MINI-LINKEandEMicro
The traff ic interface provides 2 or 2x2 Mbit/s long-haul traffic functions.
The purpose of the radio frame multiplexer / demultiplexer is multiplexing /
demultiplexing of different service type data (traffic, control and supervision
data) being sent over a hop.
In the transm itting direction, radio frame multiplexing, scrambling, Forward Error
Correction (FEC) encoding and modulation are applied.
In the receiving direction, descrambling, FEC decoding, radio frame
demultiplexing and demodulation are applied.
4.4.1 Traffic Interface
Traffic inputs and outputs are connected to/from the radio unit.
Traffic signals are shaped in a pulse regenerating circuit. The clock is generated
and the signal is line-decoded on the transmitting side and line-encoded on
the receiving side.
4.4.2 Radio Frame M ultiplexer and Forward Error Correction (FEC)
Two different data types are multiplexed into the data stream to be transmitted
over the radio path:
•Traffic
• Hop Communication Channel (HCC)
Transmit Traffic Data
Two independent data channels can be sent by the radio. The data is sent
to the multiplexer to assure data rate adaptation (stuffing). If no valid data is
present at the input, an AIS signal is inser t ed at nominal data rate.
Hop Commun ication Channel (HCC)
HCC is a data channel for exchange of control and supervision infor mation
between near and far-end radios.
Multiplexer
In the transmitting direction, traffic and hop communication data together with
check bits and frame lock bits are sent in a composite data format defined
by the frame format that is loaded into a Frame Format RAM. The 12 frame
alignment signal bits are placed at the star t of the frame. Parity bits are inserted
for control of traffic data and stuffing bits are inserted into the composite frame.
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AE/LZT 110 2012 R8C 2002- 03-04
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