You cannot draw conclusions until the standard has been released. However, I believe that public prints have put the o/h at close to 4.5 mb/seconds for one service, and IIRC, 9 for 2 services. Maybe the term isn't exactly services, but I can only refer to things which have been mentioned publicly. John Willkie -----Mensaje original----- De: opendtv-bounce@xxxxxxxxxxxxx [mailto:opendtv-bounce@xxxxxxxxxxxxx] En nombre de Bob Miller Enviado el: Thursday, August 07, 2008 9:09 AM Para: opendtv@xxxxxxxxxxxxx Asunto: [opendtv] Re: From Broadcast Engineering - WRAL tests mobile DTV That is what I would like to know. How far was I off last year when in technical ignorance but from a good source I put out numbers on what one 8-VSB mobile modulation would cost in bits. What are the numbers? What is the overhead and what is the % of bits that are real at what robustness levels? Anybody care to compare to DVB-T or H or CDMB-T or is it a big secret because it is so bad. Bob Miller On Thu, Aug 7, 2008 at 11:24 AM, <dan.grimes@xxxxxxxx> wrote: > > What is the reason for only getting one 600 Kb/s and one 300Kb/s channel out > of 4.5 Mb/s? Are the rest of the bits required for overhead or did they > just not fill all the M/H channels possible in the 4.5 Mb/s subchannel > bandwidth? > > Dan > > > > Tom Barry <trbarry@xxxxxxxxxxx> > Sent by: opendtv-bounce@xxxxxxxxxxxxx > > 08/06/2008 08:41 PM > > Please respond to > opendtv@xxxxxxxxxxxxx > To > opendtv <opendtv@xxxxxxxxxxxxx> > cc > Subject > [opendtv] From Broadcast Engineering - WRAL tests mobile DTV > > > > > Supposedly from Broadcast Engineering though I copied it from AVS > <http://www.avsforum.com/avs-vb/showthread.php?t=1056025>. I'm not sure > I understand it correctly but it looks like they got a total of 900 > kbps (2 channels, 300+600) after error correction overhead from using a > total of 4.5 mbps of the channel bandwidth. > > - Tom > > --------------------------------------------------- > From Broadcast Engineering - WRAL tests mobile DTV > Broadcast Engineering Mobile TV Update > > WRAL tests mobile DTV > > Users in Raleigh-Durham reported reliable signal reception in most parts > of the station's existing coverage area. > > WRAL-DT, the CBS affiliate in Raleigh-Durham, NC, owned by Capitol > Broadcasting Company (CBC), conducted a series of mobile DTV tests last > week using the Mobile-Pedestrian-Handheld (MPH) system promoted by > Harris Broadcast and others. Hosted by CBC's New Media Group, the tests > featured seven handsets given to station executives living in different > parts of the state. Users reported reliable signal reception in most > parts of the station's existing coverage area. > > To kick off the July 21-25 trial, the station hosted a reception last > Tuesday in which about 50 participants were driven in a bus around the > area with prototype LG Electronics mobile handsets that featured > MPH-compatible reception chips inside. Signal reception of two channels > (half rate at 600kb/s and one-quarter rate at 300kb/s) using about > 4.5Mb/s (including turbo coding) of the station's 19.4Mb/s on-air DTV > stream was reportedly strong everywhere they went during the 10-minute > ride - even at 70 miles per hour. > > The goal of the service, according to John Harris, WRAL's director of > programming, is to extend the reach of the station's television channel, > and make it available everywhere our viewers are. The initial plan is to > simulcast the on-air DTV signal. WRAL-TV broadcasts CBS network and its > own local programming in the 1080i HDTV format as well as in SD digital. > > "We're excited about the possibilities," John Harris, WRAL's director of > programming, told Broadcast Engineering. "The priority is to offer > WRAL's TV signal in another way, in another place. I took one [handset] > east of the station and I just kept driving until the signal dropped > out. I got pretty far before that happened, so I can see the potential > of this service." > > LG Electronics, Zenith Electronics and Harris, all proponents of the MPH > scheme, helped out with the field trials. WRAL-DT uses a Harris Sigma > CVD UHF transmitter, with an MPH module, for the weeklong test. > > In a statement, James F. Goodmon, CEO of CBC, said "mobile DTV > broadcasting enables WRAL to better serve our viewers, communities, and > advertisers by providing a strong combination of anywhere access, > two-way communication, and mobility." > > In 1996, Harris worked with WRAL-DT as one of the first DTV stations in > the country. Two years later, when John Glenn made his historic return > to space, Harris worked with WRAL to conduct the first live HDTV > broadcast of a space shuttle launch to audiences nationwide. Now, the > station is the first to promote mobile DTV service in the state of North > Carolina. WRAL predicts that more than 200 million portable devices will > be sold in 2008, although few if any will have the necessary MPH > reception chips inside. > > WRAL-TV and Capitol Broadcasting Company are part of the Open Mobile > Video Coalition (www.openmobilevideo.com), a nationwide group of > broadcasters driving the deployment of mobile digital broadcast > television. Commercial deployments are forecast for 2009. The group > hopes to have an established standard available to broadcasters by the > February 2009 analog shutoff date. > -- > Tom Barry trbarry@xxxxxxxxxxx > > > > > ---------------------------------------------------------------------- > You can UNSUBSCRIBE from the OpenDTV list in two ways: > > - Using the UNSUBSCRIBE command in your user configuration settings at > FreeLists.org > > - By sending a message to: opendtv-request@xxxxxxxxxxxxx with the word > unsubscribe in the subject line. > > > ---------------------------------------------------------------------- You can UNSUBSCRIBE from the OpenDTV list in two ways: - Using the UNSUBSCRIBE command in your user configuration settings at FreeLists.org - By sending a message to: opendtv-request@xxxxxxxxxxxxx with the word unsubscribe in the subject line. ---------------------------------------------------------------------- You can UNSUBSCRIBE from the OpenDTV list in two ways: - Using the UNSUBSCRIBE command in your user configuration settings at FreeLists.org - By sending a message to: opendtv-request@xxxxxxxxxxxxx with the word unsubscribe in the subject line.