centers to provide units and CPs with access to the network. The DISCOM headquarters will be
provided wire access into the MSE network through a LEN (V2) and associated line-of-sight (LOS)
radio terminal (AN/TRC-190). The equipment and soldiers are from an extension platoon of an area
signal company of the division signal battalion. Figure 2-24, page 2-20, is an example of a division
MSE network. Four node centers, represented by the symbol of a triangle inside a circle, are deployed.
SENs, symbolized by a circle with a X inside a rectangle, represent divisional units. The DISCOM is
shown in the lower right of the illustration and ties into the LEN. The LEN is further linked to the node
center, represented by the solid line drawn from the LEN to a node center, to access the MSE network.
c. The LEN usually consists of an operations shelter, a switching shelter, a management
facility, a LOS AN/TRC-109 (V4) radio assemblage, support vehicles, and generators.
d. The SEN usually consists of an AN/TTC-48 (V1) or (V2) small-extension node switch
(SENS), a LOS AN/TRC-190 (V1) radio assemblage, support vehicles, and generators. The SENS
provides local switching and network access for either 26 subscribers (V1) or 41 subscribers (V2).
e. Figure 2-25, page 2-21, illustrates a typical SEN (V1) configuration depicting the placement
of the equipment and is interconnect with other pieces of equipment. Under MSE, users, and not the
division signal battalion personnel, are responsible for installing and operating the subscriber terminal
equipment to the distribution boxes. The users connect their subscriber cables and telephones to the J-
1077 distribution boxes set up by the signal team. A call is received at the SEN where kit is sent to a
LOS radio by either radio link or cable. From the LOS radio, the signal is transmitted to a node center
and the routing process continues, sending the call to is designation. Figure 2-26, page 2-22, illustrates a
SEN (V2) with the capacity to handle network switching for up to 41 subscribers. Signal personnel
must closely supervise and monitor the installation of the subscriber terminals, whatever they may be
(telephone, facsimile, etc), to ensure that the proper connections have been made to obtain reliable
f. Mobile subscribers in the CSS units will access the MSE network via user-owned and
operated mobile subscriber radiotelephone terminals (MSRT). The MSRT consists of two major
components: the digital subscriber voice terminal (DSVT) (TSEC/KY-68) and the receiver/transmitter
RT-1539. Functional MSRT characteristics include:
(1) Secure automatic voice/data communications and internal communications security
(2) Discrete addressability.
(3) Automatic reaffiliation during movement.