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

David Lang david at lang.hm
Wed Mar 15 17:52:41 EDT 2023


On Wed, 15 Mar 2023, Dave Taht wrote:

> 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?)

no good stats this year. still using the wndr3800s. Lots of people commenting on 
how well the network did, but we were a bit behind this year and didn't get good 
monitoring in place. No cake yet.

I think this is what you mean
https://www.youtube.com/watch?v=UXvGbEYeWp0

> 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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