What is multicasting?
Multicasting allows several channels of digital programming to be broadcast at the same time, using the same space required for one analog program. So, if KNME broadcasts in analog on Channel 5, we can only offer one program, but if we broadcast in digital, Channel 5 becomes four channels: KNME 5.1, KNME 5.2, KNMD 9.1, KNMD 9-2. What should I do first? First, take an inventory of the TVs in your home. Even if you’re a cable or satellite customer, you may have one or more TVs that aren’t hooked up to your pay service. These secondary TVs, likely to be analog, won’t be able to receive a picture after the Digital Transition.
Multicasting allows viewers to choose from additional digital broadcasts. With digital television, a single station can broadcast on multiple channels simultaneously so that the consumer can select the best quality broadcast for their television. This is possible because digital programming is more efficient than analog broadcasts. Therefore, with analog programs, it used to be that one station could offer only one program. Now, instead of channel 4 only having one program, channel 4 could have a program on 4-1, 4-2, 4-3, etc. Multicasting, also known as multiplexing, gives the viewer more digital channels to choose from. Because high definition broadcasts require more space, HDTV broadcasts can limit the ability to multicast.
A. Using the same amount of spectrum required for one analog program, multicasting allows broadcast stations to offer several channels of digital programming at the same time. For example, WILX broadcasting in analog on channel 10 is only able to offer viewers one program. However, WILX broadcasting in digital on channel 10 offers viewers a digital program on channel 10-point-1, a second digital program Weathersource on channel 10-point-2. In the future there could be additional programming offered on channel 10-point-3 and so on. This means viewers get more programming choices.
