Since the beginning of TV in the late 1920s, the consumer has chosen the channel by selecting a number from the TV. For example, channels 2-13 for VHF and 14-69 UHF. Cable TV has made this easier with more channels available Ex yu tv, from just 2 to almost 99. This system is very familiar to the average consumer.
They had to create a new system when the industry started developing digital TV and compression. The Advanced Television Standards Committee, (ATSC), established the standard.
Digital compression TV is capable of transmitting more programs on one TV channel. Therefore, it was decided to give each program a Major and Minor channel numbers separated by a period. ).
A digital program carried on VHF channel 6 might be called 6.1. A second or third program would be called 6.2, 6.3, respectively. If they were broadcast on an UHF channel, they would be 45.1 to 45.3 to 45.7. Further confusing things, the FCC ordered that stations transmitting on Channels 2-6 switch to another frequency. This led to a channel known for 50 years by the name Channel 3 being transmitted on UHF channel 26, but called 3.1. This is very confusing.
It was becoming more difficult to find these programs when they were picked-up by local cable companies. This is until the introduction of the Virtual channel numbering scheme. This is because a cable system may have up to 12 programs running on one channel. The channel’s number might not match the program number.
The introduction of virtual channel numbers means that a program can have a number assigned regardless of whether it is carried on the system. This means that the number on your TV or Cable box will display between 2 and 999. It will not have duplicates nor minor numbers like a.1 or.2. Any virtual number may be assigned by the system operator.
We can see that channel 3 was transmitted by the broadcaster using UHF channel 26. It may be on channel 57.3 of the cable company’s cable, but they have it on virtual channel number 3 instead. When you pick channel 3, the channel you’ve been watching for years will be displayed.
Toner Cable can help you create your Cable System or Network. Analog headend electronics include Processors, Modulators and Satellite receivers. Digital headend electronics includes HD digital encoders, Digital multiplexers, and QAM modators.