Abstract: Access to a radio communications medium shared by at least two agents to provide peer-to-peer communication therebetween is controlled by sensing the communications medium at a first agent to determine if the communications medium is in use, transmitting from the first agent, if the first agent determines that the communications medium is not in use, a request-to-send message that includes reservation duration information, and receiving the request-to-sent message at a second agent. The second agent then transmits a clear-to-send message including reservation duration information on behalf of the first agent, after which the first agent then transmits information to the second agent while a reservation duration indicated by the reservation duration information has not elapsed. A possible third agent within receiving range of only one of the first and second agents is thereby guaranteed to receive the reservation duration information and is expected to observe the reservation according to rules disclosed.

Abstract: A spread spectrum radio communication system includes a generator for generating a pseudo-random chipping sequence, a frequency spreader for combining digital data with the pseudo-random chipping sequence to produce a spread spectrum signal, a modulator for modulating the spread spectrum signal for broadcasting over a predefined frequency band, a demodulator for demodulating broadcast spread spectrum signals, a de-spreader that employs single bit quantization and oversampling for digitally correlating the output of the demodulator means with a pseudo-random chipping sequence, and an extractor for extracting clock and data signals from the output of the de-spreader. The chipping sequence is normally selected from a set of codes including an eleven-bit Barker code, its inverse and reversals of the inverse and non-inverse code.

Abstract: A synthesizer capable of generating a multiplicity of output frequency signals with 1 hertz resolution utilizing binary mathematics in a binary circuit. The apparatus includes providing to an accumulator a stable reference input signal having a frequency value of K, a defined value of 2.sup.N where N is an integer, a rollover value R equal to 2.sup.N minus the synthesizer modulus M and a desired output frequency signal having a value V selected from the range of integer values between 1 and K. The accumulator, at the rate of K, periodically increments the accumulator contents A by the value V, until the accumulated value exceeds 2.sup.N -1. The accumulator's content A is then set at the next cycle of the reference input signal K to a value of A-2.sup.N +R+V. A convertor converts the values of A into an output signal. In the preferred embodiment, the accumulator includes digital circuitry having 2.sup.N capacity and performs binary arithmetic to accomplish the accumulations.

Abstract: A switch for providing signals indicating the position of a rotary shaft has an enclosed switch chamber. Within the chamber is at least one magnetically actuated switch device. A switch actuating magnet is mounted in a holder exterior of the chamber and coupled to the switch through a wall of the switch housing. The holder is flexibly mounted to the housing and connected to the rotary shaft. The magnet is held in a constant rotational plane with respect to the switch.

Abstract: A shaft position indicator in which the mechanical position of switch actuation is variable with the control of the switch actuators. The switch actuators are controllable through a series of setable cam operated screws or non-mechanical contacts that intercept the switch actuators as they are moved from one position to another, the movement of the cam operated screws overlapping the travel of the switches during one revolution of a lead screw moving the cam operated screws. The input shaft rotation is field adjustable to accept input rotations from 1 to 25 or more revolutions, resulting in accuation of the switch in output performance.

Abstract: A switch device (10, 10') which is responsive to various pressures is disclosed. The device (10, 10') includes a housing (18, 18') and plurality of switches (102, 104, 106, 168, 170, 172). A flexible diaphragm (40, 40') is supported external of the housing (18, 18') and has a first face adapted to face a pressure source and a second face facing an external wall (56, 56') of the housing (18, 18'). A plurality of first magnets (46, 48, 50, 182, 184, 186) are connected to the diaphragm at different locations thereon. A plurality of second magnets (108, 110, 112, 174, 176, 178) are supported in the housing and are each connected to one of the switches for activating a respective switch. Each of the second magnets is disposed adjacent one of the first magnets to form a plurality of pairs of first and second magnets whereby the motion of one of the first magnets of one of said pairs causes the second magnet of said last-mentioned pair to move and activate one of the switches to which it is connected.