User's Manual

Table Of Contents
ECLIPSE INSTALLATION MANUAL
INU -48Vdc input. -56 Vdc represents the typical float voltage for a battery-backed -
48 Vdc supply.
Figure 1-19. PCC
Data Packet Plane
The high-performance data packet plane (DPP) operates independently of the back-
plane.
The DPP is enabled via direct cable connection between the front panel packet data
port on a RAC 60E, RAC 6XE, and a front-panel port on a DAC GE3. Customer traf-
fic connected to the DACs is bridged to the RACs, and then to the RF transceiver; the
IRU 600.
Where required, customer data can also be sourced via the circuit-switched back-
plane, meaning both the DPP and backplane can be used to source/send traffic. This
has special relevance where native mixed-mode IP + TDM traffic is to be sent over an
Eclipse wireless link; GigE IP traffic via the DPP, and TDM traffic via the backplane.
Adaptive Coding and Modulation (ACM)
Advanced ACM options are provided using RAC 60E or RAC 6XE plug-ins.
l Adaptive modulation maximizes use of available channel bandwidth.
l Coding provides options for maximum throughput or maximum system gain
on each modulation rate.
Adaptive Modulation (AM)
AM uses one of four automatically and dynamically switched modulations - QPSK,
16 QAM, 64 QAM, or 256 QAM. For a given RF channel bandwidth a two-fold
improvement in data throughput is provided for a change from QPSK to 16 QAM, a
three-fold improvement to 64 QAM, and a four-fold improvement to 256 QAM.
In many instances the link parameters that supported the original system gain can
be retained. For example, the antenna sizes and Tx power used for an original QPSK
link on a 7 MHz channel are unchanged when operated on 256 QAM using adaptive
modulation. The adaptive modulation engine ensures that the highest throughput is
always provided based on link quality.
Modulation switching is hitless/errorless. During a change to a lower modulation,
remaining higher priority traffic is not affected. Similarly, existing traffic is unaf-
fected during a change to a higher modulation.
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