Actually OTA means Over The Air
As I said, that's what I assumed, but I've never heard WiFi described that way. It
is one less character to type...
I'm of an age where I can remember sitting on the floor in front of a radio listening to "The FBI, In War and Peace", "Suspense!", "Edgar Bergan & Charley McCarthy", and Groucho Marks ("You Bet Your Life!", originally on radio). So, "Over-the-air" has always meant long distance radio wave communications. Of course, "WiFi" is simply another form of radio transmission, just a much higher frequency.
I also remember "HiFi" as a "modern" sound system with two (Yes, Ladies and Gentlemen, TWO!) separate tracks! One for each ear!! That now seems to have been eclipsed by Dolby and other multi-channel processes... but we still have only two ears.
Bottom line, tens of thousands of us have been using WiFi or "OTA" for many years to update our iDevices. Not sure why you don't leave iTunes in the dust of 'history', especially when it seems to be causing so many problems for you.