JPS60226235A - Optical fiber communication system - Google Patents
Optical fiber communication systemInfo
- Publication number
- JPS60226235A JPS60226235A JP59082245A JP8224584A JPS60226235A JP S60226235 A JPS60226235 A JP S60226235A JP 59082245 A JP59082245 A JP 59082245A JP 8224584 A JP8224584 A JP 8224584A JP S60226235 A JPS60226235 A JP S60226235A
- Authority
- JP
- Japan
- Prior art keywords
- signal
- optical
- video
- selection
- switch
- 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.)
- Pending
Links
Landscapes
- Optical Communication System (AREA)
Abstract
Description
【発明の詳細な説明】
本発明は映像信号を送出する中央局装置と、映像信号を
受信する加入者装置との間の光フアイバ通信方式に関し
、とくに、加入者装置側から発生する映像信号選択信号
により中央局装置側の信号選択部が動作することによシ
加入者が希望する映像信号１チヤンネルのみを中央局装
置から加入者装置へ伝送する光フアイバ通信方式に関す
る。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an optical fiber communication system between a central office device that transmits video signals and a subscriber device that receives video signals, and particularly relates to a method for selecting video signals generated from the subscriber device side. The present invention relates to an optical fiber communication system in which only one channel of video signals desired by a subscriber is transmitted from the central office to the subscriber equipment by operating a signal selection section on the central office equipment side in response to a signal.
従来の選択形映像信号伝送方式においては、加入者装置
からの映像信号選択信号（以下上り信号と略す。）を中
央局装置からの映像信号（以下下多信号と略す。）に重
畳して伝送するために、第一の例として、下多信号伝送
用と上多信号伝送用に各々の発光素子の発光中心波長を
変えて光合分波器を利用して波長分割多重によって伝送
したシ、あるいは、第二の例として、下多信号伝送用と
上多信号伝送用の各々に光フアイバ伝送路を設置して双
方向伝送をしたシしている。In the conventional selective video signal transmission system, a video signal selection signal (hereinafter referred to as the upstream signal) from the subscriber equipment is superimposed on the video signal (hereinafter referred to as the lower multiple signal) from the central office equipment and then transmitted. In order to do this, the first example is a system in which the emission center wavelength of each light emitting element is changed for lower multiple signal transmission and upper multiple signal transmission and transmission is performed by wavelength division multiplexing using an optical multiplexer/demultiplexer. As a second example, optical fiber transmission lines are installed for lower multi-signal transmission and upper multi-signal transmission, respectively, for bidirectional transmission.
上記の様な従来技術によると、双方向の伝送は可能では
あるが、第一の例の欠点として、下り信号伝送用と上多
信号伝送用の各々に発光中心波長が互に異なる発光素子
を用いなければならず、精密な発光中心波長制御技術が
必要とな９１発光素子の製造上のコストが上昇すること
や、波長分割多重伝送を行なうために光合分波器が不可
欠であシ、その挿入損失による受光電力の低下があげら
れる。According to the conventional technology described above, bidirectional transmission is possible, but a drawback of the first example is that light emitting elements with different emission center wavelengths are used for downlink signal transmission and upper multi-signal transmission. 91, which requires precise emission center wavelength control technology, increases the manufacturing cost of light emitting devices, and optical multiplexers and demultiplexers are essential for wavelength division multiplexing transmission. One example of this is a decrease in received light power due to insertion loss.
第二の例の欠点としては、１加入者装置当りの光フアイ
バ芯線数が２本となシ伝送路コストの上昇が避けられな
いことや、低速度の映像信号選択信号を伝送する＊：り
のために光ファイバｔ１芯用意することはむだが多いこ
とがあげられる。The disadvantages of the second example are that the number of optical fiber cores per subscriber equipment is two, which inevitably increases the cost of the transmission line, and that the transmission path requires low-speed video signal selection signals. It can be said that it is wasteful to prepare the optical fiber t1 core for this purpose.
本発明の目的は、上述の従来技術の欠点を解決し、１芯
の光ファイバによシ下シ化号と上多信号を交互に伝送す
る光フアイバ通信方式を提供することにある。SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned drawbacks of the prior art and to provide an optical fiber communication system that alternately transmits a lower signal and an upper multi-core signal through a single optical fiber.
本発明の光フアイバ通信方式は、複数の映像信号の１つ
を１ち択する選択部、その出力を第一の光信号（て変換
する光送信部、前記第一の光信号、これと逆方向の第二
の光信号を通過させ、前記第二の光信号に対する前記第
一の光信号の結合比を所定値に設定した光方向性結合器
、前記第二の光信号を電気信号に変換する光受信部、前
記電気信号によって前記選択部を制御する制御部を有す
る中央局装置と、前記映像信号の切替を要求する選択信
号を前記第二の光信号に変換する光送信部、前記第一、
第二の光信号を切替える光スィッチ、前記光スィッチを
通過した前記第一の光信号を映像信号に変換する光受信
部、前記選択信号を出力し前記光スィッチ、光受信部を
制御して前記光スィッチの前記第一の光信号から前記第
二の光信号への切替後前記光受信部の雑音発生を阻止す
る制御部を有する加入者装置とを含んで構成することを
特徴とする。The optical fiber communication system of the present invention includes a selection section that selects one of a plurality of video signals, an optical transmission section that converts the output into a first optical signal, the first optical signal, and the opposite. an optical directional coupler that allows a second optical signal in the direction to pass through and sets a coupling ratio of the first optical signal to the second optical signal to a predetermined value; and converts the second optical signal into an electrical signal. a central office device having an optical receiving section for controlling the selecting section using the electric signal; an optical transmitting section that converts a selection signal requesting switching of the video signal into the second optical signal; one,
an optical switch that switches a second optical signal; an optical receiver that converts the first optical signal that has passed through the optical switch into a video signal; an optical receiver that outputs the selection signal to control the optical switch and the optical receiver; and a subscriber device having a control section that prevents the generation of noise in the optical receiving section after the optical switch switches from the first optical signal to the second optical signal.
遇択形映像佃号広送方式においては加入者装置側で訳像
信号を偶択する要求が発生してから、選択動作が光子す
るまでの時−１だけ上多信号の伝送路が構成されれぽ艮
く、またこの時間は下り信号を伝送する必要はない。促
って加入者装置側に光スィッチを用いて上多信号の伝送
の要求が発生した時点で光スイッテを切替えて上り信号
の伝送路を構成する。一方、中央局装置では下り信号と
上多信号を元方向性結合器によυ結合させる。映像信号
伝送用の下り信号と比較し１上シ信号の映像信号選択信
号は低速度の信号であるので所要受光電力が小さく、光
方向性結合器の結合比を、下り信号側に大きくとること
によシ下シ信号の伝送損失を極めて小さくすることがで
き、下多信号のＳ／Ｎ比を高くとることが可能となる。In the selection-type video program, the transmission path for multiple signals is configured for the time -1 from when a request to randomly select a translated image signal is generated on the subscriber equipment side until the selection operation is performed by a photon. Also, there is no need to transmit downlink signals during this time. An optical switch is then used on the subscriber equipment side, and when a request for transmission of multiple signals occurs, the optical switch is switched to configure a transmission path for uplink signals. On the other hand, in the central office equipment, the downlink signal and the uplink signal are combined by a directional coupler. Compared to the downlink signal for video signal transmission, the video signal selection signal of the higher signal is a low-speed signal, so the required light reception power is small, and the coupling ratio of the optical directional coupler should be set large on the downlink signal side. The transmission loss of the lower signal can be made extremely small, and the S/N ratio of the lower signal can be increased.
以１−１本発明の実施例について図面を参照して説明す
る。1-1 Examples of the present invention will be described below with reference to the drawings.
第１図は本発明の一実施例を示すブロック図である。ヘ
ッドエンド１からの複数の映像信号は映像信号選択部２
によシ特定の１チヤンネルが選択されて下シ信号光送信
部３に入力され光信号に変換されて光方向性結合器６を
通シ光ファイバ伝送路によシ光スイッチ７に導かれる。FIG. 1 is a block diagram showing one embodiment of the present invention. A plurality of video signals from the head end 1 are sent to the video signal selection section 2.
One particular channel is selected and input to the lower signal light transmitter 3, where it is converted into an optical signal, which is guided through an optical directional coupler 6 and an optical fiber transmission line to an optical switch 7.
ここで通常は光スィッチ７は下υ信号光受信部８側に切
替えられて肴シ、映像信号は８に入力される。光受信部
８によシミ気信号に変換されてテレビジョン受像機９に
映像が映し出される。加入者側で映像信号を切替する要
求が発生した場合は映像信号選択制御部１１からの制御
信号により光スィッチは上シ信号光送信部１０側に切替
えられ、光受信部８は光入力断に備えて雑音発生を阻止
する回路を動作させる。光スィッチ７の切替完了後選択
信号は制御部１１から光送信部１０に入力され光信号に
変換されて光スイ、チアを通シ光方向性結合器６に導か
れる。この結合器６によシ分岐された光信号は上シ信号
光受信部５に入力され電気信号に変換されて映像信号選
択制御部４を動作させ、映像信号選択部２によシ加入者
側から要求のあった特定０１チヤンネルを選択して下シ
信号として送出する。加入者装置では選択信号を送信後
中央局装置から映像信号が送られてくるまでのタイミン
グをとって光スィッチを下夛信号光受信部８側に戻すこ
とによシ、要求したチャンネルの映像を見ることができ
る。光方向性結合部６の結合比については、一般に上り
信号の所要受光電力は下シ信号の所要受光電力よシ小さ
いので、光送信部の光出力と発光中心波長が等しいとす
ると上シ信号の受光電力は下り信号のそれよＦ） １０
１ｏｇＸ（ｄＢ）だけ小さくなることを考慮しＸを１０
から１００程度映像信号伝送方式において、上シ信号を
伝送することが必要な時のみ光スイッチを用いて上シ回
線を構成することによシ、１芯の光ファイバで選択形映
像信号伝送方式が実現でき、従来方式における加入者装
置の光分波器を、よシ低損失な光スイ、チに置き換え、
中央局装置では伝送方向による所要受光電力差を利用し
て光方向性結合器を用いて下シ信号の伝送損失の増加を
極力抑えることが可能である。また発光素子の精密な発
光中心波長制御技術も不要となる。Normally, the optical switch 7 is switched to the lower υ signal light receiver 8 side, and the appetizer and video signals are input to the lower υ signal light receiver 8 side. The optical receiver 8 converts the signal into a blemish signal, and the image is displayed on the television receiver 9. When a request to switch the video signal occurs on the subscriber side, the optical switch is switched to the upper signal optical transmitter 10 side by a control signal from the video signal selection controller 11, and the optical receiver 8 cuts off the optical input. In preparation for this, a circuit that prevents noise generation is activated. After the switching of the optical switch 7 is completed, the selection signal is inputted from the control section 11 to the optical transmission section 10, converted into an optical signal, and guided to the optical directional coupler 6 through the optical switch and the optical switch. The optical signal branched by the coupler 6 is input to the upper signal light receiving section 5, where it is converted into an electrical signal, operates the video signal selection control section 4, and is sent to the subscriber side by the video signal selection section 2. The requested specific channel 01 is selected and sent as a lower signal. In the subscriber equipment, after transmitting the selection signal, the optical switch is returned to the lower signal optical receiver 8 side at the timing until the video signal is sent from the central office equipment, and the video of the requested channel is displayed. You can see it. As for the coupling ratio of the optical directional coupler 6, the required light reception power for the upstream signal is generally smaller than the required light reception power for the lower signal, so if the optical output of the optical transmitter and the emission center wavelength are equal, The received light power is that of the downstream signal F) 10
Considering that it will be smaller by 1ogX (dB), set X to 10
In the 100 or so video signal transmission systems, by configuring the upper line using an optical switch only when it is necessary to transmit the upper signal, a selective video signal transmission system can be achieved using a single optical fiber. It is possible to replace the optical demultiplexer in the subscriber equipment in the conventional system with a much lower loss optical switch.
In the central office equipment, it is possible to minimize the increase in transmission loss of the lower signal by using an optical directional coupler by taking advantage of the difference in required received light power depending on the transmission direction. Furthermore, precise emission center wavelength control technology for the light emitting element is not required.
第１図は本発明の実施例のブロック図である。
１・・・・・・へ、ドエンド、２・・・・・・映像信号
選択部。
３・・・・・・下多信号光送信部、４・・・・・・映像
信号選択制御部（中央局側）％５・・・・・・上多信号
光受信部、６・・・・・・Ｘ：１光方向性績合器、７・
・・・・・光スイッチ。
８・・・・・・下多信号光受信部、９・・・・・・テレ
ビジョン受像機、１０・・・・・・上υ信号光送信部、
１１・・・・・・映像信号選択制御部（加入者側）。FIG. 1 is a block diagram of an embodiment of the invention. 1... to end, 2... video signal selection section. 3...Lower multi-signal optical transmitter, 4...Video signal selection control unit (central office side)%5...Upper multi-signal optical receiver, 6... ...X: 1 light directionality combiner, 7.
...Light switch. 8... Lower multi-signal light receiving section, 9... Television receiver, 10... Upper υ signal light transmitting section,
11... Video signal selection control section (subscriber side).
Claims (1)
一の光信号に変換する光送信部、前記第一の光信号、こ
れと逆方向の第二の光信号を通過させ、前記第二の光信
号に対する前記第一の光信号の結合比を所定値に設定し
た光方向性結合器、前記第二の光信号を電気信号に変換
する光受信部、前記電気信号によって前記選択部を制御
する制御部を有する中央局装置と、前記映像信号の切替
を要求する選択信号を前記第二の光信号に変換する光送
信部、前記第一、第二の光信号を切替える光スィッチ、
前記光スィッチを通過した前記第一の光信号を映像信号
に変換する光受信部、前記選択信号を出力し前記光スィ
ッチ、光受信部を制御して前記光スィッチの前記筒−の
光信号から前記第二の光信号への切替後前記光受信部の
雑音発生を阻止する制御部を有する加入者装置とを含ん
で構成することを特徴とする光フアイバ通信方式。a selection unit that selects one of the plurality of video signals; an optical transmission unit that converts the output thereof into a first optical signal; a second optical signal that is in the opposite direction to the first optical signal; an optical directional coupler in which a coupling ratio of the first optical signal to the second optical signal is set to a predetermined value; an optical receiver that converts the second optical signal into an electrical signal; and the selection according to the electrical signal. an optical transmitter that converts a selection signal requesting switching of the video signal into the second optical signal; and an optical switch that switches the first and second optical signals. ,
an optical receiver that converts the first optical signal passed through the optical switch into a video signal; an optical receiver that outputs the selection signal and controls the optical switch and the optical receiver to convert the optical signal from the tube of the optical switch; An optical fiber communication system comprising: a subscriber device having a control section for preventing noise generation in the optical receiving section after switching to the second optical signal.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59082245A JPS60226235A (en) | 1984-04-24 | 1984-04-24 | Optical fiber communication system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59082245A JPS60226235A (en) | 1984-04-24 | 1984-04-24 | Optical fiber communication system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS60226235A true JPS60226235A (en) | 1985-11-11 |
Family
ID=13769036
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP59082245A Pending JPS60226235A (en) | 1984-04-24 | 1984-04-24 | Optical fiber communication system |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS60226235A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6346020A (en) * | 1986-08-13 | 1988-02-26 | Hiroshi Tanaka | Optical fiber wire broadcasting system |
| JPS63169133A (en) * | 1987-01-05 | 1988-07-13 | Oki Electric Ind Co Ltd | Single core two-way time division optical transmission equipment |
-
1984
- 1984-04-24 JP JP59082245A patent/JPS60226235A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6346020A (en) * | 1986-08-13 | 1988-02-26 | Hiroshi Tanaka | Optical fiber wire broadcasting system |
| JPS63169133A (en) * | 1987-01-05 | 1988-07-13 | Oki Electric Ind Co Ltd | Single core two-way time division optical transmission equipment |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP4899577B2 (en) | Optical network and node | |
| KR910007368A (en) | CATV system | |
| JPH0681348B2 (en) | Broadband integrated subscriber loop system | |
| JPH11178019A (en) | Optical node system for ring architecture and its method | |
| EP0535858A2 (en) | Selection of transmission facilities using optical wavelength division multiplexing | |
| US7577361B2 (en) | Optical network system and optical coupling apparatus | |
| US6385206B1 (en) | Communication network and method, and node and exchange node used therein | |
| JPS60226235A (en) | Optical fiber communication system | |
| JP2003046451A (en) | Method for multiplexing optical information transport | |
| JPS6189735A (en) | Time division direction control transmission system of optical communication system | |
| US20060222363A1 (en) | Drop-and-continue device | |
| JPH08288911A (en) | Optical communication equipment and its method | |
| JP3114945B2 (en) | Optical communication system | |
| US20040208567A1 (en) | Optical wavelength division multiplexing transmission system | |
| JPS6276331A (en) | Two-way optical fiber communication system | |
| JP3142063B2 (en) | Three-stage switch device | |
| US20080219665A1 (en) | Optical communication apparatus, optical communication system, and optical communication control method | |
| JP3472427B2 (en) | Optical transmission system | |
| JP3535815B2 (en) | Interface device for wavelength division multiplexing optical communication | |
| JPH11340953A (en) | High frequency optical fiber transmission system using optical wavelength multiplexing | |
| KR100602951B1 (en) | Wdm pon system appointed an optical circulator | |
| JP3304077B2 (en) | Optical wavelength division multiplexing transceiver | |
| JPS6210073B2 (en) | ||
| JPH0523090B2 (en) | ||
| JPH06232885A (en) | Communication network system |