To discourage people from betting after a point is already over. There is a delay on all tennis feeds broadcasted by Globecast and also on other sports like football
It's not NS3/NS4. At least not on 7E or 10E. Most likely all tennis have switched to fiber. At least clean feeds. What we are seeing broadcasted by Globecast for ATP are not clean feeds directly from the court so most likely all tennis is now on fiber...
Don't bother. There are no muxxes or feeds in ns3/ns4 on 7E or 10E that broadcast the AO. If you have an licesed demodulator maybe try and see if there are any channels on the hypermux at 11200 H 70 Ms/s although I don't think so.