 As a consequence, the limited available RF spectrum is subject to an aggressive spatial reuse and co-channel interference has become a major capacity limiting factor.Therefore, there have been many independent warnings
of a looming "RF spectrum crisis"
as the mobile data demands continue to increase while the network spectral efficiency saturates despite newly introduced standards and great technological advancements in the field.It is estimated that by 2017, more than 11 exabytes of data traffic will have to be transferred through mobile networks
every month.