Additional Wireless Information
Configuring Your Computer
University access points use the 802.11b "wifi" standard. You will need a notebook equipped to support this standard. Many recent notebook computers are sold "wireless ready" and will work with the University network. For older notebooks you may need to acquire a wireless card. Cards which only support 802.11a will not work on the University network. Cards which support 802.11b or 802.11g are compatible.
The teminology used with wireless cards varies significantly between systems. In configuring wireless on your computer you will therefore need to choose those options which best match the following information.
- The University wireless network does not use the standard in-built 802.11 security.
- Data encryption must be "disabled".
- Network authentication should be "open" not "shared". [No network keys or certificates are required.]
- Your wireless connection should not be connected to a "bridge".
- Do not allow interconnection sharing - don't allow others to access the Internet through your computer.
- Your Internet Protocol (TCP/IP) Properties should be set to use DHCP. This can be achieved by choosing a setting such as:
obtain your IP address (and DNS server address) automatically; or use a server-assigned IP address - Do not set your wireless connection to ad hoc or computer-to-computer. Choose instead (if the options are available) connect to access point only, or infrastructure.
- University wireless network access points have names (SSIDs) with the format usyd-XXX where the XXX is the building number or the zone that the access point is located in. Leave the SSID blank during configuration if possible.
- If you are asked "does this connection access the Internet?", indicate that it does.
Is It Secure?
The basic connection is not secure. That is why access is restrict to only the wireless setup pages and https sites such as Webmail and eLearning. In order to access other websites you will need to use the Cisco VPN Client.
Information and Instructions on how the to download the Cisco VPN Client can be found here
You will need to connect to the Cisco VPN client every time you want to access external webpages on the wireless network.
A VPN client aims to secure a path of communication from the client machine to the VPN server. All communications between the client machine and the VPN server are encrypted, then "wrapped" with enough networking information for the intervening machines to pass the network data packets to their destination. The only part of the data that intervening machines can read is the network source and destination. Machines between the VPN server and the client cannot read the contents of the data packet.
The data is encrypted until it reaches the VPN server. The VPN server then unencrypts the data it was given by the client and sends it on to its original target.
Is It Safe?
The wireless data network [WDN] uses a radiofrequency signal to link laptop computers to the University’s main network. The technology used is basically similar to that used for the cordless phone and the mobile phone, where a radiofrequency link is established between the phone and a local base station. The WDN system and the cordless phone have base stations located within buildings in close proximity to the devices, whereas the mobile phone has the base stations located outdoors. So is it safe for people to be in areas where this WDN system is installed?
The WDN system and the cordless phone operate at a frequency of 2.4GHz, which is the same as a microwave oven. It is not valid to make comparisons between these two devices since the microwave oven is designed to concentrate its energy into the oven cavity for the purpose of heating, while the WDN system is designed to disperse its energy to provide a link to laptop computers at any point in a building. Because of this design feature, the intensity of the radiofrequency signal drops off rapidly as you move away from the WDN antenna. For example, the intensity at 1m from the base station antenna is 4% of that at 0.2m.
Another significant difference is the power at which these devices operate. A small microwave oven is 500 watts, a mobile phone is 0.6 watts and the wireless data network transmitter is a maximum of 0.1 watts.
The limit for general public exposure to Radiofrequency Fields given in ARPANSA RPS3 is located at less than 3 cm from the WDN antenna [see ref 4]. In a typical configuration the user would be at least 1 m away from any base station antenna.
The WDN type systems also have to pass USA FCC requirements which address interference to other electronic devices. These include implanted medical devices such as cardiac pacemakers. The findings conclude that there are no interference problems with such devices and other equipment used in the medical field [see ref 2]
It is therefore accepted that the users exposure to emissions associated with wireless data devices, are well below recommended exposure limits[ref 1]
There are several information sheets available that provide information on the safety of this type of system. They are from industry sources, the University of Wollongong and the University of Western Australia: