how does mesh wifi work and how is it different from old school extenders?

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how does mesh wifi work and how is it different from old school extenders?

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Wifi extenders pick up and repeat the signal which originates from a single access point (wifi router). The problem with that is that you’re still loosing signal strength the further out you go from this point of origin. It’s like making a copy of a copy that keeps getting more blury.

Mesh wifi on the other hand consists of several wireless access points, each sending their own signal on their own channel but they are part of the same network and are broadcasting the same SSID. There should be some overlapping coverage on the peripheries of each WAP zone so that devices can seamlessly switch from one AP to the next without dropping the connection.

This is the type of wireless access you’ll find in large business or corporate environments, hotels…..etc. it’s a much more scalable and reliable solution than using extenders.

Wi-Fi devices like phones have a sort of tunnel vision to them. When you connect to a network, what your device is really doing is connecting to one specific access point that’s emitting a Wi-Fi signal. Once your device has locked-on, it has a death grip on that signal. It WILL NOT let go of *that specific* access point until you either force it to disconnect, or the signal genuinely goes to zero and stays there for some time. While it’s locked-on like this, your device will flat-out ignore every other access point in the vicinity, even if there are other ones nearby with stronger signals that it could switch to.

When you put an old school extender on your network, what you’re really doing is putting a second access point on your network. That way, when your phone looks up and sees the Wi-Fi networks, it will see two separate signals–one from the original access point, and one from the extender. You pick whichever one has the best signal and now your phone is locked-on.

Let’s say you are in the extender’s range when you connect. Now your phone is locked onto the extender. But then you move about your house or office or whatever and now the signal to the extender is not so good. But the signal to the other one is great now! Your phone should switch over, right? WRONG. It’s *locked-on*. Absolutely dead set on maintaining that death grip on the bad signal, unless you command your phone to drop it and switch over to the other one.

What a mesh system does differently is it essentially makes all the extenders wear funny masks that make them look exactly like the original access point, in a way that your device can’t tell them apart. When you connect to one of them, they mutter amongst themselves and decide who is physically closest to you, and whichever one gets selected will reach out to your device and establish a connection. Then, as you roam about the area and go in and out of the ranges of all the mesh extenders, they silently and seamlessly hand over the job of talking you your device, as they can detect who is the closest to you at any given time.

Essentially, mesh systems work the way you probably *expected* extenders to work all along.

All the other answers on this post so far are wrong. The following is less wrong.

There is nothing fundamentally different between a range extender and mesh network. The difference is in the software used to manage them and support for 802.12s.

Range extenders typically integrate with any WiFi network. It is just another client in the network that broadcasts a signal. To use a range extender you have to go set it up with your network using its own interface, and you will manage it separate from your main AP. They typically don’t support 802.11s.

Mesh networks are sold as entire systems. You buy as many points as you want and use a single interface to configure them. They also by definition support 802.11s, which provides rules for routing traffic and such. There’s not a major effect of that on the end user, but it probably improves performance a bit. They *may* support some extended features such as Ethernet backhaul, 3D client localization, etc

From a user perspective: the difference is just in user interface.

Also worth noting: Repeaters are even worse. They repeat the signal between you and the original AP, which reduces the throughput by 1/n with n being repeaters plus end device and increases latency by factor n. With repeaters you’re talking to the original AP directly, but your message needs to be passed along several times.

With extenders and mesh you’re talking directly to the approximately closest device. It itself will then send on its own request, be it by cable or by WiFi, which will increase latency, but in and of itself not decrease throughput. If the extender/mesh supports two separate frequencies, it can talk to you on one and the original AP/next hop on another so it won’t interfere.

Modern MESH systems work just like any semi-modern enterprise wireless system (with multiple wired APs). The real differences is the backhaul to the rest of the network is expected to be wireless to a node with wired access versus each AP being wired directly to a switch and tied into a controller (on-prem, networked or cloud). Because the backhaul between nodes is wireless, you do see some increases in latency and reductions in throughput capabilities compared to equivalent configurations in a wired setup (but it could be much worse using older technologies).

Really old MESH systems (15+ years) used the same technology early extenders did which was store and forward. As WiFi is a half duplex protocol, data can either be received or transmitted, it can’t do both. Back before dual radio extenders became popular APs and extenders only had a single radio on board. So the extender/MESH AP would listen for packets, then retransmit those packets which would double the latency and half the maximum throughput. Add more MESH APs and things would just get slower and slower to a point which is roughly an exponential factor of 4 in designs where a loop isn’t created.

More modern extenders are essentially cross band repeaters. Packets are received on one radio and transmitted almost instantaneously on another radio. Typically you see these with either a 5 GHz uplink to the AP with a 2.4 GHz client radio or vise versa. Greatly reduces the latency issue but using the different bands and channel widths without considering their throughput limitations can lead to some issues. Their biggest downfall is a lack of fast roaming support to hand off to/from the main router and they don’t scale well beyond one repeater.