Date Added: Jun 2012
The very high data rates envisioned for Fourth Generation (4G) wireless systems in reasonably large areas do not appear to be feasible with the conventional cellular architecture due to two basic reasons. First, the transmission rates envisioned for 4G systems are two orders of magnitude higher than those of 3G systems. This demand creates serious power concerns. Second, the spectrum that will be released for 4G systems will almost certainly be located well above the 2 GHz band used by the 3G systems. The radio propagation in these bands is significantly more vulnerable to non line-of-sight conditions, which is the typical mode of operation in today's urban cellular communications.