From TVNewsCheck: Dash of Broadband Could Empower ATSC 3.0
Tech vendors and broadcasters led by Sinclair and Weigel are developing ways to offer high-resolution TV and targeted advertising by layering broadband content on top of the basic ATSC 3.0 over-the-air signals.
By Glen Dickson
Broadcasters and tech vendors are working to tap the full potential of ATSC 3.0, experimenting with ways of combining 3.0 broadcast signals with broadband content to enable a hierarchy of picture resolutions — low for mobile, high for the home — and geographically and demographically targeted advertising.
And in doing so, they are repurposing core technology that already exists and is in everyday use by OTT streaming platforms and cable.
Weigel Broadcasting and encoder supplier Harmonic have tested a hybrid OTA/OTT 3.0 system based on the established DASH (Dynamic Adaptive Streaming over HTTP) protocol, the second most popular streaming format behind Apple’s HLS (HTTP Live Streaming).
The system uses DASH in both the broadcast and broadband streams, sending a 5 Mbps 1080p HD signal over the air and then delivering a full 15 Mbps 4K signal solely through broadband.
Another hybrid OTA/OTT 3.0 approach favored by many broadcasters is called Scalable HEVC (SHVC), whereby a 4 or 5 Mbps 1080p/60 HD signal would be delivered over the air, and a roughly 10 Mbps “enhancement layer” would be sent via the broadband pipe, with the two combined within the ATSC 3.0 set to display 4K.
The SHVC approach uses the MMT (MPEG Media Transport) streaming protocol, which is also included in the 3.0 standard but doesn’t yet enjoy broad support among consumer electronics and mobile devices as does DASH.
Longtime 3.0 proponent Sinclair Broadcast Group sees merit in both MMT and DASH as it looks to deliver both mobile broadcasts and targeted advertising from its stations, of which 26 are slated to launch 3.0 this year.
But it is also considering taking SHVC technology one step further by delivering both a 480p SD base layer aimed at mobile devices and a 720p HD enhancement layer aimed at TVs within its over-the-air stream.
And based on experimentation by its ONE Media subsidiary, Sinclair thinks it can potentially deliver both streams in a little over 1 Mbps, which would leave the lion’s share of its 3.0 data pipe open for multicasting, non-real-time data delivery of targeted content like cached ads or other new services.
Reprinted with permission from TVNewsCheck.