You're excitedly perched in your favorite chair with your tablet in hand. The trailer for the movie you've been dying to see has finally been released, and you can't wait to see it. You start the clip from the movie's Web site, and ... wait ... buffering ... oh, there it is. Hmmmm. It's a little stuttery. This isn't quite what you had in mind. Wouldn't it be great if someone would figure out a way to make online video streaming and downloads smoother and more efficient?
Smartphones and tablets with mobile broadband are becoming more common every day. A report published in February 2012 indicated that between 2010 and 2011, the mobile data networks behind these devices grew 133 percent, and the average smartphone nearly tripled in data usage, from 55 MB to 150 MB per month. With more powerful devices and faster network speeds, streaming video is easier to consume and now accounts for more than half that traffic [source: Cisco].
Growth like this inspires innovation, especially when overcoming barriers. If you have a limited data plan with a mobile data service provider, you have to be aware of how much data you've consumed each month so you don't exceed your limit and pay penalties. Even if you have an unlimited plan, you probably want to limit the data you download to only what you actually use so your phone or tablet runs as efficiently as possible.
That's where DASH comes in. DASH stands for Dynamic Adaptive Streaming over HTTP. As we'll explore in this article, DASH is a standard for streaming video over the Internet. It overcomes issues with some other streaming standards, including wasting bandwidth on unviewed content and lack of adaptability to your data connection's available bitrate.
The developers behind DASH include Christopher Müller, Stefan Lederer and Christian Timmerer, all associated with the Klagenfurt University in Austria. Their effort is part of a larger project called the 3rd Generation Partnership Project (3GPP) to create global standards for mobile broadband. The three researchers have chronicled DASH development in blog format, and they've presented and promoted DASH to industry colleagues around the world [sources: ITEC-DASH, Timmerer, Timmerer and Müller, Lederer et al., 3GPP].
The new technology has led to a new standard under the Moving Picture Experts Group (MPEG). If MPEG sounds familiar, it's no surprise. MPEG is the organization behind the world's most widely adopted digital media standards, including MPEG video and MP3 audio. As a standard, DASH is referred to as MPEG-DASH. As of this writing, MPEG-DASH has passed enquiry and is in the approval stage in the International Standards Organization, where it's known as ISO/IEC 23009-1.
Before we take a closer look at DASH, let's look at the state of video streaming technology prior to DASH adoption.