RDK and OTT, really? Two days with the RDK community in SKY Campus in London.

The RDK Tech SummitThe RDK Tech Summit it was just two weeks ago at the Sky Campus in London, this was the opportunity to reconnect with a vibrant community. In these two days, we saw what RDK technology has been enabling lately and we got a glimpse of how RDK will likely help scale streaming further.

First thing first, what is RDK?

The Reference Design Kit (RDK) is a collection of open-source software freely available that provides the standardised functions used in Video and Broadband devices, namely the STBs and the Home Gateways.

It is modular/portable/customisable and used by service providers like Liberty Global, Comcast, Charter, Sky, Deutsche Telekom, and NOS to package and deliver their video and/or broadband offerings.

The proposition of RDK is simple: because many core functions are available in open-source, service providers can focus their development resources on advanced functionalities, differentiating their offerings from the competition.

Service providers using RDK show that RDK can reduce development time and accelerate innovation while giving them control of the software they deploy: RDK enables them to be in charge of the design, development, deployment, maintenance of the software, and all the data generated.

The RDK community is made of 500+ companies including CPE manufacturers, SoC vendors, developers, integrators, and service providers.

What about the Tech Summit in London?

So, the summit brought the RDK community together over two days to share information related to progress, roadmap, directions, etc. The first day focused on Broadband devices and the second focused on the STB. Each day counted with about 150 people in the room.

Full house for the RDK-B session
Figure 1: Full house for the RDK-B session on day 1

Day 1 –  Broadband devices with RDK-B

The focus was clearly on expanding the functions in the home gateways, with presentations on managing LTE networks for fixed-wireless access, WiFi management across the home, and motion detection in the home. Service providers like Sky and Deutsche Telekom explained how they want to mix multiple uplink technologies in the gateway.

One of my favorite sessions was the Downloadable Application Containers (DAC) on Broadband, where Consult Red explained how 3rd party code can be deployed on the gateway using containers. DAC was initially targeting RDK-V set-top boxes and has now been extended to RDK-B devices.

In a nutshell, DAC simplifies software deployment across different devices. In my mind, it will for sure supercharge innovation on the home gateways, effectively turning home gateways into smart gateways where 3rd party code (a Broadpeak multicast ABR agent, a parental content filter, or a Domos WiFi optimiser, etc) can easily be managed independently from the underlying hardware.

Day 2 – STB with the RDK-V 

RDK-V has already been powering millions of STB in networks like Comcast, Charter, and Liberty Global.Initiatives like the ‘Video Accelerator’ RDK will continue to grow its deployment base.

So, the day 2 being about RDK-V and the STB, the scene was set for a conversation about a more mature platform. For me, the two main  themes were the evolution/support of legacy (broadcast) and the openness towards the streaming apps (ABR over IP).

Let’s start with progress on the legacy side

Ocean Blue Software showcased how to easily support a broadcast stack through their open DTVKit made of DVB Core, MHEG Engine, HbbTV Plug-In and CI+ Engine.

On the topic of legacy, the panel on Tiny RDK-V, an initiative aiming to deploy RDK-V software on devices with limited resources was particularly relevant in the context of upcycling legacy STB to an RDK stack. I really like the simple target of having an RDK system capable of rendering Full HD experience with 512MB and UHD with 1GB footprint.

Being able to prolong the life of existing STB in the field with RDK is a great initiative at a time when the streaming industry recognises that it needs to reduce its carbon emissions. By extending the life of STB in the field, and delaying its replacement, the service provider will likely reduce its carbon footprint.

Comcast and Beechwood Software on a panel about Tiny RDK-V
Figure 2: RDk, Comcast and Beechwood Software on a panel about Tiny RDK-V

Apps and streaming were the protagonists in the session about innovation and looking ahead

Liberty Global demonstrated how to port a Youtube Cobalt app using the concept of Downloadable Application Containers (DAC) that we mentioned earlier for RDK-B (where DAC is a container solution that allows binary applications to be downloaded and run without modification).

This is particularly interesting for App developers who want to reach as many RDK STB as possible in the field.

Figure 3: Installation of Youtube Cobalt using DAC
Figure 3: Installation of Youtube Cobalt using DAC

Comcast talked about the Universal Video Engine for playback of IP Video  – abstracting the source of the video content from the UI. Something very convenient in hybrid environments where some content is delivered via broadcast and some is delivered over IP – we can see how this could also source some live channels using multicast ABR or unicast ABR.

Figure 4: Comcast explaining the Universal Video Module

Comcast also discussed performance enhancements and new framework features improving the Developer Experience and extending Lightning, the platform that provides application developers an abstraction layer to build apps independent of the RDK platform.

Lightning is an open-source JavaScript development platform that uses WebGL for rendering enabling high-performance, browser-based TV Apps. It contains many of the common features needed when building TV Apps and includes smart optimisations to get the most out of the target HW (GPU and CPU).

How Lightning, Firebolt and Thunder simplify app development on RDK-V
Figure 5: How Lightning, Firebolt and Thunder simplify app development on RDK-V


Long story short, where is RDK going? 

Making the RDK an easy environment to develop software for and allowing more streaming applications for OTT consumption.

It is clear that RDK-V wants to become a very open platform for application developers: There is a big push into apps that consume ABR video: HLS or DASH formats, as opposed to legacy MPEG-Transport Streams in QAM/IPTV.

Legacy evolution is still required for some service providers and it may be very important to upcycle legacy STB to a more modern software stack.

The example I have experienced myself was when last year my experience was upgraded to ‘the Tivo software running on my Virgin Media STB was replaced smoothly by an RDK-based software developed by Liberty Global.

One of the slickest implementations on top of RDK: Sky Glass

Now, being hosted at Sky HQ was the opportunity to get demos of the Sky Glass, which a very exciting product based on RDK: unlike Sky Q the flagship product, which requires a satellite dish and a separate Sky Q box that connects to the TV, Sky Glass combines everything into a single internet-connected television.

There’s no need for a satellite dish, no need for a separate box, and no need for a separate TV either. Instead, Sky Glass is the complete package, merging the various viewing sources like live TV, Netflix, Disney+ and other streaming platforms into one seamless interface.

Launched 9 months ago, Sky Glass is a TV with Sky’s services built into it. Sky calls it “the smarter TV” and with it, everything is accessible over Wi-Fi.

The demonstration of Sky Glass at Sky HQ was very impressive, easy to use, slick interface, kudos to their demo team !

Figure 6: A very impressive demo of Sky Glass - the connected TV offered by Sky
Figure 6: A very impressive demo of Sky Glass – the connected TV offered by Sky

Sky Glass is a complete aggregation play with all the content in one place: Sky, of course, the UK broadcasters like BBC iPlayer, ALL 4, ITV Hub, STV and the leading OTT like Netflix, Prime Video, Disney+, Apple TV+, Discovery+, etc.

Voice integration makes it easy to find content and use the TV – say “Hello Sky” and you get a search across all the services.

A key innovation with Sky Glass in my opinion is on the business side: Sky is clearly hoping to emulate the model of mobile phones, with regular updates encouraging people to upgrade their screens more frequently. They are also hoping to lock customers in for the long-term through the subscription model.

Sky Glass reviewer guide
Figure 7: Sky Glass reviewer guide

Click here for the complete guide on Sky Glass

The bottom line is that Sky Glass is a neat package for all your streaming needs: no need for STB, no need for a sound bar: everything is in a single TV.

But what happens if you don’t want a new TV? Here enters the Sky Stream Puck. Sky Stream Puck is also based on RDK development and will be available as a standalone product sometime later this year.

Figure 8: Sky Stream Puck - an IP only STB recreating the Sky Glass experience
Figure 8: Sky Stream Puck – an IP only STB recreating the Sky Glass experience

Trend of the lean STB ‘streaming only’ is here – some based on RDK

Interestingly, the Sky Stream Puck is not the first ‘streaming only’ STB, this is a trend started about 2 years ago by Liberty Global with their ‘Mini TV box’ (aka Apollo) and Comcast with their ‘Xfinity Flex’STB.

Liberty Global called it “Our smallest, greenest set-top box yet” (design here)

Designed by LGI, the Mini TV Box is available in Poland and Switzerland and will be rolled out to other Liberty Global markets over time. The concept is to simplify the STB and to offer streaming-only services. That is, no tuner, no hard drive and no conditional access system. This means that the complexity is somewhere else, either in the home gateway or in the network.

Figure 9: the IP only 'Mini STB' TV box based on RDK from Liberty Global
Figure 9: the IP only ‘Mini STB’ TV box based on RDK from Liberty Global

In North America Comcast has also launched a similar ‘streaming only’ STB also based on RDK and called the Xfinity Flex. Comcast has already shipped 4M devices in the USA.


The Xfinity Flex box from Comcast and about to be offered at Charter too
Figure 10: The Xfinity Flex box from Comcast and about to be offered at Charter too

The proposition is popular and licensing deals have been discussed, one in particular that has been agreed is with another heavyweight service provider in North America: Charter. Comcast and Charter will effectively collaborate on the launch of a new Flex streaming-only device. This will be particularly interesting in a market where Roku today is in a strong position.

Finally, where does Broadpeak work with RDK?

We talked about differentiation, and how RDK enables the service providers to focus their resources on innovations, rather than the basic functions of the devices.

A recent example is how Bhimavaram Community Network (BCN) in India has been able to integrate the Broadpeak multicast ABR solution into their RDK-based STB.

Bhimavaram Community Network (BCN) digital

BCN is serving 2,300 sub-operators in India and uses RDK as their STB platform and to host the nanoCDN application.

With mABR technology, BCN scales live streaming using multicast in their networks. This results in a superior quality of experience for live streaming and reduced consumption of their networking capacity.

Going forward, we believe there is an opportunity to distribute more linear OTT content with mABR to enable better scaling and improve the experience. We know that scaling live streaming remains a challenge in many networks across the world, and with more premium live events moving to ‘OTT only’ (like Formula 1 in Europe or Football in North America), there is an opportunity for the service providers to work jointly with the OTT providers to scale live streaming.

As you can see, in this context RDK might prove to be an accelerator, allowing easy integration of mABR functions into the Customer Premises Equipment (CPE) so that the OTT streamers can deliver impeccable live experiences (UHD, low latency etc) while avoiding overloading the ISP networks.

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