A High-flying Audiovisual Backbone, Part 2
Oct 26, 2010 12:00 PM, With Bennett Liles
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The Red Bull Air Race is one of the most exciting TV events ever produced with live video from the planes, giant viewing screens for thousands of fans, and a huge job of RF transmission and audio/video networking on MediorNet. Riedel Communications made it all happen, and Thomas Riedel is here to explain MediorNet and how they used it to bring you the race.
OK, Thomas, thanks for being back with me for part 2 on the Red Bull Air Race and how Riedel's MediorNet was used for all the communications. For anyone who wasn't up on that, Riedel also bought the company that did RockNet, but MediorNet is the backbone of the whole operation at the Red Bull Air Race. So tell me a little bit about MediorNet. How does it all work?
Thomas Riedel: Well, just think about nodes within a fiber network which can be connected in whatever topology. It might be in a ring, in a star, daisy-chain, or just a point-to-point, or any combination, and these de-centralized nodes within that fiber network can be seen as a de-centralized router. So basically, we combine two disciplines here, which is routing and fiber transport. But one more discipline comes on top, which is about signal processingwhich, in the broadcast world, is called the glue featuresand that's basically all in one system, which really is a challenge on the technology, but also for people. It's a brand new idea; that's why people are not used to that. [Timestamp: 1:49]
And this is a whole video, sound, and communications network. How is this different say from 802.3 Ethernet?
Well, the main difference is we're talking about a realtime network, so it's not IP and it's really talking realtime. Talking about an event and the requirements for audio/video and data signals are realtime requirements, so you want to have no delay of, let's say, 20, 40 milliseconds, but you might accept some microseconds of delay, which an IP system could never deliver. At the same time, you want to have the advantages of the topology you might have in IP switches, and that's exactly what MediorNet does. It provides you with all the advantages and flexibility you find in modern IT infrastructures, but at the same time, it has realtime capabilities, and that's exactly the difference between these kind of systems. [Timestamp: 2:48]
And one of the features I've heard a lot about is MediorNet's ability to mix and cross-switch multiple media formats, and it handles all this in software. What video formats are you using on the air race coverage?
MediorNet accepts all kind of digital video formats: HD-SDI, SD-SDI, it might be 1080i, or 720p, or whatever format we can take in, in the inputs. And in our outputs, we just tell the output what kind of format it should deliver. So basically, that's exactly what I meant with glue features and signal processing, all conversionup-/down-/cross-conversionis done inside the engine. And talking about the Red Bull Air Race, the production format was 1080i50 while in some areas we needed still SD signals, and some other HD formats as well. But again, to our system, it doesn't matter. You just feed in what you like, and you get out what you like as well. [Timestamp: 3:45]
I was wondering about that, because the aircraft have live signals coming from them all the time with live video, and they're twisting and turning all over the place. How did you manage to avoid dropouts in the video?
Well that's a different topic, since it's a little jump from MediorNet to that topic, but it's basically also connected here. So we're talking about a COFDM technology being used for the transmission from the planes to the ground, and with several antennas on the planes to really make sure that whatever situation you have in the air, you always get proper signal to the ground to the receivers. But then these receivers are connected to MediorNet, wherever they are around the event locations, and the whole signals are shipped over fiber-optic in our network to the broadcast station, which is basically the central location where all the broadcast signals get together and where basically the feeds are produced. [Timestamp: 4:40]
You mentioned that the signal cross-conversion happens in the software. There may be some who might say that as versatile as this type of system is, maybe it's not durable or rugged enough for doing live remotes where the gear gets banged around and it's outside in the elements. How does it perform?
Well on one hand, you always think about whether you want to put all eggs in one basket or basically have several systems working together. Talking about this project, we can only say that we have never had any issue with that system, but basically we should ask our clients about that since we are the manufacturer, and we had the system in use at the World Cup in South Africa as well. The system is used in several otherin fixed locations in the mean timein Australia, in China, in Europe as well as the U.S.and all people feel that, "Well, yeah putting all eggs in one basket certainly sounds like a higher risk, but also thinking about many different systems which are in a kind of chain also provides you many more possibilities for failure." So under the bottom line, we feel that that concept is more rugged than what we have had in the past. [Timestamp: 5:56]
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