Comtech EF Data C5 - Manual (Page 27)

C5/K1/K3 Integrated Satellite Terminal System Introduction
Rev. 0 1–7
1.3 Modes of Operation
The ASYNC/AUPC option allows an additional overhead channel to be multiplexed and
demultiplexed from the data carrier. Two mechanisms are provided for automatic uplink
power control (AUPC) within a closed network.
! One method, which requires the optional ASYNC/AUPC interface card, is used
for control between two links to sustain sufficient transmit power to maintain a
programmed E
b
/N
0
at both ends.
! The second method is used for self-monitoring the carrier from the same uplink
with the local demodulator, requires no additional hardware, and is software-
selectable. This method is appropriate for applications such as paging networks,
where the uplink is transmit-to receive only devices. The self-monitoring AUPC
function is not available when the ASYNC/AUPC interface option is installed.
The IDU interfaces between Single-Channel per Carrier (SCPC) fixed-rate terminal
equipment operating within the following specifications:
! The IDU is capable of data rates from 2.4 kbit/s to 4.375 Mbit/s and includes a
1 x 10 -9 /day standard internal frequency reference.
Note: The IDU can be configured to add overhead/framing to the data.
Available modulation types include:
! Bi-Phase Shift Keying (BPSK).
! Quadrature Phase Shift Keying (QPSK).
An internal channel unit, conforming to IESS-308 and -309 emulation specifications,
provides overhead designated for an Engineering Service Channel (ESC).