The app can send commands and receives a stream of data from it. This commutation happens over Wi-Fi (which has no access to the internet)
As a result OS will throw Wi-Fi Assist alert, and offer switch to cellular data.
How to avoid this alert? In my scenario if user disconnects from Wi-Fi, he loses access to physical device.
In About Wi-Fi Assist it is mentioned
Well my app does download large amount of data from the device. Could my app be eligible for this exception?Wi-Fi Assist doesn’t activate with some third-party apps that stream audio or video, or download attachments, like an email app, as they might use large amounts of data.
There isn’t an API for Wi-Fi Assist. In general, iOS has very limited Wi-Fi APIs; I put a summary of them in TN3151 Choosing the right networking API.
I have a post, Extra-ordinary Networking, which references a bunch of other posts about networking at this level, including working with Wi-Fi accessories. I’m not sure if there’s anything in there that’ll help you specifically, but I recommend that you read it before going further.
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—
Quinn “The Eskimo!” @ Developer Technical Support @ Apple
let myEmail = "eskimo" + "1" + "@" + "apple.com"