Traditional wireless technologies, however, are not particularly well suited to meet the extremely demanding requirements of providing the very high data rates

and low cost associated with wired Internet access and the ubiquity, mobility, and portability characteristics of cellular systems. Some fundamental barriers, associated with the nature of the radio channel as well as with limited bandwidth availability at the frequencies of interest, stand in the way. As a result, the cost-per-bit in wireless is much higher than in the wired world, wherein an entire generation of Internet users has grown accustomed to accessing huge volumes of information at very high speed and negligible cost.