Abstract: To establish communication between a host and a client, electromagnetic field is generated across coils disposed in the devices. The magnetic field generated across the coil disposed in the host is used to power the client and to transfer data to the client. The data received by the client may, in turn, be used to configure the client. To receive data from the client, the coil disposed in the host is placed in a quiescent data recovery mode. The data to be transmitted from the client to the host generates variations in magnetic field formed across the client's coil. These variation, in turn, form variations in the magnetic field across the coil disposed in the host, and are subsequently decoded by the host to detect the data transmitted from the client. Supporting circuitry in both the host and client convert the electromagnetic variations into a stream of bits.

Abstract: A modular digital telephone system and method featuring a universal telephony shelf adaptable for incremental expansion of legacy telephone switches and as a building block in the construction of new telephony switches. The shelf includes identification and connectors for shelf pairing, and is adapted to receive redundant power supplies, plural line cards, and either a peripheral shelf interface unit or a switch array card which provides both a local shelf interface and three interface units for connection to the peripheral interface units of other shelves. System wide fault displays are provided.

Abstract: An apparatus and method for a telephone system includes a telephony switch comprising a timing and switch array card for effecting all switching and timing functions of the switch, a plurality of telephony line cards operatively connected to the timing and switch array card, and at least one power supply operatively connected to both the timing and switch array card and the plurality of line cards wherein said timing and switching functions comprise tone and conference functions, line card slot and alarm board interface functions, PCM switching functions, signal scanning and signal packet transfer buffer support functions, host computer interface functions, and clock and synchronization functions.

Abstract: A modular digital telephone system and method featuring a universal telephony shelf adaptable for incremental expansion of legacy telephone switches and as a building block in the construction of new telephony switches. The shelf includes identification and connectors for shelf pairing, and is adapted to receive redundant power supplies, plural line cards, and either a peripheral shelf interface unit or a switch array card which provides both a local shelf interface and three interface units for connection to the peripheral interface units of other shelves. System wide fault displays are provided.

Abstract: A modular digital telephone system and method featuring a universal telephony shelf adaptable for incremental expansion of legacy telephone switches and as a building block in the construction of new telephony switches. The shelf includes identification and connectors for shelf pairing, and is adapted to receive redundant power supplies, plural line cards, and either a peripheral shelf interface unit or a switch array card which provides both a local shelf interface and three interface units for connection to the peripheral interface units of other shelves. System wide fault displays are provided.

Abstract: Telephone loop feed apparatus in which a hybrid couples audio signals to and from the subscriber loop and presents a high impedance to the loop relative to the loop impedance. DC power is coupled to the loop by matched resistors which determine the loop feed matching resistance. DC power is blocked from the hybrid to avoid saturation.