ATSC-MH Mobile OTA DTV Technology

[Jase88]

Ottawa isn't stupid--they see money in this. Wireless mobility is a cash cow these days.

[roger1818]

Yup. It gives broadcasters another target audience without having to go through a middle man such as Rogers, Bell or Telus. Besides, for live wireless video, broadcast makes much more sense than streaming as the same bandwidth can be shared by all viewers instead of each viewer having to have their own bandwidth.

[tvlurker]

Ottawa isn't stupid--they see money in this. Wireless mobility is a cash cow these days.

I'm not sure what you mean. My understanding of Mobile ATSC is that it provides additional markets to existing broadcasters by allowing them to get revenue streams by broadcasting to wirelss devices using their existing 6 MHz broadcast channels. I don't see how Ottawa gets any extra revenue out of this, but I suppose IC could technically charge license fees for new uses. (But I'm not sure of the exact legal framework in place at the moment -- it's possible IC or the CRTC can only charge administrative costs.)

This is not the same thing as Ottawa potentially auctioning off spectrum above channel 51 for use directly by wireless providers using existing 3G or 4G or proprietary wireless protocols. I suppose it's possible Mobile ATSC could be used for non-broadcast frequencies, but I don't see the point. Some sort of OFDM-based protocol is probably more suitable for mobile operation.

[tvlurker]

A SNF is much more complicated to model than a single transmitter, as you will end up with a combination of constructive and destructive interference from the different transmitters, some which will be filtered out by the receiver.

I realize that, but you can use TVFool to figure out where the single transmitter coverage area is, by looking at where one transmitter out-shouts the others by at least 15-20 dB. I realize that real-life, with building-induced multi-path complicates matters, but at least we'll have a back-of-the-envelope first approximation.

UPDATE:

The database was updated this morning, and all five CRC-DT stations are in, although there are no coverage maps for them. Interestingly enough, my two closest stations are within 11 dB of each other, so that will be interesting to see how that works with non-directional antenna.

BTW, the other missing 'TO' status stations, as well as CIVM-DT, were added as well.

[tvlurker]

I wonder if they will do as they did in Raleigh and put TVs on buses?

Perhaps they can announce the bus stops, too

(This is a reference to a long-standing human rights complaint against the local bus system here that bus stops are not consistently announced by drivers. The city has proposed a multi-million dollar scheme to automate on-board bus stop announcements.)

[Jase88]

@tvlurker: I'm aware of the technical issues, and agree that this technology won't likely utilize new spectrum that will be auctioned. At this point, we can only predict how the new technology will be structured. But my belief is that Ottawa will find a way to extract revenue from it. And this could include auctioning existing VHF/UHF channels to "new media" providers (besides those already offered by broadcasters), and/or licensing fees.

[stampeder]

Hugh has published a couple of interesting Mobile DTV articles to the main site:

Is free Over-the-Air mobile TV the next killer app for Smartphones?

Vizio enters Mobile TV Market with Razor series

As Canada makes its transition to terrestrial DTV it is a good time for broadcasters to also plan on either dividing their existing spectrum bandwidth or applying for new slots as they roll out Mobile DTV for hand held devices. Such consumer electronics devices as mobile phones, GPSes, tablet PCs, laptops, media players, etc. will soon be arriving with integrated Mobile ATSC chipsets for local digital OTA TV, but they operate using different modulation and techniques than standard terrestrial ATSC as found in HDTV tuners, for example.

In Japan, Korea, and European regions where Mobie DTV is available to hand held devices the popularity and usage is huge. Mobile DTV presents an unbeatable value proposition for the broadcasters: consumers watch free DTV OTA on their mobile devices rather than through a carrier's data network (with its associated performance bottlenecks and costs).

Hello "Save Local TV" broadcasters: those are sets of eyes that will be watching your advertising!

[TaylorTech]

I'm in Russell, and I'll check it out with my netbook net time I'm in Ottawa, but does anyone know what exactly is being brodcast? What is the content on the network itself?


Taylor

[vejostde]

I saw a test pattern show up one afternoon. The PSIP mapped to channel 2-2. It was gone a few hours later.

[stampeder]

Mobile DTV USB tuners similar to ATSC USB tuners are coming soon from LG for a wide variety of handheld and portable devices:

Among the first products to reach consumers will be a variety of USB receivers for mobile DTV, most of which are built around LG chips for reception," said Dr. Jong Kim, president of LG's U.S. R&D lab, Zenith, in a statement. "These low-cost receivers can instantaneously transform a netbook, or laptop computer into a mobile digital TV receiver with the addition of software that will come with the USB device. LG is working with more than a dozen companies to introduce mobile DTV products in the U.S. market-all powered by LG chips.

http://www.broadcastingcable.com/art...TV_At_CTIA.php

I would expect that smartphones would be amongst the devices to be supported.

[roger1818]

From the previous link:

Broadcasters will likely need to reach deals with wireless carriers to include such capabilities in their subsidized phones before such products hit retail.

This is my biggest fear. Wireless carriers will likely want the mobile ATSC tuner disabled or removed as it would cut into their lucrative data plan revenue. Also, with the major Canadian wireless carriers also being BDUs, they may be leery about highlighting the availability of OTA broadcasts.

Without the mass market appeal of tuners on cell phones, mobile OTA likely isn't going anywhere.

[stampeder]

I thought about that too, but if the Canadian mobile carriers are smart about it (ya right) they could free up some of their bandwidth by offering local mobile DTV, allowing them to offer other stuff instead.

[holl_ands]

Mobile DTV per ATSC A/153: ATSC-M/H (Mobile/Handheld):

ATSC-Mobile/Handheld was developed so that stations could broadcast to vehicles speeding
down the highway/railway, since conventional ATSC would breakup if the speed was much
more than a crawl. It will also provide Emergency Alert Services (EAS), esp. when high
winds blow away roof-top antennas and power-line failures take down everything, so people
can watch the course of a storm via Handheld Cellphones, iPads, PC's & battery operated DTVs:
http://www.openmobilevideo.com/_ASSETS/DOCS/eas.pdf

A more robust signaling and error correction capability was adopted in ATSC A/153, including
the use of more efficient H.264 (MPEG-4):
http://www.atsc.org/cms/index.php/st...dard-parts-1-8
Candidate Standards are enhancements that are not yet approved:
http://www.atsc.org/cms/index.php/st...date-standards

The more robust performance is reflected in the ATSC-M/H Link Budget Planning Factors:
http://www2.rohde-schwarz.com/file/mh2_wp-v1.pdf
http://www.acrodyne.com/PDF/Portable_Means_Power.pdf

A user can't be expected to orient their handheld device towards the (local) tower for
optimum (horizontal polarized) reception and vehicular antennas are frequently more
sensitive to vertical polarization. Hence, many stations upgrading for ATSC-M/H have
also added a Vertically Polarized antenna, which (per FCC rules) can be driven with up
to the same power as is currently authorized for the Horizontal Antenna...effectively
doubling the total transmit power. This might help conventional ATSC reception, esp.
if using RabbitEars, or even better, Circularly Polarized Antennas:
http://www.digitalhome.ca/forum/show....php?p=1080294
http://www.digitalhome.ca/forum/show....php?p=1205374
Some Canadian DTV stations are already transmitting Circular or Elliptical Polarization:
http://www.digitalhome.ca/forum/showthread.php?t=136180

Since a handheld device will be inside buildings and has (very) negative antenna gain, reception
range will be much less than conventional OTA. "Gap-Filler" repeaters have been proposed to
expand coverage area for ATSC-M/H, usually on SAME frequency as the primary, in what is
called a Single Frequency Network (SFN)....a common configuration with DVB-T (COFDM)
systems in Europe and elsewhere. However, when ATSC tuners (esp. 3+ years old) try to
receive multiple signals with delays exceeding their Equalizer capabilities, bad things happen:
http://www.tvantenna.tv/papers/DTS%2...aper-final.pdf
Hence the need for careful OTA testing, esp. with (optional) SFN deployments:
http://www.openmobilevideo.com/about...dtv/standards/

At one point, DTV Transmitters were being sold with the understanding that ATSC-M/H
would be a simple software-only upgrade (cough--cough)....give or take a few more
boxes and software upgrades throughout the rest of the system:
http://chapters.comsoc.org/vancouver..._mobileDTV.pdf
Be sure to look at slide#36 "What's Inside the Receiver???"......it's a hoot......
Also note that the Application Framework is targeted for the SMALL SCREEN....

=====================================
Searching for "ATSC-MH" and "ATSC A/153" will find sources for Mobile DTV's
(usually a small, battery operated "personal" LCD), USB Sticks and add-on Car Tuners
(reviews can be found in various forums):
http://www.istockanalyst.com/article...icleid/4455251
Carefully read the specs...a "Mobile DTV" might be ATSC-only, vice ATSC-MH A/153,
and might even be intended for the European market, which doesn't use ATSC at all.....

The Open Mobile Video Coalition has direct links to OEM/ODM manufacturer websites,
but not to the individual products:
http://www.openmobilevideo.com/manufacturers/

=====================================
In fol. (Jan 2010) announcement, CRC announced that they would establish multiple
transmitters in a Single Frequency Network (SFN) for test purposes in the Ottawa area,
in order to evaluate the new and improved ATSC-M/H signal format:
http://www.ic.gc.ca/eic/site/ich-epi.nsf/eng/02070.html

Q1: Does anyone know if this is STILL on the air and how well it worked???

Q2: Does anyone know whether ATSC-M/H has been APPROVED for deployment throughout Canada???

There are about 147 U.S. DTV stations currently broadcasting ATSC-M/H signals in addition
to their usual mix of conventional ATSC signals (and many more coming on-line soon).
Some of them are within reception distance along the Canadian border:
http://www.rabbitears.info/market.php?request=atscmph
Here's a "map"....be sure to check back for updates:
http://www.openmobilevideo.com/about-omvc/

[tvlurker]

Originally Posted by holl_ands

Mobile DTV per ATSC A/153: ATSC-M/H (Mobile/Handheld):

Q1: Does anyone know if this is STILL on the air and how well it worked???

I haven't seen any activity on the channel 46 SFN in a while, but I don't check every day any more. When it was active, there was a video loop running every few minutes.

Sometimes, on a scan my converter box would detect two different 46.1. I assume they had different TSIDs, but I don't have a PC with a tuner stick (only a Mac with EyeTV), so I can't run TSReader to see what the stream looks like.

A screen crawl directed requests for more info to the CRC's general information email address, so you could try

info@crc.gc.ca

and see what they say about the status of the trial.

[majortom]

Speaking of Mobile DTV. Has anyone in any of the larger markets where it has been tested, had their eye on a device yet? Does it work well?