Huawei ATN 950B Hardware Description page 86

ATN 950B Multi-service Access Equipment
Hardware Description
Transmit Direction
The service signals from the AND1CXPA/AND1CXPB are sent to the service processing
module. The service processing module performs PWE3 decapsulation and PW scheduling for
the service signals, processes the service signals based on the IMA/ATM, CES, and ML-PPP
protocols, performs the E1 framing function, and sends the service signals to the service access
module. The service access module performs encoding and line drive for the signals and outputs
the signals through the backplane-side interfaces.
Receive Direction
The board accesses service signals through the backplane-side interfaces, and then the signals
are sent to the service access module. The service access module performs interference isolation,
lightning-proof, impedance matching, level conversion, signal balancing, decoding, and then
sends the processed signals to the service processing module. The service processing module
performs E1 framing, processes service signals based on the IMA/ATM, CES, and ML-PPP
protocols, implements PWE3 encapsulation and PW scheduling, and sends the signals to the
AND1CXPA/AND1CXPB through the backplane-side interfaces.
Service Access Module
This module performs the following functions:
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Service Processing Module
This module performs the following functions:
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Management Module
This module manages and controls each module on the board.
Issue 03 (2012-07-23)
In the receive direction, this module isolates common mode interference, protects circuits
against transient failures, matches the impedance in the receive direction with the internal
impedance, and performs level conversion, balancing, and decoding for the service signals.
Finally, this module sends the processed signals to the service processing module.
In the transmit direction, this module receives the service signals from the service
processing module, encodes the signals, drives the line, and outputs the service signals
through the backplane-side interfaces.
This module recovers the line clock.
In the receive direction, this module receives the signals from the service access module
and performs E1 framing. This module also identifies protocol types of the service signals,
processes the service signals based on the IMA/ATM, CES, and ML-PPP protocols (for
example, addition and deletion of IMA group members, VP/VC switching and
concatenation of ATM cells, vacant slot compression of CES services, and setup of ML-
PPP groups). Then, this module performs PWE3 encapsulation and PW scheduling, Finally,
this module converts the processed signals to high-rate signals, and then sends the signals
to the AND1CXPA/AND1CXPB through the backplane-side interfaces.
In the transmit direction, this module receives the high-rate signals from the AND1CXPA/
AND1CXPB through the backplane-side interfaces and recovers low-rate service signals.
Then, this module performs PWE3 decapsulation, identifies different protocols and
processes the service signals, and completes E1 framing. Finally, this module sends the
processed signals to the service access module.
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