Small-form-factor connectors: Just about anything goes

Network designers trying to decide which vendor's small-form-factor (SFF) fiber-optic connector is the best solution can now relax. Take your pick-as long as it meets definition, performance, and intermateability requirements recently set forth by the TIA TR-42.1 standards committee.

Network designers trying to decide which vendor's small-form-factor (SFF) fiber-optic connector is the best solution can now relax. Take your pick-as long as it meets definition, performance, and intermateability requirements recently set forth by the TIA TR-42.1 standards committee.

The SFF approval will be incorporated into the next draft of ANSI/TIA/EIA 568-B.1, expected to be published in August. Previously, only the 568SC duplex connector was recognized for use in the telecommunications work area. "This [decision] brings an end to the connector war," says Vincent Wong, chairman of the VF-45 Action Group-an independent industry organization promoting the deployment of SFF interconnects in optical-fiber networks. The decision, adds Wong, "provides some reassurance for IT decision-makers who are convinced that fiber makes sense but were waiting on a standards consensus before making the move away from copper."

Manufacturers that have been lobbying hard for acceptance have included 3M Telecom Systems Div. (Austin, TX), Siecor (Hickory, NC), Panduit Corp. (Tinley Park, IL), and Lucent Technologies (Murray Hill, NJ).

By definition, an approved SFF device is any optical-fiber duplex connector with a footprint approximating that of an 8-position modular/outlet connector typically used with 4-pair copper cable. Performance requirements focus on such areas as attenuation, return loss, temperature and humidity factors, strength of coupling mechanism, and durability.

Multimode connectors, adapters, and cable assemblies must meet these requirements at both 850- and 1300-nanometer wavelengths, while singlemode devices must qualify at both the 1310- and 1550-nm wavelengths. All devices must comply with dimensional requirements set by the Fiber Optic Intermateability Standard (FOCIS).

In May, a TR-42.1 subcommittee had approved Residential Telecommunications Cabling Standard 570-A that allowed SFF connectors at the outlet. Sweeping approval for SFF connectors was prompted in part by a growing demand for desired (easier and more affordable) use in local-area-network installations and after considerable product support from network-interface-card manufacturers and overwhelming support from BICSI (Tampa, FL) designers and end users.

-Steve Smith

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