EP0452895A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Optical communication network system and communication method using the same
Assignee: Canon Inc
•
Filing: 1991-04-17
•
Granted: —
•
Expires: 2011-04-17
Abstract
Abstract Disclosed is an optical communication network system including a base station (2) for generating a plurality of beams having different wavelengths, an optical transmission line (1a,1b) for transmitting the plurality of beams emitted by the base station (2), an optical transmitter (3,4.....10), connected to the optical transmission line, for selecting one of the plurality of beams transmitted through the optical transmission line and modulating the selected beam in accordance with a signal to be transmitted, and an optical receiver (3,4......10) connected to the optical transmission line, for receiving the signal transmitted using the selected beam. An optical communication method for the above system is also disclosed.
Inventors
- 👤 Mamoru C/O Canon Kabushiki Kaisha Uchida
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-24 22:29
CPC Classifications
H; H04; H04J; H04J14/00; H04J14/02; H04J14/03; H04J14/0307
Claims Analysis
Total Claims: 63
Claim 1
Independent Claim
88 words
An optical communication network system comprising: a base station for generating a plurality of beams having different wavelengths; an optical transmission line for transmitting the plurality of beams emitted by said base station; an optical transmitter, connected to said optical transmission line, for selecting one of the plurality of beams transmitted through said optical transmission line and modulating the selected beam in accordance with a signal to be transmitted; and an optical receiver, connected to said optical transmission line, for receiving the signal transmitted using the selected beam.
Claim 2
Dependent Claim
87 words
A system according to claim 1, wherein said optical transmission line consists of a sending line, having one end connected to said base station, for transmitting a beam in a predetermined direction and a receiving line, parallel to said sending line and connected to the other end of said sending line, for transmitting the beam transmitted along said sending line in a direction opposite to the predetermined direction, said optical transmitter is connected to said sending line, and said optical receiver is connected to said receiving line.
Claim 3
Dependent Claim
109 words
An optical communication network system comprising: a base station for generating a plurality of beams having different wavelengths; an optical transmission line for transmitting the plurality of beams emitted by said base station; and a plurality of terminal stations connected to said optical transmission line, each of said terminal stations being provided with an optical transmitter, connected to said optical transmission line, for selecting one of the plurality of beams transmitted through said optical transmission line and modulating the selected beam in accordance with a signal to be transmitted, and an optical receiver for receiving the signal transmitted using one of the plurality of beams from remaining terminal stations.
Claim 4
Dependent Claim
92 words
A system according to claim 3, wherein said optical transmission line consists of a sending line, having one end connected to said base station, for transmitting a beam in a predetermined direction and a receiving line, parallel to said sending line and connected to the other end of said sending line, for transmitting the beam transmitted along said sending line in a direction opposite to the predetermined direction, said optical transmitter of said terminal station is connected to said sending line, and said optical receiver thereof is connected to said receiving line.
Claim 5
Dependent Claim
23 words
A system according to claim 3, further comprising terminal equipments, respectively connected to said terminal stations, for instructing signal transmission and signal reception.
Claim 6
Dependent Claim
190 words
An optical communication network system comprising: a base station for generating a plurality of beams having different wavelengths; an optical transmission line for transmitting the plurality of beams emitted by said base station; and a plurality of optical transmitters/receivers connected to said optical transmission line, each of said optical transmitter/receiver being provided with: (a) an optical demultiplexing element for partially demultiplexing the plurality of beams from said optical transmission line; (b) a first wavelength variable filter for selectively extracting a beam having an arbitrary wavelength from the beams demultiplexed by said optical demultiplexing element; (c) a photosensor for detecting the beam extracted by said first wavelength variable filter; (d) a second wavelength variable filter for separating a beam having an arbitrary wavelength from other beams of the plurality of beams and extracting the separated beam from said optical transmission line; (e) an optical modulator for modulating the beam separated by said second wavelength variable filter, in accordance with the signal to be transmitted; and (f) an optical multiplexing element for multiplexing the beam modulated by said optical modulator with other beams and transmitting multiplexed light through said optical transmission line.
Claim 7
Dependent Claim
39 words
A system according to claim 6, wherein said each optical transmitter/receiver further comprises a control unit for receiving an output signal from said photosensor and controlling to drive said optical modulator and said first and second wavelength variable filters.
Claim 8
Dependent Claim
26 words
A system according to claim 7, wherein said each optical transmitter/receiver comprises a terminal equipment for instructing signal transmission and signal reception to said control unit.
Claim 9
Dependent Claim
42 words
A system according to claim 6, wherein said each optical transmitter/receiver comprises another optical demultiplexing element for partially extracting the beam separated by said second wavelength variable filter and another photosensor for detecting the beam extracted by said another optical demultiplexing element.
Claim 10
Dependent Claim
96 words
A system according to claim 6, wherein said optical transmission line consists of a sending line, having one end connected to said base station, for transmitting a beam in a predetermined direction and a receiving line, parallel to said sending line and connected to the other end of said sending line, for transmitting the beam transmitted along said sending line in a direction opposite to the predetermined direction, said optical demultiplexing element of said optical transmitter/receiver is connected midway along said receiving line, and said second wavelength variable filter thereof is connected to said sending line.
Claim 11
Dependent Claim
250 words
An optical communication network system comprising: a base station for generating a plurality of beams having different wavelengths; an optical transmission line for transmitting the plurality of beams emitted by said base station; and a plurality of optical transmitters/receivers connected to said optical transmission line, each of said optical transmitter/receiver being provided with: (a) an optical demultiplexing element for partially demultiplexing the plurality of beams from said optical transmission line; (b) a first wavelength variable filter for selectively extracting a beam having an arbitrary wavelength from the beams demultiplexed by said optical demultiplexing element; (c) a photosensor for detecting the beam extracted by said first wavelength variable filter; (d) an optical line for transmitting the plurality of beams therethrough; (e) a first optical switch, arranged midway along said transmission line, for selectively guiding the plurality of beams to one of a downstream transmission line and said optical line; (f) a second wavelength variable filter for separating a beam having an arbitrary wavelength from other beams of the plurality of beams passing through said optical line and for extracting the separated beam from said optical line; (g) an optical modulator for modulating the beam separated by said second wavelength variable filter, in accordance with a signal to be transmitted; (h) an optical multiplexing element for multiplexing the beam modulated by said optical modulator with other beams passing through said optical line; and (i) a second optical switch for returning a beam multiplexed by said multiplexing element to said transmission line again.
Claim 12
Dependent Claim
45 words
A system according to claim 11, wherein said each optical transmitter/receiver further comprises a control unit for receiving an output signal from said photosensor and controlling to drive said optical modulator, said first and second wavelength variable filters, and said first and second optical switches.
Claim 13
Dependent Claim
26 words
A system according to claim 12, wherein said each optical transmitter/receiver comprises a terminal equipment for instructing signal transmission and signal reception to said control unit.
Claim 14
Dependent Claim
42 words
A system according to claim 11, wherein said each optical transmitter/receiver comprises another optical demultiplexing element for partially extracting the beam separated by laid second wavelength variable filter and another photosensor for detecting the beam extracted by said another optical demultiplexing element.
Claim 15
Dependent Claim
98 words
A system according to claim 11, wherein said optical transmission line consists of a sending line, having one end connected to said base station, for transmitting a beam in a predetermined direction and a receiving line, parallel to said sending line and connected to the other end of said sending line, for transmitting the beam transmitted along said sending line in a direction opposite to the predetermined direction, said optical demultiplexing element of said optical transmitter/receiver is connected midway along said receiving line, and said first and second optical switches thereof are connected midway along said sending line.
Claim 16
Dependent Claim
182 words
An optical transmitter/receiver used in an optical communication network system comprising a base station for emitting a plurality of beams having different wavelengths, an optical transmission line for transmitting the plurality of beams emitted from said base station, and a plurality of optical transmitters/receivers connected to said optical transmission line, comprising: an optical demultiplexing element for partially demultiplexing the plurality of beams from said optical transmission line; a first wavelength variable filter for selectively extracting a beam having an arbitrary wavelength from the beams demultiplexed by said optical demultiplexing element; a photosensor for detecting the beam extracted by said first wavelength variable filter; a second wavelength variable filter for separating a beam having an arbitrary wavelength from other beams of the plurality of beams and extracting the separated beam from said optical transmission line; an optical modulator for modulating the beam separated by said second wavelength variable filter, in accordance with the signal to be transmitted; and an optical multiplexing element for multiplexing the beam modulated by said optical modulator with other beams and transmitting multiplexed light through said optical transmission line.
Claim 17
Dependent Claim
35 words
An optical transmitter/receiver according to claim 16, further comprising a control unit for receiving an output signal from said photosensor and controlling to drive said optical modulator and said first and second wavelength variable filters.
Claim 18
Dependent Claim
23 words
An optical transmitter/receiver according to claim 17, further comprising a terminal equipment for instructing signal transmission and signal reception to said control unit.
Claim 19
Dependent Claim
39 words
An optical transmitter/receiver according to claim 16, further comprising another optical demultiplexing element for partially extracting the beam separated by said second wavelength variable filter and another photosensor for detecting the beam extracted by said another optical demultiplexing element.
Claim 20
Dependent Claim
239 words
An optical transmitter/receiver used in an optical communication network system comprising a base station for emitting a plurality of beams having different wavelengths, an optical transmission line for transmitting the plurality of beams emitted from said base station, and a plurality of optical transmitters/receivers connected to said optical transmission line, comprising: an optical demultiplexing element for partially demultiplexing the plurality of beams from said optical transmission line; a first wavelength variable filter for selectively extracting a beam having an arbitrary wavelength from the beams demultiplexed by said optical demultiplexing element; a photosensor for detecting the beam extracted by said first wavelength variable filter; an optical line for transmitting the plurality of beams therethrough; a first optical switch, arranged midway along said transmission line, for selectively guiding the plurality of beams to one of a downstream transmission line and said optical line; a second wavelength variable filter for separating a beam having an arbitrary wavelength from other beams of the plurality of beams passing through said optical line and for extracting the separated beam from said optical line; an optical modulator for modulating the beam separated by said second wavelength variable filter, in accordance with a signal to be transmitted; an optical multiplexing element for multiplexing the beam modulated by said optical modulator with other beams passing through said optical line; and a second optical switch for returning a beam multiplexed by said multiplexing element to said transmission line again.
Claim 21
Dependent Claim
41 words
An optical transmitter/receiver according to claim 20, further comprising a control unit for receiving an output signal from said photosensor and controlling to drive said optical modulator, said first and second wavelength variable filters, and said first and second optical switches.
Claim 22
Dependent Claim
23 words
An optical transmitter/receiver according to claim 21, further comprising a terminal equipment for instructing signal transmission and signal reception to said control unit.
Claim 23
Dependent Claim
39 words
An optical transmitter/receiver according to claim 20, further comprising another optical demultiplexing element for partially extracting the beam separated by said second wavelength variable filter and another photosensor for detecting the beam extracted by said another optical demultiplexing element.
Claim 24
Dependent Claim
138 words
An optical transmitter used in an optical communication network system comprising a base station for emitting a plurality of beams having different wavelengths, an optical transmission line for transmitting the plurality of beams emitted from said base station, an optical transmitter connected to said optical transmission line, and an optical receiver connected to said optical transmission line, comprising: a wavelength variable filter for separating a beam having an arbitrary wavelength from other beams of the plurality of beams and for extracting the separated beam from said optical transmission line; an optical modulator for modulating the beam separated by said wavelength variable filter, in accordance with a signal to be transmitted; and an optical multiplexing element for multiplexing the beam modulated by said optical modulator with other beams and transmitting the resultant beam along said optical transmission line again.
Claim 25
Dependent Claim
24 words
An optical transmitter according to claim 24, further comprising a control unit for controlling to drive said optical modulator and said wavelength variable filter.
Claim 26
Dependent Claim
23 words
An optical transmitter according to claim 25, further comprising a terminal equipment for instructing signal transmission and signal reception to said control unit.
Claim 27
Dependent Claim
38 words
An optical transmitter according to claim 24, further comprising another optical demultiplexing element for partially extracting the beam separated by said wavelength variable filter and another photosensor for detecting the beam extracted by said another optical demultiplexing element.
Claim 28
Dependent Claim
192 words
An optical transmitter used in an optical communication network system comprising a base station for emitting a plurality of beams having different wavelengths, an optical transmission line for transmitting the plurality of beams emitted from said base station, an optical transmitter connected to said optical transmission line, and an optical receiver connected to said optical transmission line, comprising: an optical line for transmitting the plurality of beams therethrough; a first optical switch, arranged midway along said transmission line, for selectively guiding the plurality of beams to one of a downstream transmission line and said optical line; a wavelength variable filter for separating a beam having an arbitrary wavelength from other beams of the plurality of beams passing through said optical line and for extracting the separated beam from said optical line; an optical modulator for modulating the beam separated by said wavelength variable filter, in accordance with a signal to be transmitted; an optical multiplexing element for multiplexing the beam modulated by said optical modulator with other beams passing through said optical line; and a second optical switch for returning a beam multiplexed by said multiplexing element to said transmission line again.
Claim 29
Dependent Claim
30 words
An optical transmitter according to claim 28, further comprising a control unit for controlling to drive said optical modulator, said wavelength variable filter, and said first and second optical switches.
Claim 30
Dependent Claim
23 words
An optical transmitter according to claim 29, further comprising a terminal equipment for instructing signal transmission and signal reception to said control unit.
Claim 31
Dependent Claim
38 words
An optical transmitter according to claim 28, further comprising another optical demultiplexing element for partially extracting the beam separated by said wavelength variable filter and another photosensor for detecting the beam extracted by said another optical demultiplexing element.
Claim 32
Independent Claim
149 words
A method of performing communication using an optical communication network system comprising a base station for generating a plurality of beams having different wavelengths, an optical transmission line for transmitting the plurality of beams emitted from said base station, and a plurality of terminal stations connected to said optical transmission line, each of said terminal stations being provided with an optical transmitter and an optical receiver, comprising the steps of: selecting a beam of a plurality of beams received by an optical receiver of a first one of said terminal stations, the selected beam being not used in other terminal stations; modulating the beam selected by said optical receiver of said first terminal station, in accordance with a signal to be transmitted; and detecting the selected beam by an optical receiver of a second one of said terminal stations and receiving a signal transmitted from said first terminal station.
Claim 33
Independent Claim
367 words
A method of performing communication from a first optical transmitter/receiver to a second optical transmitter/receiver in an optical communication network system comprising a base station for generating a plurality of beams having different wavelengths, an optical transmission line for transmitting the plurality of beams emitted by said base station, and a plurality of optical transmitters/receivers connected to said optical transmission line, each of said optical transmitter/receiver being provided with an optical demultiplexing element for demultiplexing parts of the plurality of beams from said optical transmission line, a first wavelength variable filter for selectively extracting a beam having an arbitrary wavelength from the parts demultiplexed by said optical demultiplexing element, a photosensor for detecting the beam extracted by said first wavelength variable filter, a second wavelength variable filter for separating a beam having an arbitrary wavelength from other beams of the plurality of beams and extracting the separated beam from said optical transmission line, an optical modulator for modulating the beam separated by said second wavelength variable filter, in accordance with the signal to be transmitted, and an optical multiplexing element for multiplexing the beam modulated by said optical modulator with other beams and transmitting multiplexed light through said optical transmission line, comprising the steps of: scanning a wavelength range including wavelengths of the plurality of beams by said first wavelength variable filter of said first optical transmitter/receiver; detecting a beam extracted from said first wavelength variable filter during scanning by said photosensor of said first optical transmitter/receiver. thereby selecting a beam not used in other transmitters/receivers; extracting the selected beam from said optical transmission line by said second wavelength variable filter of said first transmitter/receiver; modulating the extracted light in accordance with the signal to be transmitted by said optical modulator of said first optical transmitter/receiver; multiplexing the modulated beam with other beams and transmitting the resultant beam along said optical transmission line again by said optical multiplexing element of said first optical transmitter/receiver; extracting the selected beam from said optical transmission line by said first wavelength variable filter of said second optical transmitter/receiver; and detecting the extracted beam by said photosensor of said second optical transmitter/receiver, thereby receiving the signal transmitted from said first optical transmitter/receiver.
Claim 34
Dependent Claim
120 words
A method according to claim 33, wherein the step of receiving the signal by said second optical transmitter/receiver comprises the steps of: scanning a wavelength range including wavelengths of the plurality of beams by said first wavelength variable filter of said second optical transmitter/receiver; receiving the beam extracted from said first wavelength variable filter during scanning by said photosensor of said second optical transmitter/receiver, thereby detecting the wavelength of the beam selected by said first optical transmitter/receiver; fixing an extraction wavelength of said first wavelength variable filter to a detected wavelength; and receiving, by said photosensor, the beam extracted by said first wavelength variable filter whose extraction frequency is fixed, thereby receiving the signal transmitted from said first optical transmitter/receiver.
Claim 35
Dependent Claim
40 words
A method according to claim 33, wherein said first optical transmitter/receiver adds header information representing that the signal is directed to said second optical transmitter/receiver, and modulates a beam selected in accordance with the signal added with the header information.
Claim 36
Dependent Claim
130 words
An optical communication network system comprising: an optical transmission line; a base station, connected to said optical transmission line, for transmitting at least one reference beam having a predetermined wavelength through said optical transmission line; an optical transmitter, connected to said optical transmission line, for transmitting, through said optical transmission line, a signal beam having a wavelength different from that of the reference beam and modulated in accordance with a signal to be transmitted, said optical transmitter being provided with means for detecting the reference beam and controlling the wavelength of the signal beam on the basis of the wavelength of the detected reference beam; and an optical receiver, connected to said optical transmission line, for receiving the signal beam transmitted from said optical transmitter through said optical transmission line.
Claim 37
Dependent Claim
22 words
A system according to claim 36, wherein said optical transmitter transmits a signal beam onto said optical transmission line in both directions.
Claim 38
Dependent Claim
22 words
A system according to claim 36, wherein said base station transmits two reference beams having different wavelengths through said optical transmission line.
Claim 39
Dependent Claim
17 words
A system according to claim 36, further comprising an optical amplifier arranged in said optical transmission line.
Claim 40
Dependent Claim
218 words
An optical communication network system comprising: an optical transmission line; a base station, connected to said optical transmission line, for transmitting at least one reference beam having a predetermined wavelength through said optical transmission line; and a plurality of optical transmitters/receivers connected to said optical transmission line, each of said optical transmitters/receivers being provided with: (a) a first optical element for partially demultiplexing beams transmitted through said optical transmission line from said optical transmission line; (b) a wavelength variable filter for selecting a beam having an arbitrary wavelength from the beams demultiplexed by said first optical element; (c) a photosensor for detecting the beam extracted by said wavelength variable filter; (d) a light source for generating a signal beam having a wavelength different from that of a reference beam and modulated in accordance with a signal to be transmitted; (e) a second optical element for outputting the signal light from said light source onto said optical transmission line; and (f) a control circuit for controlling an extraction wavelength of said wavelength variable filter to be equal to a wavelength of the reference beam in accordance with an output signal from said photosensor, and for controlling the wavelength of the signal beam emitted from said light source on the basis of a control signal for said wavelength variable filter.
Claim 41
Dependent Claim
57 words
A system according to claim 40, wherein a relationship between the control signal input to said light source and the wavelength of the beam emitted from said light source is almost equal to a relationship between the control signal input to said wavelength variable filter and the wavelength of the beam extracted by said wavelength variable filter.
Claim 42
Dependent Claim
63 words
A system according to claim 40, wherein said optical transmitter/receiver further comprises an optical demultiplexing element for partially demultiplexing the beams demultiplexed by said first optical element, another wavelength variable filter for selectively extracting a beam having an arbitrary wavelength from the beams demultiplexed by said optical demultiplexing element, and another photosensor for detecting the beam extracted by said another wavelength variable filter.
Claim 43
Dependent Claim
23 words
A system according to claim 40, wherein said optical transmitter/receiver comprises another photosensor for partially monitoring the beams emitted from said light source.
Claim 44
Dependent Claim
61 words
A system according to claim 40, wherein said optical transmitter/receiver further comprises another light source for emitting another signal beam having a wavelength different from those of the signal beam and the reference beam and modulated by a signal different from the signal to be transmitted, and an optical multiplexing element for multiplexing said another signal beam with the signal beam.
Claim 45
Dependent Claim
23 words
A system according to claim 40, wherein said second optical element transmits the signal beam along said optical transmission line in both directions.
Claim 46
Dependent Claim
22 words
A system according to claim 40, wherein said base station transmits two reference beams having different wavelengths along said optical transmission line.
Claim 47
Dependent Claim
17 words
A system according to claim 40, further comprising an optical amplifier arranged in said optical transmission line.
Claim 48
Dependent Claim
21 words
A system according to claim 40, wherein said light source and said wavelength variable filter comprise distribution feedback semiconductor elements, respectively.
Claim 49
Dependent Claim
44 words
A system according to claim 40, wherein said light source can emit beams having different wavelengths, and said control circuit controls said light source so that the wavelength of the signal beam is set to be a wavelength not used in other optical transmitters/receivers.
Claim 50
Dependent Claim
210 words
An optical transmitter/receiver used in an optical communication network system comprising an optical transmission line, a base station, connected to said optical transmission line, for transmitting at least one reference beam having a predetermined wavelength through said optical transmission line, and a plurality of optical transmitters/receivers connected to said optical transmission line, comprising: a first optical element for partially demultiplexing beams transmitted through said optical transmission line from said optical transmission line; a wavelength variable filter for selecting a beam having an arbitrary wavelength from the beams demultiplexed by said first optical element; a photosensor for detecting the beam extracted by said wavelength variable filter; a light source for generating a signal beam having a wavelength different from that of a reference beam and modulated in accordance with a signal to be transmitted; a second optical element for outputting the signal light from said light source onto said optical transmission line; and a control circuit for controlling an extraction wavelength of said wavelength variable filter to be equal to a wavelength of the reference beam in accordance with an output signal from said photosensor, and for controlling the wavelength of the signal beam emitted from said light source on the basis of a control signal for said wavelength variable filter.
Claim 51
Dependent Claim
58 words
An optical transmitter/receiver according to claim 50, wherein a relationship between the control signal input to said light source and the wavelength of the beam emitted from said light source is almost equal to a relationship between the control signal input to said wavelength variable filter and the wavelength of the beam extracted by said wavelength variable filter.
Claim 52
Dependent Claim
60 words
An optical transmitter/receiver according to claim 50, further comprising an optical demultiplexing element for partially demultiplexing the beams demultiplexed by said first optical element, another wavelength variable filter for selectively extracting a beam having an arbitrary wavelength from the beams demultiplexed by said optical demultiplexing element, and another photosensor for detecting the beam extracted by said another wavelength variable filter.
Claim 53
Dependent Claim
21 words
An optical transmitter/receiver according to claim 50, further comprising another photosensor for partially monitoring the beams emitted from said light source.
Claim 54
Dependent Claim
58 words
An optical transmitter/receiver according to claim 50, further comprising another light source for emitting another signal beam having a wavelength different from those of the signal beam and the reference beam and modulated by a signal different from the signal to be transmitted, and an optical multiplexing element for multiplexing said another signal beam with the signal beam.
Claim 55
Dependent Claim
22 words
An optical transmitter/receiver according to claim 50, wherein said light source and said wavelength variable filter comprise distribution feedback semiconductor elements, respectively.
Claim 56
Dependent Claim
117 words
An optical communication network system comprising: an optical transmission line; a base station, connected to said optical transmission line, for transmitting at least one reference beam having a predetermined wavelength through said optical transmission line; and a plurality of optical transmitters/receivers, each of said optical transmitters/receivers being provided with: (a) a light source for transmitting, through said optical transmission line, a signal beam having a wavelength different from that of the reference beam and modulated in accordance with the signal to be transmitted; (b) means for detecting the reference beam; and (c) means for controlling a wavelength of the signal beam emitted from said light source, on the basis of the wavelength of the detected reference light.
Claim 57
Dependent Claim
22 words
A system according to claim 56, wherein said optical transmitter/receiver transmits the signal beam along said optical transmission line in both directions.
Claim 58
Dependent Claim
22 words
A system according to claim 56, wherein said base station transmits two reference beams having different wavelengths along said optical transmission line.
Claim 59
Dependent Claim
17 words
A system according to claim 56, further comprising an optical amplifier arranged in said optical transmission line.
Claim 60
Dependent Claim
44 words
A system according to claim 56, wherein said light source can emit beams having different wavelengths, and said control means controls said light source so that the wavelength of the signal beam is set to be a wavelength not used in other optical transmitters/receivers.
Claim 61
Dependent Claim
118 words
An optical transmitter/receiver used in an optical communication network system comprising an optical transmission line, a base station, connected to said optical transmission line, for transmitting at least one reference beam having a predetermined wavelength through said optical transmission line, and a plurality of optical transmitters/receivers connected to said optical transmission line, comprising: a light source for transmitting, through said optical transmission line, a signal beam having a wavelength different from that of the reference beam and modulated in accordance with the signal to be transmitted; means for detecting the reference beam; and means for controlling a wavelength of the signal beam emitted from said light source, on the basis of the wavelength of the detected reference light.
Claim 62
Independent Claim
195 words
A method of performing communication using an optical communication network system comprising an optical transmission line, a base station, connected to said optical transmission line, for transmitting at least one reference beam having a predetermined wavelength through said optical transmission line, and a plurality of optical transmitters/receivers connected to said optical transmission line, each of said optical transmitters/receivers being provided with a light source for transmitting, through said optical transmission line, a signal beam having a wavelength different from that of the reference beam and modulated in accordance with the signal to be transmitted, means for detecting the reference beam, and means for controlling a wavelength of the signal beam emitted from said light source, comprising the steps of: detecting a reference beam transmitted from said base station by said detecting means in said optical transmitter/receiver; transmitting, from said light source to said optical transmission line, a signal beam having a wavelength different from that of the reference beam and modulated in accordance with the signal to be transmitted; and controlling a wavelength of the signal from said light source by said control means on the basis of the wavelength of the detected reference beam.
Claim 63
Independent Claim
413 words
A method of performing communication from a first optical transmitter/receiver to a second optical transmitter/receiver by using an optical communication network system comprising an optical transmission line, a base station, connected to said optical transmission line, for transmitting at least one reference beam having a predetermined wavelength through said optical transmission line, and a plurality of optical transmitters/receivers connected to said optical transmission line, each of said plurality of optical transmitters/receivers being provided with a first optical element for partially demultiplexing beams transmitted through said optical transmission line from said optical transmission line, a wavelength variable filter for selecting a beam having an arbitrary wavelength from the beams demultiplexed by said first optical element, a photosensor for detecting the beam extracted by said wavelength variable filter, a light source for generating a signal beam having a wavelength different from that of a reference beam and modulated in accordance with a signal to be transmitted, a second optical element for outputting the signal light from said light source onto said optical transmission line, and a control circuit for controlling driving of said wavelength variable filter and said light source comprising the steps of: scanning a wavelength range including the wavelength of the reference beam by said wavelength variable filter in said first optical transmitter/receiver; detecting the beam extracted by said wavelength variable filter during scanning by said photosensor; controlling a filter extraction wavelength to be equal to the wavelength of the reference beam on the basis of an output from said photosensor by said control circuit in said first optical transmitter/receiver; calculating a control signal for said light source on the basis of a filter control signal by said control circuit in said first optical transmitter/receiver; controlling said light source in said first optical transmitter/receiver by using the calculated control signal and sending the signal light from said light source onto said optical transmission line; scanning a wavelength range including the wavelength of the signal light by said wavelength variable filter in said second optical transmitter/receiver; detecting the beam extracted from said wavelength filter during scanning by said photosensor in said second optical transmitter/receiver; controlling filter extraction wavelength to be equal to the wavelength of the signal beam on the basis of an output signal from said photosensor by said control circuit in said second optical transmitter/receiver; and receiving the signal beam extracted by said filter in said second optical transmitter/receiver by said photosensor, thereby receiving a signal transmitted from said first optical transmitter/receiver.
References Cited (Backward Citations)
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