Simultaneous voice and Internet data on rural subscriber lines

We present the design of a system to provide rural telephone subscribers with simultaneous voice and Internet data service on a single telephone line. Simultaneous service allows a computer data connection to the Internet without impairing full use of the customer telephone station set. Our method employs a bi-directional frequency translation method together with standard “off-the-shelf” voiceband modems to implement voice and data frequency division multiplexing. Two experimental prototype frequency translators were constructed and used with 14.4, 28.8 and 33.6 kb/s modems. Operation was demonstrated on unloaded and on modified loaded lines at distances beyond the reach of ADSL equipment