FOR IMMEDIATE RELEASE

ANSI/TIA/EIA-568-B.3 is Ratified and Released - Revised Standard Supports the Deployment of Fiber in the Horizontal

Arlington, Va., April 14, 2000 -- After two years of intense debate and development, the Telecommunication Industry Association's TR 42 Committee has completed revisions to the section of ANSI/TIA/EIA-568 that covers optical fiber technology. During the revision process, the standard was divided into three sections. The 568-B.3 document was completed in March and is being released in advance of 568-B.1 (containing general requirements) and 568-B.2 (on balanced copper cabling). The document is available from Global Engineering Documents by calling 1-800-854-7179 (U.S. and Canada), outside the U.S. at 1-303-397-7956 or from their website at http://global.ihs.com.

The revised standard is important to the design of premises networks on several levels. Annex A of the pending TIA-568-B.1 will elevate the status of centralized optical fiber cabling from a technical service bulletin (TSB-75) to an normative annex. TIA-568-B.3 addresses the use of such critical technologies as 50/125 micron multimode fiber and small form factor connectors. According to Tony Beam, who chairs the Fiber Optic Task Group and served as Chair of TIA TR 42.8 during this process, "the new standard takes into consideration the need for companies to support higher bandwidths all the way to the workstation and gives users the protection of standards-based solutions."

Centralized Cabling Helps Lower Costs

Introduced in 1997, centralized cabling was the first premises cabling system design that complies with the Commercial Building Telecommunications Standard and allows network designers capitalize on the performance benefits offered by optical fiber cabling. Centralized cabling designs use the high bandwidth and low attenuation of multimode fiber to centralize LAN electronics in one communications room within a building. Centralized networking using optical fiber offers users the ability to contain - and even reduce - their operating costs, while simultaneously adding flexibility, control and accessibility to their networks.

More Fiber Options

TIA-568-B.3 includes 50/125 m optical fiber in the standard, which will help network designers because it offers them more options and greater flexibility in their network design. While not a recognized media in 568-A, 50 mm multimode fiber is not a new fiber design. In fact, its introduction pre-dates that of widely used 62.5 mm fiber. The revised standard includes all specifications for fiber performance, including physical, mechanical, optical and environmental. The minimum bandwidth for 50/125 m optical fiber is 500/500 MHzkm at 850/1300 nm. The minimum bandwidth for 62.5/125 m optical fiber remains at 160/500 MHzkm. The standards for cabled fiber performance for the two fiber types are the same.

"While 62.5 micron fiber meets the vast majority of network requirements, especially in the horizontal, including 50/125 micron multimode fiber gives network designers more choices in their network design," explains Beam. "50 mm multimode fiber has more bandwidth (500 MHzkm) than FDDI-grade 62.5 mm fiber (160 MHzkm) at 850 nm. While both fibers can be used with vertical cavity surface emitting lasers (VCSELs) and can run Gigabit Ethernet and higher speed protocols, 50 mm will be able to do so over longer distances at the 850 nm window. " Beam added that in the 1300 nm window, both 62.5 mm and 50 mm fibers provide similar performance and that high performance 62.5 mm fibers, that offer enhanced performance at 850 nm also are available. "It's not a question of one fiber being better than another," he said. "It simply allows network designers to choose the fiber that best meets their system requirements."

Small Form Factor Connectors Included

The other significant change to the standard relates to connectors. Rather than specifying a specific connector design to either replace or supplement the SC-duplex connector, the standard now defines connector choice through performance requirements (optical, mechanical and environmental) that an optical fiber connector or patch cord assembly used in the premises environment must meet.

Thus, TIA 568-B.3 allows the new small form factor (SFF) connectors as long as two main requirements are met. First, a Fiber Optic Connector Intermateability Standard (FOCIS) document (TIA/EIA-604-XX) is required to ensure products made by different manufacturers will mate with good results. Second, the connectors must meet the mechanical and environmental performance requirements set forth in Annex A of TIA 568-B.3. "The addition of Annex A is very significant because this establishes for the first time the complete performance requirements for premises optical fiber connectors", notes Beam. The basic minimum requirements for an optical connector are maximum loss of 0.75 dB for multimode or singlemode fibers and a minimum return loss of 20 dB for multimode and 26 dB for singlemode fiber. SC duplex and ST-compatible connectors are still allowed under these same provisions.

"Because of their small footprint, ease of connection and lower cost, the SFF connectors are facilitating the use of optical fiber further into the network," said Beam. "Including SFF connectors in this standard represents a significant step toward making fiber-based systems more affordable." The small footprint, for example, allows LAN electronics manufacturers to achieve port densities equal to copper products, leading to substantial cost reductions.

For more information on the technical advantages and affordability that optical transmission brings to local area networks and fiber-to-the desk applications, please contact the Fiber Optic LAN Section (FOLS) of the Telecommunications Industry Association (TIA). The FOLS is a consortium of leading fiber optic cable, component and electronics manufacturers. Member companies include 3M, AMP, Allied Telesyn, Berk-Tek, Belden Wire & Cable, CommScope Inc., Corning, LANCAST, Lucent Technologies, Ortronics, Panduit, Siecor, The Siemon Company, SpecTran, Sumitomo Electric Lightwave and Transition Networks.

TIA is a full-service national trade organization with membership of 1000 large and small companies that provide communications and information technology products, materials, systems, distribution services and professional services in the United States and around the world. The association's member companies manufacture or supply virtually all of the products used in global communications networks. TIA represents the telecommunications industry with its subsidiary, the MultiMedia Telecommunications Association, in association with the Electronic Industries Alliance.

Note: The opinions expressed in this release are those of the Fiber Optics LAN Section of the Telecommunications Industry Association and are not necessarily those of the entire TIA membership.