8) This describes the essential skills and knowledge and their level, required for this unit. Evidence shall show that knowledge has been acquired of safe working practices and diagnosing and rectifying faults in digital transmission systems. All knowledge and skills detailed in this unit should be contextualised to current industry practices and technologies. KS01-EH180A Digital television transmission faults Evidence shall show an understanding of advanced digital television principles, digital television transmission towers and equipment and digital television transmission faults, applying safe working practices and relevant Standards, Codes and Regulations to an extent indicated by the following aspects: T1. Audio component encompassing: Audio Encoding Audio Masking Audio sub band encoding T2. Dolby AC-3 T3. MPEG-2 System Layer encompassing: PES Packet Construction Time Stamps Programme Clock Reference (PCR) Transport Packet Header Programme Specific Information (PSI) T4. Channel Encoding Forward Error Correction (FEC) Bit Error Rate (BER) Puncturing T5. Interleaving. T6. Modulation Phase Shift Keying (PSK) Quadrature Amplitude Modulation (QAM) Orthogonal Frequency Division Multiplexing (OFDM) Coded Orthogonal Frequency Division Multiplexing (COFDM) T7. Hierarchical Modulation. Terrestrial Channel Encoder Satellite Channel Encoder Carrier to Noise Ratio (C/N) T8 Single Frequency Networks Guard Interval Megaframes T9. The requirements of DTTB program input and monitoring equipment encompassing: basic system arrangement - Example is a central router connected to a number of control rooms. Terminologies - Examples are Vertical, Multi-level; Tie-line Routing and cross point typical signal types processed by a router. the purpose of "redundant CPU's and power supply units". common control protocols used in routers. typical analogue audio and video output voltage levels present at the router. typical specifications for digital data signals present at the router. function of various test equipment used in DTTB measurements. T10. The operating characteristics of a digital television terrestrial broadcast (DTTB) transmitter encompassing: typical DTTB digital transmission system. safety precautions required when working with high power RF transmitters. operating characteristics of a typical MPEG encoder. operation of a coded orthogonal frequency division multiplex (COFDM) modulator. arrangement of subsystem components in a DTTB transmitter purpose of an up converter in a DTTB transmitter. typical characteristics of a DTTB power amplifier. advantages and disadvantages of air and liquid cooling systems used in transmitters. typical DTTB transmitter measurements techniques. T11. The performance requirements of the DTTB combiner and antenna systems encompassing: minimum channel separation required between digital and analogue TV channels typical specifications of an antenna combiner system. the need for combiner systems in DTTB systems. typical system faults in combiners and antenna system. T12. The requirements of remote monitoring and measurement equipment encompassing: purpose of control panel indicators and controls. Process by which the system manages a critical failure. -Example of component failure deemed as critical are power supplies and CPUs different system alarm signals. periodic equipment self tests and diagnostic routines on DTTB systems. DTTB systems fault diagnostic and rectification techniques. function of the basic components of a DTTB system. typical units of a DTTB Telemetry system |