Remote-splitter fiber optic cable

• US 6,215,930 B1
• Filed: 05/11/1998
• Issued: 04/10/2001
• Est. Priority Date: 05/11/1998
• Status: Expired due to Term

• Current Assignee: Bellsouth Intellectual Property Corporation (AT&T, Inc.)
• Original Assignee: BellSouth Intellectual Property Management Corporation (AT&T, Inc.)
• Inventors: Estes, Daniel L., Swanson, David P., Levenson, David W.
• Primary Examiner(s): Healy, Brian
• Assistant Examiner(s): Stahl, Michael J.
• Application Number:
  US09/075,721
• Time in Patent Office: 1,065 Days
• Field of Search: 385/100-113, 385/95-99, 385/48
• US Class Current: 385/100
• CPC Class Codes: G02B 6/4475 with provision for lateral branching G02B6/4431 takes precedence

Abstract

A fiber optic cable having a plurality of buffer tubes. Within at least one of the buffer tubes is a plurality of main fibers. Within the cable outer sheath, the main fibers are factory-spliced with optical splitters at predetermined distances. Distribution fibers are factory-spliced to the outputs of the optical splitters. The distribution fibers reside within distribution buffer tubes, and are available for access at substantially any location along the length of the fiber optic cable. A certain number of the distribution fibers from a particular optical splitter extend in an upstream direction of the fiber cable, and the remaining distribution fibers from that optical splitter extend in a downstream direction.

Claims

1. A fiber-optic telecommunications distribution medium, comprising:

a length of fiber optic cable including an optical fiber operatively associated with an optical splitter at a certain location; and

a plurality of subfibers operatively associated with the output of the optical splitter with a first subset of the subfibers extended in an upstream direction within the fiber optic cable, and a second subset of the subfibers displaced in a downstream direction within the fiber optic cable,

whereby at each point along the entire length of the fiber optic cable, at least one subfiber is accessible to be pulled for splicing to a drop to a subscriber.

2. The fiber-optic telecommunications distribution medium of claim 1, wherein the optical fiber and the plurality of subfibers are operatively associated with the optical splitter prior to the fiber optic cable being installed at a subscriber area.

3. A fiber-optic telecommunications distribution medium, comprising:

a length of fiber optic cable having an outer sheath, a first inner sheath and a second inner sheath, the first inner sheath and the second inner sheath being longitudinally extended within the outer sheath;

a main optical fiber longitudinally extended with in the first inner sheath the main optical fiber being spliced to an optical splitter at a certain location along the fiber optic cable and having a set of outputs, the splice occurring remote to a subscriber area; and

a first plurality of subfibers optically coupled to a first subset of outputs from the optical splitter, the first plurality of subfibers being longitudinally extended within the second inner sheath,

whereby at each point along the entire length of the fiber optic cable, at least one subfiber is accessible to be pulled for splicing to a drop to a subscriber.

4. The fiber-optic telecommunications distribution medium of claim 3, further comprising:

a third inner sheath longitudinally extended within the outer sheath;

the first plurality of subfibers extending in the upstream direction of the fiber optic cable; and

a second plurality of subfibers optically coupled to a second subset of the outputs from the optical splitter, the second plurality of subfibers being longitudinally extended within the third inner sheath and extending in the downstream direction of the fiber optic cable,

whereby at each point along the length of the fiber optic telecommunications distribution medium upstream of the optical splitter, at least one subfiber from the first plurality of subfibers is accessible, and

at each point along the length of the fiber optic telecommunications distribution medium downstream of the optical splitter at least one subfiber from the second plurality of subfibers is accessible.

5. The fiber-optic telecommunications distribution medium of claim 4, wherein:

the second subset of outputs from the optical splitter is the entire set of outputs from the optical splitter less the first subset of outputs from the optical splitter.

6. The fiber-optic telecommunications distribution medium of claim 5, wherein:

the first subset of outputs and the second subset of outputs from the optical splitter each comprise half of the outputs from the optical splitter.

7. A fiber-optic telecommunications distribution medium having an outer sheath, comprising:

a feeder portion, including a feeder fiber, contained within the outer sheath and extending longitudinally from an upstream end of the fiber-optic telecommunications distribution medium to a terminal end of the feeder portion;

a distribution portion including a plurality of distribution fibers, the distribution portion being contained within the outer sheath and extending longitudinally a predetermined distance; and

an optical coupler for optically coupling the feeder portion to the distribution portion, said optical coupling being contained within the outer sheath, an input of the optical coupler being operatively associated with the terminal end of the feeder portion and an output of the optical coupler being operatively associated with the distribution portion,

whereby at each point along the entire length of the fiber-optic telecommunications distribution medium, at least one distribution fiber is accessible to be pulled from the distribution portion for splicing to a drop to a subscriber.

8. The fiber-optic telecommunications distribution medium of claim 7, wherein:

a first subset of the plurality of distribution fibers and a second subset of the plurality of distribution fibers extend in mutually opposed directions within the outer sheath of the fiber-optic telecommunications distribution medium.

9. A method of manufacturing a fiber-optic telecommunications distribution medium, comprising the steps of:

forming a fiber cable having an outer sheath and a plurality of inner sheaths, each inner sheath having a plurality of optical fibers;

accessing a first inner sheath and splicing an optical splitter to an optical fiber in the first inner sheath, the optical splitter having outputs;

accessing a second inner sheath and splicing an optical fiber in the second inner sheath to an output of the optical splitter; and

performing the aforementioned steps prior to installing the distribution medium at a subscriber area.

10. The method of claim 9, further comprising the step of:

accessing a third inner sheath of the fiber cable and splicing an optical fiber within the third inner sheath to another output of the optical splitter such that the optical fiber in the second inner sheath and the optical fiber in the third inner sheath are displaced in mutually opposed directions along the length of the cable.