, just can regard the 8K pulse of a rule as.For example shown in Figure 2, sending message is that one-period is 125us, and frequency is the clock pulse of 8K.
But message is behind process PSN, and the waveform that recovers out in client may change.Influence three factors that mainly contain of this impulse waveform: intrinsic time delay T
f, random delay T
r, packet loss (incorrect order here will be handled as packet loss) is if delivery time is t
n, be T the time of reception
n
T
n=t
n+ T
f+ T
r... ... ... ... ... ... ... ... .... packet loss not
T
n=t
n+ ∞ ... ... ... ... ... ... ... ... ... .... packet loss
So the recovery waveform of client and the contrast timing chart of ideal situation are as shown in Figure 3: after message advanced PSN, will have packet loss and intrinsic time delay T is arranged
f, random delay T
rInfluence.
Intrinsic time delay can not influence the identified result to clock pulse, and random delay can cause the frequency jitter of clock pulse; Packet loss be pulse missing only otherwise the burst long time also little to the identified result influence.Reason can be by shown in Figure 4: just can obtain packet loss to the little conclusion of identified result influence by the recovered clock of the source clock of server and client is carried out the XOR phase demodulation.
Lose a pulse in the middle of the clock pulse that the client that need follow the tracks of receives, the XOR identified result is to have lost a phase demodulation information, do not adjust phase place but can not influence, so the client terminal local recovered clock recovers out clock and need the clock pulse phase difference constant pi/2 of the client reception of tracking not change.
What therefore we mainly should consider was the shake that the elimination Netowrk tape comes.The PDV time delay of real network can be regarded a Gaussian distribution model as a short time the inside, and this model is referring to Fig. 5, and probability density meets following formula:
But with practical conditions as can be seen, for a long time, the μ among Fig. 5 is not a fixed value, and promptly we cannot just regard the network fixed delay as a fixed value, so we call u (t) more accurately to μ, the probability density formula strain of time delay is
The delay volume reaction that meets (1) formula Gaussian Profile is high-frequency clock jitter, and in fact u (t) introducing is exactly the low-frequency clock drift.And because randomized jitter will be considered easily and be removed, so present subject matter is considered the low-frequency clock drift that u (t) introduces exactly, just differentiates current local recovery clock and differing because u (t) causes through the clock pulse behind the PSN network; Still because the clock of client terminal local does not have tracking upward to cause through the recovered clock pulse behind the PSN network.
U (t) is a continuous function, and is a function that the alternating current component frequency is lower, and we here give one example, and supposes u (t)=u
0+ u
1Sin (100
-1T*2 π)+u
2Sin (15
-1T*2 π), suppose that again we have constantly followed the tracks of at t=0, below we analyze, how identified result handles the triggering that the adjustment that just is unlikely to make the client terminal local clock is subjected to u (t), promptly is subjected to the time delay influence of network PSN.
Use the basic principle of digital phase-locked loop, use a high-frequency clock, identified result when being leading forward-backward counter do subtraction, forward-backward counter was done addition when identified result fell behind, set a upper and lower bound, break through the frequency that upward just improves local recovery clock in limited time when forward-backward counter, when breaking down the frequency that just reduces local recovery clock in limited time by a fall, here directly adopt local clock to get final product as high-frequency clock, suppose that present local clock is 100M, if counter zero clearing never, local recovery clock is also constant not to be adjusted and itself can not drift about, look at counter values behind the 50s and the numerical value behind the 100s
Suppose u
1=u
2=10ms, ∑ PhaseOffset (50S) ≈ 1.24E-4S so, so use the 100M clock technology, counter will add up and obtain 124000.Identical computational methods, can calculate 100S after, counter will be accumulated to 15000.
So when the result of forward-backward counter arrives 124000 words of just adjusting the local recovery clock frequency, in fact be exactly the influence that is subjected to PSN, rather than real owing to do not follow the tracks of and go up the recovered clock pulse, the frequency of when being subjected to the PSN web influence, adjusting local recovery clock can cause originally followed the tracks of accurate clock tuningout from.Suppose that the step-length of adjusting is 0.1ppm, 2M clock deviation 0.1ppm just has been offset 200s always so, and forward-backward counter will reach 1us so.This numerical value is added some factors of instability, and Gonna breakthrough 1000s is very easy with interior maximum time interval error limit for height 2us, thereby the mistuning of having carried out influenced by network PSN is put in order.
And the PSN network generally is a center type, and promptly a plurality of clients of server band will make the client recovered clock not be subjected to the influence of network transfer delay, must allow client know the waveform of current network propagation delay time.So the key of problem transforms obtaining for the network transfer delay waveform values; Obtain the network transfer delay waveform, can add Handshake Protocol the server and client side.
The embodiment of the invention mainly is exactly: preset scopes such as the shake of the reception message frequency that PSN brings and range value in prior art, the recovered clock frequency is filtered the influence of a part of network delay shake earlier; Further obtain the network delay waveform, and scopes such as shake by the reception message frequency that presets and range value, the network delay waveform that obtains is filtered, make the network delay waveform also avoid earlier influenced by PSN to a certain degree.Whether that judges dummy clock and local recovery clock then at short notice differs accumulated value above certain limit value, surpass certain limit value if differ accumulated value, then judge whether to need to adjust the local clock frequency by the network delay waveform that has filtered the PSN shake.
Referring to Fig. 6, embodiment of the invention concrete steps are:
Step 601: server sends message; Server generally is that the clock source message according to its this locality is set to the fixed length timed sending, and therefore the message that sends can be regarded the clock pulse of one section rule as, if every frame is played a bag, just can regard the 8K pulse of a rule as.
Step 602: client receives message, obtains the dummy clock frequency according to the frequency that message arrives.
Step 603: client is obtained the network transfer delay waveform.
The method that client is obtained the network transfer delay waveform has two kinds:
First kind referring to Fig. 7:
Step 701: server is periodically to client transmitting time signal calculated, this Time Calculation signal from the time interval of server to client end be t1;
Step 702: user end to server feeds back this Time Calculation signal, and the time of this feedback signal from the client to the server is t2;
Step 703: server is received the time delay that can calculate this trip path behind the Time Calculation signal of feedback.
What but client needed is the value of t1, therefore the t1 network delay can be similar to and think: (t1+t2)/2.Because server is periodic transmitting time signal calculated, therefore can obtain the value of a plurality of network delay t1.
Step 704: after server obtains the value of a plurality of network delay t1, can obtain the network transfer delay waveform according to the value of these t1;
Step 705: after obtaining the network transfer delay waveform, this waveform is sent to client.
Referring to Fig. 8, add Handshake Protocol, client also has another to obtain the method for network transfer delay oscillogram:
Step 801: server periodically sends a Time Calculation signal to client, this Time Calculation signal from the time interval of server to client end be t1;
Step 802: user end to server feeds back this Time Calculation signal, and the time of this feedback signal from the client to the server is t2;
Step 803: server is received the time delay that can calculate this trip path behind the Time Calculation signal of feedback.
What but client needed is the value of t1, therefore the t1 network delay can be similar to and think: (t1+t2)/2.Because server is periodic transmitting time signal calculated, therefore can obtain the value of a plurality of network delay t1.
Step 804: server sends to client with the value of these network delays t1;
Step 805: client is obtained the network transfer delay waveform according to the value of these t1.
More than be two kinds of methods obtaining the network transfer delay waveform.
Step 604: arrive the scope of frequency and amplitude, screen propagation delay time waveform by the message that presets.
This step can be carried out between step 606 and 607, whether promptly filter the network transfer delay shake of back in judging at certain time intervals is filtered, the execution of this step can be compared flexibly opportunity, is not limited in present embodiment and carries out described opportunity.
This step can be come the description of image by Fig. 9, Figure 10.The waveform of the network transfer delay that for example obtains such as Fig. 9: the signal of time T the inside can think that frequency is 10E-3Hz; Amplitude is 2us; The signal of T outside can think that frequency is 1Hz～10E-2Hz and 0.2us amplitude; The signal frequency of T outside and amplitude just can filter out in the scope that filter presets so, the waveform after the formation filtration shake as shown in figure 10.
Step 605: judge that in certain time interval, message arrives frequency, whether what promptly dummy clock and client terminal local recovered clock caused differs accumulated value above certain numerical value; If surpass then execution in step 607; If do not surpass then execution in step 606;
Step 606: be left intact;
Step 607: judge in this preset time interval, whether to exist to surpass the network delay waveform shake that the described message that presets arrives frequency and amplitude range, if there is then execution in step 608; If there is not then execution in step 609;
Step 608: dummy clock and client terminal local recovered clock are differed accumulated value make zero; Perhaps dummy clock and client terminal local clock are differed accumulated value, deduct in this time interval by the network transfer delay waveform obtain by differing that network transfer delay causes.
Step 609: adjust the local recovery clock frequency;
Referring to Figure 11, for example at T in the time period, the waveform of network delay is that the client filter filters and do not go, and client can select not do any clock adjustment at T in the time period; Just judge and make certain decrement treatment on the accumulated value original differing according to this time delay waveform.
The embodiment of the invention does not limit differing the processing that accumulated value does in step 608, can select different processing methods according to actual needs.
By judgement of the invention process, can effectively avoid being subjected to the influence of PSN network delay, the local clock frequency is put in order in mistuning.
The embodiment of the invention also provides a kind of client of avoiding the whole clock frequency of mistuning, and this client comprises: receiving element, Waveform fetch unit, filter element, limit value judging unit, shake judging unit, adjustment unit;
Receiving element is used to receive message;
Waveform fetch unit is used to obtain the network transfer delay waveform; Be used to also to obtain that server periodically sends travels to and fro between half of client and server network time delay value, form network transfer delay waveform by half of these described network delay values of periodically obtaining.
Filter element is used for arriving by the message that presets the scope of frequency and amplitude, filters the dummy clock pulse of the message recovery that receives; The shake of screen propagation delay time waveform;
The limit value judging unit is used for judging at preset time at interval, dummy clock and local recovery clock whether differ accumulated value above the limit value that presets;
The shake judging unit, be used for dummy clock and local recovery clock differ accumulated value when surpassing the limit value preset, judge whether to exist at interval to surpass the network delay waveform that the described message that presets arrives frequency and amplitude range and shakes at this preset time;
Adjustment unit is used for when there is not the network delay waveform shake that surpasses described message arrival frequency that presets and amplitude range in the shake judging unit, and it is consistent with the dummy clock frequency to adjust the local recovery clock frequency; Obtain existing when surpassing the described message that presets and arriving the network delay waveform shake of frequency and amplitude range at the shake judging unit, dummy clock and local recovery clock differed the accumulated value reduction.
Wherein, described adjustment unit specifically comprises: the unit that makes zero, adjustment local clock frequency cells, computing unit;
The unit that makes zero is used for obtaining existing when surpassing the described message that presets and arriving the network delay waveform shake of frequency and amplitude range at the shake judging unit, is changed to the accumulated value that differs of described dummy clock and local recovery clock zero;
Adjust the local clock frequency cells, be used for when there is not the network delay waveform shake that surpasses described message arrival frequency that presets and amplitude range in the shake judging unit, it is consistent with the dummy clock frequency to adjust the local recovery clock frequency.
Computing unit, be used for obtaining existing when surpassing the described message that presets and arriving frequency and shake with the network delay waveform of amplitude range at the shake judging unit, with current dummy clock and local recovery clock differ accumulated value deduct in this time interval by the network transfer delay waveform obtain by differing that network transfer delay causes.
The embodiment of the invention also provides a kind of system that avoids the whole clock of mistuning, and this system comprises: server and client;
Server is used for sending message to client, and periodically travels to and fro between half of client and server network time delay value to what client sent statistics;
Client, be used to receive message, arrive frequency and the scope of amplitude by the message that presets and filter the dummy clock pulse that the message that receives recovers, receive travel to and fro between client and server network time delay value half also by described value formation network transfer delay waveform; Arrive the scope of frequency and amplitude, the shake of screen propagation delay time waveform by the message that presets; Judgement preset time at interval in, dummy clock and local recovery clock whether differ accumulated value above the limit value that presets, then be left intact if not; If then judge in this preset time interval, whether to exist and surpass the network delay waveform shake that the described message that presets arrives frequency and amplitude range, it is consistent with the recovered clock frequency then to adjust the local clock frequency if not, if then the accumulated value that differs of recovered clock and local clock is reduced;
Perhaps
Server is used for sending message to client, and periodically obtains half that travel to and fro between client and server network time delay value; Send to client behind half formation network transfer delay waveform with described network delay value;
Client is used to receive message, receives the network transfer delay waveform; Arrive the scope of frequency and amplitude by the message that presets, filter the dummy clock pulse of the message recovery that receives, the shake of screen propagation delay time waveform; Judgement preset time at interval in, dummy clock and local recovery clock whether differ accumulated value above the limit value that presets, then be left intact if not; If then judge in this preset time interval, whether to exist and surpass the network delay waveform shake that the described message that presets arrives frequency and amplitude range, it is consistent with the recovered clock frequency then to adjust the local clock frequency if not, if then the accumulated value that differs of recovered clock and local clock is reduced.
More than a kind of method, client and system of the whole clock of mistuning of avoiding provided by the present invention is described in detail, used specific case herein principle of the present invention and execution mode are set forth, the explanation of above embodiment just is used for helping to understand method of the present invention and core concept thereof; Simultaneously, for one of ordinary skill in the art, according to thought of the present invention, the part that all can change in specific embodiments and applications, in sum, this description should not be construed as limitation of the present invention.
Claims (10)
1. a method of adjusting clock frequency is characterized in that, this method comprises:
Arrive the dummy clock pulse that frequency and amplitude range are filtered the message recovery that receives by the message that presets; According to the client reception server periodically send travel to and fro between client and server network time delay value half form network transfer delay waveform;
Arrive frequency and amplitude range, the shake of screen propagation delay time waveform by the message that presets; Judgement preset time at interval in, dummy clock and local recovery clock whether differ accumulated value above the limit value that presets, then be left intact if not; If then judge in this preset time interval, whether to exist and surpass the network transfer delay waveform shake that the described message that presets arrives frequency and amplitude range, it is consistent with the dummy clock frequency then to adjust the local recovery clock frequency if not, if then the accumulated value that differs of dummy clock and local recovery clock is reduced;
Perhaps
Arrive the dummy clock pulse that frequency and amplitude range are filtered the message recovery that receives by the message that presets; Obtain the network transfer delay waveform;
Judgement preset time at interval in, dummy clock and local recovery clock whether differ accumulated value above the limit value that presets, then be left intact if not; If then arrive frequency and amplitude range, the shake of screen propagation delay time waveform by the message that presets; Whether judgement exists in this preset time interval surpasses the network transfer delay waveform shake that the described message that presets arrives frequency and amplitude range, it is consistent with the dummy clock frequency then to adjust the local recovery clock frequency if not, if then the accumulated value that differs of dummy clock and local recovery clock is reduced.
2. the method for adjustment clock frequency according to claim 1 is characterized in that, the described method of obtaining the network transfer delay waveform is:
The Time Calculation signal that the client reception server periodically sends, and to server feedback Time Calculation signal, server obtains and sends and half value of feedback time signal calculated time difference, obtains the network transfer delay waveforms by a plurality of described values, and described waveform is sent to client.
3. the method for adjustment clock frequency according to claim 1 is characterized in that, the described method of obtaining the network transfer delay waveform is:
The Time Calculation signal that the client reception server periodically sends, and to server feedback Time Calculation signal, server obtains and sends half value of signal and feedback signal time difference, and all values are sent to client, client obtains the network transfer delay waveforms by a plurality of described values.
4. the method for adjustment clock frequency according to claim 1, it is characterized in that, described method by the pulse of message recovery dummy clock is: the time interval of receiving two messages is set to high level, and the duration that message arrives is set to low level; The time interval of maybe receiving two messages is set to low level, and the duration that message arrives is set to high level.
5. according to the method for one of them described adjustment clock frequency of claim 1 to 4, it is characterized in that, in the preset time interval, the accumulated value that differs of dummy clock and local recovery clock surpasses the limit value that presets, and when the network transfer delay waveform shake of preset time at interval is not filtered, with the method that differs the accumulated value reduction of dummy clock and local recovery clock be: differing of dummy clock and local recovery clock made zero; Perhaps with the accumulated value that differs of current dummy clock and local recovery clock, deduct in this time interval by the network transfer delay waveform obtain by differing that network transfer delay causes.
6. a client of adjusting clock frequency is characterized in that, this client comprises: receiving element, Waveform fetch unit, filter element, limit value judging unit, shake judging unit, adjustment unit;
Receiving element is used to receive message;
Waveform fetch unit, be used to obtain the network transfer delay waveform, be used to also to obtain that server periodically sends travels to and fro between half of client and server network time delay value, form network transfer delay waveform by half of these described network delay values of periodically obtaining;
Filter element is used for arriving by the message that presets the scope of frequency and amplitude, filters the dummy clock pulse of the message recovery that receives; The shake of screen propagation delay time waveform;
The limit value judging unit is used for judging at preset time at interval, dummy clock and local recovery clock whether differ accumulated value above the limit value that presets;
The shake judging unit, be used for dummy clock and local recovery clock differ accumulated value when surpassing the limit value preset, judge whether to exist at interval to surpass the described message that presets and arrive frequency and shakes with the network transfer delay waveform of amplitude range at this preset time;
Adjustment unit is used for when there is not the network transfer delay waveform shake that surpasses described message arrival frequency that presets and amplitude range in the shake judging unit, and it is consistent with the dummy clock frequency to adjust the local recovery clock frequency; Obtain existing when surpassing the described message that presets and arriving the network transfer delay waveform shake of frequency and amplitude range at the shake judging unit, recovered clock and local clock differed the accumulated value reduction.
7. the client of adjustment clock frequency according to claim 6, it is characterized in that, described Waveform fetch unit, be used to also to obtain that server periodically sends travels to and fro between half of client and server network time delay value, form network transfer delay waveform by half of these described network delay values of periodically obtaining.
8. the client of adjustment clock frequency according to claim 6 is characterized in that, described adjustment unit specifically comprises: the unit that makes zero, adjustment local clock frequency cells;
The unit that makes zero is used for obtaining existing when surpassing the described message that presets and arriving the network transfer delay waveform shake of frequency and amplitude range at the shake judging unit, is changed to the accumulated value that differs of described dummy clock and local recovery clock zero;
Adjust the local clock frequency cells, be used for when there is not the network transfer delay waveform shake that surpasses described message arrival frequency that presets and amplitude range in the shake judging unit, it is consistent with the dummy clock frequency to adjust the local recovery clock frequency.
9. the client of adjustment clock frequency according to claim 6 is characterized in that, described adjustment unit further comprises: computing unit;
Computing unit, be used for when the shake judging unit obtains existing the network transfer delay waveform shake that surpasses described message arrival frequency that presets and amplitude range, with the accumulated value that differs of current dummy clock and local recovery clock, deduct in this time interval by the network transfer delay waveform obtain by differing that network transfer delay causes.
10. a system that adjusts clock frequency is characterized in that, this system comprises: server and client;
Server is used for sending message to client, and periodically travels to and fro between half of client and server network time delay value to what client sent statistics;
Client, be used to receive message, arrive frequency and the scope of amplitude by the message that presets and filter the dummy clock pulse that the message that receives recovers, receive travel to and fro between client and server network time delay value half also by described value formation network transfer delay waveform; Arrive the scope of frequency and amplitude, the shake of screen propagation delay time waveform by the message that presets; Judgement preset time at interval in, dummy clock and local recovery clock whether differ accumulated value above the limit value that presets, then be left intact if not; If then judge in this preset time interval, whether to exist and surpass the network transfer delay waveform shake that the described message that presets arrives frequency and amplitude range, it is consistent with the recovered clock frequency then to adjust the local clock frequency if not, if then the accumulated value that differs of recovered clock and local clock is reduced;
Perhaps
Server is used for sending message to client, and periodically obtains half that travel to and fro between client and server network time delay value; Send to client behind half formation network transfer delay waveform with described network delay value;
Client is used to receive message, receives the network transfer delay waveform; Arrive the scope of frequency and amplitude by the message that presets, filter the dummy clock pulse of the message recovery that receives, the shake of screen propagation delay time waveform; Judgement preset time at interval in, dummy clock and local recovery clock whether differ accumulated value above the limit value that presets, then be left intact if not; If then judge in this preset time interval, whether to exist and surpass the network transfer delay waveform shake that the described message that presets arrives frequency and amplitude range, it is consistent with the recovered clock frequency then to adjust the local clock frequency if not, if then the accumulated value that differs of recovered clock and local clock is reduced.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2007100799940A CN101022416B (en) | 2007-03-06 | 2007-03-06 | Method for regulating clock frequency, client and system |
| PCT/CN2008/070401 WO2008106887A1 (en) | 2007-03-06 | 2008-03-04 | A method for adjusting clock frequency, and a client and system thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2007100799940A CN101022416B (en) | 2007-03-06 | 2007-03-06 | Method for regulating clock frequency, client and system |
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| Publication Number | Publication Date |
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| CN101022416A CN101022416A (en) | 2007-08-22 |
| CN101022416B true CN101022416B (en) | 2010-07-07 |
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| CN2007100799940A Expired - Fee Related CN101022416B (en) | 2007-03-06 | 2007-03-06 | Method for regulating clock frequency, client and system |
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| CN (1) | CN101022416B (en) |
| WO (1) | WO2008106887A1 (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101022416B (en) * | 2007-03-06 | 2010-07-07 | 华为技术有限公司 | Method for regulating clock frequency, client and system |
| CN101222288B (en) * | 2008-02-01 | 2011-07-20 | 华为技术有限公司 | IP network transmission method, system and equipment automatically adapting network jitter |
| CN101986590A (en) * | 2010-11-03 | 2011-03-16 | 烟台持久钟表集团有限公司 | Secondary clock synchronous time precision detection device and method |
| CN105743681B (en) * | 2014-12-12 | 2019-04-05 | 国家电网公司 | A kind of the time delay visual analysis method and system of process layer communication network |
| CN107147462B (en) * | 2017-04-18 | 2019-01-15 | 福建天泉教育科技有限公司 | A kind of clock correcting method and system |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1311611A (en) * | 2000-03-01 | 2001-09-05 | 朗迅科技公司 | Synchronous filtering funcltion for base station transceiver to radio network controller |
| CN1852087A (en) * | 2005-12-21 | 2006-10-25 | 华为技术有限公司 | Clock synchronizing method in bag-exchanging network and realizing apparatus tehrefor |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1428965A (en) * | 2001-12-25 | 2003-07-09 | 深圳市中兴通讯股份有限公司上海第二研究所 | Method for correcting clock ageing of telecommunication equipment |
| US7151945B2 (en) * | 2002-03-29 | 2006-12-19 | Cisco Systems Wireless Networking (Australia) Pty Limited | Method and apparatus for clock synchronization in a wireless network |
| EP1573979A1 (en) * | 2002-12-12 | 2005-09-14 | Koninklijke Philips Electronics N.V. | A system and method for adapting transmission rate of a multimedia streaming server using a "virtual clock" |
| JP2006236251A (en) * | 2005-02-28 | 2006-09-07 | Fujitsu Ltd | Time stamp device, time calibration method and time calibration program |
| CN101022416B (en) * | 2007-03-06 | 2010-07-07 | 华为技术有限公司 | Method for regulating clock frequency, client and system |
-
2007
- 2007-03-06 CN CN2007100799940A patent/CN101022416B/en not_active Expired - Fee Related
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2008
- 2008-03-04 WO PCT/CN2008/070401 patent/WO2008106887A1/en active Application Filing
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1311611A (en) * | 2000-03-01 | 2001-09-05 | 朗迅科技公司 | Synchronous filtering funcltion for base station transceiver to radio network controller |
| CN1852087A (en) * | 2005-12-21 | 2006-10-25 | 华为技术有限公司 | Clock synchronizing method in bag-exchanging network and realizing apparatus tehrefor |
Also Published As
| Publication number | Publication date |
|---|---|
| WO2008106887A1 (en) | 2008-09-12 |
| CN101022416A (en) | 2007-08-22 |
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