Sustainability Conference Illuminates Multiple Paths to Greener Streaming
By Fred Dawson
Is there any meaningful way to mitigate the impact of video streaming on global warming? And is it even worth the effort, given how little the processes used in streaming contribute to the overall digital carbon footprint?
Pessimists on these points would have found ample confirmation tuning into a recent exploration of what the streaming sector is up against in the battle against greenhouse gas emissions. But there was another, far more positive way of looking at things that came to light in a two-hour online discussion among participants in the March 14 iteration of the Sustainability Expert Series of webinars co-produced by Broadcast Projects and CTO Innovation Consulting.
Of course, as noted by moderator Benjamin Schwarz, founder and principal of CTO Innovation Consulting, emissions generated by the processes involved in distributing video to the masses are a drop in the toxic bucket. He pointed to one recent study from the French ADEME and ARCEP that found networks contribute just 15% to the digital carbon footprint in France, compared to the 79% attributable to devices and another 5% resulting from datacenter operations.
Even if the lion’s share of the distribution component were eliminated, it would be of little consequence in the grand scheme of things. “We need to address this head on,” Schwarz said.
Making matters worse, he and others noted, wherever you look across the end-to-end origin-to-device video footprint, most of the energy consumption transpires whether all the components are actually in use or idling in support of a hair-trigger response whenever they’re called to action. Conference speaker Pieter Liefooghe, business development director at Broadpeak, said this was borne out in monitoring of devices used by people viewing the 2022 World Cup.
“From a traffic perspective there was a 330% increase from lowest to peak, but power consumption only varied 15% during the same period,” Liefooghe said. In general, he added, Broadpeak has found that the average residential gateway consumes just short of 12 Watts when in fully loaded operational mode compared to 10 Watts when it’s not in use.
The Sustainability Case for Multicasting
But Liefooghe put a positive spin on that point by emphasizing a great benefit that comes with how those gateways can be employed to support a radical reduction in the amount of processing that goes into streaming live content through a conversion from unicast to multicast distribution, which is the internet’s emulation of the one-to-many efficiencies of traditional broadcasting. Using gateways to support the conversion of incoming multicast content for unicast streaming to devices in the home adds about 1.5% to 3% to the CPU processing load, “but from the power consumption perspective, the impact is negligible,” he said.
What matters when it comes to impacting power consumption in the case of multicasting or the other compelling innovations suggested by conference speakers is their role in removing substantial volumes of processing power, active or idle, from the distribution chain. The energy-saving implications of multicasting are immense considering that thousands or more unicast streams targeted to an ISP’s service area can be replaced by one multicast stream.
And much greater efficiencies would accrue were the industry to take advantage of interdomain routing protocols with multicasting. “Multicasting is extremely scalable,” Liefooghe said. “We as a community should be pushing to enable this across all networks.”
Multicasting, long used by telcos in legacy IPTV services as a way to reduce bandwidth consumption over low-capacity DSL access networks, should have been baked into the video streaming agenda a long time ago, said Dom Robinson, founder and director of Greening of Streaming. “I’m a big fan of multicasting,” he said. “It has huge validity.”
A Way to Avoid Encoding and Delivering Useless Bitrate Profiles
Another strategy touted as a well-proven way to cut back on processing power used in video streaming has to do with the types of efficiencies introduced by Ateme, which has often brought the energy-saving benefits of innovations in compression and CDN technologies to light at sustainability forums. As described by Ateme vice president of content delivery Dan Patton, another conference speaker, one of the company’s most recent innovations is what it calls “audience-aware streaming.”
This involves using an ATEME-engineered feedback loop between the CDN and its encoding platform, which tells the encoder which bitrate profiles in the commonly prescribed adaptive bitrate (ABR) profile ladder are unused by end users. “If I know profile X isn’t being used, I can have the encoder adapt in real-time,” Patton said.
This not only allows “more channels to be compressed on the same transcoder,” he noted. It reduces the CDN traffic load and cuts the amount of storage capacity consumed in network DVR and other time-shifting applications. “The cost and power consumption go down when you’re doing more things on the same platform,” he said.
But, compelling as these solutions might be, Patton, like other speakers, stressed that the sustainability story in video streaming isn’t about any one set of innovations. Citing multicasting and other ideas discussed at the session, he said, “Each vendor in the ecosystem has to optimize their own part. We want to do things in a way that allows us all to better leverage and improve their part in it.”
From top Left: Dan Patton (Ateme). Pieter Liefooghe (Broadpeak), Benjamin Schwarz (CtoiC), Mike Talbert (Broadband Forum) and Arian Koster (TNO).
The Elephant in the Room
Inevitably, this leads to considerations of what can be done about what Schwarz called “the elephant in the room,” namely, that 79% share of the streamed-video footprint attributable to devices. Conference leaders said the sustainability perspective on devices related to M&E consumption will be the focus of series sessions to come, but there was some valuable insight along these lines worth noting from the March 14 event.
One topic of discussion had to do with the fact that collective commitment from vendors on the distribution side can contribute to sustainability awareness among their service-providing customers, who could have a big role in pushing suppliers of set-top boxes, home gateways, and other devices on their purchase lists toward greener designs.
Arian Koster, innovator at Netherlands consultancy TNO, noted he’s witnessing “positive developments going in that direction.” A big factor will be the availability of objectively compiled metrics that let buyers know what the power consumption levels really are, said Dom Robinson, who cited an initiative undertaken by the Digital Impact Alliance as an example of promising developments along these lines. “There’s about 12 academic institutions looking for information in this space,” he added.
Schwarz suggested a lot could be done in terms of overcoming the “laziness” in design practices that stem from manufacturers’ efforts to simplify middleware architecture. This, he noted, is responsible for immense wastes of energy generated by “power islands” in chipsets that are always on whether or not any decoding is underway. “That has to be revisited,” he said, adding that the same goes for chipsets running Wi-Fi gateways, which are always on for different reasons.
Opportunities to Put Greener Streaming Infrastructure to Use
Perhaps the biggest challenge but also the biggest opportunity when it comes to curtailing the M&E carbon footprint has to do with connecting the hundreds of millions of users who have yet to participate in the streaming market. “Greening comes back to providing reach to new devices and new audiences,” said Allan McLennan, chief executive at the PADEM Media Group. “The sheer amount of video shifting to IP is going to have a profound effect on networks.”
The opportunity for improvement is likely greatest in unconnected regions that can become green fields for the introduction of greener networking solutions. But there’s also a big opportunity when it comes to replacing aging infrastructure everywhere else.
“Suppose we take another approach,” said Arian Koster. “Can we optimize for the 80% of traffic that is video by redesigning the internet so that it’s more sustainable?”
Such a project, he suggested, would entail getting rid of a whole lot of the packet processing that served the original purpose of what became known as the internet, which was to enable a multi-path solution to keeping communications open in the event of nuclear war. Now in an environment dominated by streamed video traffic, the goal is to keep packets together as much as possible, which can be done with a whole different packet header infrastructure and mode of communications with routers and switches, Koster asserted.
Other speakers made a similar point albeit with reference to technology that’s ready for implementation on existing infrastructure. This has to do with avoiding the complications that go into the use of Hypertext Transfer Protocol (HTTP), the dominant mode of exchanging assets between client devices and servers, and the compounding complications introduced by ABR streaming technology.
When Robinson commented that “HTTP is crap for video delivery,” he got no argument from the other participants. Referencing how the technology manages the transfer of details about the contents of each exchange on the internet, he said, “HTTP is all about provisioning, whereas RTP (Real-time Transport Protocol) is far more efficient.”
RTP is the underlying transport mechanism designed to convey audio and video content over the internet, which first went into wide use as the foundation for voice communications and today is also the foundation for video conferencing by virtue of its use with Web Real-Time Communications (WebRTC). The latter is a peer-to-peer technology that made it possible to exploit the ultra-low latency capabilities of RTP with the connecting support of browsers, obviating the need for special client plug-in software.
As Schwarz noted, ABR was designed to enable smooth streaming over HTTP when users had far less bandwidth than they do now to accommodate multi-megabit video flows. ABR overcame the problem with reliance on incessant communications between clients and servers that tell servers which of the encoded options in the bitrate profile ladder to choose with delivery of each succeeding multi-second segment of content.
ABR was “an amazing invention,” Schwarz said, but with over 70% of the populations of most developed markets now connected on links supporting over 100 Mbps of bandwidth per household, “maybe we won’t need it for much longer.”
“WebRTC is getting a strong foothold in [the video conferencing] space,” Robinson said, noting it’s “far more efficient” than ABR in terms of processing requirements. Left undiscussed were other practical issues and trendlines pertinent to comparing the two streaming modes, but it’s clear that the emergence of use cases calling for interactive video streaming at telephony-caliber latencies has generated significant momentum behind the search for new transport solutions.
Meanwhile, it’s equally clear that the only impediment to better sustainability performance no matter what streaming mode is employed is inertia. As revealed in this and many other sustainability conferences that have been cropping up with growing frequency, there’s a lot that can be accomplished with concerted commitment across all segments of the streaming ecosystem.
The next meeting in the Sustainability Expert Series is scheduled for April 11. Author and podcaster Gerry McGovern is scheduled to speak on energy waste and data problems specific to the industry. Series organizer Janet Greco, who spearheads Broadcast Projects, said other speakers may be added.
To sign up for the Sustainability Experts Series, which is platformed by Media Meet & Greet Connect 365, access is available through this signup page.
Fred Dawson, President & CEO, Broadband Information Resources, USA