Signal Processing - January 2016 - 158

[standards IN A NUTSHELL]

Richard Chernock and Jerry C. Whitaker

Next-Generation Broadcast Television: aTsc 3.0

lthough the current digital
terrestrial broadcast system
(now referred to as ATSC 1.0)
is widespread and quite successful, the basic component technologies have been in use for 20
years. Technology has evolved and viewer
expectations have changed. Television
broadcasters are under increasing pressure, due to regulatory and spectrum
issues, as well as increasing competition
for the viewer's attention. For these reasons, the Advanced Television Committee (ATSC) has been working on the
next-generation broadcast television system, known as ATSC 3.0.
The goals of ATSC 3.0 are to improve
the television viewing experience with
higher audio and video quality;
improved and more flexible reception
on both fixed and mobile devices; and
more accessibility, personalization, and
interactivity. The ATSC is also addressing changing consumer behavior and
preferences, providing TV content on a
wide variety of devices. Furthermore,
the ATSC is working to add value to the
broadcasting service platform, extending its reach and adding new business
models-all without the restriction of
backward compatibility with the legacy system.
ATSC 3.0 is being built to last. Technology advances rapidly and so methods
to gracefully evolve must be built into the
core of the system. An essential capability
is to signal when a layer or components of
a layer evolve-including the ability to
signal minor version changes and
updates, and major version changes and
updates. The goal of this flexibility is to
avoid disruptive technology transitions,

Digital Object Identifier 10.1109/MSP.2015.2479109
Date of publication: 29 December 2015

Software

Applications

* Screen Is a Web Page

Signaling
Pictures and
Sound

Presentation

* UHD
* HD and SD Multicast
* Immersive Audio

Signaling
Data Organized as
Streams and Files
Sending Bits
Over the Air
in 6 MHz

Protocols

* Internet Protocols

Signaling
Transmission
(Physical Layer)

* OFDM

Signaling
Finding the Signal

System Discovery and Signaling

* Unique Sequence

[FiG1] layers of the aTsc 3.0 system.

and to enable graceful transitions from
one technology to another.
The ATSC 3.0 standard enables system options for the broadcast industry
(not just system parameter options)
that include high robustness, spectrally
efficient operating points, flexible configuration of operating modes, a robust
bootstrap process that includes signaling basic system parameters, channel
bonding options for spectrum sharing,
and many other capabilities. It should
be noted that these standards provide
toolboxes for the broadcasters and specify how the tools are used. The selection
of which tools are utilized and how
depends upon the broadcasters' needs
and business models.
Work on ATSC 3.0 has been divided
into functional layers as illustrated in
Figure 1 and described in the following
sections. More information about the
working groups for the different layers is
available at http://atsc.org/subcommittees/
technology-group-3/.

IEEE SIGNAL PROCESSING MAGAZINE [158] jANuARy 2016

Physical layer
The physical layer for ATSC 3.0 embodies the theme of flexibility and future
evolution by starting every physical
layer frame with a bootstrap signal.
This bootstrap is extremely robust,
able to be received in very challenging
radio-frequency conditions. Besides
providing synchronization, the bootstrap also signals basic information
about the technology used in the physical layer itself (major and minor version, which enables graceful evolution
of the physical layer itself in the
future) as well as an Emergency Alert
Service wake-up bit, system bandwidth, time to the next frame of a similar service, and the sampling rate of
the current frame.
The bootstrap is followed by a preamble, which carries the information
needed to define the payload framing,
including the information needed for
the receiver to acquire the data frame.
The remainder of the physical layer

http://www.atsc.org/subcommittees/

Table of Contents for the Digital Edition of Signal Processing - January 2016