HUAWEI OptiX OSN 8800 T64/T32 Intelligent Optical Transport Platform. Product Description - part 18
As shown in Figure 5-57, one OTU board functions as a test meter. In this case, the OTU board
is called meter board. The meter board generates PRBS signals and sends the signals to the client
side of the auxiliary board at the near end. The signals are looped back by configuring a WDM-
side or client-side loopback or by applying a physical fiber loopback on the auxiliary board at
the far end.
As shown in Figure 5-58, one OTU board functions as a test meter. In this case, the OTU board
is called meter board. The meter board generates PRBS signals and sends the signals to the WDM
side of the auxiliary board at the far end. The signals are looped back on the WDM side of the
auxiliary board at the far end.
Figure 5-57 Schematic diagram of the client-side PRBS test
TX
RX
OUT
IN
Near
Far
Meter
end
1
end
2
WDM network
board
auxiliary
auxiliary
board
board
RX
TX
IN
OUT
1: Loopback on the WDM side/fiber loopback
2: Loopback on the client side/fiber loopback
Figure 5-58 Schematic diagram of the WDM-side PRBS test
OUT
IN
Far
Meter
1
end
WDM network
board
auxiliary
board
IN
OUT
1: Loopback on the WDM side
NOTE
The LEM24 and LEX4 boards are applicable to this scenario (PRBS test on the WDM side) and function
only as meter boards. When the LEM24 and LEX4 boards are used in this scenario, other OTU boards
must be used as auxiliary boards at the far end.
5.14.3 Hot Patch
The OptiX OSN 8800 supports the hot patch technique.
Certain equipment requires long-term uninterrupted operation. When a defect is found or a new
requirement need be applied to the equipment software, old codes need to be replaced with new
codes to rectify the defect or realize the new requirement without interrupting the existing
services. These new codes are referred to as a hot patch.
The hot patch technique has the following features:
180
l Solves most software problems without affecting services.
l Effectively decreases the number of software versions and avoids frequent software version
upgrade.
l Can be installed, locally or remotely, without affecting the existing services. The hot patch
also supports rollback. This helps to effectively reduce the upgrade cost and to avoid
upgrade risks.
l Can be used as an effective method of locating faults, which improves problem solving
efficiency.
181
6
NE Type and Signal Flow
About This Chapter
6.1 OTM in a DWDM System
The OptiX OSN 8800 provides OTM equipment for a DWDM system.
6.2 OLA in a DWDM System
The OptiX OSN 8800 provides OLA equipment for a DWDM system.
6.3 FOADM in a DWDM System
The OptiX OSN 8800 provides FOADM equipment.
6.4 ROADM in a DWDM System
The OptiX OSN 8800 provides ROADM equipment.
6.5 REG in a DWDM System
The REG equipment is an electrical regenerator and is used to further extend the optical
transmission distance.
6.6 OTM in a CWDM System
The OptiX OSN 8800 provides OTM equipment.
6.7 FOADM in a CWDM System
The OptiX OSN 8800 provides FOADM equipment.
6.8 TM in an SDH System
The TM multiplexes low-rate signals into high-rate synchronous digital hierarchy (SDH) optical
signals and cross-connects the line signals with the low-rate SDH signals (tributary signals). The
TM performs the reverse process.
6.9 ADM in an SDH System
The ADM is most widely used on the SDH network. The ADM integrates the functions of
synchronous multiplexing and digital cross-connection. Thus, the ADM is capable of adding or
dropping low-rate SDH signals according to the requirements.
6.10 MADM in an SDH System
182
The MADM can be considered as a combination of multiple ADMs. In addition to the functions
provided by the ADM, the MADM can cross-connect different ADMs. The transmission rate
can be different or the same for different ADMs.
183
6.1 OTM in a DWDM System
The OptiX OSN 8800 provides OTM equipment for a DWDM system.
6.1.1 OTM Node with Optical Multiplexer Board and Optical
Demultiplexer Board (40-Wavelength)
Functions
The DWDM OTM node is used at the terminal station, and logically divided into
l Transmit direction
l Receive direction
In the transmit direction, the OTM amplifies client-side signals after converging/converting the
signals. Then, the signals are multiplexed with the supervisory channel signals before line
transmission. In the receive direction, the reverse process is performed at the OTM.
This OTM node type applies to stations whose initial wavelengths are more than 16. It supports
expansion of up to 40 wavelengths without interrupting services.
Functional Units
An OTM consists of:
l Optical transponder unit (OTU)
l Optical amplifier unit (OA)
l Optical multiplexer unit (OM)
l Optical demultiplexer unit (OD)
l Unidirectional optical supervisory channel unit (SC1)
l Fiber interface unit (FIU)
l System control and communication unit (SCC)
For the boards used in each unit, see 4.2 Hardware Architecture.
Signal Flow
In the transmit direction, through the OTU, the OTM node converges/transforms the accessed
signals into signals with ITU-T G.694.1-compliant DWDM wavelengths. Then, the signals are
multiplexed by the optical multiplexer unit into the main optical path. Then, these main path
optical signals are amplified and multiplexed with the optical supervisory signal. Finally, the
multiplexed signals are sent to the line for transmission.
In the receive direction, the optical supervisory signal and the main path optical signals are
separated. Then, the optical supervisory signal is sent to the optical supervisory channel (OSC)
unit for processing, and the main path optical signals are demultiplexed by the optical
demultiplexer unit into signals of different wavelengths, and finally sent to the corresponding
client equipment after being transformed/divided by the OTUs.
The schematic diagram of this OTM node type is shown in Figure 6-1.
184
Figure 6-1 Schematic diagram of DWDM OTM node with the optical multiplexer unit and the
optical demultiplexer unit
OTU
OTU
OM
OA
OTU
SC1
FIU
OTU
OTU
OD
OA
OTU
OTU: optical transponder unit
OM: optical multiplexer unit
SC1: unidirectional OSC unit
OD: optical demultiplexer unit
FIU: fiber interface unit
OA: optical amplifier unit
ODF: Optical distribution frame
Typical Configuration
Take a 40-wavelength OTM node installed with the optical multiplexer and optical demultiplexer
for example, as shown in Figure 6-2. One cabinet and two subracks are used.
185
Figure 6-2 Typical configuration of the OTM equipment that consists of the optical multiplexer
and optical demultiplexer (40 wavelengths)
FAN
A
S
S
EF
U
T
T
EFI2
PIU
PIU
PIU
PIU
STI
ATE
I1
X
G
G
N
N
N
N
N
N
N
N
S
N
N
T
T
T
T
T
T
Q
Q
Q
Q
Q
Q
Q
Q
C
Q
Q
Q
Q
Q
Q
Q
Q
2
2
2
2
2
2
2
2
C
2
2
X
X
X
X
X
X
X
X
C
C
H
H
/
/
X
X
C
C
M
M
T
T
T
T
T
T
T
T
S
T
T
O
O
O
O
O
O
O
O
C
Q
Q
M
M
M
M
M
M
M
M
C
X
X
FAN
FAN
A
S
S
EF
U
T
T
EFI2
PIU
PIU
PIU
PIU
STI
ATE
I1
X
G
G
O
O
S
S
B
F
A
M40V
D40
C
C
U
I
U
C
1
U
1
1
S
C
C
FAN
186
6.1.2 OTM Node with Optical Multiplexer Board, Optical
Demultiplexer Board, and Interleaver Board (80-Wavelength)
Functions
The DWDM OTM node is used at the terminal station, and logically divided into
l Transmit direction
l Receive direction
In the transmit direction, the OTM amplifies client-side signals after converging/converting the
signals. Then, the signals are multiplexed with the supervisory channel signals before line
transmission. In the receive direction, the reverse process is performed at the OTM.
This OTM node type applies to stations whose initial wavelengths are more than 40. It supports
expansion of up to 80 wavelengths without interrupting services.
Functional Units
An OTM consists of:
l Optical transponder unit (OTU)
l Optical amplifier unit (OA)
l Optical multiplexer unit (OM)
l Optical demultiplexer unit (OD)
l Unidirectional optical supervisory channel unit (SC1)
l Interleaver Board (ITL)
l Wavelength monitor unit (WMU)
l Fiber interface unit (FIU)
l System control and communication unit (SCC)
For the boards used in each unit, see 4.2 Hardware Architecture.
Signal Flow
In the transmit direction, through the OTU, the OTM node converges/transforms the accessed
signals into signals with ITU-T G.694.1-compliant DWDM wavelengths. Then, the signals are
multiplexed by the optical multiplexer unit. Then, the two channels of multiplexed signals (odd-
numbered wavelengths and even-numbered wavelengths) are sent to the ITL for wavelength
multiplexing. As a result, one channel of multiplexed signals of 80 wavelengths in C band is
formed. The frequency spacing is 50 GHz. Then, these main path optical signals are amplified
and multiplexed with the optical supervisory signal. Finally, the multiplexed signals are sent to
the line for transmission.
In the receive direction, the optical supervisory signal and the main path optical signals are
separated. Then, the optical supervisory signal is sent to the optical supervisory channel (OSC)
unit for processing. After amplification, the optical signals in the main channel are demultiplexed
into two channels of multiplexed signals (odd-numbered wavelengths and even-numbered
wavelengths) with the frequency spacing of 100 GHz by the ITL. Then, each channel of
187
multiplexed signals is demultiplexed into a single channel of optical signals, and finally sent to
the corresponding client equipment after being transformed/divided by the OTUs.
NOTE
l The channel spacing within each group is 100 GHz, that is, the channel spacing at each multiplexer/
demultiplexer is 100 GHz. The spacing between two adjacent channels, for example channel 1 and
channel 2, however, is 50 GHz. Therefore, the interleaver can be used to realize 50 GHz channel
spacing.
l For example, the frequencies of a multiplexed signal are 192.1 THz, 192.2 THz...196.0 THz, totally
40 channels. The frequencies of another multiplexed signal are 192.15 THz, 192.25 THz...196.05 THz,
totally 40 channels. After passing through the interleaver, the output frequencies change to 192.1 THz,
192.15 THz, 192.2 THz, 192.25 THz...196.05 THZ, totally 80 channels with channel spacing of 50
GHz. In this way, the interleaver multiplexes or demultiplexes odd channels and even channels.
The schematic diagram of this OTM node type is shown in Figure 6-3.
Figure 6-3 Schematic diagram of DWDM OTM node with the optical multiplexer unit, the
optical demultiplexer unit and ITL board (80-wavelength)
OTU
OTU
OM
(C-ODD)
OTU
OTU
WMU
OTU
OM
OA
(C-EVEN)
OTU
ITL
FIU
SC1
OTU
OTU
OA
OD
(C-ODD)
OTU
OTU
OTU
OD
(C-EVEN)
OTU
OTU: optical transponder unit
OM: optical multiplexer unit
SC1: unidirectional OSC unit
OD: optical demultiplexer unit
FIU: fiber interface unit
OA: optical amplifier unit
ODF: optical distribution frame
WMU: wavelength monitor unit
ITL: interleaver board
C-ODD: ODD channels in C band C-EVEN: EVEN channels in C band
188
Typical Configuration
Take an 80-wavelength OTM node installed with optical multiplexer, optical demultiplexer and
ITL board for example, as shown in Figure 6-4. Two cabinets and three subracks are used.
Figure 6-4 Typical configuration of the OTM equipment that consists of the optical multiplexer,
optical demultiplexer and ITL board (80 wavelengths)
FAN
FAN
A
S
S
A
S
S
EF
U
T
T
EF
U
T
T
EFI2
PIU
PIU
PIU
PIU
STI
ATE
EFI2
PIU
PIU
PIU
PIU
STI
ATE
I1
X
G
G
I1
X
G
G
N
N
N
N
N
N
N
N
S
N
N
T
T
T
T
T
T
N
N
N
N
N
N
N
N
S
N
N
T
T
T
T
T
T
Q
Q
Q
Q
Q
Q
Q
Q
C
Q
Q
Q
Q
Q
Q
Q
Q
Q
Q
Q
Q
Q
Q
Q
Q
C
Q
Q
Q
Q
Q
Q
Q
Q
2
2
2
2
2
2
2
2
C
2
2
X
X
X
X
X
X
2
2
2
2
2
2
2
2
C
2
2
X
X
X
X
X
X
X
X
X
X
C
C
C
C
H
H
H
H
/
/
/
/
X
X
X
X
C
C
C
C
M
M
M
M
T
T
T
T
T
T
T
T
S
T
T
T
T
T
T
T
T
T
T
S
T
T
O
O
O
O
O
O
O
O
C
Q
Q
O
O
O
O
O
O
O
O
C
Q
Q
M
M
M
M
M
M
M
M
C
X
X
M
M
M
M
M
M
M
M
C
X
X
FAN
FAN
FAN
A
S
S
EF
U
T
T
EFI2
PIU
PIU
PIU
PIU
STI
ATE
I1
X
G
G
O
O
S
I
A
B
M40V
D40
C
T
D40
M40V
U
U
C
L
1
1
F
S
W
S
I
C
M
C
U
1
U
C
FAN
6.2 OLA in a DWDM System
The OptiX OSN 8800 provides OLA equipment for a DWDM system.
Functions
The DWDM OLA equipment is used for amplification of optical signals from two transmission
directions.
189
Functional Units
An OLA consists of:
l Optical amplifier unit (OA)
l Bidirectional optical supervisory channel unit (SC2)
l Fiber interface unit (FIU)
l System control and communication unit (SCC)
For the boards used in each unit, see 4.2 Hardware Architecture.
Signal Flow
The FIU board separates the optical supervisory signal from the main path optical signals and
sends the former to the OSC unit for processing.
The main path optical signals are amplified by the amplifier unit and multiplexed with the OSC
that has already been processed, and then sent to the line fiber for transmission.
The schematic diagram of DWDM OLA equipment is shown in Figure 6-5.
Figure 6-5 Schematic diagram of DWDM OLA equipment
OA
West
East
line-side
line-side
FIU
SC2
FIU
ODF
ODF
OA
FIU: fiber interface unit
OA: optical amplifier unit
SC2: bidirectional OSC unit
ODF: Optical distribution frame
Typical Configuration
The OptiX OSN 8800 is available in two types of subracks, that is, the OptiX OSN 8800 T32
subrack and the OptiX OSN 8800 T64 subrack. The OptiX OSN 8800 T32 subrack is considered
as an example to describe the typical configuration. For the differences between the OptiX OSN
8800 T32 subrack and the OptiX OSN 8800 T64 subrack, see the Hardware Description.
Figure 6-6 shows the typical configuration of an OLA node. One cabinet and one subrack are
used.
190