Effect of UE distance on throughput in FR1 and FR2

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

Graphical user interface Description automatically generated

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

  1. Set grid length as 2500m from Environment setting.

  2. Set distance between gNB_7 and UE_8 as 100m.

  3. 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

  1. 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

  1. Set Tx_Antenna_Count and Rx_Antenna Count in gNB as 2 and 2.

  2. Set Tx_Antenna_Count and Rx_Antenna_Count in UE as 2 and 2.

  3. 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

  1. The log file can enable per the information provided in Section 3.18.

  2. Plots are enabled in NetSim GUI.

  3. 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

  1. Set grid length as 2500m from Environment setting.

  2. Set distance between gNB_7 and UE_8 as 50m.

  3. 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

  1. 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

  1. Set Tx_Antenna_Count and Rx_Antenna Count in gNB as 2 and 2.

  2. Set Tx_Antenna_Count and Rx_Antenna_Count in UE as 2 and 2.

  3. 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

  1. The log file can enable per the information provided in Section 3.18.

  2. Plots are enabled in NetSim GUI.

  3. 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 LTE 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.