Alcatel-Lucent 9500 MXC, Руководство пользователя

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Vol. VI-F-8 Alcatel-Lucent
Rx and Tx Diversity Bus
This bus is not accessed for non-protected or ring configurations. Refer to
Protected and Diversity Operation on page F-10 for details.
DAC
DACs interface customer data to the TDM bus.
Different DACs support different traffic types and rates.
DAC 16x
Basic DAC functionality is explained for the DAC 16x shown in Figure F-1 on
page F-2:
Line isolation and surge protection is provided at the tributary in/out connections
prior to the Line Interface Unit (LIU).
Interface matching for E1 (75 ohms unbalanced or 120 ohms balanced), or DS1
(AMI or B8ZS encoding), is enabled within the LIU (configured from CT). The
LIU also supports trib and bus facing loopbacks (for local and remote trib
loopbacks respectively).
In the transmit direction (to the TDM Bus) trib data streams are converted within
the Bus Mux from serial to parallel data, and rate-adapted from the E1 (or DS1)
trib clock domain to the TDM bus clock. The resultant bus-framed data is
inserted onto the TDM bus in blocks NxE1 (or DS1) data, where N is the number
of tribs in use.
In the receive direction, data from the TDM Bus is de-multiplexed to extract the
tribs and trib clocking, is de-jitterized, converted back to a serial E1 (or DS1)
data format, and passed to the LIU.
The Bus Mux also supports AIS insertion, and a PRBS generator and receiver
function for trib BER measurement
1
.
1
The PRBS function is a scheduled capability.