Multiple access communication system for moveable objects
First Claim
1. A communication system comprising several moving participants (20, 21, 22, 23, 24, 25) that are each equipped with a communication device (10) for exchanging information having a transmitter, transmissions from said transmitter, and receiver (1, 2) characterized by a method, for detecting free transmission periods (8) which control the transmissions of the transmitter (1);
- means for detecting transmission periods by a transmission detector (8), its input (15) being connected to a first output (16) of the receiver (2) and its output (14) being connected with a first input (13) of the transmitter (1);
the transmission detector (8) scanning, within a predictable window of time, for the appearance of transmissions initiated by other participants with the receiver (2) and releases the transmitter (1) for communicating navigational data if such transmissions do not appear.
1 Assignment
0 Petitions
Reexamination
Accused Products
Abstract
A non-complex low cost communication, navigation and identification system and method for use with moveable or stationery objects on the same frequency without interference. The present invention listens before each transmission and transmits only when there are no other protocols transmitting, thus avoiding communication collisions and supporting high channel load scenarios.
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Citations
14 Claims
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1. A communication system comprising several moving participants (20, 21, 22, 23, 24, 25) that are each equipped with a communication device (10) for exchanging information having a transmitter, transmissions from said transmitter, and receiver (1, 2) characterized by a method, for detecting free transmission periods (8) which control the transmissions of the transmitter (1);
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means for detecting transmission periods by a transmission detector (8), its input (15) being connected to a first output (16) of the receiver (2) and its output (14) being connected with a first input (13) of the transmitter (1); the transmission detector (8) scanning, within a predictable window of time, for the appearance of transmissions initiated by other participants with the receiver (2) and releases the transmitter (1) for communicating navigational data if such transmissions do not appear.
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2. A communication system on the same RF frequency with several moving participants (20, 21, 22, 23, 24, 25) that are each equipped with a communication device (10) for exchanging information having a transmitter, transmissions from said transmitter, and receiver (1, 2) characterized by a method, for detecting free transmission periods (8) which control the transmissions of the transmitter (1);
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a second input (11) of the transmitter (1), having a time basis (5) for generating a transmission frame characterized in that methods for synchronizing the time basis (5) of each moving participant (20, 21, 22, 23, 24 and 25) only depends on a minimum of one relevant participant within the receiving range; and the time basis (5) having a steering input (43) which drives the transmission frame within a moveable time period and that the means for synchronizing the time basis (5) are provided by a synchronization unit (6) which has an output(40) connected to the steering input (43) of the time basis (5) and a second input (18) of the receiver (2) connected to the input (19) of the synchronization unit (6), so that a transmission signal is in direct timing relation to the transmission of one or more other participants. - View Dependent Claims (3, 4, 5)
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6. A communication system on the same RF frequency with several moving participants (20, 21, 22, 23, 24, 25) that are each equipped with a communication device (10) for exchanging information having a transmitter, transmissions from said transmitter, and receiver (1, 2) characterized b a method, for detecting free transmission periods (8) which control the transmission of the transmitter (1);
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the synchronization unit (6) providing the means for weighting from the receiver (2) and received transmissions with defined factors for correcting the synchronization error; and the own transmission timing correction is a function of weighting different predetermined groups and numbers of participants in those groups. - View Dependent Claims (7, 8, 9, 10, 11, 12, 13, 14)
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Specification