Coba jelasin Modulasi jeung transmisi dari Standar ATSC dalam bahasa sunda dong

Sinyal ATSC dirancang pikeun maké lega pita 6 MHz nu sarua jeung saluran televisi NTSC (sarat interferensi standar DTV A/53 jeung NTSC nu padeudeukeut atawa jeung saluran DTV lianna kacida ketatna). Lamun sinyal vidéo jeung audio geus dikompresi sarta dimultipleks, transport stréamna bisa dimodulasi maké mangrupa-rupa cara gumantung kana cara pangirimannana.

Terrestrial (local) broadcasters use 8VSB modulation that can transfer at a maximum rate of 19.39 Mbit/s, sufficient to carry several vidéo and audio programs and metadata.

Cable television stations can generally operate at a higher signal-to-noise ratio and can use 16VSB or 256-QAM to achieve a throughput of 38.78 Mbit/s, using the same 6 MHz channel.

In recent yéars, cable operators have become accustomed to compressing standard-resolution vidéo for digital cable systems, making it harder to find duplicate 6 MHz channels for local broadcasters on uncompressed "basic" cable.

Currently, the Federal Communications Commission requires cable operators in the United States to carry the analog or digital transmission of a terrestrial broadcaster (but not both), when so requested by the broadcaster (the "must-carry rule"). The Canadian Radio-television and Telecommunications Commission in Canada has similar rules in force with respect to carrying ATSC signals.

However, cable operators in the US (and to a lesser extent Canada) can determine their own method of modulation for their plants.

Consequently, most North American cable operators have added 256-QAM to the 16VSB standard originally used.

Cable operators have still been slow to add ATSC channels to their lineups for legal, regulatory, and plant & equipment related réasons.

256 QAM is a cable standard, not an ATSC standard; however, over time it is expected to be included in the ATSC standard

There is also a standard for transmitting ATSC via satellite; however, this is only used by TV networks. Very few teleports outside the US support the ATSC satellite transmission standard, but teleport support for the standard is improving.

The ATSC satellite transmission system is not used for direct broadcast satellite systems, which in North America have long used a system similar to DVB-S.