A vehicle equipped with an on-vehicle telecommunication system having an electromagnetic field shielding case installed in the vehicle and for housing a user portable communication device, which has a first communication module permitting, via a first antenna, short-range radio-frequency transmission and reception, and a second antenna permitting long-range radio-frequency transmission and reception to and from a remote radio-base station. The on-vehicle telecommunication system also has a third antenna installed in the shielding case; a second communication module connected to the third antenna to permit, inside the shielding case, short-range radio-frequency communication with the first communication module of the user portable communication device; and a user interface device, which is installed in the vehicle, is connected to the second communication module, and permits remote use by a user of the user portable communication device to effect long-range radio-frequency transmission and reception to and from the remote radio-base station.