The Evolving Specification for the HDcctv Standard
21 October 2013
The HDcctv equipment market continues to grow by an order of magnitude year-on-year: Semiconductor shipments to date impute a worldwide retail market value for HDcctv equipment easily surpassing US$1B in 2013.
The HDcctv compliance mark signifies those products that have passed certain rigorous tests. Certified products deliver the expected electrical performance, interoperability, and forward compatibility with future generation HDcctv-compliant equipment. Not all HDcctv-class cameras are yet certified HDcctv compliant, and non-certified products have been known to disappoint, so look for the HDcctv compliance mark to be sure.
The HDcctv cameras, DVRs, IP encoders, monitors, and related products coming to the market from Q4 2013 onward incorporate a much greater diversity of HDcctv-ready semiconductors than was available to the first-generation HDcctv product designers. Therefore, it is likely that a growing fraction of manufacturers committed to their customers' success will seek compliance certification. That way, then can most assuredly deliver readily inter-operable equipment delivering the most advanced capabilities.
HDcctv XR ("eXtended Reach") provides for increased transmission distance over coaxial cable, offering 3 times the transmission margin of SMPTE 292M HD-SDI.
HDcctv 1.0 XRTM is current, and surveillance equipment implementing HDcctv 1.0 XR is being developed by leading manufacturers.
HDcctv CX ("CatX") provides for transmission directly over structured cabling: Cat5e and Cat6. CCTV installers often prefer to work with CatX cable, because it is lighter and thought to be less costly than coaxial cable.
HDcctv 1.0 CXTM is current, and prototype surveillance equipment implementing HDcctv 1.0 CX is being developed by leading manufacturers.
HDcctv AT ("Advanced Transmission") provides for transmission over any conventional CCTV cabling infrastructure. AT is useful where it would be difficult to add a repeater. For example, consider analog CCTV running through a 700m cable running through a conduit buried under 8 inches of reinforced concrete with, no intermediate power sources along the run. AT allows upgrading that video feed to HD without disturbing the legacy infrastructure.
HDcctv AT has been an area of intensive work by the HDcctv Alliance Technical Committee in 2013.
HDcctv 2.0 provides for up-the-cable remote control. In 2.0, each camera serves as a Slave, sending video to a channel that includes exactly one Master (DVR, matrix, IP encoder, monitor, etc) and any number of Observers. The Master-Slave link is automatically arbitrated at power-up. If there is no Master present or no Slave present in the channel (because one end or the other is HDcctv 1.0), then the 2.0 channel operates exactly like a 1.0 channel.
HDcctv 2.0 XR, HDcctv 2.0 CX, and HDcctv 2.0 AT carry common protocols over disparate media/technologies, to best meet the diverse requirements of surveillance applications. XR/CX/AT convertsion devices are expected to be available at the same time as other 2.0-compliant equipment comes to market.
The functional specification for HDcctv 2.0 was completd mid 2013. The compliance test specification is more than 50% complete. The technical committee is on track for ratification early 2014.
The HDcctv interface standard derives from a set of specifications, including SMPTE-292M, developed by the Society of Motion Picture and Television Engineers for application in high-definition broadcast television studios. This collection of specifications, collectively called "High-Definition Serial Digital Interface," or HD-SDI, has been proven in television studios worldwide since the late 1990's. HD-SDI does not include a compliance certification standard. While the lack of independent tests for inter-operability and electrical performance is not an issue for the relatively low-volume, high-value broadcast studio market, the larger, more cost-sensitive professional surveillance market requires multi-vendor inter-operability and reliable electrical performance for mass production.
Through a unique cross-industry license agreement executed in 2009, SMPTE authorized the HDcctv Alliance to adapt HD-SDI technology for Digital HD surveillance as the HDcctv Standard.
A crucial contribution of the HDcctv Alliance Technical Committee has been the development and ratification of a comprehensive compliance certification process, including test methodology. The remarkably fragmented surveillance equipment market includes many hundreds of suppliers looking to diffrentiate their products while reducing both material and manufacturing costs to an absolute minimum. HDcctv compliance certification testing is uniquely valuable to manufacturers seeking to assure interoperability and electrical performance. The rigorous HDcctv compliance tests enable manufacturers to warrant "plug and play" interoperability with other compliant equipment, irrespective of functionality, country of origin, or price point.
Eager to enter the promising market for non-IP HD surveillance equipment, some manufacturers designed prototype cameras incorporating key components that were themselves already in production before HDcctv 1.0 was ratified. That is why some non-IP HD prototypes available in early 2012 cannot be certified as HDcctv compliant. These products are sometimes advertised as "HD-SDI." Buyers should be aware that SMPTE's HD-SDI encompasses a broad set of specifications that are not universally consistent, rather than a single comprehensive interface standard. Each "HD-SDI" product reflects individual interpretations of SMPTE's various HD-SDI specifications. Because the original HD-SDI specifications allow for great diversity, "HD-SDI" products are not certain to inter-operate among vendors. Furthermore, because there is no electrical testing standard in the HD-SDI specification suite, the manufacturers of "HD-SDI" prototypes may not have any technical basis to warrant the products' electrical performance. HDcctv compliance overcomes these concerns.
HDcctv stands as the world's only comprehensive electrical standard for Digital HD surveillance video, enabling manufacturers of compliant products to warrant:
Greater than 100m transmission distance, over even relatively narrow-gauge coaxial cable
Plug-and-play multi-vendor interoperability
Forward compatibility with future versions of the standard
Look for the distinctive HDcctv compliance mark to be sure!
720p25/30, 720p50/60, and 1080p25/30 transmission over at least 100m of RG59 coaxial cable
Ratified November 2009
Compliance Certification Standard for HDcctv 1.0 ratified September 2010
First HDcctv 1.0-compliant products certified January 2011
Figure 1 shows a block diagram of an HDcctv 1.0 channel.
HDcctv XR(tm) ("XR" derives from "eXtended Reach")
HDcctv XR is a significant transmission distance enhancement for coaxial cable, expected to result in even greater CCTV retrofit success rates.
Look for the HDcctv XR compliance mark to be sure:
HDcctv XR relies on a purely electrical technique. Although some compression schemes were considered years ago, the Technical Committee chose to reserve lightweight compression for possible use in higher-pixel-rate future versions of the standard.
Any generation of HDcctv-compliant products may be certified as XR capable. Figure 2 shows the block diagram of an HDcctv 1.0 XR channel.
As a general guide, XR increases transmission distance over new RG59 solid-core coaxial cable, as indicated in Figure 3.
The ability to transmit a signal over any given run of legacy cable is ultimately a function of the physical properties of that cable and the quality of its terminations. Length is just one factor; core composition, wire gauge, cable run geometry, the integrity of the insulating layers, and so forth, also affect the result. HDcctv XR increases the set of legacy cables that can be directly re-used in Digital HD surveillance upgrades for existing CCTV systems.
What Transmission Distance to Expect?
The minimum transmission distance for various cable makes and models is shown in Table 1.
Table 1: Minimum Transmission Distances
HDcctv 2.0(tm) (Bi-Directional Communications)
HDcctv 2.0 enables multi-vendor interoperability for up-the-cable remote control, bi-directional metadata, and optional audio.
The HDcctv 2.0 Bi-Dir communications protocol is simple, wherein paired ports exchange 255-byte packets patterned on the PSIA and Pelco-D protocols.
Hcctv 2.0 provides for an encapsulated downstream 75Mb/s payload data stream in parallel with the uncompressed HDTV signal over a single cable.
HDcctv 2.0 also provides 5Mb/s (optionally 10Mb/s) upstream payload data bandwidth, as is needed for high-quality audio.
Figure 4 illustrates the block diagram of an HDcctv 2.0 transmitter.
Figure 5 illustrates the block diagram of an HDcctv 2.0 receiver.
Figure 6 summarizes interoperability among HDcctv 1.0 and HDcctv 2.0 products.
Comparison among Surveillance Video Interface Technologies
Table 2 compares key properties of alternative video transport technologies.
Table 2: Comparison Among Video Transport Technologies
HDcctv CX ("CX" derives from "Cat-X")
HDcctv CXTM transmits uncompressed HD signals over familiar types of IP LAN cabling infrastructure: Cat5e and Cat6.
Transmission distance over new, properly terminated Cat-5e exceeds 100m.
Look for the HDcctv CX compliance mark to be sure of the electrical characteristics and the protocol, for plug and play without fail:
HDcctv CX enables a less expensive alternative to coaxial cable for greenfield HDcctv installations.
HDcctv CX also enables ready upgrades from legacy IP cameras to HDcctv, directly re-using LAN cables that are home-run to a control room.
Figure shows a block diagram of an HDcctv 1.0 CX channel.
Figure 7: HDcctv 1.0 CX Channel
Figure 8 illustrates HDcctv CX connectors on the rear panels of compliant products.
Figure 8: HDcctv CX Rear-Panel Connectors
HDcctv AT ("AT" derives from "Advanced Transmission")
HDcctv AT(tm) transmits uncompressed HDTV signals over any conventional CCTV cable.
HDcctv AT is in development by the HDcctv Alliance Technical Committee.
Legacy infrastructure and long cable runs will readily take advantage of HDcctv AT technology.
HDcctv 2.1 and Beyond
Future versions of the HDcctv standard will include these capabilities, taking advantage of the technology roadmaps for each of XR, CX, and AT:
- Universal up-the-cable control protocol
- Power up the cable (for XR and CX): up to 40W for XR
- Fibre optics: 10km, 30km, 50km laser classes
- Wireless transmission: ~ 50m
- Higher resolutions: 4K (8 megapixels), 8K (30 megapixels) and beyond, as sensors, codecs, HDDs, networks, and monitors accommodate
- Higher frame rates: 720p240 and higher, for high-speed applications such as traffic monitoring
Under the unique license agreement between HDcctv Alliance and SMPTE, the HDcctv Standard readily tracks SMPTE's video format roadmap of successively increasing resolutions. (See, for example, UHDTV.) In order to best address the unique requirements of the surveillance market, the HDcctv Alliance Technical Committee is free to consider video formats beyond those sanctioned by SMPTE.
The contents of the HDcctv standard, and the timing of new versions of the standard, are determined collectively by HDcctv Alliance Members.