Service providers are facing a landmark shift in subscriber home networks, thanks to the rise of streaming video, the Internet of Things and the sheer number of consumer devices now connecting to the Internet. Hoping to get ahead of the tidal wave, RDK Management LLC is pushing forward with its next open-source software initiative known as the Reference Design Kit for Broadband or RDK-B.
RDK for video, now known as RDK-V, was a development project started by Comcast Corp. (Nasdaq: CMCSA, CMCSK), but then turned into a collaborative effort headed by RDK Management LLC , which is now run by Comcast Cable, Time Warner Cable Inc. (NYSE: TWC) and Liberty Global Inc. (Nasdaq: LBTY). The pre-integrated RDK-V software stack gives vendors a common starting point for developing new set-top hardware. It incorporates functions such as tuning, conditional access, digital rights management and stream management, but still allows for differentiation among technology and service providers at the user interface level.
So far, RDK-V has been adopted by at least 25 pay-TV providers and is supported by a community of well over 200 consumer electronics manufacturers, chip vendors, software developers and system integrators. (See Bye Bye OCAP, Hello RDK and RDK Spreads Its Wings.)
RDK-B is a much newer effort than RDK-V and was only talked about publicly for the first time at The Cable Show in the spring of 2014. Relatively little has been said about the development process since then, but ultimately RDK-B has the potential to have an even bigger impact on the market than its video counterpart as IP services proliferate. To date, both Arris Group Inc. (Nasdaq: ARRS) and Cisco Systems Inc. (Nasdaq: CSCO) have contributed code to the RDK-B stack, with Arris announcing this week that Comcast is deploying its TG1682 gateway with RDK-B software included. (See Comcast Readies D3.1 & RDK-B and Arris Lands Gateway Deal with Comcast.)
According to Arris's CTO for customer premises equipment, Charles Cheevers, the goal of RDK-B is twofold. First, it will create a standardized IP endpoint, ensuring that critical functions are present across different silicon and outsourced hardware solutions and minimizing the costs for product testing. Second, it will create a platform to which companies can develop code.
Right now, Arris is working on two development efforts in particular under the RDK-B umbrella; one that enables home gateways to take advantage of multicast IP video, and one that will help customer premises equipment support new IoT services.
To take advantage of multicast video over IP, operators need a way to convert a multicast stream into a unicast one in the home. Arris is working on standardizing code for that function in a gateway while also ensuring that there are ways service providers can differentiate features at the network level based on the home hardware's capabilities. For example, a service provider could decide to pre-cache certain content in a home gateway, but that wouldn't be a standardized function in the RDK-B stack.
Arris also wants to make sure there's a way operators can still leverage adaptive bitrate technology when users don't have a strong enough network connection to support a high-bitrate multicast stream. So, for instance, a multicast stream might be sent out at 5 Mbit/s, but a viewer's gateway could be designed with the RDK-B software to default to a lower-bitrate unicast stream if the network connection is weak.
"In the muliticast [stream]," says Cheevers, "you don't have to send the different bitrates so you can engineer your network to be very robust and you have unicast to bail you out of jail when the problem happens."
"The architecture we have really is unicast and assisted multicast," adds Cheevers. "That's the kind of stuff that RDK-B is trying to address, to make the implementation common and have a similar feel to really good robust broadcast TV engineering that we had before but now in an IP context."
On the IoT side, Arris is working to enable multiple protocols within the RDK-B stack for broadband gateways, including OIC, AllJoyn, Thread, ZigBee, Z-Wave and Bluetooth. It's not clear that all of the protocols will survive as the IoT space evolves, but because they take up very little memory in the software stack, Arris believes it's still worth including them. With the protocol support in place, operators have the option to develop features like alerts that show up on the TV when a motion sensor is triggered or an IP video camera detects something out of the ordinary.
"You saw the Google OnHub recently," says Cheevers, referring to the new home gateway Google (Nasdaq: GOOG) launched last month, "so that device has WiFi, but it also has these IoT radios… and that model is something we're promoting to the service providers already." (See Google Debuts Smart WiFi Router OnHub.)
Cheevers also believes the timing is right to start moving RDK-B forward. With the arrival of DOCSIS 3.1, operators will have to make changes to their CPE anyway. It makes sense to start deploying RDK-B at the same time.
While the cable industry has been largely quiet about RDK-B for the past year and a half, it appears that situation may be about to change. We may learn more at next month's SCTE Cable-Tec Expo.
— Mari Silbey, Senior Editor, Cable/Video, Light Reading