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Archive for Monday, November 4, 1996

T CRACK SPEED BARRIER

November 4, 1996

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Sooner or later, everyone finds themselves wanting to get things moving faster when using their computers to connect to the Internet. Don't count on modem speeds going up any time soon -- we've just about hit the speed limit of modems as we know them, mostly because standard voice-grade phone lines simply won't support more speed than the 28.8 kilobits per second that is common today.

Data compression can yield somewhat higher throughput in some cases, and most modems today can do compression, but it only works if the data is compressible. Plain text compresses pretty well, but some graphic formats don't.

Another road to higher speed Internet bliss that has been touted in recent months is ISDN, which stands for Integrated Services Digital Network (or, as some read it, "I Still Don't Need it"). ISDN has been around for quite some time but only in the past few years has it been widely available for use by consumers in the home.

While Plain Old Telephone Service (POTS) is an analog service, ISDN is a digital service. There isn't sufficient space in this column to thoroughly explain the difference between analog and digital signals, but here's the condensed version: analog phone service operates by converting your voice into an electrical signal, amplifying it and moving it along wires until it gets to the other person's phone, where it is converted back into sound by the little speaker in the telephone handset. Digital phone service starts with the analog audio signal of your voice, then converts it into digital data, which is easier to transmit over long distances without loss of signal quality. At the other end, the digital data is converted back into analog data and is used to reproduce sound in the other person's phone handset.

Way back in the 1960s, the phone company (there was only one back then) began converting its internal network from analog to digital equipment, but the connections from the central telephone switching equipment in any given community to the phone customer's home or business were (and mostly still are) analog.

In the mid-1980s, standards for ISDN were developed, but the phone companies have been slow to implement ISDN since then, and only in the last few years has this technology become widely available. And it still isn't available everywhere -- Southwestern Bell began making it available in our area just last year.

ISDN comes in two basic flavors -- Basic Rate Interface (BRI) and Primary Rate Interface (PRI). BRI runs at 128 kbps, and PRI runs at 1.5 Mbps. BRI is what you'll normally get for use at home. PRI ISDN connections are far too expensive for the average home user.

Some would argue that ISDN is a technology whose time has come -- and gone. It may be a digital service, but it's still essentially a phone service, and depending on where you live in the United States, it can be quite expensive. In some areas, ISDN has been marketed aggressively, and is available for as little as $20 per month. In other areas (such as our area here in Kansas), it may cost you more than $100 per month. Installation fees can be quite high in some cases, and depending on what level of service you buy, there may be per-minute charges as well, just like with long-distance phone service. And that doesn't take into account the fact that you'll probably have to invest in several hundreds of dollars' worth of special hardware to make it work in your home.

Still, more Internet service providers are offering ISDN connections to the Internet, and if you really need the speed, it might be worth taking a look. But there are still other options for higher-speed access to the Internet. Next time we'll take a look at a relatively new express lane to the Net, and it comes from your cable television connection.

Oh, and by the way, why not turn off your computer long enough to get to the polls Tuesday?

-- Doug Heacock is director of the Kansas Research and Educational Network at Kansas University. You may address questions to him in care of the Lawrence Journal-World, 609 N.H., Lawrence 66044, or e-mail him at heacock

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