OPTO-ELECTRONIC BACKPLANE

TECHNICAL FIELD

[001] Embodiments of the present invention relate to opto-electronic coupling of a
plurality of line-cards mounted on a backplane.

BACKGROUND

[002] Electronics, telecommunications or computing equipment typically comprise a
plurality of line-cards that attach to, and are communicatively coupled to a backplane. Line-cards and backplanes are both constructed from circuit board materials (e.g., fiberglass, copper, etc.) and contain electronic components such as integrated circuits, transistors, resistors, etc. mounted thereon.

[003] Backplanes typically contain a plurality of slots into which one or more line-cards may be inserted, or plugged in. Line-cards may be added to a backplane as demand increases for the service rendered by said equipment. The slots on the backplanes that receive the line-cards are typically parallel to, or co-planar with each other, so that line-cards are positioned parallel to each other and each perpendicular to the backplane.

[004] For the equipment to function, the line-cards must continually exchange signals and data with each other, typically over communication lines that are laid over the backplane. In high-capacity equipment, for example, equipment typically used by computing- or communication-service providers, the rate at which data is exchanged is measured in gigabits per second, and is anticipated to further increase significantly, driven both by increasing demand and by improving technology.

[005] At higher data-rates, for example, tens of gigabits per second, it may no longer be efficient or feasible to use conventional metal inter-connects and transmission lines to effect communication betweenline-cards. In order to facilitate the higher data-rates, it may be necessary to use an optical transport medium, for example, optical fibers, to carry data between the line-cards. In turn, this necessitates, prior to a data-bit's exit across the border of a line-card, the conversion of the data-bit from electronic to optical form, in order that said data-bit be transported by optical fiber.

[006] Conventionally, data is converted from electronic to optical form by means of an opto-electronic module that is mounted on the line-card. Subsequent to conversion, data in optical form is transported via optical fiber to an exit port of the line-card, where it is received by an optical receiving port mounted on the backplane. The optical receiving port is conventionally coupled to an optical transport medium that distribute the data throughout the backplane, including to slots on which other line-cards may be plugged in.

SUMMARY

[007] An example of a method for opto-electronic coupling of a first line-card to a
second line-card, at least one of which is mounted on a backplane, includes mounting a first electrical interface to the first line-card and mounting a first opto-electronic interface on the backplane. Further, the first electrical interface is coupled to the first opto-electronic interface, and the first opto-electronic interface is coupled to a first end of an optical transport medium mounted on the backplane. Furthermore, a second electrical interface is mounted on the second line-card, and an electro-optical interface is mounted on the backplane, so that the second electrical interface and the electro-optical interface are communicatively coupled to each other. Still further, the electro-optical interface is coupled to a second end of the optical transport medium. A signal generated by the first line-card is transported to the second line-card by causing said signal to pass sequentially through the first electrical interface, the electro-optical interface, the optical transport medium, the opto-electronic interface and finally the second electrical interface to the second line-card.

[008] An example of a system for opto-electronically coupling a first line-card on a backplane to a second line-card on said backplane includes an optical transport medium mounted on the backplane for transporting signals and data between a first line-card and a second line-card, a opto-electronic interface mounted on the backplane, an electro-optic interface mounted on the backplane, a first electrical interface mounted on the first line-card and a second electrical interface mounted on the second line-card. The electro-optical interface is communicatively coupled to the first electrical interface, and is also communicatively coupled to a first end of an optical transport medium. The opto-electronic interface is communicatively coupled to the second electrical interface, and is also communicatively coupled to a second end of the optical transport medium.

[009] An example of anopto-electronic connector to couple a line-card to an optical transport medium includes an electrical interface mounted on the line-card for transporting signals and data that enter or exit the line-card and an opto-electronic interface that is mounted on a backplane for transporting signals and data that enter or exit the optical transport medium. The electrical interface includes a plurality of electrically conducting pins enclosed within a first housing, and the opto-electronic interface includes an electrical section enclosed within a second housing and a section that inter-converts between electrical and optical signals, enclosed in a dust-proof third housing. The electrical interface and the opto-electronic interface are configured to mate and exchange signals and data with each other, and are slidably engaged and mutually detachable from each other.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] In the accompanying figures, similar reference numerals may refer to identical or functionally similar elements. These reference numerals are used in the detailed description to illustrate various embodiments and to explain various aspects and advantages of the disclosure

[0011] FIG. 1 illustrates a system of inter-connected line-cards mounted on a backplane, communicatively coupled via an opto-electronic mechanism, in accordance with an embodiment of the invention.

[0012] FIG. 2 illustrates a top view of communications port for transporting data bits and signals into and out of a line-card, in accordance with an embodiment of the invention.

[0013] FIG. 3 illustrates a bottom view of a communications port for transporting data bits and signals into and out of line-card, in accordance with an embodiment of the invention.

[0014] FIG. 4 illustrates an opto-electronic interface, in accordance with an embodiment of the invention.

[0015] FIG. 5 illustrates an exploded view of an opto-electronic interface, in accordance with an embodiment of the invention.

[0016] FIG. 6 illustrates an electrical section of an opto-electronic interface, in accordance with an embodiment of the invention.

DETAILED DESCRIPTION

[0017] Embodiments of the present invention provide a mechanism for opto-electronic communication between afirst line-card and a second line-card, wherein at least one line-card is mounted on a backplane. The mechanism for opto-electronic communication includes a firstelectrical interface mounted on the first line-card, an electro-optical interface mounted on the backplane, an optical transport medium mounted on the backplane, an opto-electronic interface mounted on the backplane, and a second electrical interface mounted on the second line-card. The first electrical interface mounted on the first line-card engages slidably with electro-optical interface mounted on the backplane, and exchanges electrical signals and data with said first electro-optical interface. The electro-optical interface mounted on the backplane converts data and signals received in electrical form to optical form. The electro-optical interface is communicatively coupled to a first end of the optical transport medium, and exchanges data in optical form with the optical transport medium. A second end of the optical transport medium is communicatively coupled to the opto electronic interface mounted on the backplane. The opto-electronic interface mounted on the backplane engages slidably with the second electrical interface mounted on the second line-card, and exchanges electrical signals and data with said second electrical interface. A data bit originating at the first line-card may be transported to the second line-card by passing said data bit sequentially through the first electrical interface, the electro-optical interface, the optical transport medium, the opto-electronic interface and the second electrical interface mounted on the second line-card.

[0018] The electrical interfaces on a line-card serve as a collection point for data and signals generated from the line-card in electrical form the line-card, which data is intended for transport to another line-card. The opto-electronic and electro-optical interfaces mounted on the backplane perform the functions of receiving data and signals in electrical form from the electrical interfaces to which they are respectively coupled, and inter-converting between electrical and optical signals. In a preferred embodiment, the opto-electronic and electro-optical interfaces are mounted on the lower surface of the backplane, so as to not compete for space on the line-card with chips or other components that may be mounted thereon. In another preferred embodiment, the optical sections of the opto-electronic interface and of the electro-optical interfaces are enclosed in a dust-proof housing.

[0019] FIG. 1 illustrates a system 100 of interconnected line-cards mounted on a backplane, as may be found typically in electronics, communications or computing equipment, suitable for us by an embodiment of the invention. A backplane 102 hosts a plurality of line-cards, exemplified by a first line-card 104 and a second line-card 106. A line-card in turn hosts a variety of electronic components 108 such as integrated circuits, transistors, resistors, etc. Data may be generated by the components 108 on line-card 106 that needs to be transported to line-card 104. Such data is collected at a communications port HOby means of a network of electrical transmission lines mounted on line-card 106. Data exits the communications port 110 and, following conversion to optical form, travels along optical transport medium 112, and enters communication port 111, which directs data to line-card 104. Conversely, data that is generated on line-card 104 may be transported line-card 106 by sequentially passing via communications port 111, optical transport medium 112 and communications port 110.

[0020] FIG. 2 illustrates in greater detail communications port 110, which is in accordance with an embodiment of the invention, and to which is identical in design and construction the communications port 111.Communications port 110 includes an electrical interface 214 mounted on line-card 106, and an opto-electronic interface 216 mounted on the backplane. Line-card 106hosts components mounted thereon, an example of which is component 108. The opto-electronic interface 216 is enclosed by a housing 217, shown in cutaway view so as to reveal the internal structure of opto electronic interface 216. The electrical interface 214 and the opto-electronic interface 216 are slidably engaged, and manually detachable from each other. The FIG. 2 shows the electrical interface 214 and the opto-electronic interface 216 in a state of disengagement, with arrows indicating direction for manual engagement. The electrical interface 214 and the opto-electronic interface 216 are configured to mate with each other, and to exchange signals and data with each other. The opto-electronic interface 216 includes an electrical section 218 and an opto-electronic section that is below the backplane 102. The opto-electronic section of the opto-electronic interface 216will be described in greater detail in FIG 3. The electrical section 218 includes an array of electrically conducting pins 219 enclosed within housing 217. The electrically conducting pins 219 of electrical section 218 may be of type male, in which case the corresponding mating elements of electrical interface 214 are female. The electrically conducting pins 219 of electrical section 218 may be of type female, in which case the corresponding mating elements of electrical interface 214 are male. The housing 217 includes at least one fastening mechanism 220 for the purpose of mechanically fastening the opto-electronic interface 216 to the backplane 102. The optical transport medium 112 is communicatively coupled to a section of the opto electronic interface below the backplane 102, the details of which will be described in FIG. 3.

[0021] FIG. 3 illustrates the communications port 110, through a cutaway view of backplane 102, in accordance with and embodiment of the invention. The opto-electronic interface 216 includes the aforementioned electrical section 218, enclosed in housing 217, and an opto-electronic section 322 enclosed in a dust-proof housing 323. The opto-electronic section 322 of the opto-electronic interface 216and the electrical section 218 of the opto-electronic interface 322 are slidably engaged, and manually detachable from each other. The FIG. 3 shows the opto-electronic section 322 and the electrical section 218 in a state of engagement, with arrows indicating direction for manual disengagement. The electrical section 218 and the opto¬electronic section 322 are configured to mate with each other, and to exchange signals and data with each other.The opto-electronic section 322 couples between the electrical section 218 and the optical transport medium 112 and serves to interchange between electrical signals and optical signals. The optical transport medium 112 couples with the opto-electronic section 322 at 324.

[0022] FIG. 4 illustrates the opto-electronic interface 216 when removed from the backplane. The opto-electronic interface 216 includes electrical section 218 enclosed in housing 217, and opto-electronic section 322 enclosed in dust-proof housing 323. The housing 217 includes at least one fastening mechanism 220 for the purpose of mechanically fastening opto-electronic interface 216 to the backplane. The electrical section 218 and the opto-electronic section 322 are slidably engaged with, and manually detachable from each other. The FIG. 4 shows the electrical section 218 and the opto-electronic section 322 in a state of engagement. The opto-electronic section 322 inter-converts between electrical and optical signals, and couples between the electrical section 218 and the optical transport medium 112. In a preferred embodiment, the optoelectronic interface 216 is mounted on the lower surface of a backplane, emerging through an appropriately sized opening on the backplane, only to the extent it can mate electrically with an electrical interface mounted on the line-card.

[0023] FIG. 5 illustrates the opto-electronic interface 216 when its constituent sections, namely electrical section 218 and opto-electronic section 322, are disengaged from each other. The electrical section 218, which couples an electrical interface on the line-card with the opto-electronic section 322, includes a plurality of electrically conducting pins 526 enclosed within housing 217. The electrically conducting pins 526 may be of type male, in which case the corresponding mating elements of opto-electronic section 322 are of type female. The electrically conducting pins 526 may be of type female, in which case the corresponding mating elements of opto-electronic section 322 are of type male. The plurality of electrically conducting pins 526 include pins 528 that are specially dimensioned to carry electrical power.

[0024] FIG. 6 illustrates the face of electrical section 218 that couples to an electrical interface mounted on a line-card. The plurality of electrically conducting pins 219 include pins 628 that are specially dimensioned to carry electrical power. In a preferred embodiment, the pins 528 are connected to the pins 628, and electrical power is supplied to the opto-electronic interface 216 by virtue of pins 628 being connected to electric supply lines within electrical interface 214. FIG. 6 illustrates also a plurality of fastening mechanisms220 that are used to fasten mechanically opto¬electronic interface 216 to a backplane.

[0025] In the foregoing discussion, each of the terms "coupled" and "connected" refers to either a direct electrical connection or mechanical connection between the devices connected or an indirect connection through intermediary devices.

[0026] The foregoing description sets forth numerous specific details to convey a thorough understanding of embodiments of the disclosure. However, it will be apparent to one skilled in the art that embodiments of the disclosure may be practiced without these specific details. Some well-known features are not described in detail in order to avoid obscuring the disclosure. Other variations and embodiments are possible in light of above teachings, and it is thus intended that the scope of disclosure not be limited by this Detailed Description, but only by the Claims.

CLAIMS

I/We Claim:

1. A method for opto-electroniccoupling on a backplane, comprising:

mounting a first electrical interface to a first line-card and coupling the first electrical interface to a first electro-optical interface coupled to a first end of an optical transport medium mounted on the backplane;

mounting a second electrical interface to a second line-card and coupling the second electrical interface to a second opto-electronic interface coupled to a second end of the optical transport mediummounted on the backplane; and

transporting a signal generated by the first line-card to the second line-cardby passing said signal sequentially through the first electrical interface, the first electro-optical interface, theoptical transport medium, the second opto-electronic interface, and the second electrical interface mounted on the second line-card.

2. The method of Claim 1, wherein coupling the first electrical interface to the electro-optical interface comprises slidably engaging and causing to electrically mate the first electrical interface to the electro-optical interface, and wherein coupling the second electrical interface to the second opto-electrical interface comprises slidably engaging and causing to electrically mate the second electrical interface to the opto-electronic interface.

3. A system for opto-electronic coupling on a backplane, comprising:

an optical transport medium mounted on the backplane for transporting signals and data between a first line-card and a second line-card;

a first electro-optical interface mounted on the backplane, coupled to a first end of the optical transport medium, for transporting signals and data across a border of the first line-card;

a second opto-electronic interface mounted on the backplane, coupled to a second end of the optical transport medium, for transporting signals and data across a border of the second line-card;

a first electrical interface mounted on the first line-card for transporting signals and data across the border of the first line-card, configured to slidably engage and mate with the first electro-optical interface;

a second electrical interface mounted on the second line-card for transporting signals and data across the border of the second line-card, configured to slidably engage and mate with the second opto-electronic interface; and

configured to transport a signal generated by the first line-card to the second line-card by passing said signal sequentially through the first electrical interface, the first electro-optical interface, the optical transport medium, the second opto¬electronic interface, and the second electrical interface mounted on the second line-card.

4. The system of Claim 3, wherein the first electro-optical interface comprises a first electrical section for mating with and exchanging signals and data with the first electrical interface, and a second section that interconverts between electrical and optical signals; and wherein the second opto-electronic interface comprises a second electrical section for mating with exchanging signals and data with the second electrical interface, and a third section that interconverts between electrical and optical signals.

5. The system of Claim 4, wherein the first electrical section comprises a plurality of electrically conducting pins enclosed within a first housing and the second section that inter-converts between electrical and optical signals is enclosed within a dust-proof second housing.

6. The system of Claim 4, wherein the second electrical section comprises a plurality of electrically conducting pins enclosed within a third housing and the third section that inter-converts between electrical and optical signals is enclosed within a dust-proof fourth housing.

7. An opto-electronic connector to couple a line-card to an optical transport medium, comprising:

an electrical interface mounted on the line-cardfor transporting signals and datathat enter or exit the line-card, wherein the electrical interface comprises a plurality of electrically conducting pins enclosed within a first housing;

an opto-electronic interface that is mounted on a backplane, for exchanging signals and data with the optical transport medium, wherein the opto-electronic interface comprises an electrical section enclosed within a second housing, and a section that interconverts between optical and electrical signals, enclosed within a dust-proof third housing; and

configured to mate, and exchange signals and data with each other, wherein said electrical interface and said opto-electronic interface are slidably engaged with, and manually detachable from each other.

8. The opto-electronic connector of Claim 7, wherein the electrical section of the opto electronic interface comprises a plurality of electrically conducting pins, and wherein said electrical section electrically couples with the electrical interface mounted on the line-card.

9. The opto-electronic connector of Claim 8, wherein the electrical section and the section that interconverts between optical and electrical signals are slidably engaged with, and manually detachable from each other.

10. The opto-electronic connector of Claim 8, wherein the second housing includes a fastening mechanism to mechanically fasten the opto-electronic interface to the backplane, and wherein the fastening mechanism includes a plurality of screw-receptacles to allow the insertion of screws to mechanically fasten the opto-electronic interface to the backplane.