Quad-band - definition
Mobile device that allows voice and data connections over four separate frequency bands using a single bearer technology, such as GSM. Many European and Asia/Pacific regions, for example, have approved the deployment of GSM networks on the 900MHz and 1,800MHz spectrums, whereas GSM has been implemented on the 800MHz and 1,900MHz spectrums in North America. If the "home" operator has roaming agreements with local mobile network operators, a quad-band phone allows the user to travel automatically between networks on any of these frequencies in any of these countries.