In fact, we tested existing laptops on the market for WiFi/USB3 coexistence, and only 1 laptop ever made it flawlessly. It was a quite old Sony Vaio, where USB3 lanes were physically put under an RF shield from controller to the port.
I have never heard of interference with Iridium & GPS for USB2/3 and I worked on a team that was responsible for GPS at Apple, but it's entirely possible there's shielding needing to account for this & I just wasn't closely involved in it. If this were actually an unsolvable problem though, I would expect CarPlay & Android Auto would have a problem when you use your phone for navigation & start playing audio through USB. Maybe that's not enough traffic frequently enough to generate the noise needed to make it unusable, maybe the EE problem you were having was different, or maybe there's just good shielding in phones to avoid this as a problem.
https://usb.org/sites/default/files/327216.pdf
Paper by Intel about USB 3.0 interfering with 2.4 GHz WiFi. The fact that the USB-IF hosts this paper on their own site seems to be a strong endorsement of their conclusions too.
It is worth noting that the RF noise generated by USB 3.0 covers a fairly wide spectrum from basically zero up to the mid-4 GHz range, but it gets discussed mostly in the context of interference with 2.4 GHz because most USB 3.0 capable devices don't have any other radios in that range to interfere with.
Given the report is 8 years old, I find it hard to believe this isn't an active thing that's designed around. Hell, you can buy USB3 WiFi dongles that do 2.4 Ghz. If this were a critical flaw that's unsolvable such a device wouldn't be possible to build. Even Table 4-2 indicates different mouse models have different performance characteristics, indicating not all 2.4Ghz devices are similarly sensitive to the problem.
During all those years the only way I could avoid random drops is by connecting the dongle to usb 2.0 ports.
I've had this issue both on a old dell l502x laptop and also now on my current asrock x370 motherboard which doesn't even have native usb 2.0 ports.
Sad to know this is actually a design issue, and thus may repeat on any computer I acquire in the future.
Does "flaky" here mean connection going in & out vs inconsistent & bad speed?
Assuming we're talking about speed rather than the connection itself, two walls can be a challenge if you're on 5ghz depending on the quality of your router & dongle. Do you have any old devices on your network? Your WiFi router will run at the speed of the slowest client. Can't recall if camping is a problem - I'm less clear about the details here, but it should be. If your 802.11AC dongle is on the same frequency as 802.11N, performance will be degraded off the bat so consider moving those devices onto a different frequency if you have a dual-band router (e.g. wireless printers or older wireless TVs can be causes).
If the connection itself is flaky, check if the RSSI is really bad. Anything >= -70 dBm is good & anything <= -80 dBm is pretty bad. Note the negative sign. -90 is worse than -80. If you're on 2.4Ghz you could also be having issues from poorly shielded electronics (e.g. old microwaves) or cordless phones.
Hope this helps!
https://usb.org/sites/default/files/327216.pdf "USB 3.0 Radio Frequency Interference Impact on 2.4 GHz Wireless Devices"
Yes, USB 2 or 3 can cause issues for 2.4 Ghz if you don't shield your components properly. Are you saying that WiFi dongles, whose only job is to connect to these networks, isn't shielded properly?
"It's hard not to generate harmful interference."
We built a prototype sensor payload that included a USB3 external hard drive. Started suffering broad spectrum interference that stomped all over L-band (Iridium and GPS) reception. Made the entire system unusable!
Some references on USB3 noise:
USB 3.0 Radio Frequency Interference Impact on 2.4 GHz Wireless Devices (by Intel) https://www.usb.org/sites/default/files/327216.pdf
see especially Figure 2-2: "the data spectrum is very broadband, ranging from DC to 5 GHz"
USB 3.0 Interference - Cradlepoint Knowledgebase https://customer.cradlepoint.com/s/article/NCOS-USB-3-0-Inte...
"USB 3.0, or SuperSpeed USB, uses broadband signaling that can interfere with cellular and 2.4GHz WIFI signaling. This interference can significantly degrade cellular and 2.4GHz WIFI performance. Customers using cellular networks or 2.4GHz WIFI networks near USB 3.0 devices should take measures to reduce the impact of these devices on their network connectivity. Please note that interference is generated by both the actual USB 3.0 device as well as its cable."