after several months of thinking/testing/mistaking about full wifi camera control, I can confirm we've finally reached an interesting point, where we can set up and use a full wifi camera and rig control. Although the system is still under exploration, and for the time being limited to few cameras, I think it worths sharing, in case some of you could be interested. Or even better, could take part to explorations ;-). This idea came from the fact that many recent cameras embed some interesting way of wifi remote control.
several configs have been tested and my preference now goes for a very simple one, exiting most of repeaters or others devices to limit the configuration to 1 smartphone, 1 wifi camera, 1 standard pan/tilt rig and a device called TTGO-TCell. this is the key element since it allows to interact with camera and smartphone while being able to drive servos. It is combining a 18650 cell with an esp32 circuit, able to "talk wifi" to the arduino world. (approx stick powerbank size)
configuration is currently limited to canon cameras (at least G9x i/ii, G7x) and android environment as we need to display simultaneously on the pad the camera application for controlling the camera (with liveview) and a small browser page for controling the rig.
Current range is around 200 m, with a small latence delay. But overall equipment is simple, light and finally quite cheap, compared to some alternative solutions, assuming we already have a camera (!) and a smartphone. Finally a quite pleasant solution breaking all my initial assumtions about wifi range and consumption.
Current configuration is visible under the link (sorry in french) https://dropbox.com/s/z4bapw2q2ymzuxh/nacelle%20wifi3.pdf?dl=0
It is not yet a turnkey solution, but in case you want to explore do not hesitate.
Furthermore if anyone has experience with controlling the camera with esp32, I would be happy to receive explorations feedback. Idea is to further integrate camera control and rig with the same "application".