You also need connectivity to mobile network data in order to receive traffic data from OzRunways, AvPlan, FlightAware, FlightRadar24, AdsbExchange et al. If you don't have a mobile connection or it is out of range you won't get any traffic data seen by these services. ADSB-in is independent of the phone network and only depends on other traffic transmitting ADSB-Out. ADSB-In wont pick up transponders.