Video on demand technology is something that we're sure to see more of in



the years and decades to come. After all, what could be better than choosing

what to watch and then being able to watch it on a moments notice no matter

what time it is? Services that feature video on demand are already in

existence and several different forms of the technology already exists.

The most common form of video on demand technology involves having a

number of available videos stored on a server computer in a central location.

When a viewer wants to watch one of these videos, she or he simply requests

it, and the server computer sends that video to the viewer. This is how

streaming Internet video and the video on demand services of cable TV

companies work. They obviously use different technology to transmit the

video, but the concept is generally the same.

Another technique that can be used to deliver video on demand is through

digital video recorder technology. This is the favored technology of satellite TV

companies. Basically, the hard drive of the DVR takes the place of the server

computer in this scheme. This is a lot better for how satellite TV works in that

because satellite TV doesn't have a distinct connection with every single

household that's receiving its service, its programming has to be sent to all of

its subscribing households all at once. This model of TV transmission doesn't

allow for individual streams of programming that are necessary to deliver

video on demand service from a central location. In order to get around this,

satellite TV providers simply deliver their video on demand content to all of the

digital video recording satellite receivers that are in the homes of their

subscribers all in a single burst. Then the subscribers can access that video

when they're ready to watch it. This is done periodically in order to provide

subscribers with a fresh selection of video on demand options.

The use of digital video recorder technology to provide video on demand

service is limited in a number of obvious ways. First of all, the satellite TV

provider has to dedicate an entire channel- or several channels- to delivering

video on demand content. Second, a household DVR will have a much

smaller capacity to store video on demand offerings than a larger server

computer or bank of servers.

Neither of the above limitations are particularly dire though. For example,

satellite TV providers have enough bandwidth (and are adding more

bandwidth) so that dedicating a few channels to video on demand really isn't

much of a burden. The relatively limited capacity of household DVR receivers

also isn't much of an impediment to video on demand because the licensing

of the movies and TV shows, along with other legal issues, is holding up the

implementation of comprehensive video on demand at least as much as the

limitations of technology like hard drive space. That should give hard drive

capacities plenty of time to catch up. This is especially true when you look at

how rapidly hard drive capacities are growing these days.

In all, video on demand has a lot of promise to keep us entertained with

exactly what we want to watch, and is well on its way to becoming a reality.