Simulation of IoT based systems in Software Thank you for reading this. 

Generally there are libraries for GSM and Ultrasound sensors for the software called Proteus and you can simulate them along with you MCU and the interfacing peripherals and simulate . 

I have big problem at my hand , I want to simulate ESP8266 or any other relevant wifi module with my Arduino (Simulation Libraries for Arduino are available ) and get the data from sensor , all in software . Then , I want the wifi device (in software ) to show an ip address , so that I can log the data to an online cloud .  

The software and module does not have to be specific , I want to know , If there are any professional software that let you simulate IoT based systems.

I'am new to IoT designing and I'am always comfortable with simulating everything. 

If you have any other similar guide on how to design and simulate IoT systems , Let me know . 

Have a great day
There are tools to simulate Arduino, but it's not meant for anything beyond basic (i.e. simple circuit). Support is limited, you can't just simulate any and every sensor and shields (e.g. LAN, Wireless). Furthermore, ESP8266 is so cheap that hardly anybody has actual use-case to simulate them. I suggest you work on a real device =)

If you need to simulate data stream into your cloud or IoT platform, I suggest you just spin up a machine and run some code to generate data.