In this example we understand how the downlink UDP throughput of a UE varies as its distance from a gNB is increased. Rebuild the code to enable logs per Section 3.18 in this manual. Open NetSim, Select Examples ->5G NR ->Distance vs Throughput then click on the tile in the middle panel to load the example as shown in below screenshot
Figure 4‑29: List of scenarios for the example of Distance vs Throughput
The following network diagram illustrates, what the NetSim UI displays when you open the example configuration file.
Figure 4‑30: Network set up for studying the Distance vs Throughput
Frequency Range - FR1#
Settings done in example config file
-
Set grid length as 2500m from Environment setting.
-
Set distance between gNB_7 and UE_8 as 100m.
-
Go to Wired link properties and set the following properties as shown below.
| Wired Link Properties | |
|---|---|
| Uplink_Speed | 1000Mbps |
| Downlink_Speed | 1000Mbps |
| Uplink and downlink BER | 0.0000001 |
Table 4‑13: Wired Link Properties
- Go to gNB properties à Interface (5G_RAN) à PHYSICAL_LAYER, set the following properties as shown below Table 4‑14.
| Properties | |
|---|---|
| CA_Type | INTER_BAND_CA |
| CA_Configuration | CA_2DL_1UL_n39_n41 |
| CA1 | |
| Numerology | 2 |
| Channel Bandwidth | 40 MHz |
| CA2 | |
| Numerology | 2 |
| Channel Bandwidth | 100 MHz |
| Pathloss Model | 3GPPTR38.901-7.4.1 |
| Shadow Fading Model | None |
| Fading _and_Beamforming | NO_FADING_MIMO_UNIT_GAIN |
| O2I Building Penetration Model | Low Loss Model |
| Outdoor_Scenario | URBAN_MACRO |
| LOS_NLOS_Selection | USER_DEFINED |
| LOS_Probabillity | 0 |
Table 4‑14: gNB >Interface (5G_RAN) >Physical layer properties
-
Set Tx_Antenna_Count and Rx_Antenna Count in gNB as 2 and 2.
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Set Tx_Antenna_Count and Rx_Antenna_Count in UE as 2 and 2.
-
Go to Application properties and set the following properties as shown below Table 4‑15.
| Application Properties | |
|---|---|
| Source_Id | 10 |
| Destination_Id | 8 |
| QoS | UGS |
| Transport Protocol | UDP |
| Packet_Size | 1460Bytes |
| Inter_Arrival_time | 23μs |
| Start_Time | 1s |
Table 4‑15: Application properties
-
The LTENR Radio measurement log file can be enabled as per information provided in the Section 3.19.
-
Plots are enabled in NetSim GUI.
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Run Simulation for 2s, after simulation completes go to metrics window and note down throughput value from application metrics.
Go back to the scenario and change the distance between gNB and UE as 200, 300, 400, 500, 600, 700, 800, 900, and 1000m and note down throughput from the results window. The other parameters in table shown below can be noted down from the LTE NR log file.
Frequency Range - FR2#
Settings done in example config file
-
Set grid length as 2500m from Environment setting.
-
Set distance between gNB_7 and UE_8 as 50m.
-
Go to Wired link properties and set the following properties as shown below Table 4‑16.
| Wired Link Properties | |
|---|---|
| Uplink Speed | 10000Mbps |
| Downlink Speed | 10000Mbps |
| Uplink and downlink BER | 0.0000001 |
Table 4‑16: Wired Link Properties
- Go to gNB properties à Interface (5G_RAN) à PHYSICAL_LAYER, set the following properties as shown below Table 4‑17.
| Properties | ||
|---|---|---|
| Physical Layer Properties | ||
| Frequency Range | FR2 | |
| CA Type | INTRA_BAND_NONCONTIGUOUS_CA | |
| CA Configuration | CA_n261(7O) _n261A | |
| Numerology | Channel Bandwidth (MHz) per carrier | |
| CA1, CA2, CA3, CA4, CA5, CA6, CA7, CA8, CA9, CA10, CA11, CA12, CA13, CA14 | 3 | 100 |
| Pathloss Model | 3GPPTR38.901-7.4.1 | |
| Shadow Fading Model | None | |
| Fading and Beamforming | NO_FADING_MIMO_UNIT_GAIN | |
| O2I Building Penetration Model | Low Loss Model | |
| Outdoor Scenario | URBAN_MACRO | |
| LOS NLOS Selection | USER_DEFINED | |
| LOS Probability | 0 |
Table 4‑17: gNB >Interface (5G_RAN) >Physical layer properties
-
Set Tx_Antenna_Count and Rx_Antenna Count in gNB as 2 and 2.
-
Set Tx_Antenna_Count and Rx_Antenna_Count in UE as 2 and 2.
-
Go to Application properties and set the following properties as shown below Table 4‑18.
| Application Properties | |
|---|---|
| Source_Id | 10 |
| Destination_Id | 8 |
| QoS | UGS |
| Transport Protocol | UDP |
| Packet_Size | 1460Bytes |
| Inter_Arrival_time | 2μs |
| Start_Time | 1s |
Table 4‑18: Application properties
-
The LTENR Radio measurement log file can be enabled as per the information provided in Section 3.19.
-
Plots are enabled in NetSim GUI.
-
Run Simulation for 1.05s, after simulation completes go to metrics window and note down throughput value from application metrics.
Go back to the scenario and change the distance between gNB and UE as 50, 100, 150, and 200 and note down throughput from the results window. The other parameters in the table shown below can be noted down from the LTENR Radio Measurement log.csv
Results
Note: Filter the CA_ID to 1 in the LTENR Radio measurement log file and same values have been considered in the tables given below. (SNR and CQI are shown for downlink Layer1).
| Distance(m) | Pathloss (dB) | SNR (dB) | CQI Index | Modulation | Code Rate R*[1024] (CQI) | Code Rate R*[1024] (MCS) |
Throughput (Mbps) |
|---|---|---|---|---|---|---|---|
| 100 | 97.34 | 37.46 | 15 | 64QAM | 948 | 772 | 505.10 |
| 200 | 109.05 | 25.74 | 15 | 64QAM | 948 | 772 | 505.10 |
| 300 | 115.93 | 18.86 | 15 | 64QAM | 948 | 772 | 505.10 |
| 400 | 120.80 | 13.98 | 13 | 64QAM | 772 | 772 | 448.09 |
| 500 | 124.59 | 10.20 | 11 | 64QAM | 567 | 567 | 289.32 |
| 600 | 127.68 | 7.11 | 9 | 16QAM | 616 | 616 | 183.52 |
| 700 | 130.30 | 4.49 | 8 | 16QAM | 490 | 490 | 129.69 |
| 800 | 132.56 | 2.22 | 6 | QPSK | 602 | 602 | 79.58 |
| 900 | 134.6 | 0.22 | 5 | QPSK | 449 | 449 | 51.35 |
| 1000 | 136.35 | -1.55 | 4 | QPSK | 308 | 308 | 36.19 |
Table 4‑19: FR1 - Variation of pathloss, SNR, CQI, Modulation, code rates and throughput as the distance of the UE from the gNB is increased.
| Distance(m) | Pathloss (dB) | SNR (dB) | CQI Index | Modulation | Code Rate R*[1024] (CQI) |
Code Rate R*[1024] (MCS) |
Throughput (Mbps) |
|---|---|---|---|---|---|---|---|
| 50 | 109.10 | 21.72 | 15 | 64QAM | 948 | 772 | 4095.9 |
| 100 | 120.68 | 10.13 | 11 | 64QAM | 567 | 567 | 3074.4 |
| 150 | 127.53 | 3.28 | 7 | 16QAM | 378 | 378 | 1305.8 |
| 200 | 132.40 | -1.58 | 4 | QPSK | 308 | 308 | 512.5 |
Table 4‑20: FR 2 - Variation of pathloss, SNR, CQI, Modulation, code rates and throughput as the distance of the UE from the gNB is increased.
Increase in distance leads to an increase in pathloss, which in turn hence leads to lower received power (and lower SNR). The lower SNR leads to a lower MCS, in turn a lower CQI and thereby results in lower throughputs. The drop for FR2 happens at a much faster rate in comparison to FR1. Note that the number of information bits is got from then Transport Block Size Determination calculations given in Transport block size (TBS) determination. The throughput would depend on the TBS.