Introduction to Network Simulations

It is always interesting to learn the networking concepts by practicing. Especially, to explore and research advanced networking technologies (Internet, wireless ad-hoc, high efficiency Wi-Fi, and cellular (4G and beyond 4G)), it is a necessity to implement and evaluate your ideas. However, setting up these networking testbeds and doing your experiments involves many challenges in terms of lab space availability, cost of equipment, and complex configurations. 

I am also one of the networking technologies researchers, and faculty, I would like to share with you how I handled these issues. 

When I started my PhD, I would like to pursue my research interest in realizing Software Defined LTE networks. I had read a number of research papers and articles to understand the concepts. When I started my research it was quite a new topic, hence I did not find any suitable platform for carrying out my research activities. Initially, I was confused how to set up my testbed, finding suitable networking equipment, configurations, and lab space. I thought it may not be possible for me. 

Then, I met my guide Prof. Bheemarjuna Reddy Tamma for his help. He introduced me to a network simulator-3 (ns-3) for realizing my research dreams and answering many research queries. Ns-3 is a discrete event simulator. Using ns-3 we can write our simulation programs using C++ and use the following features. 

•  NS-3 offers a wide range of modules for exploring Internet, Routing, CSMA, P2P, Wireless Ad-hoc, Wi-Fi (802.11a/b/g/n/ac/ax) and LTE technologies. Very soon 5G supporting modules will also be included. 
• NS-3 offers various supporting modules to set up Ethernet/Wi-Fi/LTE equipment using node containers and communication channels, placement models, building models, mobility models, loss models, antenna, and a variety of network applications to set up your test scenarios in a realistic manner.
• NS-3 offers interesting features to implement and evaluate your simulations set up in a systematic approach using the flow monitor module. It helps you evaluate your network performance in terms of throughput, delay, packet loss, etc.
• NS-3 logging and packet capturing: For instance you can view and inspect which network layers messages are exchanged between two network applications.
• NS-3 also supports gdb (debugger) to handle any runtime errors, exceptions, and abrupt events.
• NS-3 attributes and tracing features will allow you to learn any complex protocols (Wi-Fi or LTE or Internet) implementation easily.
• NS-3 supporting module code is open to developers for making any extensions or changes.
• NS-3 also supports excellent simulation visualization features using NetAnimator for visualizing NS-3 node placement and mobility details, a variety of network messages exchanges, routing Tables, counters, statistics etc.

For more details please click the link: https://www.nsnam.org/

During my PhD, using ns-3 I explored Ethernet technologies, Wi-Fi, and LTE technologies.  For instance, I have explored LTE and Wi-Fi technologies using ns-3 to implement novel mobility, load balancing, interference handling, energy savings, and frame aggregation algorithms. Ns-3 has given me a lot of confidence to carry out my research activities and get success in the field of networking technologies. I am also successful in publishing my research articles with high quality publishers such as IEEE, Elsevier, and Springer. I am continuing to use ns-3 to carry out most of my research and teaching activities. 

Ns-3 is widely used by a variety of research communities to implement their ideas, evaluate and realize their research dreams. For instance, you can find a large number of good publications in the following link:

https://scholar.google.com/scholar?hl=en&as_sdt=0%2C5&q=ns-3&btnG=

Although ns-3 offering very good documentation and examples, still many beginners and users are facing difficulties and spending a lot of time in terms of doing the following:

• Quick installation guides for using all ns-3 features
• Systematic way of setting up a variety topologies (Ethernet, Wi-Fi, LTE)
• Identifying suitable performance metrics for evaluating test scenarios and projecting results
• Handling errors, abrupt events, and exceptions
• Extending existing modules and making any changes
• Quickly mapping technology knowledge to simulation environment
• Quickly finding and understanding essential technology concepts (such as 802.11n/ac, Wi-Fi 6, and LTE) to start advanced networking simulations
• Doing capacity planning and site survey activities for various networking environments
• Performing research activities