Англо-русский научно-технический словарь:
quadruplex
квадруплекс || квадруплексный
Free On-line Dictionary of Computing:
quadruplex
A kind of telegraphy system developed by
Thomas A. Edison in the 1870s combining diplex and duplex
communications to support simultaneous transmission of two
messages in each direction.
(2000-04-02) 
