What is the difference between a five-band and a dual-band signal booster?

Five-band boosters amplify all five frequency bands that the FCC allows to be boosted. Dual-band boosters are legacy devices that only boost two of the five bands.

Five-band and dual-band signal boosters are different based on the frequencies and networks that they boost. We'll cover each in depth here:

Five Band Signal Boosters

With the advent of high-speed data over 4G LTE, it was necessary to use additional frequency bands (ranges), as there was not enough room in the existing two frequency bands to handle the additional traffic. Three additional bands were added, for a total of five bands (700, 850, 1900, and 1700/2100 MHz) being used by the major carriers for their different 2G, 3G, 4G, 4G LTE and now 5G networks. 

In order to ensure that every network for every carrier was being boosted by the same signal amplifier, five band boosters were created to amplify all bands simultaneously. 

A five-band signal booster is the only recommended type of booster to ensure you can boost all current networks on all carriers, and any future network that uses any of the five main frequency bands.

Dual Band Signal Boosters

Prior to the release of 4G LTE, cell carriers provided voice calls and slower 3G data over only two frequency bands, 850 and 1900 MHz. All dual-band signal boosters will amplify these two frequencies, so any network deployed on a band outside of those two will not be boosted. Dual-band boosters are no longer manufactured and should only be used for legacy applications.