Gagan,

This would entirely depend upon the operational environment. Do you want your node to be operational for a day (which is very unlikely) or for months? With limitations in battery technology, I don't think you can set "infinite" energy to a device. A rather interesting question would be how much performance you can get with a limited energy supply. Also, if the devices are smartphones or laptops, you have the option to recharge them.

It depends on the devices used to form a network where the DSR is running.  In a lab set up, suppose somebody builds a MANET using 14-15 inch laptops, the power consumption may range from 20-100 W for each laptop with an average 60 W. Cellphone chargers when charging a cellphone consume approximately 2-6 W with an average 3 W.

I suggest the following linkshttp://energyusecalculator.com/electricity_laptop.htm

http://energyusecalculator.com/electricity_cellphone.htm