In a departure from what many have come to expect from the group, the Telecommunications Industry Association (TIA-www.tiaonline.org) has published a networking standard specifying 100Base-SX. Professionals in the cabling industry have known the TIA as a provider of system-infrastructure specifications, and generally have looked to the Institute of Electrical and Electronics Engineers (IEEE-www.ieee.org) 802 Committee for Ethernet standards. But in this case, the TIA brought forth a networking standard, in the form of TIA/EIA-785.
Specifying 100-Mbit/sec Ethernet transmission in the 850-nanometer (nm) operating wavelength, the 785 standard was submitted to the American National Standards Institute (ANSI-www.ansi.org) board of standards review in early May. The TIA Fiber Optics LAN Section (www.fols.org) said it expected the standard to be available in June.
The short-wavelength Fast Ethernet standard has been several years in the making, dating back to March 1998 when the Short Wavelength Fast Ethernet Alliance met in Dallas. A few months later, that group presented to the TIA's FO-2.2 subcommittee, which got to work on the project later that year and finished this past March.
Since the conception of the Short Wavelength Fast Ethernet Alliance, the group has promoted the specification as a cost-effective upgrade path for fiber-optic cabling users. The only previously ratified 100-Mbit/sec fiber-based standard demands 1,300-nm electronics, making an upgrade from 10- to 100-Mbit/sec an expensive proposition for fiber users.
Auto-negotiation is an optional part of the standard. In standard-compliant systems with full auto-negotiation capability, 10- and 100-Mbit/sec Ethernet ports can communicate with each other during link establishment.
Developers of the standard characterize it as a clear, simple, and inexpensive upgrade path from 10- to 100-Mbit/sec fiber-based Ethernet, and say it decreases the cost of 100-Mbit/sec fiber-to-the-desktop.
-Patrick McLaughlin
