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Comment by Firerouge | Hacker News Reader

No mention of roaming, which seems to be the biggest hurdle to stability and reliability.

Transitioning from one station to another, or worse back to call service, seems to consistently causes stability and reliability problems.

Worse still, the ability to spread connections across multiple spectrums is likely to make the roaming problem worse. 6Ghz will usually drop before 5Ghz, and that before 2.4Ghz, which has the best wall penetration. How will that impact reliability as people walk through buildings?

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Is it? It seems like a solved problem, at least when using hardware supporting the right 802.11 extensions.

I've had Skype calls on Wi-Fi walking all around campus (on a Cisco-based network) on an old Symbian smartphone back in 2011 without any audible glitches, and that was with 802.1X/WPA Enterprise/WPA-EAP which makes things more complicated.

Android couldn't do the same for the next several years though, and my Linux laptop also used to cling to the worst possible access point for dear life while sitting directly under a closer and less-loaded one, so there were clearly network and client side elements to that feature.

We are going to end up with an ap with very low power every 400sqft or something the way this is going.

That’s the preferred deployment strategy anyway (less power, more cells)

In contrast to the system of wifi access points in apartment buildings, which is more cells AND more power!

I have a 65sqm apartment with 3 APs, 5GHz set to low power. I'm pretty happy with the performance.

Doesn’t work for homes.

Absolutely works for homes. Problem is it’s more expensive and requires know how- it’s not just “plug in router with max power and 52 antennas”

Sorry I wasn’t clear:

It doesn’t work for homes for 98% of users who don’t have the know-how to implement this.

Yeah wifi works better when your ap is shouting from across your property.

I don't see why not. That's how I've built mine.

So have I. (kinda)

But you and me are probably more tech savvy than the average person.

Roaming is already defined. 802.11k,r,v

802.11r at least doesn't work on hostapd with wpa3. Supposedly it's not compatibleb may threads on that. Although there are some counter-examples which I've just found! https://forum.openwrt.org/t/802-11r-wpa3-does-it-work/135041...

It seems like most clients will stay associated with an AP until times are truly truly desperate/signal is near totally hosed. As far as I know, the only open source option to bandhsteering/ap-steering clients is Dawn, which is quite new (relatively speaking). I've been running it on my nighthawk's for a while, and it's... Ok. Clients sometimes ping pong around, or get sent to a suboptimal band or AP. But it's a huge improvement over nothing! https://openwrt.org/docs/guide-user/network/wifi/dawn

See the following videos from the Wireless LAN Professionals folks:

"IEEE 802 11kvr | Perry Correll | WLPC Phoenix 2019"

* https://www.youtube.com/watch?v=p_K9xHxFM8Y

"Effects of 802.11k/r/v | Andrew McHale | WLPC Prague 2019"

* https://www.youtube.com/watch?v=4Ua2lI6HBhE

"The Challenges of Modern Wi-Fi Roaming Including in 6 GHz | Wes Purvis | Prague 2023"

* https://www.youtube.com/watch?v=lAG5jXZCd_8

"Wi-Fi Roaming Revealed"

* https://www.youtube.com/watch?v=4ahOnG76HvQ

The Wifi infrastructure needs to send out the appropriate frames (e.g. neighbour reports), and the client has to use them to make reasonable decisions.

> Transitioning from one station to another, or worse back to call service

The former is clearly in scope for Wi-Fi protocols. The latter is clearly out of scope for Wi-Fi protocols, as it really involves work at the IP layer (or higher even).

Yeah, this looks to be what Multipath TCP / MPTCP does

Also: SCTP† multihoming.

† Of course most middleware boxes (NATs) don't support / block it, so take-up is basically non-existent.

How is multipath going to tell radios how to roam between cells?

"Back to cell service" --- you probably have radios connected to both wifi and to the cellular network. It's not the same radio.

Then you need to decide what links to send frames over (and how). MPTCP is one approach to this.

this is a terrible solution to anything except guest wireless networks

? I'm not sure you understand.

If you have a device that can use cellular and wifi, it has to figure out when it should be sending packets over wifi, or when it should give up and send packets over cellular.

MPTCP isn't mature or a good approach for this yet (and may never be), but it could present a way to smoothly roam between wifi and cellular. Imagine walking across a big campus, and having your device keep a network connection up seamlessly as you lose wifi between buildings.

Whether solved via overlay networks, or a clientside protocol like MPTCP-- this is a service networks should provide. Unfortunately, we've got no way to roam except within a single network (wifi roaming; satellite handoff; cellular handoff).

See u/mlyle's answer. There is no way that 802.11X can address this because the cell network and Wi-Fi APs are fundamentally different link layers, with very different access protocols. Even if they were the same, roaming within an administrative unit (e.g., an office) is very different from roaming between networks administered by different entities, and will require different protocols.

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