• Bandwidth variation through MCS configuration
Bandwidth variation through MCS configuration

Open NetSim, Select Examples ->Satellite Communication -> Bandwidth variation through MCS configuration then click on the tile in the middle panel to load the example as shown in below Figure.

Figure4-1

The following network diagram illustrates, what the NetSim UI displays when you open the example configuration file as shown below Figure.

Figure4-2

Settings done in example config file:

  1. Set the following property as shown in below given table:

    Satellite Properties -> Interface (Satellite) -> Physical Layer-> Forward
    BER_Model Fixed
    BER 0.00000001

  2. Set the following property as shown in below given table:

    UT_Router Properties -> Interface (Satellite) -> DataLink Layer
    Gateway Sat_Gateway_3

  3. Go to Router_4 properties -> Network_Layer ->Enable - Static IP Route ->Configure Static Route IP
    Figure4-3

  4. Set the properties in Static Route IP window as per the screenshot below and click on Add. Click on OK.
    Figure4-4
  5. Go to Sat_Gateway_3 properties -> Network_Layer ->Enable - Static IP Route ->Configure Static Route IP Set the properties in Static Route IP window as per the screenshot below and click on Add. Click on OK.
    Figure4-5
  6. Go to UT_Router_2 properties -> Network_Layer -> Enable - Static IP Route -> Configure Static Route IP Set the properties in Static Route IP window as per the screenshot below and click on Add. Click on OK. Figure4-6
  7. CBR application source id as 6 and destination id as 5 with packet size as 1460Bytes and Inter_Arrival_time as 467μs (Generation Rate=25Mbps. Transport Protocol is set to UDP.
  8. Change the Satellite Properties → Interface (Satellite) → Physical_Layer → Forward → Modulation and respective coding rates as sshown in below Table 4-3 but for return link is fixed Modulation-> 32APSK and Coding Rate ->3/4.
  9. In NetSim GUI Plots are Enabled. Run simulation for 10 seconds and observe the result.

Note: Satellite properties in the physical layer changes done only for the forward and Return layer properties.

Result: Observe the application throughput as we change the modulation scheme (Satellite Properties → Interface (Satellite) → Physical_Layer → Forward → Modulation) and respective coding rates (Satellite Properties → Interface (Satellite) → Physical_Layer → Forward → Coding_Rate).

Modulation Coding_Rate Throughput (Mbps)
QPSK 1/3 0.084
9/10 0.336
8PSK 3/5 0.380
9/10 0.507
16APSK 2/3 0.507
9/10 0.677
16QAM 3/4 0.676
5/6 0.675
32APSK 3/4 0.846
8/9 0.843