(5) Communications security (COMSEC).
(6) Operations order (OPORD).
b. Installing backbone network phase. This is the most critical element of MSE
operations. All other links are connected to the backbone.
c. Installing extension links phase. Local and remote RAUs are installed. LEN and
SEN links are established.
d. Operational management phase. The system control center (SCC) becomes the hub
for managing the network, controlling COMSEC, subscriber frequencies, switches, teams, and
Tri-Service Tactical Communications (TRITAC). TRITAC is a joint tactical command,
control, and communications program to develop and field advanced tactical and multichannel
systems. Army components of TRITAC are the AN/TTC-39 family of voice switches and the
AN/TYC-39 message switch.
a. Switching Equipment.
(1) The AN/TTC-39 circuit switch is the heart of the network and connects
telephones, message traffic, and data uses in both the secure and nonsecure mode in the EAC
(2) The AN/TYC-39 message switch provides secure, automatic switching of traffic,
using multichannel LOS, satellite communications (SATCOM), and troposcatter
b. Transmission Equipment.
(1) The AN/TRC-173 LOS radio provides access at EAC nodes.
(2) The AN/TRC-174 LOS radio repeater extends the transmission range of the
(3) The AN/TRC-175 LOS radio terminal set operate as a shortwave wideband radio
(SRWBR) and is used at the bottom-of-the-hill node. It links with the AN/TRC-138A.
(4) The AN/TRC-138A LOS radio repeater set provides the link at the top-of-the-hill
for the AN/TRC-175 at the bottom-of-the-hill.