In this well-written article, Lawton discusses an industry trend in cellular technology: high-speed data traffic for cellular devices. First-generation (1G) technology involved analog, circuit-switched, narrowband communication. This was suited for voice communication. When the technology improved to the second generation (2G), digital signals were used, but were still limited to narrowband. The 2G technology supported voice communication well, and, to a limited extent, data communication at slower speeds, such as one megabit per second (Mbps). Very quickly, the industry moved to 2.5G services, at higher data rates, such as 11 Mbps and 54 Mbps.

The two dominant 2G technologies are code division multiple access (CDMA), used widely in the US, and the global system for mobile communications (GSM), used widely in Europe and Asia. CDMA uses a different coding technique for each transmission, and thus carries signals over the same channel. GSM uses multiple channels, and by using eight time slots for each channel, it increases the available bandwidth. Two GSM enhancements in 2.5G are worth noting: general packet radio service (GPRS) and enhanced data GSM environment (EDGE).

The third-generation (3G) communication technologies introduced in 2001 have not been able to handle the demand for more high-speed services, such as mobile video conferencing, mobile high-definition TV, and gaming. These services require data rates at 100 Mbps and higher. To support higher data rates, GSM technology is being modified using wideband; this new technology is called wideband CDMA (WCDMA). However, this CDMA uses different protocols, and is thus incompatible with the US standard.

The fourth-generation (4G) communication technology called high-speed uplink packet access (HSUPA) promises to provide the necessary bandwidth, in both directions, for video conferencing and gaming. Companies such as Cingular, Vodafone, and NTT DoCoMo have started trials with this new technology. Another important contribution in this area is the CDMA2000 1xEV standard (the EV stands for “evolution”). This standard comes in two forms: data only (DO), and data and voice (DV). The EV-DO technology is supported by Verizon and Sprint in the US, KDDI in Japan, and Vivo in Brazil. Associated data rates are around 2.4 Mbps. Additional standards such as IEEE 802.16 and 802.20 support data rates up to 30 Mbps. In spite of various efforts to provide higher data rates that follow accepted standards, some large markets, such as India, China, Korea, and Japan, are planning their own 4G standards, to retain control over their markets.