How Apple AirPlay Works


Apple AirPlay lets you stream music or movies from iTunes or your mobile Apple device to any AirPlay-enabled device on the same network.
Apple.com screen capture by HowStuffWorks staff

Apple wants you to stream music and movies all over your home network. And they want you to do it wirelessly. And of course, they want you to use Apple AirPlay to do it.

AirPlay is a service that Apple devices can use to stream audio and video between electronic devices. This is similar to the way you might connect to a streaming radio or video Web site, like Pandora or YouTube, except that everything is located on your network rather than out on the Internet. Using AirPlay, you can play media from a single AirPlay-compatible source, like an iPad or iPhone, and stream it to multiple AirPlay-compatible devices on the same network, including TVs and stereo systems.

AirPlay is a leap beyond just connecting stereo speakers to your iPad or iPhone. AirPlay has two active components: a source and a receiver. The source is a device running AirPlay-enabled software, meaning that it can stream media (audio or video) using AirPlay. The receiver is an AirPlay-compatible device that can play that streaming media as well as display track information, such as the song title and artist name. A single source can send its stream to multiple receivers.

As of this writing, the list of devices that could be AirPlay sources includes the iPad, second generation or later iPod Touch, iPhone 3G and 4, and the second generation Apple TV. These devices must be running Apple iOS 4.2 or later, and any application you want to stream from must have the option to enable AirPlay streaming for that app. You can also enable AirPlay from your computer by running iTunes 10.2 or later.

Also as of this writing, devices that can be AirPlay receivers are, primarily, the Apple AirPort (a proprietary wireless hub for Apple products) and Apple TV. Some devices that could be sources also have the ability to be receivers. Apple TV is the only receiver that can stream HD video and photos from your device in addition to audio. Later, we'll look at some third-party manufacturers that have partnered with Apple to produce stereo equipment with AirPlay compatibility.

As a basic example of how you might use AirPlay, suppose you have an iPhone and you launch iTunes on it to listen to your favorite tracks. Since you'll be walking around the house a lot during the day, you decide to turn on an AirPlay-enabled stereo in your bedroom and your WiFi-connected Apple TV in your living room. To make sure there's no break in the music as you move from room to room, you go back to your iPhone and select the stereo and Apple TV as recipients of your iPhone's music stream. Since they're all accessible by network connections, and they can all use AirPlay, all you have to do is turn on the receivers, click to start streaming from the source and enjoy your music.

In this article, we focus on how Apple AirPlay streams music and whether its limitations and competition could potentially outweigh its advantages. First, let's zoom in on how you can enable and use AirPlay.

How to Connect AirPlay Devices

Click the AirPlay icon to select which devices you want to receive the signal.
Click the AirPlay icon to select which devices you want to receive the signal.
Apple.com screen capture by HowStuffWorks staff

To send and receive streaming audio and video with AirPlay, the devices you're using must first be connected to the same local network. This connection could be wireless, using WiFi or Bluetooth, or wired, using Ethernet. Though connecting with Bluetooth isn't the same as being on your home computer network, AirPlay detects Bluetooth devices automatically and lets you manage them alongside your other network-accessible AirPlay options.

For WiFi networks there are two ways you can set up your AirPlay network connections:

  • You can use an Apple AirPort Express, a small portable wireless router designed to interconnect all your Apple devices whether or not you have an Internet connection. AirPort needs no additional equipment or setup in order to use AirPlay, and you can connect a stereo directly to the AirPort to use as either the source or receiver for an AirPlay audio stream.
  • Without AirPort Express, you can use an existing home network setup, such as a wireless router. If you already use a router to share a single Internet service among multiple computers in your home, then all you need to do is connect each AirPlay-enabled device to that same network. For more about setting up your home network, see our article How Home Networking Works.

After you've added your AirPlay-enabled devices to the same network, each AirPlay source can automatically detect all its potential receivers. For example, if you add your iPad to the network, the iTunes app on your iPad will automatically detect that the Apple TV in your living room and the AirPlay-enabled speakers in your bedroom are possible remote output devices.

So how do you use it? Airplay-enabled apps will automatically scan your WiFi network for compatible devices. When an application detects that AirPlay is possible, the AirPlay icon will appear in the application display. Once you access the AirPlay menu, you can select individual devices you want to receive the streaming audio or video from that application. Note that if you wish to share your media between two computers on your network, the AirPlay icon will not appear. That's because the iTunes application for desktop and laptop computers already has a built-in library sharing function for other iTunes users on your network. AirPlay is redundant for this computer-only scenario. For more information on streaming, check out our article on How Streaming Video and Audio Works.

Next, let's consider the advantages and limitations of using AirPlay.

The Pros and Cons of Apple AirPlay

Currently, your only option for streaming video to your TV with AirPlay is to have an Apple TV device connected to that TV.
Currently, your only option for streaming video to your TV with AirPlay is to have an Apple TV device connected to that TV.
Image courtesy of Apple, Inc.

Some tech experts tout AirPlay as a revolutionary technology that will change the face of home entertainment and network data sharing. AirPlay has the following advantages that give credence to that idea:

  • There continues to be an increasing number of Apple iOS apps (for iPad, iPhone and the iPod touch) that support streaming output using AirPlay.
  • When used with Apple TV, your Apple mobile device becomes a hand-held remote control for sharing music, movies and photos on your TV.
  • Even while streaming content from it, you can keep using your Apple mobile device for other things like checking e-mail, updating your Facebook status or playing "Angry Birds."
  • Audio streams carry track information, including artist and song title, which the receiver can show on its own graphical display.
  • When you've enabled AirPlay on each of your devices, the system works without any complicated configuring.
  • If the source you're playing from is streaming HD video, AirPlay can carry that HD quality to your Apple TV (version 2 or later).

Despite these great features, AirPlay also has its limitations. Most of the criticism around AirPlay cites the following disadvantages:

  • Multiple receivers streaming from the same application all play the same content. They cannot branch off to access separate content from that same source.
  • Only one app can use AirPlay at a time.
  • Video sharing is only available to an Apple TV device.
  • An Apple TV must have an Internet connection in order to play copy-protected video content.
  • WiFi network connections outperform Bluetooth connections, though the WiFi stream does tend to drop out occasionally while it's playing.
  • Despite the efforts of other manufacturers to produce AirPlay-enabled devices, it's still primarily an Apple-only feature.

In addition to these limitations, streaming to something other than a computer requires purchasing an Apple TV or AirPort Express, each available for $99 as of this writing, or experimenting with third-party AirPlay-enabled devices. This could be a hidden agenda to sell more Apple TV devices, or it could just be a revenue stream for Apple as they charge manufacturers a $4 licensing fee per AirPlay-enabled device they sell [source: Elmer-DeWitt].

So far, we've looked at Apple AirPlay with a focus on its use by other Apple products. Now, let's look who's partnering to offer AirPlay compatibility outside of Apple, and how AirPlay compares to other media-sharing technology.

How Apple AirPlay Stacks Up

The DLNA has certified the interoperability of digital products since 2004, allowing those products to boast the "DLNA Certified" logo.
The DLNA has certified the interoperability of digital products since 2004, allowing those products to boast the "DLNA Certified" logo.
Digital Living Network Alliance screen capture by HowStuffWorks staff

As of mid-2011, Apple is working with these partners to create products that can play streaming audio using Apple AirPlay: D&M Holdings (Denon and Marantz), Bowers & Wilkins, JBL and iHome. The last three primarily make stand-alone wireless speakers while Denon and Marantz brands include sophisticated audio-video (A/V) components for home entertainment systems.

Are these components an affordable option for your home entertainment setup? Adding a Denon or Marantz A/V receiver to your system will cost several hundred dollars, not including the additional $49.99 required to enable AirPlay on each device. Only purchase one of these if you're already in the market for a high-quality A/V component. The speaker-only products offered by Bowers & Wilkins, JBL and iHome are less expensive, but not by much. The Bowers & Wilkins Zeppelin Air will set you back almost $600, the JBL On Air Wireless just under $350, and the iHome iW1 about $300.

So, while AirPlay is a free feature on Apple products, making full use of it can hit hard in the wallet. The question is, will people buy it? As developers produce more devices and applications to use AirPlay, time will tell whether AirPlay itself becomes yet a true selling feature for Apple products.

In the meantime, a lesser-known group known as the Digital Living Network Alliance (DLNA) is continuing the strides it has been making since it launched in 2003. More than 245 companies are part of the DLNA, which originally formed to establish interoperability standards among digital devices. The group published its DLNA Interoperability Guidelines in June 2004 along with a certification program to recognize products that meet the standards.

Wired and wireless DLNA-certified devices are everywhere, and they have far more interoperability features than AirPlay. For example, a certified digital media player (DMP) can access network attached storage (NAS) by way of a certified digital media server (DMS). So, instead of having to play your music or movies as a stream from a separate device, your TV or stereo can access them directly from the source.

Some of the member companies in the DLNA are household names like Microsoft, Sony and Sharp, as well as trusted tech industry favorites Logitech, Cisco and Nvidia. Conspicuously absent from the DLNA, though, is Apple. Apple has a reputation of keeping to itself and venturing to establish its company brand as its own standard.

AirPlay started its 2011 growth spurt following the release of Apple iOS 4.2. As of June 2011, it's too early to know whether AirPlay will become a long-term success, or if Apple will be able to overshadow the years of successful DLNA collaboration in the home streaming arena. Stream forward to the next page for more useful information.

More Great Links

Sources

  • Apple, Inc. "Using AirPlay." April 18, 2011. (June 12, 2011) http://support.apple.com/kb/HT4437
  • Bowers & Wilkins. "Zeppelin Air: AirPlay." (June 13, 2011) http://www.bowers-wilkins.com/iPod_and_Computer_Speakers/iPod_and_Computer_Speakers/Zeppelin_Air/airplay.html
  • Carnoy, David. "Apple AirPlay: 10 things you need to know." CNET. CBS Interactive. Apr. 4, 2011. (June 12, 2011) http://howto.cnet.com/8301-11310_39-20049405-285/apple-airplay-10-things-you-need-to-know/
  • Digital Living Network Alliance (DLNA). "About Digital Living Network Alliance." (June 12, 2011) http://www.dlna.org/about_us/about/
  • Denon. "AirPlay." D&M Holdings, Inc. (June 13, 2011) http://usa.denon.com/us/Airplayus/index.html
  • Elmer-DeWitt, Philip. "AirPlay's hidden agenda: Apple TV sets." CNN Money. Cable News Network. Time Warner. Mar. 24, 2011. (June 12, 2011) http://tech.fortune.cnn.com/2011/03/24/airplays-hidden-agenda-apple-tv-sets/
  • Gruman, Galen. "How AirPlay and iTunes could enable the 'post-PC' office." InfoWorld, Inc. The IDG Network. Feb. 1, 2011. (June 12, 2011) http://www.infoworld.com/d/mobilize/how-airplay-and-itunes-could-enable-the-post-pc-office-471
  • iHome. "Discover: AirPlay." SDI Technologies, Inc. (June 13, 2011) http://www.ihomeaudio.com/discover/airplay/
  • JBL. "JBL On Air Wireless." JBL. Harman International Industries, Inc. (June 13, 2011) http://www.jbl.com/EN-US/Products/Pages/ProductDetails.aspx?PID=JBL%20ON%20AIR%20WIRELESS
  • Marantz. "AirPlay." D&M Holdings, Inc. (June 13, 2011) http://airplayus.marantz.com/
  • Patel, Nilay. "iHome iW1 AirPlay wireless speaker hands-on." Engadget. AOL, Inc. Jan. 6, 2011. (June 13, 2011) http://www.engadget.com/2011/01/06/ihome-iw1-airplay-wireless-speaker-hands-on/