It depends on what you mean by "make a DTV signal"...
The MPEG-2 standard itself requires two tables:
- PAT (lists available programs ("subchannels"))
- PMT (links programs to elementary streams -- the audio and video streams)
In my experience, most TV sets seem to be able to decode and display OTA DTV signals that include only these two tables. However, there's no program guide or channel remapping.
Four additional tables of metadata are required by regulations:
- STT (System Time Table)
- MGT (Master Guide Table, pointers to other tables)
- TVCT (responsible for channel remapping, so that a station on physical channel 28 that wants to call itself "Channel 4" can do so.)
- EIT (program guide) (more than one of these is required -- IIRC, four at a minimum -- each covering a few hours' worth of programming.)
Most stations seem to transmit also a RRT (Ratings Region Table, describes what program ratings - PG, G, Y, etc. - are possible. The actual rating for any given program is in the EIT.). And, most stations transmit ETTs, which contain more verbose data about the programs in the EITs.
