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The Official AVS 'Mobile DTV' (M-DTV) Topic! - Page 9

post #241 of 506
Thread Starter 
Quote:
Originally Posted by Desert Hawk View Post

Can the rooftop antenna on an RV be safely left up while the vehicle is being driven? How good are they at tolerating what is effectively a 70MPH wind?

Quote:
Originally Posted by BCF68 View Post

doubtful

?


Older antennas (used for NTSC) on mobile homes were never meant to be used at speed; they typically retract to a flush with roof position. M-DTV can use low profile antennas that work perfect at 70 mph. The one I've used is a rubber ducky about 5"-6" high.
post #242 of 506
I understand the appeal of mobile DTV reception. (Too bad this was not appreciated ten years ago.)

But as one primarily interested in fixed location high definition TV, I'm more concerned about mobile's impact on the primary ATSC signal. My PBS station (WTTW Chicago) is listed on the OMVC site as offering mobile in 2011. Currently it offers 4 channels - one HD plus three SD. Perhaps one of the SD channels will be sacrificed...

I was going to ask about mobile bit rates used by various other stations, but Google reminded me that Trip already has provided that information at RabbitEars. Thanks, Trip!

Is there any anecdotal information on visual impact to the primary HD signal of stations currently offering mobile DTV?
post #243 of 506
Just curious, I've seen many TV Stations News Reporters are now
broadcasting from a moving vehicle aka "Mobile Reporter".

The Quailty is very good, some minor issues,.

How are they doing this ? what is the method?
post #244 of 506
Quote:
Originally Posted by Keith View Post

Just curious, I've seen many TV Stations News Reporters are now
broadcasting from a moving vehicle aka "Mobile Reporter".

The Quailty is very good, some minor issues,.

How are they doing this ? what is the method?

Data over mobile phone or WiMAX networks is my bet.

Various vendors have products that will bond multiple 3G or Ethernet interfaces together (for throughput) or send the same data over multiple interfaces to the same target (for higher reliability and lower latency). Some products have an A/V codec built-in (like the Streambox Avenir), while others require an external codec (like the Wired Broadcasting Mediahub). Basically, these products provide a decently reliable video link back to the studio anywhere you've got mobile phone coverage.
post #245 of 506
I'm reading through Part 3 of A/153, and it occurs to me that all of the facilities are there for M/H broadcasters to broadcast any data they wish to broadcast as long as it can be encapsulated into IPv4 frames (although section 6.2 reads like you could actually transmit arbitrary ethertypes) and doesn't blow the broadcaster's data rate budget. Have broadcasters given much thought to alternative uses for this bandwidth?

It was also interesting to read that every M/H ensemble must contain an NTPv4 packet at least once every ten minutes. Considering the constraints placed on timestamps in section 10.3.2, the reference clock will almost certainly be GPS. I'm wondering what the jitter would look like on these NTPv4 packets. There would almost certainly be a high delay from when the NTP packet is generated until the client sees it (encoding delay, STL delay, etc.), but would it be a highly variable delay?
post #246 of 506
Who really needs to watch TV in the car anyway?
post #247 of 506
Not just for the car, another good use for M-DTV would be for all the people who use portable TVs at sporting events and such. With regular DTV moving the antenna or TV just a bit can cause signal break-ups.
post #248 of 506
Quote:
Originally Posted by W4DXL View Post

Who really needs to watch TV in the car anyway?


The people who are already talking on the phone, texting, smoking, drinking coffee, putting on makeup and yelling at the kids in the back.
post #249 of 506
post #250 of 506
These 52 Stations Now Transmit Mobile DTV

http://www.tvtechnology.com/article/115146
post #251 of 506
Mobile DTV Group Lines Up Pay Wall Technology

http://www.tvtechnology.com/article/115164
post #252 of 506
Quote:
Originally Posted by R Johnson View Post

These 52 Stations Now Transmit Mobile DTV

http://www.tvtechnology.com/article/115146

There are a few stations listed there that are not transmitting, and a number which are transmitting that are not listed.

I only trust my own listing. http://www.rabbitears.info/market.php?request=atscmh

- Trip
post #253 of 506
Quote:
Originally Posted by R Johnson View Post

Mobile DTV Group Lines Up Pay Wall Technology

http://www.tvtechnology.com/article/115164

Lets hope the pay wall model burns in hell.
Lets also hope the parasitic mobile streams disappear soon for those who are broadcasting, so that bitrate can go back to the main stream where it belongs.
post #254 of 506
From what I have heard, the main objective of mobile TV is to handle the doppler effect. Does anyone know how A/153 would handle impulse noise, FM interference, multipath, adjacent channel interference, etc.?

Also according to an article by Doug Lung, "Mobile tv...allows reception with SNR in the range of 4 dB, well below the 15 dB SNR required for legacy DTV." Does this mean that you need 4 dB above the noise or does this mean you need 4 dB of signal for every dB of noise? I am true amateur, obviously

http://www.tvtechnology.com/article/61736
post #255 of 506
It seems to me that the Doppler effect isn't really much of an obstacle. It is the everchanging multipath conditions and trees that are obstacles to reception. I have a battery operated Auvio 3.5 inch tv and if I have line of sight to the mountains where the transmitters are I can usually get reception of regular ATSC while in motion. The instant a building or other vehicle or especially a tree blocks line of sight the signal goes away.
post #256 of 506
With NAB underway this week, perhaps we will hear more about new Mobile DTV products.

http://www.hd-report.com/2011/04/11/...l-integration/

http://www.nabshow.com/2011/index.asp

At NAB this week LG is introducing a Mobile TV that integrates social networking, 3D telecasts (glasses-free), and electronic coupons. The LG prototype is a 7″ mobile TV with antenna capable of displaying auto-stereoscopic images within the ATSC Mobile DTV Standard format.

LG will also show off Tweet-TV, a technology that combines social networking communication with television content which the broadcaster integrates pre-output to the air.

Electronic Coupons is another technology which LG will display on their touch CDMA device with Mobile TV capability. The smartphone based on the Android 2.2 (Froyo) operating system displays digital coupons via the ATSC Mobile Digital TV standard.

As broadcasters continue their national rollout of Mobile DTV, LG is proud to lead the transition with the latest innovations in mobile DTV services like 3D and applications like Tweet-TV and Electronic Coupons, said Dr. Skott Ahn, president and chief technology officer, LG Electronics, Inc.
post #257 of 506
ect of CioTv is its ability to receive live mobile DTV signals, which is the most cutting-edge technology available today, said Aaron Engberg, director of the Mobile Entertainment Division, Winegard. CioTv can provide everything consumers want - all in a small, portable device. It's truly the most comprehensive portable entertainment device on the market today with the first fully enclosed hi-gain internal MDTV antenna.

CioTv's PCAP touch-screen is hi-bright and provides a super fast, super clear and intuitive user-interface. This multi-standard automotive entertainment system features ATSC-MH mobile digital TV and the first fully enclosed, hi-gain internal MDTV antenna. CioTv is equipped with a 10.2-inch TFT touch-screen and progressive capacitive controls for viewing a wide range of entertainment options on the go.

CioTv supports MDTV, DVD video, iPod/iPhone video and audio, CD, MP3, SD and USB (photo, audio and video), as well as game device input. CioTv is also Wi-Fi enabled with Web browsing and supports e-mail by Opera.

CioTv will be on display at the 2011 NAB Show in the Las Vegas Convention Center's North Hall, Booth #4036, April 11 through 14.

For more information about CioTv, visit www.ciomobiletv.com.

About Winegard:

Winegard Company, headquartered in Burlington, Iowa, has been manufacturing quality television and radio reception products for more than 55 years. For consumer product questions, contact Winegard Customer Service at 800-288-8094 or visit www.winegard.com; a wide selection of downloadable CioTv press releases and images are available on CioTv's website at www.ciomobiletv.com.
post #258 of 506
Just in case anybody is interested, here is the URL for RCA Portable TV

http://rcaportabletv.com/
post #259 of 506
Thanks Jim, I might actually be more interested in the Mobile DTV Car Tuner | Model DMT3BR. I'm not sure of it's output jacks but if it has at least composite video and audio outs I could combine it with my non-MDTV digital tunered portable or my older analog tunered portable(both of which have composite inputs). Hopefully the price should be lower because it omits the screen and for sure it will have an external antenna. Very little on it though.
http://rcaportabletv.com/products/mo...v/mobile-dtv4/
post #260 of 506
http://getmyelectronics.com/products...tuner-receiver

The Pocket Mobile DTV Car Tuner Receiver is $129 with free shipping

It looks like it uses a mini to composite adapter.
http://getmyelectronics.com/collecti...gnal-connector

If I am understanding this correctly, the three with a screen work with BOTH regular ATSC AND ATSC-M/H, but the mobile only does ATSC-M/H. That might be a deal killer for me, but I will have to do some more checking on that. Our Dodge Grand Caravan has composite video input jacks, so I would like still like to be able to get regular ATSC while parked.
post #261 of 506
Too bad it's only MDTV and not ATSC also. I guess I wouldn't need ATSC with my regular digital tuner portable but doesn't do me as much good with my older analog only portable. Probably also really meant for 12v cigarette lighter operation instead of AA batteries.
post #262 of 506
Hybrid ATSC-ATSC Mobile DTV tuners Now Available

http://www.tvtechnology.com/article/119338

Ron
post #263 of 506
Three portable receivers are available under the "RCA" logo. These include a 3.5-inch portable TV that can operate on 4 "AA" batteries – ideal to have on hand in case of a large earthquake or hurricane, a 3.5-inch portable TV with built in lithium battery and an FM radio tuner, a 7-inc TV with built-in battery, and an in-car DTV tuner/receiver. Suggested retail prices range from $119 for the battery operated portable to $179 for the 7-inch portable. Go to www.RCAPortableTV.com for more information and ordering. Units ordered during NAB should be shipped from California sometime next week.

Ron, I think that article is just referring to the RCAs that Jim posted about, nice to see it's getting some buzz.
post #264 of 506
Quote:
Originally Posted by jjeff View Post
Three portable receivers are available under the "RCA" logo. These include a 3.5-inch portable TV that can operate on 4 "AA" batteries - ideal to have on hand in case of a large earthquake or hurricane, a 3.5-inch portable TV with built in lithium battery and an FM radio tuner, a 7-inc TV with built-in battery.
Those with a built in battery will be great in times of a large earthquake or hurricane.. for the first 2 hours or so until the battery dies.
post #265 of 506
post #266 of 506
Quote:
Originally Posted by bdfox18doe View Post
Those with a built in battery will be great in times of a large earthquake or hurricane.. for the first 2 hours or so until the battery dies.
I used have a Sony Watchman that we used during tornados in the basement. Ran great on AA batteries. The ones with the built in rechargeable batteries are obviously aimed at car installs or planned use. You won't have time to charge it if a tornado is coming.
post #267 of 506
I did a Google search this afternoon to see if anything new popped up for Mobile DTV. I was somewhat underwhelmed to see that not much showed up. It looks as if the RCA Mobile DTVs are being sold via the web exclusively. While that is certainly there choice, I happen to think that they would probably sell better if they are available at your local Best Buy stores, etc. I certainly don't know much about retailing, but is that typical to take that long to show up at brick and mortar stores?
post #268 of 506
I've also noticed the lack of MDTV products. Still see many ads for portable LCD TVs but they all lack a mobile tuner At this rate I can't see many more stations signing up to broadcast MDTV is no one really has tuner capable of tuning it.
post #269 of 506
I ordered several of the RCA units a while back..they never arrived.

So I'm still using the OMVC Prototype Dell Netbook and the LG DP570Mh portable..along with Decontis Mobile Tv software.. as my primary test receivers.
post #270 of 506
Quote:
Originally Posted by bdfox18doe View Post

I ordered several of the RCA units a while back..they never arrived.

So I'm still using the OMVC Prototype Dell Netbook and the LG DP570Mh portable..along with Decontis Mobile Tv software.. as my primary test receivers.

How do those compare to one another in terms of features and especially weak signal reception?
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