WiFi Direct/Miracast causing wireless interference?

Question

Good morning,

I work for a school district and we are encountering an issue where it appears that Wi-Fi Direct or Miracast is causing interference with our Wireless Access Points, which is causing network performance issues. I'm curious if anyone else has experienced this and/or knows how to get around it.

Our teachers each have a Miracast-capable laptop, which they can use to wirelessly connect to a Microsoft Wireless Display Adapter plugged into the television in their classroom. We also have one-to-one Chromebooks, so each class may have up to 25-30 students on Chromebooks connected to the wireless network at once as well.

My understanding is that when you connect to a Miracast device, your Windows computer enables a WiFi Direct virtual adapter that makes your laptop act as an access point and allows the display adapter to connect to it. However, the WiFi direct virtual adapter appears to pick a channel at random to operate on in either the 2.4 GHz spectrum or the 5 GHz spectrum. Occasionally, it operates on the same channel as the access point in the classroom and causes wireless interference, causing issues when we are trying to get 25 Chromebooks on the network at the same time.

I haven't seen this issue many times, but in the couple cases where I saw it, the wifi direct virtual adapter appeared as a rogue access point in our WLAN controller with a very strong signal. And when I asked the teacher to disconnect from the wireless display, the wifi direct virtual adapter turns off, the rogue access point disappears and her students' network connectivity improves.

Is it possible to make the WiFi Direct Virtual Adapter change channels? Or limit it to using just the 2.4 GHz spectrum?

Thank you!

Answer 1

Hello Kbwesd, how are you doing?

Welcome to the Microsoft community!

I'm glad to be able to assist you at this time.

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it appears that your laptops and Microsoft Wireless Display Adapters are causing wireless interference on the same channel as your access points.

To try and resolve this issue, you can limit the WiFi Direct virtual adapter to using just the 2.4 GHz spectrum if your laptops and Microsoft Wireless Display Adapters support it. Follow these steps:

1. Open the Start menu and search for "Device Manager."
2. In the Device Manager window, expand the "Network adapters" section.
3. Look for an adapter that is labeled "Microsoft Wi-Fi Direct Virtual Adapter." Right-click on it and select "Properties."
4. In the Properties window, go to the "Advanced" tab.
5. Look for a property called "Band Preference" or "Preferred Band." If it's available, select "2.4 GHz" as the preferred band.
6. Save your changes and restart your computer.

*Please note that not all laptops and Microsoft Wireless Display Adapters support the ability to change the preferred band for the Wi-Fi Direct virtual adapter. If this option is not available in the Properties window, then it may not be possible to limit it to using just the 2.4 GHz spectrum. In that case, you may need to consider other solutions.

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Alternatively, you could try manually assigning channels to your access points to avoid interference with the Wi-Fi Direct virtual adapter. This can be done through the settings on your access points. Make sure to choose a channel that does not overlap with the channel being used by the Wi-Fi Direct virtual adapter.

If the issue persists, consider using a different wireless display technology that does not use Wi-Fi Direct. There are several alternatives available in the market that can help you avoid interference.

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Please let me know if this response has helped resolve your issue by selecting the "Yes" or "No" button below. Your feedback is greatly appreciated and will also assist other users who may encounter similar challenges.

Answer 2

Hello again!

Maybe if you have an Automatic/Smart channel switching option on your AP's, it might fix the issue, but there isn't really much else you can do, apart from using a wired method, which probably is not convenient for you, at all. Since it's causing wireless interference, then interference can obstruct any network, whether the client is connected to the same one or not, and I think the Display Adapter can only connect via local/private networks (can't be hosted via a web server). If this was possible, then you might've been able to switch to different networks (on a different channel) and see if that would make a difference, but like I stated earlier, wireless interference could possibly interfere with any wireless network though.

Answer 3

Thank you so much for the reply.

Unfortunately, it would appear our machines are falling into the category of those where this cannot be changed.

I appreciate the input. Thanks for sharing that information.

Answer 4

Thanks for the reply, I appreciate it!

I am familiar with the app, but it really just does personalization and firmware upgrades. Our firmware is up to date on the Display Adapters. The Network tab only exists for the 4K version of the product, which we don't use.

I agree that we could change the channel used by the access points, but I've also observed that the WiFi Direct Virtual Adapter doesn't always use the same channel, so if we changed the AP configuration to deal with the virtual adapter, we could still find that the virtual adapter switches channels again and we could end up with interference again.

Answer 5

I don't think the Microsoft Wireless adapter supports changing channels or change any of the networking related settings, unless you try downloading this app: https://www.microsoft.com/en-gb/p/microsoft-wireless-display-adapter/9wzdncrfjbb1, although you might be able to find something in the Network column of the app.

You can also try updating the firmware via the app too. Firmware updates include critical performance and security enhances to improve stablilty.

If you have access to the internal access point configuration, the best thing to do is change the channel of the wireless access points until you find one that doesn't interfere. Another way to fix this is to connect via HDMI or DisplayPort, but isn't always practical. You can try a different casting method, such as using Google Chrome's casting feature, but this only works with you have an Android TV I believe.

I probably didn't help you in any way but if you have anything you want me to help you do or clarify something let me know.