HDcctv: The Third Way
by Security Electronics and Networks | @Analysis Articles | August 7, 2013, 7:00am AEST
Q: Todd, you’ve been involved in the development of the HDcctv Alliance for many years now – could you outline for us what the HDcctv Alliance is about, when it began, what it is seeking to achieve, who is involved?
A: The HDcctv Alliance, with headquarters in NSW Australia, was founded in June 2009 with the goal of providing a comprehensive standard for local-site transport of HD surveillance video. Such a standard is valuable because it provides a basis for customers to be sure about electrical performance and 100 per cent multi-vendor interoperability. The Alliance includes over 70 Member companies located around the world. The membership list is posted at www.highdefcctv.org.
Q: This is a serious group of engineers, isn’t it? Along with reputable CCTV manufacturers, cable maker Belden joined the HDcctv Alliance a couple of years ago and respected industry group SMPTE (Society of Motion Picture and Television Engineers) has been involved right from the start, hasn’t it?
A: The HDcctv Alliance is indeed very technical, because one of our 2 main activities is managing this deep technical HDcctv standard. The other main activity is educating the market about the availability of HDcctv equipment and the value of HDcctv compliance certification. More than 16 semiconductor manufacturers are among our members, because their chips implement the functions needed for HDcctv compliance certification.
The HDcctv Alliance has a special relationship with SMPTE. We are the only surveillance standards body to have executed a license agreement with SMPTE, and SMPTE has invited me to speak at the SMPTE Australia conference being held in July at the Sydney Exhibition Centre at the same time as the annual ASIAL security show.
Q: What was the process of working with SMPTE on the development of the group’s HD-SDI SMPTE 292M broadcast standard into the HDcctv 1.0 standard? How long did that take? It’s led to improvements, too – there’s 2-way audio and data, 300m long distance mode, power up the coax – all these are significant developments that should be respected as part of a legitimate alternative solution for CCTV comms?
A: The HDcctv Alliance executed a unique copyright license agreement with SMPTE in 2009. This license enabled us to directly re-use elements of the SMPTE 292M standard to define HDcctv 1.0. First we eliminated the elements that are not valuable for surveillance, making HDcctv 1.0 simpler than SMPTE 292M. Then we added elements that are necessary for mass production of 100 per cent multi-vendor interoperable devices, as well as providing for forward compatibility with subsequent generations of the HDcctv standard.
The license agreement allowed us to generate the functional specs for HDcctv 1.0 very quickly; they were completed in late 2009. The compliance test specifications, which SMPTE does not have, took about another year to develop. As a result, HDcctv 1.0 along with the compliance certification part was completed in late 2010.
HDcctv 1.0 is functionally a subset of SMPTE 292M, which accounts for some of the confusion in the marketplace today. Primarily, it is the manufacturers with the greatest commitment to quality and interoperability who have embraced HDcctv 1.0 compliance.
Certainly, CCTV installers have come to expect a broad range of capabilities from a local-site transport technology. Therefore, the HDcctv Alliance continues to work to add capabilities to the HDcctv standard. For example, the Alliance technical committee is this very month putting the finishing touches on 3 significant enhancements: HDcctv XR is an augmented PHY that doubles RG59 transmission to 200m, whereas 292M tops out at 100m. XR also provides for bi-directional communications and allows for up-the-cable power in future.
HDcctv CX is a PHY for transmission over Cat-5e/Cat-6 cabling, also providing for bi-directional communication and allowing for up-the-cable power. HDcctv 2.0 is the first logical extension from 292M, implementing up-the-cable communications and automatic discovery of Master-Slave relationships in arbitrarily complex video channels.
These 2013 enhancements are just the beginning of a series of capabilities that will be added to the HDcctv standard in future.
Q: The core strength of HDcctv 1.0 is its ability to leverage existing coaxial cable infrastructure to provide 720p and 1080p HD video. It’s a serious capability. A lot of applications I see retain significant numbers of legacy analogue cameras simply because users can’t afford to re-cable large segments of brownfield sites. Do you think end users should be more open to this ‘third way’?
A: Yes, part of the appeal of HDcctv is that it enables HD for the installed base. Catering for the constraints of legacy CCTV installations drives the Alliance to continue to consider ways to accommodate relatively poor-quality cable, poor-quality terminations, and a broad variety of media in addition to RG59 coaxial cable.
Q: I think there’s a misunderstanding in the electronic security industry, a sense that HDcctv 1.0 is somehow retrograde because it uses coaxial cable not the TCP/IP-based Cat-5/6 links most integrators use to carry their HD camera signals to local switches. But that’s not that case at all, is it? Doesn’t HDcctv 1.0 actually deliver multiple, uncompressed, no-latency HD image streams, giving the best possible performance in a bunch of demanding applications?
A: Sure, it is easy to become confused between cables, which are just metal, and interfaces, which constrain the signals carried by the cables. Legacy surveillance systems transmit CCTV signals over every kind of medium you can imagine, including blue cables, while Ethernet can also be run over any medium, including coax.
Look, IP video is a wonderful innovation. So much so, in fact, that IP video has already achieved nearly 100 per cent market penetration: IP networks are used almost exclusively for remote access to surveillance sites, and modern DVRs are highly cost effective IP network on-ramps.
The design question for every installer and integrator is not whether to use IP video; the question is where on the local site to convert TV signals to Ethernet packets. Sometimes it makes sense to do the conversion inside the camera mount; that’s what an IP camera does. Usually, however, the economics favour doing the conversion in a DVR or a multi-channel IP encoder.
An HDcctv interface allows the conversion to be deferred from the camera mount. The HDcctv interface transports an unadulterated HDTV signal from the camera to another point on the local site. At this second point, the signal can be viewed with no latency, analysed by computer algorithms, compressed for storage, or streamed for remote viewing.
HDcctv-based system architecture is generally more scalable and more future-proof than the alternative using MP IP cameras. When it comes to mixing and matching equipment from various suppliers, or to upgrading just the codec technology, HDcctv camera-based architecture provides the benefits of modularity, at lower intrinsic cost.
Q: Another thing that appeals to me when it comes to HDcctv 1.0 is the fact there’s no setup, no configuration required by installers. The devices simply connect to the coax runs and work as they should. Do you see this as a significant advantage?
A: Yes, one of the reasons that VGA IP cameras have failed as a product category is that they introduced many new complexities, costs, and vulnerabilities without providing any tangible benefits in most cases. HDcctv extends the desirable properties of CCTV system architecture directly to HD. No new skills to learn, no new vulnerabilities. Moreover, HDcctv compliance ensures out-of-the-box plug and play, which is a real boon to time-constrained installers.
Q: What’s the maximum camera/megapixel number an HDcctv 1.0 link could carry?
A: HDcctv 1.0 and HDcctv 2.0 top out at 1080p30 (~ 2 megapixels per frame @ 30 frames per second) and 720p60 (~ 1 megapixels per frame @ 60 frames per second). It is important to recognize that surveillance demands excellent low-light sensitivity, usually in a 1/3-inch optical format.
Image sensor technology is just now getting to the point of meeting surveillance sensitivity requirements. The HDcctv Alliance anticipates that, by the time 1/3-inch sensors accommodating higher resolutions are available at sufficient sensitivity for surveillance, the HDcctv standard will be capable of transporting those higher resolutions.
Q: Some installers and users are afraid of what they think are the storage demands of raw uncompressed HD. How big are these streams, how much space do they need? Or are such fears misplaced?
A: Why would anyone store uncompressed HDTV signals? Analogue DVRs don’t even store uncompressed PAL signals. DVRs allow the installer/operator to trade off the resolution, frame rate, quality, and duration of forensic evidence against the storage medium costs. There is no general prescription for how best to mitigate this complex tradeoff; it is appropriately addressed specifically for each surveillance installation, maybe for each video channel.
Q: What about managing HDcctv 1.0 solutions – do the main VMS developers support the technology seamlessly and with no additional effort on the part of installers?
A: HDcctv is a local-site transport, whereas VMS solutions operate remotely on IP video. Therefore, VMS solutions are agnostic as to where on the local site the TV signals are converted to Ethernet packets. All of the leading VMS providers seamlessly provide for HDcctv cameras. The fact that one European VMS provider, Cubitech, is a member of the HDcctv Alliance, reflects the growing awareness among VMS providers of the value of the HDcctv standard, even if there’s no such thing as an HDcctv-compliant VMS.
Q: What do you think the cost savings would be in deploying 100 HDcctv 1.0 cameras on existing coaxial cable, compared to deploying them on new Cat-6 links? Allowing for sweeping variables like size of the site – what sort of a percentage of savings might there be in not having to pull 100 links of 100m Cat-6?
A: This question is too broad to admit a valid answer. Given the constraints of a specific scenario, an integrator can calculate the costs of retro-fitting with HDcctv versus converting the infrastructure to Ethernet. You might first ask, why even bother running a LAN out to every camera mount? The live views are not better, the latency is not less, the equipment costs are not less, the installation and maintenance costs are not less, the reliability is not greater, the physical security is not greater. Unless the customer faces one of the specific challenges that is best overcome with IP cameras, IP cameras are a questionable proposition.
Q: From the point of view of an installer, how does an HDcctv 1.0 292M installation take place? Are conforming cameras and devices required? What is the process of installation as a basic step-by-step process?
A: HDcctv-compliant equipment can be mixed and matched freely, just like PAL equipment. The process of installation is exactly the same as the well-understood CCTV system implementation process.
Q: We all got sold on IP networks back in the late 1990s – partly because of that old chestnut ‘leveraging existing infrastructure’. But I can personally attest to the fact no serious surveillance applications leverage any existing infrastructure – except perhaps floor space in network rooms and support from UPS solutions.
Our IP video networks are subnets, islands, dedicated pathways that are almost never open to data networks aside from 2 or 3 authorised workstations, often with direct links. Do you think in some ways the market is failing to see what’s in front of it when it comes to the nature of our separate IP networks? Failing to see we still operate in isolation?
A: Certainly, “leveraging existing infrastructure” has never made sense to me. For example, just look where the existing RJ45 jacks are: near the floor. Now look where the cameras need to be: near the ceiling. Oops. Someone needs to augment that existing infrastructure in any case.
Moreover, the traffic from several high-quality surveillance cameras readily overwhelms the legacy LAN, bringing the MIS applications to their knees. Finally, it is entirely appropriate to maintain physical security systems in isolation from general IT systems, given the sensitive nature of physical security.
I agree with you that a collection of home runs is just another network, albeit a special one. Ethernet was not developed for the needs of always-on HD surveillance cameras, whereas HDcctv was.
Q: Finally, Todd, the proof of a technology inevitably starts flowing through as sales and there’s increasing respect for HDcctv 1.0 in the market, isn’t there, as well as growing sales worldwide? Do you feel vindicated by this growth? And what’s in the future for HDcctv 1.0? Are there new standards, new capabilities? Can HDcctv 1.0 compete with IP-based networks in a wide range of applications moving forward?
A: The first part of this question is especially germane as the Alliance is entering our 5th year of operations. HDcctv began as a concept. I’ll never forget walking around the IFSEC conference (in Birmingham, UK) in May 2009 armed only with a presentation folder. So many quizzical responses! “Isn’t the security world about to turn into one big IP camera any day now? Why do we need another transport technology?”
Now that even historically conservative IMS Research is estimating that hundreds of thousands of HDcctv cameras are being sold this year around the world, and that the number will grow by a factor of 20 over the next 4 years, there is no longer any doubt about the appeal of HDcctv. Our primary challenge henceforth is helping people to appreciate the importance of HDcctv compliance certification.
Looking forward, there is no future of SMPTE 292M. 292M was published in 1998 and has not advanced in the 15 years since. No one is working on 292M. There is no compliance test specification for 292M, no certification programme, and no guaranteed interoperability. 292M is great for connecting cameras to mixing desks in broadcast TV studios, but some work would be needed to adapt 292M to the needs of surveillance. That observation was the genesis of the HDcctv Alliance.
Meanwhile, we anticipate adding a diversity of capabilities to the HDcctv standard in coming years, for example:
* Power up the cable (targeting 45W)
* Higher Frame Rates than 720p60 (720p240)
* Higher Resolutions than 1080p (4K)
* Bi-directional Audio
* Camera motion control Commands (optimized protocol)
* Camera exposure control Commands (optimized protocol)
* Camera external I/O Commands (optimized protocol)
* Longer Transmission over SYV 75-5 coaxial cable (XR is maximum 180m)
* Longer Transmission over SYV 75-3 Coaxial Cable (XR is maximum 105m)
* Increased tolerance of low-quality terminations, such as are often found on legacy CCTV cables
* Increased cable construction flexibility, for example tolerating mid-cable taps and multiple joins (XR does not tolerate cable or connector impedance mismatches)
* Increased resistance to electro-magnetic interference
* Optical Fibre Transmission
* Telephone Wire Transmission
* Wireless Transmission.
The specific order in which these capabilities are addressed will continue to be determined by the steering members of the HDcctv Alliance, drawing on inputs from all members.