T2-MI is a special data transmission format used to deliver DVB-T2 multiplexes via satellite. On some satellites, these streams carry actual TV channels that can be received directly by a satellite receiver.
This makes T2-MI support a useful feature in a modern satellite receiver, especially for users interested in receiving less common satellite feeds and exploring different types of satellite transmissions.
How Does T2-MI Work?
In simplified form, the signal path looks like this:
satellite → DVB-S2 → T2-MI → TV channels → satellite receiver → TV.
T2-MI was originally designed to carry the data required to generate a terrestrial DVB-T2 signal. However, these streams can be transmitted via satellite and may contain television programs. With the appropriate support, a satellite receiver can receive the T2-MI stream, extract the DVB-T2 multiplex, and decode the channels it contains.
Where Can You Find T2-MI?
T2-MI streams can be found on various satellites. For example, such streams have been used at the 4.8/4.9°E and 53°E orbital positions. Depending on the particular transponder, they may carry different television packages.
This is why you may sometimes find a satellite signal but see no TV channels on a conventional receiver. The reason may be that the signal is not a standard DVB-S2 transport stream but a T2-MI stream.
Are T2-MI and Multistream the Same Thing?
No. T2-MI and Multistream (MIS) are different technologies, although they are often used together in satellite transmissions.
Multistream allows several independent streams to be transmitted within a single satellite signal. The required stream is selected using the ISI parameter. PLS may also be required.
One of these streams may contain T2-MI. As a result, when tuning some satellite transponders, you may need to specify several parameters, including MIS, ISI, PLS, and T2-MI.
Why Doesn’t a Standard Receiver Show These Channels?
The main reason is a lack of T2-MI support. A receiver may be able to receive the DVB-S2 satellite signal normally but still be unable to extract the television channels carried within the T2-MI stream.
Therefore, if you are buying a receiver specifically to receive these types of satellite feeds, you should check not only for DVB-S2/S2X and Multistream support, but also for full T2-MI support.
What Do You Need to Receive T2-MI?
Depending on the particular satellite stream, you may need support for:
— DVB-S2 / DVB-S2X;
— T2-MI;
— Multistream (MIS);
— ISI;
— PLS;
— PLP.
However, Multistream support alone does not mean that a receiver supports T2-MI. T2-MI is a separate feature, so you should check the specifications of the particular receiver model and its firmware.
Who Needs T2-MI Support?
T2-MI is not required for watching most satellite TV channels. However, if you are interested in satellite DXing, looking for additional TV packages, or want to receive television channels that are transmitted via satellite using T2-MI, this feature can be very useful.
The important thing to remember is that T2-MI is not simply service data intended for terrestrial transmitters. On some satellites, T2-MI streams carry actual television programs, and with a compatible receiver, these channels can be received and watched directly from the satellite.