As the saying goes, nothing can be accomplished without norms or standards. Fiber optic systems should also need standards and recommendation to govern optical cable characteristics and measurement methods. But since there are many different standards, it is easy to confuse and difficult to understand. Thus, we will make a systematic introduction to some common standards in this post which helps readers to understand them better.
Before introducing the standards and recommendation for fiber optic systems, we should know who sets these standards. For international standards, there are two main groups working on—the IEC (International Electrotechnical Commission) and the ITU (International Telecommunications Union).
The IEC is the International standards and conformity assessment body for all fields of electrotechnology. It is composed of technical committees who prepare technical documents on specific subjects within the scope of an application in order to define the related standards. IEC TC86 (Technical Committee 86) is dedicated to prepare standards for fiber optic systems, modules, devices and components intended for use with communications equipment. In particular, publications cover the area of tests, measurements and calibration. Additionally, there are some subcommittees of TC86, such as SC86A, SC86B and SC86C etc. that focus on specific subjects. For example, SC86A focus on the subjects of fibers and cables; SC86B focus on fiber optic interconnecting devices and passive components and SC86C focus on fiber optic systems and active device.
ITU is the United Nations specialized agency for information and communication technologies (ICTs) which defines guidelines, technical characteristics, and specifications of telecommunication systems, networks, and services. It includes optical fiber performance test and measurement applications and consists of three different sectors—Radiocommunication (ITU-R), Standardization (ITU-T) and Development (ITU-D).
Actually, in addition to the international standards, there are many national standards which are defined by some countries or union of countries in order to customize or fine tune the requirements to the specificity of the their country. Familiar organizations for national standard such as ETSI (European Telecommunications Standards Institute) and TIA (Telecommunication Industries Association) make contributions to the local standard development. ETSI defines telecommunication standards and is responsible for the standardization of ICT within Europe. TIA provides additional recommendations for United State, defining standards for fiber optics, user premises equipment, network equipment, wireless communications, and satellite communications etc.
Depending on the international standards, here is an overview of fiber optic standards which defines the specification of fiber optic cables and related applications.
|IEC 61300-3-35||Fiber optic connector end-face visual inspection|
|IEC 60793-1 IEC 60793-2||Optical fibers|
|IEC 60794-1 IEC 60794-2 IEC 60794-3||Fiber optic cables|
|ITU-T G.651||Multimode fiber standard|
|ITU-T G.652*||Standard Singlemode fiber. 4 different categories (A, B, C, D) differ in the water peak attenuation around the 1383nm window|
|ITU-T G.653||Zero Dispersion Shifted Fiber (ZDSF), having zero dispersion around the 1550nm window|
|ITU-T G.654||Cutoff shifted and low attenuation fiber, designed mainly for submarine applications|
|ITU-T G.655||Non-zero Dispersion Shifted Fiber (NZDSF), having low dispersion in the 1550nm and 1625nm windows, the DWDM region. Suited for longhaul and backbone applications. Categories A, B, C, D, E differ in PMD and dispersion values|
|ITU-T G.656||Medium Dispersion Fiber (MDF), designed for local access and longhaul fiber|
|ITU-T G.657||For FTTH (Fiber to the Home) application. Designed to bend at small radius of down to 10mm radius and 7.5mm radius|
*Equivalent standards : Telcordia GR-20, IEC 60793-2, TIA/EIA-492CAAB
When comes to fiber test and measurement, there are also some standards which are used to standardize the processes and test sets. The following table lists some common standards of generic test, PMD (Polarization Mode Dispersion) test and CD (Chromatic Dispersion) test.
|Generic Test Standards||IEC Standard||IEC 61350||Power meter calibration|
|IEC 61746||OTDR calibration|
|ITU Standard||ITU-T G.650.1||Definitions and test methods for linear, deterministic attributes of single-mode fiber and cable|
|ITU-T G.650.2||Definitions and test methods for statistical and non-linear attributes of Single-mode fiber and cable|
|PMD Test Standards||IEC Standard||IEC 60793 1-48||Optical fibers—part 1-48: measurement methods and test procedures—PMD|
|IEC/TS 61941||Techinical Specifications for PMD measurement techniques for single-mode optical fiber|
|IEC 61280-3/TIA/TR-1029||Calculation of polarization|
|IEC 61280-4-4||PMD measurement for installed links|
|ITU Standard||G.650.2||Definitions and test methods for statistical and non-linear attributes of single-mode fiber and cables|
|TIA Standard||TIA 455 FOTP-124A||PMD measurement for single-mode optical fiber and cable assemblies by interferometry|
|TIA 455 FOTP-113||PMD measurement for single-mode optical fiber by the fixed analyzer method|
|TIA 455 FOTP-122A||PMD measurement for single-mode optical fiber by the stockes parameter method|
|TIA 445 FOTP-243||PMD measurement for installed single-mode optical fibers by wavelength-scanning OTDR and state of polarization analysis|
|TIA TSB-107||Guidelines for statistical specification of PMD on optical fiber cables|
|TIA 455-196||Guidelines for PMD in single-mode fiber optic components and devices|
|Telcordia GR*||GR-2947-CORE||Generic requirements for portable PMD test sets|
|CD Test Standards||IEC Standard||IEC 60793 1-42||Optical fibers—part 1-42: measurement methods and test procedures—chromatic dispersion|
|IEC 61744||Calculation of fiber optic chromatic dispersion test sets|
|ITU Standard||G.650.1||Definitions and test methods for linear, deterministic attributes of single-mode fiber and cable|
|TIA Standard||TIA/EIA FOTP-175-B||Chromatic dispersion measurement of single-mode optical fibers|
|Telcordia GR||GR-761-CORE||Generic Criteria for chromatic dispersion test sets|
|GR-2854-CORE||Generic requirements for fiber optic dispersion compensators|
*Telcordia Generic Requirements (GRs) provide the industry view of proposed generic criteria for telecommunications equipment, systems, or services. These criteria consider a wide variety of factors, including interoperability, network integrity, participating-client expressed needs, and other inputs.
In order for various manufacturers to be able to develop components that function compatibly in fiber optic systems, a number of standards have been developed. IEC and ITU are the major groups that set international standards for the industry. And there are other national standards which are defined to better adjust to the local requirements. This paper lists some common standards of fiber optics, fiber test and measurements. The lists may be not exhaustive and releases are subject to change. For more details, please visit the official website of the corresponding organization (e.g., IEC). For fiber optic products demands, please visit www.fs.com or contact us via firstname.lastname@example.org.