Mozilla and Ericsson used WebRTC and Social API to link the phone to the browser
One of the more interesting things Mozilla is showcasing at Mobile World Conference is a WebRTC demo which marries the phone with the Firefox desktop browser.WebRTC enables voice and video calls in the mobile browser while Mozilla's Social API enables users to control their phone, which includes making calls and reading text messages, from their desktop browser.
Mozilla and Ericsson worked together to create the demo, which is only possible on Firefox for now, particularly because the Social API is Mozilla-exclusive.
Most of us aren't on the MWC show floor to experience the demo first-hand and Mozilla didn't do a great job explaining how it works.
Thankfully, it did put together a video showcasing how the Social API, WebRTC along with mobile and desktop integration work together.