Re: [time-nuts] WWVB Now a Monopoly
In reviewing the NIST document, I don't see anything particularly
difficult about the new format - either in terms of extracting the time
or phase/frequency information from the transmissions. With
undersampling, carrier recovery (to determine phase and amplitude
information) should be do-able even with a fairly low-end microprocessor.
It occurred to me that, as was the case with the old format, this new
one could still be implemented entirely in glue-logic LSI hardware
(think "7400" or "4000" series): True, it would take several dozen
chips to do this, but it would be perfectly do-able - even the
implementation of parity.
The tricky part would be the conversion of the seconds to usable
time/date with glue logic - but then again, a bit of clever use with
lookup ROMs (violating the glue logic premise a bit!) could clear that up.
About the only part that is "unknown" is the message format - which is
not essential to the operation of any receiver in terms of determining
time/frequency - which would be interesting to know more about.
Clint
KA7OEI
In message 50633BF8.9050705@ussc.com, Clint Turner writes:
In reviewing the NIST document, I don't see anything particularly
difficult about the new format - either in terms of extracting the time
or phase/frequency information from the transmissions.
As a somewhat seasoned VLF SDR radio-nut, I must admit that I find
the yelling of bloody murder over a so simple and well documented
transmission format.
Class action suit because they improve your VLF time/freq reference
signal and document the new format ?
Really ?
--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.
If the company that developed the format has a lead on tying up the IP for
marketing the new format so that others cannot play, then yes, there is a
problem. Really!
----- Original Message -----
From: "Poul-Henning Kamp" phk@phk.freebsd.dk
To: "Discussion of precise time and frequency measurement"
time-nuts@febo.com
Sent: Wednesday, September 26, 2012 2:05 PM
Subject: Re: [time-nuts] WWVB Now a Monopoly
In message 50633BF8.9050705@ussc.com, Clint Turner writes:
In reviewing the NIST document, I don't see anything particularly
difficult about the new format - either in terms of extracting the time
or phase/frequency information from the transmissions.
As a somewhat seasoned VLF SDR radio-nut, I must admit that I find
the yelling of bloody murder over a so simple and well documented
transmission format.
Class action suit because they improve your VLF time/freq reference
signal and document the new format ?
Really ?
--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
On Wed, Sep 26, 2012 at 06:05:14PM +0000, Poul-Henning Kamp wrote:
Class action suit because they improve your VLF time/freq reference
signal and document the new format ?
Speaking for myself, I'm mostly annoyed that our government was
lobbied with its own money for this*.
If these details were released earlier, and we were given a
migration timeframe up front, it'd be possible to be better prepared.
Instead, we're getting the details a couple of weeks before they change
formats. (At least, I think it's a couple of weeks. It's now 'sometime
in the fall.')
I also don't understand the point of changing the modulation
format with no receivers in the wild. Seems they could give us another
six months easily, at no real loss to anyone since there are no shipping
chipsets or receivers that understand the BPSK format.
I don't object to changing formats per se, but this has not been
handled very gracefully. With more testing, a full suite of
documentation, and a firm migration timeline announced well in advance,
I'd be much happier.
Without the docs, nobody's going to develop a receiver yet,
either, which is essentially going to kill off any commercial use of
WWVB for a while outside of wall clocks. This may actually be a
permanent shift.
Existing users have had to replace their references with GPS.
Having just made that capital investment, how likely do you think they
will be to buy a WWVB reference within the next few years. Or ever?
After all, why invest into a receiver for any US government
T&F services besides the GPS? In the last ~15 years, we've lost
Omega, the GOES TOD code, LORAN, and now WWVB (effectively.)
Each time, we have been told 'you should be using GPS anyway.'
Since it's obvious that anything but the GPS can go away at any time,
why make an investment into a new WWVB receiver at all?
If you're a commercial user, it does not make sense to bother.
The target market for the new modulation is consumer devices --
only. The time-nuts may be the only people that bother using it for
anything else.
--msa
[*] I'll explain this in another post.
Hi
I don't have a problem with going after a known format. What I have been
worried about is the existence of a portion of the format that we simply do
not know about (yet).
Of less concern are the minor details about the actual transmission. For
instance: Added AM modulation (or not) to zero carrier at the point of phase
change is as yet unmentioned.
Bob
-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On
Behalf Of Poul-Henning Kamp
Sent: Wednesday, September 26, 2012 2:05 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] WWVB Now a Monopoly
In message 50633BF8.9050705@ussc.com, Clint Turner writes:
In reviewing the NIST document, I don't see anything particularly
difficult about the new format - either in terms of extracting the time
or phase/frequency information from the transmissions.
As a somewhat seasoned VLF SDR radio-nut, I must admit that I find
the yelling of bloody murder over a so simple and well documented
transmission format.
Class action suit because they improve your VLF time/freq reference
signal and document the new format ?
Really ?
--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
With all due respect;
What I dislike is the pre-entry of a company that has direct knowledge of
the format, tying up the easy (and less expensive) methods of decoding the
time data using prior inside information and the patent system.
Let's say you find out what this PM modulation format is and decide to make
a NTP server based on the new format. Much to your surprise, the method you
want to design to has already been patented (by XW). The only option you
have is to possibly design with a more expensive and hence less marketable
device.
Sorry to keep beating this poor horse.
Regards,
Tom
----- Original Message -----
From: "Bob Camp" lists@rtty.us
To: "'Discussion of precise time and frequency measurement'"
time-nuts@febo.com
Sent: Wednesday, September 26, 2012 5:06 PM
Subject: Re: [time-nuts] WWVB Now a Monopoly
Hi
I don't have a problem with going after a known format. What I have been
worried about is the existence of a portion of the format that we simply do
not know about (yet).
Of less concern are the minor details about the actual transmission. For
instance: Added AM modulation (or not) to zero carrier at the point of phase
change is as yet unmentioned.
Bob
-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On
Behalf Of Poul-Henning Kamp
Sent: Wednesday, September 26, 2012 2:05 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] WWVB Now a Monopoly
In message 50633BF8.9050705@ussc.com, Clint Turner writes:
In reviewing the NIST document, I don't see anything particularly
difficult about the new format - either in terms of extracting the time
or phase/frequency information from the transmissions.
As a somewhat seasoned VLF SDR radio-nut, I must admit that I find
the yelling of bloody murder over a so simple and well documented
transmission format.
Class action suit because they improve your VLF time/freq reference
signal and document the new format ?
Really ?
--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
Or pay XW any royalty they demand (Viz Lipitor or Xyvox).
This could well be a high hurdle any other entrants into the marketplace.
-John
=================
With all due respect;
What I dislike is the pre-entry of a company that has direct knowledge of
the format, tying up the easy (and less expensive) methods of decoding the
time data using prior inside information and the patent system.
Let's say you find out what this PM modulation format is and decide to
make
a NTP server based on the new format. Much to your surprise, the method
you
want to design to has already been patented (by XW). The only option you
have is to possibly design with a more expensive and hence less marketable
device.
Sorry to keep beating this poor horse.
Regards,
Tom
----- Original Message -----
From: "Bob Camp" lists@rtty.us
To: "'Discussion of precise time and frequency measurement'"
time-nuts@febo.com
Sent: Wednesday, September 26, 2012 5:06 PM
Subject: Re: [time-nuts] WWVB Now a Monopoly
Hi
I don't have a problem with going after a known format. What I have been
worried about is the existence of a portion of the format that we simply
do
not know about (yet).
Of less concern are the minor details about the actual transmission. For
instance: Added AM modulation (or not) to zero carrier at the point of
phase
change is as yet unmentioned.
Bob
-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On
Behalf Of Poul-Henning Kamp
Sent: Wednesday, September 26, 2012 2:05 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] WWVB Now a Monopoly
In message 50633BF8.9050705@ussc.com, Clint Turner writes:
In reviewing the NIST document, I don't see anything particularly
difficult about the new format - either in terms of extracting the time
or phase/frequency information from the transmissions.
As a somewhat seasoned VLF SDR radio-nut, I must admit that I find
the yelling of bloody murder over a so simple and well documented
transmission format.
Class action suit because they improve your VLF time/freq reference
signal and document the new format ?
Really ?
--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by
incompetence.
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.