MAP DATA TRANSMISSION DEVICE, MAP DATA RELAY STATION, MAP DATA TRANSMISSION SYSTEM AND METHOD THERE FOR, METHOD OF TRANSMITTING AND RELAYING MAP DATA, COMPUTER- READABLE RECORDING MEDIUM HAVING RECORDED PROGRAM FOR CAUSING COMPUTER TO EXECUTE MAP DATA TRANSMISSION METHOD, AND COMPUTER-READABLE RECORDING MEDIUM HAVING RECORDED PROGRAM FOR CAUSING COMPUTER TO EXECUTE MAP DATA TRANSMISSION AND RELAY METHOD

摘要

PROBLEM TO BE SOLVED: To realize flexible transmission of map data in accordance with the real-time property of the map data. SOLUTION: A transmission area selecting section 7 selects a map area to be transmitted to a mobile terminal, according to the current location, moving speed and the like of the mobile terminal, and a precedence setting section 11 provides the order of precedence of transmission to map parts constituting the selected map area, and a time datecting section 12 detects for each of the map parts the scheduled time of display at which the mobile terminal should display each of the map parts. A transmission schedule setting section 13 sets whether or not there are a transmission schedule and the guarantee of re-transmission for each of the map parts, according to the order of precedence set for the map parts and the detected scheduled time. A packet generating section 14 stores the map parts in respective packets and a packet transmitting section 15 transmits the packets in a connection-less fashion. When a packet loss or the like occurs as to the packet for which re-transmission is ensured, a re-transmission process is carried out.