s or a 5MHz band at 6Mbps. The frequency reuse is N = 1 or N = 3, and TD-SCDMA supports the modulation schemes QPSK and 8-PSK. Many believe that the TD-SCDMA air interface will be used by some of the operators Beijing is expected to license, though the time frame for awarding licenses has been delayed several times. CDMA2000 With existing networks nearing saturation and demand for wireless services continu- ing to grow, operators have been looking at technologies that will deliver increased capacity at the lowest possible cost. In fact, one of the biggest drivers behind 3G is 3G: Moving Toward Broadband Wireless capacity improvement, and network capacity is one of the key criteria for 3G tech- nology selection. In 2000, CDMA2000 was the first 3G technology to be commer- cially deployed as part of the ITU's IMT-2000 framework. CDMA2000, the common name for IMT-2000 CDMA Multi-Carrier (CDMA-MC), increases data transmission rates for existing CDMA (cdmaOne) network operators. Figure 14.8 shows the infra- structure of a CDMA2000 wireless network. Key features of CDMA2000 devices include color displays, GPS, digital and video cameras, push-to-talk, support for streaming-type real-time video-on-demand (VOD)/audio-on-demand services, and voice recognition functions. cdmaOne and CDMA2000 are the most spectrally efficient technologies and support at least twice the maximum number of voice calls as current non-CDMA 2G technologies. The CDMA industry is also deploying new solutions that will fur- ther enhance the capacity of existing networks. CDMA's capacity advantages are real, with operators experiencing these benefits today. cdmaOne delivers the most capacity in the 2G world, even considering the latest frequency-hopping tech- niques and adaptive multirate voice codecs in GSM networks. CDMA2000, which is now being deployed worldwide, doubles the capacity of cdmaOne networks. IS-95 HDR is being used as the underlying technology for CDMA2000. IS-95 HDR is optimized for IP packets and Internet access, and it can be used to