Applicable VersionsNetSim StandardNetSim Pro


Applicable Releasesv12



Use Case: Impact of numerology on throughput and latency of a 5G NR scenario having 1 gNB connected to 25 phones, 6 sensors, and 3 cameras, with multiple TCP and UDP flows

 

Network Scenario: To model a real-world scenario, we base our simulation on the setup shown in Figure 1. At a high level, the link between the gNB and the EPC that represents the Core Network (CN) is made with a point-to-point 10 Gb/s link, without propagation delay. The Radio Area Network (RAN), is served by 1 gNB, in which different UEs share the connectivity. We have 25 smartphones, 6 sensors, 3 IP cameras. The bandwidth 100MHz, with LOS conditions and Round Robin MAC Scheduler. The position of the devices in the reference scenario depicted in Figure 1 is quasi-random. 

 

 

Fig 1: Network scenario with 25 smartphones, 6 sensors, and 3 cameras communicating with respective cloud servers

In terms of application data traffic, the camera (video) and sensor nodes have one UDP flow each, that goes in the UL towards a remote node on the Internet. These flows are fixed-rate flows: we have a continuous transmission of 5 Mb/s for the video nodes, to simulate a 720p24 HD video, and the sensors transmit a payload of 500 bytes each 2.5 ms, that gives a rate of 1.6 Mb/s. For smartphones, we use TCP as the transmission protocol. These connect to database servers. Each phone has to download a 25 MB file and to upload one file of 1.5 MB. These flows start at different times: the upload starts at a random time between the 25th and the 75th simulation seconds, while each download starts at a random time between the 1.5th and the 95th simulation seconds.

 

 

Flows

(No of devices)

Traffic Rate (Mbps)

Segment / File Size (B)

RAN Dir.

TCP ACK Dir.

Camera (UDP)

3

5

500

UL

-

Sensor (UDP)

6

1.6

500

UL

-

Smartphone Upload (TCP)

25

-

1,500,000

UL

DL

Smartphone Download (TCP)

25

-

25,000,000

DL

UL

Table 1: Various parameters of the Traffic flow models for all the devices

 

The numerology μ can take values from 0 to 3 and specifies an SCS of 15 x 2^μ kHz and a slot length of 1/(2^μ) ms. FR1 supports μ = 0, 1, and 2, while FR2 supports μ = 2 and 3.   We study the impact of different numerologies, and how they affect the end-to-end performance. The metrics measured and analyzed are a) Throughput of TCP uploads & downloads, and b) Latency of the UDP uploads

 

Results and analysis

  

Fig 2 Camera Uplink, and Sensor Uplink average throughput vs. Numerology (µ)

 

Fig 3 Smartphone Uplink, and Smartphone Downlink average throughput vs. Numerology (µ)

 

 

 Fig 4 Camera Uplink, and Sensor Uplink Latency vs. Numerology

 

For UDP applications the μ does not impact the throughput. However, higher μ leads to an obviously lower delay. The variation of delay vs. μ  is as follows:


 

Avg Delay 

(Camera)

Avg Delay

(Sensor)

 μ=0

1.809 ms

2.254 ms

 μ=1

0.903 ms

1.504 ms

 μ=2

0.452 ms

0.754 ms

 

The TCP throughput is inversely proportional to round trip time. Therefore, for applications running over TCP the throughput increases with higher numerology. This is because higher μ leads to reduced round-trip (end-to-end) times. 

 

References

  1. Natale Patriciello, Sandra Lagen, Lorenza Giupponi, Biljana Bojovic.”5G New Radio Numerologies and their Impact on the End-To-End Latency” in 2018 IEEE 23rd International Workshop on Computer Aided Modeling and Design of Communication Links and Networks (CAMAD)

 

Appendix 1: Settings done in NetSim for modeling this network

gNB Properties -> Interface (LTE_NR) 

Outdoor scenario

URBAN_MACRO

Channel Characteristics

NO_PATHLOSS

LOS Mode

USER_DEFINED

LOS Probability

1

Frequency Range  

FR1

CA Type

INTRA_BAND_CA 

CA_Configuration

CA_2DL_2UL_n40_n41

CA1

MU

0, 1, and 2

Channel Bandwidth

50 MHz

CA2

MU

0, 1, and 2

Channel Bandwidth

50 MHz

DL:UL

1:4

MCS Table

QAM64

CQI Table

TABLE1

 

Link Properties (All wired links)

Uplink/ Downlink Speed (Mbps)

10000

Uplink/ Downlink BER

0

Uplink/ Downlink Propagation Delay (μs)

0

 

Application Properties set in NetSim (Based on Table 1)

Sensor UL UDP

Generation Rate (Mbps)

1.6

Transport Protocol

UDP

Application Type

Custom

Packet Size (Bytes)

500

Inter Arrival Time (μs)

2500

 

Camera UL UDP

Generation Rate (Mbps)

5

Transport Protocol

UDP

Application Type

Custom

Packet Size (Bytes)

500

Inter Arrival Time (μs)

800

 

Phone DL TCP

Transport Protocol

TCP

Start Time (s)

1.5+4(t), Where, i=0,1,2,... ...,48 

Stop Time (s)

95 

File Size (Bytes)

25,000,000

Inter Arrival Time (s)

200 (Simulation ends at 100s and hence only one file is sent)

Application Type

FTP

 

Phone UL TCP

Application Type

FTP

Transport Protocol

TCP

Start Time (s)

 25+2(i-1)

Where, i=1,2,... ...,25 

Stop Time (s)

95

File Size (Bytes)

1,500,000

Inter Arrival Time (s)

200 (Simulation ends at 100s and hence only one file is sent)

 

Appendix 2: Detailed Results

μ=0

Camera

Uplink

Sensor

Uplink

Smartphone

Uplink

Downlink

Throughput (Mbps)

Delay (μs)

Throughput (Mbps)

Delay (μs)

Throughput (Mbps)

Throughput (Mbps)

4.99

1808.61

1.6

2257.04

86.93

101.67

4.99

1805.97

1.6

2258.44

86.93

101.67

4.99

1803.33

1.6

2251.42

86.93

101.67

 

 

1.6

2252.83

86.93

101.67

 

 

1.6

2254.23

86.93

101.67



1.6

2255.63

86.93

101.67



 

 

86.93

101.67





86.93

101.67





86.93

101.67





86.93

101.67





86.93

101.67





86.93

101.67





86.93

101.67





86.93

101.67





86.93

101.67





86.93

101.67





86.93

101.67





86.93

101.67





86.93

101.67





86.93

101.67





86.93

101.67





86.93

101.67





86.93

101.67





86.93

101.67





86.93

101.67

 

μ=1

Camera

Uplink

Sensor

Uplink

Smartphone

Uplink

Downlink

Throughput (Mbps)

Delay (μs)

Throughput (Mbps)

Delay (μs)

Throughput (Mbps)

Throughput (Mbps)

4.99

905.11

1.60

1506.98

173.83

153.13

4.99

903.48

1.60

1508.39

173.83

153.13

4.99

901.85

1.60

1501.37

173.83

153.13

 

 

1.60

1502.77

173.83

153.13

 

 

1.60

1504.18

173.8

153.13



1.60

1505.58

173.83

153.13



 

 

173.83

153.13





173.83

153.13





173.83

153.13





173.83

153.13





173.83

153.13





173.83

153.13





173.83

153.13





173.83

153.13





173.83

153.13





173.83

153.13





173.83

153.13





173.83

153.13





173.83

153.13





173.83

153.13





173.83

153.13





173.83

153.13





173.83

153.13





173.83

153.13





173.83

153.13

 

μ=2

Camera

Uplink

Sensor

Uplink

Smartphone

Uplink

Downlink

Throughput (Mbps)

Delay (μs)

Throughput (Mbps)

Delay (μs)

Throughput (Mbps)

Throughput (Mbps)

5.00

453.90

1.60

756.54

347.49

148.36

5.00

452.50

1.60

757.94

347.49

148.36

5.00

451.09

1.60

750.93

347.49

148.36

 

 

1.60

752.33

347.49

148.36

 

 

1.60

753.73

347.49

148.36



1.60

755.14

347.49

148.36



 

 

347.49

148.36





347.49

148.36





347.49

148.36





347.49

148.36





347.49

148.36





347.49

148.36





347.49

148.36





347.49

148.36





347.49

148.36





347.49

148.36





347.49

148.36





347.49

148.36





347.49

148.36





347.49

148.36





347.49

148.36





347.49

148.36





347.49

148.36





347.49

148.36





347.49

148.36

 

 The network Configuration files associated with all the three cases considered for obtaining the results mentioned above are attached to this article. The Configuration.netsim file associated with each case can be imported into NetSim using the Import Experiment Option in the Open Simulation menu of NetSim Home Screen.