Hello, I am new to this forum but not new to elevators as I am an elevator mechanic.
I can offer that most travelling cables ( large multi conductor cable that attaches the car electrics to the machine room) have an existing RG59 coax in them.
This would be the preferred method. I don't recall seeing any UTP in the traveller cable but I haven't been involved in too many modernizations/new construction jobs.
I have seen a wireless news/advertisement system with an antennae at the top of the hoistway, but it would update the program when it had a good connection/reception etc., and no live feed.