Streaming implies a one-to-one connection from the source of the content to the consumer. The internet connectivity this requires passes through multiple data centres, each of which has a massive energy demand. Already some researchers say that the internet has a larger carbon footprint than the air travel industry; others say that by 2030 data centres will represent more than 20% of global projected electricity consumption (Lancaster University study, Anders Andrae).

Global accords are committed to the reduction of carbon emissions, and governments are moving to enshrine these targets in law. In the EU, for example, the mandate is to reduce greenhouse gases by 55% by 2030; in the US the target is 50%. And, of course, alongside the environmental issues, the recent dramatic rises in the cost of energy have brought energy efficiency to the top of the agenda.

"In the EU, for example, the mandate is to reduce greenhouse gases by 55% by 2030; in the US the target is 50%."

While streaming brings direct, interactive connectivity, there are many applications when one-to-many content and data delivery is more appropriate. Alongside traditional broadcast channels, there are new applications, like pop-up channels for major sports events or festivals, driving its continued existence. In general, where large numbers want to watch content simultaneously, streaming is massively inefficient, and the more users there are – and therefore the more one-to-one connections are established – the more energy is consumed, and greenhouse gases are produced.

Terrestrial transmission delivers video content across a wide area, regardless of the number of devices tuned to it in a constant high video quality. It also has the capability of carrying additional data services.

The emerging 5G Broadcast standard allows mobile devices to receive broadcast services without the need for a SIM. That opens up new services which are best delivered over simultaneous multicast: emergency public warning services, for example; software updates as part of Mobile Device Management systems; current geographical and traffic information for autonomous vehicles; and services for IoT applications.

Using terrestrial transmission for television channels to the public, and for additional data services, is inherently more energy efficient, and more sustainable, than streaming.

In the past, transmitters were naturally heavy consumers of energy: over the lifecycle of a transmitter, 99% of carbon emissions resulted from power consumption. Therefore, high energy efficiency has a big impact on carbon and greenhouse gas emissions. For the next generation of transmitters, optimisation of energy efficiency is critical to maximise the sustainability of content and data delivery. Rohde & Schwarz’s mission is to support broadcasters in managing their operational costs and in preparing for coming challenges like increasing carbon emission targets. Therefore, we are working on the next level of energy efficient technology, which allows another significant reduction of energy consumption and carbon footprint.

Across a typical network of ten 6kW transmitters and a 10 year life, the footprint would amount to 9,000 tonnes of CO2. That next level efficiency improvement means that the predicted carbon footprint falls to 4,000 tonnes, a direct reduction of more than 50%.

But for maximum efficiency performance, it is important to consider the whole transmitter system as well as site infrastructure, which may add a significant additional energy demand, in areas like air conditioning. The design of transmitter products has a major influence on the required capabilities of the building HVAC system. For liquid cooled transmitters, the liquid cooling concept makes the key difference between low and high heat dissipation into the room. Air cooled components push their heat load into the room; liquid cooled components can push the unwanted heat outside. Not only power transistors shall be liquid cooled but also power supplies and power combiners. This saves an enormous amount of energy for air conditioning, and with that it significantly reduces the carbon footprint of the complete transmitter site.

There is no doubt that the concept of terrestrial transmission, and thus the businesses of network operators, will see significant challenges in the near future. Rohde & Schwarz, widely recognised for its engineering excellence, understands these challenges and is ready to support network operators to deliver innovative new services while providing transformative reductions in energy costs and carbon emissions, slashing lifecycle costs of the transmitter network and going a very long way to meet new environmental expectations.