CN101217334A

CN101217334A - A method and the corresponding device of low bit rate service signal in optical transport network transmission

Info

Publication number: CN101217334A
Application number: CN 200710153074
Authority: CN
Inventors: 邹世敏
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2004-08-11
Filing date: 2004-08-11
Publication date: 2008-07-09

Abstract

The invention relates to the optical communication techniques and discloses a method and a device for transmitting low-speed business signals in an optical transmission network, which leads the low-speed business signal to be mapped onto the optical transmission network with high bandwidth utilization rate, can provide a flexible scheduling mechanism and an end-to-end performance management mechanism in a level of the low-speed business signal. The method and the device for transmitting the low-speed business signal in the optical transmission network adopt a GFP mapping method for mapping the low-speed business signal (GE/FC) to an ODUGE signal which is suitable for OTN transmission; the method and the device adopt an asynchronous or synchronous multiplexing method for multiplexing the ODUGE signal in multiple ways to one-way ODUk signal; the method and the device use the mapping from ODUGE to ODUk and an ODUGE cross network for implementing the on-line and off-line business in the level of the low-speed business signal .

Description

The method and the device thereof of transmission low rate traffic signal in the optical transfer network

Technical field

The present invention relates to optical communication technique, particularly the technology of transmission low rate traffic signal in the optical transfer network.

Background technology

Development along with information technology, various new business are promptly entering people's life, particularly based on Internet protocol (Internet Protocol, the fast development of professional explosion type abbreviation " IP "), not only make people's life that great changes have taken place, simultaneously, brought deep effect also for the various aspects of telecommunications network.Current whole world IP user's number will reach more than 300,000,000, all these, to make data business volume, particularly IP operation progressively replace the main business amount that the voice service amount becomes telecommunications network, this will cause telecommunications network to be carried out the transition to inevitably with the data service by the traditional electrical phone network is the telecommunications network at center.This development trend requires following transmission net must can support data service to transmit, and in addition, transmitting that net is necessary can dynamic bandwidth allocation, to guarantee to transmit different business; Also must carry out Route Selection effectively, and detect network or link failure and performance degradation exactly, promptly recover; Make the logical topology of service network irrelevant with transmission net physical topology.

PDH (Pseudo-synchronous Digital Hierarchy) (Pseudo-synchronous Digital Hierarchy is called for short " PDH ") is a kind of digital multiplexing technology the earliest.It has experienced the technological innovation in 20 years, in optical fiber access field, is still playing the part of important role at present.But because its multiplex mode that interleaves by bit, can easily be professional up and down, at each node, must separate one-level to the end to the PDH signal and just can obtain the client signal that needs.Can only organize simple point-to-point networking, and surveillance coverage is also relative with managerial ability relatively poor.And surveillance coverage is the basis of network survivability and managerial ability, does not have accurate performance supervision ability, also just can not realize the ability of perfect network survivability.

Existing synchronous digital hierarchy (Synchronous Digital Hierarchy, be called for short " SDH ") transmit to net and adopt time division multiplexing (Time Division Multiplexing, be called for short " TDM ") technology, based on circuit, for providing the TDM of fixed-bandwidth, audio frequency and data transmit passage, data service is the serious asymmetry of IP operation particularly, and the sudden and unpredictability of traffic carrying capacity development makes SDH transmit net and produces serious poor efficiency.The SDH architectural limitation networks development and high speed business ability.Big, ring protection of expense and the too high shortcoming of network recovery cost have also greatly limited the development that SDH transmits net in the SDH signal frame structure.Same, Synchronous Optical Network (SynchronousOptical NETworks/SDH based on SDH, be called for short " SONET/SDH ") as a kind of optical transfer network technology, have better surveillance coverage, managerial ability than PDH, network survivability, and higher transmission capacity, can be arbitrarily service signal up and down.But because it is main towards speech business, for the not high needs that are not suitable for following data service dramatic growth of efficient of data services.

In recent years owing to optical element technology such as other semiconductor lasers, image intensifer, optical filter reach its maturity, make dense wave division multipurpose (Dense Wavelength Division Multiplexing, abbreviation " DWDM ") technology is flourish, DWDM also improves existing fiber and lacks phenomenon except the problem of avoiding high speed TDM transmission and bringing, and provide the wideband service of big capacity, variation, can make the networking operator under cost-effectively, transmitting bandwidth is promoted to 16,32,64 even 128 times.But DWDM has tangible deficiency on the managerial ability of networking capability and bandwidth, and for example, DWDM can only realize the networking and the ring network of point-to-point, can not networking shape (MESH) network; DWDM is at the performance supervision ability that lacks optical channel.The present performance monitoring of DWDM need be by the surveillance coverage of client signal, such as realizing by B1/B2 or the J0 byte that monitors the SDH client signal, and for gigabit Ethernet (Gigabyte Ethernet is called for short " GE ") or other non-SDH signals, just can't monitor.

In fact, for data network itself, nearly all data protocol is only paid attention to active data and is transmitted problem, and do not consider operation, management, maintenance and service (Operation, Administration, the Maintenance of network, and Provision, be called for short " OAM﹠amp; P ") problem.In order to adapt to the development of following data service, a kind of new transmission system of needs satisfies the transmission demand to the data business, and this demand has been filled up in the birth of optical transfer network (Optical Transport Networks is called for short " OTN ").The construction of dwdm system also develops to OTN from original Point-to-Point system.The construction of OTN is for providing the exchange on protection fast, restore funcitons and the realization light path to establish solid foundation on the photosphere.

At the inundant development trend of OTN, (the InternationalTelecommunications Union-Telecommunications Standardization section of international telecommunication union telecommunication standardization, be called for short " ITU-T ") worked up OTN series suggestion ITU-T G.709, G.798, G.87X, the OTN product of industry is entering commercialization.Wherein be significant with the G.709 suggestion of releasing February calendar year 2001 especially, it has pointed out the technical foundation of light networking.G.709 Jian Yi core content is exactly digital wrapper technology (Digital Wrapper).It has defined a kind of special frame format, and client signal is encapsulated the Payload Unit of incoming frame, is provided for OAM﹠amp at head; The overhead byte of P (Overhead, be called for short " OH "), and provide forward error correction (Forward Error Correction is called for short " FEC ") byte at postamble.

Digital wrapper technology accepted standard frame format as shown in Figure 1.As can be seen, digital wrapper employing standard frame is 4 row, 4080 row frame formats.Head 16 is classified overhead byte as, and afterbody 255 is classified the FEC check byte as, and middle 3808 classify payload as.The head overhead byte, the 1st row 1-7 classifies frame alignment byte (Frame Alignment Signal as, be called for short " FAS "), the 8-14 byte is k kind Optical Channel Transport Unit-k (Optical Channel Transport Unit, be called for short " OTUk ") overhead byte, here the transfer mode of the different corresponding different rates of the value of k, the capable 1-14 of 2-4 classifies Optical Channel Data Unit-k (Optical Channel Data Unit as, be called for short " ODUk ") overhead byte, the 15th, 16 classify optical channel Payload Unit (Optical Channel Payload Unit is called for short " OPUk ") overhead byte as.

The OTUk overhead byte provides and has reset among the OTN greatly, recombinated, (Reamplification when resetting, Reshaping, and Retiming, abbreviation " 3R ") monitoring function of transmission signals state between the regeneration node, the section of comprising monitoring (Section Monitoring is called for short " SM ") overhead byte, GCC0 terminal room communication channel overhead byte and three parts of RES reserve bytes.

The ODUk expense provides cascade that monitoring, channel monitoring and provide client signal adaptive by OPUk end to end are provided.ODUk provides the overhead byte that enriches (the capable 1-14 row of 2-4) to finish above-mentioned functions.Comprise channel monitoring (Path Monitoring; " PM ") expense; series-connection monitoring (TandemConnection Monitoring; be called for short " TCM ") expense; General Purpose Communication Channel (GeneralCommunication Channel; be called for short " GCC ") byte GCC1 and GCC2 expense; automatic protection switching and protection control channel (Auto-Protection Switching; Protection ControlChannel; be called for short " APS/PCC ") overhead byte; fault type and fault location (Fault Type FaultLocation; be called for short " FTFL ") information; the overhead byte (Experiment is called for short " EXP ") that uses for experiment etc.

OPUk is made up of payload and its associated overhead that client signal shines upon into.Its overhead byte comprises payload structural identification (Payload Structure Identifier, abbreviation " PSI "), client signal type indication (Payload Type, abbreviation " PT "), reserve bytes (Reserved is called for short " RES ") and mapping associated overhead (Mapping Specific Overhead) etc.

Be mapped into OTN for client signal at present following three kinds of modes are arranged.

(1) constant bit rate (Constant Bit Rate, abbreviation " CBR ") CBR2G5, CBR10G, CBR40G signal map are gone into the bit rates signals of deciding of OPUk:CBR2G5-2488320kbit/s ± 20ppm, as STM-16, CBR10G-9953280kbit/s ± 20ppm decides bit rates signals, as STM-64, CBR40G-39813120kbit/s ± 20ppm decides bit rates signals, as STM-256.Mapping can be adopted dual mode, asynchronous system and bit synchronous mode.Asynchronous system adopts the local clock that has nothing to do with client signal, is just using/negative/zero sign indicating number adjustment strategy.The clock that extracts from client signal is adopted in the bit synchronous mapping.

(2) Asynchronous Transfer Mode (Asynchronous Transfer Mode, be called for short " ATM ") signal map goes into OPUk: can be mapped among the OPUk by the fixed bit stream that ATM cell is multiplexed into OPUk payload size coupling, in multiplexing by inserting idle cell or losing cell and adjust speed.The information of ATM cell is wanted scrambler before mapping.

(3) Generic Framing Procedure (General Framing Procedure, being called for short " GFP ") the frame signal mapping that is mapped into the OPUk:GFP frame reaches the successive bits stream that is complementary with OPUk by insert idle frame in the packing stage, also carries out scrambler in this process.Also have other some signals can shine upon among the OPUk, as client signal, test signal, common client's Bitstream signal etc.

In the suggestion of present OTN, all be the mode that data cell is fitted to OPUK to be realized for the solution of data service by GFP, connect (FiberConncction is called for short " FC ") business such as the GE business or the optical fiber of low rate.Because the scheduling particle minimum of OTN is 2.5G rank (being respectively for different k value speed: k=1 corresponding speed, the corresponding 10G of k=2, the corresponding 40G of k=3), if the GE business is fitted to OPU1, utilizes the scheduling of ODU1 again, it is not high to do bandwidth availability ratio like this.Adaptive and Virtual Concatenation is multiplexed into the 2.5G signal and arrive OTN again if two GE are by GFP, and the scheduling feature of the ODUk of OTN does not just act on the GE signal so.Existing many low rate traffic signals, can be in backbone network and metropolitan area network long-term existence as GE and FC signal as a kind of client signal, backbone network particularly, realize other professional transparent transmission of GE level, managerial ability end to end is in the professional up and down flexibly ability of the intermediate node demand that is absolutely necessary.

In actual applications, there is following problem in such scheme: for the OTN mapping by GFP and SDH Virtual Concatenation, the circuit complexity, the cost costliness, can not realize based on other performance monitoring end to end of single low rate traffic signal level, can not be directly professional up and down at intermediate node, the service dispatching inconvenience; Directly shine upon for the OTN by GFP, bandwidth availability ratio is low, and the scheduling particle is too big, and reliability reduces.

Cause the main cause of this situation to be, if GE or FC service signal are fitted to the Virtual Concatenation of SDH by GFP, being multiplexed to the STM-16 signal transmits by the OTN network again, then increased the processing of SDH layer, make the Business Processing of intermediate node need pass through the conversion of SDH form, and service dispatching must be realized based on the scheduling of Virtual Concatenation; If GE or FC service signal directly are fitted to OPUk by GFP,, be used to carry the waste that low rate traffic signal about 1G can cause bandwidth, and the scheduling smallest particles also will be restricted to the 2.5G rank then because the minimum-rate rank 2.5G of OPUk is too big.

Summary of the invention

In view of this, main purpose of the present invention is to provide the method and the device thereof of transmission low rate traffic signal in a kind of optical transfer network, make the low rate traffic signal to be mapped on the optical transfer network with high bandwidth utilization, and can provide the low rate traffic signal level other flexible dispatching mechanism, can provide the low rate traffic signal level other end to end performance administrative mechanism.

For achieving the above object, the invention provides the method for transmission low rate traffic signal in a kind of optical transfer network, described low rate is to be lower than 2.5G bps speed, comprises following steps,

A with described low rate traffic signal map to low rate traffic flashlight passage Payload Unit, fill in the low rate traffic flashlight data cell overhead area that is used to realize low rate traffic management end to end, be combined into low rate traffic flashlight data cell by this optical channel Payload Unit and light data cell overhead area;

B is multiplexed into optical payload unit signals at different levels with described low rate traffic flashlight data unit signal, and regeneration light data cell and optical transport unit signal transmit on described optical transfer network.

Wherein, in the described steps A, by Generic Framing Procedure with described low rate traffic signal map to low rate traffic flashlight passage Payload Unit.

Described low rate traffic flashlight data unit frame comprises frame alignment signal, optical transport unit overhead area, described low rate traffic flashlight data cell overhead area, optical channel Payload Unit overhead area and described low rate traffic flashlight passage Payload Unit,

Wherein said frame alignment signal is positioned at the 1-7 row of first row, and described frame alignment signal also comprises multiframe alignment signal, and this multiframe alignment signal is positioned at first row the 8th row;

Described optical transport unit overhead area is positioned at the 8-14 row of first row, is used to carry out the optical transport unit management;

Described low rate traffic flashlight data cell overhead area is positioned at the second 1-14 row to four lines, is used to carry out the light data unit management;

Described low rate traffic flashlight passage Payload Unit overhead area is positioned at first the 15th, 16 row to four lines, comprises the indication of payload structure, is positioned at fourth line the 15th row, is used to indicate payload structure and type;

Described low rate traffic flashlight passage Payload Unit is positioned at the first 17-3824 row to four lines.

The size of described low rate traffic flashlight data cell is 4 * 3824 bytes, and bit rate is 1244160Kbps ± 20ppm; The size of described low rate traffic flashlight passage Payload Unit is 4 * 3808 bytes, and bit rate is 1238954.31Kbps ± 20ppm; The low rate traffic signal is fitted to described low rate traffic flashlight passage Payload Unit through described Generic Framing Procedure.

Described low rate traffic signal comprises any one in gigabit Ethernet service signal, optical fiber connection service signal, high definition digital television service signal, the Fast Ethernet service signal.

The size of the low rate traffic flashlight data cell of described transmission Fast Ethernet signal is 4 * 3824 bytes, and bit rate is 124416Kbps ± 20ppm; The size of described low rate traffic flashlight passage Payload Unit is 4 * 3808 bytes, and bit rate is 123895.431Kbps ± 20ppm; The low rate traffic signal is fitted to described low rate traffic flashlight passage Payload Unit through described Generic Framing Procedure.

Described steps A also further comprises following substep,

By decoding, transfer described low rate traffic signal to traffic spike;

By the Generic Framing Procedure encapsulation format described traffic spike is encapsulated as the Generic Framing Procedure signal;

By inserting the mode of idle frame, the total speed that makes described Generic Framing Procedure signal and described idle frame is the speed of described low rate traffic flashlight passage Payload Unit, and forms described low rate traffic flashlight passage Payload Unit;

Be provided with and adding low rate traffic flashlight passage Payload Unit overhead area, wherein said payload structure indication is used to indicate this frame payload type to be corresponding described low rate traffic signal type;

According to described other end-to-end management of low rate traffic signal level, be provided with and adding low rate traffic flashlight data cell overhead area, obtain low rate traffic flashlight data unit signal.

Described traffic spike can be that speed is 1G bps rank or 100M bps other signal of level.

Described decoding can be the decoding of 8B/10B mode or 4B/5B mode.

Among the described step B, described multiple connection comprises asynchronous multiplexing and synchronous multiplexing dual mode.

Described asynchronous multiplexing comprises following steps,

By described low rate traffic flashlight data cell mapping flow process, the described low rate traffic signal map of multichannel is obtained multi-path low speed rate service signal light data unit signal;

According to adjusting the overhead area distribution method, add low rate traffic signal Optical Channel Transport Unit-k adjustment overhead area for respectively described low rate traffic flashlight data unit signal, form the described low rate traffic flashlight of multichannel channel transfer cell signal;

Optical channel Payload Unit at different levels are divided into same number of many passages by time slot, described low rate traffic flashlight channel transfer cell signal is put into corresponding passage;

With the different low rate traffic flashlight data unit signal of value indication that the described multiframe alignment of different frame is indicated, the described low rate traffic signal Optical Channel Transport Unit-k of this low rate traffic flashlight data cell correspondence is adjusted the adjustment expense position that overhead area is put into optical channel Payload Unit at different levels described in the corresponding frame;

Described payload structure is set, and to indicate described optical channel Payload Unit at different levels be the described low rate traffic flashlight of multichannel channel transfer cell signal;

Optical channel Payload Unit overhead area at different levels, Optical Channel Data Unit-k overhead area at different levels are set, described optical channel Payload Unit at different levels are fitted to described Optical Channel Data Unit-k at different levels, add Optical Channel Transport Unit-k overhead area and described frame alignment signal formation Optical Channel Transport Unit-k and on described optical transfer network, transmit.

Described asynchronous multiplexing flow process can with 2 tunnel described low rate traffic flashlight channel data cell signal multiplexing be on other described Optical Channel Data Unit-k of 2.5G level in one tunnel speed;

Described asynchronous multiplexing flow process can with 8 tunnel described low rate traffic flashlight channel data cell signal multiplexing be on other described Optical Channel Data Unit-k of 10G level in one tunnel speed;

Described asynchronous multiplexing flow process can with 32 tunnel described low rate traffic flashlight channel data cell signal multiplexing be on other described Optical Channel Data Unit-k of 40G level in one tunnel speed.

Described asynchronous multiplexing flow process can with 20 tunnel described low rate traffic flashlight channel data cell signal multiplexing be on other described Optical Channel Data Unit-k of 2.5G level in one tunnel speed.

The present invention also provides the device of transmission low rate traffic signal in a kind of optical transfer network, described low rate is to be lower than 2.5G bps speed, comprise, a plurality of Generic Framing Procedure mapping blocks and a plurality of low rate traffic flashlight channel data unit maps module, and Optical Channel Data Unit-k terminal module

Described Generic Framing Procedure mapping block is used for that the traffic spike of importing is carried out the Generic Framing Procedure encapsulation and obtains the Generic Framing Procedure signal, the described Generic Framing Procedure signal from described low rate traffic flashlight channel data unit maps module is carried out the Generic Framing Procedure decapsulation obtain described low speed data signal;

Described low rate traffic flashlight channel data unit maps module is used for that the described Generic Framing Procedure signal from described Generic Framing Procedure mapping block is carried out low rate traffic flashlight channel data unit maps and obtains low rate traffic flashlight channel data cell signal, separates mapping and obtains described Generic Framing Procedure signal carry out low rate traffic signal Optical Channel Data Unit-k from the described low rate traffic flashlight channel data cell signal of described Optical Channel Data Unit-k terminal module;

Described Optical Channel Data Unit-k terminal module is to carrying out multiplexing one tunnel Optical Channel Data Unit-k signals at different levels that obtain from the described low rate traffic flashlight of the multichannel channel data cell signal of all described low rate traffic flashlight channel data unit maps modules, the Optical Channel Data Unit-k signals at different levels that maybe will import carry out demultiplexing and obtain the described low rate traffic flashlight of multichannel channel data cell signal, send corresponding described low rate traffic flashlight channel data unit maps module to.

Wherein, described system also comprises and a plurality of one to one low rate traffic Signal interface modules of multi-path low speed rate service signal,

This low rate traffic Signal interface module is used for the corresponding low rate traffic signal of input is decoded and obtained traffic spike, is that other signal of 1G level is encoded and obtained described low rate traffic signal to the described speed from described Generic Framing Procedure mapping block.

Described Code And Decode can be the Code And Decode of 8B/10B mode or 4B/5B mode.

Described system also comprises the Optical Channel Transport Unit-k line module, be used for and carry out the circuit relevant treatment from the Optical Channel Data Unit-k signals described at different levels of described Optical Channel Data Unit-k terminal module, the output light signal transmits on described optical transfer network, or the light signal on the described optical transfer network is carried out the circuit relevant treatment obtains described Optical Channel Data Unit-k signal at different levels.

When described device is applied to the transmission of described end to end low rate traffic signal, the described low rate traffic signal of multichannel is imported described device, processing obtains light signal, on the dense wave division multipurpose link, be transferred to the opposite end, handle recovering the described low rate traffic signal of described multichannel by the described device of opposite end.

The present invention also provides the device of transmission low rate traffic signal in a kind of optical transfer network, be applied to the network node in netted or the ring network, described low rate is to be lower than 2.5G bps speed, described device comprises, divide/close ripple unit, Optical Channel Transport Unit-k line unit, Optical Channel Data Unit-k scheduling unit and low rate traffic signal map unit, wherein

Described branch/close the ripple unit is used for receiving optical signals on described optical transfer network, carries out the photosphere signal processing, obtains the Optical Channel Transport Unit-k signal;

Described Optical Channel Transport Unit-k line unit is used for that the described Optical Channel Transport Unit-k signal from described branch/close ripple unit and low rate traffic signal map unit is carried out the circuit relevant treatment and obtains described Optical Channel Data Unit-k signal;

Described Optical Channel Data Unit-k scheduling unit is used for the described Optical Channel Data Unit-k signal from a plurality of described Optical Channel Transport Unit-k line units is carried out other cross scheduling of Optical Channel Data Unit-k level;

Described low rate traffic signal map unit is used for that the described Optical Channel Data Unit-k signal from described Optical Channel Data Unit-k scheduling unit is carried out decapsulation and conciliates mapping, is converted to the low rate traffic signal and outputs to local data network.

Wherein, described low rate traffic signal map unit also is used for the low rate traffic signal from described local data network is shone upon and encapsulates, convert low rate traffic flashlight channel data cell signal to, send to described Optical Channel Data Unit-k scheduling unit;

The Optical Channel Transport Unit-k line unit is used for that also the described Optical Channel Data Unit-k signal from described Optical Channel Data Unit-k scheduling unit is carried out the circuit relevant treatment and obtains described Optical Channel Transport Unit-k signal;

Described branch/close ripple unit is used for that also the described Optical Channel Transport Unit-k signal from described Optical Channel Transport Unit-k line unit is carried out the photosphere signal processing and obtains described light signal and transmit on described optical transfer network.

Described device also comprises low rate traffic flashlight channel data cell scheduling unit and the low rate traffic signal Optical Channel Data Unit-k adaptation unit to Optical Channel Data Unit-k;

Described low rate traffic flashlight channel data cell scheduling unit is used for being fitted to described Optical Channel Data Unit-k scheduling unit by described low rate traffic signal Optical Channel Data Unit-k to the adaptation unit of Optical Channel Data Unit-k, and a plurality of described low rate traffic flashlight channel data cell signal are carried out other cross scheduling of low rate traffic signal level;

Described low rate traffic signal Optical Channel Data Unit-k is used to realize asynchronous multiplexing and the demultiplexing between the described Optical Channel Data Unit-k signal of the described low rate traffic flashlight channel data cell signal of described low rate traffic flashlight channel data cell scheduling cell side and described Optical Channel Data Unit-k scheduling unit side to the adaptation unit of Optical Channel Data Unit-k;

Described Optical Channel Data Unit-k scheduling unit also is used for carrying out other cross scheduling of Optical Channel Data Unit-k level from described low rate traffic signal Optical Channel Data Unit-k to the Optical Channel Data Unit-k signal of the adaptation unit of Optical Channel Data Unit-k.

Described encapsulation and decapsulation can be used Generic Framing Procedure.

By finding that relatively technical scheme difference with the prior art of the present invention is, adopts the GFP mapping method that low rate traffic signal (GE/FC) is mapped to and is fit to the ODUGE signal that OTN transmits; Adopt asynchronous or the synchronous multiplexing method with multichannel ODUGE signal multiplexing to one road ODUk signal; About realizing other business of low rate traffic signal level by ODUGE to the mapping of ODUk, ODUGE crossover network.

Difference on this technical scheme has brought comparatively significantly beneficial effect, promptly sets by the administration overhead of ODUGE frame format, realizes other data service end to end performance management of GE/FC level; By the asynchronous multiplexing of multichannel GE/FC to ODUk, realize GE/FC transparent multiplexing device, realize the transparent transmission of GE/FC at OTN, improved bandwidth availability ratio simultaneously greatly; By ODUGE low order interlace algorithm network on the OTN equipment, realize about the flexible dispatching and business of GE rank data service.

Description of drawings

Fig. 1 is the standard frame format schematic diagram of digital wrapper technology;

Fig. 2 is an ODUGE frame format schematic diagram according to an embodiment of the invention;

Fig. 3 is the mapping method flow chart of low rate traffic signal according to an embodiment of the invention (GE/FC) to ODUGE;

Fig. 4 is the asynchronous multiplexing process schematic diagram of ODU2GE according to an embodiment of the invention to OPUI/ODU1;

The positive justification byte was arranged schematic diagram when Fig. 5 was an asynchronous multiplexing according to an embodiment of the invention;

Fig. 6 is the asynchronous multiplexing method flow diagram of ODUnGE according to an embodiment of the invention to OPUk/ODUk;

Fig. 7 is the multiple connection subsystem assembly structural representation of ODUnGE according to an embodiment of the invention to OPUk/ODUk;

Fig. 8 is that the device that transmits the low rate traffic signal in OTN according to an embodiment of the invention is formed structural representation;

Fig. 9 is the application schematic diagram of devices and methods therefor in diverse network that transmits the low rate traffic signal in OTN according to an embodiment of the invention.

Embodiment

For making the purpose, technical solutions and advantages of the present invention clearer, the present invention is described in further detail below in conjunction with accompanying drawing.

The present invention provides a kind of mapping method at low rate traffic signal such as GE, FC, on the ODUk linkage function basis of existing OTN, increase the linkage function of a kind of other ODUGE of GE level, make GE or FC business can on the OTN network, realize scheduling flexibly, and have other end-to-end performance management ability of GE level; Simultaneously, the present invention provides the asynchronous multiplexing method of a kind of ODUGE to OPUk, makes bandwidth availability ratio be improved.The present invention comprises the ODUGE crossover network device among frame structure definition, mapping method and the equipment thereof of ODUGE, multiple services asynchronous multiplexing method and equipment thereof, the OTN.

In one embodiment of the invention, for low rate traffic signals such as GE or FC, define a kind of frame format of Optical Channel Data Unit-k of low rate traffic signal or Optical Channel Data Unit-k (the Optical Channel Data Unit for Gigabyte Ethernet of GE, be called for short " ODUGE "), be used for the low speed service signal.Corresponding to ODUGE, the Payload Unit of GE is OPUGE.Fig. 2 shows ODUGE frame format according to an embodiment of the invention.Wherein, the grid of corresponding each each row of row is represented a byte of relevant position, and second row of preceding 14 row is the data management overhead area (ODUGE OH) of ODUGE to fourth line, and 15,16 classify payload administration overhead (OPUGE OH) as; 17 row later 3808 are classified payload section (OPUGE) as, are FEC at last.In a preferred embodiment of the present invention, the definition of each byte of ODUGE OH is identical with the defined ODU OH of digital wrapper technology, and making has an administration overhead end to end to other business of GE level, can realize GE business performance management end to end.With reference to the ITU-T suggestion G.709, first row of 1-7 row comprises frame alignment signal (FrameAlignment Signal, be called for short " FAS "), the 7th row first behavior multiframe alignment signal (MultiFrame Alignment Signal wherein, be called for short " MFAS "), the pairing frame number of overhead byte when MFAS is used to indicate the multiframe carrying.Wherein OPUGE OH comprises the PSI byte, and the 15 row fourth lines that are positioned at, and PT byte are respectively applied for the type of indicating the payload that carries.

In one embodiment of the invention, the size of ODUGE is 4 * 3824 bytes, and the specified bit rate is 12441 60Kbps ± 20ppm, is half of the payload area rate of OPU1 in the ITU-T suggestion G.709.The size of ODUGE payload section OPUGE is 4 * 3810 bytes; And the payload of OPUGE is 4 * 3808 bytes, and bit rate corresponds to:

(3808/3824)×(1244160±20ppm)＝(238/239)×(1244160±20ppm)＝1238954.31Kbps±20ppm

In a preferred embodiment of the present invention, GE or FC low speed business are passed through the payload section that GFP is fitted to OPUGE, so the positive negative justification byte of OPUGE can not used.GE or FC service signal are other speed of 1G level by the 8B/10B decoding back of circuit, and according to the GFP-T mapping, the GFP transmission bandwidth is:

1×(65/64)×(95×8×67+4+4+4)/(95×8×67)＝1.015864346Gbps

Consider that again GE has ± frequency deviation of 100ppm, as seen, the payload section of aforementioned ODUGE/OPUGE has enough capacity to transmit GE or FC through the adaptive speed of GFP-T, comprises information frame and idle frame; Also can transmit GE or FC through the speed of GFP-F after adaptive.And as required, can also transmit the management frames of GFP.

Need to prove that said other speed of 1G level of this paper is meant the speed about 1G, for example the speed of GE signal, FC signal, high definition digital television (High Definition Television is called for short " HDTV ") signal is all about 1G.Certainly also belong to other signal of 1G level after these signals being done some specific codings, the specific coding of saying here can be Forward Error Correction (ForwardError Correction is called for short " FEC ") coding or other standards or a self-defining coding.

Low rate as herein described also comprises other speed of FE level.The FE line speed is 125Mbps ± 100ppm, is the data of 100Mbps ± 100ppm after the 4B/5B decoding, has removed IDLE frame actual speed rate after the decoding less than 100Mbps.By defining a kind of other ODUFE of 100Mbps level, (1244.16Mbps ± 20ppm)/10=124.416Mbps ± 20ppm, the payload area rate of ODUFE is that (238/239) * (124.416Mbps ± 20ppm)=123.8954M ± 20ppm, this payload section has enough capacity to transmit FE payload and information such as the adaptive back of GFP-F payload frames, GFP idle frame and GFP management frames.

Fig. 3 shows the mapping method flow process of low rate traffic signal according to an embodiment of the invention (GE/FC/FE) to ODUGE.

In step 301,, be traffic spike at first with low rate traffic conversion of signals such as GE/FC/FE by decode procedure.Corresponding to GE and FC, traffic spike is that speed is that (corresponding to the FC signal is 1.06 * 0.8G) then to other signal of 1G level, and corresponding to FE, traffic spike is that speed is other signal of 100M level.

Then enter step 302, traffic spike is comprised that information and control information are encapsulated as the GFP signal by GFP encapsulation format (GFP-T or GFP-F).The packaged type of GFP is carried out according to the link layer standard that G.7041 the ITU-T suggestion provides, and adopts different business datum method for packing that different business datums is encapsulated, and comprises GFP-F and GFP-T dual mode.The GFP-F packaged type is applicable to grouped data, and the whole group data encapsulation in GFP information on load district, is not done any change to encapsulation of data, and determines whether adding loading zone detection territory as required.The GFP-T packaged type then is applicable to the blocks of data that adopts the 64B/65B coding, extracts single character from the data block that receives, and then it is mapped in the gfp frame of regular length.

Then enter step 303,, make that total speed of GFP signal and idle frame is the speed of OPUGE payload section, and form the payload of OPUGE by inserting the mode of idle frame.Because the speed of GFP signal rate and aforementioned OPUGE payload section is inconsistent, need fill up idle frame to adjust the speed of GFP signal.Because the OPUGE payload section is enough big, except needs are filled the GFP idle frame, can also fill the GFP management frames as required

Then enter step 304, be provided with and adding payload administration overhead OPUGE OH.Here G.709 the setting of the overhead byte of OPUGEOH follows the ITU-T suggestion, and wherein, it is GE/FC that PSI, PT are used to indicate this frame payload type.

Be provided with and adding data management expense ODUGE OH.Here G.709 the setting of the overhead byte of ODUGE OH follows the ITU-T suggestion, is used to finish the end-to-end management of GE business-level.

After the mapping of finishing from the low rate traffic signal to ODUGE, obtain the signal of ODUGE encapsulation, also need multiframe ODUGE is multiplexed on the OPUk/ODUk, the Optical Channel Transport Unit-k OTUGE of the two-way GE that formation can transmit, make and utilize transmission bandwidth to greatest extent, improve network resource utilization.

Above flow process also is fit to other service signal of FE level is shone upon, and different is that the 4B/5B that is decoded as of FE decodes; The mapping of FE only is fit to the GFP-F mapping; The speed of ODUFE is that 1/10. other processing of ODUGE are identical

In one embodiment of the invention, with 2 ODUGE (ODU2GE) asynchronous multiplexing to 1 OPU1/ODU1.Fig. 4 shows the asynchronous multiplexing process of ODU2GE according to an embodiment of the invention to OPU1/ODU1.The ODUGE that will comprise overhead byte ODUGE OH is as payload, each ODUGE adds adjustment expense (Justification Overhead, be called for short " JOH ") byte ODUGE JOH, obtain an ODUGE, an ODUGE JOH, the 2nd ODUGE and the 2nd ODUGE JOH four parts, promptly form ODU2GE.As shown in the figure, the method that the employing byte interleaves to OPU1, is adjusted the ODU2GE asynchronous multiplexing overhead byte and is then distributed by time slot according to the multi-frame multiplex mode.For MFAS is 0 frame, and being provided with and adjusting overhead byte JOH is an ODUGE JOH, is used to adjust the frequency difference of an ODUGE; For MFAS is 1 frame, and being provided with and adjusting overhead byte JOH is the 2nd ODUGE JOH, is used to adjust the frequency difference of the 2nd ODUGE.Payload section OPU1 afterwards then is divided into two passages at interval by certain-length, is respectively applied for to deposit an ODUGE and the 2nd ODUGE.

In one embodiment of the invention, ODU2GE comprises following steps to the asynchronous multiplexing process of OPU1/ODU1: at first, add for respectively two ODUGE and adjust expense ODTUGE JOH, form the ODTUGE signal; Then, the payload section of OPU1 is divided into two passages, classifies first passage as such as the odd number of payload section, carry an ODUGE, even number is classified second channel as, carries the 2nd ODUGE, and promptly each passage is the 3808/2=1904 row, and capacity is 4 * 1904 bytes; The data of the one ODTUGE are put into the first passage of OPU1, the data of the 2nd ODTUGE are put into the second channel of OPU1; It is 0 OPU1 JOH position that the one ODTUGE JOH is multiplexed into MFAS, and it is 1 OPU1 JOH position that the 2nd ODTUGEJOH is multiplexed into MFAS; Set PT, being used to indicate the payload of OPU1 is ODTUGE; At last, OPU1 adds ODU1 OH, OTU1 OH and FAS byte, obtains OTU1, finishes the adaptation procedure of two ODUGE to ODU1.

Positive justification byte arrangement when Fig. 5 shows asynchronous multiplexing according to an embodiment of the invention, during multiple connection from ODU2GE to OPU1/ODU1, with positive justification byte (Positive Justification, being called for short " PJ ") PJ1 and PJ2 be arranged in first row that MFAS is an OPU1 payload section in 0 the frame and the secondary series the 4th capable, wherein PJ1 represents the positive justification byte to first passage, and PJ2 represents the adjustment byte to second channel.And each byte of adjusting expense JOH has only been used latter two bit.

In another embodiment of the present invention, with 8 ODUGE (ODU8GE) asynchronous multiplexing to OPU2/ODU2.Similar with ODU2GE, 8 ODUGE and 8 corresponding adjustment expense ODUGE JOH are multiplexed in the payload and adjustment expense thereof of OPU2.Here the payload with OPU2 is divided into 8 passages by time slot, arranges 8 ODUGE respectively, among the OPU2 JOH when 8 ODUGE JOH then are arranged in MFAS respectively and are 0-7.In a preferred embodiment of the present invention, payload area rate (238/237) * 9953280Kbps ± 20ppm that considers OPU2 is more a lot of greatly than total speed 8 * 1244160Kbps ± 20ppm of 8 ODUGE, therefore when dividing the OPU2 time slot, per 238 bytes increase a fixing byte of filling in, just N * 238 byte is the fixing byte of filling in, and N is 1-16.

In one embodiment of the invention, ODU8GE comprises following steps to the asynchronous multiplexing process of OPU2/ODU2: at first, add for respectively 8 ODUGE and adjust expense ODTUGE JOH, form the ODTUGE signal; Then, the payload section of OPU2 is divided into 8 passages, classifies first passage as such as the 1st of payload section, the 2nd classifies second channel or the like as, and inserts a row idle bytes every 238 row; The data of 8 ODTUGE are put into 8 passages of OPU2; According to MFAS is 0-7, respectively 8 ODTUGE JOH is multiplexed into corresponding OPU2 JOH position; Set PT, being used to indicate the payload of OPU2 is ODTUGE; At last, OPU2 adds ODU2 OH, OTU2 OH and FAS byte, obtains OTU2, finishes the adaptation procedure of 8 ODUGE to ODU2.

In one embodiment of the invention, during multiple connection from ODU8GE to OPU2/ODU2, the positive justification byte PJ1-PJ8 of 8 passages is arranged in the 4th row in first to eight row that MFAS is an OPU2 payload section in 0 the frame.And each byte of adjusting expense JOH has only been used latter two bit.

In one embodiment of the invention, with the method for a plurality of ODUGE asynchronous multiplexings to OPUk/ODUk.Fig. 6 shows the asynchronous multiplexing process of ODUnGE according to an embodiment of the invention to OPUk/ODUk.

According to arriving OPU1/ODU1, ODU8GE description for ODU2GE respectively among above-mentioned two embodiment, provide the multiple connection process of general ODUnGE below to OPUk/ODUk to OPU2/ODU2 multiple connection method.Fig. 6 shows the multiple connection flow process of ODUnGE according to an embodiment of the invention to OPUk/ODUk.

At first enter step 601, each low rate traffic signal is fitted to the payload section of ODUGE by GFP, form n ODUGE, produce expense ODUGE OH simultaneously.Mapping method and expense producing method are as previously mentioned.

Then enter step 602, add for respectively each ODUGE and adjust expense ODTUGE JOH, form the ODTUnGE signal.Adjusting the setting and the arrangement of overhead byte carries out according to previous embodiment.

Then enter step 603, the payload section of OPUk is divided into n passage by time slot, the data (not comprising ODTUGE JOH) of each ODTUGE are put into corresponding passage.

Then enter step 604, the adjustment expense ODTUGE JOH of each ODTUGE is multiplexed into the adjustment expense position of OPUk in the corresponding frame according to multi-frame indication MFAS.Such as, MFAS is that each frame of 1-n corresponds to the 1-n passage successively.

Then enter step 605, payload pointer to structure joint PSI is set, and to indicate the payload of OPU1 be ODTUGE.Can adopt the reserve bytes RES among the PSI to define.

Then enter step 606, expense OPUk OH, ODUk OH are set, OPUK is fitted to ODUk.Adding OTU OH and FAS can form OTU and transmit on OTN.

Fig. 7 shows the multiple connection subsystem assembly structural representation of ODUnGE according to an embodiment of the invention to OPUk/ODUk.Corresponding multi-path low speed rate service signal, each road all has each self-corresponding by the mapping flow process of GE to ODUGE, comprise GE interface module 701, GFP mapping block 702 and ODUGE mapping block 703, each road ODUGE signal will be unified to be handled by ODUk terminal module 704, multiple connection is one road ODUk signal, is handled and is sent by OTUk line module 705 at last; Reversed in order then during reception.Wherein, ODUGE mapping block 703, ODUk terminal module 704 and OTUk line module 705 need be by unified timing generator controls.

During transmission, each road low rate traffic signal (GE/FC signal) is at first received low rate traffic signals such as GE/FC by GE interface module 701, the GE/FC signal is carried out the 8B/10B decoding, and obtaining speed is other signal of 1G level, sends GFP mapping block 702 to; The 1G level signal that GFP mapping block 702 sends the GE interface module is carried out the GFP encapsulation, and packaged type can be GFP-T or GFP-F; Be sent to ODUGE mapping block 703 through the GFP signal after the GFP encapsulation by GFP mapping block 702, by ODUGE mapping block 703 it is write the payload section of ODUGE, and realize rate adapted with the method for inserting the GFP idle frame, ODUGE mapping block 703 also will produce ODUGE OH and FAS afterwards, and set corresponding PT of this low rate traffic signal or PSI value.After this each road low rate traffic signal all obtains separate ODUGE signal through handling, but the frequency difference of satisfied ± 20ppm between each road ODUGE signal, each road ODUGE will send ODUk terminal module 704 to, each road is loaded signal asynchronous one road ODUk signal that is multiplexed into of ODUGE of low rate traffic signal by this module, described asynchronous multiplexing method flow is with reference to figure 6, comprise the generation of adjusting expense, passage division, adjust the distribution of byte and step be set etc.At last, ODUk signal from the loading multichannel GE/FC signal of ODUk terminal module 704 output, through the processing of OTUk line module 705, finish generation, scrambler, FEC coding, and the processing procedures such as string conversion and electric light conversion of OTUk expense OTUk OH, finally on OTN, transmit.

During reception, finish processing procedures such as opto-electronic conversion, frame alignment, string and conversion, descrambling, fec decoder by OTUk line module 705 earlier, recover the ODUk signal; Finished the termination of ODUk OH afterwards by ODUk terminal module 704, according to the indication of PSI or PT, demultiplexing obtains multichannel independent O DUGE signal, and the method for demultiplexing is opposite with aforementioned asynchronous multiplexing method; ODUGE signal input ODUGE mapping block 703 separately in every road is finished the frame alignment of ODUGE, separates simultaneously and maps out the GFP signal; Described GFP signal input GFP mapping block 702 carries out decapsulation and 8B/10B decoding according to the gfp frame form, recovers other low rate traffic signal of GE/FC level.

In a preferred embodiment of the present invention, in order to improve bandwidth availability ratio to greatest extent, n road other service signal of GE/FC level is multiplexed into the multiple connection subsystem of OTUk, wherein corresponding during with k=1, n=2; During k=2, n=8; During k=3, n=32.

In one embodiment of the invention, by above-mentioned GE/FC multiplexing to the mapping of ODUGE and multichannel ODUGE to one road ODUk, can realize transparent multiplexing device (the Transparent Multiplexer of GE/FC service signal, be called for short " TMUX "), make that multi-path low speed rate service signal can be in the OTN transparent transmission.

Above embodiment also is fit to other low-speed data service of FE level, for example, realizes that 20 road FE are mapped to separately ODUFE by GFP-F, again with 20 road ODUFE asynchronous multiplexings to 1 road OPU1/ODU1.

Fig. 8 shows the device that transmits the low rate traffic signal in OTN according to an embodiment of the invention and forms structure.Be used to transmit the Optical Add Drop Multiplexer (Optical Add/Drop Multiplexing is called for short " OADM ") of low rate traffic signal or the equipment form of optical cross connect (OpticalCross-Connect is called for short " OXC ") among OTN of this device formation.From the photosphere to the operation layer, be respectively DWDM branch/close ripple unit 801, OTUk line unit 802, ODUk scheduling unit 803, ODUGE be to the adaptation unit 804 of ODUk, ODUGE scheduling unit 805, low rate traffic signal map unit 806.Wherein, low rate traffic signal map unit 806 is used to connect the low rate traffic signal (GE/FC) of data network, and finish mapping is separated in the GFP encapsulation decapsulation and the ODUGE mapping of low rate traffic signal, and ODUGE expense termination function; ODUGE scheduling unit 805 is finished other cross scheduling of low rate traffic signal level, and the scheduling particle is ODUGE; ODUGE finishes asynchronous multiplexing and the demultiplexing of ODUGE to ODUk to the adaptation unit 804 of ODUk.

In OTN apparatus shown in Figure 8, corresponding with ODUnGE shown in Figure 7 to the multiple connection subsystem assembly of OPUk/ODUk, this multiple connection subsystem assembly is used to finish the multiplexing transmission that does not have the low rate traffic of network cross scheduling signal, realizes OTN transmission end to end.

For describing the course of work of this device in detail, provide transmission according to an embodiment of the invention below and receive the dynamic duty process.

At sending direction, at first carry out other data service of GE/FC level through the adaptive ODUGE that obtains of GFP by low rate traffic signal map unit 806; Then finish short grained ODUGE interconnection scheduling, realize about the business of GE/FC business-level by ODUGE scheduling unit 805; By the adaptation unit 804 of ODUGE, finish the multiple connection process to asynchronous multiplexing to high-order OPUk/ODUk simultaneously to multichannel low order ODUGE to ODUk; Afterwards, ODUk scheduling unit 803 is finished other service dispatching of ODUk level; At last finish ODUk adaptive to optical channel, and finish by wave multiplexer 801 closing of each optical channel involved amplification by OTUk line unit 802.

At receive direction, at first multiple signals are divided into a plurality of single wavelength signals by wavelength by channel-splitting filter 801; Finish opto-electronic conversion and frame synchronization and termination OTUk expense through OTUk line unit 802, and isolate the ODUk signal; The ODUk signal is finished scheduling through ODUk cross scheduling unit 803, according to the payload sign, the ODUk that loads the low order data service is dispatched to ODUGE low order interlace algorithm network; The ODUk signal resolves into multichannel ODUGE signal, and enters the ODUGE crossover network through the adaptation unit 804 of ODUk to ODUGE; Need recover the low rate traffic signal through separating mapping at this underground other service dispatching of GE/FC level to low rate traffic signal map unit 806 by 805 of ODUGE scheduling units.

In the scheduling mapping of carrying out the low rate traffic signal, the scheduling of other service signal of other grades is handled and will be carried out as usual, is directly handled by the professional map unit 807 of CBR after the ODUk crossover network is through scheduling such as the CBR service signal.

In one embodiment of the invention, the above-mentioned devices and methods therefor that transmits the low rate traffic signal in OTN is applied to multichannel GE, FC or high definition digital television (High DefinitionTelevision is called for short " the HDTV ") transmission of signal service in three kinds of structural networks.Fig. 9 shows the application of devices and methods therefor in diverse network of transmitting the low rate traffic signal in OTN according to an embodiment of the invention.Shown in Fig. 9 (a), when transmitting multichannel GE/FC/HDTV business, can directly carry out being connected of two ends with TMUX, and realize the carrying of multichannel GE/FC/HDTV business by mapping by DWDM branch/wave multiplexer for point-to-point; Shown in Fig. 9 (b), for netted or annular OTN network, each node all adopts equipment form shown in Figure 8, can realize about the business of GE/FC/HDTV business-level; Shown in Fig. 9 (c),, then only need to realize by the TMUX of GE for the transmission of independent GE/FC/HDTV business.

Those of ordinary skill in the art are appreciated that above-mentioned low rate traffic signal can be the business of any speed less than maximum OPUk transfer rate, for example Fast Ethernet (Fast Ethernet is called for short " FE ") business; Above-mentioned 10B/8B coded system can be other feasible coded systems; Above-mentioned GFP encapsulation mapping mode also can be other feasible encapsulation format; Above-mentioned relevant being provided with of occurrence can be made as other values as requested equivalently, can can be fixed position etc. arbitrarily in the passage for any one group of inequality value, positive justification byte location such as the value of MFAS, can finish goal of the invention, and not influence the spirit and scope of the invention.

Though by reference some preferred embodiment of the present invention, the present invention is illustrated and describes, but those of ordinary skill in the art should be understood that, can do various changes to it in the form and details, and the spirit and scope of the present invention that do not depart from appended claims and limited.

Claims

1. the method for transmission low rate traffic signal in the optical transfer network, described low rate is to be lower than 2.5G bps speed, it is characterized in that, comprises following steps,

2. the method for transmission low rate traffic signal is characterized in that in the optical transfer network according to claim 1, in the described steps A, by Generic Framing Procedure with described low rate traffic signal map to low rate traffic flashlight passage Payload Unit.

3. the method for transmission low rate traffic signal in the optical transfer network according to claim 1, it is characterized in that, described low rate traffic flashlight data unit frame, comprise frame alignment signal, optical transport unit overhead area, described low rate traffic flashlight data cell overhead area, optical channel Payload Unit overhead area and described low rate traffic flashlight passage Payload Unit

4. the method for transmission low rate traffic signal is characterized in that the size of described low rate traffic flashlight data cell is 4 * 3824 bytes in the optical transfer network according to claim 3, and bit rate is 1244160Kbps ± 20ppm; The size of described low rate traffic flashlight passage Payload Unit is 4 * 3808 bytes, and bit rate is 1238954.31Kbps ± 20ppm; The low rate traffic signal is fitted to described low rate traffic flashlight passage Payload Unit through described Generic Framing Procedure.

5. the method for transmission low rate traffic signal in the optical transfer network according to claim 1, it is characterized in that described low rate traffic signal comprises any one in gigabit Ethernet service signal, optical fiber connection service signal, high definition digital television service signal, the Fast Ethernet service signal.

6. the method for transmission low rate traffic signal in the optical transfer network according to claim 5, it is characterized in that, the size of the low rate traffic flashlight data cell of described transmission Fast Ethernet signal is 4 * 3824 bytes, and bit rate is 124416Kbps ± 20ppm; The size of described low rate traffic flashlight passage Payload Unit is 4 * 3808 bytes, and bit rate is 123895.431Kbps ± 20ppm; The low rate traffic signal is fitted to described low rate traffic flashlight passage Payload Unit through described Generic Framing Procedure.

7. according to the method for transmission low rate traffic signal in each described optical transfer network in the claim 1 to 6, it is characterized in that described steps A also further comprises following substep,

By decoding, transfer described low rate traffic signal to traffic spike;

8. the method for transmission low rate traffic signal is characterized in that described traffic spike can be that speed is 1G bps rank or 100M bps other signal of level in the optical transfer network according to claim 7.

9. the method for transmission low rate traffic signal is characterized in that described decoding can be the decoding of 8B/10B mode or 4B/5B mode in the optical transfer network according to claim 7.

10. the method for transmission low rate traffic signal is characterized in that among the described step B, described multiple connection comprises asynchronous multiplexing and synchronous multiplexing dual mode in the optical transfer network according to claim 1.

11. the method for transmission low rate traffic signal is characterized in that described asynchronous multiplexing comprises following steps in the optical transfer network according to claim 10,

12. the method for transmission low rate traffic signal in the optical transfer network according to claim 11, it is characterized in that, described asynchronous multiplexing flow process can with 2 tunnel described low rate traffic flashlight channel data cell signal multiplexing be on other described Optical Channel Data Unit-k of 2.5G level in one tunnel speed;

13. the method for transmission low rate traffic signal in the optical transfer network according to claim 11, it is characterized in that, described asynchronous multiplexing flow process can with 20 tunnel described low rate traffic flashlight channel data cell signal multiplexing be on other described Optical Channel Data Unit-k of 2.5G level in one tunnel speed.

14. the device of transmission low rate traffic signal in the optical transfer network, described low rate is to be lower than 2.5G bps speed, it is characterized in that, comprise, a plurality of Generic Framing Procedure mapping blocks and a plurality of low rate traffic flashlight channel data unit maps module, and Optical Channel Data Unit-k terminal module

15. the device of transmission low rate traffic signal is characterized in that described system also comprises and a plurality of one to one low rate traffic Signal interface modules of multi-path low speed rate service signal in the optical transfer network according to claim 14,

16. the device of transmission low rate traffic signal is characterized in that described traffic spike can be that speed is 1G bps rank or 100M bps other signal of level in the optical transfer network according to claim 15.

17. the device of transmission low rate traffic signal is characterized in that described Code And Decode can be the Code And Decode of 8B/10B mode or 4B/5B mode in the optical transfer network according to claim 16.

18. the device of transmission low rate traffic signal in the optical transfer network according to claim 15, it is characterized in that, described system also comprises the Optical Channel Transport Unit-k line module, be used for and carry out the circuit relevant treatment from the Optical Channel Data Unit-k signals described at different levels of described Optical Channel Data Unit-k terminal module, the output light signal transmits on described optical transfer network, or the light signal on the described optical transfer network is carried out the circuit relevant treatment obtains described Optical Channel Data Unit-k signal at different levels.

19. the device of transmission low rate traffic signal in the optical transfer network according to claim 18, it is characterized in that, when described device is applied to the transmission of described end to end low rate traffic signal, the described low rate traffic signal of multichannel is imported described device, processing obtains light signal, on the dense wave division multipurpose link, be transferred to the opposite end, handle recovering the described low rate traffic signal of described multichannel by the described device of opposite end.

20. the device of transmission low rate traffic signal in the optical transfer network, be applied to the network node in netted or the ring network, described low rate is to be lower than 2.5G bps speed, it is characterized in that, described device comprises, divide/close ripple unit, Optical Channel Transport Unit-k line unit, Optical Channel Data Unit-k scheduling unit and low rate traffic signal map unit, wherein

21. the device of transmission low rate traffic signal in the optical transfer network according to claim 20, it is characterized in that, described low rate traffic signal map unit also is used for the low rate traffic signal from described local data network is shone upon and encapsulates, convert low rate traffic flashlight channel data cell signal to, send to described Optical Channel Data Unit-k scheduling unit;

22. the device of transmission low rate traffic signal in the optical transfer network according to claim 20, it is characterized in that, described device also comprises low rate traffic flashlight channel data cell scheduling unit and the low rate traffic signal Optical Channel Data Unit-k adaptation unit to Optical Channel Data Unit-k;

23. the device according to transmission low rate traffic signal in each described optical transfer network in the claim 20 to 22 is characterized in that described encapsulation and decapsulation can be used Generic Framing Procedure.