Exactly what upgrades the AirPods Pro 2 will get is open to speculation, but a recent patent award suggests a new form of wireless transmission tech that supports hi-res streaming could be on the list. Apple has been rumored to be working on hi-res support for the AirPods Pro 2 for some time, probably using its own Apple Lossless (ALAC) format. But while Apple Music has already been upgraded to support high-resolution audio, Bluetooth — which is used by all AirPods — doesn’t have sufficient bandwidth to support full hi-res streams. This patent, spotted by Patently Apple, could enable the AirPods to overcome that problem by instead using a new optical audio transmission technology. And what’s more, it’s something that the Cupertino tech giant has seemingly been working on for its first mixed reality headset tipped for release later this year. In much the same way as physical optical cables are used to carry digital audio signals from hi-fi components like a music streamer or CD player, an optical signal can also be used to connect digital audio wirelessly. It’s a complex technology, not least because the transmitting device needs to be within range and line-of-sight of a receiving device, but the patent suggests that it could be used in conjunction with Bluetooth as a secondary communication tool. This would provide the much-needed confirmation of optical audio connectivity between devices, as well as providing a reliable backup connection should optical audio connectivity fail. Apple’s development of an optical audio transmission standard appears to be backed up by the company’s head of acoustics, Gary Geaves who said during an interview discussing the limitations of Bluetooth that “Obviously the wireless technology is critical for the content delivery,” and “…it’s fair to say that we would like more bandwidth…” Further evidence that the technology is being considered by Apple can be seen in the drawings that accompany the patent (opens in new tab), showing an AirPods-esque headphone connected to a smartphone via an optical signal carrying audio data. The patent is undoubtedly an exciting indicator of a potential alternative to Bluetooth connectivity and will be of particular interest to hi-fi fans looking to unleash full-fat hi-res audio and listen via true hi-res audio, wireless headphones. Of course, it’s important to remember that Apple is continually filing patents and that only a few actually ever become a reality. For more information on what Apple may be considering for its next-gen Apple AirPods, we’ve rounded up some of the most exciting possibilities in our guide to the 5 biggest rumored upgrades.