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HDBaseT: The 5 Primary Benefits

Detailing the video, audio, control, data and power capabilities of HDBaseT, called '5Play.'


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In addition to using a standardized RJ-45 connector and twisted pair cabling, HDBaseT includes several other features to enhance the HDMI standard.

The entire bundle is marketed as 5Play and includes:

  • Uncompressed high definition video
  • The same audio formats supported by HDMI
  • A variety of options for device control
  • 100BaseT Ethernet
  • Additional DC power over the same cable.

Here’s a review of each of those features.

Video: The video implementation is a simple pass-through from an HDMI chipset.  All of the same resolutions incorporated into HDMI 1.4 specifications appear to be supported. However, there currently is no public information available on how deep the bit depth will go for Deep Color. There also isn’t any information on the support for the new Color Spaces introduced with HDMI 1.4. HDBaseT does support 2K and 4K at the same frame rates in addition to the new mandatory 3D formats.  There currently is no integration with DisplayPort, but there is talk about being able to work with dual port versions (DisplayPort ++) via the HDMI interface.

Since the Display Data Channel (DDC) line, which carries the HDCP encryption handshaking, is passed through, playback of premium content is consistent with HDMI. It actually may end up being more reliable since the HDBaseT coding scheme is not as susceptible to the resistive, capacitive, and crosstalk-related electrical problems that a normal HDMI cable may experience. Coding schemes tend to have less degradation over longer distances than strictly sending out high-speed binary ones and zeros.

Audio: Audio is passed through the same as video, so all formats are included. Once again, protected audio content will work as well. At some point, we may see HDBaseT used for audio-only distribution, but the costs may prohibit its wide use.

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Control: This is where the additional features of 5Play can really add value. The technology supports both Consumer Electronics Control (CEC) and DDC. Since these also are “passed-through” from the associated HDMI chip, all of the functionality for CEC, HDCP, EDID discovery, Content Type Signaling, and things like the HDMI 3D-Structures embedded in the video stream work as they would if it were an HDMI cable.

HDBaseT participates in the same CEC topology tree as a “normal” HDMI interface. It also has the capability to support other low-speed control mediums like RS-232 and IR over the same cable. HDBaseT does not specify how these other control signals are implemented and vendors have the ability to engineer solutions to meet their specific requirements and value-added features. One of my fears is that, since the implementation of the additional control capabilities does not appear to be standardized, they potentially open the door for a level of incompatibility across different vendors’ products.  Since HDBaseT also has an Ethernet channel, IP control would be transparent, too.

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Another interesting aspect is the ability to run USB over HDBaseT. Icron Technologies Corporation, makers of several interesting long distance USB products including USB over Ethernet, has announced that it will be offering a product that uses HDBaseT for sending USB over twisted pair.  Note, however, that while HDBaseT supports USB 1.1 and 2.0, it cannot handle the higher 480 Mb/s speed of USB 2.0.

While there is no dedicated wire in the HDBaseT cable for Hot Plug Detect (HPD) like there is with HDMI, there is logic built into the chips at both ends that raises a flag on the source side whenever a new device is plugged in. This logic is used for initiating the process for obtaining the EDID information from the new device and initiating the HDCP key exchange, just as it would with an HDMI cable. Another thing to note is that the Link Layer Ethernet channel is independent of the HDMI 1.4 chipset interface.

Ethernet: HDBaseT also supports 100Mb Ethernet over the same cable. There is talk about supporting gigabit Ethernet with some future release, but 100Mb is in keeping with the new HDMI Ethernet Channel (although it still is not known if vendors will be able to bridge the two).

There is a great feature of HDBaseT that I have not seen discussed anywhere. HDBaseT has what I call an “Ethernet Fallback Mode” (EFM). Since HDBaseT uses a coding modulation similar to 100BaseT Ethernet, if you plug an HDBaseT device into an Ethernet-only infrastructure, the HDBaseT device is smart enough to realize it and only enables the Ethernet capabilities of the connection. This definitely will help eliminate any potential confusion around using a “standard” RJ-45 for both connection types and eliminates the need to have separate connectors for Ethernet and HDBaseT.



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