Valens Responds: What’s the Road Map for 4K @60 MHz HDBaseT with 4:4:4?

We get quite a few emails from savvy end users who want to dive into the smart home and 4K Ultra HD video. Recently we heard from one CEPro.com reader who wants to “future proof” for 4K @ 60Mhz with 4:4:4 color rendering. How should he wire his home? Will HDBaseT fit the bill with Cat 5 wiring? Is fiber required?

We passed the inquiry to Valens Semiconductor, developer of HDBaseT, the technology that delivers audio, video, data and control signals over a single category cable. Valens, which provides the chips for HDBaseT implementers, says it's not quite ready for 4:4:4 but is “working on a new specification which will enable 16G,” the bandwidth required for 4:4:4.

Dealers can ask Valens themselves at CEDIA 2016.

Reader: How Should I Prep for 4:4:4?

I’m in the process of building a house that I want prepared for 4k @ 60Mhz 4:4:4 color and this site and your articles have been invaluable to help me understand the multitude of standards and specs that are involved in trying to distribute video from a central location. 

I’ve come to two key conclusions: 1) I should spec Cat 7a for layer 1 [physical layer/cabling] because it is required in order to carry the 18Gbps needed for 4k @ 60Mhz 4:4:4 color, and 2) I should probably run two per location.

Even though content for 4k @ 60Mhz 4:4:4 color is now starting to emerge (very slowly), I can’t distribute it because the current Valens chips at the heart of HDBaseT will only push ~10 Gbps or 4k @60Mhz 4:2:0 color – so you can’t buy a matrix switch on the market that will meet the spec. I will be getting the LU862 8×8 switch from Leaf/Control4.

From the research I've done, I believe the max performance in a video matrix switch I can get on the market right now is 4k @60 MHz with 4:2:0 color, but 4:4:4 color UHD content is here now, albeit extremely limited.  

I plan to be in the house several years and thus foresee needing to distribute 60 MHz 4:4:4 content when equipment becomes available.

The main question for now is what to do about layer 1 (cable). It looks like it will take an 18 Gbps infrastructure to accommodate 60 MHz 4:4:4 content. So I'm specing 2 Cat 7a cables per monitor run terminated like Cat 6 (with enough cable left to re-terminate in the future with Cat 7 terminators when needed).  

The question is whether the industry is likely to go 1) multiple Cat 6 ports, 2i) a single Cat 7/8 port, or 3) fiber in order to distribute UHD content in the future.  

The second question is when might that be!?  

I'd like to protect the investment I'm making as much as possible and there is just not much info out there on how the layer 1 problem will be solved … or when. 

Because there’s not much investment protection on the switch (i.e., no ability to buy new HDBaseT cards, firmware upgrades, etc.), I wanted to know when new product might be coming.

HDBaseT/Valens Responds

As you mentioned yourself, right now the only option is 4K 60fps 4:2:0. The [HDBaseT] Alliance is working on a new specification which will enable 16G (which is equivalent to the 18G of HDMI to transmit 4K 60fps 4:4:4), but the spec is not finalized yet. Even after finalizing the standard, it will take a while for vendors to incorporate it in their products and pass certification. So it’s hard for me to give you a very definite timeframe for this.  

One thing that is central for HDBaseT is backward compatibility – meaning we strive that any future spec is backward compatible with the past specs.

Right now, the consensus I received from the team is that you probably do not need to go higher than Cat 6a for cabling. In terms of one or two cables, it is hard for me to give you a definite answer, but I can tell you that the future spec will be based on a one-cable solution. There may be 4K 4:4:4 solutions based on 2 cables, but they are not at the moment HDBaseT standard. 

Last, regarding fiber: Please note that Spec 2.0 does support fiber as the transmission channel; however, it does not allow higher bandwidth, just longer distances.  

Reader: So Here's What I'll Do …

Here's what I've determined:

1. My investment in the switch is protected for a few years. Given the spec is on the drawing board now, we probably won’t see product on the market for 3-4 years – and even then, it’s not always great to be the first adopter! So I feel comfortable that the switch I’m buying has at least a five-year life.

That’s typically about my target anyway for home computers and A/V equipment.

2. The industry is having a tough time navigating the big layer 1 issue – which shouldn’t be a big surprise. There’s a ton of old, slow copper deployed and data network professionals have been struggling with this issue for years. Manufactures have to be able to sell the equipment they design and produce.

Here's what I'm going to do:

I’m going to run two Cat 7a cables to each TV location and terminate using Cat 6a-standard 8P8C RJ-45 connectors and have the installers leave enough cable at both ends to re-terminate with Cat 7a-standard connectors (GG45, TERA, etc.) when/if needed.

Cat7a is rated at 40 Gbps which covers the 4k UHD 60 Hz 4:4:4 spec and having two cables covers the use case where the industry decides that with all the Cat 6 cables installed, product can be sold if it’s designed to use two (see Extron white paper).  I know it will cost me a little extra, but not near what it would cost in five to 10 years to retrofit new cables behind the walls.