If you wish to bring your own device to school -

How to Access the School Wireless with Your Own Device

When the NSW.det window appears, log in with your Username and password.
But, make sure you use the username and passward you use to log into the internet at school,
not the basic username and password you normally use when you log onto the school computers.

Your device needs to be able to cope with or be compatable with the 5GHz (802.11a/n) wireless
  network protocol that is used in your school.

How to check if your device can work with the 5 GHz wireless requirements.

If your device is not able to access the 5GMz wireless system you may be able to by using a
 Wireless-G USB Dongle / Adapter
This is a wireless USB adapter that can connect your computer to a high-speed wireless.
This adapter simply plugs to your computer through a USB  interface to provide up to
54Mbps wireless speed.... plug-and-play installation, this adapter is a solution for notebook
and laptop PC users needing access to fast wireless connection...