Abstract: This invention makes it possible to communicate through solid non-metallic walls or ceilings with low microwave power levels. RF beam forming couplers are driven by common networks. For connection to a LAN segment at the other side of a wall or ceiling, transceiver 4 transmits data modulated microwave RF to coupler 6 through a directional step attenuator 10. The reduced signal is received by the coupler system at the other side with a power level low enough to eliminate wireless detection from the outside. However, the directional step attenuator on the receive side reduces the signal power only by an insignificant amount due to its low directional losses during receive signal flow. Each coupler's geometry is minimizing the radiation exposed material volume by RF field concentration, therefore, enabling transmission through thick concrete walls at microwave frequencies without compromising privacy. When used as wireless access point, coupler transmits through a floor to wireless devices below.

Abstract: This invention makes it possible to communicate through solid non-metallic walls or ceilings with low microwave power levels. RF beam forming couplers are driven by common LAN (Local Area Network) circuits.

Abstract: This invention removes the requirement of cable interconnections to local area network (LAN) nodes with wireless optical relay stations suitable for high data rates. Relay sections are equipped with IR transmitters, receivers and narrow beam optics. Manual beam alignment during the LAN installation is aided by a visible light beam of equal beam width and direction. Rotational freedom of the optical antenna systems provide precise aiming. Structure couplers extend, by low-power RF coupling through nonmetallic wall and ceilings, the wireless data transmission from a single room to rooms and building floors. Shielding and wall gaskets of the structure couplers eliminate RF radiation penetration and leakage, and therefore prevent eavesdropping and jamming.

Abstract: Described is an intraoffice communication system as the final communication link of a broadband, baseband, or fiber optic LAN. Each user or workstation is a node on the network and can transmit at high data rates with bit error rates of .ltoreq.10.sup.-9 in packets through the LAN. Message relaying transponders are placed on the ceiling and walls communicating by electromagnetic waves to individual workstations by broadcast. A novel multipath rejection scheme is combining transponder placements with pseudonoise coding for robust and secure data transmission. For the present state of the art if infrared is used, we estimate a minimum light collecting aperture (receive antenna) of 1 cm.sup.2 for transmission rates of 30 to 100 Mb/s.