CN203632822U - Time-division wavelength division hybrid multiplex passive optical network system - Google Patents

Abstract

The utility model discloses a time-division wavelength-division hybrid multiplexing passive optical network system, which is mainly composed of an optical line terminal, an optical distribution network and n user units; The optical signal is generated, transmitted to the optical distribution network through the long-distance standard single-mode fiber, and the optical signal is transmitted to each optical network unit by the optical distribution network. The system adopts a new method of combining time division multiplexing and wavelength division multiplexing, and uses an optical switch array and a high-speed dual-arm Mach-Zehnder modulator to modulate optical signals of different wavelengths in a time slice manner. This method can simplify the complexity of the system protocol, greatly improve the utilization rate of the system bandwidth, thereby reducing the system cost, increasing the non-relay transmission distance of the communication system, and enhancing the later-stage upgrade capability of the system.

Description

A kind of time-division wavelength-division mixed multiplexing passive optical network system

Technical field

The utility model relates to the communications field, is specifically related to a kind of time-division wavelength-division mixed multiplexing passive optical network system.

Background technology

From whole network configuration, along with the fast development of the communication technology, make backbone network have breakthrough development; While is due to the progress of ethernet technology, more than local area network (LAN) bandwidth also develops into 1Gbps.And connect one section of wired electric territory Access Network between backbone network and local area network (LAN) and domestic consumer and become the bottleneck of whole network system.Therefore light passive access network is because the advantages such as its high bandwidth, low-loss have become the solution of Access Network optimum.

Just it seems at present, the development trend of passive optical access network is by APON(ATM-PON) develop into EPON and GPON(APON, EPON, GPON belong to mono-kind of TDM-PON), and the most at last to WDM-PON evolution.APON, through development for many years, due to its complicated ATM agreement and expensive equipment, makes it really not come into the market.And EPON and GPON are current most widely used two kinds of Access Networks, more than both bandwidth have all reached 1Gbps, and the speed of follow-on EPON and GPON will be upgraded to 10Gbps, but the associated limitations such as the restriction of device speed and agreement complexity, EPON and GPON are difficult to further develop toward higher bandwidth again.Therefore WDM-PON will be final solution.WDM-PON is take different wave length as communication port, and man-to-man mode connects user, for user provides independent bandwidth space, has also avoided E/GPON problem, the problem includes: many problems have obvious advantage at the aspect such as network management and system upgrade simultaneously.Although WDM-PON is more dominant in technical performance, it is a relatively go-beyond technology simultaneously, and international uniform standard not yet forms, and industrial chain is not reached common understanding.Meanwhile, WDM-PON cost is very high, and some technical barrier is unresolved, is difficult to extensive popularization and application.

In view of above situation, someone has proposed the mode that TDM-PON and WDM-PON combine, and forms the PON scheme of a TDM to WDM evolution.The features such as TDM/WDM-PON is having the advantage of TDM-PON low cost and mature technology, is also annexing the high bandwidth of WDM-PON, long Distance Transmission.But, current TDM/WDM-PON adopts optical branching device as ONU link at ODN end, the power of light signal is divided into N decile (N is number of users), has so not only shortened transmission range, and need strict time synchronized just can complete the transmission of multi-user's upstream data.

Utility model content

Technical problem to be solved in the utility model is to provide a kind of time-division wavelength-division mixed multiplexing passive optical network system, it can simplify the complexity of system protocol, greatly improve the utilance of system bandwidth, thereby reduction system cost, increase communication system unrepeatered transmission distance, and strengthen system later stage upgrading ability.

For addressing the above problem, the utility model is achieved through the following technical solutions:

A kind of time-division wavelength-division mixed multiplexing passive optical network system, is mainly made up of optical line terminal, an optical distribution network and n subscriber unit.Wherein optical line terminal comprises n distributed feedback laser, a n optical branching device, a n Mach-Zehnder optical switch, 3 array waveguide raster multiplexers, two parallel Mach-Zehnder modulators, frequency mixer, local high-frequency generator, direct current biasing controller, optical coupler, a n photodetector and the first erbium-doped fiber amplifiers.The output of each distributed feedback laser connects the input of an optical branching device.An output of each optical branching device is connected to one of them in n input of the first array waveguide raster multiplexer, and another input is respectively connected to one of them in n input of the second array waveguide raster multiplexer through a Mach-Zehnder optical switch.The output of the first array waveguide raster multiplexer directly connects an input of optical coupler, and the output of the second array waveguide raster multiplexer is connected to another input of optical coupler after two parallel Mach-Zehnder modulators.The output of optical coupler connects the input of the first erbium-doped fiber amplifier.Terminal downlink data and local high-frequency generator are connected on 2 inputs of frequency mixer, and the output of frequency mixer connects the radio-frequency (RF) signal input end of two parallel Mach-Zehnder modulators.Direct current biasing controller connects the DC voltage control end of two parallel Mach-Zehnder modulators.The n of a 3rd array waveguide raster multiplexer output is respectively exported n road terminal upstream data after a photodetector.The output of the first erbium-doped fiber amplifier connects total input of optical distribution network, the n of optical distribution network the each input that connects 1 subscriber unit of point output.The n of optical distribution network the each output that connects 1 subscriber unit of point input.Total output of optical distribution network connects the input of the 3rd array waveguide raster multiplexer.

In such scheme, optical distribution network comprises 2 array waveguide raster multiplexers and 2 standard single-mode fibers.The output of the first erbium-doped fiber amplifier connects the input of the 4th array waveguide raster multiplexer through the first standard single-mode fiber.The output of the 5th array waveguide raster multiplexer connects the input of the 3rd array waveguide raster multiplexer through the second standard single-mode fiber.The n of a 4th array waveguide raster multiplexer output connects respectively the input of n subscriber unit.The n of a 5th array waveguide raster multiplexer input connects respectively the output of n subscriber unit.

In such scheme, each subscriber unit comprises optical comb filter, 2 adjustable light wave-filters, optical-electrical converter, IM modulator and the second erbium-doped fiber amplifiers.The input of the each optical comb filter that connects 1 subscriber unit of the n of a 4th array waveguide raster multiplexer output.An output of optical comb filter connects the input of optical-electrical converter through an adjustable light wave-filter, the output output user downlink data of optical-electrical converter.Another output of optical comb filter connects the input of the second erbium-doped fiber amplifier through another adjustable light wave-filter, the output of the second erbium-doped fiber amplifier connects the input of IM modulator, and the control end of IM modulator connects user uplink data.The output of the each IM modulator that connects 1 subscriber unit of the n of a 5th array waveguide raster multiplexer input.

Described in such scheme, IM modulator (intensity modulator) is ROSA modulator (reflective semiconductor optical amplifier).

Described in such scheme, the span of n is between 8～32.

Described in such scheme, the value of n is 32.

Described in such scheme, the operation wavelength of the laser array of n distributed feedback laser composition is 1530～1560nm.

Wavelength interval 0.8nm described in such scheme between every 2 distributed feedback lasers.

Described in such scheme, the splitting ratio of each optical branching device is 1:1.

Compared with prior art, the utlity model has following features:

1, utilize one group of array of photoswitch and the two parallel MZ Mach-Zehnders of high speed lithium niobate to multichannel Different lightwave progress row High Speed Modulation, realized the control technology of system time-sharing multiplex.The optical signal spectrum that OLT launches, the different time periods by data signal modulation to different light carriers, recycling different wave length wavelength-division multiplex technique advantage, just data-signal can be transferred to corresponding ONU.Realize like this technology that time division multiplexing and wavelength division multiplexing combine.For WDM-PON, the utility model can have been saved a large amount of modulators, has reduced system cost.

2, utilize optical branching device and AWG to isolate a part of light at OLT, as the seed light of ONU up link.Realize like this colorless ONU technology, made ONU without extra LASER Light Source, further reduced ONU cost.

3, the utility model is except OLT, and ODN is similar with OUN structure to WDM-PON, and make no longer needs again to lay fibre circuit in the future and change ONU equipment in the time that WDM-PON upgrades, and this greatly reduces upgrade cost.

4, system bandwidth upgrading flexibly, from the design angle of OLT structure, just can make system bandwidth double whenever increasing two parallel MZ Mach-Zehnders.While increasing a modulator, only need change very fraction circuit.And along with the progress of technology in future, the reduction of device cost, increases abundant modulator and just can realize WDM-PON scheme completely.

5, TDM-WDM PON of the present utility model is without operations such as range finding, time synchronized, burst receptions, and up link is WDM working method, will make up and descending separation, improved system bandwidth, and retained the highly confidential property of data of WDM-PON.

Accompanying drawing explanation

Fig. 1 is a kind of structured flowchart of time-division wavelength-division mixed multiplexing passive optical network system.

Embodiment

A kind of time-division wavelength-division mixed multiplexing passive optical network system, as shown in Figure 1, is mainly made up of optical line terminal OLT, optical distribution network ODN and n subscriber unit ONU.

Optical line terminal OLT comprises n distributed feedback laser 1-1, n 1 × 2 optical branching device 1-2, n Mach-Zehnder optical switch 1-3,3 array waveguide raster multiplexer 1-4,1-5,1-13, two parallel Mach-Zehnder modulators 1-6, frequency mixer 1-7, local high-frequency generator 1-8, direct current biasing controller 1-10, optical coupler 1-11, a n photodetector 1-14 and the first erbium-doped fiber amplifier 1-12.The output of each distributed feedback laser 1-1 connects the input of an optical branching device 1-2.An output of each optical branching device 1-2 is connected to one of them in n the input of the first array waveguide raster multiplexer 1-4, and another input is respectively connected to one of them in n the input of the second array waveguide raster multiplexer 1-5 through a Mach-Zehnder optical switch 1-3.The output of the first array waveguide raster multiplexer 1-4 directly connects an input of optical coupler 1-11, and the output of the second array waveguide raster multiplexer 1-5 is connected to another input of optical coupler 1-11 after two parallel Mach-Zehnder modulators 1-6.The output of optical coupler 1-11 connects the input of the first erbium-doped fiber amplifier 1-12.Terminal downlink data 1-9 and local high-frequency generator 1-8 are connected on 2 inputs of frequency mixer 1-7, the output of frequency mixer 1-7 connects the radio-frequency (RF) signal input end of two parallel Mach-Zehnder modulators 1-6, and direct current biasing controller 1-10 connects the DC voltage control end of two parallel Mach-Zehnder modulators 1-6.The n of a 3rd array waveguide raster multiplexer 1-13 output is respectively exported n road terminal upstream data 1-15 after a photodetector 1-14.

Optical distribution network ODN comprises 2 array waveguide raster multiplexer 2-2,2-3 and 2 standard single-mode fiber 2-1,2-4.The output of the first erbium-doped fiber amplifier 1-12 connects the input of the 4th array waveguide raster multiplexer 2-2 through the first standard single-mode fiber 2-1.The output of the 5th array waveguide raster multiplexer 2-3 connects the input of the 3rd array waveguide raster multiplexer 1-13 through the second standard single-mode fiber 2-4.The n of a 4th array waveguide raster multiplexer 2-2 output connects respectively the input of the optical comb filter 3-1 of n subscriber unit ONU.The n of a 5th array waveguide raster multiplexer 2-3 input connects respectively the output of the IM modulator 3-5 of n subscriber unit ONU.

Each subscriber unit ONU comprises optical comb filter 3-1,2 adjustable light wave-filter 3-2, optical-electrical converter 3-3, IM modulator 3-5 and the second erbium-doped fiber amplifier 3-4.An output of optical comb filter 3-1 connects the input of optical-electrical converter 3-3 through an adjustable light wave-filter 3-2, the output output user downlink data 3-6 of optical-electrical converter 3-3.Another output of optical comb filter 3-1 connects the input of the second erbium-doped fiber amplifier 3-4 through another adjustable light wave-filter 3-2, the output of the second erbium-doped fiber amplifier 3-4 connects the input of IM modulator 3-5, and the control end of IM modulator 3-5 connects user uplink data 3-7.

In the utility model, the quantity of described distributed feedback laser 1-1 is identical with the quantity of subscriber unit ONU.In the present embodiment, number of users is that the quantity of subscriber unit ONU is 32, and now the quantity of needed distributed feedback laser 1-1 is also 32.The operation wavelength of the laser array that these 32 distributed feedback laser 1-1 form is 1530～1560nm.Wavelength interval 0.8nm between every 2 distributed feedback laser 1-1 is as 1530nm, 1530.8nm, and 1531.6nm ...The live width of each distributed feedback laser 1-1 is larger, and error rate of system is just larger, and therefore, in the utility model, the live width of described distributed feedback laser 1-1 is 10MHz.The splitting ratio of each 1 × 2 optical branching device 1-2 is 1:1.Downlink communication bandwidth of the present utility model is 40Gbps, and average each user obtains the bandwidth of 1Gbps; Each user's uplink communication bandwidth is 1Gbps.

The course of work of the present utility model is as follows:

In optical line terminal OLT, multichannel different wave length distributed feedback laser 1-1 exports continuous laser signal through optical branching device 1-2, and the light signal of Jiang Mei road wavelength is divided into two parts.A part inputs to the first array waveguide raster multiplexer 1-4, and is multiplexed in a road optical fiber.Another part inputs to Mach-Zehnder optical switch 1-3, then is transferred to the second array waveguide raster multiplexer 1-5 and carries out multiplexing; Then, the light signal of different wave length will input to that two parallel Mach-increasing Dare modulator 1-6 carries out downlink data modulation.In electric territory, realize optical carrier suppression modulation format by the parameter that direct current biasing controller 1-10, high frequency local oscillator 1-8 and frequency mixer 1-7 are set.Due to optical switch is controlled in order, in different time sections, only open the light signal of a road wavelength, make it modulated, thereby realize time-multiplexed control method, reach the effect of in different time sections, different wave length being carried out signal modulation.

The multiplexing signal of above-mentioned modulated light signal and the first array waveguide raster multiplexer 1-4 is after optical coupler 1-11 coupling, amplify through the first erbium-doped fiber amplifier 1-12, be input in the first standard single-mode fiber 2-1 of the standard in optical distribution network ODN and transmit, by the 4th array waveguide raster multiplexer 2-2 demultiplexing, isolate the light signal of different wave length and input to different subscriber unit ONU again.In each subscriber unit ONU, the light signal of input is first isolated optical carrier and optical sub-carrier signal through optical comb filter IL3-1 and two adjustable light wave-filter TOF3-2; Optical sub-carrier signal is converted to the signal of telecommunication through optical-electrical converter 3-3, after processing, electric territory obtains down user data, and optical carrier by second erbium-doped fiber amplifier 3-4 amplify after, input to again IM modulator 3-5, be used as the carrier wave of uplink user data, realized colorless ONU, in subscriber unit ONU without extra laser.Multipath light signal after modulated is multiplexing at optical distribution network ODN back warp the 5th array waveguide raster multiplexer 2-3 again, and transfer to optical line terminal OLT through the second standard single-mode fiber 2-4, again by after the 3rd array waveguide raster multiplexer 1-13 demultiplexing, every road light signal is converted to the signal of telecommunication through photodetector 1-14 respectively, obtains uplink user data after respective handling.

Claims (9)

1. A time-division wavelength-division hybrid multiplexing passive optical network system, mainly composed of an optical line terminal (OLT), an optical distribution network (ODN) and n subscriber units (ONU); it is characterized in that: The optical line terminal (OLT) includes n distributed feedback lasers (1-1), n optical splitters (1-2), n Mach-Zehnder optical switches (1-3), and 3 arrayed waveguide gratings Multiplexers (1-4, 1-5, 1-13), Dual Parallel Mach-Zehnder Modulators (1-6), Mixers (1-7), Local High Frequency Oscillators (1-8) , a DC bias controller (1-10), an optical coupler (1-11), n photodetectors (1-14) and a first erbium-doped fiber amplifier (1-12); each distributed feedback laser The output end of (1-1) is connected to the input end of an optical splitter (1-2); one output end of each optical splitter (1-2) is connected to the first arrayed waveguide grating multiplexer (1 One of the n input terminals of -4), the other input terminal is connected to the n input terminals of the second arrayed waveguide grating multiplexer (1-5) via a Mach-Zehnder optical switch (1-3) One of the terminals; the output terminal of the first arrayed waveguide grating multiplexer (1-4) is directly connected to one input terminal of the optical coupler (1-11), and the second arrayed waveguide grating multiplexer (1-5) The output end of the dual parallel Mach-Zehnder modulator (1-6) is connected to the other input end of the optocoupler (1-11); the output end of the optocoupler (1-11) is connected to the first erbium-doped The input end of the optical fiber amplifier (1-12); the terminal downlink data (1-9) and the local high frequency oscillator (1-8) are connected to the two input ends of the mixer (1-7), and the mixer The output terminals of (1-7) are connected to the radio frequency signal input terminals of the dual parallel Mach-Zehnder modulators (1-6); the DC bias controller (1-10) is connected to the dual parallel Mach-Zehnder modulators (1- 6) the DC voltage control terminal; each of the n output terminals of the third arrayed waveguide grating multiplexer (1-13) passes through a photodetector (1-14) and then outputs n channels of terminal uplink data (1-15); The output end of the first erbium-doped fiber amplifier (1-12) is connected to the main input end of the optical distribution network (ODN), and the n sub-output ends of the optical distribution network (ODN) are respectively connected to the input end of one subscriber unit (ONU). ; Each of the n sub-input terminals of the optical distribution network (ODN) is connected to the output terminal of one subscriber unit (ONU); the total output terminal of the optical distribution network (ODN) is connected to the third arrayed waveguide grating multiplexer (1-13) input terminal. the 2. A kind of time division wavelength division hybrid multiplexing passive optical network system according to claim 1, is characterized in that: The optical distribution network (ODN) includes 2 arrayed waveguide grating multiplexers (2-2, 2-3) and 2 standard single-mode fibers (2-1, 2-4); the first erbium-doped fiber amplifier (1- 12) The output end of the first standard single-mode fiber (2-1) is connected to the input end of the fourth arrayed waveguide grating multiplexer (2-2); the output of the fifth arrayed waveguide grating multiplexer (2-3) The end is connected to the input end of the third arrayed waveguide grating multiplexer (1-13) through the second standard single-mode optical fiber (2-4); the n output ends of the fourth arrayed waveguide grating multiplexer (2-2) are respectively The input terminals of n subscriber units (ONU) are connected; the n input terminals of the fifth arrayed waveguide grating multiplexer (2-3) are respectively connected with the output terminals of n subscriber units (ONU). the 3. A kind of time division wavelength division hybrid multiplexing passive optical network system according to claim 2, is characterized in that: Each subscriber unit (ONU) includes optical comb filter (3-1), 2 tunable optical filters (3-2), photoelectric converter (3-3), IM modulator (3-5) and The second erbium-doped fiber amplifier (3-4); the n output terminals of the fourth arrayed waveguide grating multiplexer (2-2) are respectively connected to an optical comb filter (3-1) of an subscriber unit (ONU) The input end of the optical comb filter (3-1) is connected to the input end of the photoelectric converter (3-3) through a tunable optical filter (3-2), and the photoelectric converter (3-3 ) output user downlink data (3-6); the other output end of the optical comb filter (3-1) is connected to the second erbium-doped fiber amplifier through another tunable optical filter (3-2) ( 3-4), the output end of the second erbium-doped fiber amplifier (3-4) is connected to the input end of the IM modulator (3-5), and the control end of the IM modulator (3-5) is connected to the user's uplink data (3-7); the n input terminals of the fifth arrayed waveguide grating multiplexer (2-3) are respectively connected to the output terminal of the IM modulator (3-5) of one subscriber unit (ONU). the 4. A time division wavelength division hybrid multiplexing passive optical network system according to claim 3, characterized in that: the IM modulator (3-5) is a ROSA modulator. the 5. A time-division wavelength-division hybrid multiplexing passive optical network system according to any one of claims 1-3, characterized in that: the value range of n is between 8-32. the 6 . A time division wavelength division hybrid multiplexing passive optical network system according to claim 5 , wherein the value of n is 32. the 7. A time-division wavelength-division hybrid multiplexing passive optical network system according to claim 1, characterized in that: the working wavelength of the laser array composed of n distributed feedback lasers (1-1) is 1530-1560 nm. the 8. A time-division wavelength-division hybrid multiplexing passive optical network system according to claim 7, characterized in that the wavelength interval between every two distributed feedback lasers (1-1) is 0.8nm. the 9. A time-division-wavelength-division hybrid multiplexing passive optical network system according to claim 1, characterized in that: the light splitting ratio of each optical splitter (1-2) is 1:1. the

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