Evolution-data optimized (EV-DO) is next step for the code division multiple access (CDMA) networks moving towards 3G. EV-DO Rev 0 promises data speeds up to 2.4 Mbps on the forward link and 153.6 kbps on the download link. Compare this with the shared 64 kbps, where a subscriber actually gets between 20–35 kbps over GPRS connectivity, and the 140–150 kbps over EDGE networks. Even the offered speed of 300–400 kbps over EV-DO is faster than any other wireless access technology.

In January 2005, there were about 125 commercial 3G operators in 56 countries, with almost 10.8 million EV-DO subscribers globally. In India, CDMA operators Reliance Infocomm and Tata Indicom have expressed their intention to launch EV-DO. In fact, Reliance has been conducting pilots at the Reliance Knowledge Center and its officials said as soon as additional spectrum is granted the services would be available throughout India.

How Does EV-DO Work?
EV-DO is part of the CDMA2000 family and hence the operators do not require any major addition or changes in the network architecture. At the user end, an EV-DO-enabled device (a laptop with a PC card, PDA, or phone) is required.

The current CDMA2000 1x supports both voice and data on the 1.25 MHz carrier. The 1x EV is optimized to carry only data traffic in single 1.25 MHz carrier.

Making Business Sense
In the 5MHz spectrum, 1x EV can deliver up to 3.2 Mbps. CDMA2000 1x and WCDMA give 1.1 Mbps and GPRS 80 kbps respectively. As the capacity of a network is limited, the cost to deliver one megabyte for 1x EV is $0.02 for CDMA2000 1x, for WCDMA it is $0.07, and GPRS comes to $0.42.

Performance of Cellular Technologies

With IP being the key, and data usage poised to grow, everyone is betting their money on EV-DO. A Qualcomm study indicates data volumes of more than 200 Mb per user per month by 2006 over the wireless networks. This makes a perfect case for better networks, applications, and mobile access devices to support high volumes of data at higher throughput.

In the migration to EV-DO, CDMA networks will require very little tweaking compared to migrating GPRS-enabled networks to WCDMA.

With BREW being promoted by Qualcomm for multimedia applications and the company putting money in MediaFlo to push in multimedia services, CDMA operators stand to gain from the EV-DO environment.

EV-DO would essentially give the user broadband access while on the move, not just wireless but a really mobile, high-speed access. Instead of getting tied to a hotspot coverage area, EV-Do would ride wherever the operator has network.

While the deployment of EV-DO Rev 0 is still in its nascent stages, vendors are already contemplating Rev A with speeds of over 3.1 Mbps. EV-DO Rev A would further enhance the data-carrying capacity and operators would be able to offer commercial-grade VoIP and other packet switched applications over wireless networks.