S3091 AMCC (Applied Micro Circuits Corp), S3091 Datasheet - Page 4

• Manufacturer Part Number: S3091
• Description: Sonet/sdh/atm OC-192 16:1 Transmitter
• Manufacturer: AMCC (Applied Micro Circuits Corp)

S3091 – SONET/SDH/ATM OC-192 16:1
Transmitter
SONET OVERVIEW
Synchronous Optical Network (SONET) is a standard
for connecting one fiber system to another at the opti-
cal level. SONET, together with the Synchronous
Digital Hierarchy (SDH) administered by the ITU-T,
forms a single international standard for fiber intercon-
nect betwe en tel ephone net works of diff erent
countries. SONET is capable of accommodating a
variety of transmission rates and applications.
The SONET standard is a layered protocol with four
separate layers defined. These are:
• Photonic
• Section
• Line
• Path
Figure 2 shows the layers and their functions. Each of
the layers has overhead bandwidth dedicated to
administration and maintenance. The photonic layer
simply handles the conversion from electrical to optical
and back with no overhead. It is responsible for trans-
mitting the electrical signals in optical form over the
physical media. The section layer handles the trans-
port of the framed electrical signals across the optical
cable from one end to the next. Key functions of this
layer are framing, scrambling, and error monitoring.
The line layer is responsible for the reliable transmis-
sion of the path layer information stream carrying
voice, data, and video signals. Its main functions are
synchronization, multiplexing, and reliable transport.
The path layer is responsible for the actual transport of
services at the appropriate signaling rates.
Data Rates and Signal Hierarchy
Table 1 contains the data rates and signal designa-
tions of the SONET hierarchy. The lowest level is
the basic SONET signal, referred to as the synchro-
nous transport signal level-1 (STS-1). An STS-N
signal is made up of N byte-interleaved STS-1 sig-
nals. The optical counterpart of each STS-N signal
is an optical carrier level-N signal (OC-N). The chip
supports OC-192 with FEC and Digital Wrapper
(9.95328 to 10.709 Gbps) rates.
4
Frame and Byte Boundary Detection
The SONET/SDH fundamental frame format for
STS-192 consists of 576 transport overhead bytes
followed by Synchronous Payload Envelope (SPE)
bytes. This pattern of 576 overhead and 16,704
SPE bytes is repeated nine times in each frame.
Frame and byte boundaries are detected using the
A1 and A2 bytes found in the transport overhead.
(See Figure 3.)
For more details on SONET operations, refer to the
Bellcore SONET standard document.
Figure 2. SONET Structure
Table 1. SONET Signal Hierarchy
STS-192
STS-12
STS-24
STS-48
STS-1
STS-3
Functions
Payload to
SPE mapping
Maintenance,
protection,
switching
Scrambling,
framing
Optical
transmission
Elec.
End Equipment
STM-16
STM-64
STM-1
STM-4
STM-8
Photonic layer
ITU-T
Section layer
Path layer
Line layer
Revision A – February 22, 2002
DEVICE SPECIFICATION
Fiber Cable
OC-192
Optical
OC-12
OC-24
OC-48
OC-3
OC-1
Photonic layer
Section layer
Path layer
Line layer
End Equipment
Data Rate
1244.16
2488.32
9953.28
(Mbps)
155.52
622.08
51.84