Question!

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Jul 27, 2013 14:47
I encountered the following sentence :

French biologist, biochemist, and inventor Pierre Calleia has designed an algae-powered streetlight that could solve the world's carbon dioxide problem, while providing clean urban lighting.

I know the sentence: While (I was) reading, I felt asleep.
So, I wonder that "it is" is omitted before "providing."

I will be grateful for any help you can provide.