These days, the vast majority of laptop PCs come equipped with wireless network adapters that let users make network connections without having to connect a cable to their computers. However, taking advantage of this convenience means understanding how to set up and use wireless network connections. Wireless networks have substantial capabilities, so it's necessary to understand how they work.

The examples and techniques in this brief focus on Windows Vista.

Understand wireless network settings and setup

Wireless networks depend on special-purpose radio receivers and transmitters that substitute the exchange of messages over the air for the exchange of messages that occurs over wired connections on conventional networks. When you power on your PC, Windows Vista automatically searches for available wireless networks.

The network icon in the system tray, shown in Figure 1, enables you to view a list of local networks that Windows Vista detects. Notice that the network icon in this figure is marked with a red X, which indicates no network connection is currently established.

Figure 1: A red X indicates no network connection is active.

When you click this icon, a window opens indicating you're not connected to a wireless network, as shown in Figure 2.

Figure 2: The detail window for the network icon provides a link to create a network connection.

The window also includes two hyperlinks: Connect to a network and Network and Sharing Center. Click the Connect to a network link to open the Connect to a network window, shown in Figure 3.

Figure 3: Connect to a network window.

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Information appears in three columns in this list:

• Network name: On the left is a list of wireless networks in the area. Any network that appears as "Unnamed Network" requires you to supply its name as part of establishing a connection.
• Security status: The center column indicates network security status. Security-enabled means the network uses encryption that requires users to have a special key or passphrase to establish a connection. Unsecured means the network is available to all users without any restrictions. This is typical for many hotspots at hotels, coffee shops, and other public locations.
• Signal strength: On the right is a signal strength indicator. Five green bars indicate maximum signal strength and quality, whereas one green bar indicates minimum signal strength and quality. You generally need at least two bars to make effective use of a network connection.

What's in a wireless network name?

To attach to a wireless network, you must be able to communicate with a wireless router or wireless AP (access point) in your immediate vicinity. Most wireless routers and APs operate in a range up to 100 meters or about 328 feet. All wireless networks are identified by a name, also known as an SSID (service set identifier). A wireless router or AP can be configured to broadcast its SSID; in that case, the name shows up in the first column in Figure 3. If SSID broadcasting is turn off, the network name displays as "Unnamed Network".

Many open source programs, such as NetStumbler, work with most wireless network adapters on laptop PCs and can easily discover SSIDs for unsecured wireless networks. Therefore, when you set up a wireless network, always use strong encryption and consider turning off SSID broadcasts as a security measure.

Understanding the WNC (Wireless Network Connection) tool

The tool that's displayed in Figure 3 is called the WNC, and it's what you use to make and break wireless connections on your Windows Vista laptop PC. When you need to manually create a network connection (meaning Windows Vista didn't automatically detect the network), you need the following information:

• Common wireless technology: To communicate with any wireless router or wireless AP in your vicinity, your wireless network adapter must be able to use the same technology the router or AP uses. In general, this means conforming to one or more versions of IEEE 802.11x, such as 802.11a, 802.11b, 802.11g, or 802.11n.

A common synonym for 802.11 is Wi-Fi (wireless fidelity), which is actually short for 802.11b Wireless Fidelity but now commonly stands for all forms of 802.11 wireless networking.

• Network name (SSID): If the SSID is broadcast, it's in plain sight for all to see and use. If it's not broadcast, you must know this case-sensitive name to access any network that shows up as "Unnamed Network" inside the WNC.
• Shared security scheme and key: If a network uses an encryption scheme, you must know which scheme it uses and the associated network key or passphrase. 802.11 networks may use WEP (Wired Equivalent Privacy), WPA (Wi-Fi Protected Access), or WPA2 (version 2) for encryption. WEP is the least secure whereas WPA2 offer the most security.

Always use the strongest security scheme your router or wireless AP and wireless network adapters can share.

More sophisticated networks use a RADIUS (Remote Authentication Dial-In User Server) server to supply keys to users with the proper credentials. Most home, hotspot, and small office networks use PSKs (pre-shared keys) instead. That's why you see options in Windows Vista for WPA-Personal and WPA-Enterprise. Personal means you use a PSK, whereas enterprise means you access a RADIUS server.

• Shared encryption: This is TKIP (Temporal Key Integrity Protocol, formerly known as WEP2) or AES (Advanced Encryption Standard).

Most 802.11 adapters offer Auto as configuration option, as well as TKIP and AES, so the adapter can use whatever the wireless router or AP uses. AES is more secure and thus preferable to TKIP.

Next, learn how to create wireless connections and connect to network.

To establish a connection to a wireless network that broadcasts its SSID, select it in the Connect list shown in Figure 3, and then click Connect.

To connect to a network that doesn't broadcast its SSID, click the network icon in the system tray, and then select Network and Sharing Center. Click Manage wireless networks in the left pane. The Manage wireless networks that use (Wireless Network Connection) window opens, as shown in Figure 4.

Figure 4: The Manage wireless networks that use (Wireless Network Connection) window.

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Click the Add button (green plus sign) to add a network. The Manually connect to a wireless network window opens. Click Manually create a network profile. A wizard screen appears that lets you enter the network name (SSID), identify the type of security (security scheme) in use and the encryption type, and supply a security key or passphrase. Figure 5 shows information for a hypothetical network defined for illustration purposes, with the Display characters checkbox checked so you can see the actual passphrase. (Ordinarily, this displays as a string of black circles to hide this information.)

Figure 5: Creating a network profile.

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Check the Start this connection automatically if you're setting up a wireless home network or office connection so your laptop PC automatically connects as soon as it's in range. Check the Connect even if the network is not broadcasting checkbox if SSIDs are turned off at the wireless router or AP so that you attempt to connect under all circumstances.

Connecting to an unsecured network is much easier. The only thing you must know is the network name (SSID), if it's not broadcast. If that SSID is broadcast, it's pretty much a "click and go" operation.

Next, find out how to set up a wireless router or AP.

If you want to operate your own wireless network, you must set up a wireless router or wireless AP to manage the wireless-to-wired part of networking. That is, you must set up a device that can handle incoming and outgoing wireless communications and also connect to a wired network or directly to a cable or DSL (digital subscriber line) modem for internet access. This can pose a problem when setting up the device for the first time because you can't establish any wireless connections until initial router or AP setup is complete. In most cases, this means you must make a wired connection from a desktop or laptop PC to the wireless router or AP to set it up for subsequent use.

What wireless routers and APs do

These devices bridge the gap between wireless clients and the wired internet and establish the format for wireless communications. When setting up a wireless router or AP, you decide whether or not to broadcast the SSID and determine the security scheme, kind of encryption, and passphrase to use.

Wireless routers and APs can also do a great deal more than establish the settings needed for wireless access. The most common additional features include:

• MAC (Media Access Control) address filtering: Lets you require that the physical address associated with a wireless network adapter be accepted or rejected if recognized. This allows only known addresses to gain entry (accepted) and refuses entry to known bad addresses (rejected).
• DHCP (Dynamic Host Configuration Protocol) service: Provides wireless clients with a network address, access to the local internet gateway (for access outside the local network), and information about name resolution and other key network services. Basically, DHCP makes it easy for computers to use the network without requiring users to know or configure all these things for themselves.

First comes the login

Wireless routers and APs are available from many vendors. In general, to access a device for setup, you must attach it to the network (see instructions that accompany the device) and log in as the administrator. You do this by entering an IP (Internet Protocol) address, such as 192.168.0.50, into the address field in a web browser. You're prompted for an administrator user name and password. Generally, routers and APs use admin as the administrator user name, by default), and no password.

You should change the default administrator user name and define a password after you log in for the first time to create a secure environment.

Then comes the configuration

When you log in for the first time, some routers and APs run a wizard that guides you through initial setup. If not, you need to configure the fields manually. Figure 6 shows a portion of a configuration screen for a popular AP.

Figure 6: A portion of an AP's wireless settings screen.

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In this screen, you see the majority of the important wireless AP setup data. This wireless AP is configured only to accept 802.11g connections. It's set up to function as an access point, as shown in the Mode field. You can also select WSD (wireless distribution system) from the Mode drop-down list, which means it can route between multiple wireless networks, with or without also acting like a wireless AP. In this example, SSID broadcast is set to Enable to make it show up in network connection listings. Authentication is set to WPA with a pre-shared key (PSK), and the passphrase is defined but hidden with black circles.

To install your configuration, click Apply or OK. This copies all the configuration data to the device, then restarts it to force all settings to be applied. After this step, you should be able to enter the same settings on your laptop PCs or other computers with wireless interfaces and establish a working wireless network connection.

Now that you understand wireless connections and how to set up a basic wireless network, read on to learn how to resolve some common connection problems.

You'll occasionally lose access to your own or another wireless network. This can occur for many reasons, which can also make troubleshooting interesting. Your first clue to trouble usually comes right after attempting a connection to a network, or when attempting to access the internet or check email, and obtaining an error message instead of a working connection. The following sections walk you network and internet connection troubleshooting.

Check the power supply to the wireless router or AP

The first thing to check is if the router or AP is turned off. Turning it back on and giving Windows Vista a few minutes to detect the settings fixes most connectivity problems.

Check your laptop PC's power plan

Check your laptop PC's power plan to ensure you're using appropriate settings. To get started, click the power icon in the system tray. You can select from Balanced, Power saver, and High performance. If you use an AC power source most of the time, select High performance. Using the Balanced or especially the Power saver plan assumes you run on battery power frequently, putting your laptop PC into a power savings mode after a certain number of minutes. This power savings mode can cause your laptop PC to drop its network connection.

Check your wireless network connection

If you have an HP laptop PC with HP Wireless Assistant installed, open HP Wireless Assistant by double-clicking its icon in the Windows Vista system tray, as shown in Figure 7.

Figure 7: The HP Wireless Assistant icon.

HP Wireless Assistant opens, as shown in Figure 8. In this tool, you can see whether the wireless LAN (local area network) interface is enabled (On) or disabled (Off). It can also display status messages when device status changes. To enable this feature, click Properties, and then check the Status change messages checkbox.

Figure 8: The HP Wireless Assistant interface.

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You can also try turning an interface off and then back on, in the HP Wireless Assistant screen.

All Windows Vista users can double-click the network icon in the system tray to display current wireless connections, and then click Connect or disconnect, as shown in Figure 9. The Connect to a network window opens.

Figure 9: The Connect or disconnect link.

If you can see networks listed but can't access a network, your wireless networking hardware is working but your connection has been dropped. Sometimes even a small power surge is enough to break a network connection link, so select a network and click Connect.

Check your wireless configurations

If you still can't connect, the problem is most likely on the wireless router or AP end of the connection. If you have access to another PC on the same subnet as the router or AP, open a web browser and attempt to access the device. If you can reach the router or AP, the problem is within the configuration. Thoroughly review the configurations for the wireless router or AP and your laptop PC's wireless adapter and ensure both agree in every detail.

If your wireless router or AP supports MAC address filtering, make sure to include the MAC address for your laptop's wireless interface in your device's configuration. Once added to the list of accepted addresses, you should have network access after restarting the wireless router or AP.

Checking wireless adapter properties

To check your wireless adapter settings, click the network icon in the system tray, and then select Network and Sharing Center. Click Manage wireless networks in the left pane, and then click Adapter properties to open the Wireless Network Connection Properties dialog box. If you're prompted for permission, click Continue. Click Configure to open the wireless adapter Properties dialog box, and then click the Advanced tab, as shown in Figure 10.

Figure 10: Wireless adapter Properties dialog box, Advanced tab.

You may need to step through each of the entries; however, the following entries usually present the most common trouble spots:

The entries listed on the Advanced tab differ depending on the wireless adapter installed in your laptop PC.

• Ad Hoc Channel 802.11 b/g: This is the radio channel on which the adapter starts looking for the wireless AP. By default, this value is set to 6. If your wireless AP is configured with a different value, set your adapter to match.
• Ad Hoc Default Wireless Mode: By default, this is set to 802.11 b/g. If you're using 802.11a, reset this value to match.
• Ad Hoc QoS Mode: QoS refers to quality of service protocol prioritization. This setting should match your wireless router or AP. This setting also comes into play when troubleshooting a slow internet connection.
• AP Compatibility Mode: If this entry is set to Higher Performance, open the drop-down list and select Broader Compatibility.
• Minimum Power Consumption: If this entry is set to Enabled, open the drop-down list and select Disabled.
• Throughput Enhancement: If you try everything else and things still don't work, disable this setting if it's enabled.
• Wireless Mode: Ensure this setting matches your wireless router or AP.

If you can't make things work by following the previous tips, open the Network and Sharing Center, and then click Diagnose and repair in the left pane. Windows Vista attempts to diagnose your network connection. If Vista finds some possible solutions, they're displayed in the Windows Network Diagnostics window. Common diagnoses include being too far away from the wireless router or AP (signal strength problems) and needing to establish a new IP address. Just click one of the diagnoses and follow the instructions.

Visit the Microsoft How to troubleshoot wireless network connections in Windows XP Service Pack 2 web page for additional problem-solving tips.

HP Instant Support

HP computer owners can also turn to the HP website for assistance when troubleshooting computing issues, including networking problems. Visit the HP Instant Support Professional Edition web page, click the Launch an online diagnostic session link, accept the agreement, enter your location and computer information, and then click Run System Health Scan. You're prompted to install an ActiveX control and then install an Online Support Services add-on. Once installation is complete, the scan begins, as shown in Figure 11. It takes several minutes for the software to complete its health scan.

Figure 11: HP System Health Scan.

This scan produces a detailed report that includes issues detected (with fixes where this portion of the list is populated), along with suggestions for optimizing your system, relevant updates, and more. On the same results page, you'll find hardware diagnostics and advanced diagnostics tabs that give you the option to investigate hardware components and subsystems selectively. The LAN diagnostics for wired and wireless connections in particular are quite helpful.

Although this brief offered many do-if-yourself solutions for common laptop PC wireless connection problems, if you've got an HP laptop PC, you always have the backing of HP support ready to help you resolve any issues. Just visit the HP Business Support Center website to learn about support and troubleshooting services.