CN101552663A - Passive optical network system and frequency and time synchronizing method thereof - Google Patents
Passive optical network system and frequency and time synchronizing method thereof Download PDFInfo
- Publication number
- CN101552663A CN101552663A CNA2008100875489A CN200810087548A CN101552663A CN 101552663 A CN101552663 A CN 101552663A CN A2008100875489 A CNA2008100875489 A CN A2008100875489A CN 200810087548 A CN200810087548 A CN 200810087548A CN 101552663 A CN101552663 A CN 101552663A
- Authority
- CN
- China
- Prior art keywords
- optical network
- network unit
- message
- line terminal
- described optical
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 230000003287 optical effect Effects 0.000 title claims abstract description 185
- 238000000034 method Methods 0.000 title claims abstract description 44
- 230000001360 synchronised effect Effects 0.000 claims abstract description 70
- 230000005540 biological transmission Effects 0.000 claims description 24
- 238000004364 calculation method Methods 0.000 claims description 13
- 238000012423 maintenance Methods 0.000 claims description 8
- 230000004044 response Effects 0.000 claims description 5
- 230000003111 delayed effect Effects 0.000 claims description 4
- 238000010586 diagram Methods 0.000 description 7
- 238000004891 communication Methods 0.000 description 4
- 238000005516 engineering process Methods 0.000 description 4
- 239000000284 extract Substances 0.000 description 4
- 238000003780 insertion Methods 0.000 description 4
- 230000037431 insertion Effects 0.000 description 4
- 230000007246 mechanism Effects 0.000 description 4
- 230000000694 effects Effects 0.000 description 3
- 238000000605 extraction Methods 0.000 description 3
- 230000006855 networking Effects 0.000 description 3
- 238000010295 mobile communication Methods 0.000 description 2
- 239000012141 concentrate Substances 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 230000009191 jumping Effects 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000002674 ointment Substances 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 238000012797 qualification Methods 0.000 description 1
- 230000008521 reorganization Effects 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
Images
Abstract
The invention provides a passive optical network system and a frequency and time synchronizing method in the same. The method comprises the following steps: the frequency and the time are synchronized towards an optical network unit in an optical line terminal; PLOAM type information is periodically alternated between the optical line terminal and the optical network unit; the time deviation of the optical line terminal and the optical network unit is obtained by calculating the time of the information; and the time deviation is dynamically compensated on the optical network unit to synchronize the time and the frequency of the optical network unit and the optical line terminal. The invention synchronizes the time and the frequency in the passive optical network.
Description
Technical field
The present invention relates to the communications field, in particular to a kind of passive optical network and the method for synchronous of frequency and time thereof.
Background technology
The implication that comprises two aspects in the communication system synchronously:
Frequency: Frequency Synchronization is to avoid slip to need separately Frequency Synchronization when being processing signals such as transmission, exchange;
Time: time synchronized is that the time and the universal time of equipment is harmonious, also claims Phase synchronization.
Communication network is to all having requirement, particularly wireless device synchronously between communication system, and following table has been listed wireless device to synchronous specific requirement:
| Wireless technology | The Clock Frequency Accuracy requirement | The time synchronized requirement |
| GSM | 0.05ppm | NA |
| WCDMA | 0.05ppm | NA |
| CDMA2000 | 0.05ppm | 3us |
| TD·SCDMA | 0.05ppm | 1.5us |
| WiMax | 0.05ppm | 1us |
| LTE | 0.05ppm | Tend to adopt time synchronized |
EPON (PON, Passive Optical Network) technology is the light access technology of a kind of point to multiple spot, it is by OLT (the Optical Line Terminal of office's side, optical line terminal), the ONU of user side (Optical Network Unit, optical network unit) and ODN (Optical Distribution Network, Optical Distribution Network) form.EPON has polytype, roughly can be divided into wavelength-division PON, power P ON and these the two kinds mixing PON that mutually combine.Power P ON is again because of the agreement difference of link layer, be divided into APON (ATM Passive Optical Network, the EPON of asynchronous transfer mode), GPON (Gigabit Passive Optical Network, Gigabit Passive Optical Network) and EPON (Ethernet Passive Optical Network, ethernet passive optical network).
Power P ON, general its descending employing TDM (Time Division Multiplex, time division multiplexing) broadcast mode, up employing TDMA (Time Division MultipleAccess, time division multiple access inserts) mode, and can form topological structures (typical structure is a tree structure) such as tree type, star-like, bus-type neatly.
So-called mixing PON is meant in an ODN network and has a plurality of power P ON simultaneously that these power P ON adopts different wavelength.
The PON network can be used as the bearer network that inserts section, and Fig. 1 shows the schematic diagram of PON in the networking and the clock transmission of moving communicating field, is illustrated in figure 1 as the typical networking of PON in mobile communication.PON need finish the transmission of two tasks: the transmission of Business Stream and the transmission of clock synchronization have provided the transmission and the method for salary distribution of clock stream in the accompanying drawing 1.
Itself has only realized Frequency Synchronization the PON procotol, and promptly ONU is synchronized with OLT, but the phase difference of each ONU is arbitrarily, promptly can't support time synchronized, can't satisfy mobile communication or the free network application that requires synchronously.
IEEE1588 can realize the frequency and the time synchronized of LA Management Room.
1) hypothesis of characteristic symmetry Network Based adopts master-slave mode, stabs mark at the enterprising line time of Packet, the cycle clock issue, and the recipient carries out clock skew and measures and delay measurements;
2) point-to-point link can provide the highest precision, introduces boundary clock, and is irrelevant with delay jitter, can reach every jumping 10ns level time accuracy;
3) can realize frequency and time synchronized.
Its detailed realization mechanism is described below, and Fig. 2 shows the schematic diagram of IEEE1588 agreement realization mechanism.
1) supposition Master (master) and Slave (from) time difference of equipment room is Offset;
2) send the sync packet of being with timestamp to Slave equipment at T1 moment Master equipment, Slave equipment receives sync message constantly at its local T2, can set up following equation, wherein Delay is that sync message is slow to the propagation delay time of Slave equipment from Master equipment.
T2＝T1+Delay+Offset-------------------(1)
3) Master equipment sends Follow_up (tracking) message to Slave equipment;
4) Slave equipment sends Delay_Req (postponing request) message to Master equipment constantly at local T3;
5) Master equipment sends Delay_Resp (delayed response) message to Slave equipment constantly at its local T4.Can set up following equation:
T4＝T3+Delay-Offset----------------(2)
6) associating equation (1) and (2) can be obtained the Offset value.
7) periodically send at Master and Slave equipment room, Sync (synchronously) message, Follow_up (tracking) message, Delay_Req (postponing request) message and Delay_Resp (delayed response) message, just can dynamically upgrade the Offset value, thereby keep Slave equipment on time and frequency, to be synchronized with Master equipment.
8) Master equipment and Slave equipment room can obtain the time accuracy of 10ns level.
From top description as can be known, the IEEE1588 agreement is based on the hypothesis of network characteristic symmetry, i.e. delay and jitter from Master equipment to Salve equipment, identical with delay and jitter from Slave equipment to Master equipment, and the link flapping size has directly determined the precision of time synchronized.
The GPON network, i.e. the ITU PON network of standard G.984.1 ~ 4, the protocol stack of GPON network carrying Ethernet protocol bag as shown in Figure 3 is adopted in its carrying to Ethernet service.For improving load-carrying efficiency, cutting and reorganization that GEM can wrap the upper-layer service data flow, a message of upper layer data stream might be cut into many parts like this, each part is sent out at unfixed different time point, whether all bursts of receiving end detection packet are here, assemble after here, recover complete upper layer data message.
In realizing process of the present invention, the inventor finds that there are the following problems at least in the prior art: concerning the upper layer data message, the GPON network is a unfixed network of delay, be that its shake is very big, the IEEE1588 agreement can't directly be moved on the GPON network, therefore, in EPON, can not guarantee ONU frequency and on the time precise synchronization in OLT.
Summary of the invention
The present invention aims to provide the method for synchronous of a kind of passive optical network and frequency and time, with solve in EPON, can not guarantee ONU frequency and on the time precise synchronization in the problem of OLT.
In an embodiment of the present invention, a kind of EPON medium frequency and the method for synchronous of time are provided, comprise: carry out Frequency Synchronization at optical line terminal to optical network unit, also comprise the steps: the message of periodically mutual PLOAM (physical layer operations management maintenance) form between optical line terminal and the optical network unit; By the Time Calculation of message being obtained the time deviation between optical line terminal and optical network unit; And at the dynamic compensation of the enterprising line time deviation of optical network unit so that frequency and time synchronized between optical network unit and optical line terminal.
Preferably, according to the method for synchronous of the embodiment of the invention, also comprised before the message of optical network unit transmission PLOAM form at optical line terminal: adopt the method for IEEE1588 agreement between the higher level equipment of optical line terminal and optical line terminal, to carry out frequency and time synchronized.
Preferably, according to the method for synchronous of the embodiment of the invention, after the dynamic compensation of the enterprising line time deviation of optical network unit, also comprise: adopt the method for IEEE1588 agreement to carry out frequency and time synchronized at the second line of a couplet equipment room of optical network unit and optical network unit.
Preferably, according to the method for synchronous of the embodiment of the invention, the message of PLOAM form specifically comprises: Sync, Follow_up, Delay_Req and Delay_Resp message.
Preferably, method for synchronous according to the embodiment of the invention, the message of periodically mutual PLOAM form specifically comprises between optical line terminal and the optical network unit: optical line terminal equipment is operated in the Master pattern of clock, and optical network unit operates in the Slave pattern of clock; Optical line terminal is to the synchronous PLOAM message Sync of optical network unit transmission band timestamp constantly at T1, and optical network unit receives synchronous PLOAM message Sync constantly at T2; Optical line terminal equipment sends Follow_up PLOAM message to device of optical network unit; Device of optical network unit sends Delay_ReqPLOAM message to optical line terminal equipment constantly at T3, and optical line terminal equipment sends Delay_Resp PLOAM message to device of optical network unit constantly at T4.
Preferably, according to the method for synchronous of the embodiment of the invention, the time deviation that obtains between optical line terminal and optical network unit by the Time Calculation to message specifically comprises: set up equation group:
T2＝T1+Delay+Offset----------------(1)
T4＝T3+Delay-Offset----------------(2)
Wherein Delay is that the propagation delay time of synchronous PLOAM message from the optical line terminal to the optical network unit is slow, therefrom obtains the Offset value as the time difference.
Preferably, according to the method for synchronous of the embodiment of the invention, the message of PLOAM form is the message of not cutting into slices.
In an embodiment of the present invention, also provide a kind of passive optical network, comprised optical line terminal and optical network unit, optical line terminal is used for the message with the periodically mutual PLOAM form of optical network unit; Optical network unit is used for by the Time Calculation of message being obtained the time deviation between optical line terminal and optical network unit, the dynamic compensation that carries out time deviation with optical line terminal frequency and time synchronized.
Preferably, passive optical network according to the embodiment of the invention, the message of periodically mutual PLOAM form specifically comprises between optical line terminal and the optical network unit: optical line terminal equipment is operated in the Master pattern of clock, and optical network unit operates in the Slave pattern of clock; Optical line terminal is to the synchronous PLOAM message Sync of optical network unit transmission band timestamp constantly at T1, and optical network unit receives synchronous PLOAM message Sync constantly at T2; Optical line terminal equipment sends Follow_up PLOAM message to device of optical network unit; Device of optical network unit sends Delay_ReqPLOAM message to optical line terminal equipment constantly at T3, and optical line terminal equipment sends Delay_Resp PLOAM message to device of optical network unit constantly at T4.
Preferably, according to the passive optical network of the embodiment of the invention, optical network unit specifically comprises: the equation module is used to set up equation group:
T2＝T1+Delay+Offset----------------(1)
T4＝T3+Delay-Offset----------------(2)
Wherein Delay is that the propagation delay time of synchronous PLOAM message from the optical line terminal to the optical network unit is slow; Computing module is used for obtaining the Offset value as the time difference from equation group.
The present invention is because adopt the method for the message of periodically mutual PLOAM form between optical line terminal and the optical network unit, so overcome in EPON, can not guarantee ONU frequency and on the time precise synchronization and then reached the effect of EPON medium frequency and time synchronized in the problem of OLT.
Description of drawings
Accompanying drawing described herein is used to provide further understanding of the present invention, constitutes the application's a part, and illustrative examples of the present invention and explanation thereof are used to explain the present invention, do not constitute improper qualification of the present invention.In the accompanying drawings:
Fig. 1 shows the schematic diagram of PON in the networking and the clock transmission of moving communicating field;
Fig. 2 shows the schematic diagram of IEEE1588 agreement realization mechanism;
Fig. 3 shows the schematic diagram of the protocol stack of GPON network carrying Ethernet protocol bag;
Fig. 4 shows according to the EPON medium frequency of the embodiment of the invention and the flow chart of the method for synchronous of time;
Fig. 5 shows the block diagram according to the passive optical network of the embodiment of the invention;
Fig. 6 shows the structure chart that the OLT side realizes and the ONU side realizes according to the embodiment of the invention;
Fig. 7 shows the flow chart of EPON medium frequency and the method for synchronous of time according to the preferred embodiment of the invention.
Embodiment
Below with reference to the accompanying drawings and in conjunction with the embodiments, describe the present invention in detail.
Fig. 4 shows according to the EPON medium frequency of the embodiment of the invention and the flow chart of the method for synchronous of time, in an embodiment of the present invention, a kind of EPON medium frequency and the method for synchronous of time are provided, comprise: carry out Frequency Synchronization at optical line terminal to optical network unit, also comprise the steps:
Step S10, the message of periodically mutual PLOAM form between optical line terminal and the optical network unit;
Step S20 is by obtaining the time deviation between optical line terminal and optical network unit to the Time Calculation of message; And
Step S30, at the dynamic compensation of the enterprising line time deviation of optical network unit so that frequency and time synchronized between optical network unit and optical line terminal.
This embodiment is because adopt the method for the message of periodically mutual PLOAM form between optical line terminal and the optical network unit, so overcome in EPON, can not guarantee ONU frequency and on the time precise synchronization and then reached the effect of EPON medium frequency and time synchronized in the problem of OLT.This method for example can be suitable for G.984.1～4 EPON of standard of ITU standard.
Preferably, according to the method for synchronous of the embodiment of the invention, also comprised before the message of optical network unit transmission PLOAM form at optical line terminal: adopt the method for IEEE1588 agreement between the higher level equipment of optical line terminal and optical line terminal, to carry out frequency and time synchronized.
Preferably, according to the method for synchronous of the embodiment of the invention, after the dynamic compensation of the enterprising line time deviation of optical network unit, also comprise: adopt the method for IEEE1588 agreement to carry out frequency and time synchronized at the second line of a couplet equipment room of optical network unit and optical network unit.And then the second line of a couplet equipment that links to each other with optical network unit of assurance is with the internetwork frequency of the first line of a couplet and the time synchronized that link to each other with optical line terminal, and then the frequency and the time synchronized of the second line of a couplet equipment room that links to each other with optical network unit of realization.Realized frequency and time relay transmission in the EPON section.
Preferably, according to the method for synchronous of the embodiment of the invention, the message of PLOAM form specifically comprises: Sync, Follow_up, Delay_Req and Delay_Resp message.
Preferably, according to the method for synchronous of the embodiment of the invention, the message of PLOAM form is the message of not cutting into slices.
This embodiment is at OLT and first line of a couplet equipment room and ONU and second line of a couplet equipment room operation IEEE1588 clock protocols, and in the PON of OLT and ONU section, adopt the method for the message of periodically mutual PLOAM form between optical line terminal and the optical network unit, the transmission of realization time and frequency, this embodiment gets up the time that reaches between second line of a couplet equipment and ONU between first line of a couplet equipment and OLT in the operation of PON section to bridge joint.
This embodiment utilizes the distinctive POLAM message of GPON, realization time and frequency are in the transmission of PON section, PLOAM is not by burst in the transmission of PON section, PLOAM message is to send as an overall time to finish when being sent out, avoid the GPON network upper-layer protocol data message is postponed unfixed characteristic, the synchronous transmission of realization time and frequency on the PON network, guarantee that each ONU has identical time and frequency, if the IEEE1588 agreement of operation standard between ONU and its subordinate equipment, ONU can also accurately pass to subordinate equipment to frequency and time, guarantees that the equipment room that connects under each ONU also has identical frequency and time.
Fig. 5 shows the block diagram according to the passive optical network of the embodiment of the invention, and passive optical network comprises optical line terminal and optical network unit:
This embodiment is because adopt the method for the message of periodically mutual PLOAM form between optical line terminal and the optical network unit, so overcome in EPON, can not guarantee ONU frequency and on the time precise synchronization and then reached the effect of EPON medium frequency and time synchronized in the problem of OLT.
Fig. 6 shows the structure chart that the OLT side realizes and the ONU side realizes according to the embodiment of the invention, example goes out the extraction and the insertion position of IEEE1588 protocol massages and PLOAM message of the present invention among the figure, and Shi Yi position is carried out the extraction of PLOAM message and IEEE1588 protocol massages and inserted the accuracy that can improve frequency and time synchronized in the drawings.
Fig. 7 shows the flow chart of EPON medium frequency and the method for synchronous of time according to the preferred embodiment of the invention, and PON network of the preferred embodiment and time synchronized mechanism implementation method specifically comprise:
In the IEEE1588 agreement of OLT and coupled equipment room operation standard, higher level equipment operates in the Master pattern, and OLT operates in the Slave pattern, OLT frequency and on the time precise synchronization in higher level equipment;
The time difference of supposing " higher level equipment " and OLT equipment room is Offset;
Send the sync message of being with timestamp in the T1 moment " higher level equipment " to OLT, OLT equipment receives sync message constantly at its local T2, sets up following equation, and wherein Delay is that the propagation delay time of sync message from " higher level equipment " to OLT is slow.
T2＝T1+Delay+Offset---------------(1)
" higher level equipment " sends Follow_up message to OLT;
OLT sends Delay_Req message to " higher level equipment " constantly at local T3;
" higher level equipment,, send Delay_Resp message to OLT constantly at its local T4.Set up following equation:
T4＝T3+Delay-Offset----------------(2)
The Offset value can be obtained in associating equation (1) and (2).
Periodically send between " higher level equipment " and OLT, Sync, Follow_up, Delay_Req and Delay_Resp message just can dynamically be upgraded the Offset value.
OLT carry out time deviation (Offset) dynamically, real-Time Compensation, just can realize that OLT is synchronized with " higher level equipment " in frequency with on the time.
Just can realize the active and standby of clock source if OLT connects two " higher level equipments " simultaneously, network reliability is provided, the selection in master/backup clock source realizes according to the IEEE15888 agreement.
Between OLT and ONU, do not move the IEEE1588 agreement of standard.The OLT equipment work is in the Master of clock pattern, and ONU operates in the Slave pattern, ONU frequency and on the time precise synchronization in OLT;
The time difference of supposing OLT and ONU equipment room is Offset;
OLT is to the synchronous PLOAM message Sync of ONU transmission band timestamp constantly at T1, and ONU receives synchronous PLOAM message constantly at its local T2, sets up following equation, and wherein Delay is that the propagation delay time of synchronous PLOAM message from OLT to ONU is slow.
T2＝T1+Delay+Offset----------------(1)
OLT equipment sends Follow_up PLOAM message to ONU equipment;
ONU equipment sends Delay_Req PLOAM message to OLT equipment constantly at local T3;
OLT equipment sends Delay_RespPLOAM message to ONU equipment constantly at its local T4, sets up following equation:
T4＝T3+Delay-Offset----------------(2)
The Offset value can be obtained in associating equation (1) and (2).
Cycle dynamics repeats a)～f) step between OLT and ONU, and ONU is dynamic with regard to energy, real-time update calculates the Offset value.
Dynamic, real-Time Compensation in the enterprising line time deviation of ONU (Offset) just can realize that ONU is synchronized with OLT in frequency with on the time.
Each ONU is synchronized with OLT, has just realized the precise synchronization of frequency and time between each ONU.
Operation standard IEEE 1588 agreements between ONU and " second line of a couplet equipment ", " second line of a couplet equipment " can frequency and on the time precise synchronization be exactly the base station in ONU at moving communicating field " second line of a couplet equipment ".
Method for synchronous according to the preferred embodiment of the invention, in order to guarantee time precision, the protocol massages of passing time is is all received and dispatched with hardware.
Structure chart with reference to Fig. 6 specific implementation of the present invention.Realization on the OLT:
1) realization on the Uplink interface:
Between last connecting port PHY and MAC, put into a slice FPGA ASIC of identical function (also), be used for the extraction and the insertion of IEEE1588 protocol massages.
Down direction: the message of receiving from the UP-link port, whether FPGA analyzes it is the IEEE1588 protocol package, if protocol massages, then extract the timestamp that comprises in this protocol massages, and write down the moment that last BIT of this protocol massages (bit) arrives, the moment of receiving this message for this locality; If not the IEEE1588 protocol massages, then give follow-up MAC (or exchange chip of master control borad) this message and further handle.
Up direction: the IEEE1588 protocol package of sending here from CPU, write in the FPGA, sent by FPGA, the timestamp that protocol package is carried is inserted when sending this message by hardware, insertion be the local zone time (send message in timestamp territory one BIT constantly local zone time) of this message when sending.FPGA also is responsible for the transmission from coupled ethernet mac (or exchange chip of master control borad) packet.
Time difference (Offset) between OLT equipment and " higher level equipment ", realize by FPGA hardware, read for CPU.
The phase locked algorithm of CPU is controlled the output of OLT system digits phase-locked loop according to Offset, system clock and control signals such as 8K, 1S pulse that the generation system needs.Because the IEEE protocol massages, the cycle sends and receives, and the time difference (Offset) between OLT equipment and " higher level equipment " also is in real time, dynamically updates, assurance OLT frequency and on the time precise synchronization in " higher level equipment ".
2) realization on the PON interface
PON MAC realizes sending and receiving with identical function Sync, Follow_up, Delay_Req and the Delay_Resp PLOAM message of IEEE 1588 protocol specifications.
CPU writes PON MAC to sync, follow_up PLOAM message, and MAC is responsible for message is sent to ONU from the PON mouth, when transmitting time is stabbed territory the one bit, the OLT local zone time is inserted into the timestamp territory of these two PLOAM message.
After OLT received the Delay_Req PLOAM message of sending from ONU, OLTMAC sent Delay_Resp PLOAM message to ONU immediately, when transmitting time is stabbed territory the one bit, the OLT local zone time was inserted into the timestamp territory of this PLOAM message.
Realization on the ONU:
1) realization on the PON interface:
PON MAC realizes sending and receiving with identical function Sync, Follow_up, Delay_Req and the Delay_Resp PLOAM message of IEEE1588 protocol specification.
Down direction: the PLOAM message of receiving from the PON interface, whether PON MAC analyzes it is sync PLOAM, if sync is PLOAM, then extract the timestamp that comprises in this protocol massages, and write down the moment that last BIT of this PLOAM arrives, the moment of receiving this sync PLOAM for this locality; If not sync PLOAM, then give follow-up functional module this PLOAM and further handle.
Down direction: the PLOAM message of receiving from the PON interface, whether PON MAC analyzes it is Follow_up PLOAM, if Follow_up is PLOAM, then respond a Delay_Req PLOAM message to OLT, and write down when sending this PLOAM message clock stamp territory the one BIT, the local time is worth constantly; If not Follow_upPLOAM, then give follow-up functional module this PLOAM and further handle.
Down direction: from the PLOAM message that the PON interface is received, whether PON MAC analyzes it is Delay_Resp PLOAM, if Delay_Resp is PLOAM, then extracts the timestamp of this PLOAM message clock zone; If not Delay_RespPLOAM PLOAM, then give follow-up functional module this PLOAM and further handle.
According to sync PLOAM, in the moment that timestamp that Delay_Req and Delay_Resp PLOAM carry and PLOAM message arrive or send, calculate the time difference (Offset) between ONU and OLT.Offset calculates by hardware and realizes, reads for CPU.
The phase locked algorithm of CPU, control the output of ONU system digits phase-locked loop according to Offset, the system clock that the generation system needs, with control signals such as 8K, 1S pulses, be used for ONU system itself and use or give " second line of a couplet equipment ", use as the base station, the base station can obtain the pulse per second (PPS) from ONU thus.Certainly this pulse per second (PPS) also may be modulated at certain expense BIT of TDM interface.
The cycle sends Sync, Follow_up, Delay_Req and Delay_Resp PLOAM message between OLT and ONU, dynamically updates the time difference (Offset) between ONU and OLT, guarantees that the ONU precise synchronization in OLT, comprises clock frequency and time.
2) realization on the uni interface
Between the PHY of uni interface and the MAC of exchange chip, put into a slice FPGA (also can be the ASIC of identical function) and realize that IEEE1588 synchronous protocol message receives and sends, operation IEEE1588 agreement between realization and ONU " second line of a couplet equipment " (base station).
Up direction: the message of receiving from uni port, whether FPGA analyzes it is the IEEE1588 protocol package, if protocol massages then extracts the timestamp that comprises in this protocol massages, and write down the moment that last BIT of this protocol massages arrives, the moment of receiving this message for this locality; If not the IEEE1588 protocol massages, then give follow-up MAC (or the exchange chip on the ONU) this message and further handle.
Down direction: the IEEE1588 protocol package of sending here from CPU, write in the FPGA, sent by FPGA, the timestamp that protocol package is carried is inserted when sending this message by hardware, insertion be the local zone time (send message in timestamp territory one BIT constantly local zone time) of this message when sending.FPGA also is responsible for the transmission from coupled ethernet mac (or exchange chip of master control borad) packet.
By operation IEEE1588 agreement on the uni interface, realize frequency and the precise synchronization of time between ONU and its " second line of a couplet equipment " (base station).
The definition of time PLOAM message:
1) Sync PLOAM message: direction OLT-＞ONU
2) Follow_up PLOAM message: direction OLT-＞ONU
3) Delay_Resp PLOAM message: direction OLT-＞ONU
4) Delay_Req PLOAM message: direction ONU-＞OLT
Obviously, those skilled in the art should be understood that, above-mentioned each module of the present invention or each step can realize with the general calculation device, they can concentrate on the single calculation element, perhaps be distributed on the network that a plurality of calculation element forms, alternatively, they can be realized with the executable program code of calculation element, thereby, they can be stored in the storage device and carry out by calculation element, perhaps they are made into each integrated circuit modules respectively, perhaps a plurality of modules in them or step are made into the single integrated circuit module and realize.Like this, the present invention is not restricted to any specific hardware and software combination.
The above is the preferred embodiments of the present invention only, is not limited to the present invention, and for a person skilled in the art, the present invention can have various changes and variation.Within the spirit and principles in the present invention all, any modification of being done, be equal to replacement, improvement etc., all should be included within protection scope of the present invention.
Claims (10)
1. EPON medium frequency and the method for synchronous of time is characterized in that, comprising: carry out Frequency Synchronization at optical line terminal to optical network unit, also comprise the steps:
The message of periodically mutual physical layer operations management maintenance form between described optical line terminal and the described optical network unit;
Obtain time deviation between described optical line terminal and described optical network unit by Time Calculation to described message; And
At the dynamic compensation that carries out described time deviation on the described optical network unit so that frequency and time synchronized between described optical network unit and described optical line terminal.
2. method for synchronous according to claim 1 is characterized in that, also comprises before the message of optical network unit transmission physical layer operations management maintenance form at optical line terminal:
Adopt the method for IEEE1588 agreement between the higher level equipment of described optical line terminal and described optical line terminal, to carry out frequency and time synchronized.
3. method for synchronous according to claim 1 is characterized in that, carries out also comprising after the dynamic compensation of described time deviation on described optical network unit:
Adopt the method for IEEE1588 agreement to carry out frequency and time synchronized at the second line of a couplet equipment room of described optical network unit and described optical network unit.
4. method for synchronous according to claim 1 is characterized in that, the message of described physical layer operations management maintenance form specifically comprises:
Synchronization message, tracking message, delay request message and delayed response message.
5. method for synchronous according to claim 4 is characterized in that, the message of periodically mutual physical layer operations management maintenance form specifically comprises between described optical line terminal and the described optical network unit:
Described optical line terminal equipment is operated in the holotype of clock, described optical network unit operate in clock from pattern;
Described optical line terminal is to the described synchronization message of described optical network unit transmission band timestamp constantly at T1, and described optical network unit receives described synchronization message constantly at T2;
Described optical line terminal equipment sends described tracking message to described device of optical network unit;
Described device of optical network unit constantly sends described delay request message to described optical line terminal equipment at T3, and described optical line terminal equipment constantly sends described delayed response message to described device of optical network unit at T4.
6. method for synchronous according to claim 5 is characterized in that, the time deviation that obtains between described optical line terminal and described optical network unit by the Time Calculation to described message specifically comprises:
Set up equation group:
T2＝T1+Delay+Offset----------------(1)
T4＝T3+Delay-Offset----------------(2)
Wherein Delay is that the propagation delay time of described synchronization message from described optical line terminal to described optical network unit is slow, therefrom obtains the Offset value as the described time difference.
7. method for synchronous according to claim 1 is characterized in that, the message of described physical layer operations management maintenance form is the message of not cutting into slices.
8. a passive optical network comprises optical line terminal and optical network unit, it is characterized in that:
Described optical line terminal is used for the message with the periodically mutual physical layer operations management maintenance form of described optical network unit;
Described optical network unit is used for obtaining time deviation between described optical line terminal and described optical network unit by the Time Calculation to described message, the dynamic compensation that carries out described time deviation with described optical line terminal time and Frequency Synchronization.
9. passive optical network according to claim 8 is characterized in that, the message of periodically mutual physical layer operations management maintenance form specifically comprises between described optical line terminal and the described optical network unit:
Described optical line terminal equipment is operated in the holotype of clock, described optical network unit operate in clock from pattern;
Described optical line terminal is to the synchronization message of described optical network unit transmission band timestamp constantly at T1, and described optical network unit receives described synchronization message constantly at T2;
Described optical line terminal equipment sends tracking message to described device of optical network unit;
Described device of optical network unit at T3 constantly to described optical line terminal equipment transmission lag request message, described optical line terminal equipment at T4 constantly to described device of optical network unit transmission lag response message.
10. passive optical network according to claim 9 is characterized in that, described optical network unit specifically comprises:
The equation module is used to set up equation group:
T2＝T1+Delay+Offset----------------(1)
T4＝T3+Delay-Offset----------------(2)
Wherein Delay is that the propagation delay time of described synchronization message from described optical line terminal to described optical network unit is slow;
Computing module is used for obtaining the Offset value as the described time difference from equation group.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200810087548 CN101552663B (en) | 2008-04-02 | 2008-04-02 | Passive optical network system and frequency and time synchronizing method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200810087548 CN101552663B (en) | 2008-04-02 | 2008-04-02 | Passive optical network system and frequency and time synchronizing method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN101552663A true CN101552663A (en) | 2009-10-07 |
| CN101552663B CN101552663B (en) | 2012-12-19 |
Family
ID=41156673
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 200810087548 Expired - Fee Related CN101552663B (en) | 2008-04-02 | 2008-04-02 | Passive optical network system and frequency and time synchronizing method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN101552663B (en) |
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2011120185A1 (en) * | 2010-03-29 | 2011-10-06 | Telefonaktebolaget L M Ericsson (Publ) | Methods and arrangements in optical network |
| WO2011143948A1 (en) * | 2011-01-26 | 2011-11-24 | 华为技术有限公司 | Method and system for implementing time synchronization |
| WO2012155762A1 (en) * | 2011-07-29 | 2012-11-22 | 中兴通讯股份有限公司 | Local oscillator synchronization method of pon system, onu and olt |
| CN105141390A (en) * | 2015-09-16 | 2015-12-09 | 浙江神州量子网络科技有限公司 | Time synchronization method in quantum network |
| WO2016045340A1 (en) * | 2014-09-23 | 2016-03-31 | 深圳市中兴微电子技术有限公司 | Clock synchronization method, optical network unit and storage medium |
| CN106130679A (en) * | 2016-06-21 | 2016-11-16 | 易事特集团股份有限公司 | Master-salve clock synchronous method and system |
| CN111030909A (en) * | 2020-03-03 | 2020-04-17 | 南京科远智慧科技集团股份有限公司 | Method for time synchronization among CAN bus multi-master device communication |
| CN112202519A (en) * | 2020-08-26 | 2021-01-08 | 浙江双成电气有限公司 | Method for controlling message transmission delay jitter |
| CN112584260A (en) * | 2019-09-30 | 2021-03-30 | 上海诺基亚贝尔股份有限公司 | Method, apparatus, device and medium for transmitting time synchronization message |
| CN114513274A (en) * | 2022-04-15 | 2022-05-17 | 清华大学 | Internet-oriented multi-hop high-precision time synchronization protocol implementation method and device |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| ES2208842T3 (en) * | 1997-07-02 | 2004-06-16 | Alcatel | Time multiplexing method and RELATED PROVISIONS FOR USE IN A CENTRAL STATION AND IN TERMINALS OF A COMMUNICATION NETWORK. |
| CN100581164C (en) * | 2006-03-15 | 2010-01-13 | 重庆邮电学院 | Accurate time synchronization method and system facing measurement and control |
| CN1960242B (en) * | 2006-10-17 | 2011-09-07 | 中控科技集团有限公司 | Method, device, system for implementing clock synchronization, and distribution system |
| CN101114896A (en) * | 2007-05-15 | 2008-01-30 | 北京东土科技股份有限公司 | Method for implementing precise synchronization clock |
-
2008
- 2008-04-02 CN CN 200810087548 patent/CN101552663B/en not_active Expired - Fee Related
Cited By (18)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2011120185A1 (en) * | 2010-03-29 | 2011-10-06 | Telefonaktebolaget L M Ericsson (Publ) | Methods and arrangements in optical network |
| CN102907020A (en) * | 2010-03-29 | 2013-01-30 | 爱立信(中国)通信有限公司 | Methods and arrangements in optical network |
| CN102907020B (en) * | 2010-03-29 | 2016-09-14 | 爱立信(中国)通信有限公司 | Method and apparatus in optical-fiber network |
| WO2011143948A1 (en) * | 2011-01-26 | 2011-11-24 | 华为技术有限公司 | Method and system for implementing time synchronization |
| CN102440040A (en) * | 2011-01-26 | 2012-05-02 | 华为技术有限公司 | Method and system for implementing time synchronization |
| CN102440040B (en) * | 2011-01-26 | 2015-05-27 | 华为技术有限公司 | Method and system for implementing time synchronization |
| US9525541B2 (en) | 2011-01-26 | 2016-12-20 | Huawei Technologies Co., Ltd. | Method and system for implementing time synchronization |
| WO2012155762A1 (en) * | 2011-07-29 | 2012-11-22 | 中兴通讯股份有限公司 | Local oscillator synchronization method of pon system, onu and olt |
| CN105515704A (en) * | 2014-09-23 | 2016-04-20 | 深圳市中兴微电子技术有限公司 | Clock synchronization method and optical network unit |
| WO2016045340A1 (en) * | 2014-09-23 | 2016-03-31 | 深圳市中兴微电子技术有限公司 | Clock synchronization method, optical network unit and storage medium |
| CN105141390A (en) * | 2015-09-16 | 2015-12-09 | 浙江神州量子网络科技有限公司 | Time synchronization method in quantum network |
| CN105141390B (en) * | 2015-09-16 | 2018-10-30 | 浙江神州量子网络科技有限公司 | A kind of method for synchronizing time in quantum network |
| CN106130679A (en) * | 2016-06-21 | 2016-11-16 | 易事特集团股份有限公司 | Master-salve clock synchronous method and system |
| CN112584260A (en) * | 2019-09-30 | 2021-03-30 | 上海诺基亚贝尔股份有限公司 | Method, apparatus, device and medium for transmitting time synchronization message |
| CN112584260B (en) * | 2019-09-30 | 2023-06-13 | 上海诺基亚贝尔股份有限公司 | Method, device, apparatus and medium for transmitting time synchronization message |
| CN111030909A (en) * | 2020-03-03 | 2020-04-17 | 南京科远智慧科技集团股份有限公司 | Method for time synchronization among CAN bus multi-master device communication |
| CN112202519A (en) * | 2020-08-26 | 2021-01-08 | 浙江双成电气有限公司 | Method for controlling message transmission delay jitter |
| CN114513274A (en) * | 2022-04-15 | 2022-05-17 | 清华大学 | Internet-oriented multi-hop high-precision time synchronization protocol implementation method and device |
Also Published As
| Publication number | Publication date |
|---|---|
| CN101552663B (en) | 2012-12-19 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101552663B (en) | Passive optical network system and frequency and time synchronizing method thereof | |
| CN101795423A (en) | Method and system for synchronizing time of passive optical network | |
| CN101431385B (en) | Frequency and time synchronization method for passive optical network | |
| CN107294634B (en) | The centralized approach of 1588 time synchronizations is realized in a kind of distributed system | |
| CN103339880B (en) | User's sidelight communicator, communication system, control device and electricity-saving control method | |
| US8942561B2 (en) | Synchronization transport over passive optical networks | |
| CN102468898B (en) | The method, apparatus and system of time synchronized are realized in time division multiplex network | |
| CN110915150B (en) | Controlling and managing a first PON using a second PON | |
| JP2010258842A (en) | Passive optical network system and operation method therefor | |
| CN102013931A (en) | Time synchronization method and system, salve timing device and main timing device | |
| WO2019184733A1 (en) | Time synchronization method in pon system, olt, onu and pon system | |
| JP2013229743A (en) | Optical communication system | |
| CN102932083A (en) | Microwave time synchronization method and device | |
| CN101582734A (en) | Access control method in wavelength division multiplexing passive optical network and device thereof | |
| CN101145846B (en) | Device and method for service transmission timing and networking timing in optical access network | |
| JP5913067B2 (en) | Time synchronization system, transmission path delay time correction method, time synchronization device | |
| JP6077084B1 (en) | Communication network time synchronization method | |
| WO2020075318A1 (en) | Station apparatus, subscriber apparatus, synchronization method, and pon system | |
| CN104981010B (en) | Time synchronizing signal, the providing method of frequency synchronization signal and device | |
| Takahashi et al. | NG-PON2 demonstration with small delay variation and low latency for 5G mobile fronthaul | |
| WO2015117319A1 (en) | Time synchronization method, device and system | |
| CN102340396A (en) | Time synchronization method for Ethernet passive optical network (EPON) | |
| KR20160024782A (en) | network synchronization apparatus and method on passive optical access network | |
| CN211880179U (en) | Wide area protection control system suitable for urban distribution network | |
| Kordnooria et al. | Time synchronization and IEEE 1588v2 solutions |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20171226 Address after: Tiefu iron rich street Pizhou city 221331 Jiangsu city of Xuzhou Province Patentee after: Huang Shaowei Address before: 510640 Guangdong City, Tianhe District Province, No. five, road, public education building, unit 371-1, unit 2401 Patentee before: GUANGDONG GAOHANG INTELLECTUAL PROPERTY OPERATION Co.,Ltd. Effective date of registration: 20171226 Address after: 510640 Guangdong City, Tianhe District Province, No. five, road, public education building, unit 371-1, unit 2401 Patentee after: GUANGDONG GAOHANG INTELLECTUAL PROPERTY OPERATION Co.,Ltd. Address before: 518057 Nanshan District science and Technology Industrial Park, Guangdong high tech Industrial Park, ZTE building Patentee before: ZTE Corp. |
|
| TR01 | Transfer of patent right | ||
| TR01 | Transfer of patent right | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20181016 Address after: 510640 2414-2416 of the main building 371, five mountain road, Tianhe District, Guangzhou, Guangdong. Patentee after: GUANGDONG GAOHANG INTELLECTUAL PROPERTY OPERATION Co.,Ltd. Address before: 221331 Jiangsu province Xuzhou city Pizhou City Tie Fu town tie Fu Street Patentee before: Huang Shaowei |
|
| TR01 | Transfer of patent right | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20181213 Address after: 221351 Industrial Park, Zhuang Town, Pizhou City, Xuzhou, Jiangsu Patentee after: Xuzhou Tie Shou hardware tools Manufacturing Co.,Ltd. Address before: 510640 2414-2416 of the main building 371, five mountain road, Tianhe District, Guangzhou, Guangdong. Patentee before: GUANGDONG GAOHANG INTELLECTUAL PROPERTY OPERATION Co.,Ltd. |
|
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20121219 Termination date: 20180402 |