| 摘要 |
<P>PROBLEM TO BE SOLVED: To make it possible to speedily recognize it when a device connected to a network is separated from the network while the device can not transmit a message denoting the separation from the network. <P>SOLUTION: A digital television receiver 302 connected to the network registers the connection of a camcorder 300 to the network on the basis of a notice transmitted from the camcorder 300 communicatably connected via the network onto the network. This registration is updated on the basis of a notice transmitted from the camcorder 300 onto the network at a first time interval (an interval of a valid period). The digital television receiver 302 sets a second time interval shorter than the first time interval to a first timer so as to discriminate whether or not the television receiver 302 receives a prescribed notice (ssdp: alive) from the camcorder 300 at a time interval shorter than the second time interval. When the first time expires, the connection state of the camcorder 300 is confirmed by a search request. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
