It does not look like there is an API to do this within the app, so let us assume the phone is rooted. I don't have any experience working with rooted phones, but here's what I've come up with so far:
The wpa_supplicant.conf file seems to be able to handle what I need. There is a parameter that can be included there, called p2p_oper_channel, which can be set to 1/6/11/whatever that forces the channel to be that, when wpa_supplicant is run.
I also found the p2p_connect command, which takes as a parameter the frequency of the channel.
Currently, the application I have is all built using the ADK and supports sending/receiving a text using multicast, to several phones, using WiFi direct. But they're all on the same channel.
Can anyone tell me how I can use one/both of the above 2 points to set up one Android phone (master) to deliver a message to the others (slaves) on WiFi Direct, with each connected to the master on a different channel? (I assume we would do this using the fact that the phone is rooted but I'm not sure as I have no experience with this). I'm using multicast. The reason I want each on a channel is to minimize interference.
Furthermore, is it even possible to open several connections with different devices, each on a different channel, using the same WiFi chip?