802.11s Mesh support?

Do I need some special hardware or 802.11s mesh support? or any router openwrt supported router with 16/128 and above specs will do it?

Hi.
Your wifi card must managed mesh, that is not the case for all of them.
Run this iw phy | grep -B 6 "mesh point"
If you can read mesh point there, than your wifi card manages it.

Supported interface modes:
                 * managed
                 * AP
                 * AP/VLAN
                 * monitor
                 * mesh point

Remember to change wpad-basic-wolfsll to wpad-mesh-wolfssl, of better wpad-wolfssl.

If your hardware drivers support mesh you will need the mesh11sd package to set essential mesh parameters that cannot be set in the wireless config.
See https://openwrt.org/docs/guide-user/network/wifi/mesh/mesh11sd

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Does this package have an app for LuCI?

No.
But for a basic multi node mesh there is nothing to set up for the package. So there is little point adding Luci support. For more complex mesh networks note that its config is dynamic and any changes made with uci will take effect immediately without restarting anything. This means there are many possibilities for autonomous management using monitor scripts without interrupting service.

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Output from my router. So it means it supports mesh?

root@OpenWrt:~# iw phy | grep -B 6 "mesh point"
        Supported interface modes:
                 * IBSS
                 * managed
                 * AP
                 * AP/VLAN
                 * monitor
                 * mesh point
--
                        * 5745 MHz [149] (26.0 dBm)
                        * 5765 MHz [153] (26.0 dBm)
                        * 5785 MHz [157] (26.0 dBm)
                        * 5805 MHz [161] (26.0 dBm)
                        * 5825 MHz [165] (26.0 dBm)
        valid interface combinations:
                 * #{ managed } <= 2048, #{ AP, mesh point } <= 8, #{ P2P-client, P2P-GO } <= 1, #{ IBSS } <= 1,
--
        Supported interface modes:
                 * IBSS
                 * managed
                 * AP
                 * AP/VLAN
                 * monitor
                 * mesh point
--
                        * 2457 MHz [10] (24.0 dBm)
                        * 2462 MHz [11] (24.0 dBm)
                        * 2467 MHz [12] (disabled)
                        * 2472 MHz [13] (disabled)
                        * 2484 MHz [14] (disabled)
        valid interface combinations:
                 * #{ managed } <= 2048, #{ AP, mesh point } <= 8, #{ P2P-client, P2P-GO } <= 1, #{ IBSS } <= 1,

Yes it supports mesh

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You can read "mesh point", so it does. You need now to replace wpad-basic-wolfssl by wpad-wolfsll and than setup the mesh.
There is no need of mesh11sd for setting up a mesh. I have always done without it. Nevertheless it seems to offer advanced features according to its doc, you may have a look at it.

It's worth checking if you actually need mesh. Marketing hype has certainly made it sound cool. Are you e.g. running a fairground that expects moving stations that come and go?

Absent such peculiar implementations it seems WDS is the more appropriate choice for the typical setup with a couple of fixed access points.

You don't "need" mesh11sd but it can get very difficult without it if you have more than a couple of mesh nodes as it is not possible to set required parameters in the uci wireless config.
With mesh11sd everything required is set correctly and monitored to make sure it stays that way, supporting from just 2 nodes close to each other right through to large geographically spread mesh backhauls - all without having to mess with settings.

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That is certainly true. Marketing by some companies, for products that use a proprietary non-mesh wifi "relay" or "extender" method, usually built into the hardware, has led to many misconceptions.

That is not the point of an 802.11s mesh. Rather the point is to enable a self configuring and resilient backhaul.

For two fixed access points even that is not true. WDS might give slightly better performance than 802.11s. The reason WDS seemed to be a better choice in the past was that configuring a mesh network was not easy and WDS configuration was well supported and understood. Technically, for two APs, there is little or no difference between using WDS or 802.11s, performance wise. More than two, then WDS gets more and more complicated and gets left behind by 802.11s mesh where every node can have identical configuration.

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Which out of mesh and WDS would give the best performance in terms of throughput and latency for typical WiFi clients such as laptops, iPads and phones in this setup:

image

Router (itself also AP) in office situated in middle floor at end of house. There is an AP on floor below and an AP at other end of house on middle floor. The additional AP's are to wirelessly connect with the router.

Is it wrong to assume higher tx power would give better overall performance (mindful of throughput, latency and 802.11r)? I just set appropriate country code (GB) and use default power.

I would expect in this scenario that WDS would be better because it is "just" sending packets, whereas 802.11s is doing layer 2 mac-routing.

I have tried both WDS and 802.11s in similar scenarios and found in practice the difference was not noticeable from a general use point of view. Sure you could do detailed measurements to find the answer and if every scrap of performance mattered to you then WDS would be the winner.

But lets say you wanted 3 more APs, 2 on the top floor and 1 more on the ground floor, then 802.11s mesh becomes very attractive. (Imagine a hotel with multiple floors, long corridors, thick walls etc. combined with a physical difficulty of installing cables with the associated business impact of cabling and cabling costs compared with wandering around plugging in a set of identically configured meshnodes. )

Generally yes it is wrong to assume that.

Me too - usually - depends on the site.

For this you need non-overlapping channels on the APs. In this scenario, for both WDS or 802.11s, the APs would have to be dual radio.

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Ah, but wait. I thought to use WDS or mesh the radios have to all be on the same channels?

You need for 802.11r I.e fast roaming, both 2.4Ghz and 5Ghz radio will be used. One acting as a mesh/WDS back haul and other will be used for fast roaming?

Yes exactly my point :wink:

If you want fast roaming then yes that is one way to do it. But then fast roaming can block clients that do not support it.....

So if needing to use WDS or mesh and setting radios to same channel and enabling FT is that bad?

I believe so, at least that is what I have read.

what is FT?