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Tutorial – cdma2000 Technology Family: 1xRTT, EVDO, UMB, and EVDV

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It is a third-generation (3G) wireless technology, based on Code Division Multiple Access (CDMA), that has evolved from cdmaOne (or IS95), a 2G technology. By contrast, UMTS is also a CDMA-based 3G technology that represents an evolutionary step forward for the 2G GSM networks. Please note that while cdmaOne was a CDMA-based system, GSM is a Time Division Multiple Access (TDMA) system.

The name cdma2000 actually denotes a family of standards that represent the successive, evolutionary stages of the underlying technology. These are, in order of evolution:

In the above nomenclature, EVDO is short for Evolution – Data Optimized and EVDV, for Evolution – Data and Voice.

History and Standards

The cdma2000 family of standards, developed by the Third Generation Partnership Project 2 (3GPP2), was intended to be deployed in several evolutionary phases:

Evolution of cdmaOne to cdma2000 1xRTT

The 1x designation in the technology’s name indicates a carrier spreading factor of approximately 1.25 MHz. The following characteristics of 1x are derived from its CDMA roots and make it backward compatible with cdmaOne:

The cdma2000 1x technology is the most spectrally efficient wide area network technology for circuit-switched voice communications and it supports packet data speeds of up to 307 kbps in a single 1.25 MHz channel. Key features of 1x include:

 

Next Step Up: cdma2000 1xEV-DO

Revision 0: EV-DO Rev 0 was the original version of 1xEV-DO and the first to be widely deployed. Revision 0 offered data rates up to 2.4 mbps, averaging 300-600 kbps in the real world. This is much faster than the 50-80 kbps typically offered by 1xRTT technology. Other key features introduced by Revision 0 include:

Revision A: EV-DO Rev. A offers fast packet establishment on both the forward and reverse links along with air interface enhancements that reduce latency and improve data rates. In addition to an increase in the maximum downlink rate from 2.45 Mb/s to 3.1 Mb/s, Rev. A incorporates 12 time improvement in the maximum uplink data rate, from 225 Kb/s to 1.8 Mb/s. EV-DO Rev. A supports low latency services (as low as 50ms) including VoIP and video telephony on the same carrier with traditional Internet packet data services. EV-DO Rev. A air-interface latency specifications have not been published, however several Qualcomm documents note latency in the “low double digit” range with the highest RSVP settings. Latency of 50ms is claimed to be possible. This compares favorably with Rev. 0 latencies of 150-200 ms.

Revision B: EV-DO Rev B is the next evolutionary step up from EV-DO Rev A. It adds the following enhancements:

Ultra Mobile Broadband: cdma2000 Rev. C

Ultra Mobile Broadband (UMB) is a breakthrough technology which will support the ITU’s vision for next generation services. It combines the best aspects of CDMA, TDM, LS-OFDM, OFDM, and OFDMA into a single air interface using advanced and highly optimized control and signaling mechanisms. It also incorporates advanced antenna techniques such as MIMO and SDMA. The combination of these techniques enables UMB to achieve higher peak data rates, very low latency, and very high spectral efficiency. The technology has a flexible and dynamic mode of operation to combine and allocate spectrum as needed for the variety of user applications and activities.

The key features of this technology include:

Strengths and Weaknesses of cdma2000 and Comparison with Other Technologies

The primary attributes of CDMA as a multiple access technology for cellular applications are as follows:

To those inherent CDMA characteristics, cdma2000 adds the following performance advantages:

Business Implications and Market Landscape

The U.S. business implications for cdma2000 and the subsequent upgrades of 1x EVDO can be compared with the competitive 3G wireless technologies using the following four key market indicators.

Global Subscriber growth in 2006: CDMA2000 and 1x EV-DO upgrades gained additional customers in 2006:
There were 301,900,000 cdma2000 subscribers (3Q) and 45,080,000 1xEV-DO subscribers in the world at the end of 3Q 2006. At the end of 2006, more than 8.5 million new customers subscribed to cdma2000 services every month. During the same period (3Q-2006), there were 81.2 million UMTS subscribers worldwide.

U.S network coverage: Verizon and Sprint Nextel are the leading cdma2000 carriers in terms of national coverage. (The latter also operates an iDEN network under the Nextel brand.) While Cingular, a GSM/UMTS carrier has only covered 52 major markets in 28 states (just over 50% of the market) thus far, both Verizon and Sprint are nearing complete nation-wide coverage.

Availability of handsets: In the critical area of handsets, EV-DO is the leader. As of Sept 2006, there were 31 3G handsets available in the market. Twenty six of those handsets were for EV-DO (15 from Verizon and 11 from Sprint Nextel) versus only five UMTS/HSDPA handsets from Cingular.

Cost of handsets: The average price of a 3G handsets in the U.S. is approximately $140 for low-end phones and $250 on the high-end. Sprint Nextel and Verizon are already testing and introducing Rev. A devices. EV-DO Rev B and Rev C are likely to be introduced in 2008 and 2009, respectively

Worldwide market growth for all wireless 3G technologies: At the end of 3Q 2006, there were 2.53 billion cellular subscribers worldwide. The 3G market share of the total world market includes 301.9 million cdma2000 subscribers and 81.2 million UMTS subscribers. Approximately 2.1 billion remaining subscribers are GSM/UMTS/EDGE (non 3G) users.

How to Learn More about cdma2000

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