> I'm curious how important the clock used is, for a cellular system
Very, that's why they bother with things like rubidium holdover clocks. A lot of things depend on precise synchronization, both locally and between multiple towers.
Thanks, that makes sense, curious how they seem to get away with a VCTCXO in this case (or at least I couldn't seem to find mention of rubidium clocks in addition).
Different qualities: Quartz crystals are better than Rb when looking at short periods. Long-term stability is normally provided by GPS. Rubidium beats crystals when it comes to stability over hours - it is added as a fallback for when GPS fails. If you don't have a requirement that your system can work lets say 24 or 48 hours without GPS sync, you can skip the Rb.
Very, that's why they bother with things like rubidium holdover clocks. A lot of things depend on precise synchronization, both locally and between multiple towers.