You are here

Is internet speed limited?

9 posts / 0 new
Last post
Is internet speed limited?

Hello everyone

Working on setting up my unit and doing a bit of testing. I noticed the max internet speed I was able to get is 1 megabit.

Using a long distance test with perfect signal, I was receiving about half a megabit.

I was just wondering if the speed is software limited? It would make sense if it was but I saw no documentation stating it.

Thank you



The speed is not limited by

The speed is not limited by any speed limiting code.

Real world performance will always be less than max theoretical performance.

Distance parameter plays some roll in max speed (if you set it way further than the nodes really are you can notice a slow down as the node 'waits' for a response it should of already received)

In addition to that antenna gain and path loss come into play.

The way wifi hardware works is that to get higher output power and stay linear it runs at a lower speed, if your at the edge of a signal for example the node will never get above 1mbps wifi speed (which means even less after you factor in wifi framing has some overhead) also at the same time the receiver is required to receive more signal to do higher speeds so to get 'highest possible speed' you need the most gain at the antenna so the node can scale back its tx power and still have a reliable connection (the Ubiquiti datasheets show how the sensitivity and tx power levels trail off in higher powers --- this is true of all wifi devices I have seen just most do not show you the curve in their datasheets)

In addition there is sharing code that when a receiver is busy receiving other stations it will not transmit (carrier sense multiple access) which also can slow down a network (somewhat an advantage of the new ham only channels)

(this is all ignoring the fact of packet loss which does occur over wireless will decrease speeds as well as packets have to be retransmitted ---- this is probably a part of your speed test if you did a standard internet speed test)

Still even a .5mbps (actual) isn't bad in my book considering the infrastructure we are replacing is .0012-.0096 mbps (max theoretical for average packet speeds overhead and other items make it much less)

kg9dw's picture
perfect signal?

What looks like a perfect signal (link quality measurement I'm assuming you're referring to) will show its true colors under load. Run some pings or transfers and see what happens. I had a link that was a perfect 100% LQ until I put some load on it. Then retries all over the place and an effective throughput of less than 500kb/s. 

If you need some additional help, let us know what equipment you're using, line of sight or not, distance, and signal to noise ratios (from both ends). 

Welcome aboard!

Mike, KG9DW

Thank you for the wonderful

Thank you for the wonderful replies. I have to research this. I had the antennas 10 ft away from each other and I was getting super slow speeds.

Time to tinker with this!

K5DLQ's picture
You might check the Distance

You might check the Distance setting in your basic setup page for the node.

the default distance is 100000 meters.  You may want to change it to 150 in your case (the smallest value is 150 according to the help page).


You can check your RF link

You can check your RF link speeds by SSHing into the node and issuing the iwinfo command.

AE6XE's picture
Best to only use the "iw

Best to only use the "iw wlan0 info" command and refrain from using "iwinfo" in the beta images onward.   "iwinfo" program was not ported to work with the newer part 97 only channels.  We need to remove iwinfo.   I'd recommend the "iw wlan0 station dump" command to see the speeds at that point in time to each neighbor.   Speeds change instantaneously, e.g. beacons sent at lowest speed.  So do the command multiple times to discover peak speeds with each neighbor.   (Note to self:  add the instantaneous link speeds to a column in wifi scan...)


w6bi's picture
Instantaneous link speeds


Thank you all for the

Thank you all for the wonderful replies. I will test this out as soon as I get my other bullet in hand.


But I dont think that would be such a bad idea to have internet limitations option added on. I wouldnt mind hooking up my node to the internet and have everyone be able to access it for basic things. The issue is I dont want it to eat up my connections.

Theme by Danetsoft and Danang Probo Sayekti inspired by Maksimer