Reclassifying IP Video

When someone uses the term "IPTV" it can be very difficult to understand the intended meaning. Did the speaker mean to indicate the highly structured television delivery systems being built by telephone companies around the world? Or was the discussion about the wild and wooly world of user-generated video content portals on the Internet? With the present terminology, it's hard to tell. So, maybe what's needed is a new way of classifying the types of video delivery than can be done over an IP network.


In any rapidly changing technology, the terms used to define the field will also tend to change over time. Witness the rapid evolution of personal computing and communication devices—laptops used to be quite distinct from mobile phones, but these categories are starting to blur with the introduction of smartphones and netbooks. This transformation is also happening in the world of IP video, where the boundaries between IPTV and Internet video are starting to break down.

Originally, two categories appeared to be enough. For example, see my Sept. 6, 2006, article "Navigating Through Terms of Confusion," when there seemed to be a clear difference between the terms "IPTV" and "Internet video." This difference still exists, but there have been a large number of new services introduced over the past three years that don't really fit into either category. For example, how do you classify a service that is delivered as a continuous stream over the Internet, is funded by advertising, and plays on a computer screen or a mobile device? Or how about a subscription-based service that allows viewers to watch movies and network programs on a television connected to a set-top box that plays content on-demand from the Internet? Neither of these examples can easily be placed into the two original categories.

To help clear up some of this confusion, it makes sense to come up with two new categories that fit in between IPTV and Internet video. The first, "Internet TV" is similar in many respects to Internet video, with a significant difference: viewers watch " of streamed content, rather than select from a collection of video files that can be played. When viewers tune in they are simply connected to the real-time stream at whatever point it happens to be; perhaps mid-song or mid-sentence. To watch different content than what is currently playing, viewers need to switch to another channel.

The second new category is "IPVoD" for professionally produced video-on-demand content that can be played over a PC or an appliance connected to a television and the Internet. Many of these services are branded by a provider and carry advertising or are available through subscription. To protect this valuable content from unauthorized use, it is often transmitted using strong digital rights management protection, which is not the case for much of the available Internet video content.

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Fig. 1: Updated Classifications for IP Video
By adding these two new classifications, it becomes possible to analyze and compare the different features of each of the four categories along a range of different attributes. Fig. 1 shows the result of this comparison in table form, which is color-coded to illustrate the relationships between the categories.

On the left side of the table is IPTV, which includes many attributes that make it the only viable choice for replacing cable TV or satellite for delivery of liner programming to the home. Because it delivers continuous channels of content in real time over a managed network, IPTV is the only one of these four services that does not require any computer literacy from the viewer. In fact, if it is implemented properly, the consumer never needs to know that an IP network was used for delivery. In the table, all of the features of IPTV are coded in pink, along with any features that are duplicated in either of the two new categories. For example, IPVoD normally provides a small selection of carefully chosen content (known as a walled garden) as is the case with IPTV, so both features are coded the same color.

Internet video is on the right side of the diagram, and similarly, all of the attributes that define its functionality are coded in green. Any areas where either of the two middle categories share the same features are also coded with green. This makes it easy to identify, for example, that IPVoD, Internet TV and Internet video all operate on unmanaged public networks.

Both IPVoD and Internet TV have some features that are unique; these features are encoded with yellow for the former and blue for the latter. For example, only IPVoD has a user experience that is similar to a DVR or an IPTV VoD system, hence that feature is coded in yellow. Another example is the (blue) feature of replicated unicasting shown for Internet TV, where a server farm or a content delivery network is employed to make a copy of the real-time stream for delivery to each viewer.

Using this table, it is now possible to classify the two services mentioned at the beginning of this article. Thus, the first service that is delivered as a continuous stream over the Internet is funded by advertising, and plays on a computer screen or a mobile device is clearly an Internet TV application. Also, the second subscription-based service that allows viewers to watch movies and network programs on a television connected to a set-top box that plays content on-demand from the Internet can be categorized as an IPVoD application.


Of course, there will be some new services offered in the future that don't fit into any of these categories, or possibly more than one. This is the nature of any classification system—there will always be some items that are hard to classify. However, that doesn't invalidate the many benefits of developing the classes. By studying these different classifications, it rapidly becomes clear that there is a great deal of overlap between the categories, which points to the underlying similarities of the task of delivering video over IP networks.

Another benefit of using these classes is to simplify communication, making it easier to understand other people when they use these terms. Also, since many entrepreneurs make a living by breaking out of established categories, maybe these classes will help to stimulate someone to come up with the next great idea. Anyone up for EoD (Everything on Demand?).

So, the next time someone uses the term "IPTV," it might be a good idea to pause for a moment and consider if that person is really talking about IPTV, Internet video, IPVoD or Internet TV. This might just make it easier to understand what that person is trying to say.

Wes Simpson is an independent consultant who refuses to be classified. Please feel free to contact him

Wes Simpson

Wes Simpson is President of Telecom Product Consulting, an independent consulting firm that focuses on video and telecommunications products. He has 30 years experience in the design, development and marketing of products for telecommunication applications. He is a frequent speaker at industry events such as IBC, NAB and VidTrans and is author of the book Video Over IP and a frequent contributor to TV Tech. Wes is a founding member of the Video Services Forum.