Wi-Fi is becoming important and a useful rule of thumb is that the spectrum in 5GHz is roughly around 10 times that of 2.4GHz and the spectrum is 60GHz is roughly around 10 times that of 5GHz. (not all spectrum is available everywhere so just use this as a rough guide).
As I mentioned in a presentation I gave this week, there are three different approaches being proposed at the radio level; LTE-U, LAA and LWA. I wrote a post on LWA not long back on the 3G4G blog here.
Dave Wright from Ruckus Wireless has kindly shared a recent presentation on different proposals for LTE operation in unlicensed spectrum. The timeline above shows how quickly things are moving. Here is a the presentation
It would be important from Wi-Fi vendors point of view that LTE-WiFI Link Aggregation is standardised as part of Release-13 as there would be an option which would be agreeable to everyone.