CN101465707B - Method and system for transferring protection time in synchronous network - Google Patents
Method and system for transferring protection time in synchronous network Download PDFInfo
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- CN101465707B CN101465707B CN 200810241642 CN200810241642A CN101465707B CN 101465707 B CN101465707 B CN 101465707B CN 200810241642 CN200810241642 CN 200810241642 CN 200810241642 A CN200810241642 A CN 200810241642A CN 101465707 B CN101465707 B CN 101465707B
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04J—MULTIPLEX COMMUNICATION
- H04J3/00—Time-division multiplex systems
- H04J3/02—Details
- H04J3/06—Synchronising arrangements
- H04J3/0635—Clock or time synchronisation in a network
- H04J3/0638—Clock or time synchronisation among nodes; Internode synchronisation
- H04J3/0658—Clock or time synchronisation among packet nodes
- H04J3/0661—Clock or time synchronisation among packet nodes using timestamps
- H04J3/0667—Bidirectional timestamps, e.g. NTP or PTP for compensation of clock drift and for compensation of propagation delays
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Abstract
The invention discloses a method and a system for protecting time transfer in synchronization network; a corresponding module is added to the prior art to use time synchronization frequency of the synchronization network as the basis of time synchronization protocol, so the network is ensured to synchronously lock clock signal; a synchronization network clock source which participates in selection is configured, and the clock source selection mode is configured; current clock source is selected according to the selection mode, and the frequency state of the current clock source is synchronously locked; the current clock source state is used as state basis of accurate time protocol port to sequentially lock time of element location nodes in the synchronization network. The corresponding module is added to the prior art to use time synchronization frequency of the synchronization network as the basis of time synchronization protocol, so the time transfer error in element location nodes is greatly reduced, and the time error in large scale networking is reduced, and the stability of synchronization network is improved in the switching process of clock sources.
Description
Technical field
The present invention relates to the network communications technology field, relate in particular to a kind of guard time transmits in Synchronization Network method and system thereof.
Background technology
Time comprise synchronously two kinds of Frequency Synchronization and time synchronized, wherein Frequency Synchronization refers to that the signal of source and destination keeps certain specific relation in frequency or phase place, be that source keeps identical with the frequency of destination in certain precision, it differs is constant, common alleged clock synchronous namely, such as synchronous ethernet, E1 interface time synchronized etc.; Time synchronized refers to that not only frequency is identical but also also identical situation of phase place.
At present, it is Frequency Synchronization and time synchronized that wireless network has two ranks for the synchronisation requirement of time, but to based on TDD (Time Division Duplex: the time division duplex) wireless system of pattern, the respective version that also comprises CDMA200/TD-SCDMA and WiMAX, all need strict time synchronized, to guarantee finishing smoothly of residential quarter switching, Frequency Synchronization can be distributed solution by the ground clock signal at present, and (Global Positioning System: global positioning system) (Universal Time Coordinated: coordinated universal time) time service realizes module tracks UTC and time synchronized is mainly by installing GPS in the base station.In the prior art, (Private Telecommunication Network: Packet Transport Network) equipment passes through 1588 PTP (Precision Time Protocol: Precision Time Protocol) transmit Frequency Synchronization and time synchronized, the fail safe that can greatly improve the TDD network in network to PTN.
IEEE 1588 agreements are that the basic function of the precision interval clock synchronous protocol of network measure and control system is to make the precise time in the distributed network keep synchronous with other times.Do not have related but present most chip producer realizes the technology that time that 1588 protocol functions adopt transmits with Synchronization Network, thereby caused the transfer delay between two boundary nodes larger, in the situation of large-scale network-estabilishing, phase place is transmitted cumulative effect and is caused phase delay apparent in view, has reduced the synchronism of time.This shows that prior art awaits further developing.
Summary of the invention
The present invention provides a kind of guard time transmits in Synchronization Network method and system thereof for solving above-mentioned defective of the prior art; clock source is carried out scientific and reasonable selection; to reduce the error that the time transmits between the network element node; reduce the phase error of large-scale network-estabilishing, the stability of Synchronization Network when improving the clock source switching.
For solving the problems of the technologies described above, the present invention program comprises:
A kind of method that guard time transmits in Synchronization Network may further comprise the steps:
A, configuration participate in the SNC synchronous network clock source of selection, and dispose the selection mode of described clock source;
B, select the present clock source according to above-mentioned selection mode, and the frequency state in genlocing present clock source;
C, will this current clock source state as the state foundation of Precision Time Protocol port, each network element node time of locking synchronization net successively.
Described guard method, wherein, described step C also comprises:
When the clock source of a network element node was the present clock source of locking, the Precision Time Protocol port of this network element node was master port, and the Precision Time Protocol port of other network element nodes is from port.
Described guard method, wherein, described step C also comprises:
During the present clock source of locking corresponding a plurality of Precision Time Protocol logic port, according to the unique master port of priority locking of Precision Time Protocol logic port.
Described guard method, wherein, described step C also comprises:
When the present clock source of locking is internal clock, the Precision Time Protocol port of having no way of then.
Described guard method, wherein, described step C also comprises:
When the present clock source of locking is valid clock source and its when not entering lock-out state fully, the time of Precision Time Protocol enters hold mode and stops to follow the tracks of and issuing time stamp information.
Described guard method, wherein, described step C also comprises:
The Precision Time Protocol port in the invalid clock source in the Synchronization Network and configurable clock generator source not is not for enabling.
Described guard method, wherein, described steps A also comprises:
When selection mode is priority mode, select clock source according to priority.
Described guard method, wherein, described steps A also comprises:
When selection mode is the credit rating mode, select clock source according to Synchronization Status Message credit rating and priority.
Described guard method, wherein, described steps A also comprises:
When selection mode is expansion credit rating mode, select clock source according to Synchronization Status Message credit rating, credit rating node jumping figure and priority.
A kind of system that is implemented in the method that guard time transmits in the Synchronization Network, wherein, described system comprises configuration module, selects locking module and control module, described configuration module, described selection locking module and described control module communicate to connect together, and described configuration module is used for the clock source of configuration synchronization net, the selection mode of the described clock source of configuration;
The frequency state that described selection locking module is used for selecting the present clock source and locks the present clock source;
Described control module be used for to be determined the state foundation of Precision Time Protocol port, each network element node time of locking synchronization net successively, and this locking comprises relocking behind the switching time of the source, and selects principal and subordinate's port.
The invention provides a kind of guard time transmits in Synchronization Network method and system thereof; increase in the prior art corresponding module; with the time synchronized frequency of the Synchronization Network basis as time synchronization protocol; greatly reduced the error that the time transmits between the network element node; reduce the time error of large-scale network-estabilishing, improved the stability of Synchronization Network when clock source switches.
Description of drawings
Fig. 1 is the time synchronized schematic flow sheet of Synchronization Network among the present invention;
Fig. 2 be among the present invention between the network element node clock time transmit the networking schematic diagram;
Fig. 3 be among the present invention between the network element node locked clock time transmit the networking schematic diagram;
Fig. 4 selects clock time to transmit the schematic diagram of port between the network element node among the present invention;
Fig. 5 is the schematic diagram that clock time transmits during switching clock source between the network element node among the present invention.
Embodiment
Below with reference to accompanying drawing, comparatively detailed explanation is carried out in each preferred embodiment among the present invention.
A kind of guard time transmits in Synchronization Network method and system thereof provided by the invention; with the time synchronized frequency of the Synchronization Network basis as time synchronization protocol; greatly improved the synchronism of time between each network element node; reduced the error that the time transmits between the network element node; reduce the time error of large-scale network-estabilishing, greatly satisfied user's demand.As shown in Figure 1, the key step with the inventive method comprises:
A, configuration participate in the SNC synchronous network clock source of selection, and dispose the selection mode of described clock source; Wherein said selection mode is priority mode, credit rating mode or expansion credit rating mode, when selection mode is priority mode, selects clock source according to priority; When selection mode is the credit rating mode, select clock source according to Synchronization Status Message credit rating and priority; When selection mode is expansion credit rating mode, select clock source according to Synchronization Status Message credit rating, credit rating node jumping figure and priority;
B, select the present clock source according to above-mentioned selection mode, and the frequency state in genlocing present clock source; Describe as an example of IEEE 1588 agreements example;
C, will this current clock source state as the state foundation of Precision Time Protocol port, each network element node time of locking synchronization net successively; When clock source is the present clock source of locking, the Precision Time Protocol port of this clock source is from port, other configurations effectively and the port that includes Precision Time Protocol be master port, and during the corresponding a plurality of Precision Time Protocol logic port in the present clock source of locking, according to the priority locking of Precision Time Protocol logic port unique from port; But when the present clock source of locking is internal clock, the Precision Time Protocol port of having no way of then; When the present clock source of locking is that valid clock source and its be not when entering lock-out state fully, the time of Precision Time Protocol enters hold mode and stops to follow the tracks of and issuing time stamp information, when relocking the present clock source then with the present clock source state that the relocks state foundation as the Precision Time Protocol port, successively each network element node time of locking synchronization net; Certainly the Precision Time Protocol port in the invalid clock source in the Synchronization Network and configurable clock generator source not is not for enabling and then can not passing time.By above description as can be known, the present invention has reduced the error that the time transmits between the network element node greatly, has improved simultaneously the stability of Synchronization Network when clock source switches.
The present invention provides adaptive system for the efficient that better improves said method, it comprises configuration module, selects locking module and control module, described configuration module, described selection locking module and described control module communicate to connect together, and described configuration module is used for the clock source of configuration synchronization net, the selection mode of the described clock source of configuration; The frequency state that described selection locking module is used for selecting the present clock source and locks the present clock source; Described control module be used for to be determined the state foundation of Precision Time Protocol port, each network element node time of locking synchronization net successively, and this locking comprises relocking behind the switching time of the source, and selects principal and subordinate's port.This shows, increase corresponding module and with the time synchronized frequency of the Synchronization Network basis as time synchronization protocol, reduced the error of large-scale network-estabilishing lock in time, satisfied greatly user's demand.
As shown in Figure 1, for vivider explanation method provided by the invention, it mainly may further comprise the steps:
Step 101: configuration participates in synchronous Ethernet clock source or the 1588 agreement recovered clock sources of selection;
Step 102: configuration participates in the above-mentioned clock source selection mode of selection;
Step 103: carry out the selection of clock source according to the mode of clock source; Change respectively step 104, step 105, step 106 over to;
Step 104: when the selection mode was the credit rating mode, (SynchronizationStatus Message: Synchronization Status Message) credit rating and priority were selected clock source, then change step 107 over to according to SSM;
Step 105: when the selection mode is the expansion credit rating, select clock source according to SSM credit rating, credit rating node jumping figure and priority, then change step 107 over to;
Step 106: when the selection mode is priority mode, select clock source according to priority, then change step 107 over to;
Step 107: select the present clock source, after the clock of Synchronization Network enters the Frequency Locking state, with the present clock source state of each network element node in the Synchronization Network state foundation as 1588 (PTP) protocol port, then change respectively step 108, step 109, step 110 and step 111 over to;
Step 108: when the clock source of a network element node is the present clock source of locking, 1588 ports of this clock source are that the Slaver port is namely from port, other ports that dispose effective clock source and comprise 1588 agreements are that the Master port is master port, but during corresponding a plurality of 1588 logic port in present clock source, determine unique Slave port according to the priority of 1588 logic ports;
Step 109: when the present clock source of locking was internal clock, 1588 protocol ports were without the Slaver port, and the valid clock source of other configuration and the port that comprises 1588 protocol ports are the Master port;
Step 110: 1588 ports in the invalid clock source in the Synchronization Network and configurable clock generator source not are not for enabling, can not passing time;
Step 111: the present clock source of locking is valid clock source and when not entering into lock-out state, when namely it was Holdover mode or trap mode, the time of 1588 agreements entered hold mode, and stops to follow the tracks of and issuing time stamp information.As from the foregoing, the inventive method has reduced the error that the time transmits between the network element node, has improved the stability of Synchronization Network.
In order further to set forth the present invention, now describe as an example of IEEE 1588 agreements and networking structure as shown in Figure 2 example.As shown in Figure 2, the clock time network that the equipment such as network element node A, B, C, D, E, F form, A equipment access clock time source node only describes as an example of the credit rating selection mode example, and other modes are identical therewith, do not repeat them here.Each node port 1 of A equipment is set to priority 1, port 2 is set to priority 2, A equipment is by another port clock frequency locking external clock source, it is the Slaver port that the another port manually is set, port one and port 2 are the Master port, and network element Node B, C, D, E, F are set to select clock according to the SSM credit rating.After this moment the whole network clock being locked, as shown in Figure 3, e1 port, F1 port and D1 port are the present clock source port, it is network element node E locking network element node F clock source, network element node F locking network element node A clock source, network element node C locking network element Node B clock source, network element Node B locking network element node A clock source is according to the indication of the arrow among Fig. 3 successively locking.
When according to above-mentioned form locked clock source, as shown in Figure 4,1588 agreements begin to start, and selecting the present clock source is the Slaver port, and the valid clock source of other configuration and the port that comprises 1588 ports are the Master port; And 1588 protocol ports in the invalid clock source in the Synchronization Network and configurable clock generator source not are not for enabling, thereby can not passing time; Pointed according to the arrow among Fig. 4, A1 port and A2 port are the Master port, and port F1, E1, D1, C1 and B1 are respectively the Slaver port, and port F2, E2, D2, C2 and B2 are respectively the Master port.When network element node F2 port and network element node e1 port generation broken string, as shown in Figure 5, the network element node E time enters hold mode, network element node E2 port outwards sends the internal clock credit rating simultaneously, when being the 0xb credit rating, network element node D1 port receives the 0xb credit rating, then the 0xb credit rating that receives of network element node D 0xb credit rating that the D1 port is received and D2 port compares, as unanimously, then the clock source of network element node E switches, be that E2 port and D2 port translation are the Slaver port, E port one and D1 port translation are the Master port, and the reverse of whole network clock lock direction, and be indicated such as the arrow among Fig. 5, relock the time of whole network, but the lock in time of whole network is still identical with the lock in time of former network.By above description as can be known, the present invention still can keep the synchronous of network time when the network element node breaks down, and has improved greatly the stability of Synchronization Network.
In sum, a kind of guard time transmits in Synchronization Network method and system thereof provided by the invention, increase in the prior art corresponding module, with the time synchronized frequency of the Synchronization Network basis as time synchronization protocol, greatly improved the synchronism of time between each network element node, reduce the error that the time transmits between the network element node, reduced the time error of large-scale network-estabilishing; When network element node switching clock source, adopt port to exchange the mode that relocks, improved the stability of Synchronization Network time transmission, greatly satisfied user's demand, be the very big progress of prior art.
Should be understood that; above-mentioned description for preferred embodiment is comparatively detailed; can not therefore think the restriction to scope of patent protection of the present invention; those of ordinary skill in the art is under enlightenment of the present invention; do not breaking away from the scope situation that claim of the present invention protects; can also make the various deformation such as replacement, simple combination, these all fall within protection scope of the present invention, and the scope of asking for protection of the present invention should be as the criterion with claims.
Claims (5)
1. method that guard time transmits in Synchronization Network may further comprise the steps:
A, configuration participate in the SNC synchronous network clock source of selection, and dispose the selection mode of described clock source, and described selection mode is priority mode, credit rating mode or expansion credit rating mode;
B, select the present clock source according to above-mentioned selection mode, and the frequency state in genlocing present clock source;
C, will this current clock source state as the state foundation of Precision Time Protocol port, each network element node time of locking synchronization net, comprise: when clock source is the present clock source of locking, the Precision Time Protocol port of this clock source is from port, other configurations effectively and the port that includes Precision Time Protocol be master port; During the present clock source of locking corresponding a plurality of Precision Time Protocol logic port, according to the priority locking of Precision Time Protocol logic port unique from port; When the present clock source of locking is internal clock, the Precision Time Protocol port port of having no way of then, and other configurations effectively and the port that includes Precision Time Protocol be master port; When the present clock source of locking is valid clock source and its when not entering lock-out state fully, the time of Precision Time Protocol enters hold mode and stops to follow the tracks of and issuing time stamp information; The Precision Time Protocol port in the invalid clock source in the Synchronization Network and configurable clock generator source not is not for enabling.
2. the method that guard time transmits in Synchronization Network according to claim 1 is characterized in that described steps A also comprises:
When selection mode is priority mode, select clock source according to priority.
3. the method that guard time transmits in Synchronization Network according to claim 1 is characterized in that described steps A also comprises:
When selection mode is the credit rating mode, select clock source according to Synchronization Status Message credit rating and priority.
4. the method that guard time transmits in Synchronization Network according to claim 1 is characterized in that described steps A also comprises:
When selection mode is expansion credit rating mode, select clock source according to Synchronization Status Message credit rating, credit rating node jumping figure and priority.
5. system that guard time transmits in Synchronization Network, it is characterized in that, described system comprises configuration module, selects locking module and control module, described configuration module, described selection locking module and the communication connection of described control module are together, described configuration module is used for the clock source of configuration synchronization net, the selection mode of the described clock source of configuration, and described selection mode is priority mode, credit rating mode or expansion credit rating mode;
The frequency state that described selection locking module is used for selecting the present clock source and locks the present clock source;
Described control module is used for determining the state foundation of Precision Time Protocol port, and each network element node time of locking synchronization net comprises:
When clock source during for the present clock source of locking, the Precision Time Protocol port of this clock source be from port, and other configurations port effective and that include Precision Time Protocol is master port;
During the present clock source of locking corresponding a plurality of Precision Time Protocol logic port, according to the priority locking of Precision Time Protocol logic port unique from port;
When the present clock source of locking is internal clock, the Precision Time Protocol port port of having no way of then, and other configurations effectively and the port that includes Precision Time Protocol be master port;
When the present clock source of locking is valid clock source and its when not entering lock-out state fully, the time of Precision Time Protocol enters hold mode and stops to follow the tracks of and issuing time stamp information;
The Precision Time Protocol port in the invalid clock source in the Synchronization Network and configurable clock generator source not is not for enabling; This locking also comprises relocking behind the switching time of the source, and selects principal and subordinate's port.
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Families Citing this family (18)
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| CN102130766B (en) * | 2010-01-15 | 2013-12-04 | 华为技术有限公司 | Method, equipment and system for synchronizing Ethernet clock tracking |
| CN102237996B (en) * | 2010-04-26 | 2014-03-19 | 中兴通讯股份有限公司 | Clock synchronization method and clock synchronization device |
| CN102457346A (en) * | 2010-10-29 | 2012-05-16 | 中兴通讯股份有限公司 | Time synchronization realizing method and clock node |
| CN102469569B (en) | 2010-11-08 | 2014-09-10 | ***通信集团公司 | Time synchronization method of mobile communication system and synchronization device thereof |
| CN102006135A (en) * | 2010-12-03 | 2011-04-06 | 北京华环电子股份有限公司 | Method and device for selecting synchronous clock source |
| CN102388556B (en) * | 2011-09-20 | 2014-02-26 | 华为技术有限公司 | Method for clockclass grading and relative device |
| CN103051405B (en) * | 2011-10-14 | 2017-09-15 | 中兴通讯股份有限公司 | The implementation method and device of a kind of clock synchronization hybrid network |
| WO2013163803A1 (en) * | 2012-05-03 | 2013-11-07 | Telefonaktiebolaget L M Ericsson (Publ) | Intelligent supervision for configuration of precision time protocol (ptp) entities |
| CN103686982B (en) * | 2012-09-17 | 2017-03-29 | ***通信集团公司 | A kind of method for synchronizing time and node device based on clock information |
| CN102946291A (en) * | 2012-11-12 | 2013-02-27 | 华为技术有限公司 | Clock maintaining method and clock equipment |
| CN102983960A (en) * | 2012-12-06 | 2013-03-20 | 盛科网络（苏州）有限公司 | Method and device for implementing rapid synchronous switching in PTP (precision time protocol) |
| US9008128B2 (en) * | 2013-04-01 | 2015-04-14 | Broadcom Corporation | Low-cost port synchronization method in multiport Ethernet devices |
| US9654242B2 (en) | 2013-04-18 | 2017-05-16 | Telefonaktiebolaget Lm Ericsson (Publ) | Node and method for selecting synchronization source |
| CN106464396B (en) | 2014-05-09 | 2020-08-14 | 太阳专利信托公司 | Device-to-device synchronization source selection |
| CN105281932A (en) * | 2014-06-23 | 2016-01-27 | 中兴通讯股份有限公司 | A clock time source selection method and device and network elements |
| RU2717341C2 (en) * | 2018-02-20 | 2020-03-23 | Сан Пэтент Траст | Selecting device-device synchronization source |
| CN115549835A (en) * | 2021-06-30 | 2022-12-30 | 中兴通讯股份有限公司 | Method for avoiding clock ring formation, upstream network element, downstream network element and storage medium |
| CN115664627B (en) * | 2022-12-14 | 2023-03-10 | 四川创智联恒科技有限公司 | 1588 protocol-based frequency synchronization precision detection method and adaptive system |
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