Abstract: A technique for enabling a peregrinating Cellular Mobile Radiotelephone (CMR) subscriber to automatically receive, in a foreign service area (that is, an area outside his home service area), calls placed to his MID at his home service area. A roaming processor is coupled through a cable or LAN to a switch associated with a foreign MTSO and is coupled, preferably through a private data network, to a switch associated with the subscriber's home MTSO. Within the roaming processor resides a program that detects the reception at the foreign switch of a predetermined code indicating that calls placed to the roamer's home MID are to be forwarded to the foreign MTSO. Subsequent to the "validation" of the roamer and to the performance of certain software housekeeping tasks, the roamer is assigned a Temporary Directory Number (TDN) for use in the remote service area. The FMR processor then commands the subscriber's home MTSO switch to forward calls, placed to the subscriber's MID at the home MTSO, to the TDN.

Abstract: A remote isolation apparatus includes double-position switch for selectively coupling or isolating a telephone company central office and a multi-wire subscriber line. The switch operates according to a remotely originated activating signal so that, until the switch is operated, the central office is connected to the subscriber line through normally closed contacts. When the switch is operated, the central office TIP and RING leads are coupled to a reference terminal, and the central office is isolated from the subscriber line.The apparatus includes circuitry for detecting the application of an activating signal to the line and for optically coupling a resulting trigger signal to a pair of monostable timers. The timer output pulses are arranged so that the relay is energized subsequent to the removal of the activating signal and remains energized during an interval established by the relative durations of the timer output pulses.

Abstract: An apparatus for enabling the performance loop resistance and DC balance checks on a subscriber line includes relay contacts coupled across the line terminals. The apparatus includes circuitry for detecting the application of an activating signal to the line and for optically coupling a resulting trigger signal to a pair of monostable timers. The timer output pulses are arranged so that the relay is energized subsequent to the removal of the activating signal and remains energized during an interval established by the relative durations of the timer output pulses.