Sorry, I should have been more clear. Not a fixed butler matrix but a device with solid state, programmable, phase shifters, 0 - 360 degrees. It's a way to
create multiple phy channels and affect and vary the off diagonal elements of a MIMO H-matrix using conducted parts. Then automation software can have more
robust RF MIMO test scenarios that are reproducible.
https://web.stanford.edu/~dntse/Chapters_PDF/Fundamentals_Wireless_Communication_chapter7.pdf
<https://web.stanford.edu/~dntse/Chapters_PDF/Fundamentals_Wireless_Communication_chapter7.pdf>
Bob
On Tue, Jul 6, 2021 at 2:24 PM Ben Greear <gree...@candelatech.com
<mailto:gree...@candelatech.com>> wrote:
We tried adding in an external butler matrix in the past, but could not
notice any useful difference. Possibly
we didn't have the right use case.
Typically we are competitive on price for full testing solutions, but you
can get stand-alone attenuators
cheaper from specialized vendors. Happy to discuss pricing offlist if you
wish.
Thanks,
Ben
On 7/6/21 1:43 PM, Bob McMahon wrote:
> The four part attenuator part would be more interesting to me if it also
had a solid state phase shifters. This allows for testing 2x2 MIMO testing per
> affecting the spatial stream eigen vectors/values.
>
> Bob
>
> PS. The price per port isn't competitive. Probably a good idea to survey
the market competition.
>
> On Tue, Jul 6, 2021 at 6:46 AM Ben Greear <gree...@candelatech.com
<mailto:gree...@candelatech.com> <mailto:gree...@candelatech.com
<mailto:gree...@candelatech.com>>> wrote:
>
> Hello,
>
> I am interested to hear wish lists for network testing features. We
make test equipment, supporting lots
> of wifi stations and a distributed architecture, with built-in udp,
tcp, ipv6, http, ... protocols,
> and open to creating/improving some of our automated tests.
>
> I know Dave has some test scripts already, so I'm not necessarily
looking to reimplement that,
> but more fishing for other/new ideas.
>
> Thanks,
> Ben
>
> On 7/2/21 4:28 PM, Bob McMahon wrote:
> > I think we need the language of math here. It seems like the
network power metric, introduced by Kleinrock and Jaffe in the late 70s, is something
useful.
> > Effective end/end queue depths per Little's law also seems
useful. Both are available in iperf 2 from a test perspective. Repurposing test
techniques to
> actual
> > traffic could be useful. Hence the question around what exact
telemetry is useful to apps making socket write() and read() calls.
> >
> > Bob
> >
> > On Fri, Jul 2, 2021 at 10:07 AM Dave Taht <dave.t...@gmail.com
<mailto:dave.t...@gmail.com> <mailto:dave.t...@gmail.com
<mailto:dave.t...@gmail.com>> <mailto:dave.t...@gmail.com <mailto:dave.t...@gmail.com>
<mailto:dave.t...@gmail.com <mailto:dave.t...@gmail.com>>>> wrote:
> >
> > In terms of trying to find "Quality" I have tried to
encourage folk to
> > both read "zen and the art of motorcycle maintenance"[0], and
Deming's
> > work on "total quality management".
> >
> > My own slice at this network, computer and lifestyle "issue"
is aiming
> > for "imperceptible latency" in all things. [1]. There's a lot
of
> > fallout from that in terms of not just addressing queuing
delay, but
> > caching, prefetching, and learning more about what a user
really needs
> > (as opposed to wants) to know via intelligent agents.
> >
> > [0] If you want to get depressed, read Pirsig's successor to
"zen...",
> > lila, which is in part about what happens when an engineer
hits an
> > insoluble problem.
> > [1] https://www.internetsociety.org/events/latency2013/
<https://www.internetsociety.org/events/latency2013/>
<https://www.internetsociety.org/events/latency2013/
<https://www.internetsociety.org/events/latency2013/>>
> >
> >
> >
> > On Thu, Jul 1, 2021 at 6:16 PM David P. Reed <dpr...@deepplum.com
<mailto:dpr...@deepplum.com> <mailto:dpr...@deepplum.com
<mailto:dpr...@deepplum.com>> <mailto:dpr...@deepplum.com
<mailto:dpr...@deepplum.com>
> <mailto:dpr...@deepplum.com <mailto:dpr...@deepplum.com>>>> wrote:
> > >
> > > Well, nice that the folks doing the conference are
willing to consider that quality of user experience has little to do with signalling
rate at the
> > physical layer or throughput of FTP transfers.
> > >
> > >
> > >
> > > But honestly, the fact that they call the problem "network
quality" suggests that they REALLY, REALLY don't understand the Internet isn't the
> hardware or
> > the routers or even the routing algorithms *to its users*.
> > >
> > >
> > >
> > > By ignoring the diversity of applications now and in the
future, and the fact that we DON'T KNOW what will be coming up, this conference will
> likely fall
> > into the usual trap that net-heads fall into - optimizing for
some imaginary reality that doesn't exist, and in fact will probably never be
what users
> > actually will do given the chance.
> > >
> > >
> > >
> > > I saw this issue in 1976 in the group developing the
original Internet protocols - a desire to put *into the network* special tricks to
optimize ASR33
> > logins to remote computers from terminal concentrators (aka
remote login), bulk file transfers between file systems on different time-sharing
> systems, and
> > "sessions" (virtual circuits) that required logins. And then trying to
exploit underlying "multicast" by building it into the IP layer,
because someone
> > thought that TV broadcast would be the dominant application.
> > >
> > >
> > >
> > > Frankly, to think of "quality" as something that can be "provided" by
"the network" misses the entire point of "end-to-end argument in
system design".
> > Quality is not a property defined or created by The Network.
If you want to talk about Quality, you need to talk about users - all the users
at all
> times,
> > now and into the future, and that's something you can't do if
you don't bother to include current and future users talking about what they might
> expect to
> > experience that they don't experience.
> > >
> > >
> > >
> > > There was much fighting back in 1976 that basically involved "network
experts" saying that the network was the place to "solve" such issues as
> quality,
> > so applications could avoid having to solve such issues.
> > >
> > >
> > >
> > > What some of us managed to do was to argue that you can't
"solve" such issues. All you can do is provide a framework that enables different
uses to
> > *cooperate* in some way.
> > >
> > >
> > >
> > > Which is why the Internet drops packets rather than
queueing them, and why diffserv cannot work.
> > >
> > > (I know the latter is conftroversial, but at the moment,
ALL of diffserv attempts to talk about end-to-end applicaiton specific metrics, but
> never, ever
> > explains what the diffserv control points actually do w.r.t.
what the IP layer can actually control. So it is meaningless - another violation
of the
> > so-called end-to-end principle).
> > >
> > >
> > >
> > > Networks are about getting packets from here to there,
multiplexing the underlying resources. That's it. Quality is a whole different thing.
> Quality can
> > be improved by end-to-end approaches, if the underlying
network provides some kind of thing that actually creates a way for end-to-end
applications to
> > affect queueing and routing decisions, and more importantly getting
"telemetry" from the network regarding what is actually going on with the
other
> > end-to-end users sharing the infrastructure.
> > >
> > >
> > >
> > > This conference won't talk about it this way. So don't
waste your time.
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > > On Wednesday, June 30, 2021 8:12pm, "Dave Taht"
<dave.t...@gmail.com <mailto:dave.t...@gmail.com> <mailto:dave.t...@gmail.com
<mailto:dave.t...@gmail.com>> <mailto:dave.t...@gmail.com
<mailto:dave.t...@gmail.com>
> <mailto:dave.t...@gmail.com <mailto:dave.t...@gmail.com>>>> said:
> > >
> > > > The program committee members are *amazing*. Perhaps,
finally, we can
> > > > move the bar for the internet's quality metrics past
endless, blind
> > > > repetitions of speedtest.
> > > >
> > > > For complete details, please see:
> > > > https://www.iab.org/activities/workshops/network-quality/
<https://www.iab.org/activities/workshops/network-quality/>
<https://www.iab.org/activities/workshops/network-quality/
<https://www.iab.org/activities/workshops/network-quality/>>
> > > >
> > > > Submissions Due: Monday 2nd August 2021, midnight AOE
(Anywhere On Earth)
> > > > Invitations Issued by: Monday 16th August 2021
> > > >
> > > > Workshop Date: This will be a virtual workshop, spread
over three days:
> > > >
> > > > 1400-1800 UTC Tue 14th September 2021
> > > > 1400-1800 UTC Wed 15th September 2021
> > > > 1400-1800 UTC Thu 16th September 2021
> > > >
> > > > Workshop co-chairs: Wes Hardaker, Evgeny Khorov, Omer
Shapira
> > > >
> > > > The Program Committee members:
> > > >
> > > > Jari Arkko, Olivier Bonaventure, Vint Cerf, Stuart
Cheshire, Sam
> > > > Crowford, Nick Feamster, Jim Gettys, Toke
Hoiland-Jorgensen, Geoff
> > > > Huston, Cullen Jennings, Katarzyna Kosek-Szott, Mirja
Kuehlewind,
> > > > Jason Livingood, Matt Mathias, Randall Meyer, Kathleen
Nichols,
> > > > Christoph Paasch, Tommy Pauly, Greg White, Keith
Winstein.
> > > >
> > > > Send Submissions to: network-quality-workshop...@iab.org
<mailto:network-quality-workshop...@iab.org>
<mailto:network-quality-workshop...@iab.org
<mailto:network-quality-workshop...@iab.org>>
> <mailto:network-quality-workshop...@iab.org
<mailto:network-quality-workshop...@iab.org>
<mailto:network-quality-workshop...@iab.org
<mailto:network-quality-workshop...@iab.org>>>.
> > > >
> > > > Position papers from academia, industry, the open source
community and
> > > > others that focus on measurements, experiences,
observations and
> > > > advice for the future are welcome. Papers that reflect
experience
> > > > based on deployed services are especially welcome. The
organizers
> > > > understand that specific actions taken by operators are
unlikely to be
> > > > discussed in detail, so papers discussing general
categories of
> > > > actions and issues without naming specific technologies,
products, or
> > > > other players in the ecosystem are expected. Papers
should not focus
> > > > on specific protocol solutions.
> > > >
> > > > The workshop will be by invitation only. Those wishing
to attend
> > > > should submit a position paper to the address above; it
may take the
> > > > form of an Internet-Draft.
> > > >
> > > > All inputs submitted and considered relevant will be
published on the
> > > > workshop website. The organisers will decide whom to
invite based on
> > > > the submissions received. Sessions will be organized
according to
> > > > content, and not every accepted submission or invited
attendee will
> > > > have an opportunity to present as the intent is to
foster discussion
> > > > and not simply to have a sequence of presentations.
> > > >
> > > > Position papers from those not planning to attend the
virtual sessions
> > > > themselves are also encouraged. A workshop report will
be published
> > > > afterwards.
> > > >
> > > > Overview:
> > > >
> > > > "We believe that one of the major factors behind this
lack of progress
> > > > is the popular perception that throughput is the often
sole measure of
> > > > the quality of Internet connectivity. With such narrow
focus, people
> > > > don’t consider questions such as:
> > > >
> > > > What is the latency under typical working conditions?
> > > > How reliable is the connectivity across longer time
periods?
> > > > Does the network allow the use of a broad range of
protocols?
> > > > What services can be run by clients of the network?
> > > > What kind of IPv4, NAT or IPv6 connectivity is offered,
and are there firewalls?
> > > > What security mechanisms are available for local
services, such as DNS?
> > > > To what degree are the privacy, confidentiality,
integrity and
> > > > authenticity of user communications guarded?
> > > >
> > > > Improving these aspects of network quality will likely
depend on
> > > > measurement and exposing metrics to all involved
parties, including to
> > > > end users in a meaningful way. Such measurements and
exposure of the
> > > > right metrics will allow service providers and network
operators to
> > > > focus on the aspects that impacts the users’ experience
most and at
> > > > the same time empowers users to choose the Internet
service that will
> > > > give them the best experience."
> > > >
> > > >
> > > > --
> > > > Latest Podcast:
> > > >
https://www.linkedin.com/feed/update/urn:li:activity:6791014284936785920/
<https://www.linkedin.com/feed/update/urn:li:activity:6791014284936785920/>
> <https://www.linkedin.com/feed/update/urn:li:activity:6791014284936785920/
<https://www.linkedin.com/feed/update/urn:li:activity:6791014284936785920/>>
> > > >
> > > > Dave Täht CTO, TekLibre, LLC
> > > > _______________________________________________
> > > > Cerowrt-devel mailing list
> > > > Cerowrt-devel@lists.bufferbloat.net
<mailto:Cerowrt-devel@lists.bufferbloat.net> <mailto:Cerowrt-devel@lists.bufferbloat.net
<mailto:Cerowrt-devel@lists.bufferbloat.net>>
<mailto:Cerowrt-devel@lists.bufferbloat.net <mailto:Cerowrt-devel@lists.bufferbloat.net>
> <mailto:Cerowrt-devel@lists.bufferbloat.net
<mailto:Cerowrt-devel@lists.bufferbloat.net>>>
> > > > https://lists.bufferbloat.net/listinfo/cerowrt-devel
<https://lists.bufferbloat.net/listinfo/cerowrt-devel>
<https://lists.bufferbloat.net/listinfo/cerowrt-devel
<https://lists.bufferbloat.net/listinfo/cerowrt-devel>>
> > > >
> >
> >
> >
> > --
> > Latest Podcast:
> >
https://www.linkedin.com/feed/update/urn:li:activity:6791014284936785920/
<https://www.linkedin.com/feed/update/urn:li:activity:6791014284936785920/>
<https://www.linkedin.com/feed/update/urn:li:activity:6791014284936785920/
<https://www.linkedin.com/feed/update/urn:li:activity:6791014284936785920/>>
> >
> > Dave Täht CTO, TekLibre, LLC
> > _______________________________________________
> > Make-wifi-fast mailing list
> > make-wifi-f...@lists.bufferbloat.net
<mailto:make-wifi-f...@lists.bufferbloat.net>
<mailto:make-wifi-f...@lists.bufferbloat.net
<mailto:make-wifi-f...@lists.bufferbloat.net>>
<mailto:make-wifi-f...@lists.bufferbloat.net
<mailto:make-wifi-f...@lists.bufferbloat.net>
> <mailto:make-wifi-f...@lists.bufferbloat.net
<mailto:make-wifi-f...@lists.bufferbloat.net>>>
> > https://lists.bufferbloat.net/listinfo/make-wifi-fast
<https://lists.bufferbloat.net/listinfo/make-wifi-fast>
<https://lists.bufferbloat.net/listinfo/make-wifi-fast
<https://lists.bufferbloat.net/listinfo/make-wifi-fast>>
> >
> >
> > This electronic communication and the information and any files
transmitted with it, or attached to it, are confidential and are intended solely
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> use of
> > the individual or entity to whom it is addressed and may contain
information that is confidential, legally privileged, protected by privacy laws, or
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> > restricted from disclosure to anyone else. If you are not the
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> > https://lists.bufferbloat.net/listinfo/starlink
<https://lists.bufferbloat.net/listinfo/starlink>
> >
>
>
> --
> Ben Greear <gree...@candelatech.com <mailto:gree...@candelatech.com>
<mailto:gree...@candelatech.com <mailto:gree...@candelatech.com>>>
> Candela Technologies Inc http://www.candelatech.com
<http://www.candelatech.com>
>
>
> This electronic communication and the information and any files
transmitted with it, or attached to it, are confidential and are intended solely
for the
use of
> the individual or entity to whom it is addressed and may contain
information that is confidential, legally privileged, protected by privacy laws, or
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> restricted from disclosure to anyone else. If you are not the intended
recipient or the person responsible for delivering the e-mail to the intended
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> you are hereby notified that any use, copying, distributing,
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--
Ben Greear <gree...@candelatech.com <mailto:gree...@candelatech.com>>
Candela Technologies Inc http://www.candelatech.com
<http://www.candelatech.com>
This electronic communication and the information and any files transmitted with it, or attached to it, are confidential and are intended solely for the use of
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