Remote telephone line switching and testing

Abstract

Apparatus for remote switching and testing of a four-wire telephone line system is disclosed. The telephone line provides four-wire service between a first location and one or more second remote locations. The switching and testing apparatus provides the capability at the first location of controlling switching circuits at the remote location and making tests of the telephone line system including customer installed equipment. The telephone line, which will include a dedicated transmission path through at least one telephone company central office, is terminated at the respective customer premises by a terminating unit which provides a connection of customer installed equipment to the four-wire line. The customer installed equipment at one of the remote customer premises may include a plurality of modems which are connected to the four-wire lines by means of a distribution bridge and collection bridge pair, also known as a split data bridge, which serves to branch the four-wire line into a plurality of channels connected to the modems. Each channel can be provided with a tone activated detection circuit which may be separately addressed by a multi-frequency tone generator at the first customer premise. This tone activated detection circuit controls switching circuits to provide loop-back related tests such as conventional four-wire loop-back, data-streaming dropout or quiet termination, and a milliwatt test signal source in a predetermined sequence on command. Thus, each channel can be individually addressed, tested and dropped or returned to service as appropriate, all on command from the first location.