Originally Posted by uhfyagi
Giacomo, this is ridicolous, why dont the FCC just pass an amendment use real channels no more psp, or virtual channels problems solved.
I am inclined to agree with you. Mandating the use of the RF channel would eliminate this added conflict that arises from time to time, and eliminate viewer interruption when a station's PSIP generator fails or is improperly configured.
That being said, an amendment would be insufficient to address the issue, and any elimination of virtual channels from the present ATSC standard at this point would be impractical for broadcasters and viewers alike. Essentially, the concept to rely entirely on RF channel numbers, at present, is impossible.
PRESENT-DAY NECESSITY FOR VIRTUAL CHANNELS
As an example, let's look at WNYW New York. That station's pre-transition DTV channel was RF channel 44, and licensee FOX elected to remain on that channel post-transition. Presumably, FOX could
have elected RF channel 5 for its post-transition operations. Its analog facility was licensed and operational, and FOX certainly would have had the funds to effectuate that outcome. But, also presumably, FOX, like other broadcasters, took note of the deficiencies of the VHF-Lo band for DTV operations, and realized that the RF channel which WNYW called home for over sixty years would soon be most inhospitable for broadcasting purposes. Consequently, FOX elected to remain on RF channel 44 following the June 2009 DTV transition.
Now, many people here on this forum will remember that during the year leading up to the transition, there existed much confusion amongst television viewers, both OTA and cable TV, regarding what would happen come 2009. The confusion remained so prevalent in late 2008, that President Barack Obama took the extraordinary step to delay the DTV transition from February 17, 2009 to June 12, 2009. There were many allegations that the FCC did not adequately educate the public, and the DTV converter box coupon program was automated and flawed. Many cable viewers felt they were also in danger of having their channels turned off as a result of the transition. Senior citizens, some of whom do not subscribe to pay TV as they generally have to be especially careful with their finances, were especially concerned and confused.
With all of this confusion and misinformation, just imagine the experience for FOX if they also had to explain to already concerned and confused viewers that FOX 5 would henceforth be known as FOX 44 or FOX NY, and would no longer be seen on channel 5.
Not only that, from a marketing perspective, many of these stations built a good portion of their reputation around their channel number. Much of that would have been sacrificed if they could not identify with a virtual channel number.
HISTORICAL USAGES OF VIRTUAL CHANNELS
From an historical perspective, virtual channel numbers have been used for over 35 years. The most obvious commercial use of virtual channels began in the late 1970s, when many cable television systems were expanded beyond 12 channels. To accomplish the upgrades, engineers expanded many cable system plants to utilize frequencies in the Midband spectrum with either nine TV channels within 121 MHz - 174 MHz or alternately fourteen TV channels within 91 MHz - 174 MHz. The Midband is that portion of the television spectrum that operates between VHF-Lo Channel 6 and VHF-Hi Channel 7. Cable TV operators use this spectrum despite the fact that this it is reserved by the FCC for other aural broadcast services, and the reason is because transmission through coaxial cable to designated subscribers does not create significant risk of interference to these other licensed services.
As an example, let's look at cable channel 14. That station's spectrum uses 121 MHz - 126 MHz. Per the North American band-plan, this channel is actually Channel A. Cable channel 15 is actually Channel B. And so on. Indeed, several cable TV converter manufacturers labeled consumer-end converters to designate stations operating in the Midband by these letters. Cable television operators soon realized that presenting subscribers with a seemingly hybrid system might be considered awkward, and so began the use of assigning numbers to these channels. Essentially, all cable subscribers who watched what they thought was channel 14 were, in fact, watching Channel A. Thus, in this example, channel 14 is a virtual channel.
As a sidenote, I do not know specifically WHY the channel immediately following Channel 6 would not become the commonly accepted channel 14, and why five channels would separate Channel 6 from the commonly accepted channel 14, but that is ultimately what happened. I can only guess that the presence of the FM band within that bandwidth played a role in that decision.