Google hosted its second Project Ara developer conference at its Mountain View campus today. During the event, company executives revealed quite a bit more about its latest modular smartphone prototype and when we can expect to see a consumer version.

The latest prototype – dubbed Spiral 2 – includes a 3G modem as well as an RF bus to support antennas. We learned last summer that Google was working with Chinese manufacturer Rockchip to build a custom SoC for the device.