Addressable or store-and-forward MPEG RX

[mbarnes]

I was looking at the notes for the NASA TV digital transition. http://www.nasa.gov/multimedia/nasatv/digital.html

They mention that some of their programming may be addressable. They also mention the use of a store-and-forward (ala DVR/PVR?) receiver.

Is there anything available in the affordable consumer market that has either of these capabilities?

It looks to me like most anything digital subscription-wise is going DCII, not DVB/MPEG. Are there any subscription type channels on MPEG?

Can an addressable DVB/MPEG receiver still be an FTA unit?

 

[Mr Tony]

Globecast is the most common subscription DVB servcie. They are on IA5 (T5). Lots of ethnic stuff.

Yes there are boxes that can get both. The Pansat 3500 (just reviewed) will accept a card for Globecast

 

[tvdxer]

I was looking at the notes for the NASA TV digital transition. http://www.nasa.gov/multimedia/nasatv/digital.html

They mention that some of their programming may be addressable. They also mention the use of a store-and-forward (ala DVR/PVR?) receiver.

Is there anything available in the affordable consumer market that has either of these capabilities?

It looks to me like most anything digital subscription-wise is going DCII, not DVB/MPEG. Are there any subscription type channels on MPEG?

Can an addressable DVB/MPEG receiver still be an FTA unit?

The normal NASA TV channel will always be free and visible on any old DVB receiver.

The "addressable" stuff is special content directed towards educational facilities and the like, I think, so you might have to be one of these entities to get it.

 

[rkrenicki]

store-and-forward sounds like VOD feeds.. where the feeds are stored on a set of hard drives for future recall by client STBs..

As far as I know, the addressable stuff is going to be PowerVu encrypted. I do not believe you can have both DC2 and DVB on the same transponder. I suppose its possible that its going to be Wegner encrypt, but PowerVu stuff is more prevolent for educational installations.

 

[mbarnes]

I do not believe you can have both DC2 and DVB on the same transponder.

There is no reason whatsoever to not have both DCII and DVB on the same transponder. One of the prime reasons to go with MCPC digital carriers is to get more programming in less bandwidth. A transponder is typically 36 MHz wide. Depending on the format used, you may get several or dozens of users on a given transponder. Keep in mind, the listings you see on lyngsat and similar only show a fraction of the actual users of these spacecraft. So, you could easily have a DVB signal from one provider take up 10 MHz with several TV channels and have another provider using another 10 MHz of DCII channels and have a whole bunch of users on the other 16 MHz.

 

[rkrenicki]

...... again, when I say transponder, I mean digital carrier.. while yes, you can have multiple digital carriers in the space of one 36mhz wide analog transponder, since this isnt an analog discussion, its a moot point

in a single carrier, located at 4040 V 26665, the encapsulation and encoding method is DVB.. now, you cannot use DCII encrypt over DVB, as the encapsulation will not line up.

If NASA decides to put another digital carrier in the same 36mhz wide space, then sure, they can put a DCII signal down the same "transponder"

Now, since they have only announced this one carrier, and that the addressable portion will be in THIS one, the assumption can be safely made that a DVB encapsulated encryption is used, such as PowerVu, Irdeto, Nagravision, Wegner, etc..etc..

 

[Mr Tony]

you can only have DVB OR DCII on a transponder

yes there can be numerous transponders within the channel (using the old analog theory where it was 1:1, digital can have 3 or more transponders in that area.)

What ulta was saying is you can't have both DVB & DCII at say 12020 V 20000....you can have DVB at 12020 V 20000 and DCII at 12025 V 20000

 

[mbarnes]

you can only have DVB OR DCII on a transponder
yes there can be numerous transponders within the channel (using the old analog theory where it was 1:1, digital can have 3 or more transponders in that area.)

Actually, you have it backwards. You can have numerous channels on a transponder.

Here's the deal. A transponder is a physical piece of equipment consisting of a receiver and transmitter. It receives everything it hears in a 36 MHz wide span, regardless of modulation type or format. It then transposes (or retransmits) the received signal to another frequency, in essence, relaying the signal exactly as it was originally broadcast. On a given spacecraft and band, there are typically 24 transponders, 12 on the vertical polarity and 12 on the horizontal polarity. In the early days of satellite communications, a typical television analog channel took a full 36 MHz transponder, hence there was a relationship between transponder and received channel. With the advent of digital transmissions, VSAT, SCPC, MCPC, etc. there may now be many users on a given transponder. In the satellite industry, these individual signals are normally referred to as carriers, although some users/providers may refer to them as channels. With space segment in high demand these days, and the effort to generate as much revenue as possible, satellite vendors will squeeze in every available kHz of bandwidth they can. Therefore, the old analog way of thinking of channels rarely fits.

The point is, when discussing apples and oranges, it is important to call apples, apples, and oranges, oranges. When you start calling apples oranges and oranges apples, confusion may be generated.

 

[Mr Tony]

The point is, when discussing apples and oranges, it is important to call apples, apples, and oranges, oranges. When you start calling apples oranges and oranges apples, confusion may be generated.

I have no clue what the rest of the post said so I'm confused

 

[rkrenicki]

I think those poor apples and oranges have been squeezed to death..

We all have our own perspectives on this, and pushing the issue does not really help either side.

The point made is that you cannot have DCII encryption on the same digital carrier that contains a DVB carrier. Since they have one carrier, which is already DVB, the encrypt will be a DVB compliant encrypt.

I hate to put it this way, but the only person who is confused is you, while your point is valid, it simply generates more confusion for the average person here. while yes, a Transponder is a specific transmitter on a satellite which has a 36mhz wide bandwidth, The term can also be used for a specific diigtal carrier coming from said transmitter.

The transponder numbers are only used (on the recieving side of things) for analog channels. Since this is a DVB discussion, the point is moot.


For simplicity sake, I really suggest that this discussion gets dropped