The Evolving Specification for the HDcctv Standard
19 Apr 2013
Amid exponential market growth, more than 200,000 HDcctv cameras were sold worldwide in 2012. Many of these cameras are certified HDcctv compliant, and a second generation of HDcctv products is in preparation.
HDcctv 1.0 is current. The high-level specifications for HDcctv 2.0®, HDcctv XR®, and HDcctv CX® are complete, with the full specification suite on track for ratification mid 2013.
Prototype cameras and DVRs implementing advanced capabilities including up-the-cable remote control, increased transmission distance over coaxial cable, and native transmission over Ethernet cable, are already being developed by leading manufacturers.
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(tm) ("CX" derives from "Cat-X")
HDcctv CX transmits uncompressed HD signals over familiar types of IP LAN cable. Any HDcctv-compliant product may be certified CX capable. Transmission distance over new, properly terminated Cat-5e exceeds 100m.
Look for the HDcctv CX compliance mark to be sure:
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 3.0 and Beyond
Future versions of the HDcctv standard will include these capabilities:
- Power up the cable: up to 40W
- Fibre optics: 10km, 30km, 50km
- Wireless transmission: 50m
- Analogue transmission: 500m
- High resolutions: 8 megapixels and higher
- High frame rates: 720p240 and higher
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.