Electronic Communication Systems 2nd Edition by Roy Blake

Exercise 35

An asynchronous communication system uses ASCII at 9600 bits/sec., with eight data bits, one start bit, one stop bit, and no parity bits.
(a) Explain what is meant by efficiency, and calculate the maximum percent efficiency in this system.
(b) Express the data rate in characters per second and in words per minute (assume a word has five letters and one space).
(c) Suppose a synchronous system with the same bit rate is used instead. Would you expect the number of characters per second to increase or decrease Why