Optical transmission system and transmitting terminal station

Claim 2

An optical transmission system comprising: a transmitting terminal station transmitting a wavelength division multiplexed (WDM) signal light to a transmission path, the WDM signal light including a plurality of signal lights at different wavelengths multiplexed together; and a receiving terminal station receiving the WDM signal light from the transmission path, the receiving terminal station including a receiving side spectrum detecting device detecting a spectrum of the received WDM signal light, and a transmission device transmitting spectrum information of the detected spectrum to the transmitting terminal station, wherein the transmitting terminal station includes a transmitting side spectrum detecting device detecting a spectrum of the WDM signal light before the WDM signal light is received by the receiving terminal station, a receiving side spectrum information detecting device detecting the spectrum information transmitted from the transmission device of the receiving terminal station, and a pre-emphasis controlling device comparing spectrum information of the spectrum detected by the transmitting side spectrum detecting device with the spectrum information detected by the receiving side spectrum information detecting device, and controlling a level and wavelength of each signal light before being multiplexed in accordance with the comparison.

Claim 3

The optical transmission system according to claim 1 , wherein, for a respective signal light, the pre-emphasis controlling device alternately and repeatedly controls the level and wavelength of the signal light.

Claim 4

The optical transmission system according to claim 1 , where if a failure occurs in the receiving side spectrum detecting device, and in the transmission device, the level and wavelength of signal lights can be controlled by the transmitting side spectrum detecting device and the pre-emphasis controlling device.

Claim 5

A transmitting terminal station in an optical transmission system for transmitting pre-emphasis information from a receiving terminal station for receiving a plurality of wavelength-division multiplexed signal lights from a transmitting station to the transmitting terminal station, comprising: transmitting side spectrum detecting means for detecting the spectrum of signal lights to be transmitted; receiving side spectrum information detecting means for detecting spectrum information from the receiving terminal station; and pre-emphasis controlling means for comparing spectrum information from the transmitting side detecting means with the spectrum information from the receiving side spectrum information detecting means, and controlling the level and wavelength of signal lights to be transmitted.

Claim 6

A transmitting terminal station in an optical transmission system for transmitting pre-emphasis information from a receiving terminal station for receiving a plurality of wavelength-division multiplexed signal lights from a transmitting station to the transmitting terminal station, comprising: transmitting side spectrum detecting means for detecting the spectrum of signal lights to be transmitted; receiving side spectrum information detecting means for detecting spectrum information from the receiving terminal station; and pre-emphasis controlling means for comparing spectrum information from the transmitting side detecting means with the spectrum information from the receiving side spectrum information detecting means, and controlling the level and wavelength of signal lights to be transmitted.

Claim 7

The transmitting terminal station according to claim 4 , wherein the level of a signal light to be transmitted and the wavelength of a signal light to be transmitted are controlled alternately and repeatedly.

Claim 8

The transmitting terminal station according to claim 4 , wherein the level and wavelength of signal lights to be transmitted can be controlled by the transmitting side spectrum detecting means and the pre-emphasis controlling means in the transmitting terminal station.

Claim 9

A wavelength-division multiplexing optical transmission system for transmitting and receiving wavelength-division multiplexed optical signals between a first terminal station and a second terminal station, wherein the first terminal station comprises first optical spectrum analyzing means for measuring the wavelength deviation of a signal light of each channel and the power level of a signal light for each wavelength of a wavelength-division multiplexed optical signal transmitted by the first terminal station; wavelength adjusting means for adjusting the wavelength of a signal light of a channel when there is a wavelength deviation in the channel; and pre-emphasis means for pre-emphasizing the power level of a signal light for each wavelength of a wavelength-division multiplexed optical signal transmitted from the first terminal station when it has been reported to the first terminal station from the second terminal station that the power level of a signal light for a wavelength of a wavelength-division multiplexed optical signal transmitted by the first terminal station is improper, and the second terminal station comprises second optical spectrum analyzing means for measuring at least the power level of a signal light for each wavelength of a wavelength-division multiplexed optical signal transmitted by the first terminal station; and transmitting means for transmitting information on the power level of a signal light for each wavelength of a wavelength-division multiplexed optical signal transmitted by the first terminal station to the first terminal station.

Claim 10

A wavelength-division multiplexing optical transmission system for transmitting and receiving wavelength-division multiplexed optical signals between a first terminal station and a second terminal station, wherein the first terminal station comprises first optical spectrum analyzing means for measuring the wavelength deviation of a signal light of each channel and the power level of a signal light for each wavelength of a wavelength-division multiplexed optical signal transmitted by the first terminal station; wavelength adjusting means for adjusting the wavelength of a signal light of a channel when there is a wavelength deviation in the channel; and pre-emphasis means for pre-emphasizing the power level of a signal light for each wavelength of a wavelength-division multiplexed optical signal transmitted from the first terminal station when it has been reported to the first terminal station from the second terminal station that the power level of a signal light for a wavelength of a wavelength-division multiplexed optical signal transmitted by the first terminal station is improper, and the second terminal station comprises second optical spectrum analyzing means for measuring at least the power level of a signal light for each wavelength of a wavelength-division multiplexed optical signal transmitted by the first terminal station; and transmitting means for transmitting information on the power level of a signal light for each wavelength of a wavelength-division multiplexed optical signal transmitted by the first terminal station to the first terminal station.

Claim 11

The optical transmission system according to claim 7 , wherein said wavelength controlling means controls the wavelength of the signal light in which there is the wavelength deviation, by controlling the temperature of the light source of the signal light based on the value measured by said first optical spectrum analyzing means.

Claim 12

The optical transmission system according to claim 7 , wherein said wavelength controlling means controls the wavelength of the signal light in which there is the wavelength deviation, by controlling the driving current applied to the light source of the signal light based on the value measured by said first optical spectrum analyzing means.

Claim 13

The optical transmission system according to claim 7 , wherein said pre-emphasizing means pre-emphasizes by controlling the gain of an optical amplifier provided to amplify a signal light for each wavelength.

Claim 14

The optical transmission system according to claim 7 , wherein said pre-emphasizing means pre-emphasizes by adjusting the attenuation of a variable optical attenuator for adjusting the output level of a signal light for each wavelength.

Claim 15

The optical transmission system according to claim 7 , wherein said transmitting means stores information on the power level of a signal light for each wavelength of a wavelength-division multiplexed optical signal transmitted from the first terminal station in the overhead of the optical signal, and transmits the signal to the first terminal station.

Claim 16

The optical transmission system according to claim 7 , wherein said transmitting means overlays information on the power level of a signal light for each wavelength of a wavelength-division multiplexed optical signal transmitted from the first terminal station, on an optical signal, and transmits the signal to the first terminal station.

Claim 17

The optical transmission system according to claim 7 , wherein said transmitting means multiplexes information on the power level of a signal light for each wavelength of a wavelength-division multiplexed optical signal transmitted from the first terminal station, to a main optical signal as an optical signal with a wavelength different from the main optical signal, and transmits the signal to the first terminal station.

Claim 18

A terminal station in a wavelength-division multiplexing system for transmitting and receiving wavelength-division multiplexed optical signals between terminal stations, comprising: first optical spectrum analyzing means for measuring the wavelength deviation of a signal light of each channel and the power level of a signal light for each wavelength of a wavelength-division multiplexed optical signal transmitted by the terminal station; wavelength adjusting means for adjusting the wavelength of a signal light of a channel when there is a deviation in wavelength of the channel; pre-emphasis means for pre-emphasizing the power level of a signal light for each wavelength of a wavelength-division multiplexed optical signal transmitted from the first terminal station when it has been reported to the terminal station from a second terminal station that the power level of a signal light for a wavelength of a wavelength-division multiplexed optical signal transmitted by the terminal station is improper; second optical spectrum analyzing means for measuring at least the power level of a signal light for each wavelength of a wavelength-division multiplexed optical signal transmitted by other terminal station; and transmitting means for transmitting information on the power level of a signal light for each wavelength of a wavelength-division multiplexed optical signal transmitted by the other terminal station to the other terminal station.

Claim 19

A terminal station in a wavelength-division multiplexing system for transmitting and receiving wavelength-division multiplexed optical signals between terminal stations, comprising: first optical spectrum analyzing means for measuring the wavelength deviation of a signal light of each channel and the power level of a signal light for each wavelength of a wavelength-division multiplexed optical signal transmitted by the terminal station; wavelength adjusting means for adjusting the wavelength of a signal light of a channel when there is a deviation in wavelength of the channel; pre-emphasis means for pre-emphasizing the power level of a signal light for each wavelength of a wavelength-division multiplexed optical signal transmitted from the first terminal station when it has been reported to the terminal station from a second terminal station that the power level of a signal light for a wavelength of a wavelength-division multiplexed optical signal transmitted by the terminal station is improper; second optical spectrum analyzing means for measuring at least the power level of a signal light for each wavelength of a wavelength-division multiplexed optical signal transmitted by other terminal station; and transmitting means for transmitting information on the power level of a signal light for each wavelength of a wavelength-division multiplexed optical signal transmitted by the other terminal station to the other terminal station.

Claim 20

The terminal station according to claim 15 , wherein said wavelength controlling means controls the wavelength of the signal light in which there is the wavelength deviation, by controlling the temperature of the light source of the signal light based on the value measured by said first optical spectrum analyzing means.

Claim 21

The terminal station according to claim 15 , wherein said wavelength controlling means controls the wavelength of the signal light in which there is the wavelength deviation, by controlling the driving current applied to the light source of the signal light based on the value measured by said first optical spectrum analyzing means.

Claim 22

The terminal station according to claim 15 , wherein said pre-emphasizing means pre-emphasizes by controlling the gain of an optical amplifier provided to amplify a signal light for each wavelength.

Claim 23

The terminal station according to claim 15 , wherein said pre-emphasizing means pre-emphasizes by adjusting the attenuation of a variable optical attenuator for adjusting the output level of a signal light for each wavelength.

Claim 24

The terminal station according to claim 15 , wherein said transmitting means stores information on the power level of a signal light for each wavelength of a wavelength-division multiplexed optical signal transmitted from the other terminal station in the overhead of the optical signal, and transmits the signal to the other terminal station.

Claim 25

The terminal station according to claim 15 , wherein said transmitting means overlays information on the power level of a signal light for each wavelength of a wavelength-division multiplexed optical signal transmitted from the other terminal station, on an optical signal, and transmits the signal to the other terminal station.

Claim 26

The terminal station according to claim 15 , wherein said transmitting means multiplexes information on the power level of a signal light for each wavelength of a wavelength-division multiplexed optical signal transmitted from the other terminal station, to a main optical signal as an optical signal with a wavelength different from the main optical signal, and transmits the signal to the other terminal station.

Claim 27

The terminal station according to claim 15 , wherein said first optical spectrum analyzing means and said second optical spectrum analyzing means comprise one optical spectrum analyzer, and the input to the optical spectrum analyzer is switched over by means of an optical switch.

Claim 28

A control method of a transmitting terminal station in an optical transmission system for transmitting pre-emphasis information from a receiving terminal station for receiving a plurality of wavelength-multiplexed signal lights from a transmitting station to the transmitting terminal station, comprising the steps of: detecting the spectrum of signal lights to be transmitted; detecting spectrum information from the receiving terminal station; and comparing the spectrum detection result of the signal lights to be transmitted with spectrum information from the receiving terminal station, and controlling the levels and wavelengths of signal lights to be transmitted.

Claim 29

A control method of a transmitting terminal station in an optical transmission system for transmitting pre-emphasis information from a receiving terminal station for receiving a plurality of wavelength-multiplexed signal lights from a transmitting station to the transmitting terminal station, comprising the steps of: detecting the spectrum of signal lights to be transmitted; detecting spectrum information from the receiving terminal station; and comparing the spectrum detection result of the signal lights to be transmitted with spectrum information from the receiving terminal station, and controlling the levels and wavelengths of signal lights to be transmitted.

Claim 36

An apparatus as in claim 27 , wherein the controller comprises: a first spectrum detector detecting said spectrum of the WDM signal light from a portion; and a second spectrum detector detecting said spectrum of the WDM signal light as received by the receiver.

Claim 37

An apparatus as in claim 27 , further comprising: a plurality of optical amplifiers amplifying the plurality of signal lights before being multiplexed together, wherein the controller controls gains of the optical amplifiers to control the power levels of the signal lights.

Claim 38

An apparatus as in claim 27 , further comprising: a plurality of light sources producing the plurality of signal lights, respectively, before being multiplexed together, wherein the controller controls a temperature of each light source to control the wavelengths of the signal lights.

Claim 39

An apparatus as in claim 28 , further comprising: a plurality of light sources producing the plurality of signal lights, respectively, before being multiplexed together, wherein the controller controls a temperature of each light source to control the wavelengths of the signal lights.

Claim 40

An apparatus as in claim 27 , further comprising: a plurality of light sources producing the plurality of signal lights, respectively, before being multiplexed together, each light source being driven by a corresponding drive current, wherein the controller controls the drive current of each light source to control the wavelengths of the signal lights.

Claim 41

An apparatus as in claim 28 , further comprising: a plurality of light sources producing the plurality of signal lights, respectively, before being multiplexed together, each light source being driven by a corresponding drive current, wherein the controller controls the drive current of each light source to control the wavelengths of the signal lights.

Claim 46

An apparatus as in claim 35 , wherein each of the level controls is an optical amplifier, and the controller controls gains of the optical amplifiers to control the power levels of the signal lights.

Claim 47

An apparatus as in claim 35 , wherein the controller controls a temperature of each light source to control the wavelengths of the signal lights.

Claim 48

An apparatus as in claim 36 , wherein the controller controls a temperature of each light source to control the wavelengths of the signal lights.

Claim 49

An apparatus as in claim 35 , wherein each light source is driven by a corresponding drive current, the controller controlling the drive current of each light source to control the wavelengths of the signal lights.

Claim 50

An apparatus as in claim 36 , wherein each light source is driven by a corresponding drive current, the controller controlling the drive current of each light source to control the wavelengths of the signal lights.