04-08-2012, 01:00 PM
Digital Communication Systems.
[attachment=30212]
Digital Communication advantages
Reliable communication; less sensitivity to changes in environmental conditions (temperature, etc.)
Easy multiplexing
Easy signaling
Hook status, address digits, call progress information
Voice and data integration
Easy processing like encryption and compression
Easy system performance monitoring
QOS monitoring
Integration of transmission and switching
Signal regeneration, operation at low SNR, superior performance
Integration of services leading to ISDN
Digital Communication System Disadvantages
Increased bandwidth
64 KB for a 4 KHz channel, without compression (However, less with compression)
Need for precision timing
Bit, character, frame synchronization needed
Analogue to Digital and Digital to Analogue conversions
Very often non-linear ADC and DAC used, some performance degradation
[attachment=30212]
Digital Communication advantages
Reliable communication; less sensitivity to changes in environmental conditions (temperature, etc.)
Easy multiplexing
Easy signaling
Hook status, address digits, call progress information
Voice and data integration
Easy processing like encryption and compression
Easy system performance monitoring
QOS monitoring
Integration of transmission and switching
Signal regeneration, operation at low SNR, superior performance
Integration of services leading to ISDN
Digital Communication System Disadvantages
Increased bandwidth
64 KB for a 4 KHz channel, without compression (However, less with compression)
Need for precision timing
Bit, character, frame synchronization needed
Analogue to Digital and Digital to Analogue conversions
Very often non-linear ADC and DAC used, some performance degradation