Huawei OptiX BWS 1600G. Technical Description - part 5
2 Product Description
Table 2-18 briefs the application and functions of the boards involved in the OAMS.
For more details, see Chapter 10 "Optical Fibre Automatic Monitoring Units" in
OptiX BWS 1600G Backbone DWDM Optical Transmission System Hardware
Description.
Table 2-18 Application and description of the fibre Automatic Monitoring System
Board name
Application
Functions
FMU
Applied to the embedded OAMS as
Measures the time domain reflection of four
its core unit.
fibres.
Applied to all types of systems.
MWA
Applied to the embedded OAMS,
During the online monitoring, it multiplexes the
including two types:
service signal of the DWDM system and the test
signal wavelength.
MWA-I: Accesses two channels of
monitoring optical signals.
MWA-II: Accesses four channels of
monitoring optical signals.
Applied to all types of systems.
MWF
Applied to the embedded OAMS,
In online monitoring, it filters out the test signal
including two types:
wavelength to eliminate its effect on the
transmission system. Used when the service
MWF-I: Filters out two channels of
signal and the test signal are co-directional.
monitoring optical signals.
MWF-II: Filters out four channels of
monitoring optical signals.
Applied to all types of systems.
2.3.7 Protection Unit
The protection unit helps to realise optical line protection, 1+1 optical channel
protection, inter-board 1+1 optical channel protection, 1:N (N≤8) channel
protection and OTU secondary power backup. It includes:
Table 2-19 Board name and category of the protection unit
Service type
Board
Board name
protection unit
OLP
Optical line protection unit
OCP
Optical channel protection unit
SCS
Sync optical channel separator unit
PBU
Power backup unit
2-24
2 Product Description
Table 2-20 briefs the application and functions of the above boards. For more
details, see Chapter 11 "Optical Protection Units" in OptiX BWS 1600G Backbone
DWDM Optical Transmission System Hardware Description.
Table 2-20 Application and description of protection units
Board name
Application
Functions
OLP
For line protection, located
Divides the optical signal into two parts at the transmit
between the FIU and the line.
end, and receives them selectively at the receive end
(OLP01)
according to the optical power.
For inter-subrack 1+1 optical
Uses the OLP board for optical line protection. Able to
channel protection, located
automatically switch the traffic to the standby fibre
between the client-side device
when the performance of the active fibre degrades.
and the OUT. (OLP03)
Realize inter-subrack 1+1 optical channel protection.
Applied to all types of systems.
The signals automatically switch to protection channel
when the working channel degrades.
OCP
Located between the client
Helps to realise the 1:N (N≤8) channel protection.
equipment and the OTU.
Applied to type I, II, III, IV and
VI systems.
SCS
Located between the client
Achieves dual-fed for optical signals.
equipment and the OTU.
Helps to realise the 1+1 channel protection. Is able to
Applied to all types of systems.
automatically switch the traffic to the standby fibre
when the signal quality in the active fibre degrades.
PBU
Serves as the secondary power
Achieves centralized protection for the power supplies
backup unit of the OTU.
of the OTU boards in the same subrack, and supports
the 3.3 V, 5 V and -5.2 V power supplies on the two
Applied to all types of systems.
OTU boards simultaneously when power fails.
2.3.8 System Control and Communication Unit
The system control and communication unit (SCC) is the control centre of the entire
system, which enables equipment management and the communications between
equipments. It includes the SCC and SCE.
Table 2-21 Board name and category of the system control and communication unit
Service type
Board
Board name
protection unit
SCC
System control and communication unit
SCE
System control and communication unit for extended subrack
Table 2-22 briefs the application and functions of the SCC and SCE. For more
details, see Chapter 12 "Optical Supervisory Units and System Control and
2-25
2 Product Description
Communication Unit" in OptiX BWS 1600G Backbone DWDM Optical
Transmission System Hardware Description.
Table 2-22 Application and description of the SCC and SCE
Board name
Application
Functions
SCC
Applied to every NE.
Accomplishes NE management, overhead processing
and the communication between equipments, and
Applied to all types of systems.
provides the interface between the 1600G system and
the NM. It is the control centre of the entire OptiX
BWS 1600G.
SCE
Applied to the extended subrack.
Supports the same functions as the SCC except the
overhead processing.
Applied to all types of systems.
2.4 System Software Architecture
The software system of the OptiX BWS 1600G is a modular structure. Mainly the
whole software is distributed in three modules, including board software, NE
software and NM system, residing respectively on the functional boards, SCC, and
NM computer.
Hierarchical structure ensures that it is highly reliable and efficient. Each layer
performs specific functions and provides service for the upper layer. The OptiX
BWS 1600G system software architecture is shown in Figure 2-4. In the diagram,
all modules are NE software except "Network Management System" and "Board
Software".
2-26
2 Product Description
Network Management
System
High Level
Communication Module
Real-time
multi-task
Equipment Management
Database
operating
Module
management
system
module
Communication Module
NE Software
Board Software
Figure 2-4 Software architecture of the OptiX BWS 1600G
2.4.1 Communication Protocols
Qx Interface
The Qx interface connects MD, QA and NE equipment through the local
communication network (LCN). At present, the QA is provided by network
element management layer. MD and OS are provided by the network management
layer. They are connected with each other via the Qx interface. According to the
ITU-T Recommendations, the Qx interface provided by the type I system is
developed on the basis of transport control protocol/internet protocol (TCP/IP)
connectionless network service (CLNS1) protocol stack.
2.4.2 Working Principles
The functions and implementation of different layers of the system software are
discussed in the following text.
Board Software
The board software runs on each board, managing, monitoring and controlling the
operation of the board. It receives the command issued from the NE software and
reports the board status to the NE software through performance events and alarm.
The specific functions include:
Alarm management
2-27
2 Product Description
Performance management
Configuration management
Communication management
It directly controls the functional circuits in corresponding boards and implements
ITU-T compliant specific functions of the NE.
NE Software
NE software manages, monitors and controls the board operations in NE. It also
assists the NM system to facilitate the centralized management over DWDM
network. According to ITU-T Recommendation M.3010, NE software is on the unit
management layer of the telecom management network, performing the functions:
network element function (NEF), partial mediation function (MF) and OS function
at network unit layer. Data communication function (DCF) provides
communication channel between NE and other components (including NM and
other NEs).
Real-time multi-task operating system
Real-time multi-task operating system of NE software is responsible for managing
public resources and support application programmes. It isolates the application
programmes from the processor and provides an application programme execution
environment, which is independent from the processor hardware.
Communication module
Communication is the interface module between NE software and board software.
According to the corresponding communication protocol, communication function
between NE software and board software is implemented for information exchange
and equipment maintenance. Via low level communication, board maintenance and
operation commands from the NE software are sent to the boards. On the other
hand, the corresponding board state and alarm and performance events are reported
to the NE software.
Equipment management module
Equipment management module is the kernel of the NE software for implementing
network element management. It includes administrator and client. Administrator
can send network management operation commands and receive events. Client can
respond to the network management operation commands sent by the administrator,
implement operations to the managed object, and send up events according to state
change of the managed object.
High level Communication module
The communication module exchanges management information between network
management system and network element and among NEs. It consists of network
communication module, serial communication module and ECC communication
module.
Database management module
2-28
2 Product Description
The database management module is an effective part of the NE software. It
includes two independent parts: data and programme. The data are organized in the
form of database and consist of network, alarm, and performance and equipment
bases. The programme implements management and accesses to the data in the
database.
Network Management System
Huawei network management system OptiX iManager, not only provides DWDM
equipment management, but it also handles the entire OptiX family members
including SDH and Metro equipment. In compliance with ITU-T Recommendation,
it is a network management system integrating standard management information
model and object-oriented management technology. It exchanges information with
NE software through the high level communication module to monitor and manage
the network equipment.
The NM software runs on a workstation or PC, managing the equipment and the
transmission network to help to operate, maintain and manage the transmission
equipment. The management functions of the NM software include:
Alarm management: collect, prompt, filter, browse, acknowledge, check,
clear, and statistics in real time; fulfill alarm insertion, alarm correlation
analysis and fault diagnosis.
Performance management: set performance monitoring; browse, analyze and
print performance data; forecast medium-term and long-term performance;
and reset performance register.
Configuration management: configure and manage interfaces, clocks,
services, trails, subnets and time.
Security management: NM user management, NE user management, NE
login management, NE login lockout, NE setting lockout and local craft
terminal (LCT) access control of the equipment.
Maintenance management: provide loopback, board resetting, automatic laser
shutdown (ALS) and optical fiber power detection, and collect equipment data to
help the maintenance personnel in troubleshooting.
2-29
3 System Configuration
3
System Configuration
The OptiX BWS 1600G offers five types of NEs:
OTM: Optical Terminal Multiplexer
OLA: Optical Line Amplifier
OADM: Optical Add/Drop Multiplexer
REG: Regenerator
OEQ: Optical Equalizer
Each NE type can operate at 160 channels at most.
3.1 OTM
3.1.1 Signal Flow
The OTM is a terminating station of the DWDM network. An OTM is divided into
the transmit end and the receive end.
At the transmit end, the OTM receives optical signals from multiple client
equipment (for example, SDH equipment), and converts these signals, multiplexes,
amplifies and sends them on a single optical fibre.
At the receive end, the OTM demultiplexes the signals into individual channels
and distributes them to the corresponding client equipment.
An OTM consists of:
Optical transponder unit (OTU)
Optical multiplexer (OM)
Optical demultiplexer (OD)
Optical amplifier (OA)
Raman pump amplifier unit (RPU)
Optical supervisory channel unit or supervisory channel and timing
transporting unit (OSC/OTC)
Fibre interface unit (FIU)
3-1
3 System Configuration
Dispersion compensation module (DCM)
Multi-channel spectrum analyser unit (MCA)
System control & communication unit (SCC)
Power backup unit (PBU)
Figure 3-1 shows the OTM signal flow.
λ01
DCM
OTU01
λ02
OTU02
OD
OA
RPU
λn
OTU n
F
Client
OSC/OTC
I
side
λ01
U
OTU01
λ02
OTU02
OA
OM
λn
OTU n
DCM
MCA
Figure 3-1 OTM signal flow
At the transmit end, up to 160 client-side signals are received at OTU boards, where
these signals are converted into standard DWDM signals in compliance with ITU-T
G.694.1.
The OM multiplexes these signals and sends them to the OA for amplification.
Meanwhile, the DCM implements dispersion compensation. Finally, the amplified
main path signal and supervisory signal are multiplexed, through the FIU, and are
sent to the optical fibre for transmission.
At the receive end, the RPU (optional), a low-noise pump amplifier, amplifies the
received main path signal. Then the main path signal is separated into supervisory
signal and service signal. After amplification and dispersion compensation, the
service signal is sent to the OD and demultiplexed by the OD. The supervisory
signal is directly processed by the OSC or OTC.
The OM, OD and OA provide optical performance monitoring port, through which
the MCA is accessed for monitoring the central wavelength, optical power and
OSNR of multiple channels of optical signals.
The integrated OTM can work without OTU at the transmit end, so 160 channels of
signals can be directly multiplexed into DWDM main optical path.
3.1.2 Structure
For the OTM of the six system types (see Chapter 1 "Overview" for the
classification of system types), each functional unit and the board(s) contained are
shown in Table 3-1.
For the functions of these boards, see Chapter 2 "Product Description".
3-2
3 System Configuration
Table 3-1 Functional units and the boards contained (six system types)
Unit
OTU
OM
OD
OA
OSC/OTC
FIU
System
I
LWF, TMX, LBE, LOG
M40+ITL,
D40+ITL
OAU, OBU, OPU
SC1, TC1
FIU-01,
V40+ITL
FIU-02
II
C + L 800 G
LWF, TMX, LBE, LOG
M40, V40
D40
OAU, OBU, OPU
SC1, TC1
FIU-01,
FIU-02
C 800G
All OTUs
M40+ITL,
D40+ITL
OAU, OBU, OPU
SC1, TC1
FIU-03
V40+ITL
III
All OTUs
M40, V40
D40
OAU, OBU, OPU
SC1, TC1
FIU-03
IV
LWF
M40, V40
D40
OAU, OBU, OPU
SC1, TC1
FIU-04
V
LWC1, LDG, FDG, LWM, LWX
M40, V40
D40
OAU, OBU, OPU
SC1, TC1
FIU-03
VI
All OTUs
M40, V40
D40
Transmit end: HBA
SC1, TC1
FIU-06
Receive end: OPU+OAU
3-3
3 System Configuration
Type I System
The type I system (1600G capacity) uses four 400 Gbit/s modules together to access
160 channels. Refer to Table 3-2.
Table 3-2 Distribution of 160 channels
Group
Frequency range
Wavelength range
Channel spacing
(THz)
(nm)
(GHz)
C-EVEN
192.10-196.00
1529.16-1560.61
100
C-ODD
192.15-196.05
100
L-EVEN
186.95-190.85
1570.42-1603.57
100
L-ODD
187.00-190.90
100
The structure of the OM, OD and OA of the type I system is shown in Figure 3-2.
Each of them has different specifications to process signals of different bands. For
example, the M40 (C-ODD) multiplexes signals of C-ODD channels, while the
M40 (C-EVEN) multiplexes signals of C-EVEN channels.
OM & OD
OA
M40
（C-ODD）
OA-C
M40
（C-EVEN）
ITL-C
D40
（C-ODD）
OA-C
D40
（C-EVEN）
M40
（L-ODD）
OA-L
M40
（L-EVEN）
ITL-L
D40
（L-ODD）
OA-L
D40
（L-EVEN）
ITL-C: C-band interleaver
ITL-L: L-band interleaver
OA-C: C-band optical amplifier unit
OA-L:L-band optical amplifier unit
M40: 40-channel multiplexing unit
D40: 40-channel demultiplexing unit
Figure 3-2 Structure of the OM, OD and OA of the type I system
The four 400 Gbit/s optical modules multiplex optical signals of each band and
send the multiplexed signal to the ITL-C and ITL-L, where the multiplexed signals
3-5
3 System Configuration
are multiplexed again into 80-channel multiplexed signal in C-band and 80-channel
multiplexed signal in L-band, with channel spacing of 50 GHz. After amplification
and dispersion compensation, the signals of two bands, together with the optical
supervisory signal or optical supervisory signal & clock signal, are sent to the
optical fibre for transmission.
Note
The channel spacing within each group is 100 GHz, that is the channel spacing at
each multiplexer/demultiplexer is 100 GHz. But the spacing between two adjacent
channels, for example channel 1 and channel 2, is 50 GHz. Therefore, the
interleaver can be used to realise 50 GHz channel spacing for the 1600G
transmission system.
For example, the frequencies of a multiplexed signal are 192.1 THz, 192.2
THz …196.0 THz, totally 40 channels, and those 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, with channel spacing of 50 GHz. In this way, the
interleaver multiplexes or demultiplexes odd channels and even channels.
Type II System
The type II system can be realised in two ways:
C+L 800G
C 800G
The channel spacing of the C+L 800G system is 100 GHz, and that of the C 800G
system is 50 GHz. The structure of the OM, OD, and OA of the type II system is
similar to that of the type I system. The OM, OD and OA of the C+L 800G system
operate at C-EVEN and L-ODD bands, and those of the C 800G system operate at
C-EVEN and C-ODD. See Figure 3-3.
3-6