Windows Tip Sheet

Cleaning Up Wireless Clutter

Before you consider buying expensive gadgets, try a low-tech approach.

• By Don Jones
• 11/03/2004

Signal Strength: Low
As a certified geek, I was the first in my family to jump on the 802.11x bandwagon. And in the apartment I'm currently living in, it's a necessity more than a luxury. My desk is so far away from the cable modem that stringing a wire would be completely out of the question. Besides, the ferrets would probably try to chew on it. So, wireless is a really good thing. But my desktop computer, which has an 802.11g card in it, always got a "Good" or "Low" signal, while my laptop computer, which sits right next to my desktop, frequently gets an "Excellent" signal. What gives?

Everyone Scatter!
It turns out the reason for my signal issues is pretty common and occurs in offices, Starbucks, and other places where wireless usage is common. Try to figure it out. My desk is a fairly typical setup, with a small cubby near the floor for the desktop box, some cabinets overhead for books and whatnot, and CD storage. The desk isn't especially close to any high-voltage lines or anything else that usually disrupts wireless services, and I don't use a cordless phone or any other device that uses the 2.5GHz range that 802.11b/g utilize. My laptop—which, remember, always gets a good signal—sits right above the desktop box. And before you ask, the desktop's signal strength doesn't change when I move the laptop.

Did you catch the problem? CDs. Those culprits are made from a thin sheet of a metallic substance sandwiched between a couple layers of plastic. CDs are basically big signal reflectors, making them as reflective of radio signals as they are of light. With a big stack of them hanging above my desktop machine, it's a miracle any signal got out. Moving the CDs got me a "Very Good" to "Excellent" signal on most days.

You wouldn't think that a metallic mass sitting above the wireless antenna would matter much, since by and large wireless antennas (at least on wireless NICs) transmit a pretty significant horizontal signal in addition to the vertical signal. In other words, the blockage above shouldn't have affected signal coming from the side, which is what needed to be clear to reach my wireless access point. But the overhanging reflective CDs bounced too much signal back down at the PC, helping to scramble all the signals and reducing the overall signal quality.

In an office, any radio-reflective obstructions—fluorescent light fixtures, metallic cube walls, even micro-blinds—can cause signal bounce-back. Get enough bounce-back close enough to the antennas and your wireless network will be trying to scream its signal through a sea of noise, with the result being diminished signal quality. Clean up that office and keep the CDs a safe distance from the NIC and you should be fine.

Micro Tips Wireless signal loss is a major cause of Microsoft Outlook lock-ups in many offices: Outlook loses the network connection for a second and freezes up because it can't see the Exchange server anymore. Outlook 2003 corrects this by working in a cached mode by default. Outlook uses its offline cache all the time, and that cache updates whenever a connection is present. Lose the connection and Outlook will hang for a second but will quickly get over it and let you continue working until the connection comes back. Wireless speed can be compromised by having too many repeaters. Ideally, you shouldn't use repeaters at all. Instead, hook up additional access points directly to the wired network. Do some testing so that each access point’s range only slightly overlaps its neighbor’s broadcast area; the more access points broadcasting into the same area, the slower data transmission will be within that area.

More Resources:
• Check out these wireless networking performance tips to put more of a zing into your wireless throughput: http://www.smallbusinesscomputing.com/webmaster/article.php/3109411
• Microsoft has a Knowledge Base article on troubleshooting XP's wireless networking capabilities: http://support.microsoft.com/default.aspx?kbid=313242
• Many major brands of wireless NICs, including those embedded in many devices, use hardware from Broadcom and carry the "54g" logo. Check out http://www.54g.org, the official Broadcom site, for details and tips.