I have spoken in the past about the interesting things I encounter while helping our customers in that we not only see a wide variety of creative uses of our products, but sometimes we also get to find the true root of problems that are more general in nature. Today I would like to speak about USB 3.0 devices and the potential for them to cause interference with Wi-Fi.
In one particular case, a customer had let us know that when she plugged her new UD-3900 docking station into her system everything with the dock worked well, but her connection to the Wi-Fi network stopped working. Unplugging the dock allowed the Wi-Fi to start working again.
This type of behavior can occur any time a USB 3.0 device is connected to a system (not just our dock), because the speed of the data flowing over the connection can emit a similar frequency to many Wi-Fi connections (2.4Ghz). Intel has actually written a detailed technical White Paper on the issue for those who are curious.
So now that we know that this can happen with any type of USB 3.0 connection, how do we solve the problem? Every person’s setup can be a little different so there will never be one definitive solution, but a few simple approaches can solve the problem in most cases.
Option One – move the device as far as away from the system as the USB cable will allow. This will try and ‘move’ the signals from both the USB connection and the Wi-Fi physically further apart. As a corollary to this, if the dock is located very close to the Wi-Fi router itself placing more distance between the two can help.
Option Two – switch to a different USB port on the system, preferably one on the opposite side of the laptop. This employs the same approach as option one, in that physically separating the two signals (in this case the physical proximity of the USB connection and the internal Wi-Fi antennas in your system) can help. If your system has both USB 3.0 and USB 2.0 ports, try using the USB 2.0 port first.
Option Three – use a USB 2.0 cable, like one used connect to a USB printer, instead of a USB 3.0 cable. All USB 3.0 devices should be backward compatible with a USB 2.0 cable, and when a device is connected at USB 2.0 speeds there is no possibility for the interference.
Option Four – switch to using a 5Ghz Wi-Fi connection. As the name implies, there are two common sets of frequencies used by most Wi-Fi networks (2.4GHz and 5GHz). If both your wireless router and the wireless network adapter in your system support a 5GHz connection (they both need to, one is not enough), connecting to your Wi-Fi in that manner will prevent the interference from happening due to the two very different frequencies in use.
Option Five – if using a 5GHz connection is not possible, changing the ‘channel’ of a 2.4 GHz connection can help. Within the 2.4Ghz band used for Wi-Fi, there are eleven different channels each using a slightly different frequency. The three most commonly used ones in the United States are channel 1, 6 and 11. Using the manual for your wireless router as a guide, switching channels can potentially help. Ideally you would want to switch the channel to the opposite end of the spectrum for the best results, for example if you are on channel one already try switching to channel eleven or vice-versa
My wireless mouse or keyboard is not working properly – RF interference
While those items can help with Wi-Fi interference, there is another type of interference that can cause problems which we refer to as RF interference. Recently, another customer emailed us for help with their UD-3900 docking station. They mentioned that their Logitech wireless keyboard and mouse were not working as expected when connected to the dock, and described the behavior as inconsistent mouse movement (almost like the batteries were dying) and inconsistent or sporadic keystrokes.
RF Option One – After it was determined that the customer had connected the small USB wireless receiver for both the keyboard and mouse to one of the front USB 3.0 ports of the docking station, I asked him to remove the USB wireless receiver from the front USB 3.0 port and place the receiver in one of the top-most USB 2.0 ports on the back of the dock. After doing so, both the mouse and keyboard worked properly.
What was happening originally and why did moving the receiver fix it? It comes back to what we learned earlier about the potential for USB 3.0 connections to cause interference on certain radio frequencies. Most USB wireless receivers use the same 2.4GHz RF band used by many Wi-Fi networks, so as a result are susceptible to the same types of interference. In most cases moving the USB receiver to a USB 2.0 port prevents this interference and solves the problem.
RF Option Two – In rarer cases when moving the receiver is not enough or if the device in question does not have a USB 2.0 port (like our UD-5900 docking station), adding a short USB 2.0 extension cable can also help mitigate the behavior. In many cases wireless mice or keyboards include such a cable for this very reason, but if one is not available our USB2-2PORT is a good solution.
In most cases using one or combination of these solutions can help mitigate or completely resolve the Wi-Fi interference/RF interference behavior with our products and potentially with others. We hope you find this information useful and encourage your feedback in the comments below.