|Applicable Versions||NetSim Standard||NetSim Pro|
Use Case: Impact of distance on the throughput of a 5G scenario where the UE continuously moves away from the gNB .
Network Scenario: To model a 5G- NR scenario, we base our simulation on the setup shown in Figure 1. The link between the gNB and the EPC that represents the Core Network (CN) is made with a point-to-point 100 Mb/s link, without propagation delay. The Radio Area Network (RAN), has 1 gNB, which serves a single UE.
The gNB is operating in the 3.5 GHz (C band / n78 band) whose bandwidth is 10MHz. The environment is an urban scenario with LOS conditions. The position of the devices are depicted in Figure 1.
Figure 1: Network scenario with a UE communicating with the server
The application data traffic is a 10 Mbps DL UDP flow from a server to the UE.
The numerology µ takes a value of 0 and specifies an SCS of 15 x 2^µ KHz and a slot length of 1/ (2^µ) ms. The FR1 3.5 GHz c-band (n78 band) has been considered.
The movement of the UE from an initial distance of 1m from the gNB to a distance of 2.5 Km from the gNB, is modeled via a mobility file
File-Based Input can be provided for modeling user-defined mobility for mobile devices in NetSim. UE > Right-Click Properties
Figure 2: Setting File-Based mobility in UE properties
Input can be provided for one or more devices based on the number of nodes in which the file-based mobility option is configured.
Mobility input can be provided in the mobility.txt file which gets opened when clicking on the Open Mobility File Option (UE > Right-Click Properties) as shown below:
Figure 3: Accessing mobility.txt file
Figure 4: Mobility file format
Mobility input is provided in such a way that it moves 100 meters every 4 seconds.
Results and analysis
Figure 5: Application Throughput (Mbps) vs Time (sec) Plot
As the UE moves away from the gNB, the Application throughput starts reducing. The maximum throughput of 10 Mbps is obtained until 48 seconds. At this time UE is 1200m away from the gNB. Then the throughput drops to 9.5 Mbps at 48 seconds and at time 56 seconds (when UE is 1400m away from gNB), the throughput drops to 6.5 Mbps and subsequently keeps dropping as till the end of the simulation as the UE continues to move further away from the gNB.
Appendix 1: Settings done in NetSim for modeling this network
Grid Environment Settings
|Grid Length||5100 m * 5100 m|
Device Co-ordinates/ positions
gNB Properties -> Interface (LTE_NR)
|gNB Height||10 m|
|Uplink MIMO Layer Count||1|
|Downlink MIMO Layer Count||2|
|DL- UL Ratio||4:1|
|Channel Bandwidth||10 MHz|
|Propagation Model||Urban Macro|
|Channel Characteristics||Pathloss Only|
|LOS Mode||T38_901 STANDARD|
Network Traffic settings
|Start Time||1 s|
|Packet Size||1460 Bytes|
|Inter Arrival Time||1168 µs|
Useful reference: How do I control the rate of traffic being generated in NetSim?
|Link Properties (All Wired Links)|
|Uplink/ Downlink Speed (Mbps)||100|
|Uplink/ Downlink BER||0|
|Uplink/ Downlink Propagation Delay (µs)||0|
UE -> General Properties
|Mobility Model||File-Based Mobility|
|NOTE: File-Based mobility input is part of the "mobility.txt" file|
|Simulation Time||100 s|
The network configuration files associated with the article for obtaining the results mentioned above are attached to this article. The *.netsim_exp file associated with NetSim Pro version and NetSim Standard version is attached separately.
Interested users can run this use case by importing the attached file into NetSim using the Import Experiment option in the Open Simulation menu of NetSim Home Screen