As default, Cf wifi card driver get into no power manage mode.
It means the card is working on max current which is between 300ma-500ma, unless the power mode is managed by hardware.
In fact, CF wifi card can be working in Sleep-Wake Mode.
1. Open terminal
2. su
3. iwconfig wlan0 power on power max period 3
4. if no error, you can iwconfig again, and find the power manage is on.
5. Some card's power light maybe blink now.
6. Set power save mode as deault:
open /etc/pcmcia/wireless.opts
append following to the end:
IWCONFIG="power on power max period 3"
save and close file
7. Enjoy your wireless internet life, and do not worry about your energy.