Abstract: An optical wireless network system is disclosed. A transmitter (45) includes a laser (36) for generating a light beam that is reflected from a micromirror (42) toward a receiver (27). The receiver (27) includes a lens (28) for receiving the incident light (I) and directing the light to a photodiode (34). A reflective ring (30) surrounds the lens (28) at the receiver (27), to reflect light back to the transmitter (45). The reflective ring (30) is preferably formed of corner cube elements (40) so that the light is reflected back toward its source, over a range of angles of incidence. A photodiode (48) at the transmitter (45) receives a signal that is applied to control circuitry (52) which in turn controls the aim of the mirror (42) in response to the reflected light (R), so that the aim of the mirror (42) may be optimized.

Abstract: A communication system is connected to a pair of telephone conductors which supply telephone service to a telephone subscriber. An optically coupled switch connects a first winding of a transformer across the telephone conductors. A second winding of the transformer is connected to a modem for communicating over the telephone conductors via the transformer. A voltage sensor circuit senses the voltage across the telephone conductors and detects a reduction in the voltage level across the conductors which indicates an off-hook condition of a telephone unit of the subscriber connected to the conductors. The voltage sensor circuit also detects the presence of a ring signal on the conductors. The switch is periodically opened so as to disconnect the transformer from the telephone conductors, and permit the voltage sensor circuit to check for an off-hook condition.