A method includes a step of dividing tag IDs of plural wireless tags into groups; a step of sequentially storing tag data items in storage areas provided for the wireless tags, each tag data item including a tag ID and related-tag data constituted by the tag IDs of other wireless tags belonging to the...http://www.google.de/patents/US7876226?utm_source=gb-gplus-sharePatent US7876226 - Method of preventing failure of reading wireless tags, and wireless tag data management system
