Are You a Data Commander?
     

Today’s headline recalls Commander Data, the android on the TV series "Star Trek: The Next Generation."

I recently toured Paramount Studios and saw workers building the sets for the coming Star Trek movie "Nemesis." I also had a chance to see some of the sets for the "Enterprise" TV series.

Why was lowly Lampen invited? Because almost every scene on the ship has video monitors in the background. In the past, where they could have maybe one or two active monitors and the rest were back-lit transparencies, now viewers want to see things moving on all the screens.

Some sets have more than 30 live screens. This means there’s more than a few feet of cable running everything. They wanted some opinions from this cable guy on the best way to do all this. And this got me to thinking about the world you live in.

Data details

I’ve discussed Category 5 data cables, especially when used to run audio or other non-data signals. I’ve only talked in passing about using them as data cables, which is what they’re designed to do. After all, this column is Wired for Sound, not Wired for Data.

But the difference between those two titles is getting pretty fuzzy. A lot of sound is running as data. Some is running as AES digital audio, which is more "digital" that it is "audio." Other audio systems are using data formats, such as Ethernet, a trademark of Xerox Corp., to run multichannel audio, such as Peak Audio’s Cobranet. Or they’re running digital on fiber optic cable, such as Klotz’s new Vadis system.

I would bet it’s pretty hard to walk into any broadcast facility, including many small radio stations, without seeing a bunch of computer monitors piled on top of that old audio console. Hard-drive, server-based systems, especially those replacing music and spots, are getting cheaper and cheaper. Of course, these are computers that just happen to run audio.

So more than a few of your installations look surprisingly like those Star Trek sets, with a pile of computers, monitors, hard drivers, servers, keyboards and lots of other control devices. The difference, of course, is that the Star Trek stuff is a set, designed to fool you into believing it’s actually working. Yours, on the other hand, had better work. Your station depends on it.

So it’s about time we talked in detail about data. If you are the data commander for your station, you probably have installed Cat-5 or 5e, or maybe even the new Category 6. In this and future columns, we’ll look at these and the data applications that run on them.

Of course, there was life before Category 5. There was a 4 and a 3. Even a 2, 1 and a 0.

Category 3 is still around, and for good reason. Last July, an FCC law went into effect. All telephone wiring, even into homes, must now be a minimum of Category 3. The reason is obvious: what’s running down these cables often is a whole lot more than telephone calls.

Basic Internet access, 56K, ISDN, DSL, XDSL, even T1 now are common on these cables. These can run into the megahertz in bandwidth, a lot more than the 3500 Hz of a phone call. So the emission of signals off of old phone cables can be substantial.

Category 3 was the first attempt to build a data cable out of a telephone cable. Once Cat-3 was in use, earlier cable designs were specified as Category 2, 1 or 0, also called POTS ("plain old telephone service") lines.

Don’t go looking for Cat-2 or lower standards. Most are no longer even recognized, at least as "data" carriers. Category 3 has a bandwidth of 16 MHz.

Then came Cat-4 and, soon after, Cat-5. Category 4 has a bandwidth of 20 MHz. Cat-5 is 100 MHz.

So it should be no surprise that TIA/EIA, which sets the standards for data cables, has eliminated Category 4. And the price differential between Cat-3 and Cat-5 is getting slim enough that many installs are now using Cat-5 for running not only computers but phone lines as well.

Crazy? Like a fox! Putting in an all-Cat 5 install means it doesn’t matter which line is the phone and which the computer.

Want to change your office to a different view? If it’s all Category 5, no problem. If you put in Category 3 for the phone, that’s pretty much all it will ever be.

Putting in all Cat-5 means that you can upgrade your external data delivery with little or no problems. Unless you want to put in something better, like Cat-5e.

Here’s a little riddle that only data "experts" would understand: When is Enhanced Category 5 not enhanced?

A little recent history will explain. Back in the distant past, when Cat-5 was first ratified, some manufacturers thought they could do better. They started to bring out cables that were tested to way more than 100 MHz, some to 350 MHz.

Other manufacturers decided they were going to get on the bandwagon. They also brought out 350 MHz cables, or even 400 MHz – at least, they said their cables worked to these high frequencies. The serious ones actually gave data on attenuation, crosstalk and other parameters out to these frequencies. These cables commonly were called Enhanced Category 5 cables.

Cat-5e

When the TIA/EIA agreed on the standard for an enhanced cable, it was ratified as Category 5e. That means the Enhanced cables, and you will note I use a capital E, may or may not be Category 5e, because they predated the specification. The earlier Enhanced cables simply meant "better than Category 5."

So if you want Category 5e, you’d better ask for Category 5e.

What exactly is Category 5e, and how is it different from Cat-5 and the coming Cat-6? We’ll get to that next time, Data Commanders!

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