Section II. SYSTEM SERVICE INTERFACES AND TYPES OF SERVICE

TM 11-5895-1012-10

tion to test and coordinate activities of intermediate

accordance with TSO's.

TCF's, another TCF can be designated as an Intermedi-

(3) Initiate chit

ate Control Office. The ICO will be designated on the

service order at the time of layout and TCF personnel

have the general responsibility of the assigned seg-

ment as well as the following:

(1) Conduct in-service testing and take corrective

action in the case of signal degradation, including

those signals not alarmed by pilot frequencies.

(2) Activate, deactivate, and change the circuit in

Section II. SYSTEM SERVICE INTERFACES AND TYPES OF SERVICE

2-7. Introduction

In this section

and the types

technical con-

of service will

troller to make the most efficient use of circuits and

systems available, an understanding of the overall

DCS and the facilities serviced is necessary. In addi-

tion to understanding the make-up of the DCS, the

technical controller should be familiar with the trans-

mission media used; communications facilities in-

volved; the facilities which use the DCS mainline

trunk routes as a transmission path; and the types of

signals which are generated by these facilities. The in-

formation covered in this Election is listed below to-

gether with appropriate paragraph references:

a. DCS common user network (para 2-8).

b. Transmission media (para 2-9).

c. Communications facilities (para 2-10).

d. Relay Centers (para 2-11).

e. Automatic Voice Network (AUTOVON) (para

2-12).

f. Automatic Digital Network (AUTODIN) (para

2-13).

g. Types of signals (para 2-14).

2-8. DCS Common User Network

a A common user network is one that provides a set

number of channels of voice or data communications

for use by an even larger number of users on a shared

basis. A user of a communications network can be a

person making a telephone call; a communications cen-

2-9. Transmission Links and Media

ter originating or receiving many teletype messages,

data or facsimile signals; or a solitary teletypewriter

maintaining contact with another like machine. The

originating user am be linked to another activity with-

in the same geographical area or in another geographi-

cal area. The point to remember is that the available

channels of communications are shared by all or they

are for "common usage". Within the DCS the majority

of the available channels are for common usage. Dedi-

cated circuits, which make up the remaining channels,

are established to support the traffic originating at

dedicated facilities which provide communications of

(1) High Frequency Radio. This media can cover

common interest, high volume, or priority traffic cus-

2-4