It is reported that in order to obtain better battery life and LTE connectivity, the new generation of HoloLens will use ARM processors. For comparison, the original HoloLens used Intel's Cherry Trail processor, which lasted only about 3 hours.
In addition to the hardware, the new generation of HoloLens will also update the operating system. It will use a new operating system built on Windows Core OS. This operating system is a derivative of Windows 10 and is built specifically for HoloLens and other MR devices.
As for the release time of the new generation HoloLens, it is still not known. However, given that Build 2018 is coming soon, we are expected to see it at the developer conference in May.