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.
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