CSFB
Circuit-Switched Fall-Back
A technology standard that allows separate LTE and CDMA wireless networks to interoperate, for seamless service with carrier companies that use both CDMA and LTE technology for their mobile networks. It allows LTE to be used as the primary network for data, with phones "falling back" to CDMA for voice calls and other circuit-switched services.
See: Circuit Switching
CSFB will eventually be replaced by VoLTE and related technologies.
See: VoLTE
Last updated Feb 11, 2022 by Rich Brome
Editor in Chief Rich became fascinated with cell phones in 1999, creating mobile web sites for phones with tiny black-and-white displays and obsessing over new phone models. Realizing a need for better info about phones, he started Phone Scoop in 2001, and has been helming the site ever since. Rich has spent two decades researching and covering every detail of the phone industry, traveling the world to tour factories, interview CEOs, and get every last spec and photo Phone Scoop readers have come to expect. As an industry veteran, Rich is a respected voice on phone technology of the past, present, and future.