MacBook Pro WiFi repeatedly drops

I made an error in my analysis of the 2.4GHz connection. I said NSS which can be read as Number of Streaming Servers -- essentially number of antennas.

I should have said MCS index of 2, Modulation and Coding Scheme index, which can vary from baseband (one bit per signing interval) up to more end more complex variations with 4 or 16 or 64 or 256 or 1024 combinations of quadrature and amplitude to provide a modulated signals with MANY more bits per signaling interval.

Higher MCS index is only possible when the signal is strong and clear of interference.

Your router isn’t encouraging your Mac over onto 2.4 Ghz; what’s called band steering.

But with the weak signal, that probably won’t help.

Most gear wants off 2.4 Ghz, because it’s usually overcrowded.

5 GHz and 6 GHz and WPA3 and Wi-Fi 6, Wi-Fi 6E and Wi-Fi 7 work better in dense signal environments, because most walls eat those signals, meaning nearby signals also drop off quickly. This usually means adding one or more wired access points, or mesh. (Mesh eats bandwidth, and increases latency.)

IEEE 802.11n is 2009-era Wi-Fi 4, and 802.11ax is Wi-Fi 6 or Wi-Fi 6E.

Subnets chosen in both 192.168/12 and 172.16/12 is a somewhat odd choice for subnetting. In a small network, I’d assume all use the same subnet, potentially also including wired connections, otherwise the local router is going to necessarily get involved in any local traffic.

Placed right next to the computer, an extender is subject to the same issues as the computer. Placed near the Router, it can do little more than the router can.

In both cases, use of a channel that is in use by your neighbors' Routers will reduce speeds dramatically.

The extender needs to be part-way between the Router and the computer for best results. it needs to be on a Not busy channel. You may need to experiment with its placement and its channel assignment to find a really good location.

WiFi Explorer is great for that work.

Grant Bennet-Alder wrote:

The extender needs to be part-way between the Router and the computer for best results. it needs to be on a Not busy channel.

Two non-busy channels. One for the clients, and one for the backhaul to the router. Unless wired. (No HDLC. 🤪)

And with the contentious “fun” that is Wi-Fi, those two “good” Wi-Fi channels will likely move around.

Automatic channel selection will work up to some busyness threshold too, then turns into cascading channel churn, as uncoordinated routers all spin through a whole band of bad channels choices. Which is 2.4 GHz in many places.

40 MHz in 2.4 GHz is kinda rude. It is probably flaky due to interference, though.

You may need to experiment with its placement and its channel assignment to find a really good location.

Likely will need to, too.

There is one more way to get a signal into a far corner of your home, but in the US with two phase power, it can be quirky.

That is power-line ethernet, with or without a built-in router at the and.

In the oversimplified description, you plug in a transmitter/receiver into a wall outlet near your router, the signal is sent along the power wiring as its cabling, and pull off the signal with a corresponding device plugged into a wall outlet at the far end. That far-end device could be an Ethernet outlet, a Wi-Fi access point, or both.

The complication is that in the US, the outlets are either on the A side or The B side of the two phase power, and plugged into the "wrong" one means the signal has to go out to the power transformer in your neighborhood and back. That does not work very well when it has to go that far.

So if you hunt around, you can sometimes find an outlet nearby that is on the "right" power phase, and get a signal slightly faster than 100 M bits/sec, rock solid.

Mine produces about 150 M bit/sec to device about 250 feet away.

if you ever tried to use power-line baby monitors, you know this drill well.

Wireless Diagnostics will reveal at least some of those uncertainties but it appears OP doesn't want to do that.

Michael Collins3 wrote:

I went to /var/tmp but didn't see a Wireless Diagnostics folder.

It's a gzip file: Use Wireless Diagnostics on your Mac - Apple Support

To provide a general overview to the wiring shown…

When extending a wireless network, wired backhaul is preferable to extenders or to mesh backhaul, and this for various reasons.

Mesh is the more common form of extension in recent times (than is an extender), and various ISPs offer add-on mesh capabilities.

The added access points (mesh or extended) boxes are usually placed half way or so between the good coverage and the bad coverage, more or less. Or the added access points are using wired backhaul, and located into the areas with weakest coverage.

All mid- and upper-range networking gear supports mixes of both mesh and wired, with varying degrees of flexibility.

terms:

mesh: a means of adding access points without adding wiring for backhaul. Not a panacea. There are trade-offs with bandwidth, latency, and sometimes with network stability. Does not do well with interference.

access point: for the purposes of Wi-Fi client access, conceptually works like a wire or a network switch. Doesn’t handle IP routing. Acts like the Wi-Fi client has a wired connection. Mostly.

router: handles IP traffic headed for a different local subnet, or for a remote subnet. (This is part of why I mentioned the use of separate subnets earlier. How the network is designed determined how it is addressed, and how it is addressed determines where the router(s) and DHCP server(s) must be located.)

There’s usually one router performing gateway and firewall and NAT functions, and often DHCP functions, sometimes with Wi-Fi, and can be zero or more access points either wired or mesh.

The three files I referenced may be the most useful. First suggested example below.

Post it using the "Additional Text" icon:

"Poor signal strength" is not a surprise and amounts to stating the obvious, but the reason remains unknown. I think you're getting closer to an answer.

As expected there is a lot of valuable information to digest. At first glance it confirms my suspicion that most of your concerns would be addressed by replacing that wireless router / gateway, but I will take some time to review everything and will reply probably sometime later today.

Edit: I will review those files as promised, but I doubt I will have much more to add than what MrHoffman already determined below.

The Verizon cellular service is obviously unrelated and would probably be best addressed with them.