Hack 55 Extend the Range of Your Wireless Network


The efficiency and throughput of WiFi networks can vary dramatically. Make sure you get maximum throughput from your wireless network.

If you have more than one PC at home, the best way to hook them together and share a high-speed Internet connection is via a wireless network?in particular, one based on the WiFi standard, which is actually a family of standards known under the umbrella term of 802.11x.

The biggest problem in setting up a home network usually involves running the wires between PCs and a residential gateway. If your PCs are on different floors of the house, you may have to drill holes in your walls, ceiling, and floors and run wire through. Even when PCs are on the same floor, you have to deal with the problem of wires snaking along the floor.

That's the problem I've had in my 150-year-old home in Cambridge. Drill through a wall, ceiling, or floor here, and you never know what you'll find (horsehair insulation was only one of our many surprises). Even my electrician shudders when he has to take out the drill.

So, for me, a wireless network was a no-brainer. I now have got half-a-dozen PCs and laptops and three printers in remote parts of the house from each other, all connected via a combination wired/wireless network and sharing a single broadband Internet connection. And when the weather is nice here (twice a year, by my last calculation), I take my laptop out on my back porch and work from there while still connected to the Internet and other PCs and printers in the house.

But there's a catch with all wireless networks, including mine. Wireless networks rarely deliver data at their rated bandwidth speed. One factor affecting bandwidth speed is the distance between the access point and the wirelessly equipped PC. Compaq, for example, notes that at a distance of 150 feet the throughput of its wireless access point drops from 11 Mbps to 5.5 Mbps, and at a distance of 300 feet it drops to 2 Mbps. Even that significantly understates the drop-off in speed, and most people find that the drop-off is much more dramatic than that, most commonly by a factor of two.

WiFi and Buying New Equipment

There are several versions of the 802.11x WiFi standard, and unfortunately, they don't all work with one another. So, when you're buying WiFi equipment such as hubs/routers, make sure they're compatible. The 802.11b standard was the first one to be ratified, is the most common type of WiFi network, and its equipment is the least expensive. (This is the standard commonly used by public wireless "hot spots" in coffee shops, airports, hotels, and other locations.) It operates in the 2.4 GHz part of the spectrum and its maximum throughput is 11 Mbps.

Increasingly popular, though, is the 802.11g standard, which also operates in the 2.4 GHz part of the spectrum but has a much higher maximum throughput: 54 Mpbs. 802.11b cards will connect to a 802.11g access point, but only at a maximum of 11 Mpbs. However, 802.11g cards can't connect to an 802.11b access point. As of this writing, problems have been reported using 802.11b hardware on an 802.11g network, however. There have been reports of incompatibilities and of the 802.11b hardware slowing the entire 802.11g network down to its slower speed. However, that's because the 802.11g hardware was built when the standard was only a draft and not a final standard. The standard has since been finalized, so if you buy new equipment, you should be safe. Be wary of buying older, used equipment, though.

Distance is only one factor affecting performance. Interference from other devices and the exact layout of the house or office can also affect it dramatically. However, there are things you can do to extend the range of your network and get more throughput throughout your home:

  • Centrally locate your wireless access point. This way, it's most likely that all of your wirelessly equipped PCs will get reasonable throughput. If you put it in one corner of the house, nearby PCs may get high throughput, but throughput for others may drop significantly.

  • Orient your access point's antennas vertically. As a general rule, transmission will be better when antennas are vertical rather than horizontal. Keep in mind, though, that this is only a starting point for positioning its antenna. The exact layout of your house may alter the best positioning of the antenna.

  • Point the antennas of your wireless PCs toward the access point. Although 802.11 technology does not require a direct line of sight, pointing them in this way tends to increase signal strength. USB wireless cards generally have small antennas that can be positioned, but frequently wireless PC cards don't, so you may have trouble figuring out the antenna orientation in a wireless PC card. If you have a wireless PC card that doesn't have what appears to be an antenna, the antenna is generally located at the periphery of the card itself, so point that at the access point.

  • Don't place your access point next to an outside wall. If you do that, you'll be broadcasting signals to the outside, not the inside, of the house. That's nice if you want to give your neighbors access to your network, but not great if you want to reach all the PCs in your house.

  • Avoid putting your access point or PCs near microwave ovens or cordless phones. Many microwave ovens and cordless phones operate in the same 2.4 GHz part of the spectrum as 802.11b WiFi equipment. So, microwave ovens and cordless phones can cause significant interference. Cordless phones tend to be the bigger problem.

  • Avoid placing the antennas of access points or PCs near filing cabinets and other large metal objects. They can both cause significant interference and dramatically reduce throughput.

  • Consider using external and booster antennas. Some PC cards, notably Orinoco cards, will accept external antennas that you can buy or build on your own. They have a small connector to which you attach a pigtail and wire and then attach that wire to an antenna. (For information about building your own antenna, see [Hack #42]). Some access points often accept booster antennas that you can buy as well.

    If you have a Linksys wireless network and are looking to improve its signal strength, you can buy a $99 add-in that promises to extend its range and strengthen its signal. The WSB24 Wireless Signal Booster sits on top of your existing wireless router. You take the antennas off your router, attach them to the booster, then attach the booster to the router via cables. I haven't tried it myself, so I can't personally vouch for it, but those who have tried claim it works.

  • Try and try again. The ultimate way to find the best placement for your access point and wireless PCs is to continuously experiment and see what kind of throughput you get. Each house and office is so different that no single configuration can suit them all.

Carefully monitor your throughput as you make these changes, so that you determine the best positioning for your access point and PCs. To determine your true throughput, use the free network analysis program QCheck [Hack #57].

5.15.1 See Also

  • [Hack #42]

  • [Hack #57]