By Steve Israelsky, Tightrope Media Systems
There has been a lot of discussion among access centers and in the trades lately about the broadcast transition to IP technology. There is a consensus that the broadcast world is moving in that direction. At this point you might be wondering what exactly does that mean, and how might this affect you.
IP stands for Internet Protocol. IP technology was built to deliver content in packets across the internet to your computer screens. The technology has evolved and improved over time and is now used for a host of other applications such as “Over the Top” or OTT transmission to a set-top appliance such as Roku or Apple TV. IP technology is also used to deliver VOD content, content to classrooms and cable boxes, and in many other applications. This is all classified as IP broadcast distribution or delivery. The need for IP technology in distribution is well established. Indeed, it is the only way to deliver content over the Internet. However, everything becomes a bit murky when integrating IP technology into the production process and into master control.
The real question here is why anyone would want to do that in the first place. There are valid reasons why any broadcaster, including a PEG channel, would want to transition to an all IP based workflow. An IP platform improves efficiency, reduces the quantity and variety of cabling required, and eliminates complexity. The cost of adding additional channels, among other things, lessens. The problem is we are far from that scenario, and in the interim a full transition to an IP based workflow is more expensive, more complex, and a lot harder to maintain.
The fact of the matter is that all of your production equipment is not IP based; it is still SDI based. Your camera outputs are not Ethernet connections; they are generally BNC connectors carrying SDI signals. These signals run into your production switcher that is also SDI based. The output of that production switcher is an SDI signal that goes into an SDI based encoder or routing switcher to be put on air. In order to utilize IP based video servers, encoders and switchers, everything needs to be converted to IP streams. Doing so requires additional hardware on the acquisition side, and in many cases, also on the distribution side since cable companies are still more comfortable taking a standard SDI or composite output from PEG channels. This conversion equipment is costly, and eventually, will be unnecessary.
According to TV Technology author James Careless, “SDI-based switching remains the way that broadcasters produce live TV these days, even in a world of video-over-IP advances. This is because the two technologies are built upon fundamentally different architectures: SDI-based/switching and routing handle individual uncompressed video streams that are frame-synchronized to each other. Video-over-IP signals are packet-based, with many streams intermingled on a common pipeline. This makes standard A/B video switching impossible without some form of technical workaround; primarily because IP transport was never designed nor meant to be a real-time switchable signal format.”
The vast majority of broadcasters have not made a transition to an all IP based workflow. In fact, a recent industry survey of 1,000 individuals at small, medium and large broadcast facilities and production houses indicates that more than two thirds of the respondents do not expect to have an all IP based workflow for at least another five years. At the last CCW Conference in New York, Turner Broadcast SVP of Technology Michael Koetter offered similar sentiments. He pointed out that he’d like the new CNN facility scheduled to open in 2018 to be completely IP based, but doesn’t think the technology will be proven by that time.
There are other concerns as well. Quality control and monitoring will require both a broadcast engineer running a waveform monitor as well as an IT expert running a packet analyzer. In addition to having a very solid video infrastructure, an equally solid IT infrastructure is needed, as a hiccup on your network will affect your on air playout. Also, IP can put the educational and government programmers in an awkward place politically as they are now officially part of the IT infrastructure.
Cost is perhaps the biggest factor. New technology and a change in workflow before that technology is adopted by the industry at large can be financially challenging. Perhaps a prudent move is to let the technology be perfected and completed by the for-profit broadcasters. On the other hand, IP technology is already what every manufacturer of PEG automation and video server hardware uses to send programming from master control to computer screens, OTT devices and mobile phones. So congratulations, you have probably already taken the most essential step in IP transmission. If you are curious about what Tightrope Media Systems is doing with IP Broadcast, check out Tighty.TV, Tightrope’s own PEG channel and view the live streaming and VOD files from your computer, mobile phone or tablet.