IN THIS CHAPTER
Wireless ethernet networking, commonly referred to as Wi-Fi, is the hottest home network technology around. When you install a wireless ethernet network, you can put away your wire crimpers and stop worrying about hiding network cables because radio waves carry your signals between PCs and other devices.
Although you no longer need to worry about running cables all over your home when you install a wireless ethernet/Wi-Fi home network, you still need to be concerned about selecting the right types of hardware for your home network. You also need to protect your network from intruders and configure your network for maximum speed. In this chapter, you learn how to deal with these challenges.
A wireless ethernet network consists of the following:
A wireless ethernet adapter for each PC or device on the network
A wireless access point (WAP) to enable Internet sharing or connections to other networks (optional)
A router connection to a broadband Internet device to enable Internet sharing (often combined with the WAP)
How does a device with a wireless network adapter connect to a network? By default, WAPs broadcast an identification known as a service set identifier (SSID). Essentially, the SSID is the wireless network’s name. Each WAP has a default SSID, usually derived from the vendor’s name. For example, WAPs made by Linksys use the default SSID Linksys. The default SSID can (and should) be changed through the WAP’s configuration utility. A properly equipped computer running Windows XP’s built-in wireless ethernet support automatically scans for SSIDs and displays the wireless networks it detects. Select one, and you connect to that network. With other versions of Windows, you might need to enter the SSID to make the connection. The maximum range of a WAP extends for several hundred feet, although brick or concrete walls can greatly reduce range.
Wireless ethernet is also known as Wi-Fi. The Wi-Fi Alliance (www.wi-fi.org) is the trade group responsible for developing standards that help different brands of wireless ethernet hardware to work together. Wireless ethernet devices that pass the certification tests put forth by the Wi-Fi Alliance are known as Wi-Fi Certified devices. Although most wireless ethernet devices that are not Wi-Fi Certified also work with Wi-Fi Certified devices, it’s generally safest and easiest for you to select devices for your home network that are Wi-Fi Certified.
Originally, wireless ethernet was based on just one network standard, IEEE 802.11b. However, today there are three different 802.11 network standards and several proprietary extensions. Mix and match some standards, and your network can still function. Mix and match others, and your network becomes a “notwork.” The following sections bring you up to speed on each technology.
IEEE 802.11b (also known as Wireless-B) is the original flavor of Wi-Fi. Initially, most Wi-Fi home networking products used this version. However, home networks are rapidly shifting to the faster 802.11g version of Wi-Fi. 802.11b hardware has a maximum speed of 11Mbps and uses the 2.4GHz frequency.
802.11a (also known as Wireless-A) was developed to provide better performance and less interference than 802.11b. 802.11a runs at a maximum speed of 54Mbps, but uses the 5GHz frequency band. Consequently, it is not directly compatible with 802.11b-compatible hardware, which runs at 2.4GHz.
802.11g (also known as Wireless-G) is the current champion of wireless ethernet home networks. It’s directly compatible with existing 802.11b hardware because it uses the same 2.4GHz frequency, but it runs at up to 54Mbps, making it comparable in speed to 802.11a.
Wi-Fi Certification covers all three types of 802.11 wireless networks, but they differ in many ways. Table 6.1 compares the major features of each network type.
It’s a story as old as the computer industry: a trade group develops a standard, and a few vendors say, “we can do better.” A number of vendors have developed proprietary speedups to 802.11b and 802.11g networks, including
D-Link AirPlus Enhanced—. 22Mbps extension to 802.11b (11Mbps)
D-Link AirPlus Xtreme G, Netgear Super G—. 108Mbps extension to 802.11g (54Mbps) using Atheros Super G chipsets.
US Robotics Wireless Turbo—. 100/125Mbps extension to 802.11g (54Mbps)
Although all of these proprietary extensions promise better performance than standard 802.11b or 802.11g networks, you should keep the following in mind:
The speed increases provided by most proprietary technologies are more modest than the names suggest.
To enable your network to run at proprietary speeds, all network devices need to support the same proprietary technology.
If you mix and match standard and proprietary network devices, your network speed will be reduced, in some cases to the highest standard speed supported by your network. This can be a major issue if you want to use media adapters, print servers, or video games on your wireless network. Most proprietary speedups are for WAPs, routers, and PC network adapters only.
Integrated wireless ethernet adapters built in to notebook or desktop computers support only standard speeds (11Mbps or 54Mbps).
Some vendors claim that WAPs or network adapters using proprietary extensions can interfere with standard 802.11b or 802.11g networks.
If your corporate office already has a wireless network and you plan to use the same notebook computer at home and at work, you could have a problem: a lot of corporate networks use 802.11a wireless ethernet. As you have already learned, 802.11a uses a different frequency than 802.11g or 802.11b. Fortunately, you can get dual-frequency network adapters for your notebook computer that handle both 802.11a and 802.11b or 802.11g networks. Figure 6.1 shows a typical dual-frequency CardBus network adapter from Cisco that supports all three Wi-Fi Certified standards.
You might not need to install a wireless ethernet (Wi-Fi) adapter in your notebook computer, particularly if it was built from mid-2003 on. Many vendors have started to incorporate wireless ethernet network adapters into most of the product lines. However, even if your notebook already has wireless ethernet on board, you might need to add a CardBus or USB adapter if you want support for the fastest wireless ethernet standards.
Originally, notebook computers with Intel’s Centrino technology incorporated an 802.11b-compatible Wi-Fi network adapter made by Intel, the Intel PRO/Wireless 2100 network adapter or the dual-mode (802.11a/b 2100A). However, recent Centrino notebooks now include one of two other adapters:
Intel PRO/Wireless 2200BG (supports 802.11g natively; interoperates with 802.11b networks)
Intel PRO/Wireless 2915ABG (supports 802.11a/b/g natively)
Consequently, any Centrino notebook can connect with an 802.11b or 802.11g wireless home network. However, only Centrino notebooks that use the Intel PRO/Wireless 2200BG or 2915ABG network adapter can work at maximum speed with either network type. As you learned earlier in this chapter, 802.11b adapters can connect to an 802.11g-based network. However, depending upon your WAP or router, your entire network might run more slowly when 802.11b and 802.11g hardware is on the same network.
You don’t need Centrino to have wireless ethernet on board. Many notebook computer vendors use various third-party network adapters to provide wireless ethernet support. See the tips in Chapter 3, “Planning Your Home Network,” to determine whether your computer has wireless ethernet already installed.
Tip: For Maximum Home Network Speed, Check Before You Buy!
If you’re in the market for a Centrino-technology notebook computer, be sure to find out which network adapter is included. Look for Centrino notebooks with the Intel PRO/Wireless 2200BG for use on home networks or public hot spots. However, if you need to connect to corporate networks that use 802.11a and don’t want to use a separate adapter, opt for Centrino notebooks that use the Intel PRO/Wireless 2100A network adapter.
If you have a PDA or smart phone, it might have built-in wireless ethernet features or offer an optional wireless ethernet/Wi-Fi card. See your PDA or smart phone manual for details.
You can add wireless ethernet hardware to an existing network or build a wireless home network from scratch. In the following sections you learn how to select and install network adapters, set up and configure a WAP or router, and configure your network adapters and WAP to communicate with each other.
Unless your computers already include wireless ethernet adapters, you will need to add them to your PCs. Table 6.2 compares the choices you have.
Table 6.2. Wireless Ethernet Adapters for PCs
Computer Type | Adapter Type | How Added | Benefits | Drawbacks |
|---|---|---|---|---|
Desktop | PCI | Installed into open PCI slot | Can’t be lost; doesn’t use up desk space; movable antenna helps improve reception | Requires opening PC; difficult to move between systems |
Notebook | CardBus | Installed into open CardBus Type II slot | Easy to install and remove; easy to store when not in use | Can’t be used with desktop PCs; fixed antenna can cause slower connection |
Desktop or Notebook | USB | Connects to open USB 2.0 or 1.1 port | Easy to install or move; works in any system with a USB port; moveable antenna and extension cord on some models help improve performance | Requires Hi-Speed USB port for best performance; more expensive than PCI card |
Figure 6.2 compares these adapter types to each other.
The process of installing a wireless ethernet adapter is similar in many ways to the process of installing an ethernet adapter.
Tip: Raise the Antenna for Best Connection Speed
If your wireless ethernet USB adapter uses a folding antenna (refer to Figure 6.2), don’t forget to unfold it after you install the adapter. Leaving it in the storage position will cause slow connections or might prevent you from making any connection to your WAP or router.
If you need to install a wireless ethernet adapter on your PC’s USB port, see “Installing a USB Adapter,” Chapter 5, “Installing and Configuring a Wired Ethernet Network,” p. 103 for details. If you need to install a wireless ethernet adapter into your notebook computer’s CardBus slot, see “Installing a PC Card or CardBus Adapter,” Chapter 5, p. 105.
If you need to install a wireless ethernet adapter into a desktop computer’s PCI card slot, follow this procedure:
Install the software supplied with the adapter. By installing the software first, you enable your computer to recognize the network adapter properly and configure it.
Take ESD precautions to prevent damage to your system or network adapter. See “Installing a PCI Adapter,” Chapter 5, p. 106, for details.
Turn off the system and unplug it. Run the Windows Shutdown procedure to shut down your system. If your power supply has a power switch, turn it off before you unplug the power cord.
Remove the screws holding the cover in place. Some systems use separate panels for each side of the cover; others use a one-piece cover for the entire system.
Remove the cover.
Remove the antenna from the PCI adapter if necessary. Some adapters use a fixed antenna; others use a cable that connects to an external antenna.
Locate an empty PCI expansion slot.
Remove the slot cover corresponding to the expansion slot. In most cases, the slot cover is held in place by a screw. However, some systems use a snap-out slot cover that might be disposable. Some compact systems use a single screw on the outside of the case to hold all cards and slot covers in place (see Figure 6.3).
Line up the PCI card with the PCI slot and push it into place (see Figure 6.4).
Fasten the card bracket to the case with the screw removed in step #8 (refer to Figure 6.3).
Close the case.
Attach the antenna to the PCI adapter (refer to Figure 6.3).
Adjust the antenna position. Lift the antenna to its normal right-angle position and adjust it so its tip is visible from the front of the PC. Keep the end of the antenna away from the bottom of the PC; you might damage it when you put the PC back into place.
Plug in the power supply and restart the system. If the power supply is turned off, turn it on before attempting to restart the system.
Provide the Windows CD if prompted. If you have already installed a modem or other network device, you might not need to provide the Windows CD. If Windows was preinstalled, Windows uses the installation files on the hard disk if needed to complete the installation.
You can connect home entertainment devices such as home theater systems, stereos, TVs, video games, and PVRs to a Wi-Fi network.
Tip: For Maximum Network Speed, Look for 802.11g Media Adapters
Some media adapters, primarily those that do not support video, support 802.11b wireless ethernet. If you use 802.11g wireless ethernet network hardware for the rest of your network, mixing 802.11b and 802.11g hardware can slow your 802.11g hardware. For best network performance, look for media adapters made especially for 802.11g networks.
To add home theater systems, stereos, or TVs to your network, connect them to a media adapter designed for use with wireless ethernet/Wi-Fi. These devices include software that enables the device to connect with a PC that contains the photo, video, or music files you want to play and a remote control for selecting and playing the files.
If you already have a media adapter connected to a wired ethernet network, you can continue to use it with your wireless ethernet network. Most media adapters have connections for both wired and wireless ethernet networks. If yours supports wired (10/100) ethernet only, you can connect it to the ethernet switch found in most wireless ethernet routers or WAPs or use an ethernet/wireless ethernet bridge.
The Microsoft Xbox is ready to connect to a 10/100 ethernet network as soon as you take it out of the box. You can connect its ethernet port to an ethernet/wireless ethernet bridge to add it to a wireless ethernet network. Before you can add a Sony PlayStation2 or Nintendo GameCube to a wireless ethernet network, you must install each unit’s ethernet adapter, and then connect each unit to an ethernet/wireless ethernet bridge.
ReplayTV PVRs have built-in 10/100 ethernet adapters. To add these units to a wireless ethernet network, use an ethernet/wireless ethernet bridge. TiVo Series 2 PVRs have built-in USB ports that can be used to connect wireless ethernet adapters.
For more details about adding home entertainment hardware to any type of home network, see Chapter 7, “Home Networks at Play.”
Stations on a wireless ethernet network can connect to each other in two ways. In ad-hoc mode, they connect directly with each other. This mode is the cheaper mode to set up, because you need only a wireless ethernet adapter for each station. However, ad-hoc mode doesn’t support sharing an Internet connection or connecting to other networks. Ad-hoc mode is best suited for uses such as
Connecting a media adapter to a PC containing media files for playback
Connecting a wireless print server to a PC needing remote printer access
In these cases, the PC might already be connected to a wired network and uses wireless ethernet/Wi-Fi just for a particular specialized task. However, if you need to share an Internet connection or build a mixed network, such as wireless ethernet plus ethernet, or wireless ethernet plus HomePlug or HomePNA, you need to use infrastructure mode, which requires you to add a wireless access point, or WAP, to your wireless ethernet network.
A WAP provides the same function to a wireless ethernet network that a switch does to a 10/100 ethernet network: It sends and receives data between stations and provides a way to connect the network to other networks via a router or bridge. Some WAPs include a router. Figure 6.5 compares typical ad-hoc and infrastructure home network configurations.
If you are adding wireless ethernet access to an existing 10/100 ethernet network, the easiest way to do it is to plug a WAP into your existing ethernet switch or router. Figure 6.6 shows front and rear views of a typical WAP.
However, if you are building a home network from scratch and want to use wireless ethernet, I recommend that you buy a WAP that includes a router and an ethernet switch. You can connect the WAP’s WAN port directly to a broadband Internet access device (such as a cable or DSL modem) to provide shared Internet access, and you can connect 10/100 ethernet network adapters to the integrated LAN ports. Figure 6.7 shows you the features of a typical wireless ethernet WAP with integrated router and 10/100 ethernet switch. Note that some of these devices have only one antenna.
After you install wireless ethernet adapters and add a WAP to your existing 10/100 ethernet network or install a WAP with router, it’s time to configure your network. In the following sections, we’ll look at wireless configuration settings common to both WAPs and WAPs that have integrated routers.
To configure the WAP, you might use one of the following methods:
Some WAPs include a wizard for basic configuration steps.
Virtually all WAPs include a browser-based configuration utility for controlling basic and advanced WAP features and router features (on models with integrated routers).
Tip: WAP or Not, Router Configuration’s About the Same
If you have a WAP with an integrated router, see Chapter 5 for configuration instructions for the WAN (router) settings.
To configure PCs with wireless network adapters, use one of the following methods:
Use the Windows XP wireless configuration utility.
Install and run the configuration utility provided by the adapter maker. This is the only way to configure a wireless adapter with versions of Windows that predate Windows XP.
To create an unsecured connection between a WAP and the stations on a wireless network, you need to set the following basic options on both devices:
SSID
Channel
Encryption standards (disabled)
Tip: Handling Multiple 802.11 Versions with a Single WAP
Just as 802.11g wireless network adapters can connect to 802.11g or 802.11b WAPs, an 802.11g WAP (including those that integrated a router and a switch) can connect with 802.11g or 802.11b network adapters.
You can buy 802.11b/a or 802.11g/a dual-mode WAPs for your home network. Choose dual-mode g/a WAPs if you need to support 802.11a network clients. As an alternative, you could connect a CardBus or USB adapter supporting your home network type (Wireless-B or Wireless-G) to those computers.
Dual-band A+G routers and network adapters from Linksys (www.linksys.com) enable high-bandwidth multimedia content to travel over the 5GHz 802.11a frequency at the same time the 802.11g/b 2.4GHz frequency handles normal web-surfing and network traffic.
The following sections cover these basic configuration options.
Because each adapter on a wireless network needs to use the same settings as the WAP, you should configure the WAP first, record the settings, and then configure each device to use matching settings.
Although a WAP is a wireless device, it’s easier (and in some cases, required) to connect it to a PC with an ethernet port or to a wired ethernet network for configuration. After you connect the WAP to your PC or to your network, plug it into a working AC power source.
If your WAP includes a wizard, start the wizard from the setup CD and select the option to change settings when prompted. If you use a web-based configuration program to set up the WAP, look up the WAP’s default IP address in its documentation. In either case, look up the default password because you need to provide it to log on to the WAP.
Figure 6.8 shows the default configuration used by a Linksys WAP54G.
To make the changes using a wizard, follow the onscreen instructions to start the setup process. In the example shown in Figure 6.8, click Yes and provide the setup password.
Wireless ethernet networks are identified by their SSIDs. By default, each different brand of wireless ethernet WAP has a different default SSID. For example, Linksys WAPs use linksys for the default SSID, Netgear WAPs use netgear, and so on. Also by default, WAPs broadcast the SSID, making it easy for wireless clients to detect the network.
Caution: Don’t Leave Your Network Open (for Long)!
To make sure your wireless network is configured correctly, you can leave the encryption settings disabled (as they are in most brands of WAPs and wireless ethernet adapters by default). However, as soon as you determine that your network is working, you should immediately enable wireless security. See “Wireless Security 101,” p. 165, this chapter, and Chapter 10, “Securing Your Home Network,” for details.
To change the SSID when using a setup wizard, type the value desired when prompted. You should change the SSID from the default to something else, even during initial setup. If network intruders detect a default SSID, they can look up the documentation for your WAP, see the default password, log on to your network and start sneaking around. By using a nonstandard SSID (such as your last name, your dog’s name, your favorite sports team, or whatever), you make it just a little bit harder to break into your network.
If your setup wizard permits it, you should also disable SSID broadcast. Leaving SSID broadcast enabled instructs your WAP to transmit the SSID to any wireless adapters within range. By disabling this option, you make it more difficult for casual snoopers to find your network.
Be sure to write down the SSID you use. If you disable SSID broadcast as I recommend, you will need to enter the WAP’s SSID into the configuration for each wireless adapter on the network. No SSID = no connection.
Tip: Another Way to Disable SSID Broadcast
You can also disable SSID broadcast by using the WAP’s built-in browser-based configuration utility. See “Using a Web Browser to Make Configuration Changes to the WAP,” p.xxx, this chapter.
Wireless ethernet networks use radio signals to communicate. As with any other radio device, you need to select a matching channel at both ends of the network to make a connection. Although 802.11b and 802.11g networks offer channels from 1 to 11, this is a bit misleading. Only Channels 1, 6, and 11 are completely separate from each other. The remainder of the channels’ frequencies partly overlap other frequencies.
By default, most WAPs are configured to use Channel 6. As a result, Channel 6 is the most crowded wireless ethernet channel, causing performance drops when many wireless networks using that channel are near enough to each other to cause signal overlap. I recommend using Channel 11 instead.
To change the channel, select a channel from the drop-down menu when prompted by the setup wizard. Figure 6.9 shows the wizard used by the Linksys WAP54G after the default SSID and channel settings have been changed.
Be sure to record the channel you selected for the WAP. You might need to configure the channel used by your WAP in the configuration for each wireless adapter on the network with some network adapters’ configuration utilities.
I’m a big believer in wireless security. In fact, I use two methods to protect my wireless networks. Much of Chapter 10 of this book is devoted to the various methods you can (and should) use to secure your wireless (and wired) networks. However, when you start to set up your wireless network, you should disable security settings. That might seem like a contradiction, but there’s a method to my madness:
If you mix and match brands of WAPs and network adapters, you could have problems caused by the differences in how various brands configure their security settings. Mismatched settings could cause your network to fail.
Even if you use the same brand of WAP and network adapter, differences in wireless security features could cause problems in initial setup if security is enabled initially.
So, the best strategy is to
Get your wireless network running properly without security settings enabled.
Enable wireless security settings as soon as you know your network is working.
Configure folder and printer sharing (Chapter 8, “Home Networks at Work and School”) after security settings have been enabled and tested.
To disable wireless security settings with the setup wizard, select Disabled when prompted for security settings.
If you are using a WAP that connects to a router, you should configure the WAP to get an IP address from the router’s DHCP server instead of using the WAP’s default IP address. This is necessary because your home network might use a different range of IP addresses than the WAP’s default, preventing the WAP and the wireless computers it hosts from connecting to the rest of the network. Select DHCP when prompted by the Wizard.
When you have made these changes with the setup wizard, save the changes when prompted and exit. The nonvolatile RAM in the WAP stores these settings for future use.
Some WAPs don’t use a setup wizard for initial configuration. Instead, you use a web-based configuration tool for both basic and advanced settings. To configure the WAP using a web-based configuration tool, follow this procedure:
Look up the IP address and default username or password for configuration in the WAP’s documentation.
Connect the WAP to your PC using its ethernet port.
Open your web browser and enter the IP address of the WAP.
Enter the default username or password to start the configuration utility.
Move through the menus and make the following changes:
Change the default SSID.
Disable SSID broadcast.
Change the default channel to 11 if it is set to 6.
Disable security (if it is enabled).
Use DHCP to obtain an IP address.
Record the settings used for SSID and default channel.
Save the changes and exit the utility.
Close the browser.
Figure 6.10 shows you an example of a browser-based configuration screen used by a U.S. Robotics WAP with integrated router and switch, the USR8054.
A WAP with a built-in router can be connected to a cable or DSL modem or other broadband Internet access device, enabling your wireless network to share Internet access (refer to Figure 6.7). When a WAP has an integrated router, you configure its router features the same way you would for a router on a 10/100 ethernet network. See “Configuring a Router for Broadband Internet Sharing,” Chapter 5, for details.
Tip: Using Save As to Record Your WAP Configuration
One of my favorite tricks for recording whatever’s in my browser window (including WAP configuration) is to use the browser’s Save As function. With Internet Explorer, you can select Web Archive to create a single file (.MHT) containing all the graphics, HTML code, text, and other features of the currently displayed page. Unlike screen captures, Save As grabs the entire page, no matter how long it is. If you use other browsers, use Save As Complete, but keep in mind that the graphics and other non-HTML elements are stored in a folder one level below where your page’s HTML file is stored. I have used these methods to build an extensive list of online articles as well as my routers’ and WAPs’ configuration settings.
After the WAP has been configured, it’s time to configure the wireless adapters on your network. In the following sections, I’ll show you how to use the Windows XP wireless network configuration utility as well as a typical vendor-supplied configuration utility to get your wireless network up and running. If you don’t use Windows XP, you must use the vendor-provided configuration utility.
After you install your network adapter (see “Installing Wi-Fi Adapters in Your PC,” p. 148, this chapter) on a computer running Windows XP, you see a network icon appear in the system tray. Right-click on the icon, and a wireless network connections menu appears (see Figure 6.11).
To select a wireless network, click View Available Wireless Networks. The Connect to Wireless Network dialog appears, showing you the wireless network(s) visible to your PC’s wireless ethernet adapter. Don’t be surprised if you see more than one wireless network listed (see Figure 6.12).
To make the connection, click on the network you want to use and click Connect. Some versions of Windows XP will display a prompt if the network is not secured, asking you whether you want to connect anyway. Check the box Allow Me to Connect to the Selected Wireless Network, even though it is not secured, then click Connect.
In most cases, you won’t need to open the Wireless Network Connection dialog shown in Figure 6.13. However, in some circumstances you might need to, including
Your computer keeps connecting to a different wireless network than yours and you want to force your system to use yours (Windows XP looks for the strongest signal and uses it by default).
You add security settings to your wireless network and need to adjust the configuration settings for your client.
You want to disable Windows XP’s built-in wireless client and use the wireless client supplied with your wireless network adapter.
If you need to configure these and other network settings, click Advanced to display the dialog box shown in Figure 6.13.
Use the following checklist to adjust your connection:
To remove other networks from the Preferred list (non-preferred networks must be added manually), select the network in the Preferred Networks window and click Remove.
To change the order of preferred networks (for example, if you use wireless networks at home, at the office, and away from home), click the network you want to use first in the Preferred Networks window and click Move Up. Repeat until it is the top network in the list.
To adjust the properties (such as security settings) for a network, select it in the Preferred list and click Properties. For an example of using this dialog, see “Wireless Security 101,” p. 165, this chapter, and also Chapter 10.
Windows XP can look for both ad-hoc and infrastructure (WAP-based) wireless networks. To control which type(s) of networks Windows XP uses, click Advanced and select the network type you want to use (see Figure 6.14). Click Close to continue.
To prevent Windows XP from logging on to non-preferred networks, clear the Automatically Connect dialog box shown in Figure 6.14 and click Close to continue. If your wireless network’s signal strength is lower than other networks, Windows XP might disconnect you from your own network and connect to a stronger signal if this box is not cleared.
After making changes to the Wireless Networks or Properties tabs, click OK. The changes take effect immediately.
If you don’t use Windows XP, you must use the wireless network configuration tool provided by your wireless adapter vendor.
If you installed the vendor-supplied configuration tool when you installed the network adapter, you should find a shortcut to it on your Start menu—click (All) Programs to see it—or on your Windows desktop. If you didn’t install the configuration tool previously, install it from the CD provided with the network adapter, or visit the vendor’s website for the latest version.
After you start the configuration utility, one of the options provided is typically a site survey. This is a more elaborate version of the Windows XP network selection screen shown earlier in Figure 6.12. Vendor-supplied configuration utilities usually provide much more information about the wireless networks available. To determine the mode, channel, and other information for any wireless network listed, click it to see a display similar to the one shown in Figure 6.15.
Tip: Using the Site Survey to Find the Best Channel to Use
Although Channel 6 is used most often by wireless networks’ default settings, many users have switched to alternative channels to avoid interference. If you find that the channel you are using is also used by other wireless networks displayed by the Site Survey tool, reconfigure your WAP to use another channel. Keep in mind that Channels 1, 6, and 11 are the best channels to use to avoid interference from other 2.4GHz devices, such as telephones and Bluetooth networks.
To connect to a secured network, provide the WEP key type, WEP key, and other information requested by the utility. You can usually store this information in a profile, which stores the connection information for reuse. To reconnect using a profile, open the profile dialog and select the profile you want to use.
After you connect to your wireless network, you can usually get even more information about your connection. In this example, the Link Information tab displays confirmation of your connection. Click More Information to see more detailed information, including TCP/IP network information, as shown in Figure 6.16.
If your PDA or smart phone has a built-in wireless ethernet adapter, use the configuration utility included in your PDA or smart phone’s operating system to configure it. If your PDA or smart phone uses an add-on card for wireless ethernet, install and run the configuration utility provided with the card to configure your connection. When prompted by the configuration utility, provide the mode (infrastructure or ad-hoc), the SSID of your WAP (infrastructure mode only), the channel (ad-hoc mode only), and the WEP or WPA encryption key used by your network. See the documentation for your PDA, smart phone, or add-on card for details.
Caution: No Internet Connection? Go to Chapter 11 for Help!
If you can’t connect to the Internet, your wireless network adapter probably didn’t receive a valid IP address from the DHCP server built in to your router. For typical causes and solutions, see “The Home Networker’s Guide to TCP/IP,” p. 316, Chapter 11, “Troubleshooting Your Home Network.”
Even before you complete the configuration of your home network (see “Using the Windows XP Network Setup Wizard,” in Chapter 5, p. 131, for details), you should be able to connect to the Internet if your network offers shared Internet access. To start your connection, double-click on the Internet Explorer icon on the desktop, or open your preferred browser from the Start, (All) Programs dialog.
To complete wireless network setup, you should enable basic wireless security and configure your PCs to be part of the same network. See the following sections for details.
You should enable basic wireless security as soon as you know your wireless network is working correctly. Every moment you delay is another moment that somebody down the hallway or in the street could spy on your home network. Grabbing bandwidth to connect to the Internet is the least of your worries—you could be vulnerable to the following:
Information in shared folders can be copied, or even erased.
Your identity could be stolen if you keep bank or credit-card information in shared folders.
You could run out of IP addresses for your own network devices because moochers are borrowing your home network, preventing you from getting on the Internet yourself.
There are many ways to lock down your wireless network (see Chapter 10 for more advanced methods), but for right now let’s discuss how to use WEP, the basic wireless security feature supported by every wireless ethernet WAP and network adapter.
WEP stands for Wireless Equivalent Privacy, but despite the name, it isn’t perfect. Think of it as one of several locks to put on the digital “doorway” into your home network.
WEP uses one of three encryption levels:
64-bit
128-bit
256-bit
The names refer to the length of the password you use; the longer the password, the harder it is for an intruder to break into your home network. In this example, I show you how to set up 64-bit WEP encryption. Why not a stronger encryption example? There are two reasons:
256-bit encryption is supported only by network hardware built for corporate uses; 128-bit is the strongest encryption generally available on home networks.
Enabling encryption can slow down your network, and 128-bit encryption has a bigger impact than 64-bit encryption.
In the long term, other security measures discussed in Chapter 10 will provide even better security with less impact on your network’s performance.
To enable 64-bit WEP encryption, follow this procedure:
Open the configuration wizard or web-based tool for your WAP.
After logging in, select the security or encryption menu.
Select 64-bit WEP security.
Enter the WEP key you want to use, or use the Passphrase option (if available) to generate one for you. Although some WAPs support plain-text WEP keys—they convert to hexadecimal for you—all wireless ethernet devices can use hexadecimal WEP keys. A 64-bit WEP key uses 10 digits (see Figure 6.17).
After you set up encryption, be sure to write down the WEP key and encryption type so you can use it on each network adapter.
Save your changes to the WAP’s configuration.
To connect to the WAP with Windows XP, follow this procedure:
Right-click the wireless network icon in the Windows system tray.
Select View Available Wireless Networks. Although you are prompted to type a network key, I find it’s better to configure the connection manually.
Click Advanced (Figure 6.18) to configure the connection.
Check the box next to Use Windows to Configure if it is not checked.
Select the network you want to connect to from the Preferred Networks windows and click Properties. The properties sheet opens.
Check Data Encryption (WEP enabled).
Note: Multiple Keys Are A-OK!
If you use the browser-based configuration utility for your WAP, you might generate multiple WEP keys. Key 1 is the default key Windows XP’s configuration utility looks for, so use that key for wireless adapter configuration. Select Key 1 as the default transmit key in the WAP’s configuration.
Clear the check box next to The Key Is Provided for Me Automatically.
Enter the Hex key code in the Network key box. Make sure you have written down the WEP key!
Select Hexadecimal digits for the Key format if necessary.
Select key length as 40 bits (10 digits, the equivalent of 64-bit encryption).
Make sure the key index is set to the first key index available; in some versions of Windows XP, the key index is 0–3, in others it is 1–4. See Figure 6.19 for an example of the completed properties sheet.
Click OK.
Click OK to exit the Wireless Networks dialog.
Right-click the wireless network icon in the system tray and select View Available Wireless Networks.
Click the network you configured and click Connect.
To check your connection, double-click the wireless network icon.
The General tab shows your connection status, speed, signal strength, and activity (Figure 6.20).
Click the Support tab to see information about your connection’s IP address and other TCP/IP settings (Figure 6.21). Click Close when done.
If your network uses a router to provide shared Internet access, the router usually provides IP addresses used on the network through DHCP. However, if you see Private IP Address instead of Assigned by DHCP, this means that this adapter did not receive an IP address from the router or other DHCP server. For help dealing with this and other IP address problems, see Chapter 11.
To enable you to share printers and folders, you need to wrap up the configuration of your home network by running the Windows XP Networking Wizard or configuring shared folders and computer and workgroup names manually. See “Using the Windows XP Network Setup Wizard,” Chapter 5, for details.
When you run the Windows XP Network Setup Wizard, it detects the network adapters installed in your PC and determines whether the network adapters are connected to a network. The wizard might not display your wireless adapter (Figure 6.22), or might determine it is disconnected. To continue running the network wizard, click the box marked “Ignore disconnected network hardware.”
After you have created a working wireless network, take some time and relax! You’ve earned it. But, if you’re not satisfied with the speed of your wireless network, or some distant computers are picking up a very weak signal (resulting in low speed) or can hardly connect at all, it may be time to consider how to improve the range and speed of your wireless network.
You can improve the speed of your wireless network with the following changes:
Reduce interference from other devices with wireless adapters.
If you use only Wireless-G (802.11g) devices on your network, configure your router to support G-type devices only.
Use alternatives to WEP encryption.
Get more information about these strategies in the following sections.
Interference from wireless phones, AC adapters, and other EMI sources can cause a 54Mbps wireless network to nosedive to barely functional 1Mbps performance. What can you do to improve the situation? Check the following:
Try a different channel for your WAP. Although Channel 6 is the traditional default used by most WAPs, many users have switched their WAPs to other channels. Channel 11 is becoming the most common alternative.
Look at interference sources near the PC with the slow connection. For example, if you can plug a USB wireless adapter into a different USB port, try it. You might find that a USB port on the front of the PC is a better choice than the ones on the rear of the PC. Adjust the antenna on a PCI card to a different position, or move a USB device on a cord away from PC or AC power sources.
Use cordless phones that run on different frequencies than your wireless network. Both 802.11b and 802.11g use the 2.4GHz frequency band. Consequently, popular 2.4GHz wireless phones pose a major potential for interference. Adjust them to use different channels, or move up to 5.8GHz cordless phones, which use a completely different frequency than 2.4GHz home networks, so they can’t interfere with your home network signals.
By default, almost all 802.11g WAPs and routers are configured to support a mixture of 802.11g and 802.11b devices. The additional overhead needed to support both types of devices can slow down your network, even if you use only 802.11g devices. Change your router configuration to use only 802.11g devices if your network doesn’t use 802.11b devices. Figure 6.23 illustrates this option on a U.S. Robotics 802.11g WAP/router.
Instead of WEP encryption, which can slow down your wireless network, you might be able to use WPA, a newer and better encryption scheme. Or, you can configure your WAP or router to work with only the network adapters and devices on your network by enabling MAC address filtering. For details, see Chapter 10.
If some of your network stations get a very poor signal or an erratic signal, slow speed connections or dropped connections are the result. You can fight back with the following:
Larger, more powerful antennas
Signal Repeaters
Using HomePlug instead of wireless ethernet for some locations
To learn more, check out the following sections.
The single or twin antennas on the top or rear of typical WAPs and routers work well in residential wood-framed homes or over relatively short distances. However, if your wireless network is trying to connect your home and a detached garage or workshop, or if brick, stone, masonry, or concrete walls or floors interfere with signals, consider antenna upgrades.
If you suspect that you need better antennas, start by selecting a brand and model of WAP or WAP/router that supports replacement antennas. Although you can remove the antenna(s) from most models, you should not attach an unapproved antenna as a replacement. To find out whether more powerful or directional antennas are available for the WAP or wireless router you have or are considering purchasing, check the vendor’s website. The following are some of the WAP and wireless router vendors that offer antenna upgrades for certain models:
Linksys (High Gain Antenna kit); http://www.linksys.com
Buffalo Technology (indoor and outdoor omnidirectional and directional antennas); http://www.buffalotech.com
D-Link (indoor and outdoor omnidirectional and directional antennas); http://www.dlink.com
Netgear (indoor and outdoor omnidirectional antennas); http://www.netgear.com
If you have two or more antennas to choose from, which should you select?
Select a directional antenna if all your stations are located in the same general direction relative to your WAP or router.
Select an omnidirectional antenna to improve the range and quality of connections for stations located in many different directions relative to your WAP or router.
Select an outdoor antenna to improve connections for users outside (patio, pool, garage, workshop). Be sure to look for models that include a lightning arrester.
Even with an antenna upgrade, you might not be able to reach all the users in a very large area with a single WAP or wireless router. In such cases, consider using a repeater to increase range. Some WAPs can be configured as repeaters, or you can buy specialized devices from some vendors that perform this function.
Although you can mix and match WAPs and network adapters, repeaters usually need to be the same brand as the WAP or wireless router they work with. Be sure to check the compatibility listings for a repeater or WAP with repeater functions before you buy.
If you use a WAP or wireless router that has a repeater option, you configure repeater options through the WAP or wireless router’s web-based configuration utility, as shown in Figure 6.24.
HomePlug networks use the AC power lines in your home as the network. Consequently, this type of network can be used when range or construction makes other types of networks, including wireless ethernet, impossible or impractical. You can connect a HomePlug network to an ethernet network with a HomePlug-ethernet bridge. The bridge device can plug into the ethernet switch built in to most wireless routers or into an ethernet switch that also hosts a WAP, making it possible for HomePlug and wireless ethernet networks to communicate with each other.
For more information about using HomePlug, see “Using HomePlug or HomePNA as an Alternative to Rewiring,” p. 126, and “Bridging Ethernet to Other Network Types,” p. 127, Chapter 5. In Chapter 2, see “HomePlug Home Networking,” p. 42, and “Building a Mix-and-Match Network,” p. 44.
In this chapter, you’ve learned how to build a wireless network with PCs. But that’s just the beginning of what a wireless network can do for you. If you want to add home entertainment devices to your wireless network, join me in Chapter 7. To learn how to use your wireless network to share printers, share folders, and get more work done at home, join me in Chapter 8.