Comcast Broadcast Specsby Robert Godard
Comcast is a commercial cable provider first established in 1963. Comcast delivers cable television to 39 states in the United States, and offers extended features such as digital voice lines and Internet services. Comcast allows for several broadcasts, each with its own specifications.
Standard Definition Cable
The most basic service offered by Comcast is the standard definition cable package. This is broadcast digitally, as is all of cable as of 2009, when Congress passed a law requiring cable providers to move their systems from analog to digital to clear the airwaves. Standard definition cable is broadcast at 480p or 480i. The "p" stands for progressive and is necessary for progressive capable televisions, while the "i" stands for interlaced, which is necessary for interlaced capable televisions.
High Definition Cable
Comcast also offers high definition cable service. While standard definition is broadcast at 480 pixel resolution, the highest quality that is possible in standard definition, high definition cable can broadcast a signal of up to 1,080 resolution. Resolution refers to the quality of an image, and the amount of information that is broadcast at one time. When using a high definition television, a standard definition signal may look fuzzy, and a high definition signal will be necessary for optimal use.
As 3D televisions have become more popular since the beginning of 2011, Comcast is now offering high definition 3D broadcast. Comcast broadcasts its 3D signal using a 1,080i signal with MPEG-2 transmission. This compresses the signal slightly, so it can be sent over digital lines, without losing noticeable quality. Since HD cable boxes are already set up to handle high definition signals, they can also handle 3D signals, though a 3D box can be purchased for further functionality, such as 3D menus.
As of the time of publication, Comcast offers several cable services that offer a variety of channel options. Hundreds of channels are available using Comcast, including premium channels. Since all cable is broadcast digitally, these options are available even in standard definition. High definition cable boxes offer both standard definition and high definition channels so that different televisions can be used, even without HD functionality.
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