To reduce the communication cost for remote maintenance for network-to-network connecting devices and to construct a remote monitoring system having high reliability and fault resistance.
A monitoring device 100 is installed, and repeaters 101, 102 are installed between the network-to-network connecting devices 111-114 each mounted in a radio section. The monitoring device 100 is connected to the repeater 101 through a telephone circuit. The repeater 101 is connected in a wireless manner to the network-to-network connecting devices 111-113 mounted in the radio section, and the repeater 102 is connected in the radio manner. The repeater 102 is connected in the wireless manner to the network-to-network connecting device 114 mounted in the radio section. The monitoring device 100 maintains through the repeaters 101, 102 the network-to-network connecting devices 111-114 mounted in the radio section and the existing network-to-network connecting devices 121, 122 from a remote location.
SUGAWARA HIROSHI
HITOMI MASAHIRO
