Dykema Gossett
Duplexed bus type network with failure changeover
 A duplexed bus type network in which a main transmission line and a stand-by transmission line are interconnected by a repeater (30), a changeover switch (40) or a two-way amplifier, a modem at each station is duplexed and connected to the main transmission line and the stand-by transmission line, and, upon trouble in one modem (11A), only the relevant station is switched over to the modem (21A) belonging to the stand-by transmission line. When the main transmission line is broken, all the stations are simultaneously switched over to the stand-by transmission line. 
Hitachi Cable Limited
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inventional inventional inventional
Teruaki Mitsuo Yasumasa Yasuo
Aoki Imai Imai Suzuki