Optical fiber cables

Abstract

Described is an optical fiber cable designed for drop cable applications that has a compact profile, and is suitable for both the indoor and outdoor portions of the installation. The new design has three functional units, an optical fiber subunit, and two strength members arranged side-by side on either side of the optical fiber. The overall cable cross section round. In a preferred embodiment, the optical fiber module of the cable has a coupled fiber design.

Description

RELATED APPLICATIONS[0001]This application claims the benefit of provisional application 60 / 927,475 filed May 3, 2007, which is incorporated herein by reference.FIELD OF THE INVENTION[0002]This invention relates to optical fiber cables specially adapted for drop line applications.BACKGROUND OF THE INVENTION[0003](Parts of this background may or may not constitute prior art.) Fiber-to-the-premises (FTTP) from local telephone and cable service providers is rapidly being implemented. This service requires a broadband optical fiber distribution network comprising local optical fiber distribution cables that are installed in neighborhoods and city streets. The local distribution cable is a large fiber count (multi-fiber) cable. Single fiber or few fiber cables are used for the “drop” line from the street to the premises. In many cases, aerial drop lines are used, and these have special requirements. In other cases, buried drop lines are used, and these have different requirements.[0004]O...

AI Technical Summary

Benefits of technology

[0016]We have designed an optical fiber cable suitable for drop cable applications that has a compact profile, and overcomes at least in part the drawbacks just mentioned. The new design has three functional units arranged side-by side, but the overall cable cross section is essentially round. In a preferred embodiment, the cable uses tight buffered optical fiber and aramid yarns that allow for rapid connectorization using standard optical connectors. Optical fiber cables with the construction of the invention may be designed for use both indoors and outdoors, thus simplifying FTTH installations.

Problems solved by technology

However, gel filled cables are time consuming to install and repair, as the gel must be completely removed from the optical fiber prior to fusion splicing operations.

Moreover, since the drop wire is typically attached to the side of a customer's home or building, bleeding of ingredients in the cable onto the customer's building may cause cosmetic or other problems.

However, factory assembly personnel pre-installing the connectors face issues with time-consuming, expensive complete removal of gel prior to connectorization.

Experience with installation and use of these cables has revealed several disadvantages to the basic cable design.1. Stiffness.

These cables are rigid and stiff and difficult to bend or handle.2. Size.

More difficult to manufacture and handle4. Not flame retardant.

However, there are several drawbacks to this also; the indoor cables are less robust than outdoor cables, and the service provider must arrange for a transition from the outdoor network to the indoor network for this application.

In summary, existing drop cable designs are large and stiff, and not suitable for use in both outside and inside installations.

Typical cable designs for inside wiring are not adequate for outside service.

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