As the contents of this month's issue were taking shape, I had several conversations with Chris DiMinico. Chris contributes this month's Standards article (page 37), which details several aspects of the forthcoming 10-Gigabit Ethernet specifications. An initial concern of ours was that the content of his article would be more technical in nature than what most of you, our readership, are used to seeing in these pages. To be honest, I was a little apprehensive at first. I had thoughts like, "I hope I'm not going to see anything that resembles those symbols from Calculus class-the same symbols that appear in the recurring nightmare I have had since 12th grade."
Just like most of my fears, that one was unfounded. No Greek-alphabet stuff this time. But make no mistake about it, this month's Standards article is a fairly heavy technical read. And it should be. The engineering efforts that go into developing specifications for Ethernet or any other transmission protocol are intense, to say the least. And the practical implications of those efforts often hit home for us in the cabling industry.
A great example, which DiMinico refers to, was the discovery of differential mode delay (DMD) in some multimode fibers during the development of the 1-Gigabit Ethernet specifications. The discovery of DMD led many cabling-system users to question the true capability of their installed multimode fiber. Although it has been difficult for many to find concrete answers to those questions, they know which questions to ask because they have paid attention to the technical goings-on in the IEEE engineering group.
Now that the 10-Gigabit Ethernet specifications appear to be on a fast track for approval, cabling-system designers and users should be on the lookout for equally relevant discoveries. As usual, cabling professionals will make decisions today that will affect what we do several years down the road. And as the prospect of implementing a 10-Gigabit Ethernet system gets closer to reality for some high-end users, many of you will make choices surrounding technologies like wavelength division multiplexing (WDM) for the first time. Previously a consideration only for longer-haul fiber-optic runs, WDM will soon be an option within some of the highest-level campus systems.
At the same time that these whispers of WDM in the campus become increasingly louder, technological developments continue with respect to 1-Gigabit Ethernet transmission. Realistically, the 1-Gigabit Ethernet specifications are more relevant to most users today than are the 10-Gigabit specifications. As today's users implement 100-Mbit/sec pipelines to the desktop, gigabit-speed backbones are becoming increasingly common. And the lead story in this month's Industry Spotlight section (see page 44) details testing that was recently done on 62.5-micron and 50-micron fiber with respect to Gigabit Ethernet transmission. In short, the test results suggest that laser-optimized 62.5-micron fiber is capable of meeting many users' transmission needs.
During 1-Gigabit Ethernet specification development, 50-micron optical fiber emerged as a hero of sorts, because it is capable of carrying gigabit-speed signals longer distances than its 62.5-micron counterpart. But preliminary results of this recent testing may prompt users to ponder the notion that 62.5-micron fiber will meet their own individual needs after all.
And so it goes. The research continues, and it continues to bring to light issues previously unconsidered or uncertain. We can look at the situation pessimistically, insisting that promises of "futureproofing" made long ago were pure bunk and that today's options are no more certain. We can look at it optimistically, lauding the minds that are making this technology possible. Or, we can look at it technically, gathering as much information as possible and making decisions that are as informed as they can be.
So, maybe some of the information you see this month is, in fact, a little more technical than what we usually provide. But, just like every other month, the information on these pages is intended to help you make decisions. We never said anything about those decisions being easy.
Cabling Installation & Maintenance Story Ideas
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Do you have an idea for a story on system design, installation, maintenance or troubleshooting? Send it to:
Patrick McLaughlin,
Chief Editor
Cabling Installation & Maintenance
98 Spit Brook Rd., Nashua, NH 03062-2801
tel: (603) 891-9222, fax: (603) 891-0587
e-mail: [email protected]
Patrick McLaughlin
Chief Editor
[email protected]