Overview

The next generation of over-the-air broadcast television is based on the ATSC 3.0 standard, branded NextGen TV. The ATSC 3.0 standard includes support for ultra high resolution (i.e. 4K) video with high dynamic range (HDR) as well as support for 7.2+4 channel audio. Additionally, the ATSC 3.0 standard includes new datacasting capabilities. To receive ATSC 3.0 broadcasts, you will need either a new TV that includes an ATSC 3.0 tuner or an ATSC 3.0 convertor box, such as the HDHomeRun QUATRO 4K.1

ATSC 1.0 v 3.0

A brief overview video, below, explains the key benefits of ATSC 3.0:

Because I am a videophile, I will focus primarily on ATSC 3.0’s new video and audio features. Notably, TV broadcasters can now deliver content with very high visual quality, comparable to over-the-top video services like Netflix, Disney+, HBO Max, or Amazon Prime Video.

Video

ATSC 1.0 uses the ancient MPEG-2 codec to encode video. ATSC 1.0 includes support for three video resolutions: 480i, 720p, and 1080i.

ATSC 3.0 uses a much more efficient codec, the High Efficiency Video Codec (HEVC). As a result, ATSC 3.0 broadcasts at a given resolution are much smaller than the same video feed from an ATSC 1.0 broadcast. For example, a 4 Mb/sec HEVC stream can provide comparable visual quality to a 16 Mb/sec HD MPEG-2 stream. For broadcasters, this means less capacity is required to deliver the same quality content, so they can deliver more subchannels of content. Or, they can deliver higher quality subchannels (e.g. 4-5 channels of 1080p content rather than 480i content).2 For consumers, if your player is able to filter a broadcast by the desired content stream (PID), this could lead to significantly less bandwidth required to distribute video streams within your home network. Similarly, far less storage is needed if you record TV shows with a DVR.

More importantly, video resolutions up to 2160p are supported at up to 120fps. ATSC 3.0’s support of wide color gamut and HDR mean that users will see higher contrast video with less color banding.

Audio

ATSC 1.0 specifies the Dolby Digital AC-3 (A/52) codec for audio. Dolby Digital enables up to 5.1 channels for audio.

The ATSC 3.0 standard includes support for Dolby AC-4 and MPEG-H 3D Audio. But most broadcasts appear to be in Dolby AC-4 format. Dolby AC-4 supports up to 5.1 core audio channels by default. Additionally, AC-4 can support up to 7.2+4 audio channels or spacial audio objects using side signals. Unfortunately, AC-4 hardware support is limited and, even where nominally included, may not be fully tested.3 Further, at the moment, there are no open-sourced AC-4 software decoders. This is the single biggest impediment to watching ATSC 3.0 broadcasts.4

Broadcasters’ Transition to ATSC 3.0

The FCC requires full power and class A TV stations to simulcast their ATSC 1.0 signal through July 2023 after they start broadcasting their ATSC 3.0 signal.5 However, unlike the transition from analog to digital, where the FCC temporarily allocated a second frequency for the digital broadcast, broadcasters must comply with this requirement by channel sharing with another local broadcaster. Typically, that means that one station transmits in ATSC 1.0 or 3.0 format with its own streams and those of a partnering station and the partner station transmits its streams as well as the first station’s streams in the other format.6 TV broadcasters call these “lighthouse” stations.

From a consumer perspective, this means that significant coordination is required among local broadcasters before ATSC 3.0 broadcasts may be available in your city. Further, when ATSC 3.0 broadcasts are available, you will likely find multiple major networks using the same ATSC 3.0 broadcast (as subchannels) for the next few years, until they sunset their ATSC 1.0 broadcast.7

Silicon Dust’s HDHomeRun QUATRO 4K

In April 2020, Silicon Dust introduced their next generation, ATSC 3.0 compatible tuner, the HDHomeRun QUATRO 4K via a campaign on Kickstarter. This device includes four tuners: two ATSC 3.0/1.0 tuners and two ATSC 1.0-only tuners, all in high definition. After several months of delay, our QUATRO 4K arrived at our home in October.

Like other HDHomeRun tuners, you can use the QUATRO 4K with a variety of clients including Microsoft’s Windows 10 PCs and XBox One consoles, Apple’s Macs, iPads and iPhones, and Google’s Android smartphones, tablets, TVs and set top boxes, all provided that they have support for HEVC and AC-4 codecs. Additionally, because the HDHomeRun outputs OTA broadcasts as MPEG-TS streams, existing DVR solutions like Plex or JellyFin can record broadcast content without issue. However, playback of recorded streams depends on client support for HEVC video and AC-4 audio codecs. Moreover, the QUATRO 4K is an ATSC 3.0 gateway, capable of serving DASH and interactive app content to players that are ATSC 3.0 aware.

For now, there are no television stations in Philadelphia (where we live) that are broadcasting in ATSC 3.0. So, all we can assess is the QUATRO 4K’s ATSC 1.0 tuners’ capabilities. In our experience, the QUATRO 4K’s ATSC 1.0 tuners are better than prior generations of HDHomeRun tuners, both in terms of number of stations detected and reception quality. With our HDHR5-4US units, we received less than 50 OTA channels with frequent macro-blocking during bad weather. With our QUATRO 4K, we receive almost 70 OTA channels with less macro-blocking. However, many of these additional channels appear to be low-power stations with less desirable content. I will update this article when ATSC 3.0 stations are available here.

Hardware

The QUATRO 4K form factor looks identical to our previous HDHR5-4US Connect. The four tuners can tune four ATSC 1.0 broadcasts simultaneously. Two of the tuners can tune ATSC 3.0 broadcasts simultaneously. Silicon Dust has promised to enable multi-channel support so that you can view or record up to 4 ATSC 3.0 sub-channels simultaneously across those ATSC 3.0 tuners.

Firmware Updates

Silicon Dust is rapidly evolving the QUATRO 4K’s firmware including addressing station-specific idiosyncrasies.8 You can confirm your firmware is up to date by viewing your HDhomerun device here. If there is a new firmware available, your current device will be highlighted in red. You can update your QUATRO 4K either on that page or by downloading a client here. (The latter method is best if you also need to update your player or DVR software).

In January 2021, Silicon Dust released a rollup firmware update that shifted  ATSC 3.0 stations to the 100+ range. Now, users can more easily distinguish between ATSC 1.0 and 3.0 simulcasts and select the preferred stream based on the maturity/stability of your local station’s ATSC 3.0 broadcast and the capabilities of your hardware/software clients.

Other ATSC 3.0 Capabilities on the Horizon

Single Frequency Networks (SFNs)

Traditionally, full power TV broadcasters used very tall towers in a single location to cover a metropolitan area. With SFN, broadcasters can use multiple, smaller transmitters to send the same broadcast signal on the same channel. Advantages of using SFN include an increased coverage area as well as more efficient use of spectrum.9 We live in a rural area outside Philadelphia, some distance from the Roxborough antenna farm. If and when local broadcasters deploy single frequency networks here, I would expect us to receive a stronger over-the-air signal in the suburbs, with less multipath interference.

Interactive Content, Targeted Advertising & the IP Return Path

For broadcasters, the ATSC 3.0 standard offers new capabilities to deliver interactive content and to insert directly targeted ads.10 The primary means of delivering this content and advertising will be through your home’s broadband connection.

Broadcasters can deliver rich content similar to HTML 5 applications. For example, a broadcaster might include their own user interface surrounding one or more video streams. This application could then allow users to select either linear or on-demand content. However, it is unclear to me how widely interactive content will be distributed because cable and satellite operators are not required by the FCC to carry this content. I suspect this will become a point of negotiation in retransmission agreements.

More likely, broadcasters will focus on the ability to either more narrowly geo-target or to personalize advertising that is inserted into the broadcast. These capabilities will enable TV broadcasters to better compete with online video service providers. And, presumably, TV broadcasters will be able to charge advertisers more for personalized advertising.

ATSC 3.0 as a Content Delivery Network

Unrelated to the QUATRO 4K, there is a company Bitpath (owned by broadcast groups, Sinclair and Nextstar Media) that seeks to leverage ATSC 3.0’s data broadcasting capabilities for a content delivery network that can either bypass or complement traditional wired line and cellular IP networks.

Confirming NextGen Stations in Your Area

I recommend three resources to determine which stations in your area is broadcasting in ATSC 3.0:

• ATSC Deployments
• Rabbit Ears ATSC Deployment List
• FCC Application Search: under Purpose, select “Modification of License (NextGen)”

Updated on April 6th, 2023