View Full Version : RF Technology Information, DTV
State by State listing of NTSC and DTV channels, transmitter power, etc. Lots of RF Technology info for those who would like to know :)
Doug Lung's RF Technology Page (http://www.transmitter.com/)
Lee
This too for information:
What is PSIP and why is it important to the DTV system?
The program and system information protocol (PSIP) is a collection of tables designed to operate within every transport stream for terrestrial broadcast of digital television. The purpose of the protocol, described in ATSC document A/65A, is to facilitate the tuning of programs by specifying the information at the system and event levels for all virtual channels carried in a particular transport stream. Additionally, information for analog channels—as well as digital channels from other transport streams—may be incorporated.
How does the two-part channel numbering scheme work?
The major channel number is used to group all services associated with a broadcaster’s NTSC brand, for example Channel 4. The minor channel number specifies a particular channel within that group. Zero (0) is reserved for the NTSC channel; all other values (1–999) are allowed for digital services. One common approach is to start with 1 and to continue numerically for different programming services. Data services must use 100 or greater. For example, the NTSC channel would be 4-0, the first digital channel signal would be 4-1, the second 4-2, and the first data service 4-100. ATSC document A/65A assigns major channel numbers for existing NTSC broadcasters to be the same as the current NTSC RF channel number (2–69). Rules for other usage are also covered, with the essential requirement that there be no duplication in a market.
Why use the major/minor channel numbering system?
The station numbering system made possible by PSIP preserves the enormous investment in branding that television stations have in their existing NTSC RF channel number. For example, in a given market Channel 4 is known to be the NBC affiliate. PSIP permits viewers to tune to the DTV Channel 4 without regard to the actual RF channel of the digital signal. This simplifies station selection by consumers and preserves the “Channel 4” brand. However, cable systems generally use one-part channel numbers for all programming.
What is Directed Channel Change?
Directed Channel Change (DCC) is an interesting feature that allows broadcasters to tailor programming or advertising based upon viewer demographics. For example, viewers who enter location information such as their zip code into a DCC-equipped receiver could receive commercials that provide specific information about retail stores in their neighborhood. Segments of newscasts, such as weather alerts that are relevant to certain areas could also be targeted based upon this location information. A channel change may also be based upon the subject matter of the content of the program. Nearly 140 categories of subject matter have been tabulated that can be assigned to describe the content of a program. A broadcaster can use this category of DCC request switching to direct a viewer to a program based upon the viewer’s desire to receive content of that subject matter.
Lee
leadvocal
09-11-2003, 04:13 AM
Maybe make this last post a sticky in the FAQ section?
The link and the post were added to the FAQ on "Antennae and OTA stuff". Thanks
