Wireless acquisition creates a level of freedom not possible with any other form of filming yet only a decade ago the technique was barely possible. The technology enabling live real-time connections over radio frequencies has advanced leaps and bounds such that there is barely an entertainment, documentary, sports or news format today that doesn’t benefit from at least one link system. That means the demands on the kit continues to rise and includes the need for fail safe multi-camera operation, ease of use and backwards compatibility all within a small, lightweight and budget-friendly package.
The classic example of RF in action is X Factor where a Steadicam operator can be on stage and conduct a 360-degree sweep around the talent without tangling cables up with the singers. In a single or multi-cam mode for live reality shows or dramatic features, the flexibility of being able to roam without the cumbersome nature and health and safety hazard of lines back to a recorder or outside broadcast truck makes the shooting environment that much more fleet of foot.
Back in the pre-digital days, wireless was inherently unreliable. Any interference from reflections off buildings or simply distance from a receiver would compromise the signal unless relayed from fixed point to point. The first digital systems began to tackle this using SD MPEG-2 compression to send multiple copies of the signal from point A to point B with the signal being decoded and recombined using all available information to improve picture quality.
The disadvantage in this process was that latency, of half a second or more, made most live wireless pictures unusable. Cameras running the touchline of a soccer game would, when cut into the main mix, routinely be caught showing the same action already broadcast. Audio wouldn’t be in-sync with the picture. Cost remained an issue with many microwave systems marketed for a prohibitive £50,000 or more.
Instead of compressing the picture through an MPEG engine a radically different approach was needed. Using Joint Source-Channel Coding (essentially the encoding of a redundant information source for transmission over a noisy channel), Boxx TV rewrote the rule book for the industry, by delivering reliable high-quality video at very low latency and an affordable price. It was a gamechanger in enabling wireless cameras to be cut perfectly with systems cameras and at a cost that opened the field to a wider range of production budgets
Advances in the intervening years have seen codec technology standardise on the more efficient H.264 (MPEG-4 AVC) in High Definition with end-to-end latency drastically down to one or two frames. Compression algorithms continue to advance. In addition, the transmitters have gradually reduced in size and weight making them far more versatile and comfortable for camera-operators to maintain on their shoulders for longer periods. There have been innovations too in battery life while simultaneously reducing the heat emitted from them.