JPH11112429A - Optical signal monitoring device and its method - Google Patents
Optical signal monitoring device and its methodInfo
- Publication number
- JPH11112429A JPH11112429A JP9268812A JP26881297A JPH11112429A JP H11112429 A JPH11112429 A JP H11112429A JP 9268812 A JP9268812 A JP 9268812A JP 26881297 A JP26881297 A JP 26881297A JP H11112429 A JPH11112429 A JP H11112429A
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- signal
- slave station
- optical
- station
- optical signal
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- Monitoring And Testing Of Transmission In General (AREA)
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Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は光信号の監視装置と
その監視方法に関し、とくに子局から親局へ送信される
光信号の監視装置とその監視方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a monitoring apparatus for optical signals and a monitoring method therefor, and more particularly to a monitoring apparatus for optical signals transmitted from a slave station to a master station and a monitoring method therefor.
【０００２】[0002]
【従来の技術】従来、例えばパッシブダブルスター方式
光通信システムは、図２に示すような基本構成を備えて
いる。すなわち、親局１は電気光変換装置（Ｅ／Ｏ装
置）および光電気変換装置（Ｏ／Ｅ装置）を備え、これ
ら装置はそれぞれスターカプラ３を介して複数の子局２
と接続している。Ｅ／Ｏ装置に接続する伝送路は親局１
から複数の子局２への下り信号が伝送され、Ｏ／Ｅ装置
に接続する伝送路は複数の子局２から親局１への上り信
号が伝送される。2. Description of the Related Art Conventionally, for example, a passive double star optical communication system has a basic configuration as shown in FIG. That is, the master station 1 includes an electro-optical converter (E / O device) and an opto-electric converter (O / E device).
Is connected to The transmission path connected to the E / O device is master station 1
A downstream signal is transmitted from the plurality of slave stations 2 to the plurality of slave stations 2, and an upstream signal from the plurality of slave stations 2 to the master station 1 is transmitted through a transmission path connected to the O / E device.
【０００３】上記光通信システムでは、各子局から親局
への送信のタイミングを決定する場合、子局の初期加入
時に行われる各子局毎の送信遅延時間の測定結果に基づ
き送信レベルを算出している。In the above optical communication system, when determining the timing of transmission from each slave station to the master station, the transmission level is calculated based on the measurement result of the transmission delay time of each slave station performed at the time of initial joining of the slave station. doing.
【０００４】これを図３を用いて説明する。親局１のＴ
ＤＭＡ制御部４は、子局の初期加入時に、各子局から送
信されるデータが伝送路上で衝突しないようにするた
め、子局の送信遅延時間を測定するための信号を各子局
に送出する。例えば所定のタイムスロットにある特定の
子局２のみが、応答を親局に返すようなデータを設定す
る。子局２がデータを返送すると、光検出部５が光受信
データＤ１を受信し、電気信号に変換し受信データＤ２
を出力する。ＴＤＭＡ制御部４は、電気信号に変換され
た受信データＤ２を受けて、各子局に対し送信遅延時間
を設定するための送信データＤ３を出力する。ＬＤ駆動
部６は送信データＤ３を受信し、駆動電流信号Ｄ４を出
力する。該駆動電流信号Ｄ４に基づきＬＤ７は光信号Ｄ
５を送信遅延時間を設定するための信号として子局２へ
送出する。子局ではこの信号によって送信遅延時間を設
定する。また、その後親局から各子局へ周期的に一斉送
出される信号に応じて、各子局はそれぞれ固有の送信遅
延時間で親局にデータ信号を送ることができる。This will be described with reference to FIG. T of master station 1
The DMA control unit 4 sends a signal for measuring the transmission delay time of each slave station to each slave station at the time of initial joining of the slave stations so that data transmitted from each slave station does not collide on the transmission path. I do. For example, data is set so that only a specific slave station 2 in a predetermined time slot returns a response to the master station. When the slave station 2 returns the data, the light detection unit 5 receives the light reception data D1, converts it into an electric signal, and converts the reception data D2.
Is output. TDMA control section 4 receives reception data D2 converted into an electric signal, and outputs transmission data D3 for setting a transmission delay time to each slave station. The LD driver 6 receives the transmission data D3 and outputs a drive current signal D4. Based on the drive current signal D4, the LD 7 outputs the optical signal D
5 is transmitted to the slave station 2 as a signal for setting the transmission delay time. The slave station sets the transmission delay time using this signal. In addition, each slave station can send a data signal to the master station with a unique transmission delay time in response to a signal periodically and simultaneously transmitted from the master station to each slave station.
【０００５】[0005]
【発明が解決しようとする課題】上述のパッシブダブル
スター方式の光バースト信号の伝送においては、各子局
の送信遅延時間の測定結果をもとに各子局の親局に対す
る光送信レベルを決定している。通常、子局または上り
方向（子局から親局へ）の伝送路に何らかの異常があっ
た場合、親局での受信レベルが所定値から低下する場合
がある。この場合、あるレベルまでのレベル低下は受信
に影響はないが、そのレベルを越えてレベルが低下する
と、親局は子局からの信号が断になったと判断する。受
信レベルが大きく変動しても受信データを受信可能とす
るには、親局でのダイナミックレンジを大きくし、受信
レベルの変動に高速で応答する構成としなければならな
い。このような構成は、複雑で高価なものとなる。In the transmission of the optical burst signal of the passive double star system described above, the optical transmission level of each slave station with respect to the master station is determined based on the measurement result of the transmission delay time of each slave station. doing. Normally, if there is any abnormality in the transmission path in the slave station or in the uplink (from the slave station to the master station), the reception level at the master station may drop from a predetermined value. In this case, the lowering of the level to a certain level does not affect reception, but if the level drops beyond that level, the master station determines that the signal from the slave station has been interrupted. In order to be able to receive the received data even when the reception level fluctuates greatly, the dynamic range at the master station must be widened and the configuration must respond to the fluctuation of the reception level at high speed. Such a configuration is complicated and expensive.
【０００６】また、逆に、ある子局からの光信号が完全
に停止しない場合、親局で受信する他の子局からの受信
信号が上記障害のある子局からの信号と重なってしま
い、適正な受信ができなくなり、システムの停止につな
がる可能性が生じる。On the other hand, if the optical signal from a certain slave station does not completely stop, the signal received by the master station from another slave station overlaps with the signal from the faulty slave station. Proper reception cannot be performed, and the system may be stopped.
【０００７】本発明の目的は、レベル変動の原因である
子局の光送信部または上り方向の伝送路の障害や劣化を
すみやかに検知し、すみやかに障害個所にアクセスする
ことにより、致命的な障害に至る前に必要な対応を可能
にする光信号監視装置とその方法を提供することを目的
とする。An object of the present invention is to immediately detect a failure or deterioration of an optical transmission unit or an upstream transmission line of a slave station which causes a level change, and to immediately access the failure location to make a fatal error. An object of the present invention is to provide an optical signal monitoring device and a method thereof that enable necessary countermeasures before a failure occurs.
【０００８】[0008]
【課題を解決するための手段】上記課題を解決する本発
明の光信号監視装置は、複数の子局から親局へ送信され
る光信号を監視する光信号監視装置であり、子局からの
光データ信号を受信し該光データ信号を電気信号に変換
して出力すると共に子局からの光データ信号の受信レベ
ルを示す信号を出力する光検出部を備えている。さら
に、上記電気信号に変換された子局からのデータ信号を
受信し親局と子局の間の伝送距離を示す伝送距離信号を
出力する制御部と、上記伝送距離信号を受信し該信号の
示す距離に応じた光受信レベル期待値を算出し出力する
距離ーレベル変換部と、上記子局からの光データ信号の
受信レベルを示す信号と光受信レベル期待値とを受信し
これらを比較し両者のレベル差が所定値を越えた場合に
警報を出力する比較部を備える。An optical signal monitoring apparatus according to the present invention for solving the above-mentioned problems is an optical signal monitoring apparatus for monitoring optical signals transmitted from a plurality of slave stations to a master station. An optical detector is provided for receiving the optical data signal, converting the optical data signal into an electric signal and outputting the signal, and outputting a signal indicating the reception level of the optical data signal from the slave station. Further, a control unit that receives a data signal from the slave station converted to the electric signal and outputs a transmission distance signal indicating a transmission distance between the master station and the slave station, and receives the transmission distance signal and receives a signal of the signal. A distance-level converter that calculates and outputs an optical reception level expected value corresponding to the indicated distance, and receives and compares the signal indicating the optical data signal reception level from the slave station and the optical reception level expected value, and compares them. And a comparator that outputs an alarm when the level difference exceeds a predetermined value.
【０００９】また、上記伝送距離信号は各子局毎の送信
遅延時間から換算し、この送信遅延時間は親局から各子
局へ信号を送出し各子局から受信したデータに基づいて
算出することができる。The transmission distance signal is converted from the transmission delay time of each slave station, and the transmission delay time is calculated based on data transmitted from the master station to each slave station and received from each slave station. be able to.
【００１０】上記制御部は前記光検出部、距離ーレベル
変換部、および比較部へタイミング信号を出力すること
ができる。The control unit can output a timing signal to the light detection unit, the distance-level conversion unit, and the comparison unit.
【００１１】上記課題を解決する他の発明は、各子局か
ら親局へ送られる光信号の受信レベルの期待値を算出
し、この期待値と実際に受信した光信号のレベルとを比
較し、その差が所定値を越えた場合は警報を出力する光
信号監視方法である。Another invention for solving the above problem is to calculate an expected value of a reception level of an optical signal transmitted from each slave station to a master station, and compare the expected value with the level of an actually received optical signal. This is an optical signal monitoring method for outputting an alarm when the difference exceeds a predetermined value.
【００１２】上記比較は所定のタイミング信号に合わせ
て行われる。また、上記受信レベルの期待値は親局と各
子局の間の伝送距離を示す伝送距離信号から算出され得
る。The above comparison is performed in accordance with a predetermined timing signal. Further, the expected value of the reception level can be calculated from a transmission distance signal indicating a transmission distance between the master station and each slave station.
【００１３】上述の構成および方法により、子局または
親局と複数の子局との間の上り方向の伝送路の障害や劣
化がすみやかに親局の管理者に検知される。According to the above configuration and method, the failure or deterioration of the upstream transmission path between the slave station or the master station and the plurality of slave stations is immediately detected by the manager of the master station.
【００１４】[0014]
【発明の実施の形態】次に、本発明の実施の形態につい
て図面を用いて説明する。図１は本発明の光信号監視装
置の構成例を示すブロック図である。Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a configuration example of the optical signal monitoring device of the present invention.
【００１５】図１は親局の一部を示す。各子局からの光
データ信号Ｓ４を受信する光検出部５は、ＴＤＭＡ制御
部４と比較部８とに接続している。光検出部５からＴＤ
ＭＡ制御部４へは電気信号に変換された各子局からのデ
ータ信号Ｓ５が送られ、同光検出部５から比較部８へ上
記光データ信号の受信レベルを表す信号Ｓ６が送られ
る。上記ＴＤＭＡ制御部４と比較部８の間には距離ーレ
ベル変換部９が配置される。ＴＤＭＡ制御部４は各子局
からのデータ信号Ｓ５を受信すると、記憶している各子
局の送信遅延時間に基づき伝送距離信号Ｓ８を算出し、
これを距離ーレベル変換部９に送る。該距離ーレベル変
換部９はＴＤＭＡ制御部４が出力した伝送距離信号Ｓ８
を受信し、該信号を基に親局と各子局との距離に応じた
光受信レベル期待値Ｓ９を比較部８に送出する。上記Ｔ
ＤＭＡ制御部４は、光検出部５、比較部８、及び距離ー
レベル変換部９と接続しており、それぞれへタイミング
パルスＳ７を送る。比較部８は、各子局についての光受
信レベル期待値と受信レベルを示す信号を比較し、両レ
ベルの差が所定値以上の場合、警報Ｓ１０を親局の監視
部（図示せず）へ送出する。また上記ＴＤＭＡ制御部４
にはＬＤ駆動部６が接続し、さらにＬＤ７が配置されて
いる。ＴＤＭＡ制御部４はこれらを介して各子局へ所定
の間隔で一斉信号を送る。FIG. 1 shows a part of the master station. The light detection unit 5 that receives the optical data signal S4 from each slave station is connected to the TDMA control unit 4 and the comparison unit 8. TD from light detector 5
The MA controller 4 receives a data signal S5 from each slave station, which has been converted into an electric signal. The light detector 5 sends a signal S6 representing the reception level of the optical data signal to the comparator 8. A distance-level converter 9 is arranged between the TDMA controller 4 and the comparator 8. Upon receiving the data signal S5 from each slave station, the TDMA control unit 4 calculates a transmission distance signal S8 based on the stored transmission delay time of each slave station,
This is sent to the distance-level converter 9. The distance-to-level converter 9 outputs the transmission distance signal S8 output from the TDMA controller 4.
And sends an expected light receiving level S9 corresponding to the distance between the master station and each slave station to the comparing section 8 based on the signal. T above
The DMA control unit 4 is connected to the light detection unit 5, the comparison unit 8, and the distance-level conversion unit 9, and sends a timing pulse S7 to each of them. The comparing unit 8 compares the expected value of the optical reception level of each slave station with the signal indicating the reception level, and if the difference between the two levels is equal to or greater than a predetermined value, sends an alarm S10 to the monitoring unit (not shown) of the master station. Send out. The TDMA control unit 4
Is connected to an LD driving unit 6, and an LD 7 is further disposed. The TDMA control unit 4 sends a broadcast signal to each slave station at a predetermined interval via these.
【００１６】次に、上記図１の構成の動作について説明
する。Next, the operation of the configuration shown in FIG. 1 will be described.
【００１７】まず従来行われている子局の初期加入の動
作を説明する。ネットワーク内で各子局の新設、増設を
行う際、初期加入の登録設定が運用上行われる。その
際、各子局から親局への送信データが伝送路上で衝突し
ないような処置がなされる。すなわち、各子局が親局へ
どの程度タイミングをずらして送信データを送出すれば
よいかを決めるために、親局のＴＤＭＡ制御部４から各
子局に対して、子局送信遅延時間を測定するためのデー
タ（基準時刻信号）を送出する。このデータに応じて各
子局から送出されたデータは、光検出部５で受信され電
気信号に変換されてＴＤＭＡ制御部４へ送られる。ＴＤ
ＭＡ制御部４は、該信号に基づき、各子局がお互いにど
の程度送信時間を遅らせればよいかに関する子局送信遅
延時間を算出し、自身で記憶すると共に該送信遅延時間
を各子局に設定するための信号を送出する。該信号はＬ
Ｄ駆動部６およびＬＤ７を介して各子局へ送出され、各
子局はそれぞれ自己の送信遅延時間を設定する。First, a description will be given of the operation of the conventional initial joining of a slave station. When new stations are added or expanded in the network, registration settings for initial subscription are made in operation. At this time, measures are taken to prevent transmission data from each slave station to the master station from colliding on the transmission path. That is, in order to determine how much timing each mobile station should transmit transmission data to the master station, the TDMA control section 4 of the master station measures the slave station transmission delay time for each slave station. To send data (reference time signal). The data transmitted from each slave station according to this data is received by the light detection unit 5, converted into an electric signal, and transmitted to the TDMA control unit 4. TD
The MA control unit 4 calculates a slave station transmission delay time concerning how much each slave station should delay the transmission time with respect to each other based on the signal, stores the slave station itself, and stores the transmission delay time in each slave station. The signal for setting to is sent. The signal is L
The data is transmitted to each slave station via the D driver 6 and the LD 7, and each slave station sets its own transmission delay time.
【００１８】以上は従来の子局の初期加入の動作である
が、本発明の特徴は以下の点にある。上記ＴＤＭＡ制御
部４は、周期的に各子局へ一斉信号を送出している。こ
の信号に応じて各子局は必要に応じて所定の送信遅延時
間で親局に信号を送る。この送出された信号は、親局が
定めた所定の順（例えば子局の加入順）で光検出部５に
届く。光検出部５は、ＴＤＭＡ制御部４へ電気信号に変
換された各子局からのデータ信号Ｓ５を送り、比較部８
へは各子局から受信した信号の受信レベルを示す信号Ｓ
６を送る。ＴＤＭＡ制御部４は、各子局からの信号を受
信すると、記憶している子局の送信遅延時間に基づき、
各子局までの伝送距離を表す伝送距離信号を算出し、距
離ーレベル変換部９へ出力する。距離ーレベル変換部９
は、受信した各子局の伝送距離信号に基づき、それぞれ
の子局からどの程度の受信レベルの信号を受けるはずで
あるかを示す受信レベル期待値を算出し、ＴＤＭＡ制御
部４が送出するタイミング信号に従って比較部８へ出力
する。一方、上述のように光検出部５は各子局から送出
された光データ信号の受信レベルを示す信号を同じく上
記タイミング信号に従って比較部８へ送出する。比較部
はＴＤＭＡ制御部４が送出するタイミング信号を受け、
このタイミングで上記受信レベル期待値と受信した光デ
ータ信号の受信レベルを比較し、両者のレベル差が所定
値を越えた場合、子局、または伝送路に異常があると判
断し、警報を親局の監視部へ出力する。この結果、警報
を受けた親局の管理者は故障個所に速やかにアクセスで
きる。なお上記レベル差としては例えば１０ｄＢ程度が
考えられる。各子局からの受信データの信号レベルが全
て変化しているときは、スターカプラと親局間の伝送路
に異常が生じたと判断できる。The above is the operation of the conventional mobile station for initial joining. The features of the present invention are as follows. The TDMA control unit 4 periodically sends a simultaneous signal to each slave station. In response to this signal, each slave station sends a signal to the master station with a predetermined transmission delay time as needed. The transmitted signal reaches the light detection unit 5 in a predetermined order determined by the master station (for example, the order of joining slave stations). The light detection unit 5 sends the data signal S5 from each slave station converted to an electric signal to the TDMA control unit 4,
Is a signal S indicating the reception level of the signal received from each slave station.
Send 6. When receiving the signal from each slave station, the TDMA control unit 4 calculates the signal based on the stored transmission delay time of the slave station.
The transmission distance signal indicating the transmission distance to each slave station is calculated and output to the distance-level converter 9. Distance-level converter 9
Is calculated based on the received transmission distance signal of each slave station, and calculates a reception level expected value indicating how much a signal of the reception level should be received from each slave station. The signal is output to the comparing section 8 according to the signal. On the other hand, as described above, the light detection unit 5 sends a signal indicating the reception level of the optical data signal sent from each slave station to the comparison unit 8 in accordance with the timing signal. The comparison unit receives the timing signal transmitted by the TDMA control unit 4,
At this timing, the expected reception level is compared with the reception level of the received optical data signal. If the difference between the two exceeds a predetermined value, it is determined that there is an abnormality in the slave station or the transmission line, and the alarm is issued. Output to the monitoring unit of the station. As a result, the administrator of the master station that has received the alert can quickly access the failure location. The level difference may be, for example, about 10 dB. When all the signal levels of the data received from the slave stations change, it can be determined that an abnormality has occurred in the transmission path between the star coupler and the master station.
【００１９】図１ではＴＤＭＡ制御部４と距離ーレベル
変換部９は別の機能ブロックとして表されているが、実
際は同じＣＰＵまたはＡＳＩＣ中に構成できる。また比
較部８も同様である。Although the TDMA control section 4 and the distance-level conversion section 9 are shown as separate function blocks in FIG. 1, they can be actually configured in the same CPU or ASIC. The same applies to the comparison unit 8.
【００２０】[0020]
【発明の効果】以上述べたように、本発明の光信号監視
装置および監視方法はパッシブダブルスター方式の光信
号伝送において、各子局毎の送信遅延時間に基づき決定
した子局毎の受信レベル期待値と実際に各子局から受信
した光受信レベルを比較、監視することにより、子局ま
たは子局から親局への上り方向の伝送路の障害および劣
化をすみやかに検出することができる。As described above, according to the optical signal monitoring apparatus and the monitoring method of the present invention, in the optical signal transmission of the passive double star system, the reception level of each slave station determined based on the transmission delay time of each slave station. By comparing and monitoring the expected value and the optical reception level actually received from each slave station, it is possible to promptly detect the failure and deterioration of the uplink transmission path from the slave station or the slave station to the master station.
【図１】本発明の光信号監視装置の構成例を示すブロッ
ク図。FIG. 1 is a block diagram showing a configuration example of an optical signal monitoring device of the present invention.
【図２】パッシブダブルスター方式光伝送システムの概
略構成図。FIG. 2 is a schematic configuration diagram of a passive double star optical transmission system.
【図３】従来の光伝送システムの一部の構成例を示すブ
ロック図。FIG. 3 is a block diagram showing a configuration example of a part of a conventional optical transmission system.
１ 親局 ２ 子局 ３ スターカプラ ４ ＴＤＭＡ制御部 ５ 光検出部 ８ 比較部 ９ 距離ーレベル変換部 Reference Signs List 1 master station 2 slave station 3 star coupler 4 TDMA control unit 5 light detection unit 8 comparison unit 9 distance-level conversion unit
Claims (8)
る光信号監視装置であって、子局からの光データ信号を
受信し該光データ信号を電気信号に変換して出力すると
共に前記光データ信号の受信レベルを表す信号を出力す
る光検出部と、 前記電気信号に変換された子局からのデータ信号を受信
し親局と該子局の間の伝送距離を示す伝送距離信号を出
力する制御部と、 前記伝送距離信号を受信し該信号の示す距離に応じた光
受信レベル期待値を算出し出力する距離ーレベル変換部
と、 前記子局からの光データ信号の受信レベルを表す信号と
該子局の光受信レベル期待値とを受信しこれらを比較し
両者の差が所定値を越えた場合に警報を出力する比較部
とを備えたことを特徴とする光伝送路監視装置。An optical signal monitoring device for monitoring an optical signal transmitted from a slave station to a master station, the optical signal monitoring apparatus receiving an optical data signal from the slave station, converting the optical data signal into an electric signal, and outputting the electric signal. A light detection unit that outputs a signal representing the reception level of the optical data signal, and a transmission distance indicating a transmission distance between the master station and the slave station, receiving the data signal from the slave station converted to the electric signal. A control unit that outputs a signal; a distance-level conversion unit that receives the transmission distance signal and calculates and outputs an expected optical reception level according to the distance indicated by the signal; and a reception level of an optical data signal from the slave station. And a comparison unit that receives a signal representing the optical reception level and an expected optical reception level of the slave station, compares them, and outputs an alarm when the difference between the two exceeds a predetermined value. Monitoring device.
ら換算したものである請求項１記載の光信号監視装置。2. The optical signal monitoring apparatus according to claim 1, wherein said transmission distance signal is converted from a transmission delay time of a slave station.
予め基準信号を送出し各子局から受信したデータに基づ
いて算出したものである請求項２記載の光信号監視装
置。3. The optical signal monitoring apparatus according to claim 2, wherein the transmission delay time of the slave station is calculated based on data transmitted from the master station to the slave station in advance and received from each slave station.
変換部、および比較部へタイミング信号を出力する請求
項１記載の光信号監視装置。4. The optical signal monitoring apparatus according to claim 1, wherein said control section outputs a timing signal to said light detection section, distance-level conversion section, and comparison section.
接続されている請求項１記載の光信号監視装置。5. The optical signal monitoring apparatus according to claim 1, wherein said master station and each slave station are connected via a star coupler.
る光信号監視方法であって、各子局から親局へ送られる
光信号の受信レベルの期待値を算出し、この期待値と実
際に受信した光信号のレベルとを比較し、両者の差が所
定値を越えた場合に警報を出力することを特徴とする光
信号監視方法。6. An optical signal monitoring method for monitoring an optical signal transmitted from a slave station to a master station, wherein an expected value of a reception level of an optical signal sent from each slave station to the master station is calculated. An optical signal monitoring method comprising comparing a value with a level of an actually received optical signal, and outputting an alarm when a difference between the two exceeds a predetermined value.
にしたがって行われる請求項６記載の光信号監視方法。7. The optical signal monitoring method according to claim 6, wherein said level comparison is performed according to a predetermined timing signal.
間の伝送距離を示す伝送距離信号から算出される請求項
６記載の光信号監視方法。8. The optical signal monitoring method according to claim 6, wherein the expected value of the reception level is calculated from a transmission distance signal indicating a transmission distance between the master station and each slave station.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9268812A JPH11112429A (en) | 1997-10-01 | 1997-10-01 | Optical signal monitoring device and its method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9268812A JPH11112429A (en) | 1997-10-01 | 1997-10-01 | Optical signal monitoring device and its method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH11112429A true JPH11112429A (en) | 1999-04-23 |
Family
ID=17463607
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP9268812A Pending JPH11112429A (en) | 1997-10-01 | 1997-10-01 | Optical signal monitoring device and its method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH11112429A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008227785A (en) * | 2007-03-12 | 2008-09-25 | Fujitsu Telecom Networks Ltd | Station-side optical subscriber-line terminating apparatus |
| JP2011066608A (en) * | 2009-09-16 | 2011-03-31 | Nec Corp | Intra-office device, subscriber device, optical communication system, method of identifying fault device, and program of device |
| WO2023095283A1 (en) * | 2021-11-26 | 2023-06-01 | 日本電信電話株式会社 | Terminal device, communication method, and program |
-
1997
- 1997-10-01 JP JP9268812A patent/JPH11112429A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008227785A (en) * | 2007-03-12 | 2008-09-25 | Fujitsu Telecom Networks Ltd | Station-side optical subscriber-line terminating apparatus |
| JP2011066608A (en) * | 2009-09-16 | 2011-03-31 | Nec Corp | Intra-office device, subscriber device, optical communication system, method of identifying fault device, and program of device |
| WO2023095283A1 (en) * | 2021-11-26 | 2023-06-01 | 日本電信電話株式会社 | Terminal device, communication method, and program |
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