Measurements of narrow-band noise on telephone facilities in connection with analog data

The recent growth of automation and the handling of data by machines have resulted in a growing need for data communication between terminals separated by many miles. Both the trend toward decentralization of business and the tendency toward centralized data-processing centers have contributed to this need. One solution to the problem of providing effective data communication is to use the telephone network which makes the interconnection of almost any two points in the country feasible.