Patent ID: 6184798
Filing Date: 2001-02-06
Classification: G08C

Abstract:
A unidirectional telemetry system comprising:a monitoring receiver operative to receive transmitted packets over successive frames, each frame being constituted by a plurality of equal length time slots, without acknowledging receipt of any of said transmitted packets; anda plurality of beacons, each beacon including a transmitter operative to transmit packets autonomously relative to any transmitter of any other beacon, and each transmitter being operative to transmit packets asynchronously relative to said monitoring receiver;wherein each said transmitter is operative to transmit a given packet a plurality of times within a corresponding frame, with each packet transmitted by a respective transmitter being transmitted within any one of said time slots and retransmitted at random times within said corresponding frame;wherein random collisions between packets transmitted and retransmitted by corresponding transmitters occur during a frame, a frequency of random packet retransmission being selected in accordance with packet length and total number of transmitters to obtain a sufficiently small probability of jamming as to ensure receipt by said monitoring receiver of information contained in each transmitted packet; andwherein no beacon receives an acknowledgement that any transmitted packet has been received by said monitoring receiver.