Fiber ribbons

Fiber ribbons

William B. Gardner, AT&T

The advantages of linear optical fiber arrays, known as ribbons, have been well documented (see Lightwave, January 1994, page 24). Efforts at fiber-ribbon standardization, however, illustrate the challenges that national, regional and international standards organizations face in working to create timely standards.

For example, the European Committee for Electrotechnical Standardization (Cenelec) has established the Cenelec Electronic Components Committee known as Cecc. This regional standards body has three working groups dealing with lightwave components: WG 26, WG 27 and WG 28.

In the past, standards adopted by regional bodies such as Cenelec were submitted to the International Electrotechnical Commission for adoption as international standards. Through analysis of the commission`s operation, a recent study discovered that the average time consumed to push international standards through this serial process was 6 years and 10 months.

To accelerate the process, IEC and Cenelec agreed on a parallel-voting procedure. The procedure states that if at least five national committees in Cenelec support a standards proposal, IEC and Cenelec can conduct their balloting processes simultaneously.

Sectional Specification IEC 1279 on Optical Telecommunication Cables provided an opportune test of the new procedure. This document, originating in Cecc WG 28, recognizes fiber ribbons as a cable component, not as a standalone product. This European classification of fiber ribbons, however, is not shared by some countries, notably the United States and Japan.

The specification passed the IEC parallel voting procedure.

When IEC Subcommittee SC86A met in Istanbul, Turkey, in September 1994, IEC 1279 was already a draft international standard, without ever having been discussed in the SC86A Working Groups.

Within IEC Subcommittee SC86A, a joint special working group on fiber ribbons had been formed to address the specification and testing of ribbons. Members of the JSWG came from both WG 1 on Fibers and WG 3 on Cables. The JSWG submitted a committee draft for the specification of optical fiber ribbons for approval at the IEC SC86A plenary in Istanbul. But because of the parallel vote, the work of the JSWG was superseded by the controversial document IEC 1279.

Because of consternation over this outcome, a proposal was made in Istanbul to authorize WG 3 to write specifications on fiber ribbons as a cable element, while WG 1 would write specifications on fiber ribbons as a standalone product. After much discussion, several Cenelec countries relented and voted for this proposal. With strong support from United States and Japanese members, the proposal passed. Satisfied with this resolution of the problem, the JSWG disbanded.

A sectional specification for Optical Fiber Ribbons (IEC 1403-1) has been prepared for submission to WG 1 at their next meeting in San Diego in February 1995. This document discusses the two major fiber-ribbon types: edge-bonded and encapsulated; it also addresses dimensions, fiber identification, mech anical integrity and test methods.

Although an acceptable compromise has been reached in the IEC, this case history illustrates the difficulties encountered while attempting to shorten the international standardization process. Due process cannot be sacrificed in the pursuit of fast-track procedures, especially if the work is already being developed within IEC Working Groups.

The focus here has been on the IEC, but International Tele communication Union Study Group 6 on Outside Plant also deals with fiber ribbons. See, for example, their Recommendation L.10, "Optical Fiber Cables for Duct, Tunnel, Aerial and Buried Applications," and Chapter I of their Optical Fiber Handbook (1994 Edition). q

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