Broadcast and select all optical network
View Patent ↗An all optical network for optical signal traffic has at least a first ring with at least one transmitter and one receiver. The first ring includes a plurality of network nodes. At least a first add/drop broadband coupler is coupled to the first ring. The broadband coupler includes an add port and a drop port to add and drop wavelengths to and or from the first ring, a pass-through direction and an add/drop direction. The first add/drop broadband coupler is configured to minimize a pass-through loss in the first ring and is positioned on the first ring.
1. An optical network, comprising:
a fiber ring of a single fiber, the fiber ring comprising a plurality of network nodes communicating via optical signals at different signal wavelengths in a first propagation direction and replicas of the optical signals at different replica signal wavelengths from the optical signals in a second, opposite propagation direction in the single fiber of the fiber ring, each network node comprising;
a first optical path operable to receive light from the fiber ring in the first propagation direction only, the first optical path comprising a first optical amplifier to amplify light, a first drop coupler operable to drop a portion of light at all wavelengths from the first optical path while allowing a remaining portion of light of all wavelengths to pass through to a next network node downstream in the first propagation direction, and a first add coupler to add light to the first optical path,
a second optical path operable to receive light from the fiber ring in the second propagation direction only, the second optical path comprising a second optical amplifier to amplify light, a second drop coupler operable to drop a portion of light at all wavelengths from the second optical path while allowing a remaining portion of light of all wavelengths to pass through to a next network node downstream in the second propagation direction, and a second add coupler to add light to the second optical path,
a first optical port connected to couple a first end of the first optical path and a first end of the second optical path to the fiber ring and to direct light in the first propagation direction in the fiber ring to the first optical path and light in the second propagation direction in the second optical path into the fiber ring,
a second optical port connected to couple a second end of the first optical path and a second end of the second optical path to the fiber ring and to direct light in the first propagation direction in the first optical path to the fiber ring and light in the second propagation direction in the fiber ring into the second optical path,
a signal add module operable to produce a first add signal at a first wavelength carrying data and a second add signal at a second wavelength carrying the same data as in the first add signal and connected to couple the first add signal to the first optical path via the first add coupler and the second add signal to the second optical path via the second add coupler, and
a signal drop module operable to receive a first drop signal from the first optical path via the first drop coupler and a second drop signal from the second optical path via the second drop coupler.
2. The optical network as in claim 1 , wherein the signal add module comprises:
a first optical transmitter operating at the first wavelength to produce the first add signal in response to the same data, and
a second optical transmitter operating at the second wavelength to produce the second add signal in response to the same data.
3. The optical network as in claim 2 , wherein the signal drop module comprises:
an optical coupler coupled to the first and second drop couplers to receive the first and second drop signals,
a tunable optical filter to receive and filter the first and second drop signals, and
an optical receiver to receive light filtered by the tunable optical filter.
4. The optical network as in claim 2 , further comprising an optical switching mechanism in the fiber ring to maintain a single break point in the single fiber of the fiber ring.
5. The optical network as in claim 4 , further comprising a central hub in the fiber ring, wherein the optical switching mechanism includes an optical switch in the central hub.
6. The optical network as in claim 1 , wherein the signal add module comprises:
a single optical transmitter to produce light at different wavelengths and to produce the first, add signal and the second add signal, respectively, to carry the same data.
7. The optical network as in claim 6 , wherein the signal add module further comprises:
an optical splitter to split the light from the single optical transmitter into a first light beam and a second light beams;
a first optical filter to filter the first light beam to transmit only light at the first wavelength as the first add signal; and
a second optical filter to filter the second light beam to transmit only light at the second wavelength as the second add signal.
8. The optical network as in claim 6 , wherein the signal drop module comprises:
an optical coupler coupled to the first and second drop coupler to receive the first and second drop signals,
a tunable optical filter to receive and filter the first and second drop signals, and
an optical receiver to receive light filtered by the tunable optical filter.
9. The optical network as in claim 6 , further comprising an optical switching mechanism in the fiber ring to maintain a single break point in the fiber ring.
10. The optical network as in claim 9 , wherein the optical switching mechanism comprises an optical switch in the fiber ring which switches open or close to maintain a single break point in the fiber ring in response to whether there is a break point in the fiber ring.
11. The optical network as in claim 9 , further comprising a central hub in the fiber ring, wherein the optical switching mechanism includes an optical switch in the central hub and wherein the optical switch switches open or close to maintain a single break point in the fiber ring in response to whether there is a break point in the fiber ring.
12. The optical network as in claim 1 , further comprising a central hub in the fiber ring to include an optical switch to maintain a single break point for each optical signal in the fiber ring, wherein the optical switch is open when there is no break point in the fiber ring and is closed when there is a break point in the fiber ring.
13. The optical network as in claim 1 , wherein the first and second optical ports are optical circulators.
14. The optical network as in claim 1 , wherein each coupler as a broadband optical coupler.
15. The optical network as in claim 1 , further comprising an optical switching mechanism in the fiber ring to maintain a single break point in the fiber ring.
16. The optical network as in claim 15 , wherein the optical switching mechanism comprises an optical switch in the fiber ring which switches open or close to maintain a single break point in the fiber ring in response to whether there is a break point in the fiber ring.
17. The optical network as in claim 15 , further comprising a central hub in the fiber ring, wherein the optical switching mechanism includes an optical switch in the central hub.
18. The optical network as in claim 17 , further comprising optical supervision channel mechanism which provides out-of-band optical supervision channel signals in the first and second propagation directions in the fiber ring that carry information of control and management of the fiber ring.
19. The optical network as in claim 18 , wherein the optical signals are C-band signals and the out-of-band optical supervision channel, signals are out of the C-band.
20. The optical network as in claim 1 , further comprising an optical supervision channel mechanism which provides optical supervision channel signals at different supervision channel wavelengths in the first and second propagation directions in the fiber ring that carry information of control and management of the fiber ring and are out of the wavelength band of the optical signals.
21. A method for optically communicating, comprising:
using a fiber ring of a single fiber to connect a plurality of network nodes and to provide communication among the network nodes via optical signals in a first propagation direction and replicas of the optical signals at different wavelengths from the optical signals in a second, opposite propagation direction in the single fiber; and
within each network node, receiving light from the fiber ring in the first propagation direction only along a first optical path,
receiving light from the fiber ring in the second propagation direction only along a second optical path,
generating a first add signal at a first wavelength to carry data and a second add signal at a second wavelength carrying the same data,
coupling the first add signal to the first optical path and the second add signal to the second optical path to add the same data in the fiber ring in the first and second propagation directions,
dropping a portion of light in all wavelengths present in the first optical path as a first drop signal from the first optical path while allowing a remaining portion of the light in all wavelengths present in the first optical path to continue to propagate to a next network node downstream in the first propagation direction, and
dropping a portion of light in all wavelengths present in the second optical path as a second drop signal while allowing a remaining portion of the light in all wavelengths present in the second optical path to continue to propagate to a next network node downstream in the second propagation direction.
22. The method as in claim 21 , further comprising using two different optical transmitters respectively at first and second wavelengths to produce the first and second add signals, respectively.
23. The method as in claim 21 , further comprising using a single optical transmitter in each network node to generate light that comprises the first and second add signals.
24. The method as in claim 23 , further comprising:
splitting the light from the single optical transmitter into a first light beam and a second light beam,
using a first optical filter to filter the first light beam to transmit only light at the first wavelength as the first add signal; and
using a second optical filter to filter the second light beam to transmit only light at the second wavelength as the second add signal.
25. The method as in claim 21 , further comprising using an optical switching mechanism in the fiber ring to maintain a single break point for an optical signal in the fiber ring.
26. The method as in claim 25 , further comprising detecting a failure condition in the fiber ring to control the optical switching mechanism.
27. The method as in claim 25 , further comprising providing optical supervision channel signals at different supervision channel wavelengths in the first and second propagation directions in the filter ring to carry information of control and management of the fiber ring, wherein optical supervision channel signals are out of the wavelength band of the optical signals.
28. An optical network, comprising:
a fiber ring formed of a single fiber to carry optical signals at different wavelengths in a first direction and replicas of the optical signals in a second, opposite direction;
a plurality of network nodes coupled to the fiber ring to communicate with one another via optical signals in a first propagation direction and a second, opposite propagation direction in the fiber ring; and
an optical switching mechanism in the fiber ring which comprises an optical switch that is closed when there is not a break in the fiber ring and is open when there is a break in the fiber ring,
wherein each network node comprises:
a first optical path to receive light from the fiber ring in the first propagation direction only, the first optical path comprising a first optical amplifier to amplify light, a first drop coupler to drop light from the first optical path, and a first add coupler to add light to the first optical path,
a second optical path to receive light from the fiber ring in the second propagation direction only, the second optical path comprising a second optical amplifier to amplify tight, a second drop coupler to drop light from the second optical path, and a second add coupler to add light to the second optical path,
a first optical port to couple a first end of the first optical path and a first end of the second optical path to the fiber ring and to direct light in the first propagation direction in the fiber ring to the first optical path and light in tho second propagation direction in the second optical path into the fiber ring,
a second optical port to couple a second end of the first optical path and a second end of the second optical path to the fiber ring and to direct light in the first propagation direction in the first optical path to the fiber ring and light in tho second propagation direction in the fiber ring into the second optical path,
a signal add module to produce a first add signal at a first wavelength carry data and a second add signal at a second wavelength carrying the same data and couple the first add signal to the first optical path via the first add coupler and the second add signal to the second optical path via the second add coupler, and
a signal drop module to receive a first drop signal from the first optical path via the first drop coupler and a second drop signal from the second optical path via the second drop coupler.
29. The optical network as in claim 28 , wherein the signal add module comprises:
a first optical transmitter operating at the first wavelength to produce the first add signal in response to the same data, and
a second optical transmitter operating at the second wavelength to produce the second add signal in response to the same data.
30. The optical network as in claim 28 , wherein the signal drop module comprises:
an optical coupler coupled to the first and second drop couplers to receive the first and second drop signals,
a tunable optical filter to receive and filter the first and second drop signals, and
an optical receiver to receive light filtered by the tunable optical filter.
31. The optical network as in claim 28 , wherein the signal add module comprises:
a single optical transmitter to produce light at different wavelengths and to produce the first add signal and the second add signal, respectively, to carry the maine data.
32. The optical network as in claim 31 , wherein the signal add module further comprises:
an optical splitter to split the light from the single optical transmitter into a first light beam and a second light beam;
a first optical filter to filter the first light beam to transmit only light at the first wavelength as the first add signal; and
a second optical filter to filter the second light beam to transmit only light at the second wavelength as the second add signal.
33. The optical network as in claim 28 , wherein the first and second optical ports are optical circulators.
34. The optical network as in claim 28 , wherein each coupler is a broadband optical coupler.
35. The optical network as in claim 28 , further comprising an optical supervision channel mechanism which provides a first optical supervision channel signal at a first supervision channel wavelength in the first propagation direction and a second optical supervision channel signal at a second different supervision channel wavelength in the second propagation direction in the fiber ring that carry information of control and management of the fiber ring and are out of the wavelength band of the optical signals.
36. The optical network as in claim 28 , further comprising a central hub in the fiber ring, wherein the optical switch is located in the central hub.