发明名称 MAP DATA DISTRIBUTION SYSTEM AND MAP DATA UPDATING METHOD
摘要 A map data distribution system includes a server which distributes map data and a mobile terminal which receives the map data. The server stores, for each area, the difference data between pieces of map data obtained before and after updated, and sends the difference data of map data of an area requested by the mobile terminal to the mobile terminal. The mobile terminal includes a database for storing map data and an updated-data store part for storing updated map data, generates updated data by using the received difference data, stores the updated data in the updated-data store part and then in the database. To fetch map data while the updated data is being stored from the updated-data store part to the database, when the map data to be fetched is stored in the updated-data store part, the mobile terminal fetches the map data from the updated-data store part.
申请公布号 US2009019095(A1) 申请公布日期 2009.01.15
申请号 US20080168950 申请日期 2008.07.08
申请人 HITACHI LTD. 发明人 ASAHARA AKINORI;NAKA KENJI;MORIOKA MICHIO;INAYOSHI HIROKAZU;TANABATA TAKANARI
分类号 G06F17/30;G01C21/26;G06F9/46;G08G1/0969;G09B29/00;G09B29/10 主分类号 G06F17/30
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