What role SDN can play in wide area network to make network cost effective and optimized ?

Question

I just know the about of term SDN i.e Software Defined Network which is used to configure white box switches at the run time.
I want to know how SDN can be used to for LTE network and where all places it can do something.

Answer 1

Theoritically by SDN, the network operator is no more depend on the big Vendor because in SDN the network machine (Switch/Router) are controlled by SDN Controller.

But I think in the end it would be the same as the traditional network as the big Vendor will dominate the SDN controller market.