Submarine power routing device and submarine cable branching architecture

Abstract

To provide a submarine power routing device and a submarine cable branching architecture for a submarine mesh network in an optical communication system.SOLUTION: In an optical switching and electricity supply architecture for a submarine mesh network, a power termination unit (PTU) 720 includes a first coupling port 725, a high voltage converter 724, and a second coupling port 726. The first coupling port 725 is coupled to a power conductor and a fiber optic cable of a submarine branch cable 730. The high voltage converter 724 is coupled to the first coupling port 725 and is connected to the power conductor via the first coupling port 725. The high voltage converter 724 converts high voltage power supplied from the power conductor into an output voltage having a lower voltage than the high voltage power.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] Examples of the present invention relate to the field of optical communication systems, and more particularly to an improved optical switching and electrical distribution architecture for undersea mesh networks in optical communication systems. [Background technology]

[0002] A long-distance optical communication system (e.g., an underwater optical communication system) may comprise many optical cables interconnected to facilitate communication transmission of data and information. The optical cables may be trunk optical cables and may include bidirectional trunk optical fiber pairs that enable two-way communication.

[0003] In submarine optical communication systems, interconnecting cables via branching units can be used to connect a first trunk optical cable to a second trunk optical cable. To function, the interconnecting cables must be powered. If the network is powered only between the power feed equipment (PFE) in the station and the subsea ground, a branch fault in any segment may prevent power from being supplied to all segments of the network. Summary of the Invention [Means for solving the problem]

[0004] A submarine power routing device is disclosed, comprising a first coupling port, a high-voltage converter, and a second coupling port. The first coupling port may be configured to be coupled to a power conductor of a submarine branch cable and an optical fiber cable. The high-voltage converter is coupled to the first coupling port and is operable to be connected to the power conductor via the first coupling port. The high-voltage converter is further operable to convert high-voltage power supplied from the power conductor to an output voltage having a lower voltage than the high-voltage power. The second coupling port may be configured to couple the high-voltage converter to an interconnection cable. When coupled to the interconnection cable, the high-voltage converter is operable to allocate the lower voltage power to the interconnection cable.

[0005] A submarine cable branching architecture is provided, comprising a switching branching unit, a branch cable, and a power terminal unit. The switching branching unit may be coupled to at least one trunk submarine optical fiber cable. The branch cable may be coupled to the switching branching unit. The branch cable may comprise at least two optical fiber pairs and at least one power conductor. The switching branching unit is operable to switch high-voltage power supplied from the at least one trunk submarine optical fiber cable to the at least one branch optical fiber cable. The power terminal unit may comprise a first port coupled to the at least one power conductor of the branch cable and a second port. The power terminal unit is operable to obtain high-voltage power from the at least one power conductor of the branch cable. The power terminal unit can convert the high-voltage power from the switching branching unit into power having a voltage lower than the high-voltage power and supply the power having the lower voltage to the second port. [Brief explanation of the drawings]

[0006] [Figure 1] 1 illustrates an exemplary optical communication system. [Figure 2] 1 illustrates an exemplary undersea mesh network. [Figure 3] Example 1 of a failure and switchover configuration is shown. [Figure 4] Example 2 of the failure and switchover configuration is shown. [Figure 5] Example 3 of a failure and switchover configuration is shown. [Figure 6] 1 illustrates an exemplary comparison between the functionality of a trunk selector based on a single optical fiber pair and an any-to-any selector based on two optical fiber pairs. [Figure 7] 1 illustrates an example configuration of an interconnection environment including details of an example switching branching unit and an example power terminal unit. [Figure 8] 1 illustrates an exemplary configuration for providing power to an exemplary downstream device or system of a power terminal unit disclosed herein. DETAILED DESCRIPTION OF THE INVENTION

[0007] The disclosed subject matter of the present invention relates to at least one improved optical switching and electrical distribution architecture for a submarine mesh network used in optical communication systems. By way of example, submarine optical switching and power conversion (e.g., via one or more DC / DC converters) techniques provide flexible optical fiber pair allocation and power between two interconnected submarine systems. The disclosed subject matter provides independent power outage protection for any trunk optical cable and branch fault protection for interconnecting cables. Additionally, the disclosed switching branching unit provides any-to-any optical switching for two optical fiber pairs, thereby providing additional pair connection options.

[0008] In an example, the trunk cables and interconnecting cables may comprise optical fibers and power conductors. As described below, switching branching units (sBUs) may be configured to connect corresponding trunk optical cables to interconnecting cables, and each sBU may be configured to route power from one trunk optical cable to the interconnecting cables. Furthermore, power termination units (PTUs) may be configured to convert the high-voltage, low-current power supply from the sBUs to a lower-voltage, higher-current supply suitable for powering submarine repeaters and other devices powered via the interconnecting cables. Thus, in an example, the PTU may provide DC / DC conversion functionality.

[0009] In an example, each end of an interconnection cable can be connected to a corresponding PTU. The two PTUs together provide flexible power allocation to the interconnection cable, e.g., adjust their respective voltage outputs to compensate for branch faults that may occur anywhere along the trunk optical cable. In another example, each sBU may include optical switching functionality to determine connectivity between optical fiber pairs in the trunk and the interconnection cable (e.g., which may be referred to as two optical fiber pair "any-to-any" (A2A) or two optical fiber pair any-to-any (2 FP A2A) connectivity).

[0010] By way of example, at least four different submarine mesh network configuration states are described for the system architecture as follows, where the configuration states are implemented by changing the state of at least four 2FP A2A sBU functions. It is understood that many more different configuration combinations or variations are supported herein. Also, although only two optical fiber pairs are shown and described, the number of available optical fiber pairs in the trunk optical cable can be divided into two sets to achieve the described functionality.

[0011] In a further example, a submarine interconnection cable between an sBU and a PTU may include a dual-conductor cable to carry power from a first branching unit (e.g., sBU) to the PTU, then back to a second branching unit and continue on the trunk optical cable. Furthermore, an interconnection branch may connect to a PTU at only one end and be grounded at the other end. In other cases, an interconnection branch without a power feed may not require a PTU but can still benefit from flexible optical switching. The interconnection cable may be provided in a simple "H" architecture, as shown in one or more of the illustrated examples. More complex "branch-of-branch" configurations may also be supported. In an example, the power feed feature is optional in an interconnection cable without repeaters.

[0012] The present invention is described with an example of two (2) optical fiber pair selector groups. Additionally, an example switching function is provided to illustrate linking two or more optical fiber pairs into configuration groups. For example, an interconnecting cable can be organized into groups having two optical fiber pairs (2FP), and each set of 2FPs can be connected to each end of the interconnecting cable with an example 2FP A2A selector function, allowing the interconnecting optical fiber pairs to be connected to an east trunk or a west trunk, or allowing the trunk to bypass the interconnecting cable entirely. It will further be appreciated that the features of the present invention and related examples can be supported by a single optical fiber pair trunk selector, as described below.

[0013] An additional optical fiber pair can be provided between the station and the sBU, thereby providing a restoration path in one trunk to an interrupted "ocean" FP without interrupting the optical fiber pair in the other trunk.

[0014] Thus, interconnection power feeds can be maintained during branch failures in the trunk, and branch fault protection can be provided in the interconnection cable regardless of the branch fault condition of the trunk optical cable. Also, system design or other architectural considerations can provide for reconfigurable routing of trunk optical fiber pairs through the interconnection cable in response to the occurrence of branch faults.

[0015] The examples, features, figures, etc. shown and described herein provide many advantages over conventional techniques. For example, the disclosed examples provide at least the advantages of (i) supporting single-ended feed operation and / or (ii) freely connecting interconnecting optical fiber pairs to either trunk traffic direction based on submarine optical switching, providing novel power feeding and switching capabilities in a new network architecture. Furthermore, many interconnecting cables can be powered independently of any trunk optical cable using PTUs. Configuring branch fault protection for the interconnecting cables is also advantageously provided. The use of 2FP A2A (and trunk selector based on a single optical fiber pair) optical switching functionality in a mesh network architecture or configuration is not only novel (providing more potential optical fiber pair connection options than other solutions), but also provides a more robust interconnecting cable power feed as described herein. The disclosed examples also provide more flexible connectivity between trunks and interconnecting optical fiber pairs, and further provide additional network configurations to allocate traffic capacity and reconfigure the network to meet traffic demands during fault events, repair periods, etc.

[0016] The disclosed examples will now be described more fully with reference to the drawings. However, the disclosed examples may be embodied in many different forms and should not be construed as limited to the examples set forth herein. On the contrary, these examples are provided to make the present invention thorough and complete, and to fully convey the scope of the disclosed subject matter to those skilled in the art. In the drawings, the same numerals always represent the same elements.

[0017] Referring to the drawings, Figure 1 shows an exemplary bidirectional optical communication system 101 capable of transmitting large amounts of data over long distances using many high-bandwidth fiber optic cables. The fiber optic cables may include many optical fibers. Bidirectional data transmission can be achieved by establishing optical fiber pairs within the fiber optic cable and transmitting one or more channels (e.g., wavelength division multiplexed channels) per optical fiber pair.

[0018] As shown in the figure, optical communication system 101 may include terminals 103 and 105 connected via two unidirectional optical paths 111 and 121, which together form a bidirectional optical fiber pair. Optical path 111 may carry information in one direction (e.g., rightward) from transmitter Tx 113 in terminal 103 to receiver Rx 115 in terminal 105. Optical path 121 may carry information in the other direction (e.g., leftward) from transmitter Tx 125 in terminal 105 to receiver Rx 123 in terminal 103. With respect to terminal 103, optical path 111 is the outbound path, and optical path 121 is the inbound path to receiver Rx 123 in terminal 103. Optical path 111 may include optical fibers 117-1 through 117-n coupled to repeaters 131-1 through 131-n, and optical amplifiers 119-1 through 119-n. The optical path 121 may include optical fibers 127-1 to 127-n, which are also coupled to repeaters 131-1 to 131-n, and optical amplifiers 129-1 to 129-n. One or more of the optical amplifiers 119-1 to 119-n and 129-1 to 129-n may be an erbium-doped optical fiber amplifier (EDFA), other rare-earth doped optical fiber amplifier, Raman amplifier, semiconductor optical amplifier (SOA), etc. It will be appreciated that in some examples, the transmitter TX 113 and the receiver RX 123 may be co-housed at the terminal 103 as a transponder, and similarly, the transmitter TX 115 and the receiver RX 125 may be co-housed at the terminal 105 as a transponder.

[0019] Optical path pairs (e.g., optical paths 111, 121) can be configured into sets of amplifier pairs 119-1-119-n and 129-1-129-n within repeaters 131-1-131-n, which can connect to optical fiber pairs 117-1-117-n and 127-1-127-n, which can be included in an optical fiber cable with optical fibers supporting additional path pairs. Each repeater 131-1-131-n can include a pair of amplifiers 119-1-119-n, 129-1-129-n for each corresponding path pair, and can also include additional amplifiers for additional path pairs. Coupling paths 133-1-133-n can be coupled between one or more optical paths 111, 121 within a corresponding repeater 131-1-131-n, for example. As used herein, the term "couple" or "coupled" broadly refers to any direct or indirect connection, coupling, link or linking, or wired or wireless connection, and unless specifically specified does not necessarily imply that coupled components or elements are directly connected to each other.

[0020] Although an illustrative example of optical communication system 101 has been shown and described, variations of optical communication system 101 are within the scope of the present invention. Optical communication system 101 may include more optical path pairs, more or fewer repeaters, utilizing power provided by a power feed and distributed via wiring along corresponding optical paths 111 and 121. Alternatively, optical communication system 101 may not include any optical amplifiers, or may instead include optical pump power supplies suitable for implementing optical gain by Raman amplification in repeaters connected via optical fibers.

[0021] It will further be understood that a transmitter, a receiver, a transponder including a transmitter and a receiver, or any other suitable device for transmitting and receiving data may be included in a corresponding sBU, which may be coupled to or include a device having at least one memory and one or more processors (e.g., a CPU, an ASIC, an FGPA, any conventional processor, etc.) for executing instructions stored in the memory.

[0022] It will further be appreciated that the optical paths (i.e., 111, 121) can be powered via the power conductor(s) of an optical cable (e.g., those power conductors shown in the examples below). Furthermore, multiple optical communication systems (e.g., optical communication system 101) can be interconnected via interconnection cables and branching units.

[0023] 2 illustrates an example mesh network according to one or more examples. As shown, mesh network 200 may include at least two trunk-north bidirectional optical fiber pairs 222 and 223 of a corresponding trunk-north optical cable 210 disposed between trunk-north terminal 220 on the west side and trunk-north terminal 225 on the east side. As further shown, mesh network 200 may similarly include at least two trunk-south bidirectional optical fiber pairs 232 and 233 of a corresponding trunk-south optical cable disposed between trunk-south terminal 230 on the west side and trunk-south terminal 235 on the east side. Each of the four terminals shown may include a power feed equipment (PFE) for providing power to at least the conductor cables (shown as 275 and 277, respectively) in the optical fiber pairs. In this example, the power feed equipment (PFE) provides mains power to the corresponding trunks 220, 225, 230, and 235.

[0024] Mesh network 200 may include four separate "switched" branching units (sBUs) 202 (also referred to as sBU #1.1), 204 (also referred to as sBU #1.2), 206 (also referred to as sBU #2.1), and 208 (also referred to as sBU #2.2), two of which are located on or coupled to trunk-north cable 210, and two of which are located on or coupled to trunk-south cable 215. As shown, sBUs 202 and #2.1 interconnect the trunk north-south cables on (or closer to) the west side, and similarly, sBUs #1.2 and 208 interconnect the cables on (or closer to) the east side via interconnecting cable 243. In the example, each of sBUs 1.1, 1.2, 2.1, and 208 is configured to perform fiber optic switching to route power to a corresponding power termination unit (PTU). For example, on the north side, sBU 202 routes power to PTU 212 and sBU 1.2 routes power to PTU 214, while on the south side, sBU 2.1 routes power to PTU 216 and sBU 2.2 routes power to PTU 218. Each of the corresponding sBUs is operable to connect at least one of the at least two optical fiber pairs (e.g., 222 and 223) of trunk optical fiber cable 210 to a corresponding one of the at least two optical fiber pairs of the branch cable (coupled to a PTU, e.g., 212).

[0025] According to an example, PTUs 212, 214, 216, and 218 may be configured to provide power to interconnection cable 241 or interconnection cable 243, respectively, and further provide branch fault protection by enabling power rerouting (and optical fiber rerouting) to mitigate the effects of a branch fault. For example, PTUs 212, 214, 216, and 218 may include one or more ports for obtaining power from an sBU (e.g., 1.1 or 2.1) and a port for providing power to an interconnection cable (e.g., interconnection cable 241 or 243). The PTUs may also include a high-voltage direct current-to-direct current (DC / DC) converter (shown in a later example). For example, the DC / DC converter may be operable to provide a constant current or voltage and limit the current and voltage to thresholds set by a controller. For example, each trunk 220, 225, 230, and 235 may be equipped with a command / response unit (CRE) that can be operated by telemetry to control the optical switching of each of the corresponding sBUs #1.1, #1.2, #2.1, and #2.2 and the power switching to the corresponding PTUs 212, 214, 216, and 218. The CRE can further control the power conversion of each corresponding PTU 212, 214, 216, and 218 by control commands via fiber optic cables coupled to the corresponding PTUs or by telemetry.

[0026] 2, for example, interconnection power between sBU 202 and sBU 2.1 and between sBU 1.2 and 208 can be provided by dual conductor interconnection cables (also referred to as DCC) included in interconnection cable 241 or interconnection cable 243. For example, interconnection cable 241 may include at least power conductor 251 and at least two optical fiber pairs (2FP) 261. Similarly, interconnection cable 243 may include at least power conductor 253 and at least two optical fiber pairs (2FP) 263. As described below, each dual optical fiber pair, any-to-any (also referred to herein as “2FP A2A”) selector function in sBU 202 provides flexible network configurations such as flexible optical switching and electrical distribution, and response (e.g., rerouting in response to conditions in the subsea environment (e.g., branch faults, etc.)).

[0027] For at least this reason, the mesh network 200 shown in FIG. 2 is considered an "all trunk" configuration, meaning that, for both the north trunk and the south trunk, for example, all trunk optical fiber pairs are connected between their respective trunk terminals, powered, and operational.

[0028] FIG. 3 illustrates an example of a branch failure and switchover configuration 300 in accordance with one or more aspects of the disclosed subject matter. For ease of interpretation, the mesh network 200 of FIG. 2 and components therein are used to describe the branch failure and switchover configuration 300 of FIG. 3. The configuration 300 can be implemented as a mesh network. As shown, a branch failure 306 may occur near the east side of the trunk-north optical fiber pair (i.e., between sBU #1.2.1 and trunk-north terminal 225). It can be understood that a branch failure can broadly refer to any type of fault (physical or otherwise) occurring in an underwater communications cable, such as when the cable's insulation is broken such that there is a short circuit from the metallic conductor core directly to seawater. Alternatively, in some examples, the cable break may have been caused by a ship's anchor, a fishing trawler, a backhoe, a current dragging the cable along the ocean floor, or the like. For example, a branch fault may be detected by, for example, determining that there has already been a loss of power or that the voltage or current has dropped by a predetermined amount in the corresponding main 210 or 215, such as by a power feeder.

[0029] For example, when a branch fault occurs, power can be cut off to at least the interconnection members between the North-South trunk optical fiber pairs (e.g., the interconnection cable between sBUs 1.1.1 and 2.1.1 and / or sBUs 1.2.1 and 2.2.1). Thus, in an example, when a branch fault is detected (or based on any determination that a branch fault will occur, or for any other reason), optical switching can be performed for one or more of sBUs 1.1.1 through 2.2.1 based on the location of the branch fault to reroute at least power. As shown in the figure, by reconfiguring the port connections of sBUs 1.2.1 and 2.2.1, both trunk-north optical fiber pairs 222 and 223 can be rerouted or switched to trunk-south optical fiber pairs 233 and 232, respectively. Advantageously, when a branch fault occurs, power can still be provided to the interconnection cable 243 between trunk-north 220 and trunk-south 235.

[0030] Figure 4 illustrates an example branch failure and switchover configuration 400 according to one or more examples. For ease of interpretation, the mesh network 200 of Figure 2 and components therein are used to explain the branch failure and switchover configuration 400 of Figure 4. The configuration 400 can be implemented as a mesh network. In the illustrated example, a branch failure 406 may occur near the "western core" or middle of the trunk-north optical fiber pair 222 and 223.

[0031] 3, when a branch fault occurs (e.g., between sBU #1.1.2 and sBU #1.2.2, as shown in FIG. 4), power can be cut to the interconnection members between north trunk optical fiber pair 222 and 223 and south trunk optical fiber pair 232 and 233 (e.g., interconnection cable 241 between sBU #1.1.2 and #2.1.2, and / or interconnection cable 243 between sBU 204 and #2.2). Upon detecting a branch fault (or based on any determination that a fault may potentially occur) due to a loss of power or a predetermined amount of voltage or current drop in the corresponding trunk 210 or 215, the corresponding one or more sBUs in the optical path of the branch fault or potential branch fault can perform optical switching to at least reroute power. In the example, reconfiguring the port connections of sBUs #1.1.2 and #2.1.2 may reroute or switch two of the trunk-north optical fiber pairs (222, 223) to trunk-south optical fiber pair 232, 233. Similarly, in the mirroring example, the port connections of sBUs #1.2.2 and #2.2.2 may be reconfigured to reroute or switch trunk-north optical fiber pair 222 and 223 to trunk-south optical fiber pair 232 and 233 to provide and maintain power to interconnect member 243 between trunk-north cable 210 and trunk-south cable 215.

[0032] FIG. 5 illustrates an example branch failure and switchover configuration 500 according to one or more examples. The configuration 500 can be implemented as a mesh network. For ease of interpretation, the mesh network 200 of FIG. 2 and components therein are used to further illustrate the branch failure and switchover configuration 500 of FIG. 4. In the illustrated example, similar to or similar to FIG. 4, a branch failure 5060 can occur near the middle of a western or trunk-north optical fiber pair.

[0033] In the alternative to FIG. 4 , as shown in FIG. 5 , only one trunk-north optical fiber pair 223 is rerouted or switched in response to the detection of a branch failure to trunk-south 230, while one optical fiber pair 232 of east trunk-south 235 maintains service with west trunk-north 220 via sBUs #1.1.3 and #2.1.3. At least at this point, there may be only one new optical fiber pair connection between trunk-north and trunk-south on the west side of mesh network 500. Advantageously, even if a branch failure occurs, the alternative configuration of FIG. 5 can still provide power to at least interconnect members 241 and 243 between trunk-north and trunk-south. For at least this reason, the 2FP A2A selection capability of the sBU(s) provides the flexibility and configuration benefits of the power switching and power routing architecture described above.

[0034] 6 illustrates an exemplary comparison 600 between a single optical fiber pair-based trunk selector (implemented by sBU 610) and a two optical fiber pair-based any-to-any (A2A) selector (implemented by sBU 620) in a corresponding sBU, according to one or more disclosed examples. As shown in the configuration of the single optical fiber pair-based trunk selector in sBU 610 and the two optical fiber pair-based A2A selector in sBU 620, each corresponding sBU 610 or 620 has at least three different ports: a trunk port, an “A1” port, and an “A2” port, with corresponding input and output connections, and may further have add and drop connections for branch optical fiber pairs. Each of the corresponding sBUs 610 and 620 is shown as having an optical switch (AL for sBU 620 and 1-12 for sBU 610) operable to selectively switch an optical fiber pair coupled to the trunk port to the A2 port or from the A1 port to the A2 port.

[0035] In an example, for a "Type 3A sub-module A2A equivalent" configuration of sBU 620, two optical fiber pairs are selected and dropped to a branch optical fiber pair, as shown in the corresponding schematic diagram. For example, FP1 and FP2 can be dropped to branch FP1, and FP1 and FP2 can be dropped to branch FP2. Such an A2A function based on two optical fiber pairs can be implemented in sBUs 1.1.3, 1.2.3, 2.1.3, and 2.2.3 of mesh network 200 of FIG. 2 described above. In an alternative example, a "Type 3A sub-module trunk selector equivalent" or a trunk selector based on a single optical fiber pair (e.g., 620) can be implemented in sBUs 1.1.3, 1.2.3, 2.1.3, and 2.2.3.

[0036] According to an example, a trunk selector based on a single optical fiber pair can have different labels for the optical fiber paths to form two independent trunk optical fiber pair selectors. In an example, a trunk optical fiber pair on the east side or the west side can be selected and dropped to a branch optical fiber pair based on each optical fiber pair, for example, between optical switch E and optical switch I. For example, one connection on one optical fiber pair may be used at a time. Furthermore, it can be understood that one or more functions or features described above in at least any of Figures 2-5 can be realized by a trunk optical fiber pair selector based on a single optical fiber pair. Furthermore, to provide at least extra connections without additional cost, it can be understood that a single optical fiber pair trunk selector may be used only in the case of an odd number of optical fiber pairs, so as to provide a connection point where all two optical fiber pairs can be connected to an A2A switch.

[0037] FIG. 7 illustrates an example configuration of an interconnection environment, including details of an example switching branching unit and an example power terminal unit.

[0038] A submarine cable branching architecture 700 including an sBU 710 and a PTU 720 can be provided and configured to withstand the physical conditions present in a deep undersea environment. The sBU 710 may be coupled to a trunk fiber optic cable 740 comprising optical fiber and power conductors (e.g., as shown in the examples of FIGS. 2-5 ) from a location (not shown) comprising a power feed equipment (PFE). The sBU 710 may be further coupled to a trunk cable 750 comprising optical fiber cable and power conductors connectable to another location and / or another sBU (neither of which are shown). In an example, a branching cable 730 may couple the sBU 710 to the PTU 720. The PTU 720 is further coupled to an interconnection cable 760.

[0039] sBU 710 provides optical switching and power switching functions. For example, sBU 710 may be configured with an optical switch and control circuit system that enables sBU 710 to establish connectivity between optical fiber pairs (not shown in this example) in trunk fiber optic cable 740 and trunk cable 750 that are coupled to corresponding ports of sBU 710 and interconnect cable 760 that is coupled to PTU 720. For example, sBU 710 is operable to connect at least one of at least two optical fiber pairs (not shown in this example) in trunk fiber optic cable 740 to a corresponding one of at least two optical fiber pairs (not shown in this example) in branch cable 730.

[0040] The branch cable 730 may be a dual conductor cable (DCC) operable to provide power between the sBU 710 and the PTU 720. The interconnect cable 740 may connect the PTU 720 to various devices or payloads, as shown in other examples.

[0041] The PTU 720 may include a high-voltage (Hi-V) converter 724. The high-voltage converter 724 enables the PTU 720 to provide controllable power from the trunk PFE to the branch payloads. The high-voltage converter 724 is operable to convert DC voltages as high as 15 kV to other voltages, such as 12.5 kV or less. The PTU 720 may have a circuit system configured to implement conventional techniques for power conversion and control (but in a subsea environment). The high-voltage converter 724 may also be operable to provide a constant current or voltage, limit the amount of current, and limit the magnitude of the voltage provided. For example, the high-voltage converter 724 may output an output current having a substantially constant value and limited based on end-user specifications. The PTU 720 may also pass optical fibers through the optical fibers for coupling to other devices and / or trunks, such as those devices and / or trunks shown in the examples of Figures 2-5. The PTU 720 may be controlled telemetrically at the mains location or at another location (e.g., a remote point-of-presence (POP), offshore facility, etc.) via a command / response device (CRE). The CRE may include a processor, a memory that stores programming code, and a telemetry circuit system operable to communicate with one or more PTUs (e.g., PTU 720).

[0042] As shown in FIG. 7 , the PTU 720 may include a first coupling port 725, a high-voltage converter 724, and a second coupling port 726. The PTU 720 may further include a suitable modem for communication transmission. The first coupling port 725 may be configured to couple to a power conductor and an optical fiber cable of a submarine branch cable (e.g., 730). In some examples, the submarine branch cable 730 may be a dual-conductor cable connected to an undersea switching branch unit (e.g., 202 in FIG. 2 ), and the first coupling port 725 is operable to couple to the dual-conductor cable. The high-voltage converter 724 is coupled to the first coupling port 725 and is operable to connect to the power conductor of the submarine branch cable 730 via the first coupling port 725. The high-voltage converter 724 may be operable, for example, to convert high-voltage power supplied from the power conductor into an output voltage having a lower voltage than the high-voltage power. The high-voltage converter 724 may be operable to output a voltage having a substantially constant value as an output voltage.

[0043] The second coupling port 726 is operable to couple the high voltage converter 724 to an interconnection cable (e.g., 760). When coupled to the interconnection cable 760, the high voltage converter 724 is operable to allocate lower voltage power to the interconnection cable 760.

[0044] Although not shown, the PTU 720 may include a processor, a telemetry circuit system, and a memory capable of storing programming code. The processor is operable to execute the stored programming code to process communication signals received from the PFE or CRE and manage the output of the high-voltage converter 724. The high-voltage converter 724 is operable to receive control signals from a remotely located power supply via a submarine branch cable 730, e.g., a trunk fiber optic cable 740. The control signals may include an indication of a branch fault and include instructions for configuring the sBU, the PTU, and their respective components. The high-voltage converter 724 is also operable to adjust its output voltage in response to a command signal indicating a branch fault, e.g., received from a CRE.

[0045] Preferably, a modem 727 may be configured to be coupled to the first coupling port and the second coupling port. The modem 727 is operable to receive communication signals via the first coupling port 725 and process the communication signals. The processing of the communication signals may be performed based on conventional communication processing techniques and protocols. The modem 727 is further operable to provide the processed communication signals to the second coupling port 726 for output to a downstream device such as a sensor. The modem 727 is also operable to receive other communication signals from downstream devices and provide them to upstream or control devices such as a CRE.

[0046] The DCC may convert or transfer the 12.5 kV to 15 kV voltage transmission to provide power to other devices downstream of PTU 720 (i.e., other devices connected to interconnection member 760), such as repeaters, amplifiers, payload devices and systems, etc. For example, high voltage converter 724 may further operate to provide power to power one or more payloads (e.g., downstream devices), which may be at least one of repeaters, amplifiers, offshore facilities, or sensors.

[0047] The interconnection cable 740 of the second port 726 coupled to the PTU 720 may be a DDC or a single conductor cable (SCC).

[0048] Preferably, PTU 720 may include a modem 727 that may provide data transmission for payload devices coupled to interconnection cable 740, which may include sensors, offshore platforms, etc.

[0049] The interconnection environment 700 can provide power switching in response to a branch fault, since it can power devices on either side of the branch fault or potential branch fault. The interconnection environment 700 can also provide fiber optic switching, as shown in the examples of Figures 2-5.

[0050] FIG. 8 illustrates an exemplary configuration for providing power to an exemplary downstream device or system of a power terminal unit disclosed herein.

[0051] Configuration 800 includes multiple examples of an interconnection environment from sBUs 812, 822, 832, and 842. In this example, each of sBUs 812, 822, 832, and 842 is coupled to trunk cable 810. Trunk cable 810 may be coupled to a power feed equipment (PFE), which provides power to the conductor(s) within trunk cable 810. Trunk cable 810 also includes a fiber optic cable having many optical fiber pairs (FP).

[0052] Each of sBUs 812, 822, 832 and 842 shows an exemplary embodiment of a respective PTU 814, 824, 834 and 844.

[0053] The exemplary embodiment includes sBU 812 coupled to PTU 814 via cable 813. This embodiment is operable to provide remote communications to an island, a high-value shoreline, or an unmanned facility via sBU 812 and PTU 814. Cable 813 may be DCC. PTU 814 (similarly configured and operable to perform functions similar to those described above for PTU 720 of FIG. 7 ) is also coupled to interconnection cable 815. Each device 817-1, 817-2, 817-3, ..., 817-N (e.g., repeaters, payload devices, etc.) is also coupled to interconnection cable 815, and each device also requires power. Cable 813 can provide power via conductors or communications via optical fiber. PTU 814 is operable to provide power and communications to interconnection cable 815. Interconnection cable 815, including power via conductors and communications via optical fiber, may be connected to beach landing 816. An exemplary embodiment comprising PTU 814 provides communication services to a remote point-of-presence (POP) 818 by providing communication services over optical cables and electrical power.

[0054] In another exemplary embodiment, sBU 822 is coupled to PTU 824 via cable 823. Cable 823 may be DCC. Such an embodiment, similar to the examples of FIGS. 2-5, is operable to provide a cross-connection to a trunk cable via sBU 822 and PTU 824. PTU 824 is similarly configured and operable to perform functions similar to those of PTU 720 of FIG. 7. PTU 824 may be coupled to an interconnection cable 825. Each device 827-1, 827-2, ..., 827-N (e.g., repeaters, payload devices, etc.) is also coupled to the interconnection cable 825, and each device may also require power. Cable 823 can provide power via conductors or communications via optical fibers. PTU 824 is operable to provide power and communications to the interconnection cable 825. The interconnection cable 825, which includes power via conductors and communications via optical fibers, may be connected to another PTU 826. PTU 826 may be configured similarly to PTU 824 to provide power conversion or grounding. In further embodiments, PTU 826 may be optional and may not be present, similar to beach landing embodiments using sBU 812 and PTU 814. In examples, interconnect cable 825 may be connected to PTU 826. A branch cable (not shown) may be coupled to another sBU 828 that is coupled to PTU 826 and connected to trunk cable 820.

[0055] In a further exemplary embodiment, sBU 832 is coupled to PTU 834 via cable 833. Cable 833 may be DCC. This embodiment is operable to provide telecommunications to an offshore facility (e.g., offshore platform 836) via sBU 832 and PTU 834. PTU 834 is similarly configured and operable to perform functions like those of PTU 720 of FIG. 7. PTU 834 may be coupled to interconnection cable 835. Interconnection cable 835 may be connected to offshore platform 836. PTU 834 is operable to provide the above-mentioned power and data communications to equipment on offshore platform 836 via, for example, a suitable modem (e.g., 727 of exemplary PTU 720 of FIG. 7).

[0056] In another exemplary embodiment, sBU 842 is coupled to PTU 844 via cable 843. Cable 843 may be DCC. This embodiment is operable to provide communications and power to subsea sensor applications (e.g., sensor 848) via sBU 842 and PTU 844. PTU 844 is similarly configured and operable to perform functions such as those of PTU 720 of FIG. 7 and data communications via a preferred modem 727. PTU 844 may be coupled to interconnection cable 845, which may be connected to a deployment pallet (DP) 847. DP 847 may be coupled to multiple sensors, such as sensor 848, which may be configured to detect temperature, salinity, seismic activity, obtain acoustic measurements, etc.

[0057] It will be appreciated that the submarine mesh network of the optical communication system and associated optical switching and powering architecture may be deployed in a variety of different configurations and is not limited to any particular configuration or any other scheme.

[0058] The present invention discloses new and unique techniques for use in improved optical switching and powering architectures in undersea mesh networks. The present invention is not limited in scope by the specific embodiments described herein. Indeed, various other embodiments and modifications of the present invention, in addition to those described herein, will be apparent to those skilled in the art from the above description and drawings.

[0059] Accordingly, all such other embodiments and modifications are intended to be included within the scope of the present invention. Moreover, while this specification has described the present disclosure in the context of particular embodiments in particular environments and for particular purposes, those skilled in the art will recognize that its utility is not limited thereto, and that the present invention may be beneficially implemented in any number of environments and for any number of purposes. Accordingly, the claims set forth below should be construed in accordance with the full breadth and spirit of the invention as described herein.

Claims

1. A first submarine switching branching unit and a second submarine switching branching unit coupled to a first trunk submarine optical fiber cable; a third submarine switching branching unit and a fourth submarine switching branching unit coupled to the second trunk submarine optical fiber cable; a first power terminal unit coupled between the first submarine switching branch unit and the third submarine switching branch unit by a first submarine branch cable; a second power terminal unit coupled between the second submarine switching branch unit and the fourth submarine switching branch unit by a second submarine branch cable; Equipped with Each of the first power terminal unit and the second power terminal unit comprises: a first coupling port adapted to couple to the power conductor and the fiber optic cable; a high-voltage converter coupled to the first coupling port, operable to be connected to the power conductor via the first coupling port, and operable to convert high-voltage power supplied from the power conductor into an output voltage having a lower voltage than the high-voltage power; a second coupling port configured to couple the high voltage converter to an interconnect cable; Equipped with the high voltage converter, when coupled to the interconnection cable, is operable to allocate the lower voltage power to the interconnection cable; Subsea power routing device assembly.

2. Each of the first power terminal unit and the second power terminal unit is a modem coupled to the first coupling port and the second coupling port, and configured to be operable to receive a communication signal via the first coupling port, process the communication signal, and output a processed communication signal via the second coupling port. Further comprising:

10. A subsea power routing device assembly as defined in claim 1.

3. the second coupling port is operable to be coupled to the interconnect cable; The interconnect cable is a dual conductor cable or a single conductor cable. A subsea power routing device assembly as claimed in claim 1 or 2.

4. The high voltage converter is further operable to provide power to power one or more payloads, the one or more payloads including at least one of a repeater, an amplifier, an offshore facility, or a sensor.

4. A subsea power routing device assembly as defined in claim 3.

5. The high-voltage converter further comprises: and operable to adjust the output voltage in response to a command signal indicating a branch fault. A subsea power routing device assembly according to any preceding claim.

6. The high-voltage converter further comprises: and operable to receive control signals from a remotely located power supply device via an undersea branch cable. A subsea power routing device assembly according to any preceding claim.

7. The high voltage converter is further operable to output as the output voltage a voltage having a substantially constant value. A subsea power routing device assembly according to any preceding claim.

8. The high voltage converter further operable to output a limited output current based on an end user specification having a substantially constant value. A subsea power routing device assembly according to any preceding claim.

9. A first switching branching unit and a second switching branching unit coupled to a first trunk submarine optical fiber cable; a third switching branching unit and a fourth switching branching unit coupled to the second trunk submarine optical fiber cable; a first branch cable coupled to the first branch unit and the third branch unit, the first branch cable including at least two optical fiber pairs and at least one power conductor; a second branch cable coupled to the second branch unit and the fourth branch unit, the second branch cable comprising at least two optical fiber pairs and at least one power conductor; a first power terminal unit coupled to the first branch cable between the first switching branch unit and the third switching branch unit, the first power terminal unit having a first port coupled to at least one power conductor of the first branch cable and a second port; a second power terminal unit coupled to the second branch cable between the second switching branch unit and the fourth switching branch unit, the second power terminal unit having a first port coupled to at least one power conductor of the second branch cable and a second port; Equipped with The first switching and branching unit is operable to switch high voltage power supplied from the first trunk submarine optical fiber cable to the first branching cable; the second switching / branching unit is operable to switch high voltage power supplied from the second trunk submarine optical fiber cable to the second branch cable; Each of the first power terminal unit and the second power terminal unit comprises: a first power conductor of said first and second branch cables, each of said first and second branch cables being operable to receive said high voltage power from said at least one power conductor of said first and second branch cables, convert said high voltage power from said respective first and second branch units to power having a lower voltage than said high voltage power, and supply said power having the lower voltage to said second port. Submarine cable branching architecture.

10. the first switching and branching unit is further operable to connect at least one optical fiber pair of the at least two optical fiber pairs of the first trunk submarine optical fiber cable to a corresponding one optical fiber pair of the at least two optical fiber pairs of the first branching cable.

10. The submarine cable branching architecture of claim 9.

11. the first power terminal unit is operable to convert a low current of the high voltage power to a higher current while converting the high voltage power from the first switching branch unit; A submarine cable branching architecture according to claim 9 or 10.

12. The first power terminal unit is further operable to adjust a voltage output to compensate for a branch fault in the first trunk submarine optical fiber cable. A submarine cable branching architecture according to any one of claims 9 to 11.

13. The first power terminal unit further comprises: Operable to receive a control signal from a power supply device located at a remote location via the first branch cable. A submarine cable branching architecture according to any one of claims 9 to 12.

14. The first power terminal unit further comprises: Operable to output as an output voltage a voltage having a substantially constant value; A submarine cable branching architecture according to any one of claims 9 to 13.

15. The first power terminal unit further comprises: and operable to output a limited output current based on an end user specification having a substantially constant value. A submarine cable branching architecture according to any one of claims 9 to 13.

16. an interconnection cable connected to the second ports of the first and second power terminal units; 16. A submarine cable branching architecture according to any one of claims 9 to 15.

17. one or more payload devices coupled to the interconnect cable; the interconnect cable allocates high current, low voltage power from the second port; and at least one payload device of the one or more payload devices is operable to use high current, low voltage power; 20. The submarine cable branching architecture of claim 16.

18. The one or more payload devices comprising a repeater, an amplifier, or a sensor.

20. The submarine cable branching architecture of claim 17.

19. The first switching branch unit comprises: providing optical switching functionality and power switching functionality and operable to establish connectivity between optical fiber pairs in said first trunk submarine optical fiber cable and an interconnection cable coupled to said first power terminal unit; 19. A submarine cable branching architecture according to any one of claims 9 to 18.

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