It seems to me, cynically maybe, that the main purpose of LTE-U is for wireless telecom companies to retain control of the communication even in cases where WiFi offload is being used now. The wireless telecom company gets free access to frequencies it did not previously have, and they can continue to charge for bytes of data sent, even when the customer might have used free WiFi previously. In other words, the wireless telecom retains control.

Usually this will be for indoor environments, such as airports or cafes, to take load off of macrocells, and to make indoor reception easier. Same general purpose as WiFi offload, but still under the control of the telecom company.

Of course, the technical problem of handover, from macrocell to LTE-U cell, is simpler than handover from a cellular scheme to IP over WiFi. But even here, most cellular traffic, 4G and beyond, is going to IP anyway, So smart people have already been working this WiFi offload problem for quite some time now.

I've always been very cynical about the purpose of LTE-U. I see it as a spectrum grab technique, for companies that already have licensed spectrum dedicated to them. In principle, even without grabbing unlicensed spectrum for low powered indoor LTE-U, what prevents the wireless company from deploying very low powered indoor cells, using its own licensed spectrum? I mean, if they feel they must retain control, rather than use WiFi offload? I would expect that this is feasible, if one uses a different frequency channel from that used in the macrocell immediately outside. Beyond that macrocell, I doubt co-channel interference would be an issue.

As to your original question about power saving techniques, it seems unlikely that LTE-U is inherently more capable of benefitting from such mechanisms than WiFi might be. And I would expect that WiFi access could be used more generally, by any device within range, as opposed to LTE-U dedicated to only the subscribers of that telecom company.

Firstly thanks for your reply, still I have some questions to ask and some answers to defense my question.  

1. The future generation already categorized the telecom industry based on user mobility, high mobility, and low mobility.  By some recent papers, it is clear that most of the data access is from low mobility users. In order to provide high data rate, the telecom industry needs more spectrum which is already fulfilled by unlicensed channel. So if we go with the recent trend it seems that telecom industry hijacked unlicensed channel. 

2. Though some papers come up with a dual environment in which LTE-U and native Wi-Fi users can sense the same spectrum i.e., unlicensed.

3. Jump to my question, in future if most of the data (not control) traveled by unlicensed channel then there will be no future of data packet (OFDMA) techniques in LTE. Same happened to the power saving techniques of LTE they will be outdated.  Since IEEE802.11 already has stable kind of data techniques.

Lokesh, good use of the term "hijacked." I concur.

Yes, in principle, LTE-U is supposed to "coexist" with WiFi. Still, in many locations, WiFi frequencies are already saturated. Something has to give.

I'm not sure about your #3. In the future, for mobile devices, while actually on the move, I expect that macrocells will still be used primarily. Offload to the unlicensed spectrum, whether that's WiFi or LTE-U, should mostly be when the mobile device is more or less stationary, although not necessarily indoors? Maybe also hotspots in public parks and such?

But in any event, "the future" of wireless broadband is looking at an entirely different unlicensed spectrum, above even 5 GHz WiFi. That's part of the attraction of 5G, whether for fixed or mobile service. Up in the 10s of GHz. Up here, there's not nearly as much contention for spectrum (yet).