A phone can only be used on a network if it supports the correct band(s). Quad-band usually refers to a phone using GSM technology. A quad-band GSM phone is one that can be used for basic service ...
"You don't need a lot of functional integration between the two GSM and 802. ... Wi-Fi could be used by carriers for voice calls using VoIP in areas where the wide-area network can't reach.
technology to enable seamless handover between GSM and Wi-Fi networks. Orange will be one of the first carriers to offer the handset, according to Nokia. UMA is a specification developed by ...