Ubiquity networks from USA has found a way to make large scale wifi deployments work: By timing transmissions in concert using GPS clocks and time of flight calculations, they have largely solved the nasty problem of hidden device interference in medium to large WiFi deployments with their invention protocol Airmax.

Normally these falls down because the “hidden device” is near to the distance WiFi AP, and seems always able to get the last word in just when distance packets are just arriving. The WiFi standards of ready to send / clear to send help a lot in WiFi 6 will make a huge difference, but Ubiquity Airmax devices with divide time evenly to avoid cross-talk.

This is the latency you mite expect from using a pair of M2 devices as backhaul between two networks, creating a virtual Ethernet cable in the sky… WDS is not enabled, Airmax is enabled with WPA2 40 Mhz…. they only talk to each other, no other non Airmax devices using the links.

Airmax is like an active switch for a wireless link: It eliminates collisions and dropped packets.

It is proprietary but thankfully the equipment is very cheap and functional.

With both my units running the same firmware: v6.3.6 (XW) and hanging on the outside of two buildings pointing at each other I see much better performance that just being a client station fighting for airtime against a host of mobile devices that have much closer proximity to the gateway. Instead, my packets go direct via Ethernet cable and cut ahead of the WiFi congestion and interference.

On the Access Point

Transmit CCQ: 98.6 % (nobody talks over me – nice)

CCQ refers to the ratio of effective transmission bandwidth and the actual total bandwidth. It reflects the quality of the actual link. A larger value means a better utilization of the bandwidth. When I am downloading, this unit is uploading/ transmitting to my other M2 below…

Channel/Frequency: 42 / 2469 MHz
Channel Width: 40 MHz (Lower)
Frequency Band: 2439 – 2479 MHz
Distance: 0.7 miles (1.1 km) * the units are not so far apart this shows I need to re-position them potentially. Surely they are only 100 m apart.

TX/RX Chains: 2X2
TX Power: 22 dBm
Antenna: Built in – 8 dBi
Noise Floor: -78 dBm
airMAX: Enabled
airMAX Quality: 71 %
airMAX Capacity: 17 %

On the Station bridge

Receiving side / Station bridge

Signal Strength:

-52 dBm (nice and strong)
Horizontal / Vertical: -57 / -54 dBm (I need to re-position)
Noise Floor: -93 dBm (great signal to noise ratio)
Transmit CCQ: 84 %

(the station finds it a little harder to reach up)
TX/RX Rate: 27 Mbps / 90 Mbps

I see regular ~5 ms pings on average +/-3ms and 0% packet loss.

is not unreasonable. 2.12 ms was the lowest today, from my Linuxbox, to TPLink switch, then to Edge Router X, then to the station M2, and then to the Access Point M2, then to Nate’s vodafone router (192.168.1.1).

Example Ping to Queen St from West Auckland on Vodafone Fibre via P2P M2 hops.

ping datacentre.co.nz
PING datacentre.co.nz (172.67.139.44) 56(84) bytes of data.
64 bytes from 172.67.139.44 (172.67.139.44): icmp_seq=1 ttl=59 time=7.62 ms
64 bytes from 172.67.139.44 (172.67.139.44): icmp_seq=2 ttl=59 time=9.72 ms
64 bytes from 172.67.139.44 (172.67.139.44): icmp_seq=3 ttl=59 time=6.54 ms
64 bytes from 172.67.139.44 (172.67.139.44): icmp_seq=4 ttl=59 time=7.63 ms
64 bytes from 172.67.139.44 (172.67.139.44): icmp_seq=5 ttl=59 time=5.55 ms
64 bytes from 172.67.139.44 (172.67.139.44): icmp_seq=6 ttl=59 time=10.4 ms
64 bytes from 172.67.139.44 (172.67.139.44): icmp_seq=7 ttl=59 time=10.1 ms
64 bytes from 172.67.139.44 (172.67.139.44): icmp_seq=8 ttl=59 time=10.5 ms
64 bytes from 172.67.139.44 (172.67.139.44): icmp_seq=9 ttl=59 time=8.09 ms
64 bytes from 172.67.139.44 (172.67.139.44): icmp_seq=10 ttl=59 time=7.71 ms
64 bytes from 172.67.139.44 (172.67.139.44): icmp_seq=11 ttl=59 time=7.31 ms
64 bytes from 172.67.139.44 (172.67.139.44): icmp_seq=12 ttl=59 time=5.48 ms
64 bytes from 172.67.139.44 (172.67.139.44): icmp_seq=13 ttl=59 time=6.81 ms
64 bytes from 172.67.139.44 (172.67.139.44): icmp_seq=14 ttl=59 time=6.21 ms
64 bytes from 172.67.139.44 (172.67.139.44): icmp_seq=15 ttl=59 time=7.01 ms
64 bytes from 172.67.139.44 (172.67.139.44): icmp_seq=16 ttl=59 time=7.17 ms
64 bytes from 172.67.139.44 (172.67.139.44): icmp_seq=17 ttl=59 time=6.81 ms
64 bytes from 172.67.139.44 (172.67.139.44): icmp_seq=18 ttl=59 time=7.33 ms
64 bytes from 172.67.139.44 (172.67.139.44): icmp_seq=19 ttl=59 time=8.23 ms
64 bytes from 172.67.139.44 (172.67.139.44): icmp_seq=20 ttl=59 time=6.03 ms
^C
— datacentre.co.nz ping statistics —
20 packets transmitted, 20 received, 0% packet loss, time 19027ms
rtt min/avg/max/mdev = 5.476/7.613/10.481/1.484 ms

After Enabling WDS Wireless Transparent Mode

Ping is now 2.0ms

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