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Comment by admax88q | Hacker News Reader

> Note, however, that roaming between APs is a feature of the 802.11 standard;

In theory yes, but man do a lot of devices have terrible roaming heuristics.

"I can still see beacons so id better stay here even though i havent received a packet in the last minute. Wouldnt want to pay the time cost of associating with that other BSS that has 5X the signal"

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The key issue is the protocol seems to have no ability to associate with multiple BSS's together.

It's so nearly there. The power management stuff means that even with single a physical radio one can associate with multiple BSS's on different frequencies by telling one BSS to hold packets for you while tuning in to the other frequency.

All that's needed to make it reality is a way to tell a BSS "If I fail to ACK a link layer packet, please forward it via the wired network to this other BSS to send to me instead".

Then a client could be connected to multiple BSS's, send packets via either, receive packets via whichever one it is currently tuned into, and not lose any packets while switching.

You can fix this on the AP side with minimum RSSI or data rate control. But that would probably push you over to either Ubiquiti (and the similar “cloud based” options) or the enterprise market to get those features, unfortunately.

On Mikrotik you can set the minimum allowed data rate, at least. That should kick clients with marginal connections to a hopefully better AP.

Have you tried setting your transmit power low (just enough to get good signal to the places intended, but definitely no more than your devices can trasmit) and increasing the minimum send rate to something reasonable (say 10-40 Mbps, beacons use minimum rate)?

It should help high power bad signal (some devices use fixed thresholds) and equalize the beacon vs. data reception quality.

I don't think openwrt had data rate config in webui, but it does support the setting in the config files (that I normally scp onto a device). The following seems to work:

  /etc/config/wireless:
  config wifi-device 'radio0'
    ...
    option txpower '1'      << 1mW (more than enough for 1 room)
    option legacy_rates '0'
    list basic_rate '24000 36000 48000 54000'
    list supported_rates '24000 36000 48000 54000'

This messes with your AP placements though. Depending on your AP placements, you may or may end up with deadspots. You need to be sure that your AP placement is sufficient when taking this strategy. And yes, I take this strategy too.

> In theory yes, but man do a lot of devices have terrible roaming heuristics.

i hear this a lot but never experienced it myself, maybe related to outdated os?

been running multi-ap with same ssid/key no special sauce for years and it just works.

I went through this when setting up wlan in a new office some years ago, looked at roaming APs etc.. finally I just bought 4 consumer Asus routers on the same SSID, worked fine for all our purposes at least.

Do people _really_ need wifi roaming in their homes?

I have multiple cheap APs setup in my house using the same SSID and it's fine. As long as I'm not holding a realtime conversation and moving around between APs I never have any problems. And since I almost never hold a Skype call while walking through my house I almost never have any issues.

You don't have stone walls. And you haven't spent the last year working in a study that's located between two APs, where clients flip now and again and Zoom would tear down the connection.

Of course you could say: Does the house have to be designed that way? Do the APs have to be located where they are, is it really necessary to have that stone wall, is it necessary to put the study in the place where it is, is it necessary to have that noise insulation around the elevator? None of that is necessary, but some Mikrotik hardware was much cheaper than getting rid of a stone wall and more pleasant than having to hear it when the neighbours use the elevators.

If you've ever lived in a country where the houses are made primarily of stone, you'd definitely understand the need for it.

Yeah I have a 2' thick stone wall in the centre of my house (old exterior wall). I have an AP on either side of it as they penetrate the ceilings/floors above fine, but nothing is getting through that wall and maintaing good signal.

A 1920's stucco bungalow with chicken-wire in the walls pretty much acts like a faraday cage in every single room.

Or earthquake-proof reinforced concrete.

Just brick that's old enough will do it. Mine's something like 150 years old, and it's absolute murder to drill into, just incredibly hard, and it's either dense enough to act like stone, or it's absorbed enough moisture over the years to look like a faraday cage to wifi.

Yep, stupid L-shaped house where the inner curve is a damn Faraday Cage. NOTHING goes through.

If I'm in the living room and need to move to the other end of the house to get away from family-related noise, the device needs to roam between two APs.

Unifi handles this without any issues.

It's not about walking and talking, it's about sticky associations.

Even if you don't "need" roaming having more coverage lets you dial down the power on all of your APs, so you can get much closer to the theoretical maximum throughput.

4 floors, 150-year-old brick, random steel girders in annoying places, and a broadband line that comes into the building at almost the least convenient place possible. Yeah, I need roaming.

Also as long as you don't have big bags of attenuating water (people) moving between you and your AP you also funny need roaming.

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