The fancy oscillators are for longer "holdover" time. It's essential that frequency not go out of spec for CDMA (etc.) networks even if the GPS signal is degra

The fancy oscillators are for longer "holdover" time. It's essential that frequency not go out of spec for CDMA (etc.) networks even if the GPS signal is degraded for whatever reason, so they use oscillators with large holdover times to buy themselves an extra layer of redundancy. I don't know if you need that for distributed transactions or not. The logic as to whether or not the time is "good" is probably a large part of the complexity of this scheme. Better hardware makes the software simpler and vulnerable to less failure modes.