The station provides the DD free dish to Doordarshan which is a multichannel free to air Direct to Home service (DTH). It has the capacity of 80 SDTV channels along with 32 Radio channels. It is available in Ku band on GSAT-15 having MPEG-2 DVB-S, 5 streams of channels with downlink frequencies 11090,11170,11470,11510 and 11550 MHz. For Andaman and Nicobar islands a separate DTH service in C band is available. Doordarshan intends to transmit 10 digital channels using one transponder bandwidth. This is achieved by providing a digital uplink facility for 10-channel system with major equipment in sufficient redundancy configuration i.e. IRDs in (10+1) configuration encoders in (10+1) configuration, and multiplexer, modulator, up converter, equalizer and HPA in 1+1 configuration. The channels to be uplinked are derived using a C-band receive antenna along with LNBC and professional digital satellite receiver (IRD). The 10 channels up linking are derived from turnaround channels i.e. the channels that are already on air are received and retransmitted after multiplexing. In-house generated programs can also be fed to the system input. These channels are multiplexed and QPSK modulated at 70 MHz This modulated stream is up-converted to C-band and further amplified by HPA and transmitted by 7.6 meter C-band antenna. |