Apple has spent some time outlining technology that would add a new level of interaction between iPhone users, such as the ability to share and control playback of digital media files like music tracks and video during a telephone call.

The concept is outlined in a 19-page patent filing discovered by AppleInsider this week titled "Methods and systems for mixing media with communications" and credited to Apple software engineer Jeffrey Terlizzi. It begins by noting that while media items are becoming increasingly portable for mobile users these days, they're still not as easily shared with others located remotely in real time.

"For example, an individual may call his friend to discuss music, but in order for the friend to listen to the music, the individual either may have to send the music to the friend using a device other than his telephone," according to the filing, "or he may have to end the phone call and use the telephone to send the friend an email with the music attached."

Cut-and-dried, Apple's approach to improving upon this limitation is to include an "Add Media" option to the iPhone's phone application that would allow users to attach and transmit media items to another iPhone user with whom they're currently engaged in a phone call. Among the listed types of media suitable for transmission during calls are music files, video, images, voicemails, and podcasts.

"For example, the user may initiate a telephone call with his friend in order to ask the friend if she is familiar with a particular song," Apple said. "Once the phone call has been established between the user and his friend, the user may select the song of interest from his communications device, and he may send the song to his friend over the same communication path used by the communications device to establish the communications operation, so that the two may continue their phone conversation while the song plays simultaneously."

Alternatively, the filing notes that "the communications device may receive a communications operation in the form of a request for a video conference, and once the conference is established, the user may select a video (e.g., a YouTube.TM. selection) to be sent back to the conference initiator by the communications device over the same communication path."

iPhone users would also have full control over playback of media items once they're shared, according to Apple. For example, they could pause and resume playback of a shared digital music track, skip to the next or previous track in the sender's music library, or switch to transmitting a different media item entirely.

Throughout the filing, the Cupertino-based company makes numerous references to interactive iPhone video conferences where digital media files are shared, something not possible with today's iPhone models because they don't include include a forward-facing video camera.

"For example, the user may wish to transmit a video media item to the recipient of a communications operation, where the ongoing communications operation is in the form of a video conference," Apple said. "Thus, there may be two video data streams to transmit to the recipient, one related to the media item and one related to the communications operation."