Headends

The SD switch-off that never was

On 14 July, the Directors of ARD made a significant decision. The switch-off of their SD satellite channels, planned for early 2021, was postponed indefinitely. The reasoning was clear: that there are still significant numbers of the German population – 6 million households at the last count[1] – who do not have HD-capable televisions or receivers.

While in previous switchovers large public information campaigns urge those affected to invest in new equipment, this was not deemed an appropriate message during the corona pandemic. In addition to economic uncertainty, TV itself is being turned to more and more for both entertainment and reliable information, so people could not be cut off from this vital source.

The pace of change

We have seen generational changes to society in just a few short months, but the postponement of the SD switch-off and a rediscovery by younger people of traditional broadcast TV nevertheless indicates that such societal shifts aren’t always taking place moving forward: that it is just as valid to embrace the status quo as it is new technologies.

Despite the pace of change, one must never assume that all are being brought along with it. Although the first analogue switch-off in Europe took place in Berlin in 2003[2], it was only by 2019 that Die Medienanstalten could finally declare that “analogue TV coverage is now part of the history of television transmission in Germany.”[3] Meanwhile, the number of ‘cord cutters’ (those whose sole source of television content is the internet) is increasing, but numbers are still modest at just 650,000 households.[4]

Prepared for the present, prepared for the future

Pay TV is increasing exponentially in Germany. The prevalence of one form of Pay TV, OTT, is also increasing, but it is not perhaps as dominant in Europe as expected: with only 1 million OTT-only households across Europe, it is still mainly complementary to existing TV distribution methods. [5] It is still affected by bandwidth availability, though 87.9% of German households now have access to 30 Mbps or more[6] and the federal government has planned the ‘gigabit society’ by 2025.[7]

So, how does this all affect decision-making when considering the next headend purchase or upgrade? To be fully prepared, one must prepare for the future, but also take into account the present and even the past.

Preparedness: factors to consider

Depending on your market, first to consider is form factor. Micro headends for the smallest installations or specific use cases, compact headends for 19” cabinet compatibility and a fixed in/out specification, modular headends for more flexibility in choosing specific input and output modules, and then the professional headends used by operators. These days, cloud-based super headends based are also a possibility, depending on bandwidth availability.

For this feature we will limit ourselves to considering headends at the local level – the installations made every day in hotels, apartment blocks, clinics and so on.

In equipping our headend we need to consider:

• What’s coming in: standard in Germany is DVB-S2. But what about further sources or additional video inputs, for example a hotel info channel or a webcam feed?
• What’s going out: what are the varieties of end-consumer equipment on the network? QAM outputs are most common in Germany, but IP may be necessary, especially in hospitality scenarios where middleware or a guest communication system is used.
• Encrypted content: what licencing in the form of CI Cards and DRM is needed?
• Network size: if the installation is part of a large network with multiple amplifiers, you’ll need a headend that can output a high signal-to-noise ratio.

As an example, in the hospitality sector, if a client only wishes to distribute standard FTA services around their premises, a micro or compact headend would be suitable, and it is here most cost savings are made. But, if they wanted to enrich their entertainment offering with programmes from other territories, or to adapt their programme list according to different types of guest, scalability suddenly becomes very important.

Scalability provides the opportunity to expand and adapt the system, and through modularity, systems can upgrade to the newest technology if required without changing the fundamental system. Updates are also invisible to the end user.

Modular headends, then, offer the most flexibility and should usually come with hot-swappable in- and output modules. The life of an installer is made easier and more cost-effective when service cases can be resolved by simply swapping out a defective module. Life for the solution owner is also easier when PID management ensures no TV reprogramming – so there’s no need for a technician to traipse round every hotel room for a day retuning TVs.

Modular headends and scalability

With modular headends you can expand and adapt the system by combining multiple input and output modules. But not only can you scale modules up or down, it is also possible to scale headend units up or down to create a multi-headend installation. With 24 RF channels per headend, you can combine up to 3 headends for up to 72 channels – that’s roughly 280 HD or 570 SD programmes, enough for even the most discerning international guest.

A further advantage is scalability of service and support. Remote access features of modular headends tend to be highly advanced, and convenient. You can take control of all your installations from your office – even more useful nowadays when access to client premises may be limited.

With modular headends you also have unlimited possibilities to multiplex services for each output modulation. This means that regardless of the input, you can configure the necessary output modules to support a broad mix of TVs of all ages, or different devices such as mobile phones or tablets.

The IP Pool

With such hardware flexibility, it’s sensible to look for flexibility in the software and modulation options, too. Some headends offer ‘IP Pool’ technology, which is a particularly effective method of managing TV programmes. From any input, transport streams are processed and collected in the same ‘pool’. The TV programmes can then be distributed via one or more output modules, for example as QAM or IPTV and managed in a TV channel list using the LCN function (Logical Channel Number). This TV channel list can also be managed and changed remotely if necessary.

You could also include a PAL module for older equipment – so in a scenario like a care home with many older analogue TVs, you can transcode any HD input into analogue PAL channels, preferably with a solution that will transcode the AC3 audio stream to a standard PAL output too.

Accommodating OTT

Having prepared a headend that caters for current and legacy modules, there is still the question of how best to accommodate OTT into the mix. Sufficient bandwidth will have to be available to all users in all buildings. If fibre rollout does continue as planned, FTTB or FTTC installations will require buildings to have the internal infrastructure to make the faster connection speeds available to the end user.

This is not always easy when the building is older and has no CAT cables. Fortunately, it is now possible to run gigabit networks over the coax cables which are installed in most buildings. Keeping the existing cables is a compelling argument for most proprietors, since any installation of new cables would result in significant disruption and the inconvenience of applying for new fire safety approvals.

This is known as ‘ethernet over coax’ and of the different technologies in use today, solutions built on G.hn are advantageous in that gigabit throughput is available both up- and downstream, and bandwidth per end point is managed dynamically – making the system smart enough to provide the best OTT service to each user from the available connection speed.

Both headends and ethernet over coax solutions can peacefully coexist in the same environment.

Conclusions

We have seen that there are many factors one must take into account when making headend purchasing or upgrading decisions. Yet what has always been the case, and what has been brought into sharp focus this year, is that while we have to prepare for change just over the horizon, we must also be mindful of people, technologies or infrastructures that do not always follow this pace of change.

Just as we are having to adapt to new situations more in our everyday lives, so too is finding the right headend configuration for now and the future important. To avoid regularly having to make costly hardware upgrades, having an appropriately configured headend as a workhorse in your TV installations is essential: keeping it ready for the future, whilst handling the signals of the past & present.

[1] SES S.A., Astra TV-Monitor 2019, https://de.astra.ses/sites/default/files/2020-04/ASTRA_TV%20Monitor_2019_1.pdf

[2] Wood, David: History of the DVB Project. 2013, p.5, https://dvb.org/wp-content/uploads/2019/12/History-of-the-DVB-Project.pdf

[3] Digitisation 2019: Video, published by die medienanstalten – ALM GbR, p.20

[4] Ibid. p.24

[5] Digitisation 2019: Video, published by die medienanstalten – ALM GbR, p. 49

[6] European Commission, Broadband Coverage in Europe 2018, p.97 https://ec.europa.eu/newsroom/dae/document.cfm?doc_id=62760 https://ec.europa.eu/digital-single-market/en/news/study-broadband-coverage-europe-2018

[7] https://ec.europa.eu/digital-single-market/en/country-information-germany