Certified IT Support Professional Learning Resources Wireless network

Learning Resources

More and more networks are operating without cables, in the wireless mode. Wireless LANs use high frequency radio signals, infrared light beams, or lasers to communicate between the workstations, servers, or hubs. Each workstation and file server on a wireless network has some sort of transceiver/antenna to send and receive the data. Information is relayed between transceivers as if they were physically connected. For longer distance, wireless communications can also take place through cellular telephone technology, microwave transmission, or by satellite.

Wireless networks are great for allowing laptop computers, portable devices, or remote computers to connect to the LAN. Wireless networks are also beneficial in older buildings where it may be difficult or impossible to install cables.

The two most common types of infrared communications used in schools are line-of-sight and scattered broadcast. Line-of-sight communication means that there must be an unblocked direct line between the workstation and the transceiver. If a person walks within the line-of-sight while there is a transmission, the information would need to be sent again. This kind of obstruction can slow down the wireless network. Scattered infrared communication is a broadcast of infrared transmissions sent out in multiple directions that bounces off walls and ceilings until it eventually hits the receiver. Networking communications with laser are virtually the same as line-of-sight infrared networks.

Wireless standards and speeds

The Wi-Fi Alliance is a global, non-profit organization that helps to ensure standards and interoperability for wireless networks, and wireless networks are often referred to as WiFi (Wireless Fidelity). The original Wi-Fi standard (IEEE 802.11) was adopted in 1997. Since then many variations have emerged (and will continue to emerge). Wi-Fi networks use the Ethernet protocol.

Standard Max Speed Typical Range
802.11a 54 Mbps 150 feet
802.11b 11 Mbps 300 feet
802.11g 54 Mbps 300 feet
802.11n 100 Mbps 300+ feet

Wireless Security

Wireless networks are much more susceptible to unauthorized use than cabled networks. Wireless network devices use radio waves to communicate with each other. The greatest vulnerability to the network is that rogue machines can "eves-drop" on the radio wave communications. Unencrypted information transmitted can be monitored by a third-party, which, with the right tools (free to download), could quickly gain access to your entire network, steal valuable passwords to local servers and online services, alter or destroy data, and/or access personal and confidential information stored in your network servers. To minimize the possibility of this, all modern access points and devices have configuration options to encrypt transmissions. These encryption methodologies are still evolving, as are the tools used by malicious hackers, so always use the strongest encryption available in your access point and connecting devices.

A NOTE ON ENCRYPTION: As of this writing WEP (Wired Equivalent Privacy) encryption can be easily hacked with readily-available free tools which circulate the internet. WPA and WPA2 (WiFi Protected Access versions 1 and 2) are much better at protecting information, but using weak passwords or passphrases when enabling these encryptions may allow them to be easily hacked. If your network is running WEP, you must be very careful about your use of sensitive passwords or other data.

Three basic techniques are used to protect networks from unauthorized wireless use. Use any and all of these techniques when setting up your wireless access points:

Enable the strongest encryption supported by the devices you will be connecting to the network. Use strong passwords (strong passwords are generally defined as passwords containing symbols, numbers, and mixed case letters, at least 14 characters long).
Use a wireless router that places all wireless connections on a subnet independent of the primary private network. This protects your private network data from pass-through internet traffic.
Hidden SSID.
Every access point has a Service Set IDentifier (SSID) that by default is broadcast to client devices so that the access point can be found. By disabling this feature, standard client connection software won't be able to "see" the access point. However, the eves-dropping programs discussed previously can easily find these access points, so this alone does little more than keep the access point name out of sight for casual wireless users.

Advantages of wireless networks:

  • Mobility - With a laptop computer or mobile device, access can be available throughout a school, at the mall, on an airplane, etc. More and more businesses are also offering free WiFi access ("Hot spots").
  • Fast setup - If your computer has a wireless adapter, locating a wireless network can be as simple as clicking "Connect to a Network" -- in some cases, you will connect automatically to networks within range.
  • Cost - Setting up a wireless network can be much more cost effective than buying and installing cables.
  • Expandability - Adding new computers to a wireless network is as easy as turning the computer on (as long as you do not exceed the maximum number of devices).

Disadvantages of wireless networks:

  • Security - Be careful. Be vigilant. Protect your sensitive data with backups, isolated private networks, strong encryption and passwords, and monitor network access traffic to and from your wireless network.
  • Interference - Because wireless networks use radio signals and similar techniques for transmission, they are susceptible to interference from lights and electronic devices.
  • Inconsistent connections - How many times have you hears "Wait a minute, I just lost my connection?" Because of the interference caused by electrical devices and/or items blocking the path of transmission, wireless connections are not nearly as stable as those through a dedicated cable.
  • Speed - The transmission speed of wireless networks is improving; however, faster options (such as gigabit Ethernet) are available via cables. If you are only using wireless for internet access, the actual internet connection for your home or school is generally slower than the wireless network devices, so that connection is the bottleneck. If you are also moving large amounts of data around a private network, a cabled connection will enable that work to proceed much faster.

Wireless network

Imagine sitting on the couch in your living room surfing the web, or chatting with friends online while relaxing in bed at night, or sending documents from the computer in the kitchen to the printer in your home office. A wireless network provides the ultimate in networking flexibility, and setting one up is easier than you might think. This article walks you through the steps to set up your wireless network and start using it.

Getting the right equipment

Before you can set up your wireless network, you need the following items:

Broadband Internet connection and modem

A broadband Internet connection is a high-speed Internet connection—in contrast to a dial-up connection, which is slower and not powerful enough to support a wireless network. Digital Subscriber Line (DSL) and cable are two of the most common broadband connections. You can get a broadband connection by contacting an Internet service provider (ISP). Typically, ISPs that provide DSL are telephone companies and ISPs that provide cable are cable TV companies. ISPs often offer broadband modems and might even install it for you. Some ISPs also offer combination modem/wireless routers. You can also find these at computer or electronics stores.

Illustration of a cable and DSL modemTypical cable modem (left) and DSL modem (right)

Wireless router

A router sends information between your network and the Internet. With a wireless router, you can connect computers to your network using radio signals instead of wires. There are a few different types of wireless network technologies, including 802.11a, 802.11b, 802.11g, and 802.11n. We recommend using a router that supports 802.11g or 802.11n because they are fast and can provide a strong wireless signal.

Illustration of a wireless routerTypical wireless router

Wireless network adapters

A network adapter is a device that connects your computer to a network. To connect your mobile PC or desktop computer to your wireless network, the computer must have a wireless network adapter. Most mobile PCs—and many desktop computers—come with a wireless network adapter already installed. To check if your computer has a wireless network adapter, follow these steps:

  1. Open Device Manager by clicking the Start button Picture of the Start button, clicking Control Panel, clicking System and Maintenance, and then clicking Device Manager. Administrator permission required If you are prompted for an administrator password or confirmation, type the password or provide confirmation.

  2. Next to Network adapters, click the plus sign (+).

  3. Look for a network adapter that includes "wireless" in the name.

Picture of Device Manager with a wireless network adapterDevice Manager showing a wireless network adapter

If your computer needs a wireless network adapter, you can purchase one from a computer or electronics store and install it yourself. The universal serial bus (USB) type are a nice choice because they are small, easy to install, and they can be moved around to different computers. Make sure that you get the same type of adapters as your wireless router. The type of adapter is usually marked on the package, typically with a letter, such as G or A.

Illustration of USB wireless network adaptersTypical USB wireless network adapters

Setting up the modem and Internet connection

Once you have all of the equipment, you need to set up your modem and Internet connection. If your modem was not set up for you by your Internet service provider (ISP), follow the instructions that came with your modem to connect it to your computer and the Internet. If you are using Digital Subscriber Line (DSL), connect your modem to a phone jack. If you are using cable, connect your modem to a cable jack.

Positioning the wireless router

You'll want to put your wireless router somewhere where it will receive the strongest signal with the least amount of interference. For the best results, follow these tips:

  • Position your wireless router in a central location. Place the router as close to the center of your home as possible to increase the strength of the wireless signal throughout your home.

  • Position the wireless router off of the floor and away from walls and metal objects, such as metal file cabinets. The fewer physical obstructions between your computer and the router's signal, the more likely that you'll be using the router's full signal strength.

  • Reduce interference. 802.11g networking equipment uses a 2.4 gigahertz (GHz) radio frequency. This is the same frequency as most microwaves and many cordless phones. If you turn on the microwave or get a call on a cordless phone, your wireless signal might be temporarily interrupted. You can avoid most of these issues by using a cordless phone with a higher frequency, such as 5.8 GHz.

Securing your wireless network

Security is always important; with a wireless network, it is even more important because your network's signal could go beyond the boundaries of your home. If you don't secure your network, people with computers nearby might be able to access the information stored on your network computers and use your Internet connection to get onto the web. To help secure your network, do the following:

  • Protect your router by changing the default user name and password. Most router manufacturers have a default user name and password on the router as well as a default network name. Someone could use this information to access your router without you knowing it. To avoid that risk, change the default user name and password for your router. Check the information that came with your device for instructions.

  • Set up a security key for your network. Just as file cabinets have keys and safes have combinations, wireless networks have a network security key to help protect them from unauthorized access. To set up a network security key, follow these steps:

    1. Open Network and Sharing Center by clicking the Start button Picture of the Start button, clicking Control Panel, clicking Network and Internet, and then clicking Network and Sharing Center.

    2. In the left pane, click Set up a connection or network.

    3. Click Set up a wireless router or access point, and then click Next.

    The wizard will walk you through creating a network name and a security key. If your router will support it, the wizard will default to Wi-Fi Protected Access (WPA) security. We recommend that you use WPA because it offers better security than the traditional Wired Equivalent Privacy (WEP) security. With WPA you can also use a passphrase, so you don’t have to remember a cryptic sequence of letters and numbers.

    Picture of Set up a router or access point wizardCreate a network security key by entering a passphrase

    Make sure that you write down the security key and keep it in a safe place. If you have one, you can also save your security key on a USB flash drive by following the instructions in the wizard.

  • Use a firewall. A firewall is hardware or software that can help protect your computer from hackers or malicious software. Running a firewall on each computer on your network can help control the spread of malicious software on your network, as well as help to protect your computers when you're accessing the Internet. Windows Firewall is included with Windows Vista

Adding computers to your network

To connect your laptop or desktop computer to your wireless network, follow these steps:

  1. Open Connect to a Network by clicking the Start button Picture of the Start button, and then clicking Connect to.

  2. In the list of networks, click the network that you want to connect to, and then click Connect.

  3. Enter the security key. You can either type in the key or insert a USB flash drive that contains the security key into a USB port on the computer.

Sharing files and printers

Most people have a wireless network so they can access the Internet from any room in the house, but they also want the freedom of accessing files and printers wirelessly.



The ability to share files and printers is not included in Windows Vista Starter.


Sharing files

The easiest way to share files on your network is to place them in the Public folder. Any file or folder you put in the Public folder is automatically shared with the people connected to your network. To turn on Public folder sharing, follow these steps:

  1. Open Network and Sharing Center by clicking the Start button Picture of the Start button, clicking Control Panel, clicking Network and Internet, and then clicking Network and Sharing Center.

  2. Click the arrow button Picture of the arrow button next to Public folder sharing, and then click one of the following options:
    • Turn on sharing so anyone with network access can open files

    • Turn on sharing so anyone with network access can open, change, and create files

    • Turn off sharing (people logged on to this computer can still access this folder)

  3. Click Apply.

    You will need to repeat the steps above on each computer that you want to share files from.

    To share your files, save them or copy them to the Public folder on your computer. There is one Public folder on each computer. Every person with a user account on the computer shares this folder. To open the Public folder:

    1. Open Documents by clicking the Start button Picture of the Start button, and then clicking Documents.

    2. In the Navigation pane, under Favorite Links, click Public.

    Picture of the Public folderThe Public folder

Sharing a printer

If you have a printer attached to one of your computers, you can print to it from any computer connected to your wireless network. To share a printer, follow these steps:

  1. Log on to computer that has the printer attached to it.

  2. Open Network and Sharing Center by clicking the Start button Picture of the Start button, clicking Control Panel, clicking Network and Internet, and then clicking Network and Sharing Center.

  3. Click the arrow button Picture of the arrow button next to Printer sharing, click Turn on printer sharing, and then click Apply.
  4. Click the arrow button Picture of the arrow button next to Password protected sharing, click Turn off password protected sharing, and then click Apply.


If you have password-protected sharing turned on, people will need a user account with a password on your computer to access your printer.


To access the printer from any computer on the network, follow these steps:

  1. Open Network by clicking the Start button Picture of the Start button, and then clicking Network.

  2. Double-click the icon for the computer that has the printer attached to it.

  3. Double-click the icon for the printer. Windows will automatically add the printer to your computer and install the printer driver.

Enjoying your freedom

And that’s it—your wireless network is ready to go. Relax on the couch or out on the deck and do some online shopping.


 For Support