PM7375-SC datasheet(71/430 Pages) PMC

71 / 430 page

PM7375 LASAR-155

DATA SHEET

PMC-931127

ISSUE 6

LOCAL ATM SAR & PHYSICAL LAYER

PROPRIETARY AND CONFIDENTIAL TO PMC-SIERRA, INC., AND FOR ITS CUSTOMERS’ INTERNAL USE

9.10

Transmit Transmitter and Overhead Processor

The Transmit Transmitter and Overhead Processor block inserts all path, line and

section overhead bytes in the outgoing STS-3c (STM-1) or STS-1 SONET/SDH

stream. Section, line and path overhead processing is performed using the

Transmit Section Overhead, Transmit Line Overhead and the Transmit Path

Overhead Processors as described below.

9.10.1 Transmit Section Overhead Processor

The Transmit Section Overhead Processor (TSOP) provides frame pattern insertion

(A1, A2), section BIP-8 (B1) insertion, scrambling and section level alarm signal

insertion. The default section overhead bytes inserted by the TSOP are shown in

the STS-3c (STM-1) Default Transport Overhead Values figure below.

The section BIP-8 code is based on a bit interleaved parity calculation using even

parity calculated over all SONET frame bytes. The calculated BIP-8 code is inserted

into the B1 byte of the following frame before scrambling.

Scrambling is performed using the generating polynomial 1 + x6 + x7. All bytes of

the SONET frame are scrambled except the framing bytes (A1, A2) and the identity

bytes (C1).

For alarm assertion and diagnostics, line AIS can be forced, all zeros may be

continuously inserted after scrambling (LOS) and BIP-8 errors may be continuously

inserted.

9.10.2 Transmit Line Overhead Processor

The Transmit Line Overhead Processor (TLOP) provides line level alarm signal

insertion and line BIP-8/24 insertion (B2). The default line overhead bytes inserted

by the TLOP are shown in the STS-3c (STM-1) Default Transport Overhead Values

figure below.

The line BIP-8/24 code is based on a bit interleaved parity calculation using even

parity calculated over all SONET frame bytes except the section overhead bytes.

The calculated BIP-8/24 code is inserted into the B2 byte(s) of the following frame.

For alarm assertion and diagnostics, line FERF can be forced (K2), line FEBE can

be automatically accumulated and inserted (Z2) and BIP-8/24 errors may be

continuously inserted.

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