Sprint is accusing AT&T of deceptive advertising.
Sprint filed a lawsuit, claiming AT&T falsely brands its 4G wireless network as 5G technology.
AT&T renamed a large portion of its 4G network, calling it "5G Evolution."
However, the new network consists of technologies that have been out for years.
The suit claims the branding confuses users who may believe they actually have the super fast 5G network.
AT&T does have a true 5G network— but it can only be accessed by invitation and is available only in parts of 12 cities.