CN102938676B - Time synchronizing method, apparatus and system - Google Patents

Abstract

The invention discloses a kind of time synchronizing method, apparatus and system, this method comprises the following steps, the time-stamping messages message for time synchronized is received using by receiving port from master clock and from the side in clock, and records the time for receiving time-stamping messages message；Record sends the time of time-stamping messages message by sending port, wherein, sending port and receiving port are synchronous with the equipment time holding at place；According to the time for receiving time-stamping messages message and the time of transmission time-stamping messages message, the temporal information for time synchronized carried in time-stamping messages message is modified；Time-stamping messages message is sent to master clock and from the opposing party in clock by sending port.By the present invention, the problem of solve EPON method for synchronizing time is complicated in the prior art, and corresponding network design is complicated, cost is high, and then time synchronizing method flow is simple, the effect that the corresponding network equipment is simple, cost is low.

Description

Time synchronizing method, apparatus and system

Technical field

The present invention relates to the communications field, in particular to time synchronizing method, apparatus and system.

Background technology

EPON (Passive Optical Network, referred to as PON) is (for example, EPON/10GEPON, GPON/ XGPON etc.) it is a kind of new broadband optical access technology, Fig. 1 is according to the structured flowchart of the EPON of prior art, is such as schemed Shown in 1, EPON includes：Optical line terminal (Optical Line Terminal, referred to as OLT), light routing network (Optical Distributable Network, referred to as ODN), multiple optical network units (Optical NetworkUnit, Referred to as ONU) or ONT Optical Network Terminal (Optical Network Terminal, referred to as ONT).

PTP IEEE1588, are a kind of packet-based time synchronization protocols, and its basic thought is matching somebody with somebody by software and hardware Close, recording synchronism clock information sends time and reception time, and adds corresponding timestamp to each information, passes through meter Calculate, recipient's can calculates oneself clocking error (i.e. time delay) in a network, so as to realize slave unit clock on network Time synchronized between master clock.

IEEE1588 has had two versions of IEEE1588V1 and IEEE1588V2, and Fig. 2 is according to of the prior art IEEE1588 principle schematic, as shown in Fig. 2 IEEE1588 is based on network characteristic symmetrically it is assumed that using master-slave mode, determine When send time message, recipient calculates skew and the circuit delay between master-salve clock according to time message, so as to this Ground is corrected synchronization from clock, its packet-based mode, and each network element on network can be made to reach synchronous.

In fig. 2, master clock sends synchronous (sync) message, and it be t1 to record the tranmitting data register moment, sync message arrival It is t2 from clock time, then master clock sends and follows (follow up) message, and this follows message to carry master clock and sends sync The temporal information t1 of message, delay_req information then is asked from clock forward delay interval, and record the tranmitting data register of the message code Moment is t3, and the delay_req message arrival master clock moment is t4, the delay response message of master clock loopback afterwards delay Resp, the message carry the temporal information t4 that delay_req message reaches master clock.

Assuming that message is Δ T from master clock to being delayed from clockwise path_ms, message is from from master clock to master clock direction Path delay is Δ T_sm, the initial deviation of master-salve clock is T_offset, thus, it is possible to obtain following relationship：

T2=t1+T_offset+ΔT_msFormula (1)

T4=t3-T_offset+ΔT_smFormula (2)

T_offset=[(t2-t4)-(t1-t3)-(Δ T_ms-ΔT_sm)]/2 formula (3)

If network is symmetrical, i.e. Δ T_ms=Δ T_sm, then：

T_offset=[(t2-t4)-(t1-t3)]/2 formula (4)

ΔT_ms=Δ T_sm=[(t2+t4)-(t1+t3)]/2 formula (5)

Adjusted in real time according to above result of calculation can it is local from clock, to reach and master clock is synchronous.

Fig. 3 is the schematic diagram of forwarding of the IEEE1588 time-stamping messages message of the prior art under DBA scheduling, is such as schemed Shown in 3, the direct transparent transmission forwarding of the IEEE1588 messages of Ethernet in PON, it can be seen from the analysis to Fig. 2 such as The delay of fruit network bi-directional is not fixed, and is changed greatly, and shake is big, then the deviation of result of calculation can be caused larger, so as to synchronous accurate Degree reduces.The characteristics of due to PON itself, uplink message delay variation caused by its up DBA scheduling is larger, causes link bidirectional Time delay error is larger, thus shakes also big.In traditional IEEE1588 messages when by each network node equipment, all can Because network congestion, various QOS algorithms and Message processing, message is not fixed in the time delay of device interior storage forwarding, thus is trembled Move and drift about and be larger, cause to calculate deviation or path delay of time shake and the drift obtained between master-salve clock by Fig. 2 algorithms It is excessive, thus the eventually synchronous degree of accuracy of influence time.

Therefore, as the above analysis, carry out at present in PON time synchronized exist shake it is larger so as to having influence on The problem of degree of accuracy of time synchronized.

The content of the invention

It is a primary object of the present invention to provide a kind of time synchronizing method, apparatus and system, to solve above-mentioned ask Topic.

According to an aspect of the present invention, there is provided a kind of time synchronizing method, comprise the following steps：Pass through passive light Receiving port in network receives the time-stamping messages message for time synchronized from master clock and from the side in clock, and Record receives the time of the time-stamping messages message；The sending port that record passes through in EPON sends the time The time of message packet is stabbed, wherein, the sending port and the receiving port are synchronous with the equipment time holding at place；According to Receive the time of the time-stamping messages message and send the time of the time-stamping messages message, to the time-stamping messages The temporal information for time synchronized carried in message is modified；By the sending port to the master clock and from when The opposing party in clock sends the time-stamping messages message.

Preferably, record, which receives time of the time-stamping messages message, includes：Record the time-stamping messages message Reach the time of the receiving port；According to the first compensation time and/or the second compensation time to reaching the receiving port Time compensates, wherein, the first compensation time is that the time-stamping messages message reaches the receiving port and arrival The delay between physical port corresponding to the receiving port, the second compensation time disappear to carry out receiving the timestamp Cease the processing time of message process；After the time that the receiving port is reached to the time-stamping messages message is compensated The obtained time, it is recorded as receiving the time of the time-stamping messages message.

Preferably, record is included by the time of the sending port transmission time-stamping messages message：Described in record Time-stamping messages message reaches the time of the sending port；According to the 3rd compensation time and/or the 4th compensation time to reaching The time of the sending port compensates, wherein, the 3rd compensation time is described in the time-stamping messages message reaches The time of sending port and the error of the time actually sent, the 4th compensation time is to be used for time synchronized to described Processing time for being modified of temporal information；The time that the sending port is reached to the time-stamping messages message is carried out The time obtained afterwards is compensated, is recorded as sending the time of the time-stamping messages message by the sending port.

Preferably, the time of the sending port and the equipment at the receiving port and place in the following manner at least it One keeps synchronous：International Telecommunication Union telecommunication standards group ITU-T G.984.3AD2, International Telecommunication Union's telecommunication Standardization group ITU-T G.987.3, IEEE802.1as.

Preferably, the time of the time-stamping messages message is received and by described by following time format record Sending port sends the time of the time-stamping messages message：The time format includes：For indicating the field on date, it is used for Indicate the field of second minute hour and the field for indicating nanosecond.

Preferably, the time of the time-stamping messages message will be received by the receiving port and by the transmission The time that port sends the time-stamping messages message is recorded in the time-stamping messages message.

According to another aspect of the present invention, there is provided a kind of time synchronizing device, including：Very first time stamp message connects Module is received, it is same for the time for being received by the receiving port in EPON from master clock and from the side in clock The time-stamping messages message of step, and record the time for receiving the time-stamping messages message；Second time-stamping messages receive mould Block, for receiving the time-stamping messages message from very first time stamp message reception module, and record by passive Sending port in optical-fiber network sends the time of the time-stamping messages message, wherein, the sending port and the receiving terminal Mouth is synchronous with the equipment time holding at place；Correcting module, for according to time and the transmission for receiving the timestamp message The time of the time-stamping messages message, the temporal information for time synchronized carried in the time-stamping messages message is entered Row amendment；Time-stamping messages sending module, for by the sending port to the master clock and from the opposing party in clock Send the time-stamping messages message.

Preferably, the very first time stamp message reception module includes：First recording unit, for recording the timestamp Message packet reaches the time of the receiving port；First compensating unit, for according to the first compensation time and/or the second compensation Time compensates to the time for reaching the receiving port, wherein, the first compensation time is the time-stamping messages report Text reaches the receiving port and reaches the delay between physical port corresponding to the receiving port, during second compensation Between be receive processing time of the time-stamping messages message process；Second recording unit, for will be to the timestamp The time that message packet reaches the receiving port compensates the time obtained afterwards, is recorded as receiving the timestamp and disappears Cease the time of message.

Preferably, the second time-stamping messages receiving module includes：3rd recording unit, for recording the timestamp Message packet reaches the time of the sending port；Second compensating unit, for according to the 3rd compensation time and/or the 4th compensation Time compensates to the time for reaching the sending port, wherein, the 3rd compensation time is the time-stamping messages report Text reaches the time of the sending port and the error of the time actually sent, and the 4th compensation time is to the use In the processing time that the temporal information of time synchronized is modified；4th recording unit, for will be to the time-stamping messages report The time that text reaches the sending port compensates the time obtained afterwards, is recorded as by described in sending port transmission The time of time-stamping messages message.

In accordance with a further aspect of the present invention, there is provided a kind of time synchronizing system, including：Clock equipment, from when Clock equipment, optical line terminal OLT, optical network unit ONU, in addition to：Above-mentioned device, wherein, described device is connected to described Clock equipment and described between clockwork, it is the clock equipment, described from clockwork, the OLT and the ONU Between relation be one below：The clock equipment and it is described from clockwork independently in the OLT and described ONU；The clock equipment is located on the OLT, it is described from clockwork independently of the OLT and the ONU；When described main Clock equipment is described to be located at from clockwork on the ONU independently of the OLT and the ONU；The clock equipment is located at institute State on OLT, it is described to be located at from clockwork on the ONU.

By the present invention, received using by the receiving port in EPON from master clock and from the side in clock To the time-stamping messages message for time synchronized, and record the time for receiving the time-stamping messages message；Record passes through Sending port in EPON sends the time of the time-stamping messages message, wherein, the sending port and described connect Receiving end mouth is synchronous with the equipment time holding at place；When according to the time for receiving the time-stamping messages message and sending described Between stab message packet time, the temporal information for time synchronized carried in the time-stamping messages message is repaiied Just；The time-stamping messages message is sent to the master clock and from the opposing party in clock by the sending port, solved Carried out in PON time synchronized exist shake it is larger so as to having influence on the degree of accuracy of time synchronized the problem of, improving Equilibrium is achieved between the time synchronized degree of accuracy and the cumbersome degree for lowering handling process.

Brief description of the drawings

Accompanying drawing described herein is used for providing a further understanding of the present invention, forms the part of the application, this hair Bright schematic description and description is used to explain the present invention, does not form inappropriate limitation of the present invention.In the accompanying drawings：

Fig. 1 is the structured flowchart according to the EPON of prior art；

Fig. 2 is the principle schematic according to IEEE1588 of the prior art；

Fig. 3 is the schematic diagram of the forwarding under DBA scheduling according to the IEEE1588 time-stamping messages message of prior art；

Fig. 4 is the principle schematic according to the IEEE1588 transparent clock of prior art；

Fig. 5 is the flow chart of method for synchronizing time according to embodiments of the present invention；

Fig. 6 is the structured flowchart of time synchronizing device according to embodiments of the present invention；

Fig. 7 is the structure of very first time stamp message reception module in time synchronism apparatus according to the preferred embodiment of the invention Block diagram；

Fig. 8 is the structure of the second time-stamping messages receiving module in time synchronism apparatus according to the preferred embodiment of the invention Block diagram；

Fig. 9 is the schematic diagram of timestamp form according to the preferred embodiment of the invention；

Figure 10 is time synchronized computational methods system architecture diagram according to the preferred embodiment of the invention；

Figure 11 is the flow chart according to the lock in time method of preferred embodiment of the present invention；

Figure 12 is the structured flowchart of passive optical network equipment according to the preferred embodiment of the invention；

Figure 13 is the flow chart of passive optical network equipment method for synchronizing time according to the preferred embodiment of the invention；

Figure 14 is the schematic diagram according to the network system of the preferred embodiment of the present invention one；

Figure 15 is the schematic diagram according to the network system of the preferred embodiment of the present invention two；

Figure 16 is the schematic diagram according to the network system of the preferred embodiment of the present invention three；

Figure 17 is the schematic diagram according to the network system of the preferred embodiment of the present invention four；

Figure 18 is the flow chart that optical line terminal one according to embodiments of the present invention is implemented；

Figure 19 is the flow chart that optical line terminal two according to embodiments of the present invention is implemented；

Figure 20 is the flow chart that optical network unit one according to embodiments of the present invention is implemented；

Figure 21 is the flow chart that optical network unit two according to embodiments of the present invention is implemented.

Embodiment

Describe the present invention in detail below with reference to accompanying drawing and in conjunction with the embodiments.It should be noted that do not conflicting In the case of, the feature in embodiment and embodiment in the application can be mutually combined.

Introduce transparent clock TC concept in IEEE1588V2, Fig. 4 is transparent according to the IEEE1588 of prior art The principle schematic of clock, as shown in figure 4, the transparent clock is a kind of solution end to end, by accurately recording The entry time and Outlet time of IEEE1588 messages each node device on network, it is possible to obtain time message and pass through institute There is the residence time of meshed network equipment, time message is obtained by the time delay at each networking by message intercommunication in addition, is most passed through afterwards Crossing algorithm amendment can just make to obtain and master clock synchronization from clock.

But the transparent clock in IEEE1588V2 for each single network node be required to calculate entrance when Between and Outlet time, calculate and flow it is more complicated, for EPON, in order that being entered with the IEEE1588 agreements Row is synchronous, is to carry out segment processing to EPON, i.e., synchronous between master clock and OLT, then same between OLT and ONU Step, last ONU and from synchronous between clock, it is synchronous especially between master clock and OLT and between clock and ONU it is synchronous, Related software and hardware is needed to solve, OLT must have similar IEEE1588 time protocol massages intercommunication and place with ONU Function is managed, software and hardware complex designing, improves cost.

In the examples below, it is EPON is overall as a transparent clock, calculate time-stamping messages message (or for time-stamping messages, timestamp message) in the residence time of EPON, so as to correct the time-stamping messages message, So that master-salve clock is synchronous.Fig. 5 is the flow chart of method for synchronizing time according to embodiments of the present invention, as shown in figure 5, this method Comprise the following steps：

Step S502, receive from master clock and from the side in clock and be used for by the receiving port in EPON The time-stamping messages message of time synchronized, and record the time for receiving the time-stamping messages message；

Step S504, record send the time of the time-stamping messages message by the sending port in EPON, its In, the sending port and the receiving port are synchronous with the equipment time holding at place, and synchronous mode can be a lot, for example, state Border telecommunication union telecommunication standards group ITU-T G.984.3AD2, International Telecommunication Union telecommunication standards group ITU-T G..987.3, IEEE802.1as etc.；

Step S506, according to receive the time-stamping messages message time and send the time-stamping messages message when Between, the temporal information for time synchronized carried in the time-stamping messages message is modified；

Step S508, the time-stamping messages report is sent to the master clock and from the opposing party in clock by the sending port Text.

By above-mentioned steps, it is separately recorded in receiving port and receives the time of time-stamping messages message and sent out in sending port The time of time-stamping messages message is sent, and the timestamp message according to above-mentioned time complexity curve is sent in the sending port, so as to real The synchronization of existing master-salve clock.The implementation method can no matter uplink message or downlink message can be directly to timestamp message In the temporal information for time synchronized be directly modified, directly represent the temporal information in timestamp message The transmission of PON and processing delay, it is no longer necessary to the asymmetric problem of up-downgoing time delay is considered, so as to relative to existing skill Shake is reduced for art and improves the degree of accuracy, also, above-mentioned steps processing is simple, it is no longer necessary to by master clock, OLT, ONU and Carried out progressively synchronously from clock, operating process is simple, and cost is relatively low, is improving the time synchronized degree of accuracy and is lowering handling process Equilibrium is achieved between cumbersome degree.

When implementing, in order that the time received recorded by receiving port is more accurate, it is contemplated that reception message, These processing such as temporal information in revision message are also to need the time, and receiving port and message are transferred to from physical port Between reaching sending port and actually sending and time delay be present, therefore, additionally provide two kinds in the present embodiment Than preferably compensation way, for both modes, can only apply one kind therein, can also two kinds apply simultaneously. If for some systems, if these processing times or delay can neglect, can also without using this two Both modes are illustrated by kind processing mode below.

Mode one, first logging timestamp message packet reach the time of receiving port；Then according to the first compensation time And/or second compensation the time to reach receiving port time compensate, wherein, this first compensation time be time-stamping messages The delay between physical port corresponding to message arrival receiving port and arrival receiving port, the second compensation time is progress Receive the processing time of time-stamping messages message process；The time that receiving port is reached to time-stamping messages message is compensated The time obtained afterwards, it is recorded as receiving the time of time-stamping messages message.The above-mentioned compensation process to the time, can basis Concrete condition during specific implementation is selected, for example, between receiving port and physical port corresponding to the receiving port When delay is negligible compared to the processing time of receive process, it is possible to the latter is directly considered, if on the contrary, received The processing time of journey relative to the delay between the physical port corresponding to receiving port and the receiving port it is negligible when Wait, it is possible to only consider the delay between the receiving port and corresponding physical port.

Mode two, such locate can also be used when record sends the time of time-stamping messages message by sending port Reason mode, i.e. logging timestamp message packet reaches the time of sending port first；According to the 3rd compensation time and/or the 4th The compensation time compensates to the time for reaching sending port, wherein, the 3rd compensation time was that the time-stamping messages message arrives Up to the time of sending port and the error of the time actually sent, the 4th compensation time be to for time synchronized when Between processing time for being modified of information；After the time that sending port is reached to the time-stamping messages message is compensated The time arrived, it is recorded as sending the time of time-stamping messages message by sending port.

When implementing, for the record of time, if receiving port and sending port are not on one device, then need On the storage device that equipment where equipment where time is recorded in into receiving port and sending port can access, certainly as one Individual easier mode, the time of record can be directly appended in corresponding time-stamping messages message and forwarded.So Processing mode realize it is easier.

When implementing, as a kind of preferably embodiment, the time that record is received to time-stamping messages message is corresponding Time format and by sending port send time-stamping messages message time format use a kind of new recording mode, example Such as, the time format includes：For indicating the field on date, for indicating the field of second minute hour and for indicating nanosecond Field.Or using similar IEEE1588 timestamps record time format mode：For indicating second field and for indicating to receive Second field, both forms are all easier to realize, specific form is realized with reference to shown in figure 9.

A kind of time synchronizing device is additionally provided in the present embodiment, and Fig. 6 is the time according to embodiments of the present invention The structured flowchart of synchronization processing apparatus, as shown in fig. 6, the device includes very first time stamp message reception module 62, the second time Message reception module 64, correcting module 66 and time-stamping messages sending module 68 are stabbed, the device is illustrated below.

The very first time stabs message reception module 62, for being received by receiving port from master clock and from the side in clock To the time-stamping messages message for time synchronized, and record and receive the time corresponding to the time-stamping messages message, according to this The time format is invented to change the timestamp message and forward；

Second time-stamping messages receiving module 64, very first time stamp message reception module 62 is connected to, is come from for receiving The correspondent time message packet that above-mentioned very first time stamp message reception module is sent, and record and the time is sent by sending port The time of message packet is stabbed, wherein, sending port and receiving port are synchronous with the equipment time holding at place；

Correcting module 66, the very first time stamp time-stamping messages receiving module 64 of message reception module 62 and second is connected to, The time of the timestamp message is received for basis and sends the time of the time-stamping messages message, to the time-stamping messages report The temporal information for time synchronized carried in text is modified；

Time-stamping messages sending module 68, be connected to correcting module 66, for by sending port to master clock and from when The opposing party in clock sends the time-stamping messages message.

Fig. 7 is the structure of very first time stamp message reception module in time synchronism apparatus according to the preferred embodiment of the invention Block diagram, as shown in fig. 7, very first time stamp message reception module 62 includes：First recording unit 622, the first compensating unit 624 With the second recording unit 626.Very first time stamp message reception module 62 is illustrated below.

First recording unit 622, the time of receiving port is reached for logging timestamp message packet；

First compensating unit 624, the first recording unit 622 is connected to, for being mended according to the first compensation time and/or second Repay the time to reach receiving port time compensate, wherein, this first compensation time be time-stamping messages message reach connects The delay between physical port corresponding to receiving end mouth and arrival receiving port, the second compensation time is to carry out receiving the time Stab the processing time of message packet process；

Second recording unit 626, the first compensating module 624 is connected to, is connect for that will be reached to the time-stamping messages message The time of receiving end mouth compensates the time obtained afterwards, is recorded as receiving the time of the time-stamping messages message.

Fig. 8 is the structure of the second time-stamping messages receiving module in time synchronism apparatus according to the preferred embodiment of the invention Block diagram；The second time-stamping messages receiving module 64 includes：3rd recording unit 642, the second compensating unit 644 and the 4th record Unit 646.The second time-stamping messages receiving module 64 is illustrated below.

3rd recording unit 642, the time of sending port is reached for logging timestamp message packet；

Second compensating unit 644, is connected to the 3rd recording unit 642, for being mended according to the 3rd compensation time and/or the 4th Repay the time to reach sending port time compensate, wherein, the 3rd compensation the time be time-stamping messages message reach hair The time of sending end mouth and the error of the time actually sent, the 4th compensation time are to the time letter for time synchronized Cease the processing time being modified；

4th recording unit 646, the second compensating module 644 is connected to, is sent for that will be reached to time-stamping messages message The time of port compensates the time obtained afterwards, is recorded as sending the time of time-stamping messages message by sending port.

A kind of time synchronizing system is additionally provided in the present embodiment, and the system includes：Clock equipment, from clock Equipment, optical line terminal OLT, optical network unit ONU, in addition to：The device of above-described embodiment or preferred embodiment, wherein, should Device is connected to clock equipment and between clockwork, clock equipment, from the relation between clockwork, OLT and ONU For one below：Clock equipment and from clockwork independently in OLT and ONU；Clock equipment is located on OLT, from when Clock equipment is independently of OLT and ONU；Clock equipment is located on ONU independently of OLT and ONU from clockwork；Clock equipment On OLT, it is located at from clockwork on ONU.

In the present embodiment and preferred embodiment, by introducing the concept of TC transparent clock, for EPON, Provide the method for synchronizing time that a kind of cost is low, design complexities are low, reliability is high, and the corresponding network equipment and point The clock synchronization system of cloth, to meet the synchronisation requirement of real-time service.It should be noted that these advantages are not above-mentioned The effect that all embodiments can obtain, some effects are that some preferred embodiments could obtain.

Illustrated with reference to a preferred embodiment, it is necessary to illustrate, the preferred embodiment combines above-mentioned reality Apply example and preferred embodiment.

In the preferred embodiment, there is provided a kind of computational methods of synchronous time of passive optical network, it is preferred real according to this The customized time-stamping messages form of example, and corresponding handling process are applied, by introducing TC transparent clock concepts, passive Optical-fiber network integrally regards TC transparent clock as, calculates time-stamping messages message and passes through the residence time of EPON, and corrects The timestamp, network master clock and network is set to obtain synchronization from clock, while synchronization accuracy and the degree of accuracy are improved.The synchronization The computational methods of time comprise the following steps：

S1, master clock and from clock passage time stamp message packet carry out intercommunication, to obtain synchronization.Time-stamping messages message Can be NTP message packets or IEEE1588 message packets or it is other it is same or similar based on point The synchronous protocol time-stamping messages message of group, concrete implementation method is with reference to figure 2.

A local system clock be present in S2, EPON, OLT and ONU by ITU-T G.984.3AD2 or G.987.3 or IEEE802.1as makes OLT and ONU be synchronized to EPON local system clock.

S3, downgoing time stamp message packet are sent from master clock, and reaching passive optical network OLT port, (port can be First line of a couplet port or internal custom port outside OLT), now downgoing time stamp message packet reaches the port pair The EPON local system time T1 answered is recorded, and temporal information T1 is inserted into downgoing time stamp message packet, The message continues the downstream ONU forwardings in EPON afterwards.

S4, local system time T1 are inserted into downgoing time and stab message packet according to message lattice provided in an embodiment of the present invention Formula is realized.

S5, carrying local system time T1 downgoing time stamp message packet reach ONU end mouth, and (port can be ONU External user port or internal custom port), now corresponding EPON local system time is T2, warp Cross the difference Δ T that processing takes T2-T1_downTo correct downgoing time stamp message packet, downgoing time stamp message packet passes through by Δ T_down After amendment, the T1 that was then inserted into originally record is stripped, time-stamping messages message continue to forwarded from clockwork (or Person T1 records are not stripped, mainly depending on specific networking and equipment form).

S6, upstream time stamp message packet are sent from from clock, and by EPON ONU end mouth, (port can be ONU external users port or internal custom port), now it is corresponding to reach the port for upstream time stamp message packet EPON local system time T3 be recorded, temporal information T3 be inserted into upstream time stamp message packet, it The message continues the upstream OLT forwardings in EPON afterwards.

S7, local system time T3 are inserted into upstream time and stab message packet according to message lattice provided in an embodiment of the present invention Formula is realized.

S8, carrying local system time T3 upstream time stamp message packet reach OLT ports, and (port can be OLT Outside first line of a couplet port or internal custom port), now corresponding EPON local system time is T4, warp Cross the difference Δ T that processing takes T4-T3_upTo correct upstream time stamp message packet, upstream time stamp message packet passes through by Δ T_upRepair After just, the T3 that was then inserted into originally record is stripped, time-stamping messages message continue to clock equipment forwarding (or T3 records are not stripped, mainly depending on specific networking and equipment form).

By calculate up-downgoing time-stamping messages message OLT ports (port can be first line of a couplet port outside OLT, Can be internal custom port) and ONU end mouth (port can be ONU external users port or internal custom Port) between residence time and amendment corresponding to up-downgoing time-stamping messages message, introduce similar IEEE1588TC it is transparent when The concept of clock, such network master clock and network are mutually sent out from clock by message, it is possible to are obtained between each other synchronous.

A kind of passive optical network equipment (function of realizing time synchronizing device) is additionally provided in the present embodiment, The passive optical network equipment includes：EPON local system clock synchronous processing module, time-stamping messages receiving module, nothing Source optical-fiber network local system time insertion module, time-stamping messages sending module, time-stamping messages code correcting module, passive optical network Network local system time strip module, is illustrated to above-mentioned module below.

EPON local system clock synchronous processing module：Mainly by ITU-T G.984.3AD2 or G.987.3 or IEEE802.1as time synchronizing method realizes the respective local clock of OLT and ONU both sides and passive optical network Network local system clock is synchronous.

Time-stamping messages receiving module：Be mainly used in recognition time stamp message packet, can by protocol type or from The method of definition distinguishes time-stamping messages message and other data messages.The module, which can be handled, carrys out master clock and from clock The time-stamping messages message sent, can also identify it is modified after the time-stamping messages inside EPON Message.The module is also responsible for recorded message and reaches EPON local system time corresponding to the module simultaneously, in addition the mould Block also has time bias function, to compensate this resume module time and message is actually reached the time error etc. of this module, with It is improved the degree of accuracy for the local system time that the time-stamping messages message is recorded.Time-stamping messages message and corresponding EPON local system time is preserved by one-to-one.

EPON local system time inserts module：It is mainly used in modification time stamp message.Time-stamping messages receive Module sends time-stamping messages and corresponding EPON local system time to this module, this module by processing, according to The message format that the embodiment of the present invention is specified, form is as shown in figure 9, when insertion EPON local system time is corresponding to Between stab message packet in.

Time-stamping messages sending module：Be mainly used in sending it is modified after time-stamping messages message (such as insertion and Time-stamping messages message after stripping).

Time-stamping messages code correcting module (function of realizing above-mentioned correcting module)：It is mainly used in calculating time-stamping messages In OLT ports (port can be first line of a couplet port or internal custom port outside OLT) and ONU end mouth (port Can be ONU external users port or internal custom port) between residence time, and to time-stamping messages report Text is modified.The module also has time bias function, to compensate this resume module time and the reality from this module to message Time error sent etc., so that the degree of accuracy for the residence time being corrected is improved.

EPON local system time strip module：It is mainly used in modification time stamp message.Time-stamping messages code is repaiied Positive module transmission is corrected time-stamping messages and peels off the EPON sheet being inserted into by processing to this module, this module Ground system time, with the original form of recovery time stamp message packet.

Illustrated with reference to the different PON network architecture.

Preferred architecture one

The network system of the framework includes optical line terminal OLT 1, at least one above-mentioned passive optical network equipment, at least one Individual optical network unit ON U1, at least one external master clock equipment and outside from clockwork.

Optical line terminal OLT 1：It is mainly used in receiving, sends time-stamping messages message.Receive and sent out from OLT1 external master clocks The time-stamping messages message to come over, and be sent to passive optical network equipment and be processed, passive optical network equipment gives its time Stamp message packet is sent by OLT1.Other OLT1 is also responsible for carrying out ranging to the ONU1 in system, the ranging of correlation Information be sent to passive optical network equipment processing, be also responsible for ONU1 intercommunications, ensure time-stamping messages message in OLT1 and ONU1 Between normally forwarded.

Optical network unit ONU 1：It is mainly used in receiving, sends time-stamping messages message.Receive and sent out outside ONU1 from clock The time-stamping messages message to come over, and be sent to passive optical network equipment and be processed, passive optical network equipment gives its time Stamp message packet is sent to outside from clock by ONU1.Other ONU1 is also responsible for normal with OLT1 intercommunications, guarantee OLT1 rangings Carry out, ensure that time-stamping messages message is normally forwarded between OLT1 and ONU1.

Passive optical network equipment：Mainly for the treatment of the time-stamping messages message sended over from OLT1 and ONU1, together When transmission processing after message packet to OLT1 and ONU1.The other equipment is also responsible for handling the ranging letter that OLT1 is sended over Breath, and make ONU1 local clocks, OLT1 local clocks and EPON local system clock are synchronous.

Master-salve clock equipment：Clock equipment is time server, can be master clock such as IEEE1588 equipment It can also be BC boundary clock, be IEEE1588 client clients from clockwork.

Preferred architecture two

The network system of the framework, including optical line terminal OLT 1, at least one above-mentioned passive optical network equipment, at least one Individual optical network unit ONU 2 and at least one clock equipment.

Optical line terminal OLT 1：It is mainly used in receiving, sends time-stamping messages message.Receive and sent out from OLT1 external master clocks The time-stamping messages message to come over, and be sent to passive optical network equipment and be processed, passive optical network equipment gives its time Stamp message packet is sent by OLT1.Other OLT1 is also responsible for carrying out ranging to the ONU2 in system, the ranging of correlation Information be sent to passive optical network equipment processing, be also responsible for ONU2 intercommunications, ensure time-stamping messages message in OLT1 and ONU2 Between normally forwarded.

Optical network unit ONU 2：It is mainly used in receiving, sends time-stamping messages message.It is placed in addition from clockwork Turn into an ONU2 part above ONU2, ONU2 is mainly responsible for and passive optical network equipment carries out time information receiving and transmitting intercommunication. ONU2 is upper to be sent to passive optical network equipment and is processed from clock time stamp message packet, passive optical network equipment to it when Between stamp message packet be sent to being handled from clockwork above ONU2.Other ONU2 is also responsible for and OLT1 intercommunications, guarantee OLT1 rangings are normally carried out, and ensure that time-stamping messages message is normally forwarded between OLT1 and ONU2.

Passive optical network equipment：Mainly for the treatment of the time-stamping messages message sended over from OLT1 and ONU2, together When transmission processing after message packet to OLT1 and ONU2.The other equipment is also responsible for handling the ranging letter that OLT is sended over Breath, and make ONU2 local clocks, OLT1 local clocks and EPON local system clock are synchronous.

Clock equipment：Clock equipment is time server, can be master clock such as IEEE1588 equipment It can be BC boundary clock.

Preferred architecture three

The network system of the framework include optical line terminal OLT 2, at least one above-mentioned passive optical network equipment, at least one Individual optical network unit ONU 1 and it is corresponding one from clockwork.

Optical line terminal OLT 2：It is mainly used in receiving, sends time-stamping messages message.Other clock equipment is placed on Turn into an OLT2 part above OLT2, OLT2 clock equipments are mainly responsible for and passive optical network equipment carries out time message receipts Intercommunication is sent out, while it is also responsible for carrying out message intercommunication with upstream clock equipment, to obtain synchronization.If the source of OLT2 upstream equipments Head is similar IEEE1588 time servers, and OLT2 clock equipments are as IEEE1588BC boundary clock, and it is responsible for and upstream Time by server carry out time message mutually to pass to acquirement synchronous, if OLT2 upstream equipments are global navigation satellite time service system System, it directly obtains time synchronization information from time dissemination system.In addition OLT2 is also responsible for carrying out ranging to the ONU1 in system, phase The ranging information of pass is sent to passive optical network equipment processing, is also responsible for existing with ONU1 intercommunications, guarantee time-stamping messages message Normally forwarded between OLT2 and ONU1.

Optical network unit ONU 1：It is mainly used in receiving, sends time-stamping messages message.Receive and sent out outside ONU1 from clock The time-stamping messages message that comes over simultaneously is sent to passive optical network equipment and is processed, and passive optical network equipment gives its timestamp Message packet is sent to outside from clock by ONU1.Other ONU1 is also responsible for normally entering with OLT2 intercommunications, guarantee OLT2 rangings OK, ensure that time-stamping messages message is normally forwarded between OLT2 and ONU1.

Passive optical network equipment：Mainly for the treatment of the time-stamping messages message sended over from OLT2 and ONU1, together When transmission processing after message packet to OLT2 and ONU1.The other equipment is also responsible for handling the ranging letter that OLT2 is sended over Breath, and make ONU1 local clocks, OLT2 local clocks and EPON local system clock are synchronous.

From clockwork：It is IEEE1588 client clients from clockwork.

Preferred architecture four

The network system of the framework include optical line terminal OLT 2, at least one above-mentioned passive optical network equipment, at least one Individual optical network unit ONU 2.

Optical line terminal OLT 2：It is mainly used in receiving, sends time-stamping messages message.Other clock equipment is placed on Turn into an OLT2 part above OLT2, OLT2 clock equipments are mainly responsible for and passive optical network equipment carries out time message receipts Intercommunication is sent out, while it is also responsible for carrying out message intercommunication with upstream clock equipment, to obtain synchronization.If the source of OLT2 upstream equipments Head is similar IEEE1588 time servers, and OLT2 clock equipments are as IEEE1588BC boundary clock, and it is responsible for and upstream Time by server carry out time message mutually to pass to acquirement synchronous, if OLT2 upstream equipments are global navigation satellite time service system System, it directly obtains time synchronization information from time dissemination system.In addition OLT2 is also responsible for carrying out ranging to the ONU2 in system, phase The ranging information of pass is sent to passive optical network equipment processing, is also responsible for existing with ONU2 intercommunications, guarantee time-stamping messages message Normally forwarded between OLT2 and ONU2.

Optical network unit ONU 2：It is mainly used in receiving, sends time-stamping messages message.It is placed in addition from clockwork Turn into an ONU2 part above ONU2, ONU2 is mainly responsible for and passive optical network equipment carries out time information receiving and transmitting intercommunication. ONU2 is upper to be sent to passive optical network equipment and is processed from clock time stamp message packet, passive optical network equipment to it when Between stamp message packet be sent to being handled from clockwork above ONU2.Other ONU2 is also responsible for and OLT2 intercommunications, guarantee OLT2 rangings are normally carried out, and ensure that time-stamping messages message is normally forwarded between OLT2 and ONU2.

Passive optical network equipment：Mainly for the treatment of the time-stamping messages message sended over from OLT2 and ONU2, together When transmission processing after message packet to OLT2 and ONU2.The other equipment is also responsible for handling the ranging letter that OLT2 is sended over Breath, and make ONU2 local clocks, OLT2 local clocks and EPON local system clock are synchronous.

A kind of optical line terminal OLT 1 is additionally provided in the preferred embodiment, is mainly included：EPON local is System clock synchronization process module, time-stamping messages receiving module, EPON local system time insertion module, timestamp disappear Cease sending module, time-stamping messages code correcting module and EPON local system time strip module.

EPON local system clock synchronous processing module：Be mainly used in by ITU-T G.984.3AD2 or G.987.3 or IEEE802.1as time synchronizing method realizes the respective local clock of OLT and ONU both sides and passive light Network local system clock is synchronous.

Time-stamping messages receiving module：Be mainly used in recognition time stamp message packet, can by protocol type or from The method of definition distinguishes time-stamping messages message and other data messages.The module can be handled from outer-portion upstream master clock The time-stamping messages message sent, can also identify it is modified after the timestamp from EPON downstream inner Message packet.While the module is also responsible for recorded message and reaches EPON local system time corresponding to the module, in addition The module also has time bias function, and this module time error etc. is actually reached to compensate this resume module time and message, So that the degree of accuracy for the local system time that the time-stamping messages message is recorded is improved.Time-stamping messages message and correspondingly EPON local system time preserved by one-to-one.

EPON local system time inserts module：It is mainly used in modification time stamp message.Time-stamping messages receive Module sends time-stamping messages and corresponding EPON local system time to this module, this module by processing, according to The message format that the present invention specifies, insertion EPON local system time is into corresponding time-stamping messages message.

Time-stamping messages sending module：Be mainly used in sending it is modified after time-stamping messages message (such as insertion and Time-stamping messages message after stripping).Send standard message after lift-off processing to OLT upstreams clock equipment or Self-defined message after insertion process is sent to OLT downstreams from clockwork.

Time-stamping messages code correcting module：It is mainly used in calculating time-stamping messages in OLT first line of a couplet port (and upstream master clock Communication interface) and ONU end mouth (port can be ONU external users port or internal custom port, mainly regard For whether clock above the ONU) between residence time, and time-stamping messages message is modified.The module also has Having time compensation function, to compensate this resume module time and from this module to the actual time error sent of message etc., So that the degree of accuracy for the residence time being corrected is improved.

EPON local system time strip module：It is mainly used in modification time stamp message.Time-stamping messages code is repaiied Positive module transmission is corrected time-stamping messages and peels off the EPON sheet being inserted into by processing to this module, this module Ground system time, with the original form of recovery time stamp message packet.

In the present embodiment, a kind of optical line terminal OLT 2 is additionally provided, is mainly included：Clock equipment, passive optical network Network local system clock synchronous processing module, time-stamping messages receiving module, EPON local system time insertion module, Time-stamping messages sending module, time-stamping messages code correcting module and EPON local system time strip module.

Clock equipment, here clock equipment be placed on above OLT, turn into an OLT part.If OLT upstreams The source of equipment is similar IEEE1588 time servers, and as IEEE1588BC boundary clock, it is responsible for OLT clock equipments Time message is carried out by server with the time of upstream and mutually pass to acquirement synchronously, if OLT upstream equipments are global navigation satellite Time dissemination system, it directly obtains time synchronization information from time dissemination system.

EPON local system clock synchronous processing module：Be mainly used in by ITU-T G.984.3AD2 or G.987.3 or IEEE802.1as time synchronizing method realizes the respective local clock of OLT and ONU both sides and passive light Network local system clock is synchronous.

Time-stamping messages receiving module：Be mainly used in recognition time stamp message packet, can by protocol type or from The method of definition distinguishes time-stamping messages message and other data messages.The module can be handled and sent out from internal master clock Come time-stamping messages message, can also identify it is modified after the time-stamping messages report inside EPON Text.The module is also responsible for recorded message and reaches EPON local system time corresponding to the module simultaneously, in addition the module Also there is time bias function, this module time error etc. is actually reached to compensate this resume module time and message, so that should The degree of accuracy for the local system time that time-stamping messages message is recorded is improved.Time-stamping messages message and corresponding passive Optical-fiber network local system time is preserved by one-to-one.

EPON local system time inserts module：It is mainly used in modification time stamp message.Time-stamping messages receive Module sends time-stamping messages and corresponding EPON local system time to this module, this module by processing, according to The message format that the present invention specifies, insertion EPON local system time is into corresponding time-stamping messages message.

Time-stamping messages sending module：Be mainly used in sending it is modified after time-stamping messages message (such as insertion and Time-stamping messages message after stripping).The standard message after lift-off processing is sent to clock equipment on OLT or hair The self-defined message that the warp let-off is crossed after insertion process is to OLT downstreams from clockwork.

Time-stamping messages code correcting module：It is mainly used in calculating time-stamping messages that (and master clock leads on OLT in OLT ports Letter interface) and ONU end mouth (port can be ONU external users port or internal custom port, it is main regarding from For whether clock above the ONU) between residence time, and time-stamping messages message is modified.The module also has Time bias function, to compensate this resume module time and from this module to the actual time error sent of message etc., with The degree of accuracy for the residence time for making to be corrected is improved.

EPON local system time strip module：It is mainly used in modification time stamp message.Time-stamping messages code is repaiied Positive module transmission is corrected time-stamping messages and peels off the EPON sheet being inserted into by processing to this module, this module Ground system time, with the original form of recovery time stamp message packet.

In the present embodiment, a kind of light NE ON U1 are additionally provided, mainly include EPON local system Clock synchronization process module, time-stamping messages receiving module, EPON local system time insertion module, time-stamping messages Sending module, time-stamping messages code correcting module and EPON local system time strip module：

EPON local system clock synchronous processing module：Be mainly used in by ITU-T G.984.3AD2 or G.987.3 or IEEE802.1as time synchronizing method realizes the respective local clock of OLT and ONU both sides and passive light Network local system clock is synchronous.

Time-stamping messages receiving module：Be mainly used in recognition time stamp message packet, can by protocol type or from The method of definition distinguishes time-stamping messages message and other data messages.The module can be handled to be sent out from outside from clock The time-stamping messages message come, can also identify it is modified after the time-stamping messages of upstream inside the EPON Message.The module is also responsible for recorded message and reaches EPON local system time corresponding to the module simultaneously, in addition the mould Block also has time bias function, and this module time error etc. is actually reached to compensate this resume module time and message, so that The degree of accuracy for the local system time that the time-stamping messages message is recorded is improved.Time-stamping messages message and corresponding nothing Source optical-fiber network local system time is preserved by one-to-one.

EPON local system time inserts module：It is mainly used in modification time stamp message.Time-stamping messages receive Module sends time-stamping messages and corresponding EPON local system time to this module, this module by processing, according to The message format that the present invention specifies, insertion EPON local system time is into corresponding time-stamping messages message.

Time-stamping messages sending module：Be mainly used in sending it is modified after time-stamping messages message (such as insertion and Time-stamping messages message after stripping).Send standard message after insertion process to ONU upstreams clock equipment or Self-defined message after lift-off processing is sent to ONU downstreams from clockwork.

Time-stamping messages code correcting module：Being mainly used in calculating time-stamping messages, (port can be OLT in OLT ports Outside first line of a couplet port or internal custom port) and ONU end mouth (port can be ONU external users port, Can be internal custom port) between residence time, and time-stamping messages message is modified.When the module also has Between compensation function, to compensate this resume module time and from this module to the actual time error sent of message etc. so that The degree of accuracy for the residence time being corrected is improved.

EPON local system time strip module：It is mainly used in modification time stamp message.Time-stamping messages code is repaiied Positive module transmission is corrected time-stamping messages and peels off the EPON sheet being inserted into by processing to this module, this module Ground system time, with the original form of recovery time stamp message packet.

In the present embodiment, a kind of optical network unit ONU 2 is additionally provided, it is main to include from clockwork, EPON Local system clock synchronous processing module, time-stamping messages receiving module, EPON local system time insertion module, when Between stab message transmission module, time-stamping messages code correcting module and EPON local system time strip module：

From clockwork, it is placed on here from clockwork above ONU, turns into an ONU part.

EPON local system clock synchronous processing module：Be mainly used in by ITU-T G.984.3AD2 or G.987.3 or IEEE802.1as time synchronizing method realizes the respective local clock of OLT and ONU both sides and passive light Network local system clock is synchronous.

Time-stamping messages receiving module：Be mainly used in recognition time stamp message packet, can by protocol type or from The method of definition distinguishes time-stamping messages message and other data messages.The module can be handled to be sent out on ONU from clock The time-stamping messages message to come over, can also identify it is modified after the timestamp of upstream inside the EPON disappear Cease message.While the module is also responsible for recorded message and reaches EPON local system time corresponding to the module, in addition should Module also has time bias function, and this module time error etc. is actually reached to compensate this resume module time and message, with It is improved the degree of accuracy for the local system time that the time-stamping messages message is recorded.Time-stamping messages message and corresponding EPON local system time is preserved by one-to-one.

EPON local system time inserts module：It is mainly used in modification time stamp message.Time-stamping messages receive Module sends time-stamping messages and corresponding EPON local system time to this module, this module by processing, according to The message format that the present invention specifies, insertion EPON local system time is into corresponding time-stamping messages message.

Time-stamping messages sending module：Be mainly used in sending it is modified after time-stamping messages message (such as insertion and Time-stamping messages message after stripping).Send standard message after insertion process to ONU upstreams clock equipment or Send self-defined message after lift-off processing on ONU from clockwork.

Time-stamping messages code correcting module：Being mainly used in calculating time-stamping messages, (port can be OLT in OLT ports Outside first line of a couplet port or internal custom port) and ONU end mouth (port can be ONU external users port, Can be internal custom port) between residence time, and time-stamping messages message is modified.When the module also has Between compensation function, to compensate this resume module time and from this module to the actual time error sent of message etc. so that The degree of accuracy for the residence time being corrected is improved.

EPON local system time strip module：It is mainly used in modification time stamp message.Time-stamping messages code is repaiied Positive module transmission is corrected time-stamping messages and peels off the EPON sheet being inserted into by processing to this module, this module Ground system time, with the original form of recovery time stamp message packet.

Illustrated with reference to another preferred embodiment, it is necessary to illustrate, the preferred embodiment combines above-mentioned Embodiment and preferred embodiment.

In the preferred embodiment, a kind of timestamp form is defined, Fig. 9 is the time according to the preferred embodiment of the invention The schematic diagram of form is stabbed, as shown in figure 9, being modified to stamp of original standard time, message is inserted and reaches EPON Corresponding local system time, local system time information format can be the forms of similar IEEE1588 record times：Using 48bit signless integers record the second, and 32 bit record nanosecond without integer is met, in this way expression time information, For example, 1ns is represented with 0,000 0,000 0001 0000H, for another example 2.5ns with 0,000 0,000 0002 8000H come table Show；In addition can also be by the way of such as " Hour Minute Second nanosecond date " come expression time, such as 06 during 24 days 5 January in 2009 Point 28 seconds 2.5 nanoseconds, the representation of nanosecond and above-mentioned identical.Original timestamp information is completely kept down, and is placed on nothing After local system time corresponding to the optical-fiber network of source.

Figure 10 is time synchronized computational methods system architecture diagram according to the preferred embodiment of the invention, and Figure 11 is according to this The flow chart of the lock in time method of invention preferred embodiment, as shown in figure 11, corresponding to Figure 10 system architecture diagram, the flow Comprise the following steps：

Step S1102, master-salve clock passage time stamp message packet carries out intercommunication, to obtain synchronization, similar IEEE1588 Twoway mode realizes synchronization, such as formula (1)~formula (5).

Step S1104, OLT and ONU by ITU-T G.984.3AD2 either G.987.3 or IEEE802.1as makes OLT EPON local system clock is synchronized to ONU, an EPON local system clock be present on OLT handles mould Block, there is also an EPON local system clock processing module above ONU, both mutually send out timing code message and can obtained It is synchronous.As shown in Figure 10, EPON local system clock referred herein there may be on OLT there may also be Above ONU, but typically it is all disposed within above OLT, maintenance is responsible for by OLT.

Step S1106, downgoing time stamp message packet are sent from master clock, reach passive optical network OLT port (port Can be first line of a couplet port or internal custom port outside OLT), during corresponding local EPON local system Between the T1 moment be recorded.

Step S1108, then the downlink message is according to this preferred embodiment form defined above, as shown in figure 9, being inserted Enter T1 moment message, then proceed to forward to from clockwork.

Step S1110, the downgoing time stamp message packet for carrying T1 reach ONU end mouth (port can be used outside ONU Family port or internal custom port), now the local EPON local system time T2 moment be recorded Come.

Step S1112, T2-T1 difference Δ T is taken by processing_downTo correct downgoing time stamp message packet, illustrate here Illustrate how to change IEEE1588 processing modes, it is descending according to IEEE1588 principles and TC clock processing modes IEEE1588event message：

SYNC message residence times are：ΔT_down=T2-T1,

If TC clocks (EPON is integrally treated as TC clocks) are one step clocks, then ONU exit ports When should be Δ T_downParameter is added to SYNC message correctionField domains.

If TC clocks are two step clocks, then should be the Δ T during ONU exit ports_downParameter is added to Follow_ Up message correctionField domains.

Downgoing time stamp message packet is stripped by the T1 records after being corrected, being then inserted into originally, the time Stamp message packet continue to forwarded from clockwork (or T1 record be not stripped, mainly regarding specific networking and equipment form Depending on).

Step S1114, upstream time stamp message packet are sent from master clock, reach EPON ONU end mouth (port Can be ONU external users port or internal custom port), during corresponding local EPON local system Between the T3 moment be recorded.

Step S1116, the form that then uplink message defines according to the preferred embodiment of the present invention, being inserted into the T3 moment disappears Breath, then proceed to forward to clock equipment.

Step S1118, the downgoing time stamp message packet for carrying T3 reach OLT ports (port can be on OLT outsides Join port or internal custom port), the now corresponding local EPON local system time T4 moment is remembered Record is got off.

Step S1120, T4-T3 difference Δ T is taken by processing_upTo correct upstream time stamp message packet, upstream time stamp Message packet is stripped by the T3 records after being corrected, being then inserted into originally, and time-stamping messages message continues to master Clockwork forwarding (or T3 records are not stripped, mainly depending on specific networking and equipment form).Here illustrate How IEEE1588 processing mode is changed, according to IEEE1588 principles and TC clock processing modes, up IEEE1588 eventmessage：

Delay_Req message residence times are：ΔT_up=T4-T3,

If TC clocks are one step clocks, then should be the Δ T during OLT exit ports_upParameter disappears from Delay_Req Breath correctionField is subtracted in domain.

If TC clocks are two step clocks, then should be the Δ T during OLT exit ports_upParameter is added to Delay_Req Message correctionField domains, then the IEEE1588 Master equipment of upstream the parameter from Delay_Resp message Subtract in correctionField domains and send again.

Finally, master-salve clock is according to time-stamping messages message intercommunication, by way of class IEEE1588, as formula (1)~ The mode of formula (5) obtains synchronization.

In the preferred embodiment, a kind of passive optical network equipment is additionally provided, Figure 12 is preferable to carry out according to the present invention The structured flowchart of the passive optical network equipment of example, as shown in figure 12, the passive optical network equipment includes：EPON local is Unite clock synchronization process module 02-1 and 02-2, time-stamping messages receiving module 01-1 and 01-2, time-stamping messages sending module 06-1 and 06-2, EPON local system time insertion module 05-1 and 05-2, the stripping of EPON local system time From module 04-1 and 04-2, time-stamping messages code correcting module 03-1 and 03-2.It should be noted that internal interface in figure and For external interface is with respect to passive optical network equipment and master-salve clock.External interface：Master-salve clock and EPON are set Interacting message interface between standby.Internal interface：Interacting message interface between passive optical network equipment internal module.Figure 13 is basis The flow chart of the passive optical network equipment method for synchronizing time of the preferred embodiment of the present invention, as shown in figure 13, the flow are included such as Lower step：

Step S1302, master-salve clock passage time stamp message packet carries out intercommunication, to obtain synchronization, similar IEEE1588 Twoway mode realizes synchronization, concrete principle and calculation formula such as formula (1)~formula (5).

Step S1304, EPON local system clock synchronous processing module 02-1 and 02-2, passes through ITU-T G.984.3AD2 either G.987.3 or IEEE802.1as time synchronizing method realizes the respective local of OLT and ONU both sides Clock and EPON local system clock are synchronous.

Step S1306, (local system clock can be with after 02-1 modules, 02-2 modules and local system clock synchronization In OLT, OLT can also be typically all disposed within ONU, be safeguarded by OLT), 02-1 modules provide EPON local system Time does timing reference to 01-1 modules, and 02-2 modules provide EPON local system time and do timing ginseng to 01-2 modules Examine.

Step S1308, from outside port downgoing time stamp message packet arrival time stamp message reception module 01-1, report It is T1 that text, which is recorded to up to EPON local system time corresponding to 01-1, and 01-1 modules also have time bias work(in addition Can, to compensate this resume module time Δ T_p-d1 and message be actually reached this module time error because message reach optical-fiber network Equipment time and message packet have a delay Δ T between reaching the time of OLT physical ports_p-d2, by compensate so that this when Between stab message packet arrival time the degree of accuracy be improved, the actual local zone time being so corrected is：

T1 '=(T1- Δs T_p-d1-ΔT_p-d2) formula (6)

Here represented with T1 ', Δ T_p-d1, Δ T_p-d2 can be corrected by way of software, can also pass through hardware Mode, directly according to formula (6) obtain, Δ T_p-d1, Δ T_p-d2 could be arranged to 0.Time-stamping messages message and corresponding nothing Source optical-fiber network local system time T1 ' is preserved by one-to-one.

Step S1310, carries downgoing time stamp message packet and corresponding T1 ' information is sent to EPON locally system The insertion module 05-1 processing of system time, T1 ' information is according to definition format of the present invention, as shown in figure 9, it is descending to be inserted into this In time-stamping messages message.

Step S1312, the downgoing time stamp message packet for carrying T1 ' information are sent to time-stamping messages sending module 06- 1, be finally sent to OLT PON mouths be forwarded to it is descending from clock.

Step S1314, the downgoing time stamp message packet arrival time stamp message reception module 01-2 of T1 ' information is carried, It is T2 that message, which is recorded to up to EPON local system time corresponding to 01-2, time-stamping messages message and corresponding passive Optical-fiber network local system time T2 is preserved by one-to-one.

Step S1316, the downgoing time stamp message packet and corresponding T2 information for carrying T1 ' information are sent to timestamp and disappeared Breath code correcting module 03-2,03-2 module also has time bias function, to compensate this resume module time Δ T_p-d3 and from this Module is to the actual time error Δ T sent of message_p-d4 etc., by compensating so that the degree of accuracy for the residence time being corrected It is improved, so actual being sent to from the time of clock is：

T2 '=(T1+ Δs T_p-d3+ΔT_p-d4) formula (7)

Here represented with T2 ', Δ T_p-d3, Δ T_p-d4 can be corrected by way of software, can also pass through hardware Mode, directly according to formula (7) obtain, Δ T_p-d3, Δ T_p-d4 could be arranged to 0.Finally by Δ T_down=T2 '-T1 ', The actual residence time of downlink message is obtained, then corrects the time-stamping messages message, specific correcting mode refers to step S1120。

Step S1318, the downgoing time stamp message packet being corrected are sent to the stripping of EPON local system time Module 04-2, downgoing time stamp message packet reference format is reduced into after treatment.

Step S1320, it is corrected time-stamping messages message that is rear and being stripped and is immediately sent to from clockwork.

Step S1322, from outside port upstream time stamp message packet arrival time stamp message reception module 01-2, report It is T3 that text, which is recorded to up to EPON local system time corresponding to 01-2, and 01-2 modules also have time bias work(in addition Can, to compensate this resume module time Δ T_p-u1 and message be actually reached this module time error because message reach optical-fiber network Equipment time and message packet have a delay Δ T between reaching the time of ONU physical ports_p-u2, by compensate so that this when Between stab message packet arrival time the degree of accuracy be improved, the actual local zone time being so corrected is：

T3 '=(T3- Δs T_p-u1-Δt_p-u2) formula (8)

Here represented with T3 ', Δ T_p-u1, Δ T_p-u2 can be corrected by way of software, can also pass through hardware Mode, directly according to formula (8) obtain, Δ T_p-u1, Δ T_p-u2 could be arranged to 0.Time-stamping messages message and corresponding nothing Source optical-fiber network local system time T3 ' is preserved by one-to-one.

Step S1324, carries upstream time stamp message packet and corresponding T3 ' information is sent to EPON locally system The insertion module 05-2 processing of system time, T3 ' information is according to definition format of the present invention, as shown in figure 9, it is descending to be inserted into this In time-stamping messages message.

Step S1326, the upstream time stamp message packet for carrying T3 ' information are sent to time-stamping messages sending module 06- 2, finally it is sent to OLT PON mouths and is forwarded to up master clock.

Step S1328, the upstream time stamp message packet arrival time stamp message reception module 01-1 of T3 ' information is carried, It is T4 that message, which is recorded to up to EPON local system time corresponding to 01-1, time-stamping messages message and corresponding passive Optical-fiber network local system time T4 is preserved by one-to-one.

Step S1330, the upstream time stamp message packet and corresponding T4 information for carrying T3 ' information are sent to timestamp and disappeared Breath code correcting module 03-1,03-1 module also has time bias function, to compensate this resume module time Δ T_p-u3 and from this Module is to the actual time error Δ T sent of message_p-u4 etc., by compensating so that the degree of accuracy for the residence time being corrected It is improved, so the actual time for being sent to master clock is：

T4 '=(T1+ Δs T_p-u3+ΔT_p-u4) formula (9)

Here represented with T4 ', Δ T_p-u3, Δ T_p-u4 can be corrected by way of software, can also pass through hardware Mode, directly according to formula (9) obtain, Δ T_p-u3, Δ T_p-u4 could be arranged to 0.Finally by Δ T_up=T4 '-T3 ', are obtained The actual residence time of uplink message is obtained, then corrects the time-stamping messages message, specific correcting mode refers to step S1120。

Step S1332, the upstream time stamp message packet being corrected are sent to the stripping of EPON local system time Module 04-1, downgoing time stamp message packet reference format is reduced into after treatment.

Step S1334, it is corrected time-stamping messages message that is rear and being stripped and is immediately sent to clock equipment.

Finally, master-salve clock passage time stamp message packet carries out intercommunication, to obtain synchronization, similar IEEE1588 two Way mode realizes synchronization, such as formula (1)~formula (5).

In the preferred embodiment, there is provided a kind of network system 1, Figure 14 are the nets according to the preferred embodiment of the present invention one The schematic diagram of network system, as shown in figure 14, the network system include：Optical line terminal OLT 1, at least one above-described embodiment or The passive optical network equipment of preferred embodiment, at least one optical network unit ONU 1, at least one external master clock equipment and outer Portion is from clockwork：

Optical line terminal OLT 1：It is mainly used in receiving, sends time-stamping messages message.Receive and sent out from OLT1 external master clocks The time-stamping messages message to come over, and be sent to passive optical network equipment and be processed, passive optical network equipment gives its time Stamp message packet is sent by OLT1.Other OLT1 is also responsible for carrying out ranging to the ONU1 in system, the ranging of correlation Information be sent to passive optical network equipment processing, be also responsible for ONU1 intercommunications, ensure time-stamping messages message in OLT1 and ONU1 Between normally forwarded.

Optical network unit ONU 1：It is mainly used in receiving, sends time-stamping messages message.Receive and sent out outside ONU1 from clock The time-stamping messages message that comes over simultaneously is sent to passive optical network equipment and is processed, and passive optical network equipment gives its timestamp Message packet is sent to outside from clock by ONU1.Other ONU1 is also responsible for normally entering with OLT1 intercommunications, guarantee OLT1 rangings OK, ensure that time-stamping messages message is normally forwarded between OLT1 and ONU1.

Passive optical network equipment：Mainly for the treatment of the time-stamping messages message sended over from OLT1 and ONU1, together When transmission processing after message packet to OLT1 and ONU1.The other equipment is also responsible for handling the ranging letter that OLT1 is sended over Breath, and make ONU1 local clocks, OLT1 local clocks and EPON local system clock are synchronous.

Master-salve clock equipment：Clock equipment is time server, can be master clock such as IEEE1588 equipment It can also be BC boundary clock, be IEEE1588client clients from clockwork.

In the preferred embodiment, a kind of network system 2 is additionally provided, Figure 15 is according to the preferred embodiment of the present invention two The schematic diagram of network system, as shown in figure 15, the network system include：Optical line terminal OLT 1, at least one above-described embodiment Or the passive optical network equipment of preferred embodiment, at least one optical network unit ONU 2 and at least one clock equipment.

Optical line terminal OLT 1：It is mainly used in receiving, sends time-stamping messages message.Receive and sent out from OLT1 external master clocks The time-stamping messages message to come over, and be sent to passive optical network equipment and be processed, passive optical network equipment gives its time Stamp message packet is sent by OLT1.Other OLT1 is also responsible for carrying out ranging to the ONU2 in system, the ranging of correlation Information be sent to passive optical network equipment processing, be also responsible for ONU2 intercommunications, ensure time-stamping messages message in OLT1 and ONU2 Between normally forwarded.

Optical network unit ONU 2：It is mainly used in receiving, sends time-stamping messages message.It is placed in addition from clockwork Turn into an ONU2 part above ONU2, ONU2 is mainly responsible for and passive optical network equipment carries out time information receiving and transmitting intercommunication. ONU2 is upper to be sent to passive optical network equipment and is processed from clock time stamp message packet, passive optical network equipment to it when Between stamp message packet be sent to being handled from clockwork above ONU2.Other ONU2 is also responsible for and OLT1 intercommunications, guarantee OLT1 rangings are normally carried out, and ensure that time-stamping messages message is normally forwarded between OLT1 and ONU2.

Passive optical network equipment：Mainly for the treatment of the time-stamping messages message sended over from OLT1 and ONU2, together When transmission processing after message packet to OLT1 and ONU2.The other equipment is also responsible for handling the ranging letter that OLT is sended over Breath, and make ONU2 local clocks, OLT1 local clocks and EPON local system clock are synchronous.

Clock equipment：Clock equipment is time server, can be master clock such as IEEE1588 equipment It can be BC boundary clock.

In the preferred embodiment, there is provided a kind of network system 3, Figure 16 are the nets according to the preferred embodiment of the present invention three The schematic diagram of network system, as shown in figure 16, the network system：Including optical line terminal OLT 2, at least one above-described embodiment or The passive optical network equipment of preferred embodiment, at least one optical network unit ONU 1 and it is corresponding one from clockwork.

Optical line terminal OLT 2：It is mainly used in receiving, sends time-stamping messages message.Other clock equipment is placed on Turn into an OLT2 part above OLT2, OLT2 clock equipments are mainly responsible for and passive optical network equipment carries out time message receipts Intercommunication is sent out, while it is also responsible for carrying out message intercommunication with upstream clock equipment, to obtain synchronization.If the source of OLT2 upstream equipments Head is similar IEEE1588 time servers, and OLT2 clock equipments are as IEEE1588BC boundary clock, and it is responsible for and upstream Time by server carry out time message mutually to pass to acquirement synchronous, if OLT2 upstream equipments are global navigation satellite time service system System, it directly obtains time synchronization information from time dissemination system.In addition OLT2 is also responsible for carrying out ranging to the ONU1 in system, phase The ranging information of pass is sent to passive optical network equipment processing, is also responsible for existing with ONU1 intercommunications, guarantee time-stamping messages message Normally forwarded between OLT2 and ONU1.

Optical network unit ONU 1：It is mainly used in receiving, sends time-stamping messages message.Receive and sent out outside ONU1 from clock The time-stamping messages message that comes over simultaneously is sent to passive optical network equipment and is processed, and passive optical network equipment gives its timestamp Message packet is sent to outside from clock by ONU1.Other ONU1 is also responsible for normally entering with OLT2 intercommunications, guarantee OLT2 rangings OK, ensure that time-stamping messages message is normally forwarded between OLT2 and ONU1.

Passive optical network equipment：Mainly for the treatment of the time-stamping messages message sended over from OLT2 and ONU1, together When transmission processing after message packet to OLT2 and ONU1.The other equipment is also responsible for handling the ranging letter that OLT2 is sended over Breath, and make ONU1 local clocks, OLT2 local clocks and EPON local system clock are synchronous.

From clockwork：It is IEEE1588client clients from clockwork.

In the preferred embodiment, there is provided a kind of network system 4, Figure 17 are the nets according to the preferred embodiment of the present invention four The schematic diagram of network system, as shown in figure 17, the network system include：Optical line terminal OLT 2, at least one above-described embodiment or The passive optical network equipment of preferred embodiment, at least one optical network unit ONU 2.

Optical line terminal OLT 2：It is mainly used in receiving, sends time-stamping messages message.Other clock equipment is placed on Turn into an OLT2 part above OLT2, OLT2 clock equipments are mainly responsible for and passive optical network equipment carries out time message receipts Intercommunication is sent out, while it is also responsible for carrying out message intercommunication with upstream clock equipment, to obtain synchronization.If the source of OLT2 upstream equipments Head is similar IEEE1588 time servers, and OLT2 clock equipments are as IEEE1588BC boundary clock, and it is responsible for and upstream Time by server carry out time message mutually to pass to acquirement synchronous, if OLT2 upstream equipments are global navigation satellite time service system System, it directly obtains time synchronization information from time dissemination system.In addition OLT2 is also responsible for carrying out ranging to the ONU2 in system, phase The ranging information of pass is sent to passive optical network equipment processing, is also responsible for existing with ONU2 intercommunications, guarantee time-stamping messages message Normally forwarded between OLT2 and ONU2.

Optical network unit ONU 2：It is mainly used in receiving, sends time-stamping messages message.It is placed in addition from clockwork Turn into an ONU2 part above ONU2, ONU2 is mainly responsible for and passive optical network equipment carries out time information receiving and transmitting intercommunication. ONU2 is upper to be sent to passive optical network equipment and is processed from clock time stamp message packet, passive optical network equipment to it when Between stamp message packet be sent to being handled from clockwork above ONU2.Other ONU2 is also responsible for and OLT2 intercommunications, guarantee OLT2 rangings are normally carried out, and ensure that time-stamping messages message is normally forwarded between OLT2 and ONU2.

Passive optical network equipment：Mainly for the treatment of the time-stamping messages message sended over from OLT2 and ONU2, together When transmission processing after message packet to OLT2 and ONU2.The other equipment is also responsible for handling the ranging letter that OLT2 is sended over Breath, and make ONU2 local clocks, OLT2 local clocks and EPON local system clock are synchronous.

In the present embodiment, there is provided a kind of optical line terminal OLT 1, Figure 18 are optical links according to embodiments of the present invention For the flow chart that terminal one is implemented, it is necessary to illustrate, the internal interface and external interface in figure are relative passive optical network equipments For master-salve clock.External interface：Interacting message interface between master-salve clock and passive optical network equipment.Internal interface： Interacting message interface between passive optical network equipment internal module.As shown in figure 18, the flow comprises the following steps：

S1, optical network device 02-1 modules and downstream ONU communicate news, by ITU-T G.984.3AD2 or G.987.3 or IEEE802.1as time synchronizing method realizes the respective local clock of OLT and ONU both sides and passive optical network Network local system clock is synchronous, and provides EPON local system time and do timing reference to 01-1 modules.

S2, the master clock time come from OLT stab message packet, reach optical network device 01-1 processing, and message is remembered EPON local system time corresponding to record arrival 01-1 is T1, and 01-1 modules also have time bias function in addition, with Compensate this resume module time and message be actually reached the time error of this module because message reach the optical network device time and Message packet has a delay between reaching the time of OLT physical ports, by compensating so that the time-stamping messages message reaches The degree of accuracy of time is improved.

S3, then downgoing time stamp message packet and corresponding T1 information are sent to the progress of optical network device 05-1 modules Processing.T1 information is according to definition format of the present invention, as shown in figure 9, being inserted into downgoing time stamp message packet.

S4, the downgoing time stamp message packet of carrying T1 information are sent to optical network device 06-1 modules and handled, most After be sent to OLT PON mouths be forwarded to it is descending from clock.

S5, reached from upstream time stamp message packet inside EPON at optical network device 01-1 modules Reason, it is T4 that message, which is recorded to up to EPON local system time corresponding to 01-1, time-stamping messages message and corresponding EPON local system time T4 is preserved by one-to-one.

S6, upstream time stamp message packet and corresponding T4 information are sent at optical network device 03-1 modules Reason, 03-1 modules also have time bias function, to compensate this resume module time and be sent out from this module to message is actual Time error gone etc., by compensating so that the degree of accuracy for the residence time being corrected is improved.It is up by calculating acquisition The actual residence time of message, then corrects the time-stamping messages message, and specific correcting mode is with reference to above-described embodiment and excellent Select embodiment.

S7, the upstream time stamp message packet being corrected is sent to optical network device 04-1 modules and handled, by stripping Message packet reference format is stabbed from upstream time is reduced into after processing.

S8, finally it is corrected time-stamping messages message that is rear and being stripped and is sent to optical network device 05-1 modules, sent out It is sent to external master clock equipment.

In the present embodiment, there is provided a kind of optical line terminal OLT 2, Figure 19 are optical links according to embodiments of the present invention For the flow chart that terminal two is implemented, it is necessary to illustrate, the internal interface and external interface in figure are relative passive optical network equipments For master-salve clock.External interface：Interacting message interface between master-salve clock and passive optical network equipment.Internal interface： Interacting message interface between passive optical network equipment internal module.As shown in figure 19, the flow comprises the following steps：

S1, clock equipment, here clock equipment be placed on above OLT, turn into an OLT part.If on OLT The source for swimming equipment is similar IEEE1588 time servers, and for OLT clock equipments as IEEE1588BC boundary clock, it is negative The time of duty and upstream carries out time message by server and mutually passes to acquirement synchronously, if OLT upstream equipments are led for global satellite Navigate time dissemination system, and it directly obtains time synchronization information from time dissemination system.

S2, optical network device 02-1 modules and downstream ONU communicate news, by ITU-T G.984.3AD2 or G.987.3 or IEEE802.1as time synchronizing method realizes the respective local clock of OLT and ONU both sides and passive optical network Network local system clock is synchronous, and provides EPON local system time and do timing reference to 01-1 modules.

S3, master clock time stabs message packet on OLT, reaches optical network device 01-1 processing, and message is remembered EPON local system time corresponding to record arrival 01-1 is T1, and 01-1 modules also have time bias function in addition, with Compensate this resume module time and message is actually reached the time error of this module, by compensating so that the time-stamping messages message The degree of accuracy of arrival time is improved.

S4, then downgoing time stamp message packet and corresponding T1 information are sent to the progress of optical network device 05-1 modules Processing.T1 information is according to definition format of the present invention, as shown in figure 9, being inserted into downgoing time stamp message packet.

S5, the downgoing time stamp message packet of carrying T1 information are sent to optical network device 06-1 modules and handled, most After be sent to OLT PON mouths be forwarded to it is descending from clock.

S6, reached from upstream time stamp message packet inside EPON at optical network device 01-1 modules Reason, it is T4 that message, which is recorded to up to EPON local system time corresponding to 01-1, time-stamping messages message and corresponding EPON local system time T4 is preserved by one-to-one.

S7, upstream time stamp message packet and corresponding T4 information are sent at optical network device 03-1 modules Reason, 03-1 modules also have time bias function, to compensate this resume module time and be sent out from this module to message is actual Time error gone etc., by compensating so that the degree of accuracy for the residence time being corrected is improved.It is up by calculating acquisition The actual residence time of message, then corrects the time-stamping messages message, and specific correcting mode is with reference to above-described embodiment and excellent Select embodiment.

S8, the upstream time stamp message packet being corrected is sent to optical network device 04-1 modules and handled, by stripping Message packet reference format is stabbed from upstream time is reduced into after processing.

S9, finally it is corrected time-stamping messages message that is rear and being stripped and is sent to optical network device 05-1 modules, sent out It is sent to clock equipment on OLT.

In the present embodiment, there is provided a kind of optical network unit ONU 1, Figure 20 are optical-fiber networks according to embodiments of the present invention For the flow chart that unit one is implemented, it is necessary to illustrate, the internal interface and external interface in figure are relative passive optical network equipments For master-salve clock.External interface：Interacting message interface between master-salve clock and passive optical network equipment.Internal interface： Interacting message interface between passive optical network equipment internal module.As shown in figure 20, the flow comprises the following steps：

S1, optical network device 02-2 modules and upstream OLT communicate news, by ITU-T G.984.3AD2 or G.987.3 or IEEE802.1as time synchronizing method realizes the respective local clock of OLT and ONU both sides and passive optical network Network local system clock is synchronous, and provides EPON local system time and do timing reference to 01-2 modules.

S2, message packet is stabbed from clock time from what ONU came, reaches optical network device 01-2 processing, message is remembered EPON local system time corresponding to record arrival 01-2 is T3, and 01-2 modules also have time bias function in addition, with Compensate this resume module time and message be actually reached the time error of this module because message reach the optical network device time and Message packet has a delay between reaching the time of ONU physical ports, by compensating so that the time-stamping messages message reaches The degree of accuracy of time is improved.

S3, then upstream time stamp message packet and corresponding T3 information are sent to the progress of optical network device 05-2 modules Processing.T3 information is according to definition format of the present invention, as shown in figure 9, being inserted into upstream time stamp message packet.

S4, the upstream time stamp message packet of carrying T3 information are sent to optical network device 06-2 modules and handled, most After be sent to ONU PON mouths and be forwarded to up master clock.

S5, reached from EPON inner downlink time-stamping messages message at optical network device 01-2 modules Reason, it is T2 that message, which is recorded to up to EPON local system time corresponding to 01-2, time-stamping messages message and corresponding EPON local system time T2 is preserved by one-to-one.

S6, downgoing time stamp message packet and corresponding T2 information are sent at optical network device 03-2 modules Reason, 03-2 modules also have time bias function, to compensate this resume module time and be sent out from this module to message is actual Time error gone etc., by compensating so that the degree of accuracy for the residence time being corrected is improved.It is up by calculating acquisition The actual residence time of message, then corrects the time-stamping messages message, and specific correcting mode is with reference to above-described embodiment and excellent Select embodiment.

S7, the downgoing time stamp message packet being corrected is sent to optical network device 04-2 modules and handled, by stripping Message packet reference format is stabbed from downgoing time is reduced into after processing.

S8, finally it is corrected time-stamping messages message that is rear and being stripped and is sent to optical network device 05-2 modules, sent out It is sent to outside from clockwork.

In the present embodiment, there is provided a kind of optical network unit ONU 2, Figure 21 are optical-fiber networks according to embodiments of the present invention For the flow chart that unit two is implemented, it is necessary to illustrate, the internal interface and external interface in figure are relative passive optical network equipments For master-salve clock.External interface：Interacting message interface between master-salve clock and passive optical network equipment.Internal interface： Interacting message interface between passive optical network equipment internal module.As shown in figure 21, the flow comprises the following steps：

S1, from clockwork, it is placed on here from clockwork above ONU, turns into an ONU part.

S2, optical network device 02-2 modules and upstream OLT communicate news, by ITU-T G.984.3AD2 or G.987.3 or IEEE802.1as time synchronizing method realizes the respective local clock of OLT and ONU both sides and passive optical network Network local system clock is synchronous, and provides EPON local system time and do timing reference to 01-2 modules.

S3, the time-stamping messages message come from ONU from clock, reach optical network device 01-2 processing, message quilt Recorded up to EPON local system time corresponding to 01-2 is T3, and 01-2 modules also have time bias function in addition, Be actually reached this module time error to compensate this resume module time and message because message reach the optical network device time and Message packet has a delay between reaching the time of ONU physical ports, by compensating so that the time-stamping messages message reaches The degree of accuracy of time is improved.

S4, then upstream time stamp message packet and corresponding T3 information are sent to the progress of optical network device 05-2 modules Processing.T3 information is according to definition format of the present invention, as shown in figure 9, being inserted into upstream time stamp message packet.

S5, the upstream time stamp message packet of carrying T3 information are sent to optical network device 06-2 modules and handled, most After be sent to ONU PON mouths and be forwarded to up master clock.

S6, reached from EPON inner downlink time-stamping messages message at optical network device 01-2 modules Reason, it is T2 that message, which is recorded to up to EPON local system time corresponding to 01-2, time-stamping messages message and corresponding EPON local system time T2 is preserved by one-to-one.

S7, downgoing time stamp message packet and corresponding T2 information are sent at optical network device 03-2 modules Reason, 03-2 modules also have time bias function, to compensate this resume module time and be sent out from this module to message is actual Time error gone etc., by compensating so that the degree of accuracy for the residence time being corrected is improved.It is up by calculating acquisition The actual residence time of message, then corrects the time-stamping messages message, and specific correcting mode is with reference to above-described embodiment and excellent Select embodiment.

S8, the downgoing time stamp message packet being corrected is sent to optical network device 04-2 modules and handled, by stripping Message packet reference format is stabbed from downgoing time is reduced into after processing.

S9, finally it is corrected time-stamping messages message that is rear and being stripped and is sent to optical network device 05-2 modules, sent out Send on ONU from clockwork.

Obviously, those skilled in the art should be understood that above-mentioned each module of the invention or each step can be with general Computing device realize that they can be concentrated on single computing device, or be distributed in multiple computing devices and formed Network on, alternatively, they can be realized with the program code that computing device can perform, so as to being stored in Performed in storage device by computing device, they are either fabricated to each integrated circuit modules respectively or by them Multiple modules or step be fabricated to single integrated circuit module to realize.So, the present invention is not restricted to any specific hard Part and software combine.

The preferred embodiments of the present invention are the foregoing is only, are not intended to limit the invention, for the skill of this area For art personnel, the present invention can have various modifications and variations.Within the spirit and principles of the invention, that is made any repaiies Change, equivalent substitution, improvement etc., should be included in the scope of the protection.

Claims (7)

1. A kind of 1. time synchronizing method, it is characterised in that comprise the following steps：

   By the receiving port in EPON from master clock and from the side in clock receive for time synchronized when Between stab message packet, and record the time for receiving the time-stamping messages message；

   The sending port that record passes through in EPON sends the time of the time-stamping messages message, wherein, the transmission Port and the receiving port are synchronous with the equipment time holding at place；

   According to the time for receiving the time-stamping messages message and send time of the time-stamping messages message, to it is described when Between stab the temporal information for time synchronized that carries in message packet and be modified；

   The time-stamping messages message is sent to the master clock and from the opposing party in clock by the sending port；

   Wherein, record, which receives time of the time-stamping messages message, includes：Record the time-stamping messages message and reach institute State the time of receiving port；The time for reaching the receiving port is entered according to the first compensation time and/or the second compensation time Row compensates, wherein, the first compensation time is to be connect described in the time-stamping messages message arrival receiving port and arrival The delay between physical port corresponding to receiving end mouth, the second compensation time is to carry out receiving the time-stamping messages message The processing time of process；The time that the receiving port is reached to the time-stamping messages message is compensated what is obtained afterwards Time, it is recorded as receiving the time of the time-stamping messages message；

   Wherein, the time of the time-stamping messages message is received and by the transmitting terminal by following time format record Mouth sends the time of the time-stamping messages message：The time format includes：It is small for indicating for indicating the field on date When second minute field and field for indicating nanosecond.
2. 2. according to the method for claim 1, it is characterised in that record sends the timestamp by the sending port and disappeared The time of breath message includes：

   Record the time that the time-stamping messages message reaches the sending port；

   The time for reaching the sending port is compensated according to the 3rd compensation time and/or the 4th compensation time, wherein, institute It is the time that the time-stamping messages message reaches the time of the sending port and actually sent to state for the 3rd compensation time Error, the 4th compensation time is processing time for being modified to the temporal information for time synchronized；

   The time that the sending port is reached to the time-stamping messages message is compensated into the time obtained afterwards, is recorded as The time of the time-stamping messages message is sent by the sending port.
3. 3. according to the method for claim 1, it is characterised in that the sending port and the receiving port and place are set The standby time keeps synchronous at least one in the following manner：

   International Telecommunication Union telecommunication standards group ITU-T G.984.3 AD2, International Telecommunication Union's telecommunication standards Group ITU-T G.987.3, IEEE802.1as.
4. 4. according to the method for claim 1, it is characterised in that the timestamp will be received by the receiving port and disappeared The time for ceasing the time of message and the time-stamping messages message being sent by the sending port is recorded in the timestamp and disappeared Cease in message.
5. A kind of 5. time synchronizing device, it is characterised in that including：

   The very first time stab message reception module, for by the receiving port in EPON from master clock and from clock One side receives the time-stamping messages message for time synchronized, and records the time for receiving the time-stamping messages message；

   Second time-stamping messages receiving module, for receiving the timestamp from very first time stamp message reception module Message packet, and the time that the sending port passed through in EPON sends the time-stamping messages message is recorded, wherein, institute It is synchronous with the equipment time holding at place to state sending port and the receiving port；

   Correcting module, for according to the time for receiving the timestamp message and send the time-stamping messages message when Between, the temporal information for time synchronized carried in the time-stamping messages message is modified；

   Time-stamping messages sending module, for being sent by the sending port to the master clock and from the opposing party in clock The time-stamping messages message；

   Wherein, the very first time stamp message reception module includes：First recording unit, for recording the time-stamping messages report Text reaches the time of the receiving port；First compensating unit, for according to the first compensation time and/or the second compensation time pair The time for reaching the receiving port compensates, wherein, the first compensation time reaches for the time-stamping messages message The receiving port and reach the delay between physical port corresponding to the receiving port, the second compensation time be into Row receives the processing time of the time-stamping messages message process；Second recording unit, for will be to the time-stamping messages report The time that text reaches the receiving port compensates the time obtained afterwards, is recorded as receiving the time-stamping messages message Time；Wherein, the time of the time-stamping messages message is received and by the hair by following time format record Sending end mouth sends the time of the time-stamping messages message：The time format includes：For indicating the field on date, for referring to Show the field of second minute hour and the field for indicating nanosecond.
6. 6. device according to claim 5, it is characterised in that the second time-stamping messages receiving module includes：

   3rd recording unit, the time of the sending port is reached for recording the time-stamping messages message；

   Second compensating unit, for according to the 3rd compensation time and/or the 4th compensation time to reach the sending port when Between compensate, wherein, the 3rd compensation time be the time-stamping messages message reach the sending port time and The error of the time actually sent, the 4th compensation time is that the temporal information for time synchronized is repaiied Positive processing time；

   4th recording unit, after the time that the sending port is reached to the time-stamping messages message is compensated The obtained time, it is recorded as sending the time of the time-stamping messages message by the sending port.
7. 7. a kind of time synchronizing system, including：Clock equipment, from clockwork, optical line terminal OLT, optical-fiber network list First ONU, it is characterised in that also include：Device described in claim 5 or 6, wherein, described device is connected to the master clock Equipment and described between clockwork, it is the clock equipment, described between clockwork, the OLT and the ONU Relation is one below：

   The clock equipment and it is described from clockwork independently in the OLT and the ONU；

   The clock equipment is located on the OLT, it is described from clockwork independently of the OLT and the ONU；

   The clock equipment is described to be located at from clockwork on the ONU independently of the OLT and the ONU；

   The clock equipment is located on the OLT, described to be located at from clockwork on the ONU.