The early days of multiroom viewing
Offering pay-television households the ability to watch their preferred live video channels on multiple screens has been a concern for video content providers for more than two decades. In the early 2000s, Direct-to-Home (DTH) operators began offering second-screen TV packages, initially enabled by the supply of two or more identical satellite set-top boxes (STBs), all connected to the same receiving antenna via coaxial distribution. At the same time, digital video recorders (DVRs) started to deploy into consumer homes, with the hope that recording and time-shifting services offered by these DVRs would be available for all household television screens. However, addressing the multiscreen expectation by deploying several DVRs within a home was neither a cost-effective or practical solution for DTH providers. So, the first dual-tuner DVRs have gradually evolved into more sophisticated multi-tuner video servers, whereby key hardware resources such as tuners, demodulators, demultiplexers and Conditional Access Subsystems (CAS) of these servers are shared with tuner-less client devices connected via a local area network (LAN).
The standardization effort
These early client-server proprietary architectures enabled in-home distribution of live, time-shifted and recorded video content to second room TV screens. Naturally, they have given birth to the SAT > IP ™ concept, in an attempt to drive the cost of solutions down through standardization of the client-server communication interface, leveraging the MPEG-2 transport stream (TS) media format.
SAT > IP leverages the IPTV principles of distributing a live TV channel over an IP network by simply encapsulating up to seven MPEG-2 TS packets of 188 bytes received over satellite into an IP frame, using RTP and UDP for IP streaming. Besides the methods for discovering the SAT > IP devices attached to the user’s LAN, the specification leverages the UPnP protocol and DLNA to include provisions for the client devices to discover the available server(s) and exchange other information that is not only required to consume live TV content, but also to optionally control the playback of recorded content.
From multiroom TV to multiscreen viewing
It is interesting to note that the genesis of SAT > IP coincides with the market launch of the first tablets (the first iPad launched in 2010). But because of its heavy dependence on MPEG-2 TS as the only supported media format, SAT > IP failed to anticipate the adoption of adaptive bitrate (ABR) streaming. ABR streaming protocols were initially defined to enable the streaming of VOD content over unmanaged broadband networks by dynamically adjusting the bitrate of the transmitted video (and thus its resolution) to the varying capacity of the end-to-end delivery network. These ABR protocols have enabled outstanding growth for VOD OTT delivery to unmanaged consumer devices, including tablets and smartphones, and have recently been introduced for OTT live video delivery, too.
Furthermore, because of satellite content origination, client devices also have to support the content protection solution (i.e., CAS) chosen by the DTH operator to control access to these live TV services. Alternatively, another content re-protection solution can be implemented by the server to re-encrypt content prior to IP distribution.
SAT > IP may thus be suitable for a retail market of free-to-air devices, but it has proven to be very costly for satellite pay-TV operators that struggle to develop and maintain custom IP client devices and applications for mobile devices. This has dramatically hindered SAT > IP commercial success.
Since SAT > IP failed to respond properly to multiscreen expectations, DTH operators are now using OTT delivery platforms to distribute their most valuable live TV channels in unicast. As a result, these channels can be watched on handheld consumer devices, with the well-known limitations of OTT unicast streaming (i.e., notably longer latency and unpredictable video quality). Operators also face streaming costs that are increasing proportionally with the number of viewers, making OTT streaming hardly sustainable for highly popular content.
Unleashing multiscreen viewing
This is where Broadpeak’s nanoCDN™ solution for satellite comes into play, merging the best of both worlds. Contrary to SAT > IP, which is a consumer premise solution, Broadpeak’s nanoCDN packages live video content in the cloud or at the satellite headend into a multicast ABR (mABR) format and performs digital right management (DRM) encryption, when required. The nanoCDN solution then carries the chosen ABR media format(s) over satellite so that it, or they, can be transparently delivered, without reprocessing, all the way to the video rendering client devices. The benefits of combining satellite delivery with mABR are vast:
- Any standard HLS- or DASH-compliant device can access the live content. Such devices include tablets and smartphones, as well as STBs, smart TVs, Chromecast dongles, Apple TVs, personal computers, and game consoles.
- Satellite distribution can benefit from adaptive bitrate technology capabilities, including de-linearization (i.e., catch-up TV, VOD) without the need for a hard drive, as well as content personalization such as regionalization or targeted advertisement.
- A regular DRM solution can be used to protect the content all the way to the display device, without the need for transcrypting content.
- Because the satellite segment is a managed network, very low latency, similar to traditional DTH broadcast, can be achieved.
- Like for DTH, video quality is predictable and fully controlled through the satellite bandwidth provisioning.
- Because of its broadcast nature, there are no peak hour service limitations.
- Thanks to the use of ABR protocols, the nanoCDN solution can seamlessly switch from satellite to broadband. It is, for example, possible and actually quite logical to configure only the most popular channels to be distributed over satellite while the long-tail channels, generating only a few concurrent connections at a given time, are only sent over broadband. The seamless fallback to unicast can also be very interesting to secure continuity of service in case of loss of the satellite reception (e.g., during rain fades).
- And most importantly, mABR over satellite provides a fully controlled capacity and pricing model.
Since 2012, Broadpeak has pioneered several commercial mABR deployments with its nanoCDN solution, addressing all types of delivery networks, including satellite, clearly demonstrating that the technology is mature and capable of delivering on its promise. Lately, as an endorsement of Broadpeak’s vision, mABR streaming has become a hot discussion topic across the video delivery industry, with several key players now investing in the technology. Similar to SAT > IP, the last baby step to adulthood is an industry effort toward standardization of mABR for use on satellite delivery networks, which Broadpeak is happy to play an active role in supporting.