TDM/FDM or CDMA

I am just wondering most of the cell phones, what kind of algorithms use from following list.

TDM
FDM
CDMA

Which is more relaible and secure.

thanks
sympton

The future with 3G is going to be CDMA

I would say the future 3G would be CDMA and maybe OFDM. OFDM is a FDM access technique that is used in WiMAX and known to be a candidate for future "super 3G" and 4G. There are pros and cons with all access techniques, but in general you can get a better spectrum utilization if OFDM is used (higer bps/hz value). Which technique that is more reliable depends on the application.