Optical Fiber Ribbon Cable Edge Fiber MAC Control

Solution Overview

Problem

Existing optical fiber cables experience high optical losses and micro bending losses during temperature cycling, particularly at negative temperatures, and suffer from edge fiber failures due to inadequate design.

Innovation Solution

The optical fiber cable design includes a plurality of stacked ribbons with edge fibers having a MAC number of at most 7.2, optimized buffer tubes with a specific diameter and water blocking tape overlap, and a structure comprising a central strength member, water swellable tape, and UV-proof layers to minimize attenuation and prevent edge fiber failures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional optical fiber cable design is used, then the cable can transmit data, but it experiences high micro bending losses and edge fiber failures at negative temperatures

Engineering Contradiction:

Improveoptical fiber cable performance at negative temperatureVSAvoidmicro bending loss

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The patent applies local quality by specifying different MAC number requirements for different fiber positions. Edge fibers (positions 1 and 12 in a 12-fiber ribbon) are required to have MAC numbers of at most 7.2, while central fibers can have higher MAC numbers up to 8.0. This localized differentiation addresses the specific vulnerability of edge fibers to microbending losses at negative temperatures without unnecessarily constraining the optical properties of central fibers.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent implements parameter changes by controlling the MAC number parameter of edge fibers to be at most 7.2. This parameter control ensures that edge fibers maintain optimal optical performance under negative temperature conditions, directly addressing the microbending loss issue through precise parameter specification rather than generic design approaches.

Inventive Principle:

Principle #35Parameter changes

2Quantity of substance

If edge fibers are included in the cable structure, then the cable can provide sufficient fiber count, but edge fibers are prone to failures at negative temperatures

Engineering Contradiction:

Improvenumber of optical fibersVSAvoidedge fiber reliability

Core Design Contradiction:

Quantity of substanceVSReliability

Solution Approach 1:

The patent applies local quality by specifying different MAC number requirements for different fiber positions. Edge fibers (positions 1 and 12 in a 12-fiber ribbon) are required to have MAC numbers of at most 7.2, while central fibers can have higher MAC numbers up to 8.0. This localized differentiation addresses the specific vulnerability of edge fibers to microbending losses at negative temperatures without unnecessarily constraining the optical properties of central fibers.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent implements parameter changes by controlling the MAC number parameter of edge fibers to be at most 7.2. This parameter control ensures that edge fibers maintain optimal optical performance under negative temperature conditions, directly addressing the microbending loss issue through precise parameter specification rather than generic design approaches.

Inventive Principle:

Principle #35Parameter changes

3Quantity of substance

If the buffer tube diameter is reduced to fit more ribbons, then the cable can accommodate more fibers, but the gap between buffer tube and ribbon stack decreases

Engineering Contradiction:

Improvenumber of stacked ribbonsVSAvoidgap between buffer tube and ribbon stack

Core Design Contradiction:

Quantity of substanceVSShape

Solution Approach 1:

The patent implements parameter changes by precisely controlling the buffer tube inner diameter to be within 6.3mm to 6.5mm and the ribbon stack diagonal distance to be within 5.85mm to 6.05mm. This results in an optimized gap of 0.20mm to 0.65mm that accommodates thermal expansion and contraction while maintaining proper fiber positioning and preventing excessive contact between the ribbon stack and buffer tube walls.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS11262522B2Multi loose tube ribbon cable

Publication Date: 2022.03.01 STERLITE TECHNOLOGIES LTD

AI summary

The present disclosure provides an optical fiber cable. The optical fiber cable includes at least one optical fiber ribbon stack. In addition, the at least one optical fiber ribbon stack includes a plurality of stacked ribbons. Further, each ribbon of the plurality of stacked ribbons includes a plurality of optical fibers. The plurality of optical fibers includes edge fibers. The edge fibers are defined as the at least one optical fiber having a mach number of at most 7.2 disposed at a first end and a second end of a first ribbon and a last ribbon of the plurality of stacked ribbons.