To maximize benefit from the directions below, have your answers ready for the following questions:
One wir eless router supports one WLAN. Use a wireless router on your network if:
Try to install your wireless router in a central location within the home. The way Wi-Fi networking works, computers closer to the router (generally in the same room or in "line of sight") realize better network speed than computers further away.
Connect the wireless router to a power outlet and optionally to a source of Internet connectivity. All wireless routers support broadband modems, and some support phone line connections to dial-up Internet service. If you need dial-up support, be sure to purchase a router having an RS-232 serial port. Finally, because wireless routers contain a built-in access point, you're a lso free to connect a wired router, switch, or hub.
Next, choose your network name. In Wi-Fi networking, the network name is often called the SSID. Your router and all computers on the WLAN must share the same SSID. Although your router shipped with a default name set by the manufacturer, it's best to change it for security reasons. Consult product documentation to find the network name for your particular wireless router, and follow this general advice for setting your SSID.
Last, follow the router documentation to enable WEP security, turn on firewall features, and set any other recommended parameters.
One wireless access point supports one WLAN. Use a wireless access point on your home network if:
Install your access point in a central location, if possible. Connect power and a dial-up Internet connection, if desired. Also cable the access point to your LAN router, switch or hub. See the diagram in the Page 3 sidebar for details.
You won't have a firewall to configure, of course, but you still must set a network name and enable WEP on your access point at this stage.
Configure your adapters after setting up the wireless router or access point (if you have one). Insert the adapters into your computers as explained in your product documentation. Wi-Fi adapters require TCP/IP be installed on the host computer.
Manufacturers each provide configuration utilities for their adapters. On the Windows operating system, for example, adapters generally have their own graphic user interface (GUI) accessible from the Start Menu or taskbar after the hardware is installed. Here's where you set the network name (SSID) and turn on WEP. You can also set a few other parameters as described in the next section. Remember, all of your wireless adapters must use the same parameter settings for your WLAN to function properly.
Every Wi-Fi adapter requires you to choose between infrastructure mode (called "access point" mode in some configuration tools) and ad-hoc ("peer to peer") mode. When using a wireless access point or router, set every wireless adapter for infrastructure mode. In this mode, wireless adapters automatically detect and set their WLAN channel number to match the access point (router).
Alternatively, set all wireless adapters to use ad hoc mode. When you enable this mode, you'll see a separate setting for channel number. All adapters on your ad hoc wireless LAN need matching channel numbers.
See the sidebar diagram on this page for a typical ad-hoc home WLAN layout. This configuration works fine in homes with only a few computers situated fairly close to each other. You can also use this configuration as a fallback option if your access point or router breaks.
As shown in the diagram, you can share an Internet connection across an ad hoc wireless network. To do this, designate one of your computers as the host (effectively a substitute for a router). That computer will keep the modem connection and must obviously be powered on whenever the network is in use. Microsoft Windows offers a feature called Internet Connection Sharing (ICS) that works with ad hoc WLANs
Now let's cover some of the finer points you need to know about home wireless LANs.
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.
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.
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.
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.
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.
If you've finished installing the components, but your home network isn't functioning correctly, troubleshoot methodically:
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 MBP 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.
Armed with the information contained in this tutorial, you're now well on your way to building a working home WLAN. Welcome to the world of wireless networking.