by BjÃƒ:¸rn Jensen
WIRELESS NETWORKING is a regular fact of life, but there are many potential pitfalls to the ubiquitous, routine installation of the necessary networking equipment. Here’s a look at some of those risks and how to avoid them.
1. Don’t ever set your home’s wireless access points (WAPs) to the same channel (unless you have a single-cell architecture) if they are located close enough to each other to create interference.
It gets easier to find open channels when using 5GHz (for now, until 802.11ac becomes more common), but when equipment operates in the 2.4GHz range, remember that there are only three non-overlapping channels in North America. :These are channels 1, 6 and 11. :Think of multiple WAPs residing on the same channel as being akin to multiple meetings going on in the same room. Splitting up the channels is like putting each meeting in its own room. It’s a good idea to use a wireless spectrum analyzer such as Metageek’s WiSpy to look at your environment and so that you choose the right channels to use.
2. Know the polarization of your antennae.
For example, too often I see WAPs with bipole antennae laying flat in a one-floor home. :Think of the antenna as if it’s holding onto a doughnut through the center of it. :This is how the “Fresnel” zone acts within this type of antenna. In most of these antennas, the signal literally looks like a large doughnut radiating outward in a circle from the pole. If it’s laying flat, the signal is mostly going up and down and not side to side. If you’re trying to reach an area on the second-floor, then this position can work. But if not, you’re wasting valuable signal. Also keep this in mind when mounting your WAP, especially as these days many come without external antennae. Of course, dual polarized WAPs are also available, and in this case you don’t really have to worry about the positioning as much.
3. Don’t slap a WAP on the back of a TV or install it in a rack.
Try your best to avoid anything that can cause RF interference, like having eight Sonos systems piled on top of each other or even something as simple as a wireless Blu-ray player. You also want to avoid light fixtures, electrical powerlines, A/C units, elevators, fish tanks, trees, and anything with lots of metal or water, as these elements will block signals from getting through. Ideally, a WAP should be mounted at least a couple of meters away from any possible RF interference and in line of sight of what they’re to be connected to. Also, mount WAPs as high as possible. :
4. Don’t just use your laptop to test signal strength.
Try your best to test with the actual devices that will be used because each device has its own power requirements, antenna polarizations and other nuances. At the very least, use your laptop as well as some handheld devices to monitor the difference. One of the best tests is to use an iPhone to connect. Apple handheld devices are notorious for having extremely poor signal strength.
5. Don’t use your name as your SSID.
This is like broadcasting to the world, “Hey this is my wireless network, now come and hack me!” Also avoid WEP encryption, since nowadays it can be hacked in mere minutes. If a legacy device requires WEP encryption because it can’t handle anything else, use MAC address filtering and put it on a secure VLAN that allows routing only to the device it needs to talk to.
Bjorn Jensen is owner of WhyReboot, a Miami-based company that specializes in the design and installation of commercial-grade networks for home automation systems.