| Applicable Versions | NetSim Standard | NetSim Pro | NetSim Academic |
| Applicable Releases | v12.2 |
NetSim allows users to input a propagation file via GUI. This option is available for wireless links in networks such as MANETs, Internetworks, etc.
Open a Wi-fi example or create a scenario in Inter-networks with a Wifi Acess Point and wireless nodes. In the wireless link connecting them the Path loss Model needs to be set as PATHLOSS_MATRIX_FILE, as shown below:
Clicking on the Configure_Pathloss_matrix link next to the pathloss_Matrix_File option will open a text file with a few comments as shown below:
The name of the trace file generated will be PathlossMatrix<Wireless Link Id>.txt and the entries added to it should be in the NetSim Pathloss Matrix File format.
The propagation loss is fixed for each pair of nodes and does not depend on their actual positions in the UI. Note that by default the propagation loss is assumed to be symmetric. The value of pathloss for each pair of nodes is read from a file.
The name of the trace file generated should be kept as PathlossMetrics<Wireless Link Id>.txt and it should be in the NetSim Pathloss Metrics File format. The NetSim Pathloss Matrix File format is as follows
Step 1: Open node (Wireless_Link) properties -> select pathloss model as PATHLOSS_MATRIX_FILE and click on Configure Pathloss metrics.
Step 2: Inside the text file and write the code in format shown below
# Commented lines
# Empty lines will be ignored
# Format for writing this file is
# SNR value must be in increasing order
# time(sec),tx,rx,loss(dB)
time <Time_in_Secs>, <Tx_Node_ID>, <Rx_Node_ID, <Pathloss(dB)>
For Example, the file input could be:
# Commented lines
# Empty lines will be ignored
# Format for writing this file is
# SNR value must be in increasing order
# time(sec),tx,rx,loss(dB)
0,1,2,0
0,2,1,0
# Empty lines will be ignored
# Format for writing this file is
# SNR value must be in increasing order
# time(sec),tx,rx,loss(dB)
0,1,2,0
0,2,1,0
This means that at time 0 (microseconds) the path loss between transmitter 1 and receiver 2 as well is transmitter 2 and receiver 1 is 0 dB.
In the following case the path loss is 90 dB
# Commented lines
# Empty lines will be ignored
# Format for writing this file is
# SNR value must be in increasing order
# time(sec),tx,rx,loss(dB)
0,1,2,90
0,2,1,90
# Empty lines will be ignored
# Format for writing this file is
# SNR value must be in increasing order
# time(sec),tx,rx,loss(dB)
0,1,2,90
0,2,1,90
The wave propagation loss text file that you have obtained from the external program needs to be converted into entries as per NetSim Pathloss Matrix File format and then pasted in the auto-generated file that is specific to each link.