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Product Article: VizionWare Active Digital Interconnects - Delivering Error-Free HD Over Longer Distances (1/9/2007)

By Ben Jamison, ViZionWare

Over the last decade we have seen tremendous advances in HDTV technologies. Entire product categories have been spawned to enable HDTV, and certainly one of the more significant innovations has been the introduction of HDMI as a digital interconnect standard for products delivering HD video and audio. Introduced in late 2002, HDMI provided the ability to run high-definition video and audio over a single wire, eliminating what had usually taken at least nine cables to achieve. The importance of HDMI can perhaps best be judged by the fact that currently over 650 companies have licensed the technology and are incorporating it into their products.

The HDMI standard was originally developed by industry giants that included Sony, Panasonic, Philips, and Hitachi. Given that these companies have very large consumer products divisions, HDMI was designed for consumer retail markets and customers. Its two main shortcomings are that it uses a fairly delicate 19-pin connector that has no latching mechanism (unlike its DVI counterpart), and that HDMI is designed to be used in cable runs that were typically 5m or less.

A very passive approach to HDMI

To provide digital interconnects for all of the new HDMI-enabled components being introduced into the market, existing cable manufacturers quickly designed HDMI cables based on the same passive cabling techniques that had successfully been used for many years in analogue cable implementations. These cables worked just fine at 480i, 480p, 720p, and 1080i, even at lengths of up to 10m. But as 1080p content has begun to become pervasive, these passive cabling products are no longer able to provide error-free video over cable lengths past 6-7m. This is due to the fact that 1080p has a bandwidth that is four times that of 480p. Complicating this even further is the fact that HDMI has gone through three major and three minor revisions to add greater bandwidth and additional capabilities such as CEC (Consumer Electronics Control) functionality.

Sales of 1080p-capable televisions and sources have increased dramatically over the past six months. In the 4th quarter of 2006, 1080p sales represented less than 5% of total television sales. In just six months, that number is now over 30% of sales.

While many retail installations may not require cable lengths of longer than 7m, almost every custom home theatre and whole-house video installation requires cabling runs that are often several times that length. As installers have begun to deploy HDMI into these more complex installations where 1080p sources and displays are installed, and longer cables lengths are required, passive HDMI cabling performance has declined dramatically, and in some cases fails to display acceptable 1080p video performance.

Several companies offer external signal amplifiers and discrete equalisation products to minimise the shortcomings in passive cables, but many of these add-ons produce marginal results, and in certain cases can even make the picture look worse, while adding significant cost to the interconnect budget.

VizionWare Hi-Wires - the active answer to HDMI

In February 2007, VizionWare introduced a full line of HDMI and DVI digital interconnects that take a radically different approach. After considering the present and potential future issues surrounding how to best deliver error-free HD over longer distances, the company developed and integrated several core technologies into two small electronics modules - one to transmit signals and one to receive these signals at the other end of a digital link. These modules were then embedded into the HDMI connector heads at either end of a host of HDMI cables of lengths ranging from 1-20m.

VizionWare ultra-slim HDMI interconnect.

By using both transmit and receive electronics at each end of the cable, VizionWare Hi-Wires HDMI cables are able to characterise the signal at the output of the source and then compare it at the other end of the cable before it is displayed. The link is optimised to deliver error-free 1080p video and audio at the display, just as it was sampled at the source, over any supported distances. In a nutshell, it creates a fully-protected link that is seamless and transparent from source to sink.

Eye pattern test showing the difference between conventional passive HDMI cables (left) and VizionWare active HDMI cables (right). The larger and cleaner the eye (highlighted in blue), the better the picture.

The complete line of is designed to HDMI 1.3 Class 1 standards for maximum compatibility. Since the cables are active, they are powered using a small A/C adaptor that can be plugged in at either end of the cable, wherever supplying power is more convenient. Another benefit of this fully active implementation is that a much smaller gauge cable can be used, resulting in cables that are much lighter and more flexible than traditional passive cables, thus simplifying installation significantly. Finally, all of this technology does not cost any more than most other premium-brand passive HDMI cables.

The future of VizionWare and HDMI

At this month's CEDIA show in Denver, USA, VizionWare will debut several new products including longer lengths of HDMI and DVI up to 100m in length, as well as a high-performance HDMI switching product. The company will also show its DVI product line and a host of accessory products for HDMI and DVI that were introduced at InfoComm earlier this year. These products include HDMI and DVI swivel adapters, a locking mount for VizionWare's HDMI cable products, and pull-through socks for HDMI and DVI that protect cable connectors as they are installed in walls and conduit.

The VizionWare locking mount firmly locks VizionWare HDMI cables into the connector input/output to virtually eliminate connection-related failures.

Conclusion

With sales of 1080p-capable televisions and sources increasing all the time, HDMI is no longer an option for AV installations. However, while passive HDMI cables are fine for short cables lengths, for the longer runs typical of home theatre installations, active technology is a must if the consumer is to get error-free picture and sound from source to sink. VizionWare Hi-Wires active HDMI cables are optimised to deliver 1080p audio and video over longer distances, in a seamless manner, using lighter and more flexible cables, and at no more cost than most other premium-brand passive HDMI cables.

Ben Jamison is Vice President of Sales and Marketing at VizionWare, and has over twenty-five years' experience in consumer electronics, professional video sales and marketing, and broadcast television. VizionWare is a Texas-based audio and video digital interconnect manufacturer.

www.vizionware.com