AT&T and Verizon are the largest mobile operators in the U.S., and T-Mobile is the fourth-largest. All three sell smartphones equipped with Wi-Fi and include Wi-Fi hotspots as part of their wireless data offerings. In 2007, T-Mobile provided free Wi-Fi routers through its hotspot@home service, which let subscribers make unlimited calls via Wi-Fi with T-Mobile phones that have the technology. Other companies that settled with CSIRO last year included Netgear, Toshiba, 3Com, Nintendo, D-Link and Buffalo Technologies.