[Bloat] [Rpm] [Starlink] [LibreQoS] On FiWi

Dave Taht dave.taht at gmail.com
Wed Mar 15 15:39:39 EDT 2023


On Wed, Mar 15, 2023 at 12:33 PM David Lang via Rpm
<rpm at lists.bufferbloat.net> wrote:
>
> if you want another example of the failure, look at any conference center, they
> have a small number of APs with wide coverage. It works well when the place is
> empty and they walk around and test it, but when it fills up with users, the
> entire network collapses.
>
> Part of this is that wifi was really designed for sparse environments, so it's
> solution to "I didn't get my message through" is to talk slower (and louder if
> possible), which just creates more interference for other users and reduces the
> available airtime.
>
> I just finished the Scale conference in Pasadena, CA. We deployed over 100 APs
> for the conference, up to 7 in a room, on the floor (so that the attendees
> bodies attenuate the signal) at low power so that the channels could be re-used
> more readily.

How did it go? You were deploying fq_codel on the wndr3800s there as
of a few years ago, and I remember you got rave reviews... (can you
repost the link to that old data/blog/podcast?)

Did you get any good stats?

Run cake anywhere?
>
> in the cell phone world they discovered 'microcells' years ago, but with wifi
> too many people are still trying to cover the max area with the fewest possible
> number of radios. As Dan says, it just doesn't work.
>
> and on mesh radios, you need to not just use a different channel for your
> uplink, you need a different band to avoid desense on the connection to your
> users. And that uplink is going to have the same hidden transmitter and airtime
> problems competing with the other nodes also doing the uplink that it's
> scalability is very limited (even with directional antennas). Wire/fiber for the
> uplink is much better.
>
> David Lang
>
>
>
>   On Wed, 15 Mar
> 2023, dan via Bloat wrote:
>
> > Trying to do all of what is currently wanted with 1 AP in a house is a huge
> > part of the current problems with WiFi networks.  MOAR power to try to
> > overcome attenuation and reflections from walls so more power bleeds into
> > the next home/suite/apartment etc.
> >
> > In the MSP space it's been rapidly moving to an AP per room with output
> > turned down to minimum.    Doing this we can reused 5Ghz channels 50ft away
> > (through 2 walls etc...) without interference.
> >
> > One issue with the RRH model is that to accomplish this 'light bulb' model,
> > ie you put a light bulb in the room you want light, is that it requires
> > infrastructure cabling.  1 RRH AP in a house is already a failure today and
> > accounts for most access complaints.
> >
> > Mesh radios have provided a bit of a gap fill, getting the access SSID
> > closer to the device and backhauling on a separate channel with better (and
> > likely fixed position ) antennas.
> >
> > regardless of my opinion on the full on failure of moving firewall off prem
> > and the associated security risks and liabilities, single AP in a home is
> > already a proven failure that has given rise to the mesh systems that are
> > top sellers and top performers today.
> >
> > IMO, there was a scheme that gained a moment of fame and then died out of
> > powerline networking and an AP per room off that powerline network.  I have
> > some of these deployed with mikrotik PLA adapters and the model works
> > fantastically, but the powerline networking has evolved slowly so I'm
> > seeing ~200Mbps practical speeds, and the mikrotik units have 802.11n
> > radios in them so also a bit of a struggle for modern speeds.   This model,
> > with some development to get ~2.5Gbps practical speeds, and WiFi6 or WiFi7
> > per room at very low output power, is a very practical and deployable by
> > consumers setup.
> >
> > WiFi7 also solves some pieces of this with AP coordination and
> > co-transmission, sort of like a MUMIMO with multiple APs, and that's in
> > early devices already (TPLINK just launched an AP).
> >
> > IMO, too many hurdles for RRH models from massive amounts of unfrastructure
> > to build, homes and appartment buildings that need re-wired, security and
> > liability concerns of homes and business not being firewall isolated by
> > stakeholders of those networks.
> >
> > On Wed, Mar 15, 2023 at 11:32 AM rjmcmahon <rjmcmahon at rjmcmahon.com> wrote:
> >
> >> The 6G is a contiguous 1200MhZ. It has low power indoor (LPI) and very
> >> low power (VLP) modes. The pluggable transceiver could be color coded to
> >> a chanspec, then the four color map problem can be used by installers
> >> per those chanspecs. https://en.wikipedia.org/wiki/Four_color_theorem
> >>
> >> There is no CTS with microwave "interference" The high-speed PHY rates
> >> combined with low-density AP/STA ratios, ideally 1/1, decrease the
> >> probability of time signal superpositions. The goal with wireless isn't
> >> high densities but to unleash humans. A bunch of humans stuck in a dog
> >> park isn't really being unleashed. It's the ability to move from block
> >> to block so-to-speak. FiWi is cheaper than sidewalks, sanitation
> >> systems, etc.
> >>
> >> The goal now is very low latency. Higher phy rates can achieve that and
> >> leave the medium free the vast most of the time and shut down the RRH
> >> too. Engineering extra capacity by orders of magnitude is better than
> >> AQM. This has been the case in data centers for decades. Congestion? Add
> >> a zero (or multiple by 10)
> >>
> >> Note: None of this is done. This is a 5-10 year project with zero
> >> engineering resources assigned.
> >>
> >> Bob
> >>> On Tue, Mar 14, 2023 at 5:11 PM Robert McMahon
> >>> <rjmcmahon at rjmcmahon.com> wrote:
> >>>
> >>>> the AP needs to blast a CTS so every other possible conversation has
> >>>> to halt.
> >>>
> >>> The wireless network is not a bus. This still ignores the hidden
> >>> transmitter problem because there is a similar network in the next
> >>> room.
> >>
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-- 
Come Heckle Mar 6-9 at: https://www.understandinglatency.com/
Dave Täht CEO, TekLibre, LLC


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