CN103139670B - Passive optical network and uplink and downlink optical signal transmitting method coexists - Google Patents

Abstract

The invention discloses one kind to coexist passive optical network and uplink and downlink optical signal transmitting method.Wherein, the system includes：XPON optical line terminals and 10G xPON optical line terminals, downlink optical signal, and the uplink optical signal that optical network unit belonging to reception is sent are sent to optical network unit by respective single fiber interface respectively；Lightguide, xPON optical line terminals and 10G xPON optical line terminals are respectively connecting to, downlink optical signal and uplink optical signal are carried out for respectively guide-lighting；Multi-mode coupler, lightguide is connected to, for downlink optical signal to be distributed into Optical Distribution Network, and uplink optical signal is coupled to lightguide；Optical Distribution Network, multi-mode coupler is connected to, for downlink optical signal to be transferred into optical network unit, and uplink optical signal is transferred to multi-mode coupler；Optical network unit, the Optical Distribution Network being each connected to, uplink optical signal is sent for receiving the downlink optical signal of input, and to xPON optical line terminals or 10G xPON optical line terminals.By the invention it is possible to the utilization ratio of PON mouths is improved, so as to reach the effect to cut operating costs.

Description

Passive optical network and uplink and downlink optical signal transmitting method coexists

Technical field

The present invention relates to the communications field, and passive optical network and uplink and downlink optical signal coexists in particular to one kindSending method.

Background technology

With the fast development of Fibre Optical Communication Technology, and inexpensive, green requirement, communication network is from coreNet, Metropolitan Area Network (MAN) to access network, the network all formed using optical fiber have become basic Consensus.

In optical-fiber network, for some more dispersed cells, each EPON only meets several users；For populationThan the cell of the cell of comparatively dense, especially some high low-end subscribers mixing, each PON (Passive OpticalNetwork, EPON) number of users of mouth institute band needs substantial amounts of PON eloquence to meet net than relatively limited, therefore in office sideNetwork needs.But, it is generally the case that the computer room space of office side is limited, causes the quantity of PON mouths can not be too many, moreover, OLTONU (Optical Network Unit, the optical-fiber network list that (Optical Line Terminal, optical line terminal) is carried byMember) quantity be almost unlimited.

Therefore, how fully to improve the utilization rate of PON mouths, cut operating costs, be that current operator compares concernSomething, in existing certain methods, some method Land use models couplers merge to PON mouths, and this method needs pairExisting OLT is transformed, and the optical module particularly in method needs to use TOSA (Transmitter OpticalSubassembly, light emission secondary module) and ROSA (Receiver Optical Subassembly, light-receiving secondary module) it is doubleFine two-way optical module.Coexisted for some EPON (refer to Fig. 1, Fig. 1 be according to the GPON of correlation technique andThe schematic diagram for the passive optical network structure that XGPON coexists.), if minimum change can be done to former OLT and can be reused originalSimplex optical module, the utilization rate of PON mouths will be greatly improved, however, not providing a kind of effective solution in the prior artCertainly method.

(PON, i.e. xPON and 10G-xPON coexists, it can be expressed as the EPON that coexists in correlation techniqueEPON and 10G-EPON or GPON and two kinds of different combination collocations of XG-PON) in PON mouths utilization rate it is relatively low the problem of, at presentNot yet propose effective solution.

The content of the invention

The present invention provides one kind and passive optical network and uplink and downlink optical signal transmitting method coexists, at least to solveState PON mouths utilization rate it is relatively low the problem of.

According to an aspect of the invention, there is provided passive optical network coexists in one kind, including：XPON optical links are wholeEnd, for sending downlink optical signal to optical network unit by its single optical fiber interface, and receive the upper of optical network unit transmissionTraveling optical signal；10G-xPON optical line terminals, for sending downlink optical signal to optical network unit by its single optical fiber interface,With the uplink optical signal for receiving optical network unit transmission；Lightguide, it is respectively connecting to xPON optical line terminals and 10G-xPON lightLine terminal, for respectively to the downlink optical signal from xPON optical line terminals and 10G-xPON optical line terminals, and come fromThe uplink optical signal of optical network unit carries out guide-lighting；Multi-mode coupler, lightguide is connected to, for downlink optical signal to be distributed toMultiple Optical Distribution Networks, and the uplink optical signal sent by Optical Distribution Network is coupled to lightguide；Optical Distribution Network, it is connected toMulti-mode coupler, for downlink optical signal to be transferred into multiple optical network units, and uplink optical signal is transferred to Multiple modes couplingDevice；Optical network unit, be connected to Optical Distribution Network, for receiving the downlink optical signal of input, and to xPON optical line terminals or10G-xPON optical line terminals send uplink optical signal.

Preferably, lightguide includes：First wave-division multiplexer filter, it is respectively connecting to xPON optical line terminals and 10G-XPON optical line terminals, for passing through ripple to the downlink optical signal from xPON optical line terminals and 10G-xPON optical line terminalsThe mode divided carries out branch, by the downlink optical signal leaded light after branch to respective image intensifer, and to from optical-fiber networkThe uplink optical signal of unit carries out branch by way of wavelength-division, and the uplink optical signal after branch is guide-lighting to xPON respectivelyOptical line terminal and 10G-xPON optical line terminals；Second wave-division multiplexer filter, its first interface are connected by image intensiferTo the first wave-division multiplexer filter, for being synthesized to the downlink optical signal after image intensifer amplifies, synthesis will be passed throughDownlink optical signal leaded light afterwards to multi-mode coupler, and, its second interface is directly connected with the first wave-division multiplexer filter, is used forUplink optical signal is directly guide-lighting to the first wave-division multiplexer filter；The system also includes：Image intensifer, it is respectively connecting to firstWave-division multiplexer filter and the second wave-division multiplexer filter, for respectively from xPON optical line terminals and 10G-xPON lightThe downlink optical signal of road terminal is amplified.

Preferably, image intensifer includes：First image intensifer, it is respectively connecting to the first wave-division multiplexer filter and the second rippleDivide multiplex filter, for being amplified to the downlink optical signal from xPON optical line terminals；Second image intensifer, connects respectivelyThe first wave-division multiplexer filter and the second wave-division multiplexer filter are connected to, for from the descending of 10G-xPON optical line terminalsOptical signal is amplified.

Preferably, the first amplifier is S-band image intensifer.

Preferably, the second amplifier is L-band image intensifer.

Preferably, S-band image intensifer is semiconductor amplifier SOA.

Preferably, L-band image intensifer is SOA or fiber amplifier EDFA.

Preferably, the wave-length coverage for the downlink optical signal that xPON optical line terminals are sent to optical network unit is：1480nmTo 1500nm；The wave-length coverage for the downlink optical signal that 10G-xPON optical line terminals are sent to optical network unit is：1575nm is extremely1581nm。

According to a further aspect of the invention, there is provided a kind of downlink optical signal sending method that EPON coexists,Including：XPON optical line terminals or 10G-PON optical line terminals send downlink optical signal to lightguide；Lightguide receives descending lightSignal, by downlink optical signal leaded light to multi-mode coupler；Multi-mode coupler receives downlink optical signal, and downlink optical signal is distributed toMultiple Optical Distribution Networks；Downstream signal is distributed to multiple optical network units by Optical Distribution Network；Optical network unit receives inputDownlink optical signal.

According to a further aspect of the invention, there is provided a kind of uplink optical signal sending method that EPON coexists,Including：Optical network unit sends uplink optical signal to Optical Distribution Network；Uplink optical signal is transferred to multimode coupling by Optical Distribution NetworkClutch；Multi-mode coupler receives uplink optical signal, and lightguide is sent to after being coupled to uplink optical signal；Lightguide is to receivingThe uplink optical signal arrived carries out leaded light, and the uplink optical signal after leaded light is input into xPON optical line terminals or 10G-PON lightRoad terminal；XPON optical line terminals or 10G-PON optical line terminals receive the uplink optical signal of input.

By the present invention, filtered using wavelength-division multiplex is added in the EPON coexisted in existing GPON and XGPONThe mode of device, multi-mode coupler and image intensifer, solve prior art to provide the utilization rate of PON mouths and need to existingThe problem of some optical line terminals (OLT) are significantly transformed so as to add cost, and then only need to be to existingOptical line terminal (OLT) carry out minimum change and can improve PON utilization rate, the effect to cut operating costs.

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 hairBright 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 schematic diagram according to the GPON and XGPON of the correlation technique passive optical network structure coexisted；

Fig. 2 is the structured flowchart according to an embodiment of the invention that passive optical network coexists；

Fig. 3 is the structured flowchart for the EPON that GPON and XGPON according to the preferred embodiment of the invention coexist；

Fig. 4 is the structural representation of the first wave-division multiplexer filter according to the preferred embodiment of the invention；

Fig. 5 is the structural representation of the second wave-division multiplexer filter according to the preferred embodiment of the invention；

Fig. 6 is the structural representation of multi-mode coupler according to the preferred embodiment of the invention；

Fig. 7 is downlink optical signal sending method flow chart according to embodiments of the present invention；

Fig. 8 is uplink optical signal sending method flow chart according to embodiments of the present invention.

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 conflictingIn the case of, the feature in embodiment and embodiment in the application can be mutually combined.

Fig. 2 is the structured flowchart according to an embodiment of the invention that passive optical network coexists, as shown in Fig. 2 shouldSystem mainly includes：XPON optical line terminals 10,10G-xPON optical line terminals 20, lightguide 30, multi-mode coupler 40, light pointDistribution network 60 and optical network unit 50.Wherein, xPON optical line terminals 10, for by its single optical fiber interface to optical-fiber network listMember 50 sends downlink optical signal, and receives the uplink optical signal that optical network unit 50 is sent；10G-xPON optical line terminals 20, useIn by its single optical fiber interface to optical network unit 50 send downlink optical signal, and receive optical network unit 50 send it is upOptical signal；Lightguide 30, xPON optical line terminals 10 and 10G-xPON optical line terminals 20 are respectively connecting to, for respectively to comingCarried out from the downlink optical signal of xPON optical line terminals 10 and 10G-xPON optical line terminals 20 guide-lighting；Multi-mode coupler 40, evenLightguide 30 is connected to, for downlink optical signal to be distributed into multiple Optical Distribution Networks 60, and it is upper by being sent by Optical Distribution NetworkTraveling optical signal is coupled to lightguide 30；Optical Distribution Network 60, multi-mode coupler 40 is connected to, it is more for downstream signal to be sent toIndividual optical network unit 50, the uplink optical signal is sent to multi-mode coupler 40；Optical network unit 50, is connected to optical distribution networkNetwork 60, sent for receiving the downlink optical signal of input, and to xPON optical line terminals 10 or 10G-xPON optical line terminals 20Uplink optical signal.

Fig. 3 is please also refer to, in actual applications, lightguide 30 can include：First wave-division multiplexer filter, connects respectivelyXPON optical line terminals 10 and 10G-xPON optical line terminals 20 are connected to, for from xPON optical line terminals 10 and 10G-The downlink optical signal of xPON optical line terminals 20 carries out branch by way of wavelength-division, and the downlink optical signal after branch is ledLight carries out branch to image intensifer, and to the uplink optical signal from optical network unit 50 by way of wavelength-division, will be through undueUplink optical signal behind road is guide-lighting to xPON optical line terminals 10 and 10G-xPON optical line terminals 20 respectively；Second wavelength-division multiplexWave filter, its first interface are connected to the first wave-division multiplexer filter by image intensifer, for amplifying by image intensiferDownlink optical signal afterwards is synthesized, by the downlink optical signal leaded light after synthesis to multi-mode coupler, and, its second interfaceDirectly it is connected with the first wave-division multiplexer filter, for uplink optical signal is directly guide-lighting to the first wave-division multiplexer filter；ShouldSystem also includes：Image intensifer, the first wave-division multiplexer filter and the second wave-division multiplexer filter are respectively connecting to, for dividingDownlink optical signal not from xPON optical line terminals 10 and 10G-xPON optical line terminals 20 is amplified.

In actual applications, image intensifer can include：First image intensifer, is respectively connecting to first waveDivide multiplex filter and the second wave-division multiplexer filter, for being put to the downlink optical signal from xPON optical line terminals 10Greatly；Second image intensifer, the first wave-division multiplexer filter and the second wave-division multiplexer filter are respectively connecting to, usedIt is amplified in the downlink optical signal from 10G-xPON optical line terminals 20.

Preferably, the first image intensifer can be S-band image intensifer, and the second image intensifer can be L-band light amplificationDevice.In actual applications, S-band image intensifer can be semiconductor amplifier (SOA)；L-band image intensifer can be SOA orFiber amplifier (EDFA)；The wave-length coverage for the downlink optical signal that xPON optical line terminals 10 are sent to optical network unit 50 is：1480nm to 1500nm；The wave-length coverage for the downlink optical signal that 10G-xPON optical line terminals 20 are sent to optical network unit 50For：1575nm to 1581nm.Here, Fig. 3 is not described in detail.

Fig. 3 is the structured flowchart for the EPON that GPON and XGPON according to the preferred embodiment of the invention coexist, belowBy taking the preferred embodiment shown in Fig. 3 as an example, said system is described in detail：

In order to realize goal of the invention, five different functional modules are newly increased in this optimum decision system, have been respectively：First waveDivide the 42, second wave-division multiplexer filter of multiplex filter (WDM1) (WDM2) 44, multi-mode coupler (40), S-band image intensifer46 and L-band image intensifer 48, each functional module is described in detail below.

First wave-division multiplexer filter (WDM1) 42：Its major function be to the carry out branch of up-downgoing light and synthesis,It can be connected by optical module of each independent multimode fibre respectively with GPON OLT optical module and XG-PON OLT,On OLT the up light directing GPON of GPON from up optical channel, and the XG-PON from up optical channel is upOn light directing XG-PON OLT；And the light of the S-band of the descending descending optical channels of light directing GPON of the OLT from GPON is putOn big device, and on the image intensifer of the L-band of the descending descending optical channels of light directing XG-PON of the OLT from XG-PON, it isA kind of passive leaded light device of multichannel, leaded light can be carried out to it by way of wavelength-division.

In actual applications, existing film filtering TFF technologies can be used, the work(is completed with three linear filter piecesCan, Fig. 4 please be participate in, Fig. 4 is the structural representation of the first wave-division multiplexer filter according to the preferred embodiment of the invention, such as Fig. 4Shown, it has two types, and a kind of is the sideband filter using 1450nm as separation, for wavelength less than 1450nm light fromIts transmission mouth disengaging, and mouth disengaging is reflected from it to light of the wavelength more than 1450nm；Another kind is using 1280nm as separationSideband filter, passed in and out for light of the wavelength less than 1280nm from its transmission mouth, and to light of the wavelength more than 1280nm fromIts reflex port passes in and out.Wherein, the general-purpose interface C of the first sideband filter is connected by multimode fibre with up optical channel, and itsTransmission mouth P is connected with the transmission interface P of the 3rd sideband filter, and its reflex port R and the second sideband filter transmission connectMouth P is connected；The general-purpose interface C of second sideband filter is connected by multimode fibre with GPON OLT optical modules, and its reflex portR is connected by single-mode fiber with the S-band image intensifer of descending optical channel；The general-purpose interface C of 3rd sideband filter passes through moreMode fiber is connected with XG-PON OLT optical modules, and its reflex port R is put by the L-band light of single-mode fiber and descending optical channelBig device is connected；The leaded light of five different passages can thus be completed.

Second wave-division multiplexer filter (WDM2) 44：Its major function be to the carry out branch of up-downgoing light and synthesis,It can be connected by multimode fibre with multi-mode coupler, Multiple modes coupling be oriented to after the descending light from different single-mode fibers is convergedOn device, and the up light of multi-mode coupler is passed through multimode fibre and is oriented on WDM1 wave filters.

In actual applications, existing film filtering TFF technologies can be used, the work(is completed with two linear filter piecesCan, refer to Fig. 5, Fig. 5 is the structural representation of the second wave-division multiplexer filter according to the preferred embodiment of the invention, such as Fig. 5Shown, it has two types, and a kind of is the sideband filter using 1450nm as separation, for wavelength less than 1450nm light fromIts transmission mouth disengaging, and mouth disengaging is reflected from it to light of the wavelength more than 1450nm；Another kind is using 1550nm as separationSideband filter, passed in and out for light of the wavelength less than 1550nm from its transmission mouth, and to light of the wavelength more than 1550nm fromIts reflex port passes in and out.Wherein, the general-purpose interface C of the first sideband filter is connected by multimode fibre with multi-mode coupler, and itsTransmission mouth P is connected by multimode fibre with WDM1 wave filters, and the general-purpose interface C of its reflex port R and the second sideband filterIt is connected；The transmission interface P of second sideband filter is connected with the image intensifer of the S-band of descending optical channel, and under its reflex port RThe image intensifer of the L-band of row optical channel is connected；The leaded light of four different passages can thus be completed.

Multi-mode coupler 40：Its major function is that up be optically coupled together from multiple ODN is input to WDM2On wave filter, and the descending light from WDM2 wave filters is evenly distributed on multiple ODN trunk optical fiber.Refer to Fig. 6,Fig. 6 is the structural representation of multi-mode coupler according to the preferred embodiment of the invention, as shown in fig. 6, up light is through single-mode fiberIt is transferred to after being polymerize by multimode fibre on WDM2 wave filters, and descending light is evenly distributed to multiple lists by multimode fibreOn mode fiber；It this flowcollector aggregation scheme FlowCollector, can be lens, the modes such as vertebral pulling and fiber waveguide can also be merged multiple single-mode fibersOptically coupling on multimode fibre.

S-band image intensifer 46：Its major function is that GPON OLT descending light is amplified, due to GPON'sDescending light is between 1480nm to 1500nm, and therefore, its service band is located at S-band, generally selects the SOA of S-band as itImage intensifer.

L-band image intensifer 48：Its major function is that XG-PON OLT descending light is amplified, due to XG-PON descending light is between 1575nm to 1581nm, and therefore, its service band is located at L-band, generally selects the EDFA of L-bandOr SOA is as its image intensifer.

Wherein, for the annexation between modules, Fig. 3 is also refer to, it is main illustratively four hereinODN consolidation problem, first, four ODN trunk optical fiber are connected with multi-mode coupler, are then filtered by multimode fibre and WDM2Ripple device is connected, and it transmits interface and is connected by multimode fibre with the general-purpose interface C of WDM1 wave filters, and WDM1 wave filters pass through notSame multimode fibre is directly connected respectively with GPON-OLT simplex optical module and the single fiber bi-directional with XG-PON-OLTOptical module is connected, and the single mode passage of last WDM1 wave filters connects each different light amplification by respective single-mode fiber respectivelyAfter device, then it is connected respectively with WDM2 wave filters by respective single-mode fiber.Certainly, in actual applications, however it is not limited to onlyIt four ODN merging, can be N number of ODN, only need to change corresponding 1:N multi-mode coupler.

The operation principle and workflow of said system are as follows：First, OLT and one of a GPON is provided with office sideXG-PON OLT, it is connected respectively with wave-division multiplexer filter WDM1 by the multimode fibre of its respective optical module, under themRow light respectively enters the respective descending optical channel being made up of respective single-mode fiber after reaching WDM1 by respective multimode fibre,The image intensifer for the S-band that wherein GPON descending light enters on GPON descending optical channel, amplified arrival wavelength-division multiplexOn wave filter WDM2, and XG-PON descending light is into the image intensifer of the L-band on XG-PON descending optical channel, amplifiedAlso reach afterwards on wave-division multiplexer filter WDM2, multi-mode coupler is then entered by multimode fibre after WDM2 multiplex, through thisCoupler enters connected ODN trunk optical fiber after being uniformly divided, by trunk optical fiber, optical splitter and branch optical fiber arriveUp on each ONU, wherein GPON ONU only receives GPON signal, and XG-PON ONU only receives XG-PON signal.AndThe up light that these ONU are uploaded, passes on coupled multi-mode coupler through corresponding ODN, is then entered by multimode fibreEntering on multiplex light guide module WDM2, be directed to up optical channel, this is a multimode fibre connection WDM2 and WDM1, byWDM1 is individually directed on the multimode fibre being connected with respective OLT optical module, subsequently on respective OLT, i.e. GPON'sUp light imported into GPON OLT, and XG-PON up light is imported on XG-PON OLT.

Specifically, first, GPON OLT descending light is reached on WDM1 wave filters by multimode fibre, while XG-PONOLT descending light reached also by another root multimode fiber on WDM1 wave filters, after leaded light, GPON descending light enters theOn the image intensifer of S-band on one descending optical channel, and XG-PON descending light also enters on the second descending optical channel simultaneouslyL-band image intensifer on, the descending light of amplified GPON descending light and XG-PON passes through respective single-mode optics respectivelyFibre is directly entered WDM2 wave filters, is reached after convergence by multimode fibre on multi-mode coupler, then uniform point its fourOn individual single-mode fiber, corresponding ODN networks are entered by connected ODN trunk optical fiber, through optical splitter, branch optical fiber arrivesUp on each ONU.

Each ONU up light is reached on corresponding ODN optical splitters by respective branch optical fiber, the master through being attached theretoDry optical fiber reaches the single-mode interface of multi-mode coupler, then goes out multi-mode interface and is reached through multimode fibre on WDM2 wave filters, through leadingLight is reached on WDM1 wave filters by multimode fibre, is then oriented to respective multi-mode interface, i.e., the GPON up light of ONU is passed through moreMode fiber is oriented on GPON-OLT optical module；And the XG-PON up light of ONU is oriented to XG- by another root multimode fiberOn PON-OLT optical module.

It should be noted that it can also be carried out for EPON and 10G-EPON with reference to above embodiment, i.e. EPON substitutionsGPON, while 10G-EPON substitutions XG-PON.

Passive optical network coexists using what above-described embodiment provided, can be only to existing optical line terminal (OLT)The problem of significantly being transformed so as to add cost, and then existing optical line terminal (OLT) need to only be enteredThe minimum change of row can improve PON utilization rate, the effect to cut operating costs.

Fig. 7 is downlink optical signal sending method flow chart according to embodiments of the present invention, as shown in fig. 7, this method is mainComprise the following steps (step S702- step S710)：

Step S702, xPON optical line terminal or 10G-xPON optical line terminals send downlink optical signal to lightguide；

Step S704, lightguide receives downlink optical signal, by downlink optical signal leaded light to multi-mode coupler；

Step S706, multi-mode coupler receive downlink optical signal, downlink optical signal are distributed into multiple Optical Distribution Networks(ODN)；

Downlink optical signal is distributed to multiple optical network units by step S708, Optical Distribution Network；

Step S710, optical network unit receive the downlink optical signal of input.

Fig. 8 is uplink optical signal sending method flow chart according to embodiments of the present invention, as shown in figure 8, this method is mainComprise the following steps (step S802- step S810)：

Step S802, optical network unit send uplink optical signal to Optical Distribution Network；

Uplink optical signal is transferred to multi-mode coupler by step S804, Optical Distribution Network；

Step S806, multi-mode coupler receive uplink optical signal, lightguide are sent to after being coupled to uplink optical signal；

Step S808, lightguide carry out leaded light to the uplink optical signal received, the uplink optical signal after leaded light are inputtedTo xPON optical line terminals or 10G-xPON optical line terminals；

Step S810, xPON optical line terminal or 10G-xPON optical line terminals receive the uplink optical signal of input.

The uplink and downlink optical signal transmitting method provided using above-described embodiment, can solve to increase in the prior art multipleOptical line terminal (OLT) and the problem of increase cost, and then only existing optical line terminal (OLT) need to be carried out minimumChange can improve PON utilization rate, the effect to cut operating costs.

As can be seen from the above description, the present invention realizes following technique effect：By existing xPON withThe mode of wave-division multiplexer filter, multi-mode coupler and image intensifer is added in the EPON that 10G-xPON coexists, is solvedPrior art in order to provide the utilization rate of PON mouths needs significantly to change existing optical line terminal (OLT)The problem of making so as to add cost, and then need to only carry out minimum change to existing optical line terminal (OLT) and bePON utilization rate, the effect to cut operating costs can be improved.

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

Claims (9)

1. passive optical network coexists in one kind, it is characterised in that including：

XPON optical line terminals, for sending downlink optical signal to optical network unit by its single optical fiber interface, and receive instituteState the uplink optical signal of optical network unit transmission；

10G-xPON optical line terminals, believe for sending the descending light to the optical network unit by its single optical fiber interfaceNumber, and receive the uplink optical signal that the optical network unit is sent；

Lightguide, the xPON optical line terminals and the 10G-xPON optical line terminals are respectively connecting to, for respectively to comingFrom the xPON optical line terminals and the downlink optical signal of the 10G-xPON optical line terminals, and from the optical-fiber networkThe uplink optical signal of unit carries out guide-lighting；

Multi-mode coupler, the lightguide is connected to, for the downlink optical signal to be distributed into multiple Optical Distribution Networks, and willThe uplink optical signal sent by Optical Distribution Network is coupled to the lightguide；

The Optical Distribution Network, the multi-mode coupler is connected to, for the downlink optical signal to be transferred into multiple optical-fiber networksUnit, and the uplink optical signal is transferred to multi-mode coupler；

The optical network unit, the Optical Distribution Network is connected to, for receiving the downlink optical signal of input, and to describedXPON optical line terminals or the 10G-xPON optical line terminals send the uplink optical signal；

The lightguide includes：

First wave-division multiplexer filter, the xPON optical line terminals and the 10G-xPON optical line terminals are respectively connecting to,For passing through wavelength-division to the downlink optical signal from the xPON optical line terminals and the 10G-xPON optical line terminalsMode carry out branch, by the downlink optical signal leaded light after branch to respective image intensifer, and to from describedThe uplink optical signal of optical network unit carries out branch by way of wavelength-division, by the uplink optical signal after branchIt is guide-lighting to the xPON optical line terminals and the 10G-xPON optical line terminals respectively；

Second wave-division multiplexer filter, its first interface are connected to first wavelength-division multiplex by the image intensifer and filteredDevice, for being synthesized to the downlink optical signal after image intensifer amplification, by under described after synthesisTraveling optical signal leaded light to the multi-mode coupler, and, its second interface is directly connected with first wave-division multiplexer filter, useIn the uplink optical signal is directly guide-lighting to first wave-division multiplexer filter；

The system also includes：The image intensifer, it is respectively connecting to first wave-division multiplexer filter and second ripplePoint multiplex filter, under described respectively from the xPON optical line terminals and the 10G-xPON optical line terminalsTraveling optical signal is amplified.

2. system according to claim 1, it is characterised in that the image intensifer includes：

First image intensifer, first wave-division multiplexer filter and second wave-division multiplexer filter are respectively connecting to, usedIt is amplified in the downlink optical signal from the xPON optical line terminals；

Second image intensifer, first wave-division multiplexer filter and second wave-division multiplexer filter are respectively connecting to, usedIt is amplified in the downlink optical signal from the 10G-xPON optical line terminals.

3. system according to claim 2, it is characterised in that first image intensifer is S-band image intensifer.

4. system according to claim 3, it is characterised in that second image intensifer is L-band image intensifer.

5. system according to claim 4, it is characterised in that the S-band image intensifer is semiconductor amplifier SOA.

6. system according to claim 4, it is characterised in that the L-band image intensifer be semiconductor amplifier SOA orFiber amplifier EDFA.

7. system according to any one of claim 1 to 6, it is characterised in that

The wave-length coverage for the downlink optical signal that the xPON optical line terminals are sent to the optical network unit is：1480nmTo 1500nm；

The wave-length coverage for the downlink optical signal that the 10G-xPON optical line terminals are sent to the optical network unit is：1575nm to 1581nm.

A kind of 8. downlink optical signal sending method that EPON coexists, it is characterised in that including：

XPON optical line terminals or 10G-xPON optical line terminals send downlink optical signal to lightguide；

The lightguide receives the downlink optical signal, by the downlink optical signal leaded light to multi-mode coupler；

The multi-mode coupler receives the downlink optical signal, and the downlink optical signal is distributed into multiple Optical Distribution Networks；

The downlink optical signal is distributed to multiple optical network units by the Optical Distribution Network；

The optical network unit receives the downlink optical signal of input；

Wherein, the lightguide is to described descending from the xPON optical line terminals and the 10G-xPON optical line terminalsOptical signal carries out branch by way of wavelength-division, by the downlink optical signal leaded light after branch to respective light amplificationDevice, and branch is carried out by way of wavelength-division to the uplink optical signal from the optical network unit, by the institute after branchIt is guide-lighting to the xPON optical line terminals and the 10G-xPON optical line terminals respectively to state uplink optical signal；

The first interface of the lightguide synthesizes to the downlink optical signal after image intensifer amplification, will be throughThe downlink optical signal leaded light crossed after synthesis to the multi-mode coupler, and, the second interface of the lightguide will be described onTraveling optical signal is directly guide-lighting to the first wave-division multiplexer filter；

The image intensifer is under described respectively from the xPON optical line terminals and the 10G-xPON optical line terminalsTraveling optical signal is amplified.

A kind of 9. uplink optical signal sending method that EPON coexists, it is characterised in that including：

Optical network unit sends uplink optical signal to Optical Distribution Network；

The uplink optical signal is transferred to multi-mode coupler by the Optical Distribution Network；

The multi-mode coupler receives the uplink optical signal, and lightguide is sent to after being coupled to the uplink optical signal；

The lightguide carries out leaded light to the uplink optical signal received, and the uplink optical signal after leaded light is input toXPON optical line terminals or 10G-xPON optical line terminals；

The xPON optical line terminals or the 10G-xPON optical line terminals receive the uplink optical signal of input；

Wherein, the lightguide from the descending light of the xPON optical line terminals and the 10G-xPON optical line terminals to believingNumber branch is carried out by way of wavelength-division, by the downlink optical signal leaded light after branch to respective image intensifer, andBranch is carried out by way of wavelength-division to the uplink optical signal from the optical network unit, described in after branchUplink optical signal is guide-lighting to the xPON optical line terminals and the 10G-xPON optical line terminals respectively；

The first interface of the lightguide synthesizes to the downlink optical signal after image intensifer amplification, will be throughThe downlink optical signal leaded light crossed after synthesis to the multi-mode coupler, and, the second interface of the lightguide will be described onTraveling optical signal is directly guide-lighting to the first wave-division multiplexer filter；

The image intensifer is under described respectively from the xPON optical line terminals and the 10G-xPON optical line terminalsTraveling optical signal is amplified.