These make it possible to effectively utilize orthogonal frequency division multiplexing which is a modulations scheme in which available bandwidth is divided into many individual low bit rate carriers.

Because the bit rate of each carrier is low, each bit is integrated over a long time frame giving this scheme a great deal of noise immunity. It is in fact possible to transmit data with a noise to signal ratio.

I believe ultimately everything will trend towards untra-wide bandwidth COFDM because of the ability to transmit high bit rates with high noise immunity and share the same spectrum with other users and the available bit rates will continue to increase and cost decrease as digital signal processors continue to improve.