Object directory system with ip-based usn

PURPOSE: An object information service system on an IP-based USN is provided to obtain desired information and service, by using sensor nodes with unique IP addresses. CONSTITUTION: A USN URL is transmitted to a local server(S210). The local server changes the USN URL into a domain name(S220). A first local ODS makes a query to a national ODS(S230). The national ODS transmits an address of a second local ODS to the first local ODS in the form of A record(S240). The national ODS transmits the address of the second local ODS in the form of A record in the first local ODS(S240). The first local ODS inquires about the location of an information server to the second local ODS(S250). The second local ODS transmits NAPTR(Naming Authority Pointer) record to the first local ODS(S260). The NAPTR record received by the first local ODS is transmitted to a local server(S270). The local server receives information of a desired sensor node(S280). The local server transmits the received information of the sensor node to the outside(S290).