In-vehicle communication system

An in-vehicle communication system comprising:

• an in-vehicle apparatus mounted to a vehicle;
• and
• a portable device capable of being carried by a passenger,
• wherein:
• the in-vehicle apparatus and the portable device are configured to be communicatable with each other;
• the portable device is further configured to be communicable with a center apparatus;
• the portable device includes a data storage area for storing information received from the center apparatus;
• the portable device is further configured such that
• when the portable device has received a data request specifying a specific data from the in-vehicle apparatus,
• the portable device determines whether the portable device can receive, from the center apparatus, a date reply containing the specific data specified by the data request;
• the portable device is further configured such that
• when the portable device determines that the portable device cannot receive, from the center apparatus, the date reply containing the specific data specified by the data request, and when the portable device determines that the specific data specified by the data request is stored in the data storage area of the portable device,
• the portable device transmits the specific data stored in the data storage area to the in-vehicle apparatus;
• and
• the in-vehicle apparatus is further configured to output the specific data when the in-vehicle apparatus has received the specific data from the portable device.