JPH0752872B2 - Time synchronization control method - Google Patents
Time synchronization control methodInfo
- Publication number
- JPH0752872B2 JPH0752872B2 JP61308032A JP30803286A JPH0752872B2 JP H0752872 B2 JPH0752872 B2 JP H0752872B2 JP 61308032 A JP61308032 A JP 61308032A JP 30803286 A JP30803286 A JP 30803286A JP H0752872 B2 JPH0752872 B2 JP H0752872B2
- Authority
- JP
- Japan
- Prior art keywords
- station
- frame
- transmission timing
- main
- measurement value
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 238000000034 method Methods 0.000 title claims description 12
- 230000005540 biological transmission Effects 0.000 claims description 34
- 238000005259 measurement Methods 0.000 claims description 23
- 238000004891 communication Methods 0.000 claims description 3
- 230000005856 abnormality Effects 0.000 claims description 2
- 238000010586 diagram Methods 0.000 description 5
- 230000001360 synchronised effect Effects 0.000 description 4
- 230000000694 effects Effects 0.000 description 2
- 238000005070 sampling Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 1
- 230000000977 initiatory effect Effects 0.000 description 1
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- Maintenance And Management Of Digital Transmission (AREA)
- Synchronisation In Digital Transmission Systems (AREA)
Description
【発明の詳細な説明】 〔産業上の利用分野〕 本発明は時刻同期方式を採用している種々のシステムの
回線障害時における同期維持方式に関する。DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention relates to a system for maintaining synchronization when a line failure occurs in various systems adopting a time synchronization system.
従来の時刻同期方式においては，上位局の下位局からの
信号の受信用の回線の障害に対して，以下の方法にて同
期系維持を行なっている。第３図，第４図，第５図及び
第６図を参照して説明する。In the conventional time synchronization system, the following system is used to maintain the synchronization system for the failure of the line for receiving the signal from the lower station of the upper station. Description will be made with reference to FIGS. 3, 4, 5, and 6.
２局間における時刻同期制御は，第６図に示す様に，上
位局にて自局のフレームの送信タイミング（ｅ）と下位
局からのフレームの受信タイミング（ｆ）との時間差
（TM）を計測し，この計測値を下位局へ送信する。下位
局では自局のフレームの送信タイミング（ｇ）と上位局
からのフレームの受信タイミング（ｈ）との時間差（T
S）を計測し，このTSと上位局から受信したTMの差が小
さくなる様に，自局のフレームの送信タイミングを制御
する。As shown in FIG. 6, the time synchronization control between two stations determines the time difference (TM) between the transmission timing (e) of the frame of its own station and the reception timing (f) of the frame from the lower station in the higher station. Measure and send the measured value to the lower station. In the lower station, the time difference (T) between the frame's frame transmission timing (g) and the frame's frame reception timing (h)
S) is measured, and the transmission timing of the frame of its own station is controlled so that the difference between this TS and the TM received from the higher station becomes smaller.
以上の制御はフレームを一定周期で送信することにより
繰返し実行され,TMとTSが等しくなる状態，つまり２局
間の時刻同期がとれた状態で安定する。The above control is repeatedly executed by transmitting the frame at a fixed cycle, and stabilizes when TM and TS are equal, that is, when the two stations have time synchronization.
第３図に示すようなA,BおよびＣ局から成る３端子構成
の場合は，常時,A局が主局となり、Ｂ局がＡ局に追従し
（即ち、Ｂ局が中間局になり）、Ｃ局がＢ局に追従する
（即ち、Ｃ局が最下位局になる）ことにより同期系は維
持される。In the case of a three-terminal configuration consisting of stations A, B, and C as shown in Fig. 3, station A is always the main station, and station B follows station A (that is, station B is the intermediate station). , C station follows B station (that is, C station becomes the lowest station), the synchronous system is maintained.
第４図に示すように,A局及びＢ局間の回線（ｃ）が障害
の場合には,B局ではＡ局からのフレームが受信出来ない
ために、,A局に追従不能となる為、Ｂ局は同期系の主局
となり，主局となったことをＡ局へＣ局経由で通知す
る。Ａ局では,B局からの通知を認識すると，主局状態を
解除し,C局に追従するように制御を開始する。この状態
ではＢ→Ｃ→Ａという同期系となり，同期が維持され
る。As shown in FIG. 4, when the line (c) between the A station and the B station has a failure, the B station cannot receive the frame from the A station, so that it cannot follow the A station. , Station B becomes the master station of the synchronization system, and notifies station A that it has become the master station via station C. When station A recognizes the notification from station B, it cancels the main station state and starts control so as to follow station C. In this state, the synchronization system is B → C → A, and the synchronization is maintained.
しかしながら，第５図に示すように,A局の下位局からの
信号の受信用の回線（ｄ）のみの障害が発生した場合に
は,A局ではTMを計測出来なくなる為，障害発生以前のTM
を保持し,B局へ送信し続けることによりＡ→Ｂ→Ｃの同
期系を維持している。However, as shown in FIG. 5, when a failure occurs only in the line (d) for receiving the signal from the lower station of station A, station A cannot measure the TM. TM
Is maintained and continues to be transmitted to station B, thereby maintaining the synchronous system of A → B → C.
上述した従来の主局の下位局（中間局）からの信号受信
用回線の障害に対する同期維持方式では，上述の回線の
障害発生中は，主局は障害発生以前のTMの値を保持し，
下位局に対して送信し続け，そのTMの値を基に同期系が
維持されている。このため，装置電源の瞬断等により，
主局が保持しているTMの値が障害発生以前のTMの値（T
M′）から他の値（TM″）に変化してしまうと，下位局
は誤ったTMの値（TM″）を基にフレームの送信タイミン
グの制御を行ない，第７図に示すように同期が維持出来
なくなるという欠点がある。In the above-mentioned conventional synchronization maintaining method for the failure of the signal receiving line from the lower station (intermediate station) of the main station, the main station retains the TM value before the failure while the line failure described above occurs.
The transmission is continued to the lower station, and the synchronization system is maintained based on the TM value. Therefore, due to momentary interruption of the device power supply,
The TM value held by the main station is the TM value (T
When M ′) changes to another value (TM ″), the lower station controls the frame transmission timing based on the incorrect TM value (TM ″) and synchronizes as shown in FIG. Has the drawback that it cannot be maintained.
第７図において,TS′は誤ったTMの値TM″により制御が
行なわれた時の下位局の時間差計測値を示す。In FIG. 7, TS 'indicates the time difference measurement value of the lower station when the control is performed with the wrong TM value TM ".
本発明の目的は、主局の中間局からの信号受信用回線の
障害時に中間局及び最下位局の同期が維持され得る時刻
同期制御方法を提供することにある。An object of the present invention is to provide a time synchronization control method capable of maintaining the synchronization between the intermediate station and the lowest station when the signal receiving line from the intermediate station of the main station fails.
［問題点を解決するための手段］ 本発明によれば、全二重回線を介して互に接続される第
１、第２、及び第３の局を有し、第１の局を主局とし、
第２の局を主局に追従する中間局とし、第３の局を中間
局に追従する最下位局とする通信システムにおいて、主
局は、主局のフレームの送信タイミングと中間局からの
フレームの受信タイミングとの時間差を第１の計測値と
して計測し、この第１の計測値を中間局へ送信し、中間
局は、中間局のフレームの送信タイミングと主局からの
フレームの受信タイミングとの時間差を第２の計測値と
して計測し、この第２の計測値と主局から受信した第１
の計測値が等しくなるように、中間局のフレームの送信
タイミングを、制御された送信タイミングに制御し、中
間局は、中間局のフレームの前記制御された送信タイミ
ングと最下位局からのフレームの受信タイミングとの時
間差を第３の計測値として計測し、この第３の計測値を
最下位局へ送信し、最下位局は、最下位局のフレームの
送信タイミングと中間局からのフレームの受信タイミン
グとの時間差を第４の計測値として計測し、この第４の
計測値と中間局から受信した第３の計測値が等しくなる
ように、最下位局のフレームの送信タイミングを制御す
る時刻同期制御方法において、 主局としての第１の局は、中間局としての第２の局から
のフレームが正常に受信出来なくなった場合に、フレー
ムに回線装置を示す第１のフラグをのせて第２の局に送
信し、 第２の局は、受信したフレームから該第１のフラグを検
出した場合と、主局としての第１の局からのフレームが
正常に受信出来なくなった場合との少なくとも一方の場
合に、中間局としてのフレームの送信タイミングの制御
を禁止し、主局としてのフレームの送信タイミングの制
御を開始し、かつ、第２の局が主局となったことを示す
第２のフラグをフレームにのせて第３の局に送信し、 第３の局は、受信したフレームから該第２のフラグを検
出した場合、最下位局としてのフレームの送信タイミン
グの制御を禁止し、中間局としてのフレームの送信タイ
ミングの制御を開始し、かつ、前記第２のフラグをその
まま第３のフラグとしてフレームにのせて第１の局に送
信し、 第１の局は、受信したフレームから該第３のフラグを検
出した場合、主局としてのフレームの送信タイミングの
制御を禁止し、最下位局としてのフレームの送信タイミ
ングの制御を開始することを特徴とする時刻同期制御方
法が得られる。[Means for Solving the Problems] According to the present invention, it has first, second, and third stations connected to each other via a full-duplex line, and the first station is the main station. age,
In a communication system in which the second station is an intermediate station that follows the main station and the third station is the lowest station that follows the intermediate station, the main station determines the frame transmission timing of the main station and the frame from the intermediate station. Is measured as a first measurement value, and the first measurement value is transmitted to the intermediate station. The intermediate station determines the frame transmission timing of the intermediate station and the frame reception timing of the main station. Is measured as the second measurement value, and the second measurement value and the first measurement value received from the master station are measured.
The transmission timing of the frame of the intermediate station is controlled to the controlled transmission timing so that the measured values of the intermediate station are equal, and the intermediate station controls the transmission timing of the frame of the intermediate station and the frame of the frame from the lowest station. The time difference from the reception timing is measured as a third measurement value, and the third measurement value is transmitted to the lowest station, and the lowest station transmits the timing of the frame of the lowest station and the reception of the frame from the intermediate station. Time synchronization that measures the time difference from the timing as the fourth measurement value, and controls the transmission timing of the frame of the lowest station so that the fourth measurement value and the third measurement value received from the intermediate station are equal. In the control method, the first station as the main station puts a first flag indicating the line device on the frame when the frame from the second station as the intermediate station cannot be received normally. The second station transmits to the second station, and the second station detects the first flag from the received frame and the case where the frame from the first station as the main station cannot be normally received. In at least one case, the control of the transmission timing of the frame as the intermediate station is prohibited, the control of the transmission timing of the frame as the main station is started, and the second station indicates that the second station has become the main station. When the second station detects the second flag from the received frame, the third station prohibits the control of the frame transmission timing as the lowest station when the second flag is transmitted to the third station. , Starts the control of the transmission timing of the frame as an intermediate station, and transmits the second flag as it is as a third flag to the frame by transmitting it to the first station, and the first station receives the received frame. From the third frame When detecting grayed prohibits the control of the transmission timing of the frame as the main station, the time synchronization control method characterized by initiating a control of the transmission timing of the frame as the lowest station is obtained.
［実施例］ 次に本発明について図面を参照して説明する。EXAMPLES Next, the present invention will be described with reference to the drawings.
第１図は本発明を３端子構成に適用した一実施例であ
る。この通信システムにおいて，同期系は，通常、Ａ局
を主局とし、Ｂ局がＡ局に追従し（即ち、Ｂ局が中間局
になり）、Ｃ局がＢ局に追従する（即ち、Ｃ局が最下位
局になる）ことにより同期がとられている。FIG. 1 is an embodiment in which the present invention is applied to a three-terminal configuration. In this communication system, the synchronous system usually has the A station as the main station, the B station follows the A station (that is, the B station becomes the intermediate station), and the C station follows the B station (that is, C station). The station will be the lowest station) has been synchronized by.
主局であるＡ局の下位局（中間局）からの信号受信用の
回線（ａ）に障害が発生した場合,A局はＢ局に回線異常
を示すフラグ１をフレームにのせて送信する。Ｂ局はＡ
局からフラグ１を受信することにより，フレームの送信
タイミング制御を禁止し、主局になる。また,B局は，第
２図に示すように，上位局からの信号受信用の回線
（ｂ）に障害が発生した場合にも，フレームの送信タイ
ミング制御を禁止し，主局になる。同時に,B局は主局に
なったことを，通知するためにＣ局へフラグ２を送信す
る。Ｃ局ではＢ局が主局となったこと（Ｂ局からフラグ
２を受信したこと）をＡ局に通知するためにＡ局へフラ
グ３を送信する（中継機能）。Ａ局ではＣ局からフラグ
３を受信することにより主局状態を解除し,C局に追従す
るために，フレームの送信タイミング制御を開始する。When a failure occurs in the signal receiving line (a) from the lower station (intermediate station) of the A station which is the main station, the A station transmits the flag 1 indicating the line abnormality to the B station in the frame. Station B is A
By receiving flag 1 from the station, the transmission timing control of the frame is prohibited and the station becomes the master station. Also, as shown in FIG. 2, station B prohibits frame transmission timing control and becomes the main station even when a failure occurs in the line (b) for signal reception from the upper station. At the same time, station B sends flag 2 to station C to notify that it has become the master station. In station C, flag 3 is transmitted to station A in order to notify station A that station B has become the main station (that flag 2 has been received from station B) (relay function). The station A cancels the state of the main station by receiving the flag 3 from the station C, and starts frame transmission timing control in order to follow the station C.
以上の手順により,A局の下位局からの信号受信用の回線
の障害時は,B局が主局となり,C局がＢ局に追従し（即
ち、Ｃ局が中間局になり）、Ａ局がＣ局に追従する（即
ち、Ａ局が最下位局になる）同期系となり，同期が維持
される。According to the above procedure, when the line for receiving the signal from the lower station of station A fails, station B becomes the main station, station C follows station B (that is, station C becomes the intermediate station), and station A becomes The station becomes a synchronization system in which the station follows the station C (that is, the station A becomes the lowest station), and the synchronization is maintained.
以上説明したように本発明は、主局が中間局からの受信
回線異常を中間局へ通知し、これにより中間局を主局に
変更させることにより，サンプリング時刻同期系等の時
刻同期系の再構成制御を可能とし，サンプリング時刻同
期等の時刻同期が維持不可能となる要因を排除出来る効
果がある。As described above, according to the present invention, the main station notifies the intermediate station of an error in the receiving line from the intermediate station, and by changing the intermediate station to the main station, the time synchronization system such as the sampling time synchronization system is re-established. This has the effect of enabling configuration control and eliminating factors that make it impossible to maintain time synchronization, such as sampling time synchronization.
第１図及び第２図は本発明の一実施例による時刻同期制
御方式を説明するためのシステム構成図である。 第３図は通常状態のシステム構成図である。 第４図及び第５図は従来の時刻同期制御方式を説明する
ためのシステム構成図である。 第６図は従来の時刻同期制御方式を説明するための図で
ある。 第７図は従来の時刻同期制御方式における同期維持不能
の状態を説明するための図である。 ａ〜ｄは回線障害箇所,e及びｇはフレーム送信タイミン
グ,f及びｈはフレーム受信タイミング,TMは上位局の時
間差計測値,TM′は保持しているTMの値,TM″は誤った値
のTM,TSは下位局の時間差計測値,TS′はTM″により制御
が行なわれた時のTSを示す。又，第１図〜第５図中の◎
は主局であることを示す。1 and 2 are system configuration diagrams for explaining a time synchronization control method according to an embodiment of the present invention. FIG. 3 is a system configuration diagram in a normal state. 4 and 5 are system configuration diagrams for explaining a conventional time synchronization control method. FIG. 6 is a diagram for explaining a conventional time synchronization control method. FIG. 7 is a diagram for explaining a state in which synchronization cannot be maintained in the conventional time synchronization control method. a to d are line fault locations, e and g are frame transmission timings, f and h are frame reception timings, TM is a time difference measurement value of the upper station, TM 'is the value of TM held, and TM "is an incorrect value. , TM and TS are time difference measurement values of the lower station, and TS ′ is TS when control is performed by TM ″. In addition, ◎ in Figs. 1 to 5
Indicates the main station.
Claims (1)
第２、及び第３の局を有し、第１の局を主局とし、第２
の局を主局に追従する中間局とし、第３の局を中間局に
追従する最下位局とする通信システムにおいて、主局
は、主局のフレームの送信タイミングと中間局からのフ
レームの受信タイミングとの時間差を第１の計測値とし
て計測し、この第１の計測値を中間局へ送信し、中間局
は、中間局のフレームの送信タイミングと主局からのフ
レームの受信タイミングとの時間差を第２の計測値とし
て計測し、この第２の計測値と主局から受信した第１の
計測値が等しくなるように、中間局のフレームの送信タ
イミングを、制御された送信タイミングに制御し、中間
局は、中間局のフレームの前記制御された送信タイミン
グと最下位局からのフレームの受信タイミングとの時間
差を第３の計測値として計測し、この第３の計測値を最
下位局へ送信し、最下位局は、最下位局のフレームの送
信タイミングと中間局からのフレームの受信タイミング
との時間差を第４の計測値として計測し、この第４の計
測値と中間局から受信した第３の計測値が等しくなるよ
うに、最下位局のフレームの送信タイミングを制御する
時刻同期制御方法において、 主局としての第１の局は、中間局としての第２の局から
のフレームが正常に受信出来なくなった場合に、フレー
ムに回線異常を示す第１のフラグをのせて第２の局に送
信し、 第２の局は、受信したフレームから該第１のフラグを検
出した場合と、主局としての第１の局からのフレームが
正常に受信出来なくなった場合との少なくとも一方の場
合に、中間局としてのフレームの送信タイミングの制御
を禁止し、主局としてのフレームの送信タイミングの制
御を開始し、かつ、第２の局が主局となったことを示す
第２のフラグをフレームにのせて第３の局に受信し、 第３の局は、受信したフレームから該第２のフラグを検
出した場合、最下位局としてのフレームの送信タイミン
グの制御を禁止し、中間局としてのフレームの送信タイ
ミングの制御を開始し、かつ、前記第２のフラグをその
まま第３のフラグとしてフレームにのせて第１の局に送
信し、 第１の局は、受信したフレームから該第３のフラグを検
出した場合、主局としてのフレームの送信タイミングの
制御を禁止し、最下位局としてのフレームの送信タイミ
ングの制御を開始することを特徴とする時刻同期制御方
法。1. A first connected to each other via a full-duplex line,
Has a second station and a third station, with the first station as the main station and the second station
In a communication system in which the station is an intermediate station that follows the main station and the third station is the lowest station that follows the intermediate station, the main station determines the frame transmission timing of the main station and the reception of the frame from the intermediate station. The time difference from the timing is measured as the first measurement value, and the first measurement value is transmitted to the intermediate station, and the intermediate station measures the time difference between the frame transmission timing of the intermediate station and the frame reception timing of the main station. Is measured as the second measurement value, and the transmission timing of the frame of the intermediate station is controlled to the controlled transmission timing so that the second measurement value and the first measurement value received from the main station are equal. The intermediate station measures a time difference between the controlled transmission timing of the frame of the intermediate station and the reception timing of the frame from the lowest station as a third measurement value, and sends the third measurement value to the lowest station. Send and up The station measures the time difference between the frame transmission timing of the lowest station and the frame reception timing of the intermediate station as a fourth measurement value, and the fourth measurement value and the third measurement received from the intermediate station. In the time synchronization control method that controls the frame transmission timing of the lowest station so that the values become equal, the first station as the main station can normally receive the frame from the second station as the intermediate station. When it disappears, a first flag indicating a line abnormality is put on the frame and transmitted to the second station, and the second station detects the first flag from the received frame and Control the transmission timing of the frame as the intermediate station and control the transmission timing of the frame as the main station in at least one of the case where the frame from the first station cannot be received normally. And a second flag indicating that the second station has become the main station is placed on the frame and received by the third station, and the third station receives the second flag from the received frame. When the flag is detected, the control of the transmission timing of the frame as the lowest station is prohibited, the control of the transmission timing of the frame as the intermediate station is started, and the second flag is used as it is as the third flag. When the first station detects the third flag from the received frame, the first station prohibits the control of the transmission timing of the frame as the main station, and the first station as the lowest station. A time synchronization control method characterized by starting control of frame transmission timing.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61308032A JPH0752872B2 (en) | 1986-12-25 | 1986-12-25 | Time synchronization control method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61308032A JPH0752872B2 (en) | 1986-12-25 | 1986-12-25 | Time synchronization control method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS63161743A JPS63161743A (en) | 1988-07-05 |
| JPH0752872B2 true JPH0752872B2 (en) | 1995-06-05 |
Family
ID=17976063
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP61308032A Expired - Lifetime JPH0752872B2 (en) | 1986-12-25 | 1986-12-25 | Time synchronization control method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0752872B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP6567846B2 (en) * | 2015-03-18 | 2019-08-28 | Kddi株式会社 | Synchronization apparatus, base station apparatus, network node, and control method |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS56166656A (en) * | 1980-05-28 | 1981-12-21 | Toshiba Corp | Data way control system |
| JPH0644753B2 (en) * | 1986-06-10 | 1994-06-08 | 三菱電機株式会社 | Sampling synchronization monitoring method |
| JPH0644754A (en) * | 1991-10-04 | 1994-02-18 | Nec Home Electron Ltd | Magnetic recording and reproducing device |
-
1986
- 1986-12-25 JP JP61308032A patent/JPH0752872B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPS63161743A (en) | 1988-07-05 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EXPY | Cancellation because of completion of term |