Q1 A data source produces 7bit IRA charactersDerive an expre

Q.1. A data source produces 7-bit IRA characters.Derive an expression of the maximum effective data rate (rate of IRA data bits) over an x-bps line for the following:

a. Asynchronous transmission,with a 1.5-unit stop element and a parity bit.

b. Synchronous transmission,with a frame consisting of 48 control bits and 128 information bits.The information field contains 8-bit (parity included) IRA characters.

c. Same as part (b),except that the information field is 1024 bits.

Solution

a. There are 7 data bits, 1 start bit, 1.5 stop bits, and 1 parity bit, then:

g = 7/(1 + 7 + 1 + 1.5) =

= 7/10.5 =

= 0.666

R = 0.666B

b. Each frame contains 48 control bits + 128 information bits, so each

frame will have a total of:

48 + 128 = 176 bits

The number of characters is 128/8 = 16, then the number of data bits will be:

16 * 7 = 112

then:

g = 112/176 =

= 0.636

then:

R = gB = 0.636B.

c. Total bits = 48 + 1024 = 1072 bits

Number of characters = 1024/8 = 128

Number of data bits = 128 * 7 = 896

g = 896/1072 =

= 0.836

R = gB = 0.836B