Foros ZackYFileS - ABERTIS sur HISPASAT 30°W Atlas WHD 200s

Para información general
Fuente Blog Enigma2.

1. Some terrestrial transmitters for National channels are fed through satellite that distributes the signal throughout the country, with the majority of Autonomical and Local channels being transmitted via fibre relays instead. To facilitate users that have no terrestrial reception, the provider also made possible the direct-to-home reception of its satellite feeds, using specific receivers of closed source. Up to this point and to make sure these channels are exclusive to the official receivers, Abertis uses a special transmission system for its channels, called TLS. I will try to explain this method as simply as I can, with any room for corrections welcome by all means! Also, please make sure to read the disclaimer below (part 5 of this presentation).

2. Transponder Layer Scrambling
TLS stands for Transponder Layer Scrambling. Contrary to PLS (Physical Layer Scrambling) which is known in the Multistream technology and requires special tuners to decapsulate with no further audio/video encryption, TLS works in a different way. The complete Transponder Stream (TS) which contains all package data (tv channels, radio, teletext, epg etc) is being encapsulated within a certain PID of a satellite transponder. Each transponder can contain multiple PIDS and each PID carries inside it a different TS. In addition and to make the decapsulation a difficult task, an encryption is applied not directly to the contents of each TS individually (as in regular transmissions) but to the whole PID which encapsulates each TS. This way the content of the PID is difficult to read as there is no direct PMT. A standard DVB-S2 receiver will either download nothing or a data channel which corresponds to the encrypted PID. Even professional programs and analyzers can only see a data stream within the encrypted PID without further recognizing the contents.
This transmission method resembles in a way the structure of an onion. The outer layer is the satellite transponder which is tuned normally with any DVB-S2 receiver, the layers below are the PIDS of this transponder and the layers inside are the TS within each PID. The encryption is being applied in the middle layer and this makes the inner layer unreadable. For reference the encryption used is the standard BISS. Each PID can have another BISS code applied to it, and this is exactly the case.

3. The idea behind the decapsulation
As explained above each PID is BISS encrypted. This scambling makes impossible to read the contents of the PID resulting in a data output rather than a PMT with the TS contents. So the basic idea would be rather simple. If there is a way to apply the decryption to the PID directly, then the PMT contained will be unlocked and this will give subsequently access to the rest of the TS data and reveal the channels contained in it. As simplistic as it sounds, there is a catch. In PCs this is easier to do using pipe. But in Enigma2 and with any software requiring an Audio/video pid to apply the decryption to, where is that special pid within this PIDS labyrinth? In simple words, how to decode if you don't have nothing visible to decode?
The SDG team gave a solution to this riddle, by patching Enigma2 in a way to permit a service attach more special pids to its contents. This will give the required data for decoding the whole encapsulated PIDs. Indeed, once the decryption is applied then the PMT is out and not-so surprisingly the channels inside are all in clear. Quite ironic actually if one has to think you have to decode something to get what is FTA in reality.

4. The use in Enigma2
As these channels have to be decapsulated (the very same idea is applied to T2-MI minus the decryption), it was not possible (at the moment) to have these channels downloaded to the receiver as normal channels. The only way to go is to re-feed these streams within the STB through internal relay as well. This method was thoroughly explained in the T2-MI how-to. In short, the Satellite Transponder data channel acts as a source and via specially edited lamedb entries and a corresponding script that strips the headers through the Astra-SM project, the channels are being led to a favourites stream user bouquet which is ready to watch on your E2 STB running the SDG image. Note again that this is indirect satellite reception and no IPTV, it's internal stream relay with no internet required at all. The main difference to T2-MI is that in order to get a working PMT running in real time, you have to additionally run a softcam along with the required biss codes. The only softcam that supports decoding of additional pids is oscam-emu and no other.

5. What you will need
i. First you need to have an E2 receiver with a supported experimental SDG image or Open ATV image , you can download from here.

ii. After you have setup the image, make sure to have good reception. It's important to note that Abertis transmits in various transponders with noticable differences in power, with the lower frequencies being generally stronger than the higher ones. In addition, for stable reception at least 10db (more than 60%) signal is required. This can cause problems in smaller dishes or/and offset LNBs. In general I estimate that for Western Europe an 80cm dish should suffice marginally for all transponders (easier near Spain of course). In Northern Greece I'm having some trouble with some transponders being very marginal during the daytime on my 1.30 although reception is 24/7 stable. Abertis uses Hispasat on 30W, except one transponder for Aragon TV which is on Hylas at 33.5W which is easier to catch within the whole Europe (and can even be received from 34.5W as well with a bigger dish).

iii. Download/create the source data channels. This can be done either via dreamboxedit or lamedb editing. Since the transponders are fixed I made a ready to go lamedb that has to be merged in your existing lamedb. Open your lamedb and add the following lines. Make sure the transponders section is added under your existing transponders section, and the services section under your own. I also include a lamedb ready at the end of this tutorial.
Make sure to completely reboot your STB after merging/editing your lamedb in order for changes to stick.