WCDMA (Wideband Code Division Multiple Access) is a 3G mobile technology standard that most GSM carriers upgraded to, with parts based on GSM technology. It allows WCDMA networks to integrate with GSM networks at certain levels and most WCDMA phones include GSM as well for backward compatibility. Developed by the global GSM community, WCDMA supports 3G mobile services and is the air interface for the ITU's 3G systems, being used in UMTS and HSPA networks.