The Alliance for Telecommunications Industry Standards yesterday released a high-level architectural standard for IPTV that has been developed by its IPTV Interoperability Forum (IIF). Dan O’Callaghan, chairman of IIF, spoke with Editor-at-Large Carol Wilson about the significance of the document.

On the process itself: We got started in 2005, and our first step was to establish IPTV requirements, then to prioritize requirements. This is our first major significant document that is not just requirements – this one provides the structure for which specifications will be written to.

On the chance for true end-to-end IPTV interoperability: Our intent is to have interoperability – that’s the second part of our name. Equipment manufacturers who choose to comply with this set of standards should be able to interoperate. But my favorite definition of standards is a common point from which to deviate. Our next step is to start generating specifications that enable devices to be built to the architecture.

On melding IMS [IP Multimedia Subsystems] and Web Services: One of the most significant things that has happened with this architecture – and it has been forwarded to ITU-T, DVB and others – is that it describes the harmonization of Web Services and IMS. We had a lot of different opinions on this, you could see how things would live in different strata in Web Services or IMS. There are certain things done in IMS like presence, or charging functions, but there are other Web ways of doing it also. So what we did was say, if you trying to build this up so devices are interoperable with IMS and Web services, here is how the architecture is being constructed so they can co-exist.

On how that was accomplished: My second favorite definition of standards is mutually unacceptable compromise. I like to describe it [the solution] as bubbles in a line. There is a red line and a blue line, and they are like layers following along the same path, until you get to a topic area, say, service provider attachment – and then the red and blue lines went around that topic in different directions. The message is the set of standards will be the same wherever possible, so the box turns on, does DHCP [dynamic host configuration protocol] and that is all the same whether talking to Web Services provider or not. Then when you attach to the service provider, if they say they do ISM, then you do the sorts of things to register there. And if its Web Services, you go through that process. You may have done registration differently but at the end come back and get the same EPG [electronic programming guide] data structures. Hopefully, you get the same guide, the same method of fetching authorization keys, etc. The bubbles are going to exist, that is what is going to happen. We are providing the option of doing certain things along the way, one way for IMS and one way for Web Services, but at the end you have to bring them back together so they are joined on as common a set of specifications for the service as possible.

On how this aids deployment: When we talk about Web services, we all assumed it to be over a managed network, not the World Wide Web. What this will allow is for service operators who choose to do this over Web Services or ISM, to maintain for them the largest pool of competitive products to implement that. Admittedly you certainly could have a vendor who only embraces only a Web Services approach, ignores IMS completely, and maybe someone who wants Web Services will buy his product, I’m not saying everything will be both. But service operators will have the ability to choose which approach to deploy their service on.

On how this helps equipment vendors: There the process is worth noting. We didn’t jump into this and say let’s start writing specs. We spent a lot of time talking with other standards bodies before the requirements document was published. IPTV does everything from watching TV to video blogging, being your own TV station. We realize this is an elephant, especially since the IIF’s mission, while everybody else focuses on service provider toconsumer interface, we are the only one who has said we are going from content owner to consumer. We looked at this elephant and said we have to eat this one bit at a time. Break it up in logical chunks. So we now have a three-phased deployment plan – first is to replicate television, the TV watching experience. People will say, ‘That’s all you’re doing’ but that’s the heavy lifting – 90% of the heavy lifting is in the phase of just getting video delivered. The second phase is what I call light interactive services such as Video on Demand, fast forwarding, etc. Then the third phase is the heavy-duty bi-directional stuff like video-conferencing or watching your DVR content from someone else’s house or two-way video.