Apple exploring HD Radio for future iPods, iPhones

A new patent application from Apple this week centers around HD Radio, a trademarked wireless radio format owned by iBiquity, which allows both AM and FM radio stations to simulcast digital and analog audio within the same channel. The application suggests that future handsets from Apple, such as the iPod or iPhone, could embrace HD Radio technology to allow users greater flexibility when listening to broadcast media.

Entitled "Digital Radio Tagging Using an RF Tuner Accessory," the application states that users could use a handheld device to scan all stations, or only for stations delivering high-quality digital audio content. Collecting a list of digital stations and the accompanying "raw digital data" broadcast with them would allow users to scan and search stations based on the content that is currently playing, or a number of other factors included in the data.

"Enhanced metadata and searching can provide the listener the ability to refine station choices without having to listen at length to any particular station, and further can facilitate tagging broadcast tracks for subsequent access and/or purchase," the application reads.

With respect to tagging and purchasing tracks, Apple already offers a similar feature on its most recent iPod nano, which features a built-in FM radio. The iPod nano's iTunes Tagging feature allows users to tag songs they like when they hear them on the radio. Songs can then be previewed and purchased from iTunes when synced with a computer.

But Apple's new portables could go beyond FM with an HD Radio tuner, allowing full integration with HD Radio — a feature that has been rumored for some time. The system describes both an external radio receiver, wirelessly transmitting audio and data to the portable device. It also suggests that such data could be shared with a stereo system in a vehicle.

Last November, The Wall Street Journal reported that Apple was in talks with iBiquity to bring HD Radio to future models of the iPhone and iPod touch. At the time, the trademark holder released the Gigaware HD Radio Receiver, a hardware accessory that — along with a free App Store application — allows users to listen to HD Radio broadcasts of local stations.

Apple and iBiquity partnered in 2007 to bring the iTunes Tagging feature to devices that receive the broadcast medium. Like with tagging on the iPod nano, iTunes Tagging with HD Radio allows users to "tag" songs they hear for a later purchase via the iTunes Store.

HD Radio was one of Microsoft's main selling points of the Zune HD, the portable media player that the Redmond, Wash., software giant hoped to position against Apple's industry leading iPod touch.