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Broadband dreams and multicast 'beams'

Internet pioneer Vint Cerf says the Internet will only make good on its true broadband promise when ISPs finally adopt multicast technology.

Imagine you come home on a Friday evening after a hard week at work and simply want to spend time watching a movie you choose with your family.

If technology pundits are to be believed, the most cutting-edge way to do this would be to fire up your home PC, download a movie (from a vast, legal online library of movies) and watch it via your wireless home network on your big-screen TV. The reality, however, is vastly different.

The Internet is not ready to be a true entertainment medium.
Watching movies over the Internet requires time, planning, and a connection between your PC and TV (wireless or otherwise). It can take too long to download a complete movie from a legitimate Internet service like Movielink or CinemaNow. And when the movie arrives, it often does not look as good as the DVD version.

What's the problem? Unfortunately, the Internet is not ready to be a true entertainment medium. It cannot provide the instant gratification and quality consumers have come to expect from DVDs--once you have the DVD, that is. As a result of its architecture, the Internet cannot cater to a vast number of people simultaneously asking for large files such as movies.

Broadband Internet service providers advertise their "fast Internet" speeds. They often claim to give you more than a megabit per second, but the reality is that at any given moment, they make available only an average of approximately 20 kilobits per second for each subscriber: one-fiftieth the bandwidth they advertise.

Yes, you may experience speeds of 1mbps or more--but most likely only when, one, you request a small piece of content like a Web page, not a movie, and two, most of your neighbors are not using their Internet connections. In other words, your ISP is counting on you spending only a tiny fraction of time using its network to look at your e-mail or check up on your eBay auction.

If you started using the network to download movies--and your neighbors did, too--your ISP would have one-fiftieth of the bandwidth required. This would make downloads slow and painful. Watching that Internet-delivered movie "on demand" becomes impossible. And forget about using the Internet to download the high-definition movies that Hollywood will be introducing in the near future: These high-def movie files require five times the data of current DVDs.

So, are you stuck with the trips to the video store to get the flicks you really want? The folks at MovieBeam don't think so.

Unfortunately, ISPs are slow to embrace multicast, and there is no plan for them to work together to deliver multicast yet.
They have built a movie service that does not use the Internet, but instead uses state-of-the-art technology to give you access to 100 movies on demand, with 10 new movies updated weekly.

How does it work? MovieBeam starts with one insight. Today's Internet fails when you are sending the same movie "file" to millions of movie watchers. A better way would be to "broadcast" the same movie to those millions. So instead of sending millions of files, MovieBeam only sends one. To do this, it built a proprietary data network that inserts the movie bits into unused television broadcast spectrum. Since the broadcast tower does all the really hard work, the investment in infrastructure is minimal. MovieBeam "beams" 10 movies a week over this network to the easy-to-install MovieBeam receiver that stores the movies in a high-capacity hard drive.

With this system, popular movies are "pre-positioned" in the MovieBeam receiver; the movie you want to watch is (hopefully) already in your home and available "on demand" when you want to watch it. There are no download issues, and the quality is not constrained by Internet bandwidth, so all movies are in DVD quality. And the system will work just as well for high-def movies.

Today's Internet simply cannot compete with MovieBeam's efficiencies. If MovieBeam wanted to use the Internet, it would be sending 10GB of data--roughly the size of 10 compressed DVDs--to every MovieBeam user. If there were a million MovieBeam users, that would translate into 10 petabytes (!) of data each week--the equivalent of 15 percent of total U.S. Internet traffic for this service alone. And, of course, should more people want the service, the network requirements would increase proportionately.

Current Internet technology simply cannot keep up. However, there is a solution to make the Internet more of a "broadcast" platform, and therefore a more effective entertainment medium.

"Multicast" is a technology that efficiently broadcasts data over the Internet. With multicast, only one copy of the movie file would cross the Internet--and that one copy would be replicated for each user who wants a copy. If the Internet were "multicast-enabled," MovieBeam would send out only 10 gigabytes per week over the Internet, no matter how many users it had.

Multicast was developed in the 1980s, and most routers that handle Internet traffic are already configured for it. So why hasn't it yet been enabled?

Unfortunately, ISPs are slow to embrace multicast, and there is no plan for them to work together to deliver multicast yet. But it is time for them to develop such a plan. One possibility: ISPs could broadcast popular content over satellite networks. Whatever the plan, it is my hope that multicast will be enabled soon, and when it is, the Internet will finally make good on its true broadband promise.