From GSM to LTE: An Introduction to Mobile Networks and Mobile Broadband

3.14 UMTS and CDMA2000

While UMTS is the dominant 3G technology in Europe, it shares the market with a similar system called CDMA2000 in other parts of the world, for example, in North America. This section compares CDMA2000 and its evolution path to the GSM, GPRS and UMTS evolution path that has been discussed in Chapters 1 to 3.

IS-95A, which is also referred to as CDMAOne, was designed similar to GSM to be mostly a voice-centric mobile network. Like GSM, it offers voice and circuit-switched data services of speeds up to 14.4 kbit/s. However, IS-95A and all evolutions of that standard are not based on GSM and as a consequence both radio and core network infrastructure and protocols are fundamentally different. In particular, the radio network is fundamentally different than GSM as it is not based on FTDMA. IS-95A was the first system to use the CDMA approach for the air interface that was later also used in the UMTS standards where it is referred to as Wideband Code Division Multiple Access or WCDMA for short.

IS-95B is a backward compatible evolution of the system which offers increased user datarates and packet data transmission of up to 64 kbit/s. Thus, it can be roughly compared to a GSM network that offers GPRS services. Similar to the earlier version of CDMAOne, it uses carriers with a bandwidth of 1.25 MHz, which multiple subscribers share by code multiplexing.

The next step in the evolution path was CDMA2000 1xRTT (Radio Transmission Technology), which can roughly be ...