The New 2.0’s: HDMI 2.0 and HD Base T
With the announcement within weeks of each other of a second generation of two technologies, you could be forgiven for thinking that there was some similarity by way of compatibility, however apart from the “2.0”, these standards all have little in common as they bring video and audio to a whole new level.
Although HDMI 2.0 was announced at end of 2012, the detailed specifications were not released until September 2013. With the availability of the new UHD displays, the need for 4K distribution and transport has also significantly grown. Since the sources currently available are using HDMI 1.4, they are limited to a maximum of 4K @ 30Hz (3840×2160 resolution, refresh rate 30Hz), which is enough for cinematographic content (whose refresh rate is 24p), but not enough for video content which uses a 50/60Hz refresh rate, depending on the location.
The UHD demo content is restricted to either movies or super-slow content, both in terms of camera movement and action with fast-moving sports content or adrenaline-thrill demos in 4K, not possible as they would appear stilted and fragmented. Thanks to HDMI 2.0, the data rate can increase to 6Gbits per channel (TMDS rate, or 14.4 Gbps effective content rate), which will gives enough room for 3840×2160 @ 60 Hz and provides new features such as Display Port 1.2 allowing for up to 63 Audio & Video streams.
As the HDMI 2.0 specifications were announced, HDBaseT Alliance simultaneously released the HDBasetT 2.0 specifications. However, the specification objectives of both are somewhat different. Whereas HDMI 2.0 is focussed on delivering higher speeds, Display port and higher resolutions, HDBaseT is providing distribution in the home in the form of a multimedia matrix.
HDBaseT 2.0 specs still complies with those of the HDMI 1.4 recommendation, which HDBaseT 1.0 followed 100% but the 5Play of HDBaseT (Video, Audio, Control, Network and Power) increases to 6 with the addition of yet another “2.00”, USB 2.0 signal. It now makes sense to have a common hub in the house connecting all the HDBaseT sources and displays or end points. HDBaseT HomePlay focuses on networking all these devices. It goes to the point of adopting the OSI model with its 7 layers.
Integral to the specifications is the chip manufacturer, Valens, whose new set of chips are not only in the sources and end points, but also in the middle. So with a new standard and a new set of chips, HDBaseT can now robustly compete with HDMI, as Matrix manufacturers will need to buy these chips to achieve the same services. This will be significant for Valens as currently a HDBaseT matrix relies on TMDS switching and matrixing (based on HDBaseT receivers, their way to matrix, switch, split HDMI signal, and HDBaseT senders). Another feature for HDBaseT is that with 2.0, the matrix can have multiple layers, individually passing and switching each HDBaseT service (well almost, as you cannot make matrix switch Power, but you can remote switch on and off an endpoint).
The shift to HDMI 2.0 is a game changer as the bandwidth has now doubled from HDMI 1.4, and quadrupled from most current sources of HDMI 1.3. Keeping in mind that most of the time, we complied with HDMI 1.4 by integrating HDBaseT 1.0 transport in our designs as an easy way to transport signals on Cat cables, and also to comply with the extra bandwidth. If we follow HDMI 2.0 specifications, the same HDMI Cat 2 cables will supposedly transport 18 Gbps signals, however in practice, the contrary is most likely. Most of the cable manufacturers are not rating their cable for 18 Gbps, especially if they have long cables of more than 5 meters, because transporting 18 Gbps over longer distances is complex and in some cases impossible. Currently, there is only one platform that can handle signals at this speed being Lightware’s 25G Hybrid platform, which also supports DisplayPort 1.2 at crazy 21.6 Gbps.
Shifting to HDBaseT 2.0 on the other hand, is quite easy if the bandwidth of your system is 10 Gbps or greater. Simply run Cat cables from sources to matrix, and from matrix to the end points, just as in HDBaseT 1.0 design. The only thing that is set to change is the matrix itself and the services it will provide. It is important to consider that the feature set of HDMI 2.0 will not be available over this framework. It will stay as HDMI 1.4 connectivity and allow the independent routing of the individual services of 5Play, along with USB 2.0 support!
Major international sporting event will soon be recorded in 4K @ 60 Hz with video editors working in an HDMI 2.0 environment and consumers looking for razor-thin, curved, HDMI 2.0 display. HDBaseT 2.0, on the other hand, may not surpass 4K @ 60 Hz, but it will certainly be more convenient, likely to be less expensive in the short term and allow a new freedom of services. Ultimately both 2.0’s will find their own particular markets.