Stuart Brown /
07.01.2013
Originally featured on BroadcastEngineering.com
Covering sports with wireless transmission
The ability to get as close to the action as possible and hold an HD signal without dropping a frame opens a Pandora’s box of possibilities — in a good way — for broadcasters worldwide.

The advent of lighter, smaller and increasingly robust wireless transmission systems is having a major impact on broadcasters’ ability to cover news, events and, perhaps most important, sports, which is a primary catalyst for the development, adoption and implementation of wireless transmission systems. The ability to get as close to the action as possible and hold an HD signal without dropping a frame opens a Pandora’s box of possibilities — in a good way — for broadcasters worldwide.

The benefits of wireless

In terms of sports and wireless transmission, there are a number of questions to answer, but the most important one is: What are the advantages of going wireless?

The first clue is in the name wireless — no bulky cables to string, store or transport. Safety officials see a marked improved in accident and injury reports because fewer people are tripping over bulky cable runs, particularly, as is often the case, in public areas. Broadcast professionals pretty much know by rote that there are cables underfoot, but going wireless reduces risks to others who may inadvertently stray into a hot zone of action.

Likewise, rigging times are far reduced by going wireless, which, in addition to reducing the risks associated with more demanding, cabled rigging scenarios, keeps management happy as it sees production costs reduced. This includes costs associated with transporting large spools of copper coax.

Wireless also provides the freedom to go anywhere, which is highly valuable to producers because it gives them the freedom to follow the action as it happens, wherever it happens. This can greatly enhance sports coverage in particular. We are seeing an accelerating trend in the use of wireless technology to, for example, provide on-board coverage for motorsport and boat racing events, as well as for point-of-view coverage for team sports such as soccer and cricket.

For example, wireless camera equipment was recently used to provide batsman and umpire cameras in Twenty20 cricket, which had never been done before and was a significant advancement in the enjoyment of the sport to cricket aficionados. The possibilities of similar applications across virtually any sport you can think of are limitless.

Of course, sending wireless signals is one thing. Controlling them and what they send is quite another, and there are several key factors that need to be taken into consideration before deployment.

Recovery after signal loss

First and foremost is the ability to recover after a loss of signal. If you’re going to be where the action is, there’s a decent chance that the action will require an onboard or shoulder-mounted camera to swing around a bend, disappear over a hill or drift too far from shore, each of which may take a camera transmitter out of range. The ability to recover a connection and resume operation, swiftly and seamlessly, is paramount — both in terms of the development of the technology and the decision whether to deploy in the first place. Of absolutely no use to anyone is a system that drops video and control signals when the wind changes direction.

Rigging

Rigging is one of the keys to wireless camera control. Actually, what’s important is reducing the required rigging, or in some cases all but eliminating it, with a wireless approach to control.

Many wireless camera systems on the market today take an all-in-one approach, which means that a single unit is used to connect to a camera control panel and generate the RF control signal. However, we believe that this approach can cause problems. For example, if an OB truck is stationed an appreciable distance from the event or activity it has been deployed to cover — perhaps a car park underneath a stadium —long lengths of RF cable have to be run from the truck to multiple points within the venue. We’ve all seen it. Long cable runs mean that the power has to be jacked up considerably to compensate for the attenuation that naturally occurs across such lengths the further they get from the truck or source. The knock-on effect of this is that it increases the overall RF noise floor and will impair the performance of every other RF systems in use such as talkback, and often the wireless camera system itself.

The best approach is to separate the RF unit from the data unit and connect them using a standard audio circuit that can, if necessary, be separated by several kilometers without any problems at all. This ensures that the RF unit is always mounted at the optimum location and enables the RF power to be reduced to a point where there’s no concern about interference.

Think about it: At any public venue — and particularly sports stadiums — there are signals flying around all over the place. Why contribute to any interference to your own system?

Spectrum management

In terms of control, frequency reuse is also important because it’s no secret that the increasing demand for spectrum means that fewer RF channels are available. We’ve combatted that by developing a system that allows up to four wireless cameras to share the same 12.5kHz bandwidth control channel, which is a significant advantage.

As you know, a number of advanced video compression standards such as HEVC H.265 are being introduced, and questions are being raised as to whether such standards will actually improve the take up of wireless systems. We think the answers is an unequivocal “yes,” and here’s why.

Advanced standards will undoubtedly benefit wireless systems because all wireless systems have to trade range for bit rate. It’s just the way the wireless world works. The higher the picture quality you want, the lower a wireless system’s achievable range will be. However, by adopting improvements in compression that come with new standards, high picture quality can be attained but at ever-lower bit rates. This in turn extends the range of the system to achieve, and maintain, the expected quality without failure. This benefits production teams because they can go ever further afield and maintain current picture quality thresholds — even up to 1080p — with no reduction, often even an extension, of the range in which they can operate.

Rapid deployment

The ability to set up fast and get on-air is particularly important for sports. You rarely get a second chance to capture that game winner. Muhammad Ali is probably the only athlete who ever asked a broadcaster (or opponent for that matter) if they wanted to see it again.

Sports broadcasters looking to set up a newsroom operation at a sporting event need to be able to do it quickly, which these days almost certainly means an IP-based system that uses wireless technology. Such a system also provides the ability to take advantage of Ka-band satellite uplinks.

Ka band

The increased availability of high-capacity Ka-band services, now and via new satellites soon to be launched, completely lifts the lid on any previous restrictions on delivering broadband-over-satellite. Satellites continue to be a prime driver in the ability of field producers to deliver high-quality video content, and the greater availability of Ka band provides a great deal more spectrum that it is now technically possible to put to good use. The suitable availability of Ka band, particularly using powerful new satellites, is only just emerging so will no doubt become an even more attractive and beneficial resource going forward.

We worked directly with Inmarsat as a development partner for its new Ka-band based Global Xpress service. The service will start delivering, via its next-generation Inmarsat-5s satellite system scheduled for launch this year, higher transmission speeds through more compact terminals at a lower cost than existing VSAT services, using far less congested spectrum. When the full service starts rolling out in 2014, with global coverage planned by the end of that year, the ability to capture and transmit bandwidth-intensive, high-quality video — from anywhere — will truly be off to the races, literally and figuratively.

Production teams will not only be able to capture events at distances never before possible, with modern wireless transmission systems that also include IP-connectivity, but also they will also be able to make video calls, watch their home team score a goal, read the news, shop or even use social media if they want to. In a way, even though they are meant to be doing their primary job, sometimes they need IP connectivity for their own use. New systems can provide all of that, and more, to keep them happy.

With the combination of these new satellites and Ka band, dishes — whether mounted on an OB truck or hand-carried in a small transport case — can now be less than 1m in diameter and still be used to transmit full HD video. This has simply never before been possible. And, as I just alluded to, a small dish has the added benefits of offering substantial economies in transportation, storage and power consumption, not to mention the vastly increased ability to take them almost anywhere.

So, as transmitters, dishes and CAPEX budgets continue to decrease, the reductions in the first two mean that you don’t have to compromise on the third. In fact, the reality is quite the opposite. A lot of power, functionality and reliability are now available for wireless systems that enable production teams and broadcasters to take their viewers to places none of them have ever been before. And, these systems actually cost less.

To achieve this, it’s important that the system includes everything required, such as a quality path for live two-ways; remote camera control; high-quality file transfer; and a high-capacity internet connection with access to base newsroom computers and mobile phones — all in a single package that can be easily transported, unpacked and in operation in minutes. Such systems are now readily available.

A compelling option

Wireless transmission is not a replacement for wired applications. However, it is a compelling, reliable and exciting extension of the possibilities available to sports production teams the world over. When there’s no wire, there’s no reason to hang your broadcast coverage


Stuart Brown is broadcast systems director at Cobham Broadcast.



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