Provided is a wireless communication device and system and a radiography system which are capable of conducting stable wireless communication. This radiography system comprises a radiation delivery device, a radiation image detection device and a control device. The radiation image detection device has a first communication unit. The control device has a second communication unit. The first communication unit includes a first transmission unit which wirelessly transmits a first radio signal of a first frequency band, a first reception unit which receives a second radio signal of a second frequency band that is different from the first frequency band, and a first transmission reception control unit which controls the same. The second communication unit includes a second transmission unit which wirelessly transmits the second radio signal, a second reception unit which receives the first radio signal, and a second transmission reception control unit which controls the same. The first and second transmission reception control units conduct communication by alternately overlapping a portion of a first communication period in which the first radio signal is transmitted and received and a second communication period in which the second radio signal is transmitted and received.La présente invention porte sur un dispositif et un système de communication sans fil et un système de radiographie qui sont capables de réaliser une communication sans fil stable. Le système de radiographie de la présente invention comprend un dispositif dadministration de rayonnement, un dispositif de détection dimage de rayonnement et un dispositif de commande. Le dispositif de détection dimage de rayonnement a une première unité de communication. Le dispositif de commande a une seconde unité de communication. La première unité de communication comprend une première unité démission qui émet de manière sans fil un premier signal radio dune première bande de fréquence, une première unité de réceptio
