Please refer the following attachment.

Thank you Mr. Prakasam

using TinyOs is better for WSN since:

- it is based on two observation regarding sensor network application: : they are event driven and support multiple streams of data.

- TinyOS programs are driven by a event/command interface, supporting fast event executing.

-  it provides parallelism by cooperative scheduling. The simple nature of TinyOS makes it very light and independent of hardware features of a particular platform.

Nowadays try Iris Motes - you can use Contiki, TinyOS and Moterunner on them

There are also: http://www.libelium.com/products/waspmote/ - quite good too.

https://www.tyndall.ie/content/wireless-sensor-network-prototyping-platforms - Running tinyos and contiki

and shimmer: http://www.shimmersensing.com/support/wireless-sensor-networks-documentation/

I hope my answer helps, but a I think it depends on the amount of processing you want for each node to do. I think an arduino won't be enough if you want heavy processing. An OS can help in that way, using heavy processing.

Thank you all for your detailed and thorough answers.

I think TinyOS is the right choice if you want to work with sensors.The advantage is a large number of external protocols already implemented. 

also contiki is suitable for IoT. 

I have found the Intel Edison quite interesting, it is easy to program and include a linux version (poky).

You can also think about Waspmote. You can easily interface so many sensors.

Thanks Mr. Dr. me Strange