me-tv-development team mailing list archive

[Alessio Gaeta <question62749@xxxxxxxxxxxxxxxxxxxxx>]

Question #62749 on Me TV changed:
https://answers.edge.launchpad.net/me-tv/+question/62749

    Status: Answered => Open

Alessio Gaeta is still having a problem:
I'm not a DVB expert, but I read something about it and, AFAIK:

- DVB-T uses same channels of analog TV in VHF and UHF bands.

- Channel frequencies vary by country or macro-area, and so is for
frequency spacing (mostly 6-7 MHz for VHF and 8 MHz for UHF); as
reference one can use something as
http://en.wikipedia.org/wiki/Television_channel_frequencies (tuning
frequency should be the center frequency between video and audio
carrier).

- Coding rate (FEC), modulation type and guard interval vary by
repeater/provider; the combination of them determines the bitrate
available (so it is related to number and quality of streams in each
MUX/radio cannel).

First two point could be solved preparing scan tables for each zone/country with all channels. 
Clearly, the third point is the most difficult to deal with. A "brute force" approach could be used, replicating each frequency line with permutations of modulation, FEC and guard, maybe being a little smart; for example, here in Bologna all MUXes use QAM64, so modulation could be country based. Or one could make bandwidth considerations: QAM64 an guard interval 1/32 provide greater bandwidth, so maybe broadcasters will likely use them (see http://happy.emu.id.au/lab/info/digtv/dvbt/ for reference).

Or one could be refer something as

http://www.dvb.org/dvb-deployment-data.xls

[ ;) I found it while writing... ]

I hope to be useful.

-- 
You received this question notification because you are a member of Me
TV Development, which is an answer contact for Me TV.