Dual Band : Dual band phones are capable of using two different frequencies of the same technologies. For example, a TDMA or CDMA phone that can use either the 800 or 1900 MHz band. There are also Triple Band phones in the GSM market that support 900, 1800, and 1900 MHz. Dual band phones allow callers to access different frequencies in the same or different geographic regions, essentially giving their phone a wider coverage area.