[time-nuts] GPS Outage..

[Tom McDermott]

The reason many cell sites went to GPS for time and frequency
synchronization is that in many cases
it was either less expensive or only possible to backhaul the cell site
traffic to the MTSO (Mobile Telephone
Switching Office) via microwave radio rather than wireline copper or fiber
carrier.

That microwave backhaul did not always provide sufficiently precise phase
and frequency reference
needed at the cell site.

-- Tom, N5EG