CN104378194A

CN104378194A - Optimization method for mutual synchronization algorithm

Info

Publication number: CN104378194A
Application number: CN201410686735.4A
Authority: CN
Inventors: 王建兵; 赵铁军; 罗明阳; 高世幸
Original assignee: Chongqing Jinmei Communication Co Ltd
Current assignee: Chongqing Jinmei Communication Co Ltd
Priority date: 2014-11-26
Filing date: 2014-11-26
Publication date: 2015-02-25

Abstract

The invention discloses an optimization method used for mutual synchronization processing of network clocks. The method ensures that when no external device takes part in mutual synchronization or all relay links containing synchronous clock information are disconnected, the working clock of a device is automatically adjusted back to the center frequency position. By means of the improvement of the synchronization algorithm, the adjustable range of the working clock of the device is narrowed to be 1 PPM from original 50 PPM (the own accuracy of a clock crystal is 0.5 PPM, and in order to reduce the influence on the accuracy of the working clock by crystal ageing, the range is doubled to be 1PPM). The optimization method has the advantages that it can be ensured that the working clock of the local device is always in a small range close to the frequency of a center clock, and the requirement for the clock accuracy of FDMA service channel devices can be met; a device clock and a faulty clock which do not support synchronous processing can be isolated; whole network mutual synchronization convergence time can be effectively shortened, and the network clock oscillation probability is effectively reduced.

Description

A kind of optimization method of mutually synchronization algorithm

Technical field

The present invention relates to clock synchronous field, particularly relate to a kind of optimization method of mutually synchronization algorithm.

Background technology

Along with the fast development of electronic technology, the steady accuracy of clock crystal itself is more and more higher, but the frequency-adjustable wider range required due to mutually synchronization, may occur that the whole network clock significantly departs from the situation of equipment local oscillator (central clock frequency) after mutually synchronization adjustment.Both have impact on the steady accuracy of the whole network work clock, in turn increased the convergence time of the whole network clock, and therefore just needed to be optimized mutually synchronization Processing Algorithm.

Summary of the invention

The invention discloses a kind of optimization method of mutually synchronization process, the method comprises: when not having external equipment participation mutually synchronization adjustment or all repeated links comprising synchronised clock information disconnect, local device work clock adjusts automatically gets back to centre frequency position; Under mutually synchronization adjustment modes, improve work clock precision to 1PPM, rate by arranging adjustment threshold value to working clock frequency; Increase the effective judgement to each trunk clock, and then realize the function of bad clock isolation.

Advantageous Effects of the present invention is: can guarantee local device work clock be in all the time near central clock frequency more among a small circle in, meet FDMA Traffic Channel equipment to the requirement of clock accuracy; The equipment clock and failing clock not supporting mutually synchronization process can be isolated; Effectively can shorten the whole network mutually synchronization convergence time and network clocking concussion probability.

Accompanying drawing explanation

Fig. 1, mutually synchronization algorithm flow chart.

Fig. 2, step-length dynamic conditioning.

Embodiment

Mutually synchronization control algolithm is a processing procedure constantly circulated, and its flow chart is shown in Figure of description 1, and detailed process is as follows:

Step 1: the microcontroller being responsible for mutually synchronization computing at a fixed time interval detects and to receive synchronous mode SyncMode(mutually synchronization that master cpu issues, master-slave synchronisation, standard synchronous etc.), Synchronization Control word (local clock frequency preset value) and each repeated link clock weighted value, and enable follow-up synchronous computing; A kind of special circumstances when main control software detects that all repeated links all disconnect, just center frequency value can be handed down to microcontroller as parameter preset, issue the instruction forbidding mutually synchronization computing simultaneously; Now, equipment works in plesiochronous mode.

Step 2: utilize high accuracy, high frequency clock to carry out frequency counting to low-frequency clocks such as each repeated link clock and local device work clocks, Qie Duimei road clock all preserves many groups of (in the design being 5 groups) continuous print count values to be used as chock smotthing;

Step 3: carry out qualification judgement to each repeated link clock, if continuous several groups of clock count value are all in effective range (50PPM), then calculates the frequency-splitting of this road clock and local device work clock; Otherwise, judge that this road clock exists fault, not allowing to participate in follow-up frequency difference evaluation work, realizing the isolation features to changing road clock.

Step 4: each road clock frequency difference that integrating step 3 calculates and each right of way weight values that master control issues, weighted calculation goes out the comprehensive frequency difference frq of local device.

Step 5: the comprehensive frequency difference obtained according to step 4 calculates the adjustment step-length of local device clock frequency; In order to not only meet synchronous convergence faster but also ensure more stable genlocing, the design have employed dynamic step length adjustment algorithm, sees Figure of description 2.

Step 6: judge current synchronous mode: if mutually synchronization pattern, carries out threshold decision to the frequency targets value that step 5 calculates, if exceed the accuracy rating of 1PPM, then local working clock frequency is directly adjusted back center frequency points; If do not exceed the accuracy rating of 1PPM, then carry out normal frequency adjustment; Finally, step 1 is got back to.

Claims

1. an optimization method for related network clock interactive synchronization process, is characterized in that: when not having external equipment participation mutually synchronization adjustment or all repeated links comprising synchronised clock information disconnect, local device work clock gets back to centre frequency position; Under mutually synchronization adjustment modes, the machine work clock precision is improved (i.e. frequency-adjustable range shorter), both met the probability that some interconnect equipment (as the FDMA Traffic Channel equipment) requirement to clock accuracy also can reduce network clocking concussion; Increase the effective judgement to each trunk clock, and then realize the function of bad clock isolation.

2. the optimization method of network clocking mutually synchronization according to claim 1 process, is characterized in that: when not having repeated link clock to can be used for mutually synchronization process reference, local device work clock recalls to centre frequency immediately; Implementation is: to the newly-increased control message of the top level control software of handle link identification, when all repeated links comprising clock information disconnect, re-issues set of frequency message, frequency is adjusted back to central value to mutually synchronization module.

3. the optimization method of network clocking mutually synchronization according to claim 1 process, is characterized in that: local clock frequency adjustable extent is reduced into 1PPM by 50PPM; Its implementation is: after original line clock frequency detection, frequency-splitting process, comprehensive weighted differences calculate, threshold decision is carried out to the predetermined frequency value obtained: if exceed the scope of 1PPM, then by frequency coarse adjustment, local device work clock is recalled to centre frequency, and then the operating frequency of other interconnect equipments is drawn back near centre frequency; If do not exceed the scope of 1PPM, then maintain original dynamic adjusting method; After reducing frequency-adjustable scope, Local clock precision is improved, and can meet such as FDMA Traffic Channel equipment one class has the application of high clock accuracy requirement; Frequency-adjustable scope shortens, and significantly can also reduce the probability of network concussion and the convergence time of mutually synchronization.

4. the optimization method of network clocking mutually synchronization according to claim 1 process, is characterized in that: the effective judgement increasing trunk clock; If detect, certain trunk clock is in abnormality or not in effective adjusting range, the weight of Ze Jianggai road clock is set to engineering noise state, not using this clock as mutually synchronization reference, realize bad clock isolation.