Cingular Wireless is one of the largest United States mobile phone company compare with all the customers, with headquarters in Atlanta, Georgia, United States. In previous we can see card-based PAYG service, where the Cingular Wirless customer purchases a reload card with a given number of minutes on it, which is based on the original service offered by AT&T Wireless.

The second, called as Plan for how many days you want it, is prepaid, but has features which are more similar to conventional post-paid calling plans and Cingular automatically billed for every month. This variation was added on by Cingular. Cingular Wireless operates a one network for multiple technologies. The most widely used by Cingular Wireless technology is Global System for Mobile Communications, or GSM.