Here's a hint about what Google might do in its quest to fix cities

Wednesday night, Google unveiled a plan to help improve cities.

The company launched a new, independent company called Sidewalk Labs run by former Bloomberg CEO Dan Doctoroff.

Sidewalk aims build products and platforms to tackle big-picture issues like cost of living, efficient transportation, and energy use for city-dwellers around the world.

Sidewalk Labs' website doesn't reveal much about its specific roadmap, but a reader tipped us off that a Reuters article from earlier this month may give a big hint at what Sidewalk Labs is interested in doing.

Sources told Reuters that Doctoroff has placed a bid to buy the pay-phone and outdoor advertising company Titan Outdoors, though negotiations are still on-going.

Late last year, New York City chose Titan Outdoor to take charge of its push to put Wi-fi and digital advertising screens in thousands of pay phone booths across the city. The Wi-fi hotspots will also offer charging stations for cell phones and free calls to anywhere in the US.

Titan came under fire in October after BuzzFeed reported that its efforts to revamp pay phones included surreptitiously inserting beacons into them. Beacons push advertisements to people's cell phones when they walk by, but they can also be used to track users' locations. New York City ultimately forced Titan to remove the beacons following BuzzFeed's report.

Turning tens of thousands of obsolete pay phone booths into hubs of digital information and communication certainly seems like something Google's Sidewalk Labs would be interested in. Titan already plans to provide Wi-fi, cell phone chargers, and ads, but Google could add in Maps, to help tourists get around, or easy search and recommendations.

Google didn't disclose how much it planned to pour into running Sidewalk Labs, but CEO Larry Page described it as a "modest investment." Sources told Reuters in early June that Titan Outdoor could be worth more than $150 million.