Hi everybody!
I would like to share with you this interesting topic about Huawei's Optical Doctor System used in the OTN equipment. Hope you find it useful!
Introduction
The Optical Doctor (OD) System provides for intelligent end-to-end, refined, and digital management of the optical layer on a WDM network. Through centralized configuration for optical-layer parameters, the OD system supports automatic monitoring, analysis, commissioning, and optimization of network performance.
Challenges for WDM Network O&M
As WDM networks adopt higher transmission rates and become meshed, reliable network maintenance plays a more important role. An easier-to-use and more professional operation and maintenance (O&M) tool is required.
Currently, WDM networks are facing the following difficulties in the deployment, commissioning, configuration, and network maintenance phases:
Lack of quick and accurate OSNR monitoring methods:
After the network rate increases to 40 Gbit/s or higher, the original spectrum monitoring method cannot quickly and accurately monitor the OSNR of a system. It is a great challenge and a trend to develop an online OSNR monitoring tool for network maintenance.
Lack of reliable and quick optical-layer O&M methods:
On meshed networks, WDM services become more flexible, and frequent service creation and deletion make network commissioning and maintenance more complex. Traditional manual OSNR monitoring cannot address WDM network development requirements from the following aspects:
Configuration is complex.
When network optical-layer performance needs to be monitored or optimized, configuration needs to be performed for each site on the network, which is time-consuming and costly. In addition, some configuration items are widely dispersed and therefore are easily neglected. As a result, commissioning engineers have to perform a network-wide check site by site, leading to low efficiency.
Network performance deterioration cannot be detected in a timely manner.
Optical power fluctuation caused by fiber aging, component aging, wavelength adding or dropping, or external environment cannot be discovered by manual monitoring in a timely manner. Network-wide data collection and analysis require a long time and high costs.
Manual optimization is inefficient.
When optical-layer performance needs to be optimized, fault points and optimization points have to be manually identified and optimization has to be manually performed span by span. On a meshed network, optimization of one link may cause power fluctuation on other links and as a result the other links have to be also optimized. The optimization is time-consuming and complex.
With the development of WDM technologies and the change of network topology, an effective network O&M tool is required.
Functions of the OD System
The OD system supports online OSNR monitoring for 40G, 100G, 200G, 400G (dual-carrier signal) wavelengths, including 40-wavelength, 80-wavelength, and FlexGrid systems, making the OSNR monitoring of 40G, 100G, 200G, 400G (dual-carrier signal) wavelengths as convenient as that of 10G wavelengths. This greatly facilitates routine maintenance and makes it easy to upgrade 10G networks to 40G, 100G, 200G, 400G (dual-carrier signal) networks.
Figure 1 Online OSNR monitoring using the OD system
The online OSNR monitoring provided by the OD system has the following features:
Simple operations
The OSNR monitoring function is integrated into the U2000. It can be performed by directly operating the U2000. The virtual meter provides graphical display of the monitored OSNR information, without using other auxiliary devices or complex operations.
High detection precision
The detection precision is better than that of traditional 10G OSNR detection.
Wide range of monitored wavelengths
All site types, all wavelengths including 10G, 40G, 100G, 200G, 400G (dual-carrier signal), and all spectrum widths (including 40-wavelength, 80-wavelength, and FlexGrid systems) can implement online OSNR monitoring.
In addition, the OD system can be used to perform O&M of the optical layer on a WDM network, as described below.
Figure 2 O&M of the optical layer on a WDM network
Centralized configuration for network-wide monitoring
The OD system supports centralized configuration for optical-layer performance monitoring parameters, greatly saving labor costs.
Automatic monitoring of optical-layer performance
The OD system can automatically monitor network-wide optical-layer performance without using any meters. It can automatically detect the channels with abnormal performance.
Automatic optimization of optical-layer performance
Based on the performance data of each channel, the OD system can automatically adjust the optical power of each channel so that the channel works in the optimal state.
End-to-end (E2E) graphical display of optical-layer performance data
The OD system graphically displays link performance, facilitating status query and fault isolation.
To sum up, the OD system can achieve OSNR monitoring of high-rate WDM networks, quick monitoring deployment, monitoring, optimization, and analysis of E2E optical-layer performance. It improves wavelength-level optical-layer O&M capabilities and provides services along the lifecycle of WDM networks, simplifying the network O&M and saving the operating expense (OPEX).
System Composition
The OD system requires the interoperation between the hardware and software. The hardware monitors and reports optical-layer performance in real time, performs corresponding adjustments, and is uniformly scheduled by the software. The software provides user-friendly GUIs, supports network-wide configuration, provides visualized reports, and achieves centralized control and uniform scheduling.
Hardware
The hardware required by the OD system includes the following boards installed on the NE:Optical amplifier (OA) boards, spectrum analysis boards: They are used to obtain optical-layer performance data, monitor all optical signals in a centralized way without interrupting services, and report the monitored optical-layer performance data to the OD system.
Electrical variable optical attenuators (EVOAs) and gain-adjustableOA boards: They are used to adjust optical signal performance parameters.
Optical Supervisory Channel (OSC) boards: They are used for inter-site communication.
Software
The OD system is integrated in the U2000. Users can deliver network-wide performance monitoring configuration commands using the U2000. After obtaining the optical-layer performance data reported by each NE, the OD system analyzes the performance data and graphically displays the analysis result. Based on the configuration policy, the OD system instructs the EVOAs and OA boards to perform adjustments and optimize optical-layer performance.
The following figure shows the interoperation between the hardware and software of the OD system:
Figure 3 Interoperation between the hardware and software of the OD system
That’s all folks, hope you found my post useful, and don’t forget to comment if you have further concerns or remarks.
Thank you very much!
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