Can't access Premium Traffic

[Roman]

I recently bought my third Qashqai, this one from Nissan Leicester (130 miles away who provided the best deal). It is a 20 registration 1.3 DIG-T 160 Tekna 5dr DCT. The Premium Traffic which I have switched to ON only works when I am in my integral garage, presumably it is picking up my home wi-fi signal. I have a Samsung smartphone which is paired with the car. Am I correct in thinking that the system relies on picking up wi-fi signals when I am driving around the country?  If so it seems a poor system as presumably the whole of the UK is not covered by wi-fi signals. In my previous Qashqai a 2015 N-TEC+ the traffic information was always there no matter where I was in the country. I believe it received  radio signals.  I would add that my mobile is a PAYG which is not used at home as we have no mobile signal, so it is only used when away from home. 

I have followed the instructions on setting the Premium Traffic and the staff member at Nissan Leicester has also provided the same information. Hope that someone can resolve this problem.

[Trevor]

I think the signal comes through the radio antenna and may need setting up in the system to function correctly.
Not sure also if it is a subscription based service