System composition and description
The system in Angola is a MMDS system which consists of 7 channels, using DVB-T modulation and the bandwidth for each channel is 56MHz, in total there are 90 programs.
The head-end system is used to process all the programs. First is the signal source processing, in this system we use HES-2038S H.264 Encoder to process the AV signals that is provided by the user and finally convert the AV signals into TS (transport stream). Second is Re-MUX, multiplexing the programs’ TSs into one TS. Then is scrambling, by using the HDS-3008 TS scrambler to carry out the CA with CAS together and scrambles all the programs. The last is modulating, here we use HDQ-5031 DVB-T modulator to carry out the modulation.
After modulation, then is the wireless coverage system. Here we will use a broadband MMDS system. Digital MMDS system is able to carry out digital TV signals transmission and offer abundant programs for hundreds and thousands of families, especially in the villages. It is an effective way of transmitting large number of high quality TV programs to every area. The transmitters receive RF signals from the modulators, then amplify the signals. Then by using a BT-26 wave guide to send the multi-channel signal to the antenna, and the antenna will send the signal out, to the terminal subscribers.
|Standard||Format: H.264 SD, CBR; Video bite rate/programs:1.7Mbps—2Mbps
Audio bite rate per program:192Kbps
|Frequency amount||7 frequencies, and each channel will transmit 12-15 programs It depends on program quality|
|Signal source Treatment||90|
|Modulation||Type: DVB-T, 64QAM
Symbol rate (s) = 6.75Mbaud
Max valid output code rate: 31.67MHz each channel
|CA Requires||Hooray Vision|