WO2007006177A1

WO2007006177A1 - A method and system for achieving cross and transparent multiplexing according to general framing protocol

Info

Publication number: WO2007006177A1
Application number: PCT/CN2005/001033
Authority: WO
Inventors: Liang Xia
Original assignee: Zte Corporation
Priority date: 2005-07-13
Filing date: 2005-07-13
Publication date: 2007-01-18
Also published as: CN101112034B; CN101112034A

Abstract

A method and system for achieving cross and transparent multiplexing according to general framing protocol. The system comprises a tributary unit, a cross unit and a line unit. When the multiplexing is processed, this method comprises the steps that the tributary unit converts the received low speed tributary signal into the electric signal, codes and encapsulates the original signal which is restore to the GFP frame, and then it is sent to the cross unit to perform cross scheduling, and then the results are sent to the corresponding line unit, wherein, the multi-path data are multiplexed and attached by a path label. The coding process is made for the above results to form OTN frame, then the OTN frame is transmitted to network. When the demultiplexing is made, this method comprises the steps that the line unit converts the line high speed signal into the low speed parallel signal, and the data are sent to each tributary path according to the path label in the OTN frame, and output to the cross unit to complete the cross scheduling, and the each path data are decoded by the tributary unit and are restored into the effective data. The effective data form the signal according with the tributary service format and the signal is sent via the tributary interface. The present invention can reduce the number of the layers of network and achieve the small communication cost and high availability for the band.

Description

Technical field

The present invention relates to a Multi-Service Transport Platform (MSTP) technology and, more particularly, to a method and apparatus for transparently multiplexing a plurality of low-speed tributary signals into one or more high-speed signals. Background technique

With the rapid development of the network, especially the rapid growth of data services, the demand for bandwidth is increasing, making multi-service transport platform (MSTP) technology one of the core technologies for next-generation transmission. Its development prospects are clear and optimistic. It has been widely adopted by major telecom operators and is steadily advancing to lower-level networks.

In the current MSTP network solution, the cross-over and transparent multiplexing (TMUX) technology is widely used. The TMU of the present invention refers to concentrating and multiplexing several low-speed branch services in a network into one or more high-speed signals, and entering The technology of transmission network transmission.

The traditional MSTP technology usually adopts the technology of IP over SDH. First, the branch service is packaged by PPP/HDLC or GFP (general framing procedure), then mapped to the virtual container VC of SDH (synchronous digital sequence), and finally OTN. (Optical transport network) framing processing. From the above analysis, it can be seen that the traditional MSTP technology has a very complicated processing process for the service. There are many network layers, and the transmission overhead is very expensive, which greatly reduces the bandwidth utilization, has low efficiency, and has weak protection switching capability for services.

In addition, the commonly used TMUX design method is to make the tributary interface and the line interface on a single board. Due to the limitation of the space and integration of the single board, generally only a few tributary signals can be multiplexed to one. In high-speed signals, this greatly limits the functionality and flexibility of the TMU.

In addition, many networks need to transmit large-capacity data services and provide protection for data services at the optical layer. If the traditional optical layer protection method is adopted, different protection functions need to be configured with corresponding protection boards due to the limitation of the integration of the optical devices. This results in an increase in the types of boards, complicated panel layout and configuration, and high cost. In addition, l:n protection, multi-channel protection and other functions are more complicated to implement with optical barriers, and lack of cost advantages. Summary of the invention

The technical problem to be solved by the present invention is to provide a method for implementing a crossover and transparent multiplexing system based on a general framing procedure, which can directly map GFP to an OTN frame, which reduces the network hierarchy, makes the overhead cost small, and has high bandwidth utilization. Additionally, the present invention also provides a system in which the method can be implemented.

In order to solve the above technical problem, the present invention provides a method for implementing cross-connection and transparent multiplexing based on a general framing procedure, which is applied to a multiplexing system including a tributary unit, a cross unit, and a line unit, including multiplexing and demultiplexing. Process, where:

The multiplexing process includes the following steps:

(a) after receiving the low-speed tributary signal from each tributary interface, the tributary unit converts it into an electrical signal, recovers the original data therefrom, and then encodes and encapsulates the data frame into a general framing procedure, and sends it to the station. Intersection unit

(b) the cross unit performs cross-scheduling on each data stream from the tributary unit and outputs to the corresponding line unit;

(c) the line unit multiplexes the received multiplexed data from the intersecting unit and marks each channel with a channel label, and then encodes the multiplexed data to form a data frame of the optical transport network, and converts the data frame into an optical signal. It is then transmitted from the line optical port to the network.

The demultiplexing process includes the following steps:

(i) after receiving the line high-speed signal, the line unit converts it into an electrical signal, converts it into a low-speed parallel signal through analysis and credit processing, and then recognizes the general framing procedure data frame in the parallel signal. a channel label with a label, the data is distributed to each branch channel by the label, and then output to the intersection unit;

(j) the cross unit performs cross-scheduling on each data stream from the line unit and outputs to the corresponding branch unit;

(k) the branch unit decodes each received data from the cross unit, recovers valid data, and then encodes the recovered data to form a signal conforming to the branch service format, and converts the signal into an optical signal. Send out from their respective branch interfaces. Further, the foregoing method may further have the following features: the system has two intersecting units of one master and one standby, and each data stream transmitted between the branch unit and the line unit is sent before being sent. The road drive is divided into two paths, and is simultaneously transmitted through the working channel of the primary cross unit and the protection channel of the alternate cross unit.

Further, the foregoing method may further have the following features: after receiving the data flow from the working channel and the protection channel belonging to the same branch, the tributary unit and the line unit first select an effective data stream according to the signal quality. Then process the data.

Further, the foregoing method may further have the following features: the system has two intersecting units of one master and one standby, and the data flow transmitted between the branch unit and the line unit passes through the main The transmission is performed by the working channel of the cross unit, and when it is faulty, it is switched to the protection channel of the spare cross unit for transmission.

Further, the above method may further have the following features: when the step (a) encapsulates the data into a data frame, and when the step (i) distributes the data frame to each branch channel, the idle insertion of the data frame is also performed. a frame to ensure that the data stream is filled to a fixed rate; at the same time, step (c) of the line unit multiplexes the multiplexed data, and step (k) tributary unit performs the received data Before decoding, the idle frames in each data are deleted first, and the delimitation of the end of the frame header of the effective frame is performed.

Further, the above method may further have the following feature: the data stream transmitted between the cross unit and the branch unit and the line unit is transmitted through a high speed data channel on the high speed backplane.

Further, the above method may further have the following features: When the step (c) is to multiplex the multiplexed data, the data sent by each channel is first written into the respective queues, and the respective channels are added when writing. The unique tag then uses the read pointer to cyclically read the data frame in each channel queue to obtain the multiplexed data. When the current queue is empty, the idle frame is inserted into the output multiplexed data for padding.

Further, the foregoing method may further have the following features: when the step (i) demultiplexes the multiplexed data, first performs channel identification on the data frame of the general framing procedure in the input data, and each number is According to the respective channel labels, the frames are respectively written into the corresponding channel queues. When the current frame is an idle frame, the frames are directly deleted, and then the data frames in each channel queue are read out.

Further, the above method may also have the following features: The method is data for the communication field

The 8B/10B service is cross-processed and transparently multiplexed.

Further, the above method may further have the following features: In the step (a), the tributary unit further parses the signal while recovering the original data, counts information of various packets, and performs performance detection on the signal.

Further, the above method may further have the following features: the step (c) before the encoding process of the multiplexed signal, and before the step (i) of distributing the data frame, performing interface conversion.

Further, the above method may further have the following features: the cross unit utilizes a space division cross matrix to dispatch any signal from the tributary unit to any one of the line units, and receive the signal of any channel from the line unit. Assigned to any tributary unit.

The system for implementing cross and transparent multiplexing based on a general framing procedure provided by the present invention comprises at least one tributary unit and at least one line unit interconnected by a cross unit, wherein:

The multiplexer unit is configured to convert the low-speed tributary signal received by each tributary interface into an electrical signal during multiplexing, recover the original data therefrom, and then encode and encapsulate the data frame into a general framing procedure, and send the data frame to The deciding unit is configured to decode the data stream from each channel of the line unit, recover valid data, and then encode the recovered data into a signal conforming to the branch service format, and convert the signal into an optical signal. Afterwards, they are sent out from their respective branch interfaces;

When the multiplexing unit is used for multiplexing, it is used for cross-scheduling each data stream from the tributary unit and outputting to the corresponding line unit; when demultiplexing, cross-scheduling each data stream from the line unit , output to the corresponding branch unit;

The multiplexing, when multiplexing, is used to multiplex the received multiplexed data from the intersecting unit and label each channel with a channel label, and then encode the multiplexed data to form a data frame of the optical transport network. Converted to an optical signal transmitted from the line optical port to the network; when demultiplexing, convert the received line high-speed signal into an electrical signal, and then convert it into a low-speed parallel signal through analysis and overhead processing The number, then identifies the channel label carried by the general framing procedure data frame in the parallel signal, distributes the data frame to each branch channel by label, and outputs to the cross unit.

Further, the above system may further have the following features: the cross unit includes an active cross unit and a spare cross unit, and the main cross unit is connected to the branch unit and the line unit through a working channel, the standby cross The unit is connected to the branch channel of the branch unit and the line unit through a protection channel.

Further, the above system may further have the following features: any one of the branch units and any branch channel on the line unit is connected to the main cross unit through a working channel, and is also connected to the main through a protection channel Alternate cross unit.

Further, the above system may further have the following features: the branch unit and the line unit are connected to the cross unit through a high speed data channel on the high speed backplane, and the cross unit includes a high speed backplane input channel and a space division crossover. Matrix and high speed backplane output channels.

Further, the above system may also have the following features: Each of the branch units, the line unit and the intersecting unit are implemented by a single board.

Further, the above system may further have the following features: The active and standby switching units have active/standby switching control logic for implementing active and standby switching control between the two intersecting units.

Further, the above system may also have the following features: The system is data for the communication field

A system for cross-over and transparent multiplexing of 8B/10B services.

Further, the above system may further have the following features: the branch unit includes at least one subunit, each subunit includes a branch optical module, a branch processing module, and a general framing procedure framing in series and bidirectional communication. , where:

The multiplexer optical module is configured to perform photoelectric conversion on the low-speed tributary signal received by the tributary interface after multiplexing, and is used to perform electro-optical conversion on the signal conforming to the service format during demultiplexing. Road interface transmission;

The multiplexer processing module is configured to decode data of the low speed tributary signal during multiplexing, recover the original data output, and perform performance detection on the signal; and perform decoding to encode the valid data. Forming a signal that conforms to the branch service format and outputting it; The universal framing procedure framer is used to encapsulate data into a data frame of a general framing procedure when multiplexed, and inserts an idle frame to transmit at a uniform rate; when demultiplexing, used for a uniform rate The signal is analyzed, the idle frame is deleted, the frame header of the effective frame is delimited, and then decoded to recover valid data.

Further, the above system may further have the following features: the cross unit includes an active cross unit and a spare cross unit, and the sub unit further includes a backplane driving module for multiplexing processing, framing from a general framing procedure The data stream of the device is multi-channel driven to obtain two data streams, which are respectively sent to the primary cross unit and the alternate cross unit.

Further, the foregoing system may further have the following features: the cross unit includes an active cross unit and a standby cross unit, and the sub unit further includes a main standby lossless switching module, where the main cross unit is used during demultiplexing The serial signal sent from the alternate cross unit is converted into a parallel signal and buffered, and then one valid data is selected from the signal quality according to the signal quality, and output to the general framing procedure framer.

Further, the above system may further have the following features: the subunit further includes an interface conversion and buffer module, configured to convert the serial signal from the cross unit into a parallel signal and cache when demultiplexing, and then The framer readout process is performed by the general framing procedure.

Further, the above system may further have the following features: the line unit includes a plurality of universal framing procedure transmission processing modules, a convergence module, an optical transmission network framer, and a line optical module, which are sequentially connected in series in the transmission direction, and further The method includes a de-aggregation module and a plurality of general framing procedure receiving processing modules, where the line optical module, the optical transport network framer, the de-aggregation module, and the universal framing procedure receiving processing module sequentially connect the communications in the receiving direction, where:

The general framing procedure transmission processing module is configured to perform multiplexing processing, process a fixed rate data stream including a general framing procedure data frame, delete an idle frame therein, and perform delimitation of a frame header end of the effective frame After output

The aggregation module is configured to multiplex the multi-path data, put a channel label on each data, and combine it into one multiplexed data and output the same;

The optical transport network framer is configured to perform encoding processing on the optical transmission network for the multiplexed data when the multiplexer is multiplexed, and output the data frame of the optical transport network, and output the high-speed signal of the line during demultiplexing. Analysis and overhead processing, conversion to low-speed parallel data output;

When the line optical module is used for multiplexing, it is used for performing optical and optical conversion on the optical transmission network data frame and then transmitting from the line optical port; when demultiplexing, it is used for photoelectrically converting the received line high-speed signal and outputting;

The de-aggregation module is configured to identify, when demultiplexing, a channel label carried by the data frame in the low-speed parallel signal, and distribute the data frame to each branch channel according to the label;

The universal framing procedure receiving processing module is configured to insert an idle frame in a data frame of each channel during demultiplexing, and output a fixed rate data stream.

Further, the above system may further have the following features: The line unit further includes an interface conversion and buffer module for multiplexing processing, converting the serial signal from the cross unit into a parallel signal and buffering, and then using the universal The framing procedure is sent to the processing module for reading and processing.

Further, the above system may further have the following features: an interface conversion module is disposed between the optical transport network framer and the convergence module and the de-aggregation module, and is configured to implement different interfaces on the two modules. Conversion of transmitted signals between.

Further, the above system may further have the following features: the cross unit includes an active cross unit and a spare cross unit, and the line unit further includes a backplane driving module for performing a general framing procedure from the time of demultiplexing The data stream of the receiving processing module is multiplexed to obtain two data streams, which are respectively sent to the primary cross unit and the alternate cross unit.

Further, the above system may further have the following features: the cross unit includes an active cross unit and a standby cross unit, and the line unit further includes a main standby lossless switching module for multiplexing processing, and the main cross unit The serial signal sent from the alternate cross unit is converted into a parallel signal and buffered, and then one valid data is selected from the signal quality according to the signal quality, and output to the general framing procedure transmission processing module.

The present invention overcomes the shortcomings of the prior art and solves the problems in the prior art. It has the following advantages:

A. The present invention multiplexes multiple channels of data through an aggregation module to directly map GFP to OTN. The frame does not need to be mapped to the virtual container VC of the SDH first, which reduces the network hierarchy. At the same time, since there is no overhead of introducing SDH, the overhead is small, and the transmission efficiency and bandwidth utilization are high.

further:

B. The branch unit and the line unit of the present invention are connected to each other on different boards through the cross unit (single board), and the signals of the branch interface can be flexibly transmitted to different line units. Therefore, it has flexible scheduling and scalability of branch service, which greatly reduces the types of branches and line units, and brings great convenience for equipment maintenance and upgrade.

C. The invention provides two main and standby cross units, which can work at the same time. Each data between the branch unit and the line unit has two channels, main and standby, and realizes data between the branch unit and the line unit. The backup of the transmission has a low cost and powerful protection switching capability. BRIEF abstract

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic diagram of a TMUX system according to an embodiment of the present invention, which depicts the composition of the system and the connection relationship between the various parts. The figure shows the working channel, which means the protection channel.

Figure 2 is a functional block diagram of a tributary unit in accordance with an embodiment of the present invention, which depicts the functional units of the tributary unit and the connection relationship therebetween.

Figure 3 is a functional block diagram of a line unit in accordance with an embodiment of the present invention, which depicts the functional units of the line unit and the connection relationship therebetween.

4 is a functional block diagram of a cross unit of an embodiment of the present invention, describing functional units of the cross unit and the connection relationship therebetween.

FIG. 5 is a schematic diagram of a convergence module according to an embodiment of the present invention.

FIG. 6 is a schematic diagram of a solution aggregation module according to an embodiment of the present invention.

Figure 7 is a diagram showing the connection relationship of the components of the branch unit of the embodiment of the present invention.

Figure 8 is a diagram showing the connection relationship of the components of the line unit in the embodiment of the present invention. BEST MODE FOR CARRYING OUT THE INVENTION

The TMUX system of this embodiment is a core part of a multi-service platform, and is used for implementing cross-connection, GFP processing, and multiplexing to data OTN of data 8B/10B services (such as GbE, SAN, etc.) in the communication field. , complete aggregation, protection, and scheduling of sub-wavelength levels. As shown in FIG. 1, the system of the embodiment mainly includes: a plurality of Tributary Access Cards, a plurality of Line Cards, a Backplane Connect (not shown), and two Crossing unit (Switching Matrix). among them:

As shown in FIG. 1, the number of branch units 001 in the TMUX system of this embodiment is configured according to the number of branch signals, and multiple blocks are arranged, and each branch unit has 8 branch interfaces, so that one branch unit It is possible to simultaneously access 8 tributary signals. The cross unit is configured with two blocks, one for the main cross unit 002 and one for the alternate cross unit 003, and the two boards are the same. There are 16 high-speed data channels (eight for receiving and transmitting) between any one of the tributary units and the main and alternate cross-units. These high-speed channels are realized by the high-speed backplane, and the connection channel with the main cross-unit is called As the working channel, the connecting channel with the alternate cross unit is called the protection channel, and the branch unit can switch between the working channel and the protection channel as needed. These switching are lossless.

The line unit 004 is also configured with a plurality of blocks, and any one of the line units 004 and the main and standby cross units have 16 high-speed data channels, and the high-speed channels are also realized by the high-speed backplane, and the connection channel with the main cross unit is called As the working channel, the connecting channel with the alternate cross unit is called the protection channel, and the line unit 004 can perform the lossless switching between the working channel and the protection channel as needed. The line optical port on the line unit is used to connect another TMUX.

Since each data stream (or referred to as a signal) on the branch unit 001 and the line unit 004 is connected to the primary cross unit 002 and the alternate cross unit 003 through the high speed backplane, the primary and backup cross units 002 003 can flexibly schedule these high-speed connections, and can dispatch the tributary signals to any one of the line units 004. Similarly, the signals received by the lines can be distributed to any tributary unit 001. At the same time, the two primary and secondary cross units of the embodiment work simultaneously, and each data between the tributary unit and the line unit is transmitted to the opposite end through two channels, thereby realizing data transmission between the tributary unit and the line unit. Hot backup, low cost and convenient protection switching.

In this embodiment, each of the above units is implemented by a single board.

The specific structure of each unit is described in detail below:

As shown in FIG. 2, the branch unit includes eight independent sub-units, which constitute eight branch channels. Eight tributary signals can be processed simultaneously. Each sub-unit includes a branch optical module 101, a branch processing module 102, a GFP framer 103, a backplane driving module 104, and a master-slave lossless switching module 105. The backplane driving module 104 and the active/standby lossless switching module 105 pass through respective The working channel 106 and the protection channel 107 are connected to the primary and backup crossover units.

The composition and completed functions of each functional module will be described below. Please refer to Figure 7 at the same time.

The tributary optical module 101 is configured to convert the low-speed branch optical signal from the branch interface into an electrical signal for output to the branch processing module during multiplexing, and to be used from the branch processing module 102 during demultiplexing. The electrical signal is converted to an optical signal and sent from the tributary interface. In Figure 7, the module corresponds to a Small Form Factor Pluggable Optical Transceiver (SFP) module 401.

The multiplexer processing module 102 is configured to perform 8B/10B decoding on the signal from the tributary optical module 101 during multiplexing, recover original data and perform performance detection on the tributary signal, and then output to the GFP framer; In the demultiplexing, the data from the GFP framer is subjected to 8B/10B encoding to form a signal conforming to the branch service format, and is output to the branch optical module 101. In Figure 7, the module corresponds to an 8B/10B Physical Coding Sublayer (PCS) processing module 402, an Ingress FIFO 405, and an Egress FIFO 406. Codec and performance detection is done by the PCS processing module.

In addition, the Ingress Monitor module 404 is configured to detect the tributary signal frame. For example, if the tributary is GbE, then the Ethernet frame is detected, and the packet information is collected. At this time, the egress monitoring module 403 and the ingress monitoring module. 404 is equivalent to the Ethernet MAC processing module, one for receiving and one for sending. When the ingress monitoring module 404 detects that the traffic of the branch is greater than its maximum processing capability, it may send a traffic control frame to the client device by inserting a flow control frame in the egress buffer 406, and the client device may suspend the transmission of the data after receiving the flow control frame.

The GFP framer 103 is configured to perform 64B/65B encoding on the data from the branch processing module 102 during multiplexing, and encapsulates the data frame according to ITUT G.7041 to generate a GFP data frame, and inserts an idle frame between the GFP frames during encapsulation. Ensure that data is sent to the high-speed backplane at a uniform rate (such as 2.5Gbps); when demultiplexing, it is used to analyze the signals from the active and standby lossless switching modules, delete idle frames, and perform frame headers of valid frames. Delimited, and 64B/65B decoding is performed to recover valid data, and then output to the branch processing module 102. In Figure 7, the module corresponds to GFP T (transparent universal framing) Protocol) / GFP - F (frame-based general framing protocol) Framer 407.

The backplane driving module 104 is configured to multiplex the data stream from the GFP framer into two 2.5G GFP data streams, and send them to the active and standby respectively through the sending working channel 414 and the sending protection channel 415. High-speed backplane input channel with cross unit connections. In Figure 7, the module corresponds to a multi-way (1:2) driver 409.

The active/standby lossless switching module 105 is configured to select one valid data from the data received by the working channel and the protection channel according to the signal quality, and output the data to the GFP framer 104. In FIG. 7, the module corresponds to the FIFO interface conversion module 413 (two, respectively receiving 2.5G GFP data from the receiving working channel 416 and the receiving protection channel 417, converting the serial signal into a parallel signal), multiplexing ( 2:1) Selector 410, Work FIFO 411, Protect FIFO 412, and Data Switching Module 408. The data switching module 408 is based on the detection result of the current signal quality by the GFPJ7 GFP-F framer 407, and generates a data switching signal to the multiplexer 410 to complete the signal selection.

The high-speed backplane uses a high-speed data backplane interface to connect the data channels between the crossover unit and the line unit and branch unit.

The primary cross unit 002 and the alternate cross unit 003 are used to complete the cross-scheduling of high-speed data between the line unit and the branch unit of the system. As shown in FIG. 4, each of the cross units includes the following parts: a high speed backplane input channel 301, a space division cross matrix 302, and a high speed backplane output channel 303. The structure is simple, and a commonly used space division cross ASIC device can be realized. . The two interleaved units also have active/standby switching control logic for implementing active and standby switching control between the two intersecting units.

As shown in FIG. 3, the line unit includes the following parts: a line optical module 201, an OTN framer 202, a transmission interface conversion module 203, a receiving interface conversion module 204, a GFP de-aggregation module 205, a GFP aggregation module 206, and a GFP reception processing module. 207. The GFP sending processing module 208, the backplane driving module 209, and the active/standby lossless switching module 210. The backplane driving module 209 and the active/standby lossless switching module 210 are connected to the high speed backplane through respective working channels 211 and protection channels 212, and the line optical modules are connected to another system through the line optical ports 211. among them: The composition and completed functions of each functional module will be described below, please refer to FIG. 8 at the same time.

The active/standby lossless switching module 210 is configured to select a valid signal from the signals received by the working channel and the protection channel according to the signal quality, and output the signal to the GFP transmission processing module 208. In FIG. 8, the module corresponds to the FIFO interface conversion module 503 (two, respectively receiving 2.5G GFP data of the working channel 501 and the protection channel 502, converting the serial signal into a parallel signal), and multiplexing (2:1) selection. The device 506, a work buffer (Work FIFO) 504, a protection buffer (Protect FIFO) 505, and a data switching module 507. The data switching module 507 generates a data switching signal to the multiplexer 506 according to the detection result of the current signal quality by the Tx_GFP processing module 508, and completes the selection of the signal.

The GFP transmission processing module 208 is configured to process the valid signal selected by the active/standby lossless switching module, delete the idle frame in the signal, and perform the delimitation of the frame header of the effective frame to send the data to the GFP aggregation module 206. In Figure 8, the module corresponds to Tx-GFP Processing Module 508 and Transmit Buffer (Tx FIFO) 509.

The GFP aggregation module 206 is configured to multiplex the received multiplexed data, add a channel label to each data, synthesize a multiplexed signal, and send it to the transmitting interface conversion module 203. In Figure 8, the module corresponds to the Tx-GFP aggregation module 510.

Referring again to FIG. 5, the aggregation module includes a queue buffer corresponding to each channel, a tag generator (not shown), and a read controller. Wherein: the queue buffer is used to buffer data sent by each channel; the tag generator is configured to add a unique tag of the respective channel when writing data to the respective queue; the read controller is used to control the read pointer The GFP data frame in each queue is cyclically read, and an idle frame is inserted in the multiplexed data when the current read queue is empty. When multiple GFP channel data are multiplexed into one multiplexed channel data, the data sent from each channel is first written into the respective queues, and the unique label of the respective channel is added when writing, and the read pointer is pressed by channel 1 The sequence of channel n cyclically reads the GFP frame in each queue. When the current queue is empty, a GFP idle frame is inserted in the output multiplexed data for padding.

The transmit interface conversion module 203 is configured to convert the data signal of the multiplexed channel into a signal conforming to the interface of the OTN framer 202. In Figure 8, the module corresponds to the Tx SF14.2 interface conversion module 511.

The OTN framer 202 is configured to perform OTN encoding and the like on the multiplexed data from the transmission interface conversion module 203 during multiplexing, and form an OTN frame and then send it to the line optical module 201; When it is used for analyzing and processing the data from the line optical module, it is converted into low-speed parallel data and sent to the receiving interface conversion module 204. In Figure 8, the module corresponds to the OTN Mapper/Demapper module 512.

When multiplexing, the line optical module 201 is configured to perform electro-optical conversion on the electrical signal from the OTN framer, send it to the line optical port, and then transmit it to the network; when demultiplexing, it is used to receive the line optical port. The incoming line high speed optical signal is converted to an electrical signal and sent to the OTN framer 202. In Figure 8, the module corresponds to the MSA300 10G optical module 513.

The receiving interface conversion module 203 is configured to convert the signal from the OTN framer 202 interface into a signal conforming to the interface of the GFP de-aggregation module 205. In Figure 8, the module corresponds to the Rx SF14.2 interface conversion module 514.

The GFP de-aggregation module 205 is configured to analyze the line signals from the OTN framer, identify the channel labels of the respective data channels, and distribute the data to the respective branch channels of the GFP receiving processing module 207 by labels. In Figure 8, the module corresponds to the Rx-GFP de-aggregation module 515.

Referring to FIG. 6, the de-aggregation module includes a queue buffer corresponding to each channel, a channel identification and write pointer controller, and a read controller, wherein: the channel identification and write pointer controller is used for Identifying a channel label carried by the GFP frame, and then controlling the write pointer to write it to the channel queue corresponding to the label, and directly deleting the idle frame; the queue buffer is configured to buffer the GFP data frame distributed to each channel; The read controller is used to fetch the GFP data frame for each channel, and if there is no data in the queue, the idle frame output is inserted.

The process of demultiplexing is basically the reverse of the above multiplexing process. First, channel identification is performed on the multiplexed GFP frame in the multiplexed input data to determine which channel the current GFP frame should be demultiplexed, and the control by writing the pointer will be Each GFP frame is respectively written into the corresponding channel queue according to the respective channel label, and is directly deleted if the current frame is a GFP idle frame. Each channel has a readout controller that fetches the GFP frames in the respective channels. If there is no data in the queue, the idle frame output is inserted.

The GFP receiving processing module 207 is configured to perform rate adaptation on the data frame of each channel, and fill the channel signal rate into a fixed rate (2.5G) signal by using a method of filling the idle frame, and then send the signal to the backplane driving module 208. In Figure 8, the module corresponds to the Rx_GFP processing module 517 and the interface Receive buffer (Rx FIFO) 516.

The backplane driving module 209 is configured to multiplex the data stream from the GFP receiving processing module 207 into two 2.5G GFP data streams, and respectively transmit them to the active and standby crossovers through the working channel 519 and the protection channel 520. High speed backplane input channel for unit connection. In Figure 8, the module corresponds to a multiplexed (1:2) driver 518.

It should be noted that the division of the above functional modules in the tributary unit and the line unit is completely changeable, such as dividing the GFP framer in FIG. 2 into two modules of a GFP framer and a deframer, or The board driving module and the active/standby lossless switching module are combined into one functional module, and the transmitting and receiving interface conversion modules in FIG. 3 are combined into one functional module and the like. These divisional changes should be regarded as the above scheme of the present embodiment. Equivalent.

Based on the above system, the flow of demultiplexing the branch low speed signal to the line high speed signal and the line high speed signal to the branch low speed signal will be described separately according to the data flow direction. Specific modules are no longer defined in the process.

The process of multiplexing the branch low speed signal to the line high speed signal includes the following steps:

S110, after receiving the low-speed tributary signal, the tributary unit converts the optical signal into an electrical signal, and then performs 8B/10B decoding, recovers the original data, and performs performance detection on the tributary signal;

S120: The tributary unit performs 64B/65B encoding on the recovered data, and performs encapsulation according to ITUT G.7041 to generate a GFP data frame, and fills the signal during encapsulation (such as inserting an idle frame between GFP frames), and ensures that the data is sent to The backplane signal is padded to a fixed high rate of 2.5 Gbps;

S130, the tributary unit multi-drives the packaged tributary signal, and sends the working channel and the transmission protection channel and the high-speed backplane input channel to the main and standby cross-unit respectively;

S140. The active and standby cross units use the space division cross matrix to perform cross-scheduling on the signals of the working channels and the transmission protection channels of each branch respectively, and output the working channels and transmission protection of the corresponding line unit through the high-speed backplane output channel. aisle;

S150. The line unit converts the serial signal sent from each branch to the working channel and the transmission protection channel, first converts to a parallel signal, selects a valid signal therefrom, deletes an idle frame in the signal, and performs a frame header of the effective frame. Delimitation of the end of the frame; S160, the line unit multiplexes the multiple data from each branch, adds a channel label to each data, synthesizes a multiplexed signal, and performs interface conversion;

S170: The line unit performs OTN encoding and the like on the multiplexed signal to form an OTN frame, and then performs electro-optical conversion, and then transmits the optical port to the network, and the multiplexing process is completed.

The demultiplexing process is basically the reverse of the multiplexing process, including the following steps:

S210, after receiving the line high-speed optical signal, the line unit performs photoelectric conversion, then performs analysis and overhead processing, converts it into a low-speed parallel signal, and completes interface conversion;

S220, the line unit analyzes the low-speed parallel signal, identifies the channel label of each data channel, distributes the data to each branch channel according to the label, and fills each channel signal with a fixed-frame signal by using a method of filling the idle frame. ;

S230, the line unit multi-drives the signals of the distributed branch channels, and sends them to the main cross unit and the standby cross unit through the receiving working channel and the receiving protection channel and the high-speed backplane input channel respectively;

S240. The active and standby cross units use the space division cross matrix to perform cross-scheduling on the signals of the receiving working channel and the receiving protection channel corresponding to each branch channel, and send the signal to the corresponding branch unit via the high-speed backplane output channel. Receiving working channel and receiving protection channel;

S250, the tributary unit receives the signal corresponding to the same branch from the receiving working channel and the receiving protection channel, first transforms into a parallel signal, and then selects a valid signal;

S260, the tributary unit analyzes the effective signals of each branch, deletes the idle frame, performs delimitation of the frame header of the effective frame, and then performs 64B/65B decoding on the data to recover valid data;

S270, the branch unit performs 8B/10B encoding on the valid data of each branch to form a signal conforming to the branch service format, and then converts the signal into an optical signal for transmission.

In summary, in the foregoing embodiment, in the data processing, the multiplexed module multiplexes the multiplexed data to directly map the GFP to the OTN frame, and does not need to first map to the virtual container VC of the SDH, thereby reducing the network hierarchy. Since there is no overhead of introducing SDH, the overhead is small, and the transmission efficiency and bandwidth utilization are high. In addition, in the embodiment, the branch unit and the line unit are disposed on different boards, and the cross-units are connected to each other, and the signals of the branch interfaces can be flexibly transmitted to different line units. Therefore, it has flexible scheduling and scalability such as branch service, which greatly reduces the types of branches and line units, and brings great convenience for equipment maintenance and upgrade.

Further, in the embodiment, in the protection mechanism, two intersection units of the main unit and the backup unit are provided, and the two units can be operated at the same time. Each of the data between the branch unit and the line unit has two channels of main and standby, and the branch is realized. Backup of data transmission between the unit and the line unit, with low cost and powerful protection switching capability.

Based on the above embodiments, various transformations can also be performed.

For example, in another embodiment, only the above-mentioned structural features in which the branch unit and the line unit are disposed on different boards and connected to each other by the intersecting unit are used, and the data processing still adopts the prior art manner. The example still has the technical effect of providing scheduling capabilities and scalability such as flexible branch service crossover.

For another example, in the above embodiment, the system of the above cross-connect structure is adopted, but the requirements for protection are not high, so the above two intersecting units and the corresponding protection channels are not provided. Correspondingly, in the branch unit and the line unit, the modules related to the selection processing of the working channel and the protection channel can be simplified. For example, the active/standby lossless switching module can be simplified as an interface conversion and buffer module, as long as there is a FIFO interface conversion module and A buffer that converts the received serial signal at a uniform rate into a parallel signal and buffers it.

Alternatively, the method of cold backup may be adopted, that is, the data stream transmitted between the tributary unit and the line unit is transmitted through the working channel of the primary cross unit when normal, and then switched to the standby cross unit when the fault occurs. Protect the channel for transmission.

Industrial applicability

The method and system of the present invention can be applied to implement cross-over and transparent multiplexing based on a general framing procedure, reducing the network hierarchy, resulting in low overhead and high bandwidth utilization.

Claims

Claim

A method for implementing cross-over and transparent multiplexing based on a general framing procedure, applied to a multiplexing system including a tributary unit, a cross unit, and a line unit, including a multiplexing and demultiplexing process, wherein: the multiplexing process Includes the following steps:

(c) the line unit multiplexes the received multiplexed data from the intersecting unit and marks each channel with a channel label, and then encodes the multiplexed data to form a digital frame of the optical transport network, which is converted into light. The signal is transmitted from the line optical port to the network.

The demultiplexing process includes the following steps:

(i) after receiving the line high-speed signal, the line unit converts it into an electrical signal, converts it into a low-speed parallel signal through analysis and overhead processing, and then recognizes the data frame of the general framing procedure in the parallel signal. Channel label, distribute data to each branch channel by label, and then output to the cross unit;

(1) The branch unit decodes each received data from the cross unit, recovers valid data, and then encodes the recovered data to form a signal conforming to the branch service format, and converts the signal into an optical signal. The respective branch interfaces are sent out.

2. The method according to claim 1, wherein two overlapping units of one master and one standby are disposed in the system, and each data stream transmitted between the branch unit and the line unit is sent. The front is divided into two paths by multi-channel driving, and is simultaneously transmitted through the working channel of the main cross-unit and the protection channel of the alternate cross-unit.

3. The method of claim 2, wherein the branch unit and the line unit After receiving the data flow from the working channel and the protection channel belonging to the same branch, first select a valid data stream according to the signal quality, and then process the data.

4. The method according to claim 1, 2 or 3, wherein, when the step of packaging data into data frames, and step G) distributing data frames to respective branch channels, Inserting an idle frame between data frames to ensure that the data stream is filled to a fixed rate; meanwhile, step (c) before the line unit multiplexes the multiplexed data, and step (k) tributary unit receives Before decoding each channel data, the idle frames in each channel data are deleted first, and the frame header end of the effective frame is delimited.

5. The method according to claim 1, 2 or 3, wherein the data stream transmitted between the cross unit and the branch unit and the line unit is transmitted through a high speed data channel on the high speed backplane. .

6. The method according to claim 1, wherein in the step (c), when multiplexing the multiplexed data, first sending the data sent by each channel into the respective queues first, and adding the data when writing. The unique label of each channel is used, and then the data frame in each channel queue is cyclically read by the read pointer to obtain multiplexed data. When the current queue is empty, an idle frame is inserted into the output multiplexed data for filling, Step (i) When demultiplexing the multiplexed data, first perform channel identification on the data frame of the general framing procedure in the input data, and write each data frame into the corresponding channel queue according to the respective channel label, at the current When the frame is an idle frame, it is directly deleted, and then the data frame in each channel queue is read out. '

7. The method according to claim 3, wherein in the step (a), the tributary unit further parses the signal while recovering the original data, counts information of various packets, and performs signal processing on the signal. Performance testing.

8. A system for implementing cross-over and transparent multiplexing based on a general framing procedure, comprising: at least one tributary unit and at least one line unit interconnected by a cross unit, wherein

The multiplexer unit is configured to convert the low-speed tributary signal received by each tributary interface into an electrical signal during multiplexing, recover the original data therefrom, and then encode and encapsulate the data frame into a general framing procedure, and send the data frame to The deciding unit is configured to decode the data stream from each channel of the line unit, recover valid data, and then encode the recovered data into a branch service format. Signals are converted to optical signals and sent out from their respective branch interfaces;

The multiplexing, when multiplexing, is used to multiplex the received multiplexed data from the intersecting unit and label each channel with a channel label, and then encode the multiplexed data to form a data frame of the optical transport network. Converting to an optical signal transmitted from the line optical port to the network; when demultiplexing, converting the received line high-speed signal into an electrical signal, converting it into a low-speed parallel signal through analysis and overhead processing, and then identifying the parallel The channel label of the data frame of the general framing procedure in the signal distributes the data frame to each branch channel according to the label, and then outputs to the intersection unit.

9. The system according to claim 8, wherein the intersecting unit comprises an active cross unit and a spare cross unit, and any one of the branch units and the branch unit is connected through a working channel. To the primary cross unit, it is also connected to the alternate cross unit via a protection channel.

10. The system according to claim 8 or 9, wherein the branch unit and the line unit are connected to the intersecting unit through a high speed data channel on the high speed backplane, and the cross unit includes a high speed backplane Input channels, space division cross matrices, and high speed backplane output channels.

11. System according to claim 8 or 9, characterized in that each of the branch units, the line unit and the cross unit are realized by a single board.

12. The system of claim 8 wherein the system is a system for cross- and transparent multiplexing of data 8B/10B traffic in the communications field.

13. The system according to claim 8, wherein the branch unit comprises at least one subunit, each subunit comprising a branch optical module, a branch processing module, and a universal assembly that are serially connected in series and can communicate bidirectionally. Frame procedure framer, where:

The branch processing module is configured to decode data of the low speed tributary signal during multiplexing, and recover Recovering the original data output and performing performance detection on the signal; when demultiplexing, it is used to encode the valid data to form a signal conforming to the branch service format and output;

The universal framing procedure framer is used to encapsulate data into a data frame of a general framing procedure when multiplexed, and inserts an idle frame to transmit at a uniform rate; when demultiplexing, used for a uniform rate The signal is analyzed, the idle frame is deleted, the frame header of the effective frame is delimited, and then decoded to recover valid data. One

14. The system of claim 13, wherein the cross unit comprises an active cross unit and a spare cross unit, the sub unit further comprising a backplane drive module for multiplexing processing, The data flow of the frame protocol framer is multi-channel driven to obtain two data streams, which are respectively sent to the primary cross unit and the alternate cross unit.

The system according to claim 13, wherein the cross unit includes an active cross unit and a spare cross unit, and the sub unit further includes a main standby lossless switching module, and when used in demultiplexing, The serial signals sent from the primary cross unit and the alternate cross unit are converted into parallel signals and buffered, and then one valid data is selected from the signal quality according to the signal quality, and output to the general framing procedure framer.

16. The system of claim 13 wherein said subunit further comprises an interface conversion and buffering module for converting a serial signal from said interleaved unit to a parallel signal upon demultiplexing And buffered, and then processed by the general framing procedure framer.

17. The system according to claim 8, wherein the line unit comprises a plurality of interface conversion and buffer modules and corresponding general framing procedure transmission processing modules and aggregation modules that are serially connected in series in a transmission direction. The optical transport network framer and the line optical module further include a de-aggregation module and a plurality of general framing procedure receiving processing modules, the line optical module, the optical transport network framer, the de-aggregation module, and the universal framing procedure receiving The processing module serially connects the communications in the receiving direction, wherein: the interface conversion and buffering module is used for multiplexing processing, converting the serial signal from the intersecting unit into a parallel signal and buffering, and then transmitting and processing by the universal framing procedure Module readout;

The general framing procedure transmission processing module is configured to perform multiplexing processing, process a fixed rate data stream including a general framing procedure data frame, delete an idle frame therein, and perform delimitation of a frame header end of the effective frame After output The aggregation module is configured to multiplex multiple channels of data, add channel labels to each channel of data, and synthesize into one channel of multiplexed data for output;

The optical transport network framer is configured to perform encoding processing on the optical transmission network for the multiplexed data when the multiplexer is multiplexed, and output the data frame of the optical transport network; and perform high-speed signal analysis on the line during demultiplexing And overhead processing, converted to low-speed parallel data output;

The system according to claim 17, wherein an interface conversion module is disposed between the optical transport network framer and the convergence module and the de-aggregation module, and is implemented in two Conversion of signals transmitted between different interfaces of the module.

The system according to claim 17, wherein the intersecting unit comprises an active cross unit and a spare cross unit, and the line unit further comprises a backplane driving module, configured to The general framing procedure receives the data stream of the processing module and performs multiplex driving to obtain two data streams, which are respectively sent to the primary cross unit and the alternate cross unit.

The system according to claim 17, wherein the cross unit includes an active cross unit and a spare cross unit, and the line unit further includes a main standby lossless switching module, configured to perform multiplexing processing, The serial signals sent from the primary cross unit and the alternate cross unit are converted into parallel signals and buffered, and then one valid data is selected from the signal quality according to the signal quality, and output to the general framing procedure transmission processing module.