WASHINGTON—The nation's phone system is changing quickly and it is time for the regulators to catch up, new Federal Communications Commission Chairman Tom Wheeler said Tuesday.

Mr. Wheeler, in a blog post, outlined his plan to move forward with what has become known as the IP Transition, the shifting of landlines from circuit-switched systems to a digital, Internet Protocol-based network. Mr. Wheeler said he expects the FCC to vote in January to begin collecting data and conducting trials, in hopes of figuring out how existing...