JPH0323023B2 - - Google Patents

Info

Publication number
JPH0323023B2
JPH0323023B2 JP59030690A JP3069084A JPH0323023B2 JP H0323023 B2 JPH0323023 B2 JP H0323023B2 JP 59030690 A JP59030690 A JP 59030690A JP 3069084 A JP3069084 A JP 3069084A JP H0323023 B2 JPH0323023 B2 JP H0323023B2
Authority
JP
Japan
Prior art keywords
signal
circuit
transmission
clock
optical
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
Application number
JP59030690A
Other languages
Japanese (ja)
Other versions
JPS60174544A (en
Inventor
Junichi Yugawa
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
NEC Corp
Original Assignee
Nippon Electric Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Nippon Electric Co Ltd filed Critical Nippon Electric Co Ltd
Priority to JP59030690A priority Critical patent/JPS60174544A/en
Publication of JPS60174544A publication Critical patent/JPS60174544A/en
Publication of JPH0323023B2 publication Critical patent/JPH0323023B2/ja
Granted legal-status Critical Current

Links

Classifications

    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04LTRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L12/00Data switching networks
    • H04L12/28Data switching networks characterised by path configuration, e.g. LAN [Local Area Networks] or WAN [Wide Area Networks]
    • H04L12/44Star or tree networks

Landscapes

  • Small-Scale Networks (AREA)
  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)

Description

【発明の詳細な説明】 本発明はスターカツプラを用いた光伝送システ
ムで、パルスバースト伝送を行なうときの衝突検
出方式に関する。
DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a collision detection method when performing pulse burst transmission in an optical transmission system using a star coupler.

第1図のように端局1(T1,T2,……TN)の
相互間で光によりパルスバーストでデータ伝送を
行なうため、スターカツプラ2を用いて各端局の
光出力10をすべての端局に分配して受信する方
式が提案されている。この方式は、自己の端局が
パルスバーストを送出しているときに他の端局が
パルスバーストを送出すると、これらが重畳され
てデータに誤りを生じるおそれがあり、このよう
な信号衝突時にデータを再送する必要がある。こ
のため自端局でパルスバーストの衝突を認識する
か、受信端局で認識して受信不成功を送信側に通
知する必要がある。
As shown in Fig. 1, in order to perform data transmission between terminal stations 1 (T 1 , T 2 , ...T N ) using pulse burst light, a star coupler 2 is used to reduce the optical output 10 of each terminal station. A method has been proposed in which the information is distributed to all terminal stations for reception. In this method, if one terminal station sends out a pulse burst while another terminal station sends out a pulse burst, there is a risk that these will be superimposed and cause errors in the data. need to be resent. Therefore, it is necessary to recognize the pulse burst collision at the own terminal station or to recognize it at the receiving terminal station and notify the transmitting side of the reception failure.

自端局で衝突を検出する方法は瞬時に認識がで
きるので、系の効率上明らかに有利である。しか
し自端局の受信回路に受信信号検出回路があれば
他局のパルスバースト送出を認識できるが、自局
だけが送出している場合にも自己の信号が受信さ
れるので、他局から送信される信号との衝突の場
合と区別がつかないという問題がある。
The method of detecting a collision at its own terminal station is clearly advantageous in terms of system efficiency, since it can be recognized instantaneously. However, if the receiving circuit of the own terminal station has a received signal detection circuit, it can recognize the pulse burst transmission from other stations, but even if only the own station is transmitting, its own signal will be received, so the other station will not be able to transmit pulse bursts. There is a problem in that it is difficult to distinguish between collisions and collisions with other signals.

本発明の目的は、スターカツプラを用いた光伝
送システムで、パルスバースト伝送を行なうとき
に生ずる各端局間の送出信号の衝突を自局から送
出されスターカツプラを経て自局に戻る信号と区
別して検出することができる衝突検出回路を提供
することにある。
An object of the present invention is to provide an optical transmission system using a star coupler, in which collisions of transmission signals between terminal stations that occur when pulse burst transmission is performed are avoided. The object of the present invention is to provide a collision detection circuit that can distinguish and detect collisions.

この発明によれば1つのスターカツプラを用い
て送信部に電気光変換回路、受信部に光電気変換
回路を有する複数の端局間でパルスバースト伝送
を行なうシステムの信号衝突検出回路において、
各端局の送信部で発生する送信電気信号を光送信
信号に変換する変換回路と、送信電気信号を分岐
して極性・位相および振幅を調整した信号を発生
する調整回路と、該調整回路の出力信号を自局で
受信回路で光電気変換された受信信号に加算して
受信信号に含まれる自局の送信信号を相殺する加
算回路と、加算された信号を波形等化して受信ク
ロツク抽出および識別を行なう等化およびクロツ
ク抽出回路と、前記送信部が送信中に発生する送
信クロツクおよび等化およびクロツク抽出回路で
抽出された受信クロツクが共に存在することを検
出する検出回路とを含む衝突検出回路が得られ
る。
According to the present invention, in a signal collision detection circuit for a system that uses one star coupler to perform pulse burst transmission between a plurality of terminal stations having an electro-optic conversion circuit in a transmitting section and an opto-electric conversion circuit in a receiving section,
A conversion circuit that converts the transmitted electrical signal generated by the transmitter of each terminal station into an optical transmitted signal, an adjustment circuit that branches the transmitted electrical signal and generates a signal with adjusted polarity, phase, and amplitude; An addition circuit adds the output signal to the received signal photoelectrically converted by the receiving circuit at the own station to cancel out the transmitted signal of the own station included in the received signal, and the added signal is waveform-equalized to extract the received clock. Collision detection comprising: an equalization and clock extraction circuit for performing identification; and a detection circuit for detecting the presence of both a transmission clock generated during transmission by the transmission section and a reception clock extracted by the equalization and clock extraction circuit. A circuit is obtained.

以下、本発明を図面を参照して説明する。 Hereinafter, the present invention will be explained with reference to the drawings.

第2図は本発明の実施例に使用される光端局装
置で、第1図で示したようなスターネツトワーク
の第n番目の端局とする。第3図は第2図の各
部波形を示したものである。第2図、第3図を参
照すると、送信データ信号101はフリツプフロ
ツプ21において送信クロツク102により読み
直されて送信駆動電圧信号103となり、これが
駆動回路22により駆動電流信号104に変換さ
れて発光素子23を駆動し、送信光信号105と
なる。この光信号が光フアイバを通じ、第1図で
説明したスターカツプラ2に送られ、他端局およ
び自端局の受信部に分岐される。一方、送信駆動
電圧信号103は分岐されて極性反転回路24、
位相調整回路25、振巾調整回路26を通つて送
信波形消去信号106となる。
FIG. 2 shows an optical terminal equipment used in an embodiment of the present invention, which is assumed to be the nth terminal of the star network as shown in FIG. FIG. 3 shows waveforms of various parts of FIG. 2. Referring to FIGS. 2 and 3, a transmission data signal 101 is reread by a transmission clock 102 in a flip-flop 21 to become a transmission drive voltage signal 103, which is converted by a drive circuit 22 into a drive current signal 104 to drive a light emitting element 23. , and becomes a transmission optical signal 105. This optical signal is sent to the star coupler 2 explained in FIG. 1 through an optical fiber, and branched to the receiving section of the other terminal station and the own terminal station. On the other hand, the transmission drive voltage signal 103 is branched to a polarity inversion circuit 24,
The signal passes through a phase adjustment circuit 25 and an amplitude adjustment circuit 26 to become a transmission waveform cancellation signal 106.

スターカツプラから送られてきた受信光信号1
07は受光素子27および受信増幅器28により
受信電気信号108に変換される。もし、他端局
からバースト信号を受信している状態で自端局送
信部に送信データ信号101および送信クロツク
102が入力し、自局のバースト信号を送出する
と、受信電気信号108は自局と他局の信号が重
畳したものとなる。加算回路29ではこの信号に
前記の送信波形消去信号106を加算し、得られ
た加算出力信号109は等化・増幅回路30で帯
域制限されて等化波形110となり、これがタイ
ミング抽出回路31および識別回路32に入力し
て受信クロツク111および受信データ信号11
2が得られる。
Received optical signal 1 sent from star coupler
07 is converted into a received electrical signal 108 by a light receiving element 27 and a receiving amplifier 28. If the transmitting data signal 101 and transmitting clock 102 are input to the transmitter of the own terminal station while receiving a burst signal from the other terminal station, and the burst signal of the own station is sent out, the received electrical signal 108 is transmitted to the transmitter of the own terminal station. The signals from other stations are superimposed. The adder circuit 29 adds the transmission waveform cancellation signal 106 to this signal, and the resulting added output signal 109 is band-limited in the equalization/amplification circuit 30 to become an equalized waveform 110, which is used by the timing extraction circuit 31 and identification. The receive clock 111 and receive data signal 11 are input to the circuit 32.
2 is obtained.

衝突検出回路33は送信クロツク102と受信
クロツク111が同時に存在するときに衝突検出
信号113を送出する。本構成により受信電気信
号108に含まれる自端局の信号成分は加算回路
29でほぼ消去される様に調整することができる
ので、受信クロツクの有無は自局の送信部から送
出されるバースト信号の有無とは関係がなくな
る。
Collision detection circuit 33 sends out collision detection signal 113 when transmitting clock 102 and receiving clock 111 are present simultaneously. With this configuration, the signal component of the own terminal station included in the received electrical signal 108 can be adjusted so as to be almost eliminated by the adding circuit 29, so the presence or absence of the receiving clock can be determined by the burst signal sent from the transmitter of the own station. It has nothing to do with the presence or absence of

以上述べた様に、本発明によればスターカツプ
ラを使用した光バースト伝送において、バースト
信号の衝突検出を簡易に行なうことができる。
As described above, according to the present invention, collision detection of burst signals can be easily performed in optical burst transmission using a star coupler.

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

第1図はスターカツプラによる光送受信システ
ムの説明図、第2図および第3図は本発明の実施
例およびその各部波形である。 第1図において1……端局、2……スターカツ
プラ、10……光出力、11……光入力、第2
図、第3図において21……フリツプフロツプ、
22……駆動回路、23……発光素子、24……
極性反転回路、25……位相調整回路、26……
振巾調整回路、27……受光素子、28……受信
増幅器、29……加算回路、30……等化増幅回
路、31……タイミング抽出回路、32……識別
回路、33……衝突検出回路、101……送信デ
ータ信号、102……送信クロツク、103……
送信駆動電圧信号、104……駆動電流信号、1
05……送信光信号、106……送信波形消去信
号、107……受信光信号、108……受信電気
号、109……加算出力信号、110……等化波
形、111……受信クロツク、112……受信デ
ータ信号、113……衝突検出信号。
FIG. 1 is an explanatory diagram of an optical transmission/reception system using a star coupler, and FIGS. 2 and 3 show an embodiment of the present invention and its waveforms. In Fig. 1, 1...Terminal station, 2...Star coupler, 10...Optical output, 11...Optical input, 2nd...
In Fig. 3, 21...flip-flop,
22... Drive circuit, 23... Light emitting element, 24...
Polarity inversion circuit, 25... Phase adjustment circuit, 26...
Amplitude adjustment circuit, 27... Light receiving element, 28... Receiving amplifier, 29... Adding circuit, 30... Equalization amplifier circuit, 31... Timing extraction circuit, 32... Discrimination circuit, 33... Collision detection circuit , 101... Transmission data signal, 102... Transmission clock, 103...
Transmission drive voltage signal, 104... Drive current signal, 1
05... Transmission optical signal, 106... Transmission waveform cancellation signal, 107... Reception optical signal, 108... Reception electrical signal, 109... Addition output signal, 110... Equalization waveform, 111... Reception clock, 112 ... Received data signal, 113 ... Collision detection signal.

Claims (1)

【特許請求の範囲】[Claims] 1 1つのスターカツプラを用いて、送信部に電
気光変換回路、受信部に光電気変換回路を有する
複数の端局間でパルスバースト伝送を行なうシス
テムの信号衝突検出回路において、各端局の送信
部で発生する送信電気信号を光送信信号に変換す
る変換回路と、前記送信電気信号を分岐して極
性・位相および振幅を調整した信号を発生する調
整回路と、該調整回路の出力信号を自局の受信回
路で光電気変換された受信信号に加算して受信信
号に含まれる自局の送信信号を相殺する加算回路
と、加算された信号を波形等化して受信クロツク
抽出および識別を行なう等化およびクロツク抽出
回路と、前記送信部が送信中に発生する送信クロ
ツクおよび前記等化およびクロツク抽出回路で抽
出された受信クロツクが共に存在することを検出
する検出回路とを含む衝突検出回路。
1. In the signal collision detection circuit of a system that uses one star coupler to perform pulse burst transmission between multiple terminal stations that have an electro-optical conversion circuit in the transmitting section and an optical-electrical conversion circuit in the receiving section, the signal collision detection circuit of each terminal station is a conversion circuit that converts a transmission electrical signal generated in a transmitter into an optical transmission signal; an adjustment circuit that branches the transmission electrical signal and generates a signal with adjusted polarity, phase, and amplitude; and an output signal of the adjustment circuit. An addition circuit that adds to the received signal photoelectrically converted by the own station's receiving circuit to cancel the own station's transmitted signal included in the received signal, and a waveform equalization of the added signal to extract and identify the received clock. A collision detection circuit comprising: an equalization and clock extraction circuit; and a detection circuit that detects the presence of both a transmission clock generated during transmission by the transmission section and a reception clock extracted by the equalization and clock extraction circuit.
JP59030690A 1984-02-21 1984-02-21 Detection system for signal collision Granted JPS60174544A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP59030690A JPS60174544A (en) 1984-02-21 1984-02-21 Detection system for signal collision

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP59030690A JPS60174544A (en) 1984-02-21 1984-02-21 Detection system for signal collision

Publications (2)

Publication Number Publication Date
JPS60174544A JPS60174544A (en) 1985-09-07
JPH0323023B2 true JPH0323023B2 (en) 1991-03-28

Family

ID=12310674

Family Applications (1)

Application Number Title Priority Date Filing Date
JP59030690A Granted JPS60174544A (en) 1984-02-21 1984-02-21 Detection system for signal collision

Country Status (1)

Country Link
JP (1) JPS60174544A (en)

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS58141053A (en) * 1982-02-16 1983-08-22 Fujitsu Ltd Collision detection system
JPS5927640A (en) * 1982-08-04 1984-02-14 Nippon Telegr & Teleph Corp <Ntt> Signal collision detecting system

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS58141053A (en) * 1982-02-16 1983-08-22 Fujitsu Ltd Collision detection system
JPS5927640A (en) * 1982-08-04 1984-02-14 Nippon Telegr & Teleph Corp <Ntt> Signal collision detecting system

Also Published As

Publication number Publication date
JPS60174544A (en) 1985-09-07

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