Alongside the release of PS4 Firmware v1.70, Sony has also released a new firmware update for the PS Vita. The new firmware updates the PS Vita System Software to version v3.15 and enhances the PS4 Remote Platy functionality.
PS4 Link update for Remote Play:
Linking your PS4 and PS Vita together will now be easier with the 3.15 update for PS Vita. It’ll enable Automatic Device Registration, which will automatically detect and pair both systems when they’re both online and the same user is signed in to both devices. This makes it even quicker for you to get started on Remote Play or access other second screen features.