Are There Any Rules Regarding Numbering Of Subchannels?

[Markxxx]

For instance, I noticed WCIU in Chicago has

26.1 Main
26.2 Me-TV
26.3 Me-Too
26.4 This TV
26.6 FBT

What happened to 26.5?

I noticed WJYS has 62.1 62.2 and 62.4

So I was wondering is there a technical reason why they skip? Or does each station choose how to number their subchannels. I know for awhile WCIU was (somewhat) comically showing 26.5 as a still that said "That TV." No program just a still with those words on it.

 

[nathannah]

The only thing the FCC really regulates is the actual virtual channel number (aka 26 in that case), although in some cases (say those stations that used to be in the 50's and 60's in the analog age), they might use their lower-numbered actual digital channel instead to identify for prestige purposes and get it by the FCC without a problem. If a station on channel 4 wanted to use the number 4.88 for a subchannel, there is really nothing stopping them besides viewer aggravation.

Usually the reason for skipping a numeral in the channel map is the possibility of a future service or affiliation or for channel feeds used sparingly (such as emergency radar display or in the past, NCAA multicasting). In fact WCIU's sister operation in Milwaukee WBME has most of their digital space set aside for test patterns on 49.2, 49.3 and then 49.5 and 49.6, while a low-power Telemundo station rebroadcasts on 49.4, just to have them mapped in the hope they'll carry a service one day.

 

[mjlarochelle]

In another twist, stations don't even always put their "main" signal on Channel x.1. WAGM/8 in Presque Isle, Maine was a CBS affiliate in analog. In digital, its main CBS signal is on Channel 8.2, and they added a FOX subchannel on Channel 8.1.

Is WAGM the only station that did this?

 

[pab]

For the longest time, WHYY in Philadelphia had different programming on 12.1 than they did on 12 analog. A SD simulcast of analog 12 was on 12.2. Of course, this was pre-transition and also when they were moving from 55 to 50 to 12 at low-power, then medium power directional, then medium power omni, and so they may not have cared that much about it.

 

[Bill_W]

For the longest time, WHYY in Philadelphia had different programming on 12.1 than they did on 12 analog. A SD simulcast of analog 12 was on 12.2. Of course, this was pre-transition and also when they were moving from 55 to 50 to 12 at low-power, then medium power directional, then medium power omni, and so they may not have cared that much about it.

And Comcast carried both, 12 analog on 12 and 12-1 digital on 240. The only time that the 2 stations showed the same programming was during prime time when PBS was showing a show in HD. Never could get WHYY-DT over the air when they were on channel 50.

 

[fybush]

For the longest time, WHYY in Philadelphia had different programming on 12.1 than they did on 12 analog. A SD simulcast of analog 12 was on 12.2. Of course, this was pre-transition and also when they were moving from 55 to 50 to 12 at low-power, then medium power directional, then medium power omni, and so they may not have cared that much about it.

This was not uncommon. Until just a couple of years ago (I want to say 2008, but it may have been 2007), there was a separate PBS HD schedule, since most of the PBS daytime national programming (and even a lot of primetime) was produced only in SD.

I remember when the PBS HD schedule launched - we're talking 2001 or so now - there was so little HD programming available that it was a repeating loop of just a handful of shows. There were a lot of "Over New England" episodes, a few nature documentaries and not much else. But early on, it was often as not the ONLY HD programming available in a lot of areas, especially during the day, and so it drew a healthy audience of first adopters showing off their $7,000 TVs and video stores trying to demonstrate their $7,000 TVs.

In Rochester, we had PBS HD on 21.1 and the simulcast of analog 21 on 21.4; that finally went away in early 2009, and now it's just PBS main (in HD) on 21.1, plus World and Create on .2 and .3.

 

[tripinva]

In another twist, stations don't even always put their "main" signal on Channel x.1. WAGM/8 in Presque Isle, Maine was a CBS affiliate in analog. In digital, its main CBS signal is on Channel 8.2, and they added a FOX subchannel on Channel 8.1.

Is WAGM the only station that did this?

WGBC in Meridian MS also did this. Former NBC analog programming is now on 30-2 and Fox was added as 30-1.

- Trip

 

[tripinva]

As for your question, Mark, there's no technical reason. In the case of WCIU, I imagine they are waiting for encoder technology to improve and then they'll come up with another service for 26-5.

- Trip

 

[Kent]

For instance, I noticed WCIU in Chicago has

26.1 Main
26.2 Me-TV
26.3 Me-Too
26.4 This TV
26.6 FBT

What happened to 26.5?

I noticed WJYS has 62.1 62.2 and 62.4

So I was wondering is there a technical reason why they skip? Or does each station choose how to number their subchannels. I know for awhile WCIU was (somewhat) comically showing 26.5 as a still that said "That TV." No program just a still with those words on it.

My guess as to what happened to 26.5 and 62.3 is that they put their PSIP data on those channels. WDAF-TV in Kansas City, for example, has that data on 34.3. It seems like the .3 is the most common place to stash the PSIP data.

As for the rules to numbering subchannels, I've been told you have to have a .1, but you can number the others pretty much any way you want. However, I am aware of at least one station that, for awhile anyway, operated at 31.31.

 

[kenrayc]

In Bakersfield KBAK CBS 29 has their sister station KBFX FOX 58 on the same channel (33) so they put KBAK on 29.1 and KBFX on 58.2 which is really 29.2. When KBFX was analog it was a low power station on channel 58 on a much lower Transmitter site (4,000 ft), so thats why they combined it the be a full power station at 7,500 ft. the only thing KBFX is not in HD its a 480i station but runs in full 16:9 size(not stretched).

 

[kenrayc]

For the longest time, WHYY in Philadelphia had different programming on 12.1 than they did on 12 analog. A SD simulcast of analog 12 was on 12.2. Of course, this was pre-transition and also when they were moving from 55 to 50 to 12 at low-power, then medium power directional, then medium power omni, and so they may not have cared that much about it.

This was not uncommon. Until just a couple of years ago (I want to say 2008, but it may have been 2007), there was a separate PBS HD schedule, since most of the PBS daytime national programming (and even a lot of primetime) was produced only in SD.

I remember when the PBS HD schedule launched - we're talking 2001 or so now - there was so little HD programming available that it was a repeating loop of just a handful of shows. There were a lot of "Over New England" episodes, a few nature documentaries and not much else. But early on, it was often as not the ONLY HD programming available in a lot of areas, especially during the day, and so it drew a healthy audience of first adopters showing off their $7,000 TVs and video stores trying to demonstrate their $7,000 TVs.

In Rochester, we had PBS HD on 21.1 and the simulcast of analog 21 on 21.4; that finally went away in early 2009, and now it's just PBS main (in HD) on 21.1, plus World and Create on .2 and .3.

KVPT 18 (PBS) in Fresno did that as well, they ran the HD feed on 18.2 and what was going out on Analog was on 18.1, now after the transition
the HD is on 18.1.

 

[Gregg]

On my Magnovox converter, WNET's main programming comes in on Channel 13.3. 13.1 is PBS Kids, 13.2 is V-Me (PBS in Spanish). I've been told, though, that could be a quirk in my converter... and that most viewers in the NYC area get WNET's main programming on 13.1.

Gregg
[email protected]

 

[nathannah]

On my Magnovox converter, WNET's main programming comes in on Channel 13.3. 13.1 is PBS Kids, 13.2 is V-Me (PBS in Spanish). I've been told, though, that could be a quirk in my converter... and that most viewers in the NYC area get WNET's main programming on 13.1.

Gregg
[email protected]

Sometimes the virtual channel numbers have underlying virtual channels of their own which are mainly used for internal structuring of bandwidth, but sometimes they flash onto your converter or set. For instance if you were to tune into WCGV in Milwaukee, the actual channel tunes to 24.3 at first, then does another (usually imperceptible) remap to the actual channel 24.1.

 

[travisl5678]

KAXT-LD in San Jose,CA has 20 Subchannels, here is a list of them http://en.wikipedia.org/wiki/KAXT-CA

 

[KeithE4]

KAXT-LD in San Jose,CA has 20 Subchannels, here is a list of them http://en.wikipedia.org/wiki/KAXT-CA

Virtual channel 1? I thought 0, 1, 37, and anything higher than 69 were no-nos per the FCC? Didn't the Weigel stations in Chicago (WCIU) and Milwaukee (WDJT) get nailed for using Channel 1.x a few years ago?

 

[travisl5678]

No its virtual channel is 22,remember it is Wikipedia

 

[w9wi]

My guess as to what happened to 26.5 and 62.3 is that they put their PSIP data on those channels. WDAF-TV in Kansas City, for example, has that data on 34.3. It seems like the .3 is the most common place to stash the PSIP data.

As for the rules to numbering subchannels, I've been told you have to have a .1, but you can number the others pretty much any way you want. However, I am aware of at least one station that, for awhile anyway, operated at 31.31.

There are no rules for the minor channel number. (beyond the size of the integer field used to transmit it. I don't think you could have channel 31.23467852, because there aren't enough bits in the field to hold 23,467,852.) It's normal practice to have your "most important" program on .1, but there's nothing, either technical or FCC-wise, requiring it.

There are rules for the *major* channel number. Generally, if the station once had an analog signal, the major channel number must be the old analog channel number. If it never had an analog signal, the major channel number must be the RF channel number. There are exceptions to both sides of the rule.

As for "stashing" PSIP data on .3... The channel number is transmitted in the PSIP data. There's only one major/minor channel pair; PSIP data, audio, and video are all transmitted on the same channel. However, if there *is no* PSIP data, many receivers will receive the station on .3. There's a reason for that:

Each audio/video/PSIP set has a "program number". This number is supposed to be invisible to the viewer. Your TV should use the PSIP data to remap this program number to a minor channel number. It should use other parts of the PSIP data to remap the RF channel to a virtual major channel number.

If this PSIP data is missing... Many TVs will "fake it". They'll use the RF channel as the major channel number and the program number as the minor channel number. For example, the station I work for has NBC on virtual channel 4.1 and Telemundo on virtual channel 4.2. We're RF channel 10. The "program number" for NBC is 3, and for Telemundo 4.

On many TVs, if you're within range of our station and you punch in channel 10-3, your TV will find our NBC program. Since our PSIP is working.. your TV will also pick up the virtual channel info, will see that we want you to think we're channel 4-1, and will change your display to 4-1.

If our PSIP *wasn't* working... your TV wouldn't pick up any virtual channel info. And we'd continue to appear to be channel 10-3; your TV would never switch to 4-1.

One of our competitors, their major virtual channel and their RF channel are the same. Because their PSIP works, they come up as channels 8-1 and 8-2. If their PSIP *didn't* work, they'd come up as 8-3 and 8-4. Doesn't mean that they're transmitting PSIP data on 8-3, it just means they're on RF channel 8; they're transmitting no PSIP at all (at least not the TVCT); and their "program number" is 3.

------------------------

Why they start with program number 3 I don't know. But we were *strongly* suggested to start from 3.

 

[Poledo]

Down here in Pensacola, W19CO is broadcasting HSN on virtual channel 1.1.

Virtual channel 1? I thought 0, 1, 37, and anything higher than 69 were no-nos per the FCC? Didn't the Weigel stations in Chicago (WCIU) and Milwaukee (WDJT) get nailed for using Channel 1.x a few years ago?

 

[tripinva]

KAXT-CD is the only station in the US with permission from the FCC to map to channel 1. The tangled mess that is channel assignments in that area led to it.

The analog was on 22, but KRCB had that. The digital was on 42, but KTNC had that. So they asked the FCC for permission to use channel 1 and they said it solved the problem and approved it.

W19CO should not be mapping to 1-1, and if it is, is doing so illegally. They should be 19-1.

- Trip

 

[kenrayc]

KAXT-CD is the only station in the US with permission from the FCC to map to channel 1. The tangled mess that is channel assignments in that area led to it.

The analog was on 22, but KRCB had that. The digital was on 42, but KTNC had that. So they asked the FCC for permission to use channel 1 and they said it solved the problem and approved it.

W19CO should not be mapping to 1-1, and if it is, is doing so illegally. They should be 19-1.

- Trip

I wonder why channel 37 can't be used for mapping it's not like the actual channel is being used.