Hundreds of standards specify the characteristics and procedures for making and using fiber optic connectors and cable assemblies. Many of these standards are for the end-users – organizations that build and operate optical networks and other fiber-based systems. For the specific needs of optical cable assembly manufacturers, however, this article will emphasize a few groups of key standards concerning product performance and production.
The standards for optical cable assembly manufacturers address the following overall goals:
- reliable, consistently produced jumpers and pigtails;
- intermateability even when using parts from different suppliers;
- reproduceable test results, demonstrating optical and mechanical performance at or above the levels needed for fiber networks and other system standards;
- uniform test methods, which let customers know how manufacturers arrived at their product specifications and let customers compare parts from different vendors.
Where standards come from
Life would be easier if we could point to one standard and say “this is THE standard, the only one needed, and here’s how to order THE document.” But that’s not how things work. Different trade associations and industry groups work on standards to address their members’ needs. Thus, we have some standards that focus on network performance, some that focus on manufacturing processes, and some that focus on application niches. The various organizations establish committees to write the standards, and these committees convene regularly to review requirements and make sure the standards are current.
That’s why there will never be a single or final document. Standards are continually evolving – being modified, expanded, and updated to reflect changes in the core technology. Even the standards-writing groups are changing – trade associations merge, establish new areas of coverage, and establish new committees. Thus, a list of key standards is essentially a moving target. Some of the standards affecting optical cable assemblies date back to the 1980s, but there have been numerous revisions or updates since the first versions.
Most standards affecting optical cable assembly manufacturers fall into two main categories: 1.) broad standards on manufacturing processes and quality management; 2.) specific product and process standards, specifying methods for measuring and characterizing assemblies’ features or performance parameters. Examples of the first category include Telcordia GR 326 and TIA BPC’s TL 9000. Examples of the second category include standards in the TIA-455 series (Fiber Optic Test Procedures) and IEC 61755 series.
These examples highlight three key organizations that have published standards on optical cable assemblies: the IEC, Telcordia, and the TIA. Many other groups also have cable assembly standards, including some that focus on specific industries or applications. Examples include ARINC, FOA, NASA, SAE, SMPTE, US DoD (Mil), etc.
Quality management system standards
Telcordia’s GR-326, Generic Requirements for Single-Mode Optical Connectors and Jumper Assemblies, may be the most widely cited standard in the optical cable assembly business. The current version is Issue Number 04, dated February 2010. It has more than 130 pages covering areas such as:
- general requirements—packaging, materials, cleaning, marking, keying, etc.;
- specific performance requirements and measurement methodology – loss, reflectance, thermal aging, humidity, mechanical tests, geometry, materials (e.g., adhesives), and environmental factors (e.g., dust and contaminants);
- service life tests – a list of the measurements that can be done to monitoring an assembly’s performance while in service;
- reliability assurance program – objectives for qualifying vendors, parts, materials, and methods for inspecting, document, and tracking parts.
Considering this breadth, we regard the GR-326 standard as providing both an overall quality management system and details on specific test criteria and methods. Other key programs that address quality management for assembly makers are the TIA’s TL 9000 and Verizon’s FOC program.
The TL 9000 program is a re-purposing and extension of the ISO 9001:2008 program with modifications specifically for the telecommunications industry. In 1998, a group called the QuEST Forum established TL 9000 with goals including: reduce the number of standards affecting telecom suppliers; establish quality management measures throughout the supply chain, and implement programs to document, collect, and report key quality measurements using a central data repository.
The QuEST Forum’s membership included more than 100 organizations – mainly telecom equipment and component manufacturers, major carriers from all regions, and other standards bodies. In 2017, the QuEST Forum merged with the Telecommunications Industry Association (TIA), and the TL 9000 now is run by a group within the TIA called BPC (Business Performance Community).
Verizon, which is among the world’s top consumers of optical cable, components, and equipment, has developed its own program for qualifying and certifying FOC (fiber optic component) suppliers. The program is based on many elements from the TL 9000 and GR-326 standards. There are several independent testing laboratories that work with Verizon to certify component vendors.
Specific product and process standards
This category has a larger number of standards covering the requirements and measurements for specific parameters. The documents for these standards are shorter than the inclusive GR-326, but an assembly manufacturer might rely on several of them at various stages of its production process. Two key sources are the TIA, which furnishes the TIA-455 series of FOTP (fiber optic test procedure) standards, and the IEC (International Electrotechnical Commission), which furnishes detailed standards on individual connector types, inspection and test methods, ferrule materials, polishing, and geometric factors.
Examples of standards associated with specific steps in the assembly-manufacturing process include:
- storage, preparation, and use of epoxies:
- GR-326, 8.2.1.3 (Qualification of Epoxies)
- GR-326, 4.4.4.2 and 5.3.6 (Adhesive Test)
- ferrule cleaning:
- IPC-8497-1, Cleaning Methods and Contamination Assessment for Optical Assembly
- visual inspection:
- IEC 61300-3-35, Fibre Optic Interconnecting Devices And Passive Components - Basic Test And Measurement Procedures - Part 3-35: Examinations And Measurements, Visual Inspection Of Fibre Optic Connectors And Fibre-Stub Transceivers
- single-fiber connector and ferrule geometry:
- IEC 61755-series of documents, covering a variety of connector types
- GR-326, section 4.4.5
- MT/MPO connector and plug geometry:
- USConec document number AEN-1915, derived in part from IEC 61755-3-31
- other geometric tests:
- TIA 455, FOTP 135, Measurement of Connector Ferrule Inside and Outside Diameter Circular Runout
- insertion loss / loss return loss testing
- TIA 455, FOTP-171, Attenuation by Substitution Measurement for Short-Length Multimode Graded-Index and Single Mode Optical Fiber Cable Assemblies
- TIA 455, FOTP-107, Determination of Component Reflectance or Link/System Return Loss Using a Loss Test Set
Assembly customers may not be familiar with many of these standards or may not request them. Thus, compliance with some standards may not be required for assembly manufacturers to meet orders. On the other hand, assembly makers may find that familiarity with a wide range of standards can help establish internal procedures, achieve greater consistency in production, and minimize scrap. Finally, we emphasize that use of standard-compliant parts and adherence to several key product and process standards is necessary to achieve intermateability of the finished connectors – a critical requirement for the assembly users.
Standards groups and reference information
ANSI
American National Standards Institute
https://www.ansi.org/
ARINC
The ARINC Industry Activities includes three standards organizations under the SAE Industry Technologies Consortium (SAE-ITC). The ARINC standards cover airline electronics, avionics maintenance, and flight simulation.
https://www.aviation-ia.com/
ASTM
American Society for Testing and Materials
https://www.astm.org/
CSA
The CSA started in Canada and is based there, but it has become a global group with a focus on standards, test methods, and certification. Through its website, it also furnishes standards from ANSI, IEC, and other organizations.
https://www.csagroup.org/
For example, going to CSA store (https://store.csagroup.org/) and searching for “fiber optic connector” will bring up a menu with filters for publisher (CSA, IEC, ISO, etc.), and applications.
FOA
The Fiber Optic Association focuses on installation practices, training, and certifying technicians. It furnishes training materials and technical information, including some summaries of key optical cable installation and measurement standards.
https://www.thefoa.org/
IEC
The International Electrotechnical Commission is one of the main international sources of standards in electronic and communications technologies. Its membership consists of National Committees – one for each country. The member representing the US, for example, is ANSI. Each National Committee appoints the individual delegates to represent it in the various IEC standards working committees.
The IEC’s work on fiber optic standards is under Technical Committee 86, and Subcommittee 86B is responsible for interconnecting devices and passive components. Key standards governing fiber optic cable assemblies developed by this committee are in the following series:
- IEC 60874 series has details on plugs and adapters for various SC connectors versions (S-M, MM, UPC, APC, etc.);
- IEC 61300 series has basic test and measurement procedures for interconnecting devices. (IEC 61300-3-35, for example, is widely accepted as the industry standard on visual inspection, and is available here: https://webstore.iec.ch/publication/22771 )
- IEC 61753 series has performance standards for connectors and passive devices in different environments.
- IEC 61754 series has details on most common fiber optic connector types, including DS, FC, MT, MPO, MU, SC, SMA,
- IEC 61755 series has standards covering angle polishing, ferrule geometry and materials, and other connector materials and parts.
https://www.iec.ch/publications
IPC
The IPC was started in 1957 as the Institute for Interconnecting and Packaging Electronic Circuits, but in 1999, it changed its name to IPC, the Association Connecting Electronics Industries. Its subcommittee for optoelectronics assembly has developed a standard on cleaning methods and contamination assessment.
http://www.ipc.org
http://www.ipc.org/TOC/IPC-8497-1.pdf
MIL-STD
Military connector standards are available from the Defense Supply Center in Columbus, OH. This organization is part of the Defense Logistics Agency.
https://www.dla.mil/LandandMaritime/Offers/Services/TechnicalSupport/DocStandDiv.aspx
NASA
The US National Aeronautics and Space Administration has a technical standards program for its internal needs. This is mentioned as an example of an application-specific standards program.
https://standards.nasa.gov/standard/nasa/nasa-std-87395
SAE International
The SAE began as the Society of Automotive Engineers, but its areas of coverage have expanded to include aerospace, commercial vehicles, and related technologies. The ARINC801-3 standard, for example, covers fiber optic connectors.
https://www.sae.org/
SMPTE
The Society of Motion Picture and Television Engineers has published more than 800 standards, including some on fiber optic connectors and cable, such as hybrid electrical-plus-optical connectors for broadcast cameras and ruggedized versions for field production. The standards are available through the IEEE Xplore Digital Library.
https://ieeexplore.ieee.org/browse/standards/number/smpte
Telcordia
Telcordia’s origins are in the former Bell Labs. When the “Bell System” was broken up in 1984, the local telephone operating companies were separated out and grouped into seven regional holding companies. The remaining parts of the Bell System, including the long-distance business, the manufacturing arm, and Bell Labs, were kept under one corporate entity, called AT&T at that time. To address the concern that the seven local operating companies would no longer have Bell Labs to provide engineering and R&D support, part of the former Bell Labs was separated out as a new R&D company called Bell Communications Research (Bellcore). At that time, it was funded by the seven “baby Bells.”
Bellcore supplied the telecom standards including GR-326 from 1984 through 1997, when SAIC purchased the company. In 1999, SAIC re-named the business, calling it Telcordia, and continued selling the standards under that name. In 2005, SAIC sold Telcordia to Providence Equity Partners and Warburg Pincus, and in 2012, Ericsson purchased the business. The former Telcordia now operates under the Ericsson brand, but the standards are still sold with the same GR-numbers. Note that under Bellcore, Telcordia, and now Ericsson, the R&D company also has had extensive activities outside of standards in areas such as software for telecom companies, including operating support systems, and telecom transmission technologies.
https://telecom-info.telcordia.com/site-cgi/ido/docs2.pl?ID=074977060&page=home
Ericsson’s website furnishes this link to the GR-326 standard’s Table of Contents:
https://telecom-info.telcordia.com/ido/AUX/GR_326_TOC.i04.pdf
TIA
The Telecommunications Industry Association is a trade organization with more than 400 members, including manufacturers of telecom components and systems, network operators, and other telecom industry participants. The TIA’s TR-42 engineering committee and various subcommittees are responsible for standards on telecommunications cabling and fiber optics, several of which affect the production and use of fiber optic cable assemblies:
1. The TIA-455 series of fiber optic test procedures (FOTP) has more than 200 documents covering “standard test procedures for fiber optic fibers, cables, transducers, connecting, and terminating devices.”
2. TIA-568 standard covers optical and metallic cabling systems for commercial buildings, often referred to as structured cabling systems. The latest version is revision D, and publication TIA-568.3-D includes specifications for components.
3. TIA-942 covers infrastructure in data centers.
TIA standards also are sanctioned and published by ANSI. TIA also has a partnership with IHS Global for selling standards documents.
http://standards.tiaonline.org/all-standards/committees/tr-42
https://global.ihs.com/csf_home.cfm?&csf=TIA
TIA BPC
The TIA’s Business Practices Committee has taken over the management, development, and reporting of the TL 9000 “telecom quality management system.”
https://tl9000.org/
Verizon
Verizon is a major international telecom company offering services throughout the US. Its predecessors include two of the seven Bell regional holding companies, GTE, MCI, AOL, Yahoo, XO Communications, Alltel, Vodafone’s US mobile operations, and many other companies.
Elements of Verizon’s FOC quality-management program include:
- ITL (Independent Testing Laboratories) certification program
https://www.verizonnebs.com/foc.html
https://www.verizonnebs.com/itl.html - NEBS (Network Equipment Building Systems) compliance
https://www.verizonnebs.com/foc.html - TPR (Technical Purchasing Requirements)
For the most recent NEBS compliance document on optical connectors and jumpers (March 2020), see:
http://www.verizonnebs.com/TPRs/VZ-TPR-9409.pdf
This document provides additional or over-riding test requirements to those in GR-326 to meet Verizon’s NEBS compliance requirements.
https://www.verizonnebs.com/index.html
