CN102075822B - WDM passive optical network system, communication means and optical line terminal equipment - Google Patents

WDM passive optical network system, communication means and optical line terminal equipment Download PDF

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CN102075822B
CN102075822B CN201110021772.XA CN201110021772A CN102075822B CN 102075822 B CN102075822 B CN 102075822B CN 201110021772 A CN201110021772 A CN 201110021772A CN 102075822 B CN102075822 B CN 102075822B
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signal
upward signal
optical network
optical
network terminal
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CN102075822A (en
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何子安
苏婕
李长垒
黄新刚
张德智
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ZTE Corp
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ZTE Corp
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Abstract

The invention discloses a kind of WDM passive optical network system, communication means and optical line terminal equipment, this equipment comprises: array waveguide grating, the multi-wavelength multiplex upward signal comprising the upward signal that each Optical Network Terminal sends for forwarding the distant-end node received carries out partial wave process, be divided into some upward signals to divide into groups described multi-wavelength multiplex upward signal, in each described upward signal grouping, comprise the upward signal of the setting number of wavelengths with setting wavelength interval; And upward signal grouping is sent to corresponding R-T unit; Described R-T unit, the upward signal grouping sent for pair array waveguide optical grating processes, and isolates the upward signal that each Optical Network Terminal sends from described upward signal grouping.First the long packet transaction of primary wave is first carried out to multi-wavelength multiplex upward signal by array waveguide grating, decrease the power consumption using optical branching device to carry out in light-splitting processing process, improve signal receiving quality.

Description

WDM passive optical network system, communication means and optical line terminal equipment
Technical field
The present invention relates to optical-fiber network technical field, espespecially a kind of ultra dense wavelength division multiple passive optical network, communication means and optical line terminal equipment.
Background technology
Wave division multiplexing passive optical network (WavelengthDivisionMultiplexing-PassiveOpticalNetwork, WDM-PON) be the novel passive optical network transmitted based on multi-wavelength single fiber, in this optical network system, each terminal use takies separately a wavelength channel, and multiple wavelength channel is transmitted in same trunk fiber by the mode of wavelength division multiplexing.
Because in current optical communication field, the wavelength channel interval of Wave division multiplexing passive optical network is generally 100GHz or 50GHz.The number of users that Wavelength division multiplexing-passive network can be supported is generally tens.If user is more than hundred, utilize existing wavelength-division multiplex technique quite difficult.Accordingly, there has been proposed the ultra dense wavelength division multiple EPON utilizing coherent detection technology to realize and wavelength channel interval is shortened to several GHz, supported number of users in optical-fiber network is made to have qualitative leap, but also improve receiving sensitivity significantly, increase the coverage rate of the user of access optical-fiber network.
In prior art, the system block diagram of the ultra dense wavelength division multiple EPON utilizing coherent reception technology to realize as shown in Figure 1.This system comprises optical line terminal equipment (OpticalLineTerminal, OLT), passive optical splitter (PassiveOpticalSplitter, and some Optical Network Terminal (OpticalNetworkUnit POS), ONU), such as: the Optical Network Terminal ONU1 shown in figure, Optical Network Terminal ONU2 ..., Optical Network Terminal ONUnm.OLT is handed down to the downstream signal (λ of each ONU d1, λ d2..., λ dnmdeng), shunt to each ONU by passive optical splitter, ONU adopts coherent detection technology to identify the downstream signal of the corresponding wavelength sending to self.Such as: the downstream signal λ being sent to ONU1 d1, be sent to the downstream signal λ of ONU2 d2..., be sent to the downstream signal λ of ONUnm dnmdeng.The upward signal that each ONU sends, such as: the upward signal λ that ONU1 sends u1, the upward signal λ that ONU2 sends u2..., the upward signal λ that ONUnm sends unmdeng, after light closes by POS in remote node place, send OLT to.The wavelength of a pair uplink and downlink signal of one of them Optical Network Terminal can relatively, and the wavelength of the signal of different Optical Network Terminal needs a few GHz in interval.
On the one hand, the support comprising the equipment set such as coherent receiver, tunable laser and external modulator is needed because coherent reception detects, therefore these equipment is expensive, therefore the relevant cost detecting the complete equipment received also is very high, when number of users is a lot, during the enormous amount of Optical Network Terminal, the cost of whole network system also can be very high.
On the other hand, when only using the light-splitting processing of passive optical splitter POS realization to the different wave length that different user uses, because POS is when carrying out light-splitting processing, for the increase exponentially level rising of power loss along with number of users being transmitted signal, therefore, cause the signal power loss in transmitting procedure very large, when the signal power arriving receiving terminal is very little, the received signal quality of receiving terminal can be affected greatly, and probably cause receiving terminal correctly not receive and even can not receive signal, therefore, although the ultra dense wavelength division multiple EPON utilizing coherent reception technology to realize to some extent solves the more limited problem of traditional WDM-PON system wavelength number, but the number of users that optical-fiber network can be supported is limited to the optical power budget of optical fiber link greatly, even if receiving sensitivity makes moderate progress, also the number of users that optical-fiber network is accessible cannot effectively be increased.
Summary of the invention
The embodiment of the present invention provides a kind of WDM passive optical network system, communication means and optical line terminal equipment, in order to solve in prior art, to adopt passive optical splitter to carry out the signal power consumption of light-splitting processing existence very large, affect signal receiving quality, the problem of the number of users of the accessible optical-fiber network of restriction.
A kind of optical line terminal equipment, comprising: array waveguide grating and R-T unit;
Described array waveguide grating, the multi-wavelength multiplex upward signal comprising the upward signal that each Optical Network Terminal sends for forwarding the distant-end node received carries out partial wave process, be divided into some upward signals to divide into groups described multi-wavelength multiplex upward signal, in each described upward signal grouping, comprise the upward signal of the setting number of wavelengths with setting wavelength interval; And described upward signal grouping is sent to corresponding R-T unit;
Described R-T unit, the upward signal grouping sent for pair array waveguide optical grating processes, and isolates the upward signal that each Optical Network Terminal sends from described upward signal grouping.
A kind of WDM passive optical network system, comprising: some Optical Network Terminal, distant-end node, trunk fiber and above-mentioned optical line terminal equipment; Described optical line terminal equipment is connected with distant-end node by described trunk fiber;
Described Optical Network Terminal, for generation of upward signal, sends to described distant-end node;
Described distant-end node, the upward signal for each Optical Network Terminal being sent pools multi-wavelength multiplex upward signal, sends to described optical line terminal equipment by described trunk fiber.
A kind of Wave division multiplexing passive optical network communication means, comprising:
Optical line terminal equipment receives the multi-wavelength multiplex upward signal comprising the upward signal that Optical Network Terminal sends that distant-end node forwards;
The array waveguide grating that optical line terminal equipment is comprised by self carries out partial wave process to receiving multi-wavelength multiplex upward signal, be divided into some upward signals to divide into groups described multi-wavelength multiplex upward signal, in each described upward signal grouping, comprise the upward signal of the setting number of wavelengths with setting wavelength interval; And the R-T unit of the correspondence sending to self to comprise that each described upward signal is divided into groups;
The upward signal grouping that described R-T unit pair array waveguide optical grating sends processes, and extracts the upward signal that each Optical Network Terminal sends from described upward signal grouping.
Beneficial effect of the present invention is as follows:
The WDM passive optical network system that the embodiment of the present invention provides, communication means and optical line terminal equipment, by array waveguide grating, wavelength grouping process is carried out to the multi-wavelength multiplex upward signal comprising the upward signal that each Optical Network Terminal sends that the distant-end node received forwards, some upward signals are divided into divide into groups multi-wavelength multiplex upward signal, the upward signal of the wavelength of the setting quantity with setting wavelength interval is comprised in each upward signal grouping, corresponding R-T unit is sent to process upward signal grouping again, the upward signal that each Optical Network Terminal sends is isolated from upward signal grouping.First the long packet transaction of primary wave is first carried out to multi-wavelength multiplex upward signal by array waveguide grating, due to array waveguide grating carry out wavelength grouping process time, power loss value for signal is relatively fixing, the significantly decay of signal power can not be caused, also decay will be increased because of the increasing number of the branch signal separated, because this reducing the power consumption in light-splitting processing process, improve signal receiving quality, thus the number of users making tolerable access increases greatly, also improve the receiving sensitivity of the optical line terminal equipment of Received signal strength simultaneously.
Accompanying drawing explanation
Fig. 1 is the structural representation of Wave division multiplexing passive optical network in prior art;
Fig. 2 is the structural representation of Wave division multiplexing passive optical network in the embodiment of the present invention one;
Fig. 3 is the structural representation of optical line terminal equipment in the embodiment of the present invention one;
Fig. 4 is the structural representation of distant-end node in the embodiment of the present invention one;
Fig. 5 is the structural representation of Optical Network Terminal in the embodiment of the present invention one;
Fig. 6 is the structural representation of optical line terminal equipment in the embodiment of the present invention two;
Fig. 7 is the structural representation of optical line terminal equipment in the embodiment of the present invention three;
Fig. 8 is the structural representation of optical line terminal equipment in the embodiment of the present invention four;
Fig. 9 is the structural representation of distant-end node in the embodiment of the present invention five;
Figure 10 is the flow chart of embodiment of the present invention medium wave division multiplexing passive optical network network communication means.
Embodiment
Embodiment one
The WDM passive optical network system that the embodiment of the present invention one provides, its structure as shown in Figure 2, comprising: optical line terminal equipment 10, distant-end node 20 and some Optical Network Terminal 30.Wherein optical line terminal equipment 10 is connected with distant-end node 20 by trunk fiber, and distant-end node 20 is connected with each Optical Network Terminal 30 by optical fiber.Wherein:
Optical Network Terminal 30, for generation of upward signal, sends to distant-end node 20; And receive the downstream branch signal of distant-end node 20 forwarding.Such as, the upward signal λ that the Optical Network Terminal (ONU1) shown in Fig. 2 produces u1, the upward signal λ that Optical Network Terminal (ONU2) produces u2..., the upward signal λ that Optical Network Terminal (ONUnm) produces unmdeng.The downstream branch signal that distant-end node 20 sends comprises: λ d1, λ d2..., λ dmn.
Distant-end node 20, pools multi-wavelength multiplex upward signal for the upward signal each Optical Network Terminal 30 sent, sends to optical line terminal equipment 10 by trunk fiber.And the multi-wavelength multiplex downstream signal to be sent by optical line terminal equipment 10 is divided into some downstream branch signals, send to corresponding Optical Network Terminal 30.Such as shown in Fig. 2, the multi-wavelength multiplex upward signal that distant-end node 20 sends comprises: λ u1, λ u2..., λ unm.Receive multi-wavelength multiplex downstream signal to comprise: λ d1, λ d2..., λ dnm.
Optical line terminal equipment 10, the multi-wavelength multiplex upward signal comprising the upward signal that each Optical Network Terminal 30 sends for forwarding the distant-end node 20 received carries out partial wave process, i.e. wavelength grouping process, some upward signals are divided into divide into groups multi-wavelength multiplex upward signal, then upward signal grouping is processed, from upward signal grouping, isolate the upward signal that each Optical Network Terminal 30 sends.Wherein comprise the upward signal of the setting number of wavelengths with setting wavelength interval in each upward signal grouping.
Optical line terminal equipment 30, also for generation of the downstream signal sent to each Optical Network Terminal 30, pools multi-wavelength multiplex downstream signal by the downstream signal of each Optical Network Terminal produced, sends to distant-end node 20.
The concrete structure of optical line terminal equipment (OLT) 10 as shown in Figure 3, comprising: array waveguide grating (ArrayWaveguideGratings, AWG) 11 and R-T unit 12.Array waveguide grating can also adopt Heatless AWG (AthermalAWG, AAWG).Wherein:
Array waveguide grating 11, the multi-wavelength multiplex upward signal comprising the upward signal that each Optical Network Terminal sends for forwarding the distant-end node received carries out wavelength grouping process, some upward signals are divided into divide into groups the multi-wavelength multiplex upward signal received, comprise the upward signal of the setting number of wavelengths with setting wavelength interval in each upward signal grouping, and upward signal grouping is sent to corresponding R-T unit 12.Array waveguide grating 11, when carrying out wavelength grouping process to multi-wavelength multiplex upward signal, divides according to wavelength, and the wavelength of the upward signal in each signal grouping marked off has certain wavelength interval, often comprises the wavelength of some in group.That is, first carry out primary wave divisional processing by array waveguide grating 11, avoid the energy ezpenditure of follow-up light-splitting processing excessive, cause the problem that poor signal quality or signal cannot receive.
R-T unit 12, the upward signal grouping sent for pair array waveguide optical grating processes, and isolates the upward signal that each Optical Network Terminal sends from upward signal grouping.
Above-mentioned R-T unit 12, also for generation of the downstream signal sent to each Optical Network Terminal 30; Accordingly, above-mentioned array waveguide grating 11, the downstream signal also for each Optical Network Terminal 30 produced by R-T unit 12 pools multi-wavelength multiplex downstream signal, sends to distant-end node 20.
Preferably, above-mentioned R-T unit 12, after producing the downstream signal sent to each Optical Network Terminal 30, the downstream signal produced is converged for downstream signal grouping, the grouping of this downstream signal and upward signal grouping correspondence, and then be sent to array waveguide grating 11, converge as multi-wavelength multiplex downstream signal.
As shown in Figure 3, array waveguide grating 11 comprises wavelength X by what receive u1, λ u2..., λ unmthe multi-wavelength multiplex upward signal of upward signal, after wavelength grouping process, be divided into: comprise wavelength X u1, λ u2..., λ umupward signal upward signal grouping ..., comprise wavelength X u (n-1) m+1, λ u (N-1) m+2..., λ unmsome upward signal groupings such as upward signal grouping of upward signal.And R-T unit 12 is sent comprise λ d1, λ d2..., λ dmdownstream signal downstream signal grouping ..., comprise wavelength X d (n-1) m+1, λ d (N-1) m+2..., λ dnmsome downstream signal packet aggregations such as downstream signal grouping of downstream signal for comprising wavelength X d1, λ d2..., λ dnmthe multi-wavelength multiplex downstream signal of downstream signal.
The concrete structure of distant-end node 20 as shown in Figure 4, comprise the optical branching device that two-stage connects, multi-wavelength multiplex downstream signal for being sent by optical line terminal equipment 10 carries out light-splitting processing, the downstream branch signal obtained is sent to each Optical Network Terminal 30 be connected with self after wavelength grouping process.
Distant-end node 20 as shown in Figure 4 comprises first order optical branching device (POS) 201 and second level optical branching device (POS) 202.Two-stage optical branching device also plays the effect that the upward signal of the converged light network terminal 30 transmission is multi-wavelength multiplex upward signal simultaneously.Distant-end node shown in Fig. 4 carries out light splitting owing to use only POS, when dividing light, the energy of multi-wavelength multiplex downstream signal is split, therefore the wavelength comprised in each downstream branch signal marked off is identical with multi-wavelength multiplex downstream signal, includes wavelength X d1, λ d2..., λ dnmdownstream signal.And when converging upward signal, first being converged by the upward signal of the Optical Network Terminal be connected with self by second level POS is one group, such as, by wavelength X u1, λ u2..., λ umupward signal converge for comprising wavelength X u1, λ u2..., λ umupward signal upward signal grouping ..., by wavelength X u (n-1) m+1, λ u (N-1) m+2..., λ unmupward signal converge for comprising wavelength X u (n-1) m+1, λ u (N-1) m+2..., λ unmupward signal upward signal grouping; Multi-wavelength multiplex upward signal is obtained after being converged for bis-times by first order POS again.
The concrete structure of Optical Network Terminal 30 as shown in Figure 5, comprising: tunable laser 301, coherent receiver 302 and external modulator 303; Wherein:
Tunable laser 301, sends to the Single wavelength light of the upward signal of optical line terminal equipment for generation of descending local oscillator light and generation.The local oscillator light produced is generally Single wavelength light.Wherein, laser can be Wavelength tunable laser, also can be laser with fixed wavelength.
Coherent receiver 302, for receive distant-end node 20 send downstream branch signal after, descending local oscillator light downstream branch signal and tunable laser 301 produced carries out beat frequency, isolates the downstream signal sending to self from downstream branch signal.Namely carry out relevant detection by coherent receiver 302, realize the separation of downstream signal.
The descending local oscillator light that downstream branch signal and tunable laser 301 produce by above-mentioned coherent receiver 302 carries out beat frequency, the downstream signal that the wavelength difference of downstream branch signal medium wavelength and descending local oscillator light is less than setting threshold is separated from downstream branch signal, is the downstream signal that optical line terminal equipment sends to self.
External modulator 303, for the Single wavelength light produced according to tunable laser, load-modulate signal generates upward signal, sends to distant-end node.
Preferably, above-mentioned Optical Network Terminal 30 also comprises optical branching device (POS) 304, for carrying out shunt to upward signal and downstream signal, other components and parts with similar function can certainly be adopted to carry out shunt.
In said system, optical line terminal equipment, what transmit between distant-end node and Optical Network Terminal is all light signal, by after coherent receiver process being then the signal of telecommunication.
Embodiment two:
The WDM passive optical network system that the embodiment of the present invention two provides, wherein, the concrete structure of optical line terminal equipment 10 as shown in Figure 6.Same above-described embodiment of structure of distant-end node 20 and Optical Network Terminal 30
Optical line terminal equipment 10 shown in Fig. 6 comprises array waveguide grating 11 and R-T unit 12.The function of array waveguide grating and R-T unit is see the description in above-described embodiment one, preferably, wherein R-T unit 12 comprises: at least one-level optical branching device (POS) 121 connected with array waveguide grating 11, the Transmit-Receive Unit 122 corresponding with each Optical Network Terminal.
Optical branching device 121, the up tributary signal that the upward signal for being sent by array waveguide grating 11 is divided into the upstream signal wavelengths quantity dividing into groups to comprise with this upward signal identical, sends the Transmit-Receive Unit 122 be connected with self to; And the downstream signal that the Transmit-Receive Unit be connected with self sent converge after be transmitted to array waveguide grating 11.
Transmit-Receive Unit 122, carries out beat frequency for the up local oscillator light up tributary signal received and self produced, and isolates the upward signal that the Optical Network Terminal corresponding with self sends from the up tributary signal received; And generation sends to the downstream signal of the Optical Network Terminal of self correspondence to send the optical branching device be connected with self to.The upward signal specifically the wavelength difference of up tributary signal medium wavelength and up local oscillator light being less than setting threshold is separated from up tributary signal.
Each above-mentioned Transmit-Receive Unit 122, comprising: coherent receiver, single wavelength light source and external modulator.Wherein:
Single wavelength light source, for generation of for demodulation upward signal up local oscillator light and produce and send to the Single wavelength light of the downstream signal of Optical Network Terminal, the local oscillator light wherein produced is Single wavelength light.
Coherent receiver, after receiving up tributary signal, the up local oscillator light utilizing single wavelength light source to produce carries out beat frequency to the up tributary signal received, and isolates the upward signal that the Optical Network Terminal corresponding with self sends from up tributary signal.
External modulator, for the Single wavelength photogenerated downstream signal produced according to single wavelength light source, sends to the optical branching device be connected with self.
Preferred each Transmit-Receive Unit can also arrange the shunt that optical branching device (POS) realizes upward signal and downstream signal.
As shown in Figure 6, Transmit-Receive Unit 122 is specially Transmit-Receive Unit 1 ..., Transmit-Receive Unit m ..., Transmit-Receive Unit (n-1) m+1 ..., Transmit-Receive Unit nm etc.POS1, coherent receiver 1, single wavelength light source 1 and external modulator 1 is comprised in Transmit-Receive Unit 1 ..., comprise POSnm, coherent receiver nm, single wavelength light source nm and external modulator nm in Transmit-Receive Unit nm.POS1 in Transmit-Receive Unit 1 will comprise wavelength X u1, λ u2..., λ umthe up tributary signal of upward signal be supplied to coherent receiver 1, the downstream signal λ produced by external modulator 1 d1send to the optical branching device 121 be connected with self.POSnm in Transmit-Receive Unit nm will comprise wavelength X u (n-1) m+1, λ u (N-1) m+2..., λ unmthe up tributary signal of upward signal be supplied to coherent receiver nm, by the downstream signal λ that external modulator nm produces dnmsend to the optical branching device 121 be connected with self.
Preferably, optical branching device 121 can be set to two-stage connection framework; After the upward signal that array waveguide grating sends by the optical branching device (first order optical branching device) be wherein connected with array waveguide grating divides into groups to carry out wavelength grouping process, send each subordinate's optical branching device (secondary light splitter) be connected with self to and carry out secondary wavelength packet transaction, obtain up tributary signal, send corresponding Transmit-Receive Unit 122 to.The framework comprising one-level optical branching device 121 is only gived in Fig. 6.
Visible, in above-described embodiment two, a Transmit-Receive Unit in the corresponding optical line terminal equipment of Optical Network Terminal of each user, each Transmit-Receive Unit receives the upward signal of an Optical Network Terminal and provides downstream signal for an Optical Network Terminal, all Transmit-Receive Units can be divided into n group, often group comprises m Transmit-Receive Unit and is connected with an optical branching device, array waveguide grating first carries out light splitting according to wave-length coverage to multi-wavelength multiplex upward signal, after upward signal is divided into groups, shunt is carried out again by optical branching device, because array waveguide grating divides into groups to signal by wavelength, therefore the significantly decay of signal energy can not be caused.Thus enable signal be divided into more multiple-limb signal, thus improve the number of users of permission.
Embodiment three:
The WDM passive optical network system that the embodiment of the present invention three provides, wherein, the concrete structure of optical line terminal equipment as shown in Figure 7.The structure of Optical Network Terminal and distant-end node is with above-described embodiment one.Optical line terminal equipment 10 shown in Fig. 7 comprises array waveguide grating 11 and R-T unit 12.The function of array waveguide grating and R-T unit is see the description in above-described embodiment one.
Preferably, wherein array waveguide grating 11 comprises: the first array waveguide grating 111 and the second array waveguide grating 112.
First array waveguide grating 111, the downstream signal for each Optical Network Terminal produced by R-T unit 12 pools multi-wavelength multiplex downstream signal, sends to distant-end node 20.
Second array waveguide grating 112, the multi-wavelength multiplex upward signal comprising the upward signal that each Optical Network Terminal 30 sends for forwarding the distant-end node 20 received carries out wavelength grouping process, be divided into some upward signals to divide into groups the multi-wavelength multiplex upward signal received, and upward signal grouping is sent to corresponding R-T unit 12.Wherein comprise the upward signal of the setting number of wavelengths with setting wavelength interval in each upward signal grouping, namely comprise one group of upward signal of setting number of wavelengths.
Preferably, optical circulator 13 is also comprised in above-mentioned optical line terminal equipment 10, multi-wavelength multiplex downstream signal for being produced by the first array waveguide grating 111 sends to distant-end node 20, and the multi-wavelength multiplex upward signal forwarded by distant-end node 20 sends to the second array waveguide grating 112.The port one of optical circulator 13 is connected with the first array waveguide grating 111, realize the transmission of multi-wavelength multiplex downstream signal by port 2 distally node 20, port 3 is connected with the second array waveguide grating 112, realizes the multi-wavelength multiplex upward signal entered by interface 2 to send to the second array waveguide grating.
Preferably, wherein R-T unit 12 comprises: the transmitting element 131 be connected with the first array waveguide grating 111 and the receiving element 132 be connected with the second array waveguide grating 112.
Transmitting element 131, for generation of the downstream signal sending to each Optical Network Terminal 30, pools multi-wavelength multiplex downstream signal by the first array waveguide grating 111 and sends to distant-end node 20; Wherein transmitting element 131 can also produce the up local oscillator light of one group of Optical Network Terminal corresponding to upward signal grouping, is supplied to receiving element 132.
Receiving element 132, after the upward signal sent for receiving the second array waveguide grating 112 divides into groups, the each up local oscillator light that each upward signal divides into groups to produce with transmitting element 131 is respectively carried out beat frequency, from each upward signal grouping, isolate one group of upward signal with certain frequency interval respectively, and obtain the upward signal of each Optical Network Terminal transmission by band filter.
Preferably, above-mentioned transmitting element 131, specifically comprises: some single wavelength light source, the external modulator be connected with each single wavelength light source, the optical sender of setting quantity coordinated with each external modulator and some optical branching devices, wherein:
Single wavelength light source, for generation of Single wavelength light, the Single wavelength light produced is for generating the downstream signal grouping of the downstream signal of the Optical Network Terminal comprising setting quantity; And producing the up local oscillator light being used for demodulation upward signal, the local oscillator light of generation is Single wavelength light.
External modulator, for the Single wavelength light load-modulate signal produced according to single wavelength light source, produces the downstream signal sending to the Optical Network Terminal of self correspondence.
Optical sender, for the downstream signal produced according to external modulator, produces the downstream signal sending to the Optical Network Terminal of self correspondence.
Described optical branching device, sends to after the downstream signal for external modulator and optical sender being produced converges and is connected array waveguide grating with self.
Preferably, above-mentioned receiving element 132, specifically comprises: some coherent receivers and band filter, and the single wavelength light source that each coherent receiver is corresponding with described transmitting element is connected; Wherein:
Coherent receiver, after receiving upward signal grouping, by upward signal grouping with and the up local oscillator light that produces of the single wavelength light source that self is connected carry out beat frequency, from upward signal divide into groups, isolate one group there is the upward signal setting wavelength interval.
Band filter, for having the upward signal setting wavelength interval carry out band filter to isolated one group of the coherent receiver be connected with self, obtains the upward signal that the one group Optical Network Terminal corresponding with self sends.
Optical line terminal equipment 10 shown in Fig. 7, transmitting element 131 in R-T unit 12, comprise some single wavelength light source such as single wavelength light source 1 ..., single wavelength light source n, each single wavelength light source produces the Single wavelength light of a Single wavelength light as one group of downstream signal, is also supplied to as the up local oscillator light of one group of upward signal the coherent receiver receiving correspondence in unit simultaneously.Transmitting element 131 in R-T unit also comprises n external modulation: external modulator 1 ..., external modulator n, be connected respectively at n single wavelength light source, also comprise n (m-1) individual optical sender: transmitter 2 ..., transmitter m, ..., transmitter (n-1) m+2 ..., transmitter nm etc.Receiving element 132 comprises n coherent receiver and n band filter, coherent receiver 1 as shown in Figure 7 ..., coherent receiver n and band filter 1 ..., band filter n.
The Single wavelength light that single wavelength light source 1 produces, is supplied to external modulator 1, obtains the downstream signal λ carrying modulation signal by external modulator 1 after adding modulation signal d1, send to optical branching device POS1.Downstream signal λ is produced again by transmitter 2 ..., transmitter m d2..., λ dm, send to optical branching device POS1.Be λ through optical branching device POS1 by one group of wavelength d1, λ d2..., λ dmdownstream signal converge after obtain comprising wavelength X d1, λ d2..., λ dmdownstream signal grouping, send to the first array waveguide grating 111.......。The Single wavelength light that single wavelength light source n produces, is supplied to external modulator n, obtains the downstream signal λ that carry modulation signal after adding modulation signal by external modulator n d (n-1) m+1, send to optical branching device POS1.Downstream signal λ is produced again by transmitter (n-1) m+2 ..., transmitter nm d (N-1) m+2..., λ dnm, send to optical branching device POSn.Be λ through optical branching device POSn by one group of wavelength d (n-1) m+1, λ d (N-1) m+2..., λ dnmdownstream signal converge after obtain comprising wavelength X d (n-1) m+1, λ d (N-1) m+2..., λ dnmdownstream signal grouping, send to the first array waveguide grating 111.
Multi-wavelength multiplex upward signal is divided into some upward signals to divide into groups by the second array waveguide grating 112, such as: will comprise wavelength X u1, λ u2..., λ umupward signal upward signal grouping send to coherent receiver 1 in receiving element 132 ..., will wavelength X be comprised u (n-1) m+1, λ u (N-1) m+2..., λ unmupward signal upward signal grouping send to coherent receiver n in receiving element 132.The up local oscillator light that coherent receiver 1 produces according to single wavelength light source 1 carries out beat frequency process, obtains one group of upward signal with certain wavelength interval, sends receiving element 132 midband filter 1 to; ...; The up local oscillator light that coherent receiver n produces according to single wavelength light source n carries out beat frequency process, obtains one group of upward signal with certain wavelength interval, sends receiving element 132 midband filter n to.The upward signal obtaining each Optical Network Terminal and send is filtered respectively by band filter 1 ..., band filter n.
Visible, in above-described embodiment three, use individual n (m-1) the individual optical sender generation downstream signal that can export the single wavelength light source of the Single wavelength light not adding modulation signal, the external modulator of a n load-modulate signal and be loaded with modulation signal output of n, producing nm downstream signal only needs n single wavelength light source.Identify that nm upward signal only needs n single wavelength light source to provide up local oscillator light and by n coherent receiver identification.Carry out while wavelength grouping process greatly reduces energy attenuation at use array waveguide grating, for one group of Optical Network Terminal, a single wavelength light source and a coherent receiver are set, be embodied as each Optical Network Terminal by optical sender and downstream signal is provided, the upward signal of each Optical Network Terminal is separated by band filter, thus greatly reduce the single wavelength light source of cost intensive and the usage quantity of coherent receiver, while allowing the number of users of access to increase, saved equipment cost input.
Embodiment four:
The WDM passive optical network system that the embodiment of the present invention four provides, wherein, the concrete structure of optical line terminal equipment as shown in Figure 8.The structure of Optical Network Terminal and distant-end node is with above-described embodiment one.Optical line terminal equipment 10 shown in Fig. 8 comprises array waveguide grating 11 and R-T unit 12.The function of array waveguide grating and R-T unit is see the description in above-described embodiment one.
Preferably, wherein array waveguide grating 11 comprises: the first array waveguide grating 111 and the second array waveguide grating 112.
First array waveguide grating 111, the downstream signal for each Optical Network Terminal produced by R-T unit 12 pools multi-wavelength multiplex downstream signal, sends to distant-end node 20.
Second array waveguide grating 112, the multi-wavelength multiplex upward signal comprising the upward signal that each Optical Network Terminal 30 sends for forwarding the distant-end node 20 received carries out wavelength grouping process, be divided into some upward signals to divide into groups the multi-wavelength multiplex upward signal received, and upward signal grouping is sent to corresponding R-T unit 12.Wherein comprise the upward signal of the setting quantity with setting wavelength interval in each upward signal grouping, namely comprise one group of upward signal of setting number of wavelengths.
Preferably, optical circulator 13 is also comprised in above-mentioned optical line terminal equipment 10, multi-wavelength multiplex downstream signal for being produced by the first array waveguide grating 111 sends to distant-end node 20, and the multi-wavelength multiplex upward signal forwarded by distant-end node 20 sends to the second array waveguide grating 112.The port one of optical circulator 13 is connected with the first array waveguide grating 111, realize the transmission of multi-wavelength multiplex downstream signal by port 2 distally node 20, port 3 is connected with the second array waveguide grating 112, realizes the multi-wavelength multiplex upward signal entered by interface 2 to send to the second array waveguide grating.
Preferably, wherein R-T unit 12 comprises: the transmitting element 141 be connected with the first array waveguide grating 111 and the receiving element 142 be connected with the second array waveguide grating 112.
Transmitting element 141, for generation of the downstream signal sending to each Optical Network Terminal 30, pools multi-wavelength multiplex downstream signal by the first array waveguide grating 111 and sends to distant-end node 20; Wherein transmitting element 141 can also produce the up local oscillator light of one group of Optical Network Terminal corresponding to upward signal grouping, is supplied to receiving element 142.
Receiving element 142, after the upward signal sent for receiving the second array waveguide grating 112 divides into groups, the each up local oscillator light that each upward signal divides into groups to produce with transmitting element 141 is respectively carried out beat frequency, from each upward signal grouping, isolate one group of upward signal with certain wavelength interval respectively, and obtain the upward signal of each Optical Network Terminal transmission by band filter.
Preferably, above-mentioned transmitting element 141, comprising: some single wavelength light source, the frequency multiplier be connected with each single wavelength light source, the 3rd array waveguide grating be connected with frequency multiplier, the some external modulators be connected with each 3rd array waveguide grating, some optical branching devices of being connected with external modulator.Wherein:
Single wavelength light source, for generation of Single wavelength light, the Single wavelength light produced is for generating the downstream signal grouping of the downstream signal of the Optical Network Terminal comprising setting quantity.
Frequency multiplier, the Single wavelength light for the single wavelength light source be connected with self is produced spread to comprise the wavelength that sets quantity there is the multi-wavelength light setting wavelength interval.The wavelength pass band interval of the multi-wavelength light obtained after frequency multiplier spread spectrum and the 3rd array waveguide grating matches, and the multiple wavelength in multi-wavelength light can be separated from each other by the 3rd array waveguide grating and obtain multiple Single wavelength light.
3rd array waveguide grating, the multi-wavelength light produced for frequency multiplier is divided into the Single wavelength light setting quantity, sends to each external modulator respectively, and sends to receiving element 142 as up local oscillator light respectively.
External modulator, for according to Single wavelength light load-modulate signal, produces the downstream signal sending to corresponding Optical Network Terminal, sends to the optical branching device be connected with self.
Optical branching device, sends to the first array waveguide grating be connected with self after the downstream signal for being produced by external modulator converges.
Preferably, above-mentioned receiving element 142, comprising: some coherent receivers and band filter, and each coherent receiver is connected with the 3rd array waveguide grating in transmitting element 141; Wherein:
Coherent receiver, after receiving upward signal grouping, by upward signal grouping with and the up local oscillator light that exports of the 3rd array waveguide grating that self is connected carry out beat frequency process, from upward signal divide into groups, isolate one group there is the upward signal setting wavelength interval.
Band filter, for having the upward signal setting wavelength interval carry out band filter to one group of the coherent receiver place of separation self connected, obtains the upward signal that the one group Optical Network Terminal corresponding with self sends.
Optical line terminal equipment as shown in Figure 8, transmitting element 141 in R-T unit 12 comprises m group for sending the equipment of downstream signal, wherein: external modulator 1, frequency multiplier 1, the 3rd array waveguide grating 1 and external modulator 1, external modulator m+1 ..., external modulator (n-1) m+1 form one group, ..., external modulator m, frequency multiplier m, the 3rd array waveguide grating m and external modulator m, external modulator 2m ..., external modulator nm form one group.The Single wavelength light that each single wavelength light source produces obtains the multi-wavelength light comprising n wavelength after spread spectrum, obtains n Single wavelength light, be supplied to n external modulator, for generation of downstream signal after the 3rd array waveguide grating partial wave process.
Wherein, first external modulator in the equipment group of each transmission downstream signal: external modulator 1, external modulator 2 ..., external modulator m, be connected with optical branching device (POS) 1, the downstream signal of generation converges through POS1 that to obtain comprising wavelength be λ d1, λ d2..., λ dmdownstream signal grouping; ...; The n-th external modulator in the equipment group of each transmission downstream signal: external modulator (n-1) m+1, external modulator (n-1) m+2 ..., external modulator nm, be connected with optical branching device (POS) n, it is λ that the downstream signal of generation obtains comprising wavelength through POSn convergence d (n-1) m+1, λ d (N-1) m+2..., λ dnmdownstream signal grouping; These downstream signals divide into groups after the first array waveguide grating 111 converges, through optical circulator 13 distally node transmission.
Receiving element 142 as shown in Figure 8 comprises n coherent receiver and n band filter, i.e. coherent receiver 1 ..., coherent receiver n and band filter 1 ..., band filter n.
The Single wavelength light that the 3rd array waveguide grating n in transmitting element 141 produces, is supplied to coherent receiver in receiving element 142 as up local oscillator light.
Multi-wavelength multiplex upward signal is divided into some upward signals to divide into groups by the second array waveguide grating 112, such as: will comprise wavelength X u1, λ u2..., λ umupward signal upward signal grouping send to coherent receiver 1 in receiving element 142 ..., will wavelength X be comprised u (n-1) m+1, λ u (N-1) m+2..., λ unmupward signal upward signal grouping send to coherent receiver n in receiving element 142.The up local oscillator light that coherent receiver 1 produces according to single wavelength light source 1 carries out beat frequency process, obtains one group of upward signal with certain wavelength interval, sends receiving element 142 midband filter 1 to; ...; The up local oscillator light that coherent receiver n produces according to single wavelength light source n carries out beat frequency process, obtains one group of upward signal with certain wavelength interval, sends receiving element 142 midband filter n to.The upward signal obtaining each Optical Network Terminal and send is filtered respectively by band filter 1 ..., band filter n.
Visible, in above-described embodiment four, use m can to export the single wavelength light source of the Single wavelength light not adding modulation signal and by m frequency multiplier and m the 3rd array waveguide grating and external modulator generation downstream signal, producing nm downstream signal only needs m single wavelength light source.Identify that nm upward signal only needs a single wavelength light source, a frequency multiplier and array waveguide grating to provide up local oscillator light and by n coherent receiver identification.Carry out while wavelength grouping process greatly reduces energy attenuation at use array waveguide grating, for one group of Optical Network Terminal, a single wavelength light source and a coherent receiver are set, be embodied as each Optical Network Terminal by frequency multiplier and array waveguide grating and downstream signal is provided, the upward signal of each Optical Network Terminal is separated by band filter, thus greatly reduce the single wavelength light source of cost intensive and the usage quantity of coherent receiver, while allowing the number of users of access to increase, saved equipment cost input.
Embodiment five:
The WDM passive optical network system that the embodiment of the present invention five provides, wherein, optical line terminal equipment 10 can be any one structure in embodiment one, two, three, four.The structure of Optical Network Terminal 30 is with above-described embodiment one.The concrete structure of its distant-end node 20 as shown in Figure 9, comprising: array waveguide grating 211 and at least one-level optical branching device (POS) 212; Wherein:
Array waveguide grating 211, the multi-wavelength multiplex downstream signal for being sent by optical line terminal equipment 10 is divided into some downstream signals to divide into groups, and sends corresponding optical branching device 212 to.
Optical branching device 212, the downstream signal for being transmitted by array waveguide grating 211 is divided into the downstream branch signal of setting quantity to send to corresponding Optical Network Terminal 30.
In addition, each optical branching device 212 sends to array waveguide grating 211 after also being converged by the upward signal that the Optical Network Terminal be connected with self sends, and being converged by array waveguide grating 211 is send to optical line terminal equipment through trunk fiber after multi-wavelength multiplex upward signal.
As shown in Figure 9, the optical branching device 212 of the top is by wavelength X u1, λ u2..., λ umupward signal converge for comprising wavelength X u1, λ u2..., λ umupward signal upward signal grouping ..., optical branching device 212 is bottom by wavelength X u (n-1) m+1, λ u (N-1) m+2..., λ unmupward signal converge for comprising wavelength X u (n-1) m+1, λ u (N-1) m+2..., λ unmupward signal upward signal grouping; By array waveguide grating 211 by individual upward signal packet aggregation for comprising λ u1, λ u2..., λ unmmulti-wavelength multiplex upward signal.
In downstream signal direction, array waveguide grating 211 will comprise wavelength X d1, λ d2..., λ dnmthe multi-wavelength multiplex downstream signal of downstream signal, by wavelength division be: comprise wavelength X d1, λ d2..., λ dmdownstream signal downstream signal grouping ..., comprise wavelength X d (n-1) m+1, λ d (N-1) m+2..., λ dnmsome downstream signal groupings such as downstream signal grouping of downstream signal, each signal grouping, after optical branching device 212 light-splitting processing, obtains the some downstream branch signals comprising phase co-wavelength.
Be that the above-mentioned Wave division multiplexing passive optical network that embodiment provides realizes the method flow of communication as shown in Figure 10 by the present invention, specifically comprise the steps:
Step S11: Optical Network Terminal sends upward signal to distant-end node.
Optical Network Terminal produces the process of upward signal see the associated description of above-mentioned Fig. 5, specifically comprises:
The tunable laser that Optical Network Terminal comprises produces the Single wavelength light sending to the upward signal of optical line terminal equipment; The Single wavelength photogenerated upward signal that the external modulator that Optical Network Terminal comprises produces according to tunable laser, sends to distant-end node.
Step S12: distant-end node obtains multi-wavelength multiplex upward signal after being converged by the upward signal of individual Optical Network Terminal, sends to optical line terminal equipment.
The upward signal that each Optical Network Terminal produces is pooled multi-wavelength multiplex upward signal by distant-end node, sends to optical line terminal equipment by trunk fiber.
Step S13: optical line terminal equipment receives the multi-wavelength multiplex upward signal that distant-end node forwards.
What optical line terminal equipment received is the multi-wavelength multiplex upward signal comprising the upward signal that Optical Network Terminal sends that distant-end node forwards.
Step S14: multi-wavelength multiplex upward signal is divided into some upward signals to divide into groups by the array waveguide grating comprised by self.
The array waveguide grating comprised by self carries out wavelength grouping process to receiving multi-wavelength multiplex upward signal, some upward signals are divided into divide into groups multi-wavelength multiplex upward signal, wherein, the upward signal of the setting number of wavelengths with setting wavelength interval is comprised in each upward signal grouping.
Array waveguide grating AWG is the grating that the fiber waveguide of one group of length-specific arrangement is formed, there is the ability of partial wave, its principle is: first the signal containing multi-wavelength is divided into several sub-light wave roughly equal to dozens of amplitude via partial wave element, again this little light wave is sequentially imported in the Waveguide array of pre-designed length, make it have separately and specifically export phase place, again via after multiple output coupling element, the light wave for specific wavelength will form Constructive interaction in specific position and export.Thus be the signal of a different wave length or different wave length group by the signal light splitting of multi-wavelength.
Step S15: each upward signal divides into groups the R-T unit of the correspondence sending to self to comprise by optical line terminal equipment.
See the specific descriptions in above-described embodiment, each array waveguide grating forwards upstream packet signal to the R-T unit be connected with self.
Step S16: the upward signal that each Optical Network Terminal sends isolated by R-T unit from upward signal grouping.
The upward signal grouping that R-T unit pair array waveguide optical grating sends processes, and isolates the upward signal that each Optical Network Terminal sends from upward signal grouping.Specifically comprise following two kinds of implementations, specifically can see the specific descriptions of embodiment two, three, four:
Mode one: the up tributary signal that the upward signal that array waveguide grating sends by least one-level optical branching device that R-T unit comprises is divided into the upstream signal wavelengths quantity dividing into groups to comprise with this upward signal identical, sends the Transmit-Receive Unit be connected with self to.The up local oscillator light that up tributary signal and self produce by the Transmit-Receive Unit that R-T unit comprises carries out beat frequency, isolates the upward signal that the Optical Network Terminal corresponding with self sends from up tributary signal.
Wherein, the up local oscillator light that up tributary signal and self produce by Transmit-Receive Unit carries out beat frequency, specifically comprise: after the coherent receiver that Transmit-Receive Unit comprises receives up tributary signal, the up local oscillator light that the single wavelength light source up tributary signal and self comprised produces carries out beat frequency.
Mode two: the transmitting element that R-T unit comprises produces the up local oscillator light of one group of Optical Network Terminal corresponding to upward signal grouping, is supplied to the receiving element that R-T unit comprises; After receiving element receives upward signal grouping, the each up local oscillator light that each upward signal divides into groups to produce with transmitting element is respectively carried out beat frequency, one group of upward signal with certain wavelength interval is isolated respectively from each upward signal grouping, and carry out band filter by the band filter that R-T unit comprises to isolating one group of upward signal with certain frequency interval, obtain the upward signal that each Optical Network Terminal sends.
Wherein, transmitting element produces the up local oscillator light of one group of Optical Network Terminal corresponding to upward signal grouping, can be the multiple single wavelength light source generations in transmitting element, also can be that the 3rd array waveguide grating be connected with a single wavelength light source in transmitting element is produced by frequency multiplier.
Step S17: the R-T unit that optical line terminal equipment comprises produces the downstream signal sent to each Optical Network Terminal.
R-T unit produces the downstream signal sent to each Optical Network Terminal, specifically comprises following three kinds of implementations, specifically can see the specific descriptions of embodiment two, three, four:
(1) downstream signal that the Transmit-Receive Unit corresponding with each Optical Network Terminal that R-T unit comprises produces the Optical Network Terminal sending to self corresponding sends the optical branching device be connected with self to; Array waveguide grating is transmitted to after the downstream signal sent by the Transmit-Receive Unit be connected with self converges.
The single wavelength light source that Transmit-Receive Unit comprises produces the Single wavelength light light sending to the downstream signal of Optical Network Terminal, and the Single wavelength photogenerated downstream signal that the external modulator that Transmit-Receive Unit comprises produces according to single wavelength light source, sends to the optical branching device be connected with self.
(2) transmitting element that R-T unit comprises produces the downstream signal sending to each Optical Network Terminal, specifically comprises:
The single wavelength light source that transmitting element comprises produces Single wavelength light, and this Single wavelength light divides into groups for generation of the downstream signal of the downstream signal comprising the Optical Network Terminal setting quantity.
The Single wavelength light load-modulate signal that the external modulator that transmitting element comprises produces according to single wavelength light source, produce the downstream signal sending to the Optical Network Terminal of self correspondence, and the downstream signal that the optical sender that comprises of transmitting element produces according to external modulator, produce the downstream signal sending to the Optical Network Terminal of self correspondence.
The downstream signal that described external modulator and optical sender produce by the optical branching device that transmitting element comprises sends to after converging and is connected array waveguide grating with self.
(3) transmitting element that R-T unit comprises produces the downstream signal sending to each Optical Network Terminal.Specifically comprise:
The single wavelength light source that transmitting element comprises produces Single wavelength light, and this Single wavelength light divides into groups for generation of the downstream signal of the downstream signal comprising the Optical Network Terminal setting quantity.
The Single wavelength light that single wavelength light source produces by the frequency multiplier that transmitting element comprises spreads to the multi-wavelength light with setting wavelength interval of the wavelength comprising setting quantity.
The 3rd array waveguide grating that transmitting element comprises, the multi-wavelength light produced for frequency multiplier is divided into the Single wavelength light setting quantity, sends to each external modulator be connected with self respectively.
The external modulator that transmitting element comprises produces the downstream signal sending to corresponding Optical Network Terminal according to Single wavelength light, send to the optical branching device be connected with self.
The downstream signal that external modulator produces by the optical branching device that transmitting element comprises sends to the first array waveguide grating be connected with self after converging.
Step S18: the downstream signal of each Optical Network Terminal that R-T unit produces by the array waveguide grating that optical line terminal equipment comprises pools multi-wavelength multiplex downstream signal and sends to distant-end node.
Array waveguide grating directly can converge the downstream signal that each Transmit-Receive Unit sends over, and also can converge each group of downstream signal grouping that transmitting element sends over.
Step S19: multi-wavelength multiplex downstream signal is divided into some downstream branch signals by distant-end node, sends to corresponding Optical Network Terminal.
The optical branching device that the two-stage that distant-end node comprises connects, carries out light-splitting processing by multi-wavelength multiplex downstream signal, the downstream branch signal obtained is sent to each Optical Network Terminal be connected with self after light-splitting processing; Or multi-wavelength multiplex downstream signal is divided into some downstream signals to divide into groups by the array waveguide grating that distant-end node comprises, send corresponding optical branching device to; Downstream signal is divided into the downstream branch signal of setting quantity to send to corresponding Optical Network Terminal by least one-level optical branching device that distant-end node comprises.
Specifically see the associated description of Fig. 4 and Fig. 9.
Step S20: Optical Network Terminal detects the downstream signal sending to self from downstream branch signal.
The tunable laser that Optical Network Terminal comprises produces descending local oscillator light, after the coherent receiver that Optical Network Terminal comprises receives the downstream branch signal of distant-end node transmission, descending local oscillator light downstream branch signal and tunable laser produced carries out beat frequency, isolates the downstream signal sending to self from downstream branch signal.
The above-mentioned WDM passive optical network system that the embodiment of the present invention provides and communication means, a kind of ultra dense wavelength division multiple passive light network transmission system based on coherent reception technology and corresponding communication means, first the long packet transaction of primary wave is first carried out to multi-wavelength multiplex upward signal by array waveguide grating, due to array waveguide grating carry out wavelength grouping process time, power loss value for signal is relatively fixing, the significantly decay of signal power can not be caused, also decay will be increased because of the increasing number of the branch signal separated, because this reducing the power consumption using optical branching device to carry out in light-splitting processing process, improve signal receiving quality, thus the number of users making tolerable access increases greatly, also improve the receiving sensitivity of the optical line terminal equipment of Received signal strength simultaneously.
Preferably, by arranging transmitting element and the receiving element of shared single wavelength light source in R-T unit, decrease the usage quantity of the expensive equipment such as coherent receiver, single wavelength light source, while supporting high access user quantity, can equipment cost be effectively reduced.Not only can break through the bottleneck at the wavelength channel interval that traditional Wave division multiplexing passive optical network exists, greatly promote number of users, and carry out primary wave divisional processing in advance by array waveguide grating, the receiving sensitivity that can also significantly improve optical line terminal equipment and the signal quality received.
Obviously, those skilled in the art can carry out various change and modification to the present invention and not depart from the spirit and scope of the present invention.Like this, if these amendments of the present invention and modification belong within the scope of the claims in the present invention and equivalent technologies thereof, then the present invention is also intended to comprise these change and modification.

Claims (28)

1. an optical line terminal equipment, is characterized in that, comprising: array waveguide grating and R-T unit;
Described array waveguide grating, the multi-wavelength multiplex upward signal comprising the upward signal that each Optical Network Terminal sends for forwarding the distant-end node received carries out partial wave process, be divided into some upward signals to divide into groups described multi-wavelength multiplex upward signal according to setting wavelength interval and setting quantity, in each described upward signal grouping, comprise the upward signal of the setting number of wavelengths with setting wavelength interval; And described upward signal grouping is sent to corresponding R-T unit;
Described R-T unit, the upward signal grouping sent for pair array waveguide optical grating processes, and isolates the upward signal that each Optical Network Terminal sends from described upward signal grouping.
2. optical line terminal equipment as claimed in claim 1, is characterized in that, described R-T unit, also for generation of the downstream signal sent to each Optical Network Terminal; Accordingly,
Described array waveguide grating, also for: the downstream signal of each Optical Network Terminal produced by described R-T unit pools multi-wavelength multiplex downstream signal, sends to distant-end node.
3. optical line terminal equipment as claimed in claim 1 or 2, it is characterized in that, described R-T unit, comprising: at least one-level optical branching device connected with array waveguide grating, the Transmit-Receive Unit corresponding with each Optical Network Terminal;
Described optical branching device, the up tributary signal that the upward signal for being sent by described array waveguide grating is divided into the upstream signal wavelengths quantity dividing into groups to comprise with this upward signal identical, sends the Transmit-Receive Unit be connected with self to; And the downstream signal that the Transmit-Receive Unit be connected with self sent converge after be transmitted to described array waveguide grating;
Described Transmit-Receive Unit, carries out beat frequency for the up local oscillator light described up tributary signal and self produced, and isolates the upward signal that the Optical Network Terminal corresponding with self sends from described up tributary signal; And generation sends to the downstream signal of the Optical Network Terminal of self correspondence and sends to the optical branching device be connected with self.
4. optical line terminal equipment as claimed in claim 3, is characterized in that, described optical branching device, is set to two-stage and connects framework; Wherein:
After the upward signal that array waveguide grating sends by the optical branching device be connected with array waveguide grating divides into groups to carry out light-splitting processing, send each subordinate's optical branching device be connected with self to and carry out secondary light-splitting processing, obtain described up tributary signal, send corresponding Transmit-Receive Unit to.
5. optical line terminal equipment as claimed in claim 3, it is characterized in that, described Transmit-Receive Unit, specifically comprises: coherent receiver, single wavelength light source and external modulator;
Described single wavelength light source, for generation of the up local oscillator light for demodulation upward signal; And produce the Single wavelength light sending to the downstream signal of Optical Network Terminal;
Described coherent receiver, after receiving described up tributary signal, the up local oscillator light utilizing described single wavelength light source to produce carries out beat frequency to described up tributary signal, extracts the upward signal that the Optical Network Terminal corresponding with self sends from described up tributary signal;
Described external modulator, generates downstream signal for the Single wavelength light load-modulate signal launched described single wavelength light source, sends to the optical branching device be connected with self.
6. optical line terminal equipment as claimed in claim 1 or 2, it is characterized in that, described array waveguide grating comprises: the first array waveguide grating and the second array waveguide grating;
Described first array waveguide grating, the downstream signal for each Optical Network Terminal produced by described R-T unit pools multi-wavelength multiplex downstream signal, sends to distant-end node;
Described second array waveguide grating, the multi-wavelength multiplex upward signal comprising the transmission of each Optical Network Terminal for forwarding the distant-end node received carries out partial wave process, be divided into some upward signals to divide into groups described multi-wavelength multiplex upward signal, in each described upward signal grouping, comprise the upward signal of the setting number of wavelengths with setting wavelength interval; And described upward signal grouping is sent to corresponding R-T unit.
7. optical line terminal equipment as claimed in claim 6, is characterized in that, also comprise: optical circulator, for:
The multi-wavelength multiplex downstream signal that first array waveguide grating produces is sent to distant-end node, and the multi-wavelength multiplex upward signal that distant-end node forwards is sent to the second array waveguide grating.
8. optical line terminal equipment as claimed in claim 6, it is characterized in that, described R-T unit, specifically comprises: the transmitting element be connected with the first array waveguide grating and the receiving element be connected with the second array waveguide grating;
Described transmitting element, for generation of the downstream signal sending to each Optical Network Terminal, pools multi-wavelength multiplex downstream signal by the first array waveguide grating and sends to distant-end node; And produce the up local oscillator light of one group of Optical Network Terminal corresponding to described upward signal grouping, be supplied to described receiving element;
Described receiving element, after receiving the grouping of described upward signal, the each up local oscillator light that each described upward signal divides into groups to produce with described transmitting element is respectively carried out beat frequency, from each described upward signal grouping, isolate one group of upward signal with certain frequency interval respectively, and obtain the upward signal of each Optical Network Terminal transmission by band filter.
9. optical line terminal equipment as claimed in claim 8, it is characterized in that, described transmitting element, specifically comprises: some single wavelength light source, the external modulator be connected with each single wavelength light source, the optical sender of setting quantity coordinated with each external modulator and some optical branching devices, wherein:
Single wavelength light source, for generation of Single wavelength light, the Single wavelength light produced is for generating the downstream signal grouping of the downstream signal of the Optical Network Terminal comprising setting quantity; And produce the up local oscillator light being used for demodulation upward signal;
External modulator, for the Single wavelength light load-modulate signal produced described single wavelength light source, produces the downstream signal sending to the Optical Network Terminal of self correspondence;
Optical sender, for the downstream signal produced according to external modulator, produces the downstream signal sending to the Optical Network Terminal of self correspondence;
Described optical branching device, sends to after the downstream signal for described external modulator and optical sender being produced converges and is connected array waveguide grating with self.
10. optical line terminal equipment as claimed in claim 9, it is characterized in that, described receiving element, specifically comprises: some coherent receivers and band filter, and the described single wavelength light source that each described coherent receiver is corresponding with described transmitting element is connected; Wherein:
Coherent receiver, after receiving the grouping of described upward signal, carries out beat frequency by the grouping of described upward signal with the up local oscillator light produced with the single wavelength light source self be connected, produces the upward signal that a group has setpoint frequency interval;
Described band filter, for and the coherent receiver that self is connected receives and produce one group of upward signal with setpoint frequency interval carries out band filter, obtains each road upward signal that the one group Optical Network Terminal corresponding with self sends respectively.
11. optical line terminal equipments as claimed in claim 8, it is characterized in that, described transmitting element, comprise: some single wavelength light source, the frequency multiplier be connected with each single wavelength light source, the 3rd array waveguide grating be connected with frequency multiplier, the some external modulators be connected with each 3rd array waveguide grating, some optical branching devices of being connected with external modulator, wherein:
Single wavelength light source, for generation of Single wavelength light, the Single wavelength light produced is for generating the downstream signal grouping of the downstream signal of the Optical Network Terminal comprising setting quantity;
Frequency multiplier, the Single wavelength light for described single wavelength light source being produced spreads to the multi-wavelength light with setting wavelength interval of the wavelength comprising described setting quantity;
3rd array waveguide grating, the multi-wavelength light for being produced by frequency multiplier is divided into the Single wavelength light of setting quantity, sends to each external modulator respectively, and sends to receiving element as up local oscillator light respectively;
External modulator, for Single wavelength light load-modulate signal, produces the downstream signal sending to corresponding Optical Network Terminal, sends to the optical branching device be connected with self;
Optical branching device, sends to the first array waveguide grating be connected with self after the downstream signal for being produced by external modulator converges.
12. optical line terminal equipments as claimed in claim 11, it is characterized in that, described receiving element, comprising: some coherent receivers and band filter, and each described coherent receiver is connected with the 3rd array waveguide grating in described transmitting element; Wherein:
Coherent receiver, after receiving upward signal grouping, carries out beat frequency by the upward signal received grouping with the up local oscillator light exported with the 3rd array waveguide grating that self is connected, produces the upward signal that a group has setpoint frequency interval;
Band filter, for and the coherent receiver that self is connected receives and produce one group of upward signal with setpoint frequency interval carries out band filter, obtains each road upward signal that the one group Optical Network Terminal corresponding with self sends respectively.
13. 1 kinds of WDM passive optical network systems, is characterized in that, comprising: some Optical Network Terminal, distant-end node, trunk fiber and as arbitrary in claim 1-12 as described in optical line terminal equipment; Described optical line terminal equipment is connected with distant-end node by described trunk fiber;
Described Optical Network Terminal, for generation of upward signal, sends to described distant-end node;
Described distant-end node, the upward signal for each Optical Network Terminal being sent pools multi-wavelength multiplex upward signal, sends to described optical line terminal equipment by described trunk fiber.
14. systems as claimed in claim 13, it is characterized in that, described distant-end node, comprise: the optical branching device that two-stage connects, multi-wavelength multiplex downstream signal for being sent by described optical line terminal equipment carries out light-splitting processing, the downstream branch signal obtained is sent to each Optical Network Terminal be connected with self after light-splitting processing.
15. systems as claimed in claim 13, it is characterized in that, described distant-end node, comprising: array waveguide grating and at least one-level optical branching device; Wherein:
Array waveguide grating, the multi-wavelength multiplex downstream signal for being sent by described optical line terminal equipment is divided into some downstream signals to divide into groups, and sends corresponding optical branching device to;
Optical branching device, sends to corresponding Optical Network Terminal for described downstream signal being divided into the downstream branch signal of setting quantity.
16. as arbitrary in claim 13-15 as described in system, it is characterized in that, described Optical Network Terminal, comprising: coherent receiver, tunable laser and external modulator; Wherein:
Tunable laser, sends to the Single wavelength light of the upward signal of optical line terminal equipment for generation of descending local oscillator light and generation;
Coherent receiver, for receive distant-end node send downstream branch signal after, the descending local oscillator light described downstream branch signal and tunable laser produced carries out beat frequency, from described downstream branch signal, extract the downstream signal sending to self;
External modulator, for the Single wavelength light load-modulate signal produced tunable laser, produces the upward signal sending to described distant-end node.
17. 1 kinds of Wave division multiplexing passive optical network communication meanss, is characterized in that, comprising:
Optical line terminal equipment receives the multi-wavelength multiplex upward signal comprising the upward signal that Optical Network Terminal sends that distant-end node forwards;
The array waveguide grating that optical line terminal equipment is comprised by self carries out partial wave process to receiving multi-wavelength multiplex upward signal, be divided into some upward signals to divide into groups described multi-wavelength multiplex upward signal according to setting wavelength interval and setting quantity, in each described upward signal grouping, comprise the upward signal of the setting number of wavelengths with setting wavelength interval; And the R-T unit of the correspondence sending to self to comprise that each described upward signal is divided into groups;
The upward signal grouping that described R-T unit pair array waveguide optical grating sends processes, and extracts the upward signal that each Optical Network Terminal sends from described upward signal grouping.
18. methods as claimed in claim 17, is characterized in that, the multi-wavelength multiplex upward signal comprising the upward signal that Optical Network Terminal sends of described reception distant-end node forwarding, comprising:
The upward signal that each Optical Network Terminal produces is pooled multi-wavelength multiplex upward signal by described distant-end node, sends to described optical line terminal equipment by trunk fiber;
Described optical line terminal equipment receives the multi-wavelength multiplex upward signal comprising the upward signal that Optical Network Terminal sends that distant-end node forwards.
19. methods as claimed in claim 17, is characterized in that, Optical Network Terminal produces upward signal and specifically comprises:
The tunable laser that described Optical Network Terminal comprises produces the Single wavelength light sending to the upward signal of optical line terminal equipment;
The Single wavelength light load-modulate signal that the external modulator that described Optical Network Terminal comprises produces tunable laser, produces the upward signal sending to described distant-end node.
20. methods as claimed in claim 17, is characterized in that, the upward signal grouping that described R-T unit pair array waveguide optical grating sends processes, and isolate the upward signal that each Optical Network Terminal sends, specifically comprise from described upward signal grouping:
The up tributary signal that the upward signal that described array waveguide grating sends by least one-level optical branching device that described R-T unit comprises is divided into the upstream signal wavelengths quantity dividing into groups to comprise with this upward signal identical, sends the Transmit-Receive Unit be connected with self to;
The up local oscillator light that described up tributary signal and self produce by the Transmit-Receive Unit that described R-T unit comprises carries out beat frequency, isolates the upward signal that the Optical Network Terminal corresponding with self sends from described up tributary signal.
21. methods as claimed in claim 20, is characterized in that, the up local oscillator light that described up tributary signal and self produce by described Transmit-Receive Unit carries out beat frequency, specifically comprises:
After the coherent receiver that described Transmit-Receive Unit comprises receives described up tributary signal, the up local oscillator light that described up tributary signal and the single wavelength light source that self comprises produce is carried out beat frequency.
22. methods as claimed in claim 17, is characterized in that, the upward signal grouping that described R-T unit pair array waveguide optical grating sends processes, and isolate the upward signal that each Optical Network Terminal sends, specifically comprise from described upward signal grouping:
The transmitting element that described R-T unit comprises produces the up local oscillator light of one group of Optical Network Terminal corresponding to described upward signal grouping, is supplied to the receiving element that described R-T unit comprises;
After described receiving element receives the grouping of described upward signal, the each up local oscillator light that each described upward signal divides into groups to produce with described transmitting element is respectively carried out beat frequency, obtain one group of upward signal with certain frequency interval, and carry out band filter by the band filter that described R-T unit comprises to isolating one group of upward signal with certain frequency interval, obtain the upward signal that each Optical Network Terminal sends.
23. methods as claimed in claim 17, is characterized in that, also comprise:
The R-T unit that described optical line terminal equipment comprises produces the downstream signal sent to each Optical Network Terminal, the downstream signal of each Optical Network Terminal that described R-T unit produces by the array waveguide grating that described optical line terminal equipment comprises pools multi-wavelength multiplex downstream signal, sends to distant-end node;
Described multi-wavelength multiplex downstream signal is divided into some downstream branch signals by described distant-end node, sends to corresponding Optical Network Terminal;
Described Optical Network Terminal detects the downstream signal sending to self from described downstream branch signal.
24. methods as claimed in claim 23, is characterized in that, described R-T unit produces the downstream signal sent to each Optical Network Terminal, specifically comprises:
The downstream signal that the Transmit-Receive Unit corresponding with each Optical Network Terminal that described R-T unit comprises produces the Optical Network Terminal sending to self corresponding sends the optical branching device be connected with self to;
Described array waveguide grating is transmitted to after the described downstream signal sent by the Transmit-Receive Unit be connected with self converges.
25. methods as claimed in claim 24, is characterized in that, described Transmit-Receive Unit produces the downstream signal sending to the Optical Network Terminal of self correspondence, specifically comprises:
The single wavelength light source that described Transmit-Receive Unit comprises produces the Single wavelength light sending to the downstream signal of Optical Network Terminal;
The Single wavelength light load-modulate signal that the external modulator that described Transmit-Receive Unit comprises produces described single wavelength light source, produces the downstream signal sending to the optical branching device be connected with self.
26. methods as claimed in claim 23, is characterized in that, described R-T unit produces the downstream signal sent to each Optical Network Terminal, comprising: the transmitting element that described R-T unit comprises produces the downstream signal sending to each Optical Network Terminal, specifically comprises:
The single wavelength light source that described transmitting element comprises produces Single wavelength light, and this Single wavelength light divides into groups for generation of the downstream signal of the downstream signal comprising the Optical Network Terminal setting quantity; The Single wavelength light load-modulate signal that the external modulator that described transmitting element comprises produces described single wavelength light source, produce the downstream signal sending to the Optical Network Terminal of self correspondence, and the downstream signal that the optical sender that comprises of described transmitting element produces according to external modulator, produce the downstream signal sending to the Optical Network Terminal of self correspondence; The downstream signal that described external modulator and optical sender produce by the optical branching device that described transmitting element comprises sends to after converging and is connected array waveguide grating with self; Or
The single wavelength light source that described transmitting element comprises produces Single wavelength light, and this Single wavelength light divides into groups for generation of the downstream signal of the downstream signal comprising the Optical Network Terminal setting quantity; The Single wavelength light that described single wavelength light source produces by the frequency multiplier that described transmitting element comprises spreads to the multi-wavelength light with setting wavelength interval of the wavelength comprising described setting quantity; The 3rd array waveguide grating that described transmitting element comprises, the multi-wavelength light for being produced by frequency multiplier is divided into the Single wavelength light of setting quantity, sends to each external modulator respectively; The external modulator that described transmitting element comprises produces the downstream signal sending to corresponding Optical Network Terminal according to Single wavelength light, send to the optical branching device be connected with self; The downstream signal that external modulator produces by the optical branching device that described transmitting element comprises sends to the first array waveguide grating be connected with self after converging.
27. methods as claimed in claim 23, it is characterized in that, described multi-wavelength multiplex downstream signal is divided into some downstream branch signals by described distant-end node, specifically comprises:
The optical branching device that the two-stage that described distant-end node comprises connects, carries out light-splitting processing by described multi-wavelength multiplex downstream signal, the downstream branch signal obtained is sent to each Optical Network Terminal be connected with self after light-splitting processing; Or
Described multi-wavelength multiplex downstream signal is divided into some downstream signals to divide into groups by the array waveguide grating that described distant-end node comprises, and sends corresponding optical branching device to; Described downstream signal is divided into the downstream branch signal of setting quantity to send to corresponding Optical Network Terminal by least optical branching device described in one-level that described distant-end node comprises.
28. as arbitrary in claim 23-27 as described in method, it is characterized in that, described Optical Network Terminal detects the downstream signal sending to self from described downstream branch signal, specifically comprises:
The tunable laser that described Optical Network Terminal comprises produces descending local oscillator light;
After the coherent receiver that described Optical Network Terminal comprises receives the downstream branch signal of described distant-end node transmission, the descending local oscillator light described downstream branch signal and tunable laser produced carries out beat frequency, from described downstream branch signal, extract the downstream signal sending to self.
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