[ntp:questions] NTP over DRM: RDS on FM only accurate to 100ms and no tracability mechinsim exists

Max Power mikehack at u.washington.edu
Wed Mar 21 07:38:08 UTC 2007

NPR stations that use RDS are only accurate to within 100ms, due to RDS's 
time transmission design flaws.
No accuracy or traceability mechanism exists for RDS-TC (Time Clock, or TS: 
Time Service) service.
IP packets are of no meaning here, RDS cannot really encapsulate them.

This is a non-TCP_IP use of NTP.

NTP is a data transmission format for time separate of its IP4 and IP6 
multihop measurement mechanisms.

NTP over DRM: http://hireme.geek.nz/NTP.html

> NPR currently uses NTP to synchronize the local broadcast time to the 
> satellite feed. The crucial issue is to encapsulate the compressed audio 
> in IP packets, not the other way around. I suspect PBS might do the same 
> thing as well, as their programs start time deltas are be in the low 
> milliseconds relative to UTC. The DRM page cited is riddled with errors. 
> Somebody (me?) should send a comprehensive bug report.
>> Yes, but a BCD Time and Date is t deltasansmitted -- not NTP.
>> NTP is a proven workhorse for time signal distribution -- and can be 
>> implemented beyond the WWW.

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