Summary of the invention
For solving the bandwidth problem that prior art exists, the invention provides a kind of multi-wavelength passive optical network system.
Multi-wavelength passive optical network system provided by the invention comprises optical line terminal, Optical Distribution Network and a plurality of optical network unit, and described optical line terminal is connected to described optical network unit by described Optical Distribution Network in the mode of putting multiple spot; Wherein, described a plurality of optical network unit is divided into many groups, each group optical network unit adopts different up-downgoing wavelength respectively, described Optical Distribution Network comprises first order optical splitter and a plurality of second level optical splitter, the public port of wherein said first order optical splitter is connected to described optical line terminal by trunk optical fiber, and its branch port connects branch optical fiber respectively and is connected to one group of optical network unit by different partial wave assemblies and one of them second level optical splitter, described partial wave assembly comprises four ports light rings and fiber grating, the fiber grating of described different partial wave assemblies has different reflectance spectrums, described four ports light rings comprise first port, second port, the 3rd port and the 4th port, first port and the 3rd port of described four ports light rings connect described branch optical fiber respectively, and second port of described ring of light device connects described fiber grating; Wherein, described optical line terminal comprises the HLend territory to the frame head of the descending XGTC frame that described optical-fiber network sends, and described HLend territory comprises the wavelength indication field, and described wavelength indication field is used for carrying wavelength indication information.
In multi-wavelength passive optical network system one preferred embodiment provided by the invention, described a plurality of optical network unit is divided into four groups, and described first order optical splitter comprises four branch port, each branch port corresponds respectively to wherein one group of optical network unit, and described four branch port are the corresponding first partial wave assembly, the second partial wave assembly, the 3rd partial wave assembly and the 4th partial wave assembly respectively.
In multi-wavelength passive optical network system one preferred embodiment provided by the invention, the fiber grating reflection wavelength of the described first partial wave assembly is the downstream wavelength of first group of optical network unit, the fiber grating reflection wavelength of the described second partial wave assembly is the downstream wavelength of second group of optical network unit, the fiber grating reflection wavelength of described the 3rd partial wave assembly is the downstream wavelength of the 3rd group of optical network unit, and the fiber grating reflection wavelength of described the 4th partial wave assembly is the downstream wavelength of the 4th group of optical network unit.
In multi-wavelength passive optical network system one preferred embodiment provided by the invention, described Optical Distribution Network also comprises the upgoing wave division multiplexer, the public port of described upgoing wave division multiplexer is coupled to trunk optical fiber by the trunk coupler, and the branch port of described upgoing wave division multiplexer respectively the 4th port of the optical circulator by connecting described different partial wave assemblies be coupled to one of them branch optical fiber.
In multi-wavelength passive optical network system one preferred embodiment provided by the invention, channel center's wavelength of a plurality of branch port of described upgoing wave division multiplexer is respectively the up wavelength of the up wavelength of the up wavelength of described first group of optical network unit, described second group of optical network unit, described the 3rd group of optical network unit and the up wavelength of described the 4th group of optical network unit.
In multi-wavelength passive optical network system one preferred embodiment provided by the invention, described optical line terminal comprises a plurality of optical transmitting sets, and wherein the emission wavelength of each optical transmitting set is distinguished the wherein downstream wavelength of one group of optical network unit.
In multi-wavelength passive optical network system one preferred embodiment provided by the invention, described optical line terminal also comprises a plurality of optical receivers, and wherein the reception wavelength of each optical receiver is distinguished the wherein up wavelength of one group of optical network unit.
Multi-wavelength passive optical network system provided by the invention is divided into many groups with described optical network unit, and the branch port at described first order optical splitter adopts described different partial wave assembly to realize the downstream wavelength separation, thereby realize adopting respectively many data of wavelength being carried not optical network unit on the same group respectively, thus, section just can utilize different wave length to transmit the data of a plurality of optical network units simultaneously at one time, thereby effectively the overall bandwidth of elevator system satisfies user's broadband services to the increased requirement of bandwidth.
Embodiment
To the technical scheme in the embodiment of the invention be clearly and completely described below, obviously, described embodiment only is a part of embodiment of the present invention, rather than whole embodiment.Based on the embodiment among the present invention, those of ordinary skills belong to the scope of protection of the invention not making all other embodiment that obtain under the creative work prerequisite.
See also Fig. 1, it is the schematic diagram of a kind of preferred embodiment of multi-wavelength passive optical network system provided by the invention.Described passive optical network 100 comprises at least one optical line terminal (OLT) 110, a plurality of optical network unit (ONU) 120-1~120-n and Optical Distribution Network (ODN) 130.Described optical line terminal 110 is connected to described a plurality of optical network unit 120-1~120-n by described Optical Distribution Network 130 with the form of putting multiple spot.Wherein, the direction from described optical line terminal 110 to described optical network unit 120-1~120-n is defined as down direction, and the direction from described optical network unit 120-1~120-n to described optical line terminal 110 is up direction.
Described passive optical network 100 can be the communication network of realizing the data distribution between described optical line terminal 110 and the described optical network unit 120-1~120-n without any need for active device, such as, in specific embodiment, the data distribution between described optical line terminal 110 and the described optical network unit 120-1~120-n can realize by the Passive Optical Components in the described Optical Distribution Network 130 (such as optical splitter or multiplexer).
Described optical line terminal 110 is usually located at the center, and (central office Central Office for example, CO), they can the described a plurality of optical network unit 120-1~120-n of unified management.Described optical line terminal 110 can serve as the media between described optical network unit 120-1~120-n and the upper layer network (not shown), to be forwarded to described optical network unit 120-1~120-n as downlink data from the data that described upper layer network receives, and will be forwarded to described upper layer network from the upstream data that described optical network unit 120-1~120-n receives.
Described optical network unit 120-1~120-n can be arranged on user's side position (such as user resident) by distributed earth.Described optical network unit 120-1~120-n can be the network equipment that is used for communicating with described optical line terminal 110 and user, particularly, described optical network unit 120-1~120-n can serve as the media between described optical line terminal 110 and the described user, for example, described optical network unit 120-1~120-n can be forwarded to described user with the downlink data that receives from described optical line terminal 110, and will be forwarded to described optical line terminal 110 as upstream data from the data that described user receives.Should be appreciated that the structure of described optical network unit 120-1~120-n and Optical Network Terminal (Optical Network Terminal, ONT) close, therefore in the scheme that present specification provides, can exchange between optical network unit and the Optical Network Terminal.
Described Optical Distribution Network 130 can be a data dissemination system, and it can comprise optical fiber, optical coupler, optical branching device, optical multiplexer and/or other equipment.In one embodiment, described optical fiber, optical coupler, optical branching device, optical multiplexer and/or other equipment can be Passive Optical Components, specifically, described optical fiber, optical coupler, optical branching device, optical multiplexer and/or other equipment can be that distribute data signals is the device that does not need power supply to support between described optical line terminal 110 and described optical network unit 120-1~120-n.In addition, in other embodiments, this Optical Distribution Network 130 can also comprise one or more treatment facilities, for example, and image intensifer or trunking (Relay device).In branched structure as shown in Figure 1, described Optical Distribution Network 130 specifically can extend to described a plurality of optical network unit 120-1~120-n from described optical line terminal 110, but also can be configured to other any points to the structure of multiple spot.
In multi-wavelength passive optical network system provided by the invention, described a plurality of optical network unit 120-1~120-n can be divided into many groups, and same group optical network unit adopts respectively with a pair of up-downgoing wavelength, and adopt time division multiplexing mode to carry out multiplexing; The up-downgoing wavelength difference that adopts of optical network unit on the same group not, and (Wavelength Division Multiplexing, WDM) mode is not carried out multiplexing with wavelength division multiplexing by different wave length between on the same group the optical network unit.
Such as, multi-wavelength passive optical network system 100 shown in Figure 1 can adopt four pairs of up-downgoing wavelength, for ease of describing, below described four pairs of up-downgoing wavelength are designated as the first up wavelength X u1 and the first downstream wavelength λ d1, the second up wavelength X u2 and the second downstream wavelength λ d2, the 3rd up wavelength X u3 and the 3rd downstream wavelength λ d3, the 4th up wavelength X u4 and the 4th downstream wavelength λ d4 respectively.And, described a plurality of optical network unit 120-1~120-n can be divided into four groups, wherein the up-downgoing wavelength of first group of optical network unit adopts the described first up wavelength X u1 and the first downstream wavelength λ d1 respectively, the up-downgoing wavelength of second group of optical network unit adopts the described second up wavelength X u2 and the second downstream wavelength λ d2 respectively, the up-downgoing wavelength of the 3rd group of optical network unit adopts the described the 3rd up wavelength X u3 and the 3rd downstream wavelength λ d3 respectively, and the up-downgoing wavelength of the 4th group of optical network unit adopts the described the 4th up wavelength X u4 and the 4th downstream wavelength λ d4 respectively.
Described optical line terminal 110 comprises a plurality of optical transmitting set Tx1~Tx4 and a plurality of optical receiver Rx1~Rx4, wherein said optical transmitting set Tx1~Tx4 is used for launching downlink data to described optical network unit 120-1~120-n, and the emission wavelength of described optical transmitting set Tx1~Tx4 is respectively the described first downstream wavelength λ d1, the described second downstream wavelength λ d2, described the 3rd downstream wavelength λ d3 and described the 4th downstream wavelength λ d4; Described optical receiver Rx1~Rx4 is used for receiving the upstream data from described optical network unit 120-1~120-n, and the reception wavelength of described optical receiver Rx1~Rx4 is respectively the described first up wavelength X u1, the described second up wavelength X u2, the described the 3rd up wavelength X u3 and the 4th up wavelength X u4.
Described optical transmitting set Tx1~Tx4 can be connected to optical coupler 113 by multiplexer 111, thereby described multiplexer 111 can carry out multiplexing formation multi-wavelength downstream signal with the downlink data of described optical transmitting set Tx1~Tx4 emission.Described optical receiver Rx1~Rx4 can be connected to described optical coupler 113 by demodulation multiplexer 112, and described demodulation multiplexer 112 can will be demultiplexed into described optical receiver Rx1~Rx4 respectively from described a plurality of 120-1~120-n and the upstream data that carries through described Optical Distribution Network 130 transmission multi-wavelength upward signals.Described optical coupler 113 can further be connected to Optical Distribution Network 130, described optical coupler 113 will be coupled to described Optical Distribution Network 130 from the multi-wavelength downstream signal of described multiplexer 111 on the one hand, will be coupled to described demodulation multiplexer 112 from the multi-wavelength upward signal of described Optical Distribution Network on the other hand.In specific embodiment, described optical coupler 113 can be wavelength division multiplexing (WDM) device.
Described Optical Distribution Network 130 can adopt two-stage light splitting framework, and it comprises first order optical splitter 131, second level optical splitter 132-1~132-4, upgoing wave division multiplexer 133, trunk coupler 135 and a plurality of different partial wave assemblies 139.
Described first order optical splitter 131 can be the optical branching device of 1:4 for splitting ratio, it comprises a public port and four branch port, the public port of described first order optical splitter 131 is connected to trunk optical fiber 136 by described trunk coupler 135, and the other end of described trunk optical fiber is connected to the optical coupler 113 of described optical line terminal 110 inside.Four branch port of described first order optical splitter 131 are connected with branch optical fiber 137 respectively, and the other end of each branch optical fiber is connected to the public port of one of them second level optical splitter 132-1~132-4 respectively by a partial wave assembly 139.Each described partial wave assembly 139 comprises four ports light rings 101 and fiber grating 102, the fiber grating 102 of described different partial wave assemblies 139 has different reflectance spectrums, described four ports light rings 101 comprise first port, second port, the 3rd port and the 4th port (among the figure not label), first port of described four ports light rings 101 and the 3rd port connect described branch optical fiber 137 respectively, and second port of described four port ring of light devices 101 connects described fiber grating 102.
In the present embodiment, it is the optical branching device of 1:8,1:16,1:32 or 1:64 that described second level optical splitter 132-1~132-4 can adopt branching ratio, and namely it has a public port and a plurality of branch port.The branch port of each second level optical splitter 132-1~132-4 is connected to wherein one group of optical network unit by profile fiber 138 respectively, and wherein each profile fiber connects the described second level one of them branch port of optical splitter 132-1~132-4 and its corresponding optical network unit 120-1~120-n.
On the other hand, described upgoing wave division multiplexer 133 also comprises public port and four branch port, wherein, the public port of described upgoing wave division multiplexer 133 is connected to described trunk coupler 135, and each branch port of described upgoing wave division multiplexer 133 is connected to the 4th port (among the figure not label) of the described four-port photocirculator 101 of its correspondence respectively by optical fiber, and is coupled to its corresponding branch optical fiber 137 by described four-port photocirculator 101.In specific embodiment, channel center's wavelength of described four branch port can be respectively the described first up wavelength X u1, the described second up wavelength X u2, the described the 3rd up wavelength X u3 and the described the 4th up wavelength X u4.
In the present embodiment, four branch port of described first order optical splitter 131 can be distinguished the corresponding first partial wave assembly, the second partial wave assembly, the 3rd partial wave assembly and the 4th partial wave assembly, the fiber grating of the wherein said first partial wave assembly, the fiber grating of the described second partial wave assembly, the fiber grating of the fiber grating of described the 3rd partial wave assembly and described the 4th partial wave assembly has different reflectance spectrums respectively, particularly, the fiber grating reflection wavelength of the described first partial wave assembly can be the described first downstream wavelength λ d1, the fiber grating reflection wavelength of the described second partial wave assembly can be the described second downstream wavelength λ d2, the fiber grating reflection wavelength of described the 3rd partial wave assembly can be described the 3rd downstream wavelength λ d3, and the fiber grating reflection wavelength of described the 4th partial wave assembly can be described the 4th downstream wavelength λ d4.Based on above-mentioned fiber grating, the downlink data that described partial wave assembly 139 just can be realized the different wave length that carries in will the multi-wavelength downstream signal from described optical line terminal 110 is further exported to not on the same group optical network unit by described second level optical splitter 132-1~132-4 again by different branch optical fiber 137 respectively.
Particularly, at down direction, the multi-wavelength downstream signal of described optical line terminal 110 outputs is through after described trunk optical fiber 136 transmission, be coupled to described first order optical splitter 131 by described trunk coupler 135,131 pairs of described multi-wavelength downstream signals of described first order optical splitter carry out the power light splitting and form after a plurality of multi-wavelength downstream signals, export to described a plurality of branch optical fiber 137 by its branch port respectively.Because each branch optical fiber 137 connects different partial wave assemblies 139, described multi-wavelength downstream signal is via first port input of four ports light rings 101, second port by four ports light rings 101 outputs to fiber grating 102 again, fiber grating 102 reflects the wavelength downstream signal that satisfies its Bragg condition, again via second port input of four ports light rings 101, exported by the 3rd port of four ports light rings 101 at last.The fiber grating 102 of different partial wave assemblies 139 has different reflectance spectrums.Therefore, when described multi-wavelength downstream signal passes four ports light rings 101 of described partial wave assembly 139, have only the light signal of one of them wavelength to pass through, the light signal of other wavelength is then by fiber grating 102 filterings.
Such as, the light signal of the 3rd port output of four ports light rings 101 of the described first partial wave assembly is the downlink data with described first downstream wavelength λ d1, i.e. the downlink data of described optical transmitting set Tx1 emission; The light signal of the 3rd port output of four ports light rings 101 of the described second partial wave assembly is the downlink data with described second downstream wavelength λ d2, i.e. the downlink data of described optical transmitting set Tx2 emission; The light signal of the 3rd port output of four ports light rings 101 of described the 3rd partial wave assembly is the downlink data with described the 3rd downstream wavelength λ d3, i.e. the downlink data of described optical transmitting set Tx3 emission; The light signal of the 3rd port output of four ports light rings 101 of described the 4th partial wave assembly is the downlink data with described the 4th downstream wavelength λ d4, i.e. the downlink data of described optical transmitting set Tx4 emission.
Therefore, the light signal that is transferred to described second level optical splitter 132-1~132-4 by each branch optical fiber 137 is respectively the downlink data of the emission of described optical transmitting set Tx1~Tx4, described downlink data carries out after the power light splitting through described second level optical splitter 132-1~132-4, further is transferred to the optical network unit of corresponding group by described profile fiber 138.
And aspect up, the time slot transmission upstream data that the light network unit of each group adopts its up wavelength X u1~λ u4 respectively and authorizes at described optical line terminal 110, because each group optical network unit adopts different up wavelength respectively, therefore same time slot can have the optical network unit of the different up wavelength of a plurality of employings to send upstream data simultaneously.After the upstream data of the different wave length that described not on the same group optical network unit sends converges by its corresponding second level optical splitter 132-1~132-4 respectively, via the 3rd port input of four ports light rings 101 of different partial wave assemblies 139, made it to be coupled to the different branch port of described upgoing wave division multiplexer 133 again by the 4th port output of four ports light rings 101.Described up wavelength multiplexer 133 is further carried out wavelength division multiplexing to the upstream data of described different wave length and is formed after the multi-wavelength upward signal, be coupled to described trunk optical fiber 136 by described trunk coupler 135, and be transferred to described optical line terminal 110 by described trunk optical fiber 136.
Multi-wavelength passive optical network system 100 provided by the invention is because described optical network unit 120-1~120-n is divided into many groups and each group adopts different operation wavelengths respectively, therefore, for certain optical network unit, which up-downgoing wavelength it does not also know oneself need be operated in.For realizing load balancing and avoid occurring the wavelength conflict that described optical line terminal 110 needs to specify to optical network unit assigned work wavelength, is about to the wavelength indication information and passes to described optical network unit.
In described multi-wavelength passive optical network system 100, though optical network unit does not adopt the mode of wavelength division multiplexing to carry out work on the same group, but can communicate according to the XGPON agreement between described optical line terminal 110 and each group optical network unit, concrete protocol contents can be with reference to ITU-T series standard G.987.
In one embodiment, described optical line terminal 110 can be carried on described wavelength information descending XGTC (XG-PON Transmission Convergence, the XGPON Transmission Convergence) frame, and by described descending XGTC frame described wavelength indication information is offered described optical network unit.See also Fig. 2, the frame structure schematic diagram of a kind of embodiment of the descending XGTC frame that it can adopt for multi-wavelength passive optical network system 100 provided by the invention.Described descending XGTC frame can comprise XGTC frame head and XGTC payload.Described XGTC frame head can comprise HLend territory, bandwidth map (Bandwidth map, BWmap) territory and down physical layer operation management maintain (Physical Layer Operations, Administration and Maintenance downstream, PLOAMd) territory.Wherein, wherein, described Hlend territory can define wavelength indication territory.Particularly, described Hlend territory can comprise wavelength indication field, bandwidth map length (BWmap Length) field, PLOAM counting (PLOAM count) field and hybrid error correction (Hybrid Error Correction, HEC) field.Described wavelength indication field is used for carrying described wavelength indication information, and in specific embodiment, described wavelength indication information can be numbered for wavelength.
Multi-wavelength passive optical network system 100 provided by the invention is divided into many groups with described optical network unit 120-1~120-n, and the branch port at described first order optical splitter 131 adopts described different partial wave assembly 139 to realize the downstream wavelength separation, adopt described upgoing wave division multiplexer 133 to realize up wavelength multiplexing, thereby realize adopting respectively many up-downgoing data of the up-downgoing wavelength being carried not optical network unit on the same group respectively, thus, section just can utilize different wave length to transmit the data of a plurality of optical network units simultaneously at one time, thereby effectively the overall bandwidth of elevator system satisfies user's broadband services to the increased requirement of bandwidth.
The above only is embodiments of the invention; be not so limit claim of the present invention; every equivalent structure or equivalent flow process conversion that utilizes description of the present invention to do; or directly or indirectly be used in other relevant technical field, all in like manner be included in the scope of patent protection of the present invention.