A redundant undersea cable architecture facilitating shared landing sites

Abstract

The present invention is titled "Submarine Cable Architecture with Redundancy for Facilitating Shared Landing Sites". The present invention discloses a submarine optical cable architecture, which includes: a beach manhole (BMH) installed at a land location; a land station connected to the BMH through a land optical cable; a first landing cable extending from the BMH into the territorial sea adjacent to the land location and connected to a first enhanced branch unit (EBU) located in the territorial sea; a second landing cable extending from the BMH into the territorial sea and connected to a second EBU located in the territorial sea; a restoration path cable connecting the first EBU to the second EBU; a first trunk cable extending from the first EBU into the international sea area; and a second trunk cable extending from the second EBU into the international sea area.

Description

[0001] Related Applications

[0002] This application claims the benefit and priority of U.S. Provisional Application No. 62 / 943,600, filed on Dec. 4, 2019, entitled “SUBMARINE CABLE ARCHITECTURE WITH REDUDANCY FOR FACILITING SHARED LANDING SITE”. The entire content of the above patent application is incorporated herein by reference. Field of the Invention

[0003] The present disclosure generally relates to the field of undersea communication networks, and more particularly, to architectures for implementing multiple undersea optical cables having redundant connections to a shared landing site. Background Art

[0004] Undersea optical cables are commonly used to transmit data across oceanic landfall sites, which are typically located in different countries and different continents. Laying new undersea optical cables generally requires obtaining cable landing permits issued by governments in order to own and operate the undersea optical cables and their associated landing stations, which must be installed at each landfall site and in the adjacent territorial sea. The process of obtaining such cable landing permits can be difficult, time-consuming, and expensive. Accordingly, it would be advantageous to provide an undersea optical cable architecture in which multiple cables can share a single landfall site. It would be another advantage to provide such an architecture that facilitates the incorporation of additional cables (i.e., cables added after initial installation) that use the same landfall site. It would be another advantage to provide such an architecture that facilitates redundant routing of signal traffic between multiple cables and the landing site, thereby enhancing the reliability of the architecture.

[0005] In view of these and other considerations, improvements in the present disclosure may be useful. Summary of the Invention

[0006] The Summary of the Invention is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. The Summary of the Invention is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to help determine the scope of the claimed subject matter.

[0007] The undersea optical cable architecture according to an exemplary embodiment of the present disclosure may include: a beach manhole (BMH) installed at a land location; a land station connected to the BMH via a land optical cable; a first landing cable extending from the BMH into the territorial sea adjacent to the land location and connected to a first enhanced branch unit (EBU) located in the territorial sea; a second landing cable extending from the BMH into the territorial sea and connected to a second EBU located in the territorial sea; a restoration path cable connecting the first EBU to the second EBU; a first trunk cable extending from the first EBU into the international waters; and a second trunk cable extending from the second EBU into the international waters.

[0008] The undersea optical 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 the territorial sea adjacent to the land location and connected to a first enhanced branch unit (EBU) located in the territorial sea; a second landing cable extending from the second BMH into the territorial sea and connected to a second EBU located in the territorial sea; a restoration path cable connecting the first EBU to the second EBU; a first trunk cable extending from the first EBU into the international waters; and a second trunk cable extending from the second EBU into the international waters. Description of the Drawings

[0009] Figure 1 is a schematic diagram showing an exemplary embodiment of the undersea optical cable architecture according to the present disclosure;

[0010] Figure 2A is a schematic diagram showing another exemplary embodiment of the undersea optical cable architecture according to the present disclosure;

[0011] Figure 2B is a schematic diagram showing Figure 2A a fault condition in the undersea optical cable architecture of

[0012] Figure 2C is a schematic diagram showing Figure 2A another fault condition in the undersea optical cable architecture of

[0013] Figure 3 is a schematic diagram showing Figure 2A the power distribution in the undersea optical cable architecture of Detailed Description

[0014] The undersea cable architecture according to the present disclosure will now be described more fully with reference to the accompanying drawings, in which preferred embodiments of the undersea cable architecture are presented. However, the undersea cable architecture can be implemented in many different forms and should not be construed as limited to the embodiments set forth herein. Instead, these embodiments are provided so that the present disclosure will convey certain exemplary aspects of the undersea cable architecture to those skilled in the art.

[0015] Referring to Figure 1 , which shows an undersea cable architecture 10 (hereinafter referred to as "architecture 10") according to an exemplary embodiment of the present disclosure. Architecture 10 may include a beach manhole (BMH) 12 installed at a land location 13 (e.g., along a coastline) for connecting undersea optical fibers 14, 16 to a land cable 18. The land cable 18 may extend to a land station 20, which may be configured to transmit and receive communication signals via the land cable 18. The land-based elements of architecture 10 (i.e., the BMH 12, the land cable 18, and the land station 20) may have a conventional architecture / configuration familiar to those of ordinary skill in the art and will therefore not be discussed in more detail herein.

[0016] The undersea cables 14, 16 of architecture 10 (hereinafter referred to as "the first landing cable 14 and the second landing cable 16") may extend from the BMH 12 into the territorial sea 21, which is adjacent to the land location 13 and is under the jurisdiction of the entity owning / managing the land location 13. The first landing cable 14 and the second landing cable 16 may extend to and may be connected to respective first enhanced branch units (EBUs) 22 and second enhanced branch units 24, which are located within the territorial sea 21 and are connected to each other by an undersea cable 26 (hereinafter referred to as "the restoration path cable 26"). Thus, the BMH 12, the first EBU 22, and the second EBU 24 are interconnected by the first landing cable 14, the second landing cable 16, and the restoration path cable 26 to define a ring topology.

[0017] Submarine optical cables 28, 30 (hereinafter referred to as "first trunk cable 28 and second trunk cable 30") can extend from the first EBU 22 and the second EBU 24 respectively, and can extend into international waters to connect the first EBU 22 and the second EBU 24 to remote land stations (for example, land stations located in different countries and different continents, not shown). In a non-limiting embodiment of the present disclosure, the first trunk cable 28 and the second trunk cable 30 can each include a set of 8 pairs of bidirectional optical fibers 32, 34, and each of the first landing cable 14 and the second landing cable 16 and the restoration path cable 26 can include a first set of 8 pairs of bidirectional optical fibers 36a, 36b, 36c and a second set of 8 pairs of bidirectional optical fibers 38a, 38b, 38c respectively. Thus, the ring topology of the architecture 10 can include a total of 16 pairs of bidirectional optical fibers. The present disclosure is not limited in this regard. It is contemplated that, without departing from the present disclosure, the first trunk cable 28 and the second trunk cable 30, the first landing cable 14 and the second landing cable 16, and the restoration path cable 26 can include a greater or lesser number of fiber pairs.

[0018] Each of the first EBU 22 and the second EBU 24 may include optical switches for selectively routing each optical fiber pair in the respective trunk cables 28, 30 directly to the BMH 12 via the first landing cable 14 and the second landing cable 16, respectively, or for selectively routing each optical fiber pair in the respective trunk cables to the BMH 12 via the recovery path cable 26. For example, during normal operation of the architecture 10, the first EBU 22 may route the input signal traffic of the bidirectional optical fiber pair 32 from the first trunk cable 28 to the BMH 12 via the first set of bidirectional optical fiber pairs 36a in the first landing cable 14. However, if the first landing cable 14 is damaged, the optical switch in the first EBU 22 may re-route the input signal traffic of the bidirectional optical fiber pair 32 from the first trunk cable 28 to the first set of bidirectional optical fiber pairs 36c in the recovery path cable 26, where the traffic may then be transmitted to the BMH 12 via the second EBU 24 and the first set of bidirectional optical fiber pairs 36b in the second landing cable 16. Similarly, during normal operation of the architecture 10, the second EBU 24 may route the input signal traffic of the bidirectional optical fiber pair 34 from the second trunk cable 30 to the BMH 12 via the second set of bidirectional optical fiber pairs 38b in the second landing cable 16. However, if the second landing cable 16 is damaged, the optical switch in the second EBU 24 may re-route the input signal traffic of the bidirectional optical fiber pair 34 from the second trunk cable 30 to the second set of bidirectional optical fiber pairs 38c in the recovery path cable 26, where the traffic may then be transmitted to the BMH 12 via the first EBU 22 and the second set of bidirectional optical fiber pairs 38a in the first landing cable 14. In various embodiments, the first EBU 22 and the second EBU 24 may be controlled by a telemetry transceiver located in the land station 20 via the first landing cable 14 and / or the second landing cable 16.

[0019] Accordingly, it should be understood that the architecture 10 of the present disclosure facilitates redundant routing of signal traffic between multiple cables and a single landing site, thereby providing enhanced reliability. Another advantage provided by the architecture 10 of the present disclosure is that it facilitates connecting additional trunk cables to the BMH 12 in the future (i.e., after the initial installation of the architecture 10) without the operator obtaining additional cable landing permits. For example, during the installation of the architecture 10, additional EBUs may be provided in the ring topology of the architecture 10 to accommodate future connection of additional trunk cables. Alternatively, additional EBUs may be spliced into the ring topology without interrupting signal traffic. For example, referring to Figure 1 the exemplary embodiment of the architecture 10 shown, the second EBU 24 may re-route the input signal traffic on the second trunk 30 (as described above) from the second landing cable 16 to the recovery path cable 26, thereby allowing an additional EBU to be spliced into the second landing cable 16 without interrupting the signal traffic in the architecture 10.

[0020] See Figure 2A Figure 2A , which shows another undersea cable architecture 100 (hereinafter referred to as "architecture 100") according to an exemplary embodiment of the present disclosure. Architecture 100 may include a first beach manhole (BMH) 112 installed at a first land location (e.g., along the coastline) and a second BMH 114 installed at a second land location. The first BMH 112 and the second BMH 114 may connect undersea cables 116, 118 to corresponding land cables (not shown) that extend to corresponding land stations (not shown), and these land stations may be configured to transmit and receive communication signals via the land cables. The land-based elements of architecture 100 (i.e., BMHs 112, 114, land cables, and land stations) may have a conventional architecture / configuration familiar to those of ordinary skill in the art, and thus will not be discussed in more detail herein.

[0021] The undersea cables 116, 118 of architecture 100 (hereinafter referred to as "the first landing cable 116 and the second landing cable 118") may extend from the BMHs 112, 114, respectively, into the territorial sea 121 that adjoins the land locations where the BMHs 112, 114 are located. The first landing cable 116 and the second landing cable 118 may extend to and may be connected to a corresponding first enhanced branch unit (EBU) 122 and a second enhanced branch unit 124, and the first enhanced branch unit and the second enhanced branch unit are also located within the territorial sea 121 and are connected to each other by an undersea cable 126 (hereinafter referred to as "the restoration path cable 126"). Thus, the first BMH 112 and the second BMH 114, as well as the first EBU 122 and the second EBU 124, are interconnected by the first landing cable 116 and the second landing cable 118 and the restoration path cable 126 to define a ring topology.

[0022] The undersea cables 128, 130 (hereinafter referred to as "the first trunk cable 128 and the second trunk cable 130") may extend from the first EBU 122 and the second EBU 124, respectively, and may extend into the international waters to connect the first EBU 122 and the second EBU 124 to remote land stations (e.g., land stations located in different countries and different continents, not shown). In a non-limiting embodiment of the present disclosure, the restoration path cable 126, as well as the first trunk cable 128 and the second trunk cable 130, may each include a set of 12 pairs of bidirectional optical fibers 131, 132, 134, and each of the first landing cable 116 and the second landing cable 118 may include a first set of 12 pairs of bidirectional optical fibers 136a, 136b and a second set of 12 pairs of bidirectional optical fibers 138a, 138b. For clarity, in Figure 2AThe foregoing sets of bidirectional optical fiber pairs are schematically represented by single pairs of incoming and outgoing lines. The present disclosure is not limited to the specific number of bidirectional optical fiber pairs listed above, and it is contemplated that the first backbone cable 128 and the second backbone cable 130, the first landing cable 116 and the second landing cable 118, and the restoration path cable 126 may include more or fewer bidirectional optical fiber pairs without departing from the present disclosure. However, generally speaking, the restoration path cable 126 and the first backbone cable 128 and the second backbone cable 130 will include half the number of bidirectional optical fiber pairs of the first landing cable 116 and the second landing cable 118.

[0023] Each of the first EBU 122 and the second EBU 124 may include optical switches for selectively routing the respective optical fiber pairs in the corresponding backbone cables 128, 130 to the corresponding BMHs 112, 114 via the first landing cable 116 and the second landing cable 118, or selectively routing them to the BMHs 112 or 114 associated with other EBUs 122 or 124 via the restoration path cable 126. For example, during normal operation of the architecture 100, the first EBU 122 may facilitate the transfer of signal traffic between the bidirectional optical fiber pair 132 of the first backbone cable 128 and the first set of bidirectional optical fiber pairs 136a in the first landing cable 116 to the first BMH 112. Similarly, during normal operation of the architecture 100, the second EBU 124 may facilitate the transfer of signal traffic between the bidirectional optical fiber pair 134 of the second backbone cable 130 and the second set of bidirectional optical fiber pairs 138b in the second landing cable 118 to the second BMH 114. However, if the first landing cable 116 is Figure 2B disabled (e.g., cut off) as shown, the optical switches in the first EBU 122 may reroute the signal traffic from the bidirectional optical fiber pair 132 of the first backbone cable 128 to the bidirectional optical fiber pair 131 of the restoration path cable 126, where the traffic may then be transmitted to the second BMH 114 via the second EBU 124 and the first set of bidirectional optical fiber pairs 136b in the second landing cable 118. Similarly, if the second landing cable 118 is Figure 2CIf the shown one is disabled, the optical switch in the second EBU 124 can reroute the signal traffic of the bidirectional fiber pair 134 of the second trunk cable 130 to the bidirectional fiber pair 131 of the restoration path cable 126, where the traffic can then be transmitted to the first BMH 112 via the first EBU 122 and the second set of bidirectional fiber pairs 138a in the first landing cable 116. In various embodiments, the first EBU 122 and the second EBU 124 can be controlled by a telemetry transceiver located in a land station (not shown) associated with the first BMH 112 and the second BMH 114 via the first landing cable 116 and the second landing cable 118 and / or by a telemetry transceiver (not shown) located in a land station (not shown) associated with the BMH at the distal ends of the first trunk cable 128 and the second trunk cable 130.

[0024] Accordingly, it should be understood that the architecture 100 of the present disclosure allows maintaining signal traffic on multiple trunk cables even if the landing cables of the architecture are disabled.

[0025] Now refer to Figure 3 , which shows a schematic diagram of power distribution as shown in the architecture 100 described above. In addition to Figures 2A to 2C the components of the architecture 100 shown, Figure 3 including components located at the distal ends of the trunk cables 128, 130 relative to the first BMH 112 and the second BMH 114. These components include a third BMH 142 and a fourth BMH 144 located at respective land locations (e.g., along the coastline); a third landing cable 146 and a fourth landing cable 148 extending from the BMHs 142, 144 respectively; a third EBU 152 and a fourth EBU 154 connecting the third landing cable 146 and the fourth landing cable 148 to the first trunk cable 128 and the second trunk cable 130; and a restoration cable 156 connecting the first EBU 152 and the second EBU 154 to each other. These components can be configured in substantially the same manner as the components of the architecture described above and Figures 2A to 2C shown.

[0026] During normal operation of the architecture 100, and as Figure 3As indicated by the arrow lines shown, the power feeding equipment (PFE) associated with the first BMH 112 can be powered through the first landing cable 116 and the first trunk cable 128; the PFE associated with the second BMH 114 can be powered through the second landing cable 118 and the restoration cable 126; the PFE associated with the third BMH 142 can be powered through the third landing cable 146 and the restoration cable 156; and the PFE associated with the fourth BMH 144 can be powered through the fourth landing cable 148 and the second trunk cable 130. However, if there is a fault in any of the cables (e.g., shunt fault, cable break, etc.), the EBUs 112, 114, 152, 154 can be configured to redirect the power flow to the undamaged cables. Various non-limiting examples of fault conditions and corresponding power rerouting in the architecture 100 will now be described.

[0027] In the case of a shunt fault occurring in the restoration cable 126, the power feeding equipment (PFE) associated with the first BMH 112 can be powered through the first landing cable 116, the first trunk cable 128, and the third landing cable 146; the PFE associated with the second BMH 114 can be powered through the second landing cable 118 and the second trunk cable 130; and the PFE associated with the fourth BMH 144 can be powered through the fourth landing cable 148 and the restoration cable 156.

[0028] In the case of a shunt fault occurring in the restoration cable 156, the power feeding equipment (PFE) associated with the first BMH 112 can be powered through the first landing cable 116, the first trunk cable 128, and the third landing cable 146; the PFE associated with the second BMH 114 can be powered through the second landing cable 118 and the restoration cable 126; and the PFE associated with the fourth BMH 144 can be powered through the fourth landing cable 148 and the second trunk cable 130.

[0029] In the case of a shunt fault occurring in the restoration cable 126 and a cable break occurring in the second landing cable 118, the power feeding equipment (PFE) associated with the first BMH 112 can be powered through the first landing cable 116, the first trunk cable 128, and the third landing cable 146; and the PFE associated with the fourth BMH 144 can be powered through the fourth landing cable 148 and the restoration cable 156.

[0030] In the case of a shunt fault occurring in the restoration cable 126 and a cable break occurring in the fourth landing cable 148, the power feeding equipment (PFE) associated with the first BMH 112 can be powered through the first landing cable 116, the first trunk cable 128, and the third landing cable 146; and the PFE associated with the second BMH 114 can be powered through the second landing cable 118, the second trunk cable 130, and the restoration cable 156.

[0031] In the case of a shunt fault occurring in the restoration cable 126 and a cable interruption occurring in the third landing cable 146, the power feeding equipment (PFE) associated with the first BMH 112 can be powered through the first landing cable 116, the first main cable 128, the restoration path cable 156, and the fourth landing cable 148; and the PFE associated with the second BMH 114 can be powered through the second landing cable 118 and the second main cable 130.

[0032] In the case of a cable interruption occurring in the first main cable 128, the power feeding equipment (PFE) associated with the first BMH 112 can be powered through the first landing cable 116 and the restoration path cable 126; the PFE associated with the second BMH 114 can be powered through the second landing cable 118 and the second main cable 130; and the PFE associated with the fourth BMH 144 can be powered through the fourth landing cable 148 and the restoration cable 156.

[0033] As used herein, unless such exclusions are explicitly recited, an element or step recited in the singular and beginning with the word "a" or "an" should be understood not to exclude a plurality of elements or steps. Additionally, a reference to "one embodiment" of the present disclosure is not intended to be construed as excluding the existence of additional embodiments that also incorporate the recited features.

[0034] Although the present disclosure refers to certain embodiments, many modifications, changes, and alterations to the described embodiments are possible without departing from the spirit and scope of the present disclosure as defined in the appended claims. Accordingly, the present disclosure is intended to be limited not to the described embodiments, but rather to have the full scope defined by the language of the appended claims and their equivalents.

Claims

1. An undersea optical cable architecture, comprising: A beach manhole (BMH) installed at a land location, the BMH being communicatively connected via a land optical cable to a land station including one or more telemetry transceivers, the BMH including power supply equipment; A first enhanced branch unit (EBU) located in the territorial sea adjacent to the land location; A second EBU located in the territorial sea adjacent to the land location; A first landing cable extending from the BMH and connecting to the first EBU, the one or more telemetry transceivers controlling the first EBU via the first landing cable; A second landing cable extending from the BMH and connecting to the second EBU, the one or more telemetry transceivers controlling the second EBU via the second landing cable; A restoration path cable connecting the first EBU to the second EBU, the first EBU, the second EBU, the first landing cable, and the second landing cable being disposed at a first underwater location; A first trunk cable extending from the first EBU into the international waters, the first trunk cable being separated from the first underwater location and extending away from the first underwater location; and A second trunk cable extending from the second EBU into the international waters, wherein: Signal traffic is transmitted to the land station, and When one of the first landing cable and the second landing cable is disabled, the corresponding first EBU or second EBU is operated to reroute signal traffic via the restoration path cable to the corresponding second EBU or first EBU and the corresponding second landing cable or first landing cable; The power supply equipment in the BMH routes power along one or more routes defined by at least one combination of the first EBU and second EBU, the first landing cable and second landing cable, the first trunk cable and second trunk cable, and the restoration path cable based on the determination of at least one of: a fault in the restoration path cable, one or more interruptions of at least one of the first landing cable and second landing cable, and one or more interruptions of at least one of the first trunk cable and second trunk cable, Wherein, the BMH, the first EBU, and the second EBU are interconnected by the first landing cable, the second landing cable, and the restoration path cable defining a ring topology configured to accommodate one or more additional EBUs for connecting additional trunk cables.

2. The undersea optical cable architecture according to claim 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 restoration path cable.

3. The undersea cable architecture according to claim 1, wherein the second EBU includes one or more optical switches for selectively routing traffic on the second trunk cable to the second landing cable or the restoration path cable.

4. The undersea cable architecture according to claim 1, wherein each of the first landing cable, the second landing cable, and the restoration path cable includes a first set of eight pairs of bidirectional optical fibers and a second set of eight pairs of bidirectional optical fibers, and wherein the ring topology includes a total of sixteen pairs of bidirectional optical fibers.

5. The undersea cable architecture according to claim 1, wherein one or more additional EBUs are spliced into the ring topology without interrupting traffic.

6. An undersea cable architecture, comprising: a first beach manhole (BMH) installed at a first land location, the first BMH including a first power supply device; a second BMH installed at the first land location, the second BMH including a second power supply device, at least one of the first BMH and the second BMH being communicatively coupled to one or more land stations including one or more telemetry transceivers via one or more land cables; a first landing cable extending from the first BMH into the territorial sea adjacent to the land location and connected to a first enhanced branch unit (EBU) located in the territorial sea, the one or more telemetry transceivers controlling the first EBU via the first landing cable; a second landing cable extending from the second BMH into the territorial sea adjacent to the land location and connected to a second EBU located in the territorial sea, the one or more telemetry transceivers controlling the second EBU via the second landing cable; a restoration path cable connecting the first EBU to the second EBU, the first landing cable and the second landing cable being disposed in an underwater location; a first trunk cable extending from the first EBU into the international waters, the first trunk cable being separated from and extending away from the underwater location; and a second trunk cable extending from the second EBU into the international waters, wherein: traffic is transmitted to the one or more land stations, and When one of the first landing cable and the second landing cable is disabled, the corresponding first EBU or second EBU is operated to reroute traffic signals via the recovery path cable to the corresponding second EBU or first EBU and the corresponding second landing cable or first landing cable; at least one of the first power supply device and the second power supply device in the corresponding first BMH and second BMH routes power along one or more routes defined by at least one combination of the first EBU and second EBU, the first landing cable and second landing cable, the first trunk cable and second trunk cable, and the recovery path cable based on a determination of at least one of: a fault in the recovery path cable, one or more interruptions in at least one of the first landing cable and second landing cable, and one or more interruptions in at least one of the first trunk cable and second trunk cable. Wherein, the first BMH, the second BMH, the first EBU and the second EBU are interconnected by the first landing cable, the second landing cable and the recovery path cable defining a ring topology, the ring topology being configured to accommodate one or more additional EBUs for connecting additional trunk cables.

7. The undersea optical cable architecture according to claim 6, wherein the first EBU includes one or more optical switches for selectively routing input traffic signals on the first trunk cable to the first landing cable or the recovery path cable.

8. The undersea optical cable architecture according to claim 6, wherein the second EBU includes one or more optical switches for selectively routing input traffic signals on the second trunk cable to the second landing cable or the recovery path cable.

9. The undersea optical cable architecture according to claim 6, wherein each of the first landing cable and the second landing cable includes a first set of twelve pairs of bidirectional optical fibers and a second set of twelve pairs of bidirectional optical fibers.

10. The undersea optical cable architecture according to claim 6, wherein the first EBU and the second EBU are controlled by one or more telemetry transceivers in a land station associated with one or more BMHs located at the distal ends of the first trunk cable and the second trunk cable.

11. The undersea optical cable architecture according to claim 6, wherein one or more additional EBUs are spliced into the ring topology without interrupting traffic signals.

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