On 1 February 2021, China Central TV (CCTV), supported by China Mobile, China Telecom, China Unicom and China Radio and Television, broadcast its first live 8K Ultra High Definition (UHD) TV channel broadcast test signals over a 5G network from the Beijing National Grand Theatre and Shanghai International.
CCTV has been upgrading its studios to 4K/UHD specifications with IP connectivity over the last several years. CCTV’s resulting IP network is more versatile and simpler compared with traditional SDI networks. However, with an IP network at the scale of this test, some challenges exist.
If 8K signals up to 33Gbps are transmitted across the IP network, issues can occur such as packet loss and disorder, separate video, audio and uncertainty about whether all the auxiliary data is present. Also, the main and backup signals may not be consistent, and it may not be possible to lock PTP clock synchronisation.
As all these issues need to be considered and resolved to ensure high-quality, high-volume broadcasts of 8K signals, close monitoring is used throughout the production and distribution workflows. The test broadcast on 1 February used Telestream’s 2110 IP system including its Inspect 2110 IP monitoring system, PRISM waveform monitor and SPG8000A precision multiformat video signal generator, suitable for master synchronisation and reference applications.
More than 30 UHD large screens and China’s first consignment of 8K TVs broadcast the images in public places across nine cities, including Shanghai, Guangzhou, Shenzhen, Chengdu, Hangzhou, Jinan, Haikou and Qingdao. CCTV reports that this was the world's first 8K UHD TV live broadcast across a 5G network.
CCTV also intends to broadcast the Chinese New Year's Eve celebrations using its 8K UHD TV channel, broadcast live as part of CCTV’s Spring Festival Gala, which is the largest live show on Chinese New Year’s Eve. The first time the Spring Festival Gala was broadcast in 4K was in 2019, from a studio upgraded to IP in Beijing.
In 2022, CCTV will start broadcasting 8K UHD channels in the run-up to the Beijing Winter Olympics, and plans to implement 8K UHD as the standard production format for the Games, including full-time comprehensive 8K Telestream live monitoring from content production to editing and broadcasting.
CCTV is using Telestream’s Inspect 2110 and Prism monitors to monitor IP 2110 8K signals in real-time around the clock. Telestream supplies IP 2110 network health protection and automatic alarm functions, and checks the consistency of the main and backup channels.
The Inspect 2110 probes monitor and record multiple RTP indicators in real-time – even the smallest amount of packet loss and disorder that cannot be detected by the naked eye – to give early warning and record IP network problems. The system also compares the main and backup signals, confirms PTP system synchronisation and can accurately identify any inconsistency in audio and video content and auxiliary data, alerting the operational staff.
When the staff encounter a serious issue, Inspect 2110 maintains a direct link to PRISM for in-depth diagnosis and analysis of the problem video stream, which shortens the network troubleshooting time and ensures the health of CCTV’s 8K broadcast system. www.telestream.net
