This section describes how to add data to upstream or downstream of design. To view the existing design, click on View button to view a particular network design. If user selects test network from the list of available link engineering design, it redirects to new page which has both upstream and downstream design.
Available sections
Between any two nodes, there are two paths for traffic. One path is labeled as downstream and another as upstream. Following are the two available sections which discusses about downstream and upstream traffics respectively:
Downstream: Source and destination node provided by the user in the form are as associated, as a convention, with the downstream traffic.
Upstream: Upstream traffic by convention will have source node and destination node exchanged to what is provided by the user, meaning the source node of the downstream traffic will become destination node for the upstream traffic and the destination node of the downstream traffic will become source Node for the same upstream traffic.
Available buttons
Following are the available buttons:
Replicate to Downstream: To replicate upstream components to DownStream click on Replicate to Downstream which is available at the top-right corner.
Update: To update and to run simulation click on Update button which is available at the top-right corner. Click on Update button to add or modify Upstream or Downstream components with in the upstream or downstream page.
NOTE: Replication function cannot perform complete replication of all components with parameters, please check before running simulation for downstream.
User cannot change the channel number after creating the design.
Steps to add or modify any design
This section describes steps to modify or update any design. Click on Update button which is available at the top-right corner. Following table is displayed as shown in figure.
Following are the nine columns:
Node Name: Add node name properly to distinct components of different nodes and click on node name by clicking left mouse button in the displayed list to modify the node name.
Component Type: Currently the following components are supported:
Line card: It is an electrical device from which data traffic originates through lasers.
MDU: With this device with this device we can either multiplex the optical signal or demultiplex based on source and destination.
ROADM: It is an optical device and stands for Reconfigurable Optical Add and Drop Module.
Fiber: This is the medium through which the optical signal travels from source to destination.
Attenuator: This device is used for attenuating the signal power.
OFA: EDFA Amplier used for amplifying the signal strength.
ORA: RAMAN Amplier used in special cases or when there high link loss.
DCM/DCU: It is and optical device and stands for Dispersion Compensation Module/Unit.
PSCM: It is an optical device and stands for Power Splitter and Combiner Module. Splitter splits the power into multiple parts depending the device type. Combiner combines multiple powers into one.
OSC: Optical supervisory channel
Component Name: After selecting the Component Type, application will show the available components based on configuration like number of lambda per fiber.
NOTE: For 80 channels design, ILU will not be shown as independent component but will show along with MDU as MDU40E-MDU40O-ILU component (if there are 40 even channels MDU and 40 odd channels MDU, then ILU is used to combine channels)
Direction Each component type takes different directions as mentioned below:
Line Card add and drop direction
MDU add and drop direction
ROADM add and drop direction
Fiber Only add direction
Attenuator only add direction
OFA Only add direction
ORA Only add direction
DCM Only add direction
DCU Only add direction
OSC Only add direction
Device Loss: As soon as we click on Device Loss, tool takes default loss value of mentioned device, otherwise enter the device loss accordingly.
Parameter 1: Click on Parameter1 with left mouse button with respect for each component type. Each component type takes different parameters:
Line Card: For add direction select the data rate, channel , enable FEC and enter valid Channel power.
MDU: For add direction select the channel.
MDU: For drop direction select the channel.
ROADM: For add direction select the channel and provide channel power. Balanced power and attenuation will be taken care by the APT application. If power equalization required, then select Auto Power Equalization as shown in figure. If a lambda is checked in the drop ROADM, it is dropped at the card itself. Adding a lambda can be done in the add ROADM by enabling the checkbox and specifying power( if any value other than default value is used). Passthrough lambdas should be enabled in the add ROADM. For passthrough lambdas, attenuation can be specified.
For drop direction select the channel as shown in figure.
Fiber: Provide distance value (km).
Attenuator: Provide the loss value (dB).
OFA: Provide gain value (dB).
ORA: Provide gain value (dB).
Parameter 2: Only applicable for Fiber and VG-MSA amplifier types.
NOTE: Component Parameter 2 for Fiber takes only measured loss. Measured loss considered only when it is greater than (distance x attenuation).
Application finds the wrong configuration and warns the user. All the configurations checks are not verified by the application. If some configuration is not allowed, please consider it as limitation. Fiber G.652 is considered and dispersion 17 ps/nm-km. It can be changed in the design parameters.
Enable: Enable or Disable the component from the design simulation by clicking on it.
Once all the components are added, click on Save which is available at the top-right corner.
Click on Validate to validate the design which is available at the top-right corner and application will return the design results.
NOTE: All the component simulations are verified against practical component performance
After validating the design, application will give the OSNR report as shown in below figure. The figure explains that when services flow through a link, they pass through multiple devices and certain loss occurs because of which OSNR degrades.
If user want to download the complete simulation results in excel file, then click on Download Result button available at the center of the screen to download the file. File has each component optical parameters like Input Power, Output Power, Input OSNR, Output OSNR, Input Dispersion and Output Dispersion for each lambda.
User must run simulation for upstream and downstream separately.
NOTE: Manual Link Design is independent of network system design. Networks which are designed by APT cannot be modified.
User can also download each optical parameter separately in pdf, png, jpg and SVG image format by clicking on chart context menu available the right corner of the screen as shown in figure.
