Back in May at the I/O, Google announced the second generation of its Nearby Connections toolkit and that it will become available to Android developers. In the video below you can see more about the company's announcement about the Nearby Connection API from around 24 minutes.
The update framework uses Bluetooth and WiFi to find nearby devices, connect them and perform tasks without requiring an internet connection. The toolkit supports both mesh networks, where devices form an independent network on the spot as well as a centralized connection where one device rules the roost.
It'll take a while for the new Nearby Connections to wind its way into the apps you use, but there are already companies who've had a head start. The Weather Channel is installing mesh networks in areas with poor internet access to help send weather warnings, Hotstar is offering offline media sharing and GameInsight will help you find and play people offline. And of course, Google has its own; an upcoming Android TV remote app will use Nearby Connections to get you started and turn on second-screen experiences while you're watching shows.