AT&T will later this year carry the ATIV Smart PC, first unveiled in August.
Advocacy groups plan to file a complaint against AT&T, alleging violating the U.S. FCC's net neutrality rules.
Powerline networks operate by sending a modulated carrier signal over your regular AC wiring.
The company’s move is no surprise: Half of its smartphone users -- about 17 million customers -- are on so-called unlimited plans and it could find itself in a legal nightmare if other customers win similar cases.
The bottom line: Industry titan AT&T finished last, while two smaller carriers that piggyback on AT&T's network, Consumer Cellular and U.S. Cellular, ranked tops.