AT&T is rolling out a technology upgrade to HSPA 7.2 that will double the speed of its wireless network. AT&T customers in Chicago, Dallas, Houston, Los Angeles, Miami and Charlotte will be the first to experience the speed boost over the next few months, with most other cities being upgraded over the next two years. Starting next year, AT&T will begin testing an even speedier technology called LTE for Long Term Evolution, which could increase speeds by more than 20 times current rates. AT&T has taken a lot of flack recently for not being able to accommodate the data transfer demands of iPhone users. Most other cellular carriers are also experimenting with LTE or WiMAX in order to compete in the rapidly approaching 4G cellular battle that will revolutionize mobile computing.