Power Efficiency: Network mode 4G LTE vs 3G GSM/WCDMA? Which network mode is more power efficient: LTE 4G or GSM 3G? 
I assume using a 4G network uses more power even if you don't use the data connection, as from the little I understand about mobile networks - the frequency/encoding is completely different to 3G.

When I have "LTE/WCDMA/GSM (auto connect)" network mode active on my phone, I typically get 0-1 bars signal. But with "WCDMA/GSM (auto connect)" mode, my phone consistently has 4 bars signal. 

Does the way Android handles network connections require less power when there is a stronger network signal - whether the connection is LTE or WCDMA or GSM - (I am thinking something like the network connection refresh rate might be dependant on the signal strength?!), or does the technology behind 4G simply require more power to keep connected and it doesn't matter what OS version you are using?

In case it's relevant, I'm using Samsung Galaxy Note 4 (SM-N910C) on stock Android 5.0.1.
This is a big one which is tough to give a complete definitive answer.

There are a ton of variables involved that could easily change the the end data as per you. A few of things are involved are conditions like theory, optimal, or real world environment:


The carrier and their network, the technology they utilize.
The data type itself and whose definition of what is really needs to be met to be considered truly that type.


To give you an idea in your question about refresh rate, first, whose definition of efficiency should you go by meaning? Is it solely based on an acceptable signal strength? Like, one data type refreshes at an exact unit of time because there's just maybe a chance of a better signal even if it's already at a super strong level, then add the tower hand-offs, oh my. Wow that grew fast.

Check out this excerpt from a book reference by O'Reilly which includes references to reports and papers to go deeper if wanted.