Of particular interest is the MediaFLO standard selected by AT&T,
Verizon, and others for U.S. mobile TV. DVB-H was also widely considered,
but not chosen for reasons unknown to this point. (The
European Union did adopt DVB-H, though.) Old UHF TV channel 55
(716-722 MHz) will be used throughout the U.S. in all major cities
with MediaFLO.
Qualcomm, which developed MediaFLO, recently acquired former
UHF TV channels 53, 56, and 58 in the recent 700-MHz spectrum
auction for additional capacity. Broadcast stations are expected to
generate up to 50-kW effective radiated power (ERP) from antennas
on towers 300 m high.
Most worldwide mobile TV will use one of these common standards.
However, several other standards that are kicking around
could see some action. S-DMB, a proprietary format from Toshiba in
Japan, uses code-division modulation (CDM) in a 25-MHz bandwidth
that can accommodate up to 20 channels.
Another standard, TDtv, employs the UMTS 3G technology
TD-CDMA, which uses time-division duplexing rather than the
frequency-division duplexing of the 3GPP’s WCDMA cell-phone
standard. With 3GPP’s Release 6 Multimedia Broadcast Multicast
Service (MBMS)
standard, operators
using 3G UMTS WCDMA can offer broadcast
TV in an unpaired 5-MHz band. The 1900- and 2100-
MHz bands are available worldwide for the standard. This
overlay technology is a much lower-cost alternative for mobile TV.
It also offloads the video network, keeping maximum capacity for
voice and data.
There’s been some discussion of a mobile version of the
Advanced Television Systems Committee (ATSC) HD and digital TV
system in the U.S. It uses an MPEG-2 compressed video stream
and 8VSB modulation rather than coded OFDM (COFDM). Last year,
the ATSC solicited proposals for a mobile and handheld (M/H)
version of this standard that can provide digital programming to
portable and mobile units. Nokia, Qualcomm, Samsung with Rohde
& Schwarz, LG Electronics with Harris, Thomson, and other major
companies all submitted proposals.
Developed jointly by multiple members of the ATSC, Advanced
VSB is a slower version of the HD ATSC protocol designed for
mobile TV receivers to make cell-phone and portable TV devices
possible. The MPH in-band mobile digital TV system developed by
LG, Harris, and Zenith provides a low-bit-rate TV signal derived from
the 19.39-Mbit/s signal used for fixed digital TV in the U.S.
MPH would permit current HDTV broadcasters to supply free overthe-
air programming to mobile, pedestrian, and handheld devices
in current 6-MHz channels. IC receivers designed for this standard,
with slower video and smaller screens, would be needed. The main
question is which carriers who control handset design will build-in
A-ATSC receivers.
OBSTACLES TO ADOPTION
When it comes to adoption, integration shouldn’t be a problem.
IC receivers are already available from sources like Analog Devices,
Broadcom, DiBcom, Freescale, Frontier Silicon, Newport Media,
Qualcomm, STMicroelectronics, and Texas Instruments. Critical
engineering challenges do exist, though.
For instance, there’s trying to find space for the chip and the
antenna. Even more daunting may be power consumption, as the
chip and larger color screens will certainly eat more energy. A real
challenge for ASTC mobile receivers will be the extra-long antennas
needed for good reception. Remember early portable TV receivers
like Sony’s Watchman and its long whip antenna?
Another issue is cost of service. All carriers will charge extra for
TV. Fees in the $15 to $30 per month range are expected, but a
structured system with a selectable number of channels may get
adopted. There’s no doubt the TV service will be added onto any
high-speed data plan.
The business model for carriers is critical. If they can’t make
money, mobile TV won’t happen. So far, TV/video hasn’t been a
success with carriers offering TV over the network. But with broadcast
services beginning this year, and with content already out
there, mobile TV is expected to take off. Still, good content will ultimately swing the “success” pendulum one way
or the other.
Qualcomm’s subsidiary MediaFLO USA
offers a group of channels for its services with
AT&T and Verizon, including CBS Mobile, CBS
College Sports, CBS News, Comedy Central,
ESPN Mobile TV, Fox Mobile, Fox News, MTV,
NBC News 2Go, NBC 2Go, CNBC, MSNBC,
NickToons, and Nickelodeon. Both AT&T (Mobile
TV) and Verizon (V Cast) use MediaFLO and
offer these channels along with two or three
special channels of their own to distinguish
their services.
AT&T Mobile TV subscribers get Sony’s
PIX movie channel and CNN Mobile Live. All
MediaFLO services from both carriers are available
in more than 50 major metropolitan areas.
Currently, mobile TV handsets are available
from LG, Motorola, and Samsung (Fig. 1).
Another challenge involves converting existing
video material to a mobile format. Screen size
and data rates as well as compression formats
are different from fixed video methods and products.
MediaExcel solved the problem with its
hardware, which performs real-time conversion
from one format to another (Fig. 2).
Mobile television will mean much more than
just TV on a cell phone. Other portable devices
will also be available. Perhaps a new version of
the Sony Watchman is in the works. Backseat
TV sets for cars will be available as well, such
as the Sirius Satellite Radio Backseat TV now
offered in some Chrysler vehicles.
See Associated Table 1
See Associated Table 2