Applications and services for the B3G/4G era

he first generation (1G) of mobile systems pioneered commercial mobile voice services, allowing communication on the move for the first time. Initially, the quality was poor, service was expensive , and penetration was low. The quality improved somewhat, and service became more affordable. Penetration increased significantly. However , the analog infrastructure limited the number of supported concurrent subscribers per cell to small numbers. The quality was still far from that offered by wireline telephony. Shortly, these limitations were eliminated by the advent of second generation (2G) of mobile systems. By using digital technology, 2G systems such as Global System for Mobile Communications (GSM), IS-95, and IS-136 increased the number of supported users within a cell (and the spectral efficiency) and enhanced voice quality significantly. The cost of service kept on lowering, and cellular telephony started replacing wireline telephony. While some data services were offered on analog systems, these services, albeit at low data rates, started proliferating with the digital technologies of 2G. In particular , short message service (SMS) has been very successful and profitable for almost a decade. 2G's success story prompted development of the 2.5G and third-generation (3G) mobile systems. General packet radio service (GPRS), as a 2.5G service, has focused on higher-speed data services on GSM-type network infrastructure. Unlike 2G and 2.5G technologies, all 3G technologies are code-division multiple access (CDMA)-based. 3G-1x provides higher voice capacity, and 3G-1x-EV-DO provides high-speed data using one IS carrier. Universal Mobile Telecommunications System (UMTS) standards were developed to provide higher voice capacity and high-speed data using a wideband carrier (5 MHz). Higher data rates were designed to provide new innovative services, like mobile videophone, video streaming, and voice over IP. Up to 2 Mb/s data rates were promised by UMTS and further enhancements in 3G Partnership Project (3GPP) standards. Moreover, wider coverage was promised by implementing hierarchical layers of macro, micro, and pico cells, each using different carriers with a penalty of more expensive base stations (the so-called Node B) in small coverage areas. Techniques such as cell sectoriza-tion and multiple input multiple output (MIMO) would be employed in 3G to maximize capacity. While 3G-1x has done quite well, higher speed data penetration and migration to IP-based infrastructure has been disappointing. Voice is still carried over the 2G circuit-switched infrastructure (not the promised IP), and the majority of deployed systems have a maximum speed of 384 kb/s downstream (and only 64 …