Currently, mainstream CDMA operators in North America are upgrading their CDMA networks to EVDO Rev.A. For example, Verizon Wireless has upgraded about 60% to 70% of its base stations to CDMA EVDO and 1x dual-frequency base stations. Its EVDO network has covered 242 major cities and 180 airports, with a population of about 208 million. Verizon wireless plans to upgrade all base stations to EVDO Rev.A version within a few months, covering 260 million people. Sprint Nextel has also upgraded the CDMA network to the EVDO Rev.A version since 2006, and plans to cover 225 million people with the EVDO Rev.A network by the end of this year. TELUS, Canada's second largest telecom operator, is also upgrading its CDMA network to EVDO Rev.A.
CDMA 850-894MHz is composed of several technologies such as spread spectrum, multiple access, cellular networking and frequency multiplexing, and contains a cooperation of three-dimensional signal processing in frequency domain, time domain and code domain, so it has anti Good interference, anti-multipath fading, high confidentiality and security, the same frequency can be reused in multiple cells, and there is a trade-off between capacity and quality.