For nearly a hundred years telecommunications provided mainly voice services and very low speed data (telegraph and telex). With the advent of the Internet, several data services became mainstream in telecommunications; to the point that voice is becoming an accessory to IP-centric data networks. Today, high-speed data services are already part of our daily lives at work and at home (web surfing, e-mail, virtual private networks, VoIP, virtual meetings, chats…). The demand for high-speed data services will grow even more with the increasing number of people telecommuting.
Wireless circuit switched voice networks have experienced in the past two decades, an evolution towards mobility and today's users take for granted the universal availability of voice services. This demand is migrating to the data domain where 4G wireless networks have become essential.
Wireless networks became feasible with the advent of 1G networks (AMPS and ETACS) that provided analog voice services. With the increase in demand, more efficient technologies were required and 2G networks (TDMA, GSM, CDMA), designed for digital voice and higher spectral efficiency, were created.
The explosive demand of wireless services required even more spectrum efficient networks and the need for wireless data services started to emerge. 3G technologies (cdma2000, UMTS) developed to meet this demand were extensions of old voice switched networks and provided relatively low data speeds when compared to terrestrial networks. ...