From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-ew0-f177.google.com ([209.85.219.177]:49416 "EHLO mail-ew0-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752609AbZCPJH7 (ORCPT ); Mon, 16 Mar 2009 05:07:59 -0400 Received: by ewy25 with SMTP id 25so3375302ewy.37 for ; Mon, 16 Mar 2009 02:07:55 -0700 (PDT) Date: Mon, 16 Mar 2009 10:07:46 +0100 (CET) From: BOUWSMA Barry To: Benjamin Zores cc: linux-media@vger.kernel.org, Christoph Pfister Subject: Re: [PATCH] add new frequency table for Strasbourg, France In-Reply-To: <49BBEFC3.5070901@gmail.com> Message-ID: References: <49BBEFC3.5070901@gmail.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-media-owner@vger.kernel.org List-ID: On Sat, 14 Mar 2009, Benjamin Zores wrote: > Attached patch updates the current dvb-t/fr-Strasbourg file with > relevant transponders frequency values. Hi, I have a problem with some of these values. Well, to be truthful, all of these values. I don't have a good 'net connection to be able to check these things online at the moment, so I'm going to have to go by some possibly-outdated downloads... First, every frequency is given an offset from the nominal centre frequency of the 8MHz envelope. I am aware this is common in the UK where the switchover is happening gradually so as not to interfere with adjacent analogue services, and I also know that last I checked, the number of french analogue services I could receive weakly had dropped, but at least one was still visible. I've also read in a forum that complete analogue switchoff is planned Real Soon Now with a corresponding increase in ERP from the Alsace transmitters, but I don't know details. My mailer doesn't include the attachment in the reply, so I've had to paste the lines below... +T 482167000 8MHz 2/3 NONE QAM64 8k 1/32 NONE I have some recent german Bundesnetzagentur (BNetzA) data, and this lists the Nordheim frequencies as TVDRStrasbourg 22 482.000KT that is, no offset. I still have not wrapped my head around the meaning of the `KT' status field. The rest of the fields match what I predicted earlier (pasted from my file created for the neighbouring part of germany): ### In the west to southwest, one may receive a number of broadcasts from ### the Alsace in France. These are horizontally polarised. ### Strasbourg Nordheim 22-47-48-51-61-69 # ACHTUNG! file fr-Strasbourg contains no content! FIXME! ### need to verify FEC 2/3 + GI 1/32 (MFN), fix freqs # T 482000000 8MHz 2/3 NONE QAM64 8k 1/32 NONE # K22 # T 682000000 8MHz 2/3 NONE QAM64 8k 1/32 NONE # K47 # T 690000000 8MHz 2/3 NONE QAM64 8k 1/32 NONE # K48 # T 714000000 8MHz 2/3 NONE QAM64 8k 1/32 NONE # K51 # T 794000000 8MHz 2/3 NONE QAM64 8k 1/32 NONE # K61 # T 858000000 8MHz 2/3 NONE QAM64 8k 1/32 NONE # K69 Now, back to your diffs... +T 570167000 8MHz 2/3 NONE QAM16 8k 1/32 NONE This frequency looks very suspicious, as it is (without the offset) in use with different parameters by a Single- Frequency Network along the Hoch- and Oberrhein, including a non-directional 50kW tower at the Totenkopf, Vogtsburg/ Kaiserstuhl, and somewhat closer at Baden Baden Fremserberg, which should blast well into much of the Alsace. Certainly, when I was within walking distance of the Totenkopf but within the Rhein valley, I had no problems receiving the analogue french broadcasts with a simple indoor antenna. These may have been from Colmar, much closer. I can't imagine that the french would either try to re-use this frequency or attempt to jam it... +T 618167000 8MHz 2/3 NONE QAM64 8k 1/32 NONE My BNetzA data lists an additional frequency that neither your list, nor mine, includes: TVDRStrasbourg 40 626.000K4 As I said, I don't know how to interpret the `K4' status field to match up with today's reality. Your frequency, however, is different, and matches a second frequency used non-directionally from the Totenkopf (but this time, not in a SFN with Baden Baden). However, nearly all the modulation parameters bear no similarity to the ones you give. My BNetzA data lists another additional allocation: TVDRStrasbourg 46 674.000K4 This, like the above, is a 47dBW non-directional field, with multiplex labels such as F___F__00428, which should be situated 3 metres higher up the tower from the other existing frequencies, all of which are directional with about 40dBW, reduced by 6dBW -- somewhere I've saved graphs of the directional pattern, but I can't find them now -- the reduced strength is usually towards germany. +T 682167000 8MHz 2/3 NONE QAM64 8k 1/32 NONE +T 690167000 8MHz 2/3 NONE QAM64 8k 1/32 NONE These match the BNetzA data, and my predictions, apart from the offset. The analogue BNetzA data lists two frequencies for a `Strasbourg', one being for `Strasbourg Port Du Rhin', with the geographic data and antenna data matching the latter. No analogue frequencies are presently shown for the Alsace Strasbourg (or Elsaß, Straßburg), though one is listed for Mulhouse, which is probably what I was seeing a year or so ago, so I'm not sure whether an offset is really needed, as I have not been paying much attention to the process of switching on the digital, and eventually switching off the remaining analogue frequencies in this area... (For example, Colmar is assigned digital frequencies with vertical polarisation, directional, and about 20dBW less power toward germany, but I know only of Mulhouse and Strasbourg being in operation) +T 698167000 8MHz 2/3 NONE QAM64 8k 1/32 NONE This is not listed in the BNetzA data, but tramples on a multiplex out of Baden Baden (see 618MHz above with the same content, except that the SFN MUX is BW00864 from Baden Baden and BW00835 from Vogtsburg, which may be reflected by different NIT contents). +T 714167000 8MHz 2/3 NONE QAM64 8k 1/32 NONE This (apart from the offset) matches the BNetzA frequency data. +T 722167000 8MHz 2/3 NONE QAM64 8k 1/32 NONE Again, this frequency is in use from the Totenkopf, but with very different parameters, and so is unlikely to be reused for a MFN in so short a distance. +T 786167000 8MHz 2/3 NONE QAM64 8k 1/32 NONE This frequency is in use with similar contents to the above from the Fremserberg, with SFN MUX BW00865, or BW00840 from Vogtsburg/Kaiserstuhl. +T 794167000 8MHz 2/3 NONE QAM64 8k 1/32 NONE This matches the BNetzA data. In addition, that data includes an additional frequency in the range 61-69: TVDRStrasbourg 69 858.000AT Again, with a different `AT' status. I know that in some lands, the 61-69 range, or parts thereof, are to be reassigned from DVB-T to something else, but with all the different lands and plans, I can't remember the details... Sorry for the delay, and lack of checking against current TNT sources, as well as quoting some Bundesnetzagentur data without fully understanding the details. barry bouwsma