Persistent WifiDirect P2P connection?

Jason 1

I am relatively new to UWP / WifiDirect. Using the Microsoft UWP "WifiDirect" c# sample application (win 10), I am able to pair a Wifi Direct device and also open a socket and communicate across it. Works great. When the pairing is established I can see that a virtual network adapter is created. While it exists, I can also ping the device.

When the application closes, the virtual network adapter goes away. The DeviceWatcher can still find the device and observes that the IsPaired state of the device it true. Pinging is not successful at this point, probably because the virtual adapter is gone.

I then fire up a new application session. I verify that the DeviceWatcher reports that the device is still paired. I then attempt to use WiFiDirectDevice.FromIdAsync() to get handle on the already paired device. The call always fails.

So the questions are:
Is there a way to make a persistent P2P connection so that the virtual adapter does not go away when the application closes? If so, what parameter or setting allows this?
If it is not possible, what is the proper mechanism by which a software session can obtain a handle on a device that is currently paired with the PC?

Is this even possible?

Currently I have to unpair and then re-pair in order to successfully obtain a new WifiDirectDevice object. Unfortunately, the documentation is sparse.

Here is a reference to the MS sample app mentioned above:

https://learn.microsoft.com/samples/microsoft/windows-universal-samples/wifidirect/

Richard Zhang-MSFT 6,936 Reputation points

2020-07-20T01:48:02.597+00:00

Hello, UWP applications currently cannot build a persistent P2P connection. After the application is closed, the connection will be terminated. In addition, I tried to use the Wifi-Direct sample to connect to an Android phone. After closing and restarting the application, the device can still be found through DeviceWatcher and WiFiDirectDevice can be obtained through WiFiDirectDevice.FromIdAsync(discoveredDevice.DeviceInfo.Id). Please check that your device is in Whether you are in the same Wifi environment when connecting and allow Wifi Direct.
Richard Zhang-MSFT 6,936 Reputation points

2020-07-27T01:15:48.377+00:00

Hello, I am getting in touch with the engineer, but there are some questions that need to be confirmed with you. You encountered an error when connecting to a paired device. What is the specific information of the error? Another point to clarify, usually the connected device only needs to be paired once, after the pairing is completed, there is no need to pair again
Jason 1 Reputation point

2020-07-27T15:19:13.46+00:00

I believe the problem I have encountered is specific to just one device (unfortunately the one I need to interface).
After encountering the problem, I verified that two other devices behave as expected.
I am working with the firmware developer of the problematic device. It appears to be a firmware issue.
Richard Zhang-MSFT 6,936 Reputation points

2020-07-31T07:00:11.127+00:00

Hi Jason, thanks for your message, if there are new test results, you can update this question, I will continue to follow this question.
Jason 1 Reputation point

2020-08-04T18:27:25.223+00:00

In a previous post you said that: "...UWP applications currently cannot build a persistent P2P connection".
Is there a Microsoft WifiDirect whitepaper that details stuff like this and/or the various modes of connecting (standard vs persistent group)?
I have been referencing Huges WifiDirect whitepaper, but would prefer one written by Microsoft: https://hsc.com/portals/0/uploads/articles/wfd_technology_whitepaper_v_1.7635035318321315728.pdf

The wifi chip I am trying to interface is the CC3100 by Texas Instruments.
https://www.ti.com/lit/ug/swru368b/swru368b.pdf
Jason 1 Reputation point

2020-08-04T18:30:24.783+00:00

Correspondence with TI support indicates that the CC3100 does not support the optional "P2P Invitation procedure". They "...only support the invite procedure for reconnecting to an existing persistent group".

I am relatively new to WifiDirect, but it sounds like the only way to re-connect to the CC3100 chip using Windows10 (after closing the test app or the chip goes out of range) is to unpair and then re-pair again. Unfortunately, this process is slow because it can take a minute for the chip show in the device discovery list after the unpair occurs.

Does my assessment of the problem sound correct? ... and that the only work-around is to unpair and pair again?

Thanks
Richard Zhang-MSFT 6,936 Reputation points

2020-08-05T12:49:03.81+00:00

Hello, what I mean is that UWP cannot build a persistent P2P connection, which means that when the application is closed, the application will interrupt the established connection. This is determined by the life cycle of the application, not just connecting, most of the activities of the application will be terminated. This should be different from the persistent group you mentioned. Generally speaking, there is no need to repeat pairing for devices that have already been paired. But if the device restricts this, you need to contact the device provider and confirm this.

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Persistent WifiDirect P2P connection?

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