WIRELESS HARDWARE ANNOYANCES

YOUR ELECTRIC GARAGE DOOR ISN'T A PROBLEM

The Annoyance:

I want to expand my wired network with wireless technology, but I keep hearing about interference with the wireless signals. Is it true that opening an electric garage door can stop wireless communications, or that sending data from a wireless computer can open the garage door?

The Fix:

I hear that question constantly, and I've never figured out how that warning became so ubiquitous. Even though wireless computers and remote-controlled garage doors operate with radio frequency (RF) technology, they're on frequencies far, far apart from each other. Most (probably all) garage doors, and the doohickeys you use to open them remotely, use the 433MHz frequency range. Wireless computers in home networks (802.11b and 802.11g) operate in the 2.4GHz range.

AVOIDING STUFF THAT BLOCKS WIRELESS TRANSMISSIONS

The Annoyance:

I like the idea of wireless connections. Can you give me a list of things to avoid so that the transmissions aren't blocked?

The Fix:

Wireless users, and manufacturers of wireless equipment, have pretty much agreed on a list of things that are sure to cause problems. Here are the "top five":

• Metal. Don't put an antenna under a metal desk or next to a metal file cabinet. Metal in the walls and ceilings can also block transmissions.

• Water. Drain your moat if you want to use your computer outdoors. Move that large fish tank to a room that doesn't have a wireless device.

• Cordless telephones (when they're in use).

• Microwave ovens (when they're in use).

• Amateur radios (when they're in use).

Other transmission blockers exist, but those listed here are the "sure things."

WORKING WITH OMNIDIRECTIONAL ANTENNAS

The Annoyance:

Our wireless signals occasionally drop out, but even when the computers are communicating, the signal is weak and data transmissions are slow.

The Fix:

A common reason for these problems is incorrect placement of the antennas. The antennas that come with most wireless devices are omnidirectional, which means they radiate signals in every directiona 360-degree arc. However, most users put their wireless devices (computers, access points, routers) near a wall. If the wall has any material that can block transmissions (metal) or degrade the signal (brick, cement, thick glass), the signal in that portion of the 360-degree arc is compromised. The antenna doesn't strengthen the signal going toward the middle of the room enough to make up for the lost signal.

With omnidirectional antennas, the way to maintain signal strength and speed is to put all the wireless devices in the middle of the room. And I mean the middle of the room, not the middle of the floor. You can locate this by finding the midpoint of the horizontal plane and the midpoint of the vertical plane. If your room is 10 feet by 12 feet, with an 8-foot ceiling, the midpoint of the room is 5 feet in from one wall, 6 feet in from the other wall, and 4 feet above the ground.

It's difficult to put a computer in the middle of a room because it messes up the décor. However, you should make every effort to "middleize" (I think I invented a word) the router and any access points you might have added to your system. Hang the router from the center of the ceilingduct tape is a great tool. Or investigate directional antennas.

DO I NEED A DIRECTIONAL ANTENNA?

The Annoyance:

Our wireless router is perched on a bookshelf in the corner of a room, and a geeky friend told me to use a directional antenna on it. How do I do this, and what difference will it make?

The Fix:

You can buy a directional antenna from any manufacturer of network devices, and replace the existing antenna (they're removable on some devices). A directional antenna uses all its energy to transmit and receive signals from a single direction (forwardso position it according to the instructions), instead of spreading its signal in a 360-degree sweep. When an antenna is in a corner, or against a wall, it's usually more efficient to use a directional antenna.

SIGNAL DISTANCE PROBLEMS

The Annoyance:

Our wireless network works fine until one of the computers moves more than 40 or 50 feet away from the router. What's the maximum distance for wireless?

The Fix:

The "rated" maximum distance for wireless network adapters is usually about 1,500 feet outdoors and 300 feet indoors. The word "rated" means "under perfect circumstances," and that's something to think about carefully.

For outdoor distance maximums, "perfect circumstances" means your entire network is outdoorsthe router, any access points, and all the computers on the network. The indoor distance maximum depends on structural elements in the house. I've never seen a building that passes a "perfect circumstances" test. Almost anything in the walls, except for air, can block or degrade the wireless signal. Because no wall stays up with air as the only component, you lose some of the signal as soon as you ask it to pass through a wall. The nails in the studs, metal in plaster lath, air conditioning ducts, cast iron pipes, and even lead paint can interfere with the signal. In the end, don't count on getting more than about a 50-foot range, a little more if you're lucky.

DON'T GET TOO CLOSE TO THE ROUTER

The Annoyance:

One of the computers on our wireless network sits on the same table as the router, and yet it frequently can't communicate with the network or get to the Internet. What's going on?

The Fix:

Too close for comfortI'm not singing the song (though I am humming it as I type this), I'm telling you what's going on. Usually, the "don't get too close" problem isn't documented in the manual that comes with your network adapter. Search the support files at manufacturers' web sites, or call their support technicians and you'll be told that a computer directly below the antenna of an access point or router will have a weak or nonexistent signal.

DISTANCE, BUT NO SPEED

The Annoyance:

I can take my wireless laptop to the next floor, or even out on the front porch, without losing the signal. However, the transmission speed drops so much that it takes almost a full minute to open or copy a small file from another computer. What good is a wireless network if you're not totally portable?

The Fix:

There's an inverse ratio between speed and distance in wireless transmissions; it's just one of those things (oh no, another old song). You can try to eliminate some of the things degrading the signal. For example, your front door might be metal, or have metal parts. Move away from it, perhaps close to a window.

GIVE YOUR SIGNAL A BOOST

The Annoyance:

I see that manufacturers offer new routers and other devices advertised as "boosters." Are they worth buying to improve signal speed and distance?

The Fix:

Speed, yes; distance, no. The boosters do improve the speed of communications, but they don't help you achieve greater distances. Even with boosters, as you move away from the other wireless devices, you lose speed. However, a boosted signal means the speed loss isn't as dramatic until you move far, far away. Also investigate replacing the antenna with a more powerful model (almost all routers or access points permit you to replace the antenna).

ROUTERS ARE ALSO ACCESS POINTS

The Annoyance:

I'm planning to buy an access point so that I can get the additional security it provides for wireless networks. Can I put the access point near the wireless router, or will the signals interfere with each other?

The Fix:

Your router already has a built-in access point, and it provides all the same security advantages that a standalone access point would give you. I just saved you some money!