Submarine cable architecture with redundancy to facilitate a shared landing site

Abstract

To provide an undersea optical fiber cable architecture that facilitates incorporation of additional cables (i.e., cables added after initial installation) using the same terrestrial landing site.SOLUTION: The undersea optical fiber cable architecture 10 includes a beach manhole (BMH) installed at a ground location, a ground station connected to the BMH by a terrestrial optical fiber cable, a first landing cable extending from the BMH to territorial waters adjacent to the ground location and connected to a first enhanced branching unit (EBU) 22 located in the territorial waters, a second landing cable extending from the BMH to territorial waters and connected to a second EBU24 located in the territorial waters, a recovery path cable 26 connecting the first EBU to the second EBU, a first trunk cable 28 extending from the first EBU to an international water area, and a second trunk cable 30 extending from the second EBU to the international water area.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] (Related Applications) This application claims priority to and the benefit of U.S. Provisional Patent Application No. 62 / 943,600, entitled "SUBMARINE CABLE ARCHITECTURE WITH REDUDANCY FOR FACILITING SHARED LANDING SITE," filed December 4, 2019, the contents of which are incorporated herein by reference in their entirety.

[0002] FIELD OF THE INVENTION The present disclosure relates generally to the field of undersea communication networks, and more particularly to an architecture for implementing multiple undersea fiber optic cables with redundant connections to a common landing location. [Background technology]

[0003] Submarine optical fiber cables are commonly used to transmit data across ocean currents between terrestrial landing locations, often located in different countries and on different continents. Implementing a new submarine optical fiber cable generally requires obtaining a government-issued cable landing license to own and operate the submarine optical fiber cable and associated landing stations, which must be installed at each terrestrial landing location and in adjacent territorial waters. The process for obtaining such a cable landing license can be difficult, time-consuming, and expensive. Therefore, it would be advantageous to provide a submarine optical fiber cable architecture that allows multiple cables to share a single terrestrial landing location. It would be a further advantage to provide such an architecture that facilitates the incorporation of additional cables (i.e., cables added after initial installation) using the same terrestrial landing location. It would be a further advantage to provide such an architecture that facilitates redundant routing of signal traffic between multiple cables and landing locations to increase the reliability of the architecture.

[0004] With respect to these and other considerations, the improvements of the present invention may be useful. Summary of the Invention

[0005] This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended as an aid in determining the scope of the claimed subject matter.

[0006] A submarine fiber optic cable architecture according to an exemplary embodiment of the present disclosure may include a beach manhole (BMH) installed at a land location; a ground station connected to the BMH by a terrestrial fiber optic cable; a first landing cable extending from the BMH into territorial waters adjacent to the land location and connected to a first expansion branching unit (EBU) located in the territorial waters; a second landing cable extending from the BMH into the territorial waters and connected to a second EBU located in the territorial waters; a return cable connecting the first EBU to the second EBU; a first trunk cable extending from the first EBU into international waters; and a second trunk cable extending from the second EBU into international waters.

[0007] A submarine optical fiber cable architecture according to another exemplary embodiment of the present disclosure may include a first beach manhole (BMH) installed at a first land location, a second BMH installed at the first land location, a first landing cable extending from the first BMH into territorial waters adjacent to the land location and connected to a first expansion branch unit (EBU) located in the territorial waters, a second landing cable extending from the second BMH into the territorial waters and connected to the second EBU located in the territorial waters, a return cable connecting the first EBU to the second EBU, a first trunk cable extending from the first EBU into international waters, and a second trunk cable extending from the second EBU into international waters. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic diagram illustrating an exemplary embodiment of a submarine fiber optic cable architecture in accordance with the present disclosure.

[0009] [Figure 2A] FIG. 2 is a schematic diagram illustrating another exemplary embodiment of a submarine fiber optic cable architecture in accordance with the present disclosure.

[0010] [Figure 2B] 2B is a schematic diagram illustrating a fault condition in the submarine fiber optic cable architecture of FIG. 2A.

[0011] [Figure 2C] 2B is a schematic diagram illustrating another fault condition in the submarine fiber optic cable architecture of FIG. 2A.

[0012] [Figure 3] 2B is a schematic diagram illustrating power distribution in the undersea fiber optic cable architecture of FIG. 2A. DETAILED DESCRIPTION OF THE INVENTION

[0013] A submarine fiber optic cable architecture according to the present disclosure will now be more fully described with reference to the accompanying drawings, in which a preferred embodiment of the submarine fiber optic cable architecture is presented. However, the submarine fiber optic cable architecture may be embodied in many different forms and should not be construed as limited to the embodiment described herein. Rather, the embodiment is provided so that the present disclosure will convey certain exemplary aspects of the submarine fiber optic cable architecture to those skilled in the art.

[0014] Referring to Figure 1, a submarine fiber optic cable architecture 10 (hereinafter "architecture 10") according to an exemplary embodiment of the present disclosure is presented. The architecture 10 may include a beach manhole (BMH) 12 installed at a land location 13 (e.g., along a coastline) for coupling submarine fiber optic cables 14, 16 to a terrestrial fiber optic cable 18. The terrestrial fiber optic cable 18 may extend to a ground station 20 that may be configured to transmit and receive communication signals via the terrestrial fiber optic cable 18. The land-based elements of the architecture 10 (i.e., the beach manhole 12, the terrestrial fiber optic cable 18, and the ground station 20) may be of conventional structure / configuration well known to those skilled in the art and, therefore, will not be described in further detail herein.

[0015] The submarine fiber optic cables 14, 16 of the architecture 10, hereinafter referred to as the “first and second landing cables 14, 16,” may extend from the BMH 12 to territorial waters 21 adjacent to the land location 13 and under the jurisdiction of the entity that owns / controls the land location 13. The first and second landing cables 14, 16 may extend to and be coupled to respective first and second expansion branch units (EBUs) 22, 24 located within the territorial waters 21 and connected to each other by a submarine fiber optic cable 26, hereinafter referred to as the “return cable 26.” Thus, the BMH 12, the first EBU 22, and the second EBU 24 are interconnected by the first and second landing cables 14, 16 and the return cable 26 to define a ring topology.

[0016] Submarine optical fiber cables 28, 30, hereinafter referred to as “first and second trunk cables 28, 30,” may extend from the first and second EBUs 22, 24, respectively, and may extend into international waters to connect the first and second EBUs 22, 24 to remote ground stations (e.g., ground stations located in different countries and on different continents). In a non-limiting embodiment of the present disclosure, the first and second trunk cables 28, 30 may include groups of eight bidirectional fiber pairs 32, 34, respectively, and the first and second landing cables 14, 16, respectively, and the return cable 26 may include a first group of eight bidirectional fiber pairs 36a, 36b, 36c, respectively, and a second group of eight bidirectional fiber pairs 38a, 38b, 38c, respectively. Thus, the ring topology of the architecture 10 may include a total of 16 bidirectional fiber pairs. The present disclosure is not limited in this respect. It is contemplated that the first and second trunk cables 28, 30, the first and second landing cables 14, 16, and the return cable 26 may include a greater or lesser number of fiber pairs without departing from this disclosure.

[0017] Each of the first and second EBUs 22, 24 may include an optical switch for selectively routing individual fiber pairs in the respective trunk cables 28, 30 directly to the BMH 12 via the first and second landing cables 14, 16, respectively, or via the return cable 26. For example, during normal operation of the architecture 10, the first EBU 22 may route incoming signal traffic from the bi-directional fiber pairs 32 of the first trunk cable 28 to the BMH 12 via the first group of bi-directional fiber pairs 36a of the first landing cable 14. However, if the first landing cable 14 is damaged, the optical switch within the first EBU 22 may reroute the incoming signal traffic from the bi-directional fiber pairs 32 of the first trunk cable 28 to the first group of bi-directional fiber pairs 36c of the return cable 26, and then transmit the traffic to the BMH 12 via the second EBU 24 and the first group of bi-directional fiber pairs 36b in the second landing cable 16. Similarly, during normal operation of the architecture 10, the second EBU 24 can route incoming signal traffic from the bi-directional fiber pairs 34 of the second trunk cable 30 to the BMH 12 via the second group of bi-directional fiber pairs 38 b in the second landing cable 16. However, if the second landing cable 16 is damaged, an optical switch in the second EBU 24 can reroute the incoming signal traffic from the bi-directional fiber pairs 34 of the second trunk cable 30 to the second group of bi-directional fiber pairs 38 c in the return cable 26, and then transmit the traffic to the BMH 12 via the first EBU 22 and the second group of bi-directional fiber pairs 38 a in the first landing cable 14. In various embodiments, the first and second EBUs 22, 24 may be controlled by a telemetry transceiver located in the ground station 20 via the first landing cable 14 and / or the second landing cable 16.

[0018] It will thus be appreciated that the architecture 10 of the present disclosure facilitates redundant routing of signal traffic between multiple cables and a single landing site to improve reliability. Additionally, the architecture 10 of the present disclosure provides the further advantage of facilitating the future connection of additional trunk cables to the BMH 12 (i.e., after the initial installation of the architecture 10) without requiring the operator to obtain additional cable landing licenses. For example, during installation of the architecture 10, additional EBUs may be provided in the ring topology of the architecture 10 to accommodate the connection of additional trunk cables at a later point in time. Alternatively, additional EBUs may be connected to the ring topology without interrupting signal traffic. For example, with reference to the exemplary embodiment of the architecture 10 shown in FIG. 1 , incoming signal traffic on the second trunk 30 may be rerouted by the second EBU 24 (as described above) from the second landing cable 16 to the return cable 26, thereby enabling additional EBUs to be connected to the second landing cable 16 without interrupting signal traffic within the architecture 10.

[0019] Referring to FIG. 2A , another submarine fiber optic cable architecture 100 (hereinafter, “architecture 100”) according to an exemplary embodiment of the present disclosure is presented. Architecture 100 may include a first beach manhole (BMH) 112 installed at a first terrestrial location and a second BMH 114 installed at a second terrestrial location. The first and second BMHs 112, 114 may couple submarine fiber optic cables 116, 118 to respective terrestrial fiber optic cables (not shown) that extend to respective ground stations (not shown) that may be configured to transmit and receive communication signals via the terrestrial fiber optic cables. The land-based elements of architecture 100 (i.e., the BMHs 112, 114, the terrestrial fiber optic cables, and the ground stations) may be of conventional construction / configuration familiar to those skilled in the art and, therefore, will not be described in further detail herein.

[0020] The submarine fiber optic cables 116, 118 of the architecture 100, hereinafter referred to as the "first and second landing cables 116, 118," may extend from the BMHs 112, 114 into territorial waters 121 adjacent to the land locations where the BMHs 112, 114 are located. The first and second landing cables 116, 118 may extend to and be coupled to respective first and second expansion branching units (EBUs) 122, 124 that are also located in the territorial waters 121 and connected to each other by the submarine fiber optic cable 126, hereinafter referred to as the "return cable 126." Thus, the first and second BMHs 112, 114 and the first and second EBUs 122, 124 are interconnected by the first and second landing cables 116, 118 and the return cable 126 to define a ring topology.

[0021] The submarine fiber optic cables 128, 130, hereinafter referred to as "first and second trunk cables 128, 130," may extend from the first and second EBUs 122, 124, respectively, and may extend into international waters to connect the first and second EBUs 122, 124 to remote ground stations (e.g., ground stations located in different countries and on different continents). In a non-limiting embodiment of the present disclosure, the return cable 126 and the first and second trunk cables 128, 130 may each include a group of twelve bi-directional fiber pairs 131, 132, 134, and the first and second landing cables 116, 118 may each include a first group of twelve bi-directional fiber pairs 136 a, 136 b and a second group of twelve bi-directional fiber pairs 138 a, 138 b. Each of the groups of bi-directional fiber pairs described above is represented schematically in FIG. 2A by a single pair of input and output lines for clarity. The present disclosure is not limited to the specific number of bi-directional fiber pairs listed above, and it is contemplated that the first and second trunk cables 128, 130, the first and second landing cables 116, 118, and the return cable 126 may include a greater or lesser number of bi-directional fiber pairs without departing from the present disclosure. However, in general, the return cable 126 and the first and second trunk cables 128, 130 include half of as many bi-directional fiber pairs as the first and second landing cables 116, 118.

[0022] Each of the first and second EBUs 122, 124 may include an optical switch for selectively routing individual fiber pairs in the respective trunk cables 128, 130 to the respective BMHs 112, 114 via the first and second landing cables 116, 118, or to the BMHs 112 or 114 associated with the other EBUs 122 or 124 via the return cable 126. For example, during normal operation of the architecture 100, the first EBU 122 may facilitate signal traffic between the bidirectional fiber pair 132 of the first trunk cable 128 to the first BMH 112 and the first group of bidirectional fiber pairs 136a of the first landing cable 116. Similarly, during normal operation of the architecture 100, the second EBU 124 can facilitate signal traffic between the bi-directional fiber pair 134 of the second trunk cable 130 and the second group of bi-directional fiber pairs 138b of the second landing cable 118 to the second BMH 114. However, if the first landing cable 116 is disabled (e.g., cut) as shown in FIG. 2B , the optical switch within the first EBU 122 can route the signal traffic from the bi-directional fiber pair 132 of the first trunk cable 128 to the bi-directional fiber pair 131 of the return cable 126, and then transmit the traffic to the second BMH 114 via the second EBU 124 and the first group of bi-directional fiber pairs 136b in the second landing cable 118. Similarly, if the second landing cable 118 is disabled as shown in FIG. 2C , the optical switch in the second EBU 124 can route signal traffic from the bidirectional fiber pair 134 of the second trunk cable 130 to the bidirectional fiber pair 131 of the return cable 126, and then transmit the traffic to the first BMH 112 via the first EBU 122 and the second group of bidirectional fiber pairs 138 a in the first landing cable 116.In various embodiments, the first and second EBUs 122, 124 may be controlled by a telemetry transceiver located in a ground station (not shown) associated with the first and second BMHs 112, 114 via the first and second landing cables 116, 118, and / or by a telemetry transceiver located in a ground station (not shown) associated with the BMHs at the remote ends of the first and second trunk cables 128, 130.

[0023] It will therefore be appreciated that the architecture 100 of the present disclosure is capable of maintaining signal traffic on multiple trunk cables even when the landing cables of the architecture are disabled.

[0024] Referring now to Figure 3, a schematic diagram illustrating power distribution in the architecture 100 described above is shown. In addition to the components of the architecture 100 shown in Figures 2A-2C, Figure 3 includes components located at the distal ends of the trunk cables 128, 130 relative to the first and second BMHs 112, 114. These components include third and fourth BMHs 142, 144 located at respective land locations (e.g., along the shoreline), third and fourth landing cables 146, 148 extending from the BMHs 142, 144, respectively, third and fourth EBUs 152, 154 connecting the third and fourth landing cables 146, 148 to the first and second trunk cables 128, 130, and a recovery cable 156 connecting the first and second EBUs 152, 154 to each other. These components can be configured in substantially the same manner as the components of the architecture described above and shown in Figures 2A-2C.

[0025] During normal operation of the architecture 100, and as indicated by the arrows shown in FIG. 3 , the power feed equipment (PFE) associated with the first BMH 112 may provide power via the first landing cable 116 and the first main cable 128. The PFE associated with the second BMH 114 may provide power via the second landing cable 118 and the return cable 126. The PFE associated with the third BMH 142 may provide power via the third landing cable 146 and the return cable 156, and the PFE associated with the fourth BMH 144 may provide power via the fourth landing cable 148 and the second main cable 130. However, if a fault exists in any of the cables (e.g., a shunt fault, a cable cut, etc.), the EBUs 112, 114, 152, 154 may be configured to redirect the flow of power to the undamaged cables. Various non-limiting examples of fault conditions and corresponding power rerouting within the architecture 100 will now be described.

[0026] In the event of a shunt failure of the recovery cable 126, the power feed equipment (PFE) associated with the first BMH 112 can provide power via the first landing cable 116, the first main cable 128, and the third landing cable 146. The PFE associated with the second BMH 114 can provide power via the second landing cable 118 and the second main cable 130, and the PFE associated with the fourth BMH 144 can provide power via the fourth landing cable 148 and the recovery cable 156.

[0027] In the event of a shunt failure of the recovery cable 156, the power feed equipment (PFE) associated with the first BMH 112 can provide power via the first landing cable 116, the first main cable 128, and the third landing cable 146. The PFE associated with the second BMH 114 can provide power via the second landing cable 118 and the recovery cable 126, and the PFE associated with the fourth BMH 144 can provide power via the fourth landing cable 148 and the second main cable 130.

[0028] In the event of a shunt failure of the recovery cable 126 and a cable cut of the second landing cable 118, the power supply equipment (PFE) associated with the first BMH 112 can supply power via the first landing cable 116, the first main cable 128, and the third landing cable 146, and the PFE associated with the fourth BMH 144 can supply power via the fourth landing cable 148 and the recovery cable 156.

[0029] In the event of a shunt failure of the recovery cable 126 and a cable cut of the fourth landing cable 148, the power supply equipment (PFE) associated with the first BMH 112 can supply power via the first landing cable 116, the first main cable 128, and the third landing cable 146, and the PFE associated with the second BMH 114 can supply power via the second landing cable 118, the second main cable 130, and the recovery cable 156.

[0030] In the event of a shunt failure of the recovery cable 126 and a cable cut of the third landing cable 146, the power supply equipment (PFE) associated with the first BMH 112 can supply power via the first landing cable 116, the first main cable 128, the recovery cable 156, and the fourth landing cable 148, and the PFE associated with the second BMH 114 can supply power via the second landing cable 118 and the second main cable 130.

[0031] In the event of a cable cut on the first trunk cable 128, the power feed equipment (PFE) associated with the first BMH 112 can provide power via the first landing cable 116 and the return cable 126. The PFE associated with the second BMH 114 can provide power via the second landing cable 118 and the second trunk cable 130, and the PFE associated with the fourth BMH 144 can provide power via the fourth landing cable 148 and the return cable 156.

[0032] As used herein, elements or steps listed in the singular and preceded by the word "a" or "an" should be understood as not excluding a plurality of elements or steps, unless such exclusion is expressly stated. Furthermore, references to "one embodiment" of the present disclosure are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features.

[0033] While the present disclosure refers to particular embodiments, numerous modifications, alterations, and variations to the described embodiments are possible without departing from the sphere and scope of the disclosure, as defined in the appended claims. Accordingly, it is intended that the present disclosure not be limited to the described embodiments, but rather have the full scope defined by the language of the following claims and their equivalents. [Item 1] 1. A submarine optical fiber cable architecture, comprising: Beach manholes (BMH) installed at ground level, a first Expanded Branching Unit (EBU) located in territorial waters adjacent to the land location; a second EBU located in said territorial waters adjacent to said land location; a first landing cable extending from the BMH and connected to the first EBU; a second landing cable extending from the BMH and connected to the second EBU; a return cable connecting the first EBU to the second EBU; a first trunk cable extending from the first EBU to international waters; a second trunk cable extending from the second EBU to the international waters. [Item 2] Item 2. The submarine optical fiber cable architecture of item 1, wherein the first EBU includes one or more optical switches for selectively routing signal traffic on the first trunk cable to the first landing cable or the return cable. [Item 3] 3. The submarine optical fiber cable architecture of claim 1, wherein the second EBU includes one or more optical switches for selectively routing signal traffic on the second trunk cable to the second landing cable or the return cable. [Item 4] 4. The submarine fiber optic cable architecture of any one of claims 1 to 3, further comprising a ground station connected to said BMH by a terrestrial fiber optic cable. [Item 5] 5. The submarine optical fiber cable architecture of any one of claims 1 to 4, wherein the BMH, the first EBU, and the second EBU interconnected by the first landing cable, the second landing cable, and the return cable define a ring topology. [Item 6] each of the first landing cable, the second landing cable, and the return cable includes a first group of eight bidirectional fiber pairs and a second group of eight bidirectional fiber pairs; Item 6. The submarine optical fiber cable architecture of item 5, wherein the ring topology includes a total of 16 bidirectional fiber pairs. [Item 7] 5. The submarine optical fiber cable architecture of claim 4, wherein the first EBU and the second EBU are controlled by one or more telemetry transceivers located at the ground station via the first landing cable and / or the second landing cable. [Item 8] Item 6. The submarine optical fiber cable architecture of item 5, wherein the ring topology is configured to accommodate one or more additional EBUs for connecting additional trunk cables. [Item 9] Item 6. The submarine optical fiber cable architecture according to item 5, wherein one or more additional EBUs are connected to the ring topology without interrupting signal traffic. [Item 10] 1. A submarine optical fiber cable architecture, comprising: a first beach manhole (BMH) installed at a first above-ground location; a second BMH located at said first ground location; and a first landing cable extending from the first BMH into territorial waters adjacent to the first land location and connected to a first expansion branching unit (EBU) located in the territorial waters; a second landing cable extending from the second BMH into the territorial waters adjacent to the first land location and connected to a second EBU located in the territorial waters; a return cable connecting the first EBU to the second EBU; a first trunk cable extending from the first EBU to international waters; a second trunk cable extending from the second EBU to the international waters. [Item 11] Item 11. The submarine optical fiber cable architecture of item 10, wherein the first EBU includes one or more optical switches for selectively routing incoming signal traffic on the first trunk cable to the first landing cable or the return cable. [Item 12] 12. The submarine optical fiber cable architecture of claim 10 or 11, wherein the second EBU includes one or more optical switches for selectively routing incoming signal traffic on the second trunk cable to the second landing cable or the return cable. [Item 13] 13. The submarine fiber optic cable architecture of any one of items 10 to 12, further comprising a ground station connected to the first BMH or the second BMH by a terrestrial fiber optic cable. [Item 14] 14. The submarine optical fiber cable architecture of any one of items 10 to 13, wherein the first BMH, the second BMH, the first EBU, and the second EBU interconnected by the first landing cable, the second landing cable, and the return cable define a ring topology. [Item 15] 15. The submarine optical fiber cable architecture of any one of items 10 to 14, wherein each of the first landing cable and the second landing cable includes a first group of 12 bidirectional fiber pairs and a second group of 12 bidirectional fiber pairs. [Item 16] 16. The submarine optical fiber cable architecture of any one of items 10 to 15, wherein the first EBU and second EBU are controlled by one or more telemetry transceivers located in ground stations associated with the first BMH and second BMH via the first landing cable and second landing cable, and / or by one or more telemetry transceivers located in ground stations associated with one or more BMH at distal ends of the first trunk cable and second trunk cable. [Item 17] Item 15. The submarine optical fiber cable architecture of item 14, wherein the ring topology is configured to accommodate one or more additional EBUs for connecting additional trunk cables. [Item 18] Item 15. The submarine optical fiber cable architecture according to item 14, wherein one or more additional EBUs are connected to the ring topology without interrupting signal traffic.

Claims

[Claim 1] 1. A submarine optical fiber cable architecture, comprising: Beach manholes (BMHs) installed at ground level; a first expansion branching unit (EBU) located in territorial waters adjacent to the land location; a second EBU located in the territorial waters adjacent to the land location; a first landing cable extending from the BMH and connected to the first EBU; a second landing cable extending from the BMH and connected to the second EBU; a return cable connecting the first EBU to the second EBU; a first trunk cable extending from the first EBU to international waters; a second trunk cable extending from the second EBU to the international waters.

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