[time-nuts] CDMA NTP servers beginning to fail

[Steven Sommars]

In the past few months I've noticed problems on multiple US-based public
NTP stratum 1 servers that use CDMA as their stratum 0 clock..  EndRun
Technologies Tempus LX (
https://endruntechnologies.com/pdf/USM3014-0000-000.pdf) is an example.

This is not a surprise. In the US Verizon has announced plans to shut down
its legacy CDMA service though the end-date keeps changing (
https://usatcorp.com/verizon-extends-cdma-network-date/).  As the number of
CDMA channels and base stations drops the NTP servers have difficulty
finding an acceptable signal.

Failure modes include:  rapidly increasing root dispersion, reported time
drifting over the course of many weeks, 1024-week rollover(!), and complete
failure.

I don't know how users will adapt.  Other radio-based technologies have
poorer in-building coverage.

Steve Sommars