Fiber optic crossover cable

A fiber optic crossover cable includes a first cable portion, a second cable portion, a crossover distribution unit, and fiber optic subunits. The first cable portion includes an M number of first cable units. Each of the M number of first cable units includes an N number of the fiber optic subunits. The second cable portion includes an N number of second cable units. Each of the N number of second cable units includes an M number of the fiber optic subunits. The M number of first cable units and the N number of second cable units are arranged in the crossover distribution unit. The N number of fiber optic subunits respectively extend to the N number of second cable units. The M number of fiber optic subunits respectively extend to the M number of first cable units.

FIELD

The subject matter herein generally relates to fiber optics, and more particularly to a fiber optic crossover cable for coupling a plurality of fiber optic subunits of a plurality of switches.

BACKGROUND

In telecommunications networks, signals are often transmitted from an input switch to multiple output switches, such as in data centers. Currently, switching cabinets are generally used to enable mutual communication among data center switches. However, an adapter cabinet of the related art includes two fiber optic connection backplanes, each of which is provided with a fiber connector, so that two switches can be connected through two fiber connectors. An improved adapter cabinet includes a fiber optic connection backplane with fiber optic connectors on the fiber optic backplane such that the two switches can be connected by one fiber optic connector. However, the above described adapter cabinets may experience large connection loss and require many components, which increases cost.

DETAILED DESCRIPTION

FIG. 1shows a first embodiment of a fiber optic crossover cable100for communication among a plurality of switches200. In one embodiment, the fiber optic crossover cable100can establish communication between a first switch group and the second switch group. The first switch group and the second switch group respectively include a plurality of switches200, each of which includes one or more ports210.

The fiber optic crossover cable100includes a first cable portion10, a second cable portion20, and a crossover distribution unit30disposed between the first cable portion10and the second cable portion20. The first cable portion10and the second cable portion20are respectively arranged at opposite sides of the fiber optic crossover cable100.

The fiber optic crossover cable100further includes a plurality of fiber optic subunits40that extend in the first cable portion10, the crossover distribution unit30, and the second cable portion20. Each fiber optic subunit40includes at least one optical fiber.

Two ends of each fiber optic subunit40extend in the first cable portion10and the second cable portion20, respectively. Each fiber optic subunit40includes two opposite end portions401. Each end portion401is coupled to a corresponding port210of one of the switches200by a joint connector. A joint connector type may be MPO, MT, LC, or other joint connector type known in the art, but is not limited thereto. A number of the fiber optic subunits40is M*N. In one embodiment, both M and N are integers greater than or equal to 1, and M and N may be equal or unequal.

The first cable portion10includes an M number of first cable units11, and each of the first cable units11bundles together an N number of fiber optic subunits40. Each of the first cable units11is configured to couple to the ports210of one corresponding switch200. Therefore, the first cable portion10is coupled to an M number of switches200.

The second cable portion20includes an N number of second cable units21, and each of the second cable units21bundles together an M number of fiber optic subunits40. Each of the second cable units21is configured to couple to the ports210of one corresponding switch200. Therefore, the second cable portion20is coupled to an N number of switches200.

It can be understood that the first cable portion10, the second cable portion20, the first cable units11, the second cable units21, and the fiber optic subunits40can each be bound by a corresponding jacket (not shown).

The first cable portion10and the second cable portion20extend to the crossover distribution unit30, and a plurality of fiber optic subunits40extend from the first cable portion10and the second cable portion20. The plurality of fiber optic subunits40are arranged in the crossover distribution unit30such that the N number of fiber optic subunits40of each of the first cable units11respectively extend into the N number of second cable units21, and the M number of fiber optic subunits40of each of the second cable units21respectively extend into the M number of first cable units11. In other words, the plurality of fiber optic subunits40of the first cable units11in the first cable portion10are bundled into the plurality of second cable units21of the second cable portion20through the crossover distribution unit30, and the plurality of fiber optic subunits40of the second cable units21in the second cable portion20are bundled into the plurality of first cable units11of the first cable portion10through the crossover distribution unit30.

In at least one embodiment, referring toFIG. 2, each of the first cable units11includes an outer cover101made of flame resistant polyethylene (PE) and surrounding a central tensile body102located centrally within the outer casing101. The plurality of fiber optic subunits40are arranged surrounding the central tensile body102. A Kevlar fabric layer103is arranged within the outer casing101and surrounding the plurality of fiber optic subunits40. In one embodiment, the first cable unit11further includes a protective layer (not shown) coated on an outer side of the central tensile body102. It can be understood that in other embodiments, the protective layer may be omitted.

Each fiber optic subunit40includes a subunit jacket41and a plurality of optical fibers42housed within the subunit jacket41. The subunit jacket41can be made of a flame resistant PE material. It can be understood that in other embodiments, the first cable portion10can also be other existing cable structures.

The fiber optic subunits40in each of the first cable units11are respectively bundled in the plurality of second cable units21through the crossover distribution unit30to couple to the corresponding switches200. Likewise, the fiber optic subunits40in each of the second cable units21are respectively bundled in the plurality of first cable units11through the crossover distribution unit30to couple to the corresponding switches200.

For example, the first switch group and the second switch each have eight switches200, and each switch200has eight ports210. The fiber optic crossover cable100is coupled between the first switch group and the second switch group. The first cable portion10includes eight first cable units11, and the second cable portion20includes eight second cable units21. The number of the fiber optic subunits40is 64, and each of the first cable units11and each of the second cable units21is coupled to a corresponding switch200. The fiber optic crossover cable100can coupled the fiber optic subunits40of each switch200in the first switch group with the eight switches200in the second switch group, and simultaneously couple the fiber optic subunits40of each switch200in the second switch group with the eight switches200in the first switch group.

FIGS. 3-5show a second embodiment of a fiber optic crossover cable100. The same reference numerals are used for the same elements shown in the first embodiment.

Similar to the first embodiment, the fiber optic crossover cable100includes a first cable portion10, a second cable portion20, a crossover distribution unit30disposed between the first cable portion10and the second cable portion20, and a plurality of fiber optic subunits40. The first cable portion10includes an M number of first cable units11, and each of the first cable units11bundles together an N number of fiber optic subunits40. The second cable portion20includes an N number of second cable units21, and each of the second cable units21bundles together an M number of fiber optic subunits40. The first cable portion10and the second cable portion20extend to the crossover distribution unit30, and the plurality of fiber optic subunits40extend from the first cable portion10and the second cable portion20. The plurality of fiber optic subunits40are arranged in the crossover distribution unit30, such that the N number of fiber optic subunits40in each first cable unit11are respectively bundled into the N number of second cable units21, and the M number of fiber optic subunits40in each second cable unit21are respectively bundled into the M number of first cable units11.

The fiber optic crossover cable100further includes two cable jackets50respectively sleeved over the first cable portion10and the second cable portion20to contain the M number of first cable units11and the N number of second cable units21within a single cable.

Referring toFIG. 4, in the second embodiment, the plurality of fiber optic subunits40are arranged in the crossover distribution unit30in an M number of rows and an N number of columns. For ease of understanding, this embodiment and subsequent embodiments are merely illustrative of a portion of the fiber optic subunits40.

The crossover distribution unit30includes a housing31, two brackets32received in the housing31, and a telescopic cover33covering the housing31.

A substantially circular cavity is defined in the housing31, and two ends of an inner wall of the housing31each include a latching ridge311. The two brackets32are respectively latched with the two latching ridges311, and the two brackets32respectively support and position the first cable units11and the second cable units21.

Each of the brackets32has a disk shape and includes an annular portion321and a plurality of latching portions322arranged around an outer periphery of the annular portion321. A bottom surface of each of the latching portions322is circular arc-shaped.

In the second embodiment, the housing31includes two detachably coupled housing portions312. The crossover distribution unit30further includes two cable ties34that are respectively located at opposite ends of the housing31to couple together the two housing portions312.

The telescopic cover33protects the crossover distribution unit30. It will be understood that in other embodiments, the telescopic outer cover33may be omitted.

In at least one embodiment, each of the first cable units11and each of the second cable units21include a jacket (not shown) to contain the fiber optic subunits40therein.

In at least one embodiment, one or more of the two cable jackets50, the first cable units11, and the second cable units21may be composed of a woven mesh structure, but is not limited thereto.

In at least one embodiment, the first cable units11or the second cable units21may be replaced by the structure shown inFIG. 2.

FIGS. 6-8show a third embodiment of a fiber optic crossover cable100, and the same reference numerals are used for the same elements shown in the first and second embodiments. The portions of the third embodiment that are different from the second embodiment will be described below.

In the third embodiment, each first cable unit11includes a first jacket111and a first reinforcement sheath112. The first reinforcement sheath112is located at an end of the first jacket111. The first jacket111bundles together the plurality of fiber optic subunits40into a single cable, and the first reinforcing sheath112is configured to thicken the end of the first cable units11. Similarly, the second cable unit21includes a second jacket211and a second reinforcing sheath212. The second reinforcing sheath212is located at an end of the second jacket211. The second jacket211bundles together the plurality of fiber optic subunits40into a single cable.

Two cable jackets50are respectively sleeved over the first cable portion10and the second cable portion20. The cable jackets50are substantially hollow columnar-shaped.

The fiber optic crossover cable100further includes one or more cable strengthening members60that extends in the first cable portion10, the crossover distribution unit30, and the second cable portion20to provide strength support for the fiber optic crossover cable100and prevent damage to the optical fibers. The cable strengthening member60may be a Kevlar load-bearing cable. In one embodiment, the cable strengthening member60is located between the M number of first cable units11and the N number of second cable units21. It will be appreciated that in other embodiments, the cable strengthening member60may be omitted.

The crossover distribution unit30includes a distribution portion sheath131. The distribution portion sheath131is substantially hollow columnar-shaped, and two ends of the distribution portion sheath131are respectively sleeved over an end portion of the first cable portion10and an end portion of the second cable portion20and partially covered over the two cable jackets50. The crossover distribution unit30further includes a telescopic cover (not shown), and the telescopic cover is covered on an outer side of the distribution portion sheath131.

It will be appreciated that in other embodiments, lengths of the plurality of first cable units11or of the plurality of second cable units21extending into the crossover distribution unit30may be different.

In at least one embodiment, one or more of the two cable jackets50, the first jacket111, and the second jacket211may be composed of a woven mesh structure, but is not limited thereto.

In at least one embodiment, the first cable units11or the second cable units21may be replaced by the structures shown inFIG. 2.

Referring toFIG. 8, each of the fiber optic subunits40includes a subunit jacket41, a plurality of optical fibers42housed within the subunit jacket41, and Kevlar43. It can be understood that in other embodiments, the number of the optical fibers42may be one or more than one, and the Kevlar43may be omitted.

FIGS. 9-10show a fourth embodiment of a fiber optic crossover cable100, and the same reference numerals are used for the same elements as shown in the previous embodiments. The differences between the fourth embodiment and the second embodiment will be described below.

In the fourth embodiment, the plurality of fiber optic subunits40are bundled together in the crossover distribution unit30to form a fiber optic subunit assembly400. The crossover distribution unit30includes two brackets231, an extension sheath232, and two branch sheaths233.

The two brackets231are respectively disposed at an end of the first cable portion10and an end of the second cable portion20and are respectively received in the two cable jackets50to support and position the first cable units11and the second cable units21. Each of the brackets231includes an annular portion2311and a plurality of latching portions2312arranged around an inner periphery of the annular portion2311. A bottom surface of each of the latching portions2312is substantially circular arc-shaped.

The extension sheath232covers the fiber optic subunit assembly400. The extension sheath232is substantially hollow columnar-shaped, and two ends of the extension sheath232are respectively spaced apart from the two cable jackets50.

Two branch sheaths233are respectively disposed at two intersection points of the fiber optic subunits40. One of the branch sheaths233is sleeved over an end of the optical cable jacket50of the first cable portion10and an end of the extension sheath232. The other branch sheath233is sleeved over an end of the cable jacket50of the second cable portion20and the other end of the extension sheath232.

FIG. 11shows a schematic view of a fifth embodiment of a crossover distribution unit30. The crossover distribution unit30includes one or more branching devices331. The plurality of fiber optic subunits40are bundled into a fiber optic subunit assembly400in the crossover distribution unit30, and the fiber optic subunits40of the fiber optic subunit assembly400are divided into the plurality of second cable units21by one or more branching devices331. The second cable units21are coupled to the corresponding switches200(not shown).

FIGS. 12-13show the branching device331. The branching device331includes a branch housing3311and three connecting rings3312. An inner cavity of the branch housing3311has a substantially T-shaped cross-section and includes a main portion3313and a branch portion3314. The main portion3313and the branch portion3314are substantially perpendicularly coupled together. The main portion3313receives the fiber optic subunit assembly400, and the branch portion3314is coupled to the second cable unit21. Each of the second cable units21bundles together a plurality of the fiber optic subunits40of the fiber optic subunit assembly400. The number of the second cable units21can be set as desired.

Two connecting rings3312are respectively located at two sides of the main portion3313, and the third connecting ring3312is sleeved on the branching portion3314to couple the branch housing3311to the second cable unit21.

Referring toFIG. 14, an operation principle of the fiber optic crossover cable100will be described below. The fiber optic crossover cable100is coupled between a first switch group and a second switch group. The first switch group and the second switch group each include four switches200. Taking a switch200of the first switch group as an example, the switch200has four channels for generating signals. The switch200is coupled to the first cable unit11of the fiber crossover cable100, and the first cable unit11bundles together four fiber optic subunits40. The four fiber optic subunits40are rearranged in the crossover distribution unit30. The four fiber optic subunits40are respectively divided into the four second cable units21, and the four second cable units21are respectively coupled to the four switches200. Therefore, the signals in the four channels of one switch200in the first switch group can be transmitted respectively to the four switches200of the second switch group through the fiber crossover cable100. Since the optical signals of the switch200do not need to transmit through any gaps to the second set of switches200, signal loss in the optical fiber is negligible.

The embodiments described above are based on the Clos principle design, but are not limited thereto, and can also be customized according to user requirements.

In the related art, an 8 by 8 switch using a traditional adapter cabinet requires two MPO backplanes and one cabinet. For the sixteen switches, 128 MPO connectors are required, and a connection loss of each switch is about 0.8 dB.

Using a modified adapter cabinet, one MPO backplane and one cabinet are required for the sixteen switches. The sixteen switches require 128 MPO connectors, and the connection loss of each two switches is about 0.4 dB. Therefore, using the modified adapter cabinet to connect the switches is costly and has a large connection loss.

By using the fiber optic crossover cable100, it is not necessary to set up the MPO backplane and the cabinet. Only 128 MPO connectors are required, and the connection loss is negligible.

Therefore, the optical fiber cross-over cable100disclosed in the present disclosure can establish communication among the switches200. The cost is low, and the connection loss is negligible. Furthermore, the above-disclosed optical fiber cross-over cable100can reduce a required transmission power of the switches, thereby reducing the overall power of the data center and saving energy.

It can be understood that in other embodiments, the structure of the crossover distribution unit30can be set according to requirements. For example, the brackets32may be omitted, as long as the plurality of fiber optic subunits40can be arranged accordingly.