CATV Digital TV Broadcasting System Overview

The digital cable TV (DVB-C) system is composed of encoder, multiplexer, CA system, EPG, other value added system.. It.is applied to the programs record, management, broadcasting control, A/V encoder, data protocol transform, TS multiplex.

CATV Digital TV Broadcasting System Application
The solution is applicable for all DTV operators and companies to establish the DTV headend system.

CATV Digital TV Broadcasting Solution Features
1. The Digital TV headend system solution is designed customized for operators, which is the best high performance system.

2 Support various CA system, and the same key operation.

3 All equipments is designed in modules, it can be optical according to customers?demand, which is much more flexible for operation. For example, the DMB-9000 professional IRD can increase the CAM module to support descrambling function.

4 High correction ability, low bit error rate, highly reliable in receiving.

5. The multiplexer supports two independent output channel, which can choose 1-8 MEPG-2 signal output or multi-program output.

CATV DTV Signal Testing Solution

System in details

1. Program Source
At precent, DTV operators and companies get the TV programs mainly from: Satellite, upper ground SDH network, self-running programs.

1.1 Satellite
The DMB-9000 DVB-S Professional IRD receives the RF signal directly from satellite, and demodulate the RF signal to TS stream, which is multiplexed by the multipexer with other TS stream.

1.2 SDH network
Generally, most of the TV programs are from the upper ground SDH network, the TV programs pass by the DS3 network adapter to convert the DS3 signal to ASI, it adapts the E3 signal from DS3 channel to TS stream, which then is multiplexed with other TS in Multiplexer.

1.3 self-running programs
The self-running programs are all in A/V signal, which is encoded by the DMB-9300 or DMB-9310 MPEG-2 Encoder to TS stream, and is multiplexed with other TS in Multiplexer.

1.4 EPG
DTV EPG PIS/IS is transmitted by TSD-1028 1 to 16ASI distributor, then each distributed EPG information will be multiplexed with TV programs.

2 TS Steam Multiplexing
In order to make the TS convenient for transmitting, all TS stream of TV programs are multiplexed, in addition, the EPG and other value added broadcasting TV system should be inserted into programs, in this case, our DMB-9100 and DMB-9110 Multiplexer is the best choose.

3 TS Scrambling
It is mainly aimed to scramble the TV programs, it is make up of scrambler, SMS and CAS.
To scramble the TV programs is to scramble the TS, control word business key and the business key to protect.

4 TS Modulating
After scrambling the TS, in order to reduce the loss in long distance transmitting, the TS stream need to be modulated to RF signal. In the DVB-C system, our DMB-5000 and DMB-5100 QAM modulator can meet you expectation.

5 Signal Transmitting
Upon modulating, all RF signal will be mixed by the mixer, the mixed RF signal will be transmitted by transmitter into the HFC system.

6 Signal Receiving

At the terminal, end-users can use the DVB-C receiver and TV set to watch all DTV programs available.
The RF signal is downconverted by tuner to baseband signal, which is descrambled and decodered into A/V signal to pass to the TV set to allowed the end-users to watch TV programs.