CDMA has GPS in the base station (for accurate time reference).

What new Cingular GSM phone has a "GPS chip?"

wmbray@hotmail.com (William Bray) wrote in article
<vl8729j70r03ce@corp.supernews.com>:

Not sure where you heard that about Cingular's phones. Cingular's E-911
plans have never involved GPS. Certainly none of their current phones
have that kind of technology.

Cingular at one time planned to use E-OTD technology, which does require
special software in the phones. Some phones they currently sell do have
that technology, although it has nothing to do with GPS. But Cingular
has dropped plans to use E-OTD, and they are now going with a technology
that doesn't require anything special in the phones at all.

Most of Sprint and Verizon's CDMA phones do have GPS technology, but
it's not a complete GPS system in the phone. The phone can receive GPS
signals directly from the satellites, but it can only take raw signal
readings, not interpret them and determine location. The phone requires
help from the network to take the readings (it needs to know which
satellites to look for) and the final calculations to determine location
are done by a location server on the network.

The GPS-based technology is more accurate. Cingular's network-side
technology is less accurate, but that's the nature of network-only
technologies. You can only be so accurate without the phone being
actively involved. The FCC recognizes that fact, and their standards are
less strict for network-only technologies.