William Unruh wrote:
On 2014-03-18, Martin Burnicki wrote:
Magnus Danielson wrote:
On 17/03/14 09:48, Martin Burnicki wrote:
You'd need hardware (FPGA?) which can be clocked at 1 GHz, and even in
the hardware signal processing you'd need to account for a number of
signal propagation delays wh
Brian Inglis wrote:
On 2014-03-18 02:59, Martin Burnicki wrote:
All depends on how accurate and precise you can get your timestamps,
and this
is probably easier with network packet timestampers at both sides of a
cable
than with a wireless time transfer method like GPS which usually
suffers fro
Magnus Danielson wrote:
Indeed. If you read the right article from 1990 you also know you can do
it on L1 C/A only by monitoring both code and carrier phase, as their
ionospheric effect have opposite signs.
That's interesting, and I didn't know about this.
Do you have a pointer to this article
On Tue, Mar 18, 2014 at 10:20:08PM +0100, Magnus Danielson wrote:
> No, it's not. NTP is being perceived to be "software timestamping"
> but nothing prohibits you from doing it in hardware. Similarly can
> you implement PTP with software time-stamping (with shitty
> performance).
>
> Doing HNTP ma
Magnus Danielson wrote:
On 18/03/14 10:17, Martin Burnicki wrote:
We have mades some tests and found that NTP can yield the same accuracy
as NTP if also hardware timestamping of NTP packets is supported on all
nodes, similar as for PTP.
In fact this isn't surprising, is it?
No, it's not. NTP
E-Mail Sent to this address will be added to the BlackLists wrote:
Why not just NTP with a PTP RefClock Driver?
People Already Run (& sell) Appliances that are both
PTP & NTP servers {which doesn't seem like it should be too hard};
I know. We at Meinberg are selling such appliances. ;-)
In article <5328aaa6.70...@rubidium.dyndns.org>, Magnus Danielson
wrote:
> On 18/03/14 01:36, Joe Gwinn wrote:
> > In article <5327757e.5040...@rubidium.dyndns.org>, Magnus Danielson
> > wrote:
> >
> >> Joe,
> >>
> >> On 16/03/14 23:16, Joe Gwinn wrote:
> >>> I recall seeing something from Dr. M
On 2014-03-19 03:30, Martin Burnicki wrote:
Brian Inglis wrote:
On 2014-03-18 02:59, Martin Burnicki wrote:
All depends on how accurate and precise you can get your timestamps,
and this
is probably easier with network packet timestampers at both sides of a
cable
than with a wireless time trans
Sort of
Lots of interesting stuff.
https://www.fbo.gov/index?s=opportunity&mode=form&id=4f5c8b176af03d89abb1a318624c944b
SUMMARY: National Institute of Standards and Technology (NIST), Department
of Commerce, seeks information from the public on NIST's potential
transition of time services f
Martin Burnicki wrote:
> Magnus Danielson wrote:
>> Indeed. If you read the right article from 1990 you
>> also know you can do it on L1 C/A only by monitoring
>> both code and carrier phase, as their ionospheric
>> effect have opposite signs.
>
> That's interesting, and I didn't know about this
Joe Gwinn wrote:> What greatly helps is to have a LAN for the heavy
> applications traffic, and a different LAN for NTP
> and the like, forcing different paths in the OS
> kernel to be taken.
If you see a difference, I would have though it more likely
to be different usage of the IP stacks
Paul wrote:
> https://www.fbo.gov/index?s=opportunity&mode=form&id=4f5c8b176af03d89abb1a318624c944b
> SUMMARY: National Institute of Standards and Technology
> (NIST), Department of Commerce, seeks information from
> the public on NIST's potential transition of time services
> from a NIST-only s
On Wed, Mar 19, 2014 at 12:20:55PM -0700, E-Mail Sent to this address will be
added to the BlackLists wrote:
> Certichron (Time-Evidence Services) via
> (USTS) The United States Time Server Foundation
> is already doing that?
No, they're not.
> They are already a significant portion
Brian Inglis wrote:
> Martin Burnicki wrote:
>> At the single nanosecond accuracy level it would also be
>> important to *which* local realizations UTC(k) you are referring,
>> UTC(NIST), UTC(USNO), UTC(PTB), ...
>
> The source would need to provided by or calibrated against the ref,
>> at some
On Wed, Mar 19, 2014 at 3:20 PM, E-Mail Sent to this address will be added
to the BlackLists wrote:
> Certichron is already doing that?
>
I'm curious what punctuation you intended.
> They are already a significant portion of the NIST NTP servers
>
They were. Certichron appears to have left
On 2014-03-19 12:01, E-Mail Sent to this address will be added to the
BlackLists wrote:
Brian Inglis wrote:
Martin Burnicki wrote:
At the single nanosecond accuracy level it would also be
important to *which* local realizations UTC(k) you are referring,
UTC(NIST), UTC(USNO), UTC(PTB), ...
On Wed, Mar 19, 2014 at 6:16 PM, Brian Inglis <
brian.ing...@systematicsw.ab.ca> wrote:
> Each constellation has its own epoch, TAI or UTC time scale, and
> uncertainty:
I'm unclear how various time scales relate to PTP. It would appear that
the design intent is local (LAN) process control. An
On 2014-03-19 16:32, Paul wrote:
On Wed, Mar 19, 2014 at 6:16 PM, Brian Inglis <
brian.ing...@systematicsw.ab.ca> wrote:
Each constellation has its own epoch, TAI or UTC time scale, and
uncertainty:
I'm unclear how various time scales relate to PTP. It would appear that
the design intent is
On Wed, Mar 19, 2014 at 7:04 PM, Brian Inglis <
brian.ing...@systematicsw.ab.ca> wrote:
> While 1ns precision may be doable, accuracy depends on what
> controls the GM, and its traceability to a reference.
>
Sure. My point is I haven't seen a use case in this thread for nanosecond
*accuracy* re
In article , E-Mail Sent to this address
will be added to the BlackLists
wrote:
> Joe Gwinn wrote:> What greatly helps is to have a LAN for the heavy
> > applications traffic, and a different LAN for NTP
> > and the like, forcing different paths in the OS
> > kernel to be taken.
>
> If yo
In article , Martin
Burnicki wrote:
> Joe Gwinn wrote:
> > I've used IRIG-B004 DCLS before, for cables two meters long within a
> > cabinet. Worked well. How well do they handle 100 meter cables, in
> > areas where the concept of "ground" can be elusive?
>
>
> You could use fiber optics to tr
In article <5328ad2...@rubidium.dyndns.org>, Magnus Danielson
wrote:
> On 18/03/14 01:24, Joe Gwinn wrote:
> > In article <532778bf.50...@rubidium.dyndns.org>, Magnus Danielson
> > wrote:
> >
> >> On 17/03/14 13:50, Joe Gwinn wrote:
> >>> In article , William Unruh
> >>> wrote:
> >>>
> On
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