The term radio-wire integration (RWI) is being replaced by Net
Radio Interface (NRI). The functions and operations remain the same,
but the name change more closely reflects the service provided. NRI
systems can be secured through the use of the Vinson (KY-57 and
KY-58) secure systems.
The HYX-57 provides the interface for the KY-57 to a standard
2- or 4-wire telephone transmission line, but it does not encrypt or
decrypt. This is done by the KY-57. Distance between HYX-57s should
be no greater than 16 kilometers (10 miles). If a secure wire line
is required over a distance greater than 16 kilometers (10 miles),
two HYX-57s can be placed back-to-back to double the range.
