Networking

What's up with wireless networking technologies?

Are you still waiting for wireless technology to free you from cables and desks? Frustrated that they've not? Read on as Bryan Pfaffenberger brings to light some reasons why wireless is not ready for prime time.


Have you ever wired a home or an office for a cable-based local area network (LAN)? Unless you’re lucky enough to do so while the building is still under construction, you’re in for an expensive, wall-rending job—or a mess of wires running around on the floor, just waiting to be tripped over. But the days of physical cabling may be numbered for many light- to medium-duty LANs, thanks to a bevy of new wireless local area networking (WLAN) technologies. The most widely known (and easily obtained) WLAN technology is based on IEEE standard 802.11b (also called Wi-Fi), but there’s a new kid on the block called Bluetooth. If you’re thinking about going the WLAN route, which is for you?

If you’re creating a wireless LAN right now, the question is easy enough to answer because Bluetooth isn’t yet available. So you’ll set up your network using 802.11b products, which enable you to create an 11Mbps wireless LAN using the 2.4-GHz ISM (Industrial, Scientific, and Medical) frequency. But what about the future? Although Bluetooth is having some trouble getting off the ground, most observers believe its advantages will make it a major player. If you’re thinking about moving to a wireless LAN, should you wait for Bluetooth?

As this Daily Feature explains, this is a classic apples-and-oranges problem: 802.11b and Bluetooth differ not only in their underlying protocols but also in what they’re designed to accomplish. As you’ll see, 802.11b was designed from the get-go as a fast, flexible wireless networking technology—a LAN without wires. In contrast, Bluetooth goes after a much wider market. Bluetooth isn’t designed to replace LANs so much as all those vexing connectors needed to interface notebook computers, printers, cellular telephones, personal digital assistants (PDAs), and pagers. One way of putting this point is that 802.11b is a wireless technology for LANs, while Bluetooth is a wireless technology for personal area networks (PANs). If you’re not quite sure what a personal area network is, don’t be dismayed—they don’t exist yet, really. But once you’ve grasped the point, you’ll probably agree with the Bluetooth enthusiasts who believe that Bluetooth, despite its rocky start, is going to be a winner.

Introducing wireless personal area networks (WPANs)
To understand the rationale for Bluetooth (and WPANs in general), just take a look at my briefcase. It looks like a snake pit. I pack around at least a dozen incompatible connecting cables—cables to link my Palm to my Vaio, cables to connect my Vaio to my digital cellular phone, cables to connect with my portable printer, cables to connect with phone lines, and, since I’m a completely out-of-control gadget freak, cables to connect with a portable Geographic Positioning System (GPS). And I’ll tell you, it’s a nightmare. The cables all look alike; they get tangled; I can never find the correct one when I need it; the connectors break or become corroded. My wife is absolutely convinced that I have her missing Nokia charging cable, so she keeps taking cables out of my bag more or less randomly—and somehow, they don’t find their way back. I’m ready to chuck the whole thing and go back to a telephone and typewriter!

If you’ve been through anything like this, you’ll understand the rationale for Bluetooth. It won’t replace charging cables, but as long as data is involved, Bluetooth is ready. Essentially, Bluetooth is a communications protocol that, like 802.11b, uses the 2.4-GHz ISM band, but it’s also a hardware specification; Bluetooth development is focusing on creating a super-cheap, mass-produced wireless networking chip that can be embedded at very low cost in just about any device capable of digital communication (including digital cellular phones, printers, modems, notebook and desktop computers, personal digital assistants, pagers, and GPS devices). A key Bluetooth goal is transparency: Getting two Bluetooth-enabled devices to communicate should be as simple as bringing them within 30 feet of each other. Think of the convenience! While you’re traveling, you can get on the Internet and get your e-mail by merely bringing your Bluetooth-enabled PDA into the requisite proximity to a Bluetooth-enabled connection point in your hotel.

A WPAN, in short, is intended to enable individuals to get their entire grab bag of mobile digital devices communicating happily without dozens of incompatible cables and lengthy, difficult-to-remember procedures. And the cost won’t break the bank. If Bluetooth pans out, the Bluetooth chip will be so inexpensive that it will be included in every mobile device sold.

Sounds great, huh? Before you get too excited about Bluetooth, though, bear in mind that the technology is suffering from two major problems. First, it’s taking a longtime for this particular aircraft to get off the runway and into the air. Vendors have been slow to commit to Bluetooth, and a much-ballyhooed demonstration at a Hanover, Germany trade show turned into a major embarrassment when conference attendees couldn’t get their devices to connect. Microsoft created further grist for the journalist’s mills by announcing that the firm would hold back on building Bluetooth support into its flagship operating system, Microsoft Windows XP. Still, these are the problems typically experienced at the youthful end of the growth curve. The predictions people are still saying that they expect 1.4billionBluetooth-enabled devices to ship in 2005.

The more vexing problem is the second: There’s good evidence that Bluetooth will interfere with the most widely used WLAN protocol, 802.11b; you won’t be able to use them in close proximity to each other. In short, Bluetooth won’t replace WLAN technologies—it’s too slow, and it really wasn’t designed for local area networking purposes—but itwillvery likely interfere with them. That’s bad news indeed, and it’s a safe bet that consumer and business purchasers aren’t going to like this situation. Wireless LANs are hot sellers. How are you going to react when you’re told you have to shut down your 802.11b network in order to use a Bluetooth device?

Will 802.15 provide a solution?
In sum, 802.11b and Bluetooth are designed for very different applications—802.11b implements wireless local area networks, while Bluetooth implements transparent connectivity for an individual’s array of digital devices (or, to use the uptown lingo, they’re designed to implement wireless personal area networks). The trouble is, the two wireless technologies interfere with each other. And that’s precisely why the folks at IEEE are busily working on a new wireless local area networking protocol, called 802.15, which will fully implement the Bluetooth protocol while remaining downwardly compatible with 802.11b devices. Wish them luck!

In case you missed the moral of the story, here’s the spelled-out version: With Bluetooth and 802.15 looming on the horizon, 802.11b might be short-lived. If you need a small wireless LAN, don’t hesitate to make use of 802.11b devices, but you’d be wise to wait a year or two before making a major technological commitment.

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