Table 1-2 Tabulated Data-Continued

TM 11-5895-1123-34

Table 1-2

Tabulated Data-Continued

Crosstalk

Not to exceed - 50 dBm O between any terminated audio line and high level TTY line as

measured in any VF channel of 300 to 3400 Hz.

LOW LEVEL TELETYPE:

Voltage Levels

+6 volts and -6 volts

BASEBAND DIGITAL DATA USER

INTERFACE:

Data Rates

20 kb/s

50 kbls

256 kb/s

512 kb/s

9.9999 Mb/s (10 Mb/s) externally processed.

Bit Error Rate

The amount of time for error free performance:

User Rate

Time

20 kb/s

9 minutes minimum

50 kb/s

4 minutes minimum

256 kb/s

40 seconds minimum

512 kb/s

20 seconds minimum

Logic Levels

Low level +6 volts and -6 volts

Impedance

78 ohms balanced

Pulse Coded Modulation

Return to bias except for the externally processed 9.9999 Mb/s (10 Mb/s) which is NRZ.

IF OUTPUT INTERFACE:

Frequency Output

70 MHz + 1 kHz center frequency, double sideband suppressed carrier.

Power Level

+ 10 dBm (terminated)

Impedance

50 ohms, + 10%, unbalanced

Type Modulation

NRZ Quadraphase or biphase shift keying (QPSK/BPSK)

Data Rates

1544 kb/s internally processed 9.9999 Mb/s (10 Mb/s) externally processed.

The CSS accepts Voice Frequency (VF), teletype (TTY),

IF to SHF for transmission to the communications

and baseband digital signals from external cable

satellite.

b. For maximum processing of VF, the CSS can

transmission networks and combines them with onboard

teletype and voice orderwire signals to form a composite,

handle up to 12 VF (four wire or two wire) sets with an

multiplexed, digital signal called the mission bit stream.

additional two channels for the orderwire and TTY.

c. The CSS can process up to nine duplex TTY

This bit stream is applied to a bulk encryption device for

channel utilization security before routing to the digital

channels, five of which are dedicated to remote FSK

data modem. The modulated 70-MHz Intermediate

users. The remaining four channels may be apportioned

Frequency (IF) signal from the modem, defined as the

among any combination of high-level and lowlevel TTY

output signal of the CSS, interfaces with the RSS via the

users, except that the number of high-level circuits is

IF patch panel. The IF patch panel is the radio-side

limited to a maximum of three.

terminus of the communications subsystem while the

d. The CSS is equipped to process baseband

signal entry panels at the shelter wall form the user-side

digital signals which, at the maximum multiplexer

of the CSS. Received communications from the far-end

capability, may consist of two 50 kb/s and four 0-20 kb/s

radio system flow through the CSS in the reverse order

asynchronous bit streams, together with one

from the IF patch panel to the user by way of the signal

synchronous bit stream that may be at either a 256 or a

entry panel. Various critical equipments in the CSS are

512 kb/s data rate.

redundant for reliability enhancement. In addition, a

e. Various combinations of VF, TTY, and digital

group of test equipments is included to support specific

signals can be simultaneously processed, with the total

CSS requirements.

multiplexed data rate not to exceed 1544 kb/s. The

multiplexer can operate at the lower data rates of 192,

384, or 768 kb/s for conservation of transmitted if power

1-7. Description

and bandwidth, but at these lower data rates, the number

The AN/TSC-86 terminal CSS is capable of interfac-

and/or types of input signals must be reduced

ing with various types of DCS field user communica-

accordingly.

tions and the RSS.

f. The CSS is also capable of receiving an

a. The CSS is able to receive VF, TTY, and

externally processed 9. Mb/s (10 Mb/s) data stream at

baseband digital signals and process them into

the input of either modem to be modulated on a 70-MHz

multiplexed, encryptioned bit stream modulated on a 70-

IF carrier for insertion into the RS for transmission.

MHz IF carrier compatible with the input requirements of

the RSS.

The

RSS

then

converts

the

1-5