Three Steps to Online Broadcasting - Page 11

Content production and programming

Preparing audio content for Internet delivery is covered pretty thoroughly in the Web Audio Workshop series of columns. Once you have the content, you face the task of organizing it into programs for the end user. This may involve a sequential program (live or recorded), a library of on-demand clips, or both. As our discussion of the theoretical Perfect Radio Station in the last two columns demonstrates that, on the Internet, the level of user interactivity is theoretically unlimited. Thus, rather than assembling fixed programs to be delivered to the user, programmers will be assembling a user environment within which the listener can create his or her own program.

Hosting and Network Services

Just as most organizations subcontract with a Web hosting service to run their Web servers, most will do so with their streaming servers, preferably with a host that has specialized expertise in streaming.

User interface design and production

With the advent of customizable browsers and increasingly sophisticated application development tools, a user interface for online multimedia can be just about anything you want it to be. A/V can be delivered from within a traditional Web page, through one of the popular commercial media players, through a custom viewer, or within a multimedia presentation created with SMIL. The bewildering array of choices may be enough to convince many broadcasters to opt for a pre-packaged solution into which they can simply insert their content. In next month's column, we'll look at some of the possibilities for an Internet broadcasting "front end."

For now however, let's examine the back end - the hardware and network infrastructure that gets the media to the user. Outsourcing your streaming needs may involve not only choosing a host, but a Streaming Media Network provider as well. In the next section, we'll see why SMNs are one of the hottest segments of the computing industry.

Bandwidth, Bottlenecks and Business Models

Although Internet bandwidth is expanding rapidly, it remains limited when it comes to audio and video, and it's safe to say that bandwidth constraints are still the biggest problem confronting the Internet broadcaster. In a previous article, we listed the components of an online broadcast system, the centerpiece of which was a streaming server connected to the Internet by a high-bandwidth connection, just as a Web server would be. While there are thousands of such servers online delivering oodles of A/V content every day, most sites deliver audio and video of medium quality at best, and are plagued by the erratic service levels and unreliability that the Internet is famous for.

Strictly speaking, bandwidth is not the only culprit, although the problems are usually lumped together under that term. At the risk of telling a twice-told tale, we'll observe that the architecture of the Internet is far from optimal for sequential media such as audio and video. The packet-switching nature of the Net sends data to the user by whatever route is most efficient at the time, and even allows packets of data to be broken up and reassembled at their destination. This works wonderfully for static data such as text and graphics. But audio and video must be delivered at a constant rate, with no interruptions. When an A/V packet gets bounced around from one server to the next, sliced, diced and shuffled back together like a deck of cards, the result is glitches, dropouts, jerky motion, clicks, pops and all the other hated hallmarks of bad-quality digital media.

Furthermore, a sudden surge of requests to a particular server can clog it up like a wreck at rush hour. Webcasting a live event, which will draw a large number of users at the same time, is practically impossible without incredibly huge server capacity. For these reasons, it should be plain that simply hooking up a streaming server to the Internet is likely to deliver low- to medium-quality A/V at best. Even a farm of streaming servers with load balancing is no guarantee of a high- quality end user experience, for there is no knowing what bottlenecks lie between server and client. All is lost! Alas!

But lo! There is a simple (we didn't say cheap) solution! To get around all the problems of the Internet, just detour around the Internet itself. After all, delivering streaming media to a set number of users on an internal network isn't a problem, and many organizations have been doing so for years. Ethernet, or better yet, Fast Ethernet, offers quite adequate bandwidth for most audio and video applications, and dedicated networks are far more reliable than the wild and wooly Internet.

Now, if instead of simply blasting your streaming signal out over the labyrinthine byways of the public Internet, you could route it in such a way that for at least most of its journey to the user, it traveled over high-bandwidth, streaming-optimized networks, you should see large improvements in quality and reliability.

Next Wave of the Web: Streaming Media Service Providers - Page 10
Next Wave of the Web
MBONE - Page 12