Wireless Routers / Access Point Interference within the Home
When installing an 802.11b or 802.11g access point or router, beware of signal interference from other home appliances. In particular, do not install the unit within 3-10 feet (about 1-3 m) from a microwave oven. Other common sources of wireless interference are 2.4 GHz cordless phones, baby monitors, garage door openers, and some home automation devices.If you live in a home with brick or plaster walls, or one with metal framing, you're may encounter difficulty maintaining a strong WLAN signal. Wi-Fi is designed to support signal range up to 300 feet (about 100 m), but barriers reduce this range substantially. All 802.11 communications (802.11a most of all) are affected by obstructions; keep this in mind when installing your access point.
Wireless Routers / Access Point Interference from Outside
In densely populated areas, it's not uncommon for wireless signals from one person's home network to penetrate a neighboring home and interfere with their WLAN. This happens when both households set conflicting communication channels. Fortunately, when configuring an 802.11b or 802.11g access point or router, you can (except in a few locales) change the channel number employed.
In the United States, for example, you may choose any WLAN channel number between 1 and 11. If you encounter interference from neighbors, you should coordinate channel settings with them. Simply using different channel numbers won't always solve the problem. However, if both parties use a different one of the channel numbers 1, 6 or 11, that will guarantee elimination of cross-WLAN interference.
MAC Address Filtering
Newer wireless routers and access points support a handy security feature called MAC address filtering. I wholeheartedly recommend it. This feature allows you to register wireless adapters with your access point (or router), and force the unit to reject communications from any wireless device that isn't on your list. MAC address filtering combined with WEP encryption affords very good security protection.Wireless Adapter Profiles
Many wireless adapters support a feature called profiles that allows you to set up and save multiple WLAN configurations. For example, you can create an ad hoc configuration for your home WLAN and an infrastructure mode configuration for your office, then switch between the two profiles as needed. I recommend setting up profiles on any computers you plan to move between your home network and some other WLAN; the time you spend now will save much more time and aggravation later.WEP Encryption
Among the options you'll see for activating wireless encryption, 128-bit WEP is a safe bet. Older 40 or 64-bit WEP offers inadequate protection. A few 802.11g products support 152-bit or 256-bit WEP, that is fine too, if all of your gear supports it. Newer equipment offers WPA. General-purpose WPA is unnecessarily complex for a home WLAN, but WPA-PSK works well.
To set 128-bit WEP, pick and assign a number called a WEP passkey. You must apply the same WEP settings and passkey to the access point (router) and all adapters.
General Tips
If you've finished installing the components, but your home network isn't functioning correctly, troubleshoot methodically:
- Can't reach the Internet? Temporarily turn off your firewall to determine whether you have a firewall configuration problem, or some other issue.
- Likewise, turn on and test your wireless adapters one by one, to determine if problems are isolated to a single computer or common to all.
- Try ad hoc networking if infrastructure networking isn't functional, and perhaps you'll identify a problem with your access point or router.
- To help you work methodically, as you build your network, write down on paper the key settings like network name, WEP passkey, MAC addresses, and channel numbers (then eat the evidence afterward!).
- Don't worry about making mistakes; you can go back and alter any of your WLAN settings any time.
Finally, don't be surprised if your wireless LAN performance doesn't match the numbers quoted by the manufacturer. For example, although 802.11b equipment technically supports 11 Mbps bandwidth, that is a theoretical maximum never achieved in practice. A significant amount of Wi-Fi network bandwidth is consumed by overhead that you cannot control. Expect to see more than about one-half the maximum bandwidth (5.5 Mbps at most for 802.11b, about 20 Mbps at most for the others) on your home WLAN.
