EV-DO is a high-speed network protocol used for wireless data communications, primarily Internet access. EV-DO is considered a broadband technology like DSL or cable modem Internet services.
Certain classes of cellular phones support EV-DO. These phones may be available from various phone carriers around the world including Sprint and Verizon in the U.S. Additionally, various PCMCIA adapters and external modem hardware exists to enable laptops and handheld devices for EV-DO.
The EV-DO protocol uses asymmetric communications, allocating more bandwidth for downloads than for uploads. The original EVDO Revision 0 standard supports up to 2.4 Mbps data rates down but only 0.15 Mbps (about 150 Kbps) up.
An improved version of EV-DO called Revision A increases download speeds up to 3.1 Mbps and uploads to 0.8 Mbps (800 Kbps). EV-DO providers have gradually been upgrading their equipment from Rev 0 to support Rev A.
A future version of EV-DO called Revision B (not yet widely deployed) promised to offer much higher data rates as this protocol is capable of aggregating bandwidth from multiple wireless channels. Early trials have achieved EV-DO Rev B downloads of greater than 9 Mbps.
As with many other network protocols, the theoretical maximum data rates of EV-DO are not achieved in practice. Real-world networks may run at 50% or less of the rated speeds.
CDMA2000 1x EV-DO cell phone system is a standard that has evolved from the CDMA2000 mobile phone system and it is now firmly established in many areas of the world. The letters EV-DO stand for Evolution Data Only or Data Optimised. From the title it can be seen that it is a data only mobile telecommunications standard that can be run on CDMA2000 networks.
The EV-DO cell phone system is capable of providing the full 3G data rates up to 3.1 Mbps now that release A of the standard has been issued. The first commercial CDMA2000 1xEV-DO network was deployed by SK Telecom (Korea) in January 2002.
No comments:
Post a Comment