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Discussion Starter #1
Is HD broadcasting required for DTV in Canada? Also, what about multi-casting?

There are plenty of markets in the US, especially smaller markets, where major network affiliates and other stations lease space from other broadcasters, instead of building their own.

If prohibited, I think this should be looked at. If not, SD is better than nothing. Even SD widescreen can look decent (better than 2 HD's on one RF channel).
 

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@ Falcon 77

HD is not required when transitionning to DTV. HD and SD modes are only formats that can be transmitted over an ATSC channel. Not all channels are transmiting HD programs. Of course you can sure that major networks will carry HD programming. But some educational or ethnic stations could transmit multiple channels in SD instead of one channel in HD like it's done in the USA.

One example of this is WMBC-DT in New-York city. This station broadcast 6 channels with multiple language in SD and 2 audio streams. This situation also exist in many big US cities.

For the case of having 2 different stations sharing the same transmitter, forget about it. FCC and CRTC rules forbids the use of 2 different call sings over one transmitter. For a project like this to be realised, one station would have to drop it's licence and call sign and merge with the other station. They would have to re-summit their application to the authorities. By doing this both stations would loose both their identities and indenpendance.

The only time I saw the FCC allow something like this happened 3 years ago in the Plattsburg, NY area. PBS alliliate WCFE tower collapsed during an ice storm. WCAX came to the rescue of the station. Together they petitionned the FCC to allow WCFE to be become a sub-channel of WCAX with their own call sign. This was allowed as an emergency solution while WCFE rebuild their tower and transmitter. (About 5 months). Everything was gone. The tower collapsed on itself, destroying everything under.

For US stations, often when you can get other networks on the same channel, they are usualy sub-networks owened by the big networks. (EX: Abc and CW, NBC and This, PBS and Create, V-me, etc.):cool:
 

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Falcon_77 said:
There are plenty of markets in the US, especially smaller markets, where major network affiliates and other stations lease space from other broadcasters, instead of building their own.
In Canada the actual broadcast tower sites are generally owned & operated individually by the station(s), their network(s), or a third party. A well known and very unusual situation exists in Toronto in which the CN Tower is home to a wide variety of TV broadcast entities. In some cases like on Mt-Royal in Montréal the broadcast antennas are co-located on the same candelabra or platform. Broadcast locations across Canada are often shared, sometimes with shared towers, usually with separate.
Falcon_77 said:
Is HD broadcasting required for DTV in Canada? Also, what about multi-casting?
Since DTV began in Canada about 8 years ago the policy of the federal licensing regulator (the CRTC) has only been softly stated that stations must broadcast at their highest quality possible, yet sub-channels have occasionally been used by some stations. In Ontario a DTV station called SunTV ran an HD and an SD feed for awhile, and currently in Saskatoon, Saskatchewan the Global TV Network affiliate is doing that same thing. We have not had the type of sub-channel use seen in the U.S., although it is in intriguing possibility discussed here at length: DTV Subchannels in Canada's Future?

We've discussed these issues over the years here so your questions are a bit "old hat" for us, but hopefully these replies clear things up. :)
 

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I'm in agreement with stampeder that the sub-channel discussion is old hat, but it's worthy to keep an eye on the possibility of Canadian sub-channel markets surfacing in the near future once the August 2011 transitions are done and debugged. There have been some significant advanced transmitter equipment developments in the US that can now accommodate additional sub-channels without sacrificing too much quality from the station's main broadcast. DTV is still in the birthing stages, some US broadcasters have recognized that there is a 'direct bottom line profit' advertising revenue opportunity without adding much equipment cost to their capital investments and 'in my opinion', there will be new OTA sub-channels in the future. I suspect that Channel Zero and SunTV may be the Canadian broadcasters that will be first to jump onto the sub-channel bandwagon.

Time will tell!
 

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What is multiplexing? [sub-channels]

I found this to be an interesting source to explain MUX/DEMUX/IMUX multiplexing.

http://multiplexing.co.tv/

In telecommunications and computer networks, multiplexing (also known as muxing) is a process where multiple analog message signals or digital data streams are combined into one signal over a shared medium. The aim is to share an expensive resource. For example, in telecommunications, several phone calls may be transferred using one wire. It originated in telegraphy, and is now widely applied in communications.

The multiplexed signal is transmitted over a communication channel, which may be a physical transmission medium. The multiplexing divides the capacity of the low-level communication channel into several higher-level logical channels, one for each message signal or data stream to be transferred. A reverse process, known as demultiplexing, can extract the original channels on the receiver side.

A device that performs the multiplexing is called a multiplexer (MUX), and a device that performs the reverse process is called a demultiplexer (DEMUX).

Inverse multiplexing (IMUX) has the opposite aim as multiplexing, namely to break one data stream into several streams, transfer them simultaneously over several communication channels, and recreate the original data stream.
 

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Discussion Starter #6
Originally Posted by RFMAN

For the case of having 2 different stations sharing the same transmitter, forget about it. FCC and CRTC rules forbids the use of 2 different call sings over one transmitter.
Thank you for the info, though it makes me wonder how and why this is very frequently circumvented. So much so, that I don't really understand why, in the US, the FCC feels it necessary to adopt channel sharing in code.

Maybe it is simply because sub-channels are leased and not owned by the secondary stations?

The most obvious example I can think of is KESQ in the Palm Springs area. Here is their sub-channel line-up.

02-3 42.7 480i DD2.0 KCWQ-DT CW+ "The CW 5" (KCWQ-LP)
15-1 42.8 480i DD2.0 KUNA-DT Telemundo "Telemundo 15" (KUNA-LP)
33-2 42.4 480i DD2.0 KDFX-DT FOX "Fox 11" (KDFX-CA)
42-1 42.3 720p DD5.1 KESQ-HD ABC "NewsChannel 3 HD"
42-2 42.9 480i DD2.0 KESQ-WX AccuWeather "First Alert Weather Channel"

So, Fox, ABC, the CW & Telemundo all on one transmitter & all different call major signs, except the weather sub.

I need to do some more research on this.
 

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Sub-channels usage

It is my guess that sub-channels will mostly be used in ethnics and education stations, like Omni in Toronto and CFTU in Montreal. CFTU is an University of Montreal owned station that broadcast education programs all day long.

I think these stations would benefit greatly from multicasting since they could broadcast multiple programs at once, gaining more audience and be more effective. I'll have a close look at these stations in Montreal after the transition. :)
 

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For the case of having 2 different stations sharing the same transmitter, forget about it.
I have been a mod on a US forum for many years and have also heard of transmitters with two (or more) stations on the one transmitter. I believe the one I was aware of had ABC and PBS, but I couldn't be sure of that. I believe they both used the same format either 720P or 1080i which meant one of them was different than their other affiliates (although Buffalo PBS was 720P for a while on their own transmitter due to problems they had at 1080i. They have since switched back to 1080i - this was a couple of years back.)
 

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Every station has a single, unique call sign. The question is how to identify individual program streams. Thanks to PSIP, a sub channel can be independently labelled for the convenience of viewers, and that's all it is - a label. The station's actual call needs to be visually presented on all the subchannels once an hour, I believe. I know that at least one operator in my market puts the call and community of license in a grey bar at the top of the screen of every subchannel at the top of every hour.
 

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I have been a mod on a US forum for many years and have also heard of transmitters with two (or more) stations on the one transmitter. I believe the one I was aware of had ABC and PBS, but I couldn't be sure of that...)
Yes, one transmitter can use multiple call signs for sub channels, but once each channel sign is established for use, it can not change that callsign until they have applied for a callsign change.

I have bolded the callsigns that Eries channel 12RF can legally use on air.

12.1 1080i 16:9 main WICU-TV programming / NBC HD
12.2 480i 4:3 WSEE-DT2 "The CW Erie"
12.3 480i 4:3 WSEE programming / CBS SD

http://en.wikipedia.org/wiki/WICU-TV
 

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In another case of OTA subchannel usage, WNGS use 67.1 for broadcasting both 'ThisTV' & 'WNGS Yankees' broadcasts, on 67.2 it broadcasts just 'ThisTV' programing and on 67.3 is just 'Daysta'r religion programing. Soon though, there will likely be a fourth 'MeTV' broadcast that could show up on either 67.1 or 67.4.
In 2011, WNGS signed an affiliation deal with MeTV, which will air on a new digital subchannel. However, no firm date for MeTV Buffalo's launch has been set yet.
http://www.digitalhome.ca/forum/newreply.php?do=newreply&noquote=1&p=1261881
 

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Yes, one transmitter can use multiple call signs for sub channels, but once each channel sign is established for use, it can not change that callsign until they have applied for a callsign change.

I have bolded the callsigns that Eries channel 12RF can legally use on air.
The only FCC-assigned call sign in relation to 12 in Erie is WICU-TV. All subchannels must ID with "WICU-TV Erie" at the top of each hour. That's the extent of the requirements.

And as for WNGS, I'm making the assumption that WNGS will not be adding any subchannels, since I would suspect they're not about to replace the encoder Daystar left them with. I could be mistaken.

- Trip
 

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No, not really. WNYF-CD broadcasts on its own channel 35 transmitter. WWNY puts in a subchannel in order to provide wider coverage than channel 35's low power can do.
In fact, there are five WNYFs - WNYF-LP ch. 28 in Massena, WNYF-LD channel 18 from South Colton, WNYF-CD channel 35 and WNYF CA channel 28 Watertown.
Not sure if the 28s are still broadcasting, but they still show up in the FCC database,

As noted earlier, the PSIP channel labels are just that -- labels. The official call for 7.2 is still WWNY.
 

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That wasn't always the case, but sure. Just saying that for Canadians, they likely won't receive the UHF 35 as the coverage is limited. So it's a clever use of a sub-channel to increase the viewing area for Fox in upstate New York and Easter Ontario. CHCH should consider leasing a sub-channel here in the GTA to Global-DT as their coverage is poor.
 

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Global will be 100kW from the CN Tower come Septmeber. They won't need any help.

The situation with WWNY and WNYF is somewhat comples. United Communications, onner of both stations, broadcasts Fox on an SD subchannel of channel 7 to give viewers in outlying areas access to Fox programming they might not have been able to receive directly from channel 35.

The Massena transmitters rebroadcast the channel 7 CBS-HD and Fox-SD signals, as that is the simplest/cheapest way to relay the signals from Watertown to the tower in South Colton. This is also done to fill in some holes in WWNY coverage along the edges of its coveage area.
 

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In Watertown, upstate New York, CBS affiliate WWNY-TV-7.1, HD, and the Fox WNYF-Fox 28 (7.2, SD)share the same VHF DTV transmitter.
They also have an HD version of WNYF on the same tower, on RF35. It is a low power transmitter, however. Too bad they couldn't make that transmitter a full power transmitter and drop the SD version and replace it with an NBC subchannel.
 

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Too bad the CBC couldn't subchannel SRC and free up all of those redundant transmitters, here in Ontario. So could TVO and TVOF. It would save the taxpayers a hell of a lot of public money, to transition them and the frequencies saved could be used for other broadcasters, in underserved areas. Here in eastern Ontario, we have no CITY, OMNI or CHCH transmitters, but do have all kinds of SRC and TVOF transmitters broadcasting, that a very few people actually tune into.
 
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