As far as I studied, I know following options that can be used for LTE and Wifi interworking:
1- LTE - U (LTE Unlicensed)
2. LAA (Licensed Assisted Access)
3. LWA (LTE wifi aggregation)
4. MPTCP (Multi path TCP)
Out of above options, there might be other options which I don't know. But out of above four which one is best and due to what reason operator will choose the best one ?