Patent ID: 8667129

Claim:
A server for differentiating among a plurality of network-connected terminals each installed in a given location, the server comprising: a storage section pre-storing a table in which server—terminal transmission distances are respectively associated with each of the locations where the terminals are installed; a transmission/reception section configured to transmit messages to, and receive response messages from, the terminals via the network; a terminal information acquisition section configured to, based on the response message received from each of the terminals by the transmission/reception section, acquire identification information identifying the terminals individually, and acquire respectively for each of the terminals delay times for round-trip or one-way transmission between the server and each terminal; and a terminal installation location-identifying section configured to correlate the transmission delay times with the server—terminal transmission distances to match the acquired transmission delay times with the server—terminal transmission distances in the pre-stored table, and specify the identification information corresponding to the matched transmission delay times, as information identifying which terminal is installed in the respective installation locations associated with the transmission distances in the pre-stored table; wherein: in matching transmission delay times with server—terminal transmission distances, the terminal installation location-identifying section associates the transmission delay times with the transmission distances such that the transmission distances in order of length correspond with the transmission delay times in order of length.