Earlier this week, Google’s Sundar Pichai himself confirmed reports about the company working on its own wireless network that it intends to launch in the United States in the coming months. The Wall Street Journal is now reporting that Google is planning to launch its network by the end of March, though it will only work on one smartphone for now — the Nexus 6.

As Pichai had revealed, Google’s mobile network is an experimental network that aims to seamlessly combine Wi-Fi and mobile networks into one for better data speeds and voice quality. Google will be relying on Sprint and T-Mobile’s mobile network and open Wi-Fi networks to create its own wireless network.

This requires a deep integration between the hardware and software on a smartphone, which is why Google initially plans on making this feature available to the Nexus 6. It is likely that the upcoming Android 5.1 update will add the necessary code for Google’s wireless network.

WSJ’s sources also confirmed that Google’s wireless network will not be work with older Nexus devices like the Nexus 5 and Nexus 4 as well. While Google plans to launch the network by the end of March, there is still a possibility that it might be delayed just like before.