JP5301375B2

JP5301375B2 - Optical transmission apparatus, optical transmission system, and optical transmission method

Info

Publication number: JP5301375B2
Application number: JP2009158521A
Authority: JP
Inventors: 達也島田; 尚也桜井
Original assignee: Nippon Telegraph and Telephone Corp; NTT Inc USA
Current assignee: NTT Inc; NTT Inc USA
Priority date: 2009-07-03
Filing date: 2009-07-03
Publication date: 2013-09-25
Anticipated expiration: 2029-07-03
Also published as: JP2011015252A

Description

本発明は、光信号のまま伝送する低遅延伝送と、電気処理が必要となる信号の追加抽出を可能にする光伝送装置、光伝送システムおよび光伝送方法に関する。 The present invention relates to an optical transmission apparatus, an optical transmission system, and an optical transmission method that enable low-delay transmission that transmits an optical signal as it is and additional extraction of a signal that requires electrical processing.

近年、インターネットにおけるトラフィック量の増大に伴い、中継網の伝送装置にて生じるルーティングなどの電気処理による伝送遅延の回避、伝送装置処理部の規模縮小化等に向け、ＯＥＯ（Optical- Electrical-Optical）変換を行わないフォトニックネットワークの研究が活発に行われている（非特許文献１参照）。しかし、光パケットスイッチング技術を用いたフォトニックネットワークでは、光バッファの実現が難しいことから、将来のネットワークにおいては、全てがフォトニックネットワークに置き換わっていくのではなく、電気処理をベースとした既存ネットワークと、これらフォトニックネットワークが共存するネットワーク構成になるものと考えられる。 In recent years, OEO (Optical-Electrical-Optical-Optical) is aimed at avoiding transmission delays due to electrical processing such as routing, etc., which occurs in transmission devices in relay networks, and reducing the scale of transmission device processing units as the traffic volume on the Internet increases. Research on photonic networks that do not perform conversion has been actively conducted (see Non-Patent Document 1). However, in photonic networks using optical packet switching technology, it is difficult to realize an optical buffer, so in future networks, not all will be replaced by photonic networks, but existing networks based on electrical processing. It is considered that these photonic networks will coexist.

図８に、以上の背景をもとにしたネットワーク構成例を示す。図８に示すネットワークは、アクセス網１と、電気処理をベースとした既存ネットワーク２と、フォトニックネットワーク３で構成される。アクセス網１にある光端末装置１１−１〜１１−Ｎから伝送されてくる光信号は、アクセス網１の光終端装置２１−１〜２１−Ｎにて信号の種類に応じて既存ネットワーク２とフォトニックネットワーク３に振り分けられる。ここで、光終端装置２１−１〜２１−Ｎでは、電気処理をベースとした既存ネットワーク２へは、電気処理を行った後に光信号を伝送する。すなわち、光端末装置１１−１〜１１−Ｎからの光信号を一旦電気信号に変換した後に再度光信号にするＯＥＯ（Optical-Electrical-Optical）変換を行った後に既存ネットワーク２に伝送する。一方で、フォトニックネットワーク３の光伝送装置３１−１〜３１−Ｎへは、電気処理による伝送遅延を回避するために、光信号のまま伝送することが要求される。このように光信号のまま伝送する方法としては、アクセス網１から伝送されてきた光信号をそのままＥＤＦＡ（Erbium Doped Fiber Amplifier）などの光増幅器を用いて伝送する方法や、あるいはアクセス網１から伝送されてきた光信号を波長変換してから伝送する方法などが挙げられる。 FIG. 8 shows a network configuration example based on the above background. The network shown in FIG. 8 includes an access network 1, an existing network 2 based on electrical processing, and a photonic network 3. The optical signals transmitted from the optical terminal devices 11-1 to 11-N in the access network 1 are transmitted to the existing network 2 in accordance with the signal types in the optical terminal devices 21-1 to 21-N of the access network 1. Sorted to the photonic network 3. Here, in the optical termination devices 21-1 to 21-N, an optical signal is transmitted to the existing network 2 based on the electrical processing after the electrical processing is performed. In other words, optical signals from the optical terminal devices 11-1 to 11-N are once converted into electrical signals, and then subjected to OEO (Optical-Electrical-Optical) conversion to be optical signals again, and then transmitted to the existing network 2. On the other hand, the optical transmission devices 31-1 to 31-N of the photonic network 3 are required to transmit optical signals as they are in order to avoid transmission delay due to electrical processing. As a method of transmitting an optical signal as it is, a method of transmitting an optical signal transmitted from the access network 1 as it is using an optical amplifier such as an EDFA (Erbium Doped Fiber Amplifier), or a transmission from the access network 1 For example, there is a method of transmitting the optical signal after wavelength conversion.

しかし、上述した光増幅を行う方法や、波長変換を行う方法を用いると、アクセス網１から伝送されてきた信号は、全てフォトニックネットワーク３に伝送されてしまい、既存ネットワーク２に伝送するためには、フォトニックネットワーク３を経由してから、既存ネットワーク２に伝送するといった遠回りをする必要がある。あるいは、光終端装置２１−１〜２１−Ｎにて光スプリッタを用いて既存ネットワーク用とフォトニックネットワーク用にアクセス網１からの光信号を分岐し、両方に同じ信号を伝送する方法も考えられる。このようにすることで既存ネットワーク２に伝送すべき信号の抽出は可能となるが、両方のネットワークにとって不要な信号が伝送されることになるため、両方のネットワークの帯域利用効率等に悪影響を及ぼすことになる。また、既存ネットワーク２からの信号をフォトニックネットワーク３へ伝送しようとすると、アクセス網１からフォトニックネットワーク３へ送る光信号の波長とは別の波長の光信号を伝送する必要が生じ、新たに波長を分離する機能が必要となる。以上の問題は、フォトニックネットワーク３からアクセス網１へ伝送するときにも同様に生じる。 However, if the above-described optical amplification method or wavelength conversion method is used, all signals transmitted from the access network 1 are transmitted to the photonic network 3 and are transmitted to the existing network 2. Needs to make a detour such as transmitting to the existing network 2 after passing through the photonic network 3. Alternatively, a method of branching the optical signal from the access network 1 for the existing network and the photonic network using an optical splitter in the optical termination devices 21-1 to 21-N and transmitting the same signal to both is also conceivable. . By doing so, it is possible to extract signals to be transmitted to the existing network 2, but since signals unnecessary for both networks are transmitted, it adversely affects the bandwidth utilization efficiency of both networks. It will be. In addition, when trying to transmit a signal from the existing network 2 to the photonic network 3, it becomes necessary to transmit an optical signal having a wavelength different from the wavelength of the optical signal sent from the access network 1 to the photonic network 3. A function to separate wavelengths is required. The above problem also occurs when data is transmitted from the photonic network 3 to the access network 1.

S.J.Ben Yoo, “Optical Packet and Burst Switching Technologies for the Future Photonic Internet,” JOURNAL OF LIGHTWAVE TECHNOLOGY, Vol.24, No.12, pp.4468-4492, December 2006.S.J.Ben Yoo, “Optical Packet and Burst Switching Technologies for the Future Photonic Internet,” JOURNAL OF LIGHTWAVE TECHNOLOGY, Vol.24, No.12, pp.4468-4492, December 2006. Satoshi Narikawa, “Gbit-Class Transmission Using SOA Data Rewriter for WDM-PON,” IEICE TRANS COMMUN., Vol.E91-B, No.2, pp.399-408, February 2008.Satoshi Narikawa, “Gbit-Class Transmission Using SOA Data Rewriter for WDM-PON,” IEICE TRANS COMMUN., Vol.E91-B, No.2, pp.399-408, February 2008.

本発明は、以上のような背景のもとで成されたものであり、本発明の目的は、アクセス網と、電気処理をベースとした既存ネットワークおよびフォトニックネットワークとを接続する手段であり、不要なトラフィックや遠回りとなる伝送ルートをとることなく、フォトニックネットワークの求める低遅延伝送を行うことと、電気処理が必要となる信号の追加抽出を行うことができる光伝送装置と、この光伝送装置を用いた光伝送システムおよび光伝送方法を提供することにある。 The present invention has been made under the background as described above, and an object of the present invention is a means for connecting an access network to an existing network and a photonic network based on electrical processing, An optical transmission device capable of performing low-delay transmission required by a photonic network and additional extraction of a signal that requires electrical processing without taking unnecessary traffic or a detour transmission route, and this optical transmission An object of the present invention is to provide an optical transmission system and an optical transmission method using the apparatus.

上記目的を達成するため、本発明の光伝送装置は、電気処理が必要となる信号がないときには光信号のまま伝送し、電気処理が必要となる信号があるときには、電気処理による信号の追加抽出を行う２つの処理を１つの装置で実現するものである。 In order to achieve the above object, the optical transmission apparatus of the present invention transmits an optical signal as it is when there is no signal that requires electrical processing, and additional signal extraction by electrical processing when there is a signal that requires electrical processing. The two processes for performing the above are realized by one apparatus.

すなわち、本発明の光伝送装置は、一方の光装置から受信した信号のうち、抽出すべき信号があるか否かを判定し、かつ、当該受信した信号に追加する信号があるか否かを確認し、抽出すべき信号も追加すべき信号もない場合は、一方の光装置からの信号を電気信号に変換することなく他方の光装置に送信し、抽出すべき信号があり、追加すべき信号がない場合は、当該受信した信号のうち抽出すべき信号を除いた信号を他方の光装置に送信し、抽出すべき信号がなく、追加すべき信号がある場合は、当該受信した信号を追加すべき信号よりも優先的に読出し、当該受信した信号および追加すべき信号により光変調した信号を他方の光装置に送信し、抽出すべき信号も追加すべき信号もある場合は、当該受信した信号のうち抽出すべき信号を除いた信号を追加すべき信号よりも優先的に読出し、当該受信した信号のうち抽出すべき信号を除いた信号と追加すべき信号により光変調した信号を他方の光装置に送信する第１の光再生変調部と、他方の光装置から受信した信号のうち、抽出すべき信号があるか否かを判定し、かつ、当該受信した信号に追加する信号があるか否かを確認し、抽出すべき信号も追加すべき信号もない場合は、他方の光装置からの信号を電気信号に変換することなく一方の光装置に送信し、抽出すべき信号があり、追加すべき信号がない場合は、当該受信した信号のうち抽出すべき信号を除いた信号を一方の光装置に送信し、抽出すべき信号がなく、追加すべき信号がある場合は、当該受信した信号を追加すべき信号よりも優先的に読出し、当該受信した信号および追加すべき信号により光変調した信号を一方の光装置に送信し、抽出すべき信号も追加すべき信号もある場合は、当該受信した信号のうち抽出すべき信号を除いた信号を追加すべき信号よりも優先的に読出し、当該受信した信号のうち抽出すべき信号を除いた信号と追加すべき信号により光変調した信号を一方の光装置に送信する第２の光再生変調部とを備えることを特徴とする。 That is, the optical transmission device of the present invention determines whether there is a signal to be extracted from the signals received from one optical device, and whether there is a signal to be added to the received signal. If there is no signal to be extracted or added, the signal from one optical device is transmitted to the other optical device without being converted into an electrical signal. If there is no signal, a signal excluding the signal to be extracted is transmitted to the other optical device, and if there is no signal to be extracted and there is a signal to be added, the received signal is to be added signal preferentially read than to transmit a signal light modulated by the received signal and the additional signal to be on the other optical apparatus, if the extracted signal to be also some signals to be added, the received Signal to be extracted First light transmitting had signal to be added signal preferentially reads than a, a signal light modulated by the signal and the signal to be added except for the signal to be extracted out of the received signal to the other light device It is determined whether or not there is a signal to be extracted from the signals received from the reproduction modulation unit and the other optical device, and whether or not there is a signal to be added to the received signal is extracted. If there is no signal to be added or a signal to be added, the signal from the other optical device is transmitted to one optical device without being converted into an electrical signal, and there is a signal to be extracted and there is no signal to be added. The signal except the signal to be extracted among the received signals is transmitted to one optical device, and when there is no signal to be extracted and there is a signal to be added, the received signal is added from the signal to be added. read also preferentially, the received signal The optical modulation signal transmitted to one of the optical device by the preliminary to be added signal, if the extracted signal to be also some signals to be added, add the signals except the signal to be extracted out of the received signal A second optical regenerative modulation unit that reads a signal prior to the power signal, removes the signal to be extracted from the received signal, and transmits a signal optically modulated by the signal to be added to one optical device; It is characterized by providing.

また、本発明の光伝送装置は、一方の光装置から伝送される第１波長の光信号を受信し制御して、他方の光装置へ第１波長の光信号を送信する第１の光再生変調部と、他方の光装置から伝送される第２波長の光信号を受信し制御して、一方の光装置へ第２波長の光信号を送信する第２の光再生変調部とを備え、前記第１および第２の光再生変調部が、それぞれ、受信した光信号を分岐する光スプリッタと、分岐された光信号のうち、一方の光信号を受信する光受信器と、前記光受信器の信号を蓄える電気バッファと、追加すべき信号を蓄える追加電気バッファと、前記光受信器で受信した前記光信号のヘッダ情報から抽出すべき信号であるかないかを判定し、かつ前記電気バッファと前記追加電気バッファから信号を読み出す判定制御回路と、前記分岐された光信号のうち、もう一方の光信号を透過する光遅延線と、前記光遅延線からの光信号を再生あるいは光飽和する半導体光増幅器と、前記半導体光増幅器からの飽和信号を変調する光変調器と、前記判定制御回路により抽出すべき信号と判定された信号を蓄える抽出電気バッファとで構成され、前記判定制御回路が、前記追加電気バッファに追加すべき信号がない場合は、前記光変調器への変調信号の送信を停止し、前記追加電気バッファに追加すべき信号がなく前記電気バッファに抽出すべき信号がない場合は、前記半導体光増幅器に対し全ての光信号を再生させるための動作を行い、前記追加電気バッファに追加すべき信号がなく前記電気バッファに抽出すべき信号がある場合は、抽出すべき信号を前記電気バッファから前記抽出電気バッファに送信し、抽出対象外の信号のみ伝送されるように、前記半導体光増幅器の制御を行い、前記追加電気バッファに追加すべき信号がある場合は、前記半導体光増幅器に対し、光飽和の制御を行い、前記追加電気バッファに追加すべき信号があり前記電気バッファに抽出すべき信号がない場合は、前記電気バッファから読み出した信号と前記追加電気バッファから読み出した信号とに基づく変調信号を前記光変調器へ伝送し、前記追加電気バッファに追加すべき信号があり前記電気バッファに抽出すべき信号がある場合は、抽出すべき信号を前記電気バッファから前記抽出電気バッファに送信し、前記電気バッファから読み出した抽出対象外の信号と前記追加電気バッファから読み出した信号とに基づく変調信号を前記光変調器へ送信することを特徴とする。 The optical transmission device of the present invention also receives and controls a first wavelength optical signal transmitted from one optical device, and transmits the first wavelength optical signal to the other optical device. A modulation unit, and a second optical regenerative modulation unit that receives and controls the optical signal of the second wavelength transmitted from the other optical device, and transmits the optical signal of the second wavelength to the one optical device, The first and second optical regenerative modulation units each branch an optical splitter that branches the received optical signal, an optical receiver that receives one of the branched optical signals, and the optical receiver An electrical buffer for storing a signal to be added, an additional electrical buffer for storing a signal to be added, a signal to be extracted from header information of the optical signal received by the optical receiver, and the electrical buffer; A determination control circuit for reading a signal from the additional electrical buffer; Among the branched optical signals, an optical delay line that transmits the other optical signal, a semiconductor optical amplifier that regenerates or optically saturates the optical signal from the optical delay line, and a saturation signal from the semiconductor optical amplifier. When the optical modulator to be modulated and an extraction electric buffer that stores a signal determined to be extracted by the determination control circuit, the determination control circuit has no signal to be added to the additional electric buffer. When the transmission of the modulation signal to the optical modulator is stopped and there is no signal to be added to the additional electrical buffer and there is no signal to be extracted to the electrical buffer, all optical signals are sent to the semiconductor optical amplifier. It performs an operation for reproducing, when a signal to be added to the additional electrical buffer is a signal to be extracted in the electrical buffer rather, a signal to be extracted from the electrical buffer The semiconductor optical amplifier is controlled so that only the signals not to be extracted are transmitted to the extraction electrical buffer, and when there is a signal to be added to the additional electrical buffer, for the semiconductor optical amplifier, and controls the light saturation, if the no additional electrical buffer may signal to be added to the signal to be extracted to the electric buffer, based on the signal read signal read from the electrical buffer from said additional electrical buffer Transmit a modulation signal to the optical modulator, and if there is a signal to be added to the additional electrical buffer and there is a signal to be extracted from the electrical buffer, transmit the signal to be extracted from the electrical buffer to the extraction electrical buffer and, a modulated signal based on the signal read from the extraction target outside the signal read from the electrical buffer and said additional electric buffer varying the optical It transmits to a controller.

本発明の光伝送装置は、前記追加電気バッファに追加すべき信号があるときには、前記電気バッファと前記追加電気バッファから信号を読み出すときに、電気バッファの信号を優先的に読出すことが好ましい。 When there is a signal to be added to the additional electrical buffer, the optical transmission device of the present invention preferably reads the signal from the electrical buffer preferentially when reading the signal from the electrical buffer and the additional electrical buffer.

このように構成されることにより、本発明の光伝送装置は、１つの装置でフォトニックネットワークの求める低遅延伝送を行うことと、電気処理が必要となる信号の追加抽出を行うことができる。 With this configuration, the optical transmission apparatus of the present invention can perform low-delay transmission required by the photonic network and additional extraction of signals that require electrical processing.

また、本発明の光伝送装置は、光受信器からヘッダ情報を読み取って、半導体光増幅器の制御を行うものであり、光信号の再生に際し、追加電気バッファに信号があるかないかを判定し、信号があるときには、半導体光増幅器に対し再生のための動作を行うのではなく、変調器のための光信号へと光飽和させることで、光信号のまま伝送する機能と電気信号に変換して伝送する機能を実現している。 Further, the optical transmission device of the present invention reads the header information from the optical receiver and controls the semiconductor optical amplifier, and determines whether or not there is a signal in the additional electric buffer when reproducing the optical signal, When there is a signal, the semiconductor optical amplifier does not perform an operation for reproduction, but optically saturates the optical signal for the modulator, thereby converting it into an optical signal and a function for transmitting the optical signal as it is. The transmission function is realized.

また、本発明は、直列に接続される３台以上の光伝送装置を含む光伝送システムにおいて、前記光伝送装置が、一方の光伝送装置から受信した信号のうち、抽出すべき信号があるか否かを判定し、かつ、当該受信した信号に追加する信号があるか否かを確認し、抽出すべき信号も追加すべき信号もない場合は、一方の光伝送装置からの信号を電気信号に変換することなく他方の光伝送装置に送信し、抽出すべき信号があり、追加すべき信号がない場合は、当該受信した信号のうち抽出すべき信号を除いた信号を他方の光伝送装置に送信し、抽出すべき信号がなく、追加すべき信号がある場合は、当該受信した信号を追加すべき信号よりも優先的に読出し、当該受信した信号および追加すべき信号により光変調した信号を他方の光伝送装置に送信し、抽出すべき信号も追加すべき信号もある場合は、当該受信した信号のうち抽出すべき信号を除いた信号を追加すべき信号よりも優先的に読出し、当該受信した信号のうち抽出すべき信号を除いた信号と追加すべき信号により光変調した信号を他方の光伝送装置に送信する第１の光再生変調部と、他方の光伝送装置から受信した信号のうち、抽出すべき信号があるか否かを判定し、かつ、当該受信した信号に追加する信号があるか否かを確認し、抽出すべき信号も追加すべき信号もない場合は、他方の光伝送装置からの信号を電気信号に変換することなく一方の光伝送装置に送信し、抽出すべき信号があり、追加すべき信号がない場合は、当該受信した信号のうち抽出すべき信号を除いた信号を一方の光伝送装置に送信し、抽出すべき信号がなく、追加すべき信号がある場合は、当該受信した信号を追加すべき信号よりも優先的に読出し、当該受信した信号および追加すべき信号により光変調した信号を一方の光伝送装置に送信し、抽出すべき信号も追加すべき信号もある場合は、当該受信した信号のうち抽出すべき信号を除いた信号を追加すべき信号よりも優先的に読出し、当該受信した信号のうち抽出すべき信号を除いた信号と追加すべき信号により光変調した信号を一方の光伝送装置に送信する第２の光再生変調部とを備えることを特徴とする。 In addition, according to the present invention, in an optical transmission system including three or more optical transmission devices connected in series, whether there is a signal to be extracted from signals received by the optical transmission device from one of the optical transmission devices. And if there is a signal to be added to the received signal, and if there is no signal to be extracted or added, the signal from one of the optical transmission devices is an electrical signal. If there is a signal to be extracted and not to be added to the other optical transmission device without conversion to the other optical transmission device, the signal other than the signal to be extracted among the received signals is excluded from the other optical transmission device. When there is no signal to be extracted and there is a signal to be added, the received signal is read prior to the signal to be added, and is optically modulated by the received signal and the signal to be added. To the other optical transmission device. And, if the extracted signal to be also some signals to be added, to extract the received preferentially read than the signal to be added to signals except the signal to be extracted out of the signal, among the received signal A signal to be extracted out of a signal received from the first optical regenerative modulation unit and a signal received from the other optical transmission device, the first optical regenerative modulation unit transmitting a signal optically modulated by the signal excluding the power signal and the signal to be added And if there is a signal to be added to the received signal, and if there is no signal to be extracted or added, the signal from the other optical transmission device If there is a signal to be extracted and there is no signal to be added, the signal excluding the signal to be extracted is excluded from the received signal. Signals to be sent to the optical transmission equipment and extracted No, if there is to be added signal is transmitted the received signal to be added signal preferentially reads than a, a signal light modulated by the received signal and the additional signal to be on one of the optical transmission device If there are signals to be extracted and signals to be added, the signals other than the signals to be extracted are read out of the received signals with priority over the signals to be added, and the signals are extracted from the received signals. And a second optical regenerative modulation unit that transmits a signal optically modulated with a signal to be added and a signal to be added to one of the optical transmission apparatuses.

また、本発明は、直列に接続される３台以上の光伝送装置を含む光伝送システムにおいて、前記光伝送装置が、一方の光伝送装置から伝送される第１波長の光信号を受信し制御して、他方の光伝送装置へ第１波長の光信号を送信する第１の光再生変調部と、他方の光伝送装置から伝送される第２波長の光信号を受信し制御して、一方の光伝送装置へ第２波長の光信号を送信する第２の光再生変調部とを備え、前記第１および第２の光再生変調部が、それぞれ、受信した光信号を分岐する光スプリッタと、分岐された光信号のうち、一方の光信号を受信する光受信器と、前記光受信器の信号を蓄える電気バッファと、追加すべき信号を蓄える追加電気バッファと、前記光受信器で受信した前記光信号のヘッダ情報から抽出すべき信号であるかないかを判定し、かつ前記電気バッファと前記追加電気バッファから信号を読み出す判定制御回路と、前記分岐された光信号のうち、もう一方の光信号を透過する光遅延線と、前記光遅延線からの光信号を再生あるいは光飽和する半導体光増幅器と、前記半導体光増幅器からの飽和信号を変調する光変調器と、前記判定制御回路により抽出すべき信号と判定された信号を蓄える抽出電気バッファとで構成され、前記判定制御回路が、前記追加電気バッファに追加すべき信号がない場合は、前記光変調器への変調信号の送信を停止し、前記追加電気バッファに追加すべき信号がなく前記電気バッファに抽出すべき信号がない場合は、前記半導体光増幅器に対し全ての光信号を再生させるための動作を行い、前記追加電気バッファに追加すべき信号がなく前記電気バッファに抽出すべき信号がある場合は、抽出すべき信号を前記電気バッファから前記抽出電気バッファに送信し、抽出対象外の信号のみ伝送されるように、前記半導体光増幅器の制御を行い、前記追加電気バッファに追加すべき信号がある場合は、前記半導体光増幅器に対し、光飽和の制御を行い、前記追加電気バッファに追加すべき信号があり前記電気バッファに抽出すべき信号がない場合は、前記電気バッファから読み出した信号と前記追加電気バッファから読み出した信号とに基づく変調信号を前記光変調器へ伝送し、前記追加電気バッファに追加すべき信号があり前記電気バッファに抽出すべき信号がある場合は、抽出すべき信号を前記電気バッファから前記抽出電気バッファに送信し、前記電気バッファから読み出した抽出対象外の信号と前記追加電気バッファから読み出した信号とに基づく変調信号を前記光変調器へ送信することを特徴とする。 According to the present invention, in an optical transmission system including three or more optical transmission apparatuses connected in series, the optical transmission apparatus receives and controls an optical signal having a first wavelength transmitted from one optical transmission apparatus. And receiving and controlling the first optical regenerative modulation unit that transmits the optical signal of the first wavelength to the other optical transmission device, and the second optical signal transmitted from the other optical transmission device, A second optical regenerative modulation unit that transmits an optical signal having a second wavelength to the optical transmission device, wherein the first and second optical regenerative modulation units each branch an optical signal received, An optical receiver that receives one of the branched optical signals, an electrical buffer that stores the signal of the optical receiver, an additional electrical buffer that stores a signal to be added, and received by the optical receiver The signal to be extracted from the header information of the optical signal. And a determination control circuit that reads a signal from the electrical buffer and the additional electrical buffer, an optical delay line that transmits the other optical signal among the branched optical signals, and an optical delay line A semiconductor optical amplifier that reproduces or optically saturates the optical signal, an optical modulator that modulates the saturation signal from the semiconductor optical amplifier, and an extraction electric buffer that stores a signal determined to be extracted by the determination control circuit; And when the determination control circuit has no signal to be added to the additional electric buffer, the transmission of the modulation signal to the optical modulator is stopped, and there is no signal to be added to the additional electric buffer. If there is no signal to be extracted to an electrical buffer, the performed operation to reproduce all the optical signal to the semiconductor optical amplifier, the signal to be added to the additional electrical buffer If there is a signal to be not extracted to the electric buffer, a signal to be extracted to send to the extracted electric buffer from said electric buffer, to be transmitted only extracted exempt signal, the control of the semiconductor optical amplifier If there is a signal to be added to the additional electrical buffer, optical saturation control is performed on the semiconductor optical amplifier, and there is a signal to be added to the additional electrical buffer and a signal to be extracted to the electrical buffer. If not, the modulation signal based on the read signal from the electrical buffer read signal and said additional electric buffer and transmitted to the optical modulator, there are signals to be added to the additional electrical buffer extraction to the electrical buffer If there is a signal to be transmitted, the signal to be extracted is transmitted from the electrical buffer to the extraction electrical buffer and read from the electrical buffer. A modulated signal based on the extracted signal not to be extracted and the signal read from the additional electrical buffer is transmitted to the optical modulator.

本発明は、前記光伝送システムにおいて、前記追加電気バッファに追加すべき信号があるときには、前記電気バッファと前記追加電気バッファから信号を読み出すときに、電気バッファの信号を優先的に読出すことが好ましい。 According to the present invention, in the optical transmission system, when there is a signal to be added to the additional electric buffer, when the signal is read from the electric buffer and the additional electric buffer, the signal of the electric buffer is preferentially read. preferable.

また、本発明は、光装置と光装置との間に位置する光伝送装置の光伝送方法であって、一方の光装置から受信した信号のうち、抽出すべき信号があるか否かを判定し、かつ、当該受信した信号に追加する信号があるか否かを確認し、抽出すべき信号も追加すべき信号もない場合は、一方の光装置からの信号を電気信号に変換することなく他方の光装置に送信し、抽出すべき信号があり、追加すべき信号がない場合は、当該受信した信号のうち抽出すべき信号を除いた信号を他方の光装置に送信し、抽出すべき信号がなく、追加すべき信号がある場合は、当該受信した信号を追加すべき信号よりも優先的に読出し、当該受信した信号および追加すべき信号により光変調した信号を他方の光装置に送信し、抽出すべき信号も追加すべき信号もある場合は、当該受信した信号のうち抽出すべき信号を除いた信号を追加すべき信号よりも優先的に読出し、当該受信した信号のうち抽出すべき信号を除いた信号と追加すべき信号により光変調した信号を他方の光装置に送信し、他方の光装置から受信した信号のうち、抽出すべき信号があるか否かを判定し、かつ、当該受信した信号に追加する信号があるか否かを確認し、抽出すべき信号も追加すべき信号もない場合は、他方の光装置からの信号を電気信号に変換することなく一方の光装置に送信し、抽出すべき信号があり、追加すべき信号がない場合は、当該受信した信号のうち抽出すべき信号を除いた信号を一方の光装置に送信し、抽出すべき信号がなく、追加すべき信号がある場合は、当該受信した信号を追加すべき信号よりも優先的に読出し、当該受信した信号および追加すべき信号により光変調した信号を一方の光装置に送信し、抽出すべき信号も追加すべき信号もある場合は、当該受信した信号のうち抽出すべき信号を除いた信号を追加すべき信号よりも優先的に読出し、当該受信した信号のうち抽出すべき信号を除いた信号と追加すべき信号により光変調した信号を一方の光装置に送信することを特徴とする。 The present invention also relates to an optical transmission method for an optical transmission apparatus located between optical apparatuses, and determines whether there is a signal to be extracted from signals received from one optical apparatus. In addition, it is confirmed whether there is a signal to be added to the received signal, and if there is no signal to be extracted or added, the signal from one optical device is not converted into an electrical signal. If there is a signal to be extracted and transmitted to the other optical device, but there is no signal to be added, a signal excluding the signal to be extracted among the received signals should be transmitted to the other optical device and extracted. When there is no signal and there is a signal to be added, the received signal is read with priority over the signal to be added, and the received signal and a signal optically modulated by the signal to be added are transmitted to the other optical device. And some signals to extract and some to add If the light by extraction signal to be signal preferentially than the signal should be added to read except for the signal and the signal to be added except for the signal to be extracted out of the received signal among the received signals Transmits the modulated signal to the other optical device, determines whether there is a signal to be extracted from the signals received from the other optical device, and whether there is a signal to be added to the received signal If there is no signal to be extracted or added, the signal from the other optical device is transmitted to one optical device without being converted into an electrical signal. When there is no signal to be transmitted, a signal excluding the signal to be extracted among the received signals is transmitted to one optical device. When there is no signal to be extracted and there is a signal to be added, the received signal is received. Prioritize the signal that should be added Out, it transmits a signal light modulated by the received signal and the additional signal to be on one of the optical device, if the extracted signal to be also some signals to be added, the signal to be extracted out of the received signal The removed signal is read preferentially over the signal to be added, and the signal obtained by removing the signal to be extracted from the received signal and the signal optically modulated by the signal to be added are transmitted to one optical device. And

本発明の光伝送装置によれば、光信号のまま伝送する機能と電気信号に変換して伝送する機能とを有するので、本発明の光伝送装置を用いて、アクセス網と、電気処理をベースとした既存ネットワークおよびフォトニックネットワークとを接続した際に、不要なトラフィックや遠回りとなる伝送ルートをとることなく、フォトニックネットワークの求める低遅延伝送を行うことと、電気処理が必要となる信号の追加抽出を行うことができる。 According to the optical transmission device of the present invention, since it has a function of transmitting an optical signal as it is and a function of converting it into an electrical signal and transmitting it, the optical transmission device of the present invention is used to base an access network and electrical processing. When connecting to existing networks and photonic networks, the low-delay transmission required by the photonic network and the processing of signals that require electrical processing can be performed without taking unnecessary traffic or a transmission route that makes a detour. Additional extraction can be performed.

本発明の光伝送装置が用いられる光伝送システムの全体構成図である。1 is an overall configuration diagram of an optical transmission system in which an optical transmission apparatus of the present invention is used. 追加電気バッファに信号がなく、電気バッファに抽出すべき信号がないときの光再生変調部の制御例を示す図である。It is a figure which shows the example of control of an optical reproduction modulation part when there is no signal in an additional electric buffer and there is no signal which should be extracted in an electric buffer. 追加電気バッファに信号がなく、電気バッファに抽出すべき信号があるときの光再生変調部の制御例を示す図である。It is a figure which shows the example of control of an optical reproduction modulation part when there is no signal in an additional electric buffer and there exists a signal which should be extracted in an electric buffer. 追加電気バッファに信号があり、電気バッファに抽出すべき信号がないときの光再生変調部の制御例を示す図である。It is a figure which shows the example of control of an optical reproduction modulation part when there exists a signal in an additional electrical buffer and there is no signal which should be extracted in an electrical buffer. 追加電気バッファに信号があり、電気バッファに抽出すべき信号があるときの光再生変調部の制御例を示す図である。It is a figure which shows the example of control of an optical reproduction modulation part when there exists a signal in an additional electric buffer and there exists a signal which should be extracted in an electric buffer. 光再生変調部における制御方式のフローチャートを示す図である。It is a figure which shows the flowchart of the control system in an optical reproduction modulation part. 本発明の光伝送システムをリング状に接続したときのネットワーク構成例を示す図である。It is a figure which shows the network structural example when the optical transmission system of this invention is connected in ring shape. 従来のネットワーク構成例を示す図である。It is a figure which shows the example of a conventional network structure.

本発明の実施の形態について図面を参照して説明する。図１は、本発明の光伝送装置が適用される光伝送システムの全体構成図である。
本発明の光伝送装置２０は、光伝送装置１０と光伝送装置３０の間に位置し、２つの光再生変調部２１０、２２０と、２つの波長スプリッタ２００１、２００２を備える。光再生変調部２１０と光再生変調部２２０は、それぞれ波長スプリッタ２００１と波長スプリッタ２００２に接続され、光再生変調部２１０は、光伝送装置１０から伝送される波長λ_１の光信号を受信し制御して、光伝送装置３０へ波長λ_１の光信号を送信し、光再生変調部２２０は、光伝送装置３０から伝送される波長λ_２の光信号を受信し制御して、光伝送装置１０へ波長λ_２の光信号を送信する。 Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an overall configuration diagram of an optical transmission system to which an optical transmission apparatus of the present invention is applied.
The optical transmission device 20 of the present invention is located between the optical transmission device 10 and the optical transmission device 30 and includes two optical regenerative modulation units 210 and 220 and two wavelength splitters 2001 and 2002. The optical regenerative modulation unit 210 and the optical regenerative modulation unit 220 are connected to the wavelength splitter 2001 and the wavelength splitter 2002, respectively. The optical regenerative modulation unit 210 receives and controls the optical signal having the wavelength λ ₁ transmitted from the optical transmission apparatus 10. Then, the optical signal with the wavelength λ ₁ is transmitted to the optical transmission device 30, and the optical regenerative modulation unit 220 receives and controls the optical signal with the wavelength λ ₂ transmitted from the optical transmission device 30, and the optical transmission device 10. An optical signal of wavelength λ ₂ is transmitted to

光再生変調部２１０は、波長λ_１の光信号を制御するもので、波長λ_１の光信号を分岐する光スプリッタ２１００と、分岐された光信号のうち、一方の光信号を受信して電気信号に変換する光受信器２１０１と、光受信器２１０１から出力された電気信号を蓄える電気バッファ２１０２と、光伝送装置１０以外の他の光伝送装置や他のネットワークから受信した、光伝送装置３０へ送るべき信号（追加すべき信号）を蓄える追加電気バッファ２１０３と、光受信器２１０１から波長λ_１の光信号のヘッダ情報を読み取り、ヘッダ情報から抽出すべき信号であるかないかを判定し、かつ電気バッファ２１０２と追加電気バッファ２１０３から電気信号を読み出する判定制御回路２１０４と、分岐された光信号のうち、もう一方の光信号を透過する光遅延線２１０６と、光遅延線２１０６からの光信号を再生あるいは光飽和する半導体光増幅器２１０７と、半導体光増幅器２１０７からの飽和信号を変調する光変調器２１０８と、判定制御回路２１０４により抽出すべき信号と判定された、他の光伝送装置（光伝送装置３０以外）や他のネットワークに送るべき電気信号（抽出すべき信号）を蓄える抽出電気バッファ２１０５で構成される。 Optical reproduction modulating unit 210 is for controlling the optical signal of the wavelength lambda _1, the optical splitter 2100 splits the optical signal of the wavelength lambda _1, among the branched optical signals, receives one of the optical signals the electric An optical receiver 2101 for converting to a signal, an electric buffer 2102 for storing an electric signal output from the optical receiver 2101, and an optical transmission device 30 received from another optical transmission device other than the optical transmission device 10 or another network. An additional electric buffer 2103 for storing a signal to be sent to (a signal to be added), and reading the header information of the optical signal of wavelength λ ₁ from the optical receiver 2101 to determine whether the signal should be extracted from the header information; In addition, the determination control circuit 2104 that reads an electric signal from the electric buffer 2102 and the additional electric buffer 2103 and the other optical signal among the branched optical signals are transmitted. An optical delay line 2106, a semiconductor optical amplifier 2107 that reproduces or optically saturates an optical signal from the optical delay line 2106, an optical modulator 2108 that modulates a saturation signal from the semiconductor optical amplifier 2107, and a determination control circuit 2104 An extraction electric buffer 2105 that stores other optical transmission apparatuses (other than the optical transmission apparatus 30) and electric signals to be sent to other networks (signals to be extracted) that are determined to be power signals is configured.

光再生変調部２２０は、波長λ_２の光信号を制御するもので、光再生変調部２１０と同一に構成され、波長λ_２の光信号を分岐する光スプリッタ２２００と、分岐された光信号のうち、一方の光信号を受信して電気信号に変換する光受信器２２０１と、光受信器２２０１から出力された電気信号を蓄える電気バッファ２２０２と、光伝送装置３０以外の他の光伝送装置や他のネットワークから受信し、光伝送装置３０から受信した光信号とともに光伝送装置１０へ送るべき信号（追加すべき信号）を蓄える追加電気バッファ２２０３と、光受信器２２０１から波長λ_２の光信号のヘッダ情報を読み取り、ヘッダ情報から抽出すべき信号であるかないかを判定し、かつ電気バッファ２２０２と追加電気バッファ２２０３からの電気信号を読み出す判定制御回路２２０４と、分岐された光信号のうち、もう一方の光信号を透過する光遅延線２２０６と、光遅延線２２０６からの光信号を再生あるいは光飽和する半導体光増幅器２２０７と、半導体光増幅器２２０７からの飽和信号を変調する光変調器２２０８と、判定制御回路２２０４により抽出すべき信号と判定された、他の光伝送装置（光伝送装置１０以外）や他のネットワークに送るべき電気信号（抽出すべき信号）を蓄える抽出電気バッファ２２０５で構成される。 The optical regenerative modulation unit 220 controls the optical signal having the wavelength λ _2. The optical regenerative modulation unit 220 is configured in the same manner as the optical regenerative modulation unit 210, and splits the optical signal having the wavelength λ ₂ . Among them, an optical receiver 2201 that receives one optical signal and converts it into an electrical signal, an electrical buffer 2202 that stores the electrical signal output from the optical receiver 2201, and other optical transmission devices other than the optical transmission device 30 An additional electric buffer 2203 for storing a signal (a signal to be added) to be transmitted to the optical transmission device 10 together with an optical signal received from another network and received from the optical transmission device 30, and an optical signal having a wavelength λ ₂ from the optical receiver 2201 Read out the header information, determine whether the signal should be extracted from the header information, and read out the electrical signals from the electrical buffer 2202 and the additional electrical buffer 2203 A determination control circuit 2204; an optical delay line 2206 that transmits the other of the branched optical signals; a semiconductor optical amplifier 2207 that regenerates or optically saturates the optical signal from the optical delay line 2206; An optical modulator 2208 that modulates the saturation signal from the amplifier 2207, and an electrical signal to be sent to another optical transmission device (other than the optical transmission device 10) or another network determined as a signal to be extracted by the determination control circuit 2204 An extraction electric buffer 2205 for storing (signal to be extracted) is configured.

光再生変調部２１０は、追加電気バッファ２１０３に追加すべき信号がなく、かつ電気バッファ２１０２に抽出すべき信号がないときには、光変調器２１０８への変調信号の送信を停止し、半導体光増幅器２１０７に伝送されてくる全ての光信号を再生し、追加電気バッファ２１０３に追加すべき信号がなく、かつ電気バッファ２１０２に抽出すべき信号があるときには、抽出すべき信号を電気バッファ２１０２から抽出電気バッファ２１０５に送信し、光変調器２１０８への変調信号の送信を停止し、半導体光増幅器２１０７に伝送されてくる光信号のうち、抽出対象外の光信号のみを再生し、追加電気バッファ２１０３に追加すべき信号があり、かつ電気バッファ２１０２に抽出すべき信号がないときには、半導体光増幅器２１０７を光飽和し、電気バッファ２１０２の信号と追加電気バッファ２１０３の信号を読み出した後、読み出した信号をもとに光変調器２１０８へ変調信号を送信し、追加電気バッファ２１０３に追加すべき信号があり、かつ電気バッファ２１０２に抽出すべき信号があるときには、抽出すべき信号を電気バッファ２１０２から抽出電気バッファ２１０５に送信し、半導体光増幅器２１０７を光飽和し、電気バッファ２１０２の前記抽出すべき信号以外の信号と追加電気バッファ２１０３の信号を読み出した後、読み出した信号をもとに光変調器２１０８へ変調信号を送信する。 When there is no signal to be added to the additional electrical buffer 2103 and there is no signal to be extracted from the electrical buffer 2102, the optical regenerative modulation unit 210 stops transmission of the modulation signal to the optical modulator 2108, and the semiconductor optical amplifier 2107. When there is no signal to be added to the additional electric buffer 2103 and there is a signal to be extracted in the electric buffer 2102, the signal to be extracted is extracted from the electric buffer 2102. 2105, the transmission of the modulation signal to the optical modulator 2108 is stopped, and only the optical signal not to be extracted is reproduced from the optical signal transmitted to the semiconductor optical amplifier 2107 and added to the additional electric buffer 2103. When there is a signal to be output and there is no signal to be extracted in the electric buffer 2102, the semiconductor optical amplifier 2107 is connected to the optical amplifier 2107. After summing and reading the signal of the electric buffer 2102 and the signal of the additional electric buffer 2103, the modulated signal is transmitted to the optical modulator 2108 based on the read signal, and there is a signal to be added to the additional electric buffer 2103, When there is a signal to be extracted in the electric buffer 2102, the signal to be extracted is transmitted from the electric buffer 2102 to the extraction electric buffer 2105, the semiconductor optical amplifier 2107 is optically saturated, and the signal other than the signal to be extracted from the electric buffer 2102 is transmitted. After reading the signal and the signal of the additional electric buffer 2103, the modulation signal is transmitted to the optical modulator 2108 based on the read signal.

光再生変調部２２０は、追加電気バッファ２２０３に追加すべき信号がなく、かつ電気バッファ２２０２に抽出すべき信号がないときには、光変調器２２０８への変調信号の送信を停止し、半導体光増幅器２２０７に伝送されてくる全ての光信号を再生し、追加電気バッファ２２０３に追加すべき信号がなく、かつ電気バッファ２２０２に抽出すべき信号があるときには、抽出すべき信号を電気バッファ２２０２から抽出電気バッファ２２０５に送信し、光変調器２２０８への変調信号の送信を停止し、半導体光増幅器２２０７に伝送されてくる光信号のうち、抽出対象外の光信号のみを再生し、追加電気バッファ２２０３に追加すべき信号があり、かつ電気バッファ２２０２に抽出すべき信号がないときには、半導体光増幅器２２０７を光飽和し、電気バッファ２２０２の信号と追加電気バッファ２２０３の信号を読み出した後、読み出した信号をもとに光変調器２２０８へ変調信号を送信し、追加電気バッファ２２０３に追加すべき信号があり、かつ電気バッファ２２０２に抽出すべき信号があるときには、抽出すべき信号を電気バッファ２２０２から抽出電気バッファ２２０５に送信し、半導体光増幅器２２０７を光飽和し、電気バッファ２２０２の前記抽出すべき信号以外の信号と追加電気バッファ２２０３の信号を読み出した後、読み出した信号をもとに光変調器２２０８へ変調信号を送信する。 When there is no signal to be added to the additional electrical buffer 2203 and there is no signal to be extracted from the electrical buffer 2202, the optical regenerative modulation unit 220 stops the transmission of the modulation signal to the optical modulator 2208, and the semiconductor optical amplifier 2207 When there is no signal to be added to the additional electric buffer 2203 and there is a signal to be extracted in the electric buffer 2202, the signal to be extracted is extracted from the electric buffer 2202. 2205, transmission of the modulation signal to the optical modulator 2208 is stopped, and only the optical signal not to be extracted is reproduced from the optical signal transmitted to the semiconductor optical amplifier 2207 and added to the additional electric buffer 2203. When there is a signal to be output and there is no signal to be extracted in the electrical buffer 2202, the semiconductor optical amplifier 2207 is connected to the optical After summing and reading the signal of the electric buffer 2202 and the signal of the additional electric buffer 2203, the modulated signal is transmitted to the optical modulator 2208 based on the read signal, and there is a signal to be added to the additional electric buffer 2203, When there is a signal to be extracted in the electric buffer 2202, the signal to be extracted is transmitted from the electric buffer 2202 to the extraction electric buffer 2205, the semiconductor optical amplifier 2207 is optically saturated, and the signal other than the signal to be extracted in the electric buffer 2202 After reading the signal and the signal of the additional electric buffer 2203, the modulation signal is transmitted to the optical modulator 2208 based on the read signal.

本発明の光伝送装置は、上述のように光信号を制御することにより、フォトニックネットワークの求める低遅延伝送を行うことと、電気処理が必要となる信号の追加抽出を行うことができる。 The optical transmission apparatus of the present invention can perform low-delay transmission required by the photonic network and additional extraction of signals that require electrical processing by controlling the optical signal as described above.

なお、本発明の光伝送装置は、一方（上流側）の光伝送装置１０を光終端装置等の他の光装置とし、および／または他方（下流側）の光伝送装置３０を光終端装置等の他の光装置とした光伝送システムにも適用できるものである。また、図１では、光伝送装置が３台のときの光伝送システムを示しているが、本発明の光伝送装置は、直列に接続される３台以上の光伝送装置を含む光伝送システムに適用できるものである。 In the optical transmission device of the present invention, one (upstream) optical transmission device 10 is another optical device such as an optical termination device, and / or the other (downstream) optical transmission device 30 is an optical termination device or the like. The present invention can also be applied to an optical transmission system as another optical device. Further, FIG. 1 shows an optical transmission system with three optical transmission apparatuses, but the optical transmission apparatus of the present invention is an optical transmission system including three or more optical transmission apparatuses connected in series. Applicable.

図２は、追加電気バッファ２１０３に追加すべき信号がなく、電気バッファ２１０２に抽出すべき信号がないときの光再生変調部２１０の制御例を示す図である。図２の左側から伝送されてくる光信号αは、光スプリッタ２１００で分岐された後、一方は光受信器２１０１で受信される。受信された光信号αのヘッダ情報は、判定制御回路２１０４に送られ、判定制御回路２１０４は、ヘッダ情報から抽出すべき信号であるかないかを判定する。本制御例では、抽出すべき信号はなく、また追加電気バッファ２１０３に信号がないため、判定制御回路２１０４は、光スプリッタ２１００で分岐されたもう一方の信号αの全てが再生されるように半導体光増幅器２１０７の制御を行う。同時に、判定制御回路２１０４は、光変調器２１０８へ変調信号を送信することを停止する。
光再生変調部２１０は、このように制御することにより、光信号αを、電気信号に変換することなく光信号のまま伝送することができる。 FIG. 2 is a diagram illustrating a control example of the optical regenerative modulation unit 210 when there is no signal to be added to the additional electrical buffer 2103 and there is no signal to be extracted from the electrical buffer 2102. The optical signal α transmitted from the left side of FIG. 2 is branched by the optical splitter 2100, and one is received by the optical receiver 2101. The received header information of the optical signal α is sent to the determination control circuit 2104, and the determination control circuit 2104 determines whether or not the signal should be extracted from the header information. In this control example, there is no signal to be extracted, and there is no signal in the additional electrical buffer 2103. Therefore, the determination control circuit 2104 is configured to regenerate all of the other signal α branched by the optical splitter 2100. The optical amplifier 2107 is controlled. At the same time, the determination control circuit 2104 stops transmitting the modulation signal to the optical modulator 2108.
By controlling in this way, the optical regenerative modulation unit 210 can transmit the optical signal α as it is without converting it into an electrical signal.

図３は、追加電気バッファ２１０３に追加すべき信号がなく、電気バッファ２１０２に抽出すべき信号があるときの光再生変調部２１０の制御例を示す図である。図３の左側から伝送されてくる光信号αは、光スプリッタ２１００で分岐された後、一方は光受信器２１０１で受信される。受信された光信号αのヘッダ情報は、判定制御回路２１０４に送られ、判定制御回路２１０４は、ヘッダ情報から抽出すべき信号であるかないかを判定する。本制御例では、抽出すべき信号があるため、抽出すべき信号と判定された信号は、電気バッファ２１０２から取り出され、抽出電気バッファ２１０５に送信される。また、判定制御回路２１０４は、光スプリッタ２１００で分岐されたもう一方の光信号αのうち、抽出すべき信号と判定された光信号が送信されないように、また、抽出対象外の光信号が送信されるように半導体光増幅器２１０７のＯＮ／ＯＦＦ制御を行う。同時に判定制御回路２１０４は、光変調器２１０８へ変調信号を送信することを停止する。 FIG. 3 is a diagram illustrating a control example of the optical regenerative modulation unit 210 when there is no signal to be added to the additional electrical buffer 2103 and there is a signal to be extracted from the electrical buffer 2102. The optical signal α transmitted from the left side of FIG. 3 is branched by the optical splitter 2100, and one is received by the optical receiver 2101. The received header information of the optical signal α is sent to the determination control circuit 2104, and the determination control circuit 2104 determines whether or not the signal should be extracted from the header information. In this control example, since there is a signal to be extracted, a signal determined to be a signal to be extracted is extracted from the electric buffer 2102 and transmitted to the extraction electric buffer 2105. In addition, the determination control circuit 2104 transmits an optical signal not to be extracted so that an optical signal determined as the signal to be extracted from the other optical signal α branched by the optical splitter 2100 is not transmitted. As described above, ON / OFF control of the semiconductor optical amplifier 2107 is performed. At the same time, the determination control circuit 2104 stops transmitting the modulation signal to the optical modulator 2108.

ここで、光遅延線２１０６は、光受信器２１０１による信号受信処理、判定制御回路２１０４における信号判定処理に要する時間に比べ十分長い時間分の光遅延線とする。また、判定制御回路２１０４は、光受信器２１０１からの信号をもとに、クロック信号を生成する機能を有し、クロック信号と設計された光遅延線２１０６の距離、光受信器２１０１による信号受信処理、判定制御回路２１０４における信号判定処理に要する時間を考慮し、光遅延線２１０６を通過した再生すべき光信号が半導体光増幅器２１０７を通過するタイミングと、半導体光増幅器２１０７の制御タイミングを一致させる。
光再生変調部２１０は、このように制御することにより、光信号αを、抽出すべき信号を除いた光信号α’として、電気信号に変換することなく光信号のまま伝送することができる。 Here, the optical delay line 2106 is an optical delay line for a time sufficiently longer than the time required for the signal reception processing by the optical receiver 2101 and the signal determination processing by the determination control circuit 2104. The determination control circuit 2104 also has a function of generating a clock signal based on the signal from the optical receiver 2101, the distance between the clock signal and the designed optical delay line 2106, and signal reception by the optical receiver 2101. In consideration of the time required for signal determination processing in the processing and determination control circuit 2104, the timing at which the optical signal to be reproduced that has passed through the optical delay line 2106 passes through the semiconductor optical amplifier 2107 and the control timing of the semiconductor optical amplifier 2107 are matched. .
By controlling in this way, the optical regenerative modulation unit 210 can transmit the optical signal α as the optical signal α ′ without converting the signal to be extracted into an electric signal α ′ without converting it into an electrical signal.

図４は、追加電気バッファ２１０３に追加すべき信号があり、電気バッファ２１０２に抽出すべき信号がないときの光再生変調部２１０の制御例を示す図である。図４の左側から伝送されてくる光信号αは、光スプリッタ２１００で分岐された後、一方は光受信器２１０１で受信される。受信された光信号αのヘッダ情報は、判定制御回路２１０４に送られ、判定制御回路２１０４は、ヘッダ情報から抽出すべき信号であるかないかを判定する。本制御例では、抽出すべき信号はないが追加電気バッファ２１０３に信号があるため、判定制御回路２１０４は、全ての光信号αのデータを一度全て削除するために、半導体光増幅器２１０７に対し光飽和の制御を行う。また、判定制御回路２１０４は、電気バッファ２１０２から信号αと追加電気バッファ２１０３から信号βを読み出し、読み出した信号をもとに変調信号を光変調器２１０８に送信する。光変調器２１０８は、半導体光増幅器２１０７で光飽和された光信号を変調し、光信号α、βを伝送する。
光再生変調部２１０は、このように制御することにより、電気信号の処理が必要となる信号の追加処理を行うことができる。 FIG. 4 is a diagram illustrating a control example of the optical regenerative modulation unit 210 when there is a signal to be added to the additional electrical buffer 2103 and there is no signal to be extracted from the electrical buffer 2102. The optical signal α transmitted from the left side of FIG. 4 is branched by the optical splitter 2100, and one is received by the optical receiver 2101. The received header information of the optical signal α is sent to the determination control circuit 2104, and the determination control circuit 2104 determines whether or not the signal should be extracted from the header information. In this control example, there is no signal to be extracted, but there is a signal in the additional electrical buffer 2103. Therefore, the determination control circuit 2104 causes the semiconductor optical amplifier 2107 to transmit the optical data in order to delete all the data of all the optical signals α. Perform saturation control. Also, the determination control circuit 2104 reads the signal α from the electrical buffer 2102 and the signal β from the additional electrical buffer 2103, and transmits a modulation signal to the optical modulator 2108 based on the read signal. The optical modulator 2108 modulates the optical signal optically saturated by the semiconductor optical amplifier 2107 and transmits the optical signals α and β.
By controlling in this way, the optical regenerative modulation unit 210 can perform additional processing of signals that require processing of electrical signals.

ここで半導体光増幅器の光飽和によるデータ削除は、非特許文献２等に記載の半導体光増幅器の特性を利用することにより実現可能である。 Here, data deletion due to light saturation of the semiconductor optical amplifier can be realized by utilizing the characteristics of the semiconductor optical amplifier described in Non-Patent Document 2 and the like.

図５は、追加電気バッファ２１０３に追加すべき信号があり、電気バッファ２１０２に抽出すべき信号があるときの光再生変調部２１０の制御例を示す図である。図５の左側から伝送されてくる光信号αは、光スプリッタ２１００で分岐された後、一方は光受信器２１０１で受信される。受信された光信号αのヘッダ情報は、判定制御回路２１０４に送られ、判定制御回路２１０４は、ヘッダ情報から抽出すべき信号であるかないかを判定する。本制御例では、抽出すべき信号があり、追加電気バッファ２１０３にも信号があるため、判定制御回路２１０４は、全ての光信号αのデータを一度全て削除するために、半導体光増幅器２１０７に対し光飽和の制御を行う。判定制御回路２１０４にて抽出すべき信号と判定された信号は、電気バッファ２１０２から取り出され、抽出電気バッファ２１０５に送信される。また、判定制御回路２１０４は、電気バッファ２１０２から抽出対象外の信号α’を読み出し、追加電気バッファ２１０３から信号βを読み出し、読み出した信号をもとに変調信号を光変調器２１０８に送信する。光変調器２１０８は、半導体光増幅器２１０７で光飽和された光信号を変調し、光信号α’、βを伝送する。
光再生変調部２１０は、このように制御することにより、電気信号の処理が必要となる信号の追加抽出処理を行うことができる。 FIG. 5 is a diagram illustrating a control example of the optical regenerative modulation unit 210 when there is a signal to be added to the additional electrical buffer 2103 and there is a signal to be extracted from the electrical buffer 2102. The optical signal α transmitted from the left side of FIG. 5 is branched by the optical splitter 2100, and one is received by the optical receiver 2101. The received header information of the optical signal α is sent to the determination control circuit 2104, and the determination control circuit 2104 determines whether or not the signal should be extracted from the header information. In this control example, since there is a signal to be extracted and there is also a signal in the additional electrical buffer 2103, the determination control circuit 2104 sends to the semiconductor optical amplifier 2107 in order to delete all the data of all the optical signals α once. Controls light saturation. The signal determined to be extracted by the determination control circuit 2104 is extracted from the electric buffer 2102 and transmitted to the extraction electric buffer 2105. Further, the determination control circuit 2104 reads out the signal α ′ that is not to be extracted from the electric buffer 2102, reads out the signal β from the additional electric buffer 2103, and transmits a modulation signal to the optical modulator 2108 based on the read signal. The optical modulator 2108 modulates the optical signal optically saturated by the semiconductor optical amplifier 2107 and transmits optical signals α ′ and β.
By controlling in this way, the optical regenerative modulation unit 210 can perform additional signal extraction processing that requires processing of electrical signals.

次に、判定制御回路２１０４が電気バッファ２１０２と追加電気バッファ２１０３から信号を読み出すときの他の制御例を説明する。図４および図５の制御例では、判定制御回路２１０４は、電気バッファ２１０２と追加電気バッファ２１０３の両方から信号を読み出すが、ここで例えば、電気バッファ２１０２→追加電気バッファ２１０３→電気バッファ２１０２→追加電気バッファ２１０３・・・のように両方の信号を平等に読み出す場合に対し、電気バッファ２１０２→電気バッファ２１０２→追加電気バッファ２１０３→電気バッファ２１０２→電気バッファ２１０２→追加電気バッファ２１０３→・・・のように電気バッファ２１０２に蓄えられた信号を追加電気バッファ２１０３に蓄えられた信号に比べ優先的に読み出すならば、電気バッファ２１０２の信号は、バッファに滞留する時間が短くなるため、追加電気バッファ２１０３の信号に比べ低遅延で伝送されることになる。そのため、図１の光伝送装置１０から伝送されてくる光信号の低遅延伝送が期待できる。 Next, another control example when the determination control circuit 2104 reads signals from the electric buffer 2102 and the additional electric buffer 2103 will be described. 4 and 5, the determination control circuit 2104 reads signals from both the electric buffer 2102 and the additional electric buffer 2103. Here, for example, the electric buffer 2102 → the additional electric buffer 2103 → the electric buffer 2102 → addition. In the case of reading both signals equally as in the case of the electric buffer 2103..., The electric buffer 2102 → the electric buffer 2102 → the additional electric buffer 2103 → the electric buffer 2102 → the electric buffer 2102 → the additional electric buffer 2103 →. Thus, if the signal stored in the electrical buffer 2102 is read preferentially compared to the signal stored in the additional electrical buffer 2103, the signal stored in the electrical buffer 2102 has a shorter residence time in the buffer. Compared with It becomes Rukoto. Therefore, low-delay transmission of an optical signal transmitted from the optical transmission device 10 of FIG. 1 can be expected.

図６は、判定制御回路の動作を説明するフローチャートである。判定制御回路２１０４は、はじめに追加電気バッファ２１０３に信号があるかないかを判定する（Ｓ１０１）。追加電気バッファ２１０３に信号がない場合（Ｎｏの場合）には、光変調器２１０８への変調信号の送信を停止する（Ｓ１０８）。次に、電気バッファ２１０２に抽出すべき信号があるかないかを判定する（Ｓ１０９）。電気バッファ２１０２に抽出すべき信号がない場合（Ｎｏの場合）には、半導体光増幅器２１０７に対し全ての光信号を再生させるための動作を行う（Ｓ１１２）。また、電気バッファ２１０２に抽出すべき信号がある場合（Ｓ１０９においてＹｅｓの場合）には、抽出すべき信号を電気バッファ２１０２から抽出電気バッファ２１０５に送信する（Ｓ１１０）。そして、抽出対象外の信号のみ伝送されるように、半導体光増幅器２１０７のＯＮ／ＯＦＦ制御を行う（Ｓ１１１）。 FIG. 6 is a flowchart for explaining the operation of the determination control circuit. The determination control circuit 2104 first determines whether or not there is a signal in the additional electrical buffer 2103 (S101). When there is no signal in the additional electrical buffer 2103 (in the case of No), transmission of the modulation signal to the optical modulator 2108 is stopped (S108). Next, it is determined whether or not there is a signal to be extracted in the electrical buffer 2102 (S109). If there is no signal to be extracted in the electrical buffer 2102 (in the case of No), the semiconductor optical amplifier 2107 is operated to regenerate all the optical signals (S112). If there is a signal to be extracted in the electrical buffer 2102 (Yes in S109), the signal to be extracted is transmitted from the electrical buffer 2102 to the extraction electrical buffer 2105 (S110). Then, ON / OFF control of the semiconductor optical amplifier 2107 is performed so that only signals that are not to be extracted are transmitted (S111).

一方で、追加電気バッファ２１０３に信号がある場合（Ｓ１０１においてＹｅｓの場合）には、半導体光増幅器２１０７に対し、光飽和の制御を行う（Ｓ１０２）。その後、電気バッファ２１０２に抽出すべき信号があるかないかを判定する（Ｓ１０３）。電気バッファ２１０２に抽出すべき信号がない場合（Ｎｏの場合）には、電気バッファ２１０２と追加電気バッファ２１０３から電気信号を読み出し（Ｓ１０６）、変調信号を光変調器２１０８へ伝送する（Ｓ１０７）。また、電気バッファ２１０２に抽出すべき信号がある場合（Ｓ１０３においてＹｅｓの場合）には、抽出すべき信号を電気バッファ２１０２から抽出電気バッファ２１０５に送信する（Ｓ１０４）。そして、電気バッファ２１０２にある抽出対象外の信号と追加電気バッファ２１０３の信号を読み出し（Ｓ１０５）、変調信号を光変調器２１０８へ送信する（Ｓ１０７）。 On the other hand, when there is a signal in the additional electrical buffer 2103 (Yes in S101), the optical saturation is controlled for the semiconductor optical amplifier 2107 (S102). Thereafter, it is determined whether or not there is a signal to be extracted in the electric buffer 2102 (S103). When there is no signal to be extracted in the electrical buffer 2102 (in the case of No), the electrical signal is read from the electrical buffer 2102 and the additional electrical buffer 2103 (S106), and the modulated signal is transmitted to the optical modulator 2108 (S107). If there is a signal to be extracted in the electrical buffer 2102 (Yes in S103), the signal to be extracted is transmitted from the electrical buffer 2102 to the extraction electrical buffer 2105 (S104). Then, the signal not to be extracted in the electric buffer 2102 and the signal of the additional electric buffer 2103 are read (S105), and the modulated signal is transmitted to the optical modulator 2108 (S107).

本発明の光伝送装置は、このように制御することにより、光信号のまま伝送する機能と電気信号に変換して伝送する機能の両方を実現することができる。 By controlling in this way, the optical transmission apparatus of the present invention can realize both the function of transmitting an optical signal as it is and the function of converting it into an electrical signal and transmitting it.

なお、上述した実施の形態では、光再生変調部２１０の動作について説明したが、光再生変調部２２０も同様の動作を行うものである。 In the above-described embodiment, the operation of the optical reproduction modulation unit 210 has been described. However, the optical reproduction modulation unit 220 also performs the same operation.

図７は、本発明の光伝送装置をリング状に接続したときのネットワーク構成例を示す図である。図７に示すネットワークは、１台の光送受信装置５００と、本発明のＮ台の光伝送装置２０−１〜２０−Ｎで構成される。光送受信装置５００は、波長λ_１用の光送信器５００１および光受信器５００３と、波長λ_２用の光送信器５００２および光受信器５００４と、波長λ_１と波長λ_２を分波するための２つの波長スプリッタ５００５、５００６で構成される。
光送信器５００１から送信される波長λ_１の光信号は、波長スプリッタ５００５を通過した後、光伝送装置２０−１→光伝送装置２０−２→・・・→光伝送装置２０−Ｎ−１→光伝送装置２０−Ｎの順に伝送され、波長スプリッタ５００６を通過した後、光受信器５００３で受信される。
一方、光送信器５００２から送信される波長λ_２の光信号は、波長スプリッタ５００６を通過した後、光伝送装置２０−Ｎ→光伝送装置２０−Ｎ−１→・・・→光伝送装置２０−２→光伝送装置２０−１の順に伝送され、波長スプリッタ５００５を通過した後、光受信器５００４で受信される。
ここで各光伝送装置２０−１〜２０−Ｎでは、追加電気バッファに追加すべき信号があるかないか、電気バッファに抽出すべき信号があるかないかを判定し、上述した光再生変調部の制御を行う。このように構成・制御することにより、光信号のまま伝送する機能と電気信号に変換して伝送する機能の両方を有するリング状のネットワークを構成することができる。 FIG. 7 is a diagram showing a network configuration example when the optical transmission apparatuses of the present invention are connected in a ring shape. The network shown in FIG. 7 includes one optical transmission / reception device 500 and N optical transmission devices 20-1 to 20-N according to the present invention. The optical transceiver 500 demultiplexes the optical transmitter 5001 and the optical receiver 5003 for the wavelength λ ₁ , the optical transmitter 5002 and the optical receiver 5004 for the wavelength λ ₂ , and the wavelengths λ ₁ and λ _2. The two wavelength splitters 5005 and 5006.
The optical signal having the wavelength λ ₁ transmitted from the optical transmitter 5001 passes through the wavelength splitter 5005, and then the optical transmission device 20-1 → the optical transmission device 20-2 →... → the optical transmission device 20 -N−1. → Transmitted in the order of the optical transmission device 20 -N, and after passing through the wavelength splitter 5006, is received by the optical receiver 5003.
On the other hand, the optical signal having the wavelength λ ₂ transmitted from the optical transmitter 5002 passes through the wavelength splitter 5006, and then the optical transmission device 20 -N → the optical transmission device 20 -N−1 →. −2 → the optical transmission device 20-1, passes through the wavelength splitter 5005, and is received by the optical receiver 5004.
Here, in each of the optical transmission devices 20-1 to 20-N, it is determined whether there is a signal to be added to the additional electrical buffer or whether there is a signal to be extracted from the electrical buffer. Take control. By configuring and controlling in this way, it is possible to configure a ring network having both the function of transmitting an optical signal as it is and the function of converting it into an electrical signal and transmitting it.

１アクセス網
２電気処理をベースとした既存ネットワーク
３フォトニックネットワーク
１０，２０，３０，２０−１〜２０−Ｎ，３１−１〜３１−Ｎ光伝送装置
１１−１〜１１−Ｎ，２１−１〜２１−Ｎ光終端装置
２１０，２２０光再生変調部
２００１，２００２，５００５，５００６波長スプリッタ
２１０１，２２０１，５００３，５００４光受信器
２１０２，２２０２電気バッファ
２１０３，２２０３追加電気バッファ
２１０４，２２０４判定制御回路
２１０５，２２０５抽出電気バッファ
２１０６，２２０６光遅延線
２１０７，２２０７半導体光増幅器
２１０８，２２０８光変調器
５００光送受信装置
５００１，５００２光送信器 DESCRIPTION OF SYMBOLS 1 Access network 2 Existing network based on electrical processing 3 Photonic network 10, 20, 30, 20-1 to 20-N, 31-1 to 31-N Optical transmission devices 11-1 to 11-N, 21- 1 to 21-N optical terminator 210,220 optical regenerative modulation unit 2001,2002,5005,5006 wavelength splitter 2101,201,5003,5004 optical receiver 2102,2202 electric buffer 2103,2203 additional electric buffer 2104,2204 judgment control Circuits 2105 and 2205 Extraction electric buffers 2106 and 2206 Optical delay lines 2107 and 2207 Semiconductor optical amplifiers 2108 and 2208 Optical modulator 500 Optical transceiver 5001 and 5002 Optical transmitter

Claims

It is determined whether there is a signal to be extracted from the signals received from one optical device, and whether there is a signal to be added to the received signal, and also adds a signal to be extracted. If there is no signal to be transmitted, the signal from one optical device is transmitted to the other optical device without being converted into an electrical signal. If there is a signal to be extracted and there is no signal to be added, the received signal The signal excluding the signal to be extracted is transmitted to the other optical device, and when there is no signal to be extracted and there is a signal to be added, the received signal is read with priority over the signal to be added. When the received signal and the signal optically modulated by the signal to be added are transmitted to the other optical device, and there are signals to be extracted and signals to be added, the signals to be extracted are excluded from the received signals. Than the signal that should be added A first light reproduction modulator for transmitting an optical modulated signal to the other optical device by the previous manner readout, signal and the signal to be added except for the signal to be extracted out of the received signal,
It is determined whether there is a signal to be extracted from the signals received from the other optical device, and whether there is a signal to be added to the received signal, and also adds a signal to be extracted. If there is no signal to be transmitted, the signal from the other optical device is transmitted to one optical device without being converted into an electrical signal. If there is a signal to be extracted and there is no signal to be added, the received signal The signal excluding the signal to be extracted is transmitted to one optical device, and when there is no signal to be extracted and there is a signal to be added, the received signal is read with priority over the signal to be added. When the received signal and the signal optically modulated by the signal to be added are transmitted to one optical device, and there are signals to be extracted and signals to be added, the signals to be extracted are excluded from the received signals. Than the signal that should be added A second optical reproducing modulator for transmitting an optical modulated signal in one optical device by the previous manner readout, signal and the signal to be added except for the signal to be extracted out of the received signal,
An optical transmission device comprising:

A first optical regenerative modulation unit that receives and controls an optical signal of the first wavelength transmitted from one optical device, and transmits the optical signal of the first wavelength to the other optical device;
A second optical regenerative modulation unit that receives and controls an optical signal of the second wavelength transmitted from the other optical device, and transmits the optical signal of the second wavelength to the one optical device;
The first and second optical regenerative modulation units are respectively
An optical splitter for branching the received optical signal;
An optical receiver that receives one of the branched optical signals;
An electrical buffer for storing the signal of the optical receiver;
An additional electrical buffer to store the signal to be added,
A determination control circuit for determining whether or not the signal is to be extracted from header information of the optical signal received by the optical receiver, and for reading a signal from the electrical buffer and the additional electrical buffer;
Among the branched optical signals, an optical delay line that transmits the other optical signal;
A semiconductor optical amplifier that reproduces or optically saturates the optical signal from the optical delay line;
An optical modulator for modulating a saturation signal from the semiconductor optical amplifier;
An extraction electric buffer for storing a signal determined to be extracted by the determination control circuit;
When there is no signal to be added to the additional electrical buffer, the determination control circuit stops transmission of the modulation signal to the optical modulator, and there is no signal to be added to the additional electrical buffer, and the signal is extracted to the electrical buffer. When there is no signal to be performed, the semiconductor optical amplifier is caused to regenerate all the optical signals, and when there is no signal to be added to the additional electrical buffer and there is a signal to be extracted to the electrical buffer. The signal to be extracted is transmitted from the electrical buffer to the extraction electrical buffer, and the semiconductor optical amplifier is controlled so that only signals not to be extracted are transmitted, and there is a signal to be added to the additional electrical buffer. If the to the semiconductor optical amplifier, and controls the light saturation, the additional electrical buffer may signal to be added to the play no signal should be extracted to the electrical buffer The modulated signal based on the signal read signal read from the electrical buffer from said additional electrical buffer and transmitted to the optical modulator, to be extracted in the electrical buffer may signal to be added to the additional electrical buffer When there is a signal, the signal to be extracted is transmitted from the electric buffer to the extraction electric buffer , and a modulation signal based on the signal that is not extracted and read from the additional electric buffer is read from the electric buffer. An optical transmission device that transmits to an optical modulator.

3. The light according to claim 2, wherein when there is a signal to be added to the additional electrical buffer, the signal of the electrical buffer is preferentially read when the signal is read from the electrical buffer and the additional electrical buffer. Transmission equipment.

In an optical transmission system including three or more optical transmission devices connected in series,
The optical transmission device is:
It is determined whether there is a signal to be extracted from the signals received from one of the optical transmission devices, and whether there is a signal to be added to the received signal, and the signal to be extracted is also added. When there is no signal to be transmitted, the signal from one optical transmission device is transmitted to the other optical transmission device without being converted into an electrical signal, and there is a signal to be extracted, and there is no signal to be added, Send the received signal except the signal to be extracted to the other optical transmission device. If there is no signal to be extracted and there is a signal to be added, the received signal is more than the signal to be added. Preferentially read and transmit the received signal and the signal optically modulated by the signal to be added to the other optical transmission device, and if there are signals to be extracted and signals to be added, extract them from the received signals The signal excluding the signal to be First light reproduction modulation to transmit preferentially than the signal to be pressurized read, a signal light modulated by the signal and the signal to be added except for the signal to be extracted out of the received signal to the other optical transmission device And
It is determined whether there is a signal to be extracted from the signals received from the other optical transmission device, and whether there is a signal to be added to the received signal, and also adds a signal to be extracted. If there is no signal to be transmitted, the signal from the other optical transmission device is transmitted to one optical transmission device without being converted into an electrical signal, and there is a signal to be extracted. The received signal, except for the signal to be extracted, is transmitted to one optical transmission device. If there is no signal to be extracted and there is a signal to be added, the received signal is more than the signal to be added. Preferentially read and transmit the received signal and the signal optically modulated by the signal to be added to one optical transmission device, and if there are signals to be extracted and signals to be added, extract those received signals. The signal excluding the signal to be Preferentially over the signal to be pressurized read, the second light reproduction modulation for transmitting an optical modulation signal to one optical transmission apparatus by a signal and the signal to be added except for the signal to be extracted out of the received signal And
An optical transmission system comprising:

In an optical transmission system including three or more optical transmission devices connected in series,
The optical transmission device is:
A first optical regenerative modulation unit that receives and controls an optical signal of the first wavelength transmitted from one optical transmission device, and transmits the optical signal of the first wavelength to the other optical transmission device;
A second optical regenerative modulation unit that receives and controls the optical signal of the second wavelength transmitted from the other optical transmission device and transmits the optical signal of the second wavelength to the one optical transmission device;
The first and second optical regenerative modulation units are respectively
An optical splitter for branching the received optical signal;
An optical receiver that receives one of the branched optical signals;
An electrical buffer for storing the signal of the optical receiver;
An additional electrical buffer to store the signal to be added,
A determination control circuit for determining whether or not the signal is to be extracted from header information of the optical signal received by the optical receiver, and for reading a signal from the electrical buffer and the additional electrical buffer;
Among the branched optical signals, an optical delay line that transmits the other optical signal;
A semiconductor optical amplifier that reproduces or optically saturates the optical signal from the optical delay line;
An optical modulator for modulating a saturation signal from the semiconductor optical amplifier;
An extraction electric buffer for storing a signal determined to be extracted by the determination control circuit;
When there is no signal to be added to the additional electrical buffer, the determination control circuit stops transmission of the modulation signal to the optical modulator, and there is no signal to be added to the additional electrical buffer, and the signal is extracted to the electrical buffer. When there is no signal to be performed, the semiconductor optical amplifier is caused to regenerate all the optical signals, and when there is no signal to be added to the additional electrical buffer and there is a signal to be extracted to the electrical buffer. The signal to be extracted is transmitted from the electrical buffer to the extraction electrical buffer, and the semiconductor optical amplifier is controlled so that only signals not to be extracted are transmitted, and there is a signal to be added to the additional electrical buffer. If the to the semiconductor optical amplifier, and controls the light saturation, the additional electrical buffer may signal to be added to the play no signal should be extracted to the electrical buffer The modulated signal based on the signal read signal read from the electrical buffer from said additional electrical buffer and transmitted to the optical modulator, to be extracted in the electrical buffer may signal to be added to the additional electrical buffer When there is a signal, the signal to be extracted is transmitted from the electric buffer to the extraction electric buffer , and a modulation signal based on the signal that is not extracted and read from the additional electric buffer is read from the electric buffer. An optical transmission system for transmitting to an optical modulator.

6. The light according to claim 5, wherein when there is a signal to be added to the additional electrical buffer, the signal of the electrical buffer is preferentially read when the signal is read from the electrical buffer and the additional electrical buffer. Transmission system.

An optical transmission method of an optical transmission device located between an optical device and an optical device,
It is determined whether there is a signal to be extracted from the signals received from one optical device, and whether there is a signal to be added to the received signal, and also adds a signal to be extracted. If there is no signal to be transmitted, the signal from one optical device is transmitted to the other optical device without being converted into an electrical signal. If there is a signal to be extracted and there is no signal to be added, the received signal The signal excluding the signal to be extracted is transmitted to the other optical device, and when there is no signal to be extracted and there is a signal to be added, the received signal is read with priority over the signal to be added. When the received signal and the signal optically modulated by the signal to be added are transmitted to the other optical device, and there are signals to be extracted and signals to be added, the signals to be extracted are excluded from the received signals. Than the signal that should be added Above to send read, an optical modulation signal to the other optical device by the signal and the signal to be added except for the signal to be extracted out of the received signal,
It is determined whether there is a signal to be extracted from the signals received from the other optical device, and whether there is a signal to be added to the received signal, and also adds a signal to be extracted. If there is no signal to be transmitted, the signal from the other optical device is transmitted to one optical device without being converted into an electrical signal. If there is a signal to be extracted and there is no signal to be added, the received signal The signal excluding the signal to be extracted is transmitted to one optical device, and when there is no signal to be extracted and there is a signal to be added, the received signal is read with priority over the signal to be added. When the received signal and the signal optically modulated by the signal to be added are transmitted to one optical device, and there are signals to be extracted and signals to be added, the signals to be extracted are excluded from the received signals. Than the signal that should be added Previously to read, transmit optical modulated signal to one of the optical device by the signal and the signal to be added except for the signal to be extracted out of the received signal,
An optical transmission method characterized by the above.