User Manual
Product information and planning
9500 MPR Rel. 3.1
3DB18809AAAA Issue 1 169/980
This is achieved through a multi-tap equalizer consisting of two registers, one with feed-forward taps, the
other with feed-back taps. Each of these registers multiply successive delayed samples of the received
signal by weighting-coefficients to remove propagation induced inter-symbol interference.
2.8.12.6 Link identifier
The amount of microwave links, especially in urban areas puts the problem of possible interferences
during installation and turn-on phase.
The digital frame incorporates link identity coding capabilities to prevent the capture of an unwanted
signal.
In case of “Link Identifier Mismatch” all the traffic is dropped.
The Link identifier management can be enabled or disabled by the management systems.
2.8.12.7 Loopbacks with MPT-HC/MPT-HC V2/MPT-MC
To facilitate the installation/commissioning and the remote maintenance one loopback is available.
As the activation of a loopback affects the traffic, the presence of a loopback is indicated to the
management systems as an abnormal condition.
The loopback is "loop and continue" type (the signal sent after the loopback execution is the same signal
sent back).
The loopbacks supported are shown in the following figure.
Figure 80. Available loopbacks
1) Core facing radio loopback: this loopback routes data from the output of the Tx Data Awareness
block (after compression) to the input of the Rx data awareness (decompression).
This is an internal loopback provided by the MPT FPGA.
It is a Loop and Continue. It is possible to enable this loopback only at aggregate level.
When this loopback is activated the behavior is the following:
– Compressed flows (TDM2TDM,TDM2ETH and ATM PW) are forwarded back to Core
module with proper assignment of source and destination MAC addresses (e.g. incoming
MAC SA is used as MAC DA for looped frame, while MAC SA in the looped frame is the
MAC assigned to slot hosting radio card).
– For TDM2ETH flows the loopback works only if the ECID Tx and ECID Rx are the same,
in case of ECID Tx is different form ECID Rx the loopback doesn't work.
– For ATM PW flows the loopback works only if the Inbound and Outbound PW Labels are
the same, in case they are different the loopback doesn't work.
PDH board
MPT Access
board
CORE
SWITCH
NxE1
LIU
FPGA
SerDes
FPGA
FPGA
12
MPT-HC
FPGA
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