Philips Electronics North America Corporation

Free Electron Technology Inc.

Srinagesh Satyanarayana

George A Melnik

Yongping Xia

Frank C Guida

Pawan Gogna

Thomas E Jednacz

A crosspoint switch architecture implements high-speed packet switches and incorporates a power-saving bias control circuit with each switch cell. Each switch cell is equipped with two memory cells and a bias control circuit. Power savings are obtained by controlling the bias current of the switch cell as a function of the switch state. Although the additional circuitry accompanying each switch cell adds complexity and a minimal additional power consumption, the power saving realized in the switch cell results in a crosspoint switch with much lower power consumption as compared to existing architectures. The presence of two bits of memory for each switch core allows for fast reconfiguration. The result is an overall power savings and lower cost design.

Crosspoint switch with reduced power consumption

A method of biasing an MOS IC includes the steps of providing the IC with two MOS transistors having substantially similar characteristics and maintaining these two transistors at different temperatures. During operation of the IC, an output voltage is generated from each of the two transistors, and a bias voltage is generated as a function of the difference between the two output voltages. This bias voltage is then fed back to the gate terminals of the two MOS transistors to set the bias voltage to a steady-state level at which the circuit will operate at a zero temperature coefficient point. This bias voltage is also coupled to the gate electrodes of other transistors within the IC, to operate these transistors at the zero temperature coefficient point. An IC operated in accordance with biasing method will exhibit superior stability with variations in ambient temperature.

Method of biasing an MOS IC to operate at the zero temperature

A method for installing a wireless network, which includes the steps of physically installing a plurality of nodes in respective different locations in a building, connecting the nodes to a power supply and powering up the nodes, using a wireless installation device to program a respective address into the nodes, using the wireless installation device to program one or more default settings into the nodes, using the wireless installation device to verify operation of the nodes, and, using the wireless installation device to dump at least information regarding the physical location and associated address of the nodes to a building computer. In a presently preferred embodiment, the wireless installation device is preferably an RF portable computer which has an RF transmitter which has a variable power setting, and an RF receiver which also has a variable power setting. During installation of each node, the RF portable computer assigns a unique address to that node, and then loads the assigned address and all appropriate default settings into that node. The address data and default settings are preferably stored in nonvolatile memory provided in each node. The wireless programming of the nodes is preferably accomplished using a software 'handshaking' procedure which ensures that the address and default setting data is only loaded into the node currently being programmed, and not inadvertently into one or more other nearby nodes. In this connection, an iterative power reduction scheme can be utilized to prevent multiple nodes from being inadvertently assigned the same address. Also disclosed is a method for installing one or more nodes in an existing wireless network, which method is performed in essentially the same manner as that described above in connection with the original installation of the wireless network itself, with the exception being that instead of an entire network of nodes being installed, only one or more nodes are installed in a pre-existing wireless network.

Method for installing a wireless network which transmits node addresses

Packets of data are transmitted over a distributed communications network formed by a number of transceivers. To minimize interference by other signals, the carrier frequency of each transmission is varied compared with the last transmission by that transceiver, for example by using a linearly sliding carrier frequency which varies continuously during periods of inactivity and while transmitting. The receivers scan the band at a rate sufficient to detect a preamble carrier burst preceding each data packet. The transceivers operate asynchronously with low data rate FSK signals, using carrier frequencies between 900 and 950 MHz.

Packet hopping system with sliding frequency, and transciever for the

Building lights are master controlled to reduce power consumption under building master control, or in response to electric utility commands to the building computer. Each lighting wall control unit includes a transceiver which can communicate to at least one neighbor transceiver, thereby forming a distributed communication network extending back to the building computer. The transceivers operate asynchronously with low data rate FSK signals, using carrier frequencies between 900 and 950 MHz. Different communications protocols control packet forwarding and acknowledgement so that messages reach their destination but are not forwarded in endless circles, and so that collisions are minimized.

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Tarrytown, NY, United States of America

Srinagesh Satyanarayana