A geographic-based communications service system has a mobile unit for transmitting/receiving information, and access points connected to a network. The access points are arranged in a known geographic locations and transmit and receive information from the mobile unit. When one of the access points...http://www.google.com.hk/patents/US7009556?utm_source=gb-gplus-share專利 US7009556 - Providing geographic based promotion services to a computing device
