Ask the experts: your questions on wireless camera systems


Stuart Brown TV-Bay Magazine
Read ezine online
by Stuart Brown
Issue 81 - September 2013
tv-bay talks to Stuart Brown, Broadcast Systems Director at Cobham Broadcast about your questions on wireless camera systems.
What makes wireless camera systems a viable option now as opposed to only a few years ago?

When the COFDM modulation scheme was introduced over a decade ago, it revolutionised event coverage and newsgathering. It meant that digital wireless camera systems could be used for the first time to transmit non-line-of-sight digital signals, which gave producers complete freedom to go live from locations that were previously out of the question with wired systems.

However, its fair to say that early versions of such systems had drawbacks, which meant that the uptake got off to a staged and somewhat troubled start.

Although MPEG-2 served the wireless camera industry adequately for a number of years, the introduction of HD and its vastly increased bit rates put a lot of pressure on the availability of RF spectrum, which was already stretched. Some began to question whether going wireless was actually worthwhile.

Then along came H.264 encoding, which prompted users to take another look at whether H.264 encoding was, or could be made, viable for wireless camera systems. In their earliest manifestations, H.264 encoders were considered too large and power-hungry to be useful for wireless cameras.

However, like most technology advances that loosely follow a corollary of Moores law, encoders soon became far more compact yet more reliable and required less power, using as little as 10W. (If I may, we recently introduced a mini HD transmitter the worlds smallest that consumes only 7 watts!)

Problem solved, then?

At the time, not quite. The resolution of the size and power questions still left concerns over latency, which was a major issue with early versions of H.264 encoders. Such systems typically had latencies in excess of 500ms, which was wholly unacceptable for large multi-camera events because it caused very noticeable lip-sync issues when mixing cabled and wireless cameras. This problem was particularly acute for newsgathering applications because the addition of encoding delays on top of those already present in an SNG encoder and satellite hop made live two-ways very difficult. Fortunately, in the last few years, new encoding techniques have dropped latency to below 100ms, which has not only made H.264 encoding a viable option for wireless communication, but a preferred one.

Are all H.264 systems pretty much the same?

Not necessarily. While H.264 encoding for wireless systems has been widely adopted, it has to be said that not all H.264 encoders are created equal. Its relatively easy to make exaggerated claims about latency and/or encoding efficiency often citing the encoders response to test patterns as proof, only for the user to discover, too often during a live shoot, that the picture quality/encoding efficiency they were meant to achieve came nowhere near the stated claims when the system is used with real pictures. There have been instances in which a deployed H.264 system had to operate at MPEG-2 bitrates to provide acceptable picture quality. Whats the point in that? A well-engineered H.264 system should deliver at least a 30-50% efficiency improvement over a comparable MPEG-2 system. It is that level of efficiency that enables wireless camera systems to thrive.
So, what should I look for in a wireless system?

Ive talked about some of the technical issues that have now been overcome, but there are practical considerations that need to be taken into account when deciding if wireless transmission is right for your operation. One of the most important is whether the selected wireless transmitter has a proven, demonstrable ability to recover quickly after loss of signal. This is what hampered so many early attempts at wireless transmission systems. They simply couldnt be counted on when the going got tough. During any deployment a camera is bound to stray out of range or suddenly de-power to indicate the need for a battery change. Both situations are particularly acute when you are in the field covering a live event. A wireless systems must be able to recover instantly and resume operation seamlessly, which, if carefully selected, they now do.

Ease of rigging is also an important factor. There are a number of wireless camera control systems on the market that take an all-in-one approach, meaning that a single unit is used to connect to a camera control panel and generate an RF control signal. This, however, can be an issue if an OB truck is parked some distance from the event (such as a car park in the basement of a stadium). This means that going wireless is difficult because you have to run long lengths of RF cable from the truck into the venue. However, its a given that the longer the length of cable, the greater the loss of signal, which in turn means that the RF power has to be increased to compensate. The problem with that is that it increases the overall RF noise floor, which will impair performance of other RF systems in use, such as talkback. It can even cause RF noise problems with the wireless camera system itself. In our case, we combat this issue by separating the RF unit from the data unit. They are connected using a standard audio circuit and can be separated by several kilometres if necessary. This ensures the RF unit is mounted at the optimum location, and RF power can be reduced as a result.

IP infrastructure is now common in modern OB trucks and is often used to route camera control signals, with all-in-one master control panels gaining favour. Our latest camera control system now has Ethernet connectivity as an option and our wireless camera receiver all have IP streaming in/out capability.

Frequency reuse is also very important because increasing demand for spectrum means that fewer RF channels are available. Our approach allows up to four wireless cameras to share the same 12.5 KHz bandwidth control channel, which has proven to be a substantial benefit to users.

Are there still technical hurdles to making wireless links reliable?

In short, no, not really. The introduction of advanced video compression standards like HEVC H.265 will inevitably benefit wireless transmission in live production. Whether the manufacturer admits it or not, all wireless systems have to trade a certain amount of bit rate to achieve extensions in range. The higher the picture quality required, the lower the achievable range. Its as simple as that. However, improved compression will enable better picture quality to be achieved at lower bitrates, so production teams will not only benefit from increased range at current picture quality thresholds, but improved compression will also enable the use of even higher picture quality settings (such as 1080p) without requiring a tightening of what we would consider normal wireless camera coverage circles. Basically, at normal thresholds you can extend your range much, much further, but if you are transmitting at the highest image settings, you wont have to worry about losing your signal if you cross from one side of the football pitch to the other.

Another important development in terms of wireless connectivity particularly for newsgathering is the ongoing change in satellite technology to meet the increasing desire to utilise Ka-band. Demand for traditional Ku-band access at times outstrips capacity, which can make it expensive. However, the development and deployment of a number of large, multi-transponder Ka-band satellites and Ka-band satellite networks is increasingly offering a viable and economic alternative to Ku-band.

What does the near-term future hold?

Encoders specifically engineered for high capacity broadcast applications that feature IP connectivity via 3G, 4G and LAN to ensure access to super-fast wireless 3G internet connections from even the most remote locations are now on the market and will be a major game changer. The ability to set up an IP-based newsroom and enable field reporters to get on air almost instantly, and wirelessly, is a massive benefit to producers.

Video-over-IP is also having an impact as a viable means of remote newsgathering due to substantial improvements in compression algorithms, encoding technology and wireless connectivity. This will enable the industry to develop even smaller and more economic transmission devices, which will allow journalists to cover news from just about anywhere they can physically reach.

The use of wireless technology by journalists in the field to quickly establish all the technology they need for a live broadcast, including a broadcast quality transmission path for live two-ways; the ability to control a camera remotely from the studio; perform file transfers; use a high capacity internet connection, have access to the base newsroom computer, and offer mobile phone access - all from a single unit will very soon bring live events to our screens - whether its the big one in our living room or the small one we carry around with us in ways and from perspectives we until recently never thought possible.


Tags: iss081 | wireless camera systems | cobham | stuart brown | broadcast systems | wireless | camera | transmitter | receiver | ask the experts | Stuart Brown
Contributing Author Stuart Brown

Read this article in the tv-bay digital magazine
Article Copyright tv-bay limited. All trademarks recognised.
Reproduction of the content strictly prohibited without written consent.

Related Interviews
  • Cobham on BroadcastShow LIVE at IBC 2013

    Cobham on BroadcastShow LIVE at IBC 2013

  • Cobham: Mini RF Transmitters at NAB 2013

    Cobham: Mini RF Transmitters at NAB 2013

  • Cobham: RF Transmitter at NAB 2013

    Cobham: RF Transmitter at NAB 2013

  • Cobham new receiver at IBC 2014

    Cobham new receiver at IBC 2014

  • Cobham satellite EXPLORER products at IBC 2014

    Cobham satellite EXPLORER products at IBC 2014

  • Cobham transmitters at IBC 2013

    Cobham transmitters at IBC 2013

  • Cobham at IBC 2012

    Cobham at IBC 2012

  • Videosys Wireless Transmitters at BVE 2014

    Videosys Wireless Transmitters at BVE 2014

  • VideoSys at BVE North 2012

    VideoSys at BVE North 2012

  • Inmarsat: Global Xpress and Explorer at NAB 2013

    Inmarsat: Global Xpress and Explorer at NAB 2013

  • Wireless Transmitters for Boxx TV at NAB 2018

    Wireless Transmitters for Boxx TV at NAB 2018

  • Wireless 4K Transmitter from DTC Domo Broadcast at IBC 2017

    Wireless 4K Transmitter from DTC Domo Broadcast at IBC 2017

  • Pliant Technologies CrewComm Wireless Intercom at IBC 2017

    Pliant Technologies CrewComm Wireless Intercom at IBC 2017

  • Boxx TV Wireless Transmission with Meridian, Atom and Zenith on show at IBC 2017

    Boxx TV Wireless Transmission with Meridian, Atom and Zenith on show at IBC 2017

  • Sony Wireless Microphones at BVE 2014

    Sony Wireless Microphones at BVE 2014

  • Anton Bauer at NAB 2012

    Anton Bauer at NAB 2012

  • Gearhouse Broadcast on Tour May 2013

    Gearhouse Broadcast on Tour May 2013

  • IMT Broadcast at NAB 2012

    IMT Broadcast at NAB 2012

  • Boxx TV updates at NAB 2017

    Boxx TV updates at NAB 2017

  • Thomson Broadcast at IBC 2014

    Thomson Broadcast at IBC 2014

  • Boxx TV Company Overview at NAB 2018

    Boxx TV Company Overview at NAB 2018

  • Atom Lite from Boxx at NAB 2017

    Atom Lite from Boxx at NAB 2017

  • Quantum C80 from Cineo at NAB 2017

    Quantum C80 from Cineo at NAB 2017

  • Pliant Technologies at IBC 2016

    Pliant Technologies at IBC 2016

  • Clear-Com FreeSpeak II at NAB 2016

    Clear-Com FreeSpeak II at NAB 2016

  • Clear-Com LinQ at IBC 2014

    Clear-Com LinQ at IBC 2014

  • Clear-Com FreeSpeak II at IBC 2014

    Clear-Com FreeSpeak II at IBC 2014

  • SIS LIVE ManPak and LoStow at IBC 2014

    SIS LIVE ManPak and LoStow at IBC 2014

  • Dejero at NAB 2014

    Dejero at NAB 2014

  • Tally Technologies at BVE 2014

    Tally Technologies at BVE 2014

  • Trilogy on BroadcastShow LIVE at IBC 2013

    Trilogy on BroadcastShow LIVE at IBC 2013

  • Clear-Com: Tempest at NAB 2013

    Clear-Com: Tempest at NAB 2013

  • Anton Bauer at NAB 2013

    Anton Bauer at NAB 2013

  • IDX at BVE North 2011

    IDX at BVE North 2011

  • RTS Telex at IBC2011

    RTS Telex at IBC2011

  • Telecast at IBC2011

    Telecast at IBC2011

  • Blackmagic Design Pocket Cinema Camera BMPCC 4K at IBC 2018

    Blackmagic Design Pocket Cinema Camera BMPCC 4K at IBC 2018

  • JVC 4K Connected Camera GY-HC550 and 500 at IBC 2018

    JVC 4K Connected Camera GY-HC550 and 500 at IBC 2018

  • Marshall Electronics Miniature Cameras at NAB 2018

    Marshall Electronics Miniature Cameras at NAB 2018

  • Blackmagic Pocket Cinema Camera 4K at NAB 2018

    Blackmagic Pocket Cinema Camera 4K at NAB 2018

  • Front Row Camera with VER at NAB 2018

    Front Row Camera with VER at NAB 2018

  • GY-LS300 Camera from JVC at NAB 2017

    GY-LS300 Camera from JVC at NAB 2017

  • IDT O10 Camera at BVE 2017

    IDT O10 Camera at BVE 2017

  • Antelope Camera Systems at IBC 2016

    Antelope Camera Systems at IBC 2016

  • Ikegami 8k camera at IBC 2016

    Ikegami 8k camera at IBC 2016

  • Ikegami UHK-430 camera at IBC 2016

    Ikegami UHK-430 camera at IBC 2016

  • Miller Camera Support at IBC 2016

    Miller Camera Support at IBC 2016

  • CameraCorps at BVE 2015

    CameraCorps at BVE 2015

  • Den Lennie considers what kit and cameras to buy for 2015

    Den Lennie considers what kit and cameras to buy for 2015

  • Sonys new cameras at IBC 2014 - including the FS7

    Sonys new cameras at IBC 2014 - including the FS7

  • Cineline Fluid Head from Miller Camera Support at NAB 2014

    Cineline Fluid Head from Miller Camera Support at NAB 2014

  • Blackmagic Studio Camera at NAB 2014

    Blackmagic Studio Camera at NAB 2014

  • Hireacamera at BVE 2014

    Hireacamera at BVE 2014

  • JVC GY-HM600 series camera updates at IBC 2013

    JVC GY-HM600 series camera updates at IBC 2013

  • Lighting cameraman Jonathan Harrison shows the Celeb and Tegra at IBC 2013

    Lighting cameraman Jonathan Harrison shows the Celeb and Tegra at IBC 2013

  • Hireacamera at BVE 2013

    Hireacamera at BVE 2013

  • Hireacamera at BVE North 2012

    Hireacamera at BVE North 2012

  • Hireacamera at BVE 2012

    Hireacamera at BVE 2012

  • Hireacamera at ProVideo2011

    Hireacamera at ProVideo2011

  • Hague Camera Supports at ProVideo2011

    Hague Camera Supports at ProVideo2011

  • Hireacamera at BVE North 2011

    Hireacamera at BVE North 2011

  • Camera Corps at IBC2011

    Camera Corps at IBC2011

  • Dejero on BroadcastShow LIVE at IBC 2013

    Dejero on BroadcastShow LIVE at IBC 2013

  • Skyline 90 from Miller at NAB 2017

    Skyline 90 from Miller at NAB 2017

  • JVC at BVE 2017

    JVC at BVE 2017

  • Videosys at NAB 2016

    Videosys at NAB 2016

  • Miller Cineline tripods at IBC 2015

    Miller Cineline tripods at IBC 2015

  • Miller Compass tripods at IBC 2015

    Miller Compass tripods at IBC 2015

  • NewTek at IBC 2015

    NewTek at IBC 2015

  • Sachtler Bags at BVE 2015

    Sachtler Bags at BVE 2015

  • LCA - Inteca products at BVE 2015

    LCA - Inteca products at BVE 2015

  • LCA - LITEGEAR at BVE 2015

    LCA - LITEGEAR at BVE 2015

  • BeyondHD - Drones at BVE 2015

    BeyondHD - Drones at BVE 2015

  • LCA - Snapgrid lighting control - BVE 2015

    LCA - Snapgrid lighting control - BVE 2015

  • BeyondHD - Letus Helix Gimbal System at BVE 2015

    BeyondHD - Letus Helix Gimbal System at BVE 2015

  • JVC at BVE 2015

    JVC at BVE 2015

  • Grass Valley at BVE 2015

    Grass Valley at BVE 2015

  • Gearhouse Broadcast at BVE 2015

    Gearhouse Broadcast at BVE 2015

  • KITPLUS rig setup at IBC 2014

    KITPLUS rig setup at IBC 2014

  • Air Alloy Tripod System from Miller Fluid Heads at IBC 2014

    Air Alloy Tripod System from Miller Fluid Heads at IBC 2014

  • CueScript EMC prompter and control surface at IBC 2014

    CueScript EMC prompter and control surface at IBC 2014

  • JVC GY-LS300 prototype at IBC 2014

    JVC GY-LS300 prototype at IBC 2014

  • MultiDyne SilverBACK at IBC 2014

    MultiDyne SilverBACK at IBC 2014

  • Hitachi at IBC 2014

    Hitachi at IBC 2014

  • NewTek TalkShow at IBC 2014

    NewTek TalkShow at IBC 2014

  • Softron MovieRecorder updates at NAB 2014

    Softron MovieRecorder updates at NAB 2014

  • JVC GY-HM850 and GY-HM650 at NAB 2014

    JVC GY-HM850 and GY-HM650 at NAB 2014

  • Libec ALLEX slider system at NAB 2014

    Libec ALLEX slider system at NAB 2014

  • Blackmagic URSA at NAB 2014

    Blackmagic URSA at NAB 2014

  • Cintel Film Scanner: Blackmagic Design at NAB 2014

    Cintel Film Scanner: Blackmagic Design at NAB 2014

  • BeSteady on the Production Gear stand at BVE 2014

    BeSteady on the Production Gear stand at BVE 2014

  • Sony Camcorders at BVE 2014

    Sony Camcorders at BVE 2014

  • NewTek TriCaster at BVE 2014

    NewTek TriCaster at BVE 2014

  • Camdec at BVE 2014

    Camdec at BVE 2014

  • Atomos with the Samurai Blade on BroadcastShow LIVE at IBC 2013

    Atomos with the Samurai Blade on BroadcastShow LIVE at IBC 2013

  • Polecam talk accessories on BroadcastShow LIVE 2013

    Polecam talk accessories on BroadcastShow LIVE 2013

  • Multidyne SilverBack, BullDog and Spider at IBC 2013

    Multidyne SilverBack, BullDog and Spider at IBC 2013

  • ChyronHego Paint at IBC 2013

    ChyronHego Paint at IBC 2013

  • ChyronHego Virtual Placement at IBC 2013

    ChyronHego Virtual Placement at IBC 2013

  • Holdan on BroadcastShow Tour May 2013

    Holdan on BroadcastShow Tour May 2013

  • JVC GY-HM70 at NAB 2013

    JVC GY-HM70 at NAB 2013

  • MultiDyne: SilverBACK at NAB 2013

    MultiDyne: SilverBACK at NAB 2013

  • Blackmagic Design: Products at NAB 2013

    Blackmagic Design: Products at NAB 2013

  • Thear Technology at BVE 2013

    Thear Technology at BVE 2013

  • Tiffen Steadicam at BVE 2013

    Tiffen Steadicam at BVE 2013

  • Lemo at BVE 2013

    Lemo at BVE 2013

  • DJI Innovations at BVE 2013

    DJI Innovations at BVE 2013

  • Cambo at BVE 2013

    Cambo at BVE 2013

  • Featured Clip: Geoff Boyle comments on NAB 2012

    Featured Clip: Geoff Boyle comments on NAB 2012

  • Vinten Radamec at NAB 2012

    Vinten Radamec at NAB 2012

  • JVC at NAB 2012

    JVC at NAB 2012

  • Bexel at NAB 2012

    Bexel at NAB 2012

  • Blackmagic Design at NAB 2012

    Blackmagic Design at NAB 2012

  • LiveU at NAB 2012

    LiveU at NAB 2012

  • Atomos Samurai at NAB 2012

    Atomos Samurai at NAB 2012

  • JVC at BVE 2012

    JVC at BVE 2012

  • Thear Technology Limited at BVE 2012

    Thear Technology Limited at BVE 2012

  • Vision Research at BVE 2012

    Vision Research at BVE 2012

  • Editec at BVE 2012

    Editec at BVE 2012

  • Real Life Kit at ProVideo2011

    Real Life Kit at ProVideo2011

  • JVC Professional at ProVideo2011

    JVC Professional at ProVideo2011

  • Thear Technology Limited at ProVideo2011

    Thear Technology Limited at ProVideo2011

  • Audio Developments at ProVideo2011

    Audio Developments at ProVideo2011

  • JVC at BVE North 2011

    JVC at BVE North 2011

  • Holdan and DaVinci at BVE North 2011

    Holdan and DaVinci at BVE North 2011

  • Holdan and Panasonic at BVE North 2011

    Holdan and Panasonic at BVE North 2011

  • FOR-A at IBC2011

    FOR-A at IBC2011

  • Brickhouse Video at IBC2011

    Brickhouse Video at IBC2011

  • Argosy at IBC2011

    Argosy at IBC2011

  • Sony at IBC2011

    Sony at IBC2011

  • Marshall Electronics at IBC2011

    Marshall Electronics at IBC2011

  • Bradley at IBC2011

    Bradley at IBC2011

  • IMT Vislink HCAM 4k UHD transmitter at IBC 2018

    IMT Vislink HCAM 4k UHD transmitter at IBC 2018

  • The CFU5 4k Transmitter from Vislink at IBC 2017

    The CFU5 4k Transmitter from Vislink at IBC 2017

  • Smallest COFDM Transmitter from IMT-Solutions at NAB 2017

    Smallest COFDM Transmitter from IMT-Solutions at NAB 2017

  • Shure at BVE North 2011

    Shure at BVE North 2011

  • Dejero at IBC 2016

    Dejero at IBC 2016

  • AVIWEST at BVE 2015

    AVIWEST at BVE 2015

  • AVIWEST at IBC 2014

    AVIWEST at IBC 2014

  • Thomson Broadcast at NAB 2014

    Thomson Broadcast at NAB 2014

  • IMT at NAB 2014

    IMT at NAB 2014

  • Nucomm on BroadcastShow LIVE at IBC 2013

    Nucomm on BroadcastShow LIVE at IBC 2013

  • IMT DR3 IP Diversity Receiver at NAB 2016

    IMT DR3 IP Diversity Receiver at NAB 2016


Related Shows
  • PTZ Cameras at BVE

    PTZ Cameras at BVE


Articles
Perimeter LED screens management
Nicolas Houel Opened in January 2016, Parc Olympique Lyonnais, also known as Groupama Stadium, is the new home of Olympique Lyonnais football club, one of the most popular clubs in France. Since its inauguration, the stadium was a host of UEFA Euro 2016, and was also chosen to stage, among other important events, the 2018 UEFA Europa League Final and football at the 2024 Summer Olympics.
Tags: iss133 | 3dstorm | graphics | groupama stadium | liveexpert | livecg | deltacast | Nicolas Houel
Contributing Author Nicolas Houel Click to read or download PDF
Why are trade shows still important
Mike Crimp First, the disclaimer: as the CEO of a rather large trade show, my opinion is likely to be skewed. However, I wouldn’t be here – now in my eighth year at IBC - if I didn’t truly believe that well-curated trade shows like IBC are a hugely important resource for our industry.
Tags: iss133 | ibc | innovation award | Mike Crimp
Contributing Author Mike Crimp Click to read or download PDF
Taking on a self employed placement year
Joshua Round The idea of being self-employed or freelancing has always been somewhat terrifying for me. There is a level of uncertainty and responsibility that comes with the freedom of being self-employed, the likes of which makes me wonder why I chose to give it a go for my placement year as part of my university course - (BSc) Television and Broadcasting.
Tags: iss133 | placement year | university | student | education | portsmouth | Joshua Round
Contributing Author Joshua Round Click to read or download PDF
Creating Authentic Content That Counts
Frank le Mair We’re deep into the 2010’s and the way in which we consume content has changed forever. Broadcasters and content owners are fighting for eyeballs in a saturated market where consumers are watching their favourite shows on different devices across a number of platforms. To target millennials and younger generations, who generally consume short bursts of video on YouTube and social media - particularly Snapchat, Instagram and now IGTV - media companies are creating more and more authentic stories and are using platforms that are compelling for this demographic. Unlike generations before them, they have totally new video viewing patterns and ideals.
Tags: iss133 | insight tv | monster energy | amazon | millennial | Frank le Mair
Contributing Author Frank le Mair Click to read or download PDF
How todays technology platforms can make AMAZING seem mundane
Bruce Devlin - new Some things never change. It's September and it's time for another IBC. Maybe I'm getting old and maybe I have selective memory about the past, but recently there hasn't been the buzz of years gone by. Sure, as you wander around the vast halls there will be lots of enthusiastic sales people trying to give you the best demo possible, but something has changed and to survive, I believe that vendors and customers need to change too.
Tags: iss133 | ibc | class | vulture | imf user group | Bruce Devlin - new
Contributing Author Bruce Devlin - new Click to read or download PDF