Redundancy Myths

Some TV people become concerned when all their eggs are in one basket. In fact, when everything is in one basket, you always know exactly where the basket is.

Airplanes use redundant systems. They have redundancy system plans A and B, and use Plan C as a last resort. Redundant systems are designed to keep airplanes from crashing. Redundant broadcast systems are designed to keep stations from crashing. Dual power supplies in a critical computer or rack frame are not redundancy. They are a redundancy myth. TV stations need fully redundant systems.

Airplanes are a most extreme example because they are pure reality and subject to every law of physics. Live TV is an illusion. That luxury is not a parachute, it’s a curtain. TV can use all the smoke and mirrors it takes to hide a critical live system failure from the audience.

When television stations crash, careers can be casualties. What TV station wants to be the lead story on their competitors’ newscasts? What engineer wants to paint their station into a corner?

TV master controls systems typically have some redundancy built in, such as a routing switcher to fill in for a broken master control switcher. It may not be a perfect substitute, but it beats a patch panel, and the show goes on. If an operator can keep up with the log with local manual control, most viewers probably won’t notice. It can be a pain, but tolerable if an operator is nearby.

Better yet would be a parallel system that would switch in automatically, but in the pre-IP video world parallel video systems can be expensive. In today’s IP-based TV facilities, there is no need for distribution amplifiers, a routing switcher or extra monitors. Two systems can operate in parallel economically.

Newsroom redundancy

Newsrooms are at the opposite end of the simplicity scale from Master Control. There are many active electronic components and content sources in a newsroom and newscast. Any component can break at any time. If a live newscast melts down on the air, everyone gets to watch. If it could possibly be emergency-switched with a routing switcher control panel, it probably won’t be pretty. Live news and sports tend to push technology and coordinating it to the limit.

The GV XSWITCH master module backplane. Courtesy Grass Valley.

The GV XSWITCH master module backplane. Courtesy Grass Valley.

Moving a typical existing SDI-based newsroom system to full redundancy can easily become big capital investment that doesn’t always make economic sense. It would require a mirror system operating in parallel with the main system, and a master change-over switch that would transfer all SDI inputs, outputs, graphics and monitoring from System A to System B without a noticeable glitch, in the studio, the control room and on TV. Dual Grass Valley Ignite systems connected by a GV XSWITCH is one example that’s been available for more than a decade. An integrated IP-based system can achieve near aviation-class redundancy for a fraction of the price.

Live newscasts and the newsrooms that produce them require a symphony of digital electronics to work seamlessly in harmony, and the Newsroom Computer System (NRCS) is the conductor. At the center of many newsroom system drawings is a graphics system, a production switcher or an automation system. It often depends on who made the drawing. In fact, the NRCS is where the news starts and it’s the center of the universe in newsrooms.

The NRCS is at the center because it has all the information important to the production gear such as the switcher, graphics, lighting, clip servers and cameras. This information can be used in automation systems with the Media Object Server (MOS) protocol, which talks to production equipment through MOS interfaces, or gateways. A MOS gateway adds another layer of complexity, and more complexity increases potential for failure.

Each piece of equipment connected to the NRCS needs a specific MOS driver. There are hundreds of drivers for products from dozens of manufacturers in categories from audio mixers and audio servers to video servers and VTRs. Drivers aren’t always available for all possible combinations of legacy gear.

Affordable redundancy

The NewTek TriCaster and IP Series are the enabling technology for affordable redundancy, because NewTek spent millions of manhours building and tweaking all of the gear required for a modern live TV news production into one box. All the TriCaster and IP series needed was a MOS-based automation system to make it a perfect fit for live news production.

Rundown changes immediately update the TriCaster.

Rundown changes immediately update the TriCaster.

With unlimited choices of NDI sources available under NewsMaker automation control, the TriCaster and IP Series becomes a routing switcher with virtually infinite inputs and outputs.

The NewsCaster MOS interface to the MOS enabled-NRCS enables the TriCaster’s and IP Series wide range of internal production capabilities to be placed as “MOS objects” directly into the newsroom rundown as the scripts are created. This includes the video switcher, mix/effects, audio, IFB, CG, clips, virtual sets, and PTZ or robotic cameras.

Based on the rundown order of the NRCS, NewsCaster automatically loads all the production elements into TriCaster and IP Series media bins which are immediately available to the operator, cued and ready for air. Any rundown changes immediately update the TriCaster and IP Series.

The show can be run from the control surface, a button box, keyboard and mouse, touch screen, or in the fully automated, “hands-off” mode from show start to show finish. Daily newscasts, including their complicated graphics, don’t need to be assembled on-air and in real-time by a room-full of production people. Time consumed by that type of work can be substantially reduced or eliminated depending on the level of automation dialed into the NewsMaker.

Behind the scenes secrets

The power of fully-integrated redundant IP systems means that if System A fails, System B switches itself in automatically. It doesn’t need DAs like traditional systems, and operators and viewers shouldn’t even notice. A blue screen from System A could trigger a switch in one frame.

The simplicity of an all-IP system is that everything is just an “If, Then” IP event away. For instance, a blue screen triggers a software routine that results in a global reassignment of subnet addresses, and the switch is made. The show continues, but using another IP network path. The switch could be automatic, manual or both.

The all-IP redundant System B doesn’t have to reside in the same location as System A. The systems can be separated by a rack or communicate across a WAN. It would also allow any sister station on the WAN to run any other similarly-equipped station on the WAN, if necessary.

The author thanks Lan Merrill, NewsMaker VP for much of the information in this article.

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