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4K is good to go over Homeplug AV2 MIMO networks

ETSI, the European Telecommunications Standards Institute, says that the MIMO version of HomePlug, combined with HEVC encoded video, “will facilitate the distribution of UHD video-on-demand and 4K video streaming, linking home network gateways (DSL, cable, satellite and fiber to the home) to 4K UHD receiving devices (smart TV sets, set-tops etc).

Really the statement should be attributed to the ETSI Powerline working group, which put together a paper which suggests what is required from a Home Networking system for UHD was a sustained real world performance of 80 Mbps, for 10 or 12 bit color with 60 frames per second UHD.

The chart below shows the real world performance attributed to the original AV version of Homeplug, plus AV2 in single wire SISO mode. Given that the range of signal strengths it expects to be found in the average home were 30dB, 15dB and 5dB, both AV and AVs SISO would fail, fairly catastrophically, especially if noise increased on a home’s electricity network, with UHD video being shut out.

It was only in the MIMO version of AV2 that the ETSI committee thought that 80 Mbps could be sustained at the three different power levels.

SNR 30 dB              15 dB            5 dB

AV2 MIMO              300 Mbps                150 Mbps    80 Mbps

AV2 SISO                 150 Mbps                70 Mbps      30 Mbps

AV                              80 Mbps                  50 Mbps      20 Mbps

The report, which can be found on the IEEE site, said “This clearly illustrates the fact that AV has a limited capacity that may not allow dealing with the transport of UHD streams which would require peak bitrates of more than 80 Mbps, and clearly show that AV2 MIMO is a better technology candidate for such a transport.”

What it does NOT say, is that MoCA, which has recently been tested at 350 Mbps around a home for 95% of its outlets and 400 Mbps at 90%, is an even greater certainty as a UHD carriage technology.

The report also suggests that this all only works if UHD HEVC video delivery is optimized with a 16 frame GOP. A GOP is a group of pictures, and is the regulated gap on flat bit rate video delivery, between I Frames. Most existing IPTV and Cable TV delivery has a 12 or 15 frame GOP, right now.

ETSI’s Powerline Telecommunications Technical Committee published the report which assesses three emerging technologies and how they impact one another: “the new generation of MIMO powerline telecommunication modems, the recently standardized High Efficiency Video Coding (HEVC) video codec, the successor of MPEG-4 and Ultra High Definition Television transmission.” The report is called “Power Line Telecommunications; Powerline recommendations for very high bitrate services” and is quite technical and can be downloaded from its web site.

However the paper does not offer data on G.hn over powerline, which may offer a superior  performance, but on the other hand, nobody is quite sure yet. We suspect that this working group is a Homeplug biased grouping.

The report conclusion says, “MIMO-PLT [HomePlug] networks are recommended for high speed Internet services such as UHD SVOD and video streaming services for whole home distribution.”

The essence of ETSI’s report is that 4K videos can be delivered flicker free over home networks that use HomePlug’s AV2 MIMO technology.

There is a separate report called “PowerLine Telecommunications (PLT); MIMO PLT, about the MIMO version of HomePlug powerline technology at ETSI.”

The first report looks at the impact of HEVC-compressed videos on powerline networks and provides technical guidance to powerline equipment vendors to cope with very high bitrate services such as 4K videos being streamed over HomePlug networks to UHD TVs.

ESTI says, “As gigabit home networking products based on MIMO-PLT modems enter the market, TC PLT explored additional channels provided by ground wiring, improving the performance of powerline telecommunication links. Measurements made in the electrical network within real homes in six European countries showed great improvements of MIMO-PLT networks on home coverage and robustness compared to existing Single Input-Single Output (SISO) PLT technologies.

Roger Samy, the Chairman of ETSI TC PLT, said, “Transmission of UHD Phase 1 video streams based on HEVC video compression over MIMO-PLT networks enables whole home coverage of current and forthcoming video services.”

We asked HomePlug Alliance president Rob Ranck about the reports. He said, “These reports are effective, independent confirmation of our prior assertions that HomePlug AV2 MIMO and WiFi are a compelling combination for whole-home coverage and streaming multiple 4K UHD videos. And of course, I’m not the least bit surprised (or disappointed) that apparently HomePlug is the only PLC standard that was included in the ETSI testing.”

A couple of things that are interesting about the reports:
They confirm that the goal for HEVC/H.265 was “to reach a video coding standard that provides a bit-rate reduction of 50 % at the same subjective quality,” which is what was accomplished. Videos that are compressed by HEVC consume half the bandwidth of files compressed with the older MPEG-4 compression technology — regardless of the videos’ resolution, whether 1080p or 4K. All videos compressed by HEVC are transmitted in half the bandwidth of those compressed by the older but still predominantly used H.264.

Without being compressed by HEVC, 4K videos are four times as large as 1080p HD videos. Pay TV and OTT services are about to use HEVC gear to compress 4K videos, so they can be transmitted to the home, otherwise 4K is too big for most to handle. Makers of every viewing device from TVs to smartphones are adding HEVC decompression chips to play the HEVC 4K streams. ETSI has over 750 member organizations from 64 countries across 5 continents world-wide.

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