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NAB: NHK test transmits 8K

While others at NAB were still getting to grips with 4K, Japan's NHK, demonstrated realtime over-the-air transmission and reception of 8K broadcasting for the first time outside Japan. Also new at the show for Super Hi-Vision was the AstroDesign AH-4800 8K camera head.

Almost unbelievably, while vendors begin to push 4K tech into the market, the first 8K product is emerging. Leading the pack is Japanese broadcaster NHK, which at NAB demonstrated for the first time outside Japan realtime over-the-air transmission and reception of 8K broadcasting.

The broadcaster restated its aim is to begin 4K tests next year with a view to starting a 4K satellite service in 2016. It will then begin 8K tests with a view to introducing an 8K broadcast service in 2020.

The NAB demonstration featured the latest iteration of its Super Hi-Vision system, which supports 8K video and 22.2-multichannel sound. The broadcast was of a recorded SHV programme compressed in H.264 (MPEG4) and transmitted using two UHF television channels and in combination with dual polarized MIMO and ultra-multilevel OFDM technologies.

The transmission antenna was located within NHK’s exhibit, and the reception antenna to the left of the display booth, at a distance of about 20 metres. Output power was about 100mW per channel.

“The two antennas are not placed in each other’s line of sight because we want to show how transmission by the dual polarized MIMO technology is achieved without error in a non-line of sight reception environment,” explained NHK spokesperson Haruyuki Ichinohashi.

The C/N with 4096QAM (Quadrature Amplitude Modulation) used in the demonstration was about 32dB and the transmission capacity about 90Mbps per channel meaning that the bulk transmission on two channels achieved about 180Mbps.

Featured production technology for the Super Hi-Vision system included a 120-frames-per-second Super Hi-Vision three-chip camera; an 8K 60fps single-chip compact camera; and a 22.2 multichannel sound production system. A demonstration of the NHK Hybridcast system encompassed capabilities of a converged broadband/broadcast service.

Last year NHK fed live coverage of the Olympics from London over several international research and education internet networks, JANET, GEANT, SINET4 and GEMnet2 to sites in the UK, back to Tokyo and also to a screening in Washington DC.

A terrestrial transmission demonstration had previously been conducted in Japan, but this was the first made in North America.

Also on the show floor, the Japanese developer AstroDesign showed the 8K AH-4800 camera head (pictured left).

It uses a 2.5-inch 33-million pixel CMOS sensor developed by NHK, with a 12-channel parallel optical-fibre output.

The AH-4800 has an active resolution of 7680×4320 pixels and it comes in a body weighing 2kg with a PL lens mount.

Adrian Pennington