SPLIT TERRESTRIAL BACKHAUL SYSTEMS AND METHODS FOR SUBSEA OPTICAL COMMUNICATION LINKS
20190140744 ยท 2019-05-09
Inventors
- Nitin Kumar Goel (Mountain View, CA, US)
- Herve Albert Pierre Fevrier (Redwood City, CA, US)
- Gayathrinath Nagarajan (Saratoga, CA, US)
Cpc classification
International classification
Abstract
The disclosed method may include, at a cable landing site for a subsea optical fiber, (1) receiving a plurality of optical signals carried over the subsea optical fiber, the plurality of optical signals including a first set of optical signals in a first wavelength band and at least one additional set of optical signals in at least one additional wavelength band that is different from the first wavelength band, (2) optically splitting the plurality of optical signals into the first set of optical signals and the additional set of optical signals, (3) introducing, after optically splitting the plurality of optical signals, the first set of optical signals onto a first terrestrial optical fiber, and (4) introducing, after optically splitting the plurality of optical signals, the additional set of optical signals onto at least one additional terrestrial optical fiber different from the first terrestrial optical fiber. Various other methods and systems are also disclosed.
Claims
1. A method comprising: receiving, at a cable landing site for a subsea optical fiber, a plurality of optical signals carried over the subsea optical fiber, the plurality of optical signals comprising a first set of optical signals in a first wavelength band and at least one additional set of optical signals in at least one additional wavelength band that is different from the first wavelength band; optically splitting, at the cable landing site, the plurality of optical signals into the first set of optical signals and the at least one additional set of optical signals; introducing, at the cable landing site after optically splitting the plurality of optical signals, the first set of optical signals onto a first terrestrial optical fiber; and introducing, at the cable landing site after optically splitting the plurality of optical signals, the at least one additional set of optical signals onto at least one additional terrestrial optical fiber that is different from the first terrestrial optical fiber.
2. The method of claim 1, wherein the first wavelength band comprises a C optical wavelength band, and the at least one additional wavelength band comprises an L optical wavelength band.
3. The method of claim 1, further comprising optically amplifying the plurality of optical signals before optically splitting the plurality of optical signals.
4. The method of claim 1, further comprising: optically amplifying the first set of optical signals after optically splitting the plurality of optical signals; and optically amplifying the at least one additional set of optical signals after optically splitting the plurality of optical signals.
5. The method of claim 1, further comprising: carrying, by the first terrestrial optical fiber, the first set of optical signals from the cable landing site to a network point of presence; and carrying, by the at least one additional terrestrial optical fiber, the at least one additional set of optical signals from the cable landing site to the network point of presence.
6. The method of claim 5, wherein the first terrestrial optical fiber follows a first path and the at least one additional terrestrial optical fiber follows at least one additional path that is different from the first path.
7. The method of claim 1, further comprising: carrying, by the first terrestrial optical fiber, the first set of optical signals from the cable landing site to a first network point of presence; and carrying, by the at least one additional terrestrial optical fiber, the at least one additional set of optical signals from the cable landing site to at least one network point of presence different from the first network point of presence.
8. A method comprising: receiving, at a cable landing site for a subsea optical fiber, a first set of optical signals carried over a first terrestrial optical fiber in a first wavelength band; receiving, at the cable landing site, at least one set of optical signals carried over at least one additional terrestrial optical fiber in at least one additional wavelength band that is different from the first wavelength band; optically combining, at the cable landing site, the first set of optical signals and the at least one additional set of optical signals to form a plurality of optical signals; and introducing, at the cable landing site after optically combining the first set of optical signals and the at least one additional set of optical signals, the plurality of optical signals onto the subsea optical fiber.
9. The method of claim 8, wherein the first wavelength band comprises a C optical wavelength band, and the at least one additional wavelength band comprises an L optical wavelength band.
10. The method of claim 8, further comprising optically amplifying the plurality of optical signals after optically combining the first set of optical signals and the at least one additional set of optical signals.
11. The method of claim 8, further comprising: optically amplifying the first set of optical signals before optically combining the first set of optical signals and the at least one additional set of optical signals; and optically amplifying the at least one additional set of optical signals before optically combining the first set of optical signals and the at least one additional set of optical signals.
12. The method of claim 8, further comprising: carrying, by the first terrestrial optical fiber, the first set of optical signals from a network point of presence to the cable landing site; and carrying, by the at least one additional terrestrial optical fiber, the at least one additional set of optical signals from the network point of presence to the cable landing site.
13. The method of claim 12, wherein the first terrestrial optical fiber follows a first path and the at least one additional terrestrial optical fiber follows at least one additional path that is different from the first path.
14. The method of claim 8, further comprising: carrying, by the first terrestrial optical fiber, the first set of optical signals from a first network point of presence to the cable landing site; and carrying, by the at least one additional terrestrial optical fiber, the at least one additional set of optical signals from at least one additional network point of presence that is different from the first network point of presence to the cable landing site.
15. A system comprising: an optical signal splitter, located at a cable landing site, that optically splits a first plurality of optical signals received from a first subsea optical fiber into a first set of optical signals in a first wavelength band for introduction onto a first terrestrial optical fiber, and a second set of optical signals in a second wavelength band different from the first wavelength band for introduction onto a second terrestrial optical fiber different from the first terrestrial optical fiber; and an optical signal combiner, located at the cable landing site, that optically combines a third set of optical signals in the first wavelength band received from a third terrestrial optical fiber and a fourth set of optical signals in the second wavelength band received from a fourth terrestrial optical fiber to form a second plurality of optical signals for introduction onto a second subsea optical fiber.
16. The system of claim 15, wherein the second subsea optical fiber is the first subsea optical fiber.
17. The system of claim 15, wherein the third terrestrial optical fiber is the first terrestrial optical fiber.
18. The system of claim 15, wherein the fourth terrestrial optical fiber is the second terrestrial optical fiber.
19. The system of claim 15, wherein: the first terrestrial optical fiber and the third terrestrial optical fiber couple the cable landing site to a network point of presence along a first path; and the second terrestrial optical fiber and the fourth terrestrial optical fiber couple the cable landing site to the network point of presence along a second path different from the first path.
20. The system of claim 15, wherein: the first terrestrial optical fiber and the third terrestrial optical fiber couple the cable landing site to a first network point of presence along a first path; and the second terrestrial optical fiber and the fourth terrestrial optical fiber couple the cable landing site to a second network point of presence different from the first network point of presence along a second path different from the first path.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] The accompanying drawings illustrate a number of exemplary embodiments and are a part of the specification. Together with the following description, these drawings demonstrate and explain various principles of the instant disclosure.
[0022]
[0023]
[0024]
[0025]
[0026]
[0027] Throughout the drawings, identical reference characters and descriptions indicate similar, but not necessarily identical, elements. While the exemplary embodiments described herein are susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and will be described in detail herein. However, the exemplary embodiments described herein are not intended to be limited to the particular forms disclosed. Rather, the instant disclosure covers all modifications, equivalents, and alternatives falling within the scope of the appended claims.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0028] The present disclosure s generally directed to split backhaul systems and methods for subsea optical communication links. As will be explained in greater detail below, embodiments of the instant disclosure may include, for a cable landing site for a subsea optical fiber, (1) receiving a plurality of optical signals carried over the subsea optical fiber, the plurality of optical signals comprising a first set of optical signals in a first wavelength band and at least one additional set of optical signals in at least one additional wavelength band that is different from the first wavelength band, (2) optically splitting the plurality of optical signals into the first set of optical signals and the at least one additional set of optical signals, (3) introducing, after optically splitting the plurality of optical signals, the first set of optical signals onto a first terrestrial optical fiber, and (4) introducing, after optically splitting the plurality of optical signals, the at least one additional set of optical signals onto at least one additional terrestrial optical fiber that is different from the first terrestrial optical fiber.
[0029] Also for a cable landing site for a subsea optical fiber, some embodiments of the instant disclosure may include (1) receiving a first set of optical signals carried over a first terrestrial optical fiber in a first wavelength band, (2) receiving at least one additional set of optical signals carried over at least one additional terrestrial optical fiber in at least one additional wavelength band that is different from the first wavelength band, (3) optically combining the first set of optical signals and the at least one additional set of optical signals to form a plurality of optical signals, and (4) introducing, after optically combining the first set of optical signals and the at least one additional set of optical signals, the plurality of optical signals onto the subsea optical fiber.
[0030] By splitting the optical signals received from a subsea optical fiber into separate wavelength bands at a cable landing site and introducing the signals of the separate bands onto different terrestrial optical fibers, the disclosed systems and methods may greatly reduce the probability of a single terrestrial fiber cut causing a failure of all signals carried on the subsea optical fiber. Further, by splitting the signals in such a manner, the disclosed systems and methods may maintain the signals in the optical domain, thus possibly avoiding inefficiencies often associated with converting the signals between the optical and electrical domains.
[0031] The following will provide, with reference to
[0032]
[0033] As illustrated in
[0034] At step 120, the plurality of optical signals may be optically split at the cable landing site into the first set of optical signals and the second set of optical signals. In one example, a band-wise wavelength-selective optical splitter may be employed to split the optical signals received at an end of the subsea optical fiber into a first optical beam carrying the first set of optical signals and a second optical beam carrying the second set of optical signals. In some embodiments, the optical splitter may be directly coupled to the subsea optical fiber to receive the plurality of optical signals.
[0035] Thereafter, at step 130, the first set of optical signals may be introduced onto a first terrestrial optical fiber, and at step 140, the second set of optical signals may be introduced onto a second terrestrial optical fiber different from the first terrestrial optical fiber. In some examples, an end of the first terrestrial optical fiber and an end of the second terrestrial optical fiber may be coupled directly to the optical splitter.
[0036] While a single subsea optical fiber is referenced above in relation to method 100 of
[0037]
[0038] At step 230, the first set of optical signals received from the first terrestrial optical fiber and the second set of optical signals received from the second terrestrial optical fiber may be optically combined at the cable landing site to form a plurality of optical signals. At step 240, the plurality of optical signals may then be introduced onto a subsea optical fiber. In some examples, an optical combiner may combine the optical beams carrying the first and second set of optical signals from the terrestrial optical fibers and combine them into a single optical beam that is introduced onto the subsea optical fiber. In some embodiments, the optical combiner may be directly coupled to the subsea optical fiber to introduce the plurality of optical signals.
[0039] While a single subsea optical fiber is referenced above in relation to method 200 of
[0040] As is described in greater detail below in conjunction with
[0041] In some examples, a cable landing site may operate according to both method 100 and method 200. For example, one subsea optical fiber may be used for method 100, while a separate subsea optical fiber may be used for method 200, such that each subsea optical fiber carries optical signals in a single direction. Also in some examples, separate first terrestrial optical fibers and separate second terrestrial optical fibers may be used to carry associated sets of optical signals unidirectionally. In other embodiments, a single subsea optical fiber may be employed in both method 100 and method 200, thereby operating bidirectionally by carrying two different pluralities of optical signals, one in each direction along the subsea optical fiber. Similarly, a single first terrestrial optical fiber and/or a single second terrestrial optical fiber each may be employed to carry sets of optical signals in a bidirectional manner. In other examples, separate first and/or second terrestrial optical fibers may be employed for method 100 and method 200, with each terrestrial optical fiber carrying a set of optical signals in a single direction.
[0042] While method 100 and method 200 each involves a first wavelength band and a second wavelength band, along with corresponding first and second terrestrial optical fibers, three or more wavelength bands, with corresponding numbers of terrestrial optical fibers, may be employed in other examples with a single subsea optical fiber. For example, the optical signals of a subsea optical fiber may be optically split into sets of optical signals in first, second, and third separate wavelength bands, with each set being carried over a separate terrestrial optical fiber. Sets of optical signals in four or more wavelength bands may be optically split and carried in a corresponding manner. Similarly, the combining and carrying of sets of the optical signals in three or more separate wavelength bands may be performed in an associated fashion.
[0043]
[0044] In examples depicted in
[0045] In examples illustrated in
[0046] As illustrated in both
[0047] As to
[0048] In some examples of both
[0049] In some embodiments, each of terrestrial optical cables 304 and 306 and subsea optical cable 302, as depicted in
[0050]
[0051] In cable landing site 310A of
[0052] In cable landing site 310A of
[0053] In
[0054] In
[0055] In some examples of
[0056] Also, in subsea optical communication links that carry optical communication signals in both directions, various combinations of
[0057] As explained above in conjunction with
[0058] The process parameters and sequence of the steps described and/or illustrated herein are given by way of example only and can be varied as desired. For example, while the steps illustrated and/or described herein may be shown or discussed in a particular order, these steps do not necessarily need to be performed in the order illustrated or discussed. The various exemplary methods described and/or illustrated herein may also omit one or more of the steps described or illustrated herein or include additional steps in addition to those disclosed.
[0059] The preceding description has been provided to enable others skilled in the art to best utilize various aspects of the exemplary embodiments disclosed herein. This exemplary description is not intended to be exhaustive or to be limited to any precise form disclosed. Many modifications and variations are possible without departing from the spirit and scope of the instant disclosure. The embodiments disclosed herein should be considered in all respects illustrative and not restrictive. Reference should be made to the appended claims and their equivalents in determining the scope of the instant disclosure.
[0060] Unless otherwise noted, the terms connected to and coupled to (and their derivatives), as used in the specification and claims, are to be construed as permitting both direct and indirect (i.e., via other elements or components) connection. In addition, the terms a or an, as used in the specification and claims, are to be construed as meaning at least one of. Finally, for ease of use, the terms including and having (and their derivatives), as used in the specification and claims, are interchangeable with and have the same meaning as the word comprising.