Author: Dave Strickler

When building a Unifi network with APs, it’s tempting to find an open channel, free from neighboring networks, and put all your APs on that same channel, but that would be a mistake.

Channel frequencies are, at their core, radio signals on a certain frequency. If you put to APs close enough that their radio signal can be seen by a device like a laptop, that device will jump between them endlessly. From the device’s standpoint, it sees radio signals coming from both directions, with the same SSID, and neither AP backing down – each one demands “Connect to me” over and over. The result is your device see WiFi as “unstable”, and to be sure, it is.

A better way to do this is to look at the frequencies and pick two that, if they are seen by the same device at the same time, at least are on different frequencies. At this point, the device is still confused, but it does see two different APs – progress.

Better still, use a minimum RSSI value to allow “hopping”. This allows the signals to overlap with different frequencies, as stated above, but now at a minimal RSSI level – typically about 70- 75 dB. Let’s say you set each AP’s minimum connection threshold to 70 dB. By taking your laptop and moving from room to room, you should move farther away from one AP (its signal value will go up in dB as it weakens), and you’ll also move closer to the other AP (its signal value will go down as it gets stronger). Somewhere in this journey, your laptop will say “I have a signal of 65db from one AP and an 85 dB from another,” and it will choose the AP with the lower dB value. This is how your laptop knows to “hop” from one AP to another. It sees one as weakening and the other getting stronger, and “hops” to the stronger AP.

But how do you know what dB level to set the AP at? Trial and error? A good gut feel for networks? That used to work: a notebook, lots of pencil scratching, and some math. Or you can use Claude, my preferred method. Let it do the math for you, and it will tell you what to set your RSSI values to. But don’t expect it to spit out numbers instantly. It will need you to move from room to room, run some tests in each room, adjust your APs, and rinse and repeat. This is a process, but it can tune your network as well as (maybe better) than a professional network installer.

So, in summary, don’t let the AP channel frequencies overlap unless they are well out of range of each other, and if the APs are close enough that their signals overlap, use Claude to help you adjust the RSSI values.

When setting up a Unifi network, especially if it’s at home or somewhere that’s not commercially wired, it’s pretty common to run into a room where you just can’t get a good signal from the nearest wired Unifi AP. The logical next step it to put a new Unifi AP in between this room and the nearest wired Unifi AP, and configure it as a “Child” in a mesh network, also know as a repeater.

Now, while that often magically works the first time you do it, you may be tempted to start dropping in meshed APs all over, but that would be a big mistake. To understand why, you need to back up a little and understand how UniFi’s Mesh technology works, which is similar to other manufacturers.

Let’s use the simple example above: a wired AP and a mesh AP, connected to the wired AP via WiFi itself. While this works well, you will notice that connecting to the mesh AP gives slower throughput because your network packets are handed off through the wired AP, and the negotiation overhead translates to roughly 50-75% slower throughput. Also, each time you connect a meshed AP to a wired AP, the wired AP needs to stop and send data to the meshed AP. While this is fast, if more than one meshed AP is connected to the same wired AP, it will slow down everyone’s throughput to the wired AP.

Think of of this way: a mesh AP with a single radio doing both jobs has to receive each packet from its parent over the air, then retransmit it to you over the air — same radio, same channel. Every bit crosses the airwaves twice, so the radio’s airtime is split between backhaul and serving you.

Now a smart engineer would design around this with multiple radios, but that would also need some serious CPU power to handle this. Luckily, these units are on the market, although they’re not expensive.

If you can’t get one of these new multi-radio APs, you should consider UniFi’s “AC-LR” AP. The “LR” stands for long range, and through some beam-forming tricks, they focus the same radio signal into a cone shape to achieve a stronger signal over a longer range. Think of it like yelling through a megaphone; same yell, but it sounds louder. While the spec says 600 feet outdoors, my experience has been closer to 300 feet outdoors, and 150 feet indoors. Now think about 150 feet inside a residential house – that’s a long way. I recently put an AC-LR in a loft in my house that had no other way of connecting an AP. While the throughput was only about 30-60Mb/s when connecting to this AC-LR in mesh mode, that’s plenty fast for a video call.

In summary, don’t put any more than a single meshed AP attached to each wired AP, and try to use a new model with multiple radios. If you can’t find one of those, then look into an AC-LR.