Question

What is the percentage overhead of a system that sends 12 seven-bit ASCII characters as a block proceeded by 1 start bit, then followed by 1 parity bit and 14 stop bits? The bit time for this system is 0.000625 seconds per bit. Provide your answer with no units and give two places after the decimal point (yes you need a decimal point in this case). Do not provide units and do not use the % symbol, though you should give your answer as a percentage.

Answer 1

Total number ofASСП blocks Size of each block 7 bits Start bit-1bit Parity bit for each block- 1bit Number of stop bits 14 bits 12 Total number ofbits Start bit + 12(Size of each block+ Parity bit)+Number of stop bits 112(7+1)+ 14 = 1 + 96 + 14 Overhead bits - Start bit 12 (Parity bit) + Number of stop bits 1+12(1)+ 14 =27 Overhead percentage of a system (Overhead bits/ Total number of bits)*100 27 x100 0.243243 x100 24.3243 24.32 To send 12 seven-bit ASCII characters as a block preceded by 1 start bit, followed by 1 parity bit and 14 stop bits, the overhead percentage is 24.32. The time required to transmit one bit -0.000625 sec per bit Time required for transmitting total number of bits: -111x0.000625 0.069375 Time required for transmitting overhead bits =27×0.000625 0.016875 Calculate the overhead time percentage of a system as below: 0.016875 0.069375 0.243243 x100 X100 - 24.3243 24.32 To send 12 seven-bit ASCII characters as a block preceded by 1 start bit, followed by 1 parity bit and 14 stop bits, the overhead time percentage is 24.32.