CN101848054B

CN101848054B - System and method for leading wavelength division multiplexing passive optical network to realize broadcast function with self-healing function

Info

Publication number: CN101848054B
Application number: CN201010167567XA
Authority: CN
Inventors: 杨登峰; 甘朝钦; 曹娅婻; 阮浩
Original assignee: University of Shanghai for Science and Technology
Current assignee: University of Shanghai for Science and Technology
Priority date: 2010-05-06
Filing date: 2010-05-06
Publication date: 2013-08-28
Anticipated expiration: 2030-05-06
Also published as: CN101848054A

Abstract

The invention relates to a system and a method for leading a wavelength division multiplexing passive optical network to realize the broadcast function with the self-healing function. The system adopts 1 optical line terminal OLT which is connected with a remote node RN through two single-mode optical fibers, and the remote node RN is connected with N-1 optical network units ONU, wherein the remote node RN mainly consists of 2 optical fiber Bragg gratings FBG, two 1 multiplied by (N-1) star couplers and 1 N multiplied by N AWG; broadcast signals sharing wavelength are reflected back by the optical fiber Bragg gratings FBG, divided by the 1 multiplied by (N-1) star couplers and then sent to N-1 input ports of an arrayed waveguide grating AWG; the transmission of the broadcast signals and point-to-point signals can be realized through the properties of the arrayed waveguide grating AWG; symmetric structures are adopted at two ends of the N multiplied N AWG for realizing the self-healing function of the system; and the transmission of the point-to-point uplink signals in the system is realized by utilizing the remodulation technology of a reflective semiconductor optical amplifier RSOA. The scheme can realize the transmission of the broadcast signals by only changing the structure of the system, and further balance the cost and the performances of the system.

Description

Wave division multiplexing passive optical network with self-healing function is realized the system and method for broadcast capability

Technical field

The present invention relates to optical communication field, specifically relate to a kind of Wave division multiplexing passive optical network (WDM-PON) with self-healing function and realize the broadcast capability system and method.

Background technology

Along with the develop rapidly of information-intensive society, the demand of business such as broadband video-on-demand, multimedia constantly increases, and particularly Internet fast development has proposed requirements at the higher level for the transmission of data.Along with the development of DWDM technology, the multiplexing number of channel constantly increases, and bearer cap and the transmission rate of optical transfer network sharply enlarge.Particularly development of fiber technology makes link transmission speed reach several 10Gbps, in the optical transfer network of this ultrahigh speed, vast capacity, when network failure takes place when, article one, the damage of link will influence a large amount of applied business, if can not in time repair network, to cause tremendous influence and loss to society, this makes the reliability of network and survival ability be subjected to very big challenge.Therefore, the survivability problem of optical-fiber network becomes the focus of optical-fiber network research.

The Wave division multiplexing passive optical network WDM-PON technology bandwidth of can upgrading under the situation that does not change physical basis equipment promotes the transmission capacity of network significantly, gathers around to have broad application prospects in optical access network, is considered to the final selection of the following evolution of FTTx.WDM-PON communicates for each ONU has distributed (or a pair of) wavelength, thereby has realized point-to-point transmission virtual between ONU and the OLT, but this transmission means makes that the broadcast singal transmission of point-to-multipoint is comparatively difficult.Therefore the present invention has important effect in Wave division multiplexing passive optical network WDM-PON system.

Realize among the WDM-PON of broadcast capability in routine, generally be in WDM-PON, to superpose a TDM-PON with the transmission broadcast singal, perhaps utilize the mode of phase modulation to be written into broadcast message, but the transmission of the former broadcast singal is except there being the Insertion Loss that will bear various devices, also need to bear the power division loss, so its power is lower with respect to point-to-point signal, and then have influence on performance and the transmission capacity of network; The latter then needs to increase phase place modulation and demodulation device in system, and this just all has higher requirement to equipment and the cost of network.

In fact, based on the WDM-PON optical access network of future generation of B-TV, can make system in compatible broadcast business and point-to-point service by the reasonable arrangement to the network architecture, also will between the performance of system and cost, average out, the WDM-PON development in future will be had material impact.The present invention is exactly that architectural framework to system has carried out rational arrangement, and not only broadcast singal and point-to-point signal can be transmitted in system, and system also can reach perfect condition between cost and performance.

Summary of the invention

The objective of the invention is to the defective at the prior art existence; provide a kind of Wave division multiplexing passive optical network (WDM-PON) with self-healing function to realize the broadcast capability system and method; broadcast singal can not only effectively be transmitted in this system in WDM-PON, but also effectively realizes defencive function.

For achieving the above object, design of the present invention is: adopted a kind of new structure configuration mode at the RN place, the frame mode by this new distant-end node RN can overcome the defective that existing method is transmitted broadcast singal.

The present invention adopts at the RN place to have device--the reflection type optical fiber bragg grating FBG of wavelength selection function, and the NxN AWG with loop cycle displacement character, and utilizes the symmetry characteristic of NxN AWG to realize the self-healing function of network.Like this, just can finish at the RN place uplink and downlink signals separation, close the road, each ONU can receive broadcast singal and point-to-point data-signal simultaneously.

According to the foregoing invention design, the present invention adopts following scheme:

A kind of Wave division multiplexing passive optical network with self-healing function is realized the broadcast capability system, optical line terminal OLT is by the DFB optical sender, the sharing wavelength transmitter is connected first optical circulator and an optical switch formation through 1xN waveguide optical grating AWG respectively with optical receiver with 1x array waveguide grating AWG, it is characterized in that: described distant-end node RN comprises four optical circulators---second optical circulator, the 3rd optical circulator, the 4th optical circulator and the 5th optical circulator, two optical fiber bragg grating FBGs---first optical fiber bragg grating FBG and second optical fiber bragg grating FBG, the array waveguide grating AWG of the starlike coupler of two 1x---the first starlike coupler and the second starlike coupler and a NxN; Optical switch through the OLT end makes monomode fiber I and monomode fiber II be connected to second optical circulator and the 4th optical circulator, first optical fiber bragg grating FBG and second optical fiber bragg grating FBG are connected to first input port of a NxN array waveguide grating AWG respectively through the 3rd optical circulator and the 5th optical circulator, the reflector port of described first optical fiber bragg grating FBG and second optical fiber bragg grating FBG is connected to the first starlike coupler and the second starlike coupler of 1x (N-1) respectively, and this working end three-dB coupler and protection end three-dB coupler are connected to all the other N interface of a NxN array waveguide grating AWG; The first starlike coupler of described starlike coupler, the second starlike coupler and its working end three-dB coupler, protection end three-dB coupler are connected to each ONU by profile fiber and the corresponding protection optical fiber that distributes respectively.

Total N-1 described optical network unit ONU, each optical network unit ONU is identical, and each optical network unit ONU is by two optical couplers---first optical coupler and second optical coupler, two optical switches, two monitoring units, two control units, two broadcast signal receivers, two point-to-point signal receivers and two RSOA form; Described profile fiber connects optical switch, and protection optical fiber connects optical switch through first optical coupler, and optical switch connects broadcast signal receiver through optical coupler, and is connected the optical switch control end with control unit through monitoring unit.

A kind of Wave division multiplexing passive optical network is realized the method for broadcast capability, adopt said system to broadcast, it is characterized in that: when descending, (DFB optical sender 2, sharing wavelength transmitter N wavelength and the shared broadcasting wave length signal launched enter optical switch through first circulator to laser in the described optical line terminal OLT, and two output ports of optical switch are connected to respectively in monomode fiber I and the monomode fiber II and transmit.After signal enters distant-end node RN, enter first optical fiber bragg grating FBG through second optical circulator, first optical fiber bragg grating FBG will be shared signal reflex and return, broadcast singal carries out shunt through the first starlike coupler, broadcast singal along separate routes is connected to AWGN port of NxN array waveguide grating by the working end three-dB coupler, and optical fiber bragg grating FBG is connected to first port of array waveguide grating AWG; Downstream signal and broadcast singal are sent to each optical network unit ONU by demultiplexing and the routing function of NxN array waveguide grating AWG respectively, and RN is connected to optical switch among the ONU by profile fiber, and are connected to watch-dog and controller by the 3dB optical coupler.The downstream signal that optical network unit ONU will be shared the signal that receives with broadcast singal and point-to-point by optical filter is separated reception respectively; On the up direction, in optical network unit ONU, adopt reflection type semiconductor amplifier RSOA to realize the recycling of downstream wavelength and the remodulates of upward signal, then by profile fiber the upward signal of each optical network unit ONU is delivered to carry out among the NxN array waveguide grating AWG of distant-end node RN multiplexing, upward signal after multiplexing is successively by the 3rd optical circulator, second optical circulator, feeder line optical fiber, optical switch, first circulator is sent among 1x (N-1) the array waveguide grating AWG in the optical line terminal OLT, and then enter corresponding receiver, thereby finish the reception of upward signal.

The present invention has following apparent outstanding substantive distinguishing features and remarkable advantage compared with prior art: (1) can make the transmission of the very simple realization broadcast message of network by the new structure of distant-end node RN; (2) only be that network configuration is arranged, less demanding to device makes the network system that makes easy to implement reach an equilibrium between cost and performance, makes network possess self-healing function; (3) uplink and downlink signals is adopting same wavelength to transmit, and what make does not need other extra light source in ONU, realized " colourlessization " of network, and then reduced system cost.

Description of drawings

Fig. 1 realizes the system architecture diagram of self-healing function and broadcast capability for one embodiment of the invention card Wave division multiplexing passive optical network.

Fig. 2 is under the normal operation, the equivalence work schematic diagram of system.

Fig. 3 is after feeder line optical fiber goes wrong, the equivalence work schematic diagram of system.

Embodiment

Accompanying drawings, an exemplifying embodiment of the present invention is as follows: referring to Fig. 1, the Wave division multiplexing passive optical network WDM-PON that originally has self-healing function realizes that the broadcast capability system comprises optical line terminal OLT 1, distant-end node RN 23 and optical network unit ONU 26 3 parts.Optical line terminal OLT 1 is by two monomode fibers----monomode fiber I 10 and monomode fiber II 11 and remote node of the connection RN 23, distant-end node RN 23 is connected a plurality of optical network unit ONU 26 by profile fiber 24 with protection optical fiber 25 and constitutes, described optical line terminal OLT 1 is by DFB optical sender 2, sharing wavelength transmitter 6 is connected first optical circulator 4 and optical switch 5 formations through 1xN waveguide optical grating AWG 3 respectively with optical receiver 7 with 1x (N-1) array waveguide grating AWG 9, described distant-end node RN 23 comprises four optical circulators---second optical circulator 12, the 3rd optical circulator 14, the 4th optical circulator 15 and 17, two optical fiber bragg grating FBGs of the 5th optical circulator---first optical fiber bragg grating FBG 13 and second optical fiber bragg grating FBG 18, the array waveguide grating AWG 20 of the starlike coupler of two 1x (N-1)---the first starlike coupler 16 and the second starlike coupler 21 and a NxN; Optical switch 5 through the OLT end makes monomode fiber I 10 and monomode fiber II 11 be connected to second optical circulator 12 and the 4th optical circulator 15, first optical fiber bragg grating FBG 13 and second optical fiber bragg grating FBG 18 are connected to first input port of a NxN array waveguide grating AWG 20 respectively through the 3rd optical circulator 14 and the 5th optical circulator 17, the reflector port of described first optical fiber bragg grating FBG 13 and second optical fiber bragg grating FBG 18 is connected to the first starlike coupler 16 and the second starlike coupler 21 of 1x (N-1) respectively, and this working end three-dB coupler 19 and protection end three-dB coupler 22 are connected to all the other N interface of a NxN array waveguide grating AWG 20; The first starlike coupler 16 of described starlike coupler, the second starlike coupler 21 and its working end three-dB coupler 19, protection end three-dB coupler 22 are connected to each ONU 26 by profile fiber 24 and the corresponding protection optical fiber 25 that distributes respectively.

Total N-1 described optical network unit ONU 26, each optical network unit ONU is identical, and each optical network unit ONU 26 is by two optical couplers---first optical coupler 28 and second optical coupler 35, two optical switches 30, two monitoring units 27, two control units 29, two broadcast signal receivers 32, two point-to-point signal receivers 33 and two RSOA 34 form; Described profile fiber 24 connects optical switch 30, and protection optical fiber 25 connects optical switch 30 through first optical coupler 28, and optical switch 30 connects broadcast signal receiver 32 through optical coupler 31, and is connected optical switch 30 control ends with control unit 29 through monitoring unit 27.

Originally have the self-healing function Wave division multiplexing passive optical network and realize the broadcast capability method, adopt said system to broadcast, when descending, N wavelength and shared broadcasting wave length signal that laser in the described optical line terminal OLT 1 (DFB optical sender 2, sharing wavelength transmitter 6) is launched enter optical switch 5 through first circulator 4, and two output ports of optical switch 5 are connected to transmission in monomode fiber I 10 and the monomode fiber II 11 respectively.After signal enters distant-end node RN 23, enter first optical fiber bragg grating FBG 13 through second optical circulator 12, first optical fiber bragg grating FBG 13 will be shared signal reflex and return, broadcast singal carries out shunt through the first starlike coupler 16, broadcast singal along separate routes is connected to 20N port of NxN array waveguide grating AWG by working end three-dB coupler 19, and optical fiber bragg grating FBG 13 is connected to array waveguide grating AWG 20 first ports; Downstream signal and broadcast singal are sent to each optical network unit ONU 26 by demultiplexing and the routing function of NxN array waveguide grating AWG 20 respectively, RN 23 is connected to optical switch 30 among the ONU 26 by profile fiber 24, and is connected to watch-dog 27 and controller 29 by 3dB optical coupler 28.The downstream signal that optical network unit ONU 26 will be shared the signal that receives with broadcast singal and point-to-point by optical filter 31 is separated reception respectively; On the up direction, in optical network unit ONU 26, adopt reflection type semiconductor amplifier RSOA 34 to realize the recycling of downstream wavelength and the remodulates of upward signal, then by profile fiber 24 upward signal of each optical network unit ONU 26 is delivered to carry out among the NxN array waveguide grating AWG 20 of distant-end node RN 23 multiplexing, upward signal after multiplexing is successively by the 3rd optical circulator 14, second optical circulator 12, feeder line optical fiber 10, optical switch 5, first circulator 4 is sent among 1x (N-1) the array waveguide grating AWG 9 in the optical line terminal OLT 1, and then enter corresponding receiver, thereby finish the reception of upward signal.Under normal circumstances, the equivalent schematic diagram of system works as shown in Figure 2.

When mistake appearred in working optical fibre, supervisory circuit and corresponding control circuit can be made a response, and the operating state of optical switch will change by control circuit, and the fundamental diagram of device equivalence as shown in Figure 3.

Claims

1. the Wave division multiplexing passive optical network with self-healing function is realized the system of broadcast capability, by optical line terminal OLT (1) by two monomode fibers----monomode fiber I (10) and monomode fiber II (11) and remote node of the connection RN(23), each optical network unit ONU (26) is to be connected to distant-end node RN(23 by two optical fiber) constitute, wherein, one is profile fiber (24), one is protection optical fiber (25), total N-1 optical network unit; N-1 distributed feed-back formula optical sender DFB(2), a sharing wavelength transmitter (6) described optical line terminal OLT (1) comprising:, N-1 receiver (7), a 1xN waveguide optical grating AWG(3), a 1x(N-1) array waveguide grating AWG(9), first optical circulator (4) and an optical switch (5); N-1 DFB optical sender (2) and sharing wavelength transmitter (6) are connected to 1 x N waveguide optical grating AWG(3) input port, 1 x N waveguide optical grating AWG(3) delivery outlet is connected to first optical circulator (4), this first optical circulator (4) is connected to optical switch (5), and two outputs of optical switch (5) are connected respectively to monomode fiber I (10) and monomode fiber II (11); N-1 receiver is connected to 1 x (N-1) array waveguide grating AWG(9), AWG(9) output is connected to first optical circulator (4), it is characterized in that:

A. described distant-end node RN(23) comprise four optical circulators---second optical circulator (12), the 3rd optical circulator (14), the 4th optical circulator (15) and the 5th optical circulator (17), the array waveguide grating AWG(20 of two optical fiber bragg grating FBGs---starlike couplers of first optical fiber bragg grating FBG (13) and second optical fiber bragg grating FBG (18), two 1 x (N-1)---first starlike coupler (16) and the second starlike coupler (21) and a N x N); Optical switch (5) through the OLT end makes monomode fiber I (10) and monomode fiber II (11) RespectivelyBe connected to second optical circulator (12) and the 4th optical circulator (15), first optical fiber bragg grating FBG (13) and second optical fiber bragg grating FBG (18) are connected to a N x N array waveguide grating AWG(20 through the 3rd optical circulator (14) and the 5th optical circulator (17) respectively) Both sidesFirst input port, the reflector port of described first optical fiber bragg grating FBG (13) and second optical fiber bragg grating FBG (18) is connected to 1x(N-1 respectively) the first starlike coupler (16) and the second starlike coupler (21), the output of the first starlike coupler (16) connects N-1 working end three-dB coupler (19), and the output of the second starlike coupler (21) connects N-1 protection end three-dB coupler (22); This N-1 working end three-dB coupler (19) and protection end three-dB coupler (22) are connected to a N x N array waveguide grating AWG(20) all the other N-1 port; Each working end three-dB coupler (19) has the another one delivery outlet to be connected to profile fiber (24) in addition, and each protection end three-dB coupler (22) has the another one delivery outlet to be connected to protection optical fiber (25);

B. have N-1 described optical network unit ONU (26), each optical network unit ONU is identical, and each optical network unit ONU (26) is by two optical couplers---first optical coupler (28) and second optical coupler (35), an optical switch (30), a monitoring unit (27), a control unit (29), a broadcast signal receiver (32), a point-to-point signal receiver (33) and a reflective semiconductor optical amplifier RSOA(34) form; Optical switch (30) connects broadcast signal receiver (32) and second optical coupler (35) through optical filter (31), and second optical coupler (35) is connected to downlink receiver (33) and RSOA(34); Described protection optical fiber (25) connects optical switch (30); described profile fiber (24) connects optical switch (30) through first optical coupler (28); other one tunnel output of this first optical coupler is connected to monitoring unit (27); monitoring unit (27) is connected to control unit (29), and control unit (29) is used for controlling optical switch (30).

2. the Wave division multiplexing passive optical network with self-healing function is realized the method for broadcast capability, adopt the Wave division multiplexing passive optical network with self-healing function according to claim 1 to realize that the system of broadcast capability broadcasts, it is characterized in that: when descending, N-1 DFB optical sender (2) in the optical line terminal OLT (1), a sharing wavelength transmitter (6) is launched N wavelength signals altogether and is entered optical switch (5) through first optical circulator (4), and two output ports of optical switch (5) are connected to transmission in feeder line optical fiber (10) and the monomode fiber II (11) respectively; Signal enters distant-end node RN(23) after, enter first optical fiber bragg grating FBG (13) through second optical circulator (12), first optical fiber bragg grating FBG (13) reflects broadcast singal, broadcast singal carries out shunt through the first starlike coupler (16), and the broadcast singal after is connected to N x N array waveguide grating AWG(20 by working end three-dB coupler (19) along separate routes) a N-1 port; Downstream signal and broadcast singal are respectively by N x N array waveguide grating AWG(20) demultiplexing and routing function be sent to each optical network unit ONU (26), RN(23) be connected to ONU(26 by profile fiber (24)) in optical switch (30), and be connected to monitoring unit (27) and control unit (29) by 3dB first optical coupler (28); Optical network unit ONU (26) is separated the signal that receives respectively with the downstream signal of broadcast singal and point-to-point by optical filter (31) and is received; On the up direction, employing reflection type semiconductor amplifier RSOA(34 in optical network unit ONU (26)) realizes the recycling of downstream wavelength and the remodulates of upward signal, by profile fiber (24) upward signal of each optical network unit ONU (26) is delivered to distant-end node RN(23 then) N x N array waveguide grating AWG(20) in carry out multiplexing, upward signal after multiplexing is successively by the 3rd optical circulator (14), second optical circulator (12), feeder line optical fiber (10), optical switch (5), first optical circulator (4) is sent into 1 x(N-1 in the optical line terminal OLT (1)) array waveguide grating AWG(9) in, and then enter corresponding receiver, thereby finish the reception of upward signal.