Sept. 7, 2021 - HDMI 2.1 is a revolutionary change in the way HDMI signals are transmitted, increasing the maximum possible bandwidth to 48Gbps. This allows advanced features such as 4K120Hz (High Frame Rate), Quick Media Switching, and Dynamic HDR, which continuously enhance the entertainment and viewing experience.
Unfortunately, these enhancements take a toll on the ability to distribute the HDMI 2.1 signal. The maximum specification length of a passive copper HDMI cable has decreased from 10 meters in HDMI 2.0 to only 5 meters in HDMI 2.1. Even with compression, traditional Cat5e does not have the capacity to extend HDMI 2.1 signals effectively over distance. So, what steps can you take to prepare your infrastructure for HDMI 2.1 extension?
THREE ROUTES CAN BE TAKEN:
The Uncompressed Fiber Route
Fiber today is much different from the fiber of the past. Today’s fiber (such as Cleerline SSF) is easily field terminatable, flexible, and is unaffected by EMI. Integrators have a few options for fiber solutions; HDMI Active Optical Cables feature strands of internal fiber, allowing for direct HDMI cables up to 100 Meters, typically using multiple strands of OM2. Other external fiber solutions may utilize micro-distribution OM2 or a single simplex OM3 to achieve the same results.
If deciding to use fiber in your extension solution, it is recommended to run at least a duplex run of OM3 to allow for future HDMI revisions and changes to the solution used in a zone, leaving the integrator with approximately an 80Gbps infrastructure at 100 meters.
The Compressed Category & Fiber Route
To some, compression is a scary word, but it doesn’t have to be. Compressed solutions provide a stable transmission while allowing integrators to utilize cheaper Category and Duplex OM2 Fiber runs. While picture quality may be affected, quality is usually determined by the type and overall amount of compression. Many AVoIP solutions will take advantage of 10G Ethernet transmissions for a 4+:1 compression ratio. HDBaseT 3.0 solutions will have a transmission rate up to 16Gbps, allowing for a smaller 3:1 ratio and providing a solid transmission over Cat 6A/7 cabling or duplex OM2 up to 100 meters. Because of the increase in signal bandwidth when using Category cabling, it is recommended to use shielded cabling and connectors and use appropriate size cable bundles (6-8 cables max at 10G) to prevent Alien Crosstalk. This can cause unstable transmission or prevent it altogether.
If using a compressed extension solution, it is recommended to have at least two Category runs or a single Category run with an additional run of duplex OM2. This will give the integrator approximately a 60Gbps infrastructure at 100 meters.
The Preferred Route
Regardless of the solution, the preferred route is to have at least a single run of Duplex OM3 combined with at least two runs of Category 6A Shielded (Minimum). Having a combination of High Bandwidth Fiber and Universal Category cabling is like putting a Swiss Army Knife in the wall. It can be used in various combinations to extend Audio, Video, Control Signals, Ethernet, and POE; all while providing future-proofing for the installation with a minimum 120Gbps infrastructure backbone at 100-meter distances.
Overall, infrastructure will be determined mainly by client budget and site status. For best results, a discussion with the client determining the needed bandwidth and a roadmap for future upgrades/changes is recommended.
By Sam Metivier