
USB 3.0 Radio Frequency Interference on 2.4 GHz Devices (2012) - marcopolis
http://www.intel.com/content/www/us/en/io/universal-serial-bus/usb3-frequency-interference-paper.html
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johnm1019
TLDR; USB3.0 high speed signals when not properly shielded can cause RF
interference with RF devices operating under 5Ghz due to the broadband nature
of the signal.

@Mods, could be titled with [2012]

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derefr
I have one USB3 128GB flash drive—manufactured right on the cusp of single-
package 128GB NAND becoming available—where whenever I plug it into any
device, it slow's that device's wi-fi to a crawl, and multiplies tenfold the
jitter for any connected Bluetooth input peripherals. None of my other USB3
devices do it. I always figured it was a grounding problem or something.

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GoToRO
put tinfoil around it.

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chocolatebunny
So, if you put tinfoil around it and attach the tinfoil to a data line, does
that make it more disruptive?

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serialpreneur
I have had this annoying problem and had no idea what was going on until I
stumbled upon forums somewhere after many Google searches. My Anker USB 3.0
hub would cause my bluetooth keyboard/mouse receivers to become unresponsive
at random times (in retrospect at times when the hub was placed close to the
Macbook Pro). I placed the hub at some distance from the MBP and voila the
issue went away!

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justusw
I'm glad to see that problems with Anker USB 3.0 Hubs happen not only for me.
In my case, the Wifi became unusable once the Hub was connected. Quite a shame
for a nice looking, affordable device to have a breaking issue with shielding.

~~~
CardenB
Nice looking, affordable, doesn't break stuff.

Pick two.

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tlb
The graphs show an interesting quirk of RFI. In figure 2-1, the theoretical
USB 3.0 emission spectrum has a zero at 5.0 GHz (equal to its signaling rate).
In figure 2-2 the measurement has a significant narrowband spike at 5.0 GHz.
Never believe zeros in spectra, there's usually something lurking under them.
2nd harmonic distortion probably causes it here.

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blinkingled
Good timing - just last night I had my speakers plugged into the NUC make
weird noises every time I scrolled using a USB mouse receiver plugged into a
USB 3 port. I knew it was interference but couldn't have made the USB 3
connection without reading this.

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Zagitta
If it's a skylake CPU, chances are it has nothing todo with USB3. There are
some coilwhine issues in the power delivery system when the GPU is entering
and exiting power saving modes and is heavily plaguing the recent Dell XPS 13
model amongst others.

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voltagex_
I'm guessing it's not really worth RMA'ing my 9350 for that coil whine issue.
The problem where the Dell WiFi driver causes screen flickering might be,
though.

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Zagitta
I talked to a very nice service rep about the coilwhine and he said there
wasn't much point because all of them suffer from it in varying degrees and
they would only do something about it if it was very audible and then only if
RMA'ed within the first 2 months or so. His suggestion was to disable the GPU
power states but that sort of defeats the whole point of an ultrabook. It's a
sad issue because it really detracts from an otherwise excellent laptop. I
have not heard about that specific wifi issue though, have you updated to the
latest firmware? I know there's been quite a lot of versions with various
fixes.

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eggy
I'll have to read through it, but I sometimes shut my wireless mouse and put
it in its cradle when downloading a large file over my WiFi-tethered mobile
phone, place the phone in a 45-degree angle instead of flat on my desk. No
scientific reason, just guessing it puts it more in direct line with the WiFi
antenna in my notebook and the tower.

It is my sole internet connection here in SE Asia, and this seems to help, but
maybe I am wish-biased!

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cleeus
Wireless input devices usually talk in the 2.4GHz and 5GHz bands of wifi. They
are allowed to, since the spectrum is basically open for anything (AFAIK) but
they effectively jam wifi when in use. So this is intentional while the USB3.0
cables jamming wifi seems unintentional.

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Arnt
Wireless mice usually don't talk very much. Mine runs for about a year on a
single battery (the spec says up to 18 months). That's MUCH too little power
to be able to effectively jam anyone's wifi.

Reduce its capacity by a small fraction while the mouse is moving, yes,
effectively jam, no way. That would need much more power than a wireless mouse
has.

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therealmarv
I also heard about this problem with Seagate 2.5" USB 3.0 external drives.
Their cable included was not good shielded and it was causing problems with
WiFi. Once the cable was exchanged with a good shielded one the problems are
gone.

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azernik
_well_ shielded :-)

How did you specifically shop for shielded cables? Are they advertised as
such, or did you just look for something more expensive and hope for good
build quality?

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thesmok
I have a Seagate USB3 drive and it is giving me bluetooth problems. Its cable
is very thin for a USB3 cable. A shielded USB3 cable typically is as thick as
CAT5 Ethernet.

The problem is, it's hard to tell how thick a cable is looking at the pictures
on Amazon. I need a good quality 1 ft long USB3 cable and I don't know how to
find it. Both my short (1 ft) cables are not shielded.

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pjc50
This is what all that tedious EMI testing and certification is supposed to
prevent. Although I think it's much laxer for "conducted" emissions ..

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rimantas
Found out about this the hard way. I was confused why my Wi-Fi was slow.
Disconnected USB3.0 external drive and bam, fast network again. Now I just
have this drive as far away from the computer as possible, works fine.

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y04nn
I had problems sometimes with 2.4Ghz Wi-Fi, I permanently switched to 5GHz Wi-
Fi which solved the problem. It may have been the USB3 hub I was using, I'll
do more test.

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Relys
I found out about this issue while purchasing an AC spec router last year:

[https://community.netgear.com/t5/Nighthawk-WiFi-
Routers/Netg...](https://community.netgear.com/t5/Nighthawk-WiFi-
Routers/Netgear-R7000-Vs-Asus-RT-AC68U/td-p/442063/page/7)

The Asus RT-AC68U did not have proper shielding on their USB 3.0 hub (at least
in their launch hardware revision) which lead to interference.

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chocolatebunny
Is there an easy way to test for this? I just bought an AC router (TP-LINK
AC1900) and I had planned to use the USB port.

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Relys
I would assume running USB 3.0 read/write tests with radio on vs off would
provide a good benchmark.

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jackvalentine
...does this explain why my bluetooth mouse or trackpad becomes unresponsive
on my 2012 MacBook Air?

I haven't noticed a correlation with USB disk access and the mouse going limp,
but now i'll be looking out for it.

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haikuginger
Apple actually has a support article on the topic[0].

[0] [https://support.apple.com/en-us/HT203729](https://support.apple.com/en-
us/HT203729)

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heywire
This is almost a daily annoyance for me. I have a WD Passport Ultra HDD at
work, and any time I plug it into the USB3.0 ports on my Dell E6430, my mouse
(Microsoft Wireless Mouse 4000) gets laggy.

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jokoon
I remember listening to FM radio with either my smartphone or a nokia
candybar, when I was in the bus or tram, the radio "cut" for 2 or 10s or even
longer.

I think I remember it happened on both devices.

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Spooky23
Certain carriers were worse for this. When I had a Nextel phone, my PC
speakers would give me advance warning of calls ahead of the phone ringing.

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wainstead
Found this out the hard way when I bought a little USB 3.0 hub off Amazon. You
can plug it in and watch ping lose its lunch, then unplug it and the wifi
returns to normal. (On a 2015 MBP).

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paulgerhardt
Would this work the other way around too? I.E. use SDR to simulate a connected
device over USB 3?

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haikuginger
To cripple WiFi/Bluetooth in the area? Sure, but at that point, you might
start to get in trouble with the FCC (in the US) or other regulatory
authority.

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infocollector
Does anyone have pointers to good shielded usb 3 cables of different lengths?

