Wireless network access

What is a wireless network?

A wireless network is an infrastructure which makes it possible to connect a computer to a network without a physical connection like a cable.

How does a wireless network work?

To communicate with other computers across a wireless network, your computer needs a wireless network adapter. You can get such cards for both stationary and portable computers, but they are mostly used on the latter. A wireless network adapter has an antenna to communicate with wireless access points.

What is the range of a wireless network?

The range of a wireless network depends on several factors:

• The power of the signals sent from the wireless access point
• The power of the signals sent from the wireless adapter
• The number or objects between your computer and the access point, and the materials used in these.
• The weather

The signals used in a wireless network are radio waves, and thus have the same weaknesses as other radio waves. They are weakened by obstacles like walls and ceilings. Wooden walls are usually not a problem, while walls made of concrete and similar materials considerably reduce the range. Signals are also weakened by rain and snow.

As a rule of thumb, the range outdoors in clear weather is approximately 150-200 meters. Indoors the signals travel approximately 20 meters through walls and ceilings.

Why use wireless networks?

The main reason for using wireless networks is to avoid being bound to one place by a cable. By connecting to a wireless network you can move and still be connected to the network. When travelling from one access point's area of coverage to another, the computer automatically switches to the access point with the strongest signal.

Why are not all networks wireless?

There are some negative aspects of wireless networks.

To begin with, the speed of a wireless network connection is considerably lower than with a physical network. Many physical networks can achieve speeds above 1 Gbit/sec, while wireless networks are limited to 54 Mbit/sec - 1/20th the speed. In addition, the experienced speed is as mentioned dependent on walls, weather and other obstructions. If an access point has many connected users, all the users will notice reduced speeds. The advantages of mobility does not always outweigh the costs and disadvantages of setting up a wireless network.

The wireless network at NTNU

Work is being put into expanding the NTNU wireless network all over campus, both at Gløshaugen and at Dragvoll. At the moment the coverage isn't total, but this will change soon.

To get access to the Internet while connected to the wireless network at NTNU, you may use the VPN client, or you can use the Web Authentication. More information about those can be found on the following pages:VPN, Webauth.