Contrary to what you’d think, WCDMA is an evolution of GSM, while EVDO is an evolution of CDMA , which is why a carrier or device will support either GSM/WCDMA or CDMA/EVDO, but not CDMA/WCDMA or GSM/EVDO. EDGE is an enhancement of the GSM protocol, while HSPA/HSPA+ are enhancements of the WCDMA protocol.