Flying Without a Wire

Imagine you're relaxing in you backyard, sipping a cool drink, while you surf the internet. Or perhaps you're at the airport, waiting for your flight, and checking your email. These are both realistic examples of what's possible with current wireless technology.

Until recently, connecting one computer to another, or to a network, or to the Internet, required network cables. If the computers in question were sitting side-by-side on a desk, this was not a problem. But if they were in different rooms or different buildings it required the expense of running cables through walls and ceilings, or the mess of laying them across the floor.

Wireless technology, or Wi-Fi, changes all that.

There are a number of options available, but in line with our moniker we're going to keep the discussion relatively simple.

To start, you need a wireless network adapter. Many newer models of notebook computers -- such as Apple's PowerBooks -- come with an adapter built in. For those that don't, for older machines, and for desktop computers, you should be able to purchase a wireless network card for less than $50 US.

Once you've installed your network adapter and configured any necessary drivers and utilities, you're ready to connect. Now you need something on the other end. This could be another wireless-enabled computer (for peer-to-peer or ad hoc mode) or a base station or wireless access point (for client-server or infrastructure mode.) This will probably cost you less than $100 US.

If you're connecting to a base station, that base station could then connect you to a network composed of servers, client computers (both wired and wireless), printers, and the Internet.

Of course, nothing is ever that simple. Let's look at some details.

Wireless devices communicate via set standards. (We're referring here specifically to wireless computing, not such devices as garage door openers, cell phones, pagers, and so forth which have their own standards.) As to be expected, there are several standards in use, each with advantages and disadvantages. The most common right now are 802.11a, b, and g.

Here's how they compare:

From that list, we may think it would make sense to just stick to 802.11g. It's faster than 802.11b and has better range than 802.11a. However, 2.4 GHz is an unregulated frequency. That means anyone can use it, and there's no protection from devices like microwave ovens. It is also the same frequency used by cell phones and Bluetooth devices (a short-range wireless system often used by handheld devices; we'll discuss it more at another time) so there may be interference problems between systems. Further, 802.11a, while limited in range, allows more channels over it's frequency, and thus greater security.

Since 802.11b and 802.11g work at the same frequency, they are generally compatible. That is, if you have an 802.11g network adapter, you should be able to connect to an 802.11b base station. Of course, you would be limited to the maximum speed of the slowest device. 11b/11g are not compatible with 802.11a systems.

Most vendors offer hardware that adheres to 802.11b or 802.11g standards and, as you might expect, the slower of the two is generally cheaper. But 802.11b, with a maximum speed of 11 mbps, is fast enough for most applications. If you're browsing the Internet, chances are your connection through cable or DSL is only 1 mbps or less. That will be your limiting factor, not the speed of your wireless connection.

We should also emphasize that the figures quoted above are theoretical maximums. You will almost never achieve those speeds or distances, and should count yourself lucky if you get half that indicated. Walls, furniture, plants, and people will reduce your range. And, generally, the further you get from the base station or other device, the slower your connection will be. If you want to increase your range, you may need to use an extender or repeater.

Once you've got your notebook configured for wireless networking you may be able to hitch a ride on a public access point, called a Hotspot. These are often available in cafes, libraries, highway truck stops, and airports. Some are free, most are available for a one-time or subscription fee.

Of course, security is always an important concern no matter what type of networking you're using. But wireless networks, because there's no cable to splice into, are inherently less secure than wired networking. An intruder could park a car outside your home or office and tap into your network. So it's vital to implement reasonable security precautions.

Most network devices, particularly base stations, allow you to set a password for administrative use. You should always change the default password to something only you know.

You may also be able to change the Service Set Identifier (SSID) on your network. All devices that communicate together must have the same SSID.

802.11b and 802.11g support up to 14 channels. (Available channels may be limited by government regulations.) You may be able to restrict allowed devices to a single channel.

Check your base station's documentation to determine if you can enable MAC filtering. Every network device has a unique Media Access Control (MAC) address, also known as a hardware address. You may be able to set up a filter so only addresses you specify are allowed access.

Use encryption in your wireless devices. Wireless Encryption Protocol (WEP) is standard, but not very secure. Wi-Fi Protected Access (WPA) is stronger, but not all systems support it.

Secure the rest of your network. Install and enable firewalls on all your computers. Use encryption when sending sensitive email. Never purchase products or services from web sites that do not enable SSL security. (Most web browsers will have some way of indicating whether you're on a secure page, such as a padlock icon.)

Connecting your computer to a network or to the Internet is just the beginning of the wireless world. You can now purchase print servers, wireless cameras (great for setting up an inexpensive security system), and adapters for your stereo system and television. In the future, look for wireless devices for your car, and wireless appliances.