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Circuit Pack Descriptions
7-82 Issue 3 June 2001
Transmit Functions (Low-Speed Mode) 7
The STS1E transmit (low-speed mode) functions are as follows:
â– Receives B3ZS-encoded and scrambled EC-1 (STS-1) signal from STSX-1
â– B3ZS decodes and descrambles the signal and removes transport
overhead
â– Processes STS-1 pointers and frame synchronizes the signal
â– Optionally provides 6.48 Mb/s reference clock for TG circuit packs
â– Terminates STS-1 path (VT-based only).
Receive Functions (High-Speed Mode) 7
The STS1E receive functions (high-speed mode) are as follows:
â– Receives B3ZS-encoded and scrambled EC-1 signal from STSX-1
â– B3ZS decodes and descrambles signal and removes transport overhead
â– Processes STS-1 pointers and frame synchronizes the STS-1 signal
â– Optionally provides 6.48 Mb/s reference clock for TG circuit packs
â– Terminates STS-1 path
â– Demultiplexes the SPE into seven VT-G signals and supplies VT-G signals
to the DS1/DS1PM circuit packs.
Receive Functions (Low-Speed Mode) 7
The STS1E receive (low-speed mode) functions are as follows:
â– Selects an STS-1 input from the OLIU circuit pack and adds transport
overhead
â– B3ZS encodes and scrambles data, converts to bipolar format, and sends it
to the STSX-1.
Control Functions 7
The major control functions are as follows:
â– STS-1 path overhead processing
â– Protection switching for OLIU and DS1/DS1PM circuit packs
â– Protection switching for TG circuit packs
â– Inventory information (
CLEI
code, date of manufacture, etc.).
Maintenance Signal Functions (High-Speed Mode) 7
The STS1E major maintenance signal functions (high-speed mode) are as
follows: