Evolution, Data Optimized or Evolution, Data Only (EV-DO, 1xEvDO, or 1xEV-DO) is a Third Generation (3G) wireless broadband data standard. “CDMA2000, High Rate Packet Data Air Interface” is its official name. Aside from it, there are also other, competing standards like W-CDMA (Wireless Code Division Multiple Access).
3G provides high-speed voice data transfer, all in a mobile environment. It utilizes the cellular method employed by mobile phone networks.
The operations of high-speed wireless networks are hindered because of the lack of bandwidth (range of accessible frequencies). Only a certain amount of data can be transmitted through the available bandwidth, so Qualcomm designed the CDMA technology to surpass this threshold. EV-DO is a variation of that technology.
Multiple wireless devices can simultaneously transmit on a single frequency under CDMA. A specific mathematical signature is assigned to each wireless device. CDMA then applies the signature to the initial signal and sends the modified signal. A receiver recovers the initial signal by applying the opposite mathematical operation to the modified signal.
EV-DO was developed in 1999 to reach an ideal target transmission speed of over 2MBps in stationary communications. Realistically, EV-DO mobile users are able to download at rates of 400-700 KBps when signal strength is high, interference is low and speeds are beyond 2 KBps. The download speed is influenced by the signal speed.
EV-DO works with the same approach used by the Internet. Internet Protocol (IP) breaks data down into smaller portions called packets. Each packet is transmitted independently to others. Upon access to an Internet website, no bandwidth is consumed until it starts up the Web page.
With EV-DO, no packets are sent when neither person in a phone call speaks. In that instance, the connection does not use up the bandwidth and the bandwidth use is saved for other devices.
EV-DO can enable pervasive computing, wherein various devices under a continuous high-speed Internet connection are in a seamless network. EV-DO optimizes Virtual Private Networks (VPNs), allowing a user to connect to media applications and services such as IPTV and VoIP.