By Adrian Ickeringill, Wyrestorm.
While cable may seem like the most basic aspect of an installation - and it can be if you make the right initial choices - ironically, this is precisely where a great many HD projects run into trouble. The use of CAT5e or CAT6 cable that is poor quality, incorrectly terminated and/or badly installed can mean massive headaches for any installer in terms of bandwidth and the successful transmission of the increasingly higher definition signals found in modern digital content - not to mention passing reliable IR control signals to and from connected devices.
It is important to use high quality cable, of the correct gauge, that is properly terminated and that suites the application. In addition, to safeguard the integrity of installations, we also always recommend surge protection on every job as a matter of course, and advise installers to be aware that poorly-maintained, dirty or unreliable mains supplies can impact negatively on distribution.
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High-quality cables are a basic requirement.[/caption]
These concerns are compounded when inheriting a retrofit project using existing cable resources, as the installer never really knows what they are working with. The cable is often buried in the wall, possibly including patch panels and wall plates which can affect the successful reception of a transmission. Who knows what condition the cable itself is in; bent or twisted, restricting the bandwidth like a foot on a hose pipe, not to mention electromagnetic interference from the surrounding environment, and possible sub-standard terminations. It's a lot to consider, and a lot that can go wrong, particularly with conventional twin-cable UTP distribution.
Since all of these factors are so difficult to determine in retrofit installations, the emphasis on testing before commencing installation becomes even more important. However, in recent years, the advent of HDBaseT has gone some way in alleviating some of the pains traditionally associated with HDMI distribution over dual CAT5e, which is why the industry has become so excited.
The Benefits of HDBaseT
HDBaseT is an installer's dream. You are getting more for less, and you are getting it faster, easier and more reliably to provide significant reductions both in cable infrastructure and installation times, while at the same time future-proofing your installation.
Yes, you get the same delivery of full 3D 1080p HD video, HD audio and two-way IR and RS232 control between source and display as with typical dual-cable UTP installations, but you get it over lengths of up to 100m using only a single standard CAT5e or CAT6 cable. As the installer has one less cable run per output to worry about, and that single cable reaches twice the distance, it offers an obvious initial saving.
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HDBaseT only requires one Category cable to deliver full 3D 1080p HD video, HD audio and two-way IR and RS232 control between source and display.[/caption]
Furthermore, it also includes several important feature upgrades that are unavailable with conventional HD distribution over CAT5, that will become increasingly necessary in modern HD installations as content and devices continue to evolve. These include LAN access (Local Area Network Ethernet pass-through) and power-over-Ethernet (PoE) as well as support for 48-bit Deep Colour and 4k resolutions. These additions mean that not only is HDBaseT a tailor-made solution for the ever-rising popularity of Smart TVs and innovative wireless control options using iDevices etc., it is also future-ready for the next generation of 4k Ultra High Definition displays that are now finally beginning to find their way onto the market.
On top of the technical improvements, a key benefit of HDBaseT is its resistance to the electromagnetic interference that is so problematic in typical installations. This is combined with a vastly decreased susceptibility to the adverse effects of inferior cable or the use of patch panels and wall outlets. This is not to say that HDBaseT means installers need not care about cable quality or the suitability of the installation environment. Rather, an HDBaseT distribution is far less likely to cripple your installation - it's the closest we have come in the industry actual plug-and-play HD distribution.
Cabling Infrastructure
For HDBaseT transmissions using CAT5e cable as a distribution medium, we recommend well-terminated RJ45 connectors and straight-through connections. If you have inherited a retrofit project with preinstalled CAT5e, your HDBaseT distribution system, carrying bandwidth-heavy content such as 3D, Blu-ray, gigabit Ethernet and control signals, will all function just fine with the existing cable, provided it is in good condition.
However, given that the bandwidth needed to handle modern content is continually expanding, we generally suggest CAT6 cable for new installations in order to avoid future bandwidth issues with 4k content for example.
Hardware Requirements
In terms of hardware needed for HDBaseT distribution, the choices are simple: either an HDBaseT transmitter and receiver for simple extension of HDMI devices, or an HDBaseT matrix or digital amplifier with an HDBaseT receiver at the end of the transmission.
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Wyrestorm HDBaseT matrices for example, offer features such as Ethernet pass-through, 48-bit Deep Colour, 4k resolution and 100m cable runs and two-way IR control over a single CAT5e/6 cable up to 100m.[/caption]
Testing and Troubleshooting Existing Cabling
Using a point-to-point HDBaseT extender set is a quick and easy way of checking the integrity of the installed cable, but there are also test kits available. The Wyrestorm test kit for example, comprises a signal pattern generator, full HD 7" portable monitor and battery packs. Such test kits allow the installer to more thoroughly examine cable resources, bandwidth and the compatibility of EDID, HDCP handshakes between devices to be connected.
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Test Kit comprising full HD test screen, signal pattern generator, single cable extender set battery packs, HDMI leads, CAT5e and CAT6 test cables in a foam-padded protective case.[/caption]
Modern HD distribution is more subtle and involved than analogue distribution used to be, and problem solving is part and parcel of any installation. Once connections between devices and power supplies have been checked and you are sure you are well within transmission range, a good place to start would be to make sure that all devices are set to output the same type of signal.
HDBaseT is designed for compatibility, meaning that it will try and output to the minimum resolution detected for maximum chance of signal reception - if it encounters any conflict the result is no picture. In this case, reduce the output resolution settings of displays to see if that solves the problem. If so, work back from there to find the cause of the conflict.
The same can be said for cable - bandwidth bottlenecks over CAT5 can happen for many reasons, as outlined before, but reducing the settings of each individual display to lessen the signal bandwidth will reveal if something is putting a strain on the capacity of the cable. If in doubt, swap the cable over to another fully-working output port to see if the problem follows you, or if possible, test source and display with a completely different cable - go back point by point until you reach the cause of the problem.
For more information on troubleshooting your project, we offer detailed advice and FAQs on all aspects of HD distribution on our website and product manuals.
Conclusion
There are many advantages of HDBaseT over conventional dual-cable UTP distribution, and these help reduce the materials, time, effort and money needed to complete projects that are becoming increasingly complex. Indeed the time is fast approaching when twin CAT5 will feel as antiquated as component, with its limitations fully exposed as soon as 4k resolution and 48-bit colour content, sources and displays become established.
As the capabilities of multi-location digital distribution and control are being realised, single-cable HDBaseT technology is emerging as the only medium currently capable of handling such content, and the possibilities of HDBaseT that were just glimpsed only twelve months ago are well within reach today -whether in a new project or using existing cabling.
Adrian Ickeringill is the General Manager of Wyrestorm Technologies, provider of total AV solutions and specialist in the manufacture of HD distribution and control products for residential and commercial markets.
www.wyrestorm.com