AirPlay: How Does It Work and What Devices Can Use It?

How Do You Use AirPlay to Stream Digital Music?

AirPlay Icon
AirPlay can be used to wirelessly stream music video. Image Courtesy of Apple.

If you've seen the AirPlay function on your iPhone, iPad, or iPod Touch, you might think it's connected in some way to AirDrop—another wireless option built into iOS. However, AirPlay isn't for file sharing like AirDrop.

It is a wireless technology that was developed by Apple for streaming content rather than transferring files. It was originally called AirTunes because only digital audio was supported, but it was renamed AirPlay when more features were added.

It can now stream video and photos as well as audio.

AirPlay is made up of a proprietary set of protocols that enables you to use your Mac computer or iOS mobile device to stream media over a Wi-Fi network.

How Can Music be Streamed?

For digital music, you can stream to your TV equipped with an Apple TV box, share with other devices using an Airport Express, or listen with AirPlay-compatible speakers. It's also possible to stream digital music to several rooms equipped with AirPlay speakers using iTunes on the PC and Mac.

Hardware Devices That Use AirPlay

Just like any wireless network, you need a device that transmits information (AirPlay Sender) and one that receives it (AirPlay Receiver).

  • AirPlay Sender Hardware: Apple portable devices running the iOS operating system—iPhone, iPod Touch, and iPad—are senders. They must be running at least iOS version 4.2 or higher to use AirPlay. A Mac or PC with iTunes can also be set up as an AirPlay sender device.
  • AirPlay Receiver Hardware: Apple TV, Airport Express, and AirPlay-compatible speakers are the main ways of receiving wireless media from AirPlay senders. However, other examples include stereo systems, audio-visual receivers, and docks.

Can AirPlay Transmit Metadata?

Yes, it can. For example, if you use Apple TV to stream music, videos, and photos from your iOS device to your HDTV, then metadata such as song title, artist, and genre can be displayed.

Album art can also be transmitted and displayed using AirPlay. The JPEG image format is used to send cover art.

How Does AirPlay Work and What Audio Format Is Used?

To stream digital music over Wi-Fi, AirPlay uses the RTSP protocol—Real Time Streaming Protocol. The Apple Lossless audio codec is used over the UDP transport layer protocol to stream two audio channels at 44100 hertz.

The audio data is scrambled by the AirPlay server device, which uses a private key-based encryption system.

How to Use AirPlay to Mirror Your Mac Display

You can use AirPlay to mirror your Mac display to an Apple TV-equipped projector or TV, which is handy when you are giving presentations or training groups of employees.  When both devices are turned on and connected to the same Wi-Fi network, click on the AirPlay status menu in the menu bar of the Mac and select the projector or television from the drop-down menu.