JPH04100326A - Line switching system - Google Patents

Abstract

PURPOSE:To attain quick switch-back from a standby line to an active line by providing a clock distribution means distributing one clock of the standby line to each of plural active lines to each relay station. CONSTITUTION:A clock distribution means 1 provided to each intermediate relay station between a transmission terminal station and a reception terminal station distributes a clock CKS of one standby line to each of N sets of active lines. Active lines after the production of a fault when one active line is faulty select a clock CKN of the active lines into a clock CKS of the standby line and activate a restorer 10 at a timing (t) synchronously with the clock CKS of the standby line to make the active lines after the block having a fault normal. Thus, the fault caused in the active line is recovered and restored normally, then the time for clock synchronization between both the likes does not take long at the switch back from the standby line to the active line and the synchronization is taken in a short time.

Description

【発明の詳細な説明】 〔概要〕 Ｎ個の現用回線の中の１回線の或る区間で障害が発生し
た時、１個の予備回線が正常の場合、該Ｎ＋１回線の送
端局と受端局で該障害の現用回線を予備回線に切替える
回線切替方式に関し、或る現用回線に発生した障害が直
り正常に復旧した時の予備回線から該現用回線への切戻
し時に。[Detailed Description of the Invention] [Summary] When a failure occurs in a certain section of one of the N working lines, if one protection line is normal, the transmitting end station and receiving station of the N+1 line Regarding a line switching method in which a faulty working line is switched to a protection line at a terminal station, when switching back from the protection line to the working line when a fault that has occurred in a certain working line has been corrected and normality has been restored.

両回線のクロック同期のための時間が長くならないよう
な回線切替方式の提供を目的とし、送端局と受端局の中
間の各中継局に該１個の予備回線のクロックをＮ個の現
用回線の各回線に分配するクロック分配手段を設け、 或る１つの現用回線の障害時に該障害の発生区間以降の
現用回線が該クロック分配手段により該現用回線のクロ
ックを予備回線のクロックに切替え、予備回線のクロッ
クに同期したタイミングにより、レストアラ−を動作さ
せ、障害発生区間以降の現用回線を正常にするように構
成する。In order to provide a line switching method that does not take too long to synchronize the clocks of both lines, each relay station between the sending and receiving stations uses the clock of one protection line for N working lines. A clock distribution means for distributing to each line of the line is provided, and when a certain working line has a failure, the working line after the section where the failure occurs switches the clock of the working line to the clock of the protection line by the clock distribution means, The restorer is operated at a timing synchronized with the clock of the protection line, and the system is configured to restore the working line to normal after the section where the fault has occurred.

〔産業上の利用分野〕[Industrial application field]

本発明はディジタル伝送のＮ個の現用回線と。 The present invention uses N working lines for digital transmission.

１個の予備回線からなるＮ＋１回線の回線切替方式〔従
来の技術〕 従来のＮ＋１回線の回線切替方式は、Ｎ個の現用回線の
中の１回線の或る区間で障害が発生した時、１個の予備
回線が正常の場合は該予備回線に切替えられるが、障害
の発生した現用回線は、その障害発生区間以降の回線が
、時間基準のクロックの再生回路ＢＴＲが所謂フリーラ
ンとなる。Line switching system for N+1 line consisting of one protection line [Prior art] In the conventional line switching system for N+1 line, when a failure occurs in a certain section of one line among N working lines, one If the protection line is normal, the line is switched to the protection line, but in the working line where a fault has occurred, the time reference clock regeneration circuit BTR is in a so-called free run state for the line after the section where the fault has occurred.

〔発明が解決しようとする課題〕[Problem to be solved by the invention]

そのため、下記の問題、■或る現用回線の障害発生区間
以降の回線において、監視信号や打金電話信号等のサー
ビスチャンネルを生かすために、該回線を正常にする所
謂レストアラ−回路を持つが該レストアラ−回路には専
用のマスター発振器を必要とするので、全体システムが
高価となる。Therefore, in order to make use of service channels such as monitoring signals and callback telephone signals on the line after the faulty section of a certain working line, there is a so-called restorer circuit that restores the line to normality. The restorer circuit requires a dedicated master oscillator, making the entire system expensive.

■クロック再生回路ＢＴＲが上記の如くフリーランとな
るので、障害となった現用回線が直り正常に復旧した時
の予備回線から該回線への所謂切戻し時に、予備回線と
現用回線のクロックの同期のための時間が長くなるとい
う問題があった。本発明の課題は、或る現用回線の発生
障害が直り正常に復旧した時の予備回線から該現用回線
への切戻し時に９両回線のクロック同期のための時間が
長くならないような回線切替方式の提供にある。■Since the clock regeneration circuit BTR free-runs as described above, the clocks of the protection line and the working line can be synchronized when the faulty working line is repaired and restored to normal and the protection line is switched back to the line. There was a problem that it took a long time. An object of the present invention is to provide a line switching system that does not require a long period of time for clock synchronization of both lines when switching back from a protection line to the working line when a failure occurs in a certain working line and the line is restored to normal. It is provided by.

〔課題を解決するための手段〕[Means to solve the problem]

この課題は、第１図の原理図の如く、送端局と受端局の
中間の各中継局に、１個の予備回線のクロックＣＫｓを
Ｎ個の現用回線の各回線に分配するクロック分配手段１
を設け、或る現用回線の障害時に該障害の発生区間以降
の現用回線が該クロック分配手段により該現用回線のク
ロックＣＫＮを予備回線のクロックＣＫｓに切替え予備
回線のクロックＣＫｓに同期したタイミングｔにより、
レストアラ−１０を動作させ、障害の発生した区間以降
の現用回線を正常にするようにした本発明によって達成
される。As shown in the principle diagram in Figure 1, this problem involves clock distribution in which the clock CKs of one protection line is distributed to each of the N working lines at each relay station between the transmitting end station and the receiving end station. Means 1
is provided, and when a certain working line fails, the working line after the section where the failure occurs switches the clock CKN of the working line to the clock CKs of the protection line by the clock distribution means at a timing t synchronized with the clock CKs of the protection line. ,
This is achieved by the present invention, which operates the restorer 10 and restores the working line after the section where the failure occurred.

〔作用〕[Effect]

送端局と受端局の中間の各中間中継局に設けたクロック
分配手段ｌは、１個の予備回線のクロックＣＫｓをＮ個
の現用回線の各回線に分配し、或る１つの現用回線の障
害時に該障害の発生区間以降の現用回線が該現用回線の
クロックＣＫＮを予備回線のクロックＧＫ、に切り替え
、予備回線のクロックＣＫ、に同期したタイミングｔに
よりレストアラ−１０を動作させ、障害発生区間以降の
現用回線を正常にする。The clock distribution means l provided in each intermediate relay station between the sending end station and the receiving end station distributes the clock CKs of one protection line to each of the N working lines, and When a failure occurs, the working line after the section where the failure occurs switches the clock CKN of the working line to the clock GK of the protection line, operates the restorer 10 at timing t synchronized with the clock CK of the protection line, and when the failure occurs. Make the working line normal after the section.

〔実施例〕〔Example〕

第２図は本発明の実施例の回線切替方式の構成を示すブ
ロック図であり、送端局と受端局の中間の中間中継局に
設けられるクロック分配手段ｌは、スイッチｓｈとビッ
トタイミング再生回路ＢＴＲで構成される。そしてスイ
ッチＳ−が、或る１つの現用回線の障害時に該回線の復
調器ＤＥＭの出力に発生するアラームＡＬＭにより駆動
され、障害発生区間以降の現用回線のクロックＣＫＮを
予備回線のクロックＣＭ、に切り替えて、ビットタイミ
ング再生回路ＢＴＩ？にて、予備回線のクロックＣＫ、
に同期したタイミングｔを発生して復調器ＤＥＭとレス
トアラ−１０を駆動する。そしてレストアラ−１０の出
力により、セレクターＳＥＬを駆動して、復調器ＤＨ？
ｌの出力の現用回線のクロックＣＫｉ、に同期した出力
ではなくて、遅延器Φにより時間を調整した予備回線の
クロックＣＫ、に同期した出力を選択する。そして、回
線の保守等に必要なサービスチャンネル信号も付加し、
変調器？ｌＯＤで変調して次の受端局へ送出する。従っ
て或る現用回線に発生した障害が直り正常に復旧した時
の予備回線から現用回線への切戻し時に１両回線のクロ
ック同期のための時間が長くならず、短時間で同期がと
れるので問題は無い。FIG. 2 is a block diagram showing the configuration of a line switching system according to an embodiment of the present invention, in which a clock distribution means l provided in an intermediate relay station between a sending end station and a receiving end station consists of a switch sh and a bit timing regeneration system. Consists of circuit BTR. The switch S- is driven by an alarm ALM generated at the output of the demodulator DEM of one working line when a failure occurs in the working line, and changes the clock CKN of the working line after the failure period to the clock CM of the protection line. Switch, bit timing recovery circuit BTI? , clock CK of the backup line,
A timing t synchronized with is generated to drive the demodulator DEM and the restorer 10. Then, the selector SEL is driven by the output of the restorer 10, and the demodulator DH?
Instead of the output synchronized with the clock CKi of the working line of the output of l, the output synchronized with the clock CK of the protection line whose time has been adjusted by the delay device Φ is selected. Then, service channel signals necessary for line maintenance etc. are also added,
Modulator? It is modulated with lOD and sent to the next receiving end station. Therefore, when a fault that occurs in a certain working line is corrected and normal operation is restored, when switching back from the protection line to the working line, the time required to synchronize the clocks of both lines will not be long, and synchronization can be achieved in a short time, which is a problem. There is no.

〔発明の効果〕 以上説明した如く、本発明によれば、或る現用回線の或
る区間で障害が発生した場合に該区間以降の現用回線を
正常にするためのレストアラ−を働かせる従来の特別の
マスター発振器を必要とせず、単にクロック再生回路Ｂ
ＴＲＯ前にスイッチＳＷを持ち、現用のクロックを予備
のクロックと切り替えるだけで以降の現用回線が正常と
なるので、■障害となったサービスチャンネルの救済方
法が安価となる効果、■予備回線から現用回線への切戻
しが速くなり予備回線を有効利用することが出来て１回
線品質を向上する効果が得られる。[Effects of the Invention] As explained above, according to the present invention, when a failure occurs in a certain section of a certain working line, a restorer is activated to normalize the working line after that section. No need for a master oscillator, just clock recovery circuit B
By having a switch SW in front of the TRO and simply switching the working clock to the backup clock, the working line will become normal from now on. ■ The effect of reducing the cost of repairing a faulty service channel; ■ Switching from the backup line to the working line Switching back to the line becomes faster, the protection line can be used more effectively, and the quality of one line can be improved.

【図面の簡単な説明】[Brief explanation of drawings]

第１図は本発明の回線切替方式の基本構成を示す原理図
、 第２図は本発明の実施例の回線切替方式の構成を示すブ
ロック図である。FIG. 1 is a principle diagram showing the basic configuration of a line switching system according to the present invention, and FIG. 2 is a block diagram showing the configuration of a line switching system according to an embodiment of the present invention.

Claims (1)

【特許請求の範囲】[Claims] Ｎ個の現用回線の中の１回線の或る区間で障害が発生し
た時、１個の予備回線が正常の場合、該Ｎ＋１回線の送
端局と受端局で該障害の現用回線を予備回線に切替える
回線切替方式において、該送端局と受端局の中間の各中
継局に該１個の予備回線のクロック（ＣＫ＿Ｓ）をＮ個
の現用回線の各回線に分配するクロック分配手段（１）
を設け、或る１つの現用回線の障害時に該障害の発生区
間以降の現用回線が該クロック分配手段により該現用回
線のクロック（ＣＫ＿Ｎ）を予備回線のクロック（ＣＫ
＿Ｓ）に切替え予備回線のクロック（ＣＫ＿Ｓ）に同期
したタイミングにより、レストアラー（１０）を動作さ
せ、障害発生区間以降の現用回線を正常にすることを特
徴とした回線切替方式。When a failure occurs in a certain section of one of the N working lines, if one protection line is normal, the sending and receiving stations of the N+1 line will protect the failed working line. In the line switching system, a clock distribution means (CK_S) of the one protection line is distributed to each of the N working lines at each relay station between the sending end station and the receiving end station. 1)
When a failure occurs in one working line, the working line after the section where the failure occurs uses the clock distribution means to transfer the clock (CK_N) of the working line to the clock (CK_N) of the protection line.
A line switching method characterized in that a restorer (10) is operated at a timing synchronized with a clock (CK_S) of a protection line switched to _S), and the working line after the fault occurrence section is restored to normal.