By Paul Kish, Director of Systems and Standards, Belden
Just in case full high-definition resolution isn’t enough, 4K is the next generation resolution that will deliver a whole new level of clarity at roughly four times the resolution of 1080p.
Despite limited 4K content currently available to consumers, Samsung, LG, Sony, Panasonic and others are already selling 4K TV sets and widespread adoption is eventually expected. An ABI Research report from last year expects 4K to surpass 10% of North American TV households by 2018.
4K covers two formats that are both supported in the HDMI 1.4 specification – 3840p X 2160p and 4096p X 2160p. While HDMI 1.4 supports 4K resolution, adds an audio channel that enables upstream audio connections, and can deliver 100 Mbps IP-based applications with an added Ethernet channel, there are some cabling and connectivity challenges to consider that include distance limitations, installation and testing.
HDBaseT resolves these issues.
What is HDBaseT?
Introduced in 2010 by the HDBaseT Alliance, the HDBaseT networking technology enables HDMI signals to be transported up to 100 m (328 ft) in an uncompressed format over balanced twisted-pair cabling with modular RJ-45 connectors.
HDBaseT can be delivered using direct RJ-45 connections from an audio-video source (i.e., set top box, Blu-Ray player, video server) to a display or through the use of HDMI-to-HDBaseT converters. Referred to as 5Play™, one of the key benefits of HDBaseT is its ability to transmit uncompressed full HD video, audio, Ethernet, control and power over a single network cable.
HDBaseT provides up to 4 Gbps of throughput for downstream in Basic Mode and up to 8 Gbps of throughput for downstream in Enhanced Mode. Upstream HDBaseT carries the sink to source portion of the Ethernet data and the controls of the return channel at up to 150 Mbps.
Better than HDMI
While the HDMI specification does not define a maximum cable length, most HDMI cable constructions are no longer than 5 to 15 meters. Beyond these distances, HD signal integrity significantly degrades. And when it comes to properly delivering uncompressed, low-latency 4K signals over HDMI, cable lengths will likely need to decrease even more.
While these shorter distances may be adequate for some residential consumers, it is definitely not an option for commercial applications such as digital signage in environments like hospitals, airports and hospitality venues. With HDBaseT’s ability to deliver HDMI content up to 100 meters, these distance limitations can be avoided.
Not only can HDMI connectors become easily dislodged, they are also virtually impossible to terminate in the field and they make it difficult to pass HDMI cables through conduits. The ability to field terminate HDBaseT cables with common RJ-45 connectors reduces complexity by eliminating the need to predetermine lengths and saves on labor cost through easier, familiar installation practices.
Specialized equipment is also needed to test and qualify HDMI cables. With similar coding and bandwidth to 10GBASE-T, HDBaseT can be tested using typical network testing equipment.
While HDBaseT is uniquely positioned to reduce the cost and complexity of delivering HD video, and therefore expected to further drive the increase of 4K adoption, there are some cabling considerations.
In general, shorter cable lengths will provide a stronger signal at the input to the HDBaseT receiver and can tolerate more alien crosstalk noise between cables in a bundle. In bundled cable configurations, Category 5e UTP cables can only support HDBaseT for distances of up to 10 meters and Category 6 UTP can only support HDBaseT to 40 meters. To achieve the full 100 meter distance benefit, Category 6A UTP or shielded Category 5e or 6 is required.
While shielded cables suppress alien crosstalk noise to support 100 meter distances, shield integrity must be maintained at all connection points to provide the uniform, low-resistance path to ground required to maintain a clear HD picture. Category 6A UTP like the Belden 10GX system is therefore the ideal choice for AV networks that plan to use HDBaseT technology.
If you’re in the Dallas, Texas area and want to learn more about HDBaseT, including horizontal cabling design options and testing, please come to the BICSI U.S. South-Central Region Breakfast Club on December 15th at Hilton Garden Inn Hotel Dallas/Lewisville – the event is free and worth 4 BICSI CECs. I will be presenting on HDBaseT, as well as other new applications that are driving the need for high performance cabling.