Direct-to-Home (DTH) satellite television is becoming a buzzword in the satellite
broadcast industry due to the fact that DTH offers immense opportunities to both broadcasters and viewers. Thanks to the rapid development of digital technology, DTH broadcast operators worldwide have been able to introduce a large number of new interactive applications in the television market besides a large number of entertainment programmes over a single delivery platform. In addition, since digital technology permits a highly efficient exploitation of the frequency spectrum, the number of TV channels that can be broadcast using digital technology is significantly higher than with analogue technology. The increased number of television channels allows the operator to satisfy the demand of a number of niche markets with dedicated transmissions.
In general, DTH service is the one in which a large number of channels are digitally compressed, encrypted and beamed from very high power satellites. The programmes can be directly received at homes. This mode of reception facilitates the use of small receive dish antennas of 45 to 60 cm diameter installed at convenient location in individual buildings without needing elaborate foundation /space etc. Also, DTH transmission eliminates local cable operator completely, since an individual user is directly connected to the service providers. However, a digital receiver is needed to receive the multiplexed signals and view them on a TV. DTH, in sharp contrast to Cable TV, lends itself to easy monitoring and control.
Transmission in Ku band is most appropriate and widely used for the purpose. As mentioned above, all the encoded transmission signals are digital - thus providing higher resolution picture quality and better audio than traditional analog signals. All the advantages of the digital transmission, as applicable to the terrestrial transmission are relevant in the satellite transmission also.
DOWNLINK PARAMETERS OF DD-KERALAM/DD MALAYALAM DTH SERVICE
SATELLITE
| INSAT 4B |
LOOKING ANGLE |
93.5 Degree East
|
| 10990 MHz Vertical
11150 MHz Vertical 11490 MHZ Vertical
11570 MHZ Vertical |
SYMBOL RATE | 27500 KSPS or 27.5 MSPS |
FEC | ¾ |
