CN102158354B - Method for preventing defect transparent transmission of section layer of synchronous digital hierarchy equipment - Google Patents

Abstract

The invention discloses a method for preventing the defect transparent transmission of a section layer of synchronous digital hierarchy equipment, which relates to the technical field of synchronous digital transmission. The method comprises the following steps of: detecting a main service data frame of a service data interface, jointed with a crossing unit, on the optical interface unit system side of the synchronous digital hierarchy (SDH) equipment in real time, and judging the main service data frame gives an out of frame (OOF) alarm or not; when the main service data frame is judged to give the OOF alarm, inserting an administrative unit-alarm indication signal (AU-AIS) in the direction of the optical interface unit line side of the SDH equipment; and when the AU-AIS passes through the optical interface unit line side of the SDH equipment, performing scrambler processing and downwards transmitting the processed AU-AIS. By the method, clock abnormities can be prevented from causing the defects of error codes, alarm and the like of the section layer comprising a regenerator section and/or a multiplexing section at each downstream site, so the security of services of sites non-adjacent to a failing site is greatly improved.

Description

Prevent the method for defect transparent transmission of section layer of synchronous digital hierarchy equipment

Technical field

The present invention relates to the synchronous digital transmission technical field, particularly relate to a kind of method that prevents defect transparent transmission of section layer of synchronous digital hierarchy equipment.

Background technology

At SDH (Synchronous Digital Hierarchy, SDH (Synchronous Digital Hierarchy)) in, Frame is from being divided in logic regenerator section, multiplex section and 3 aspect of higher order path layer, wherein, regenerator section and multiplex section are overhead byte, RSOH and MSOH can classify as section overhead, be mainly used in normally operation of maintenance system, looped network or chain normal operation, and the higher order path layer mainly are comprised of Higher Order Path Overhead and the business datum that will transmit.Under normal circumstances, section overhead only exists at adjacent website, for example, supposes that section overhead is created in certain website, and so, at the website adjacent with this website, section overhead will be terminated.

But, in actual engineering application, when some specific fault appears in certain website, for example, clock occurs abnormal, except the defect (alarm or error code) of the adjacent with it website section of there will be layer, the next website of this adjacent sites, section defect of layer, all likely appear in even lower next website, from presentation, the defect of section layer down " transparent transmission ".Below from the reason of the analysis in essence " transparent transmission " of synchronous digital transmission.

Shown in Figure 1, between SDH device optical interface unit A, B and cross unit C, adopt electrical interface to be connected, SDH device optical interface unit A comprises descrambling module A11, A12 and scrambler modules A 21, A22, SDH device optical interface unit B comprises descrambling module B 11, B12 and scrambler module B21, B22, and cross unit C comprises descrambling module C11, C12 and scrambler module C21, C22.Because the length in transmitting procedure " 0 " or long " 1 " can cause receiving data units can't extract the clock in digital signal, and then can cause data to recover, therefore need to carry out the scrambler processing before the transmission data, scrambler is processed and can be avoided in transmitting procedure occurring long " 0 " or long " 1 ".Receive data terminal and extract clock before scramble process, with the clock extracted, receive data.But, even the scrambler through SDH device optical interface unit is processed, when there is shake in the clock source provided when the SDH system clock unit, there is long " 0 " or long " 1 " in the data before judgement scrambler that can be wrong, cause having long " 0 " or long " 1 " in the data of electrical interface output.Now, due to the clock recovery existing problems, can there be OOF (Out Of Frame, OOF) alarm in the data that cross unit receives.Because the OOF alarm is the transient state alarm, can constantly produce along with the shake of clock, disappear.

Shown in Figure 1, for cross unit C, 1. the signal of telecommunication received, to carry out through SDH device optical interface unit A the data that scrambler has been processed, these data are sent to SDH device optical interface unit B after by the descrambling of 1. locating in cross unit C, the scrambler of 2. locating, again the descrambling by SDH device optical interface unit B, originating party to process and scrambler after, be converted to light signal from 3. sending.If the signal of telecommunication 1. received the situation of long " 0 " length " 1 " occurs because of clock jitter, known according to above-mentioned decoding, scrambler matching principle, the data of 3. locating will be reduced to the data of 1. locating.This light signal is transferred to remote station again, when the receiving circuit of remote station extracting clock, while recovering data, can even OOF, LOF (Loss Of Frame of B1, B2 error code appear because extracting clock failure, LOF) or LOS (Lost of Signal, dropout) alarm.The like, the decoding of remote station, scrambler are processed, length " 0 " or long " 1 " can be continued down to transmit again, thus the defect transparent transmission of the section of causing layer.

In sum, in actual engineering application, when some specific fault appears in certain website, the section layer defects transparent transmission phenomenon of SDH (Synchronous Digital Hierarchy) SDH equipment, make to be affected with the fail safe of the business of the non-conterminous website of fault website, therefore how to prevent the section layer defects transparent transmission of SDH (Synchronous Digital Hierarchy) SDH equipment, become synchronous digital transmission technical field technical problem urgently to be resolved hurrily.

Summary of the invention

The objective of the invention is in order to overcome the deficiency of above-mentioned background technology, a kind of method that prevents defect transparent transmission of section layer of synchronous digital hierarchy equipment is provided, can prevent that the defects such as the error code, alarm of section layer (being regenerator section and/or multiplex section) from appearring in each website of the downstream that extremely causes because of clock, make greatly to improve with the fail safe of the business of the non-conterminous website of fault website.

The method that prevents defect transparent transmission of section layer of synchronous digital hierarchy equipment provided by the invention, comprise the following steps: (1) detects the main business Frame of the business datum mouth that SDH (Synchronous Digital Hierarchy) SDH device optical interface cellular system side docks with cross unit in real time, judges on described main business Frame and OOF OOF alarm whether occurs; (2), while the OOF alarm occurring on judging described main business Frame, at SDH device optical interface unit line side direction, insert in real time Administration unit alarm indication signal AU-AIS; (3), when the AU-AIS signal is through SDH device optical interface unit wires trackside, after processing, down transmits scrambler.

In technique scheme, while in step (2), the OOF alarm occurring, at SDH device optical interface unit line side direction, clean He transmission channel is inserted to the AU-AIS signal.

In technique scheme, the described process to clean He transmission channel insertion AU-AIS signal is that the payload part data are set to " 1 " code entirely.

In technique scheme, be set to the payload part data of complete " 1 " code after SDH device optical interface unit line stresses new framing, then carry out the scrambler processing.

Compared with prior art, advantage of the present invention is as follows:

On SDH equipment, when the clock unit of certain website breaks down, apply method of the present invention, only in adjacent sites, the layer defects such as the section such as B1 error code, B2 error code or OOF, LOF alarm occurs, and can these section layer defects still not occur at every station point.The present invention can prevent that the defects such as section error code of layer (being regenerator section and/or multiplex section), alarm from appearring in each website of downstream extremely caused because of clock, make greatly to improve with the fail safe of the business of the non-conterminous website of fault website, the assurance business is stablized to important in inhibiting.

The accompanying drawing explanation

Fig. 1 is the annexation schematic diagram of SDH device optical interface unit and cross unit;

Fig. 2 is the structured flowchart of SDH equipment cross unit;

Fig. 3 is the structured flowchart of SDH device optical interface unit.

Embodiment

Below in conjunction with drawings and Examples, the present invention is described in further detail.

The method that prevents SDH (Synchronous Digital Hierarchy) SDH equipment section layer defects transparent transmission that the embodiment of the present invention provides comprises the following steps:

(1) detect in real time the main business Frame of the business datum mouth that SDH (Synchronous Digital Hierarchy) SDH device optical interface cellular system side docks with cross unit, judge on described main business Frame and OOF OOF alarm whether occurs;

(2) while the OOF alarm occurring on judging described main business Frame, at SDH device optical interface unit line side direction, clean He transmission channel is inserted to AU-AIS (Administrative Unit-Alarm Indication Signal in real time, Administration unit alarm indication signal), be about to the payload part data and be set to " 1 " code entirely;

(3) the payload part data that are set to complete " 1 " code, after SDH device optical interface unit line stresses new framing, then carry out down transmitting after the scrambler processing.

The principle of the embodiment of the present invention is elaborated as follows:

Shown in Figure 2, scrambler module and descrambling module that SDH equipment cross unit comprises cross-connect module and is separately positioned on cross-connect module input port, delivery outlet, outlet in the scrambler module, it is the D place of Fig. 2, the clock source that may provide because of the clock unit of SDH system has shake, and the signal of long " 0 " or long " 1 " occurs.

Shown in Figure 3, SDH device optical interface unit comprises the first descrambling module, the first payload processing module, expense regeneration module, the first scrambler module, LOS detection module, the second descrambling module, the second payload processing module and the second scrambler module.If SDH device optical interface unit is from XCU (Transmission Control Unit, transmission control unit) side has been received the signal of length " 0 " or long " 1 ", after passing through so the one-level scrambler in one-level descrambling, line side of system side in SDH device optical interface unit, can recover the signal of growing " 0 " or long " 1 " in the F place in Fig. 3, and continue to transmit toward the downstream website, this has just formed " section layer defects transparent transmission ".

Because the interface of system side in SDH device optical interface unit is the SDH interface of standard, this interface is when receiving the signal of above-mentioned existence long " 0 " or long " 1 ", must there will be OOF alarm (this OOF alarm slightly is different from the OOF alarm in line side, and the OOF alarm in line side continues when 3ms is above to become the LOF alarm).While the OOF alarm occurring, if at this direction (the E place in Fig. 3), clean He transmission channel is inserted to AIS (Alarm Indication Signal, alarm indication signal) process, be that the payload part data are set to " 1 " code entirely, the payload part data that are set to " AIS " the transmitter side of SDH device optical interface unit framing again, and through scrambler, process after, just can guarantee that long " 0 " or long " 1 " phenomenon no longer appear in light mouth output signal, downstream FRAMER chip also just can normally detect the A1A2 header signal, completes the functions such as Clock Extraction, framing.

When the clock unit of certain website breaks down, long " 0 " or long " 1 " signal appear in the D place in Fig. 2, shown in Figure 3, this signal, after the first descrambling module descrambling of SDH device optical interface unit, has been no longer just long " 0 " or long " 1 " signal at the E place.But, again after the first scrambler module is carried out the scrambler processing, because scrambler, descrambling on system are taked same multinomial, so the F place in Fig. 3 restores again long " 0 " or long " 1 " signal, what cause sending to the downstream website is still long " 0 " or long " 1 " signal, and such signal can't carry out clock recovery in each light-receiving side, data are extracted and frame alignment is processed.

The signal of long " 0 " or long " 1 " appears in the D place in Fig. 2, shown in Figure 3, and after the first descrambling module descrambling, the signal at E place has not been in fact the signal of long " 0 " or long " 1 ".The E place of the embodiment of the present invention in Fig. 3 inserted the AIS processing, be equivalent to so at the E place, the data of the payload part after descrambling become " 1 " entirely, the payload of this complete " 1 " is again after the first scrambler module is carried out the scrambler processing, the light signal sent from F just no longer includes long " 0 " or length " 1 ", so downstream can work, terminated length " 0 " or long " 1 " signal of this AIS update just.

The method of the embodiment of the present invention is applied on SDH equipment FonsWeaver780A/B equipment, has successfully solved the problem of SDH equipment section layer defects transparent transmission.

Obviously, those skilled in the art can carry out various changes and modification and not break away from the spirit and scope of the present invention the present invention.Like this, if within of the present invention these are revised and modification belongs to the scope of the claims in the present invention and equivalent technologies thereof, the present invention also is intended to comprise these changes and modification interior.

The content be not described in detail in this specification belongs to the known prior art of professional and technical personnel in the field.

Claims (1)

1. a method that prevents defect transparent transmission of section layer of synchronous digital hierarchy equipment is characterized in that comprising the following steps:

(1) detect in real time the main business Frame of the business datum mouth that SDH (Synchronous Digital Hierarchy) SDH device optical interface cellular system side docks with cross unit, judge on described main business Frame and OOF 00F alarm whether occurs;

(2) in SDH device optical interface unit, the interface of system side receives the signal that has long " 0 " or long " 1 ", while causing on described main business Frame the OOF alarm occurring, at SDH device optical interface unit line side direction, clean He transmission channel is inserted to Administration unit alarm indication signal AU-AIS in real time: the payload part data are set to " 1 " code entirely;

(3) the payload part data that are set to complete " 1 " code, after SDH device optical interface unit line stresses new framing, then carry out down transmitting after the scrambler processing.

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