EVDO is a type of wireless telecommunications transfer.  It is primarily used for cell phones.  EVDO stands for Evolution Data Optimized or Evolution Data Only.  If you use a cell phone, you have at one point utilized an EVDO network.  Basically, EVDO transmits signals over the air via radio towers  It utilizes time division multiple access (TDMA) and code division multiple access (CDMA) to balance out drop outs, busy data traffic and other issues that arise during EVDO transmission.  Every cell phone provider uses one or the other to provide service to its users.

Most cell phone networks use EVDO as a base and provide other, faster services, such as 3G networking, on phones that are capable of such speeds.  If your phone is not that fast, your phone falls back and transmits over the EVDO network.  Depending on the area, if higher network speeds are not available, your cell phone no matter the model will automatically switch over to the EVDO network so you do not lose service.  You will not even notice the change unless you begin using the Internet or other multimedia features on your phone.  While this may not seem like a big deal to some, when you are used to higher transmission speeds, it can be downright dreadful to use something slower.

Motorola in particular has worked to perfect the EVDO service and introduces several innovations towards developing a more stable platform.  However, all EVDO standards are run through the gamut by the 3^rd Generation Partnership Project 2.  This helps ensure that cell phone networks are kept up to par with the traffic, transmission and other things necessary to have a stable network.  Many cell phone companies continue to make phones capable of utilizing EVDO to their fullest potential.  As more consumers invest in 3G phone technology, EVDO will slowly become obsolete.