[LibreQoS] Rain Fade (was Ack-filtering)

Dave Taht dave.taht at gmail.com
Tue Oct 25 12:56:51 EDT 2022

On Mon, Oct 24, 2022 at 4:25 PM dan <dandenson at gmail.com> wrote:
>> How bad are y'all's gear doing with rain fade on various techs and
>> bands? in 08, in nica, I'd go from a working 70 db 10 mile shot to
>> nothin at 5ghz when it rained, and I just laughed at the people trying
>> to deploy 60ghz - but times change. I see a vendor trying to ship 60
>> with *really good antennas* into the office market...
>> big question to ask when so busy, please ignore me.
> I have extensive testing with almost every gear out there.
> 5Ghz, no appreciable fade in snow or rain.  Longest shot on network right now is 26 miles on AF5xHD 5Ghz on 2' dishes and we push a solid 300Mbps across this with zero fade.  Actually gets a tiny bit better in the rain, ie it is technically fading a bit but so is all the noise so it's a minor improvement.
> I have 2x 7 miles force 425 links that are pushing 550Mbps.  And a 10 miles force 400c on 2' ubiquiti dishes that pushes 940 unidirectional in 80Mhz.  No rain fade.  Lots of af5xhd and force4x links in different distances.  We even mix in some LTU PtMP as PTP for price, ie LTU AP <> LTU-LR or LTU-Pro for PTP.  Works well enough though this product is susceptible to noise more than any other we use.
> Cambium 60Mhz cnwave is fantastic, legit 120 meters per link node to node or small CPE, 500M to big CPE, about 300 to the not-quite-released mid CPE.  Pushing 1.7Gbps FDX on against my preseem box and my m2 macbook with nperf UDP.
> Ubiquiti gigabeam line, <1km ok, <800m even better.  AF 'LR' and 'XR' rock solid at 2km, up to about 5km until they're down too much to be usable.  Always backed up by a 5Ghz radio.
> Ubiquiti Wave, legit AP<>CPE out 2km and never fails over.  4km w/ wifi6 failover.  Fantastic product... probably the one to beat.
> Mikrotik 60Ghz 'ay about 200m on AP to small CPE, 500m AP to nRay.  Can get a little more but it's really close and rain fade gets you.  These have 'ac wireless backup in them so we can EASILY push 300m on the small and 800m on the nRay knowing we have about 4 hours a year in 5Ghz failover.
> Basically, and MIMO 5Ghz, 6Ghz, or 2.4Ghz product isn't going to noticably fade.  MOST fade in these bands is actually thermal ducting 'turning' the beam off aim.
> 60Ghz should be considered 2 separate bands.  channels 1-4 are short range, <1km in PTP, <300m in PtMP if you want to have links stay up.  channels 5,6 are 2-3x longer.  Unfortunately, only ubiquiti really playing in this space right now, mikrotik's channel 5 support is at a lower output power so it's 'ok'.  Tachyon coming into this space as well, but unproven and AFAIK zero beta deployments.
> 5Ghz <=200M service plans today with a well built network and good AP/Antenna choices, <=500Mbps with WiFi6 tech.  technically a bit more, but with reasonable ratios this is about right
> 6Ghz <=900Mbps plans on live beta users.  OFDMA+MUMIMO is really delivering here.
> 60Ghz 'low' band cambium, 1.7Gbps legit across the mesh, twice that with upcoming channel bonding.  base CPE 1Gbps port, mid 2.5gbps port, long 10Gbps port(s).  Build out model here is for 'In the rain' so no effective fade if built right.  if built wrong, fade to death.
> 60Ghz 'high' band ubiquiti wave.  <=800Mbps.  Technically a bit more but I haven't convinced a Wave AP to a Wave LR to do it.  I can however get 2 customers/radios up to 1.5Gbps across the AP.  Plan with built in fade and intentional fail to 5Ghz beyond 2km.   Acceptable in Montana.

Thx for such a deep dive! How about Tarana?

How does "Terragraph" derived tech tie back into shipping products?

I've been involved with a bunch of other highly speculative
technologies over the years.

# Free space optics

Koruza showed promise at one point: http://www.koruza.net/

Google's been trying to line up folk for this for a while:


# Radios

... I appreciate the data on all these radios, their relative
performance and range. This stuff needs to  end up in
a wiki chart somewhere. ?
... but it's not knowing the buffering on em that bugs me the most. :/
Got all kinds of measurement tools for that

crusader, in particular, is coming along.
packet caps from iperf sessions...
flent to a raspi on the other side of the link...

# Still a hardware guy at heart

Back in 2013 I had thought hard about entering the market for radios
in the 11ghz (and wispa just freed up a lot of space in the 10? or 12?
band for future use) licensed spectrums, but I couldn't stomach
working with qualcomm again. I have some hope a mediatek might get
into that, and I could work with them.

anyone got devices that can use channel 172 yet? That just got freed up too.


This song goes out to all the folk that thought Stadia would work:
Dave Täht CEO, TekLibre, LLC

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