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The Challenges Of Launching A Real-Time UHD Channel By Satellite: An AsiaSat Perspective
By Captain Ip, Communications Systems Engineer, AsiaSat


Ultra HD (UHD) broadcasting via satellite is becoming increasingly popular, especially as satellites operated by AsiaSat, SES, Intelsat and Eutelsat continue to demonstrate the feasibility of delivering content to viewers using this advanced technology.  

These initiatives also help validate that satellites have an advantage over other distribution means in  handling high data rate of UHD  content delivery particularly in rural and remote areas where terrestrial networks are inadequate. Moreover, satellite links are more reliable than terrestrial connections due to its simple infrastructure. Most of these channels are free-to-air (FTA) for promoting UHD in different countries and regions. However, among these channels, only a few are real full-time, UHD channels, i.e., without repeating the content for at least 24 hours. This article examines some of the challenges that broadcasters and content providers face in launching a full-time, UHD channel via satellite and offers some recommendations and solutions that have been experienced by the industry. 

Modern Workflows For UHD Broadcast Networks  UHD content can be encoded either off-line or in real time. The two workflows use different equipment that offer distinct interfaces and possess their own pros and cons, as summarized in Table 1.

The challenges in launching a full-time UHD channel, especially over satellite are:  

Lack of UHD content
At least several hundred hours of content is required to sustain a full-time channel. Although native UHD shooting has been available for some years, producing enough UHD content remains quite difficult.  UHD improves the video quality for a better viewing experience. However, this is not the only factor required to retain audiences. One of the lessons learned during the transition from SD to HD was, and is, that “Content is King.”

The best way to attract and retain audiences is to produce unique and interesting content, such as special live events, music concerts and large sports competitions. As these events require long production times to create attractive content, a great deal of time to gather sufficient UHD content for the deployment of a full-time UHD channel is necessary. 

Expensive UHD HEVC Set-Top Box (STB)
HEVC is a new encoding technology and only a few models of STBs are available to support HEVC with UHD resolution. As a result, the price of UHD HEVC STB is much higher than that of an ordinary HD STB. Currently the price of a UHD HEVC STB varies from a hundred to several hundreds of USD. Moreover, the requirement to customize middleware and conditional access solutions for DTH operators further increases the cost. As a result, the prices of a UHD subscription would be much higher than that of HD, significantly affecting uptake of UHD service. For example, Videocon d2h, one of the major DTH service providers in India, has approximately 15 million of subscribers in total1 but only 8,000 to 9,000 of them are UHD subscribers2.

Inefficient UHD Monitoring Device/System 
To launch a full-time UHD channel over satellite, encoding equipment and decoding devices are necessary. DTH service providers should monitor their channels to make certain all the programs are operating smoothly. In the past, UHD STBs and TVs were used to monitor the UHD channel, with a pair of STB and TV for each channel/program. This, however, failed to provide any alarms or event logs for error checking or bug fixing when the channel went abnormal. Moreover, this process consumed a lot of resources, including manpower and physical space to monitor UHD programs. Inefficient monitoring methods have limited the growth of UHD services on satellites.

Dearth of Professional UHD IRD/Decoder
Professional IRDs (PIRDs) are widely used in the broadcast networks, especially for cable TV headend operation in order to provide a reliable and stable service. HEVC is the latest compression method which provides higher compression efficiency than MPEG 4. Many vendors integrate HEVC into their PIRDs to support HD/SD service. However, only a few PIRDs in the market can support UHD resolution, and none of the HEVC PIRDs support both UHD and conditional access features. As a result, the expansion of UHD channels over satellites has been restricted.

UHD Video Security
One of the major concerns in launching a commercial full-time UHD service is the immaturity of UHD content protection. Despite being widely recognized by many industry practitioners and the introduction of a series of security guidelines, this still needs time before vendors can design and implement chipsets and devices that fully meet the UHD security requirements.

Solutions From The Industry
The operators and vendors of the broadcasting industry have done a lot of work to promote UHD content development and for the deployment of UHD channels.

Table 1. Pros and Cons of Different UHD Encoding Methods Off-air means transcoding UHD programs in HEVC format first—the transcoded file is stored and will playout as scheduled. Off-line transcoding is usually software based. Real-time means encoding the UHD programs in HEVC and the encoded stream is immediately broadcast on-air. There are two different ways of UHD playout to support the workflows: playout outputs the uncompressed UHD signal via 4x3G-SDI for real-time case, and MPEG transport stream (T.S.) by IP for off-air. Chart is courtesy of AsiaSat.

Upscaling HD To UHD 
Upscaling the existing valuable HD content to UHD is one of the most generally adopted solutions to expand the UHD content database. There are different products to upscale the content for both real-time and pre-record HD content.

Benefiting from the latest computer hardware and GPU capabilities, we can upscale the HD live content to UHD through software. HEVC encoding could be applied as well in the T.S. over IP output. A typical example is ArcVideo Live3 from ArcVideo. 

Unlike the live content, there are many solutions to upscale the pre-record HD content to UHD before broadcasting. For example, we can upscale the HD content to UHD, encode the content with a file transcoder and play via a playout server. One of the examples is the ProMedia Xpress4 and Sapphire playout server5 from Harmonic. Another way of upscaling is to use rendering software: we can render the HD to UHD without HEVC encoding, store it in the playout server which outputs 4X3G SDI, then play and encode it when necessary. Real time HEVC encoder is required for this solution. An example is the UHD solutions from Rohde & Schwarz. 

Launch Of UHD HEVC Professional Decoders
Many UHD HEVC decoders are available in the market, including the VH-4000 model from VILLAGE island6; BMM-810 from Rohde & Schwarz7 and UHD-1000 and UHD-1500 from NTTAT8. These decoders can output UHD signal via 3G SDI (uncompressed) or ASI (compressed). In addition, as HEVC is still under development, most of the available decoders are software based. However, the decoders mentioned above do not support any digital content protection technologies such as CA and DRM.

Figure 1: Block Diagram of Different UHD Encoding Methods

Launch Of UHD Chipsets That Support UHD Protection Specification By MovieLabs A growing number of UHD chipsets are available to support the Specification for Next Generation Video and Enhanced Content Protection set by MovieLabs (Motion Picture Laboratories, Inc.). SoCs (System-on-chip) from chipset vendors such as Broadcom, Marvel, MStar and HiSilicon fulfill protection specifications and have received the Verimatrix ViewRight Security Certification for UHD-capable chipsets9. With the launches of these new UHD chipsets, STB and TV manufacturers can design their own systems/solutions that fully support full UHD security.

Availability Of UHD Monitoring System

UHD monitoring systems available in the market are providing more flexible and better features. For example, Kaleido-MX 4K multiviewer from Grass Valley10 and the IP based multiviewer called Supervisor from ArcVideo11 are but two of these systems. Their products support HD/SD videos and can downscale the UHD video to HD or even SD, which can reduce the cost of monitoring devices. Furthermore, they integrate with alarm servers which can provide complete monitoring service for full-time UHD channels.

There is no doubt that full-blown, commercial UHD services will be the future trend of the satellite TV market. NSR’s latest report on UltraHD via Satellite forecasts there will be 785 UHD channels on satellites by the year 2025. The additional leasing revenues of these intensive UHD channels will top $280 million annually12. However, rapid growth of UHD channels over the next couple of years is not expected to materialize. As the specification of UHD-1 Phase 2 has not yet been finalized by ITU, the current UHD format is just a milestone for the UHD-1 standard. Broadcasters are expected to launch their UHD full-time commercial services only after the finalization and implementation of the UHD-1 standard to minimize the migration cost. 

1Videocon d2h Limited Quarter Ended December 31, 2015 Earnings Release. PRNewswire, Jan 27, 2016. Retrieved from http://www.prnewswire.com/news-releases/videocon-d2h-limited-quarter-ended-december-31-2015-earnings-release-300211191.html
2 India: 20 UHD channels by 2020. Chris Forrester, Oct 9, 2015. Retrieved from http://advanced-television.com/2015/10/09/india-20-uhd-channels-by-2020/
3 Available at: http://www.arcvideo.cn/products/arcvideo-online/
4 Available at: http://www.harmonicinc.com/product/promedia-xpress
5 Available at: https://www.thomson-networks.com/product/capture-playout/sapphire-mpeg-stream-server/
6 Available at: https://village-island.com/en/villageisland/hardware/encode-decode/vh4000-4k-decoder/
7 Available at: https://www.rohde-schwarz.com/us/solutions/broadcast-media/4k-uhdtv/multiplexing-encoding-monitoring/multiplexing-encoding-monitoring_229273.html
8 Available at: http://www.ntt-at.co.jp/product/list_mmp.html
9 Verimatrix Unveils Program of Security Certification for UHD-capable Chipsets and Devices. Verimatrix Press Release, Apr 13, 2016. Retrieved from http://www.verimatrix.com/press-releases/verimatrix-unveils-program-security-certification-uhd-capable-chipsets-and-devices
10 Available at: https://www.grassvalley.com/products/kaleido-mx_4k
11 Available at: http://www.arcvideo.cn/products/arcvideo-Supervisor/
12 Satellite UHD to top 785 channels. Advanced Television Ltd, Mar 29, 2016. Retrieved from http://advanced-television.com/2016/03/29/satellite-uhd-to-top-785-channels/